+/*************************************************
+* Handle SMTP exit when QUIT is not given *
+*************************************************/
+
+/* This function provides a logging/statistics hook for when an SMTP connection
+is dropped on the floor or the other end goes away. It's a global function
+because it's called from receive.c as well as this module. As well as running
+the NOTQUIT ACL, if there is one, this function also outputs a final SMTP
+response, either with a custom message from the ACL, or using a default. There
+is one case, however, when no message is output - after "drop". In that case,
+the ACL that obeyed "drop" has already supplied the custom message, and NULL is
+passed to this function.
+
+In case things go wrong while processing this function, causing an error that
+may re-enter this funtion, there is a recursion check.
+
+Arguments:
+ reason What $smtp_notquit_reason will be set to in the ACL;
+ if NULL, the ACL is not run
+ code The error code to return as part of the response
+ defaultrespond The default message if there's no user_msg
+
+Returns: Nothing
+*/
+
+void
+smtp_notquit_exit(uschar *reason, uschar *code, uschar *defaultrespond, ...)
+{
+int rc;
+uschar *user_msg = NULL;
+uschar *log_msg = NULL;
+
+/* Check for recursive acll */
+
+if (smtp_exit_function_called)
+ {
+ log_write(0, LOG_PANIC, "smtp_notquit_exit() called more than once (%s)",
+ reason);
+ return;
+ }
+smtp_exit_function_called = TRUE;
+
+/* Call the not-QUIT ACL, if there is one, unless no reason is given. */
+
+if (acl_smtp_notquit && reason)
+ {
+ smtp_notquit_reason = reason;
+ if ((rc = acl_check(ACL_WHERE_NOTQUIT, NULL, acl_smtp_notquit, &user_msg,
+ &log_msg)) == ERROR)
+ log_write(0, LOG_MAIN|LOG_PANIC, "ACL for not-QUIT returned ERROR: %s",
+ log_msg);
+ }
+
+/* Write an SMTP response if we are expected to give one. As the default
+responses are all internal, they should always fit in the buffer, but code a
+warning, just in case. Note that string_vformat() still leaves a complete
+string, even if it is incomplete. */
+
+if (code && defaultrespond)
+ {
+ if (user_msg)
+ smtp_respond(code, 3, TRUE, user_msg);
+ else
+ {
+ uschar buffer[128];
+ va_list ap;
+ va_start(ap, defaultrespond);
+ if (!string_vformat(buffer, sizeof(buffer), CS defaultrespond, ap))
+ log_write(0, LOG_MAIN|LOG_PANIC, "string too large in smtp_notquit_exit()");
+ smtp_printf("%s %s\r\n", code, buffer);
+ va_end(ap);
+ }
+ mac_smtp_fflush();
+ }
+}
+
+
+
+
+/*************************************************
+* Verify HELO argument *
+*************************************************/
+
+/* This function is called if helo_verify_hosts or helo_try_verify_hosts is
+matched. It is also called from ACL processing if verify = helo is used and
+verification was not previously tried (i.e. helo_try_verify_hosts was not
+matched). The result of its processing is to set helo_verified and
+helo_verify_failed. These variables should both be FALSE for this function to
+be called.
+
+Note that EHLO/HELO is legitimately allowed to quote an address literal. Allow
+for IPv6 ::ffff: literals.
+
+Argument: none
+Returns: TRUE if testing was completed;
+ FALSE on a temporary failure
+*/
+
+BOOL
+smtp_verify_helo(void)
+{
+BOOL yield = TRUE;
+
+HDEBUG(D_receive) debug_printf("verifying EHLO/HELO argument \"%s\"\n",
+ sender_helo_name);
+
+if (sender_helo_name == NULL)
+ {
+ HDEBUG(D_receive) debug_printf("no EHLO/HELO command was issued\n");
+ }
+
+/* Deal with the case of -bs without an IP address */
+
+else if (sender_host_address == NULL)
+ {
+ HDEBUG(D_receive) debug_printf("no client IP address: assume success\n");
+ helo_verified = TRUE;
+ }
+
+/* Deal with the more common case when there is a sending IP address */
+
+else if (sender_helo_name[0] == '[')
+ {
+ helo_verified = Ustrncmp(sender_helo_name+1, sender_host_address,
+ Ustrlen(sender_host_address)) == 0;
+
+ #if HAVE_IPV6
+ if (!helo_verified)
+ {
+ if (strncmpic(sender_host_address, US"::ffff:", 7) == 0)
+ helo_verified = Ustrncmp(sender_helo_name + 1,
+ sender_host_address + 7, Ustrlen(sender_host_address) - 7) == 0;
+ }
+ #endif
+
+ HDEBUG(D_receive)
+ { if (helo_verified) debug_printf("matched host address\n"); }
+ }
+
+/* Do a reverse lookup if one hasn't already given a positive or negative
+response. If that fails, or the name doesn't match, try checking with a forward
+lookup. */
+
+else
+ {
+ if (sender_host_name == NULL && !host_lookup_failed)
+ yield = host_name_lookup() != DEFER;
+
+ /* If a host name is known, check it and all its aliases. */
+
+ if (sender_host_name)
+ if ((helo_verified = strcmpic(sender_host_name, sender_helo_name) == 0))
+ {
+ sender_helo_dnssec = sender_host_dnssec;
+ HDEBUG(D_receive) debug_printf("matched host name\n");
+ }
+ else
+ {
+ uschar **aliases = sender_host_aliases;
+ while (*aliases)
+ if ((helo_verified = strcmpic(*aliases++, sender_helo_name) == 0))
+ {
+ sender_helo_dnssec = sender_host_dnssec;
+ break;
+ }
+
+ HDEBUG(D_receive) if (helo_verified)
+ debug_printf("matched alias %s\n", *(--aliases));
+ }
+
+ /* Final attempt: try a forward lookup of the helo name */
+
+ if (!helo_verified)
+ {
+ int rc;
+ host_item h;
+ dnssec_domains d;
+ host_item *hh;
+
+ h.name = sender_helo_name;
+ h.address = NULL;
+ h.mx = MX_NONE;
+ h.next = NULL;
+ d.request = US"*";
+ d.require = US"";
+
+ HDEBUG(D_receive) debug_printf("getting IP address for %s\n",
+ sender_helo_name);
+ rc = host_find_bydns(&h, NULL, HOST_FIND_BY_A,
+ NULL, NULL, NULL, &d, NULL, NULL);
+ if (rc == HOST_FOUND || rc == HOST_FOUND_LOCAL)
+ for (hh = &h; hh; hh = hh->next)
+ if (Ustrcmp(hh->address, sender_host_address) == 0)
+ {
+ helo_verified = TRUE;
+ if (h.dnssec == DS_YES) sender_helo_dnssec = TRUE;
+ HDEBUG(D_receive)
+ {
+ debug_printf("IP address for %s matches calling address\n"
+ "Forward DNS security status: %sverified\n",
+ sender_helo_name, sender_helo_dnssec ? "" : "un");
+ }
+ break;
+ }
+ }
+ }
+
+if (!helo_verified) helo_verify_failed = TRUE; /* We've tried ... */
+return yield;
+}
+
+
+
+
+/*************************************************
+* Send user response message *
+*************************************************/
+
+/* This function is passed a default response code and a user message. It calls
+smtp_message_code() to check and possibly modify the response code, and then
+calls smtp_respond() to transmit the response. I put this into a function
+just to avoid a lot of repetition.
+
+Arguments:
+ code the response code
+ user_msg the user message
+
+Returns: nothing
+*/
+
+static void
+smtp_user_msg(uschar *code, uschar *user_msg)
+{
+int len = 3;
+smtp_message_code(&code, &len, &user_msg, NULL, TRUE);
+smtp_respond(code, len, TRUE, user_msg);
+}
+
+
+
+static int
+smtp_in_auth(auth_instance *au, uschar ** s, uschar ** ss)
+{
+const uschar *set_id = NULL;
+int rc, i;
+
+/* Run the checking code, passing the remainder of the command line as
+data. Initials the $auth<n> variables as empty. Initialize $0 empty and set
+it as the only set numerical variable. The authenticator may set $auth<n>
+and also set other numeric variables. The $auth<n> variables are preferred
+nowadays; the numerical variables remain for backwards compatibility.
+
+Afterwards, have a go at expanding the set_id string, even if
+authentication failed - for bad passwords it can be useful to log the
+userid. On success, require set_id to expand and exist, and put it in
+authenticated_id. Save this in permanent store, as the working store gets
+reset at HELO, RSET, etc. */
+
+for (i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL;
+expand_nmax = 0;
+expand_nlength[0] = 0; /* $0 contains nothing */
+
+rc = (au->info->servercode)(au, smtp_cmd_data);
+if (au->set_id) set_id = expand_string(au->set_id);
+expand_nmax = -1; /* Reset numeric variables */
+for (i = 0; i < AUTH_VARS; i++) auth_vars[i] = NULL; /* Reset $auth<n> */
+
+/* The value of authenticated_id is stored in the spool file and printed in
+log lines. It must not contain binary zeros or newline characters. In
+normal use, it never will, but when playing around or testing, this error
+can (did) happen. To guard against this, ensure that the id contains only
+printing characters. */
+
+if (set_id) set_id = string_printing(set_id);
+
+/* For the non-OK cases, set up additional logging data if set_id
+is not empty. */
+
+if (rc != OK)
+ set_id = set_id && *set_id
+ ? string_sprintf(" (set_id=%s)", set_id) : US"";
+
+/* Switch on the result */
+
+switch(rc)
+ {
+ case OK:
+ if (!au->set_id || set_id) /* Complete success */
+ {
+ if (set_id) authenticated_id = string_copy_malloc(set_id);
+ sender_host_authenticated = au->name;
+ authentication_failed = FALSE;
+ authenticated_fail_id = NULL; /* Impossible to already be set? */
+
+ received_protocol =
+ (sender_host_address ? protocols : protocols_local)
+ [pextend + pauthed + (tls_in.active >= 0 ? pcrpted:0)];
+ *s = *ss = US"235 Authentication succeeded";
+ authenticated_by = au;
+ break;
+ }
+
+ /* Authentication succeeded, but we failed to expand the set_id string.
+ Treat this as a temporary error. */
+
+ auth_defer_msg = expand_string_message;
+ /* Fall through */
+
+ case DEFER:
+ if (set_id) authenticated_fail_id = string_copy_malloc(set_id);
+ *s = string_sprintf("435 Unable to authenticate at present%s",
+ auth_defer_user_msg);
+ *ss = string_sprintf("435 Unable to authenticate at present%s: %s",
+ set_id, auth_defer_msg);
+ break;
+
+ case BAD64:
+ *s = *ss = US"501 Invalid base64 data";
+ break;
+
+ case CANCELLED:
+ *s = *ss = US"501 Authentication cancelled";
+ break;
+
+ case UNEXPECTED:
+ *s = *ss = US"553 Initial data not expected";
+ break;
+
+ case FAIL:
+ if (set_id) authenticated_fail_id = string_copy_malloc(set_id);
+ *s = US"535 Incorrect authentication data";
+ *ss = string_sprintf("535 Incorrect authentication data%s", set_id);
+ break;
+
+ default:
+ if (set_id) authenticated_fail_id = string_copy_malloc(set_id);
+ *s = US"435 Internal error";
+ *ss = string_sprintf("435 Internal error%s: return %d from authentication "
+ "check", set_id, rc);
+ break;
+ }
+
+return rc;
+}
+
+
+
+
+
+static int
+qualify_recipient(uschar ** recipient, uschar * smtp_cmd_data, uschar * tag)
+{
+int rd;
+if (allow_unqualified_recipient || strcmpic(*recipient, US"postmaster") == 0)
+ {
+ DEBUG(D_receive) debug_printf("unqualified address %s accepted\n",
+ *recipient);
+ rd = Ustrlen(recipient) + 1;
+ *recipient = rewrite_address_qualify(*recipient, TRUE);
+ return rd;
+ }
+smtp_printf("501 %s: recipient address must contain a domain\r\n",
+ smtp_cmd_data);
+log_write(L_smtp_syntax_error,
+ LOG_MAIN|LOG_REJECT, "unqualified %s rejected: <%s> %s%s",
+ tag, *recipient, host_and_ident(TRUE), host_lookup_msg);
+return 0;
+}
+
+
+
+
+static void
+smtp_quit_handler(uschar ** user_msgp, uschar ** log_msgp)
+{
+HAD(SCH_QUIT);
+incomplete_transaction_log(US"QUIT");
+if (acl_smtp_quit)
+ {
+ int rc = acl_check(ACL_WHERE_QUIT, NULL, acl_smtp_quit, user_msgp, log_msgp);
+ if (rc == ERROR)
+ log_write(0, LOG_MAIN|LOG_PANIC, "ACL for QUIT returned ERROR: %s",
+ *log_msgp);
+ }
+if (*user_msgp)
+ smtp_respond(US"221", 3, TRUE, *user_msgp);
+else
+ smtp_printf("221 %s closing connection\r\n", smtp_active_hostname);
+
+#ifdef SUPPORT_TLS
+tls_close(TRUE, TRUE);
+#endif
+
+log_write(L_smtp_connection, LOG_MAIN, "%s closed by QUIT",
+ smtp_get_connection_info());
+}
+
+
+static void
+smtp_rset_handler(void)
+{
+HAD(SCH_RSET);
+incomplete_transaction_log(US"RSET");
+smtp_printf("250 Reset OK\r\n");
+cmd_list[CMD_LIST_RSET].is_mail_cmd = FALSE;
+}
+
+
+