1 /* $Cambridge: exim/src/src/transports/smtp.c,v 1.8 2005/03/22 15:45:35 ph10 Exp $ */
3 /*************************************************
4 * Exim - an Internet mail transport agent *
5 *************************************************/
7 /* Copyright (c) University of Cambridge 1995 - 2005 */
8 /* See the file NOTICE for conditions of use and distribution. */
14 #define PENDING_DEFER (PENDING + DEFER)
15 #define PENDING_OK (PENDING + OK)
18 /* Options specific to the smtp transport. This transport also supports LMTP
19 over TCP/IP. The options must be in alphabetic order (note that "_" comes
20 before the lower case letters). Some live in the transport_instance block so as
21 to be publicly visible; these are flagged with opt_public. */
23 optionlist smtp_transport_options[] = {
24 { "allow_localhost", opt_bool,
25 (void *)offsetof(smtp_transport_options_block, allow_localhost) },
26 { "authenticated_sender", opt_stringptr,
27 (void *)offsetof(smtp_transport_options_block, authenticated_sender) },
28 { "command_timeout", opt_time,
29 (void *)offsetof(smtp_transport_options_block, command_timeout) },
30 { "connect_timeout", opt_time,
31 (void *)offsetof(smtp_transport_options_block, connect_timeout) },
32 { "connection_max_messages", opt_int | opt_public,
33 (void *)offsetof(transport_instance, connection_max_messages) },
34 { "data_timeout", opt_time,
35 (void *)offsetof(smtp_transport_options_block, data_timeout) },
36 { "delay_after_cutoff", opt_bool,
37 (void *)offsetof(smtp_transport_options_block, delay_after_cutoff) },
38 #ifdef EXPERIMENTAL_DOMAINKEYS
39 { "dk_canon", opt_stringptr,
40 (void *)offsetof(smtp_transport_options_block, dk_canon) },
41 { "dk_domain", opt_stringptr,
42 (void *)offsetof(smtp_transport_options_block, dk_domain) },
43 { "dk_headers", opt_stringptr,
44 (void *)offsetof(smtp_transport_options_block, dk_headers) },
45 { "dk_private_key", opt_stringptr,
46 (void *)offsetof(smtp_transport_options_block, dk_private_key) },
47 { "dk_selector", opt_stringptr,
48 (void *)offsetof(smtp_transport_options_block, dk_selector) },
49 { "dk_strict", opt_stringptr,
50 (void *)offsetof(smtp_transport_options_block, dk_strict) },
52 { "dns_qualify_single", opt_bool,
53 (void *)offsetof(smtp_transport_options_block, dns_qualify_single) },
54 { "dns_search_parents", opt_bool,
55 (void *)offsetof(smtp_transport_options_block, dns_search_parents) },
56 { "fallback_hosts", opt_stringptr,
57 (void *)offsetof(smtp_transport_options_block, fallback_hosts) },
58 { "final_timeout", opt_time,
59 (void *)offsetof(smtp_transport_options_block, final_timeout) },
60 { "gethostbyname", opt_bool,
61 (void *)offsetof(smtp_transport_options_block, gethostbyname) },
62 { "helo_data", opt_stringptr,
63 (void *)offsetof(smtp_transport_options_block, helo_data) },
64 { "hosts", opt_stringptr,
65 (void *)offsetof(smtp_transport_options_block, hosts) },
66 { "hosts_avoid_esmtp", opt_stringptr,
67 (void *)offsetof(smtp_transport_options_block, hosts_avoid_esmtp) },
69 { "hosts_avoid_tls", opt_stringptr,
70 (void *)offsetof(smtp_transport_options_block, hosts_avoid_tls) },
72 { "hosts_max_try", opt_int,
73 (void *)offsetof(smtp_transport_options_block, hosts_max_try) },
74 { "hosts_max_try_hardlimit", opt_int,
75 (void *)offsetof(smtp_transport_options_block, hosts_max_try_hardlimit) },
77 { "hosts_nopass_tls", opt_stringptr,
78 (void *)offsetof(smtp_transport_options_block, hosts_nopass_tls) },
80 { "hosts_override", opt_bool,
81 (void *)offsetof(smtp_transport_options_block, hosts_override) },
82 { "hosts_randomize", opt_bool,
83 (void *)offsetof(smtp_transport_options_block, hosts_randomize) },
84 { "hosts_require_auth", opt_stringptr,
85 (void *)offsetof(smtp_transport_options_block, hosts_require_auth) },
87 { "hosts_require_tls", opt_stringptr,
88 (void *)offsetof(smtp_transport_options_block, hosts_require_tls) },
90 { "hosts_try_auth", opt_stringptr,
91 (void *)offsetof(smtp_transport_options_block, hosts_try_auth) },
92 { "interface", opt_stringptr,
93 (void *)offsetof(smtp_transport_options_block, interface) },
94 { "keepalive", opt_bool,
95 (void *)offsetof(smtp_transport_options_block, keepalive) },
96 { "max_rcpt", opt_int | opt_public,
97 (void *)offsetof(transport_instance, max_addresses) },
98 { "multi_domain", opt_bool | opt_public,
99 (void *)offsetof(transport_instance, multi_domain) },
100 { "port", opt_stringptr,
101 (void *)offsetof(smtp_transport_options_block, port) },
102 { "protocol", opt_stringptr,
103 (void *)offsetof(smtp_transport_options_block, protocol) },
104 { "retry_include_ip_address", opt_bool,
105 (void *)offsetof(smtp_transport_options_block, retry_include_ip_address) },
106 { "serialize_hosts", opt_stringptr,
107 (void *)offsetof(smtp_transport_options_block, serialize_hosts) },
108 { "size_addition", opt_int,
109 (void *)offsetof(smtp_transport_options_block, size_addition) }
111 ,{ "tls_certificate", opt_stringptr,
112 (void *)offsetof(smtp_transport_options_block, tls_certificate) },
113 { "tls_crl", opt_stringptr,
114 (void *)offsetof(smtp_transport_options_block, tls_crl) },
115 { "tls_privatekey", opt_stringptr,
116 (void *)offsetof(smtp_transport_options_block, tls_privatekey) },
117 { "tls_require_ciphers", opt_stringptr,
118 (void *)offsetof(smtp_transport_options_block, tls_require_ciphers) },
119 { "tls_tempfail_tryclear", opt_bool,
120 (void *)offsetof(smtp_transport_options_block, tls_tempfail_tryclear) },
121 { "tls_verify_certificates", opt_stringptr,
122 (void *)offsetof(smtp_transport_options_block, tls_verify_certificates) }
126 /* Size of the options list. An extern variable has to be used so that its
127 address can appear in the tables drtables.c. */
129 int smtp_transport_options_count =
130 sizeof(smtp_transport_options)/sizeof(optionlist);
132 /* Default private options block for the smtp transport. */
134 smtp_transport_options_block smtp_transport_option_defaults = {
136 NULL, /* fallback_hosts */
138 NULL, /* fallback_hostlist */
139 NULL, /* authenticated_sender */
140 US"$primary_hostname", /* helo_data */
141 NULL, /* interface */
143 US"smtp", /* protocol */
144 NULL, /* serialize_hosts */
145 NULL, /* hosts_try_auth */
146 NULL, /* hosts_require_auth */
147 NULL, /* hosts_require_tls */
148 NULL, /* hosts_avoid_tls */
149 NULL, /* hosts_avoid_esmtp */
150 NULL, /* hosts_nopass_tls */
151 5*60, /* command_timeout */
152 5*60, /* connect_timeout; shorter system default overrides */
153 5*60, /* data timeout */
154 10*60, /* final timeout */
155 1024, /* size_addition */
156 5, /* hosts_max_try */
157 50, /* hosts_max_try_hardlimit */
158 FALSE, /* allow_localhost */
159 FALSE, /* gethostbyname */
160 TRUE, /* dns_qualify_single */
161 FALSE, /* dns_search_parents */
162 TRUE, /* delay_after_cutoff */
163 FALSE, /* hosts_override */
164 FALSE, /* hosts_randomize */
165 TRUE, /* keepalive */
166 TRUE /* retry_include_ip_address */
168 ,NULL, /* tls_certificate */
170 NULL, /* tls_privatekey */
171 NULL, /* tls_require_ciphers */
172 NULL, /* tls_verify_certificates */
173 TRUE /* tls_tempfail_tryclear */
175 #ifdef EXPERIMENTAL_DOMAINKEYS
176 ,NULL, /* dk_canon */
177 NULL, /* dk_domain */
178 NULL, /* dk_headers */
179 NULL, /* dk_private_key */
180 NULL, /* dk_selector */
188 static uschar *smtp_command; /* Points to last cmd for error messages */
189 static uschar *mail_command; /* Points to MAIL cmd for error messages */
192 /*************************************************
193 * Setup entry point *
194 *************************************************/
196 /* This function is called when the transport is about to be used,
197 but before running it in a sub-process. It is used for two things:
199 (1) To set the fallback host list in addresses, when delivering.
200 (2) To pass back the interface, port, and protocol options, for use during
201 callout verification.
204 tblock pointer to the transport instance block
205 addrlist list of addresses about to be transported
206 tf if not NULL, pointer to block in which to return options
207 errmsg place for error message (not used)
209 Returns: OK always (FAIL, DEFER not used)
213 smtp_transport_setup(transport_instance *tblock, address_item *addrlist,
214 transport_feedback *tf, uschar **errmsg)
216 smtp_transport_options_block *ob =
217 (smtp_transport_options_block *)(tblock->options_block);
219 errmsg = errmsg; /* Keep picky compilers happy */
221 /* Pass back options if required. This interface is getting very messy. */
225 tf->interface = ob->interface;
227 tf->protocol = ob->protocol;
228 tf->hosts = ob->hosts;
229 tf->hosts_override = ob->hosts_override;
230 tf->hosts_randomize = ob->hosts_randomize;
231 tf->gethostbyname = ob->gethostbyname;
232 tf->qualify_single = ob->dns_qualify_single;
233 tf->search_parents = ob->dns_search_parents;
236 /* Set the fallback host list for all the addresses that don't have fallback
237 host lists, provided that the local host wasn't present in the original host
240 if (!testflag(addrlist, af_local_host_removed))
242 for (; addrlist != NULL; addrlist = addrlist->next)
243 if (addrlist->fallback_hosts == NULL)
244 addrlist->fallback_hosts = ob->fallback_hostlist;
252 /*************************************************
253 * Initialization entry point *
254 *************************************************/
256 /* Called for each instance, after its options have been read, to
257 enable consistency checks to be done, or anything else that needs
260 Argument: pointer to the transport instance block
265 smtp_transport_init(transport_instance *tblock)
267 smtp_transport_options_block *ob =
268 (smtp_transport_options_block *)(tblock->options_block);
270 /* Retry_use_local_part defaults FALSE if unset */
272 if (tblock->retry_use_local_part == TRUE_UNSET)
273 tblock->retry_use_local_part = FALSE;
275 /* Set the default port according to the protocol */
277 if (ob->port == NULL)
278 ob->port = (strcmpic(ob->protocol, US"lmtp") == 0)? US"lmtp" : US"smtp";
280 /* Set up the setup entry point, to be called before subprocesses for this
283 tblock->setup = smtp_transport_setup;
285 /* Complain if any of the timeouts are zero. */
287 if (ob->command_timeout <= 0 || ob->data_timeout <= 0 ||
288 ob->final_timeout <= 0)
289 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
290 "command, data, or final timeout value is zero for %s transport",
293 /* If hosts_override is set and there are local hosts, set the global
294 flag that stops verify from showing router hosts. */
296 if (ob->hosts_override && ob->hosts != NULL) tblock->overrides_hosts = TRUE;
298 /* If there are any fallback hosts listed, build a chain of host items
299 for them, but do not do any lookups at this time. */
301 host_build_hostlist(&(ob->fallback_hostlist), ob->fallback_hosts, FALSE);
308 /*************************************************
309 * Set delivery info into all active addresses *
310 *************************************************/
312 /* Only addresses whose status is >= PENDING are relevant. A lesser
313 status means that an address is not currently being processed.
316 addrlist points to a chain of addresses
317 errno_value to put in each address's errno field
318 msg to put in each address's message field
319 rc to put in each address's transport_return field
321 If errno_value has the special value ERRNO_CONNECTTIMEOUT, ETIMEDOUT is put in
322 the errno field, and RTEF_CTOUT is ORed into the more_errno field, to indicate
323 this particular type of timeout.
329 void set_errno(address_item *addrlist, int errno_value, uschar *msg, int rc)
333 if (errno_value == ERRNO_CONNECTTIMEOUT)
335 errno_value = ETIMEDOUT;
336 orvalue = RTEF_CTOUT;
338 for (addr = addrlist; addr != NULL; addr = addr->next)
340 if (addr->transport_return < PENDING) continue;
341 addr->basic_errno = errno_value;
342 addr->more_errno |= orvalue;
343 if (msg != NULL) addr->message = msg;
344 addr->transport_return = rc;
350 /*************************************************
351 * Check an SMTP response *
352 *************************************************/
354 /* This function is given an errno code and the SMTP response buffer
355 to analyse, together with the host identification for generating messages. It
356 sets an appropriate message and puts the first digit of the response code into
357 the yield variable. If no response was actually read, a suitable digit is
361 host the current host, to get its name for messages
362 errno_value pointer to the errno value
363 more_errno from the top address for use with ERRNO_FILTER_FAIL
364 buffer the SMTP response buffer
365 yield where to put a one-digit SMTP response code
366 message where to put an errror message
368 Returns: TRUE if an SMTP "QUIT" command should be sent, else FALSE
371 static BOOL check_response(host_item *host, int *errno_value, int more_errno,
372 uschar *buffer, int *yield, uschar **message)
376 if (smtp_use_pipelining &&
377 (Ustrcmp(smtp_command, "MAIL") == 0 ||
378 Ustrcmp(smtp_command, "RCPT") == 0 ||
379 Ustrcmp(smtp_command, "DATA") == 0))
382 *yield = '4'; /* Default setting is to give a temporary error */
384 /* Handle response timeout */
386 if (*errno_value == ETIMEDOUT)
388 *message = US string_sprintf("SMTP timeout while connected to %s [%s] "
389 "after %s%s", host->name, host->address, pl, smtp_command);
390 if (transport_count > 0)
391 *message = US string_sprintf("%s (%d bytes written)", *message,
396 /* Handle malformed SMTP response */
398 if (*errno_value == ERRNO_SMTPFORMAT)
400 uschar *malfresp = string_printing(buffer);
401 while (isspace(*malfresp)) malfresp++;
403 *message = string_sprintf("Malformed SMTP reply (an empty line) from "
404 "%s [%s] in response to %s%s", host->name, host->address, pl,
407 *message = string_sprintf("Malformed SMTP reply from %s [%s] in response "
408 "to %s%s: %s", host->name, host->address, pl, smtp_command, malfresp);
412 /* Handle a failed filter process error; can't send QUIT as we mustn't
415 if (*errno_value == ERRNO_FILTER_FAIL)
417 *message = US string_sprintf("transport filter process failed (%d)%s",
419 (more_errno == EX_EXECFAILED)? ": unable to execute command" : "");
423 /* Handle a failed add_headers expansion; can't send QUIT as we mustn't
426 if (*errno_value == ERRNO_CHHEADER_FAIL)
429 US string_sprintf("failed to expand headers_add or headers_remove: %s",
430 expand_string_message);
434 /* Handle failure to write a complete data block */
436 if (*errno_value == ERRNO_WRITEINCOMPLETE)
438 *message = US string_sprintf("failed to write a data block");
442 /* Handle error responses from the remote mailer. */
446 uschar *s = string_printing(buffer);
447 *message = US string_sprintf("SMTP error from remote mailer after %s%s: "
448 "host %s [%s]: %s", pl, smtp_command, host->name, host->address, s);
453 /* No data was read. If there is no errno, this must be the EOF (i.e.
454 connection closed) case, which causes deferral. Otherwise, put the host's
455 identity in the message, leaving the errno value to be interpreted as well. In
456 all cases, we have to assume the connection is now dead. */
458 if (*errno_value == 0)
460 *errno_value = ERRNO_SMTPCLOSED;
461 *message = US string_sprintf("Remote host %s [%s] closed connection "
462 "in response to %s%s", host->name, host->address, pl, smtp_command);
464 else *message = US string_sprintf("%s [%s]", host->name, host->address);
471 /*************************************************
472 * Write error message to logs *
473 *************************************************/
475 /* This writes to the main log and to the message log.
478 addr the address item containing error information
479 host the current host
485 write_logs(address_item *addr, host_item *host)
487 if (addr->message != NULL)
489 uschar *message = addr->message;
490 if (addr->basic_errno > 0)
491 message = string_sprintf("%s: %s", message, strerror(addr->basic_errno));
492 log_write(0, LOG_MAIN, "%s", message);
493 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
497 log_write(0, LOG_MAIN, "%s [%s]: %s",
500 strerror(addr->basic_errno));
501 deliver_msglog("%s %s [%s]: %s\n",
505 strerror(addr->basic_errno));
511 /*************************************************
512 * Synchronize SMTP responses *
513 *************************************************/
515 /* This function is called from smtp_deliver() to receive SMTP responses from
516 the server, and match them up with the commands to which they relate. When
517 PIPELINING is not in use, this function is called after every command, and is
518 therefore somewhat over-engineered, but it is simpler to use a single scheme
519 that works both with and without PIPELINING instead of having two separate sets
522 The set of commands that are buffered up with pipelining may start with MAIL
523 and may end with DATA; in between are RCPT commands that correspond to the
524 addresses whose status is PENDING_DEFER. All other commands (STARTTLS, AUTH,
525 etc.) are never buffered.
527 Errors after MAIL or DATA abort the whole process leaving the response in the
528 buffer. After MAIL, pending responses are flushed, and the original command is
529 re-instated in big_buffer for error messages. For RCPT commands, the remote is
530 permitted to reject some recipient addresses while accepting others. However
531 certain errors clearly abort the whole process. Set the value in
532 transport_return to PENDING_OK if the address is accepted. If there is a
533 subsequent general error, it will get reset accordingly. If not, it will get
534 converted to OK at the end.
537 addrlist the complete address list
538 include_affixes TRUE if affixes include in RCPT
539 sync_addr ptr to the ptr of the one to start scanning at (updated)
540 host the host we are connected to
541 count the number of responses to read
542 pending_MAIL true if the first response is for MAIL
543 pending_DATA 0 if last command sent was not DATA
544 +1 if previously had a good recipient
545 -1 if not previously had a good recipient
546 inblock incoming SMTP block
547 timeout timeout value
548 buffer buffer for reading response
549 buffsize size of buffer
551 Returns: 3 if at least one address had 2xx and one had 5xx
552 2 if at least one address had 5xx but none had 2xx
553 1 if at least one host had a 2xx response, but none had 5xx
554 0 no address had 2xx or 5xx but no errors (all 4xx, or just DATA)
555 -1 timeout while reading RCPT response
556 -2 I/O or other non-response error for RCPT
557 -3 DATA or MAIL failed - errno and buffer set
561 sync_responses(address_item *addrlist, BOOL include_affixes,
562 address_item **sync_addr, host_item *host, int count, BOOL pending_MAIL,
563 int pending_DATA, smtp_inblock *inblock, int timeout, uschar *buffer,
566 address_item *addr = *sync_addr;
569 /* Handle the response for a MAIL command. On error, reinstate the original
570 command in big_buffer for error message use, and flush any further pending
571 responses before returning, except after I/O errors and timeouts. */
576 if (!smtp_read_response(inblock, buffer, buffsize, '2', timeout))
578 Ustrcpy(big_buffer, mail_command); /* Fits, because it came from there! */
579 if (errno == 0 && buffer[0] != 0)
581 uschar flushbuffer[4096];
584 if (!smtp_read_response(inblock, flushbuffer, sizeof(flushbuffer),
586 && (errno != 0 || flushbuffer[0] == 0))
594 if (pending_DATA) count--; /* Number of RCPT responses to come */
596 /* Read and handle the required number of RCPT responses, matching each one up
597 with an address by scanning for the next address whose status is PENDING_DEFER.
602 while (addr->transport_return != PENDING_DEFER) addr = addr->next;
604 /* The address was accepted */
606 if (smtp_read_response(inblock, buffer, buffsize, '2', timeout))
609 addr->transport_return = PENDING_OK;
611 /* If af_dr_retry_exists is set, there was a routing delay on this address;
612 ensure that any address-specific retry record is expunged. */
614 if (testflag(addr, af_dr_retry_exists))
615 retry_add_item(addr, addr->address_retry_key, rf_delete);
618 /* Timeout while reading the response */
620 else if (errno == ETIMEDOUT)
622 int save_errno = errno;
623 uschar *message = string_sprintf("SMTP timeout while connected to %s [%s] "
624 "after RCPT TO:<%s>", host->name, host->address,
625 transport_rcpt_address(addr, include_affixes));
626 set_errno(addrlist, save_errno, message, DEFER);
627 retry_add_item(addr, addr->address_retry_key, 0);
628 host->update_waiting = FALSE;
632 /* Handle other errors in obtaining an SMTP response by returning -1. This
633 will cause all the addresses to be deferred. Restore the SMTP command in
634 big_buffer for which we are checking the response, so the error message
637 else if (errno != 0 || buffer[0] == 0)
639 string_format(big_buffer, big_buffer_size, "RCPT TO:<%s>",
640 transport_rcpt_address(addr, include_affixes));
644 /* Handle SMTP permanent and temporary response codes. */
649 string_sprintf("SMTP error from remote mailer after RCPT TO:<%s>: "
650 "host %s [%s]: %s", transport_rcpt_address(addr, include_affixes),
651 host->name, host->address, string_printing(buffer));
652 deliver_msglog("%s %s\n", tod_stamp(tod_log), addr->message);
654 /* The response was 5xx */
656 if (buffer[0] == '5')
658 addr->transport_return = FAIL;
662 /* The response was 4xx */
666 int bincode = (buffer[1] - '0')*10 + buffer[2] - '0';
668 addr->transport_return = DEFER;
669 addr->basic_errno = ERRNO_RCPT4XX;
670 addr->more_errno |= bincode << 8;
672 /* Log temporary errors if there are more hosts to be tried. */
674 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", addr->message);
676 /* Do not put this message on the list of those waiting for this host,
677 as otherwise it is likely to be tried too often. */
679 host->update_waiting = FALSE;
681 /* Add a retry item for the address so that it doesn't get tried
684 retry_add_item(addr, addr->address_retry_key, 0);
687 } /* Loop for next RCPT response */
689 /* Update where to start at for the next block of responses, unless we
690 have already handled all the addresses. */
692 if (addr != NULL) *sync_addr = addr->next;
694 /* Handle a response to DATA. If we have not had any good recipients, either
695 previously or in this block, the response is ignored. */
697 if (pending_DATA != 0 &&
698 !smtp_read_response(inblock, buffer, buffsize, '3', timeout))
702 if (pending_DATA > 0 || (yield & 1) != 0) return -3;
703 (void)check_response(host, &errno, 0, buffer, &code, &msg);
704 DEBUG(D_transport) debug_printf("%s\nerror for DATA ignored: pipelining "
705 "is in use and there were no good recipients\n", msg);
708 /* All responses read and handled; MAIL (if present) received 2xx and DATA (if
709 present) received 3xx. If any RCPTs were handled and yielded anything other
710 than 4xx, yield will be set non-zero. */
717 /*************************************************
718 * Deliver address list to given host *
719 *************************************************/
721 /* If continue_hostname is not null, we get here only when continuing to
722 deliver down an existing channel. The channel was passed as the standard
725 Otherwise, we have to make a connection to the remote host, and do the
726 initial protocol exchange.
728 When running as an MUA wrapper, if the sender or any recipient is rejected,
729 temporarily or permanently, we force failure for all recipients.
732 addrlist chain of potential addresses to deliver; only those whose
733 transport_return field is set to PENDING_DEFER are currently
734 being processed; others should be skipped - they have either
735 been delivered to an earlier host or IP address, or been
736 failed by one of them.
737 host host to deliver to
738 host_af AF_INET or AF_INET6
739 port TCP/IP port to use, in host byte order
740 interface interface to bind to, or NULL
741 tblock transport instance block
742 copy_host TRUE if host set in addr->host_used must be copied, because
743 it is specific to this call of the transport
744 message_defer set TRUE if yield is OK, but all addresses were deferred
745 because of a non-recipient, non-host failure, that is, a
746 4xx response to MAIL FROM, DATA, or ".". This is a defer
747 that is specific to the message.
748 suppress_tls if TRUE, don't attempt a TLS connection - this is set for
749 a second attempt after TLS initialization fails
751 Returns: OK - the connection was made and the delivery attempted;
752 the result for each address is in its data block.
753 DEFER - the connection could not be made, or something failed
754 while setting up the SMTP session, or there was a
755 non-message-specific error, such as a timeout.
756 ERROR - a filter command is specified for this transport,
757 and there was a problem setting it up; OR helo_data
758 or add_headers or authenticated_sender is specified
759 for this transport, and the string failed to expand
763 smtp_deliver(address_item *addrlist, host_item *host, int host_af, int port,
764 uschar *interface, transport_instance *tblock, BOOL copy_host,
765 BOOL *message_defer, BOOL suppress_tls)
768 address_item *sync_addr;
769 address_item *first_addr = addrlist;
774 time_t start_delivery_time = time(NULL);
775 smtp_transport_options_block *ob =
776 (smtp_transport_options_block *)(tblock->options_block);
777 BOOL lmtp = strcmpic(ob->protocol, US"lmtp") == 0;
779 BOOL send_rset = TRUE;
780 BOOL send_quit = TRUE;
781 BOOL setting_up = TRUE;
782 BOOL completed_address = FALSE;
785 smtp_inblock inblock;
786 smtp_outblock outblock;
787 int max_rcpt = tblock->max_addresses;
788 uschar *local_authenticated_sender = authenticated_sender;
790 uschar *message = NULL;
791 uschar new_message_id[MESSAGE_ID_LENGTH + 1];
794 uschar inbuffer[4096];
795 uschar outbuffer[1024];
797 suppress_tls = suppress_tls; /* stop compiler warning when no TLS support */
799 *message_defer = FALSE;
800 smtp_command = US"initial connection";
801 if (max_rcpt == 0) max_rcpt = 999999;
803 /* Set up the buffer for reading SMTP response packets. */
805 inblock.buffer = inbuffer;
806 inblock.buffersize = sizeof(inbuffer);
807 inblock.ptr = inbuffer;
808 inblock.ptrend = inbuffer;
810 /* Set up the buffer for holding SMTP commands while pipelining */
812 outblock.buffer = outbuffer;
813 outblock.buffersize = sizeof(outbuffer);
814 outblock.ptr = outbuffer;
815 outblock.cmd_count = 0;
816 outblock.authenticating = FALSE;
818 /* Expand the greeting message */
820 helo_data = expand_string(ob->helo_data);
821 if (helo_data == NULL)
823 uschar *message = string_sprintf("failed to expand helo_data: %s",
824 expand_string_message);
825 set_errno(addrlist, 0, message, DEFER);
829 /* If an authenticated_sender override has been specified for this transport
830 instance, expand it. If the expansion is forced to fail, and there was already
831 an authenticated_sender for this message, the original value will be used.
832 Other expansion failures are serious. An empty result is ignored, but there is
833 otherwise no check - this feature is expected to be used with LMTP and other
834 cases where non-standard addresses (e.g. without domains) might be required. */
836 if (ob->authenticated_sender != NULL)
838 uschar *new = expand_string(ob->authenticated_sender);
841 if (!expand_string_forcedfail)
843 uschar *message = string_sprintf("failed to expand "
844 "authenticated_sender: %s", expand_string_message);
845 set_errno(addrlist, 0, message, DEFER);
849 else if (new[0] != 0) local_authenticated_sender = new;
852 /* Make a connection to the host if this isn't a continued delivery, and handle
853 the initial interaction and HELO/EHLO/LHLO. Connect timeout errors are handled
854 specially so they can be identified for retries. */
856 if (continue_hostname == NULL)
858 inblock.sock = outblock.sock =
859 smtp_connect(host, host_af, port, interface, ob->connect_timeout,
861 if (inblock.sock < 0)
863 set_errno(addrlist, (errno == ETIMEDOUT)? ERRNO_CONNECTTIMEOUT : errno,
868 /* The first thing is to wait for an initial OK response. The dreaded "goto"
869 is nevertheless a reasonably clean way of programming this kind of logic,
870 where you want to escape on any error. */
872 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
873 ob->command_timeout)) goto RESPONSE_FAILED;
875 /** Debugging without sending a message
876 addrlist->transport_return = DEFER;
880 /* Errors that occur after this point follow an SMTP command, which is
881 left in big_buffer by smtp_write_command() for use in error messages. */
883 smtp_command = big_buffer;
885 /* Tell the remote who we are...
887 February 1998: A convention has evolved that ESMTP-speaking MTAs include the
888 string "ESMTP" in their greeting lines, so make Exim send EHLO if the
889 greeting is of this form. The assumption was that the far end supports it
890 properly... but experience shows that there are some that give 5xx responses,
891 even though the banner includes "ESMTP" (there's a bloody-minded one that
892 says "ESMTP not spoken here"). Cope with that case.
894 September 2000: Time has passed, and it seems reasonable now to always send
895 EHLO at the start. It is also convenient to make the change while installing
898 July 2003: Joachim Wieland met a broken server that advertises "PIPELINING"
899 but times out after sending MAIL FROM, RCPT TO and DATA all together. There
900 would be no way to send out the mails, so there is now a host list
901 "hosts_avoid_esmtp" that disables ESMTP for special hosts and solves the
902 PIPELINING problem as well. Maybe it can also be useful to cure other
903 problems with broken servers.
905 Exim originally sent "Helo" at this point and ran for nearly a year that way.
906 Then somebody tried it with a Microsoft mailer... It seems that all other
907 mailers use upper case for some reason (the RFC is quite clear about case
908 independence) so, for peace of mind, I gave in. */
910 esmtp = verify_check_this_host(&(ob->hosts_avoid_esmtp), NULL,
911 host->name, host->address, NULL) != OK;
915 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n",
916 lmtp? "LHLO" : "EHLO", helo_data) < 0)
918 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
919 ob->command_timeout))
921 if (errno != 0 || buffer[0] == 0 || lmtp) goto RESPONSE_FAILED;
928 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
933 if (smtp_write_command(&outblock, FALSE, "HELO %s\r\n", helo_data) < 0)
935 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
936 ob->command_timeout)) goto RESPONSE_FAILED;
939 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
942 tls_offered = esmtp &&
943 pcre_exec(regex_STARTTLS, NULL, CS buffer, Ustrlen(buffer), 0,
944 PCRE_EOPT, NULL, 0) >= 0;
948 /* For continuing deliveries down the same channel, the socket is the standard
949 input, and we don't need to redo EHLO here (but may need to do so for TLS - see
950 below). Set up the pointer to where subsequent commands will be left, for
951 error messages. Note that smtp_use_size and smtp_use_pipelining will have been
952 set from the command line if they were set in the process that passed the
957 inblock.sock = outblock.sock = fileno(stdin);
958 smtp_command = big_buffer;
961 /* If TLS is available on this connection, whether continued or not, attempt to
962 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
963 send another EHLO - the server may give a different answer in secure mode. We
964 use a separate buffer for reading the response to STARTTLS so that if it is
965 negative, the original EHLO data is available for subsequent analysis, should
966 the client not be required to use TLS. If the response is bad, copy the buffer
967 for error analysis. */
970 if (tls_offered && !suppress_tls &&
971 verify_check_this_host(&(ob->hosts_avoid_tls), NULL, host->name,
972 host->address, NULL) != OK)
974 uschar buffer2[4096];
975 if (smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") < 0)
978 /* If there is an I/O error, transmission of this message is deferred. If
979 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
980 false, we also defer. However, if there is a temporary rejection of STARTTLS
981 and tls_tempfail_tryclear is true, or if there is an outright rejection of
982 STARTTLS, we carry on. This means we will try to send the message in clear,
983 unless the host is in hosts_require_tls (tested below). */
985 if (!smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
986 ob->command_timeout))
988 Ustrncpy(buffer, buffer2, sizeof(buffer));
989 if (errno != 0 || buffer2[0] == 0 ||
990 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
991 goto RESPONSE_FAILED;
994 /* STARTTLS accepted: try to negotiate a TLS session. */
998 int rc = tls_client_start(inblock.sock, host, addrlist,
999 NULL, /* No DH param */
1000 ob->tls_certificate,
1002 ob->tls_verify_certificates,
1004 ob->tls_require_ciphers,
1005 ob->command_timeout);
1007 /* TLS negotiation failed; give an error. From outside, this function may
1008 be called again to try in clear on a new connection, if the options permit
1009 it for this host. */
1013 save_errno = ERRNO_TLSFAILURE;
1014 message = US"failure while setting up TLS session";
1019 /* TLS session is set up */
1021 for (addr = addrlist; addr != NULL; addr = addr->next)
1023 addr->cipher = tls_cipher;
1024 addr->peerdn = tls_peerdn;
1029 /* If we started TLS, redo the EHLO/LHLO exchange over the secure channel. */
1031 if (tls_active >= 0)
1033 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n", lmtp? "LHLO" : "EHLO",
1036 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1037 ob->command_timeout))
1038 goto RESPONSE_FAILED;
1041 /* If the host is required to use a secure channel, ensure that we
1044 else if (verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
1045 host->address, NULL) == OK)
1047 save_errno = ERRNO_TLSREQUIRED;
1048 message = string_sprintf("a TLS session is required for %s [%s], but %s",
1049 host->name, host->address,
1050 tls_offered? "an attempt to start TLS failed" :
1051 "the server did not offer TLS support");
1056 /* If TLS is active, we have just started it up and re-done the EHLO command,
1057 so its response needs to be analyzed. If TLS is not active and this is a
1058 continued session down a previously-used socket, we haven't just done EHLO, so
1061 if (continue_hostname == NULL
1068 uschar *fail_reason = US"server did not advertise AUTH support";
1070 /* If the response to EHLO specified support for the SIZE parameter, note
1071 this, provided size_addition is non-negative. */
1073 smtp_use_size = esmtp && ob->size_addition >= 0 &&
1074 pcre_exec(regex_SIZE, NULL, CS buffer, Ustrlen(CS buffer), 0,
1075 PCRE_EOPT, NULL, 0) >= 0;
1077 /* Note whether the server supports PIPELINING. If hosts_avoid_esmtp matched
1078 the current host, esmtp will be false, so PIPELINING can never be used. */
1080 smtp_use_pipelining = esmtp &&
1081 pcre_exec(regex_PIPELINING, NULL, CS buffer, Ustrlen(CS buffer), 0,
1082 PCRE_EOPT, NULL, 0) >= 0;
1084 DEBUG(D_transport) debug_printf("%susing PIPELINING\n",
1085 smtp_use_pipelining? "" : "not ");
1087 /* Note if the response to EHLO specifies support for the AUTH extension.
1088 If it has, check that this host is one we want to authenticate to, and do
1089 the business. The host name and address must be available when the
1090 authenticator's client driver is running. */
1092 smtp_authenticated = FALSE;
1093 require_auth = verify_check_this_host(&(ob->hosts_require_auth), NULL,
1094 host->name, host->address, NULL);
1096 if (esmtp && regex_match_and_setup(regex_AUTH, buffer, 0, -1))
1098 uschar *names = string_copyn(expand_nstring[1], expand_nlength[1]);
1099 expand_nmax = -1; /* reset */
1101 /* Must not do this check until after we have saved the result of the
1102 regex match above. */
1104 if (require_auth == OK ||
1105 verify_check_this_host(&(ob->hosts_try_auth), NULL, host->name,
1106 host->address, NULL) == OK)
1109 fail_reason = US"no common mechanisms were found";
1111 DEBUG(D_transport) debug_printf("scanning authentication mechanisms\n");
1113 /* Scan the configured authenticators looking for one which is configured
1114 for use as a client and whose name matches an authentication mechanism
1115 supported by the server. If one is found, attempt to authenticate by
1116 calling its client function. */
1118 for (au = auths; !smtp_authenticated && au != NULL; au = au->next)
1121 if (!au->client) continue;
1123 /* Loop to scan supported server mechanisms */
1128 int len = Ustrlen(au->public_name);
1129 while (isspace(*p)) p++;
1131 if (strncmpic(au->public_name, p, len) != 0 ||
1132 (p[len] != 0 && !isspace(p[len])))
1134 while (*p != 0 && !isspace(*p)) p++;
1138 /* Found data for a listed mechanism. Call its client entry. Set
1139 a flag in the outblock so that data is overwritten after sending so
1140 that reflections don't show it. */
1142 fail_reason = US"authentication attempt(s) failed";
1143 outblock.authenticating = TRUE;
1144 rc = (au->info->clientcode)(au, &inblock, &outblock,
1145 ob->command_timeout, buffer, sizeof(buffer));
1146 outblock.authenticating = FALSE;
1147 DEBUG(D_transport) debug_printf("%s authenticator yielded %d\n",
1150 /* A temporary authentication failure must hold up delivery to
1151 this host. After a permanent authentication failure, we carry on
1152 to try other authentication methods. If all fail hard, try to
1153 deliver the message unauthenticated unless require_auth was set. */
1158 smtp_authenticated = TRUE; /* stops the outer loop */
1161 /* Failure after writing a command */
1166 /* Failure after reading a response */
1169 if (errno != 0 || buffer[0] != '5') goto RESPONSE_FAILED;
1170 log_write(0, LOG_MAIN, "%s authenticator failed H=%s [%s] %s",
1171 au->name, host->name, host->address, buffer);
1174 /* Failure by some other means. In effect, the authenticator
1175 decided it wasn't prepared to handle this case. Typically this
1176 is the result of "fail" in an expansion string. Do we need to
1177 log anything here? */
1182 /* Internal problem, message in buffer. */
1186 set_errno(addrlist, 0, string_copy(buffer), DEFER);
1190 break; /* If not authenticated, try next authenticator */
1191 } /* Loop for scanning supported server mechanisms */
1192 } /* Loop for further authenticators */
1196 /* If we haven't authenticated, but are required to, give up. */
1198 if (require_auth == OK && !smtp_authenticated)
1201 set_errno(addrlist, ERRNO_AUTHFAIL,
1202 string_sprintf("authentication required but %s", fail_reason), DEFER);
1207 /* The setting up of the SMTP call is now complete. Any subsequent errors are
1208 message-specific. */
1212 /* If there is a filter command specified for this transport, we can now
1213 set it up. This cannot be done until the identify of the host is known. */
1215 if (tblock->filter_command != NULL)
1219 sprintf(CS buffer, "%.50s transport", tblock->name);
1220 rc = transport_set_up_command(&transport_filter_argv, tblock->filter_command,
1221 TRUE, DEFER, addrlist, buffer, NULL);
1223 /* On failure, copy the error to all addresses, abandon the SMTP call, and
1228 set_errno(addrlist->next, addrlist->basic_errno, addrlist->message, DEFER);
1235 /* For messages that have more than the maximum number of envelope recipients,
1236 we want to send several transactions down the same SMTP connection. (See
1237 comments in deliver.c as to how this reconciles, heuristically, with
1238 remote_max_parallel.) This optimization was added to Exim after the following
1239 code was already working. The simplest way to put it in without disturbing the
1240 code was to use a goto to jump back to this point when there is another
1241 transaction to handle. */
1244 sync_addr = first_addr;
1248 completed_address = FALSE;
1251 /* Initiate a message transfer. If we know the receiving MTA supports the SIZE
1252 qualification, send it, adding something to the message size to allow for
1253 imprecision and things that get added en route. Exim keeps the number of lines
1254 in a message, so we can give an accurate value for the original message, but we
1255 need some additional to handle added headers. (Double "." characters don't get
1256 included in the count.) */
1263 sprintf(CS p, " SIZE=%d", message_size+message_linecount+ob->size_addition);
1267 /* Add the authenticated sender address if present */
1269 if (smtp_authenticated && local_authenticated_sender != NULL)
1271 string_format(p, sizeof(buffer) - (p-buffer), " AUTH=%s",
1272 auth_xtextencode(local_authenticated_sender,
1273 Ustrlen(local_authenticated_sender)));
1276 /* From here until we send the DATA command, we can make use of PIPELINING
1277 if the server host supports it. The code has to be able to check the responses
1278 at any point, for when the buffer fills up, so we write it totally generally.
1279 When PIPELINING is off, each command written reports that it has flushed the
1282 pending_MAIL = TRUE; /* The block starts with MAIL */
1284 rc = smtp_write_command(&outblock, smtp_use_pipelining,
1285 "MAIL FROM:<%s>%s\r\n", return_path, buffer);
1286 mail_command = string_copy(big_buffer); /* Save for later error message */
1290 case -1: /* Transmission error */
1293 case +1: /* Block was sent */
1294 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1295 ob->command_timeout)) goto RESPONSE_FAILED;
1296 pending_MAIL = FALSE;
1300 /* Pass over all the relevant recipient addresses for this host, which are the
1301 ones that have status PENDING_DEFER. If we are using PIPELINING, we can send
1302 several before we have to read the responses for those seen so far. This
1303 checking is done by a subroutine because it also needs to be done at the end.
1304 Send only up to max_rcpt addresses at a time, leaving first_addr pointing to
1305 the next one if not all are sent.
1307 In the MUA wrapper situation, we want to flush the PIPELINING buffer for the
1308 last address because we want to abort if any recipients have any kind of
1309 problem, temporary or permanent. We know that all recipient addresses will have
1310 the PENDING_DEFER status, because only one attempt is ever made, and we know
1311 that max_rcpt will be large, so all addresses will be done at once. */
1313 for (addr = first_addr;
1314 address_count < max_rcpt && addr != NULL;
1320 if (addr->transport_return != PENDING_DEFER) continue;
1323 no_flush = smtp_use_pipelining && (!mua_wrapper || addr->next != NULL);
1325 /* Now send the RCPT command, and process outstanding responses when
1326 necessary. After a timeout on RCPT, we just end the function, leaving the
1327 yield as OK, because this error can often mean that there is a problem with
1328 just one address, so we don't want to delay the host. */
1330 count = smtp_write_command(&outblock, no_flush, "RCPT TO:<%s>\r\n",
1331 transport_rcpt_address(addr, tblock->rcpt_include_affixes));
1332 if (count < 0) goto SEND_FAILED;
1335 switch(sync_responses(first_addr, tblock->rcpt_include_affixes,
1336 &sync_addr, host, count, pending_MAIL, 0, &inblock,
1337 ob->command_timeout, buffer, sizeof(buffer)))
1339 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1340 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1343 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1344 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1345 case 0: /* No 2xx or 5xx, but no probs */
1348 case -1: goto END_OFF; /* Timeout on RCPT */
1349 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL error */
1351 pending_MAIL = FALSE; /* Dealt with MAIL */
1353 } /* Loop for next address */
1355 /* If we are an MUA wrapper, abort if any RCPTs were rejected, either
1356 permanently or temporarily. We should have flushed and synced after the last
1361 address_item *badaddr;
1362 for (badaddr = first_addr; badaddr != NULL; badaddr = badaddr->next)
1364 if (badaddr->transport_return != PENDING_OK) break;
1366 if (badaddr != NULL)
1368 set_errno(addrlist, 0, badaddr->message, FAIL);
1373 /* If ok is TRUE, we know we have got at least one good recipient, and must now
1374 send DATA, but if it is FALSE (in the normal, non-wrapper case), we may still
1375 have a good recipient buffered up if we are pipelining. We don't want to waste
1376 time sending DATA needlessly, so we only send it if either ok is TRUE or if we
1377 are pipelining. The responses are all handled by sync_responses(). */
1379 if (ok || (smtp_use_pipelining && !mua_wrapper))
1381 int count = smtp_write_command(&outblock, FALSE, "DATA\r\n");
1382 if (count < 0) goto SEND_FAILED;
1383 switch(sync_responses(first_addr, tblock->rcpt_include_affixes, &sync_addr,
1384 host, count, pending_MAIL, ok? +1 : -1, &inblock,
1385 ob->command_timeout, buffer, sizeof(buffer)))
1387 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1388 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1391 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1392 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1393 case 0: break; /* No 2xx or 5xx, but no probs */
1395 case -1: goto END_OFF; /* Timeout on RCPT */
1396 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */
1400 /* Save the first address of the next batch. */
1404 /* If there were no good recipients (but otherwise there have been no
1405 problems), just set ok TRUE, since we have handled address-specific errors
1406 already. Otherwise, it's OK to send the message. Use the check/escape mechanism
1407 for handling the SMTP dot-handling protocol, flagging to apply to headers as
1408 well as body. Set the appropriate timeout value to be used for each chunk.
1409 (Haven't been able to make it work using select() for writing yet.) */
1411 if (!ok) ok = TRUE; else
1413 sigalrm_seen = FALSE;
1414 transport_write_timeout = ob->data_timeout;
1415 smtp_command = US"sending data block"; /* For error messages */
1416 DEBUG(D_transport|D_v)
1417 debug_printf(" SMTP>> writing message and terminating \".\"\n");
1418 transport_count = 0;
1419 #ifdef EXPERIMENTAL_DOMAINKEYS
1420 if ( (ob->dk_private_key != NULL) && (ob->dk_selector != NULL) )
1421 ok = dk_transport_write_message(addrlist, inblock.sock,
1422 topt_use_crlf | topt_end_dot | topt_escape_headers |
1423 (tblock->body_only? topt_no_headers : 0) |
1424 (tblock->headers_only? topt_no_body : 0) |
1425 (tblock->return_path_add? topt_add_return_path : 0) |
1426 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1427 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1428 0, /* No size limit */
1429 tblock->add_headers, tblock->remove_headers,
1430 US".", US"..", /* Escaping strings */
1431 tblock->rewrite_rules, tblock->rewrite_existflags,
1432 ob->dk_private_key, ob->dk_domain, ob->dk_selector,
1433 ob->dk_canon, ob->dk_headers, ob->dk_strict);
1436 ok = transport_write_message(addrlist, inblock.sock,
1437 topt_use_crlf | topt_end_dot | topt_escape_headers |
1438 (tblock->body_only? topt_no_headers : 0) |
1439 (tblock->headers_only? topt_no_body : 0) |
1440 (tblock->return_path_add? topt_add_return_path : 0) |
1441 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1442 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1443 0, /* No size limit */
1444 tblock->add_headers, tblock->remove_headers,
1445 US".", US"..", /* Escaping strings */
1446 tblock->rewrite_rules, tblock->rewrite_existflags);
1448 /* transport_write_message() uses write() because it is called from other
1449 places to write to non-sockets. This means that under some OS (e.g. Solaris)
1450 it can exit with "Broken pipe" as its error. This really means that the
1451 socket got closed at the far end. */
1453 transport_write_timeout = 0; /* for subsequent transports */
1455 /* Failure can either be some kind of I/O disaster (including timeout),
1456 or the failure of a transport filter or the expansion of added headers. */
1460 buffer[0] = 0; /* There hasn't been a response */
1461 goto RESPONSE_FAILED;
1464 /* We used to send the terminating "." explicitly here, but because of
1465 buffering effects at both ends of TCP/IP connections, you don't gain
1466 anything by keeping it separate, so it might as well go in the final
1467 data buffer for efficiency. This is now done by setting the topt_end_dot
1470 smtp_command = US"end of data";
1472 /* For SMTP, we now read a single response that applies to the whole message.
1473 If it is OK, then all the addresses have been delivered. */
1475 if (!lmtp) ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1478 /* For LMTP, we get back a response for every RCPT command that we sent;
1479 some may be accepted and some rejected. For those that get a response, their
1480 status is fixed; any that are accepted have been handed over, even if later
1481 responses crash - at least, that's how I read RFC 2033.
1483 If all went well, mark the recipient addresses as completed, record which
1484 host/IPaddress they were delivered to, and cut out RSET when sending another
1485 message down the same channel. Write the completed addresses to the journal
1486 now so that they are recorded in case there is a crash of hardware or
1487 software before the spool gets updated. Also record the final SMTP
1488 confirmation if needed (for SMTP only). */
1493 int delivery_time = (int)(time(NULL) - start_delivery_time);
1496 uschar *conf = NULL;
1499 /* Make a copy of the host if it is local to this invocation
1500 of the transport. */
1504 thost = store_get(sizeof(host_item));
1506 thost->name = string_copy(host->name);
1507 thost->address = string_copy(host->address);
1511 /* Set up confirmation if needed - applies only to SMTP */
1513 if ((log_extra_selector & LX_smtp_confirmation) != 0 && !lmtp)
1515 uschar *s = string_printing(buffer);
1516 conf = (s == buffer)? (uschar *)string_copy(s) : s;
1519 /* Process all transported addresses - for LMTP, read a status for
1522 for (addr = addrlist; addr != first_addr; addr = addr->next)
1524 if (addr->transport_return != PENDING_OK) continue;
1526 /* LMTP - if the response fails badly (e.g. timeout), use it for all the
1527 remaining addresses. Otherwise, it's a return code for just the one
1532 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1535 if (errno != 0 || buffer[0] == 0) goto RESPONSE_FAILED;
1536 addr->message = string_sprintf("LMTP error after %s: %s",
1537 big_buffer, string_printing(buffer));
1538 addr->transport_return = (buffer[0] == '5')? FAIL : DEFER;
1541 completed_address = TRUE; /* NOW we can set this flag */
1544 /* SMTP, or success return from LMTP for this address. Pass back the
1545 actual port used. */
1547 addr->transport_return = OK;
1548 addr->more_errno = delivery_time;
1550 addr->host_used = thost;
1551 addr->special_action = flag;
1552 addr->message = conf;
1555 /* Update the journal. For homonymic addresses, use the base address plus
1556 the transport name. See lots of comments in deliver.c about the reasons
1557 for the complications when homonyms are involved. Just carry on after
1558 write error, as it may prove possible to update the spool file later. */
1560 if (testflag(addr, af_homonym))
1561 sprintf(CS buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
1563 sprintf(CS buffer, "%.500s\n", addr->unique);
1565 DEBUG(D_deliver) debug_printf("journalling %s", buffer);
1566 len = Ustrlen(CS buffer);
1567 if (write(journal_fd, buffer, len) != len)
1568 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
1569 "%s: %s", buffer, strerror(errno));
1572 /* Ensure the journal file is pushed out to disk. */
1574 if (fsync(journal_fd) < 0)
1575 log_write(0, LOG_MAIN|LOG_PANIC, "failed to fsync journal: %s",
1581 /* Handle general (not specific to one address) failures here. The value of ok
1582 is used to skip over this code on the falling through case. A timeout causes a
1583 deferral. Other errors may defer or fail according to the response code, and
1584 may set up a special errno value, e.g. after connection chopped, which is
1585 assumed if errno == 0 and there is no text in the buffer. If control reaches
1586 here during the setting up phase (i.e. before MAIL FROM) then always defer, as
1587 the problem is not related to this specific message. */
1596 send_quit = check_response(host, &save_errno, addrlist->more_errno,
1597 buffer, &code, &message);
1603 message = US string_sprintf("send() to %s [%s] failed: %s",
1604 host->name, host->address, strerror(save_errno));
1608 /* This label is jumped to directly when a TLS negotiation has failed,
1609 or was not done for a host for which it is required. Values will be set
1610 in message and save_errno, and setting_up will always be true. Treat as
1611 a temporary error. */
1618 /* If the failure happened while setting up the call, see if the failure was
1619 a 5xx response (this will either be on connection, or following HELO - a 5xx
1620 after EHLO causes it to try HELO). If so, fail all addresses, as this host is
1621 never going to accept them. For other errors during setting up (timeouts or
1622 whatever), defer all addresses, and yield DEFER, so that the host is not
1623 tried again for a while. */
1626 ok = FALSE; /* For when reached by GOTO */
1632 set_errno(addrlist, save_errno, message, FAIL);
1636 set_errno(addrlist, save_errno, message, DEFER);
1641 /* If there was an I/O error or timeout or other transportation error,
1642 indicated by errno being non-zero, defer all addresses and yield DEFER,
1643 except for the case of failed add_headers expansion, or a transport filter
1644 failure, when the yield should be ERROR, to stop it trying other hosts.
1646 However, handle timeouts after MAIL FROM or "." and loss of connection after
1647 "." specially. They can indicate a problem with the sender address or with
1648 the contents of the message rather than a real error on the connection.
1649 Therefore, treat these cases in the same way as a 4xx response.
1651 The following condition tests for NOT these special cases. */
1653 else if (save_errno != 0 &&
1654 (save_errno != ETIMEDOUT ||
1655 (Ustrncmp(smtp_command,"MAIL",4) != 0 &&
1656 Ustrncmp(smtp_command,"end ",4) != 0)) &&
1657 (save_errno != ERRNO_SMTPCLOSED ||
1658 Ustrncmp(smtp_command,"end ",4) != 0))
1660 yield = (save_errno == ERRNO_CHHEADER_FAIL ||
1661 save_errno == ERRNO_FILTER_FAIL)? ERROR : DEFER;
1662 set_errno(addrlist, save_errno, message, DEFER);
1665 /* Otherwise we have a message-specific error response from the remote
1666 host. This is one of
1667 (a) negative response or timeout after "mail from"
1668 (b) negative response after "data"
1669 (c) negative response or timeout or dropped connection after "."
1670 It won't be a negative response or timeout after "rcpt to", as that is dealt
1671 with separately above. The action in all cases is to set an appropriate
1672 error code for all the addresses, but to leave yield set to OK because
1673 the host itself has not failed. [It might in practice have failed for a
1674 timeout after MAIL FROM, or "." but if so, we'll discover that at the next
1675 delivery attempt.] For a temporary error, set the message_defer flag, and
1676 write to the logs for information if this is not the last host. The error for
1677 the last host will be logged as part of the address's log line. */
1681 if (mua_wrapper) code = '5'; /* Force hard failure in wrapper mode */
1683 set_errno(addrlist, save_errno, message, (code == '5')? FAIL : DEFER);
1685 /* If there's an errno, the message contains just the identity of
1688 if (code != '5') /* Anything other than 5 is treated as temporary */
1691 message = US string_sprintf("%s: %s", message, strerror(save_errno));
1692 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", message);
1693 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
1694 *message_defer = TRUE;
1700 /* If all has gone well, send_quit will be set TRUE, implying we can end the
1701 SMTP session tidily. However, if there were too many addresses to send in one
1702 message (indicated by first_addr being non-NULL) we want to carry on with the
1703 rest of them. Also, it is desirable to send more than one message down the SMTP
1704 connection if there are several waiting, provided we haven't already sent so
1705 many as to hit the configured limit. The function transport_check_waiting looks
1706 for a waiting message and returns its id. Then transport_pass_socket tries to
1707 set up a continued delivery by passing the socket on to another process. The
1708 variable send_rset is FALSE if a message has just been successfully transfered.
1710 If we are already sending down a continued channel, there may be further
1711 addresses not yet delivered that are aimed at the same host, but which have not
1712 been passed in this run of the transport. In this case, continue_more will be
1713 true, and all we should do is send RSET if necessary, and return, leaving the
1716 However, if no address was disposed of, i.e. all addresses got 4xx errors, we
1717 do not want to continue with other messages down the same channel, because that
1718 can lead to looping between two or more messages, all with the same,
1719 temporarily failing address(es). [The retry information isn't updated yet, so
1720 new processes keep on trying.] We probably also don't want to try more of this
1721 message's addresses either.
1723 If we have started a TLS session, we have to end it before passing the
1724 connection to a new process. However, not all servers can handle this (Exim
1725 can), so we do not pass such a connection on if the host matches
1726 hosts_nopass_tls. */
1729 debug_printf("ok=%d send_quit=%d send_rset=%d continue_more=%d "
1730 "yield=%d first_address is %sNULL\n", ok, send_quit, send_rset,
1731 continue_more, yield, (first_addr == NULL)? "":"not ");
1733 if (completed_address && ok && send_quit)
1736 if (first_addr != NULL || continue_more ||
1739 verify_check_this_host(&(ob->hosts_nopass_tls), NULL, host->name,
1740 host->address, NULL) != OK)
1742 transport_check_waiting(tblock->name, host->name,
1743 tblock->connection_max_messages, new_message_id, &more)
1750 if (! (ok = smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0))
1752 msg = US string_sprintf("send() to %s [%s] failed: %s", host->name,
1753 host->address, strerror(save_errno));
1756 else if (! (ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1757 ob->command_timeout)))
1760 send_quit = check_response(host, &errno, 0, buffer, &code, &msg);
1763 DEBUG(D_transport) debug_printf("%s\n", msg);
1768 /* Either RSET was not needed, or it succeeded */
1772 if (first_addr != NULL) /* More addresses still to be sent */
1773 { /* in this run of the transport */
1774 continue_sequence++; /* Causes * in logging */
1777 if (continue_more) return yield; /* More addresses for another run */
1779 /* Pass the socket to a new Exim process. Before doing so, we must shut
1780 down TLS. Not all MTAs allow for the continuation of the SMTP session
1781 when TLS is shut down. We test for this by sending a new EHLO. If we
1782 don't get a good response, we don't attempt to pass the socket on. */
1785 if (tls_active >= 0)
1788 ok = smtp_write_command(&outblock,FALSE,"EHLO %s\r\n",helo_data) >= 0 &&
1789 smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1790 ob->command_timeout);
1794 /* If the socket is successfully passed, we musn't send QUIT (or
1795 indeed anything!) from here. */
1797 if (ok && transport_pass_socket(tblock->name, host->name, host->address,
1798 new_message_id, inblock.sock))
1804 /* If RSET failed and there are addresses left, they get deferred. */
1806 else set_errno(first_addr, errno, msg, DEFER);
1810 /* End off tidily with QUIT unless the connection has died or the socket has
1811 been passed to another process. There has been discussion on the net about what
1812 to do after sending QUIT. The wording of the RFC suggests that it is necessary
1813 to wait for a response, but on the other hand, there isn't anything one can do
1814 with an error response, other than log it. Exim used to do that. However,
1815 further discussion suggested that it is positively advantageous not to wait for
1816 the response, but to close the session immediately. This is supposed to move
1817 the TCP/IP TIME_WAIT state from the server to the client, thereby removing some
1818 load from the server. (Hosts that are both servers and clients may not see much
1819 difference, of course.) Further discussion indicated that this was safe to do
1820 on Unix systems which have decent implementations of TCP/IP that leave the
1821 connection around for a while (TIME_WAIT) after the application has gone away.
1822 This enables the response sent by the server to be properly ACKed rather than
1823 timed out, as can happen on broken TCP/IP implementations on other OS.
1825 This change is being made on 31-Jul-98. After over a year of trouble-free
1826 operation, the old commented-out code was removed on 17-Sep-99. */
1829 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1837 /* Close the socket, and return the appropriate value, first setting
1838 continue_transport and continue_hostname NULL to prevent any other addresses
1839 that may include the host from trying to re-use a continuation socket. This
1840 works because the NULL setting is passed back to the calling process, and
1841 remote_max_parallel is forced to 1 when delivering over an existing connection,
1843 If all went well and continue_more is set, we shouldn't actually get here if
1844 there are further addresses, as the return above will be taken. However,
1845 writing RSET might have failed, or there may be other addresses whose hosts are
1846 specified in the transports, and therefore not visible at top level, in which
1847 case continue_more won't get set. */
1849 close(inblock.sock);
1850 continue_transport = NULL;
1851 continue_hostname = NULL;
1858 /*************************************************
1859 * Closedown entry point *
1860 *************************************************/
1862 /* This function is called when exim is passed an open smtp channel
1863 from another incarnation, but the message which it has been asked
1864 to deliver no longer exists. The channel is on stdin.
1866 We might do fancy things like looking for another message to send down
1867 the channel, but if the one we sought has gone, it has probably been
1868 delivered by some other process that itself will seek further messages,
1869 so just close down our connection.
1871 Argument: pointer to the transport instance block
1876 smtp_transport_closedown(transport_instance *tblock)
1878 smtp_transport_options_block *ob =
1879 (smtp_transport_options_block *)(tblock->options_block);
1880 smtp_inblock inblock;
1881 smtp_outblock outblock;
1883 uschar inbuffer[4096];
1884 uschar outbuffer[16];
1886 inblock.sock = fileno(stdin);
1887 inblock.buffer = inbuffer;
1888 inblock.buffersize = sizeof(inbuffer);
1889 inblock.ptr = inbuffer;
1890 inblock.ptrend = inbuffer;
1892 outblock.sock = inblock.sock;
1893 outblock.buffersize = sizeof(outbuffer);
1894 outblock.buffer = outbuffer;
1895 outblock.ptr = outbuffer;
1896 outblock.cmd_count = 0;
1897 outblock.authenticating = FALSE;
1899 (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1900 (void)smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1901 ob->command_timeout);
1902 close(inblock.sock);
1907 /*************************************************
1908 * Prepare addresses for delivery *
1909 *************************************************/
1911 /* This function is called to flush out error settings from previous delivery
1912 attempts to other hosts. It also records whether we got here via an MX record
1913 or not in the more_errno field of the address. We are interested only in
1914 addresses that are still marked DEFER - others may have got delivered to a
1915 previously considered IP address. Set their status to PENDING_DEFER to indicate
1916 which ones are relevant this time.
1919 addrlist the list of addresses
1920 host the host we are delivering to
1922 Returns: the first address for this delivery
1925 static address_item *
1926 prepare_addresses(address_item *addrlist, host_item *host)
1928 address_item *first_addr = NULL;
1930 for (addr = addrlist; addr != NULL; addr = addr->next)
1932 if (addr->transport_return != DEFER) continue;
1933 if (first_addr == NULL) first_addr = addr;
1934 addr->transport_return = PENDING_DEFER;
1935 addr->basic_errno = 0;
1936 addr->more_errno = (host->mx >= 0)? 'M' : 'A';
1937 addr->message = NULL;
1939 addr->cipher = NULL;
1940 addr->peerdn = NULL;
1948 /*************************************************
1949 * Main entry point *
1950 *************************************************/
1952 /* See local README for interface details. As this is a remote transport, it is
1953 given a chain of addresses to be delivered in one connection, if possible. It
1954 always returns TRUE, indicating that each address has its own independent
1955 status set, except if there is a setting up problem, in which case it returns
1959 smtp_transport_entry(
1960 transport_instance *tblock, /* data for this instantiation */
1961 address_item *addrlist) /* addresses we are working on */
1965 int hosts_defer = 0;
1967 int hosts_looked_up = 0;
1968 int hosts_retry = 0;
1969 int hosts_serial = 0;
1970 int hosts_total = 0;
1971 int total_hosts_tried = 0;
1973 BOOL expired = TRUE;
1974 BOOL continuing = continue_hostname != NULL;
1975 uschar *expanded_hosts = NULL;
1977 uschar *tid = string_sprintf("%s transport", tblock->name);
1978 smtp_transport_options_block *ob =
1979 (smtp_transport_options_block *)(tblock->options_block);
1980 host_item *hostlist = addrlist->host_list;
1981 host_item *host = NULL;
1985 debug_printf("%s transport entered\n", tblock->name);
1986 for (addr = addrlist; addr != NULL; addr = addr->next)
1987 debug_printf(" %s\n", addr->address);
1988 if (continuing) debug_printf("already connected to %s [%s]\n",
1989 continue_hostname, continue_host_address);
1992 /* If a host list is not defined for the addresses - they must all have the
1993 same one in order to be passed to a single transport - or if the transport has
1994 a host list with hosts_override set, use the host list supplied with the
1995 transport. It is an error for this not to exist. */
1997 if (hostlist == NULL || (ob->hosts_override && ob->hosts != NULL))
1999 if (ob->hosts == NULL)
2001 addrlist->message = string_sprintf("%s transport called with no hosts set",
2003 addrlist->transport_return = PANIC;
2004 return FALSE; /* Only top address has status */
2007 DEBUG(D_transport) debug_printf("using the transport's hosts: %s\n",
2010 /* If the transport's host list contains no '$' characters, and we are not
2011 randomizing, it is fixed and therefore a chain of hosts can be built once
2012 and for all, and remembered for subsequent use by other calls to this
2013 transport. If, on the other hand, the host list does contain '$', or we are
2014 randomizing its order, we have to rebuild it each time. In the fixed case,
2015 as the hosts string will never be used again, it doesn't matter that we
2016 replace all the : characters with zeros. */
2018 if (ob->hostlist == NULL)
2020 uschar *s = ob->hosts;
2022 if (Ustrchr(s, '$') != NULL)
2024 expanded_hosts = expand_string(s);
2025 if (expanded_hosts == NULL)
2027 addrlist->message = string_sprintf("failed to expand list of hosts "
2028 "\"%s\" in %s transport: %s", s, tblock->name, expand_string_message);
2029 addrlist->transport_return = search_find_defer? DEFER : PANIC;
2030 return FALSE; /* Only top address has status */
2032 DEBUG(D_transport) debug_printf("expanded list of hosts \"%s\" to "
2033 "\"%s\"\n", s, expanded_hosts);
2037 if (ob->hosts_randomize) s = expanded_hosts = string_copy(s);
2039 host_build_hostlist(&hostlist, s, ob->hosts_randomize);
2041 /* If there was no expansion of hosts, save the host list for
2044 if (expanded_hosts == NULL) ob->hostlist = hostlist;
2047 /* This is not the first time this transport has been run in this delivery;
2048 the host list was built previously. */
2050 else hostlist = ob->hostlist;
2053 /* The host list was supplied with the address. If hosts_randomize is set, we
2054 must sort it into a random order if it did not come from MX records and has not
2055 already been randomized (but don't bother if continuing down an existing
2058 else if (ob->hosts_randomize && hostlist->mx == MX_NONE && !continuing)
2060 host_item *newlist = NULL;
2061 while (hostlist != NULL)
2063 host_item *h = hostlist;
2064 hostlist = hostlist->next;
2066 h->sort_key = random_number(100);
2068 if (newlist == NULL)
2073 else if (h->sort_key < newlist->sort_key)
2080 host_item *hh = newlist;
2081 while (hh->next != NULL)
2083 if (h->sort_key < hh->next->sort_key) break;
2091 hostlist = addrlist->host_list = newlist;
2095 /* Sort out the port. Set up a string for adding to the retry key if the port
2096 number is not the standard SMTP port. */
2098 if (!smtp_get_port(ob->port, addrlist, &port, tid)) return FALSE;
2099 pistring = string_sprintf(":%d", port);
2100 if (Ustrcmp(pistring, ":25") == 0) pistring = US"";
2103 /* For each host-plus-IP-address on the list:
2105 . If this is a continued delivery and the host isn't the one with the
2106 current connection, skip.
2108 . If the status is unusable (i.e. previously failed or retry checked), skip.
2110 . If no IP address set, get the address, either by turning the name into
2111 an address, calling gethostbyname if gethostbyname is on, or by calling
2112 the DNS. The DNS may yield multiple addresses, in which case insert the
2113 extra ones into the list.
2115 . Get the retry data if not previously obtained for this address and set the
2116 field which remembers the state of this address. Skip if the retry time is
2117 not reached. If not, remember whether retry data was found. The retry string
2118 contains both the name and the IP address.
2120 . Scan the list of addresses and mark those whose status is DEFER as
2121 PENDING_DEFER. These are the only ones that will be processed in this cycle
2124 . Make a delivery attempt - addresses marked PENDING_DEFER will be tried.
2125 Some addresses may be successfully delivered, others may fail, and yet
2126 others may get temporary errors and so get marked DEFER.
2128 . The return from the delivery attempt is OK if a connection was made and a
2129 valid SMTP dialogue was completed. Otherwise it is DEFER.
2131 . If OK, add a "remove" retry item for this host/IPaddress, if any.
2133 . If fail to connect, or other defer state, add a retry item.
2135 . If there are any addresses whose status is still DEFER, carry on to the
2136 next host/IPaddress, unless we have tried the number of hosts given
2137 by hosts_max_try or hosts_max_try_hardlimit; otherwise return. Note that
2138 there is some fancy logic for hosts_max_try that means its limit can be
2139 overstepped in some circumstances.
2141 If we get to the end of the list, all hosts have deferred at least one address,
2142 or not reached their retry times. If delay_after_cutoff is unset, it requests a
2143 delivery attempt to those hosts whose last try was before the arrival time of
2144 the current message. To cope with this, we have to go round the loop a second
2145 time. After that, set the status and error data for any addresses that haven't
2146 had it set already. */
2148 for (cutoff_retry = 0; expired &&
2149 cutoff_retry < ((ob->delay_after_cutoff)? 1 : 2);
2152 host_item *nexthost = NULL;
2153 int unexpired_hosts_tried = 0;
2155 for (host = hostlist;
2157 unexpired_hosts_tried < ob->hosts_max_try &&
2158 total_hosts_tried < ob->hosts_max_try_hardlimit;
2164 BOOL serialized = FALSE;
2165 BOOL host_is_expired = FALSE;
2166 BOOL message_defer = FALSE;
2167 BOOL ifchanges = FALSE;
2168 BOOL some_deferred = FALSE;
2169 address_item *first_addr = NULL;
2170 uschar *interface = NULL;
2171 uschar *retry_host_key = NULL;
2172 uschar *retry_message_key = NULL;
2173 uschar *serialize_key = NULL;
2175 /* Set the flag requesting that this host be added to the waiting
2176 database if the delivery fails temporarily or if we are running with
2177 queue_smtp or a 2-stage queue run. This gets unset for certain
2178 kinds of error, typically those that are specific to the message. */
2180 host->update_waiting = TRUE;
2182 /* If the address hasn't yet been obtained from the host name, look it up
2183 now, unless the host is already marked as unusable. If it is marked as
2184 unusable, it means that the router was unable to find its IP address (in
2185 the DNS or wherever) OR we are in the 2nd time round the cutoff loop, and
2186 the lookup failed last time. We don't get this far if *all* MX records
2187 point to non-existent hosts; that is treated as a hard error.
2189 We can just skip this host entirely. When the hosts came from the router,
2190 the address will timeout based on the other host(s); when the address is
2191 looked up below, there is an explicit retry record added.
2193 Note that we mustn't skip unusable hosts if the address is not unset; they
2194 may be needed as expired hosts on the 2nd time round the cutoff loop. */
2196 if (host->address == NULL)
2198 uschar *canonical_name;
2200 if (host->status >= hstatus_unusable)
2202 DEBUG(D_transport) debug_printf("%s has no address and is unusable - skipping\n",
2207 DEBUG(D_transport) debug_printf("getting address for %s\n", host->name);
2211 /* Find by name if so configured, or if it's an IP address. We don't
2212 just copy the IP address, because we need the test-for-local to happen. */
2214 if (ob->gethostbyname || string_is_ip_address(host->name, NULL) > 0)
2215 rc = host_find_byname(host, NULL, &canonical_name, TRUE);
2218 int flags = HOST_FIND_BY_A;
2219 if (ob->dns_qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
2220 if (ob->dns_search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
2221 rc = host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
2222 &canonical_name, NULL);
2225 /* Failure to find the host at this time (usually DNS temporary failure)
2226 is really a kind of routing failure rather than a transport failure.
2227 Therefore we add a retry item of the routing kind, not to stop us trying
2228 to look this name up here again, but to ensure the address gets timed
2229 out if the failures go on long enough. A complete failure at this point
2230 commonly points to a configuration error, but the best action is still
2231 to carry on for the next host. */
2233 if (rc == HOST_FIND_AGAIN || rc == HOST_FIND_FAILED)
2235 retry_add_item(addrlist, string_sprintf("R:%s", host->name), 0);
2237 if (rc == HOST_FIND_AGAIN) hosts_defer++; else hosts_fail++;
2238 DEBUG(D_transport) debug_printf("rc = %s for %s\n", (rc == HOST_FIND_AGAIN)?
2239 "HOST_FIND_AGAIN" : "HOST_FIND_FAILED", host->name);
2240 host->status = hstatus_unusable;
2242 for (addr = addrlist; addr != NULL; addr = addr->next)
2244 if (addr->transport_return != DEFER) continue;
2245 addr->basic_errno = ERRNO_UNKNOWNHOST;
2247 string_sprintf("failed to lookup IP address for %s", host->name);
2252 /* If the host is actually the local host, we may have a problem, or
2253 there may be some cunning configuration going on. In the problem case,
2254 log things and give up. The default transport status is already DEFER. */
2256 if (rc == HOST_FOUND_LOCAL && !ob->allow_localhost)
2258 for (addr = addrlist; addr != NULL; addr = addr->next)
2260 addr->basic_errno = 0;
2261 addr->message = string_sprintf("%s transport found host %s to be "
2262 "local", tblock->name, host->name);
2266 } /* End of block for IP address lookup */
2268 /* If this is a continued delivery, we are interested only in the host
2269 which matches the name of the existing open channel. The check is put
2270 here after the local host lookup, in case the name gets expanded as a
2271 result of the lookup. Set expired FALSE, to save the outer loop executing
2274 if (continuing && (Ustrcmp(continue_hostname, host->name) != 0 ||
2275 Ustrcmp(continue_host_address, host->address) != 0))
2278 continue; /* With next host */
2281 /* The default next host is the next host. :-) But this can vary if the
2282 hosts_max_try limit is hit (see below). NOTE: we cannot put this setting
2283 earlier than this, because a multihomed host whose addresses are not looked
2284 up till just above will add to the host list. */
2286 nexthost = host->next;
2288 /* If queue_smtp is set (-odqs or the first part of a 2-stage run), or the
2289 domain is in queue_smtp_domains, we don't actually want to attempt any
2290 deliveries. When doing a queue run, queue_smtp_domains is always unset. If
2291 there is a lookup defer in queue_smtp_domains, proceed as if the domain
2292 were not in it. We don't want to hold up all SMTP deliveries! Except when
2293 doing a two-stage queue run, don't do this if forcing. */
2295 if ((!deliver_force || queue_2stage) && (queue_smtp ||
2296 match_isinlist(addrlist->domain, &queue_smtp_domains, 0, NULL, NULL,
2297 MCL_DOMAIN, TRUE, NULL) == OK))
2300 for (addr = addrlist; addr != NULL; addr = addr->next)
2302 if (addr->transport_return != DEFER) continue;
2303 addr->message = US"domain matches queue_smtp_domains, or -odqs set";
2305 continue; /* With next host */
2308 /* Count hosts being considered - purely for an intelligent comment
2309 if none are usable. */
2313 /* Set $host and $host address now in case they are needed for the
2314 interface expansion or the serialize_hosts check; they remain set if an
2315 actual delivery happens. */
2317 deliver_host = host->name;
2318 deliver_host_address = host->address;
2320 /* Select IPv4 or IPv6, and choose an outgoing interface. If the interface
2321 string changes upon expansion, we must add it to the key that is used for
2322 retries, because connections to the same host from a different interface
2323 should be treated separately. */
2325 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET : AF_INET6;
2326 if (!smtp_get_interface(ob->interface, host_af, addrlist, &ifchanges,
2329 if (ifchanges) pistring = string_sprintf("%s/%s", pistring, interface);
2331 /* The first time round the outer loop, check the status of the host by
2332 inspecting the retry data. The second time round, we are interested only
2333 in expired hosts that haven't been tried since this message arrived. */
2335 if (cutoff_retry == 0)
2337 /* Ensure the status of the address is set by checking retry data if
2338 necessary. There maybe host-specific retry data (applicable to all
2339 messages) and also data for retries of a specific message at this host.
2340 If either of these retry records are actually read, the keys used are
2341 returned to save recomputing them later. */
2343 host_is_expired = retry_check_address(addrlist->domain, host, pistring,
2344 ob->retry_include_ip_address, &retry_host_key, &retry_message_key);
2346 DEBUG(D_transport) debug_printf("%s [%s]%s status = %s\n", host->name,
2347 (host->address == NULL)? US"" : host->address, pistring,
2348 (host->status == hstatus_usable)? "usable" :
2349 (host->status == hstatus_unusable)? "unusable" :
2350 (host->status == hstatus_unusable_expired)? "unusable (expired)" : "?");
2352 /* Skip this address if not usable at this time, noting if it wasn't
2353 actually expired, both locally and in the address. */
2355 switch (host->status)
2357 case hstatus_unusable:
2359 setflag(addrlist, af_retry_skipped);
2362 case hstatus_unusable_expired:
2365 case hwhy_retry: hosts_retry++; break;
2366 case hwhy_failed: hosts_fail++; break;
2367 case hwhy_deferred: hosts_defer++; break;
2370 /* If there was a retry message key, implying that previously there
2371 was a message-specific defer, we don't want to update the list of
2372 messages waiting for this host. */
2374 if (retry_message_key != NULL) host->update_waiting = FALSE;
2375 continue; /* With the next host or IP address */
2379 /* Second time round the loop: if the address is set but expired, and
2380 the message is newer than the last try, let it through. */
2384 if (host->address == NULL ||
2385 host->status != hstatus_unusable_expired ||
2386 host->last_try > received_time)
2389 debug_printf("trying expired host %s [%s]%s\n",
2390 host->name, host->address, pistring);
2391 host_is_expired = TRUE;
2394 /* Setting "expired=FALSE" doesn't actually mean not all hosts are expired;
2395 it remains TRUE only if all hosts are expired and none are actually tried.
2400 /* If this host is listed as one to which access must be serialized,
2401 see if another Exim process has a connection to it, and if so, skip
2402 this host. If not, update the database to record our connection to it
2403 and remember this for later deletion. Do not do any of this if we are
2404 sending the message down a pre-existing connection. */
2407 verify_check_this_host(&(ob->serialize_hosts), NULL, host->name,
2408 host->address, NULL) == OK)
2410 serialize_key = string_sprintf("host-serialize-%s", host->name);
2411 if (!enq_start(serialize_key))
2414 debug_printf("skipping host %s because another Exim process "
2415 "is connected to it\n", host->name);
2422 /* OK, we have an IP address that is not waiting for its retry time to
2423 arrive (it might be expired) OR (second time round the loop) we have an
2424 expired host that hasn't been tried since the message arrived. Have a go
2425 at delivering the message to it. First prepare the addresses by flushing
2426 out the result of previous attempts, and finding the first address that
2427 is still to be delivered. */
2429 first_addr = prepare_addresses(addrlist, host);
2431 DEBUG(D_transport) debug_printf("delivering %s to %s [%s] (%s%s)\n",
2432 message_id, host->name, host->address, addrlist->address,
2433 (addrlist->next == NULL)? "" : ", ...");
2435 set_process_info("delivering %s to %s [%s] (%s%s)",
2436 message_id, host->name, host->address, addrlist->address,
2437 (addrlist->next == NULL)? "" : ", ...");
2439 /* This is not for real; don't do the delivery. If there are
2440 any remaining hosts, list them. */
2445 set_errno(addrlist, 0, NULL, OK);
2446 for (addr = addrlist; addr != NULL; addr = addr->next)
2448 addr->host_used = host;
2449 addr->special_action = '*';
2450 addr->message = US"delivery bypassed by -N option";
2454 debug_printf("*** delivery by %s transport bypassed by -N option\n"
2455 "*** host and remaining hosts:\n", tblock->name);
2456 for (host2 = host; host2 != NULL; host2 = host2->next)
2457 debug_printf(" %s [%s]\n", host2->name,
2458 (host2->address == NULL)? US"unset" : host2->address);
2463 /* This is for real. If the host is expired, we don't count it for
2464 hosts_max_retry. This ensures that all hosts must expire before an address
2465 is timed out, unless hosts_max_try_hardlimit (which protects against
2466 lunatic DNS configurations) is reached.
2468 If the host is not expired and we are about to hit the hosts_max_retry
2469 limit, check to see if there is a subsequent hosts with a different MX
2470 value. If so, make that the next host, and don't count this one. This is a
2471 heuristic to make sure that different MXs do get tried. With a normal kind
2472 of retry rule, they would get tried anyway when the earlier hosts were
2473 delayed, but if the domain has a "retry every time" type of rule - as is
2474 often used for the the very large ISPs, that won't happen. */
2478 if (!host_is_expired && ++unexpired_hosts_tried >= ob->hosts_max_try)
2482 debug_printf("hosts_max_try limit reached with this host\n");
2483 for (h = host; h != NULL; h = h->next)
2484 if (h->mx != host->mx) break;
2488 unexpired_hosts_tried--;
2489 DEBUG(D_transport) debug_printf("however, a higher MX host exists "
2490 "and will be tried\n");
2494 /* Attempt the delivery. */
2496 total_hosts_tried++;
2497 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2498 expanded_hosts != NULL, &message_defer, FALSE);
2501 OK => connection made, each address contains its result;
2502 message_defer is set for message-specific defers (when all
2503 recipients are marked defer)
2504 DEFER => there was a non-message-specific delivery problem;
2505 ERROR => there was a problem setting up the arguments for a filter,
2506 or there was a problem with expanding added headers
2509 /* If the result is not OK, there was a non-message-specific problem.
2510 If the result is DEFER, we need to write to the logs saying what happened
2511 for this particular host, except in the case of authentication and TLS
2512 failures, where the log has already been written. If all hosts defer a
2513 general message is written at the end. */
2515 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL &&
2516 first_addr->basic_errno != ERRNO_TLSFAILURE)
2517 write_logs(first_addr, host);
2519 /* If STARTTLS was accepted, but there was a failure in setting up the
2520 TLS session (usually a certificate screwup), and the host is not in
2521 hosts_require_tls, and tls_tempfail_tryclear is true, try again, with
2522 TLS forcibly turned off. We have to start from scratch with a new SMTP
2523 connection. That's why the retry is done from here, not from within
2524 smtp_deliver(). [Rejections of STARTTLS itself don't screw up the
2525 session, so the in-clear transmission after those errors, if permitted,
2526 happens inside smtp_deliver().] */
2529 if (rc == DEFER && first_addr->basic_errno == ERRNO_TLSFAILURE &&
2530 ob->tls_tempfail_tryclear &&
2531 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
2532 host->address, NULL) != OK)
2534 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
2535 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
2536 first_addr = prepare_addresses(addrlist, host);
2537 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2538 expanded_hosts != NULL, &message_defer, TRUE);
2539 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL)
2540 write_logs(first_addr, host);
2545 /* Delivery attempt finished */
2547 rs = (rc == OK)? US"OK" : (rc == DEFER)? US"DEFER" : (rc == ERROR)?
2550 set_process_info("delivering %s: just tried %s [%s] for %s%s: result %s",
2551 message_id, host->name, host->address, addrlist->address,
2552 (addrlist->next == NULL)? "" : " (& others)", rs);
2554 /* Release serialization if set up */
2556 if (serialized) enq_end(serialize_key);
2558 /* If the result is DEFER, or if a host retry record is known to exist, we
2559 need to add an item to the retry chain for updating the retry database
2560 at the end of delivery. We only need to add the item to the top address,
2561 of course. Also, if DEFER, we mark the IP address unusable so as to skip it
2562 for any other delivery attempts using the same address. (It is copied into
2563 the unusable tree at the outer level, so even if different address blocks
2564 contain the same address, it still won't get tried again.) */
2566 if (rc == DEFER || retry_host_key != NULL)
2568 int delete_flag = (rc != DEFER)? rf_delete : 0;
2569 if (retry_host_key == NULL)
2571 retry_host_key = ob->retry_include_ip_address?
2572 string_sprintf("T:%S:%s%s", host->name, host->address, pistring) :
2573 string_sprintf("T:%S%s", host->name, pistring);
2576 /* If a delivery of another message over an existing SMTP connection
2577 yields DEFER, we do NOT set up retry data for the host. This covers the
2578 case when there are delays in routing the addresses in the second message
2579 that are so long that the server times out. This is alleviated by not
2580 routing addresses that previously had routing defers when handling an
2581 existing connection, but even so, this case may occur (e.g. if a
2582 previously happily routed address starts giving routing defers). If the
2583 host is genuinely down, another non-continued message delivery will
2584 notice it soon enough. */
2586 if (delete_flag != 0 || !continuing)
2587 retry_add_item(first_addr, retry_host_key, rf_host | delete_flag);
2589 /* We may have tried an expired host, if its retry time has come; ensure
2590 the status reflects the expiry for the benefit of any other addresses. */
2594 host->status = (host_is_expired)?
2595 hstatus_unusable_expired : hstatus_unusable;
2596 host->why = hwhy_deferred;
2600 /* If message_defer is set (host was OK, but every recipient got deferred
2601 because of some message-specific problem), or if that had happened
2602 previously so that a message retry key exists, add an appropriate item
2603 to the retry chain. Note that if there was a message defer but now there is
2604 a host defer, the message defer record gets deleted. That seems perfectly
2605 reasonable. Also, stop the message from being remembered as waiting
2608 if (message_defer || retry_message_key != NULL)
2610 int delete_flag = message_defer? 0 : rf_delete;
2611 if (retry_message_key == NULL)
2613 retry_message_key = ob->retry_include_ip_address?
2614 string_sprintf("T:%S:%s%s:%s", host->name, host->address, pistring,
2616 string_sprintf("T:%S%s:%s", host->name, pistring, message_id);
2618 retry_add_item(addrlist, retry_message_key,
2619 rf_message | rf_host | delete_flag);
2620 host->update_waiting = FALSE;
2623 /* Any return other than DEFER (that is, OK or ERROR) means that the
2624 addresses have got their final statuses filled in for this host. In the OK
2625 case, see if any of them are deferred. */
2629 for (addr = addrlist; addr != NULL; addr = addr->next)
2631 if (addr->transport_return == DEFER)
2633 some_deferred = TRUE;
2639 /* If no addresses deferred or the result was ERROR, return. We do this for
2640 ERROR because a failing filter set-up or add_headers expansion is likely to
2641 fail for any host we try. */
2643 if (rc == ERROR || (rc == OK && !some_deferred))
2645 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2646 return TRUE; /* Each address has its status */
2649 /* If the result was DEFER or some individual addresses deferred, let
2650 the loop run to try other hosts with the deferred addresses, except for the
2651 case when we were trying to deliver down an existing channel and failed.
2652 Don't try any other hosts in this case. */
2654 if (continuing) break;
2656 /* If the whole delivery, or some individual addresses, were deferred and
2657 there are more hosts that could be tried, do not count this host towards
2658 the hosts_max_try limit if the age of the message is greater than the
2659 maximum retry time for this host. This means we may try try all hosts,
2660 ignoring the limit, when messages have been around for some time. This is
2661 important because if we don't try all hosts, the address will never time
2662 out. NOTE: this does not apply to hosts_max_try_hardlimit. */
2664 if ((rc == DEFER || some_deferred) && nexthost != NULL)
2667 retry_config *retry = retry_find_config(host->name, NULL, 0, 0);
2669 if (retry != NULL && retry->rules != NULL)
2671 retry_rule *last_rule;
2672 for (last_rule = retry->rules;
2673 last_rule->next != NULL;
2674 last_rule = last_rule->next);
2675 timedout = time(NULL) - received_time > last_rule->timeout;
2677 else timedout = TRUE; /* No rule => timed out */
2681 unexpired_hosts_tried--;
2682 DEBUG(D_transport) debug_printf("temporary delivery error(s) override "
2683 "hosts_max_try (message older than host's retry time)\n");
2686 } /* End of loop for trying multiple hosts. */
2688 /* This is the end of the loop that repeats iff expired is TRUE and
2689 ob->delay_after_cutoff is FALSE. The second time round we will
2690 try those hosts that haven't been tried since the message arrived. */
2694 debug_printf("all IP addresses skipped or deferred at least one address\n");
2695 if (expired && !ob->delay_after_cutoff && cutoff_retry == 0)
2696 debug_printf("retrying IP addresses not tried since message arrived\n");
2701 /* Get here if all IP addresses are skipped or defer at least one address. In
2702 MUA wrapper mode, this will happen only for connection or other non-message-
2703 specific failures. Force the delivery status for all addresses to FAIL. */
2707 for (addr = addrlist; addr != NULL; addr = addr->next)
2708 addr->transport_return = FAIL;
2712 /* In the normal, non-wrapper case, add a standard message to each deferred
2713 address if there hasn't been an error, that is, if it hasn't actually been
2714 tried this time. The variable "expired" will be FALSE if any deliveries were
2715 actually tried, or if there was at least one host that was not expired. That
2716 is, it is TRUE only if no deliveries were tried and all hosts were expired. If
2717 a delivery has been tried, an error code will be set, and the failing of the
2718 message is handled by the retry code later.
2720 If queue_smtp is set, or this transport was called to send a subsequent message
2721 down an existing TCP/IP connection, and something caused the host not to be
2722 found, we end up here, but can detect these cases and handle them specially. */
2724 for (addr = addrlist; addr != NULL; addr = addr->next)
2726 /* If host is not NULL, it means that we stopped processing the host list
2727 because of hosts_max_try or hosts_max_try_hardlimit. In the former case, this
2728 means we need to behave as if some hosts were skipped because their retry
2729 time had not come. Specifically, this prevents the address from timing out.
2730 However, if we have hit hosts_max_try_hardlimit, we want to behave as if all
2731 hosts were tried. */
2735 if (total_hosts_tried >= ob->hosts_max_try_hardlimit)
2738 debug_printf("hosts_max_try_hardlimit reached: behave as if all "
2739 "hosts were tried\n");
2744 debug_printf("hosts_max_try limit caused some hosts to be skipped\n");
2745 setflag(addr, af_retry_skipped);
2749 if (queue_smtp) /* no deliveries attempted */
2751 addr->transport_return = DEFER;
2752 addr->basic_errno = 0;
2753 addr->message = US"SMTP delivery explicitly queued";
2756 else if (addr->transport_return == DEFER &&
2757 (addr->basic_errno == ERRNO_UNKNOWNERROR || addr->basic_errno == 0) &&
2758 addr->message == NULL)
2760 addr->basic_errno = ERRNO_HRETRY;
2761 if (continue_hostname != NULL)
2763 addr->message = US"no host found for existing SMTP connection";
2767 addr->message = (ob->delay_after_cutoff)?
2768 US"retry time not reached for any host after a long failure period" :
2769 US"all hosts have been failing for a long time and were last tried "
2770 "after this message arrived";
2772 /* If we are already using fallback hosts, or there are no fallback hosts
2773 defined, convert the result to FAIL to cause a bounce. */
2775 if (addr->host_list == addr->fallback_hosts ||
2776 addr->fallback_hosts == NULL)
2777 addr->transport_return = FAIL;
2781 if (hosts_retry == hosts_total)
2782 addr->message = US"retry time not reached for any host";
2783 else if (hosts_fail == hosts_total)
2784 addr->message = US"all host address lookups failed permanently";
2785 else if (hosts_defer == hosts_total)
2786 addr->message = US"all host address lookups failed temporarily";
2787 else if (hosts_serial == hosts_total)
2788 addr->message = US"connection limit reached for all hosts";
2789 else if (hosts_fail+hosts_defer == hosts_total)
2790 addr->message = US"all host address lookups failed";
2791 else addr->message = US"some host address lookups failed and retry time "
2792 "not reached for other hosts or connection limit reached";
2797 /* Update the database which keeps information about which messages are waiting
2798 for which hosts to become available. Each host in the list has a flag which is
2799 set if the data is to be updated. For some message-specific errors, the flag is
2800 turned off because we don't want follow-on deliveries in those cases. */
2802 transport_update_waiting(hostlist, tblock->name);
2806 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2808 return TRUE; /* Each address has its status */
2811 /* End of transport/smtp.c */