1 /* $Cambridge: exim/src/src/transports/smtp.c,v 1.25 2006/03/09 15:10:16 ph10 Exp $ */
3 /*************************************************
4 * Exim - an Internet mail transport agent *
5 *************************************************/
7 /* Copyright (c) University of Cambridge 1995 - 2006 */
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 { "authenticated_sender_force", opt_bool,
29 (void *)offsetof(smtp_transport_options_block, authenticated_sender_force) },
30 { "command_timeout", opt_time,
31 (void *)offsetof(smtp_transport_options_block, command_timeout) },
32 { "connect_timeout", opt_time,
33 (void *)offsetof(smtp_transport_options_block, connect_timeout) },
34 { "connection_max_messages", opt_int | opt_public,
35 (void *)offsetof(transport_instance, connection_max_messages) },
36 { "data_timeout", opt_time,
37 (void *)offsetof(smtp_transport_options_block, data_timeout) },
38 { "delay_after_cutoff", opt_bool,
39 (void *)offsetof(smtp_transport_options_block, delay_after_cutoff) },
40 #ifdef EXPERIMENTAL_DOMAINKEYS
41 { "dk_canon", opt_stringptr,
42 (void *)offsetof(smtp_transport_options_block, dk_canon) },
43 { "dk_domain", opt_stringptr,
44 (void *)offsetof(smtp_transport_options_block, dk_domain) },
45 { "dk_headers", opt_stringptr,
46 (void *)offsetof(smtp_transport_options_block, dk_headers) },
47 { "dk_private_key", opt_stringptr,
48 (void *)offsetof(smtp_transport_options_block, dk_private_key) },
49 { "dk_selector", opt_stringptr,
50 (void *)offsetof(smtp_transport_options_block, dk_selector) },
51 { "dk_strict", opt_stringptr,
52 (void *)offsetof(smtp_transport_options_block, dk_strict) },
54 { "dns_qualify_single", opt_bool,
55 (void *)offsetof(smtp_transport_options_block, dns_qualify_single) },
56 { "dns_search_parents", opt_bool,
57 (void *)offsetof(smtp_transport_options_block, dns_search_parents) },
58 { "fallback_hosts", opt_stringptr,
59 (void *)offsetof(smtp_transport_options_block, fallback_hosts) },
60 { "final_timeout", opt_time,
61 (void *)offsetof(smtp_transport_options_block, final_timeout) },
62 { "gethostbyname", opt_bool,
63 (void *)offsetof(smtp_transport_options_block, gethostbyname) },
64 { "helo_data", opt_stringptr,
65 (void *)offsetof(smtp_transport_options_block, helo_data) },
66 { "hosts", opt_stringptr,
67 (void *)offsetof(smtp_transport_options_block, hosts) },
68 { "hosts_avoid_esmtp", opt_stringptr,
69 (void *)offsetof(smtp_transport_options_block, hosts_avoid_esmtp) },
71 { "hosts_avoid_tls", opt_stringptr,
72 (void *)offsetof(smtp_transport_options_block, hosts_avoid_tls) },
74 { "hosts_max_try", opt_int,
75 (void *)offsetof(smtp_transport_options_block, hosts_max_try) },
76 { "hosts_max_try_hardlimit", opt_int,
77 (void *)offsetof(smtp_transport_options_block, hosts_max_try_hardlimit) },
79 { "hosts_nopass_tls", opt_stringptr,
80 (void *)offsetof(smtp_transport_options_block, hosts_nopass_tls) },
82 { "hosts_override", opt_bool,
83 (void *)offsetof(smtp_transport_options_block, hosts_override) },
84 { "hosts_randomize", opt_bool,
85 (void *)offsetof(smtp_transport_options_block, hosts_randomize) },
86 { "hosts_require_auth", opt_stringptr,
87 (void *)offsetof(smtp_transport_options_block, hosts_require_auth) },
89 { "hosts_require_tls", opt_stringptr,
90 (void *)offsetof(smtp_transport_options_block, hosts_require_tls) },
92 { "hosts_try_auth", opt_stringptr,
93 (void *)offsetof(smtp_transport_options_block, hosts_try_auth) },
94 { "interface", opt_stringptr,
95 (void *)offsetof(smtp_transport_options_block, interface) },
96 { "keepalive", opt_bool,
97 (void *)offsetof(smtp_transport_options_block, keepalive) },
98 { "lmtp_ignore_quota", opt_bool,
99 (void *)offsetof(smtp_transport_options_block, lmtp_ignore_quota) },
100 { "max_rcpt", opt_int | opt_public,
101 (void *)offsetof(transport_instance, max_addresses) },
102 { "multi_domain", opt_bool | opt_public,
103 (void *)offsetof(transport_instance, multi_domain) },
104 { "port", opt_stringptr,
105 (void *)offsetof(smtp_transport_options_block, port) },
106 { "protocol", opt_stringptr,
107 (void *)offsetof(smtp_transport_options_block, protocol) },
108 { "retry_include_ip_address", opt_bool,
109 (void *)offsetof(smtp_transport_options_block, retry_include_ip_address) },
110 { "serialize_hosts", opt_stringptr,
111 (void *)offsetof(smtp_transport_options_block, serialize_hosts) },
112 { "size_addition", opt_int,
113 (void *)offsetof(smtp_transport_options_block, size_addition) }
115 ,{ "tls_certificate", opt_stringptr,
116 (void *)offsetof(smtp_transport_options_block, tls_certificate) },
117 { "tls_crl", opt_stringptr,
118 (void *)offsetof(smtp_transport_options_block, tls_crl) },
119 { "tls_privatekey", opt_stringptr,
120 (void *)offsetof(smtp_transport_options_block, tls_privatekey) },
121 { "tls_require_ciphers", opt_stringptr,
122 (void *)offsetof(smtp_transport_options_block, tls_require_ciphers) },
123 { "tls_tempfail_tryclear", opt_bool,
124 (void *)offsetof(smtp_transport_options_block, tls_tempfail_tryclear) },
125 { "tls_verify_certificates", opt_stringptr,
126 (void *)offsetof(smtp_transport_options_block, tls_verify_certificates) }
130 /* Size of the options list. An extern variable has to be used so that its
131 address can appear in the tables drtables.c. */
133 int smtp_transport_options_count =
134 sizeof(smtp_transport_options)/sizeof(optionlist);
136 /* Default private options block for the smtp transport. */
138 smtp_transport_options_block smtp_transport_option_defaults = {
140 NULL, /* fallback_hosts */
142 NULL, /* fallback_hostlist */
143 NULL, /* authenticated_sender */
144 US"$primary_hostname", /* helo_data */
145 NULL, /* interface */
147 US"smtp", /* protocol */
148 NULL, /* serialize_hosts */
149 NULL, /* hosts_try_auth */
150 NULL, /* hosts_require_auth */
151 NULL, /* hosts_require_tls */
152 NULL, /* hosts_avoid_tls */
153 NULL, /* hosts_avoid_esmtp */
154 NULL, /* hosts_nopass_tls */
155 5*60, /* command_timeout */
156 5*60, /* connect_timeout; shorter system default overrides */
157 5*60, /* data timeout */
158 10*60, /* final timeout */
159 1024, /* size_addition */
160 5, /* hosts_max_try */
161 50, /* hosts_max_try_hardlimit */
162 FALSE, /* allow_localhost */
163 FALSE, /* authenticated_sender_force */
164 FALSE, /* gethostbyname */
165 TRUE, /* dns_qualify_single */
166 FALSE, /* dns_search_parents */
167 TRUE, /* delay_after_cutoff */
168 FALSE, /* hosts_override */
169 FALSE, /* hosts_randomize */
170 TRUE, /* keepalive */
171 FALSE, /* lmtp_ignore_quota */
172 TRUE /* retry_include_ip_address */
174 ,NULL, /* tls_certificate */
176 NULL, /* tls_privatekey */
177 NULL, /* tls_require_ciphers */
178 NULL, /* tls_verify_certificates */
179 TRUE /* tls_tempfail_tryclear */
181 #ifdef EXPERIMENTAL_DOMAINKEYS
182 ,NULL, /* dk_canon */
183 NULL, /* dk_domain */
184 NULL, /* dk_headers */
185 NULL, /* dk_private_key */
186 NULL, /* dk_selector */
194 static uschar *smtp_command; /* Points to last cmd for error messages */
195 static uschar *mail_command; /* Points to MAIL cmd for error messages */
198 /*************************************************
199 * Setup entry point *
200 *************************************************/
202 /* This function is called when the transport is about to be used,
203 but before running it in a sub-process. It is used for two things:
205 (1) To set the fallback host list in addresses, when delivering.
206 (2) To pass back the interface, port, and protocol options, for use during
207 callout verification.
210 tblock pointer to the transport instance block
211 addrlist list of addresses about to be transported
212 tf if not NULL, pointer to block in which to return options
213 uid the uid that will be set (not used)
214 gid the gid that will be set (not used)
215 errmsg place for error message (not used)
217 Returns: OK always (FAIL, DEFER not used)
221 smtp_transport_setup(transport_instance *tblock, address_item *addrlist,
222 transport_feedback *tf, uid_t uid, gid_t gid, uschar **errmsg)
224 smtp_transport_options_block *ob =
225 (smtp_transport_options_block *)(tblock->options_block);
227 errmsg = errmsg; /* Keep picky compilers happy */
231 /* Pass back options if required. This interface is getting very messy. */
235 tf->interface = ob->interface;
237 tf->protocol = ob->protocol;
238 tf->hosts = ob->hosts;
239 tf->hosts_override = ob->hosts_override;
240 tf->hosts_randomize = ob->hosts_randomize;
241 tf->gethostbyname = ob->gethostbyname;
242 tf->qualify_single = ob->dns_qualify_single;
243 tf->search_parents = ob->dns_search_parents;
246 /* Set the fallback host list for all the addresses that don't have fallback
247 host lists, provided that the local host wasn't present in the original host
250 if (!testflag(addrlist, af_local_host_removed))
252 for (; addrlist != NULL; addrlist = addrlist->next)
253 if (addrlist->fallback_hosts == NULL)
254 addrlist->fallback_hosts = ob->fallback_hostlist;
262 /*************************************************
263 * Initialization entry point *
264 *************************************************/
266 /* Called for each instance, after its options have been read, to
267 enable consistency checks to be done, or anything else that needs
270 Argument: pointer to the transport instance block
275 smtp_transport_init(transport_instance *tblock)
277 smtp_transport_options_block *ob =
278 (smtp_transport_options_block *)(tblock->options_block);
280 /* Retry_use_local_part defaults FALSE if unset */
282 if (tblock->retry_use_local_part == TRUE_UNSET)
283 tblock->retry_use_local_part = FALSE;
285 /* Set the default port according to the protocol */
287 if (ob->port == NULL)
288 ob->port = (strcmpic(ob->protocol, US"lmtp") == 0)? US"lmtp" : US"smtp";
290 /* Set up the setup entry point, to be called before subprocesses for this
293 tblock->setup = smtp_transport_setup;
295 /* Complain if any of the timeouts are zero. */
297 if (ob->command_timeout <= 0 || ob->data_timeout <= 0 ||
298 ob->final_timeout <= 0)
299 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
300 "command, data, or final timeout value is zero for %s transport",
303 /* If hosts_override is set and there are local hosts, set the global
304 flag that stops verify from showing router hosts. */
306 if (ob->hosts_override && ob->hosts != NULL) tblock->overrides_hosts = TRUE;
308 /* If there are any fallback hosts listed, build a chain of host items
309 for them, but do not do any lookups at this time. */
311 host_build_hostlist(&(ob->fallback_hostlist), ob->fallback_hosts, FALSE);
318 /*************************************************
319 * Set delivery info into all active addresses *
320 *************************************************/
322 /* Only addresses whose status is >= PENDING are relevant. A lesser
323 status means that an address is not currently being processed.
326 addrlist points to a chain of addresses
327 errno_value to put in each address's errno field
328 msg to put in each address's message field
329 rc to put in each address's transport_return field
330 pass_message if TRUE, set the "pass message" flag in the address
332 If errno_value has the special value ERRNO_CONNECTTIMEOUT, ETIMEDOUT is put in
333 the errno field, and RTEF_CTOUT is ORed into the more_errno field, to indicate
334 this particular type of timeout.
340 set_errno(address_item *addrlist, int errno_value, uschar *msg, int rc,
345 if (errno_value == ERRNO_CONNECTTIMEOUT)
347 errno_value = ETIMEDOUT;
348 orvalue = RTEF_CTOUT;
350 for (addr = addrlist; addr != NULL; addr = addr->next)
352 if (addr->transport_return < PENDING) continue;
353 addr->basic_errno = errno_value;
354 addr->more_errno |= orvalue;
358 if (pass_message) setflag(addr, af_pass_message);
360 addr->transport_return = rc;
366 /*************************************************
367 * Check an SMTP response *
368 *************************************************/
370 /* This function is given an errno code and the SMTP response buffer
371 to analyse, together with the host identification for generating messages. It
372 sets an appropriate message and puts the first digit of the response code into
373 the yield variable. If no response was actually read, a suitable digit is
377 host the current host, to get its name for messages
378 errno_value pointer to the errno value
379 more_errno from the top address for use with ERRNO_FILTER_FAIL
380 buffer the SMTP response buffer
381 yield where to put a one-digit SMTP response code
382 message where to put an errror message
383 pass_message set TRUE if message is an SMTP response
385 Returns: TRUE if an SMTP "QUIT" command should be sent, else FALSE
388 static BOOL check_response(host_item *host, int *errno_value, int more_errno,
389 uschar *buffer, int *yield, uschar **message, BOOL *pass_message)
393 if (smtp_use_pipelining &&
394 (Ustrcmp(smtp_command, "MAIL") == 0 ||
395 Ustrcmp(smtp_command, "RCPT") == 0 ||
396 Ustrcmp(smtp_command, "DATA") == 0))
399 *yield = '4'; /* Default setting is to give a temporary error */
401 /* Handle response timeout */
403 if (*errno_value == ETIMEDOUT)
405 *message = US string_sprintf("SMTP timeout while connected to %s [%s] "
406 "after %s%s", host->name, host->address, pl, smtp_command);
407 if (transport_count > 0)
408 *message = US string_sprintf("%s (%d bytes written)", *message,
413 /* Handle malformed SMTP response */
415 if (*errno_value == ERRNO_SMTPFORMAT)
417 uschar *malfresp = string_printing(buffer);
418 while (isspace(*malfresp)) malfresp++;
420 *message = string_sprintf("Malformed SMTP reply (an empty line) from "
421 "%s [%s] in response to %s%s", host->name, host->address, pl,
424 *message = string_sprintf("Malformed SMTP reply from %s [%s] in response "
425 "to %s%s: %s", host->name, host->address, pl, smtp_command, malfresp);
429 /* Handle a failed filter process error; can't send QUIT as we mustn't
432 if (*errno_value == ERRNO_FILTER_FAIL)
434 *message = US string_sprintf("transport filter process failed (%d)%s",
436 (more_errno == EX_EXECFAILED)? ": unable to execute command" : "");
440 /* Handle a failed add_headers expansion; can't send QUIT as we mustn't
443 if (*errno_value == ERRNO_CHHEADER_FAIL)
446 US string_sprintf("failed to expand headers_add or headers_remove: %s",
447 expand_string_message);
451 /* Handle failure to write a complete data block */
453 if (*errno_value == ERRNO_WRITEINCOMPLETE)
455 *message = US string_sprintf("failed to write a data block");
459 /* Handle error responses from the remote mailer. */
463 uschar *s = string_printing(buffer);
464 *message = US string_sprintf("SMTP error from remote mail server after %s%s: "
465 "host %s [%s]: %s", pl, smtp_command, host->name, host->address, s);
466 *pass_message = TRUE;
471 /* No data was read. If there is no errno, this must be the EOF (i.e.
472 connection closed) case, which causes deferral. An explicit connection reset
473 error has the same effect. Otherwise, put the host's identity in the message,
474 leaving the errno value to be interpreted as well. In all cases, we have to
475 assume the connection is now dead. */
477 if (*errno_value == 0 || *errno_value == ECONNRESET)
479 *errno_value = ERRNO_SMTPCLOSED;
480 *message = US string_sprintf("Remote host %s [%s] closed connection "
481 "in response to %s%s", host->name, host->address, pl, smtp_command);
483 else *message = US string_sprintf("%s [%s]", host->name, host->address);
490 /*************************************************
491 * Write error message to logs *
492 *************************************************/
494 /* This writes to the main log and to the message log.
497 addr the address item containing error information
498 host the current host
504 write_logs(address_item *addr, host_item *host)
506 if (addr->message != NULL)
508 uschar *message = addr->message;
509 if (addr->basic_errno > 0)
510 message = string_sprintf("%s: %s", message, strerror(addr->basic_errno));
511 log_write(0, LOG_MAIN, "%s", message);
512 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
517 ((log_extra_selector & LX_outgoing_port) != 0)?
518 string_sprintf("%s [%s]:%d", host->name, host->address,
519 (host->port == PORT_NONE)? 25 : host->port)
521 string_sprintf("%s [%s]", host->name, host->address);
522 log_write(0, LOG_MAIN, "%s %s", msg, strerror(addr->basic_errno));
523 deliver_msglog("%s %s %s\n", tod_stamp(tod_log), msg,
524 strerror(addr->basic_errno));
530 /*************************************************
531 * Synchronize SMTP responses *
532 *************************************************/
534 /* This function is called from smtp_deliver() to receive SMTP responses from
535 the server, and match them up with the commands to which they relate. When
536 PIPELINING is not in use, this function is called after every command, and is
537 therefore somewhat over-engineered, but it is simpler to use a single scheme
538 that works both with and without PIPELINING instead of having two separate sets
541 The set of commands that are buffered up with pipelining may start with MAIL
542 and may end with DATA; in between are RCPT commands that correspond to the
543 addresses whose status is PENDING_DEFER. All other commands (STARTTLS, AUTH,
544 etc.) are never buffered.
546 Errors after MAIL or DATA abort the whole process leaving the response in the
547 buffer. After MAIL, pending responses are flushed, and the original command is
548 re-instated in big_buffer for error messages. For RCPT commands, the remote is
549 permitted to reject some recipient addresses while accepting others. However
550 certain errors clearly abort the whole process. Set the value in
551 transport_return to PENDING_OK if the address is accepted. If there is a
552 subsequent general error, it will get reset accordingly. If not, it will get
553 converted to OK at the end.
556 addrlist the complete address list
557 include_affixes TRUE if affixes include in RCPT
558 sync_addr ptr to the ptr of the one to start scanning at (updated)
559 host the host we are connected to
560 count the number of responses to read
561 pending_MAIL true if the first response is for MAIL
562 pending_DATA 0 if last command sent was not DATA
563 +1 if previously had a good recipient
564 -1 if not previously had a good recipient
565 inblock incoming SMTP block
566 timeout timeout value
567 buffer buffer for reading response
568 buffsize size of buffer
570 Returns: 3 if at least one address had 2xx and one had 5xx
571 2 if at least one address had 5xx but none had 2xx
572 1 if at least one host had a 2xx response, but none had 5xx
573 0 no address had 2xx or 5xx but no errors (all 4xx, or just DATA)
574 -1 timeout while reading RCPT response
575 -2 I/O or other non-response error for RCPT
576 -3 DATA or MAIL failed - errno and buffer set
580 sync_responses(address_item *addrlist, BOOL include_affixes,
581 address_item **sync_addr, host_item *host, int count, BOOL pending_MAIL,
582 int pending_DATA, smtp_inblock *inblock, int timeout, uschar *buffer,
585 address_item *addr = *sync_addr;
588 /* Handle the response for a MAIL command. On error, reinstate the original
589 command in big_buffer for error message use, and flush any further pending
590 responses before returning, except after I/O errors and timeouts. */
595 if (!smtp_read_response(inblock, buffer, buffsize, '2', timeout))
597 Ustrcpy(big_buffer, mail_command); /* Fits, because it came from there! */
598 if (errno == 0 && buffer[0] != 0)
600 uschar flushbuffer[4096];
602 if (buffer[0] == '4')
604 save_errno = ERRNO_MAIL4XX;
605 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
609 if (!smtp_read_response(inblock, flushbuffer, sizeof(flushbuffer),
611 && (errno != 0 || flushbuffer[0] == 0))
620 if (pending_DATA) count--; /* Number of RCPT responses to come */
622 /* Read and handle the required number of RCPT responses, matching each one up
623 with an address by scanning for the next address whose status is PENDING_DEFER.
628 while (addr->transport_return != PENDING_DEFER) addr = addr->next;
630 /* The address was accepted */
632 if (smtp_read_response(inblock, buffer, buffsize, '2', timeout))
635 addr->transport_return = PENDING_OK;
637 /* If af_dr_retry_exists is set, there was a routing delay on this address;
638 ensure that any address-specific retry record is expunged. */
640 if (testflag(addr, af_dr_retry_exists))
641 retry_add_item(addr, addr->address_retry_key, rf_delete);
644 /* Timeout while reading the response */
646 else if (errno == ETIMEDOUT)
648 int save_errno = errno;
649 uschar *message = string_sprintf("SMTP timeout while connected to %s [%s] "
650 "after RCPT TO:<%s>", host->name, host->address,
651 transport_rcpt_address(addr, include_affixes));
652 set_errno(addrlist, save_errno, message, DEFER, FALSE);
653 retry_add_item(addr, addr->address_retry_key, 0);
654 host->update_waiting = FALSE;
658 /* Handle other errors in obtaining an SMTP response by returning -1. This
659 will cause all the addresses to be deferred. Restore the SMTP command in
660 big_buffer for which we are checking the response, so the error message
663 else if (errno != 0 || buffer[0] == 0)
665 string_format(big_buffer, big_buffer_size, "RCPT TO:<%s>",
666 transport_rcpt_address(addr, include_affixes));
670 /* Handle SMTP permanent and temporary response codes. */
675 string_sprintf("SMTP error from remote mail server after RCPT TO:<%s>: "
676 "host %s [%s]: %s", transport_rcpt_address(addr, include_affixes),
677 host->name, host->address, string_printing(buffer));
678 setflag(addr, af_pass_message);
679 deliver_msglog("%s %s\n", tod_stamp(tod_log), addr->message);
681 /* The response was 5xx */
683 if (buffer[0] == '5')
685 addr->transport_return = FAIL;
689 /* The response was 4xx */
693 addr->transport_return = DEFER;
694 addr->basic_errno = ERRNO_RCPT4XX;
695 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
697 /* Log temporary errors if there are more hosts to be tried. */
699 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", addr->message);
701 /* Do not put this message on the list of those waiting for this host,
702 as otherwise it is likely to be tried too often. */
704 host->update_waiting = FALSE;
706 /* Add a retry item for the address so that it doesn't get tried
709 retry_add_item(addr, addr->address_retry_key, 0);
712 } /* Loop for next RCPT response */
714 /* Update where to start at for the next block of responses, unless we
715 have already handled all the addresses. */
717 if (addr != NULL) *sync_addr = addr->next;
719 /* Handle a response to DATA. If we have not had any good recipients, either
720 previously or in this block, the response is ignored. */
722 if (pending_DATA != 0 &&
723 !smtp_read_response(inblock, buffer, buffsize, '3', timeout))
728 if (pending_DATA > 0 || (yield & 1) != 0)
730 if (errno == 0 && buffer[0] == '4')
732 errno = ERRNO_DATA4XX;
733 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
737 (void)check_response(host, &errno, 0, buffer, &code, &msg, &pass_message);
738 DEBUG(D_transport) debug_printf("%s\nerror for DATA ignored: pipelining "
739 "is in use and there were no good recipients\n", msg);
742 /* All responses read and handled; MAIL (if present) received 2xx and DATA (if
743 present) received 3xx. If any RCPTs were handled and yielded anything other
744 than 4xx, yield will be set non-zero. */
751 /*************************************************
752 * Deliver address list to given host *
753 *************************************************/
755 /* If continue_hostname is not null, we get here only when continuing to
756 deliver down an existing channel. The channel was passed as the standard
759 Otherwise, we have to make a connection to the remote host, and do the
760 initial protocol exchange.
762 When running as an MUA wrapper, if the sender or any recipient is rejected,
763 temporarily or permanently, we force failure for all recipients.
766 addrlist chain of potential addresses to deliver; only those whose
767 transport_return field is set to PENDING_DEFER are currently
768 being processed; others should be skipped - they have either
769 been delivered to an earlier host or IP address, or been
770 failed by one of them.
771 host host to deliver to
772 host_af AF_INET or AF_INET6
773 port default TCP/IP port to use, in host byte order
774 interface interface to bind to, or NULL
775 tblock transport instance block
776 copy_host TRUE if host set in addr->host_used must be copied, because
777 it is specific to this call of the transport
778 message_defer set TRUE if yield is OK, but all addresses were deferred
779 because of a non-recipient, non-host failure, that is, a
780 4xx response to MAIL FROM, DATA, or ".". This is a defer
781 that is specific to the message.
782 suppress_tls if TRUE, don't attempt a TLS connection - this is set for
783 a second attempt after TLS initialization fails
785 Returns: OK - the connection was made and the delivery attempted;
786 the result for each address is in its data block.
787 DEFER - the connection could not be made, or something failed
788 while setting up the SMTP session, or there was a
789 non-message-specific error, such as a timeout.
790 ERROR - a filter command is specified for this transport,
791 and there was a problem setting it up; OR helo_data
792 or add_headers or authenticated_sender is specified
793 for this transport, and the string failed to expand
797 smtp_deliver(address_item *addrlist, host_item *host, int host_af, int port,
798 uschar *interface, transport_instance *tblock, BOOL copy_host,
799 BOOL *message_defer, BOOL suppress_tls)
802 address_item *sync_addr;
803 address_item *first_addr = addrlist;
808 time_t start_delivery_time = time(NULL);
809 smtp_transport_options_block *ob =
810 (smtp_transport_options_block *)(tblock->options_block);
811 BOOL lmtp = strcmpic(ob->protocol, US"lmtp") == 0;
813 BOOL send_rset = TRUE;
814 BOOL send_quit = TRUE;
815 BOOL setting_up = TRUE;
816 BOOL completed_address = FALSE;
819 BOOL pass_message = FALSE;
820 smtp_inblock inblock;
821 smtp_outblock outblock;
822 int max_rcpt = tblock->max_addresses;
823 uschar *igquotstr = US"";
824 uschar *local_authenticated_sender = authenticated_sender;
826 uschar *message = NULL;
827 uschar new_message_id[MESSAGE_ID_LENGTH + 1];
830 uschar inbuffer[4096];
831 uschar outbuffer[1024];
833 suppress_tls = suppress_tls; /* stop compiler warning when no TLS support */
835 *message_defer = FALSE;
836 smtp_command = US"initial connection";
837 if (max_rcpt == 0) max_rcpt = 999999;
839 /* Set up the buffer for reading SMTP response packets. */
841 inblock.buffer = inbuffer;
842 inblock.buffersize = sizeof(inbuffer);
843 inblock.ptr = inbuffer;
844 inblock.ptrend = inbuffer;
846 /* Set up the buffer for holding SMTP commands while pipelining */
848 outblock.buffer = outbuffer;
849 outblock.buffersize = sizeof(outbuffer);
850 outblock.ptr = outbuffer;
851 outblock.cmd_count = 0;
852 outblock.authenticating = FALSE;
854 /* Expand the greeting message */
856 helo_data = expand_string(ob->helo_data);
857 if (helo_data == NULL)
859 uschar *message = string_sprintf("failed to expand helo_data: %s",
860 expand_string_message);
861 set_errno(addrlist, 0, message, DEFER, FALSE);
865 /* If an authenticated_sender override has been specified for this transport
866 instance, expand it. If the expansion is forced to fail, and there was already
867 an authenticated_sender for this message, the original value will be used.
868 Other expansion failures are serious. An empty result is ignored, but there is
869 otherwise no check - this feature is expected to be used with LMTP and other
870 cases where non-standard addresses (e.g. without domains) might be required. */
872 if (ob->authenticated_sender != NULL)
874 uschar *new = expand_string(ob->authenticated_sender);
877 if (!expand_string_forcedfail)
879 uschar *message = string_sprintf("failed to expand "
880 "authenticated_sender: %s", expand_string_message);
881 set_errno(addrlist, 0, message, DEFER, FALSE);
885 else if (new[0] != 0) local_authenticated_sender = new;
888 /* Make a connection to the host if this isn't a continued delivery, and handle
889 the initial interaction and HELO/EHLO/LHLO. Connect timeout errors are handled
890 specially so they can be identified for retries. */
892 if (continue_hostname == NULL)
894 inblock.sock = outblock.sock =
895 smtp_connect(host, host_af, port, interface, ob->connect_timeout,
897 if (inblock.sock < 0)
899 set_errno(addrlist, (errno == ETIMEDOUT)? ERRNO_CONNECTTIMEOUT : errno,
904 /* The first thing is to wait for an initial OK response. The dreaded "goto"
905 is nevertheless a reasonably clean way of programming this kind of logic,
906 where you want to escape on any error. */
908 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
909 ob->command_timeout)) goto RESPONSE_FAILED;
911 /** Debugging without sending a message
912 addrlist->transport_return = DEFER;
916 /* Errors that occur after this point follow an SMTP command, which is
917 left in big_buffer by smtp_write_command() for use in error messages. */
919 smtp_command = big_buffer;
921 /* Tell the remote who we are...
923 February 1998: A convention has evolved that ESMTP-speaking MTAs include the
924 string "ESMTP" in their greeting lines, so make Exim send EHLO if the
925 greeting is of this form. The assumption was that the far end supports it
926 properly... but experience shows that there are some that give 5xx responses,
927 even though the banner includes "ESMTP" (there's a bloody-minded one that
928 says "ESMTP not spoken here"). Cope with that case.
930 September 2000: Time has passed, and it seems reasonable now to always send
931 EHLO at the start. It is also convenient to make the change while installing
934 July 2003: Joachim Wieland met a broken server that advertises "PIPELINING"
935 but times out after sending MAIL FROM, RCPT TO and DATA all together. There
936 would be no way to send out the mails, so there is now a host list
937 "hosts_avoid_esmtp" that disables ESMTP for special hosts and solves the
938 PIPELINING problem as well. Maybe it can also be useful to cure other
939 problems with broken servers.
941 Exim originally sent "Helo" at this point and ran for nearly a year that way.
942 Then somebody tried it with a Microsoft mailer... It seems that all other
943 mailers use upper case for some reason (the RFC is quite clear about case
944 independence) so, for peace of mind, I gave in. */
946 esmtp = verify_check_this_host(&(ob->hosts_avoid_esmtp), NULL,
947 host->name, host->address, NULL) != OK;
951 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n",
952 lmtp? "LHLO" : "EHLO", helo_data) < 0)
954 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
955 ob->command_timeout))
957 if (errno != 0 || buffer[0] == 0 || lmtp) goto RESPONSE_FAILED;
964 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
969 if (smtp_write_command(&outblock, FALSE, "HELO %s\r\n", helo_data) < 0)
971 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
972 ob->command_timeout)) goto RESPONSE_FAILED;
975 /* Set IGNOREQUOTA if the response to LHLO specifies support and the
976 lmtp_ignore_quota option was set. */
978 igquotstr = (lmtp && ob->lmtp_ignore_quota &&
979 pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer, Ustrlen(CS buffer), 0,
980 PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
982 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
985 tls_offered = esmtp &&
986 pcre_exec(regex_STARTTLS, NULL, CS buffer, Ustrlen(buffer), 0,
987 PCRE_EOPT, NULL, 0) >= 0;
991 /* For continuing deliveries down the same channel, the socket is the standard
992 input, and we don't need to redo EHLO here (but may need to do so for TLS - see
993 below). Set up the pointer to where subsequent commands will be left, for
994 error messages. Note that smtp_use_size and smtp_use_pipelining will have been
995 set from the command line if they were set in the process that passed the
1000 inblock.sock = outblock.sock = fileno(stdin);
1001 smtp_command = big_buffer;
1004 /* If TLS is available on this connection, whether continued or not, attempt to
1005 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
1006 send another EHLO - the server may give a different answer in secure mode. We
1007 use a separate buffer for reading the response to STARTTLS so that if it is
1008 negative, the original EHLO data is available for subsequent analysis, should
1009 the client not be required to use TLS. If the response is bad, copy the buffer
1010 for error analysis. */
1013 if (tls_offered && !suppress_tls &&
1014 verify_check_this_host(&(ob->hosts_avoid_tls), NULL, host->name,
1015 host->address, NULL) != OK)
1017 uschar buffer2[4096];
1018 if (smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") < 0)
1021 /* If there is an I/O error, transmission of this message is deferred. If
1022 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
1023 false, we also defer. However, if there is a temporary rejection of STARTTLS
1024 and tls_tempfail_tryclear is true, or if there is an outright rejection of
1025 STARTTLS, we carry on. This means we will try to send the message in clear,
1026 unless the host is in hosts_require_tls (tested below). */
1028 if (!smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
1029 ob->command_timeout))
1031 Ustrncpy(buffer, buffer2, sizeof(buffer));
1032 if (errno != 0 || buffer2[0] == 0 ||
1033 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
1034 goto RESPONSE_FAILED;
1037 /* STARTTLS accepted: try to negotiate a TLS session. */
1041 int rc = tls_client_start(inblock.sock, host, addrlist,
1042 NULL, /* No DH param */
1043 ob->tls_certificate,
1045 ob->tls_verify_certificates,
1047 ob->tls_require_ciphers,
1048 ob->command_timeout);
1050 /* TLS negotiation failed; give an error. From outside, this function may
1051 be called again to try in clear on a new connection, if the options permit
1052 it for this host. */
1056 save_errno = ERRNO_TLSFAILURE;
1057 message = US"failure while setting up TLS session";
1062 /* TLS session is set up */
1064 for (addr = addrlist; addr != NULL; addr = addr->next)
1066 if (addr->transport_return == PENDING_DEFER)
1068 addr->cipher = tls_cipher;
1069 addr->peerdn = tls_peerdn;
1075 /* If we started TLS, redo the EHLO/LHLO exchange over the secure channel. */
1077 if (tls_active >= 0)
1079 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n", lmtp? "LHLO" : "EHLO",
1082 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1083 ob->command_timeout))
1084 goto RESPONSE_FAILED;
1087 /* If the host is required to use a secure channel, ensure that we
1090 else if (verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
1091 host->address, NULL) == OK)
1093 save_errno = ERRNO_TLSREQUIRED;
1094 message = string_sprintf("a TLS session is required for %s [%s], but %s",
1095 host->name, host->address,
1096 tls_offered? "an attempt to start TLS failed" :
1097 "the server did not offer TLS support");
1102 /* If TLS is active, we have just started it up and re-done the EHLO command,
1103 so its response needs to be analyzed. If TLS is not active and this is a
1104 continued session down a previously-used socket, we haven't just done EHLO, so
1107 if (continue_hostname == NULL
1114 uschar *fail_reason = US"server did not advertise AUTH support";
1116 /* Set for IGNOREQUOTA if the response to LHLO specifies support and the
1117 lmtp_ignore_quota option was set. */
1119 igquotstr = (lmtp && ob->lmtp_ignore_quota &&
1120 pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer, Ustrlen(CS buffer), 0,
1121 PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
1123 /* If the response to EHLO specified support for the SIZE parameter, note
1124 this, provided size_addition is non-negative. */
1126 smtp_use_size = esmtp && ob->size_addition >= 0 &&
1127 pcre_exec(regex_SIZE, NULL, CS buffer, Ustrlen(CS buffer), 0,
1128 PCRE_EOPT, NULL, 0) >= 0;
1130 /* Note whether the server supports PIPELINING. If hosts_avoid_esmtp matched
1131 the current host, esmtp will be false, so PIPELINING can never be used. */
1133 smtp_use_pipelining = esmtp &&
1134 pcre_exec(regex_PIPELINING, NULL, CS buffer, Ustrlen(CS buffer), 0,
1135 PCRE_EOPT, NULL, 0) >= 0;
1137 DEBUG(D_transport) debug_printf("%susing PIPELINING\n",
1138 smtp_use_pipelining? "" : "not ");
1140 /* Note if the response to EHLO specifies support for the AUTH extension.
1141 If it has, check that this host is one we want to authenticate to, and do
1142 the business. The host name and address must be available when the
1143 authenticator's client driver is running. */
1145 smtp_authenticated = FALSE;
1146 require_auth = verify_check_this_host(&(ob->hosts_require_auth), NULL,
1147 host->name, host->address, NULL);
1149 if (esmtp && regex_match_and_setup(regex_AUTH, buffer, 0, -1))
1151 uschar *names = string_copyn(expand_nstring[1], expand_nlength[1]);
1152 expand_nmax = -1; /* reset */
1154 /* Must not do this check until after we have saved the result of the
1155 regex match above. */
1157 if (require_auth == OK ||
1158 verify_check_this_host(&(ob->hosts_try_auth), NULL, host->name,
1159 host->address, NULL) == OK)
1162 fail_reason = US"no common mechanisms were found";
1164 DEBUG(D_transport) debug_printf("scanning authentication mechanisms\n");
1166 /* Scan the configured authenticators looking for one which is configured
1167 for use as a client and whose name matches an authentication mechanism
1168 supported by the server. If one is found, attempt to authenticate by
1169 calling its client function. */
1171 for (au = auths; !smtp_authenticated && au != NULL; au = au->next)
1174 if (!au->client) continue;
1176 /* Loop to scan supported server mechanisms */
1181 int len = Ustrlen(au->public_name);
1182 while (isspace(*p)) p++;
1184 if (strncmpic(au->public_name, p, len) != 0 ||
1185 (p[len] != 0 && !isspace(p[len])))
1187 while (*p != 0 && !isspace(*p)) p++;
1191 /* Found data for a listed mechanism. Call its client entry. Set
1192 a flag in the outblock so that data is overwritten after sending so
1193 that reflections don't show it. */
1195 fail_reason = US"authentication attempt(s) failed";
1196 outblock.authenticating = TRUE;
1197 rc = (au->info->clientcode)(au, &inblock, &outblock,
1198 ob->command_timeout, buffer, sizeof(buffer));
1199 outblock.authenticating = FALSE;
1200 DEBUG(D_transport) debug_printf("%s authenticator yielded %d\n",
1203 /* A temporary authentication failure must hold up delivery to
1204 this host. After a permanent authentication failure, we carry on
1205 to try other authentication methods. If all fail hard, try to
1206 deliver the message unauthenticated unless require_auth was set. */
1211 smtp_authenticated = TRUE; /* stops the outer loop */
1214 /* Failure after writing a command */
1219 /* Failure after reading a response */
1222 if (errno != 0 || buffer[0] != '5') goto RESPONSE_FAILED;
1223 log_write(0, LOG_MAIN, "%s authenticator failed H=%s [%s] %s",
1224 au->name, host->name, host->address, buffer);
1227 /* Failure by some other means. In effect, the authenticator
1228 decided it wasn't prepared to handle this case. Typically this
1229 is the result of "fail" in an expansion string. Do we need to
1230 log anything here? Feb 2006: a message is now put in the buffer
1231 if logging is required. */
1235 log_write(0, LOG_MAIN, "%s authenticator cancelled "
1236 "authentication H=%s [%s] %s", au->name, host->name,
1237 host->address, buffer);
1240 /* Internal problem, message in buffer. */
1244 set_errno(addrlist, 0, string_copy(buffer), DEFER, FALSE);
1248 break; /* If not authenticated, try next authenticator */
1249 } /* Loop for scanning supported server mechanisms */
1250 } /* Loop for further authenticators */
1254 /* If we haven't authenticated, but are required to, give up. */
1256 if (require_auth == OK && !smtp_authenticated)
1259 set_errno(addrlist, ERRNO_AUTHFAIL,
1260 string_sprintf("authentication required but %s", fail_reason), DEFER,
1266 /* The setting up of the SMTP call is now complete. Any subsequent errors are
1267 message-specific. */
1271 /* If there is a filter command specified for this transport, we can now
1272 set it up. This cannot be done until the identify of the host is known. */
1274 if (tblock->filter_command != NULL)
1278 sprintf(CS buffer, "%.50s transport", tblock->name);
1279 rc = transport_set_up_command(&transport_filter_argv, tblock->filter_command,
1280 TRUE, DEFER, addrlist, buffer, NULL);
1282 /* On failure, copy the error to all addresses, abandon the SMTP call, and
1287 set_errno(addrlist->next, addrlist->basic_errno, addrlist->message, DEFER,
1295 /* For messages that have more than the maximum number of envelope recipients,
1296 we want to send several transactions down the same SMTP connection. (See
1297 comments in deliver.c as to how this reconciles, heuristically, with
1298 remote_max_parallel.) This optimization was added to Exim after the following
1299 code was already working. The simplest way to put it in without disturbing the
1300 code was to use a goto to jump back to this point when there is another
1301 transaction to handle. */
1304 sync_addr = first_addr;
1308 completed_address = FALSE;
1311 /* Initiate a message transfer. If we know the receiving MTA supports the SIZE
1312 qualification, send it, adding something to the message size to allow for
1313 imprecision and things that get added en route. Exim keeps the number of lines
1314 in a message, so we can give an accurate value for the original message, but we
1315 need some additional to handle added headers. (Double "." characters don't get
1316 included in the count.) */
1323 sprintf(CS p, " SIZE=%d", message_size+message_linecount+ob->size_addition);
1327 /* Add the authenticated sender address if present */
1329 if ((smtp_authenticated || ob->authenticated_sender_force) &&
1330 local_authenticated_sender != NULL)
1332 string_format(p, sizeof(buffer) - (p-buffer), " AUTH=%s",
1333 auth_xtextencode(local_authenticated_sender,
1334 Ustrlen(local_authenticated_sender)));
1337 /* From here until we send the DATA command, we can make use of PIPELINING
1338 if the server host supports it. The code has to be able to check the responses
1339 at any point, for when the buffer fills up, so we write it totally generally.
1340 When PIPELINING is off, each command written reports that it has flushed the
1343 pending_MAIL = TRUE; /* The block starts with MAIL */
1345 rc = smtp_write_command(&outblock, smtp_use_pipelining,
1346 "MAIL FROM:<%s>%s\r\n", return_path, buffer);
1347 mail_command = string_copy(big_buffer); /* Save for later error message */
1351 case -1: /* Transmission error */
1354 case +1: /* Block was sent */
1355 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1356 ob->command_timeout))
1358 if (errno == 0 && buffer[0] == '4')
1360 errno = ERRNO_MAIL4XX;
1361 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1363 goto RESPONSE_FAILED;
1365 pending_MAIL = FALSE;
1369 /* Pass over all the relevant recipient addresses for this host, which are the
1370 ones that have status PENDING_DEFER. If we are using PIPELINING, we can send
1371 several before we have to read the responses for those seen so far. This
1372 checking is done by a subroutine because it also needs to be done at the end.
1373 Send only up to max_rcpt addresses at a time, leaving first_addr pointing to
1374 the next one if not all are sent.
1376 In the MUA wrapper situation, we want to flush the PIPELINING buffer for the
1377 last address because we want to abort if any recipients have any kind of
1378 problem, temporary or permanent. We know that all recipient addresses will have
1379 the PENDING_DEFER status, because only one attempt is ever made, and we know
1380 that max_rcpt will be large, so all addresses will be done at once. */
1382 for (addr = first_addr;
1383 address_count < max_rcpt && addr != NULL;
1389 if (addr->transport_return != PENDING_DEFER) continue;
1392 no_flush = smtp_use_pipelining && (!mua_wrapper || addr->next != NULL);
1394 /* Now send the RCPT command, and process outstanding responses when
1395 necessary. After a timeout on RCPT, we just end the function, leaving the
1396 yield as OK, because this error can often mean that there is a problem with
1397 just one address, so we don't want to delay the host. */
1399 count = smtp_write_command(&outblock, no_flush, "RCPT TO:<%s>%s\r\n",
1400 transport_rcpt_address(addr, tblock->rcpt_include_affixes), igquotstr);
1401 if (count < 0) goto SEND_FAILED;
1404 switch(sync_responses(first_addr, tblock->rcpt_include_affixes,
1405 &sync_addr, host, count, pending_MAIL, 0, &inblock,
1406 ob->command_timeout, buffer, sizeof(buffer)))
1408 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1409 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1412 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1413 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1414 case 0: /* No 2xx or 5xx, but no probs */
1417 case -1: goto END_OFF; /* Timeout on RCPT */
1418 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL error */
1420 pending_MAIL = FALSE; /* Dealt with MAIL */
1422 } /* Loop for next address */
1424 /* If we are an MUA wrapper, abort if any RCPTs were rejected, either
1425 permanently or temporarily. We should have flushed and synced after the last
1430 address_item *badaddr;
1431 for (badaddr = first_addr; badaddr != NULL; badaddr = badaddr->next)
1433 if (badaddr->transport_return != PENDING_OK) break;
1435 if (badaddr != NULL)
1437 set_errno(addrlist, 0, badaddr->message, FAIL,
1438 testflag(badaddr, af_pass_message));
1443 /* If ok is TRUE, we know we have got at least one good recipient, and must now
1444 send DATA, but if it is FALSE (in the normal, non-wrapper case), we may still
1445 have a good recipient buffered up if we are pipelining. We don't want to waste
1446 time sending DATA needlessly, so we only send it if either ok is TRUE or if we
1447 are pipelining. The responses are all handled by sync_responses(). */
1449 if (ok || (smtp_use_pipelining && !mua_wrapper))
1451 int count = smtp_write_command(&outblock, FALSE, "DATA\r\n");
1452 if (count < 0) goto SEND_FAILED;
1453 switch(sync_responses(first_addr, tblock->rcpt_include_affixes, &sync_addr,
1454 host, count, pending_MAIL, ok? +1 : -1, &inblock,
1455 ob->command_timeout, buffer, sizeof(buffer)))
1457 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1458 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1461 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1462 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1463 case 0: break; /* No 2xx or 5xx, but no probs */
1465 case -1: goto END_OFF; /* Timeout on RCPT */
1466 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */
1470 /* Save the first address of the next batch. */
1474 /* If there were no good recipients (but otherwise there have been no
1475 problems), just set ok TRUE, since we have handled address-specific errors
1476 already. Otherwise, it's OK to send the message. Use the check/escape mechanism
1477 for handling the SMTP dot-handling protocol, flagging to apply to headers as
1478 well as body. Set the appropriate timeout value to be used for each chunk.
1479 (Haven't been able to make it work using select() for writing yet.) */
1481 if (!ok) ok = TRUE; else
1483 sigalrm_seen = FALSE;
1484 transport_write_timeout = ob->data_timeout;
1485 smtp_command = US"sending data block"; /* For error messages */
1486 DEBUG(D_transport|D_v)
1487 debug_printf(" SMTP>> writing message and terminating \".\"\n");
1488 transport_count = 0;
1489 #ifdef EXPERIMENTAL_DOMAINKEYS
1490 if ( (ob->dk_private_key != NULL) && (ob->dk_selector != NULL) )
1491 ok = dk_transport_write_message(addrlist, inblock.sock,
1492 topt_use_crlf | topt_end_dot | topt_escape_headers |
1493 (tblock->body_only? topt_no_headers : 0) |
1494 (tblock->headers_only? topt_no_body : 0) |
1495 (tblock->return_path_add? topt_add_return_path : 0) |
1496 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1497 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1498 0, /* No size limit */
1499 tblock->add_headers, tblock->remove_headers,
1500 US".", US"..", /* Escaping strings */
1501 tblock->rewrite_rules, tblock->rewrite_existflags,
1502 ob->dk_private_key, ob->dk_domain, ob->dk_selector,
1503 ob->dk_canon, ob->dk_headers, ob->dk_strict);
1506 ok = transport_write_message(addrlist, inblock.sock,
1507 topt_use_crlf | topt_end_dot | topt_escape_headers |
1508 (tblock->body_only? topt_no_headers : 0) |
1509 (tblock->headers_only? topt_no_body : 0) |
1510 (tblock->return_path_add? topt_add_return_path : 0) |
1511 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1512 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1513 0, /* No size limit */
1514 tblock->add_headers, tblock->remove_headers,
1515 US".", US"..", /* Escaping strings */
1516 tblock->rewrite_rules, tblock->rewrite_existflags);
1518 /* transport_write_message() uses write() because it is called from other
1519 places to write to non-sockets. This means that under some OS (e.g. Solaris)
1520 it can exit with "Broken pipe" as its error. This really means that the
1521 socket got closed at the far end. */
1523 transport_write_timeout = 0; /* for subsequent transports */
1525 /* Failure can either be some kind of I/O disaster (including timeout),
1526 or the failure of a transport filter or the expansion of added headers. */
1530 buffer[0] = 0; /* There hasn't been a response */
1531 goto RESPONSE_FAILED;
1534 /* We used to send the terminating "." explicitly here, but because of
1535 buffering effects at both ends of TCP/IP connections, you don't gain
1536 anything by keeping it separate, so it might as well go in the final
1537 data buffer for efficiency. This is now done by setting the topt_end_dot
1540 smtp_command = US"end of data";
1542 /* For SMTP, we now read a single response that applies to the whole message.
1543 If it is OK, then all the addresses have been delivered. */
1547 ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1549 if (!ok && errno == 0 && buffer[0] == '4')
1551 errno = ERRNO_DATA4XX;
1552 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1556 /* For LMTP, we get back a response for every RCPT command that we sent;
1557 some may be accepted and some rejected. For those that get a response, their
1558 status is fixed; any that are accepted have been handed over, even if later
1559 responses crash - at least, that's how I read RFC 2033.
1561 If all went well, mark the recipient addresses as completed, record which
1562 host/IPaddress they were delivered to, and cut out RSET when sending another
1563 message down the same channel. Write the completed addresses to the journal
1564 now so that they are recorded in case there is a crash of hardware or
1565 software before the spool gets updated. Also record the final SMTP
1566 confirmation if needed (for SMTP only). */
1571 int delivery_time = (int)(time(NULL) - start_delivery_time);
1574 uschar *conf = NULL;
1577 /* Make a copy of the host if it is local to this invocation
1578 of the transport. */
1582 thost = store_get(sizeof(host_item));
1584 thost->name = string_copy(host->name);
1585 thost->address = string_copy(host->address);
1589 /* Set up confirmation if needed - applies only to SMTP */
1591 if ((log_extra_selector & LX_smtp_confirmation) != 0 && !lmtp)
1593 uschar *s = string_printing(buffer);
1594 conf = (s == buffer)? (uschar *)string_copy(s) : s;
1597 /* Process all transported addresses - for LMTP, read a status for
1600 for (addr = addrlist; addr != first_addr; addr = addr->next)
1602 if (addr->transport_return != PENDING_OK) continue;
1604 /* LMTP - if the response fails badly (e.g. timeout), use it for all the
1605 remaining addresses. Otherwise, it's a return code for just the one
1606 address. For temporary errors, add a retry item for the address so that
1607 it doesn't get tried again too soon. */
1611 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1614 if (errno != 0 || buffer[0] == 0) goto RESPONSE_FAILED;
1615 addr->message = string_sprintf("LMTP error after %s: %s",
1616 big_buffer, string_printing(buffer));
1617 setflag(addr, af_pass_message); /* Allow message to go to user */
1618 if (buffer[0] == '5')
1619 addr->transport_return = FAIL;
1622 errno = ERRNO_DATA4XX;
1623 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1624 addr->transport_return = DEFER;
1625 retry_add_item(addr, addr->address_retry_key, 0);
1629 completed_address = TRUE; /* NOW we can set this flag */
1632 /* SMTP, or success return from LMTP for this address. Pass back the
1633 actual host that was used. */
1635 addr->transport_return = OK;
1636 addr->more_errno = delivery_time;
1637 addr->host_used = thost;
1638 addr->special_action = flag;
1639 addr->message = conf;
1642 /* Update the journal. For homonymic addresses, use the base address plus
1643 the transport name. See lots of comments in deliver.c about the reasons
1644 for the complications when homonyms are involved. Just carry on after
1645 write error, as it may prove possible to update the spool file later. */
1647 if (testflag(addr, af_homonym))
1648 sprintf(CS buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
1650 sprintf(CS buffer, "%.500s\n", addr->unique);
1652 DEBUG(D_deliver) debug_printf("journalling %s", buffer);
1653 len = Ustrlen(CS buffer);
1654 if (write(journal_fd, buffer, len) != len)
1655 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
1656 "%s: %s", buffer, strerror(errno));
1659 /* Ensure the journal file is pushed out to disk. */
1661 if (fsync(journal_fd) < 0)
1662 log_write(0, LOG_MAIN|LOG_PANIC, "failed to fsync journal: %s",
1668 /* Handle general (not specific to one address) failures here. The value of ok
1669 is used to skip over this code on the falling through case. A timeout causes a
1670 deferral. Other errors may defer or fail according to the response code, and
1671 may set up a special errno value, e.g. after connection chopped, which is
1672 assumed if errno == 0 and there is no text in the buffer. If control reaches
1673 here during the setting up phase (i.e. before MAIL FROM) then always defer, as
1674 the problem is not related to this specific message. */
1683 send_quit = check_response(host, &save_errno, addrlist->more_errno,
1684 buffer, &code, &message, &pass_message);
1690 message = US string_sprintf("send() to %s [%s] failed: %s",
1691 host->name, host->address, strerror(save_errno));
1695 /* This label is jumped to directly when a TLS negotiation has failed,
1696 or was not done for a host for which it is required. Values will be set
1697 in message and save_errno, and setting_up will always be true. Treat as
1698 a temporary error. */
1705 /* If the failure happened while setting up the call, see if the failure was
1706 a 5xx response (this will either be on connection, or following HELO - a 5xx
1707 after EHLO causes it to try HELO). If so, fail all addresses, as this host is
1708 never going to accept them. For other errors during setting up (timeouts or
1709 whatever), defer all addresses, and yield DEFER, so that the host is not
1710 tried again for a while. */
1713 ok = FALSE; /* For when reached by GOTO */
1719 set_errno(addrlist, save_errno, message, FAIL, pass_message);
1723 set_errno(addrlist, save_errno, message, DEFER, pass_message);
1728 /* We want to handle timeouts after MAIL or "." and loss of connection after
1729 "." specially. They can indicate a problem with the sender address or with
1730 the contents of the message rather than a real error on the connection. These
1731 cases are treated in the same way as a 4xx response. This next bit of code
1732 does the classification. */
1743 message_error = TRUE;
1747 message_error = Ustrncmp(smtp_command,"MAIL",4) == 0 ||
1748 Ustrncmp(smtp_command,"end ",4) == 0;
1751 case ERRNO_SMTPCLOSED:
1752 message_error = Ustrncmp(smtp_command,"end ",4) == 0;
1756 message_error = FALSE;
1760 /* Handle the cases that are treated as message errors. These are:
1762 (a) negative response or timeout after MAIL
1763 (b) negative response after DATA
1764 (c) negative response or timeout or dropped connection after "."
1766 It won't be a negative response or timeout after RCPT, as that is dealt
1767 with separately above. The action in all cases is to set an appropriate
1768 error code for all the addresses, but to leave yield set to OK because the
1769 host itself has not failed. Of course, it might in practice have failed
1770 when we've had a timeout, but if so, we'll discover that at the next
1771 delivery attempt. For a temporary error, set the message_defer flag, and
1772 write to the logs for information if this is not the last host. The error
1773 for the last host will be logged as part of the address's log line. */
1777 if (mua_wrapper) code = '5'; /* Force hard failure in wrapper mode */
1778 set_errno(addrlist, save_errno, message, (code == '5')? FAIL : DEFER,
1781 /* If there's an errno, the message contains just the identity of
1784 if (code != '5') /* Anything other than 5 is treated as temporary */
1787 message = US string_sprintf("%s: %s", message, strerror(save_errno));
1788 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", message);
1789 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
1790 *message_defer = TRUE;
1794 /* Otherwise, we have an I/O error or a timeout other than after MAIL or
1795 ".", or some other transportation error. We defer all addresses and yield
1796 DEFER, except for the case of failed add_headers expansion, or a transport
1797 filter failure, when the yield should be ERROR, to stop it trying other
1802 yield = (save_errno == ERRNO_CHHEADER_FAIL ||
1803 save_errno == ERRNO_FILTER_FAIL)? ERROR : DEFER;
1804 set_errno(addrlist, save_errno, message, DEFER, pass_message);
1810 /* If all has gone well, send_quit will be set TRUE, implying we can end the
1811 SMTP session tidily. However, if there were too many addresses to send in one
1812 message (indicated by first_addr being non-NULL) we want to carry on with the
1813 rest of them. Also, it is desirable to send more than one message down the SMTP
1814 connection if there are several waiting, provided we haven't already sent so
1815 many as to hit the configured limit. The function transport_check_waiting looks
1816 for a waiting message and returns its id. Then transport_pass_socket tries to
1817 set up a continued delivery by passing the socket on to another process. The
1818 variable send_rset is FALSE if a message has just been successfully transfered.
1820 If we are already sending down a continued channel, there may be further
1821 addresses not yet delivered that are aimed at the same host, but which have not
1822 been passed in this run of the transport. In this case, continue_more will be
1823 true, and all we should do is send RSET if necessary, and return, leaving the
1826 However, if no address was disposed of, i.e. all addresses got 4xx errors, we
1827 do not want to continue with other messages down the same channel, because that
1828 can lead to looping between two or more messages, all with the same,
1829 temporarily failing address(es). [The retry information isn't updated yet, so
1830 new processes keep on trying.] We probably also don't want to try more of this
1831 message's addresses either.
1833 If we have started a TLS session, we have to end it before passing the
1834 connection to a new process. However, not all servers can handle this (Exim
1835 can), so we do not pass such a connection on if the host matches
1836 hosts_nopass_tls. */
1839 debug_printf("ok=%d send_quit=%d send_rset=%d continue_more=%d "
1840 "yield=%d first_address is %sNULL\n", ok, send_quit, send_rset,
1841 continue_more, yield, (first_addr == NULL)? "":"not ");
1843 if (completed_address && ok && send_quit)
1846 if (first_addr != NULL || continue_more ||
1849 verify_check_this_host(&(ob->hosts_nopass_tls), NULL, host->name,
1850 host->address, NULL) != OK)
1852 transport_check_waiting(tblock->name, host->name,
1853 tblock->connection_max_messages, new_message_id, &more)
1861 if (! (ok = smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0))
1863 msg = US string_sprintf("send() to %s [%s] failed: %s", host->name,
1864 host->address, strerror(save_errno));
1867 else if (! (ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1868 ob->command_timeout)))
1871 send_quit = check_response(host, &errno, 0, buffer, &code, &msg,
1875 DEBUG(D_transport) debug_printf("%s\n", msg);
1880 /* Either RSET was not needed, or it succeeded */
1884 if (first_addr != NULL) /* More addresses still to be sent */
1885 { /* in this run of the transport */
1886 continue_sequence++; /* Causes * in logging */
1889 if (continue_more) return yield; /* More addresses for another run */
1891 /* Pass the socket to a new Exim process. Before doing so, we must shut
1892 down TLS. Not all MTAs allow for the continuation of the SMTP session
1893 when TLS is shut down. We test for this by sending a new EHLO. If we
1894 don't get a good response, we don't attempt to pass the socket on. */
1897 if (tls_active >= 0)
1900 ok = smtp_write_command(&outblock,FALSE,"EHLO %s\r\n",helo_data) >= 0 &&
1901 smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1902 ob->command_timeout);
1906 /* If the socket is successfully passed, we musn't send QUIT (or
1907 indeed anything!) from here. */
1909 if (ok && transport_pass_socket(tblock->name, host->name, host->address,
1910 new_message_id, inblock.sock))
1916 /* If RSET failed and there are addresses left, they get deferred. */
1918 else set_errno(first_addr, errno, msg, DEFER, FALSE);
1922 /* End off tidily with QUIT unless the connection has died or the socket has
1923 been passed to another process. There has been discussion on the net about what
1924 to do after sending QUIT. The wording of the RFC suggests that it is necessary
1925 to wait for a response, but on the other hand, there isn't anything one can do
1926 with an error response, other than log it. Exim used to do that. However,
1927 further discussion suggested that it is positively advantageous not to wait for
1928 the response, but to close the session immediately. This is supposed to move
1929 the TCP/IP TIME_WAIT state from the server to the client, thereby removing some
1930 load from the server. (Hosts that are both servers and clients may not see much
1931 difference, of course.) Further discussion indicated that this was safe to do
1932 on Unix systems which have decent implementations of TCP/IP that leave the
1933 connection around for a while (TIME_WAIT) after the application has gone away.
1934 This enables the response sent by the server to be properly ACKed rather than
1935 timed out, as can happen on broken TCP/IP implementations on other OS.
1937 This change is being made on 31-Jul-98. After over a year of trouble-free
1938 operation, the old commented-out code was removed on 17-Sep-99. */
1941 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1949 /* Close the socket, and return the appropriate value, first setting
1950 continue_transport and continue_hostname NULL to prevent any other addresses
1951 that may include the host from trying to re-use a continuation socket. This
1952 works because the NULL setting is passed back to the calling process, and
1953 remote_max_parallel is forced to 1 when delivering over an existing connection,
1955 If all went well and continue_more is set, we shouldn't actually get here if
1956 there are further addresses, as the return above will be taken. However,
1957 writing RSET might have failed, or there may be other addresses whose hosts are
1958 specified in the transports, and therefore not visible at top level, in which
1959 case continue_more won't get set. */
1961 (void)close(inblock.sock);
1962 continue_transport = NULL;
1963 continue_hostname = NULL;
1970 /*************************************************
1971 * Closedown entry point *
1972 *************************************************/
1974 /* This function is called when exim is passed an open smtp channel
1975 from another incarnation, but the message which it has been asked
1976 to deliver no longer exists. The channel is on stdin.
1978 We might do fancy things like looking for another message to send down
1979 the channel, but if the one we sought has gone, it has probably been
1980 delivered by some other process that itself will seek further messages,
1981 so just close down our connection.
1983 Argument: pointer to the transport instance block
1988 smtp_transport_closedown(transport_instance *tblock)
1990 smtp_transport_options_block *ob =
1991 (smtp_transport_options_block *)(tblock->options_block);
1992 smtp_inblock inblock;
1993 smtp_outblock outblock;
1995 uschar inbuffer[4096];
1996 uschar outbuffer[16];
1998 inblock.sock = fileno(stdin);
1999 inblock.buffer = inbuffer;
2000 inblock.buffersize = sizeof(inbuffer);
2001 inblock.ptr = inbuffer;
2002 inblock.ptrend = inbuffer;
2004 outblock.sock = inblock.sock;
2005 outblock.buffersize = sizeof(outbuffer);
2006 outblock.buffer = outbuffer;
2007 outblock.ptr = outbuffer;
2008 outblock.cmd_count = 0;
2009 outblock.authenticating = FALSE;
2011 (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
2012 (void)smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2013 ob->command_timeout);
2014 (void)close(inblock.sock);
2019 /*************************************************
2020 * Prepare addresses for delivery *
2021 *************************************************/
2023 /* This function is called to flush out error settings from previous delivery
2024 attempts to other hosts. It also records whether we got here via an MX record
2025 or not in the more_errno field of the address. We are interested only in
2026 addresses that are still marked DEFER - others may have got delivered to a
2027 previously considered IP address. Set their status to PENDING_DEFER to indicate
2028 which ones are relevant this time.
2031 addrlist the list of addresses
2032 host the host we are delivering to
2034 Returns: the first address for this delivery
2037 static address_item *
2038 prepare_addresses(address_item *addrlist, host_item *host)
2040 address_item *first_addr = NULL;
2042 for (addr = addrlist; addr != NULL; addr = addr->next)
2044 if (addr->transport_return != DEFER) continue;
2045 if (first_addr == NULL) first_addr = addr;
2046 addr->transport_return = PENDING_DEFER;
2047 addr->basic_errno = 0;
2048 addr->more_errno = (host->mx >= 0)? 'M' : 'A';
2049 addr->message = NULL;
2051 addr->cipher = NULL;
2052 addr->peerdn = NULL;
2060 /*************************************************
2061 * Main entry point *
2062 *************************************************/
2064 /* See local README for interface details. As this is a remote transport, it is
2065 given a chain of addresses to be delivered in one connection, if possible. It
2066 always returns TRUE, indicating that each address has its own independent
2067 status set, except if there is a setting up problem, in which case it returns
2071 smtp_transport_entry(
2072 transport_instance *tblock, /* data for this instantiation */
2073 address_item *addrlist) /* addresses we are working on */
2077 int hosts_defer = 0;
2079 int hosts_looked_up = 0;
2080 int hosts_retry = 0;
2081 int hosts_serial = 0;
2082 int hosts_total = 0;
2083 int total_hosts_tried = 0;
2085 BOOL expired = TRUE;
2086 BOOL continuing = continue_hostname != NULL;
2087 uschar *expanded_hosts = NULL;
2089 uschar *tid = string_sprintf("%s transport", tblock->name);
2090 smtp_transport_options_block *ob =
2091 (smtp_transport_options_block *)(tblock->options_block);
2092 host_item *hostlist = addrlist->host_list;
2093 host_item *host = NULL;
2097 debug_printf("%s transport entered\n", tblock->name);
2098 for (addr = addrlist; addr != NULL; addr = addr->next)
2099 debug_printf(" %s\n", addr->address);
2100 if (continuing) debug_printf("already connected to %s [%s]\n",
2101 continue_hostname, continue_host_address);
2104 /* If a host list is not defined for the addresses - they must all have the
2105 same one in order to be passed to a single transport - or if the transport has
2106 a host list with hosts_override set, use the host list supplied with the
2107 transport. It is an error for this not to exist. */
2109 if (hostlist == NULL || (ob->hosts_override && ob->hosts != NULL))
2111 if (ob->hosts == NULL)
2113 addrlist->message = string_sprintf("%s transport called with no hosts set",
2115 addrlist->transport_return = PANIC;
2116 return FALSE; /* Only top address has status */
2119 DEBUG(D_transport) debug_printf("using the transport's hosts: %s\n",
2122 /* If the transport's host list contains no '$' characters, and we are not
2123 randomizing, it is fixed and therefore a chain of hosts can be built once
2124 and for all, and remembered for subsequent use by other calls to this
2125 transport. If, on the other hand, the host list does contain '$', or we are
2126 randomizing its order, we have to rebuild it each time. In the fixed case,
2127 as the hosts string will never be used again, it doesn't matter that we
2128 replace all the : characters with zeros. */
2130 if (ob->hostlist == NULL)
2132 uschar *s = ob->hosts;
2134 if (Ustrchr(s, '$') != NULL)
2136 expanded_hosts = expand_string(s);
2137 if (expanded_hosts == NULL)
2139 addrlist->message = string_sprintf("failed to expand list of hosts "
2140 "\"%s\" in %s transport: %s", s, tblock->name, expand_string_message);
2141 addrlist->transport_return = search_find_defer? DEFER : PANIC;
2142 return FALSE; /* Only top address has status */
2144 DEBUG(D_transport) debug_printf("expanded list of hosts \"%s\" to "
2145 "\"%s\"\n", s, expanded_hosts);
2149 if (ob->hosts_randomize) s = expanded_hosts = string_copy(s);
2151 host_build_hostlist(&hostlist, s, ob->hosts_randomize);
2153 /* If there was no expansion of hosts, save the host list for
2156 if (expanded_hosts == NULL) ob->hostlist = hostlist;
2159 /* This is not the first time this transport has been run in this delivery;
2160 the host list was built previously. */
2162 else hostlist = ob->hostlist;
2165 /* The host list was supplied with the address. If hosts_randomize is set, we
2166 must sort it into a random order if it did not come from MX records and has not
2167 already been randomized (but don't bother if continuing down an existing
2170 else if (ob->hosts_randomize && hostlist->mx == MX_NONE && !continuing)
2172 host_item *newlist = NULL;
2173 while (hostlist != NULL)
2175 host_item *h = hostlist;
2176 hostlist = hostlist->next;
2178 h->sort_key = random_number(100);
2180 if (newlist == NULL)
2185 else if (h->sort_key < newlist->sort_key)
2192 host_item *hh = newlist;
2193 while (hh->next != NULL)
2195 if (h->sort_key < hh->next->sort_key) break;
2203 hostlist = addrlist->host_list = newlist;
2207 /* Sort out the default port. */
2209 if (!smtp_get_port(ob->port, addrlist, &port, tid)) return FALSE;
2212 /* For each host-plus-IP-address on the list:
2214 . If this is a continued delivery and the host isn't the one with the
2215 current connection, skip.
2217 . If the status is unusable (i.e. previously failed or retry checked), skip.
2219 . If no IP address set, get the address, either by turning the name into
2220 an address, calling gethostbyname if gethostbyname is on, or by calling
2221 the DNS. The DNS may yield multiple addresses, in which case insert the
2222 extra ones into the list.
2224 . Get the retry data if not previously obtained for this address and set the
2225 field which remembers the state of this address. Skip if the retry time is
2226 not reached. If not, remember whether retry data was found. The retry string
2227 contains both the name and the IP address.
2229 . Scan the list of addresses and mark those whose status is DEFER as
2230 PENDING_DEFER. These are the only ones that will be processed in this cycle
2233 . Make a delivery attempt - addresses marked PENDING_DEFER will be tried.
2234 Some addresses may be successfully delivered, others may fail, and yet
2235 others may get temporary errors and so get marked DEFER.
2237 . The return from the delivery attempt is OK if a connection was made and a
2238 valid SMTP dialogue was completed. Otherwise it is DEFER.
2240 . If OK, add a "remove" retry item for this host/IPaddress, if any.
2242 . If fail to connect, or other defer state, add a retry item.
2244 . If there are any addresses whose status is still DEFER, carry on to the
2245 next host/IPaddress, unless we have tried the number of hosts given
2246 by hosts_max_try or hosts_max_try_hardlimit; otherwise return. Note that
2247 there is some fancy logic for hosts_max_try that means its limit can be
2248 overstepped in some circumstances.
2250 If we get to the end of the list, all hosts have deferred at least one address,
2251 or not reached their retry times. If delay_after_cutoff is unset, it requests a
2252 delivery attempt to those hosts whose last try was before the arrival time of
2253 the current message. To cope with this, we have to go round the loop a second
2254 time. After that, set the status and error data for any addresses that haven't
2255 had it set already. */
2257 for (cutoff_retry = 0; expired &&
2258 cutoff_retry < ((ob->delay_after_cutoff)? 1 : 2);
2261 host_item *nexthost = NULL;
2262 int unexpired_hosts_tried = 0;
2264 for (host = hostlist;
2266 unexpired_hosts_tried < ob->hosts_max_try &&
2267 total_hosts_tried < ob->hosts_max_try_hardlimit;
2273 BOOL serialized = FALSE;
2274 BOOL host_is_expired = FALSE;
2275 BOOL message_defer = FALSE;
2276 BOOL ifchanges = FALSE;
2277 BOOL some_deferred = FALSE;
2278 address_item *first_addr = NULL;
2279 uschar *interface = NULL;
2280 uschar *retry_host_key = NULL;
2281 uschar *retry_message_key = NULL;
2282 uschar *serialize_key = NULL;
2284 /* Default next host is next host. :-) But this can vary if the
2285 hosts_max_try limit is hit (see below). It may also be reset if a host
2286 address is looked up here (in case the host was multihomed). */
2288 nexthost = host->next;
2290 /* Set the flag requesting that this host be added to the waiting
2291 database if the delivery fails temporarily or if we are running with
2292 queue_smtp or a 2-stage queue run. This gets unset for certain
2293 kinds of error, typically those that are specific to the message. */
2295 host->update_waiting = TRUE;
2297 /* If the address hasn't yet been obtained from the host name, look it up
2298 now, unless the host is already marked as unusable. If it is marked as
2299 unusable, it means that the router was unable to find its IP address (in
2300 the DNS or wherever) OR we are in the 2nd time round the cutoff loop, and
2301 the lookup failed last time. We don't get this far if *all* MX records
2302 point to non-existent hosts; that is treated as a hard error.
2304 We can just skip this host entirely. When the hosts came from the router,
2305 the address will timeout based on the other host(s); when the address is
2306 looked up below, there is an explicit retry record added.
2308 Note that we mustn't skip unusable hosts if the address is not unset; they
2309 may be needed as expired hosts on the 2nd time round the cutoff loop. */
2311 if (host->address == NULL)
2315 uschar *canonical_name;
2317 if (host->status >= hstatus_unusable)
2319 DEBUG(D_transport) debug_printf("%s has no address and is unusable - skipping\n",
2324 DEBUG(D_transport) debug_printf("getting address for %s\n", host->name);
2326 /* The host name is permitted to have an attached port. Find it, and
2327 strip it from the name. Just remember it for now. */
2329 new_port = host_item_get_port(host);
2331 /* Count hosts looked up */
2335 /* Find by name if so configured, or if it's an IP address. We don't
2336 just copy the IP address, because we need the test-for-local to happen. */
2338 if (ob->gethostbyname || string_is_ip_address(host->name, NULL) != 0)
2339 rc = host_find_byname(host, NULL, &canonical_name, TRUE);
2342 int flags = HOST_FIND_BY_A;
2343 if (ob->dns_qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
2344 if (ob->dns_search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
2345 rc = host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
2346 &canonical_name, NULL);
2349 /* Update the host (and any additional blocks, resulting from
2350 multihoming) with a host-specific port, if any. */
2352 for (hh = host; hh != nexthost; hh = hh->next) hh->port = new_port;
2354 /* Failure to find the host at this time (usually DNS temporary failure)
2355 is really a kind of routing failure rather than a transport failure.
2356 Therefore we add a retry item of the routing kind, not to stop us trying
2357 to look this name up here again, but to ensure the address gets timed
2358 out if the failures go on long enough. A complete failure at this point
2359 commonly points to a configuration error, but the best action is still
2360 to carry on for the next host. */
2362 if (rc == HOST_FIND_AGAIN || rc == HOST_FIND_FAILED)
2364 retry_add_item(addrlist, string_sprintf("R:%s", host->name), 0);
2366 if (rc == HOST_FIND_AGAIN) hosts_defer++; else hosts_fail++;
2367 DEBUG(D_transport) debug_printf("rc = %s for %s\n", (rc == HOST_FIND_AGAIN)?
2368 "HOST_FIND_AGAIN" : "HOST_FIND_FAILED", host->name);
2369 host->status = hstatus_unusable;
2371 for (addr = addrlist; addr != NULL; addr = addr->next)
2373 if (addr->transport_return != DEFER) continue;
2374 addr->basic_errno = ERRNO_UNKNOWNHOST;
2376 string_sprintf("failed to lookup IP address for %s", host->name);
2381 /* If the host is actually the local host, we may have a problem, or
2382 there may be some cunning configuration going on. In the problem case,
2383 log things and give up. The default transport status is already DEFER. */
2385 if (rc == HOST_FOUND_LOCAL && !ob->allow_localhost)
2387 for (addr = addrlist; addr != NULL; addr = addr->next)
2389 addr->basic_errno = 0;
2390 addr->message = string_sprintf("%s transport found host %s to be "
2391 "local", tblock->name, host->name);
2395 } /* End of block for IP address lookup */
2397 /* If this is a continued delivery, we are interested only in the host
2398 which matches the name of the existing open channel. The check is put
2399 here after the local host lookup, in case the name gets expanded as a
2400 result of the lookup. Set expired FALSE, to save the outer loop executing
2403 if (continuing && (Ustrcmp(continue_hostname, host->name) != 0 ||
2404 Ustrcmp(continue_host_address, host->address) != 0))
2407 continue; /* With next host */
2410 /* Reset the default next host in case a multihomed host whose addresses
2411 are not looked up till just above added to the host list. */
2413 nexthost = host->next;
2415 /* If queue_smtp is set (-odqs or the first part of a 2-stage run), or the
2416 domain is in queue_smtp_domains, we don't actually want to attempt any
2417 deliveries. When doing a queue run, queue_smtp_domains is always unset. If
2418 there is a lookup defer in queue_smtp_domains, proceed as if the domain
2419 were not in it. We don't want to hold up all SMTP deliveries! Except when
2420 doing a two-stage queue run, don't do this if forcing. */
2422 if ((!deliver_force || queue_2stage) && (queue_smtp ||
2423 match_isinlist(addrlist->domain, &queue_smtp_domains, 0,
2424 &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL) == OK))
2427 for (addr = addrlist; addr != NULL; addr = addr->next)
2429 if (addr->transport_return != DEFER) continue;
2430 addr->message = US"domain matches queue_smtp_domains, or -odqs set";
2432 continue; /* With next host */
2435 /* Count hosts being considered - purely for an intelligent comment
2436 if none are usable. */
2440 /* Set $host and $host address now in case they are needed for the
2441 interface expansion or the serialize_hosts check; they remain set if an
2442 actual delivery happens. */
2444 deliver_host = host->name;
2445 deliver_host_address = host->address;
2447 /* Set up a string for adding to the retry key if the port number is not
2448 the standard SMTP port. A host may have its own port setting that overrides
2451 pistring = string_sprintf(":%d", (host->port == PORT_NONE)?
2453 if (Ustrcmp(pistring, ":25") == 0) pistring = US"";
2455 /* Select IPv4 or IPv6, and choose an outgoing interface. If the interface
2456 string changes upon expansion, we must add it to the key that is used for
2457 retries, because connections to the same host from a different interface
2458 should be treated separately. */
2460 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET : AF_INET6;
2461 if (!smtp_get_interface(ob->interface, host_af, addrlist, &ifchanges,
2464 if (ifchanges) pistring = string_sprintf("%s/%s", pistring, interface);
2466 /* The first time round the outer loop, check the status of the host by
2467 inspecting the retry data. The second time round, we are interested only
2468 in expired hosts that haven't been tried since this message arrived. */
2470 if (cutoff_retry == 0)
2472 /* Ensure the status of the address is set by checking retry data if
2473 necessary. There maybe host-specific retry data (applicable to all
2474 messages) and also data for retries of a specific message at this host.
2475 If either of these retry records are actually read, the keys used are
2476 returned to save recomputing them later. */
2478 host_is_expired = retry_check_address(addrlist->domain, host, pistring,
2479 ob->retry_include_ip_address, &retry_host_key, &retry_message_key);
2481 DEBUG(D_transport) debug_printf("%s [%s]%s status = %s\n", host->name,
2482 (host->address == NULL)? US"" : host->address, pistring,
2483 (host->status == hstatus_usable)? "usable" :
2484 (host->status == hstatus_unusable)? "unusable" :
2485 (host->status == hstatus_unusable_expired)? "unusable (expired)" : "?");
2487 /* Skip this address if not usable at this time, noting if it wasn't
2488 actually expired, both locally and in the address. */
2490 switch (host->status)
2492 case hstatus_unusable:
2494 setflag(addrlist, af_retry_skipped);
2497 case hstatus_unusable_expired:
2500 case hwhy_retry: hosts_retry++; break;
2501 case hwhy_failed: hosts_fail++; break;
2502 case hwhy_deferred: hosts_defer++; break;
2505 /* If there was a retry message key, implying that previously there
2506 was a message-specific defer, we don't want to update the list of
2507 messages waiting for this host. */
2509 if (retry_message_key != NULL) host->update_waiting = FALSE;
2510 continue; /* With the next host or IP address */
2514 /* Second time round the loop: if the address is set but expired, and
2515 the message is newer than the last try, let it through. */
2519 if (host->address == NULL ||
2520 host->status != hstatus_unusable_expired ||
2521 host->last_try > received_time)
2524 debug_printf("trying expired host %s [%s]%s\n",
2525 host->name, host->address, pistring);
2526 host_is_expired = TRUE;
2529 /* Setting "expired=FALSE" doesn't actually mean not all hosts are expired;
2530 it remains TRUE only if all hosts are expired and none are actually tried.
2535 /* If this host is listed as one to which access must be serialized,
2536 see if another Exim process has a connection to it, and if so, skip
2537 this host. If not, update the database to record our connection to it
2538 and remember this for later deletion. Do not do any of this if we are
2539 sending the message down a pre-existing connection. */
2542 verify_check_this_host(&(ob->serialize_hosts), NULL, host->name,
2543 host->address, NULL) == OK)
2545 serialize_key = string_sprintf("host-serialize-%s", host->name);
2546 if (!enq_start(serialize_key))
2549 debug_printf("skipping host %s because another Exim process "
2550 "is connected to it\n", host->name);
2557 /* OK, we have an IP address that is not waiting for its retry time to
2558 arrive (it might be expired) OR (second time round the loop) we have an
2559 expired host that hasn't been tried since the message arrived. Have a go
2560 at delivering the message to it. First prepare the addresses by flushing
2561 out the result of previous attempts, and finding the first address that
2562 is still to be delivered. */
2564 first_addr = prepare_addresses(addrlist, host);
2566 DEBUG(D_transport) debug_printf("delivering %s to %s [%s] (%s%s)\n",
2567 message_id, host->name, host->address, addrlist->address,
2568 (addrlist->next == NULL)? "" : ", ...");
2570 set_process_info("delivering %s to %s [%s] (%s%s)",
2571 message_id, host->name, host->address, addrlist->address,
2572 (addrlist->next == NULL)? "" : ", ...");
2574 /* This is not for real; don't do the delivery. If there are
2575 any remaining hosts, list them. */
2580 set_errno(addrlist, 0, NULL, OK, FALSE);
2581 for (addr = addrlist; addr != NULL; addr = addr->next)
2583 addr->host_used = host;
2584 addr->special_action = '*';
2585 addr->message = US"delivery bypassed by -N option";
2589 debug_printf("*** delivery by %s transport bypassed by -N option\n"
2590 "*** host and remaining hosts:\n", tblock->name);
2591 for (host2 = host; host2 != NULL; host2 = host2->next)
2592 debug_printf(" %s [%s]\n", host2->name,
2593 (host2->address == NULL)? US"unset" : host2->address);
2598 /* This is for real. If the host is expired, we don't count it for
2599 hosts_max_retry. This ensures that all hosts must expire before an address
2600 is timed out, unless hosts_max_try_hardlimit (which protects against
2601 lunatic DNS configurations) is reached.
2603 If the host is not expired and we are about to hit the hosts_max_retry
2604 limit, check to see if there is a subsequent hosts with a different MX
2605 value. If so, make that the next host, and don't count this one. This is a
2606 heuristic to make sure that different MXs do get tried. With a normal kind
2607 of retry rule, they would get tried anyway when the earlier hosts were
2608 delayed, but if the domain has a "retry every time" type of rule - as is
2609 often used for the the very large ISPs, that won't happen. */
2613 if (!host_is_expired && ++unexpired_hosts_tried >= ob->hosts_max_try)
2617 debug_printf("hosts_max_try limit reached with this host\n");
2618 for (h = host; h != NULL; h = h->next)
2619 if (h->mx != host->mx) break;
2623 unexpired_hosts_tried--;
2624 DEBUG(D_transport) debug_printf("however, a higher MX host exists "
2625 "and will be tried\n");
2629 /* Attempt the delivery. */
2631 total_hosts_tried++;
2632 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2633 expanded_hosts != NULL, &message_defer, FALSE);
2636 OK => connection made, each address contains its result;
2637 message_defer is set for message-specific defers (when all
2638 recipients are marked defer)
2639 DEFER => there was a non-message-specific delivery problem;
2640 ERROR => there was a problem setting up the arguments for a filter,
2641 or there was a problem with expanding added headers
2644 /* If the result is not OK, there was a non-message-specific problem.
2645 If the result is DEFER, we need to write to the logs saying what happened
2646 for this particular host, except in the case of authentication and TLS
2647 failures, where the log has already been written. If all hosts defer a
2648 general message is written at the end. */
2650 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL &&
2651 first_addr->basic_errno != ERRNO_TLSFAILURE)
2652 write_logs(first_addr, host);
2654 /* If STARTTLS was accepted, but there was a failure in setting up the
2655 TLS session (usually a certificate screwup), and the host is not in
2656 hosts_require_tls, and tls_tempfail_tryclear is true, try again, with
2657 TLS forcibly turned off. We have to start from scratch with a new SMTP
2658 connection. That's why the retry is done from here, not from within
2659 smtp_deliver(). [Rejections of STARTTLS itself don't screw up the
2660 session, so the in-clear transmission after those errors, if permitted,
2661 happens inside smtp_deliver().] */
2664 if (rc == DEFER && first_addr->basic_errno == ERRNO_TLSFAILURE &&
2665 ob->tls_tempfail_tryclear &&
2666 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
2667 host->address, NULL) != OK)
2669 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
2670 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
2671 first_addr = prepare_addresses(addrlist, host);
2672 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2673 expanded_hosts != NULL, &message_defer, TRUE);
2674 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL)
2675 write_logs(first_addr, host);
2680 /* Delivery attempt finished */
2682 rs = (rc == OK)? US"OK" : (rc == DEFER)? US"DEFER" : (rc == ERROR)?
2685 set_process_info("delivering %s: just tried %s [%s] for %s%s: result %s",
2686 message_id, host->name, host->address, addrlist->address,
2687 (addrlist->next == NULL)? "" : " (& others)", rs);
2689 /* Release serialization if set up */
2691 if (serialized) enq_end(serialize_key);
2693 /* If the result is DEFER, or if a host retry record is known to exist, we
2694 need to add an item to the retry chain for updating the retry database
2695 at the end of delivery. We only need to add the item to the top address,
2696 of course. Also, if DEFER, we mark the IP address unusable so as to skip it
2697 for any other delivery attempts using the same address. (It is copied into
2698 the unusable tree at the outer level, so even if different address blocks
2699 contain the same address, it still won't get tried again.) */
2701 if (rc == DEFER || retry_host_key != NULL)
2703 int delete_flag = (rc != DEFER)? rf_delete : 0;
2704 if (retry_host_key == NULL)
2706 retry_host_key = ob->retry_include_ip_address?
2707 string_sprintf("T:%S:%s%s", host->name, host->address, pistring) :
2708 string_sprintf("T:%S%s", host->name, pistring);
2711 /* If a delivery of another message over an existing SMTP connection
2712 yields DEFER, we do NOT set up retry data for the host. This covers the
2713 case when there are delays in routing the addresses in the second message
2714 that are so long that the server times out. This is alleviated by not
2715 routing addresses that previously had routing defers when handling an
2716 existing connection, but even so, this case may occur (e.g. if a
2717 previously happily routed address starts giving routing defers). If the
2718 host is genuinely down, another non-continued message delivery will
2719 notice it soon enough. */
2721 if (delete_flag != 0 || !continuing)
2722 retry_add_item(first_addr, retry_host_key, rf_host | delete_flag);
2724 /* We may have tried an expired host, if its retry time has come; ensure
2725 the status reflects the expiry for the benefit of any other addresses. */
2729 host->status = (host_is_expired)?
2730 hstatus_unusable_expired : hstatus_unusable;
2731 host->why = hwhy_deferred;
2735 /* If message_defer is set (host was OK, but every recipient got deferred
2736 because of some message-specific problem), or if that had happened
2737 previously so that a message retry key exists, add an appropriate item
2738 to the retry chain. Note that if there was a message defer but now there is
2739 a host defer, the message defer record gets deleted. That seems perfectly
2740 reasonable. Also, stop the message from being remembered as waiting
2743 if (message_defer || retry_message_key != NULL)
2745 int delete_flag = message_defer? 0 : rf_delete;
2746 if (retry_message_key == NULL)
2748 retry_message_key = ob->retry_include_ip_address?
2749 string_sprintf("T:%S:%s%s:%s", host->name, host->address, pistring,
2751 string_sprintf("T:%S%s:%s", host->name, pistring, message_id);
2753 retry_add_item(addrlist, retry_message_key,
2754 rf_message | rf_host | delete_flag);
2755 host->update_waiting = FALSE;
2758 /* Any return other than DEFER (that is, OK or ERROR) means that the
2759 addresses have got their final statuses filled in for this host. In the OK
2760 case, see if any of them are deferred. */
2764 for (addr = addrlist; addr != NULL; addr = addr->next)
2766 if (addr->transport_return == DEFER)
2768 some_deferred = TRUE;
2774 /* If no addresses deferred or the result was ERROR, return. We do this for
2775 ERROR because a failing filter set-up or add_headers expansion is likely to
2776 fail for any host we try. */
2778 if (rc == ERROR || (rc == OK && !some_deferred))
2780 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2781 return TRUE; /* Each address has its status */
2784 /* If the result was DEFER or some individual addresses deferred, let
2785 the loop run to try other hosts with the deferred addresses, except for the
2786 case when we were trying to deliver down an existing channel and failed.
2787 Don't try any other hosts in this case. */
2789 if (continuing) break;
2791 /* If the whole delivery, or some individual addresses, were deferred and
2792 there are more hosts that could be tried, do not count this host towards
2793 the hosts_max_try limit if the age of the message is greater than the
2794 maximum retry time for this host. This means we may try try all hosts,
2795 ignoring the limit, when messages have been around for some time. This is
2796 important because if we don't try all hosts, the address will never time
2797 out. NOTE: this does not apply to hosts_max_try_hardlimit. */
2799 if ((rc == DEFER || some_deferred) && nexthost != NULL)
2802 retry_config *retry = retry_find_config(host->name, NULL, 0, 0);
2804 if (retry != NULL && retry->rules != NULL)
2806 retry_rule *last_rule;
2807 for (last_rule = retry->rules;
2808 last_rule->next != NULL;
2809 last_rule = last_rule->next);
2810 timedout = time(NULL) - received_time > last_rule->timeout;
2812 else timedout = TRUE; /* No rule => timed out */
2816 unexpired_hosts_tried--;
2817 DEBUG(D_transport) debug_printf("temporary delivery error(s) override "
2818 "hosts_max_try (message older than host's retry time)\n");
2821 } /* End of loop for trying multiple hosts. */
2823 /* This is the end of the loop that repeats iff expired is TRUE and
2824 ob->delay_after_cutoff is FALSE. The second time round we will
2825 try those hosts that haven't been tried since the message arrived. */
2829 debug_printf("all IP addresses skipped or deferred at least one address\n");
2830 if (expired && !ob->delay_after_cutoff && cutoff_retry == 0)
2831 debug_printf("retrying IP addresses not tried since message arrived\n");
2836 /* Get here if all IP addresses are skipped or defer at least one address. In
2837 MUA wrapper mode, this will happen only for connection or other non-message-
2838 specific failures. Force the delivery status for all addresses to FAIL. */
2842 for (addr = addrlist; addr != NULL; addr = addr->next)
2843 addr->transport_return = FAIL;
2847 /* In the normal, non-wrapper case, add a standard message to each deferred
2848 address if there hasn't been an error, that is, if it hasn't actually been
2849 tried this time. The variable "expired" will be FALSE if any deliveries were
2850 actually tried, or if there was at least one host that was not expired. That
2851 is, it is TRUE only if no deliveries were tried and all hosts were expired. If
2852 a delivery has been tried, an error code will be set, and the failing of the
2853 message is handled by the retry code later.
2855 If queue_smtp is set, or this transport was called to send a subsequent message
2856 down an existing TCP/IP connection, and something caused the host not to be
2857 found, we end up here, but can detect these cases and handle them specially. */
2859 for (addr = addrlist; addr != NULL; addr = addr->next)
2861 /* If host is not NULL, it means that we stopped processing the host list
2862 because of hosts_max_try or hosts_max_try_hardlimit. In the former case, this
2863 means we need to behave as if some hosts were skipped because their retry
2864 time had not come. Specifically, this prevents the address from timing out.
2865 However, if we have hit hosts_max_try_hardlimit, we want to behave as if all
2866 hosts were tried. */
2870 if (total_hosts_tried >= ob->hosts_max_try_hardlimit)
2873 debug_printf("hosts_max_try_hardlimit reached: behave as if all "
2874 "hosts were tried\n");
2879 debug_printf("hosts_max_try limit caused some hosts to be skipped\n");
2880 setflag(addr, af_retry_skipped);
2884 if (queue_smtp) /* no deliveries attempted */
2886 addr->transport_return = DEFER;
2887 addr->basic_errno = 0;
2888 addr->message = US"SMTP delivery explicitly queued";
2891 else if (addr->transport_return == DEFER &&
2892 (addr->basic_errno == ERRNO_UNKNOWNERROR || addr->basic_errno == 0) &&
2893 addr->message == NULL)
2895 addr->basic_errno = ERRNO_HRETRY;
2896 if (continue_hostname != NULL)
2898 addr->message = US"no host found for existing SMTP connection";
2902 setflag(addr, af_pass_message); /* This is not a security risk */
2903 addr->message = (ob->delay_after_cutoff)?
2904 US"retry time not reached for any host after a long failure period" :
2905 US"all hosts have been failing for a long time and were last tried "
2906 "after this message arrived";
2908 /* If we are already using fallback hosts, or there are no fallback hosts
2909 defined, convert the result to FAIL to cause a bounce. */
2911 if (addr->host_list == addr->fallback_hosts ||
2912 addr->fallback_hosts == NULL)
2913 addr->transport_return = FAIL;
2917 if (hosts_retry == hosts_total)
2918 addr->message = US"retry time not reached for any host";
2919 else if (hosts_fail == hosts_total)
2920 addr->message = US"all host address lookups failed permanently";
2921 else if (hosts_defer == hosts_total)
2922 addr->message = US"all host address lookups failed temporarily";
2923 else if (hosts_serial == hosts_total)
2924 addr->message = US"connection limit reached for all hosts";
2925 else if (hosts_fail+hosts_defer == hosts_total)
2926 addr->message = US"all host address lookups failed";
2927 else addr->message = US"some host address lookups failed and retry time "
2928 "not reached for other hosts or connection limit reached";
2933 /* Update the database which keeps information about which messages are waiting
2934 for which hosts to become available. Each host in the list has a flag which is
2935 set if the data is to be updated. For some message-specific errors, the flag is
2936 turned off because we don't want follow-on deliveries in those cases. */
2938 transport_update_waiting(hostlist, tblock->name);
2942 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2944 return TRUE; /* Each address has its status */
2947 /* End of transport/smtp.c */