* Exim - an Internet mail transport agent *
*************************************************/
-/* Copyright (c) University of Cambridge 1995 - 2012 */
+/* Copyright (c) University of Cambridge 1995 - 2018 */
+/* Copyright (c) The Exim Maintainers 2020 */
/* See the file NOTICE for conditions of use and distribution. */
/* Functions for handling an incoming SMTP call. */
#include "exim.h"
+#include <assert.h>
/* Initialize for TCP wrappers if so configured. It appears that the macro
/* Size of buffer for reading SMTP commands. We used to use 512, as defined
by RFC 821. However, RFC 1869 specifies that this must be increased for SMTP
commands that accept arguments, and this in particular applies to AUTH, where
-the data can be quite long. More recently this value was 2048 in Exim;
+the data can be quite long. More recently this value was 2048 in Exim;
however, RFC 4954 (circa 2007) recommends 12288 bytes to handle AUTH. Clients
-such as Thunderbird will send an AUTH with an initial-response for GSSAPI.
-The maximum size of a Kerberos ticket under Windows 2003 is 12000 bytes, and
+such as Thunderbird will send an AUTH with an initial-response for GSSAPI.
+The maximum size of a Kerberos ticket under Windows 2003 is 12000 bytes, and
we need room to handle large base64-encoded AUTHs for GSSAPI.
*/
-#define smtp_cmd_buffer_size 16384
+#define SMTP_CMD_BUFFER_SIZE 16384
/* Size of buffer for reading SMTP incoming packets */
-#define in_buffer_size 8192
+#define IN_BUFFER_SIZE 8192
/* Structure for SMTP command list */
VRFY_CMD, EXPN_CMD, NOOP_CMD, /* RFC as requiring synchronization */
ETRN_CMD, /* This by analogy with TURN from the RFC */
STARTTLS_CMD, /* Required by the STARTTLS RFC */
+ TLS_AUTH_CMD, /* auto-command at start of SSL */
/* This is a dummy to identify the non-sync commands when pipelining */
NON_SYNC_CMD_NON_PIPELINING,
+ /* RFC3030 section 2: "After all MAIL and RCPT responses are collected and
+ processed the message is sent using a series of BDAT commands"
+ implies that BDAT should be synchronized. However, we see Google, at least,
+ sending MAIL,RCPT,BDAT-LAST in a single packet, clearly not waiting for
+ processing of the RCPT response(s). We shall do the same, and not require
+ synch for BDAT. Worse, as the chunk may (very likely will) follow the
+ command-header in the same packet we cannot do the usual "is there any
+ follow-on data after the command line" even for non-pipeline mode.
+ So we'll need an explicit check after reading the expected chunk amount
+ when non-pipe, before sending the ACK. */
+
+ BDAT_CMD,
+
/* I have been unable to find a statement about the use of pipelining
with AUTH, so to be on the safe side it is here, though I kind of feel
it should be up there with the synchronized commands. */
QUIT_CMD, HELP_CMD,
+#ifdef SUPPORT_PROXY
+ PROXY_FAIL_IGNORE_CMD,
+#endif
+
/* These are specials that don't correspond to actual commands */
EOF_CMD, OTHER_CMD, BADARG_CMD, BADCHAR_CMD, BADSYN_CMD,
* Local static variables *
*************************************************/
-static auth_instance *authenticated_by;
-static BOOL auth_advertised;
-#ifdef SUPPORT_TLS
-static BOOL tls_advertised;
+static struct {
+ BOOL auth_advertised :1;
+#ifndef DISABLE_TLS
+ BOOL tls_advertised :1;
+#endif
+ BOOL dsn_advertised :1;
+ BOOL esmtp :1;
+ BOOL helo_verify_required :1;
+ BOOL helo_verify :1;
+ BOOL helo_seen :1;
+ BOOL helo_accept_junk :1;
+#ifndef DISABLE_PIPE_CONNECT
+ BOOL pipe_connect_acceptable :1;
#endif
-static BOOL esmtp;
-static BOOL helo_required = FALSE;
-static BOOL helo_verify = FALSE;
-static BOOL helo_seen;
-static BOOL helo_accept_junk;
-static BOOL count_nonmail;
-static BOOL pipelining_advertised;
-static BOOL rcpt_smtp_response_same;
-static BOOL rcpt_in_progress;
+ BOOL rcpt_smtp_response_same :1;
+ BOOL rcpt_in_progress :1;
+ BOOL smtp_exit_function_called :1;
+#ifdef SUPPORT_I18N
+ BOOL smtputf8_advertised :1;
+#endif
+} fl = {
+ .helo_verify_required = FALSE,
+ .helo_verify = FALSE,
+ .smtp_exit_function_called = FALSE,
+};
+
+static auth_instance *authenticated_by;
+static int count_nonmail;
static int nonmail_command_count;
-static BOOL smtp_exit_function_called = 0;
static int synprot_error_count;
static int unknown_command_count;
static int sync_cmd_limit;
forced TRUE, to allow for the re-authentication that can happen at that point.
QUIT is also "falsely" labelled as a mail command so that it doesn't up the
-count of non-mail commands and possibly provoke an error. */
+count of non-mail commands and possibly provoke an error.
+
+tls_auth is a pseudo-command, never expected in input. It is activated
+on TLS startup and looks for a tls authenticator. */
static smtp_cmd_list cmd_list[] = {
+ /* name len cmd has_arg is_mail_cmd */
+
{ "rset", sizeof("rset")-1, RSET_CMD, FALSE, FALSE }, /* First */
{ "helo", sizeof("helo")-1, HELO_CMD, TRUE, FALSE },
{ "ehlo", sizeof("ehlo")-1, EHLO_CMD, TRUE, FALSE },
{ "auth", sizeof("auth")-1, AUTH_CMD, TRUE, TRUE },
- #ifdef SUPPORT_TLS
+#ifndef DISABLE_TLS
{ "starttls", sizeof("starttls")-1, STARTTLS_CMD, FALSE, FALSE },
- #endif
+ { "tls_auth", 0, TLS_AUTH_CMD, FALSE, FALSE },
+#endif
/* If you change anything above here, also fix the definitions below. */
{ "mail from:", sizeof("mail from:")-1, MAIL_CMD, TRUE, TRUE },
{ "rcpt to:", sizeof("rcpt to:")-1, RCPT_CMD, TRUE, TRUE },
{ "data", sizeof("data")-1, DATA_CMD, FALSE, TRUE },
+ { "bdat", sizeof("bdat")-1, BDAT_CMD, TRUE, TRUE },
{ "quit", sizeof("quit")-1, QUIT_CMD, FALSE, TRUE },
{ "noop", sizeof("noop")-1, NOOP_CMD, TRUE, FALSE },
{ "etrn", sizeof("etrn")-1, ETRN_CMD, TRUE, FALSE },
#define CMD_LIST_EHLO 2
#define CMD_LIST_AUTH 3
#define CMD_LIST_STARTTLS 4
+#define CMD_LIST_TLS_AUTH 5
/* This list of names is used for performing the smtp_no_mail logging action.
It must be kept in step with the SCH_xxx enumerations. */
-static uschar *smtp_names[] =
+uschar * smtp_names[] =
{
- US"NONE", US"AUTH", US"DATA", US"EHLO", US"ETRN", US"EXPN", US"HELO",
- US"HELP", US"MAIL", US"NOOP", US"QUIT", US"RCPT", US"RSET", US"STARTTLS",
- US"VRFY" };
+ US"NONE", US"AUTH", US"DATA", US"BDAT", US"EHLO", US"ETRN", US"EXPN",
+ US"HELO", US"HELP", US"MAIL", US"NOOP", US"QUIT", US"RCPT", US"RSET",
+ US"STARTTLS", US"VRFY" };
-static uschar *protocols[] = {
+static uschar *protocols_local[] = {
US"local-smtp", /* HELO */
US"local-smtps", /* The rare case EHLO->STARTTLS->HELO */
US"local-esmtp", /* EHLO */
US"local-esmtpa", /* EHLO->AUTH */
US"local-esmtpsa" /* EHLO->STARTTLS->EHLO->AUTH */
};
+static uschar *protocols[] = {
+ US"smtp", /* HELO */
+ US"smtps", /* The rare case EHLO->STARTTLS->HELO */
+ US"esmtp", /* EHLO */
+ US"esmtps", /* EHLO->STARTTLS->EHLO */
+ US"esmtpa", /* EHLO->AUTH */
+ US"esmtpsa" /* EHLO->STARTTLS->EHLO->AUTH */
+ };
#define pnormal 0
#define pextend 2
#define pcrpted 1 /* added to pextend or pnormal */
#define pauthed 2 /* added to pextend */
-#define pnlocal 6 /* offset to remove "local" */
+
+/* Sanity check and validate optional args to MAIL FROM: envelope */
+enum {
+ ENV_MAIL_OPT_NULL,
+ ENV_MAIL_OPT_SIZE, ENV_MAIL_OPT_BODY, ENV_MAIL_OPT_AUTH,
+#ifndef DISABLE_PRDR
+ ENV_MAIL_OPT_PRDR,
+#endif
+ ENV_MAIL_OPT_RET, ENV_MAIL_OPT_ENVID,
+#ifdef SUPPORT_I18N
+ ENV_MAIL_OPT_UTF8,
+#endif
+ };
+typedef struct {
+ uschar * name; /* option requested during MAIL cmd */
+ int value; /* enum type */
+ BOOL need_value; /* TRUE requires value (name=value pair format)
+ FALSE is a singleton */
+ } env_mail_type_t;
+static env_mail_type_t env_mail_type_list[] = {
+ { US"SIZE", ENV_MAIL_OPT_SIZE, TRUE },
+ { US"BODY", ENV_MAIL_OPT_BODY, TRUE },
+ { US"AUTH", ENV_MAIL_OPT_AUTH, TRUE },
+#ifndef DISABLE_PRDR
+ { US"PRDR", ENV_MAIL_OPT_PRDR, FALSE },
+#endif
+ { US"RET", ENV_MAIL_OPT_RET, TRUE },
+ { US"ENVID", ENV_MAIL_OPT_ENVID, TRUE },
+#ifdef SUPPORT_I18N
+ { US"SMTPUTF8",ENV_MAIL_OPT_UTF8, FALSE }, /* rfc6531 */
+#endif
+ /* keep this the last entry */
+ { US"NULL", ENV_MAIL_OPT_NULL, FALSE },
+ };
/* When reading SMTP from a remote host, we have to use our own versions of the
C input-reading functions, in order to be able to flush the SMTP output only
static int smtp_had_error;
+/* forward declarations */
+static int smtp_read_command(BOOL check_sync, unsigned buffer_lim);
+static int synprot_error(int type, int code, uschar *data, uschar *errmess);
+static void smtp_quit_handler(uschar **, uschar **);
+static void smtp_rset_handler(void);
+
/*************************************************
-* SMTP version of getc() *
+* Recheck synchronization *
*************************************************/
-/* This gets the next byte from the SMTP input buffer. If the buffer is empty,
-it flushes the output, and refills the buffer, with a timeout. The signal
-handler is set appropriately by the calling function. This function is not used
-after a connection has negotated itself into an TLS/SSL state.
+/* Synchronization checks can never be perfect because a packet may be on its
+way but not arrived when the check is done. Normally, the checks happen when
+commands are read: Exim ensures that there is no more input in the input buffer.
+In normal cases, the response to the command will be fast, and there is no
+further check.
-Arguments: none
-Returns: the next character or EOF
+However, for some commands an ACL is run, and that can include delays. In those
+cases, it is useful to do another check on the input just before sending the
+response. This also applies at the start of a connection. This function does
+that check by means of the select() function, as long as the facility is not
+disabled or inappropriate. A failure of select() is ignored.
+
+When there is unwanted input, we read it so that it appears in the log of the
+error.
+
+Arguments: none
+Returns: TRUE if all is well; FALSE if there is input pending
*/
-int
-smtp_getc(void)
+static BOOL
+wouldblock_reading(void)
{
-if (smtp_inptr >= smtp_inend)
- {
- int rc, save_errno;
- fflush(smtp_out);
- if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout);
- rc = read(fileno(smtp_in), smtp_inbuffer, in_buffer_size);
- save_errno = errno;
- alarm(0);
- if (rc <= 0)
- {
- /* Must put the error text in fixed store, because this might be during
- header reading, where it releases unused store above the header. */
- if (rc < 0)
- {
- smtp_had_error = save_errno;
- smtp_read_error = string_copy_malloc(
- string_sprintf(" (error: %s)", strerror(save_errno)));
- }
- else smtp_had_eof = 1;
- return EOF;
- }
-#ifndef DISABLE_DKIM
- dkim_exim_verify_feed(smtp_inbuffer, rc);
+int fd, rc;
+fd_set fds;
+struct timeval tzero = {.tv_sec = 0, .tv_usec = 0};
+
+#ifndef DISABLE_TLS
+if (tls_in.active.sock >= 0)
+ return !tls_could_read();
#endif
- smtp_inend = smtp_inbuffer + rc;
- smtp_inptr = smtp_inbuffer;
- }
-return *smtp_inptr++;
-}
+if (smtp_inptr < smtp_inend)
+ return FALSE;
+
+fd = fileno(smtp_in);
+FD_ZERO(&fds);
+FD_SET(fd, &fds);
+rc = select(fd + 1, (SELECT_ARG2_TYPE *)&fds, NULL, NULL, &tzero);
+if (rc <= 0) return TRUE; /* Not ready to read */
+rc = smtp_getc(GETC_BUFFER_UNLIMITED);
+if (rc < 0) return TRUE; /* End of file or error */
-/*************************************************
-* SMTP version of ungetc() *
-*************************************************/
+smtp_ungetc(rc);
+return FALSE;
+}
-/* Puts a character back in the input buffer. Only ever
-called once.
+static BOOL
+check_sync(void)
+{
+if (!smtp_enforce_sync || !sender_host_address || f.sender_host_notsocket)
+ return TRUE;
-Arguments:
- ch the character
+return wouldblock_reading();
+}
-Returns: the character
-*/
-int
-smtp_ungetc(int ch)
+/* If there's input waiting (and we're doing pipelineing) then we can pipeline
+a reponse with the one following. */
+
+static BOOL
+pipeline_response(void)
{
-*(--smtp_inptr) = ch;
-return ch;
+if ( !smtp_enforce_sync || !sender_host_address
+ || f.sender_host_notsocket || !f.smtp_in_pipelining_advertised)
+ return FALSE;
+
+if (wouldblock_reading()) return FALSE;
+f.smtp_in_pipelining_used = TRUE;
+return TRUE;
}
+#ifndef DISABLE_PIPE_CONNECT
+static BOOL
+pipeline_connect_sends(void)
+{
+if (!sender_host_address || f.sender_host_notsocket || !fl.pipe_connect_acceptable)
+ return FALSE;
+if (wouldblock_reading()) return FALSE;
+f.smtp_in_early_pipe_used = TRUE;
+return TRUE;
+}
+#endif
/*************************************************
-* SMTP version of feof() *
+* Log incomplete transactions *
*************************************************/
-/* Tests for a previous EOF
+/* This function is called after a transaction has been aborted by RSET, QUIT,
+connection drops or other errors. It logs the envelope information received
+so far in order to preserve address verification attempts.
-Arguments: none
-Returns: non-zero if the eof flag is set
+Argument: string to indicate what aborted the transaction
+Returns: nothing
*/
-int
-smtp_feof(void)
+static void
+incomplete_transaction_log(uschar *what)
{
-return smtp_had_eof;
-}
+if (!sender_address /* No transaction in progress */
+ || !LOGGING(smtp_incomplete_transaction))
+ return;
+/* Build list of recipients for logging */
+if (recipients_count > 0)
+ {
+ raw_recipients = store_get(recipients_count * sizeof(uschar *), FALSE);
+ for (int i = 0; i < recipients_count; i++)
+ raw_recipients[i] = recipients_list[i].address;
+ raw_recipients_count = recipients_count;
+ }
+log_write(L_smtp_incomplete_transaction, LOG_MAIN|LOG_SENDER|LOG_RECIPIENTS,
+ "%s incomplete transaction (%s)", host_and_ident(TRUE), what);
+}
-/*************************************************
-* SMTP version of ferror() *
-*************************************************/
-/* Tests for a previous read error, and returns with errno
-restored to what it was when the error was detected.
-Arguments: none
-Returns: non-zero if the error flag is set
-*/
-int
-smtp_ferror(void)
+void
+smtp_command_timeout_exit(void)
{
-errno = smtp_had_error;
-return smtp_had_error;
+log_write(L_lost_incoming_connection,
+ LOG_MAIN, "SMTP command timeout on%s connection from %s",
+ tls_in.active.sock >= 0 ? " TLS" : "", host_and_ident(FALSE));
+if (smtp_batched_input)
+ moan_smtp_batch(NULL, "421 SMTP command timeout"); /* Does not return */
+smtp_notquit_exit(US"command-timeout", US"421",
+ US"%s: SMTP command timeout - closing connection",
+ smtp_active_hostname);
+exim_exit(EXIT_FAILURE);
}
+void
+smtp_command_sigterm_exit(void)
+{
+log_write(0, LOG_MAIN, "%s closed after SIGTERM", smtp_get_connection_info());
+if (smtp_batched_input)
+ moan_smtp_batch(NULL, "421 SIGTERM received"); /* Does not return */
+smtp_notquit_exit(US"signal-exit", US"421",
+ US"%s: Service not available - closing connection", smtp_active_hostname);
+exim_exit(EXIT_FAILURE);
+}
+void
+smtp_data_timeout_exit(void)
+{
+log_write(L_lost_incoming_connection,
+ LOG_MAIN, "SMTP data timeout (message abandoned) on connection from %s F=<%s>",
+ sender_fullhost ? sender_fullhost : US"local process", sender_address);
+receive_bomb_out(US"data-timeout", US"SMTP incoming data timeout");
+/* Does not return */
+}
-/*************************************************
-* Test for characters in the SMTP buffer *
-*************************************************/
+void
+smtp_data_sigint_exit(void)
+{
+log_write(0, LOG_MAIN, "%s closed after %s",
+ smtp_get_connection_info(), had_data_sigint == SIGTERM ? "SIGTERM":"SIGINT");
+receive_bomb_out(US"signal-exit",
+ US"Service not available - SIGTERM or SIGINT received");
+/* Does not return */
+}
-/* Used at the end of a message
-Arguments: none
-Returns: TRUE/FALSE
+
+/* Refill the buffer, and notify DKIM verification code.
+Return false for error or EOF.
*/
-BOOL
-smtp_buffered(void)
+static BOOL
+smtp_refill(unsigned lim)
{
-return smtp_inptr < smtp_inend;
+int rc, save_errno;
+if (!smtp_out) return FALSE;
+fflush(smtp_out);
+if (smtp_receive_timeout > 0) ALARM(smtp_receive_timeout);
+
+/* Limit amount read, so non-message data is not fed to DKIM.
+Take care to not touch the safety NUL at the end of the buffer. */
+
+rc = read(fileno(smtp_in), smtp_inbuffer, MIN(IN_BUFFER_SIZE-1, lim));
+save_errno = errno;
+if (smtp_receive_timeout > 0) ALARM_CLR(0);
+if (rc <= 0)
+ {
+ /* Must put the error text in fixed store, because this might be during
+ header reading, where it releases unused store above the header. */
+ if (rc < 0)
+ {
+ if (had_command_timeout) /* set by signal handler */
+ smtp_command_timeout_exit(); /* does not return */
+ if (had_command_sigterm)
+ smtp_command_sigterm_exit();
+ if (had_data_timeout)
+ smtp_data_timeout_exit();
+ if (had_data_sigint)
+ smtp_data_sigint_exit();
+
+ smtp_had_error = save_errno;
+ smtp_read_error = string_copy_perm(
+ string_sprintf(" (error: %s)", strerror(save_errno)), FALSE);
+ }
+ else
+ smtp_had_eof = 1;
+ return FALSE;
+ }
+#ifndef DISABLE_DKIM
+dkim_exim_verify_feed(smtp_inbuffer, rc);
+#endif
+smtp_inend = smtp_inbuffer + rc;
+smtp_inptr = smtp_inbuffer;
+return TRUE;
}
-
-
/*************************************************
-* Write formatted string to SMTP channel *
+* SMTP version of getc() *
*************************************************/
-/* This is a separate function so that we don't have to repeat everything for
-TLS support or debugging. It is global so that the daemon and the
-authentication functions can use it. It does not return any error indication,
-because major problems such as dropped connections won't show up till an output
-flush for non-TLS connections. The smtp_fflush() function is available for
-checking that: for convenience, TLS output errors are remembered here so that
-they are also picked up later by smtp_fflush().
-
-Arguments:
- format format string
- ... optional arguments
+/* This gets the next byte from the SMTP input buffer. If the buffer is empty,
+it flushes the output, and refills the buffer, with a timeout. The signal
+handler is set appropriately by the calling function. This function is not used
+after a connection has negotiated itself into an TLS/SSL state.
-Returns: nothing
+Arguments: lim Maximum amount to read/buffer
+Returns: the next character or EOF
*/
-void
-smtp_printf(const char *format, ...)
+int
+smtp_getc(unsigned lim)
{
-va_list ap;
-
-va_start(ap, format);
-smtp_vprintf(format, ap);
-va_end(ap);
+if (smtp_inptr >= smtp_inend)
+ if (!smtp_refill(lim))
+ return EOF;
+return *smtp_inptr++;
}
-/* This is split off so that verify.c:respond_printf() can, in effect, call
-smtp_printf(), bearing in mind that in C a vararg function can't directly
-call another vararg function, only a function which accepts a va_list. */
+uschar *
+smtp_getbuf(unsigned * len)
+{
+unsigned size;
+uschar * buf;
+
+if (smtp_inptr >= smtp_inend)
+ if (!smtp_refill(*len))
+ { *len = 0; return NULL; }
+
+if ((size = smtp_inend - smtp_inptr) > *len) size = *len;
+buf = smtp_inptr;
+smtp_inptr += size;
+*len = size;
+return buf;
+}
void
-smtp_vprintf(const char *format, va_list ap)
+smtp_get_cache(void)
{
-BOOL yield;
+#ifndef DISABLE_DKIM
+int n = smtp_inend - smtp_inptr;
+if (chunking_state == CHUNKING_LAST && chunking_data_left < n)
+ n = chunking_data_left;
+if (n > 0)
+ dkim_exim_verify_feed(smtp_inptr, n);
+#endif
+}
-yield = string_vformat(big_buffer, big_buffer_size, format, ap);
-DEBUG(D_receive)
- {
- void *reset_point = store_get(0);
- uschar *msg_copy, *cr, *end;
- msg_copy = string_copy(big_buffer);
- end = msg_copy + Ustrlen(msg_copy);
- while ((cr = Ustrchr(msg_copy, '\r')) != NULL) /* lose CRs */
- memmove(cr, cr + 1, (end--) - cr);
- debug_printf("SMTP>> %s", msg_copy);
- store_reset(reset_point);
- }
+/* Forward declarations */
+static inline void bdat_push_receive_functions(void);
+static inline void bdat_pop_receive_functions(void);
-if (!yield)
- {
- log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_printf()");
- smtp_closedown(US"Unexpected error");
- exim_exit(EXIT_FAILURE);
- }
-/* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
-have had the same. Note: this code is also present in smtp_respond(). It would
-be tidier to have it only in one place, but when it was added, it was easier to
-do it that way, so as not to have to mess with the code for the RCPT command,
-which sometimes uses smtp_printf() and sometimes smtp_respond(). */
+/* Get a byte from the smtp input, in CHUNKING mode. Handle ack of the
+previous BDAT chunk and getting new ones when we run out. Uses the
+underlying smtp_getc or tls_getc both for that and for getting the
+(buffered) data byte. EOD signals (an expected) no further data.
+ERR signals a protocol error, and EOF a closed input stream.
-if (rcpt_in_progress)
- {
- if (rcpt_smtp_response == NULL)
- rcpt_smtp_response = string_copy(big_buffer);
- else if (rcpt_smtp_response_same &&
- Ustrcmp(rcpt_smtp_response, big_buffer) != 0)
- rcpt_smtp_response_same = FALSE;
- rcpt_in_progress = FALSE;
- }
+Called from read_bdat_smtp() in receive.c for the message body, but also
+by the headers read loop in receive_msg(); manipulates chunking_state
+to handle the BDAT command/response.
+Placed here due to the correlation with the above smtp_getc(), which it wraps,
+and also by the need to do smtp command/response handling.
-/* Now write the string */
+Arguments: lim (ignored)
+Returns: the next character or ERR, EOD or EOF
+*/
+
+int
+bdat_getc(unsigned lim)
+{
+uschar * user_msg = NULL;
+uschar * log_msg;
-#ifdef SUPPORT_TLS
-if (tls_active >= 0)
+for(;;)
{
- if (tls_write(big_buffer, Ustrlen(big_buffer)) < 0) smtp_write_error = -1;
- }
-else
+#ifndef DISABLE_DKIM
+ unsigned dkim_save;
#endif
-if (fprintf(smtp_out, "%s", big_buffer) < 0) smtp_write_error = -1;
-}
+ if (chunking_data_left > 0)
+ return lwr_receive_getc(chunking_data_left--);
+ bdat_pop_receive_functions();
+#ifndef DISABLE_DKIM
+ dkim_save = dkim_collect_input;
+ dkim_collect_input = 0;
+#endif
+ /* Unless PIPELINING was offered, there should be no next command
+ until after we ack that chunk */
-/*************************************************
-* Flush SMTP out and check for error *
-*************************************************/
+ if (!f.smtp_in_pipelining_advertised && !check_sync())
+ {
+ unsigned n = smtp_inend - smtp_inptr;
+ if (n > 32) n = 32;
-/* This function isn't currently used within Exim (it detects errors when it
-tries to read the next SMTP input), but is available for use in local_scan().
-For non-TLS connections, it flushes the output and checks for errors. For
-TLS-connections, it checks for a previously-detected TLS write error.
+ incomplete_transaction_log(US"sync failure");
+ log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol synchronization error "
+ "(next input sent too soon: pipelining was not advertised): "
+ "rejected \"%s\" %s next input=\"%s\"%s",
+ smtp_cmd_buffer, host_and_ident(TRUE),
+ string_printing(string_copyn(smtp_inptr, n)),
+ smtp_inend - smtp_inptr > n ? "..." : "");
+ (void) synprot_error(L_smtp_protocol_error, 554, NULL,
+ US"SMTP synchronization error");
+ goto repeat_until_rset;
+ }
-Arguments: none
-Returns: 0 for no error; -1 after an error
-*/
+ /* If not the last, ack the received chunk. The last response is delayed
+ until after the data ACL decides on it */
-int
-smtp_fflush(void)
-{
-if (tls_active < 0 && fflush(smtp_out) != 0) smtp_write_error = -1;
-return smtp_write_error;
-}
+ if (chunking_state == CHUNKING_LAST)
+ {
+#ifndef DISABLE_DKIM
+ dkim_exim_verify_feed(NULL, 0); /* notify EOD */
+#endif
+ return EOD;
+ }
+ smtp_printf("250 %u byte chunk received\r\n", FALSE, chunking_datasize);
+ chunking_state = CHUNKING_OFFERED;
+ DEBUG(D_receive) debug_printf("chunking state %d\n", (int)chunking_state);
+ /* Expect another BDAT cmd from input. RFC 3030 says nothing about
+ QUIT, RSET or NOOP but handling them seems obvious */
-/*************************************************
-* SMTP command read timeout *
-*************************************************/
+next_cmd:
+ switch(smtp_read_command(TRUE, 1))
+ {
+ default:
+ (void) synprot_error(L_smtp_protocol_error, 503, NULL,
+ US"only BDAT permissible after non-LAST BDAT");
+
+ repeat_until_rset:
+ switch(smtp_read_command(TRUE, 1))
+ {
+ case QUIT_CMD: smtp_quit_handler(&user_msg, &log_msg); /*FALLTHROUGH */
+ case EOF_CMD: return EOF;
+ case RSET_CMD: smtp_rset_handler(); return ERR;
+ default: if (synprot_error(L_smtp_protocol_error, 503, NULL,
+ US"only RSET accepted now") > 0)
+ return EOF;
+ goto repeat_until_rset;
+ }
-/* Signal handler for timing out incoming SMTP commands. This attempts to
-finish off tidily.
+ case QUIT_CMD:
+ smtp_quit_handler(&user_msg, &log_msg);
+ /*FALLTHROUGH*/
+ case EOF_CMD:
+ return EOF;
-Argument: signal number (SIGALRM)
-Returns: nothing
-*/
+ case RSET_CMD:
+ smtp_rset_handler();
+ return ERR;
-static void
-command_timeout_handler(int sig)
-{
-sig = sig; /* Keep picky compilers happy */
-log_write(L_lost_incoming_connection,
- LOG_MAIN, "SMTP command timeout on%s connection from %s",
- (tls_active >= 0)? " TLS" : "",
- host_and_ident(FALSE));
-if (smtp_batched_input)
- moan_smtp_batch(NULL, "421 SMTP command timeout"); /* Does not return */
-smtp_notquit_exit(US"command-timeout", US"421",
- US"%s: SMTP command timeout - closing connection", smtp_active_hostname);
-exim_exit(EXIT_FAILURE);
+ case NOOP_CMD:
+ HAD(SCH_NOOP);
+ smtp_printf("250 OK\r\n", FALSE);
+ goto next_cmd;
+
+ case BDAT_CMD:
+ {
+ int n;
+
+ if (sscanf(CS smtp_cmd_data, "%u %n", &chunking_datasize, &n) < 1)
+ {
+ (void) synprot_error(L_smtp_protocol_error, 501, NULL,
+ US"missing size for BDAT command");
+ return ERR;
+ }
+ chunking_state = strcmpic(smtp_cmd_data+n, US"LAST") == 0
+ ? CHUNKING_LAST : CHUNKING_ACTIVE;
+ chunking_data_left = chunking_datasize;
+ DEBUG(D_receive) debug_printf("chunking state %d, %d bytes\n",
+ (int)chunking_state, chunking_data_left);
+
+ if (chunking_datasize == 0)
+ if (chunking_state == CHUNKING_LAST)
+ return EOD;
+ else
+ {
+ (void) synprot_error(L_smtp_protocol_error, 504, NULL,
+ US"zero size for BDAT command");
+ goto repeat_until_rset;
+ }
+
+ bdat_push_receive_functions();
+#ifndef DISABLE_DKIM
+ dkim_collect_input = dkim_save;
+#endif
+ break; /* to top of main loop */
+ }
+ }
+ }
}
+uschar *
+bdat_getbuf(unsigned * len)
+{
+uschar * buf;
+if (chunking_data_left <= 0)
+ { *len = 0; return NULL; }
-/*************************************************
-* SIGTERM received *
-*************************************************/
+if (*len > chunking_data_left) *len = chunking_data_left;
+buf = lwr_receive_getbuf(len); /* Either smtp_getbuf or tls_getbuf */
+chunking_data_left -= *len;
+return buf;
+}
-/* Signal handler for handling SIGTERM. Again, try to finish tidily.
+void
+bdat_flush_data(void)
+{
+while (chunking_data_left)
+ {
+ unsigned n = chunking_data_left;
+ if (!bdat_getbuf(&n)) break;
+ }
-Argument: signal number (SIGTERM)
-Returns: nothing
-*/
+bdat_pop_receive_functions();
-static void
-command_sigterm_handler(int sig)
-{
-sig = sig; /* Keep picky compilers happy */
-log_write(0, LOG_MAIN, "%s closed after SIGTERM", smtp_get_connection_info());
-if (smtp_batched_input)
- moan_smtp_batch(NULL, "421 SIGTERM received"); /* Does not return */
-smtp_notquit_exit(US"signal-exit", US"421",
- US"%s: Service not available - closing connection", smtp_active_hostname);
-exim_exit(EXIT_FAILURE);
+if (chunking_state != CHUNKING_LAST)
+ {
+ chunking_state = CHUNKING_OFFERED;
+ DEBUG(D_receive) debug_printf("chunking state %d\n", (int)chunking_state);
+ }
}
+static inline void
+bdat_push_receive_functions(void)
+{
+/* push the current receive_* function on the "stack", and
+replace them by bdat_getc(), which in turn will use the lwr_receive_*
+functions to do the dirty work. */
+if (lwr_receive_getc == NULL)
+ {
+ lwr_receive_getc = receive_getc;
+ lwr_receive_getbuf = receive_getbuf;
+ lwr_receive_ungetc = receive_ungetc;
+ }
+else
+ {
+ DEBUG(D_receive) debug_printf("chunking double-push receive functions\n");
+ }
+
+receive_getc = bdat_getc;
+receive_getbuf = bdat_getbuf;
+receive_ungetc = bdat_ungetc;
+}
+
+static inline void
+bdat_pop_receive_functions(void)
+{
+if (lwr_receive_getc == NULL)
+ {
+ DEBUG(D_receive) debug_printf("chunking double-pop receive functions\n");
+ return;
+ }
+receive_getc = lwr_receive_getc;
+receive_getbuf = lwr_receive_getbuf;
+receive_ungetc = lwr_receive_ungetc;
+lwr_receive_getc = NULL;
+lwr_receive_getbuf = NULL;
+lwr_receive_ungetc = NULL;
+}
/*************************************************
-* Read one command line *
+* SMTP version of ungetc() *
*************************************************/
-/* Strictly, SMTP commands coming over the net are supposed to end with CRLF.
-There are sites that don't do this, and in any case internal SMTP probably
-should check only for LF. Consequently, we check here for LF only. The line
-ends up with [CR]LF removed from its end. If we get an overlong line, treat as
-an unknown command. The command is read into the global smtp_cmd_buffer so that
-it is available via $smtp_command.
-
-The character reading routine sets up a timeout for each block actually read
-from the input (which may contain more than one command). We set up a special
-signal handler that closes down the session on a timeout. Control does not
-return when it runs.
+/* Puts a character back in the input buffer. Only ever
+called once.
Arguments:
- check_sync if TRUE, check synchronization rules if global option is TRUE
+ ch the character
-Returns: a code identifying the command (enumerated above)
+Returns: the character
*/
-static int
-smtp_read_command(BOOL check_sync)
+int
+smtp_ungetc(int ch)
{
-int c;
-int ptr = 0;
-smtp_cmd_list *p;
-BOOL hadnull = FALSE;
+if (smtp_inptr <= smtp_inbuffer)
+ log_write(0, LOG_MAIN|LOG_PANIC_DIE, "buffer underflow in smtp_ungetc");
-os_non_restarting_signal(SIGALRM, command_timeout_handler);
+*--smtp_inptr = ch;
+return ch;
+}
-while ((c = (receive_getc)()) != '\n' && c != EOF)
- {
- if (ptr >= smtp_cmd_buffer_size)
- {
- os_non_restarting_signal(SIGALRM, sigalrm_handler);
- return OTHER_CMD;
- }
- if (c == 0)
- {
- hadnull = TRUE;
- c = '?';
- }
- smtp_cmd_buffer[ptr++] = c;
- }
-receive_linecount++; /* For BSMTP errors */
-os_non_restarting_signal(SIGALRM, sigalrm_handler);
+int
+bdat_ungetc(int ch)
+{
+chunking_data_left++;
+bdat_push_receive_functions(); /* we're not done yet, calling push is safe, because it checks the state before pushing anything */
+return lwr_receive_ungetc(ch);
+}
-/* If hit end of file, return pseudo EOF command. Whether we have a
-part-line already read doesn't matter, since this is an error state. */
-if (c == EOF) return EOF_CMD;
-/* Remove any CR and white space at the end of the line, and terminate the
-string. */
+/*************************************************
+* SMTP version of feof() *
+*************************************************/
-while (ptr > 0 && isspace(smtp_cmd_buffer[ptr-1])) ptr--;
-smtp_cmd_buffer[ptr] = 0;
+/* Tests for a previous EOF
-DEBUG(D_receive) debug_printf("SMTP<< %s\n", smtp_cmd_buffer);
+Arguments: none
+Returns: non-zero if the eof flag is set
+*/
-/* NULLs are not allowed in SMTP commands */
+int
+smtp_feof(void)
+{
+return smtp_had_eof;
+}
-if (hadnull) return BADCHAR_CMD;
-/* Scan command list and return identity, having set the data pointer
-to the start of the actual data characters. Check for SMTP synchronization
-if required. */
-for (p = cmd_list; p < cmd_list_end; p++)
- {
- if (strncmpic(smtp_cmd_buffer, US p->name, p->len) == 0 &&
- (smtp_cmd_buffer[p->len-1] == ':' || /* "mail from:" or "rcpt to:" */
- smtp_cmd_buffer[p->len] == 0 ||
- smtp_cmd_buffer[p->len] == ' '))
- {
- if (smtp_inptr < smtp_inend && /* Outstanding input */
- p->cmd < sync_cmd_limit && /* Command should sync */
- check_sync && /* Local flag set */
- smtp_enforce_sync && /* Global flag set */
- sender_host_address != NULL && /* Not local input */
- !sender_host_notsocket) /* Really is a socket */
- return BADSYN_CMD;
- /* The variables $smtp_command and $smtp_command_argument point into the
- unmodified input buffer. A copy of the latter is taken for actual
- processing, so that it can be chopped up into separate parts if necessary,
- for example, when processing a MAIL command options such as SIZE that can
- follow the sender address. */
+/*************************************************
+* SMTP version of ferror() *
+*************************************************/
- smtp_cmd_argument = smtp_cmd_buffer + p->len;
- while (isspace(*smtp_cmd_argument)) smtp_cmd_argument++;
- Ustrcpy(smtp_data_buffer, smtp_cmd_argument);
- smtp_cmd_data = smtp_data_buffer;
+/* Tests for a previous read error, and returns with errno
+restored to what it was when the error was detected.
- /* Count non-mail commands from those hosts that are controlled in this
- way. The default is all hosts. We don't waste effort checking the list
- until we get a non-mail command, but then cache the result to save checking
- again. If there's a DEFER while checking the host, assume it's in the list.
+Arguments: none
+Returns: non-zero if the error flag is set
+*/
- Note that one instance of RSET, EHLO/HELO, and STARTTLS is allowed at the
- start of each incoming message by fiddling with the value in the table. */
+int
+smtp_ferror(void)
+{
+errno = smtp_had_error;
+return smtp_had_error;
+}
- if (!p->is_mail_cmd)
- {
- if (count_nonmail == TRUE_UNSET) count_nonmail =
- verify_check_host(&smtp_accept_max_nonmail_hosts) != FAIL;
- if (count_nonmail && ++nonmail_command_count > smtp_accept_max_nonmail)
- return TOO_MANY_NONMAIL_CMD;
- }
- /* If there is data for a command that does not expect it, generate the
- error here. */
- return (p->has_arg || *smtp_cmd_data == 0)? p->cmd : BADARG_CMD;
- }
- }
+/*************************************************
+* Test for characters in the SMTP buffer *
+*************************************************/
-/* Enforce synchronization for unknown commands */
+/* Used at the end of a message
-if (smtp_inptr < smtp_inend && /* Outstanding input */
- check_sync && /* Local flag set */
- smtp_enforce_sync && /* Global flag set */
- sender_host_address != NULL && /* Not local input */
- !sender_host_notsocket) /* Really is a socket */
- return BADSYN_CMD;
+Arguments: none
+Returns: TRUE/FALSE
+*/
-return OTHER_CMD;
+BOOL
+smtp_buffered(void)
+{
+return smtp_inptr < smtp_inend;
}
/*************************************************
-* Recheck synchronization *
+* Write formatted string to SMTP channel *
*************************************************/
-/* Synchronization checks can never be perfect because a packet may be on its
-way but not arrived when the check is done. Such checks can in any case only be
-done when TLS is not in use. Normally, the checks happen when commands are
-read: Exim ensures that there is no more input in the input buffer. In normal
-cases, the response to the command will be fast, and there is no further check.
+/* This is a separate function so that we don't have to repeat everything for
+TLS support or debugging. It is global so that the daemon and the
+authentication functions can use it. It does not return any error indication,
+because major problems such as dropped connections won't show up till an output
+flush for non-TLS connections. The smtp_fflush() function is available for
+checking that: for convenience, TLS output errors are remembered here so that
+they are also picked up later by smtp_fflush().
-However, for some commands an ACL is run, and that can include delays. In those
-cases, it is useful to do another check on the input just before sending the
-response. This also applies at the start of a connection. This function does
-that check by means of the select() function, as long as the facility is not
-disabled or inappropriate. A failure of select() is ignored.
+This function is exposed to the local_scan API; do not change the signature.
-When there is unwanted input, we read it so that it appears in the log of the
-error.
+Arguments:
+ format format string
+ more further data expected
+ ... optional arguments
-Arguments: none
-Returns: TRUE if all is well; FALSE if there is input pending
+Returns: nothing
*/
-static BOOL
-check_sync(void)
+void
+smtp_printf(const char *format, BOOL more, ...)
{
-int fd, rc;
-fd_set fds;
-struct timeval tzero;
+va_list ap;
-if (!smtp_enforce_sync || sender_host_address == NULL ||
- sender_host_notsocket || tls_active >= 0)
- return TRUE;
+va_start(ap, more);
+smtp_vprintf(format, more, ap);
+va_end(ap);
+}
-fd = fileno(smtp_in);
-FD_ZERO(&fds);
-FD_SET(fd, &fds);
-tzero.tv_sec = 0;
-tzero.tv_usec = 0;
-rc = select(fd + 1, (SELECT_ARG2_TYPE *)&fds, NULL, NULL, &tzero);
+/* This is split off so that verify.c:respond_printf() can, in effect, call
+smtp_printf(), bearing in mind that in C a vararg function can't directly
+call another vararg function, only a function which accepts a va_list.
-if (rc <= 0) return TRUE; /* Not ready to read */
-rc = smtp_getc();
-if (rc < 0) return TRUE; /* End of file or error */
-
-smtp_ungetc(rc);
-rc = smtp_inend - smtp_inptr;
-if (rc > 150) rc = 150;
-smtp_inptr[rc] = 0;
-return FALSE;
-}
-
-
-
-/*************************************************
-* Forced closedown of call *
-*************************************************/
-
-/* This function is called from log.c when Exim is dying because of a serious
-disaster, and also from some other places. If an incoming non-batched SMTP
-channel is open, it swallows the rest of the incoming message if in the DATA
-phase, sends the reply string, and gives an error to all subsequent commands
-except QUIT. The existence of an SMTP call is detected by the non-NULLness of
-smtp_in.
-
-Arguments:
- message SMTP reply string to send, excluding the code
-
-Returns: nothing
+This function is exposed to the local_scan API; do not change the signature.
*/
+/*XXX consider passing caller-info in, for string_vformat-onward */
void
-smtp_closedown(uschar *message)
+smtp_vprintf(const char *format, BOOL more, va_list ap)
{
-if (smtp_in == NULL || smtp_batched_input) return;
-receive_swallow_smtp();
-smtp_printf("421 %s\r\n", message);
+gstring gs = { .size = big_buffer_size, .ptr = 0, .s = big_buffer };
+BOOL yield;
-for (;;)
+/* Use taint-unchecked routines for writing into big_buffer, trusting
+that we'll never expand it. */
+
+yield = !! string_vformat(&gs, SVFMT_TAINT_NOCHK, format, ap);
+string_from_gstring(&gs);
+
+DEBUG(D_receive)
{
- switch(smtp_read_command(FALSE))
- {
- case EOF_CMD:
- return;
+ uschar *msg_copy, *cr, *end;
+ msg_copy = string_copy(gs.s);
+ end = msg_copy + gs.ptr;
+ while ((cr = Ustrchr(msg_copy, '\r')) != NULL) /* lose CRs */
+ memmove(cr, cr + 1, (end--) - cr);
+ debug_printf("SMTP>> %s", msg_copy);
+ }
- case QUIT_CMD:
- smtp_printf("221 %s closing connection\r\n", smtp_active_hostname);
- mac_smtp_fflush();
- return;
+if (!yield)
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_printf()");
+ smtp_closedown(US"Unexpected error");
+ exim_exit(EXIT_FAILURE);
+ }
- case RSET_CMD:
- smtp_printf("250 Reset OK\r\n");
- break;
+/* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
+have had the same. Note: this code is also present in smtp_respond(). It would
+be tidier to have it only in one place, but when it was added, it was easier to
+do it that way, so as not to have to mess with the code for the RCPT command,
+which sometimes uses smtp_printf() and sometimes smtp_respond(). */
- default:
- smtp_printf("421 %s\r\n", message);
- break;
- }
+if (fl.rcpt_in_progress)
+ {
+ if (rcpt_smtp_response == NULL)
+ rcpt_smtp_response = string_copy(big_buffer);
+ else if (fl.rcpt_smtp_response_same &&
+ Ustrcmp(rcpt_smtp_response, big_buffer) != 0)
+ fl.rcpt_smtp_response_same = FALSE;
+ fl.rcpt_in_progress = FALSE;
}
-}
+/* Now write the string */
+
+if (
+#ifndef DISABLE_TLS
+ tls_in.active.sock >= 0 ? (tls_write(NULL, gs.s, gs.ptr, more) < 0) :
+#endif
+ (fwrite(gs.s, gs.ptr, 1, smtp_out) == 0)
+ )
+ smtp_write_error = -1;
+}
/*************************************************
-* Set up connection info for logging *
+* Flush SMTP out and check for error *
*************************************************/
-/* This function is called when logging information about an SMTP connection.
-It sets up appropriate source information, depending on the type of connection.
-If sender_fullhost is NULL, we are at a very early stage of the connection;
-just use the IP address.
+/* This function isn't currently used within Exim (it detects errors when it
+tries to read the next SMTP input), but is available for use in local_scan().
+It flushes the output and checks for errors.
-Argument: none
-Returns: a string describing the connection
+Arguments: none
+Returns: 0 for no error; -1 after an error
*/
-uschar *
-smtp_get_connection_info(void)
+int
+smtp_fflush(void)
{
-uschar *hostname = (sender_fullhost == NULL)?
- sender_host_address : sender_fullhost;
-
-if (host_checking)
- return string_sprintf("SMTP connection from %s", hostname);
-
-if (sender_host_unknown || sender_host_notsocket)
- return string_sprintf("SMTP connection from %s", sender_ident);
-
-if (is_inetd)
- return string_sprintf("SMTP connection from %s (via inetd)", hostname);
+if (tls_in.active.sock < 0 && fflush(smtp_out) != 0) smtp_write_error = -1;
-if ((log_extra_selector & LX_incoming_interface) != 0 &&
- interface_address != NULL)
- return string_sprintf("SMTP connection from %s I=[%s]:%d", hostname,
- interface_address, interface_port);
+if (
+#ifndef DISABLE_TLS
+ tls_in.active.sock >= 0 ? (tls_write(NULL, NULL, 0, FALSE) < 0) :
+#endif
+ (fflush(smtp_out) != 0)
+ )
+ smtp_write_error = -1;
-return string_sprintf("SMTP connection from %s", hostname);
+return smtp_write_error;
}
/*************************************************
-* Log lack of MAIL if so configured *
+* SMTP command read timeout *
*************************************************/
-/* This function is called when an SMTP session ends. If the log selector
-smtp_no_mail is set, write a log line giving some details of what has happened
-in the SMTP session.
+/* Signal handler for timing out incoming SMTP commands. This attempts to
+finish off tidily.
-Arguments: none
-Returns: nothing
+Argument: signal number (SIGALRM)
+Returns: nothing
*/
-void
-smtp_log_no_mail(void)
+static void
+command_timeout_handler(int sig)
{
-int size, ptr, i;
-uschar *s, *sep;
-
-if (smtp_mailcmd_count > 0 || (log_extra_selector & LX_smtp_no_mail) == 0)
- return;
+had_command_timeout = sig;
+}
-s = NULL;
-size = ptr = 0;
-if (sender_host_authenticated != NULL)
- {
- s = string_append(s, &size, &ptr, 2, US" A=", sender_host_authenticated);
- if (authenticated_id != NULL)
- s = string_append(s, &size, &ptr, 2, US":", authenticated_id);
- }
-#ifdef SUPPORT_TLS
-if ((log_extra_selector & LX_tls_cipher) != 0 && tls_cipher != NULL)
- s = string_append(s, &size, &ptr, 2, US" X=", tls_cipher);
-if ((log_extra_selector & LX_tls_certificate_verified) != 0 &&
- tls_cipher != NULL)
- s = string_append(s, &size, &ptr, 2, US" CV=",
- tls_certificate_verified? "yes":"no");
-if ((log_extra_selector & LX_tls_peerdn) != 0 && tls_peerdn != NULL)
- s = string_append(s, &size, &ptr, 3, US" DN=\"",
- string_printing(tls_peerdn), US"\"");
-if ((log_extra_selector & LX_tls_sni) != 0 && tls_sni != NULL)
- s = string_append(s, &size, &ptr, 3, US" SNI=\"",
- string_printing(tls_sni), US"\"");
-#endif
+/*************************************************
+* SIGTERM received *
+*************************************************/
-sep = (smtp_connection_had[SMTP_HBUFF_SIZE-1] != SCH_NONE)?
- US" C=..." : US" C=";
-for (i = smtp_ch_index; i < SMTP_HBUFF_SIZE; i++)
- {
- if (smtp_connection_had[i] != SCH_NONE)
- {
- s = string_append(s, &size, &ptr, 2, sep,
- smtp_names[smtp_connection_had[i]]);
- sep = US",";
- }
- }
+/* Signal handler for handling SIGTERM. Again, try to finish tidily.
-for (i = 0; i < smtp_ch_index; i++)
- {
- s = string_append(s, &size, &ptr, 2, sep, smtp_names[smtp_connection_had[i]]);
- sep = US",";
- }
+Argument: signal number (SIGTERM)
+Returns: nothing
+*/
-if (s != NULL) s[ptr] = 0; else s = US"";
-log_write(0, LOG_MAIN, "no MAIL in SMTP connection from %s D=%s%s",
- host_and_ident(FALSE),
- readconf_printtime(time(NULL) - smtp_connection_start), s);
+static void
+command_sigterm_handler(int sig)
+{
+had_command_sigterm = sig;
}
+
+#ifdef SUPPORT_PROXY
/*************************************************
-* Check HELO line and set sender_helo_name *
+* Check if host is required proxy host *
*************************************************/
+/* The function determines if inbound host will be a regular smtp host
+or if it is configured that it must use Proxy Protocol. A local
+connection cannot.
-/* Check the format of a HELO line. The data for HELO/EHLO is supposed to be
-the domain name of the sending host, or an ip literal in square brackets. The
-arrgument is placed in sender_helo_name, which is in malloc store, because it
-must persist over multiple incoming messages. If helo_accept_junk is set, this
-host is permitted to send any old junk (needed for some broken hosts).
-Otherwise, helo_allow_chars can be used for rogue characters in general
-(typically people want to let in underscores).
-
-Argument:
- s the data portion of the line (already past any white space)
-
-Returns: TRUE or FALSE
+Arguments: none
+Returns: bool
*/
static BOOL
-check_helo(uschar *s)
+check_proxy_protocol_host()
{
-uschar *start = s;
-uschar *end = s + Ustrlen(s);
-BOOL yield = helo_accept_junk;
-
-/* Discard any previous helo name */
+int rc;
-if (sender_helo_name != NULL)
+if ( sender_host_address
+ && (rc = verify_check_this_host(CUSS &hosts_proxy, NULL, NULL,
+ sender_host_address, NULL)) == OK)
{
- store_free(sender_helo_name);
- sender_helo_name = NULL;
+ DEBUG(D_receive)
+ debug_printf("Detected proxy protocol configured host\n");
+ proxy_session = TRUE;
}
+return proxy_session;
+}
-/* Skip tests if junk is permitted. */
-if (!yield)
- {
- /* Allow the new standard form for IPv6 address literals, namely,
- [IPv6:....], and because someone is bound to use it, allow an equivalent
- IPv4 form. Allow plain addresses as well. */
+/*************************************************
+* Read data until newline or end of buffer *
+*************************************************/
+/* While SMTP is server-speaks-first, TLS is client-speaks-first, so we can't
+read an entire buffer and assume there will be nothing past a proxy protocol
+header. Our approach normally is to use stdio, but again that relies upon
+"STARTTLS\r\n" and a server response before the client starts TLS handshake, or
+reading _nothing_ before client TLS handshake. So we don't want to use the
+usual buffering reads which may read enough to block TLS starting.
+
+So unfortunately we're down to "read one byte at a time, with a syscall each,
+and expect a little overhead", for all proxy-opened connections which are v1,
+just to handle the TLS-on-connect case. Since SSL functions wrap the
+underlying fd, we can't assume that we can feed them any already-read content.
+
+We need to know where to read to, the max capacity, and we'll read until we
+get a CR and one more character. Let the caller scream if it's CR+!LF.
+
+Return the amount read.
+*/
- if (*s == '[')
- {
- if (end[-1] == ']')
- {
- end[-1] = 0;
- if (strncmpic(s, US"[IPv6:", 6) == 0)
- yield = (string_is_ip_address(s+6, NULL) == 6);
- else if (strncmpic(s, US"[IPv4:", 6) == 0)
- yield = (string_is_ip_address(s+6, NULL) == 4);
- else
- yield = (string_is_ip_address(s+1, NULL) != 0);
- end[-1] = ']';
- }
- }
+static int
+swallow_until_crlf(int fd, uschar *base, int already, int capacity)
+{
+uschar *to = base + already;
+uschar *cr;
+int have = 0;
+int ret;
+int last = 0;
- /* Non-literals must be alpha, dot, hyphen, plus any non-valid chars
- that have been configured (usually underscore - sigh). */
+/* For "PROXY UNKNOWN\r\n" we, at time of writing, expect to have read
+up through the \r; for the _normal_ case, we haven't yet seen the \r. */
- else if (*s != 0)
+cr = memchr(base, '\r', already);
+if (cr != NULL)
+ {
+ if ((cr - base) < already - 1)
{
- yield = TRUE;
- while (*s != 0)
- {
- if (!isalnum(*s) && *s != '.' && *s != '-' &&
- Ustrchr(helo_allow_chars, *s) == NULL)
- {
- yield = FALSE;
- break;
- }
- s++;
- }
+ /* \r and presumed \n already within what we have; probably not
+ actually proxy protocol, but abort cleanly. */
+ return 0;
}
+ /* \r is last character read, just need one more. */
+ last = 1;
}
-/* Save argument if OK */
+while (capacity > 0)
+ {
+ do { ret = read(fd, to, 1); } while (ret == -1 && errno == EINTR && !had_command_timeout);
+ if (ret == -1)
+ return -1;
+ have++;
+ if (last)
+ return have;
+ if (*to == '\r')
+ last = 1;
+ capacity--;
+ to++;
+ }
-if (yield) sender_helo_name = string_copy_malloc(start);
-return yield;
+/* reached end without having room for a final newline, abort */
+errno = EOVERFLOW;
+return -1;
}
+/*************************************************
+* Setup host for proxy protocol *
+*************************************************/
+/* The function configures the connection based on a header from the
+inbound host to use Proxy Protocol. The specification is very exact
+so exit with an error if do not find the exact required pieces. This
+includes an incorrect number of spaces separating args.
+Arguments: none
+Returns: Boolean success
+*/
+static void
+setup_proxy_protocol_host()
+{
+union {
+ struct {
+ uschar line[108];
+ } v1;
+ struct {
+ uschar sig[12];
+ uint8_t ver_cmd;
+ uint8_t fam;
+ uint16_t len;
+ union {
+ struct { /* TCP/UDP over IPv4, len = 12 */
+ uint32_t src_addr;
+ uint32_t dst_addr;
+ uint16_t src_port;
+ uint16_t dst_port;
+ } ip4;
+ struct { /* TCP/UDP over IPv6, len = 36 */
+ uint8_t src_addr[16];
+ uint8_t dst_addr[16];
+ uint16_t src_port;
+ uint16_t dst_port;
+ } ip6;
+ struct { /* AF_UNIX sockets, len = 216 */
+ uschar src_addr[108];
+ uschar dst_addr[108];
+ } unx;
+ } addr;
+ } v2;
+} hdr;
+
+/* Temp variables used in PPv2 address:port parsing */
+uint16_t tmpport;
+char tmpip[INET_ADDRSTRLEN];
+struct sockaddr_in tmpaddr;
+char tmpip6[INET6_ADDRSTRLEN];
+struct sockaddr_in6 tmpaddr6;
+
+/* We can't read "all data until end" because while SMTP is
+server-speaks-first, the TLS handshake is client-speaks-first, so for
+TLS-on-connect ports the proxy protocol header will usually be immediately
+followed by a TLS handshake, and with N TLS libraries, we can't reliably
+reinject data for reading by those. So instead we first read "enough to be
+safely read within the header, and figure out how much more to read".
+For v1 we will later read to the end-of-line, for v2 we will read based upon
+the stated length.
+
+The v2 sig is 12 octets, and another 4 gets us the length, so we know how much
+data is needed total. For v1, where the line looks like:
+PROXY TCPn L3src L3dest SrcPort DestPort \r\n
+
+However, for v1 there's also `PROXY UNKNOWN\r\n` which is only 15 octets.
+We seem to support that. So, if we read 14 octets then we can tell if we're
+v2 or v1. If we're v1, we can continue reading as normal.
+
+If we're v2, we can't slurp up the entire header. We need the length in the
+15th & 16th octets, then to read everything after that.
+
+So to safely handle v1 and v2, with client-sent-first supported correctly,
+we have to do a minimum of 3 read calls, not 1. Eww.
+*/
+#define PROXY_INITIAL_READ 14
+#define PROXY_V2_HEADER_SIZE 16
+#if PROXY_INITIAL_READ > PROXY_V2_HEADER_SIZE
+# error Code bug in sizes of data to read for proxy usage
+#endif
-/*************************************************
-* Extract SMTP command option *
-*************************************************/
-
-/* This function picks the next option setting off the end of smtp_cmd_data. It
-is called for MAIL FROM and RCPT TO commands, to pick off the optional ESMTP
-things that can appear there.
+int get_ok = 0;
+int size, ret;
+int fd = fileno(smtp_in);
+const char v2sig[12] = "\x0D\x0A\x0D\x0A\x00\x0D\x0A\x51\x55\x49\x54\x0A";
+uschar * iptype; /* To display debug info */
+socklen_t vslen = sizeof(struct timeval);
+BOOL yield = FALSE;
-Arguments:
- name point this at the name
- value point this at the data string
+os_non_restarting_signal(SIGALRM, command_timeout_handler);
+ALARM(proxy_protocol_timeout);
-Returns: TRUE if found an option
-*/
+do
+ {
+ /* The inbound host was declared to be a Proxy Protocol host, so
+ don't do a PEEK into the data, actually slurp up enough to be
+ "safe". Can't take it all because TLS-on-connect clients follow
+ immediately with TLS handshake. */
+ ret = read(fd, &hdr, PROXY_INITIAL_READ);
+ }
+ while (ret == -1 && errno == EINTR && !had_command_timeout);
-static BOOL
-extract_option(uschar **name, uschar **value)
-{
-uschar *n;
-uschar *v = smtp_cmd_data + Ustrlen(smtp_cmd_data) - 1;
-while (isspace(*v)) v--;
-v[1] = 0;
+if (ret == -1)
+ goto proxyfail;
-while (v > smtp_cmd_data && *v != '=' && !isspace(*v)) v--;
-if (*v != '=') return FALSE;
+/* For v2, handle reading the length, and then the rest. */
+if ((ret == PROXY_INITIAL_READ) && (memcmp(&hdr.v2, v2sig, sizeof(v2sig)) == 0))
+ {
+ int retmore;
+ uint8_t ver;
-n = v;
-while(isalpha(n[-1])) n--;
+ /* First get the length fields. */
+ do
+ {
+ retmore = read(fd, (uschar*)&hdr + ret, PROXY_V2_HEADER_SIZE - PROXY_INITIAL_READ);
+ } while (retmore == -1 && errno == EINTR && !had_command_timeout);
+ if (retmore == -1)
+ goto proxyfail;
+ ret += retmore;
-/* RFC says SP, but TAB seen in wild and other major MTAs accept it */
-if (!isspace(n[-1])) return FALSE;
+ ver = (hdr.v2.ver_cmd & 0xf0) >> 4;
-n[-1] = 0;
-*name = n;
-*v++ = 0;
-*value = v;
-return TRUE;
-}
+ /* May 2014: haproxy combined the version and command into one byte to
+ allow two full bytes for the length field in order to proxy SSL
+ connections. SSL Proxy is not supported in this version of Exim, but
+ must still separate values here. */
+ if (ver != 0x02)
+ {
+ DEBUG(D_receive) debug_printf("Invalid Proxy Protocol version: %d\n", ver);
+ goto proxyfail;
+ }
+ /* The v2 header will always be 16 bytes per the spec. */
+ size = 16 + ntohs(hdr.v2.len);
+ DEBUG(D_receive) debug_printf("Detected PROXYv2 header, size %d (limit %d)\n",
+ size, (int)sizeof(hdr));
+ /* We should now have 16 octets (PROXY_V2_HEADER_SIZE), and we know the total
+ amount that we need. Double-check that the size is not unreasonable, then
+ get the rest. */
+ if (size > sizeof(hdr))
+ {
+ DEBUG(D_receive) debug_printf("PROXYv2 header size unreasonably large; security attack?\n");
+ goto proxyfail;
+ }
+ do
+ {
+ do
+ {
+ retmore = read(fd, (uschar*)&hdr + ret, size-ret);
+ } while (retmore == -1 && errno == EINTR && !had_command_timeout);
+ if (retmore == -1)
+ goto proxyfail;
+ ret += retmore;
+ DEBUG(D_receive) debug_printf("PROXYv2: have %d/%d required octets\n", ret, size);
+ } while (ret < size);
-/*************************************************
-* Reset for new message *
-*************************************************/
+ } /* end scope for getting rest of data for v2 */
-/* This function is called whenever the SMTP session is reset from
-within either of the setup functions.
+/* At this point: if PROXYv2, we've read the exact size required for all data;
+if PROXYv1 then we've read "less than required for any valid line" and should
+read the rest". */
-Argument: the stacking pool storage reset point
-Returns: nothing
-*/
+if (ret >= 16 && memcmp(&hdr.v2, v2sig, 12) == 0)
+ {
+ uint8_t cmd = (hdr.v2.ver_cmd & 0x0f);
-static void
-smtp_reset(void *reset_point)
-{
-store_reset(reset_point);
-recipients_list = NULL;
-rcpt_count = rcpt_defer_count = rcpt_fail_count =
- raw_recipients_count = recipients_count = recipients_list_max = 0;
-message_linecount = 0;
-message_size = -1;
-acl_added_headers = NULL;
-queue_only_policy = FALSE;
-rcpt_smtp_response = NULL;
-rcpt_smtp_response_same = TRUE;
-rcpt_in_progress = FALSE;
-deliver_freeze = FALSE; /* Can be set by ACL */
-freeze_tell = freeze_tell_config; /* Can be set by ACL */
-fake_response = OK; /* Can be set by ACL */
-#ifdef WITH_CONTENT_SCAN
-no_mbox_unspool = FALSE; /* Can be set by ACL */
-#endif
-submission_mode = FALSE; /* Can be set by ACL */
-suppress_local_fixups = suppress_local_fixups_default; /* Can be set by ACL */
-active_local_from_check = local_from_check; /* Can be set by ACL */
-active_local_sender_retain = local_sender_retain; /* Can be set by ACL */
-sender_address = NULL;
-submission_name = NULL; /* Can be set by ACL */
-raw_sender = NULL; /* After SMTP rewrite, before qualifying */
-sender_address_unrewritten = NULL; /* Set only after verify rewrite */
-sender_verified_list = NULL; /* No senders verified */
-memset(sender_address_cache, 0, sizeof(sender_address_cache));
-memset(sender_domain_cache, 0, sizeof(sender_domain_cache));
-authenticated_sender = NULL;
-#ifdef EXPERIMENTAL_BRIGHTMAIL
-bmi_run = 0;
-bmi_verdicts = NULL;
-#endif
-#ifndef DISABLE_DKIM
-dkim_signers = NULL;
-dkim_disable_verify = FALSE;
-dkim_collect_input = FALSE;
-#endif
-#ifdef EXPERIMENTAL_SPF
-spf_header_comment = NULL;
-spf_received = NULL;
-spf_result = NULL;
-spf_smtp_comment = NULL;
-#endif
-body_linecount = body_zerocount = 0;
-
-sender_rate = sender_rate_limit = sender_rate_period = NULL;
-ratelimiters_mail = NULL; /* Updated by ratelimit ACL condition */
- /* Note that ratelimiters_conn persists across resets. */
-
-/* Reset message ACL variables */
-
-acl_var_m = NULL;
-
-/* The message body variables use malloc store. They may be set if this is
-not the first message in an SMTP session and the previous message caused them
-to be referenced in an ACL. */
-
-if (message_body != NULL)
- {
- store_free(message_body);
- message_body = NULL;
+ switch (cmd)
+ {
+ case 0x01: /* PROXY command */
+ switch (hdr.v2.fam)
+ {
+ case 0x11: /* TCPv4 address type */
+ iptype = US"IPv4";
+ tmpaddr.sin_addr.s_addr = hdr.v2.addr.ip4.src_addr;
+ inet_ntop(AF_INET, &tmpaddr.sin_addr, CS &tmpip, sizeof(tmpip));
+ if (!string_is_ip_address(US tmpip, NULL))
+ {
+ DEBUG(D_receive) debug_printf("Invalid %s source IP\n", iptype);
+ goto proxyfail;
+ }
+ proxy_local_address = sender_host_address;
+ sender_host_address = string_copy(US tmpip);
+ tmpport = ntohs(hdr.v2.addr.ip4.src_port);
+ proxy_local_port = sender_host_port;
+ sender_host_port = tmpport;
+ /* Save dest ip/port */
+ tmpaddr.sin_addr.s_addr = hdr.v2.addr.ip4.dst_addr;
+ inet_ntop(AF_INET, &tmpaddr.sin_addr, CS &tmpip, sizeof(tmpip));
+ if (!string_is_ip_address(US tmpip, NULL))
+ {
+ DEBUG(D_receive) debug_printf("Invalid %s dest port\n", iptype);
+ goto proxyfail;
+ }
+ proxy_external_address = string_copy(US tmpip);
+ tmpport = ntohs(hdr.v2.addr.ip4.dst_port);
+ proxy_external_port = tmpport;
+ goto done;
+ case 0x21: /* TCPv6 address type */
+ iptype = US"IPv6";
+ memmove(tmpaddr6.sin6_addr.s6_addr, hdr.v2.addr.ip6.src_addr, 16);
+ inet_ntop(AF_INET6, &tmpaddr6.sin6_addr, CS &tmpip6, sizeof(tmpip6));
+ if (!string_is_ip_address(US tmpip6, NULL))
+ {
+ DEBUG(D_receive) debug_printf("Invalid %s source IP\n", iptype);
+ goto proxyfail;
+ }
+ proxy_local_address = sender_host_address;
+ sender_host_address = string_copy(US tmpip6);
+ tmpport = ntohs(hdr.v2.addr.ip6.src_port);
+ proxy_local_port = sender_host_port;
+ sender_host_port = tmpport;
+ /* Save dest ip/port */
+ memmove(tmpaddr6.sin6_addr.s6_addr, hdr.v2.addr.ip6.dst_addr, 16);
+ inet_ntop(AF_INET6, &tmpaddr6.sin6_addr, CS &tmpip6, sizeof(tmpip6));
+ if (!string_is_ip_address(US tmpip6, NULL))
+ {
+ DEBUG(D_receive) debug_printf("Invalid %s dest port\n", iptype);
+ goto proxyfail;
+ }
+ proxy_external_address = string_copy(US tmpip6);
+ tmpport = ntohs(hdr.v2.addr.ip6.dst_port);
+ proxy_external_port = tmpport;
+ goto done;
+ default:
+ DEBUG(D_receive)
+ debug_printf("Unsupported PROXYv2 connection type: 0x%02x\n",
+ hdr.v2.fam);
+ goto proxyfail;
+ }
+ /* Unsupported protocol, keep local connection address */
+ break;
+ case 0x00: /* LOCAL command */
+ /* Keep local connection address for LOCAL */
+ iptype = US"local";
+ break;
+ default:
+ DEBUG(D_receive)
+ debug_printf("Unsupported PROXYv2 command: 0x%x\n", cmd);
+ goto proxyfail;
+ }
}
-
-if (message_body_end != NULL)
+else if (ret >= 8 && memcmp(hdr.v1.line, "PROXY", 5) == 0)
{
- store_free(message_body_end);
- message_body_end = NULL;
- }
-
-/* Warning log messages are also saved in malloc store. They are saved to avoid
-repetition in the same message, but it seems right to repeat them for different
-messages. */
+ uschar *p;
+ uschar *end;
+ uschar *sp; /* Utility variables follow */
+ int tmp_port;
+ int r2;
+ char *endc;
+
+ /* get the rest of the line */
+ r2 = swallow_until_crlf(fd, (uschar*)&hdr, ret, sizeof(hdr)-ret);
+ if (r2 == -1)
+ goto proxyfail;
+ ret += r2;
+
+ p = string_copy(hdr.v1.line);
+ end = memchr(p, '\r', ret - 1);
+
+ if (!end || (end == (uschar*)&hdr + ret) || end[1] != '\n')
+ {
+ DEBUG(D_receive) debug_printf("Partial or invalid PROXY header\n");
+ goto proxyfail;
+ }
+ *end = '\0'; /* Terminate the string */
+ size = end + 2 - p; /* Skip header + CRLF */
+ DEBUG(D_receive) debug_printf("Detected PROXYv1 header\n");
+ DEBUG(D_receive) debug_printf("Bytes read not within PROXY header: %d\n", ret - size);
+ /* Step through the string looking for the required fields. Ensure
+ strict adherence to required formatting, exit for any error. */
+ p += 5;
+ if (!isspace(*(p++)))
+ {
+ DEBUG(D_receive) debug_printf("Missing space after PROXY command\n");
+ goto proxyfail;
+ }
+ if (!Ustrncmp(p, CCS"TCP4", 4))
+ iptype = US"IPv4";
+ else if (!Ustrncmp(p,CCS"TCP6", 4))
+ iptype = US"IPv6";
+ else if (!Ustrncmp(p,CCS"UNKNOWN", 7))
+ {
+ iptype = US"Unknown";
+ goto done;
+ }
+ else
+ {
+ DEBUG(D_receive) debug_printf("Invalid TCP type\n");
+ goto proxyfail;
+ }
-while (acl_warn_logged != NULL)
+ p += Ustrlen(iptype);
+ if (!isspace(*(p++)))
+ {
+ DEBUG(D_receive) debug_printf("Missing space after TCP4/6 command\n");
+ goto proxyfail;
+ }
+ /* Find the end of the arg */
+ if ((sp = Ustrchr(p, ' ')) == NULL)
+ {
+ DEBUG(D_receive)
+ debug_printf("Did not find proxied src %s\n", iptype);
+ goto proxyfail;
+ }
+ *sp = '\0';
+ if(!string_is_ip_address(p, NULL))
+ {
+ DEBUG(D_receive)
+ debug_printf("Proxied src arg is not an %s address\n", iptype);
+ goto proxyfail;
+ }
+ proxy_local_address = sender_host_address;
+ sender_host_address = p;
+ p = sp + 1;
+ if ((sp = Ustrchr(p, ' ')) == NULL)
+ {
+ DEBUG(D_receive)
+ debug_printf("Did not find proxy dest %s\n", iptype);
+ goto proxyfail;
+ }
+ *sp = '\0';
+ if(!string_is_ip_address(p, NULL))
+ {
+ DEBUG(D_receive)
+ debug_printf("Proxy dest arg is not an %s address\n", iptype);
+ goto proxyfail;
+ }
+ proxy_external_address = p;
+ p = sp + 1;
+ if ((sp = Ustrchr(p, ' ')) == NULL)
+ {
+ DEBUG(D_receive) debug_printf("Did not find proxied src port\n");
+ goto proxyfail;
+ }
+ *sp = '\0';
+ tmp_port = strtol(CCS p, &endc, 10);
+ if (*endc || tmp_port == 0)
+ {
+ DEBUG(D_receive)
+ debug_printf("Proxied src port '%s' not an integer\n", p);
+ goto proxyfail;
+ }
+ proxy_local_port = sender_host_port;
+ sender_host_port = tmp_port;
+ p = sp + 1;
+ if ((sp = Ustrchr(p, '\0')) == NULL)
+ {
+ DEBUG(D_receive) debug_printf("Did not find proxy dest port\n");
+ goto proxyfail;
+ }
+ tmp_port = strtol(CCS p, &endc, 10);
+ if (*endc || tmp_port == 0)
+ {
+ DEBUG(D_receive)
+ debug_printf("Proxy dest port '%s' not an integer\n", p);
+ goto proxyfail;
+ }
+ proxy_external_port = tmp_port;
+ /* Already checked for /r /n above. Good V1 header received. */
+ }
+else
{
- string_item *this = acl_warn_logged;
- acl_warn_logged = acl_warn_logged->next;
- store_free(this);
+ /* Wrong protocol */
+ DEBUG(D_receive) debug_printf("Invalid proxy protocol version negotiation\n");
+ (void) swallow_until_crlf(fd, (uschar*)&hdr, ret, sizeof(hdr)-ret);
+ goto proxyfail;
}
-}
+done:
+ DEBUG(D_receive)
+ debug_printf("Valid %s sender from Proxy Protocol header\n", iptype);
+ yield = proxy_session;
+/* Don't flush any potential buffer contents. Any input on proxyfail
+should cause a synchronization failure */
+proxyfail:
+ DEBUG(D_receive) if (had_command_timeout)
+ debug_printf("Timeout while reading proxy header\n");
+
+bad:
+ if (yield)
+ {
+ sender_host_name = NULL;
+ (void) host_name_lookup();
+ host_build_sender_fullhost();
+ }
+ else
+ {
+ f.proxy_session_failed = TRUE;
+ DEBUG(D_receive)
+ debug_printf("Failure to extract proxied host, only QUIT allowed\n");
+ }
+ALARM(0);
+return;
+}
+#endif
/*************************************************
-* Initialize for incoming batched SMTP message *
+* Read one command line *
*************************************************/
-/* This function is called from smtp_setup_msg() in the case when
-smtp_batched_input is true. This happens when -bS is used to pass a whole batch
-of messages in one file with SMTP commands between them. All errors must be
-reported by sending a message, and only MAIL FROM, RCPT TO, and DATA are
-relevant. After an error on a sender, or an invalid recipient, the remainder
-of the message is skipped. The value of received_protocol is already set.
+/* Strictly, SMTP commands coming over the net are supposed to end with CRLF.
+There are sites that don't do this, and in any case internal SMTP probably
+should check only for LF. Consequently, we check here for LF only. The line
+ends up with [CR]LF removed from its end. If we get an overlong line, treat as
+an unknown command. The command is read into the global smtp_cmd_buffer so that
+it is available via $smtp_command.
-Argument: none
-Returns: > 0 message successfully started (reached DATA)
- = 0 QUIT read or end of file reached
- < 0 should not occur
+The character reading routine sets up a timeout for each block actually read
+from the input (which may contain more than one command). We set up a special
+signal handler that closes down the session on a timeout. Control does not
+return when it runs.
+
+Arguments:
+ check_sync if TRUE, check synchronization rules if global option is TRUE
+ buffer_lim maximum to buffer in lower layer
+
+Returns: a code identifying the command (enumerated above)
*/
static int
-smtp_setup_batch_msg(void)
+smtp_read_command(BOOL check_sync, unsigned buffer_lim)
{
-int done = 0;
-void *reset_point = store_get(0);
-
-/* Save the line count at the start of each transaction - single commands
-like HELO and RSET count as whole transactions. */
-
-bsmtp_transaction_linecount = receive_linecount;
-
-if ((receive_feof)()) return 0; /* Treat EOF as QUIT */
-
-smtp_reset(reset_point); /* Reset for start of message */
+int c;
+int ptr = 0;
+BOOL hadnull = FALSE;
-/* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE
-value. The values are 2 larger than the required yield of the function. */
+had_command_timeout = 0;
+os_non_restarting_signal(SIGALRM, command_timeout_handler);
-while (done <= 0)
+while ((c = (receive_getc)(buffer_lim)) != '\n' && c != EOF)
{
- uschar *errmess;
- uschar *recipient = NULL;
- int start, end, sender_domain, recipient_domain;
-
- switch(smtp_read_command(FALSE))
+ if (ptr >= SMTP_CMD_BUFFER_SIZE)
{
- /* The HELO/EHLO commands set sender_address_helo if they have
- valid data; otherwise they are ignored, except that they do
- a reset of the state. */
-
- case HELO_CMD:
- case EHLO_CMD:
-
- check_helo(smtp_cmd_data);
- /* Fall through */
+ os_non_restarting_signal(SIGALRM, sigalrm_handler);
+ return OTHER_CMD;
+ }
+ if (c == 0)
+ {
+ hadnull = TRUE;
+ c = '?';
+ }
+ smtp_cmd_buffer[ptr++] = c;
+ }
- case RSET_CMD:
- smtp_reset(reset_point);
- bsmtp_transaction_linecount = receive_linecount;
- break;
+receive_linecount++; /* For BSMTP errors */
+os_non_restarting_signal(SIGALRM, sigalrm_handler);
+/* If hit end of file, return pseudo EOF command. Whether we have a
+part-line already read doesn't matter, since this is an error state. */
- /* The MAIL FROM command requires an address as an operand. All we
- do here is to parse it for syntactic correctness. The form "<>" is
- a special case which converts into an empty string. The start/end
- pointers in the original are not used further for this address, as
- it is the canonical extracted address which is all that is kept. */
+if (c == EOF) return EOF_CMD;
- case MAIL_CMD:
- if (sender_address != NULL)
- /* The function moan_smtp_batch() does not return. */
- moan_smtp_batch(smtp_cmd_buffer, "503 Sender already given");
+/* Remove any CR and white space at the end of the line, and terminate the
+string. */
- if (smtp_cmd_data[0] == 0)
- /* The function moan_smtp_batch() does not return. */
- moan_smtp_batch(smtp_cmd_buffer, "501 MAIL FROM must have an address operand");
+while (ptr > 0 && isspace(smtp_cmd_buffer[ptr-1])) ptr--;
+smtp_cmd_buffer[ptr] = 0;
- /* Reset to start of message */
+DEBUG(D_receive) debug_printf("SMTP<< %s\n", smtp_cmd_buffer);
- smtp_reset(reset_point);
+/* NULLs are not allowed in SMTP commands */
- /* Apply SMTP rewrite */
+if (hadnull) return BADCHAR_CMD;
- raw_sender = ((rewrite_existflags & rewrite_smtp) != 0)?
- rewrite_one(smtp_cmd_data, rewrite_smtp|rewrite_smtp_sender, NULL, FALSE,
- US"", global_rewrite_rules) : smtp_cmd_data;
+/* Scan command list and return identity, having set the data pointer
+to the start of the actual data characters. Check for SMTP synchronization
+if required. */
- /* Extract the address; the TRUE flag allows <> as valid */
+for (smtp_cmd_list * p = cmd_list; p < cmd_list_end; p++)
+ {
+#ifdef SUPPORT_PROXY
+ /* Only allow QUIT command if Proxy Protocol parsing failed */
+ if (proxy_session && f.proxy_session_failed && p->cmd != QUIT_CMD)
+ continue;
+#endif
+ if ( p->len
+ && strncmpic(smtp_cmd_buffer, US p->name, p->len) == 0
+ && ( smtp_cmd_buffer[p->len-1] == ':' /* "mail from:" or "rcpt to:" */
+ || smtp_cmd_buffer[p->len] == 0
+ || smtp_cmd_buffer[p->len] == ' '
+ ) )
+ {
+ if (smtp_inptr < smtp_inend && /* Outstanding input */
+ p->cmd < sync_cmd_limit && /* Command should sync */
+ check_sync && /* Local flag set */
+ smtp_enforce_sync && /* Global flag set */
+ sender_host_address != NULL && /* Not local input */
+ !f.sender_host_notsocket) /* Really is a socket */
+ return BADSYN_CMD;
- raw_sender =
- parse_extract_address(raw_sender, &errmess, &start, &end, &sender_domain,
- TRUE);
+ /* The variables $smtp_command and $smtp_command_argument point into the
+ unmodified input buffer. A copy of the latter is taken for actual
+ processing, so that it can be chopped up into separate parts if necessary,
+ for example, when processing a MAIL command options such as SIZE that can
+ follow the sender address. */
- if (raw_sender == NULL)
- /* The function moan_smtp_batch() does not return. */
- moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess);
+ smtp_cmd_argument = smtp_cmd_buffer + p->len;
+ while (isspace(*smtp_cmd_argument)) smtp_cmd_argument++;
+ Ustrcpy(smtp_data_buffer, smtp_cmd_argument);
+ smtp_cmd_data = smtp_data_buffer;
- sender_address = string_copy(raw_sender);
+ /* Count non-mail commands from those hosts that are controlled in this
+ way. The default is all hosts. We don't waste effort checking the list
+ until we get a non-mail command, but then cache the result to save checking
+ again. If there's a DEFER while checking the host, assume it's in the list.
- /* Qualify unqualified sender addresses if permitted to do so. */
+ Note that one instance of RSET, EHLO/HELO, and STARTTLS is allowed at the
+ start of each incoming message by fiddling with the value in the table. */
- if (sender_domain == 0 && sender_address[0] != 0 && sender_address[0] != '@')
+ if (!p->is_mail_cmd)
{
- if (allow_unqualified_sender)
- {
- sender_address = rewrite_address_qualify(sender_address, FALSE);
- DEBUG(D_receive) debug_printf("unqualified address %s accepted "
- "and rewritten\n", raw_sender);
- }
- /* The function moan_smtp_batch() does not return. */
- else moan_smtp_batch(smtp_cmd_buffer, "501 sender address must contain "
- "a domain");
+ if (count_nonmail == TRUE_UNSET) count_nonmail =
+ verify_check_host(&smtp_accept_max_nonmail_hosts) != FAIL;
+ if (count_nonmail && ++nonmail_command_count > smtp_accept_max_nonmail)
+ return TOO_MANY_NONMAIL_CMD;
}
- break;
+ /* If there is data for a command that does not expect it, generate the
+ error here. */
- /* The RCPT TO command requires an address as an operand. All we do
- here is to parse it for syntactic correctness. There may be any number
- of RCPT TO commands, specifying multiple senders. We build them all into
- a data structure that is in argc/argv format. The start/end values
- given by parse_extract_address are not used, as we keep only the
- extracted address. */
+ return (p->has_arg || *smtp_cmd_data == 0)? p->cmd : BADARG_CMD;
+ }
+ }
- case RCPT_CMD:
- if (sender_address == NULL)
- /* The function moan_smtp_batch() does not return. */
- moan_smtp_batch(smtp_cmd_buffer, "503 No sender yet given");
+#ifdef SUPPORT_PROXY
+/* Only allow QUIT command if Proxy Protocol parsing failed */
+if (proxy_session && f.proxy_session_failed)
+ return PROXY_FAIL_IGNORE_CMD;
+#endif
- if (smtp_cmd_data[0] == 0)
- /* The function moan_smtp_batch() does not return. */
- moan_smtp_batch(smtp_cmd_buffer, "501 RCPT TO must have an address operand");
+/* Enforce synchronization for unknown commands */
- /* Check maximum number allowed */
+if ( smtp_inptr < smtp_inend /* Outstanding input */
+ && check_sync /* Local flag set */
+ && smtp_enforce_sync /* Global flag set */
+ && sender_host_address /* Not local input */
+ && !f.sender_host_notsocket) /* Really is a socket */
+ return BADSYN_CMD;
- if (recipients_max > 0 && recipients_count + 1 > recipients_max)
- /* The function moan_smtp_batch() does not return. */
- moan_smtp_batch(smtp_cmd_buffer, "%s too many recipients",
- recipients_max_reject? "552": "452");
+return OTHER_CMD;
+}
- /* Apply SMTP rewrite, then extract address. Don't allow "<>" as a
- recipient address */
- recipient = ((rewrite_existflags & rewrite_smtp) != 0)?
- rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"",
- global_rewrite_rules) : smtp_cmd_data;
- /* rfc821_domains = TRUE; << no longer needed */
- recipient = parse_extract_address(recipient, &errmess, &start, &end,
- &recipient_domain, FALSE);
- /* rfc821_domains = FALSE; << no longer needed */
+/*************************************************
+* Forced closedown of call *
+*************************************************/
- if (recipient == NULL)
- /* The function moan_smtp_batch() does not return. */
- moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess);
+/* This function is called from log.c when Exim is dying because of a serious
+disaster, and also from some other places. If an incoming non-batched SMTP
+channel is open, it swallows the rest of the incoming message if in the DATA
+phase, sends the reply string, and gives an error to all subsequent commands
+except QUIT. The existence of an SMTP call is detected by the non-NULLness of
+smtp_in.
- /* If the recipient address is unqualified, qualify it if permitted. Then
- add it to the list of recipients. */
+Arguments:
+ message SMTP reply string to send, excluding the code
- if (recipient_domain == 0)
- {
- if (allow_unqualified_recipient)
- {
- DEBUG(D_receive) debug_printf("unqualified address %s accepted\n",
- recipient);
- recipient = rewrite_address_qualify(recipient, TRUE);
- }
- /* The function moan_smtp_batch() does not return. */
- else moan_smtp_batch(smtp_cmd_buffer, "501 recipient address must contain "
- "a domain");
- }
- receive_add_recipient(recipient, -1);
- break;
+Returns: nothing
+*/
+void
+smtp_closedown(uschar *message)
+{
+if (!smtp_in || smtp_batched_input) return;
+receive_swallow_smtp();
+smtp_printf("421 %s\r\n", FALSE, message);
- /* The DATA command is legal only if it follows successful MAIL FROM
- and RCPT TO commands. This function is complete when a valid DATA
- command is encountered. */
+for (;;) switch(smtp_read_command(FALSE, GETC_BUFFER_UNLIMITED))
+ {
+ case EOF_CMD:
+ return;
- case DATA_CMD:
- if (sender_address == NULL || recipients_count <= 0)
- {
- /* The function moan_smtp_batch() does not return. */
- if (sender_address == NULL)
- moan_smtp_batch(smtp_cmd_buffer,
- "503 MAIL FROM:<sender> command must precede DATA");
- else
- moan_smtp_batch(smtp_cmd_buffer,
- "503 RCPT TO:<recipient> must precede DATA");
- }
- else
- {
- done = 3; /* DATA successfully achieved */
- message_ended = END_NOTENDED; /* Indicate in middle of message */
- }
+ case QUIT_CMD:
+ f.smtp_in_quit = TRUE;
+ smtp_printf("221 %s closing connection\r\n", FALSE, smtp_active_hostname);
+ mac_smtp_fflush();
+ return;
+
+ case RSET_CMD:
+ smtp_printf("250 Reset OK\r\n", FALSE);
break;
+ default:
+ smtp_printf("421 %s\r\n", FALSE, message);
+ break;
+ }
+}
- /* The VRFY, EXPN, HELP, ETRN, and NOOP commands are ignored. */
- case VRFY_CMD:
- case EXPN_CMD:
- case HELP_CMD:
- case NOOP_CMD:
- case ETRN_CMD:
- bsmtp_transaction_linecount = receive_linecount;
- break;
- case EOF_CMD:
- case QUIT_CMD:
- done = 2;
- break;
+/*************************************************
+* Set up connection info for logging *
+*************************************************/
+/* This function is called when logging information about an SMTP connection.
+It sets up appropriate source information, depending on the type of connection.
+If sender_fullhost is NULL, we are at a very early stage of the connection;
+just use the IP address.
- case BADARG_CMD:
- /* The function moan_smtp_batch() does not return. */
- moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected argument data");
- break;
+Argument: none
+Returns: a string describing the connection
+*/
+uschar *
+smtp_get_connection_info(void)
+{
+const uschar * hostname = sender_fullhost
+ ? sender_fullhost : sender_host_address;
- case BADCHAR_CMD:
- /* The function moan_smtp_batch() does not return. */
- moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected NULL in SMTP command");
- break;
+if (host_checking)
+ return string_sprintf("SMTP connection from %s", hostname);
+if (f.sender_host_unknown || f.sender_host_notsocket)
+ return string_sprintf("SMTP connection from %s", sender_ident);
- default:
- /* The function moan_smtp_batch() does not return. */
- moan_smtp_batch(smtp_cmd_buffer, "500 Command unrecognized");
- break;
- }
- }
+if (f.is_inetd)
+ return string_sprintf("SMTP connection from %s (via inetd)", hostname);
-return done - 2; /* Convert yield values */
-}
+if (LOGGING(incoming_interface) && interface_address)
+ return string_sprintf("SMTP connection from %s I=[%s]:%d", hostname,
+ interface_address, interface_port);
+return string_sprintf("SMTP connection from %s", hostname);
+}
-/*************************************************
-* Start an SMTP session *
-*************************************************/
+#ifndef DISABLE_TLS
+/* Append TLS-related information to a log line
-/* This function is called at the start of an SMTP session. Thereafter,
-smtp_setup_msg() is called to initiate each separate message. This
-function does host-specific testing, and outputs the banner line.
+Arguments:
+ g String under construction: allocated string to extend, or NULL
-Arguments: none
-Returns: FALSE if the session can not continue; something has
- gone wrong, or the connection to the host is blocked
+Returns: Allocated string or NULL
*/
-
-BOOL
-smtp_start_session(void)
+static gstring *
+s_tlslog(gstring * g)
{
-int size = 256;
-int ptr, esclen;
-uschar *user_msg, *log_msg;
-uschar *code, *esc;
-uschar *p, *s, *ss;
-
-smtp_connection_start = time(NULL);
-for (smtp_ch_index = 0; smtp_ch_index < SMTP_HBUFF_SIZE; smtp_ch_index++)
- smtp_connection_had[smtp_ch_index] = SCH_NONE;
-smtp_ch_index = 0;
-
-/* Default values for certain variables */
+if (LOGGING(tls_cipher) && tls_in.cipher)
+ {
+ g = string_append(g, 2, US" X=", tls_in.cipher);
+#ifndef DISABLE_TLS_RESUME
+ if (LOGGING(tls_resumption) && tls_in.resumption & RESUME_USED)
+ g = string_catn(g, US"*", 1);
+#endif
+ }
+if (LOGGING(tls_certificate_verified) && tls_in.cipher)
+ g = string_append(g, 2, US" CV=", tls_in.certificate_verified? "yes":"no");
+if (LOGGING(tls_peerdn) && tls_in.peerdn)
+ g = string_append(g, 3, US" DN=\"", string_printing(tls_in.peerdn), US"\"");
+if (LOGGING(tls_sni) && tls_in.sni)
+ g = string_append(g, 2, US" SNI=", string_printing2(tls_in.sni, SP_TAB|SP_SPACE));
+return g;
+}
+#endif
-helo_seen = esmtp = helo_accept_junk = FALSE;
-smtp_mailcmd_count = 0;
-count_nonmail = TRUE_UNSET;
-synprot_error_count = unknown_command_count = nonmail_command_count = 0;
-smtp_delay_mail = smtp_rlm_base;
-auth_advertised = FALSE;
-pipelining_advertised = FALSE;
-pipelining_enable = TRUE;
-sync_cmd_limit = NON_SYNC_CMD_NON_PIPELINING;
-smtp_exit_function_called = FALSE; /* For avoiding loop in not-quit exit */
-memset(sender_host_cache, 0, sizeof(sender_host_cache));
-/* If receiving by -bs from a trusted user, or testing with -bh, we allow
-authentication settings from -oMaa to remain in force. */
+static gstring *
+s_connhad_log(gstring * g)
+{
+const uschar * sep = smtp_connection_had[SMTP_HBUFF_SIZE-1] != SCH_NONE
+ ? US" C=..." : US" C=";
-if (!host_checking && !sender_host_notsocket) sender_host_authenticated = NULL;
-authenticated_by = NULL;
+for (int i = smtp_ch_index; i < SMTP_HBUFF_SIZE; i++)
+ if (smtp_connection_had[i] != SCH_NONE)
+ {
+ g = string_append(g, 2, sep, smtp_names[smtp_connection_had[i]]);
+ sep = US",";
+ }
+for (int i = 0; i < smtp_ch_index; i++, sep = US",")
+ g = string_append(g, 2, sep, smtp_names[smtp_connection_had[i]]);
+return g;
+}
-#ifdef SUPPORT_TLS
-tls_cipher = tls_peerdn = NULL;
-tls_advertised = FALSE;
-#endif
-/* Reset ACL connection variables */
+/*************************************************
+* Log lack of MAIL if so configured *
+*************************************************/
-acl_var_c = NULL;
+/* This function is called when an SMTP session ends. If the log selector
+smtp_no_mail is set, write a log line giving some details of what has happened
+in the SMTP session.
-/* Allow for trailing 0 in the command and data buffers. */
+Arguments: none
+Returns: nothing
+*/
-smtp_cmd_buffer = (uschar *)malloc(2*smtp_cmd_buffer_size + 2);
-if (smtp_cmd_buffer == NULL)
- log_write(0, LOG_MAIN|LOG_PANIC_DIE,
- "malloc() failed for SMTP command buffer");
-smtp_cmd_buffer[0] = 0;
-smtp_data_buffer = smtp_cmd_buffer + smtp_cmd_buffer_size + 1;
+void
+smtp_log_no_mail(void)
+{
+uschar * s;
+gstring * g = NULL;
-/* For batched input, the protocol setting can be overridden from the
-command line by a trusted caller. */
+if (smtp_mailcmd_count > 0 || !LOGGING(smtp_no_mail))
+ return;
-if (smtp_batched_input)
+if (sender_host_authenticated)
{
- if (received_protocol == NULL) received_protocol = US"local-bsmtp";
+ g = string_append(g, 2, US" A=", sender_host_authenticated);
+ if (authenticated_id) g = string_append(g, 2, US":", authenticated_id);
}
-/* For non-batched SMTP input, the protocol setting is forced here. It will be
-reset later if any of EHLO/AUTH/STARTTLS are received. */
+#ifndef DISABLE_TLS
+g = s_tlslog(g);
+#endif
-else
- received_protocol =
- protocols[pnormal] + ((sender_host_address != NULL)? pnlocal : 0);
+g = s_connhad_log(g);
-/* Set up the buffer for inputting using direct read() calls, and arrange to
-call the local functions instead of the standard C ones. */
+if (!(s = string_from_gstring(g))) s = US"";
-smtp_inbuffer = (uschar *)malloc(in_buffer_size);
-if (smtp_inbuffer == NULL)
- log_write(0, LOG_MAIN|LOG_PANIC_DIE, "malloc() failed for SMTP input buffer");
-receive_getc = smtp_getc;
-receive_ungetc = smtp_ungetc;
-receive_feof = smtp_feof;
-receive_ferror = smtp_ferror;
-receive_smtp_buffered = smtp_buffered;
-smtp_inptr = smtp_inend = smtp_inbuffer;
-smtp_had_eof = smtp_had_error = 0;
+log_write(0, LOG_MAIN, "no MAIL in %sSMTP connection from %s D=%s%s",
+ f.tcp_in_fastopen ? f.tcp_in_fastopen_data ? US"TFO* " : US"TFO " : US"",
+ host_and_ident(FALSE), string_timesince(&smtp_connection_start), s);
+}
-/* Set up the message size limit; this may be host-specific */
-thismessage_size_limit = expand_string_integer(message_size_limit, TRUE);
-if (expand_string_message != NULL)
- {
- if (thismessage_size_limit == -1)
- log_write(0, LOG_MAIN|LOG_PANIC, "unable to expand message_size_limit: "
- "%s", expand_string_message);
- else
- log_write(0, LOG_MAIN|LOG_PANIC, "invalid message_size_limit: "
- "%s", expand_string_message);
- smtp_closedown(US"Temporary local problem - please try later");
- return FALSE;
- }
+/* Return list of recent smtp commands */
-/* When a message is input locally via the -bs or -bS options, sender_host_
-unknown is set unless -oMa was used to force an IP address, in which case it
-is checked like a real remote connection. When -bs is used from inetd, this
-flag is not set, causing the sending host to be checked. The code that deals
-with IP source routing (if configured) is never required for -bs or -bS and
-the flag sender_host_notsocket is used to suppress it.
+uschar *
+smtp_cmd_hist(void)
+{
+gstring * list = NULL;
+uschar * s;
-If smtp_accept_max and smtp_accept_reserve are set, keep some connections in
-reserve for certain hosts and/or networks. */
+for (int i = smtp_ch_index; i < SMTP_HBUFF_SIZE; i++)
+ if (smtp_connection_had[i] != SCH_NONE)
+ list = string_append_listele(list, ',', smtp_names[smtp_connection_had[i]]);
-if (!sender_host_unknown)
- {
- int rc;
- BOOL reserved_host = FALSE;
+for (int i = 0; i < smtp_ch_index; i++)
+ list = string_append_listele(list, ',', smtp_names[smtp_connection_had[i]]);
- /* Look up IP options (source routing info) on the socket if this is not an
- -oMa "host", and if any are found, log them and drop the connection.
+s = string_from_gstring(list);
+return s ? s : US"";
+}
- Linux (and others now, see below) is different to everyone else, so there
- has to be some conditional compilation here. Versions of Linux before 2.1.15
- used a structure whose name was "options". Somebody finally realized that
- this name was silly, and it got changed to "ip_options". I use the
- newer name here, but there is a fudge in the script that sets up os.h
- to define a macro in older Linux systems.
- Sigh. Linux is a fast-moving target. Another generation of Linux uses
- glibc 2, which has chosen ip_opts for the structure name. This is now
- really a glibc thing rather than a Linux thing, so the condition name
- has been changed to reflect this. It is relevant also to GNU/Hurd.
- Mac OS 10.x (Darwin) is like the later glibc versions, but without the
- setting of the __GLIBC__ macro, so we can't detect it automatically. There's
- a special macro defined in the os.h file.
- Some DGUX versions on older hardware appear not to support IP options at
- all, so there is now a general macro which can be set to cut out this
- support altogether.
+/*************************************************
+* Check HELO line and set sender_helo_name *
+*************************************************/
- How to do this properly in IPv6 is not yet known. */
+/* Check the format of a HELO line. The data for HELO/EHLO is supposed to be
+the domain name of the sending host, or an ip literal in square brackets. The
+argument is placed in sender_helo_name, which is in malloc store, because it
+must persist over multiple incoming messages. If helo_accept_junk is set, this
+host is permitted to send any old junk (needed for some broken hosts).
+Otherwise, helo_allow_chars can be used for rogue characters in general
+(typically people want to let in underscores).
- #if !HAVE_IPV6 && !defined(NO_IP_OPTIONS)
+Argument:
+ s the data portion of the line (already past any white space)
- #ifdef GLIBC_IP_OPTIONS
- #if (!defined __GLIBC__) || (__GLIBC__ < 2)
- #define OPTSTYLE 1
- #else
- #define OPTSTYLE 2
- #endif
- #elif defined DARWIN_IP_OPTIONS
- #define OPTSTYLE 2
- #else
- #define OPTSTYLE 3
- #endif
+Returns: TRUE or FALSE
+*/
- if (!host_checking && !sender_host_notsocket)
- {
- #if OPTSTYLE == 1
- EXIM_SOCKLEN_T optlen = sizeof(struct ip_options) + MAX_IPOPTLEN;
- struct ip_options *ipopt = store_get(optlen);
- #elif OPTSTYLE == 2
- struct ip_opts ipoptblock;
- struct ip_opts *ipopt = &ipoptblock;
- EXIM_SOCKLEN_T optlen = sizeof(ipoptblock);
- #else
- struct ipoption ipoptblock;
- struct ipoption *ipopt = &ipoptblock;
- EXIM_SOCKLEN_T optlen = sizeof(ipoptblock);
- #endif
+static BOOL
+check_helo(uschar *s)
+{
+uschar *start = s;
+uschar *end = s + Ustrlen(s);
+BOOL yield = fl.helo_accept_junk;
- /* Occasional genuine failures of getsockopt() have been seen - for
- example, "reset by peer". Therefore, just log and give up on this
- call, unless the error is ENOPROTOOPT. This error is given by systems
- that have the interfaces but not the mechanism - e.g. GNU/Hurd at the time
- of writing. So for that error, carry on - we just can't do an IP options
- check. */
+/* Discard any previous helo name */
- DEBUG(D_receive) debug_printf("checking for IP options\n");
+sender_helo_name = NULL;
- if (getsockopt(fileno(smtp_out), IPPROTO_IP, IP_OPTIONS, (uschar *)(ipopt),
- &optlen) < 0)
- {
- if (errno != ENOPROTOOPT)
- {
- log_write(0, LOG_MAIN, "getsockopt() failed from %s: %s",
- host_and_ident(FALSE), strerror(errno));
- smtp_printf("451 SMTP service not available\r\n");
- return FALSE;
- }
- }
+/* Skip tests if junk is permitted. */
- /* Deal with any IP options that are set. On the systems I have looked at,
- the value of MAX_IPOPTLEN has been 40, meaning that there should never be
- more logging data than will fit in big_buffer. Nevertheless, after somebody
- questioned this code, I've added in some paranoid checking. */
+if (!yield)
- else if (optlen > 0)
+ /* Allow the new standard form for IPv6 address literals, namely,
+ [IPv6:....], and because someone is bound to use it, allow an equivalent
+ IPv4 form. Allow plain addresses as well. */
+
+ if (*s == '[')
+ {
+ if (end[-1] == ']')
{
- uschar *p = big_buffer;
- uschar *pend = big_buffer + big_buffer_size;
- uschar *opt, *adptr;
- int optcount;
- struct in_addr addr;
+ end[-1] = 0;
+ if (strncmpic(s, US"[IPv6:", 6) == 0)
+ yield = (string_is_ip_address(s+6, NULL) == 6);
+ else if (strncmpic(s, US"[IPv4:", 6) == 0)
+ yield = (string_is_ip_address(s+6, NULL) == 4);
+ else
+ yield = (string_is_ip_address(s+1, NULL) != 0);
+ end[-1] = ']';
+ }
+ }
- #if OPTSTYLE == 1
- uschar *optstart = (uschar *)(ipopt->__data);
- #elif OPTSTYLE == 2
- uschar *optstart = (uschar *)(ipopt->ip_opts);
- #else
- uschar *optstart = (uschar *)(ipopt->ipopt_list);
- #endif
+ /* Non-literals must be alpha, dot, hyphen, plus any non-valid chars
+ that have been configured (usually underscore - sigh). */
- DEBUG(D_receive) debug_printf("IP options exist\n");
+ else if (*s)
+ for (yield = TRUE; *s; s++)
+ if (!isalnum(*s) && *s != '.' && *s != '-' &&
+ Ustrchr(helo_allow_chars, *s) == NULL)
+ {
+ yield = FALSE;
+ break;
+ }
- Ustrcpy(p, "IP options on incoming call:");
- p += Ustrlen(p);
+/* Save argument if OK */
- for (opt = optstart; opt != NULL &&
- opt < (uschar *)(ipopt) + optlen;)
- {
- switch (*opt)
- {
- case IPOPT_EOL:
- opt = NULL;
- break;
+if (yield) sender_helo_name = string_copy_perm(start, TRUE);
+return yield;
+}
- case IPOPT_NOP:
- opt++;
- break;
- case IPOPT_SSRR:
- case IPOPT_LSRR:
- if (!string_format(p, pend-p, " %s [@%s",
- (*opt == IPOPT_SSRR)? "SSRR" : "LSRR",
- #if OPTSTYLE == 1
- inet_ntoa(*((struct in_addr *)(&(ipopt->faddr))))))
- #elif OPTSTYLE == 2
- inet_ntoa(ipopt->ip_dst)))
- #else
- inet_ntoa(ipopt->ipopt_dst)))
- #endif
- {
- opt = NULL;
- break;
- }
- p += Ustrlen(p);
- optcount = (opt[1] - 3) / sizeof(struct in_addr);
- adptr = opt + 3;
- while (optcount-- > 0)
- {
- memcpy(&addr, adptr, sizeof(addr));
- if (!string_format(p, pend - p - 1, "%s%s",
- (optcount == 0)? ":" : "@", inet_ntoa(addr)))
- {
- opt = NULL;
- break;
- }
- p += Ustrlen(p);
- adptr += sizeof(struct in_addr);
- }
- *p++ = ']';
- opt += opt[1];
- break;
- default:
- {
- int i;
- if (pend - p < 4 + 3*opt[1]) { opt = NULL; break; }
- Ustrcat(p, "[ ");
- p += 2;
- for (i = 0; i < opt[1]; i++)
- {
- sprintf(CS p, "%2.2x ", opt[i]);
- p += 3;
- }
- *p++ = ']';
- }
- opt += opt[1];
- break;
- }
- }
- *p = 0;
- log_write(0, LOG_MAIN, "%s", big_buffer);
+/*************************************************
+* Extract SMTP command option *
+*************************************************/
- /* Refuse any call with IP options. This is what tcpwrappers 7.5 does. */
+/* This function picks the next option setting off the end of smtp_cmd_data. It
+is called for MAIL FROM and RCPT TO commands, to pick off the optional ESMTP
+things that can appear there.
- log_write(0, LOG_MAIN|LOG_REJECT,
- "connection from %s refused (IP options)", host_and_ident(FALSE));
+Arguments:
+ name point this at the name
+ value point this at the data string
- smtp_printf("554 SMTP service not available\r\n");
- return FALSE;
- }
+Returns: TRUE if found an option
+*/
- /* Length of options = 0 => there are no options */
+static BOOL
+extract_option(uschar **name, uschar **value)
+{
+uschar *n;
+uschar *v;
+if (Ustrlen(smtp_cmd_data) <= 0) return FALSE;
+v = smtp_cmd_data + Ustrlen(smtp_cmd_data) - 1;
+while (v > smtp_cmd_data && isspace(*v)) v--;
+v[1] = 0;
- else DEBUG(D_receive) debug_printf("no IP options found\n");
+while (v > smtp_cmd_data && *v != '=' && !isspace(*v))
+ {
+ /* Take care to not stop at a space embedded in a quoted local-part */
+ if (*v == '"')
+ {
+ do v--; while (v > smtp_cmd_data && *v != '"');
+ if (v <= smtp_cmd_data) return FALSE;
}
- #endif /* HAVE_IPV6 && !defined(NO_IP_OPTIONS) */
+ v--;
+ }
+if (v <= smtp_cmd_data) return FALSE;
- /* Set keep-alive in socket options. The option is on by default. This
- setting is an attempt to get rid of some hanging connections that stick in
- read() when the remote end (usually a dialup) goes away. */
+n = v;
+if (*v == '=')
+ {
+ while (n > smtp_cmd_data && isalpha(n[-1])) n--;
+ /* RFC says SP, but TAB seen in wild and other major MTAs accept it */
+ if (n <= smtp_cmd_data || !isspace(n[-1])) return FALSE;
+ n[-1] = 0;
+ }
+else
+ {
+ n++;
+ }
+*v++ = 0;
+*name = n;
+*value = v;
+return TRUE;
+}
- if (smtp_accept_keepalive && !sender_host_notsocket)
- ip_keepalive(fileno(smtp_out), sender_host_address, FALSE);
- /* If the current host matches host_lookup, set the name by doing a
- reverse lookup. On failure, sender_host_name will be NULL and
- host_lookup_failed will be TRUE. This may or may not be serious - optional
- checks later. */
- if (verify_check_host(&host_lookup) == OK)
- {
- (void)host_name_lookup();
- host_build_sender_fullhost();
- }
- /* Delay this until we have the full name, if it is looked up. */
- set_process_info("handling incoming connection from %s",
- host_and_ident(FALSE));
+/*************************************************
+* Reset for new message *
+*************************************************/
- /* Start up TLS if tls_on_connect is set. This is for supporting the legacy
- smtps port for use with older style SSL MTAs. */
+/* This function is called whenever the SMTP session is reset from
+within either of the setup functions; also from the daemon loop.
- #ifdef SUPPORT_TLS
- if (tls_on_connect &&
- tls_server_start(tls_require_ciphers) != OK)
- return FALSE;
- #endif
+Argument: the stacking pool storage reset point
+Returns: nothing
+*/
- /* Test for explicit connection rejection */
+void *
+smtp_reset(void *reset_point)
+{
+recipients_list = NULL;
+rcpt_count = rcpt_defer_count = rcpt_fail_count =
+ raw_recipients_count = recipients_count = recipients_list_max = 0;
+message_linecount = 0;
+message_size = -1;
+message_body = message_body_end = NULL;
+acl_added_headers = NULL;
+acl_removed_headers = NULL;
+f.queue_only_policy = FALSE;
+rcpt_smtp_response = NULL;
+fl.rcpt_smtp_response_same = TRUE;
+fl.rcpt_in_progress = FALSE;
+f.deliver_freeze = FALSE; /* Can be set by ACL */
+freeze_tell = freeze_tell_config; /* Can be set by ACL */
+fake_response = OK; /* Can be set by ACL */
+#ifdef WITH_CONTENT_SCAN
+f.no_mbox_unspool = FALSE; /* Can be set by ACL */
+#endif
+f.submission_mode = FALSE; /* Can be set by ACL */
+f.suppress_local_fixups = f.suppress_local_fixups_default; /* Can be set by ACL */
+f.active_local_from_check = local_from_check; /* Can be set by ACL */
+f.active_local_sender_retain = local_sender_retain; /* Can be set by ACL */
+sending_ip_address = NULL;
+return_path = sender_address = NULL;
+deliver_localpart_data = deliver_domain_data =
+recipient_data = sender_data = NULL; /* Can be set by ACL */
+recipient_verify_failure = NULL;
+deliver_localpart_parent = deliver_localpart_orig = NULL;
+deliver_domain_parent = deliver_domain_orig = NULL;
+callout_address = NULL;
+submission_name = NULL; /* Can be set by ACL */
+raw_sender = NULL; /* After SMTP rewrite, before qualifying */
+sender_address_unrewritten = NULL; /* Set only after verify rewrite */
+sender_verified_list = NULL; /* No senders verified */
+memset(sender_address_cache, 0, sizeof(sender_address_cache));
+memset(sender_domain_cache, 0, sizeof(sender_domain_cache));
- if (verify_check_host(&host_reject_connection) == OK)
- {
- log_write(L_connection_reject, LOG_MAIN|LOG_REJECT, "refused connection "
- "from %s (host_reject_connection)", host_and_ident(FALSE));
- smtp_printf("554 SMTP service not available\r\n");
- return FALSE;
- }
+authenticated_sender = NULL;
+#ifdef EXPERIMENTAL_BRIGHTMAIL
+bmi_run = 0;
+bmi_verdicts = NULL;
+#endif
+dnslist_domain = dnslist_matched = NULL;
+#ifdef SUPPORT_SPF
+spf_header_comment = spf_received = spf_result = spf_smtp_comment = NULL;
+spf_result_guessed = FALSE;
+#endif
+#ifndef DISABLE_DKIM
+dkim_cur_signer = dkim_signers =
+dkim_signing_domain = dkim_signing_selector = dkim_signatures = NULL;
+dkim_cur_signer = dkim_signers = dkim_signing_domain = dkim_signing_selector = NULL;
+f.dkim_disable_verify = FALSE;
+dkim_collect_input = 0;
+dkim_verify_overall = dkim_verify_status = dkim_verify_reason = NULL;
+dkim_key_length = 0;
+#endif
+#ifdef SUPPORT_DMARC
+f.dmarc_has_been_checked = f.dmarc_disable_verify = f.dmarc_enable_forensic = FALSE;
+dmarc_domain_policy = dmarc_status = dmarc_status_text =
+dmarc_used_domain = NULL;
+#endif
+#ifdef EXPERIMENTAL_ARC
+arc_state = arc_state_reason = NULL;
+arc_received_instance = 0;
+#endif
+dsn_ret = 0;
+dsn_envid = NULL;
+deliver_host = deliver_host_address = NULL; /* Can be set by ACL */
+#ifndef DISABLE_PRDR
+prdr_requested = FALSE;
+#endif
+#ifdef SUPPORT_I18N
+message_smtputf8 = FALSE;
+#endif
+body_linecount = body_zerocount = 0;
- /* Test with TCP Wrappers if so configured. There is a problem in that
- hosts_ctl() returns 0 (deny) under a number of system failure circumstances,
- such as disks dying. In these cases, it is desirable to reject with a 4xx
- error instead of a 5xx error. There isn't a "right" way to detect such
- problems. The following kludge is used: errno is zeroed before calling
- hosts_ctl(). If the result is "reject", a 5xx error is given only if the
- value of errno is 0 or ENOENT (which happens if /etc/hosts.{allow,deny} does
- not exist). */
+sender_rate = sender_rate_limit = sender_rate_period = NULL;
+ratelimiters_mail = NULL; /* Updated by ratelimit ACL condition */
+ /* Note that ratelimiters_conn persists across resets. */
- #ifdef USE_TCP_WRAPPERS
- errno = 0;
- tcp_wrappers_name = expand_string(tcp_wrappers_daemon_name);
- if (tcp_wrappers_name == NULL)
- {
- log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" "
- "(tcp_wrappers_name) failed: %s", string_printing(tcp_wrappers_name),
- expand_string_message);
- }
- if (!hosts_ctl(tcp_wrappers_name,
- (sender_host_name == NULL)? STRING_UNKNOWN : CS sender_host_name,
- (sender_host_address == NULL)? STRING_UNKNOWN : CS sender_host_address,
- (sender_ident == NULL)? STRING_UNKNOWN : CS sender_ident))
- {
- if (errno == 0 || errno == ENOENT)
- {
- HDEBUG(D_receive) debug_printf("tcp wrappers rejection\n");
- log_write(L_connection_reject,
- LOG_MAIN|LOG_REJECT, "refused connection from %s "
- "(tcp wrappers)", host_and_ident(FALSE));
- smtp_printf("554 SMTP service not available\r\n");
- }
- else
- {
- int save_errno = errno;
- HDEBUG(D_receive) debug_printf("tcp wrappers rejected with unexpected "
- "errno value %d\n", save_errno);
- log_write(L_connection_reject,
- LOG_MAIN|LOG_REJECT, "temporarily refused connection from %s "
- "(tcp wrappers errno=%d)", host_and_ident(FALSE), save_errno);
- smtp_printf("451 Temporary local problem - please try later\r\n");
- }
- return FALSE;
- }
- #endif
+/* Reset message ACL variables */
- /* Check for reserved slots. The value of smtp_accept_count has already been
- incremented to include this process. */
+acl_var_m = NULL;
- if (smtp_accept_max > 0 &&
- smtp_accept_count > smtp_accept_max - smtp_accept_reserve)
- {
- if ((rc = verify_check_host(&smtp_reserve_hosts)) != OK)
- {
- log_write(L_connection_reject,
- LOG_MAIN, "temporarily refused connection from %s: not in "
- "reserve list: connected=%d max=%d reserve=%d%s",
- host_and_ident(FALSE), smtp_accept_count - 1, smtp_accept_max,
- smtp_accept_reserve, (rc == DEFER)? " (lookup deferred)" : "");
- smtp_printf("421 %s: Too many concurrent SMTP connections; "
- "please try again later\r\n", smtp_active_hostname);
- return FALSE;
- }
- reserved_host = TRUE;
- }
+/* Warning log messages are saved in malloc store. They are saved to avoid
+repetition in the same message, but it seems right to repeat them for different
+messages. */
- /* If a load level above which only messages from reserved hosts are
- accepted is set, check the load. For incoming calls via the daemon, the
- check is done in the superior process if there are no reserved hosts, to
- save a fork. In all cases, the load average will already be available
- in a global variable at this point. */
+while (acl_warn_logged)
+ {
+ string_item *this = acl_warn_logged;
+ acl_warn_logged = acl_warn_logged->next;
+ store_free(this);
+ }
- if (smtp_load_reserve >= 0 &&
- load_average > smtp_load_reserve &&
- !reserved_host &&
- verify_check_host(&smtp_reserve_hosts) != OK)
- {
- log_write(L_connection_reject,
- LOG_MAIN, "temporarily refused connection from %s: not in "
- "reserve list and load average = %.2f", host_and_ident(FALSE),
- (double)load_average/1000.0);
- smtp_printf("421 %s: Too much load; please try again later\r\n",
- smtp_active_hostname);
- return FALSE;
- }
+message_tidyup();
+store_reset(reset_point);
- /* Determine whether unqualified senders or recipients are permitted
- for this host. Unfortunately, we have to do this every time, in order to
- set the flags so that they can be inspected when considering qualifying
- addresses in the headers. For a site that permits no qualification, this
- won't take long, however. */
+message_start();
+return store_mark();
+}
- allow_unqualified_sender =
- verify_check_host(&sender_unqualified_hosts) == OK;
- allow_unqualified_recipient =
- verify_check_host(&recipient_unqualified_hosts) == OK;
- /* Determine whether HELO/EHLO is required for this host. The requirement
- can be hard or soft. */
- helo_required = verify_check_host(&helo_verify_hosts) == OK;
- if (!helo_required)
- helo_verify = verify_check_host(&helo_try_verify_hosts) == OK;
- /* Determine whether this hosts is permitted to send syntactic junk
- after a HELO or EHLO command. */
+/*************************************************
+* Initialize for incoming batched SMTP message *
+*************************************************/
- helo_accept_junk = verify_check_host(&helo_accept_junk_hosts) == OK;
- }
+/* This function is called from smtp_setup_msg() in the case when
+smtp_batched_input is true. This happens when -bS is used to pass a whole batch
+of messages in one file with SMTP commands between them. All errors must be
+reported by sending a message, and only MAIL FROM, RCPT TO, and DATA are
+relevant. After an error on a sender, or an invalid recipient, the remainder
+of the message is skipped. The value of received_protocol is already set.
-/* For batch SMTP input we are now done. */
+Argument: none
+Returns: > 0 message successfully started (reached DATA)
+ = 0 QUIT read or end of file reached
+ < 0 should not occur
+*/
-if (smtp_batched_input) return TRUE;
+static int
+smtp_setup_batch_msg(void)
+{
+int done = 0;
+rmark reset_point = store_mark();
-/* Run the ACL if it exists */
+/* Save the line count at the start of each transaction - single commands
+like HELO and RSET count as whole transactions. */
-user_msg = NULL;
-if (acl_smtp_connect != NULL)
- {
- int rc;
- rc = acl_check(ACL_WHERE_CONNECT, NULL, acl_smtp_connect, &user_msg,
- &log_msg);
- if (rc != OK)
- {
- (void)smtp_handle_acl_fail(ACL_WHERE_CONNECT, rc, user_msg, log_msg);
- return FALSE;
- }
- }
+bsmtp_transaction_linecount = receive_linecount;
-/* Output the initial message for a two-way SMTP connection. It may contain
-newlines, which then cause a multi-line response to be given. */
+if ((receive_feof)()) return 0; /* Treat EOF as QUIT */
-code = US"220"; /* Default status code */
-esc = US""; /* Default extended status code */
-esclen = 0; /* Length of esc */
+cancel_cutthrough_connection(TRUE, US"smtp_setup_batch_msg");
+reset_point = smtp_reset(reset_point); /* Reset for start of message */
-if (user_msg == NULL)
- {
- s = expand_string(smtp_banner);
- if (s == NULL)
- log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" (smtp_banner) "
- "failed: %s", smtp_banner, expand_string_message);
- }
-else
+/* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE
+value. The values are 2 larger than the required yield of the function. */
+
+while (done <= 0)
{
- int codelen = 3;
- s = user_msg;
- smtp_message_code(&code, &codelen, &s, NULL);
- if (codelen > 4)
+ uschar *errmess;
+ uschar *recipient = NULL;
+ int start, end, sender_domain, recipient_domain;
+
+ switch(smtp_read_command(FALSE, GETC_BUFFER_UNLIMITED))
{
- esc = code + 4;
- esclen = codelen - 4;
- }
- }
+ /* The HELO/EHLO commands set sender_address_helo if they have
+ valid data; otherwise they are ignored, except that they do
+ a reset of the state. */
-/* Remove any terminating newlines; might as well remove trailing space too */
+ case HELO_CMD:
+ case EHLO_CMD:
-p = s + Ustrlen(s);
-while (p > s && isspace(p[-1])) p--;
-*p = 0;
+ check_helo(smtp_cmd_data);
+ /* Fall through */
-/* It seems that CC:Mail is braindead, and assumes that the greeting message
-is all contained in a single IP packet. The original code wrote out the
-greeting using several calls to fprint/fputc, and on busy servers this could
-cause it to be split over more than one packet - which caused CC:Mail to fall
-over when it got the second part of the greeting after sending its first
-command. Sigh. To try to avoid this, build the complete greeting message
-first, and output it in one fell swoop. This gives a better chance of it
-ending up as a single packet. */
+ case RSET_CMD:
+ cancel_cutthrough_connection(TRUE, US"RSET received");
+ reset_point = smtp_reset(reset_point);
+ bsmtp_transaction_linecount = receive_linecount;
+ break;
-ss = store_get(size);
-ptr = 0;
-p = s;
-do /* At least once, in case we have an empty string */
- {
- int len;
- uschar *linebreak = Ustrchr(p, '\n');
- ss = string_cat(ss, &size, &ptr, code, 3);
- if (linebreak == NULL)
- {
- len = Ustrlen(p);
- ss = string_cat(ss, &size, &ptr, US" ", 1);
- }
- else
- {
- len = linebreak - p;
- ss = string_cat(ss, &size, &ptr, US"-", 1);
- }
- ss = string_cat(ss, &size, &ptr, esc, esclen);
- ss = string_cat(ss, &size, &ptr, p, len);
- ss = string_cat(ss, &size, &ptr, US"\r\n", 2);
- p += len;
- if (linebreak != NULL) p++;
- }
-while (*p != 0);
+ /* The MAIL FROM command requires an address as an operand. All we
+ do here is to parse it for syntactic correctness. The form "<>" is
+ a special case which converts into an empty string. The start/end
+ pointers in the original are not used further for this address, as
+ it is the canonical extracted address which is all that is kept. */
+
+ case MAIL_CMD:
+ smtp_mailcmd_count++; /* Count for no-mail log */
+ if (sender_address)
+ /* The function moan_smtp_batch() does not return. */
+ moan_smtp_batch(smtp_cmd_buffer, "503 Sender already given");
+
+ if (smtp_cmd_data[0] == 0)
+ /* The function moan_smtp_batch() does not return. */
+ moan_smtp_batch(smtp_cmd_buffer, "501 MAIL FROM must have an address operand");
+
+ /* Reset to start of message */
+
+ cancel_cutthrough_connection(TRUE, US"MAIL received");
+ reset_point = smtp_reset(reset_point);
+
+ /* Apply SMTP rewrite */
+
+ raw_sender = rewrite_existflags & rewrite_smtp
+ /* deconst ok as smtp_cmd_data was not const */
+ ? US rewrite_one(smtp_cmd_data, rewrite_smtp|rewrite_smtp_sender, NULL,
+ FALSE, US"", global_rewrite_rules)
+ : smtp_cmd_data;
+
+ /* Extract the address; the TRUE flag allows <> as valid */
+
+ raw_sender =
+ parse_extract_address(raw_sender, &errmess, &start, &end, &sender_domain,
+ TRUE);
+
+ if (!raw_sender)
+ /* The function moan_smtp_batch() does not return. */
+ moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess);
+
+ sender_address = string_copy(raw_sender);
+
+ /* Qualify unqualified sender addresses if permitted to do so. */
+
+ if ( !sender_domain
+ && sender_address[0] != 0 && sender_address[0] != '@')
+ if (f.allow_unqualified_sender)
+ {
+ /* deconst ok as sender_address was not const */
+ sender_address = US rewrite_address_qualify(sender_address, FALSE);
+ DEBUG(D_receive) debug_printf("unqualified address %s accepted "
+ "and rewritten\n", raw_sender);
+ }
+ /* The function moan_smtp_batch() does not return. */
+ else
+ moan_smtp_batch(smtp_cmd_buffer, "501 sender address must contain "
+ "a domain");
+ break;
-ss[ptr] = 0; /* string_cat leaves room for this */
-/* Before we write the banner, check that there is no input pending, unless
-this synchronisation check is disabled. */
+ /* The RCPT TO command requires an address as an operand. All we do
+ here is to parse it for syntactic correctness. There may be any number
+ of RCPT TO commands, specifying multiple senders. We build them all into
+ a data structure that is in argc/argv format. The start/end values
+ given by parse_extract_address are not used, as we keep only the
+ extracted address. */
-if (!check_sync())
- {
- log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol "
- "synchronization error (input sent without waiting for greeting): "
- "rejected connection from %s input=\"%s\"", host_and_ident(TRUE),
- string_printing(smtp_inptr));
- smtp_printf("554 SMTP synchronization error\r\n");
- return FALSE;
- }
+ case RCPT_CMD:
+ if (!sender_address)
+ /* The function moan_smtp_batch() does not return. */
+ moan_smtp_batch(smtp_cmd_buffer, "503 No sender yet given");
+
+ if (smtp_cmd_data[0] == 0)
+ /* The function moan_smtp_batch() does not return. */
+ moan_smtp_batch(smtp_cmd_buffer,
+ "501 RCPT TO must have an address operand");
+
+ /* Check maximum number allowed */
+
+ if (recipients_max > 0 && recipients_count + 1 > recipients_max)
+ /* The function moan_smtp_batch() does not return. */
+ moan_smtp_batch(smtp_cmd_buffer, "%s too many recipients",
+ recipients_max_reject? "552": "452");
+
+ /* Apply SMTP rewrite, then extract address. Don't allow "<>" as a
+ recipient address */
+
+ recipient = rewrite_existflags & rewrite_smtp
+ /* deconst ok as smtp_cmd_data was not const */
+ ? US rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"",
+ global_rewrite_rules)
+ : smtp_cmd_data;
+
+ recipient = parse_extract_address(recipient, &errmess, &start, &end,
+ &recipient_domain, FALSE);
+
+ if (!recipient)
+ /* The function moan_smtp_batch() does not return. */
+ moan_smtp_batch(smtp_cmd_buffer, "501 %s", errmess);
+
+ /* If the recipient address is unqualified, qualify it if permitted. Then
+ add it to the list of recipients. */
+
+ if (!recipient_domain)
+ if (f.allow_unqualified_recipient)
+ {
+ DEBUG(D_receive) debug_printf("unqualified address %s accepted\n",
+ recipient);
+ /* deconst ok as recipient was not const */
+ recipient = US rewrite_address_qualify(recipient, TRUE);
+ }
+ /* The function moan_smtp_batch() does not return. */
+ else
+ moan_smtp_batch(smtp_cmd_buffer,
+ "501 recipient address must contain a domain");
-/* Now output the banner */
+ receive_add_recipient(recipient, -1);
+ break;
-smtp_printf("%s", ss);
-return TRUE;
-}
+ /* The DATA command is legal only if it follows successful MAIL FROM
+ and RCPT TO commands. This function is complete when a valid DATA
+ command is encountered. */
+ case DATA_CMD:
+ if (!sender_address || recipients_count <= 0)
+ /* The function moan_smtp_batch() does not return. */
+ if (!sender_address)
+ moan_smtp_batch(smtp_cmd_buffer,
+ "503 MAIL FROM:<sender> command must precede DATA");
+ else
+ moan_smtp_batch(smtp_cmd_buffer,
+ "503 RCPT TO:<recipient> must precede DATA");
+ else
+ {
+ done = 3; /* DATA successfully achieved */
+ message_ended = END_NOTENDED; /* Indicate in middle of message */
+ }
+ break;
+ /* The VRFY, EXPN, HELP, ETRN, and NOOP commands are ignored. */
-/*************************************************
-* Handle SMTP syntax and protocol errors *
-*************************************************/
+ case VRFY_CMD:
+ case EXPN_CMD:
+ case HELP_CMD:
+ case NOOP_CMD:
+ case ETRN_CMD:
+ bsmtp_transaction_linecount = receive_linecount;
+ break;
-/* Write to the log for SMTP syntax errors in incoming commands, if configured
-to do so. Then transmit the error response. The return value depends on the
-number of syntax and protocol errors in this SMTP session.
-Arguments:
- type error type, given as a log flag bit
- code response code; <= 0 means don't send a response
- data data to reflect in the response (can be NULL)
- errmess the error message
+ case QUIT_CMD:
+ f.smtp_in_quit = TRUE;
+ case EOF_CMD:
+ done = 2;
+ break;
-Returns: -1 limit of syntax/protocol errors NOT exceeded
- +1 limit of syntax/protocol errors IS exceeded
-These values fit in with the values of the "done" variable in the main
-processing loop in smtp_setup_msg(). */
+ case BADARG_CMD:
+ /* The function moan_smtp_batch() does not return. */
+ moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected argument data");
+ break;
-static int
-synprot_error(int type, int code, uschar *data, uschar *errmess)
-{
-int yield = -1;
-log_write(type, LOG_MAIN, "SMTP %s error in \"%s\" %s %s",
- (type == L_smtp_syntax_error)? "syntax" : "protocol",
- string_printing(smtp_cmd_buffer), host_and_ident(TRUE), errmess);
+ case BADCHAR_CMD:
+ /* The function moan_smtp_batch() does not return. */
+ moan_smtp_batch(smtp_cmd_buffer, "501 Unexpected NULL in SMTP command");
+ break;
-if (++synprot_error_count > smtp_max_synprot_errors)
- {
- yield = 1;
- log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
- "syntax or protocol errors (last command was \"%s\")",
- host_and_ident(FALSE), smtp_cmd_buffer);
- }
-if (code > 0)
- {
- smtp_printf("%d%c%s%s%s\r\n", code, (yield == 1)? '-' : ' ',
- (data == NULL)? US"" : data, (data == NULL)? US"" : US": ", errmess);
- if (yield == 1)
- smtp_printf("%d Too many syntax or protocol errors\r\n", code);
+ default:
+ /* The function moan_smtp_batch() does not return. */
+ moan_smtp_batch(smtp_cmd_buffer, "500 Command unrecognized");
+ break;
+ }
}
-return yield;
+return done - 2; /* Convert yield values */
}
-/*************************************************
-* Log incomplete transactions *
-*************************************************/
+#ifndef DISABLE_TLS
+static BOOL
+smtp_log_tls_fail(uschar * errstr)
+{
+uschar * conn_info = smtp_get_connection_info();
-/* This function is called after a transaction has been aborted by RSET, QUIT,
-connection drops or other errors. It logs the envelope information received
-so far in order to preserve address verification attempts.
+if (Ustrncmp(conn_info, US"SMTP ", 5) == 0) conn_info += 5;
+/* I'd like to get separated H= here, but too hard for now */
-Argument: string to indicate what aborted the transaction
-Returns: nothing
-*/
+log_write(0, LOG_MAIN, "TLS error on %s %s", conn_info, errstr);
+return FALSE;
+}
+#endif
+
+
+
+#ifdef TCP_FASTOPEN
static void
-incomplete_transaction_log(uschar *what)
+tfo_in_check(void)
{
-if (sender_address == NULL || /* No transaction in progress */
- (log_write_selector & L_smtp_incomplete_transaction) == 0 /* Not logging */
- ) return;
+# ifdef __FreeBSD__
+int is_fastopen;
+socklen_t len = sizeof(is_fastopen);
-/* Build list of recipients for logging */
+/* The tinfo TCPOPT_FAST_OPEN bit seems unreliable, and we don't see state
+TCP_SYN_RCV (as of 12.1) so no idea about data-use. */
-if (recipients_count > 0)
+if (getsockopt(fileno(smtp_out), IPPROTO_TCP, TCP_FASTOPEN, &is_fastopen, &len) == 0)
{
- int i;
- raw_recipients = store_get(recipients_count * sizeof(uschar *));
- for (i = 0; i < recipients_count; i++)
- raw_recipients[i] = recipients_list[i].address;
- raw_recipients_count = recipients_count;
+ if (is_fastopen)
+ {
+ DEBUG(D_receive)
+ debug_printf("TFO mode connection (TCP_FASTOPEN getsockopt)\n");
+ f.tcp_in_fastopen = TRUE;
+ }
}
+else DEBUG(D_receive)
+ debug_printf("TCP_INFO getsockopt: %s\n", strerror(errno));
-log_write(L_smtp_incomplete_transaction, LOG_MAIN|LOG_SENDER|LOG_RECIPIENTS,
- "%s incomplete transaction (%s)", host_and_ident(TRUE), what);
-}
-
+# elif defined(TCP_INFO)
+struct tcp_info tinfo;
+socklen_t len = sizeof(tinfo);
+if (getsockopt(fileno(smtp_out), IPPROTO_TCP, TCP_INFO, &tinfo, &len) == 0)
+# ifdef TCPI_OPT_SYN_DATA /* FreeBSD 11,12 do not seem to have this yet */
+ if (tinfo.tcpi_options & TCPI_OPT_SYN_DATA)
+ {
+ DEBUG(D_receive)
+ debug_printf("TFO mode connection (ACKd data-on-SYN)\n");
+ f.tcp_in_fastopen_data = f.tcp_in_fastopen = TRUE;
+ }
+ else
+# endif
+ if (tinfo.tcpi_state == TCP_SYN_RECV) /* Not seen on FreeBSD 12.1 */
+ {
+ DEBUG(D_receive)
+ debug_printf("TFO mode connection (state TCP_SYN_RECV)\n");
+ f.tcp_in_fastopen = TRUE;
+ }
+else DEBUG(D_receive)
+ debug_printf("TCP_INFO getsockopt: %s\n", strerror(errno));
+# endif
+}
+#endif
/*************************************************
-* Send SMTP response, possibly multiline *
+* Start an SMTP session *
*************************************************/
-/* There are, it seems, broken clients out there that cannot handle multiline
-responses. If no_multiline_responses is TRUE (it can be set from an ACL), we
-output nothing for non-final calls, and only the first line for anything else.
+/* This function is called at the start of an SMTP session. Thereafter,
+smtp_setup_msg() is called to initiate each separate message. This
+function does host-specific testing, and outputs the banner line.
-Arguments:
- code SMTP code, may involve extended status codes
- codelen length of smtp code; if > 4 there's an ESC
- final FALSE if the last line isn't the final line
- msg message text, possibly containing newlines
-
-Returns: nothing
+Arguments: none
+Returns: FALSE if the session can not continue; something has
+ gone wrong, or the connection to the host is blocked
*/
-void
-smtp_respond(uschar* code, int codelen, BOOL final, uschar *msg)
+BOOL
+smtp_start_session(void)
{
-int esclen = 0;
-uschar *esc = US"";
+int esclen;
+uschar *user_msg, *log_msg;
+uschar *code, *esc;
+uschar *p, *s;
+gstring * ss;
+
+gettimeofday(&smtp_connection_start, NULL);
+for (smtp_ch_index = 0; smtp_ch_index < SMTP_HBUFF_SIZE; smtp_ch_index++)
+ smtp_connection_had[smtp_ch_index] = SCH_NONE;
+smtp_ch_index = 0;
-if (!final && no_multiline_responses) return;
+/* Default values for certain variables */
-if (codelen > 4)
+fl.helo_seen = fl.esmtp = fl.helo_accept_junk = FALSE;
+smtp_mailcmd_count = 0;
+count_nonmail = TRUE_UNSET;
+synprot_error_count = unknown_command_count = nonmail_command_count = 0;
+smtp_delay_mail = smtp_rlm_base;
+fl.auth_advertised = FALSE;
+f.smtp_in_pipelining_advertised = f.smtp_in_pipelining_used = FALSE;
+f.pipelining_enable = TRUE;
+sync_cmd_limit = NON_SYNC_CMD_NON_PIPELINING;
+fl.smtp_exit_function_called = FALSE; /* For avoiding loop in not-quit exit */
+
+/* If receiving by -bs from a trusted user, or testing with -bh, we allow
+authentication settings from -oMaa to remain in force. */
+
+if (!host_checking && !f.sender_host_notsocket)
+ sender_host_auth_pubname = sender_host_authenticated = NULL;
+authenticated_by = NULL;
+
+#ifndef DISABLE_TLS
+tls_in.ver = tls_in.cipher = tls_in.peerdn = NULL;
+tls_in.ourcert = tls_in.peercert = NULL;
+tls_in.sni = NULL;
+tls_in.ocsp = OCSP_NOT_REQ;
+fl.tls_advertised = FALSE;
+#endif
+fl.dsn_advertised = FALSE;
+#ifdef SUPPORT_I18N
+fl.smtputf8_advertised = FALSE;
+#endif
+
+/* Reset ACL connection variables */
+
+acl_var_c = NULL;
+
+/* Allow for trailing 0 in the command and data buffers. Tainted. */
+
+smtp_cmd_buffer = store_get_perm(2*SMTP_CMD_BUFFER_SIZE + 2, TRUE);
+
+smtp_cmd_buffer[0] = 0;
+smtp_data_buffer = smtp_cmd_buffer + SMTP_CMD_BUFFER_SIZE + 1;
+
+/* For batched input, the protocol setting can be overridden from the
+command line by a trusted caller. */
+
+if (smtp_batched_input)
{
- esc = code + 4;
- esclen = codelen - 4;
+ if (!received_protocol) received_protocol = US"local-bsmtp";
}
-/* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
-have had the same. Note: this code is also present in smtp_printf(). It would
-be tidier to have it only in one place, but when it was added, it was easier to
-do it that way, so as not to have to mess with the code for the RCPT command,
-which sometimes uses smtp_printf() and sometimes smtp_respond(). */
+/* For non-batched SMTP input, the protocol setting is forced here. It will be
+reset later if any of EHLO/AUTH/STARTTLS are received. */
+
+else
+ received_protocol =
+ (sender_host_address ? protocols : protocols_local) [pnormal];
+
+/* Set up the buffer for inputting using direct read() calls, and arrange to
+call the local functions instead of the standard C ones. Place a NUL at the
+end of the buffer to safety-stop C-string reads from it. */
+
+if (!(smtp_inbuffer = US malloc(IN_BUFFER_SIZE)))
+ log_write(0, LOG_MAIN|LOG_PANIC_DIE, "malloc() failed for SMTP input buffer");
+smtp_inbuffer[IN_BUFFER_SIZE-1] = '\0';
-if (rcpt_in_progress)
+receive_getc = smtp_getc;
+receive_getbuf = smtp_getbuf;
+receive_get_cache = smtp_get_cache;
+receive_ungetc = smtp_ungetc;
+receive_feof = smtp_feof;
+receive_ferror = smtp_ferror;
+receive_smtp_buffered = smtp_buffered;
+lwr_receive_getc = NULL;
+lwr_receive_getbuf = NULL;
+lwr_receive_ungetc = NULL;
+smtp_inptr = smtp_inend = smtp_inbuffer;
+smtp_had_eof = smtp_had_error = 0;
+
+/* Set up the message size limit; this may be host-specific */
+
+thismessage_size_limit = expand_string_integer(message_size_limit, TRUE);
+if (expand_string_message)
{
- if (rcpt_smtp_response == NULL)
- rcpt_smtp_response = string_copy(msg);
- else if (rcpt_smtp_response_same &&
- Ustrcmp(rcpt_smtp_response, msg) != 0)
- rcpt_smtp_response_same = FALSE;
- rcpt_in_progress = FALSE;
+ if (thismessage_size_limit == -1)
+ log_write(0, LOG_MAIN|LOG_PANIC, "unable to expand message_size_limit: "
+ "%s", expand_string_message);
+ else
+ log_write(0, LOG_MAIN|LOG_PANIC, "invalid message_size_limit: "
+ "%s", expand_string_message);
+ smtp_closedown(US"Temporary local problem - please try later");
+ return FALSE;
}
-/* Not output the message, splitting it up into multiple lines if necessary. */
+/* When a message is input locally via the -bs or -bS options, sender_host_
+unknown is set unless -oMa was used to force an IP address, in which case it
+is checked like a real remote connection. When -bs is used from inetd, this
+flag is not set, causing the sending host to be checked. The code that deals
+with IP source routing (if configured) is never required for -bs or -bS and
+the flag sender_host_notsocket is used to suppress it.
-for (;;)
+If smtp_accept_max and smtp_accept_reserve are set, keep some connections in
+reserve for certain hosts and/or networks. */
+
+if (!f.sender_host_unknown)
{
- uschar *nl = Ustrchr(msg, '\n');
- if (nl == NULL)
- {
- smtp_printf("%.3s%c%.*s%s\r\n", code, final? ' ':'-', esclen, esc, msg);
- return;
- }
- else if (nl[1] == 0 || no_multiline_responses)
- {
- smtp_printf("%.3s%c%.*s%.*s\r\n", code, final? ' ':'-', esclen, esc,
- (int)(nl - msg), msg);
- return;
- }
- else
+ int rc;
+ BOOL reserved_host = FALSE;
+
+ /* Look up IP options (source routing info) on the socket if this is not an
+ -oMa "host", and if any are found, log them and drop the connection.
+
+ Linux (and others now, see below) is different to everyone else, so there
+ has to be some conditional compilation here. Versions of Linux before 2.1.15
+ used a structure whose name was "options". Somebody finally realized that
+ this name was silly, and it got changed to "ip_options". I use the
+ newer name here, but there is a fudge in the script that sets up os.h
+ to define a macro in older Linux systems.
+
+ Sigh. Linux is a fast-moving target. Another generation of Linux uses
+ glibc 2, which has chosen ip_opts for the structure name. This is now
+ really a glibc thing rather than a Linux thing, so the condition name
+ has been changed to reflect this. It is relevant also to GNU/Hurd.
+
+ Mac OS 10.x (Darwin) is like the later glibc versions, but without the
+ setting of the __GLIBC__ macro, so we can't detect it automatically. There's
+ a special macro defined in the os.h file.
+
+ Some DGUX versions on older hardware appear not to support IP options at
+ all, so there is now a general macro which can be set to cut out this
+ support altogether.
+
+ How to do this properly in IPv6 is not yet known. */
+
+#if !HAVE_IPV6 && !defined(NO_IP_OPTIONS)
+
+ #ifdef GLIBC_IP_OPTIONS
+ #if (!defined __GLIBC__) || (__GLIBC__ < 2)
+ #define OPTSTYLE 1
+ #else
+ #define OPTSTYLE 2
+ #endif
+ #elif defined DARWIN_IP_OPTIONS
+ #define OPTSTYLE 2
+ #else
+ #define OPTSTYLE 3
+ #endif
+
+ if (!host_checking && !f.sender_host_notsocket)
{
- smtp_printf("%.3s-%.*s%.*s\r\n", code, esclen, esc, (int)(nl - msg), msg);
- msg = nl + 1;
- while (isspace(*msg)) msg++;
- }
- }
-}
+ #if OPTSTYLE == 1
+ EXIM_SOCKLEN_T optlen = sizeof(struct ip_options) + MAX_IPOPTLEN;
+ struct ip_options *ipopt = store_get(optlen, FALSE);
+ #elif OPTSTYLE == 2
+ struct ip_opts ipoptblock;
+ struct ip_opts *ipopt = &ipoptblock;
+ EXIM_SOCKLEN_T optlen = sizeof(ipoptblock);
+ #else
+ struct ipoption ipoptblock;
+ struct ipoption *ipopt = &ipoptblock;
+ EXIM_SOCKLEN_T optlen = sizeof(ipoptblock);
+ #endif
+ /* Occasional genuine failures of getsockopt() have been seen - for
+ example, "reset by peer". Therefore, just log and give up on this
+ call, unless the error is ENOPROTOOPT. This error is given by systems
+ that have the interfaces but not the mechanism - e.g. GNU/Hurd at the time
+ of writing. So for that error, carry on - we just can't do an IP options
+ check. */
+ DEBUG(D_receive) debug_printf("checking for IP options\n");
+ if (getsockopt(fileno(smtp_out), IPPROTO_IP, IP_OPTIONS, US (ipopt),
+ &optlen) < 0)
+ {
+ if (errno != ENOPROTOOPT)
+ {
+ log_write(0, LOG_MAIN, "getsockopt() failed from %s: %s",
+ host_and_ident(FALSE), strerror(errno));
+ smtp_printf("451 SMTP service not available\r\n", FALSE);
+ return FALSE;
+ }
+ }
-/*************************************************
-* Parse user SMTP message *
-*************************************************/
+ /* Deal with any IP options that are set. On the systems I have looked at,
+ the value of MAX_IPOPTLEN has been 40, meaning that there should never be
+ more logging data than will fit in big_buffer. Nevertheless, after somebody
+ questioned this code, I've added in some paranoid checking. */
-/* This function allows for user messages overriding the response code details
-by providing a suitable response code string at the start of the message
-user_msg. Check the message for starting with a response code and optionally an
-extended status code. If found, check that the first digit is valid, and if so,
-change the code pointer and length to use the replacement. An invalid code
-causes a panic log; in this case, if the log messages is the same as the user
-message, we must also adjust the value of the log message to show the code that
-is actually going to be used (the original one).
+ else if (optlen > 0)
+ {
+ uschar *p = big_buffer;
+ uschar *pend = big_buffer + big_buffer_size;
+ uschar *adptr;
+ int optcount;
+ struct in_addr addr;
-This function is global because it is called from receive.c as well as within
-this module.
+ #if OPTSTYLE == 1
+ uschar *optstart = US (ipopt->__data);
+ #elif OPTSTYLE == 2
+ uschar *optstart = US (ipopt->ip_opts);
+ #else
+ uschar *optstart = US (ipopt->ipopt_list);
+ #endif
-Note that the code length returned includes the terminating whitespace
-character, which is always included in the regex match.
+ DEBUG(D_receive) debug_printf("IP options exist\n");
-Arguments:
- code SMTP code, may involve extended status codes
- codelen length of smtp code; if > 4 there's an ESC
- msg message text
- log_msg optional log message, to be adjusted with the new SMTP code
+ Ustrcpy(p, "IP options on incoming call:");
+ p += Ustrlen(p);
-Returns: nothing
-*/
+ for (uschar * opt = optstart; opt && opt < US (ipopt) + optlen; )
+ switch (*opt)
+ {
+ case IPOPT_EOL:
+ opt = NULL;
+ break;
-void
-smtp_message_code(uschar **code, int *codelen, uschar **msg, uschar **log_msg)
-{
-int n;
-int ovector[3];
+ case IPOPT_NOP:
+ opt++;
+ break;
-if (msg == NULL || *msg == NULL) return;
+ case IPOPT_SSRR:
+ case IPOPT_LSRR:
+ if (!string_format(p, pend-p, " %s [@%s",
+ (*opt == IPOPT_SSRR)? "SSRR" : "LSRR",
+ #if OPTSTYLE == 1
+ inet_ntoa(*((struct in_addr *)(&(ipopt->faddr))))))
+ #elif OPTSTYLE == 2
+ inet_ntoa(ipopt->ip_dst)))
+ #else
+ inet_ntoa(ipopt->ipopt_dst)))
+ #endif
+ {
+ opt = NULL;
+ break;
+ }
-n = pcre_exec(regex_smtp_code, NULL, CS *msg, Ustrlen(*msg), 0,
- PCRE_EOPT, ovector, sizeof(ovector)/sizeof(int));
-if (n < 0) return;
+ p += Ustrlen(p);
+ optcount = (opt[1] - 3) / sizeof(struct in_addr);
+ adptr = opt + 3;
+ while (optcount-- > 0)
+ {
+ memcpy(&addr, adptr, sizeof(addr));
+ if (!string_format(p, pend - p - 1, "%s%s",
+ (optcount == 0)? ":" : "@", inet_ntoa(addr)))
+ {
+ opt = NULL;
+ break;
+ }
+ p += Ustrlen(p);
+ adptr += sizeof(struct in_addr);
+ }
+ *p++ = ']';
+ opt += opt[1];
+ break;
-if ((*msg)[0] != (*code)[0])
- {
- log_write(0, LOG_MAIN|LOG_PANIC, "configured error code starts with "
- "incorrect digit (expected %c) in \"%s\"", (*code)[0], *msg);
- if (log_msg != NULL && *log_msg == *msg)
- *log_msg = string_sprintf("%s %s", *code, *log_msg + ovector[1]);
- }
-else
- {
- *code = *msg;
- *codelen = ovector[1]; /* Includes final space */
- }
-*msg += ovector[1]; /* Chop the code off the message */
-return;
-}
+ default:
+ {
+ if (pend - p < 4 + 3*opt[1]) { opt = NULL; break; }
+ Ustrcat(p, "[ ");
+ p += 2;
+ for (int i = 0; i < opt[1]; i++)
+ p += sprintf(CS p, "%2.2x ", opt[i]);
+ *p++ = ']';
+ }
+ opt += opt[1];
+ break;
+ }
+ *p = 0;
+ log_write(0, LOG_MAIN, "%s", big_buffer);
+ /* Refuse any call with IP options. This is what tcpwrappers 7.5 does. */
+ log_write(0, LOG_MAIN|LOG_REJECT,
+ "connection from %s refused (IP options)", host_and_ident(FALSE));
-/*************************************************
-* Handle an ACL failure *
-*************************************************/
+ smtp_printf("554 SMTP service not available\r\n", FALSE);
+ return FALSE;
+ }
-/* This function is called when acl_check() fails. As well as calls from within
-this module, it is called from receive.c for an ACL after DATA. It sorts out
-logging the incident, and sets up the error response. A message containing
-newlines is turned into a multiline SMTP response, but for logging, only the
-first line is used.
+ /* Length of options = 0 => there are no options */
-There's a table of default permanent failure response codes to use in
-globals.c, along with the table of names. VFRY is special. Despite RFC1123 it
-defaults disabled in Exim. However, discussion in connection with RFC 821bis
-(aka RFC 2821) has concluded that the response should be 252 in the disabled
-state, because there are broken clients that try VRFY before RCPT. A 5xx
-response should be given only when the address is positively known to be
-undeliverable. Sigh. Also, for ETRN, 458 is given on refusal, and for AUTH,
-503.
+ else DEBUG(D_receive) debug_printf("no IP options found\n");
+ }
+#endif /* HAVE_IPV6 && !defined(NO_IP_OPTIONS) */
-From Exim 4.63, it is possible to override the response code details by
-providing a suitable response code string at the start of the message provided
-in user_msg. The code's first digit is checked for validity.
+ /* Set keep-alive in socket options. The option is on by default. This
+ setting is an attempt to get rid of some hanging connections that stick in
+ read() when the remote end (usually a dialup) goes away. */
-Arguments:
- where where the ACL was called from
- rc the failure code
- user_msg a message that can be included in an SMTP response
- log_msg a message for logging
+ if (smtp_accept_keepalive && !f.sender_host_notsocket)
+ ip_keepalive(fileno(smtp_out), sender_host_address, FALSE);
-Returns: 0 in most cases
- 2 if the failure code was FAIL_DROP, in which case the
- SMTP connection should be dropped (this value fits with the
- "done" variable in smtp_setup_msg() below)
-*/
+ /* If the current host matches host_lookup, set the name by doing a
+ reverse lookup. On failure, sender_host_name will be NULL and
+ host_lookup_failed will be TRUE. This may or may not be serious - optional
+ checks later. */
-int
-smtp_handle_acl_fail(int where, int rc, uschar *user_msg, uschar *log_msg)
-{
-BOOL drop = rc == FAIL_DROP;
-int codelen = 3;
-uschar *smtp_code;
-uschar *lognl;
-uschar *sender_info = US"";
-uschar *what =
-#ifdef WITH_CONTENT_SCAN
- (where == ACL_WHERE_MIME)? US"during MIME ACL checks" :
-#endif
- (where == ACL_WHERE_PREDATA)? US"DATA" :
- (where == ACL_WHERE_DATA)? US"after DATA" :
- (smtp_cmd_data == NULL)?
- string_sprintf("%s in \"connect\" ACL", acl_wherenames[where]) :
- string_sprintf("%s %s", acl_wherenames[where], smtp_cmd_data);
+ if (verify_check_host(&host_lookup) == OK)
+ {
+ (void)host_name_lookup();
+ host_build_sender_fullhost();
+ }
-if (drop) rc = FAIL;
+ /* Delay this until we have the full name, if it is looked up. */
-/* Set the default SMTP code, and allow a user message to change it. */
+ set_process_info("handling incoming connection from %s",
+ host_and_ident(FALSE));
-smtp_code = (rc != FAIL)? US"451" : acl_wherecodes[where];
-smtp_message_code(&smtp_code, &codelen, &user_msg, &log_msg);
+ /* Expand smtp_receive_timeout, if needed */
-/* We used to have sender_address here; however, there was a bug that was not
-updating sender_address after a rewrite during a verify. When this bug was
-fixed, sender_address at this point became the rewritten address. I'm not sure
-this is what should be logged, so I've changed to logging the unrewritten
-address to retain backward compatibility. */
+ if (smtp_receive_timeout_s)
+ {
+ uschar * exp;
+ if ( !(exp = expand_string(smtp_receive_timeout_s))
+ || !(*exp)
+ || (smtp_receive_timeout = readconf_readtime(exp, 0, FALSE)) < 0
+ )
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "bad value for smtp_receive_timeout: '%s'", exp ? exp : US"");
+ }
-#ifndef WITH_CONTENT_SCAN
-if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA)
-#else
-if (where == ACL_WHERE_RCPT || where == ACL_WHERE_DATA || where == ACL_WHERE_MIME)
+ /* Test for explicit connection rejection */
+
+ if (verify_check_host(&host_reject_connection) == OK)
+ {
+ log_write(L_connection_reject, LOG_MAIN|LOG_REJECT, "refused connection "
+ "from %s (host_reject_connection)", host_and_ident(FALSE));
+ smtp_printf("554 SMTP service not available\r\n", FALSE);
+ return FALSE;
+ }
+
+ /* Test with TCP Wrappers if so configured. There is a problem in that
+ hosts_ctl() returns 0 (deny) under a number of system failure circumstances,
+ such as disks dying. In these cases, it is desirable to reject with a 4xx
+ error instead of a 5xx error. There isn't a "right" way to detect such
+ problems. The following kludge is used: errno is zeroed before calling
+ hosts_ctl(). If the result is "reject", a 5xx error is given only if the
+ value of errno is 0 or ENOENT (which happens if /etc/hosts.{allow,deny} does
+ not exist). */
+
+#ifdef USE_TCP_WRAPPERS
+ errno = 0;
+ if (!(tcp_wrappers_name = expand_string(tcp_wrappers_daemon_name)))
+ log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" "
+ "(tcp_wrappers_name) failed: %s", string_printing(tcp_wrappers_name),
+ expand_string_message);
+
+ if (!hosts_ctl(tcp_wrappers_name,
+ sender_host_name ? CS sender_host_name : STRING_UNKNOWN,
+ sender_host_address ? CS sender_host_address : STRING_UNKNOWN,
+ sender_ident ? CS sender_ident : STRING_UNKNOWN))
+ {
+ if (errno == 0 || errno == ENOENT)
+ {
+ HDEBUG(D_receive) debug_printf("tcp wrappers rejection\n");
+ log_write(L_connection_reject,
+ LOG_MAIN|LOG_REJECT, "refused connection from %s "
+ "(tcp wrappers)", host_and_ident(FALSE));
+ smtp_printf("554 SMTP service not available\r\n", FALSE);
+ }
+ else
+ {
+ int save_errno = errno;
+ HDEBUG(D_receive) debug_printf("tcp wrappers rejected with unexpected "
+ "errno value %d\n", save_errno);
+ log_write(L_connection_reject,
+ LOG_MAIN|LOG_REJECT, "temporarily refused connection from %s "
+ "(tcp wrappers errno=%d)", host_and_ident(FALSE), save_errno);
+ smtp_printf("451 Temporary local problem - please try later\r\n", FALSE);
+ }
+ return FALSE;
+ }
#endif
- {
- sender_info = string_sprintf("F=<%s>%s%s%s%s ",
- sender_address_unrewritten ? sender_address_unrewritten : sender_address,
- sender_host_authenticated ? US" A=" : US"",
- sender_host_authenticated ? sender_host_authenticated : US"",
- sender_host_authenticated && authenticated_id ? US":" : US"",
- sender_host_authenticated && authenticated_id ? authenticated_id : US""
- );
- }
-/* If there's been a sender verification failure with a specific message, and
-we have not sent a response about it yet, do so now, as a preliminary line for
-failures, but not defers. However, always log it for defer, and log it for fail
-unless the sender_verify_fail log selector has been turned off. */
+ /* Check for reserved slots. The value of smtp_accept_count has already been
+ incremented to include this process. */
-if (sender_verified_failed != NULL &&
- !testflag(sender_verified_failed, af_sverify_told))
- {
- BOOL save_rcpt_in_progress = rcpt_in_progress;
- rcpt_in_progress = FALSE; /* So as not to treat these as the error */
+ if (smtp_accept_max > 0 &&
+ smtp_accept_count > smtp_accept_max - smtp_accept_reserve)
+ {
+ if ((rc = verify_check_host(&smtp_reserve_hosts)) != OK)
+ {
+ log_write(L_connection_reject,
+ LOG_MAIN, "temporarily refused connection from %s: not in "
+ "reserve list: connected=%d max=%d reserve=%d%s",
+ host_and_ident(FALSE), smtp_accept_count - 1, smtp_accept_max,
+ smtp_accept_reserve, (rc == DEFER)? " (lookup deferred)" : "");
+ smtp_printf("421 %s: Too many concurrent SMTP connections; "
+ "please try again later\r\n", FALSE, smtp_active_hostname);
+ return FALSE;
+ }
+ reserved_host = TRUE;
+ }
- setflag(sender_verified_failed, af_sverify_told);
+ /* If a load level above which only messages from reserved hosts are
+ accepted is set, check the load. For incoming calls via the daemon, the
+ check is done in the superior process if there are no reserved hosts, to
+ save a fork. In all cases, the load average will already be available
+ in a global variable at this point. */
- if (rc != FAIL || (log_extra_selector & LX_sender_verify_fail) != 0)
- log_write(0, LOG_MAIN|LOG_REJECT, "%s sender verify %s for <%s>%s",
- host_and_ident(TRUE),
- ((sender_verified_failed->special_action & 255) == DEFER)? "defer":"fail",
- sender_verified_failed->address,
- (sender_verified_failed->message == NULL)? US"" :
- string_sprintf(": %s", sender_verified_failed->message));
+ if (smtp_load_reserve >= 0 &&
+ load_average > smtp_load_reserve &&
+ !reserved_host &&
+ verify_check_host(&smtp_reserve_hosts) != OK)
+ {
+ log_write(L_connection_reject,
+ LOG_MAIN, "temporarily refused connection from %s: not in "
+ "reserve list and load average = %.2f", host_and_ident(FALSE),
+ (double)load_average/1000.0);
+ smtp_printf("421 %s: Too much load; please try again later\r\n", FALSE,
+ smtp_active_hostname);
+ return FALSE;
+ }
- if (rc == FAIL && sender_verified_failed->user_message != NULL)
- smtp_respond(smtp_code, codelen, FALSE, string_sprintf(
- testflag(sender_verified_failed, af_verify_pmfail)?
- "Postmaster verification failed while checking <%s>\n%s\n"
- "Several RFCs state that you are required to have a postmaster\n"
- "mailbox for each mail domain. This host does not accept mail\n"
- "from domains whose servers reject the postmaster address."
- :
- testflag(sender_verified_failed, af_verify_nsfail)?
- "Callback setup failed while verifying <%s>\n%s\n"
- "The initial connection, or a HELO or MAIL FROM:<> command was\n"
- "rejected. Refusing MAIL FROM:<> does not help fight spam, disregards\n"
- "RFC requirements, and stops you from receiving standard bounce\n"
- "messages. This host does not accept mail from domains whose servers\n"
- "refuse bounces."
- :
- "Verification failed for <%s>\n%s",
- sender_verified_failed->address,
- sender_verified_failed->user_message));
+ /* Determine whether unqualified senders or recipients are permitted
+ for this host. Unfortunately, we have to do this every time, in order to
+ set the flags so that they can be inspected when considering qualifying
+ addresses in the headers. For a site that permits no qualification, this
+ won't take long, however. */
+
+ f.allow_unqualified_sender =
+ verify_check_host(&sender_unqualified_hosts) == OK;
- rcpt_in_progress = save_rcpt_in_progress;
+ f.allow_unqualified_recipient =
+ verify_check_host(&recipient_unqualified_hosts) == OK;
+
+ /* Determine whether HELO/EHLO is required for this host. The requirement
+ can be hard or soft. */
+
+ fl.helo_verify_required = verify_check_host(&helo_verify_hosts) == OK;
+ if (!fl.helo_verify_required)
+ fl.helo_verify = verify_check_host(&helo_try_verify_hosts) == OK;
+
+ /* Determine whether this hosts is permitted to send syntactic junk
+ after a HELO or EHLO command. */
+
+ fl.helo_accept_junk = verify_check_host(&helo_accept_junk_hosts) == OK;
}
-/* Sort out text for logging */
+/* For batch SMTP input we are now done. */
+
+if (smtp_batched_input) return TRUE;
-log_msg = (log_msg == NULL)? US"" : string_sprintf(": %s", log_msg);
-lognl = Ustrchr(log_msg, '\n');
-if (lognl != NULL) *lognl = 0;
+/* If valid Proxy Protocol source is connecting, set up session.
+Failure will not allow any SMTP function other than QUIT. */
-/* Send permanent failure response to the command, but the code used isn't
-always a 5xx one - see comments at the start of this function. If the original
-rc was FAIL_DROP we drop the connection and yield 2. */
+#ifdef SUPPORT_PROXY
+proxy_session = FALSE;
+f.proxy_session_failed = FALSE;
+if (check_proxy_protocol_host())
+ setup_proxy_protocol_host();
+#endif
-if (rc == FAIL) smtp_respond(smtp_code, codelen, TRUE, (user_msg == NULL)?
- US"Administrative prohibition" : user_msg);
+/* Start up TLS if tls_on_connect is set. This is for supporting the legacy
+smtps port for use with older style SSL MTAs. */
-/* Send temporary failure response to the command. Don't give any details,
-unless acl_temp_details is set. This is TRUE for a callout defer, a "defer"
-verb, and for a header verify when smtp_return_error_details is set.
+#ifndef DISABLE_TLS
+if (tls_in.on_connect)
+ {
+ if (tls_server_start(&user_msg) != OK)
+ return smtp_log_tls_fail(user_msg);
+ cmd_list[CMD_LIST_TLS_AUTH].is_mail_cmd = TRUE;
+ }
+#endif
-This conditional logic is all somewhat of a mess because of the odd
-interactions between temp_details and return_error_details. One day it should
-be re-implemented in a tidier fashion. */
+/* Run the connect ACL if it exists */
+
+user_msg = NULL;
+if (acl_smtp_connect)
+ {
+ int rc;
+ if ((rc = acl_check(ACL_WHERE_CONNECT, NULL, acl_smtp_connect, &user_msg,
+ &log_msg)) != OK)
+ {
+ (void) smtp_handle_acl_fail(ACL_WHERE_CONNECT, rc, user_msg, log_msg);
+ return FALSE;
+ }
+ }
+
+/* Output the initial message for a two-way SMTP connection. It may contain
+newlines, which then cause a multi-line response to be given. */
+
+code = US"220"; /* Default status code */
+esc = US""; /* Default extended status code */
+esclen = 0; /* Length of esc */
+if (!user_msg)
+ {
+ if (!(s = expand_string(smtp_banner)))
+ log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Expansion of \"%s\" (smtp_banner) "
+ "failed: %s", smtp_banner, expand_string_message);
+ }
else
{
- if (acl_temp_details && user_msg != NULL)
+ int codelen = 3;
+ s = user_msg;
+ smtp_message_code(&code, &codelen, &s, NULL, TRUE);
+ if (codelen > 4)
{
- if (smtp_return_error_details &&
- sender_verified_failed != NULL &&
- sender_verified_failed->message != NULL)
- {
- smtp_respond(smtp_code, codelen, FALSE, sender_verified_failed->message);
- }
- smtp_respond(smtp_code, codelen, TRUE, user_msg);
+ esc = code + 4;
+ esclen = codelen - 4;
+ }
+ }
+
+/* Remove any terminating newlines; might as well remove trailing space too */
+
+p = s + Ustrlen(s);
+while (p > s && isspace(p[-1])) p--;
+s = string_copyn(s, p-s);
+
+/* It seems that CC:Mail is braindead, and assumes that the greeting message
+is all contained in a single IP packet. The original code wrote out the
+greeting using several calls to fprint/fputc, and on busy servers this could
+cause it to be split over more than one packet - which caused CC:Mail to fall
+over when it got the second part of the greeting after sending its first
+command. Sigh. To try to avoid this, build the complete greeting message
+first, and output it in one fell swoop. This gives a better chance of it
+ending up as a single packet. */
+
+ss = string_get(256);
+
+p = s;
+do /* At least once, in case we have an empty string */
+ {
+ int len;
+ uschar *linebreak = Ustrchr(p, '\n');
+ ss = string_catn(ss, code, 3);
+ if (!linebreak)
+ {
+ len = Ustrlen(p);
+ ss = string_catn(ss, US" ", 1);
}
else
- smtp_respond(smtp_code, codelen, TRUE,
- US"Temporary local problem - please try later");
+ {
+ len = linebreak - p;
+ ss = string_catn(ss, US"-", 1);
+ }
+ ss = string_catn(ss, esc, esclen);
+ ss = string_catn(ss, p, len);
+ ss = string_catn(ss, US"\r\n", 2);
+ p += len;
+ if (linebreak) p++;
}
+while (*p);
-/* Log the incident to the logs that are specified by log_reject_target
-(default main, reject). This can be empty to suppress logging of rejections. If
-the connection is not forcibly to be dropped, return 0. Otherwise, log why it
-is closing if required and return 2. */
+/* Before we write the banner, check that there is no input pending, unless
+this synchronisation check is disabled. */
-if (log_reject_target != 0)
- log_write(0, log_reject_target, "%s %s%srejected %s%s",
- host_and_ident(TRUE),
- sender_info, (rc == FAIL)? US"" : US"temporarily ", what, log_msg);
+#ifndef DISABLE_PIPE_CONNECT
+fl.pipe_connect_acceptable =
+ sender_host_address && verify_check_host(&pipe_connect_advertise_hosts) == OK;
-if (!drop) return 0;
+if (!check_sync())
+ if (fl.pipe_connect_acceptable)
+ f.smtp_in_early_pipe_used = TRUE;
+ else
+#else
+if (!check_sync())
+#endif
+ {
+ unsigned n = smtp_inend - smtp_inptr;
+ if (n > 128) n = 128;
+
+ log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol "
+ "synchronization error (input sent without waiting for greeting): "
+ "rejected connection from %s input=\"%s\"", host_and_ident(TRUE),
+ string_printing(string_copyn(smtp_inptr, n)));
+ smtp_printf("554 SMTP synchronization error\r\n", FALSE);
+ return FALSE;
+ }
-log_write(L_smtp_connection, LOG_MAIN, "%s closed by DROP in ACL",
- smtp_get_connection_info());
+/* Now output the banner */
+/*XXX the ehlo-resp code does its own tls/nontls bit. Maybe subroutine that? */
-/* Run the not-quit ACL, but without any custom messages. This should not be a
-problem, because we get here only if some other ACL has issued "drop", and
-in that case, *its* custom messages will have been used above. */
+smtp_printf("%s",
+#ifndef DISABLE_PIPE_CONNECT
+ fl.pipe_connect_acceptable && pipeline_connect_sends(),
+#else
+ FALSE,
+#endif
+ string_from_gstring(ss));
-smtp_notquit_exit(US"acl-drop", NULL, NULL);
-return 2;
+/* Attempt to see if we sent the banner before the last ACK of the 3-way
+handshake arrived. If so we must have managed a TFO. */
+
+#ifdef TCP_FASTOPEN
+if (sender_host_address && !f.sender_host_notsocket) tfo_in_check();
+#endif
+
+return TRUE;
}
+
/*************************************************
-* Handle SMTP exit when QUIT is not given *
+* Handle SMTP syntax and protocol errors *
*************************************************/
-/* This function provides a logging/statistics hook for when an SMTP connection
-is dropped on the floor or the other end goes away. It's a global function
-because it's called from receive.c as well as this module. As well as running
-the NOTQUIT ACL, if there is one, this function also outputs a final SMTP
-response, either with a custom message from the ACL, or using a default. There
-is one case, however, when no message is output - after "drop". In that case,
-the ACL that obeyed "drop" has already supplied the custom message, and NULL is
-passed to this function.
-
-In case things go wrong while processing this function, causing an error that
-may re-enter this funtion, there is a recursion check.
+/* Write to the log for SMTP syntax errors in incoming commands, if configured
+to do so. Then transmit the error response. The return value depends on the
+number of syntax and protocol errors in this SMTP session.
Arguments:
- reason What $smtp_notquit_reason will be set to in the ACL;
- if NULL, the ACL is not run
- code The error code to return as part of the response
- defaultrespond The default message if there's no user_msg
+ type error type, given as a log flag bit
+ code response code; <= 0 means don't send a response
+ data data to reflect in the response (can be NULL)
+ errmess the error message
-Returns: Nothing
-*/
+Returns: -1 limit of syntax/protocol errors NOT exceeded
+ +1 limit of syntax/protocol errors IS exceeded
-void
-smtp_notquit_exit(uschar *reason, uschar *code, uschar *defaultrespond, ...)
+These values fit in with the values of the "done" variable in the main
+processing loop in smtp_setup_msg(). */
+
+static int
+synprot_error(int type, int code, uschar *data, uschar *errmess)
{
-int rc;
-uschar *user_msg = NULL;
-uschar *log_msg = NULL;
+int yield = -1;
-/* Check for recursive acll */
+log_write(type, LOG_MAIN, "SMTP %s error in \"%s\" %s %s",
+ type == L_smtp_syntax_error ? "syntax" : "protocol",
+ string_printing(smtp_cmd_buffer), host_and_ident(TRUE), errmess);
-if (smtp_exit_function_called)
+if (++synprot_error_count > smtp_max_synprot_errors)
{
- log_write(0, LOG_PANIC, "smtp_notquit_exit() called more than once (%s)",
- reason);
- return;
+ yield = 1;
+ log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
+ "syntax or protocol errors (last command was \"%s\", %s)",
+ host_and_ident(FALSE), string_printing(smtp_cmd_buffer),
+ string_from_gstring(s_connhad_log(NULL))
+ );
}
-smtp_exit_function_called = TRUE;
-/* Call the not-QUIT ACL, if there is one, unless no reason is given. */
-
-if (acl_smtp_notquit != NULL && reason != NULL)
+if (code > 0)
{
- smtp_notquit_reason = reason;
- rc = acl_check(ACL_WHERE_NOTQUIT, NULL, acl_smtp_notquit, &user_msg,
- &log_msg);
- if (rc == ERROR)
- log_write(0, LOG_MAIN|LOG_PANIC, "ACL for not-QUIT returned ERROR: %s",
- log_msg);
+ smtp_printf("%d%c%s%s%s\r\n", FALSE, code, yield == 1 ? '-' : ' ',
+ data ? data : US"", data ? US": " : US"", errmess);
+ if (yield == 1)
+ smtp_printf("%d Too many syntax or protocol errors\r\n", FALSE, code);
}
-/* Write an SMTP response if we are expected to give one. As the default
-responses are all internal, they should always fit in the buffer, but code a
-warning, just in case. Note that string_vformat() still leaves a complete
-string, even if it is incomplete. */
-
-if (code != NULL && defaultrespond != NULL)
- {
- if (user_msg == NULL)
- {
- uschar buffer[128];
- va_list ap;
- va_start(ap, defaultrespond);
- if (!string_vformat(buffer, sizeof(buffer), CS defaultrespond, ap))
- log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_notquit_exit()");
- smtp_printf("%s %s\r\n", code, buffer);
- va_end(ap);
- }
- else
- smtp_respond(code, 3, TRUE, user_msg);
- mac_smtp_fflush();
- }
+return yield;
}
/*************************************************
-* Verify HELO argument *
+* Send SMTP response, possibly multiline *
*************************************************/
-/* This function is called if helo_verify_hosts or helo_try_verify_hosts is
-matched. It is also called from ACL processing if verify = helo is used and
-verification was not previously tried (i.e. helo_try_verify_hosts was not
-matched). The result of its processing is to set helo_verified and
-helo_verify_failed. These variables should both be FALSE for this function to
-be called.
+/* There are, it seems, broken clients out there that cannot handle multiline
+responses. If no_multiline_responses is TRUE (it can be set from an ACL), we
+output nothing for non-final calls, and only the first line for anything else.
-Note that EHLO/HELO is legitimately allowed to quote an address literal. Allow
-for IPv6 ::ffff: literals.
+Arguments:
+ code SMTP code, may involve extended status codes
+ codelen length of smtp code; if > 4 there's an ESC
+ final FALSE if the last line isn't the final line
+ msg message text, possibly containing newlines
-Argument: none
-Returns: TRUE if testing was completed;
- FALSE on a temporary failure
+Returns: nothing
*/
-BOOL
-smtp_verify_helo(void)
+void
+smtp_respond(uschar* code, int codelen, BOOL final, uschar *msg)
{
-BOOL yield = TRUE;
-
-HDEBUG(D_receive) debug_printf("verifying EHLO/HELO argument \"%s\"\n",
- sender_helo_name);
-
-if (sender_helo_name == NULL)
- {
- HDEBUG(D_receive) debug_printf("no EHLO/HELO command was issued\n");
- }
-
-/* Deal with the case of -bs without an IP address */
-
-else if (sender_host_address == NULL)
- {
- HDEBUG(D_receive) debug_printf("no client IP address: assume success\n");
- helo_verified = TRUE;
- }
+int esclen = 0;
+uschar *esc = US"";
-/* Deal with the more common case when there is a sending IP address */
+if (!final && f.no_multiline_responses) return;
-else if (sender_helo_name[0] == '[')
+if (codelen > 4)
{
- helo_verified = Ustrncmp(sender_helo_name+1, sender_host_address,
- Ustrlen(sender_host_address)) == 0;
-
- #if HAVE_IPV6
- if (!helo_verified)
- {
- if (strncmpic(sender_host_address, US"::ffff:", 7) == 0)
- helo_verified = Ustrncmp(sender_helo_name + 1,
- sender_host_address + 7, Ustrlen(sender_host_address) - 7) == 0;
- }
- #endif
-
- HDEBUG(D_receive)
- { if (helo_verified) debug_printf("matched host address\n"); }
+ esc = code + 4;
+ esclen = codelen - 4;
}
-/* Do a reverse lookup if one hasn't already given a positive or negative
-response. If that fails, or the name doesn't match, try checking with a forward
-lookup. */
+/* If this is the first output for a (non-batch) RCPT command, see if all RCPTs
+have had the same. Note: this code is also present in smtp_printf(). It would
+be tidier to have it only in one place, but when it was added, it was easier to
+do it that way, so as not to have to mess with the code for the RCPT command,
+which sometimes uses smtp_printf() and sometimes smtp_respond(). */
-else
+if (fl.rcpt_in_progress)
{
- if (sender_host_name == NULL && !host_lookup_failed)
- yield = host_name_lookup() != DEFER;
+ if (rcpt_smtp_response == NULL)
+ rcpt_smtp_response = string_copy(msg);
+ else if (fl.rcpt_smtp_response_same &&
+ Ustrcmp(rcpt_smtp_response, msg) != 0)
+ fl.rcpt_smtp_response_same = FALSE;
+ fl.rcpt_in_progress = FALSE;
+ }
- /* If a host name is known, check it and all its aliases. */
+/* Now output the message, splitting it up into multiple lines if necessary.
+We only handle pipelining these responses as far as nonfinal/final groups,
+not the whole MAIL/RCPT/DATA response set. */
- if (sender_host_name != NULL)
+for (;;)
+ {
+ uschar *nl = Ustrchr(msg, '\n');
+ if (nl == NULL)
{
- helo_verified = strcmpic(sender_host_name, sender_helo_name) == 0;
-
- if (helo_verified)
- {
- HDEBUG(D_receive) debug_printf("matched host name\n");
- }
- else
- {
- uschar **aliases = sender_host_aliases;
- while (*aliases != NULL)
- {
- helo_verified = strcmpic(*aliases++, sender_helo_name) == 0;
- if (helo_verified) break;
- }
- HDEBUG(D_receive)
- {
- if (helo_verified)
- debug_printf("matched alias %s\n", *(--aliases));
- }
- }
+ smtp_printf("%.3s%c%.*s%s\r\n", !final, code, final ? ' ':'-', esclen, esc, msg);
+ return;
}
-
- /* Final attempt: try a forward lookup of the helo name */
-
- if (!helo_verified)
+ else if (nl[1] == 0 || f.no_multiline_responses)
{
- int rc;
- host_item h;
- h.name = sender_helo_name;
- h.address = NULL;
- h.mx = MX_NONE;
- h.next = NULL;
- HDEBUG(D_receive) debug_printf("getting IP address for %s\n",
- sender_helo_name);
- rc = host_find_byname(&h, NULL, 0, NULL, TRUE);
- if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
- {
- host_item *hh = &h;
- while (hh != NULL)
- {
- if (Ustrcmp(hh->address, sender_host_address) == 0)
- {
- helo_verified = TRUE;
- HDEBUG(D_receive)
- debug_printf("IP address for %s matches calling address\n",
- sender_helo_name);
- break;
- }
- hh = hh->next;
- }
- }
+ smtp_printf("%.3s%c%.*s%.*s\r\n", !final, code, final ? ' ':'-', esclen, esc,
+ (int)(nl - msg), msg);
+ return;
+ }
+ else
+ {
+ smtp_printf("%.3s-%.*s%.*s\r\n", TRUE, code, esclen, esc, (int)(nl - msg), msg);
+ msg = nl + 1;
+ Uskip_whitespace(&msg);
}
}
-
-if (!helo_verified) helo_verify_failed = TRUE; /* We've tried ... */
-return yield;
}
/*************************************************
-* Send user response message *
+* Parse user SMTP message *
*************************************************/
-/* This function is passed a default response code and a user message. It calls
-smtp_message_code() to check and possibly modify the response code, and then
-calls smtp_respond() to transmit the response. I put this into a function
-just to avoid a lot of repetition.
+/* This function allows for user messages overriding the response code details
+by providing a suitable response code string at the start of the message
+user_msg. Check the message for starting with a response code and optionally an
+extended status code. If found, check that the first digit is valid, and if so,
+change the code pointer and length to use the replacement. An invalid code
+causes a panic log; in this case, if the log messages is the same as the user
+message, we must also adjust the value of the log message to show the code that
+is actually going to be used (the original one).
+
+This function is global because it is called from receive.c as well as within
+this module.
+
+Note that the code length returned includes the terminating whitespace
+character, which is always included in the regex match.
Arguments:
- code the response code
- user_msg the user message
+ code SMTP code, may involve extended status codes
+ codelen length of smtp code; if > 4 there's an ESC
+ msg message text
+ log_msg optional log message, to be adjusted with the new SMTP code
+ check_valid if true, verify the response code
-Returns: nothing
+Returns: nothing
*/
-static void
-smtp_user_msg(uschar *code, uschar *user_msg)
+void
+smtp_message_code(uschar **code, int *codelen, uschar **msg, uschar **log_msg,
+ BOOL check_valid)
{
-int len = 3;
-smtp_message_code(&code, &len, &user_msg, NULL);
-smtp_respond(code, len, TRUE, user_msg);
+int n;
+int ovector[3];
+
+if (!msg || !*msg) return;
+
+if ((n = pcre_exec(regex_smtp_code, NULL, CS *msg, Ustrlen(*msg), 0,
+ PCRE_EOPT, ovector, sizeof(ovector)/sizeof(int))) < 0) return;
+
+if (check_valid && (*msg)[0] != (*code)[0])
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC, "configured error code starts with "
+ "incorrect digit (expected %c) in \"%s\"", (*code)[0], *msg);
+ if (log_msg != NULL && *log_msg == *msg)
+ *log_msg = string_sprintf("%s %s", *code, *log_msg + ovector[1]);
+ }
+else
+ {
+ *code = *msg;
+ *codelen = ovector[1]; /* Includes final space */
+ }
+*msg += ovector[1]; /* Chop the code off the message */
+return;
}
/*************************************************
-* Initialize for SMTP incoming message *
+* Handle an ACL failure *
*************************************************/
-/* This function conducts the initial dialogue at the start of an incoming SMTP
-message, and builds a list of recipients. However, if the incoming message
-is part of a batch (-bS option) a separate function is called since it would
-be messy having tests splattered about all over this function. This function
-therefore handles the case where interaction is occurring. The input and output
-files are set up in smtp_in and smtp_out.
+/* This function is called when acl_check() fails. As well as calls from within
+this module, it is called from receive.c for an ACL after DATA. It sorts out
+logging the incident, and sends the error response. A message containing
+newlines is turned into a multiline SMTP response, but for logging, only the
+first line is used.
-The global recipients_list is set to point to a vector of recipient_item
-blocks, whose number is given by recipients_count. This is extended by the
-receive_add_recipient() function. The global variable sender_address is set to
-the sender's address. The yield is +1 if a message has been successfully
-started, 0 if a QUIT command was encountered or the connection was refused from
-the particular host, or -1 if the connection was lost.
+There's a table of default permanent failure response codes to use in
+globals.c, along with the table of names. VFRY is special. Despite RFC1123 it
+defaults disabled in Exim. However, discussion in connection with RFC 821bis
+(aka RFC 2821) has concluded that the response should be 252 in the disabled
+state, because there are broken clients that try VRFY before RCPT. A 5xx
+response should be given only when the address is positively known to be
+undeliverable. Sigh. We return 252 if there is no VRFY ACL or it provides
+no explicit code, but if there is one we let it know best.
+Also, for ETRN, 458 is given on refusal, and for AUTH, 503.
-Argument: none
+From Exim 4.63, it is possible to override the response code details by
+providing a suitable response code string at the start of the message provided
+in user_msg. The code's first digit is checked for validity.
-Returns: > 0 message successfully started (reached DATA)
- = 0 QUIT read or end of file reached or call refused
- < 0 lost connection
+Arguments:
+ where where the ACL was called from
+ rc the failure code
+ user_msg a message that can be included in an SMTP response
+ log_msg a message for logging
+
+Returns: 0 in most cases
+ 2 if the failure code was FAIL_DROP, in which case the
+ SMTP connection should be dropped (this value fits with the
+ "done" variable in smtp_setup_msg() below)
*/
int
-smtp_setup_msg(void)
+smtp_handle_acl_fail(int where, int rc, uschar *user_msg, uschar *log_msg)
{
-int done = 0;
-BOOL toomany = FALSE;
-BOOL discarded = FALSE;
-BOOL last_was_rej_mail = FALSE;
-BOOL last_was_rcpt = FALSE;
-void *reset_point = store_get(0);
+BOOL drop = rc == FAIL_DROP;
+int codelen = 3;
+uschar *smtp_code;
+uschar *lognl;
+uschar *sender_info = US"";
+uschar *what;
-DEBUG(D_receive) debug_printf("smtp_setup_msg entered\n");
+if (drop) rc = FAIL;
-/* Reset for start of new message. We allow one RSET not to be counted as a
-nonmail command, for those MTAs that insist on sending it between every
-message. Ditto for EHLO/HELO and for STARTTLS, to allow for going in and out of
-TLS between messages (an Exim client may do this if it has messages queued up
-for the host). Note: we do NOT reset AUTH at this point. */
+/* Set the default SMTP code, and allow a user message to change it. */
-smtp_reset(reset_point);
-message_ended = END_NOTSTARTED;
+smtp_code = rc == FAIL ? acl_wherecodes[where] : US"451";
+smtp_message_code(&smtp_code, &codelen, &user_msg, &log_msg,
+ where != ACL_WHERE_VRFY);
-cmd_list[CMD_LIST_RSET].is_mail_cmd = TRUE;
-cmd_list[CMD_LIST_HELO].is_mail_cmd = TRUE;
-cmd_list[CMD_LIST_EHLO].is_mail_cmd = TRUE;
-#ifdef SUPPORT_TLS
-cmd_list[CMD_LIST_STARTTLS].is_mail_cmd = TRUE;
+/* We used to have sender_address here; however, there was a bug that was not
+updating sender_address after a rewrite during a verify. When this bug was
+fixed, sender_address at this point became the rewritten address. I'm not sure
+this is what should be logged, so I've changed to logging the unrewritten
+address to retain backward compatibility. */
+
+switch (where)
+ {
+#ifdef WITH_CONTENT_SCAN
+ case ACL_WHERE_MIME: what = US"during MIME ACL checks"; break;
#endif
+ case ACL_WHERE_PREDATA: what = US"DATA"; break;
+ case ACL_WHERE_DATA: what = US"after DATA"; break;
+#ifndef DISABLE_PRDR
+ case ACL_WHERE_PRDR: what = US"after DATA PRDR"; break;
+#endif
+ default:
+ {
+ uschar * place = smtp_cmd_data ? smtp_cmd_data : US"in \"connect\" ACL";
+ int lim = 100;
-/* Set the local signal handler for SIGTERM - it tries to end off tidily */
+ if (where == ACL_WHERE_AUTH) /* avoid logging auth creds */
+ {
+ uschar * s;
+ for (s = smtp_cmd_data; *s && !isspace(*s); ) s++;
+ lim = s - smtp_cmd_data; /* atop after method */
+ }
+ what = string_sprintf("%s %.*s", acl_wherenames[where], lim, place);
+ }
+ }
+switch (where)
+ {
+ case ACL_WHERE_RCPT:
+ case ACL_WHERE_DATA:
+#ifdef WITH_CONTENT_SCAN
+ case ACL_WHERE_MIME:
+#endif
+ sender_info = string_sprintf("F=<%s>%s%s%s%s ",
+ sender_address_unrewritten ? sender_address_unrewritten : sender_address,
+ sender_host_authenticated ? US" A=" : US"",
+ sender_host_authenticated ? sender_host_authenticated : US"",
+ sender_host_authenticated && authenticated_id ? US":" : US"",
+ sender_host_authenticated && authenticated_id ? authenticated_id : US""
+ );
+ break;
+ }
-os_non_restarting_signal(SIGTERM, command_sigterm_handler);
+/* If there's been a sender verification failure with a specific message, and
+we have not sent a response about it yet, do so now, as a preliminary line for
+failures, but not defers. However, always log it for defer, and log it for fail
+unless the sender_verify_fail log selector has been turned off. */
-/* Batched SMTP is handled in a different function. */
+if (sender_verified_failed &&
+ !testflag(sender_verified_failed, af_sverify_told))
+ {
+ BOOL save_rcpt_in_progress = fl.rcpt_in_progress;
+ fl.rcpt_in_progress = FALSE; /* So as not to treat these as the error */
-if (smtp_batched_input) return smtp_setup_batch_msg();
+ setflag(sender_verified_failed, af_sverify_told);
-/* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE
-value. The values are 2 larger than the required yield of the function. */
+ if (rc != FAIL || LOGGING(sender_verify_fail))
+ log_write(0, LOG_MAIN|LOG_REJECT, "%s sender verify %s for <%s>%s",
+ host_and_ident(TRUE),
+ ((sender_verified_failed->special_action & 255) == DEFER)? "defer":"fail",
+ sender_verified_failed->address,
+ (sender_verified_failed->message == NULL)? US"" :
+ string_sprintf(": %s", sender_verified_failed->message));
-while (done <= 0)
- {
- uschar **argv;
- uschar *etrn_command;
- uschar *etrn_serialize_key;
- uschar *errmess;
- uschar *log_msg, *smtp_code;
- uschar *user_msg = NULL;
- uschar *recipient = NULL;
- uschar *hello = NULL;
- uschar *set_id = NULL;
- uschar *s, *ss;
- BOOL was_rej_mail = FALSE;
- BOOL was_rcpt = FALSE;
- void (*oldsignal)(int);
- pid_t pid;
- int start, end, sender_domain, recipient_domain;
- int ptr, size, rc;
- int c, i;
- auth_instance *au;
+ if (rc == FAIL && sender_verified_failed->user_message)
+ smtp_respond(smtp_code, codelen, FALSE, string_sprintf(
+ testflag(sender_verified_failed, af_verify_pmfail)?
+ "Postmaster verification failed while checking <%s>\n%s\n"
+ "Several RFCs state that you are required to have a postmaster\n"
+ "mailbox for each mail domain. This host does not accept mail\n"
+ "from domains whose servers reject the postmaster address."
+ :
+ testflag(sender_verified_failed, af_verify_nsfail)?
+ "Callback setup failed while verifying <%s>\n%s\n"
+ "The initial connection, or a HELO or MAIL FROM:<> command was\n"
+ "rejected. Refusing MAIL FROM:<> does not help fight spam, disregards\n"
+ "RFC requirements, and stops you from receiving standard bounce\n"
+ "messages. This host does not accept mail from domains whose servers\n"
+ "refuse bounces."
+ :
+ "Verification failed for <%s>\n%s",
+ sender_verified_failed->address,
+ sender_verified_failed->user_message));
- switch(smtp_read_command(TRUE))
- {
- /* The AUTH command is not permitted to occur inside a transaction, and may
- occur successfully only once per connection. Actually, that isn't quite
- true. When TLS is started, all previous information about a connection must
- be discarded, so a new AUTH is permitted at that time.
+ fl.rcpt_in_progress = save_rcpt_in_progress;
+ }
- AUTH may only be used when it has been advertised. However, it seems that
- there are clients that send AUTH when it hasn't been advertised, some of
- them even doing this after HELO. And there are MTAs that accept this. Sigh.
- So there's a get-out that allows this to happen.
+/* Sort out text for logging */
- AUTH is initially labelled as a "nonmail command" so that one occurrence
- doesn't get counted. We change the label here so that multiple failing
- AUTHS will eventually hit the nonmail threshold. */
+log_msg = log_msg ? string_sprintf(": %s", log_msg) : US"";
+if ((lognl = Ustrchr(log_msg, '\n'))) *lognl = 0;
- case AUTH_CMD:
- HAD(SCH_AUTH);
- authentication_failed = TRUE;
- cmd_list[CMD_LIST_AUTH].is_mail_cmd = FALSE;
+/* Send permanent failure response to the command, but the code used isn't
+always a 5xx one - see comments at the start of this function. If the original
+rc was FAIL_DROP we drop the connection and yield 2. */
- if (!auth_advertised && !allow_auth_unadvertised)
- {
- done = synprot_error(L_smtp_protocol_error, 503, NULL,
- US"AUTH command used when not advertised");
- break;
- }
- if (sender_host_authenticated != NULL)
- {
- done = synprot_error(L_smtp_protocol_error, 503, NULL,
- US"already authenticated");
- break;
- }
- if (sender_address != NULL)
- {
- done = synprot_error(L_smtp_protocol_error, 503, NULL,
- US"not permitted in mail transaction");
- break;
- }
+if (rc == FAIL)
+ smtp_respond(smtp_code, codelen, TRUE,
+ user_msg ? user_msg : US"Administrative prohibition");
- /* Check the ACL */
+/* Send temporary failure response to the command. Don't give any details,
+unless acl_temp_details is set. This is TRUE for a callout defer, a "defer"
+verb, and for a header verify when smtp_return_error_details is set.
- if (acl_smtp_auth != NULL)
- {
- rc = acl_check(ACL_WHERE_AUTH, NULL, acl_smtp_auth, &user_msg, &log_msg);
- if (rc != OK)
- {
- done = smtp_handle_acl_fail(ACL_WHERE_AUTH, rc, user_msg, log_msg);
- break;
- }
- }
+This conditional logic is all somewhat of a mess because of the odd
+interactions between temp_details and return_error_details. One day it should
+be re-implemented in a tidier fashion. */
- /* Find the name of the requested authentication mechanism. */
+else
+ if (f.acl_temp_details && user_msg)
+ {
+ if ( smtp_return_error_details
+ && sender_verified_failed
+ && sender_verified_failed->message
+ )
+ smtp_respond(smtp_code, codelen, FALSE, sender_verified_failed->message);
- s = smtp_cmd_data;
- while ((c = *smtp_cmd_data) != 0 && !isspace(c))
- {
- if (!isalnum(c) && c != '-' && c != '_')
- {
- done = synprot_error(L_smtp_syntax_error, 501, NULL,
- US"invalid character in authentication mechanism name");
- goto COMMAND_LOOP;
- }
- smtp_cmd_data++;
- }
+ smtp_respond(smtp_code, codelen, TRUE, user_msg);
+ }
+ else
+ smtp_respond(smtp_code, codelen, TRUE,
+ US"Temporary local problem - please try later");
- /* If not at the end of the line, we must be at white space. Terminate the
- name and move the pointer on to any data that may be present. */
+/* Log the incident to the logs that are specified by log_reject_target
+(default main, reject). This can be empty to suppress logging of rejections. If
+the connection is not forcibly to be dropped, return 0. Otherwise, log why it
+is closing if required and return 2. */
- if (*smtp_cmd_data != 0)
- {
- *smtp_cmd_data++ = 0;
- while (isspace(*smtp_cmd_data)) smtp_cmd_data++;
- }
+if (log_reject_target != 0)
+ {
+#ifndef DISABLE_TLS
+ gstring * g = s_tlslog(NULL);
+ uschar * tls = string_from_gstring(g);
+ if (!tls) tls = US"";
+#else
+ uschar * tls = US"";
+#endif
+ log_write(where == ACL_WHERE_CONNECT ? L_connection_reject : 0,
+ log_reject_target, "%s%s%s %s%srejected %s%s",
+ LOGGING(dnssec) && sender_host_dnssec ? US" DS" : US"",
+ host_and_ident(TRUE),
+ tls,
+ sender_info,
+ rc == FAIL ? US"" : US"temporarily ",
+ what, log_msg);
+ }
- /* Search for an authentication mechanism which is configured for use
- as a server and which has been advertised (unless, sigh, allow_auth_
- unadvertised is set). */
+if (!drop) return 0;
- for (au = auths; au != NULL; au = au->next)
- {
- if (strcmpic(s, au->public_name) == 0 && au->server &&
- (au->advertised || allow_auth_unadvertised)) break;
- }
+log_write(L_smtp_connection, LOG_MAIN, "%s closed by DROP in ACL",
+ smtp_get_connection_info());
- if (au == NULL)
- {
- done = synprot_error(L_smtp_protocol_error, 504, NULL,
- string_sprintf("%s authentication mechanism not supported", s));
- break;
- }
+/* Run the not-quit ACL, but without any custom messages. This should not be a
+problem, because we get here only if some other ACL has issued "drop", and
+in that case, *its* custom messages will have been used above. */
- /* Run the checking code, passing the remainder of the command line as
- data. Initials the $auth<n> variables as empty. Initialize $0 empty and set
- it as the only set numerical variable. The authenticator may set $auth<n>
- and also set other numeric variables. The $auth<n> variables are preferred
- nowadays; the numerical variables remain for backwards compatibility.
+smtp_notquit_exit(US"acl-drop", NULL, NULL);
+return 2;
+}
- Afterwards, have a go at expanding the set_id string, even if
- authentication failed - for bad passwords it can be useful to log the
- userid. On success, require set_id to expand and exist, and put it in
- authenticated_id. Save this in permanent store, as the working store gets
- reset at HELO, RSET, etc. */
- for (i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL;
- expand_nmax = 0;
- expand_nlength[0] = 0; /* $0 contains nothing */
- c = (au->info->servercode)(au, smtp_cmd_data);
- if (au->set_id != NULL) set_id = expand_string(au->set_id);
- expand_nmax = -1; /* Reset numeric variables */
- for (i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL; /* Reset $auth<n> */
- /* The value of authenticated_id is stored in the spool file and printed in
- log lines. It must not contain binary zeros or newline characters. In
- normal use, it never will, but when playing around or testing, this error
- can (did) happen. To guard against this, ensure that the id contains only
- printing characters. */
+/*************************************************
+* Handle SMTP exit when QUIT is not given *
+*************************************************/
- if (set_id != NULL) set_id = string_printing(set_id);
+/* This function provides a logging/statistics hook for when an SMTP connection
+is dropped on the floor or the other end goes away. It's a global function
+because it's called from receive.c as well as this module. As well as running
+the NOTQUIT ACL, if there is one, this function also outputs a final SMTP
+response, either with a custom message from the ACL, or using a default. There
+is one case, however, when no message is output - after "drop". In that case,
+the ACL that obeyed "drop" has already supplied the custom message, and NULL is
+passed to this function.
- /* For the non-OK cases, set up additional logging data if set_id
- is not empty. */
+In case things go wrong while processing this function, causing an error that
+may re-enter this function, there is a recursion check.
- if (c != OK)
- {
- if (set_id != NULL && *set_id != 0)
- set_id = string_sprintf(" (set_id=%s)", set_id);
- else set_id = US"";
- }
+Arguments:
+ reason What $smtp_notquit_reason will be set to in the ACL;
+ if NULL, the ACL is not run
+ code The error code to return as part of the response
+ defaultrespond The default message if there's no user_msg
- /* Switch on the result */
+Returns: Nothing
+*/
- switch(c)
- {
- case OK:
- if (au->set_id == NULL || set_id != NULL) /* Complete success */
- {
- if (set_id != NULL) authenticated_id = string_copy_malloc(set_id);
- sender_host_authenticated = au->name;
- authentication_failed = FALSE;
- received_protocol =
- protocols[pextend + pauthed + ((tls_active >= 0)? pcrpted:0)] +
- ((sender_host_address != NULL)? pnlocal : 0);
- s = ss = US"235 Authentication succeeded";
- authenticated_by = au;
- break;
- }
+void
+smtp_notquit_exit(uschar *reason, uschar *code, uschar *defaultrespond, ...)
+{
+int rc;
+uschar *user_msg = NULL;
+uschar *log_msg = NULL;
- /* Authentication succeeded, but we failed to expand the set_id string.
- Treat this as a temporary error. */
+/* Check for recursive call */
- auth_defer_msg = expand_string_message;
- /* Fall through */
+if (fl.smtp_exit_function_called)
+ {
+ log_write(0, LOG_PANIC, "smtp_notquit_exit() called more than once (%s)",
+ reason);
+ return;
+ }
+fl.smtp_exit_function_called = TRUE;
- case DEFER:
- s = string_sprintf("435 Unable to authenticate at present%s",
- auth_defer_user_msg);
- ss = string_sprintf("435 Unable to authenticate at present%s: %s",
- set_id, auth_defer_msg);
- break;
+/* Call the not-QUIT ACL, if there is one, unless no reason is given. */
- case BAD64:
- s = ss = US"501 Invalid base64 data";
- break;
+if (acl_smtp_notquit && reason)
+ {
+ smtp_notquit_reason = reason;
+ if ((rc = acl_check(ACL_WHERE_NOTQUIT, NULL, acl_smtp_notquit, &user_msg,
+ &log_msg)) == ERROR)
+ log_write(0, LOG_MAIN|LOG_PANIC, "ACL for not-QUIT returned ERROR: %s",
+ log_msg);
+ }
- case CANCELLED:
- s = ss = US"501 Authentication cancelled";
- break;
+/* If the connection was dropped, we certainly are no longer talking TLS */
+tls_in.active.sock = -1;
- case UNEXPECTED:
- s = ss = US"553 Initial data not expected";
- break;
+/* Write an SMTP response if we are expected to give one. As the default
+responses are all internal, they should be reasonable size. */
- case FAIL:
- s = US"535 Incorrect authentication data";
- ss = string_sprintf("535 Incorrect authentication data%s", set_id);
- break;
+if (code && defaultrespond)
+ {
+ if (user_msg)
+ smtp_respond(code, 3, TRUE, user_msg);
+ else
+ {
+ gstring * g;
+ va_list ap;
- default:
- s = US"435 Internal error";
- ss = string_sprintf("435 Internal error%s: return %d from authentication "
- "check", set_id, c);
- break;
- }
+ va_start(ap, defaultrespond);
+ g = string_vformat(NULL, SVFMT_EXTEND|SVFMT_REBUFFER, CS defaultrespond, ap);
+ va_end(ap);
+ smtp_printf("%s %s\r\n", FALSE, code, string_from_gstring(g));
+ }
+ mac_smtp_fflush();
+ }
+}
- smtp_printf("%s\r\n", s);
- if (c != OK)
- log_write(0, LOG_MAIN|LOG_REJECT, "%s authenticator failed for %s: %s",
- au->name, host_and_ident(FALSE), ss);
- break; /* AUTH_CMD */
- /* The HELO/EHLO commands are permitted to appear in the middle of a
- session as well as at the beginning. They have the effect of a reset in
- addition to their other functions. Their absence at the start cannot be
- taken to be an error.
- RFC 2821 says:
+/*************************************************
+* Verify HELO argument *
+*************************************************/
- If the EHLO command is not acceptable to the SMTP server, 501, 500,
- or 502 failure replies MUST be returned as appropriate. The SMTP
- server MUST stay in the same state after transmitting these replies
- that it was in before the EHLO was received.
+/* This function is called if helo_verify_hosts or helo_try_verify_hosts is
+matched. It is also called from ACL processing if verify = helo is used and
+verification was not previously tried (i.e. helo_try_verify_hosts was not
+matched). The result of its processing is to set helo_verified and
+helo_verify_failed. These variables should both be FALSE for this function to
+be called.
- Therefore, we do not do the reset until after checking the command for
- acceptability. This change was made for Exim release 4.11. Previously
- it did the reset first. */
+Note that EHLO/HELO is legitimately allowed to quote an address literal. Allow
+for IPv6 ::ffff: literals.
- case HELO_CMD:
- HAD(SCH_HELO);
- hello = US"HELO";
- esmtp = FALSE;
- goto HELO_EHLO;
+Argument: none
+Returns: TRUE if testing was completed;
+ FALSE on a temporary failure
+*/
- case EHLO_CMD:
- HAD(SCH_EHLO);
- hello = US"EHLO";
- esmtp = TRUE;
+BOOL
+smtp_verify_helo(void)
+{
+BOOL yield = TRUE;
- HELO_EHLO: /* Common code for HELO and EHLO */
- cmd_list[CMD_LIST_HELO].is_mail_cmd = FALSE;
- cmd_list[CMD_LIST_EHLO].is_mail_cmd = FALSE;
+HDEBUG(D_receive) debug_printf("verifying EHLO/HELO argument \"%s\"\n",
+ sender_helo_name);
- /* Reject the HELO if its argument was invalid or non-existent. A
- successful check causes the argument to be saved in malloc store. */
+if (sender_helo_name == NULL)
+ {
+ HDEBUG(D_receive) debug_printf("no EHLO/HELO command was issued\n");
+ }
- if (!check_helo(smtp_cmd_data))
- {
- smtp_printf("501 Syntactically invalid %s argument(s)\r\n", hello);
+/* Deal with the case of -bs without an IP address */
- log_write(0, LOG_MAIN|LOG_REJECT, "rejected %s from %s: syntactically "
- "invalid argument(s): %s", hello, host_and_ident(FALSE),
- (*smtp_cmd_argument == 0)? US"(no argument given)" :
- string_printing(smtp_cmd_argument));
+else if (sender_host_address == NULL)
+ {
+ HDEBUG(D_receive) debug_printf("no client IP address: assume success\n");
+ f.helo_verified = TRUE;
+ }
- if (++synprot_error_count > smtp_max_synprot_errors)
- {
- log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
- "syntax or protocol errors (last command was \"%s\")",
- host_and_ident(FALSE), smtp_cmd_buffer);
- done = 1;
- }
+/* Deal with the more common case when there is a sending IP address */
- break;
- }
+else if (sender_helo_name[0] == '[')
+ {
+ f.helo_verified = Ustrncmp(sender_helo_name+1, sender_host_address,
+ Ustrlen(sender_host_address)) == 0;
- /* If sender_host_unknown is true, we have got here via the -bs interface,
- not called from inetd. Otherwise, we are running an IP connection and the
- host address will be set. If the helo name is the primary name of this
- host and we haven't done a reverse lookup, force one now. If helo_required
- is set, ensure that the HELO name matches the actual host. If helo_verify
- is set, do the same check, but softly. */
+#if HAVE_IPV6
+ if (!f.helo_verified)
+ {
+ if (strncmpic(sender_host_address, US"::ffff:", 7) == 0)
+ f.helo_verified = Ustrncmp(sender_helo_name + 1,
+ sender_host_address + 7, Ustrlen(sender_host_address) - 7) == 0;
+ }
+#endif
- if (!sender_host_unknown)
- {
- BOOL old_helo_verified = helo_verified;
- uschar *p = smtp_cmd_data;
+ HDEBUG(D_receive)
+ { if (f.helo_verified) debug_printf("matched host address\n"); }
+ }
- while (*p != 0 && !isspace(*p)) { *p = tolower(*p); p++; }
- *p = 0;
+/* Do a reverse lookup if one hasn't already given a positive or negative
+response. If that fails, or the name doesn't match, try checking with a forward
+lookup. */
- /* Force a reverse lookup if HELO quoted something in helo_lookup_domains
- because otherwise the log can be confusing. */
+else
+ {
+ if (sender_host_name == NULL && !host_lookup_failed)
+ yield = host_name_lookup() != DEFER;
- if (sender_host_name == NULL &&
- (deliver_domain = sender_helo_name, /* set $domain */
- match_isinlist(sender_helo_name, &helo_lookup_domains, 0,
- &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL)) == OK)
- (void)host_name_lookup();
+ /* If a host name is known, check it and all its aliases. */
- /* Rebuild the fullhost info to include the HELO name (and the real name
- if it was looked up.) */
+ if (sender_host_name)
+ if ((f.helo_verified = strcmpic(sender_host_name, sender_helo_name) == 0))
+ {
+ sender_helo_dnssec = sender_host_dnssec;
+ HDEBUG(D_receive) debug_printf("matched host name\n");
+ }
+ else
+ {
+ uschar **aliases = sender_host_aliases;
+ while (*aliases)
+ if ((f.helo_verified = strcmpic(*aliases++, sender_helo_name) == 0))
+ {
+ sender_helo_dnssec = sender_host_dnssec;
+ break;
+ }
+
+ HDEBUG(D_receive) if (f.helo_verified)
+ debug_printf("matched alias %s\n", *(--aliases));
+ }
- host_build_sender_fullhost(); /* Rebuild */
- set_process_info("handling%s incoming connection from %s",
- (tls_active >= 0)? " TLS" : "", host_and_ident(FALSE));
+ /* Final attempt: try a forward lookup of the helo name */
- /* Verify if configured. This doesn't give much security, but it does
- make some people happy to be able to do it. If helo_required is set,
- (host matches helo_verify_hosts) failure forces rejection. If helo_verify
- is set (host matches helo_try_verify_hosts), it does not. This is perhaps
- now obsolescent, since the verification can now be requested selectively
- at ACL time. */
+ if (!f.helo_verified)
+ {
+ int rc;
+ host_item h =
+ {.name = sender_helo_name, .address = NULL, .mx = MX_NONE, .next = NULL};
+ dnssec_domains d =
+ {.request = US"*", .require = US""};
- helo_verified = helo_verify_failed = FALSE;
- if (helo_required || helo_verify)
- {
- BOOL tempfail = !smtp_verify_helo();
- if (!helo_verified)
+ HDEBUG(D_receive) debug_printf("getting IP address for %s\n",
+ sender_helo_name);
+ rc = host_find_bydns(&h, NULL, HOST_FIND_BY_A | HOST_FIND_BY_AAAA,
+ NULL, NULL, NULL, &d, NULL, NULL);
+ if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
+ for (host_item * hh = &h; hh; hh = hh->next)
+ if (Ustrcmp(hh->address, sender_host_address) == 0)
{
- if (helo_required)
- {
- smtp_printf("%d %s argument does not match calling host\r\n",
- tempfail? 451 : 550, hello);
- log_write(0, LOG_MAIN|LOG_REJECT, "%srejected \"%s %s\" from %s",
- tempfail? "temporarily " : "",
- hello, sender_helo_name, host_and_ident(FALSE));
- helo_verified = old_helo_verified;
- break; /* End of HELO/EHLO processing */
- }
- HDEBUG(D_all) debug_printf("%s verification failed but host is in "
- "helo_try_verify_hosts\n", hello);
+ f.helo_verified = TRUE;
+ if (h.dnssec == DS_YES) sender_helo_dnssec = TRUE;
+ HDEBUG(D_receive)
+ debug_printf("IP address for %s matches calling address\n"
+ "Forward DNS security status: %sverified\n",
+ sender_helo_name, sender_helo_dnssec ? "" : "un");
+ break;
}
- }
- }
+ }
+ }
-#ifdef EXPERIMENTAL_SPF
- /* set up SPF context */
- spf_init(sender_helo_name, sender_host_address);
-#endif
+if (!f.helo_verified) f.helo_verify_failed = TRUE; /* We've tried ... */
+return yield;
+}
- /* Apply an ACL check if one is defined; afterwards, recheck
- synchronization in case the client started sending in a delay. */
- if (acl_smtp_helo != NULL)
- {
- rc = acl_check(ACL_WHERE_HELO, NULL, acl_smtp_helo, &user_msg, &log_msg);
- if (rc != OK)
- {
- done = smtp_handle_acl_fail(ACL_WHERE_HELO, rc, user_msg, log_msg);
- sender_helo_name = NULL;
- host_build_sender_fullhost(); /* Rebuild */
- break;
- }
- else if (!check_sync()) goto SYNC_FAILURE;
- }
- /* Generate an OK reply. The default string includes the ident if present,
- and also the IP address if present. Reflecting back the ident is intended
- as a deterrent to mail forgers. For maximum efficiency, and also because
- some broken systems expect each response to be in a single packet, arrange
- that the entire reply is sent in one write(). */
- auth_advertised = FALSE;
- pipelining_advertised = FALSE;
- #ifdef SUPPORT_TLS
- tls_advertised = FALSE;
- #endif
+/*************************************************
+* Send user response message *
+*************************************************/
- smtp_code = US"250 "; /* Default response code plus space*/
- if (user_msg == NULL)
- {
- s = string_sprintf("%.3s %s Hello %s%s%s",
- smtp_code,
- smtp_active_hostname,
- (sender_ident == NULL)? US"" : sender_ident,
- (sender_ident == NULL)? US"" : US" at ",
- (sender_host_name == NULL)? sender_helo_name : sender_host_name);
+/* This function is passed a default response code and a user message. It calls
+smtp_message_code() to check and possibly modify the response code, and then
+calls smtp_respond() to transmit the response. I put this into a function
+just to avoid a lot of repetition.
- ptr = Ustrlen(s);
- size = ptr + 1;
+Arguments:
+ code the response code
+ user_msg the user message
- if (sender_host_address != NULL)
- {
- s = string_cat(s, &size, &ptr, US" [", 2);
- s = string_cat(s, &size, &ptr, sender_host_address,
- Ustrlen(sender_host_address));
- s = string_cat(s, &size, &ptr, US"]", 1);
- }
- }
+Returns: nothing
+*/
- /* A user-supplied EHLO greeting may not contain more than one line. Note
- that the code returned by smtp_message_code() includes the terminating
- whitespace character. */
+static void
+smtp_user_msg(uschar *code, uschar *user_msg)
+{
+int len = 3;
+smtp_message_code(&code, &len, &user_msg, NULL, TRUE);
+smtp_respond(code, len, TRUE, user_msg);
+}
- else
- {
- char *ss;
- int codelen = 4;
- smtp_message_code(&smtp_code, &codelen, &user_msg, NULL);
- s = string_sprintf("%.*s%s", codelen, smtp_code, user_msg);
- if ((ss = strpbrk(CS s, "\r\n")) != NULL)
- {
- log_write(0, LOG_MAIN|LOG_PANIC, "EHLO/HELO response must not contain "
- "newlines: message truncated: %s", string_printing(s));
- *ss = 0;
- }
- ptr = Ustrlen(s);
- size = ptr + 1;
- }
- s = string_cat(s, &size, &ptr, US"\r\n", 2);
- /* If we received EHLO, we must create a multiline response which includes
- the functions supported. */
+static int
+smtp_in_auth(auth_instance *au, uschar ** s, uschar ** ss)
+{
+const uschar *set_id = NULL;
+int rc;
- if (esmtp)
- {
- s[3] = '-';
+/* Run the checking code, passing the remainder of the command line as
+data. Initials the $auth<n> variables as empty. Initialize $0 empty and set
+it as the only set numerical variable. The authenticator may set $auth<n>
+and also set other numeric variables. The $auth<n> variables are preferred
+nowadays; the numerical variables remain for backwards compatibility.
- /* I'm not entirely happy with this, as an MTA is supposed to check
- that it has enough room to accept a message of maximum size before
- it sends this. However, there seems little point in not sending it.
- The actual size check happens later at MAIL FROM time. By postponing it
- till then, VRFY and EXPN can be used after EHLO when space is short. */
+Afterwards, have a go at expanding the set_id string, even if
+authentication failed - for bad passwords it can be useful to log the
+userid. On success, require set_id to expand and exist, and put it in
+authenticated_id. Save this in permanent store, as the working store gets
+reset at HELO, RSET, etc. */
- if (thismessage_size_limit > 0)
- {
- sprintf(CS big_buffer, "%.3s-SIZE %d\r\n", smtp_code,
- thismessage_size_limit);
- s = string_cat(s, &size, &ptr, big_buffer, Ustrlen(big_buffer));
- }
- else
- {
- s = string_cat(s, &size, &ptr, smtp_code, 3);
- s = string_cat(s, &size, &ptr, US"-SIZE\r\n", 7);
- }
+for (int i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL;
+expand_nmax = 0;
+expand_nlength[0] = 0; /* $0 contains nothing */
- /* Exim does not do protocol conversion or data conversion. It is 8-bit
- clean; if it has an 8-bit character in its hand, it just sends it. It
- cannot therefore specify 8BITMIME and remain consistent with the RFCs.
- However, some users want this option simply in order to stop MUAs
- mangling messages that contain top-bit-set characters. It is therefore
- provided as an option. */
+rc = (au->info->servercode)(au, smtp_cmd_data);
+if (au->set_id) set_id = expand_string(au->set_id);
+expand_nmax = -1; /* Reset numeric variables */
+for (int i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL; /* Reset $auth<n> */
- if (accept_8bitmime)
- {
- s = string_cat(s, &size, &ptr, smtp_code, 3);
- s = string_cat(s, &size, &ptr, US"-8BITMIME\r\n", 11);
- }
+/* The value of authenticated_id is stored in the spool file and printed in
+log lines. It must not contain binary zeros or newline characters. In
+normal use, it never will, but when playing around or testing, this error
+can (did) happen. To guard against this, ensure that the id contains only
+printing characters. */
- /* Advertise ETRN if there's an ACL checking whether a host is
- permitted to issue it; a check is made when any host actually tries. */
+if (set_id) set_id = string_printing(set_id);
- if (acl_smtp_etrn != NULL)
- {
- s = string_cat(s, &size, &ptr, smtp_code, 3);
- s = string_cat(s, &size, &ptr, US"-ETRN\r\n", 7);
- }
+/* For the non-OK cases, set up additional logging data if set_id
+is not empty. */
- /* Advertise EXPN if there's an ACL checking whether a host is
- permitted to issue it; a check is made when any host actually tries. */
+if (rc != OK)
+ set_id = set_id && *set_id
+ ? string_sprintf(" (set_id=%s)", set_id) : US"";
- if (acl_smtp_expn != NULL)
- {
- s = string_cat(s, &size, &ptr, smtp_code, 3);
- s = string_cat(s, &size, &ptr, US"-EXPN\r\n", 7);
- }
+/* Switch on the result */
- /* Exim is quite happy with pipelining, so let the other end know that
- it is safe to use it, unless advertising is disabled. */
+switch(rc)
+ {
+ case OK:
+ if (!au->set_id || set_id) /* Complete success */
+ {
+ if (set_id) authenticated_id = string_copy_perm(set_id, TRUE);
+ sender_host_authenticated = au->name;
+ sender_host_auth_pubname = au->public_name;
+ authentication_failed = FALSE;
+ authenticated_fail_id = NULL; /* Impossible to already be set? */
+
+ received_protocol =
+ (sender_host_address ? protocols : protocols_local)
+ [pextend + pauthed + (tls_in.active.sock >= 0 ? pcrpted:0)];
+ *s = *ss = US"235 Authentication succeeded";
+ authenticated_by = au;
+ break;
+ }
- if (pipelining_enable &&
- verify_check_host(&pipelining_advertise_hosts) == OK)
- {
- s = string_cat(s, &size, &ptr, smtp_code, 3);
- s = string_cat(s, &size, &ptr, US"-PIPELINING\r\n", 13);
- sync_cmd_limit = NON_SYNC_CMD_PIPELINING;
- pipelining_advertised = TRUE;
- }
+ /* Authentication succeeded, but we failed to expand the set_id string.
+ Treat this as a temporary error. */
- /* If any server authentication mechanisms are configured, advertise
- them if the current host is in auth_advertise_hosts. The problem with
- advertising always is that some clients then require users to
- authenticate (and aren't configurable otherwise) even though it may not
- be necessary (e.g. if the host is in host_accept_relay).
+ auth_defer_msg = expand_string_message;
+ /* Fall through */
- RFC 2222 states that SASL mechanism names contain only upper case
- letters, so output the names in upper case, though we actually recognize
- them in either case in the AUTH command. */
+ case DEFER:
+ if (set_id) authenticated_fail_id = string_copy_perm(set_id, TRUE);
+ *s = string_sprintf("435 Unable to authenticate at present%s",
+ auth_defer_user_msg);
+ *ss = string_sprintf("435 Unable to authenticate at present%s: %s",
+ set_id, auth_defer_msg);
+ break;
- if (auths != NULL)
- {
- if (verify_check_host(&auth_advertise_hosts) == OK)
- {
- auth_instance *au;
- BOOL first = TRUE;
- for (au = auths; au != NULL; au = au->next)
- {
- if (au->server && (au->advertise_condition == NULL ||
- expand_check_condition(au->advertise_condition, au->name,
- US"authenticator")))
- {
- int saveptr;
- if (first)
- {
- s = string_cat(s, &size, &ptr, smtp_code, 3);
- s = string_cat(s, &size, &ptr, US"-AUTH", 5);
- first = FALSE;
- auth_advertised = TRUE;
- }
- saveptr = ptr;
- s = string_cat(s, &size, &ptr, US" ", 1);
- s = string_cat(s, &size, &ptr, au->public_name,
- Ustrlen(au->public_name));
- while (++saveptr < ptr) s[saveptr] = toupper(s[saveptr]);
- au->advertised = TRUE;
- }
- else au->advertised = FALSE;
- }
- if (!first) s = string_cat(s, &size, &ptr, US"\r\n", 2);
- }
- }
+ case BAD64:
+ *s = *ss = US"501 Invalid base64 data";
+ break;
- /* Advertise TLS (Transport Level Security) aka SSL (Secure Socket Layer)
- if it has been included in the binary, and the host matches
- tls_advertise_hosts. We must *not* advertise if we are already in a
- secure connection. */
+ case CANCELLED:
+ *s = *ss = US"501 Authentication cancelled";
+ break;
- #ifdef SUPPORT_TLS
- if (tls_active < 0 &&
- verify_check_host(&tls_advertise_hosts) != FAIL)
- {
- s = string_cat(s, &size, &ptr, smtp_code, 3);
- s = string_cat(s, &size, &ptr, US"-STARTTLS\r\n", 11);
- tls_advertised = TRUE;
- }
- #endif
+ case UNEXPECTED:
+ *s = *ss = US"553 Initial data not expected";
+ break;
- /* Finish off the multiline reply with one that is always available. */
+ case FAIL:
+ if (set_id) authenticated_fail_id = string_copy_perm(set_id, TRUE);
+ *s = US"535 Incorrect authentication data";
+ *ss = string_sprintf("535 Incorrect authentication data%s", set_id);
+ break;
- s = string_cat(s, &size, &ptr, smtp_code, 3);
- s = string_cat(s, &size, &ptr, US" HELP\r\n", 7);
- }
+ default:
+ if (set_id) authenticated_fail_id = string_copy_perm(set_id, TRUE);
+ *s = US"435 Internal error";
+ *ss = string_sprintf("435 Internal error%s: return %d from authentication "
+ "check", set_id, rc);
+ break;
+ }
- /* Terminate the string (for debug), write it, and note that HELO/EHLO
- has been seen. */
+return rc;
+}
- s[ptr] = 0;
- #ifdef SUPPORT_TLS
- if (tls_active >= 0) (void)tls_write(s, ptr); else
- #endif
- (void)fwrite(s, 1, ptr, smtp_out);
- DEBUG(D_receive)
- {
- uschar *cr;
- while ((cr = Ustrchr(s, '\r')) != NULL) /* lose CRs */
- memmove(cr, cr + 1, (ptr--) - (cr - s));
- debug_printf("SMTP>> %s", s);
- }
- helo_seen = TRUE;
- /* Reset the protocol and the state, abandoning any previous message. */
- received_protocol = (esmtp?
- protocols[pextend +
- ((sender_host_authenticated != NULL)? pauthed : 0) +
- ((tls_active >= 0)? pcrpted : 0)]
- :
- protocols[pnormal + ((tls_active >= 0)? pcrpted : 0)])
- +
- ((sender_host_address != NULL)? pnlocal : 0);
+static int
+qualify_recipient(uschar ** recipient, uschar * smtp_cmd_data, uschar * tag)
+{
+int rd;
+if (f.allow_unqualified_recipient || strcmpic(*recipient, US"postmaster") == 0)
+ {
+ DEBUG(D_receive) debug_printf("unqualified address %s accepted\n",
+ *recipient);
+ rd = Ustrlen(recipient) + 1;
+ /* deconst ok as *recipient was not const */
+ *recipient = US rewrite_address_qualify(*recipient, TRUE);
+ return rd;
+ }
+smtp_printf("501 %s: recipient address must contain a domain\r\n", FALSE,
+ smtp_cmd_data);
+log_write(L_smtp_syntax_error,
+ LOG_MAIN|LOG_REJECT, "unqualified %s rejected: <%s> %s%s",
+ tag, *recipient, host_and_ident(TRUE), host_lookup_msg);
+return 0;
+}
- smtp_reset(reset_point);
- toomany = FALSE;
- break; /* HELO/EHLO */
- /* The MAIL command requires an address as an operand. All we do
- here is to parse it for syntactic correctness. The form "<>" is
- a special case which converts into an empty string. The start/end
- pointers in the original are not used further for this address, as
- it is the canonical extracted address which is all that is kept. */
- case MAIL_CMD:
- HAD(SCH_MAIL);
- smtp_mailcmd_count++; /* Count for limit and ratelimit */
- was_rej_mail = TRUE; /* Reset if accepted */
+static void
+smtp_quit_handler(uschar ** user_msgp, uschar ** log_msgp)
+{
+HAD(SCH_QUIT);
+f.smtp_in_quit = TRUE;
+incomplete_transaction_log(US"QUIT");
+if ( acl_smtp_quit
+ && acl_check(ACL_WHERE_QUIT, NULL, acl_smtp_quit, user_msgp, log_msgp)
+ == ERROR)
+ log_write(0, LOG_MAIN|LOG_PANIC, "ACL for QUIT returned ERROR: %s",
+ *log_msgp);
+
+#ifdef EXIM_TCP_CORK
+(void) setsockopt(fileno(smtp_out), IPPROTO_TCP, EXIM_TCP_CORK, US &on, sizeof(on));
+#endif
- if (helo_required && !helo_seen)
- {
- smtp_printf("503 HELO or EHLO required\r\n");
- log_write(0, LOG_MAIN|LOG_REJECT, "rejected MAIL from %s: no "
- "HELO/EHLO given", host_and_ident(FALSE));
- break;
- }
+if (*user_msgp)
+ smtp_respond(US"221", 3, TRUE, *user_msgp);
+else
+ smtp_printf("221 %s closing connection\r\n", FALSE, smtp_active_hostname);
- if (sender_address != NULL)
- {
- done = synprot_error(L_smtp_protocol_error, 503, NULL,
- US"sender already given");
- break;
- }
+#ifdef SERVERSIDE_CLOSE_NOWAIT
+# ifndef DISABLE_TLS
+tls_close(NULL, TLS_SHUTDOWN_NOWAIT);
+# endif
- if (smtp_cmd_data[0] == 0)
- {
- done = synprot_error(L_smtp_protocol_error, 501, NULL,
- US"MAIL must have an address operand");
- break;
- }
+log_write(L_smtp_connection, LOG_MAIN, "%s closed by QUIT",
+ smtp_get_connection_info());
+#else
- /* Check to see if the limit for messages per connection would be
- exceeded by accepting further messages. */
+# ifndef DISABLE_TLS
+tls_close(NULL, TLS_SHUTDOWN_WAIT);
+# endif
- if (smtp_accept_max_per_connection > 0 &&
- smtp_mailcmd_count > smtp_accept_max_per_connection)
- {
- smtp_printf("421 too many messages in this connection\r\n");
- log_write(0, LOG_MAIN|LOG_REJECT, "rejected MAIL command %s: too many "
- "messages in one connection", host_and_ident(TRUE));
- break;
- }
+log_write(L_smtp_connection, LOG_MAIN, "%s closed by QUIT",
+ smtp_get_connection_info());
+
+/* Pause, hoping client will FIN first so that they get the TIME_WAIT.
+The socket should become readble (though with no data) */
- /* Reset for start of message - even if this is going to fail, we
- obviously need to throw away any previous data. */
+ {
+ int fd = fileno(smtp_in);
+ fd_set fds;
+ struct timeval t_limit = {.tv_sec = 0, .tv_usec = 200*1000};
- smtp_reset(reset_point);
- toomany = FALSE;
- sender_data = recipient_data = NULL;
+ FD_ZERO(&fds);
+ FD_SET(fd, &fds);
+ (void) select(fd + 1, (SELECT_ARG2_TYPE *)&fds, NULL, NULL, &t_limit);
+ }
+#endif /*!DAEMON_CLOSE_NOWAIT*/
+}
- /* Loop, checking for ESMTP additions to the MAIL FROM command. */
- if (esmtp) for(;;)
- {
- uschar *name, *value, *end;
- unsigned long int size;
+static void
+smtp_rset_handler(void)
+{
+HAD(SCH_RSET);
+incomplete_transaction_log(US"RSET");
+smtp_printf("250 Reset OK\r\n", FALSE);
+cmd_list[CMD_LIST_RSET].is_mail_cmd = FALSE;
+}
- if (!extract_option(&name, &value)) break;
- /* Handle SIZE= by reading the value. We don't do the check till later,
- in order to be able to log the sender address on failure. */
+static int
+expand_mailmax(const uschar * s)
+{
+if (!(s = expand_cstring(s)))
+ log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand smtp_accept_max_per_connection");
+return *s ? Uatoi(s) : 0;
+}
- if (strcmpic(name, US"SIZE") == 0 &&
- ((size = Ustrtoul(value, &end, 10)), *end == 0))
- {
- if ((size == ULONG_MAX && errno == ERANGE) || size > INT_MAX)
- size = INT_MAX;
- message_size = (int)size;
- }
+/*************************************************
+* Initialize for SMTP incoming message *
+*************************************************/
- /* If this session was initiated with EHLO and accept_8bitmime is set,
- Exim will have indicated that it supports the BODY=8BITMIME option. In
- fact, it does not support this according to the RFCs, in that it does not
- take any special action for forwarding messages containing 8-bit
- characters. That is why accept_8bitmime is not the default setting, but
- some sites want the action that is provided. We recognize both "8BITMIME"
- and "7BIT" as body types, but take no action. */
-
- else if (accept_8bitmime && strcmpic(name, US"BODY") == 0 &&
- (strcmpic(value, US"8BITMIME") == 0 ||
- strcmpic(value, US"7BIT") == 0)) {}
-
- /* Handle the AUTH extension. If the value given is not "<>" and either
- the ACL says "yes" or there is no ACL but the sending host is
- authenticated, we set it up as the authenticated sender. However, if the
- authenticator set a condition to be tested, we ignore AUTH on MAIL unless
- the condition is met. The value of AUTH is an xtext, which means that +,
- = and cntrl chars are coded in hex; however "<>" is unaffected by this
- coding. */
-
- else if (strcmpic(name, US"AUTH") == 0)
- {
- if (Ustrcmp(value, "<>") != 0)
- {
- int rc;
- uschar *ignore_msg;
+/* This function conducts the initial dialogue at the start of an incoming SMTP
+message, and builds a list of recipients. However, if the incoming message
+is part of a batch (-bS option) a separate function is called since it would
+be messy having tests splattered about all over this function. This function
+therefore handles the case where interaction is occurring. The input and output
+files are set up in smtp_in and smtp_out.
- if (auth_xtextdecode(value, &authenticated_sender) < 0)
- {
- /* Put back terminator overrides for error message */
- name[-1] = ' ';
- value[-1] = '=';
- done = synprot_error(L_smtp_syntax_error, 501, NULL,
- US"invalid data for AUTH");
- goto COMMAND_LOOP;
- }
+The global recipients_list is set to point to a vector of recipient_item
+blocks, whose number is given by recipients_count. This is extended by the
+receive_add_recipient() function. The global variable sender_address is set to
+the sender's address. The yield is +1 if a message has been successfully
+started, 0 if a QUIT command was encountered or the connection was refused from
+the particular host, or -1 if the connection was lost.
- if (acl_smtp_mailauth == NULL)
- {
- ignore_msg = US"client not authenticated";
- rc = (sender_host_authenticated != NULL)? OK : FAIL;
- }
- else
- {
- ignore_msg = US"rejected by ACL";
- rc = acl_check(ACL_WHERE_MAILAUTH, NULL, acl_smtp_mailauth,
- &user_msg, &log_msg);
- }
+Argument: none
- switch (rc)
- {
- case OK:
- if (authenticated_by == NULL ||
- authenticated_by->mail_auth_condition == NULL ||
- expand_check_condition(authenticated_by->mail_auth_condition,
- authenticated_by->name, US"authenticator"))
- break; /* Accept the AUTH */
-
- ignore_msg = US"server_mail_auth_condition failed";
- if (authenticated_id != NULL)
- ignore_msg = string_sprintf("%s: authenticated ID=\"%s\"",
- ignore_msg, authenticated_id);
-
- /* Fall through */
-
- case FAIL:
- authenticated_sender = NULL;
- log_write(0, LOG_MAIN, "ignoring AUTH=%s from %s (%s)",
- value, host_and_ident(TRUE), ignore_msg);
- break;
+Returns: > 0 message successfully started (reached DATA)
+ = 0 QUIT read or end of file reached or call refused
+ < 0 lost connection
+*/
- /* Should only get DEFER or ERROR here. Put back terminator
- overrides for error message */
+int
+smtp_setup_msg(void)
+{
+int done = 0;
+BOOL toomany = FALSE;
+BOOL discarded = FALSE;
+BOOL last_was_rej_mail = FALSE;
+BOOL last_was_rcpt = FALSE;
+rmark reset_point = store_mark();
- default:
- name[-1] = ' ';
- value[-1] = '=';
- (void)smtp_handle_acl_fail(ACL_WHERE_MAILAUTH, rc, user_msg,
- log_msg);
- goto COMMAND_LOOP;
- }
- }
- }
+DEBUG(D_receive) debug_printf("smtp_setup_msg entered\n");
- /* Unknown option. Stick back the terminator characters and break
- the loop. An error for a malformed address will occur. */
+/* Reset for start of new message. We allow one RSET not to be counted as a
+nonmail command, for those MTAs that insist on sending it between every
+message. Ditto for EHLO/HELO and for STARTTLS, to allow for going in and out of
+TLS between messages (an Exim client may do this if it has messages queued up
+for the host). Note: we do NOT reset AUTH at this point. */
- else
- {
- name[-1] = ' ';
- value[-1] = '=';
- break;
- }
- }
+reset_point = smtp_reset(reset_point);
+message_ended = END_NOTSTARTED;
- /* If we have passed the threshold for rate limiting, apply the current
- delay, and update it for next time, provided this is a limited host. */
+chunking_state = f.chunking_offered ? CHUNKING_OFFERED : CHUNKING_NOT_OFFERED;
- if (smtp_mailcmd_count > smtp_rlm_threshold &&
- verify_check_host(&smtp_ratelimit_hosts) == OK)
- {
- DEBUG(D_receive) debug_printf("rate limit MAIL: delay %.3g sec\n",
- smtp_delay_mail/1000.0);
- millisleep((int)smtp_delay_mail);
- smtp_delay_mail *= smtp_rlm_factor;
- if (smtp_delay_mail > (double)smtp_rlm_limit)
- smtp_delay_mail = (double)smtp_rlm_limit;
- }
+cmd_list[CMD_LIST_RSET].is_mail_cmd = TRUE;
+cmd_list[CMD_LIST_HELO].is_mail_cmd = TRUE;
+cmd_list[CMD_LIST_EHLO].is_mail_cmd = TRUE;
+#ifndef DISABLE_TLS
+cmd_list[CMD_LIST_STARTTLS].is_mail_cmd = TRUE;
+#endif
- /* Now extract the address, first applying any SMTP-time rewriting. The
- TRUE flag allows "<>" as a sender address. */
+if (lwr_receive_getc != NULL)
+ {
+ /* This should have already happened, but if we've gotten confused,
+ force a reset here. */
+ DEBUG(D_receive) debug_printf("WARNING: smtp_setup_msg had to restore receive functions to lowers\n");
+ bdat_pop_receive_functions();
+ }
- raw_sender = ((rewrite_existflags & rewrite_smtp) != 0)?
- rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"",
- global_rewrite_rules) : smtp_cmd_data;
+/* Set the local signal handler for SIGTERM - it tries to end off tidily */
- /* rfc821_domains = TRUE; << no longer needed */
- raw_sender =
- parse_extract_address(raw_sender, &errmess, &start, &end, &sender_domain,
- TRUE);
- /* rfc821_domains = FALSE; << no longer needed */
+had_command_sigterm = 0;
+os_non_restarting_signal(SIGTERM, command_sigterm_handler);
- if (raw_sender == NULL)
- {
- done = synprot_error(L_smtp_syntax_error, 501, smtp_cmd_data, errmess);
- break;
- }
+/* Batched SMTP is handled in a different function. */
- sender_address = raw_sender;
+if (smtp_batched_input) return smtp_setup_batch_msg();
- /* If there is a configured size limit for mail, check that this message
- doesn't exceed it. The check is postponed to this point so that the sender
- can be logged. */
+#ifdef TCP_QUICKACK
+if (smtp_in) /* Avoid pure-ACKs while in cmd pingpong phase */
+ (void) setsockopt(fileno(smtp_in), IPPROTO_TCP, TCP_QUICKACK,
+ US &off, sizeof(off));
+#endif
- if (thismessage_size_limit > 0 && message_size > thismessage_size_limit)
- {
- smtp_printf("552 Message size exceeds maximum permitted\r\n");
- log_write(L_size_reject,
- LOG_MAIN|LOG_REJECT, "rejected MAIL FROM:<%s> %s: "
- "message too big: size%s=%d max=%d",
- sender_address,
- host_and_ident(TRUE),
- (message_size == INT_MAX)? ">" : "",
- message_size,
- thismessage_size_limit);
- sender_address = NULL;
- break;
- }
+/* Deal with SMTP commands. This loop is exited by setting done to a POSITIVE
+value. The values are 2 larger than the required yield of the function. */
- /* Check there is enough space on the disk unless configured not to.
- When smtp_check_spool_space is set, the check is for thismessage_size_limit
- plus the current message - i.e. we accept the message only if it won't
- reduce the space below the threshold. Add 5000 to the size to allow for
- overheads such as the Received: line and storing of recipients, etc.
- By putting the check here, even when SIZE is not given, it allow VRFY
- and EXPN etc. to be used when space is short. */
-
- if (!receive_check_fs(
- (smtp_check_spool_space && message_size >= 0)?
- message_size + 5000 : 0))
- {
- smtp_printf("452 Space shortage, please try later\r\n");
- sender_address = NULL;
- break;
- }
+while (done <= 0)
+ {
+ const uschar **argv;
+ uschar *etrn_command;
+ uschar *etrn_serialize_key;
+ uschar *errmess;
+ uschar *log_msg, *smtp_code;
+ uschar *user_msg = NULL;
+ uschar *recipient = NULL;
+ uschar *hello = NULL;
+ uschar *s, *ss;
+ BOOL was_rej_mail = FALSE;
+ BOOL was_rcpt = FALSE;
+ void (*oldsignal)(int);
+ pid_t pid;
+ int start, end, sender_domain, recipient_domain;
+ int rc;
+ int c;
+ uschar *orcpt = NULL;
+ int dsn_flags;
+ gstring * g;
+
+#ifdef AUTH_TLS
+ /* Check once per STARTTLS or SSL-on-connect for a TLS AUTH */
+ if ( tls_in.active.sock >= 0
+ && tls_in.peercert
+ && tls_in.certificate_verified
+ && cmd_list[CMD_LIST_TLS_AUTH].is_mail_cmd
+ )
+ {
+ cmd_list[CMD_LIST_TLS_AUTH].is_mail_cmd = FALSE;
+
+ for (auth_instance * au = auths; au; au = au->next)
+ if (strcmpic(US"tls", au->driver_name) == 0)
+ {
+ if ( acl_smtp_auth
+ && (rc = acl_check(ACL_WHERE_AUTH, NULL, acl_smtp_auth,
+ &user_msg, &log_msg)) != OK
+ )
+ done = smtp_handle_acl_fail(ACL_WHERE_AUTH, rc, user_msg, log_msg);
+ else
+ {
+ smtp_cmd_data = NULL;
+
+ if (smtp_in_auth(au, &s, &ss) == OK)
+ { DEBUG(D_auth) debug_printf("tls auth succeeded\n"); }
+ else
+ { DEBUG(D_auth) debug_printf("tls auth not succeeded\n"); }
+ }
+ break;
+ }
+ }
+#endif
- /* If sender_address is unqualified, reject it, unless this is a locally
- generated message, or the sending host or net is permitted to send
- unqualified addresses - typically local machines behaving as MUAs -
- in which case just qualify the address. The flag is set above at the start
- of the SMTP connection. */
+ switch(smtp_read_command(
+#ifndef DISABLE_PIPE_CONNECT
+ !fl.pipe_connect_acceptable,
+#else
+ TRUE,
+#endif
+ GETC_BUFFER_UNLIMITED))
+ {
+ /* The AUTH command is not permitted to occur inside a transaction, and may
+ occur successfully only once per connection. Actually, that isn't quite
+ true. When TLS is started, all previous information about a connection must
+ be discarded, so a new AUTH is permitted at that time.
- if (sender_domain == 0 && sender_address[0] != 0)
- {
- if (allow_unqualified_sender)
- {
- sender_domain = Ustrlen(sender_address) + 1;
- sender_address = rewrite_address_qualify(sender_address, FALSE);
- DEBUG(D_receive) debug_printf("unqualified address %s accepted\n",
- raw_sender);
- }
- else
- {
- smtp_printf("501 %s: sender address must contain a domain\r\n",
- smtp_cmd_data);
- log_write(L_smtp_syntax_error,
- LOG_MAIN|LOG_REJECT,
- "unqualified sender rejected: <%s> %s%s",
- raw_sender,
- host_and_ident(TRUE),
- host_lookup_msg);
- sender_address = NULL;
- break;
- }
- }
+ AUTH may only be used when it has been advertised. However, it seems that
+ there are clients that send AUTH when it hasn't been advertised, some of
+ them even doing this after HELO. And there are MTAs that accept this. Sigh.
+ So there's a get-out that allows this to happen.
- /* Apply an ACL check if one is defined, before responding. Afterwards,
- when pipelining is not advertised, do another sync check in case the ACL
- delayed and the client started sending in the meantime. */
+ AUTH is initially labelled as a "nonmail command" so that one occurrence
+ doesn't get counted. We change the label here so that multiple failing
+ AUTHS will eventually hit the nonmail threshold. */
- if (acl_smtp_mail == NULL) rc = OK; else
- {
- rc = acl_check(ACL_WHERE_MAIL, NULL, acl_smtp_mail, &user_msg, &log_msg);
- if (rc == OK && !pipelining_advertised && !check_sync())
- goto SYNC_FAILURE;
- }
+ case AUTH_CMD:
+ HAD(SCH_AUTH);
+ authentication_failed = TRUE;
+ cmd_list[CMD_LIST_AUTH].is_mail_cmd = FALSE;
+
+ if (!fl.auth_advertised && !f.allow_auth_unadvertised)
+ {
+ done = synprot_error(L_smtp_protocol_error, 503, NULL,
+ US"AUTH command used when not advertised");
+ break;
+ }
+ if (sender_host_authenticated)
+ {
+ done = synprot_error(L_smtp_protocol_error, 503, NULL,
+ US"already authenticated");
+ break;
+ }
+ if (sender_address)
+ {
+ done = synprot_error(L_smtp_protocol_error, 503, NULL,
+ US"not permitted in mail transaction");
+ break;
+ }
+
+ /* Check the ACL */
+
+ if ( acl_smtp_auth
+ && (rc = acl_check(ACL_WHERE_AUTH, NULL, acl_smtp_auth,
+ &user_msg, &log_msg)) != OK
+ )
+ {
+ done = smtp_handle_acl_fail(ACL_WHERE_AUTH, rc, user_msg, log_msg);
+ break;
+ }
+
+ /* Find the name of the requested authentication mechanism. */
+
+ s = smtp_cmd_data;
+ for (; (c = *smtp_cmd_data) && !isspace(c); smtp_cmd_data++)
+ if (!isalnum(c) && c != '-' && c != '_')
+ {
+ done = synprot_error(L_smtp_syntax_error, 501, NULL,
+ US"invalid character in authentication mechanism name");
+ goto COMMAND_LOOP;
+ }
+
+ /* If not at the end of the line, we must be at white space. Terminate the
+ name and move the pointer on to any data that may be present. */
+
+ if (*smtp_cmd_data)
+ {
+ *smtp_cmd_data++ = 0;
+ while (isspace(*smtp_cmd_data)) smtp_cmd_data++;
+ }
+
+ /* Search for an authentication mechanism which is configured for use
+ as a server and which has been advertised (unless, sigh, allow_auth_
+ unadvertised is set). */
+
+ {
+ auth_instance * au;
+ for (au = auths; au; au = au->next)
+ if (strcmpic(s, au->public_name) == 0 && au->server &&
+ (au->advertised || f.allow_auth_unadvertised))
+ break;
+
+ if (au)
+ {
+ c = smtp_in_auth(au, &s, &ss);
+
+ smtp_printf("%s\r\n", FALSE, s);
+ if (c != OK)
+ log_write(0, LOG_MAIN|LOG_REJECT, "%s authenticator failed for %s: %s",
+ au->name, host_and_ident(FALSE), ss);
+ }
+ else
+ done = synprot_error(L_smtp_protocol_error, 504, NULL,
+ string_sprintf("%s authentication mechanism not supported", s));
+ }
+
+ break; /* AUTH_CMD */
- if (rc == OK || rc == DISCARD)
- {
- if (user_msg == NULL) smtp_printf("250 OK\r\n");
- else smtp_user_msg(US"250", user_msg);
- smtp_delay_rcpt = smtp_rlr_base;
- recipients_discarded = (rc == DISCARD);
- was_rej_mail = FALSE;
- }
- else
- {
- done = smtp_handle_acl_fail(ACL_WHERE_MAIL, rc, user_msg, log_msg);
- sender_address = NULL;
- }
- break;
+ /* The HELO/EHLO commands are permitted to appear in the middle of a
+ session as well as at the beginning. They have the effect of a reset in
+ addition to their other functions. Their absence at the start cannot be
+ taken to be an error.
+ RFC 2821 says:
- /* The RCPT command requires an address as an operand. There may be any
- number of RCPT commands, specifying multiple recipients. We build them all
- into a data structure. The start/end values given by parse_extract_address
- are not used, as we keep only the extracted address. */
+ If the EHLO command is not acceptable to the SMTP server, 501, 500,
+ or 502 failure replies MUST be returned as appropriate. The SMTP
+ server MUST stay in the same state after transmitting these replies
+ that it was in before the EHLO was received.
- case RCPT_CMD:
- HAD(SCH_RCPT);
- rcpt_count++;
- was_rcpt = rcpt_in_progress = TRUE;
+ Therefore, we do not do the reset until after checking the command for
+ acceptability. This change was made for Exim release 4.11. Previously
+ it did the reset first. */
- /* There must be a sender address; if the sender was rejected and
- pipelining was advertised, we assume the client was pipelining, and do not
- count this as a protocol error. Reset was_rej_mail so that further RCPTs
- get the same treatment. */
+ case HELO_CMD:
+ HAD(SCH_HELO);
+ hello = US"HELO";
+ fl.esmtp = FALSE;
+ goto HELO_EHLO;
- if (sender_address == NULL)
- {
- if (pipelining_advertised && last_was_rej_mail)
- {
- smtp_printf("503 sender not yet given\r\n");
- was_rej_mail = TRUE;
- }
- else
- {
- done = synprot_error(L_smtp_protocol_error, 503, NULL,
- US"sender not yet given");
- was_rcpt = FALSE; /* Not a valid RCPT */
- }
- rcpt_fail_count++;
- break;
- }
+ case EHLO_CMD:
+ HAD(SCH_EHLO);
+ hello = US"EHLO";
+ fl.esmtp = TRUE;
- /* Check for an operand */
+ HELO_EHLO: /* Common code for HELO and EHLO */
+ cmd_list[CMD_LIST_HELO].is_mail_cmd = FALSE;
+ cmd_list[CMD_LIST_EHLO].is_mail_cmd = FALSE;
+
+ /* Reject the HELO if its argument was invalid or non-existent. A
+ successful check causes the argument to be saved in malloc store. */
+
+ if (!check_helo(smtp_cmd_data))
+ {
+ smtp_printf("501 Syntactically invalid %s argument(s)\r\n", FALSE, hello);
+
+ log_write(0, LOG_MAIN|LOG_REJECT, "rejected %s from %s: syntactically "
+ "invalid argument(s): %s", hello, host_and_ident(FALSE),
+ *smtp_cmd_argument == 0 ? US"(no argument given)" :
+ string_printing(smtp_cmd_argument));
+
+ if (++synprot_error_count > smtp_max_synprot_errors)
+ {
+ log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
+ "syntax or protocol errors (last command was \"%s\", %s)",
+ host_and_ident(FALSE), string_printing(smtp_cmd_buffer),
+ string_from_gstring(s_connhad_log(NULL))
+ );
+ done = 1;
+ }
+
+ break;
+ }
+
+ /* If sender_host_unknown is true, we have got here via the -bs interface,
+ not called from inetd. Otherwise, we are running an IP connection and the
+ host address will be set. If the helo name is the primary name of this
+ host and we haven't done a reverse lookup, force one now. If helo_verify_required
+ is set, ensure that the HELO name matches the actual host. If helo_verify
+ is set, do the same check, but softly. */
+
+ if (!f.sender_host_unknown)
+ {
+ BOOL old_helo_verified = f.helo_verified;
+ uschar *p = smtp_cmd_data;
+
+ while (*p != 0 && !isspace(*p)) { *p = tolower(*p); p++; }
+ *p = 0;
+
+ /* Force a reverse lookup if HELO quoted something in helo_lookup_domains
+ because otherwise the log can be confusing. */
+
+ if ( !sender_host_name
+ && match_isinlist(sender_helo_name, CUSS &helo_lookup_domains, 0,
+ &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL) == OK)
+ (void)host_name_lookup();
+
+ /* Rebuild the fullhost info to include the HELO name (and the real name
+ if it was looked up.) */
+
+ host_build_sender_fullhost(); /* Rebuild */
+ set_process_info("handling%s incoming connection from %s",
+ tls_in.active.sock >= 0 ? " TLS" : "", host_and_ident(FALSE));
+
+ /* Verify if configured. This doesn't give much security, but it does
+ make some people happy to be able to do it. If helo_verify_required is set,
+ (host matches helo_verify_hosts) failure forces rejection. If helo_verify
+ is set (host matches helo_try_verify_hosts), it does not. This is perhaps
+ now obsolescent, since the verification can now be requested selectively
+ at ACL time. */
+
+ f.helo_verified = f.helo_verify_failed = sender_helo_dnssec = FALSE;
+ if (fl.helo_verify_required || fl.helo_verify)
+ {
+ BOOL tempfail = !smtp_verify_helo();
+ if (!f.helo_verified)
+ {
+ if (fl.helo_verify_required)
+ {
+ smtp_printf("%d %s argument does not match calling host\r\n", FALSE,
+ tempfail? 451 : 550, hello);
+ log_write(0, LOG_MAIN|LOG_REJECT, "%srejected \"%s %s\" from %s",
+ tempfail? "temporarily " : "",
+ hello, sender_helo_name, host_and_ident(FALSE));
+ f.helo_verified = old_helo_verified;
+ break; /* End of HELO/EHLO processing */
+ }
+ HDEBUG(D_all) debug_printf("%s verification failed but host is in "
+ "helo_try_verify_hosts\n", hello);
+ }
+ }
+ }
+
+#ifdef SUPPORT_SPF
+ /* set up SPF context */
+ spf_conn_init(sender_helo_name, sender_host_address);
+#endif
- if (smtp_cmd_data[0] == 0)
- {
- done = synprot_error(L_smtp_syntax_error, 501, NULL,
- US"RCPT must have an address operand");
- rcpt_fail_count++;
- break;
- }
+ /* Apply an ACL check if one is defined; afterwards, recheck
+ synchronization in case the client started sending in a delay. */
+
+ if (acl_smtp_helo)
+ if ((rc = acl_check(ACL_WHERE_HELO, NULL, acl_smtp_helo,
+ &user_msg, &log_msg)) != OK)
+ {
+ done = smtp_handle_acl_fail(ACL_WHERE_HELO, rc, user_msg, log_msg);
+ sender_helo_name = NULL;
+ host_build_sender_fullhost(); /* Rebuild */
+ break;
+ }
+#ifndef DISABLE_PIPE_CONNECT
+ else if (!fl.pipe_connect_acceptable && !check_sync())
+#else
+ else if (!check_sync())
+#endif
+ goto SYNC_FAILURE;
+
+ /* Generate an OK reply. The default string includes the ident if present,
+ and also the IP address if present. Reflecting back the ident is intended
+ as a deterrent to mail forgers. For maximum efficiency, and also because
+ some broken systems expect each response to be in a single packet, arrange
+ that the entire reply is sent in one write(). */
+
+ fl.auth_advertised = FALSE;
+ f.smtp_in_pipelining_advertised = FALSE;
+#ifndef DISABLE_TLS
+ fl.tls_advertised = FALSE;
+#endif
+ fl.dsn_advertised = FALSE;
+#ifdef SUPPORT_I18N
+ fl.smtputf8_advertised = FALSE;
+#endif
- /* Apply SMTP rewriting then extract the working address. Don't allow "<>"
- as a recipient address */
+ /* Expand the per-connection message count limit option */
+ smtp_mailcmd_max = expand_mailmax(smtp_accept_max_per_connection);
+
+ smtp_code = US"250 "; /* Default response code plus space*/
+ if (!user_msg)
+ {
+ /* sender_host_name below will be tainted, so save on copy when we hit it */
+ g = string_get_tainted(24, TRUE);
+ g = string_fmt_append(g, "%.3s %s Hello %s%s%s",
+ smtp_code,
+ smtp_active_hostname,
+ sender_ident ? sender_ident : US"",
+ sender_ident ? US" at " : US"",
+ sender_host_name ? sender_host_name : sender_helo_name);
+
+ if (sender_host_address)
+ g = string_fmt_append(g, " [%s]", sender_host_address);
+ }
+
+ /* A user-supplied EHLO greeting may not contain more than one line. Note
+ that the code returned by smtp_message_code() includes the terminating
+ whitespace character. */
- recipient = ((rewrite_existflags & rewrite_smtp) != 0)?
- rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"",
- global_rewrite_rules) : smtp_cmd_data;
+ else
+ {
+ char *ss;
+ int codelen = 4;
+ smtp_message_code(&smtp_code, &codelen, &user_msg, NULL, TRUE);
+ s = string_sprintf("%.*s%s", codelen, smtp_code, user_msg);
+ if ((ss = strpbrk(CS s, "\r\n")) != NULL)
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC, "EHLO/HELO response must not contain "
+ "newlines: message truncated: %s", string_printing(s));
+ *ss = 0;
+ }
+ g = string_cat(NULL, s);
+ }
+
+ g = string_catn(g, US"\r\n", 2);
+
+ /* If we received EHLO, we must create a multiline response which includes
+ the functions supported. */
+
+ if (fl.esmtp)
+ {
+ g->s[3] = '-';
+
+ /* I'm not entirely happy with this, as an MTA is supposed to check
+ that it has enough room to accept a message of maximum size before
+ it sends this. However, there seems little point in not sending it.
+ The actual size check happens later at MAIL FROM time. By postponing it
+ till then, VRFY and EXPN can be used after EHLO when space is short. */
+
+ if (thismessage_size_limit > 0)
+ g = string_fmt_append(g, "%.3s-SIZE %d\r\n", smtp_code,
+ thismessage_size_limit);
+ else
+ {
+ g = string_catn(g, smtp_code, 3);
+ g = string_catn(g, US"-SIZE\r\n", 7);
+ }
+
+#ifdef EXPERIMENTAL_ESMTP_LIMITS
+ if ( (smtp_mailcmd_max > 0 || recipients_max)
+ && verify_check_host(&limits_advertise_hosts) == OK)
+ {
+ g = string_fmt_append(g, "%.3s-LIMITS", smtp_code);
+ if (smtp_mailcmd_max > 0)
+ g = string_fmt_append(g, " MAILMAX=%d", smtp_mailcmd_max);
+ if (recipients_max)
+ g = string_fmt_append(g, " RCPTMAX=%d", recipients_max);
+ g = string_catn(g, US"\r\n", 2);
+ }
+#endif
- /* rfc821_domains = TRUE; << no longer needed */
- recipient = parse_extract_address(recipient, &errmess, &start, &end,
- &recipient_domain, FALSE);
- /* rfc821_domains = FALSE; << no longer needed */
+ /* Exim does not do protocol conversion or data conversion. It is 8-bit
+ clean; if it has an 8-bit character in its hand, it just sends it. It
+ cannot therefore specify 8BITMIME and remain consistent with the RFCs.
+ However, some users want this option simply in order to stop MUAs
+ mangling messages that contain top-bit-set characters. It is therefore
+ provided as an option. */
+
+ if (accept_8bitmime)
+ {
+ g = string_catn(g, smtp_code, 3);
+ g = string_catn(g, US"-8BITMIME\r\n", 11);
+ }
+
+ /* Advertise DSN support if configured to do so. */
+ if (verify_check_host(&dsn_advertise_hosts) != FAIL)
+ {
+ g = string_catn(g, smtp_code, 3);
+ g = string_catn(g, US"-DSN\r\n", 6);
+ fl.dsn_advertised = TRUE;
+ }
+
+ /* Advertise ETRN/VRFY/EXPN if there's are ACL checking whether a host is
+ permitted to issue them; a check is made when any host actually tries. */
+
+ if (acl_smtp_etrn)
+ {
+ g = string_catn(g, smtp_code, 3);
+ g = string_catn(g, US"-ETRN\r\n", 7);
+ }
+ if (acl_smtp_vrfy)
+ {
+ g = string_catn(g, smtp_code, 3);
+ g = string_catn(g, US"-VRFY\r\n", 7);
+ }
+ if (acl_smtp_expn)
+ {
+ g = string_catn(g, smtp_code, 3);
+ g = string_catn(g, US"-EXPN\r\n", 7);
+ }
+
+ /* Exim is quite happy with pipelining, so let the other end know that
+ it is safe to use it, unless advertising is disabled. */
+
+ if ( f.pipelining_enable
+ && verify_check_host(&pipelining_advertise_hosts) == OK)
+ {
+ g = string_catn(g, smtp_code, 3);
+ g = string_catn(g, US"-PIPELINING\r\n", 13);
+ sync_cmd_limit = NON_SYNC_CMD_PIPELINING;
+ f.smtp_in_pipelining_advertised = TRUE;
+
+#ifndef DISABLE_PIPE_CONNECT
+ if (fl.pipe_connect_acceptable)
+ {
+ f.smtp_in_early_pipe_advertised = TRUE;
+ g = string_catn(g, smtp_code, 3);
+ g = string_catn(g, US"-" EARLY_PIPE_FEATURE_NAME "\r\n", EARLY_PIPE_FEATURE_LEN+3);
+ }
+#endif
+ }
- if (recipient == NULL)
- {
- done = synprot_error(L_smtp_syntax_error, 501, smtp_cmd_data, errmess);
- rcpt_fail_count++;
- break;
- }
- /* If the recipient address is unqualified, reject it, unless this is a
- locally generated message. However, unqualified addresses are permitted
- from a configured list of hosts and nets - typically when behaving as
- MUAs rather than MTAs. Sad that SMTP is used for both types of traffic,
- really. The flag is set at the start of the SMTP connection.
+ /* If any server authentication mechanisms are configured, advertise
+ them if the current host is in auth_advertise_hosts. The problem with
+ advertising always is that some clients then require users to
+ authenticate (and aren't configurable otherwise) even though it may not
+ be necessary (e.g. if the host is in host_accept_relay).
- RFC 1123 talks about supporting "the reserved mailbox postmaster"; I always
- assumed this meant "reserved local part", but the revision of RFC 821 and
- friends now makes it absolutely clear that it means *mailbox*. Consequently
- we must always qualify this address, regardless. */
+ RFC 2222 states that SASL mechanism names contain only upper case
+ letters, so output the names in upper case, though we actually recognize
+ them in either case in the AUTH command. */
- if (recipient_domain == 0)
- {
- if (allow_unqualified_recipient ||
- strcmpic(recipient, US"postmaster") == 0)
- {
- DEBUG(D_receive) debug_printf("unqualified address %s accepted\n",
- recipient);
- recipient_domain = Ustrlen(recipient) + 1;
- recipient = rewrite_address_qualify(recipient, TRUE);
- }
- else
- {
- rcpt_fail_count++;
- smtp_printf("501 %s: recipient address must contain a domain\r\n",
- smtp_cmd_data);
- log_write(L_smtp_syntax_error,
- LOG_MAIN|LOG_REJECT, "unqualified recipient rejected: "
- "<%s> %s%s", recipient, host_and_ident(TRUE),
- host_lookup_msg);
- break;
- }
- }
+ if ( auths
+#ifdef AUTH_TLS
+ && !sender_host_authenticated
+#endif
+ && verify_check_host(&auth_advertise_hosts) == OK
+ )
+ {
+ BOOL first = TRUE;
+ for (auth_instance * au = auths; au; au = au->next)
+ {
+ au->advertised = FALSE;
+ if (au->server)
+ {
+ DEBUG(D_auth+D_expand) debug_printf_indent(
+ "Evaluating advertise_condition for %s %s athenticator\n",
+ au->name, au->public_name);
+ if ( !au->advertise_condition
+ || expand_check_condition(au->advertise_condition, au->name,
+ US"authenticator")
+ )
+ {
+ int saveptr;
+ if (first)
+ {
+ g = string_catn(g, smtp_code, 3);
+ g = string_catn(g, US"-AUTH", 5);
+ first = FALSE;
+ fl.auth_advertised = TRUE;
+ }
+ saveptr = g->ptr;
+ g = string_catn(g, US" ", 1);
+ g = string_cat (g, au->public_name);
+ while (++saveptr < g->ptr) g->s[saveptr] = toupper(g->s[saveptr]);
+ au->advertised = TRUE;
+ }
+ }
+ }
+
+ if (!first) g = string_catn(g, US"\r\n", 2);
+ }
+
+ /* RFC 3030 CHUNKING */
+
+ if (verify_check_host(&chunking_advertise_hosts) != FAIL)
+ {
+ g = string_catn(g, smtp_code, 3);
+ g = string_catn(g, US"-CHUNKING\r\n", 11);
+ f.chunking_offered = TRUE;
+ chunking_state = CHUNKING_OFFERED;
+ }
+
+ /* Advertise TLS (Transport Level Security) aka SSL (Secure Socket Layer)
+ if it has been included in the binary, and the host matches
+ tls_advertise_hosts. We must *not* advertise if we are already in a
+ secure connection. */
+
+#ifndef DISABLE_TLS
+ if (tls_in.active.sock < 0 &&
+ verify_check_host(&tls_advertise_hosts) != FAIL)
+ {
+ g = string_catn(g, smtp_code, 3);
+ g = string_catn(g, US"-STARTTLS\r\n", 11);
+ fl.tls_advertised = TRUE;
+ }
+#endif
- /* Check maximum allowed */
+#ifndef DISABLE_PRDR
+ /* Per Recipient Data Response, draft by Eric A. Hall extending RFC */
+ if (prdr_enable)
+ {
+ g = string_catn(g, smtp_code, 3);
+ g = string_catn(g, US"-PRDR\r\n", 7);
+ }
+#endif
- if (rcpt_count > recipients_max && recipients_max > 0)
- {
- if (recipients_max_reject)
- {
- rcpt_fail_count++;
- smtp_printf("552 too many recipients\r\n");
- if (!toomany)
- log_write(0, LOG_MAIN|LOG_REJECT, "too many recipients: message "
- "rejected: sender=<%s> %s", sender_address, host_and_ident(TRUE));
- }
- else
- {
- rcpt_defer_count++;
- smtp_printf("452 too many recipients\r\n");
- if (!toomany)
- log_write(0, LOG_MAIN|LOG_REJECT, "too many recipients: excess "
- "temporarily rejected: sender=<%s> %s", sender_address,
- host_and_ident(TRUE));
- }
+#ifdef SUPPORT_I18N
+ if ( accept_8bitmime
+ && verify_check_host(&smtputf8_advertise_hosts) != FAIL)
+ {
+ g = string_catn(g, smtp_code, 3);
+ g = string_catn(g, US"-SMTPUTF8\r\n", 11);
+ fl.smtputf8_advertised = TRUE;
+ }
+#endif
- toomany = TRUE;
- break;
- }
+ /* Finish off the multiline reply with one that is always available. */
- /* If we have passed the threshold for rate limiting, apply the current
- delay, and update it for next time, provided this is a limited host. */
+ g = string_catn(g, smtp_code, 3);
+ g = string_catn(g, US" HELP\r\n", 7);
+ }
- if (rcpt_count > smtp_rlr_threshold &&
- verify_check_host(&smtp_ratelimit_hosts) == OK)
- {
- DEBUG(D_receive) debug_printf("rate limit RCPT: delay %.3g sec\n",
- smtp_delay_rcpt/1000.0);
- millisleep((int)smtp_delay_rcpt);
- smtp_delay_rcpt *= smtp_rlr_factor;
- if (smtp_delay_rcpt > (double)smtp_rlr_limit)
- smtp_delay_rcpt = (double)smtp_rlr_limit;
- }
+ /* Terminate the string (for debug), write it, and note that HELO/EHLO
+ has been seen. */
- /* If the MAIL ACL discarded all the recipients, we bypass ACL checking
- for them. Otherwise, check the access control list for this recipient. As
- there may be a delay in this, re-check for a synchronization error
- afterwards, unless pipelining was advertised. */
+#ifndef DISABLE_TLS
+ if (tls_in.active.sock >= 0)
+ (void)tls_write(NULL, g->s, g->ptr,
+# ifndef DISABLE_PIPE_CONNECT
+ fl.pipe_connect_acceptable && pipeline_connect_sends());
+# else
+ FALSE);
+# endif
+ else
+#endif
+ (void) fwrite(g->s, 1, g->ptr, smtp_out);
+
+ DEBUG(D_receive)
+ {
+ uschar *cr;
+
+ (void) string_from_gstring(g);
+ while ((cr = Ustrchr(g->s, '\r')) != NULL) /* lose CRs */
+ memmove(cr, cr + 1, (g->ptr--) - (cr - g->s));
+ debug_printf("SMTP>> %s", g->s);
+ }
+ fl.helo_seen = TRUE;
+
+ /* Reset the protocol and the state, abandoning any previous message. */
+ received_protocol =
+ (sender_host_address ? protocols : protocols_local)
+ [ (fl.esmtp
+ ? pextend + (sender_host_authenticated ? pauthed : 0)
+ : pnormal)
+ + (tls_in.active.sock >= 0 ? pcrpted : 0)
+ ];
+ cancel_cutthrough_connection(TRUE, US"sent EHLO response");
+ reset_point = smtp_reset(reset_point);
+ toomany = FALSE;
+ break; /* HELO/EHLO */
- if (recipients_discarded) rc = DISCARD; else
- {
- rc = acl_check(ACL_WHERE_RCPT, recipient, acl_smtp_rcpt, &user_msg,
- &log_msg);
- if (rc == OK && !pipelining_advertised && !check_sync())
- goto SYNC_FAILURE;
- }
- /* The ACL was happy */
+ /* The MAIL command requires an address as an operand. All we do
+ here is to parse it for syntactic correctness. The form "<>" is
+ a special case which converts into an empty string. The start/end
+ pointers in the original are not used further for this address, as
+ it is the canonical extracted address which is all that is kept. */
- if (rc == OK)
- {
- if (user_msg == NULL) smtp_printf("250 Accepted\r\n");
- else smtp_user_msg(US"250", user_msg);
- receive_add_recipient(recipient, -1);
- }
+ case MAIL_CMD:
+ HAD(SCH_MAIL);
+ smtp_mailcmd_count++; /* Count for limit and ratelimit */
+ message_start();
+ was_rej_mail = TRUE; /* Reset if accepted */
+ env_mail_type_t * mail_args; /* Sanity check & validate args */
+
+ if (!fl.helo_seen)
+ if ( fl.helo_verify_required
+ || verify_check_host(&hosts_require_helo) == OK)
+ {
+ smtp_printf("503 HELO or EHLO required\r\n", FALSE);
+ log_write(0, LOG_MAIN|LOG_REJECT, "rejected MAIL from %s: no "
+ "HELO/EHLO given", host_and_ident(FALSE));
+ break;
+ }
+ else if (smtp_mailcmd_max < 0)
+ smtp_mailcmd_max = expand_mailmax(smtp_accept_max_per_connection);
+
+ if (sender_address)
+ {
+ done = synprot_error(L_smtp_protocol_error, 503, NULL,
+ US"sender already given");
+ break;
+ }
+
+ if (!*smtp_cmd_data)
+ {
+ done = synprot_error(L_smtp_protocol_error, 501, NULL,
+ US"MAIL must have an address operand");
+ break;
+ }
+
+ /* Check to see if the limit for messages per connection would be
+ exceeded by accepting further messages. */
+
+ if (smtp_mailcmd_max > 0 && smtp_mailcmd_count > smtp_mailcmd_max)
+ {
+ smtp_printf("421 too many messages in this connection\r\n", FALSE);
+ log_write(0, LOG_MAIN|LOG_REJECT, "rejected MAIL command %s: too many "
+ "messages in one connection", host_and_ident(TRUE));
+ break;
+ }
+
+ /* Reset for start of message - even if this is going to fail, we
+ obviously need to throw away any previous data. */
+
+ cancel_cutthrough_connection(TRUE, US"MAIL received");
+ reset_point = smtp_reset(reset_point);
+ toomany = FALSE;
+ sender_data = recipient_data = NULL;
+
+ /* Loop, checking for ESMTP additions to the MAIL FROM command. */
+
+ if (fl.esmtp) for(;;)
+ {
+ uschar *name, *value, *end;
+ unsigned long int size;
+ BOOL arg_error = FALSE;
+
+ if (!extract_option(&name, &value)) break;
+
+ for (mail_args = env_mail_type_list;
+ mail_args->value != ENV_MAIL_OPT_NULL;
+ mail_args++
+ )
+ if (strcmpic(name, mail_args->name) == 0)
+ break;
+ if (mail_args->need_value && strcmpic(value, US"") == 0)
+ break;
+
+ switch(mail_args->value)
+ {
+ /* Handle SIZE= by reading the value. We don't do the check till later,
+ in order to be able to log the sender address on failure. */
+ case ENV_MAIL_OPT_SIZE:
+ if (((size = Ustrtoul(value, &end, 10)), *end == 0))
+ {
+ if ((size == ULONG_MAX && errno == ERANGE) || size > INT_MAX)
+ size = INT_MAX;
+ message_size = (int)size;
+ }
+ else
+ arg_error = TRUE;
+ break;
+
+ /* If this session was initiated with EHLO and accept_8bitmime is set,
+ Exim will have indicated that it supports the BODY=8BITMIME option. In
+ fact, it does not support this according to the RFCs, in that it does not
+ take any special action for forwarding messages containing 8-bit
+ characters. That is why accept_8bitmime is not the default setting, but
+ some sites want the action that is provided. We recognize both "8BITMIME"
+ and "7BIT" as body types, but take no action. */
+ case ENV_MAIL_OPT_BODY:
+ if (accept_8bitmime) {
+ if (strcmpic(value, US"8BITMIME") == 0)
+ body_8bitmime = 8;
+ else if (strcmpic(value, US"7BIT") == 0)
+ body_8bitmime = 7;
+ else
+ {
+ body_8bitmime = 0;
+ done = synprot_error(L_smtp_syntax_error, 501, NULL,
+ US"invalid data for BODY");
+ goto COMMAND_LOOP;
+ }
+ DEBUG(D_receive) debug_printf("8BITMIME: %d\n", body_8bitmime);
+ break;
+ }
+ arg_error = TRUE;
+ break;
+
+ /* Handle the two DSN options, but only if configured to do so (which
+ will have caused "DSN" to be given in the EHLO response). The code itself
+ is included only if configured in at build time. */
+
+ case ENV_MAIL_OPT_RET:
+ if (fl.dsn_advertised)
+ {
+ /* Check if RET has already been set */
+ if (dsn_ret > 0)
+ {
+ done = synprot_error(L_smtp_syntax_error, 501, NULL,
+ US"RET can be specified once only");
+ goto COMMAND_LOOP;
+ }
+ dsn_ret = strcmpic(value, US"HDRS") == 0
+ ? dsn_ret_hdrs
+ : strcmpic(value, US"FULL") == 0
+ ? dsn_ret_full
+ : 0;
+ DEBUG(D_receive) debug_printf("DSN_RET: %d\n", dsn_ret);
+ /* Check for invalid invalid value, and exit with error */
+ if (dsn_ret == 0)
+ {
+ done = synprot_error(L_smtp_syntax_error, 501, NULL,
+ US"Value for RET is invalid");
+ goto COMMAND_LOOP;
+ }
+ }
+ break;
+ case ENV_MAIL_OPT_ENVID:
+ if (fl.dsn_advertised)
+ {
+ /* Check if the dsn envid has been already set */
+ if (dsn_envid)
+ {
+ done = synprot_error(L_smtp_syntax_error, 501, NULL,
+ US"ENVID can be specified once only");
+ goto COMMAND_LOOP;
+ }
+ dsn_envid = string_copy(value);
+ DEBUG(D_receive) debug_printf("DSN_ENVID: %s\n", dsn_envid);
+ }
+ break;
+
+ /* Handle the AUTH extension. If the value given is not "<>" and either
+ the ACL says "yes" or there is no ACL but the sending host is
+ authenticated, we set it up as the authenticated sender. However, if the
+ authenticator set a condition to be tested, we ignore AUTH on MAIL unless
+ the condition is met. The value of AUTH is an xtext, which means that +,
+ = and cntrl chars are coded in hex; however "<>" is unaffected by this
+ coding. */
+ case ENV_MAIL_OPT_AUTH:
+ if (Ustrcmp(value, "<>") != 0)
+ {
+ int rc;
+ uschar *ignore_msg;
+
+ if (auth_xtextdecode(value, &authenticated_sender) < 0)
+ {
+ /* Put back terminator overrides for error message */
+ value[-1] = '=';
+ name[-1] = ' ';
+ done = synprot_error(L_smtp_syntax_error, 501, NULL,
+ US"invalid data for AUTH");
+ goto COMMAND_LOOP;
+ }
+ if (!acl_smtp_mailauth)
+ {
+ ignore_msg = US"client not authenticated";
+ rc = sender_host_authenticated ? OK : FAIL;
+ }
+ else
+ {
+ ignore_msg = US"rejected by ACL";
+ rc = acl_check(ACL_WHERE_MAILAUTH, NULL, acl_smtp_mailauth,
+ &user_msg, &log_msg);
+ }
+
+ switch (rc)
+ {
+ case OK:
+ if (authenticated_by == NULL ||
+ authenticated_by->mail_auth_condition == NULL ||
+ expand_check_condition(authenticated_by->mail_auth_condition,
+ authenticated_by->name, US"authenticator"))
+ break; /* Accept the AUTH */
+
+ ignore_msg = US"server_mail_auth_condition failed";
+ if (authenticated_id != NULL)
+ ignore_msg = string_sprintf("%s: authenticated ID=\"%s\"",
+ ignore_msg, authenticated_id);
+
+ /* Fall through */
+
+ case FAIL:
+ authenticated_sender = NULL;
+ log_write(0, LOG_MAIN, "ignoring AUTH=%s from %s (%s)",
+ value, host_and_ident(TRUE), ignore_msg);
+ break;
+
+ /* Should only get DEFER or ERROR here. Put back terminator
+ overrides for error message */
+
+ default:
+ value[-1] = '=';
+ name[-1] = ' ';
+ (void)smtp_handle_acl_fail(ACL_WHERE_MAILAUTH, rc, user_msg,
+ log_msg);
+ goto COMMAND_LOOP;
+ }
+ }
+ break;
+
+#ifndef DISABLE_PRDR
+ case ENV_MAIL_OPT_PRDR:
+ if (prdr_enable)
+ prdr_requested = TRUE;
+ break;
+#endif
- /* The recipient was discarded */
+#ifdef SUPPORT_I18N
+ case ENV_MAIL_OPT_UTF8:
+ if (!fl.smtputf8_advertised)
+ {
+ done = synprot_error(L_smtp_syntax_error, 501, NULL,
+ US"SMTPUTF8 used when not advertised");
+ goto COMMAND_LOOP;
+ }
+
+ DEBUG(D_receive) debug_printf("smtputf8 requested\n");
+ message_smtputf8 = allow_utf8_domains = TRUE;
+ if (Ustrncmp(received_protocol, US"utf8", 4) != 0)
+ {
+ int old_pool = store_pool;
+ store_pool = POOL_PERM;
+ received_protocol = string_sprintf("utf8%s", received_protocol);
+ store_pool = old_pool;
+ }
+ break;
+#endif
- else if (rc == DISCARD)
- {
- if (user_msg == NULL) smtp_printf("250 Accepted\r\n");
- else smtp_user_msg(US"250", user_msg);
- rcpt_fail_count++;
- discarded = TRUE;
- log_write(0, LOG_MAIN|LOG_REJECT, "%s F=<%s> rejected RCPT %s: "
- "discarded by %s ACL%s%s", host_and_ident(TRUE),
- (sender_address_unrewritten != NULL)?
- sender_address_unrewritten : sender_address,
- smtp_cmd_argument, recipients_discarded? "MAIL" : "RCPT",
- (log_msg == NULL)? US"" : US": ",
- (log_msg == NULL)? US"" : log_msg);
- }
+ /* No valid option. Stick back the terminator characters and break
+ the loop. Do the name-terminator second as extract_option sets
+ value==name when it found no equal-sign.
+ An error for a malformed address will occur. */
+ case ENV_MAIL_OPT_NULL:
+ value[-1] = '=';
+ name[-1] = ' ';
+ arg_error = TRUE;
+ break;
+
+ default: assert(0);
+ }
+ /* Break out of for loop if switch() had bad argument or
+ when start of the email address is reached */
+ if (arg_error) break;
+ }
+
+ /* If we have passed the threshold for rate limiting, apply the current
+ delay, and update it for next time, provided this is a limited host. */
+
+ if (smtp_mailcmd_count > smtp_rlm_threshold &&
+ verify_check_host(&smtp_ratelimit_hosts) == OK)
+ {
+ DEBUG(D_receive) debug_printf("rate limit MAIL: delay %.3g sec\n",
+ smtp_delay_mail/1000.0);
+ millisleep((int)smtp_delay_mail);
+ smtp_delay_mail *= smtp_rlm_factor;
+ if (smtp_delay_mail > (double)smtp_rlm_limit)
+ smtp_delay_mail = (double)smtp_rlm_limit;
+ }
+
+ /* Now extract the address, first applying any SMTP-time rewriting. The
+ TRUE flag allows "<>" as a sender address. */
+
+ raw_sender = rewrite_existflags & rewrite_smtp
+ /* deconst ok as smtp_cmd_data was not const */
+ ? US rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"",
+ global_rewrite_rules)
+ : smtp_cmd_data;
+
+ raw_sender =
+ parse_extract_address(raw_sender, &errmess, &start, &end, &sender_domain,
+ TRUE);
+
+ if (!raw_sender)
+ {
+ done = synprot_error(L_smtp_syntax_error, 501, smtp_cmd_data, errmess);
+ break;
+ }
+
+ sender_address = raw_sender;
+
+ /* If there is a configured size limit for mail, check that this message
+ doesn't exceed it. The check is postponed to this point so that the sender
+ can be logged. */
+
+ if (thismessage_size_limit > 0 && message_size > thismessage_size_limit)
+ {
+ smtp_printf("552 Message size exceeds maximum permitted\r\n", FALSE);
+ log_write(L_size_reject,
+ LOG_MAIN|LOG_REJECT, "rejected MAIL FROM:<%s> %s: "
+ "message too big: size%s=%d max=%d",
+ sender_address,
+ host_and_ident(TRUE),
+ (message_size == INT_MAX)? ">" : "",
+ message_size,
+ thismessage_size_limit);
+ sender_address = NULL;
+ break;
+ }
+
+ /* Check there is enough space on the disk unless configured not to.
+ When smtp_check_spool_space is set, the check is for thismessage_size_limit
+ plus the current message - i.e. we accept the message only if it won't
+ reduce the space below the threshold. Add 5000 to the size to allow for
+ overheads such as the Received: line and storing of recipients, etc.
+ By putting the check here, even when SIZE is not given, it allow VRFY
+ and EXPN etc. to be used when space is short. */
+
+ if (!receive_check_fs(
+ smtp_check_spool_space && message_size >= 0
+ ? message_size + 5000 : 0))
+ {
+ smtp_printf("452 Space shortage, please try later\r\n", FALSE);
+ sender_address = NULL;
+ break;
+ }
+
+ /* If sender_address is unqualified, reject it, unless this is a locally
+ generated message, or the sending host or net is permitted to send
+ unqualified addresses - typically local machines behaving as MUAs -
+ in which case just qualify the address. The flag is set above at the start
+ of the SMTP connection. */
+
+ if (!sender_domain && *sender_address)
+ if (f.allow_unqualified_sender)
+ {
+ sender_domain = Ustrlen(sender_address) + 1;
+ /* deconst ok as sender_address was not const */
+ sender_address = US rewrite_address_qualify(sender_address, FALSE);
+ DEBUG(D_receive) debug_printf("unqualified address %s accepted\n",
+ raw_sender);
+ }
+ else
+ {
+ smtp_printf("501 %s: sender address must contain a domain\r\n", FALSE,
+ smtp_cmd_data);
+ log_write(L_smtp_syntax_error,
+ LOG_MAIN|LOG_REJECT,
+ "unqualified sender rejected: <%s> %s%s",
+ raw_sender,
+ host_and_ident(TRUE),
+ host_lookup_msg);
+ sender_address = NULL;
+ break;
+ }
+
+ /* Apply an ACL check if one is defined, before responding. Afterwards,
+ when pipelining is not advertised, do another sync check in case the ACL
+ delayed and the client started sending in the meantime. */
+
+ if (acl_smtp_mail)
+ {
+ rc = acl_check(ACL_WHERE_MAIL, NULL, acl_smtp_mail, &user_msg, &log_msg);
+ if (rc == OK && !f.smtp_in_pipelining_advertised && !check_sync())
+ goto SYNC_FAILURE;
+ }
+ else
+ rc = OK;
+
+ if (rc == OK || rc == DISCARD)
+ {
+ BOOL more = pipeline_response();
+
+ if (!user_msg)
+ smtp_printf("%s%s%s", more, US"250 OK",
+ #ifndef DISABLE_PRDR
+ prdr_requested ? US", PRDR Requested" : US"",
+ #else
+ US"",
+ #endif
+ US"\r\n");
+ else
+ {
+ #ifndef DISABLE_PRDR
+ if (prdr_requested)
+ user_msg = string_sprintf("%s%s", user_msg, US", PRDR Requested");
+ #endif
+ smtp_user_msg(US"250", user_msg);
+ }
+ smtp_delay_rcpt = smtp_rlr_base;
+ f.recipients_discarded = (rc == DISCARD);
+ was_rej_mail = FALSE;
+ }
+ else
+ {
+ done = smtp_handle_acl_fail(ACL_WHERE_MAIL, rc, user_msg, log_msg);
+ sender_address = NULL;
+ }
+ break;
- /* Either the ACL failed the address, or it was deferred. */
- else
- {
- if (rc == FAIL) rcpt_fail_count++; else rcpt_defer_count++;
- done = smtp_handle_acl_fail(ACL_WHERE_RCPT, rc, user_msg, log_msg);
- }
- break;
+ /* The RCPT command requires an address as an operand. There may be any
+ number of RCPT commands, specifying multiple recipients. We build them all
+ into a data structure. The start/end values given by parse_extract_address
+ are not used, as we keep only the extracted address. */
+
+ case RCPT_CMD:
+ HAD(SCH_RCPT);
+ /* We got really to many recipients. A check against configured
+ limits is done later */
+ if (rcpt_count < 0 || rcpt_count >= INT_MAX/2)
+ log_write(0, LOG_MAIN|LOG_PANIC_DIE, "Too many recipients: %d", rcpt_count);
+ rcpt_count++;
+ was_rcpt = fl.rcpt_in_progress = TRUE;
+
+ /* There must be a sender address; if the sender was rejected and
+ pipelining was advertised, we assume the client was pipelining, and do not
+ count this as a protocol error. Reset was_rej_mail so that further RCPTs
+ get the same treatment. */
+
+ if (sender_address == NULL)
+ {
+ if (f.smtp_in_pipelining_advertised && last_was_rej_mail)
+ {
+ smtp_printf("503 sender not yet given\r\n", FALSE);
+ was_rej_mail = TRUE;
+ }
+ else
+ {
+ done = synprot_error(L_smtp_protocol_error, 503, NULL,
+ US"sender not yet given");
+ was_rcpt = FALSE; /* Not a valid RCPT */
+ }
+ rcpt_fail_count++;
+ break;
+ }
+
+ /* Check for an operand */
+
+ if (smtp_cmd_data[0] == 0)
+ {
+ done = synprot_error(L_smtp_syntax_error, 501, NULL,
+ US"RCPT must have an address operand");
+ rcpt_fail_count++;
+ break;
+ }
+
+ /* Set the DSN flags orcpt and dsn_flags from the session*/
+ orcpt = NULL;
+ dsn_flags = 0;
+
+ if (fl.esmtp) for(;;)
+ {
+ uschar *name, *value;
+
+ if (!extract_option(&name, &value))
+ break;
+
+ if (fl.dsn_advertised && strcmpic(name, US"ORCPT") == 0)
+ {
+ /* Check whether orcpt has been already set */
+ if (orcpt)
+ {
+ done = synprot_error(L_smtp_syntax_error, 501, NULL,
+ US"ORCPT can be specified once only");
+ goto COMMAND_LOOP;
+ }
+ orcpt = string_copy(value);
+ DEBUG(D_receive) debug_printf("DSN orcpt: %s\n", orcpt);
+ }
+
+ else if (fl.dsn_advertised && strcmpic(name, US"NOTIFY") == 0)
+ {
+ /* Check if the notify flags have been already set */
+ if (dsn_flags > 0)
+ {
+ done = synprot_error(L_smtp_syntax_error, 501, NULL,
+ US"NOTIFY can be specified once only");
+ goto COMMAND_LOOP;
+ }
+ if (strcmpic(value, US"NEVER") == 0)
+ dsn_flags |= rf_notify_never;
+ else
+ {
+ uschar *p = value;
+ while (*p != 0)
+ {
+ uschar *pp = p;
+ while (*pp != 0 && *pp != ',') pp++;
+ if (*pp == ',') *pp++ = 0;
+ if (strcmpic(p, US"SUCCESS") == 0)
+ {
+ DEBUG(D_receive) debug_printf("DSN: Setting notify success\n");
+ dsn_flags |= rf_notify_success;
+ }
+ else if (strcmpic(p, US"FAILURE") == 0)
+ {
+ DEBUG(D_receive) debug_printf("DSN: Setting notify failure\n");
+ dsn_flags |= rf_notify_failure;
+ }
+ else if (strcmpic(p, US"DELAY") == 0)
+ {
+ DEBUG(D_receive) debug_printf("DSN: Setting notify delay\n");
+ dsn_flags |= rf_notify_delay;
+ }
+ else
+ {
+ /* Catch any strange values */
+ done = synprot_error(L_smtp_syntax_error, 501, NULL,
+ US"Invalid value for NOTIFY parameter");
+ goto COMMAND_LOOP;
+ }
+ p = pp;
+ }
+ DEBUG(D_receive) debug_printf("DSN Flags: %x\n", dsn_flags);
+ }
+ }
+
+ /* Unknown option. Stick back the terminator characters and break
+ the loop. An error for a malformed address will occur. */
+
+ else
+ {
+ DEBUG(D_receive) debug_printf("Invalid RCPT option: %s : %s\n", name, value);
+ name[-1] = ' ';
+ value[-1] = '=';
+ break;
+ }
+ }
+
+ /* Apply SMTP rewriting then extract the working address. Don't allow "<>"
+ as a recipient address */
+
+ recipient = rewrite_existflags & rewrite_smtp
+ /* deconst ok as smtp_cmd_data was not const */
+ ? US rewrite_one(smtp_cmd_data, rewrite_smtp, NULL, FALSE, US"",
+ global_rewrite_rules)
+ : smtp_cmd_data;
+
+ if (!(recipient = parse_extract_address(recipient, &errmess, &start, &end,
+ &recipient_domain, FALSE)))
+ {
+ done = synprot_error(L_smtp_syntax_error, 501, smtp_cmd_data, errmess);
+ rcpt_fail_count++;
+ break;
+ }
+
+ /* If the recipient address is unqualified, reject it, unless this is a
+ locally generated message. However, unqualified addresses are permitted
+ from a configured list of hosts and nets - typically when behaving as
+ MUAs rather than MTAs. Sad that SMTP is used for both types of traffic,
+ really. The flag is set at the start of the SMTP connection.
+
+ RFC 1123 talks about supporting "the reserved mailbox postmaster"; I always
+ assumed this meant "reserved local part", but the revision of RFC 821 and
+ friends now makes it absolutely clear that it means *mailbox*. Consequently
+ we must always qualify this address, regardless. */
+
+ if (!recipient_domain)
+ if (!(recipient_domain = qualify_recipient(&recipient, smtp_cmd_data,
+ US"recipient")))
+ {
+ rcpt_fail_count++;
+ break;
+ }
+
+ /* Check maximum allowed */
+
+ if (rcpt_count+1 < 0 || rcpt_count > recipients_max && recipients_max > 0)
+ {
+ if (recipients_max_reject)
+ {
+ rcpt_fail_count++;
+ smtp_printf("552 too many recipients\r\n", FALSE);
+ if (!toomany)
+ log_write(0, LOG_MAIN|LOG_REJECT, "too many recipients: message "
+ "rejected: sender=<%s> %s", sender_address, host_and_ident(TRUE));
+ }
+ else
+ {
+ rcpt_defer_count++;
+ smtp_printf("452 too many recipients\r\n", FALSE);
+ if (!toomany)
+ log_write(0, LOG_MAIN|LOG_REJECT, "too many recipients: excess "
+ "temporarily rejected: sender=<%s> %s", sender_address,
+ host_and_ident(TRUE));
+ }
+
+ toomany = TRUE;
+ break;
+ }
+
+ /* If we have passed the threshold for rate limiting, apply the current
+ delay, and update it for next time, provided this is a limited host. */
+
+ if (rcpt_count > smtp_rlr_threshold &&
+ verify_check_host(&smtp_ratelimit_hosts) == OK)
+ {
+ DEBUG(D_receive) debug_printf("rate limit RCPT: delay %.3g sec\n",
+ smtp_delay_rcpt/1000.0);
+ millisleep((int)smtp_delay_rcpt);
+ smtp_delay_rcpt *= smtp_rlr_factor;
+ if (smtp_delay_rcpt > (double)smtp_rlr_limit)
+ smtp_delay_rcpt = (double)smtp_rlr_limit;
+ }
+
+ /* If the MAIL ACL discarded all the recipients, we bypass ACL checking
+ for them. Otherwise, check the access control list for this recipient. As
+ there may be a delay in this, re-check for a synchronization error
+ afterwards, unless pipelining was advertised. */
+
+ if (f.recipients_discarded)
+ rc = DISCARD;
+ else
+ if ( (rc = acl_check(ACL_WHERE_RCPT, recipient, acl_smtp_rcpt, &user_msg,
+ &log_msg)) == OK
+ && !f.smtp_in_pipelining_advertised && !check_sync())
+ goto SYNC_FAILURE;
+
+ /* The ACL was happy */
+
+ if (rc == OK)
+ {
+ BOOL more = pipeline_response();
+
+ if (user_msg)
+ smtp_user_msg(US"250", user_msg);
+ else
+ smtp_printf("250 Accepted\r\n", more);
+ receive_add_recipient(recipient, -1);
+
+ /* Set the dsn flags in the recipients_list */
+ recipients_list[recipients_count-1].orcpt = orcpt;
+ recipients_list[recipients_count-1].dsn_flags = dsn_flags;
+
+ /* DEBUG(D_receive) debug_printf("DSN: orcpt: %s flags: %d\n",
+ recipients_list[recipients_count-1].orcpt,
+ recipients_list[recipients_count-1].dsn_flags); */
+ }
+
+ /* The recipient was discarded */
+
+ else if (rc == DISCARD)
+ {
+ if (user_msg)
+ smtp_user_msg(US"250", user_msg);
+ else
+ smtp_printf("250 Accepted\r\n", FALSE);
+ rcpt_fail_count++;
+ discarded = TRUE;
+ log_write(0, LOG_MAIN|LOG_REJECT, "%s F=<%s> RCPT %s: "
+ "discarded by %s ACL%s%s", host_and_ident(TRUE),
+ sender_address_unrewritten ? sender_address_unrewritten : sender_address,
+ smtp_cmd_argument, f.recipients_discarded ? "MAIL" : "RCPT",
+ log_msg ? US": " : US"", log_msg ? log_msg : US"");
+ }
+
+ /* Either the ACL failed the address, or it was deferred. */
+
+ else
+ {
+ if (rc == FAIL) rcpt_fail_count++; else rcpt_defer_count++;
+ done = smtp_handle_acl_fail(ACL_WHERE_RCPT, rc, user_msg, log_msg);
+ }
+ break;
/* The DATA command is legal only if it follows successful MAIL FROM
(often indicating some kind of system error), it is helpful to include it
with the DATA rejection (an idea suggested by Tony Finch). */
- case DATA_CMD:
- HAD(SCH_DATA);
- if (!discarded && recipients_count <= 0)
- {
- if (rcpt_smtp_response_same && rcpt_smtp_response != NULL)
- {
- uschar *code = US"503";
- int len = Ustrlen(rcpt_smtp_response);
- smtp_respond(code, 3, FALSE, US"All RCPT commands were rejected with "
- "this error:");
- /* Responses from smtp_printf() will have \r\n on the end */
- if (len > 2 && rcpt_smtp_response[len-2] == '\r')
- rcpt_smtp_response[len-2] = 0;
- smtp_respond(code, 3, FALSE, rcpt_smtp_response);
- }
- if (pipelining_advertised && last_was_rcpt)
- smtp_printf("503 Valid RCPT command must precede DATA\r\n");
- else
- done = synprot_error(L_smtp_protocol_error, 503, NULL,
- US"valid RCPT command must precede DATA");
- break;
- }
-
- if (toomany && recipients_max_reject)
+ case BDAT_CMD:
{
- sender_address = NULL; /* This will allow a new MAIL without RSET */
- sender_address_unrewritten = NULL;
- smtp_printf("554 Too many recipients\r\n");
- break;
+ int n;
+
+ HAD(SCH_BDAT);
+ if (chunking_state != CHUNKING_OFFERED)
+ {
+ done = synprot_error(L_smtp_protocol_error, 503, NULL,
+ US"BDAT command used when CHUNKING not advertised");
+ break;
+ }
+
+ /* grab size, endmarker */
+
+ if (sscanf(CS smtp_cmd_data, "%u %n", &chunking_datasize, &n) < 1)
+ {
+ done = synprot_error(L_smtp_protocol_error, 501, NULL,
+ US"missing size for BDAT command");
+ break;
+ }
+ chunking_state = strcmpic(smtp_cmd_data+n, US"LAST") == 0
+ ? CHUNKING_LAST : CHUNKING_ACTIVE;
+ chunking_data_left = chunking_datasize;
+ DEBUG(D_receive) debug_printf("chunking state %d, %d bytes\n",
+ (int)chunking_state, chunking_data_left);
+
+ f.bdat_readers_wanted = TRUE; /* FIXME: redundant vs chunking_state? */
+ f.dot_ends = FALSE;
+
+ goto DATA_BDAT;
}
- /* If there is an ACL, re-check the synchronization afterwards, since the
- ACL may have delayed. */
-
- if (acl_smtp_predata == NULL) rc = OK; else
- {
- enable_dollar_recipients = TRUE;
- rc = acl_check(ACL_WHERE_PREDATA, NULL, acl_smtp_predata, &user_msg,
- &log_msg);
- enable_dollar_recipients = FALSE;
- if (rc == OK && !check_sync()) goto SYNC_FAILURE;
- }
+ case DATA_CMD:
+ HAD(SCH_DATA);
+ f.dot_ends = TRUE;
+ f.bdat_readers_wanted = FALSE;
- if (rc == OK)
- {
- if (user_msg == NULL)
- smtp_printf("354 Enter message, ending with \".\" on a line by itself\r\n");
- else smtp_user_msg(US"354", user_msg);
+ DATA_BDAT: /* Common code for DATA and BDAT */
+#ifndef DISABLE_PIPE_CONNECT
+ fl.pipe_connect_acceptable = FALSE;
+#endif
+ if (!discarded && recipients_count <= 0)
+ {
+ if (fl.rcpt_smtp_response_same && rcpt_smtp_response != NULL)
+ {
+ uschar *code = US"503";
+ int len = Ustrlen(rcpt_smtp_response);
+ smtp_respond(code, 3, FALSE, US"All RCPT commands were rejected with "
+ "this error:");
+ /* Responses from smtp_printf() will have \r\n on the end */
+ if (len > 2 && rcpt_smtp_response[len-2] == '\r')
+ rcpt_smtp_response[len-2] = 0;
+ smtp_respond(code, 3, FALSE, rcpt_smtp_response);
+ }
+ if (f.smtp_in_pipelining_advertised && last_was_rcpt)
+ smtp_printf("503 Valid RCPT command must precede %s\r\n", FALSE,
+ smtp_names[smtp_connection_had[SMTP_HBUFF_PREV(smtp_ch_index)]]);
+ else
+ done = synprot_error(L_smtp_protocol_error, 503, NULL,
+ smtp_connection_had[SMTP_HBUFF_PREV(smtp_ch_index)] == SCH_DATA
+ ? US"valid RCPT command must precede DATA"
+ : US"valid RCPT command must precede BDAT");
+
+ if (chunking_state > CHUNKING_OFFERED)
+ {
+ bdat_push_receive_functions();
+ bdat_flush_data();
+ }
+ break;
+ }
+
+ if (toomany && recipients_max_reject)
+ {
+ sender_address = NULL; /* This will allow a new MAIL without RSET */
+ sender_address_unrewritten = NULL;
+ smtp_printf("554 Too many recipients\r\n", FALSE);
+
+ if (chunking_state > CHUNKING_OFFERED)
+ {
+ bdat_push_receive_functions();
+ bdat_flush_data();
+ }
+ break;
+ }
+
+ if (chunking_state > CHUNKING_OFFERED)
+ rc = OK; /* No predata ACL or go-ahead output for BDAT */
+ else
+ {
+ /* If there is an ACL, re-check the synchronization afterwards, since the
+ ACL may have delayed. To handle cutthrough delivery enforce a dummy call
+ to get the DATA command sent. */
+
+ if (acl_smtp_predata == NULL && cutthrough.cctx.sock < 0)
+ rc = OK;
+ else
+ {
+ uschar * acl = acl_smtp_predata ? acl_smtp_predata : US"accept";
+ f.enable_dollar_recipients = TRUE;
+ rc = acl_check(ACL_WHERE_PREDATA, NULL, acl, &user_msg,
+ &log_msg);
+ f.enable_dollar_recipients = FALSE;
+ if (rc == OK && !check_sync())
+ goto SYNC_FAILURE;
+
+ if (rc != OK)
+ { /* Either the ACL failed the address, or it was deferred. */
+ done = smtp_handle_acl_fail(ACL_WHERE_PREDATA, rc, user_msg, log_msg);
+ break;
+ }
+ }
+
+ if (user_msg)
+ smtp_user_msg(US"354", user_msg);
+ else
+ smtp_printf(
+ "354 Enter message, ending with \".\" on a line by itself\r\n", FALSE);
+ }
+
+ if (f.bdat_readers_wanted)
+ bdat_push_receive_functions();
+
+#ifdef TCP_QUICKACK
+ if (smtp_in) /* all ACKs needed to ramp window up for bulk data */
+ (void) setsockopt(fileno(smtp_in), IPPROTO_TCP, TCP_QUICKACK,
+ US &on, sizeof(on));
+#endif
done = 3;
message_ended = END_NOTENDED; /* Indicate in middle of data */
- }
-
- /* Either the ACL failed the address, or it was deferred. */
- else
- done = smtp_handle_acl_fail(ACL_WHERE_PREDATA, rc, user_msg, log_msg);
- break;
+ break;
case VRFY_CMD:
- HAD(SCH_VRFY);
- rc = acl_check(ACL_WHERE_VRFY, NULL, acl_smtp_vrfy, &user_msg, &log_msg);
- if (rc != OK)
- done = smtp_handle_acl_fail(ACL_WHERE_VRFY, rc, user_msg, log_msg);
- else
{
- uschar *address;
- uschar *s = NULL;
-
- /* rfc821_domains = TRUE; << no longer needed */
- address = parse_extract_address(smtp_cmd_data, &errmess, &start, &end,
- &recipient_domain, FALSE);
- /* rfc821_domains = FALSE; << no longer needed */
-
- if (address == NULL)
- s = string_sprintf("501 %s", errmess);
- else
- {
- address_item *addr = deliver_make_addr(address, FALSE);
- switch(verify_address(addr, NULL, vopt_is_recipient | vopt_qualify, -1,
- -1, -1, NULL, NULL, NULL))
- {
- case OK:
- s = string_sprintf("250 <%s> is deliverable", address);
- break;
-
- case DEFER:
- s = (addr->user_message != NULL)?
- string_sprintf("451 <%s> %s", address, addr->user_message) :
- string_sprintf("451 Cannot resolve <%s> at this time", address);
- break;
+ uschar * address;
- case FAIL:
- s = (addr->user_message != NULL)?
- string_sprintf("550 <%s> %s", address, addr->user_message) :
- string_sprintf("550 <%s> is not deliverable", address);
- log_write(0, LOG_MAIN, "VRFY failed for %s %s",
- smtp_cmd_argument, host_and_ident(TRUE));
- break;
- }
- }
-
- smtp_printf("%s\r\n", s);
- }
- break;
-
-
- case EXPN_CMD:
- HAD(SCH_EXPN);
- rc = acl_check(ACL_WHERE_EXPN, NULL, acl_smtp_expn, &user_msg, &log_msg);
- if (rc != OK)
- done = smtp_handle_acl_fail(ACL_WHERE_EXPN, rc, user_msg, log_msg);
- else
- {
- BOOL save_log_testing_mode = log_testing_mode;
- address_test_mode = log_testing_mode = TRUE;
- (void) verify_address(deliver_make_addr(smtp_cmd_data, FALSE),
- smtp_out, vopt_is_recipient | vopt_qualify | vopt_expn, -1, -1, -1,
- NULL, NULL, NULL);
- address_test_mode = FALSE;
- log_testing_mode = save_log_testing_mode; /* true for -bh */
- }
- break;
+ HAD(SCH_VRFY);
+ if (!(address = parse_extract_address(smtp_cmd_data, &errmess,
+ &start, &end, &recipient_domain, FALSE)))
+ {
+ smtp_printf("501 %s\r\n", FALSE, errmess);
+ break;
+ }
- #ifdef SUPPORT_TLS
+ if (!recipient_domain)
+ if (!(recipient_domain = qualify_recipient(&address, smtp_cmd_data,
+ US"verify")))
+ break;
- case STARTTLS_CMD:
- HAD(SCH_STARTTLS);
- if (!tls_advertised)
- {
- done = synprot_error(L_smtp_protocol_error, 503, NULL,
- US"STARTTLS command used when not advertised");
+ if ((rc = acl_check(ACL_WHERE_VRFY, address, acl_smtp_vrfy,
+ &user_msg, &log_msg)) != OK)
+ done = smtp_handle_acl_fail(ACL_WHERE_VRFY, rc, user_msg, log_msg);
+ else
+ {
+ uschar * s = NULL;
+ address_item * addr = deliver_make_addr(address, FALSE);
+
+ switch(verify_address(addr, NULL, vopt_is_recipient | vopt_qualify, -1,
+ -1, -1, NULL, NULL, NULL))
+ {
+ case OK:
+ s = string_sprintf("250 <%s> is deliverable", address);
+ break;
+
+ case DEFER:
+ s = (addr->user_message != NULL)?
+ string_sprintf("451 <%s> %s", address, addr->user_message) :
+ string_sprintf("451 Cannot resolve <%s> at this time", address);
+ break;
+
+ case FAIL:
+ s = (addr->user_message != NULL)?
+ string_sprintf("550 <%s> %s", address, addr->user_message) :
+ string_sprintf("550 <%s> is not deliverable", address);
+ log_write(0, LOG_MAIN, "VRFY failed for %s %s",
+ smtp_cmd_argument, host_and_ident(TRUE));
+ break;
+ }
+
+ smtp_printf("%s\r\n", FALSE, s);
+ }
break;
}
- /* Apply an ACL check if one is defined */
- if (acl_smtp_starttls != NULL)
- {
- rc = acl_check(ACL_WHERE_STARTTLS, NULL, acl_smtp_starttls, &user_msg,
- &log_msg);
+ case EXPN_CMD:
+ HAD(SCH_EXPN);
+ rc = acl_check(ACL_WHERE_EXPN, NULL, acl_smtp_expn, &user_msg, &log_msg);
if (rc != OK)
- {
- done = smtp_handle_acl_fail(ACL_WHERE_STARTTLS, rc, user_msg, log_msg);
- break;
- }
- }
-
- /* RFC 2487 is not clear on when this command may be sent, though it
- does state that all information previously obtained from the client
- must be discarded if a TLS session is started. It seems reasonble to
- do an implied RSET when STARTTLS is received. */
-
- incomplete_transaction_log(US"STARTTLS");
- smtp_reset(reset_point);
- toomany = FALSE;
- cmd_list[CMD_LIST_STARTTLS].is_mail_cmd = FALSE;
-
- /* There's an attack where more data is read in past the STARTTLS command
- before TLS is negotiated, then assumed to be part of the secure session
- when used afterwards; we use segregated input buffers, so are not
- vulnerable, but we want to note when it happens and, for sheer paranoia,
- ensure that the buffer is "wiped".
- Pipelining sync checks will normally have protected us too, unless disabled
- by configuration. */
-
- if (receive_smtp_buffered())
- {
- DEBUG(D_any)
- debug_printf("Non-empty input buffer after STARTTLS; naive attack?");
- if (tls_active < 0)
- smtp_inend = smtp_inptr = smtp_inbuffer;
- /* and if TLS is already active, tls_server_start() should fail */
- }
-
- /* There is nothing we value in the input buffer and if TLS is succesfully
- negotiated, we won't use this buffer again; if TLS fails, we'll just read
- fresh content into it. The buffer contains arbitrary content from an
- untrusted remote source; eg: NOOP <shellcode>\r\nSTARTTLS\r\n
- It seems safest to just wipe away the content rather than leave it as a
- target to jump to. */
-
- memset(smtp_inbuffer, 0, in_buffer_size);
-
- /* Attempt to start up a TLS session, and if successful, discard all
- knowledge that was obtained previously. At least, that's what the RFC says,
- and that's what happens by default. However, in order to work round YAEB,
- there is an option to remember the esmtp state. Sigh.
-
- We must allow for an extra EHLO command and an extra AUTH command after
- STARTTLS that don't add to the nonmail command count. */
-
- if ((rc = tls_server_start(tls_require_ciphers)) == OK)
- {
- if (!tls_remember_esmtp)
- helo_seen = esmtp = auth_advertised = pipelining_advertised = FALSE;
- cmd_list[CMD_LIST_EHLO].is_mail_cmd = TRUE;
- cmd_list[CMD_LIST_AUTH].is_mail_cmd = TRUE;
- if (sender_helo_name != NULL)
- {
- store_free(sender_helo_name);
- sender_helo_name = NULL;
- host_build_sender_fullhost(); /* Rebuild */
- set_process_info("handling incoming TLS connection from %s",
- host_and_ident(FALSE));
- }
- received_protocol = (esmtp?
- protocols[pextend + pcrpted +
- ((sender_host_authenticated != NULL)? pauthed : 0)]
- :
- protocols[pnormal + pcrpted])
- +
- ((sender_host_address != NULL)? pnlocal : 0);
-
- sender_host_authenticated = NULL;
- authenticated_id = NULL;
- sync_cmd_limit = NON_SYNC_CMD_NON_PIPELINING;
- DEBUG(D_tls) debug_printf("TLS active\n");
- break; /* Successful STARTTLS */
- }
-
- /* Some local configuration problem was discovered before actually trying
- to do a TLS handshake; give a temporary error. */
-
- else if (rc == DEFER)
- {
- smtp_printf("454 TLS currently unavailable\r\n");
+ done = smtp_handle_acl_fail(ACL_WHERE_EXPN, rc, user_msg, log_msg);
+ else
+ {
+ BOOL save_log_testing_mode = f.log_testing_mode;
+ f.address_test_mode = f.log_testing_mode = TRUE;
+ (void) verify_address(deliver_make_addr(smtp_cmd_data, FALSE),
+ smtp_out, vopt_is_recipient | vopt_qualify | vopt_expn, -1, -1, -1,
+ NULL, NULL, NULL);
+ f.address_test_mode = FALSE;
+ f.log_testing_mode = save_log_testing_mode; /* true for -bh */
+ }
break;
- }
-
- /* Hard failure. Reject everything except QUIT or closed connection. One
- cause for failure is a nested STARTTLS, in which case tls_active remains
- set, but we must still reject all incoming commands. */
- DEBUG(D_tls) debug_printf("TLS failed to start\n");
- while (done <= 0)
- {
- switch(smtp_read_command(FALSE))
- {
- case EOF_CMD:
- log_write(L_smtp_connection, LOG_MAIN, "%s closed by EOF",
- smtp_get_connection_info());
- smtp_notquit_exit(US"tls-failed", NULL, NULL);
- done = 2;
- break;
-
- /* It is perhaps arguable as to which exit ACL should be called here,
- but as it is probably a situtation that almost never arises, it
- probably doesn't matter. We choose to call the real QUIT ACL, which in
- some sense is perhaps "right". */
- case QUIT_CMD:
- user_msg = NULL;
- if (acl_smtp_quit != NULL)
- {
- rc = acl_check(ACL_WHERE_QUIT, NULL, acl_smtp_quit, &user_msg,
- &log_msg);
- if (rc == ERROR)
- log_write(0, LOG_MAIN|LOG_PANIC, "ACL for QUIT returned ERROR: %s",
- log_msg);
- }
- if (user_msg == NULL)
- smtp_printf("221 %s closing connection\r\n", smtp_active_hostname);
- else
- smtp_respond(US"221", 3, TRUE, user_msg);
- log_write(L_smtp_connection, LOG_MAIN, "%s closed by QUIT",
- smtp_get_connection_info());
- done = 2;
- break;
+ #ifndef DISABLE_TLS
- default:
- smtp_printf("554 Security failure\r\n");
- break;
- }
- }
- tls_close(TRUE);
- break;
+ case STARTTLS_CMD:
+ HAD(SCH_STARTTLS);
+ if (!fl.tls_advertised)
+ {
+ done = synprot_error(L_smtp_protocol_error, 503, NULL,
+ US"STARTTLS command used when not advertised");
+ break;
+ }
+
+ /* Apply an ACL check if one is defined */
+
+ if ( acl_smtp_starttls
+ && (rc = acl_check(ACL_WHERE_STARTTLS, NULL, acl_smtp_starttls,
+ &user_msg, &log_msg)) != OK
+ )
+ {
+ done = smtp_handle_acl_fail(ACL_WHERE_STARTTLS, rc, user_msg, log_msg);
+ break;
+ }
+
+ /* RFC 2487 is not clear on when this command may be sent, though it
+ does state that all information previously obtained from the client
+ must be discarded if a TLS session is started. It seems reasonable to
+ do an implied RSET when STARTTLS is received. */
+
+ incomplete_transaction_log(US"STARTTLS");
+ cancel_cutthrough_connection(TRUE, US"STARTTLS received");
+ reset_point = smtp_reset(reset_point);
+ toomany = FALSE;
+ cmd_list[CMD_LIST_STARTTLS].is_mail_cmd = FALSE;
+
+ /* There's an attack where more data is read in past the STARTTLS command
+ before TLS is negotiated, then assumed to be part of the secure session
+ when used afterwards; we use segregated input buffers, so are not
+ vulnerable, but we want to note when it happens and, for sheer paranoia,
+ ensure that the buffer is "wiped".
+ Pipelining sync checks will normally have protected us too, unless disabled
+ by configuration. */
+
+ if (receive_smtp_buffered())
+ {
+ DEBUG(D_any)
+ debug_printf("Non-empty input buffer after STARTTLS; naive attack?\n");
+ if (tls_in.active.sock < 0)
+ smtp_inend = smtp_inptr = smtp_inbuffer;
+ /* and if TLS is already active, tls_server_start() should fail */
+ }
+
+ /* There is nothing we value in the input buffer and if TLS is successfully
+ negotiated, we won't use this buffer again; if TLS fails, we'll just read
+ fresh content into it. The buffer contains arbitrary content from an
+ untrusted remote source; eg: NOOP <shellcode>\r\nSTARTTLS\r\n
+ It seems safest to just wipe away the content rather than leave it as a
+ target to jump to. */
+
+ memset(smtp_inbuffer, 0, IN_BUFFER_SIZE);
+
+ /* Attempt to start up a TLS session, and if successful, discard all
+ knowledge that was obtained previously. At least, that's what the RFC says,
+ and that's what happens by default. However, in order to work round YAEB,
+ there is an option to remember the esmtp state. Sigh.
+
+ We must allow for an extra EHLO command and an extra AUTH command after
+ STARTTLS that don't add to the nonmail command count. */
+
+ s = NULL;
+ if ((rc = tls_server_start(&s)) == OK)
+ {
+ if (!tls_remember_esmtp)
+ fl.helo_seen = fl.esmtp = fl.auth_advertised = f.smtp_in_pipelining_advertised = FALSE;
+ cmd_list[CMD_LIST_EHLO].is_mail_cmd = TRUE;
+ cmd_list[CMD_LIST_AUTH].is_mail_cmd = TRUE;
+ cmd_list[CMD_LIST_TLS_AUTH].is_mail_cmd = TRUE;
+ if (sender_helo_name)
+ {
+ sender_helo_name = NULL;
+ host_build_sender_fullhost(); /* Rebuild */
+ set_process_info("handling incoming TLS connection from %s",
+ host_and_ident(FALSE));
+ }
+ received_protocol =
+ (sender_host_address ? protocols : protocols_local)
+ [ (fl.esmtp
+ ? pextend + (sender_host_authenticated ? pauthed : 0)
+ : pnormal)
+ + (tls_in.active.sock >= 0 ? pcrpted : 0)
+ ];
+
+ sender_host_auth_pubname = sender_host_authenticated = NULL;
+ authenticated_id = NULL;
+ sync_cmd_limit = NON_SYNC_CMD_NON_PIPELINING;
+ DEBUG(D_tls) debug_printf("TLS active\n");
+ break; /* Successful STARTTLS */
+ }
+ else
+ (void) smtp_log_tls_fail(s);
+
+ /* Some local configuration problem was discovered before actually trying
+ to do a TLS handshake; give a temporary error. */
+
+ if (rc == DEFER)
+ {
+ smtp_printf("454 TLS currently unavailable\r\n", FALSE);
+ break;
+ }
+
+ /* Hard failure. Reject everything except QUIT or closed connection. One
+ cause for failure is a nested STARTTLS, in which case tls_in.active remains
+ set, but we must still reject all incoming commands. Another is a handshake
+ failure - and there may some encrypted data still in the pipe to us, which we
+ see as garbage commands. */
+
+ DEBUG(D_tls) debug_printf("TLS failed to start\n");
+ while (done <= 0) switch(smtp_read_command(FALSE, GETC_BUFFER_UNLIMITED))
+ {
+ case EOF_CMD:
+ log_write(L_smtp_connection, LOG_MAIN, "%s closed by EOF",
+ smtp_get_connection_info());
+ smtp_notquit_exit(US"tls-failed", NULL, NULL);
+ done = 2;
+ break;
+
+ /* It is perhaps arguable as to which exit ACL should be called here,
+ but as it is probably a situation that almost never arises, it
+ probably doesn't matter. We choose to call the real QUIT ACL, which in
+ some sense is perhaps "right". */
+
+ case QUIT_CMD:
+ f.smtp_in_quit = TRUE;
+ user_msg = NULL;
+ if ( acl_smtp_quit
+ && ((rc = acl_check(ACL_WHERE_QUIT, NULL, acl_smtp_quit, &user_msg,
+ &log_msg)) == ERROR))
+ log_write(0, LOG_MAIN|LOG_PANIC, "ACL for QUIT returned ERROR: %s",
+ log_msg);
+ if (user_msg)
+ smtp_respond(US"221", 3, TRUE, user_msg);
+ else
+ smtp_printf("221 %s closing connection\r\n", FALSE, smtp_active_hostname);
+ log_write(L_smtp_connection, LOG_MAIN, "%s closed by QUIT",
+ smtp_get_connection_info());
+ done = 2;
+ break;
+
+ default:
+ smtp_printf("554 Security failure\r\n", FALSE);
+ break;
+ }
+ tls_close(NULL, TLS_SHUTDOWN_NOWAIT);
+ break;
#endif
message. */
case QUIT_CMD:
- HAD(SCH_QUIT);
- incomplete_transaction_log(US"QUIT");
- if (acl_smtp_quit != NULL)
- {
- rc = acl_check(ACL_WHERE_QUIT, NULL, acl_smtp_quit, &user_msg, &log_msg);
- if (rc == ERROR)
- log_write(0, LOG_MAIN|LOG_PANIC, "ACL for QUIT returned ERROR: %s",
- log_msg);
- }
- if (user_msg == NULL)
- smtp_printf("221 %s closing connection\r\n", smtp_active_hostname);
- else
- smtp_respond(US"221", 3, TRUE, user_msg);
-
- #ifdef SUPPORT_TLS
- tls_close(TRUE);
- #endif
-
- done = 2;
- log_write(L_smtp_connection, LOG_MAIN, "%s closed by QUIT",
- smtp_get_connection_info());
- break;
+ smtp_quit_handler(&user_msg, &log_msg);
+ done = 2;
+ break;
case RSET_CMD:
- HAD(SCH_RSET);
- incomplete_transaction_log(US"RSET");
- smtp_reset(reset_point);
- toomany = FALSE;
- smtp_printf("250 Reset OK\r\n");
- cmd_list[CMD_LIST_RSET].is_mail_cmd = FALSE;
- break;
+ smtp_rset_handler();
+ cancel_cutthrough_connection(TRUE, US"RSET received");
+ reset_point = smtp_reset(reset_point);
+ toomany = FALSE;
+ break;
case NOOP_CMD:
- HAD(SCH_NOOP);
- smtp_printf("250 OK\r\n");
- break;
+ HAD(SCH_NOOP);
+ smtp_printf("250 OK\r\n", FALSE);
+ break;
/* Show ETRN/EXPN/VRFY if there's an ACL for checking hosts; if actually
response. */
case HELP_CMD:
- HAD(SCH_HELP);
- smtp_printf("214-Commands supported:\r\n");
- {
- uschar buffer[256];
- buffer[0] = 0;
- Ustrcat(buffer, " AUTH");
- #ifdef SUPPORT_TLS
- if (tls_active < 0 &&
- verify_check_host(&tls_advertise_hosts) != FAIL)
- Ustrcat(buffer, " STARTTLS");
- #endif
- Ustrcat(buffer, " HELO EHLO MAIL RCPT DATA");
- Ustrcat(buffer, " NOOP QUIT RSET HELP");
- if (acl_smtp_etrn != NULL) Ustrcat(buffer, " ETRN");
- if (acl_smtp_expn != NULL) Ustrcat(buffer, " EXPN");
- if (acl_smtp_vrfy != NULL) Ustrcat(buffer, " VRFY");
- smtp_printf("214%s\r\n", buffer);
- }
- break;
-
-
- case EOF_CMD:
- incomplete_transaction_log(US"connection lost");
- smtp_notquit_exit(US"connection-lost", US"421",
- US"%s lost input connection", smtp_active_hostname);
-
- /* Don't log by default unless in the middle of a message, as some mailers
- just drop the call rather than sending QUIT, and it clutters up the logs.
- */
-
- if (sender_address != NULL || recipients_count > 0)
- log_write(L_lost_incoming_connection,
- LOG_MAIN,
- "unexpected %s while reading SMTP command from %s%s",
- sender_host_unknown? "EOF" : "disconnection",
- host_and_ident(FALSE), smtp_read_error);
-
- else log_write(L_smtp_connection, LOG_MAIN, "%s lost%s",
- smtp_get_connection_info(), smtp_read_error);
-
- done = 1;
- break;
-
-
- case ETRN_CMD:
- HAD(SCH_ETRN);
- if (sender_address != NULL)
- {
- done = synprot_error(L_smtp_protocol_error, 503, NULL,
- US"ETRN is not permitted inside a transaction");
- break;
- }
-
- log_write(L_etrn, LOG_MAIN, "ETRN %s received from %s", smtp_cmd_argument,
- host_and_ident(FALSE));
-
- rc = acl_check(ACL_WHERE_ETRN, NULL, acl_smtp_etrn, &user_msg, &log_msg);
- if (rc != OK)
- {
- done = smtp_handle_acl_fail(ACL_WHERE_ETRN, rc, user_msg, log_msg);
- break;
- }
-
- /* Compute the serialization key for this command. */
-
- etrn_serialize_key = string_sprintf("etrn-%s\n", smtp_cmd_data);
-
- /* If a command has been specified for running as a result of ETRN, we
- permit any argument to ETRN. If not, only the # standard form is permitted,
- since that is strictly the only kind of ETRN that can be implemented
- according to the RFC. */
-
- if (smtp_etrn_command != NULL)
- {
- uschar *error;
- BOOL rc;
- etrn_command = smtp_etrn_command;
- deliver_domain = smtp_cmd_data;
- rc = transport_set_up_command(&argv, smtp_etrn_command, TRUE, 0, NULL,
- US"ETRN processing", &error);
- deliver_domain = NULL;
- if (!rc)
- {
- log_write(0, LOG_MAIN|LOG_PANIC, "failed to set up ETRN command: %s",
- error);
- smtp_printf("458 Internal failure\r\n");
- break;
- }
- }
-
- /* Else set up to call Exim with the -R option. */
-
- else
- {
- if (*smtp_cmd_data++ != '#')
- {
- done = synprot_error(L_smtp_syntax_error, 501, NULL,
- US"argument must begin with #");
- break;
- }
- etrn_command = US"exim -R";
- argv = child_exec_exim(CEE_RETURN_ARGV, TRUE, NULL, TRUE, 2, US"-R",
- smtp_cmd_data);
- }
-
- /* If we are host-testing, don't actually do anything. */
-
- if (host_checking)
- {
- HDEBUG(D_any)
- {
- debug_printf("ETRN command is: %s\n", etrn_command);
- debug_printf("ETRN command execution skipped\n");
- }
- if (user_msg == NULL) smtp_printf("250 OK\r\n");
- else smtp_user_msg(US"250", user_msg);
+ HAD(SCH_HELP);
+ smtp_printf("214-Commands supported:\r\n", TRUE);
+ {
+ uschar buffer[256];
+ buffer[0] = 0;
+ Ustrcat(buffer, US" AUTH");
+ #ifndef DISABLE_TLS
+ if (tls_in.active.sock < 0 &&
+ verify_check_host(&tls_advertise_hosts) != FAIL)
+ Ustrcat(buffer, US" STARTTLS");
+ #endif
+ Ustrcat(buffer, US" HELO EHLO MAIL RCPT DATA BDAT");
+ Ustrcat(buffer, US" NOOP QUIT RSET HELP");
+ if (acl_smtp_etrn) Ustrcat(buffer, US" ETRN");
+ if (acl_smtp_expn) Ustrcat(buffer, US" EXPN");
+ if (acl_smtp_vrfy) Ustrcat(buffer, US" VRFY");
+ smtp_printf("214%s\r\n", FALSE, buffer);
+ }
break;
- }
- /* If ETRN queue runs are to be serialized, check the database to
- ensure one isn't already running. */
+ case EOF_CMD:
+ incomplete_transaction_log(US"connection lost");
+ smtp_notquit_exit(US"connection-lost", US"421",
+ US"%s lost input connection", smtp_active_hostname);
+
+ /* Don't log by default unless in the middle of a message, as some mailers
+ just drop the call rather than sending QUIT, and it clutters up the logs.
+ */
+
+ if (sender_address || recipients_count > 0)
+ log_write(L_lost_incoming_connection, LOG_MAIN,
+ "unexpected %s while reading SMTP command from %s%s%s D=%s",
+ f.sender_host_unknown ? "EOF" : "disconnection",
+ f.tcp_in_fastopen_logged
+ ? US""
+ : f.tcp_in_fastopen
+ ? f.tcp_in_fastopen_data ? US"TFO* " : US"TFO "
+ : US"",
+ host_and_ident(FALSE), smtp_read_error,
+ string_timesince(&smtp_connection_start)
+ );
- if (smtp_etrn_serialize && !enq_start(etrn_serialize_key))
- {
- smtp_printf("458 Already processing %s\r\n", smtp_cmd_data);
+ else
+ log_write(L_smtp_connection, LOG_MAIN, "%s %slost%s D=%s",
+ smtp_get_connection_info(),
+ f.tcp_in_fastopen && !f.tcp_in_fastopen_logged ? US"TFO " : US"",
+ smtp_read_error,
+ string_timesince(&smtp_connection_start)
+ );
+
+ done = 1;
break;
- }
-
- /* Fork a child process and run the command. We don't want to have to
- wait for the process at any point, so set SIGCHLD to SIG_IGN before
- forking. It should be set that way anyway for external incoming SMTP,
- but we save and restore to be tidy. If serialization is required, we
- actually run the command in yet another process, so we can wait for it
- to complete and then remove the serialization lock. */
-
- oldsignal = signal(SIGCHLD, SIG_IGN);
- if ((pid = fork()) == 0)
- {
- smtp_input = FALSE; /* This process is not associated with the */
- (void)fclose(smtp_in); /* SMTP call any more. */
- (void)fclose(smtp_out);
-
- signal(SIGCHLD, SIG_DFL); /* Want to catch child */
- /* If not serializing, do the exec right away. Otherwise, fork down
- into another process. */
-
- if (!smtp_etrn_serialize || (pid = fork()) == 0)
- {
- DEBUG(D_exec) debug_print_argv(argv);
- exim_nullstd(); /* Ensure std{in,out,err} exist */
- execv(CS argv[0], (char *const *)argv);
- log_write(0, LOG_MAIN|LOG_PANIC_DIE, "exec of \"%s\" (ETRN) failed: %s",
- etrn_command, strerror(errno));
- _exit(EXIT_FAILURE); /* paranoia */
- }
+ case ETRN_CMD:
+ HAD(SCH_ETRN);
+ if (sender_address)
+ {
+ done = synprot_error(L_smtp_protocol_error, 503, NULL,
+ US"ETRN is not permitted inside a transaction");
+ break;
+ }
+
+ log_write(L_etrn, LOG_MAIN, "ETRN %s received from %s", smtp_cmd_argument,
+ host_and_ident(FALSE));
+
+ if ((rc = acl_check(ACL_WHERE_ETRN, NULL, acl_smtp_etrn,
+ &user_msg, &log_msg)) != OK)
+ {
+ done = smtp_handle_acl_fail(ACL_WHERE_ETRN, rc, user_msg, log_msg);
+ break;
+ }
+
+ /* Compute the serialization key for this command. */
+
+ etrn_serialize_key = string_sprintf("etrn-%s\n", smtp_cmd_data);
+
+ /* If a command has been specified for running as a result of ETRN, we
+ permit any argument to ETRN. If not, only the # standard form is permitted,
+ since that is strictly the only kind of ETRN that can be implemented
+ according to the RFC. */
+
+ if (smtp_etrn_command)
+ {
+ uschar *error;
+ BOOL rc;
+ etrn_command = smtp_etrn_command;
+ deliver_domain = smtp_cmd_data;
+ rc = transport_set_up_command(&argv, smtp_etrn_command, TRUE, 0, NULL,
+ US"ETRN processing", &error);
+ deliver_domain = NULL;
+ if (!rc)
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC, "failed to set up ETRN command: %s",
+ error);
+ smtp_printf("458 Internal failure\r\n", FALSE);
+ break;
+ }
+ }
+
+ /* Else set up to call Exim with the -R option. */
- /* Obey this if smtp_serialize and the 2nd fork yielded non-zero. That
- is, we are in the first subprocess, after forking again. All we can do
- for a failing fork is to log it. Otherwise, wait for the 2nd process to
- complete, before removing the serialization. */
+ else
+ {
+ if (*smtp_cmd_data++ != '#')
+ {
+ done = synprot_error(L_smtp_syntax_error, 501, NULL,
+ US"argument must begin with #");
+ break;
+ }
+ etrn_command = US"exim -R";
+ argv = CUSS child_exec_exim(CEE_RETURN_ARGV, TRUE, NULL, TRUE,
+ *queue_name ? 4 : 2,
+ US"-R", smtp_cmd_data,
+ US"-MCG", queue_name);
+ }
+
+ /* If we are host-testing, don't actually do anything. */
+
+ if (host_checking)
+ {
+ HDEBUG(D_any)
+ {
+ debug_printf("ETRN command is: %s\n", etrn_command);
+ debug_printf("ETRN command execution skipped\n");
+ }
+ if (user_msg == NULL) smtp_printf("250 OK\r\n", FALSE);
+ else smtp_user_msg(US"250", user_msg);
+ break;
+ }
+
+
+ /* If ETRN queue runs are to be serialized, check the database to
+ ensure one isn't already running. */
+
+ if (smtp_etrn_serialize && !enq_start(etrn_serialize_key, 1))
+ {
+ smtp_printf("458 Already processing %s\r\n", FALSE, smtp_cmd_data);
+ break;
+ }
+
+ /* Fork a child process and run the command. We don't want to have to
+ wait for the process at any point, so set SIGCHLD to SIG_IGN before
+ forking. It should be set that way anyway for external incoming SMTP,
+ but we save and restore to be tidy. If serialization is required, we
+ actually run the command in yet another process, so we can wait for it
+ to complete and then remove the serialization lock. */
+
+ oldsignal = signal(SIGCHLD, SIG_IGN);
+
+ if ((pid = exim_fork(US"etrn-command")) == 0)
+ {
+ smtp_input = FALSE; /* This process is not associated with the */
+ (void)fclose(smtp_in); /* SMTP call any more. */
+ (void)fclose(smtp_out);
+
+ signal(SIGCHLD, SIG_DFL); /* Want to catch child */
+
+ /* If not serializing, do the exec right away. Otherwise, fork down
+ into another process. */
+
+ if ( !smtp_etrn_serialize
+ || (pid = exim_fork(US"etrn-serialised-command")) == 0)
+ {
+ DEBUG(D_exec) debug_print_argv(argv);
+ exim_nullstd(); /* Ensure std{in,out,err} exist */
+ execv(CS argv[0], (char *const *)argv);
+ log_write(0, LOG_MAIN|LOG_PANIC_DIE, "exec of \"%s\" (ETRN) failed: %s",
+ etrn_command, strerror(errno));
+ _exit(EXIT_FAILURE); /* paranoia */
+ }
+
+ /* Obey this if smtp_serialize and the 2nd fork yielded non-zero. That
+ is, we are in the first subprocess, after forking again. All we can do
+ for a failing fork is to log it. Otherwise, wait for the 2nd process to
+ complete, before removing the serialization. */
+
+ if (pid < 0)
+ log_write(0, LOG_MAIN|LOG_PANIC, "2nd fork for serialized ETRN "
+ "failed: %s", strerror(errno));
+ else
+ {
+ int status;
+ DEBUG(D_any) debug_printf("waiting for serialized ETRN process %d\n",
+ (int)pid);
+ (void)wait(&status);
+ DEBUG(D_any) debug_printf("serialized ETRN process %d ended\n",
+ (int)pid);
+ }
+
+ enq_end(etrn_serialize_key);
+ exim_underbar_exit(EXIT_SUCCESS);
+ }
+
+ /* Back in the top level SMTP process. Check that we started a subprocess
+ and restore the signal state. */
if (pid < 0)
- log_write(0, LOG_MAIN|LOG_PANIC, "2nd fork for serialized ETRN "
- "failed: %s", strerror(errno));
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC, "fork of process for ETRN failed: %s",
+ strerror(errno));
+ smtp_printf("458 Unable to fork process\r\n", FALSE);
+ if (smtp_etrn_serialize) enq_end(etrn_serialize_key);
+ }
else
- {
- int status;
- DEBUG(D_any) debug_printf("waiting for serialized ETRN process %d\n",
- (int)pid);
- (void)wait(&status);
- DEBUG(D_any) debug_printf("serialized ETRN process %d ended\n",
- (int)pid);
- }
-
- enq_end(etrn_serialize_key);
- _exit(EXIT_SUCCESS);
- }
-
- /* Back in the top level SMTP process. Check that we started a subprocess
- and restore the signal state. */
-
- if (pid < 0)
- {
- log_write(0, LOG_MAIN|LOG_PANIC, "fork of process for ETRN failed: %s",
- strerror(errno));
- smtp_printf("458 Unable to fork process\r\n");
- if (smtp_etrn_serialize) enq_end(etrn_serialize_key);
- }
- else
- {
- if (user_msg == NULL) smtp_printf("250 OK\r\n");
- else smtp_user_msg(US"250", user_msg);
- }
+ if (!user_msg)
+ smtp_printf("250 OK\r\n", FALSE);
+ else
+ smtp_user_msg(US"250", user_msg);
- signal(SIGCHLD, oldsignal);
- break;
+ signal(SIGCHLD, oldsignal);
+ break;
case BADARG_CMD:
- done = synprot_error(L_smtp_syntax_error, 501, NULL,
- US"unexpected argument data");
- break;
+ done = synprot_error(L_smtp_syntax_error, 501, NULL,
+ US"unexpected argument data");
+ break;
/* This currently happens only for NULLs, but could be extended. */
case BADCHAR_CMD:
- done = synprot_error(L_smtp_syntax_error, 0, NULL, /* Just logs */
- US"NULL character(s) present (shown as '?')");
- smtp_printf("501 NULL characters are not allowed in SMTP commands\r\n");
- break;
+ done = synprot_error(L_smtp_syntax_error, 0, NULL, /* Just logs */
+ US"NUL character(s) present (shown as '?')");
+ smtp_printf("501 NUL characters are not allowed in SMTP commands\r\n",
+ FALSE);
+ break;
case BADSYN_CMD:
SYNC_FAILURE:
- if (smtp_inend >= smtp_inbuffer + in_buffer_size)
- smtp_inend = smtp_inbuffer + in_buffer_size - 1;
- c = smtp_inend - smtp_inptr;
- if (c > 150) c = 150;
- smtp_inptr[c] = 0;
- incomplete_transaction_log(US"sync failure");
- log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol synchronization error "
- "(next input sent too soon: pipelining was%s advertised): "
- "rejected \"%s\" %s next input=\"%s\"",
- pipelining_advertised? "" : " not",
- smtp_cmd_buffer, host_and_ident(TRUE),
- string_printing(smtp_inptr));
- smtp_notquit_exit(US"synchronization-error", US"554",
- US"SMTP synchronization error");
- done = 1; /* Pretend eof - drops connection */
- break;
+ if (smtp_inend >= smtp_inbuffer + IN_BUFFER_SIZE)
+ smtp_inend = smtp_inbuffer + IN_BUFFER_SIZE - 1;
+ c = smtp_inend - smtp_inptr;
+ if (c > 150) c = 150; /* limit logged amount */
+ smtp_inptr[c] = 0;
+ incomplete_transaction_log(US"sync failure");
+ log_write(0, LOG_MAIN|LOG_REJECT, "SMTP protocol synchronization error "
+ "(next input sent too soon: pipelining was%s advertised): "
+ "rejected \"%s\" %s next input=\"%s\"",
+ f.smtp_in_pipelining_advertised ? "" : " not",
+ smtp_cmd_buffer, host_and_ident(TRUE),
+ string_printing(smtp_inptr));
+ smtp_notquit_exit(US"synchronization-error", US"554",
+ US"SMTP synchronization error");
+ done = 1; /* Pretend eof - drops connection */
+ break;
case TOO_MANY_NONMAIL_CMD:
- s = smtp_cmd_buffer;
- while (*s != 0 && !isspace(*s)) s++;
- incomplete_transaction_log(US"too many non-mail commands");
- log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
- "nonmail commands (last was \"%.*s\")", host_and_ident(FALSE),
- s - smtp_cmd_buffer, smtp_cmd_buffer);
- smtp_notquit_exit(US"bad-commands", US"554", US"Too many nonmail commands");
- done = 1; /* Pretend eof - drops connection */
- break;
+ s = smtp_cmd_buffer;
+ while (*s != 0 && !isspace(*s)) s++;
+ incomplete_transaction_log(US"too many non-mail commands");
+ log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
+ "nonmail commands (last was \"%.*s\")", host_and_ident(FALSE),
+ (int)(s - smtp_cmd_buffer), smtp_cmd_buffer);
+ smtp_notquit_exit(US"bad-commands", US"554", US"Too many nonmail commands");
+ done = 1; /* Pretend eof - drops connection */
+ break;
+#ifdef SUPPORT_PROXY
+ case PROXY_FAIL_IGNORE_CMD:
+ smtp_printf("503 Command refused, required Proxy negotiation failed\r\n", FALSE);
+ break;
+#endif
default:
- if (unknown_command_count++ >= smtp_max_unknown_commands)
- {
- log_write(L_smtp_syntax_error, LOG_MAIN,
- "SMTP syntax error in \"%s\" %s %s",
- string_printing(smtp_cmd_buffer), host_and_ident(TRUE),
- US"unrecognized command");
- incomplete_transaction_log(US"unrecognized command");
- smtp_notquit_exit(US"bad-commands", US"500",
- US"Too many unrecognized commands");
- done = 2;
- log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
- "unrecognized commands (last was \"%s\")", host_and_ident(FALSE),
- smtp_cmd_buffer);
- }
- else
- done = synprot_error(L_smtp_syntax_error, 500, NULL,
- US"unrecognized command");
- break;
+ if (unknown_command_count++ >= smtp_max_unknown_commands)
+ {
+ log_write(L_smtp_syntax_error, LOG_MAIN,
+ "SMTP syntax error in \"%s\" %s %s",
+ string_printing(smtp_cmd_buffer), host_and_ident(TRUE),
+ US"unrecognized command");
+ incomplete_transaction_log(US"unrecognized command");
+ smtp_notquit_exit(US"bad-commands", US"500",
+ US"Too many unrecognized commands");
+ done = 2;
+ log_write(0, LOG_MAIN|LOG_REJECT, "SMTP call from %s dropped: too many "
+ "unrecognized commands (last was \"%s\")", host_and_ident(FALSE),
+ string_printing(smtp_cmd_buffer));
+ }
+ else
+ done = synprot_error(L_smtp_syntax_error, 500, NULL,
+ US"unrecognized command");
+ break;
}
/* This label is used by goto's inside loops that want to break out to
return done - 2; /* Convert yield values */
}
+
+
+gstring *
+authres_smtpauth(gstring * g)
+{
+if (!sender_host_authenticated)
+ return g;
+
+g = string_append(g, 2, US";\n\tauth=pass (", sender_host_auth_pubname);
+
+if (Ustrcmp(sender_host_auth_pubname, "tls") == 0)
+ g = authenticated_id
+ ? string_append(g, 2, US") x509.auth=", authenticated_id)
+ : string_cat(g, US") reason=x509.auth");
+else
+ g = authenticated_id
+ ? string_append(g, 2, US") smtp.auth=", authenticated_id)
+ : string_cat(g, US", no id saved)");
+
+if (authenticated_sender)
+ g = string_append(g, 2, US" smtp.mailfrom=", authenticated_sender);
+return g;
+}
+
+
+
+/* vi: aw ai sw=2
+*/
/* End of smtp_in.c */
projects / user / henk / code / exim.git / blobdiff