1 /* $Cambridge: exim/src/src/transports/smtp.c,v 1.17 2005/08/09 13:31:53 ph10 Exp $ */
3 /*************************************************
4 * Exim - an Internet mail transport agent *
5 *************************************************/
7 /* Copyright (c) University of Cambridge 1995 - 2005 */
8 /* See the file NOTICE for conditions of use and distribution. */
14 #define PENDING_DEFER (PENDING + DEFER)
15 #define PENDING_OK (PENDING + OK)
18 /* Options specific to the smtp transport. This transport also supports LMTP
19 over TCP/IP. The options must be in alphabetic order (note that "_" comes
20 before the lower case letters). Some live in the transport_instance block so as
21 to be publicly visible; these are flagged with opt_public. */
23 optionlist smtp_transport_options[] = {
24 { "allow_localhost", opt_bool,
25 (void *)offsetof(smtp_transport_options_block, allow_localhost) },
26 { "authenticated_sender", opt_stringptr,
27 (void *)offsetof(smtp_transport_options_block, authenticated_sender) },
28 { "command_timeout", opt_time,
29 (void *)offsetof(smtp_transport_options_block, command_timeout) },
30 { "connect_timeout", opt_time,
31 (void *)offsetof(smtp_transport_options_block, connect_timeout) },
32 { "connection_max_messages", opt_int | opt_public,
33 (void *)offsetof(transport_instance, connection_max_messages) },
34 { "data_timeout", opt_time,
35 (void *)offsetof(smtp_transport_options_block, data_timeout) },
36 { "delay_after_cutoff", opt_bool,
37 (void *)offsetof(smtp_transport_options_block, delay_after_cutoff) },
38 #ifdef EXPERIMENTAL_DOMAINKEYS
39 { "dk_canon", opt_stringptr,
40 (void *)offsetof(smtp_transport_options_block, dk_canon) },
41 { "dk_domain", opt_stringptr,
42 (void *)offsetof(smtp_transport_options_block, dk_domain) },
43 { "dk_headers", opt_stringptr,
44 (void *)offsetof(smtp_transport_options_block, dk_headers) },
45 { "dk_private_key", opt_stringptr,
46 (void *)offsetof(smtp_transport_options_block, dk_private_key) },
47 { "dk_selector", opt_stringptr,
48 (void *)offsetof(smtp_transport_options_block, dk_selector) },
49 { "dk_strict", opt_stringptr,
50 (void *)offsetof(smtp_transport_options_block, dk_strict) },
52 { "dns_qualify_single", opt_bool,
53 (void *)offsetof(smtp_transport_options_block, dns_qualify_single) },
54 { "dns_search_parents", opt_bool,
55 (void *)offsetof(smtp_transport_options_block, dns_search_parents) },
56 { "fallback_hosts", opt_stringptr,
57 (void *)offsetof(smtp_transport_options_block, fallback_hosts) },
58 { "final_timeout", opt_time,
59 (void *)offsetof(smtp_transport_options_block, final_timeout) },
60 { "gethostbyname", opt_bool,
61 (void *)offsetof(smtp_transport_options_block, gethostbyname) },
62 { "helo_data", opt_stringptr,
63 (void *)offsetof(smtp_transport_options_block, helo_data) },
64 { "hosts", opt_stringptr,
65 (void *)offsetof(smtp_transport_options_block, hosts) },
66 { "hosts_avoid_esmtp", opt_stringptr,
67 (void *)offsetof(smtp_transport_options_block, hosts_avoid_esmtp) },
69 { "hosts_avoid_tls", opt_stringptr,
70 (void *)offsetof(smtp_transport_options_block, hosts_avoid_tls) },
72 { "hosts_max_try", opt_int,
73 (void *)offsetof(smtp_transport_options_block, hosts_max_try) },
74 { "hosts_max_try_hardlimit", opt_int,
75 (void *)offsetof(smtp_transport_options_block, hosts_max_try_hardlimit) },
77 { "hosts_nopass_tls", opt_stringptr,
78 (void *)offsetof(smtp_transport_options_block, hosts_nopass_tls) },
80 { "hosts_override", opt_bool,
81 (void *)offsetof(smtp_transport_options_block, hosts_override) },
82 { "hosts_randomize", opt_bool,
83 (void *)offsetof(smtp_transport_options_block, hosts_randomize) },
84 { "hosts_require_auth", opt_stringptr,
85 (void *)offsetof(smtp_transport_options_block, hosts_require_auth) },
87 { "hosts_require_tls", opt_stringptr,
88 (void *)offsetof(smtp_transport_options_block, hosts_require_tls) },
90 { "hosts_try_auth", opt_stringptr,
91 (void *)offsetof(smtp_transport_options_block, hosts_try_auth) },
92 { "interface", opt_stringptr,
93 (void *)offsetof(smtp_transport_options_block, interface) },
94 { "keepalive", opt_bool,
95 (void *)offsetof(smtp_transport_options_block, keepalive) },
96 { "lmtp_ignore_quota", opt_bool,
97 (void *)offsetof(smtp_transport_options_block, lmtp_ignore_quota) },
98 { "max_rcpt", opt_int | opt_public,
99 (void *)offsetof(transport_instance, max_addresses) },
100 { "multi_domain", opt_bool | opt_public,
101 (void *)offsetof(transport_instance, multi_domain) },
102 { "port", opt_stringptr,
103 (void *)offsetof(smtp_transport_options_block, port) },
104 { "protocol", opt_stringptr,
105 (void *)offsetof(smtp_transport_options_block, protocol) },
106 { "retry_include_ip_address", opt_bool,
107 (void *)offsetof(smtp_transport_options_block, retry_include_ip_address) },
108 { "serialize_hosts", opt_stringptr,
109 (void *)offsetof(smtp_transport_options_block, serialize_hosts) },
110 { "size_addition", opt_int,
111 (void *)offsetof(smtp_transport_options_block, size_addition) }
113 ,{ "tls_certificate", opt_stringptr,
114 (void *)offsetof(smtp_transport_options_block, tls_certificate) },
115 { "tls_crl", opt_stringptr,
116 (void *)offsetof(smtp_transport_options_block, tls_crl) },
117 { "tls_privatekey", opt_stringptr,
118 (void *)offsetof(smtp_transport_options_block, tls_privatekey) },
119 { "tls_require_ciphers", opt_stringptr,
120 (void *)offsetof(smtp_transport_options_block, tls_require_ciphers) },
121 { "tls_tempfail_tryclear", opt_bool,
122 (void *)offsetof(smtp_transport_options_block, tls_tempfail_tryclear) },
123 { "tls_verify_certificates", opt_stringptr,
124 (void *)offsetof(smtp_transport_options_block, tls_verify_certificates) }
128 /* Size of the options list. An extern variable has to be used so that its
129 address can appear in the tables drtables.c. */
131 int smtp_transport_options_count =
132 sizeof(smtp_transport_options)/sizeof(optionlist);
134 /* Default private options block for the smtp transport. */
136 smtp_transport_options_block smtp_transport_option_defaults = {
138 NULL, /* fallback_hosts */
140 NULL, /* fallback_hostlist */
141 NULL, /* authenticated_sender */
142 US"$primary_hostname", /* helo_data */
143 NULL, /* interface */
145 US"smtp", /* protocol */
146 NULL, /* serialize_hosts */
147 NULL, /* hosts_try_auth */
148 NULL, /* hosts_require_auth */
149 NULL, /* hosts_require_tls */
150 NULL, /* hosts_avoid_tls */
151 NULL, /* hosts_avoid_esmtp */
152 NULL, /* hosts_nopass_tls */
153 5*60, /* command_timeout */
154 5*60, /* connect_timeout; shorter system default overrides */
155 5*60, /* data timeout */
156 10*60, /* final timeout */
157 1024, /* size_addition */
158 5, /* hosts_max_try */
159 50, /* hosts_max_try_hardlimit */
160 FALSE, /* allow_localhost */
161 FALSE, /* gethostbyname */
162 TRUE, /* dns_qualify_single */
163 FALSE, /* dns_search_parents */
164 TRUE, /* delay_after_cutoff */
165 FALSE, /* hosts_override */
166 FALSE, /* hosts_randomize */
167 TRUE, /* keepalive */
168 FALSE, /* lmtp_ignore_quota */
169 TRUE /* retry_include_ip_address */
171 ,NULL, /* tls_certificate */
173 NULL, /* tls_privatekey */
174 NULL, /* tls_require_ciphers */
175 NULL, /* tls_verify_certificates */
176 TRUE /* tls_tempfail_tryclear */
178 #ifdef EXPERIMENTAL_DOMAINKEYS
179 ,NULL, /* dk_canon */
180 NULL, /* dk_domain */
181 NULL, /* dk_headers */
182 NULL, /* dk_private_key */
183 NULL, /* dk_selector */
191 static uschar *smtp_command; /* Points to last cmd for error messages */
192 static uschar *mail_command; /* Points to MAIL cmd for error messages */
195 /*************************************************
196 * Setup entry point *
197 *************************************************/
199 /* This function is called when the transport is about to be used,
200 but before running it in a sub-process. It is used for two things:
202 (1) To set the fallback host list in addresses, when delivering.
203 (2) To pass back the interface, port, and protocol options, for use during
204 callout verification.
207 tblock pointer to the transport instance block
208 addrlist list of addresses about to be transported
209 tf if not NULL, pointer to block in which to return options
210 errmsg place for error message (not used)
212 Returns: OK always (FAIL, DEFER not used)
216 smtp_transport_setup(transport_instance *tblock, address_item *addrlist,
217 transport_feedback *tf, uschar **errmsg)
219 smtp_transport_options_block *ob =
220 (smtp_transport_options_block *)(tblock->options_block);
222 errmsg = errmsg; /* Keep picky compilers happy */
224 /* Pass back options if required. This interface is getting very messy. */
228 tf->interface = ob->interface;
230 tf->protocol = ob->protocol;
231 tf->hosts = ob->hosts;
232 tf->hosts_override = ob->hosts_override;
233 tf->hosts_randomize = ob->hosts_randomize;
234 tf->gethostbyname = ob->gethostbyname;
235 tf->qualify_single = ob->dns_qualify_single;
236 tf->search_parents = ob->dns_search_parents;
239 /* Set the fallback host list for all the addresses that don't have fallback
240 host lists, provided that the local host wasn't present in the original host
243 if (!testflag(addrlist, af_local_host_removed))
245 for (; addrlist != NULL; addrlist = addrlist->next)
246 if (addrlist->fallback_hosts == NULL)
247 addrlist->fallback_hosts = ob->fallback_hostlist;
255 /*************************************************
256 * Initialization entry point *
257 *************************************************/
259 /* Called for each instance, after its options have been read, to
260 enable consistency checks to be done, or anything else that needs
263 Argument: pointer to the transport instance block
268 smtp_transport_init(transport_instance *tblock)
270 smtp_transport_options_block *ob =
271 (smtp_transport_options_block *)(tblock->options_block);
273 /* Retry_use_local_part defaults FALSE if unset */
275 if (tblock->retry_use_local_part == TRUE_UNSET)
276 tblock->retry_use_local_part = FALSE;
278 /* Set the default port according to the protocol */
280 if (ob->port == NULL)
281 ob->port = (strcmpic(ob->protocol, US"lmtp") == 0)? US"lmtp" : US"smtp";
283 /* Set up the setup entry point, to be called before subprocesses for this
286 tblock->setup = smtp_transport_setup;
288 /* Complain if any of the timeouts are zero. */
290 if (ob->command_timeout <= 0 || ob->data_timeout <= 0 ||
291 ob->final_timeout <= 0)
292 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
293 "command, data, or final timeout value is zero for %s transport",
296 /* If hosts_override is set and there are local hosts, set the global
297 flag that stops verify from showing router hosts. */
299 if (ob->hosts_override && ob->hosts != NULL) tblock->overrides_hosts = TRUE;
301 /* If there are any fallback hosts listed, build a chain of host items
302 for them, but do not do any lookups at this time. */
304 host_build_hostlist(&(ob->fallback_hostlist), ob->fallback_hosts, FALSE);
311 /*************************************************
312 * Set delivery info into all active addresses *
313 *************************************************/
315 /* Only addresses whose status is >= PENDING are relevant. A lesser
316 status means that an address is not currently being processed.
319 addrlist points to a chain of addresses
320 errno_value to put in each address's errno field
321 msg to put in each address's message field
322 rc to put in each address's transport_return field
323 pass_message if TRUE, set the "pass message" flag in the address
325 If errno_value has the special value ERRNO_CONNECTTIMEOUT, ETIMEDOUT is put in
326 the errno field, and RTEF_CTOUT is ORed into the more_errno field, to indicate
327 this particular type of timeout.
333 set_errno(address_item *addrlist, int errno_value, uschar *msg, int rc,
338 if (errno_value == ERRNO_CONNECTTIMEOUT)
340 errno_value = ETIMEDOUT;
341 orvalue = RTEF_CTOUT;
343 for (addr = addrlist; addr != NULL; addr = addr->next)
345 if (addr->transport_return < PENDING) continue;
346 addr->basic_errno = errno_value;
347 addr->more_errno |= orvalue;
351 if (pass_message) setflag(addr, af_pass_message);
353 addr->transport_return = rc;
359 /*************************************************
360 * Check an SMTP response *
361 *************************************************/
363 /* This function is given an errno code and the SMTP response buffer
364 to analyse, together with the host identification for generating messages. It
365 sets an appropriate message and puts the first digit of the response code into
366 the yield variable. If no response was actually read, a suitable digit is
370 host the current host, to get its name for messages
371 errno_value pointer to the errno value
372 more_errno from the top address for use with ERRNO_FILTER_FAIL
373 buffer the SMTP response buffer
374 yield where to put a one-digit SMTP response code
375 message where to put an errror message
376 pass_message set TRUE if message is an SMTP response
378 Returns: TRUE if an SMTP "QUIT" command should be sent, else FALSE
381 static BOOL check_response(host_item *host, int *errno_value, int more_errno,
382 uschar *buffer, int *yield, uschar **message, BOOL *pass_message)
386 if (smtp_use_pipelining &&
387 (Ustrcmp(smtp_command, "MAIL") == 0 ||
388 Ustrcmp(smtp_command, "RCPT") == 0 ||
389 Ustrcmp(smtp_command, "DATA") == 0))
392 *yield = '4'; /* Default setting is to give a temporary error */
394 /* Handle response timeout */
396 if (*errno_value == ETIMEDOUT)
398 *message = US string_sprintf("SMTP timeout while connected to %s [%s] "
399 "after %s%s", host->name, host->address, pl, smtp_command);
400 if (transport_count > 0)
401 *message = US string_sprintf("%s (%d bytes written)", *message,
406 /* Handle malformed SMTP response */
408 if (*errno_value == ERRNO_SMTPFORMAT)
410 uschar *malfresp = string_printing(buffer);
411 while (isspace(*malfresp)) malfresp++;
413 *message = string_sprintf("Malformed SMTP reply (an empty line) from "
414 "%s [%s] in response to %s%s", host->name, host->address, pl,
417 *message = string_sprintf("Malformed SMTP reply from %s [%s] in response "
418 "to %s%s: %s", host->name, host->address, pl, smtp_command, malfresp);
422 /* Handle a failed filter process error; can't send QUIT as we mustn't
425 if (*errno_value == ERRNO_FILTER_FAIL)
427 *message = US string_sprintf("transport filter process failed (%d)%s",
429 (more_errno == EX_EXECFAILED)? ": unable to execute command" : "");
433 /* Handle a failed add_headers expansion; can't send QUIT as we mustn't
436 if (*errno_value == ERRNO_CHHEADER_FAIL)
439 US string_sprintf("failed to expand headers_add or headers_remove: %s",
440 expand_string_message);
444 /* Handle failure to write a complete data block */
446 if (*errno_value == ERRNO_WRITEINCOMPLETE)
448 *message = US string_sprintf("failed to write a data block");
452 /* Handle error responses from the remote mailer. */
456 uschar *s = string_printing(buffer);
457 *message = US string_sprintf("SMTP error from remote mail server after %s%s: "
458 "host %s [%s]: %s", pl, smtp_command, host->name, host->address, s);
459 *pass_message = TRUE;
464 /* No data was read. If there is no errno, this must be the EOF (i.e.
465 connection closed) case, which causes deferral. Otherwise, put the host's
466 identity in the message, leaving the errno value to be interpreted as well. In
467 all cases, we have to assume the connection is now dead. */
469 if (*errno_value == 0)
471 *errno_value = ERRNO_SMTPCLOSED;
472 *message = US string_sprintf("Remote host %s [%s] closed connection "
473 "in response to %s%s", host->name, host->address, pl, smtp_command);
475 else *message = US string_sprintf("%s [%s]", host->name, host->address);
482 /*************************************************
483 * Write error message to logs *
484 *************************************************/
486 /* This writes to the main log and to the message log.
489 addr the address item containing error information
490 host the current host
496 write_logs(address_item *addr, host_item *host)
498 if (addr->message != NULL)
500 uschar *message = addr->message;
501 if (addr->basic_errno > 0)
502 message = string_sprintf("%s: %s", message, strerror(addr->basic_errno));
503 log_write(0, LOG_MAIN, "%s", message);
504 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
509 ((log_extra_selector & LX_outgoing_port) != 0)?
510 string_sprintf("%s [%s]:%d", host->name, host->address,
511 (host->port == PORT_NONE)? 25 : host->port)
513 string_sprintf("%s [%s]", host->name, host->address);
514 log_write(0, LOG_MAIN, "%s %s", msg, strerror(addr->basic_errno));
515 deliver_msglog("%s %s %s\n", tod_stamp(tod_log), msg,
516 strerror(addr->basic_errno));
522 /*************************************************
523 * Synchronize SMTP responses *
524 *************************************************/
526 /* This function is called from smtp_deliver() to receive SMTP responses from
527 the server, and match them up with the commands to which they relate. When
528 PIPELINING is not in use, this function is called after every command, and is
529 therefore somewhat over-engineered, but it is simpler to use a single scheme
530 that works both with and without PIPELINING instead of having two separate sets
533 The set of commands that are buffered up with pipelining may start with MAIL
534 and may end with DATA; in between are RCPT commands that correspond to the
535 addresses whose status is PENDING_DEFER. All other commands (STARTTLS, AUTH,
536 etc.) are never buffered.
538 Errors after MAIL or DATA abort the whole process leaving the response in the
539 buffer. After MAIL, pending responses are flushed, and the original command is
540 re-instated in big_buffer for error messages. For RCPT commands, the remote is
541 permitted to reject some recipient addresses while accepting others. However
542 certain errors clearly abort the whole process. Set the value in
543 transport_return to PENDING_OK if the address is accepted. If there is a
544 subsequent general error, it will get reset accordingly. If not, it will get
545 converted to OK at the end.
548 addrlist the complete address list
549 include_affixes TRUE if affixes include in RCPT
550 sync_addr ptr to the ptr of the one to start scanning at (updated)
551 host the host we are connected to
552 count the number of responses to read
553 pending_MAIL true if the first response is for MAIL
554 pending_DATA 0 if last command sent was not DATA
555 +1 if previously had a good recipient
556 -1 if not previously had a good recipient
557 inblock incoming SMTP block
558 timeout timeout value
559 buffer buffer for reading response
560 buffsize size of buffer
562 Returns: 3 if at least one address had 2xx and one had 5xx
563 2 if at least one address had 5xx but none had 2xx
564 1 if at least one host had a 2xx response, but none had 5xx
565 0 no address had 2xx or 5xx but no errors (all 4xx, or just DATA)
566 -1 timeout while reading RCPT response
567 -2 I/O or other non-response error for RCPT
568 -3 DATA or MAIL failed - errno and buffer set
572 sync_responses(address_item *addrlist, BOOL include_affixes,
573 address_item **sync_addr, host_item *host, int count, BOOL pending_MAIL,
574 int pending_DATA, smtp_inblock *inblock, int timeout, uschar *buffer,
577 address_item *addr = *sync_addr;
580 /* Handle the response for a MAIL command. On error, reinstate the original
581 command in big_buffer for error message use, and flush any further pending
582 responses before returning, except after I/O errors and timeouts. */
587 if (!smtp_read_response(inblock, buffer, buffsize, '2', timeout))
589 Ustrcpy(big_buffer, mail_command); /* Fits, because it came from there! */
590 if (errno == 0 && buffer[0] != 0)
592 uschar flushbuffer[4096];
595 if (!smtp_read_response(inblock, flushbuffer, sizeof(flushbuffer),
597 && (errno != 0 || flushbuffer[0] == 0))
605 if (pending_DATA) count--; /* Number of RCPT responses to come */
607 /* Read and handle the required number of RCPT responses, matching each one up
608 with an address by scanning for the next address whose status is PENDING_DEFER.
613 while (addr->transport_return != PENDING_DEFER) addr = addr->next;
615 /* The address was accepted */
617 if (smtp_read_response(inblock, buffer, buffsize, '2', timeout))
620 addr->transport_return = PENDING_OK;
622 /* If af_dr_retry_exists is set, there was a routing delay on this address;
623 ensure that any address-specific retry record is expunged. */
625 if (testflag(addr, af_dr_retry_exists))
626 retry_add_item(addr, addr->address_retry_key, rf_delete);
629 /* Timeout while reading the response */
631 else if (errno == ETIMEDOUT)
633 int save_errno = errno;
634 uschar *message = string_sprintf("SMTP timeout while connected to %s [%s] "
635 "after RCPT TO:<%s>", host->name, host->address,
636 transport_rcpt_address(addr, include_affixes));
637 set_errno(addrlist, save_errno, message, DEFER, FALSE);
638 retry_add_item(addr, addr->address_retry_key, 0);
639 host->update_waiting = FALSE;
643 /* Handle other errors in obtaining an SMTP response by returning -1. This
644 will cause all the addresses to be deferred. Restore the SMTP command in
645 big_buffer for which we are checking the response, so the error message
648 else if (errno != 0 || buffer[0] == 0)
650 string_format(big_buffer, big_buffer_size, "RCPT TO:<%s>",
651 transport_rcpt_address(addr, include_affixes));
655 /* Handle SMTP permanent and temporary response codes. */
660 string_sprintf("SMTP error from remote mail server after RCPT TO:<%s>: "
661 "host %s [%s]: %s", transport_rcpt_address(addr, include_affixes),
662 host->name, host->address, string_printing(buffer));
663 setflag(addr, af_pass_message);
664 deliver_msglog("%s %s\n", tod_stamp(tod_log), addr->message);
666 /* The response was 5xx */
668 if (buffer[0] == '5')
670 addr->transport_return = FAIL;
674 /* The response was 4xx */
678 int bincode = (buffer[1] - '0')*10 + buffer[2] - '0';
680 addr->transport_return = DEFER;
681 addr->basic_errno = ERRNO_RCPT4XX;
682 addr->more_errno |= bincode << 8;
684 /* Log temporary errors if there are more hosts to be tried. */
686 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", addr->message);
688 /* Do not put this message on the list of those waiting for this host,
689 as otherwise it is likely to be tried too often. */
691 host->update_waiting = FALSE;
693 /* Add a retry item for the address so that it doesn't get tried
696 retry_add_item(addr, addr->address_retry_key, 0);
699 } /* Loop for next RCPT response */
701 /* Update where to start at for the next block of responses, unless we
702 have already handled all the addresses. */
704 if (addr != NULL) *sync_addr = addr->next;
706 /* Handle a response to DATA. If we have not had any good recipients, either
707 previously or in this block, the response is ignored. */
709 if (pending_DATA != 0 &&
710 !smtp_read_response(inblock, buffer, buffsize, '3', timeout))
715 if (pending_DATA > 0 || (yield & 1) != 0) return -3;
716 (void)check_response(host, &errno, 0, buffer, &code, &msg, &pass_message);
717 DEBUG(D_transport) debug_printf("%s\nerror for DATA ignored: pipelining "
718 "is in use and there were no good recipients\n", msg);
721 /* All responses read and handled; MAIL (if present) received 2xx and DATA (if
722 present) received 3xx. If any RCPTs were handled and yielded anything other
723 than 4xx, yield will be set non-zero. */
730 /*************************************************
731 * Deliver address list to given host *
732 *************************************************/
734 /* If continue_hostname is not null, we get here only when continuing to
735 deliver down an existing channel. The channel was passed as the standard
738 Otherwise, we have to make a connection to the remote host, and do the
739 initial protocol exchange.
741 When running as an MUA wrapper, if the sender or any recipient is rejected,
742 temporarily or permanently, we force failure for all recipients.
745 addrlist chain of potential addresses to deliver; only those whose
746 transport_return field is set to PENDING_DEFER are currently
747 being processed; others should be skipped - they have either
748 been delivered to an earlier host or IP address, or been
749 failed by one of them.
750 host host to deliver to
751 host_af AF_INET or AF_INET6
752 port default TCP/IP port to use, in host byte order
753 interface interface to bind to, or NULL
754 tblock transport instance block
755 copy_host TRUE if host set in addr->host_used must be copied, because
756 it is specific to this call of the transport
757 message_defer set TRUE if yield is OK, but all addresses were deferred
758 because of a non-recipient, non-host failure, that is, a
759 4xx response to MAIL FROM, DATA, or ".". This is a defer
760 that is specific to the message.
761 suppress_tls if TRUE, don't attempt a TLS connection - this is set for
762 a second attempt after TLS initialization fails
764 Returns: OK - the connection was made and the delivery attempted;
765 the result for each address is in its data block.
766 DEFER - the connection could not be made, or something failed
767 while setting up the SMTP session, or there was a
768 non-message-specific error, such as a timeout.
769 ERROR - a filter command is specified for this transport,
770 and there was a problem setting it up; OR helo_data
771 or add_headers or authenticated_sender is specified
772 for this transport, and the string failed to expand
776 smtp_deliver(address_item *addrlist, host_item *host, int host_af, int port,
777 uschar *interface, transport_instance *tblock, BOOL copy_host,
778 BOOL *message_defer, BOOL suppress_tls)
781 address_item *sync_addr;
782 address_item *first_addr = addrlist;
787 time_t start_delivery_time = time(NULL);
788 smtp_transport_options_block *ob =
789 (smtp_transport_options_block *)(tblock->options_block);
790 BOOL lmtp = strcmpic(ob->protocol, US"lmtp") == 0;
792 BOOL send_rset = TRUE;
793 BOOL send_quit = TRUE;
794 BOOL setting_up = TRUE;
795 BOOL completed_address = FALSE;
798 BOOL pass_message = FALSE;
799 smtp_inblock inblock;
800 smtp_outblock outblock;
801 int max_rcpt = tblock->max_addresses;
802 uschar *igquotstr = US"";
803 uschar *local_authenticated_sender = authenticated_sender;
805 uschar *message = NULL;
806 uschar new_message_id[MESSAGE_ID_LENGTH + 1];
809 uschar inbuffer[4096];
810 uschar outbuffer[1024];
812 suppress_tls = suppress_tls; /* stop compiler warning when no TLS support */
814 *message_defer = FALSE;
815 smtp_command = US"initial connection";
816 if (max_rcpt == 0) max_rcpt = 999999;
818 /* Set up the buffer for reading SMTP response packets. */
820 inblock.buffer = inbuffer;
821 inblock.buffersize = sizeof(inbuffer);
822 inblock.ptr = inbuffer;
823 inblock.ptrend = inbuffer;
825 /* Set up the buffer for holding SMTP commands while pipelining */
827 outblock.buffer = outbuffer;
828 outblock.buffersize = sizeof(outbuffer);
829 outblock.ptr = outbuffer;
830 outblock.cmd_count = 0;
831 outblock.authenticating = FALSE;
833 /* Expand the greeting message */
835 helo_data = expand_string(ob->helo_data);
836 if (helo_data == NULL)
838 uschar *message = string_sprintf("failed to expand helo_data: %s",
839 expand_string_message);
840 set_errno(addrlist, 0, message, DEFER, FALSE);
844 /* If an authenticated_sender override has been specified for this transport
845 instance, expand it. If the expansion is forced to fail, and there was already
846 an authenticated_sender for this message, the original value will be used.
847 Other expansion failures are serious. An empty result is ignored, but there is
848 otherwise no check - this feature is expected to be used with LMTP and other
849 cases where non-standard addresses (e.g. without domains) might be required. */
851 if (ob->authenticated_sender != NULL)
853 uschar *new = expand_string(ob->authenticated_sender);
856 if (!expand_string_forcedfail)
858 uschar *message = string_sprintf("failed to expand "
859 "authenticated_sender: %s", expand_string_message);
860 set_errno(addrlist, 0, message, DEFER, FALSE);
864 else if (new[0] != 0) local_authenticated_sender = new;
867 /* Make a connection to the host if this isn't a continued delivery, and handle
868 the initial interaction and HELO/EHLO/LHLO. Connect timeout errors are handled
869 specially so they can be identified for retries. */
871 if (continue_hostname == NULL)
873 inblock.sock = outblock.sock =
874 smtp_connect(host, host_af, port, interface, ob->connect_timeout,
876 if (inblock.sock < 0)
878 set_errno(addrlist, (errno == ETIMEDOUT)? ERRNO_CONNECTTIMEOUT : errno,
883 /* The first thing is to wait for an initial OK response. The dreaded "goto"
884 is nevertheless a reasonably clean way of programming this kind of logic,
885 where you want to escape on any error. */
887 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
888 ob->command_timeout)) goto RESPONSE_FAILED;
890 /** Debugging without sending a message
891 addrlist->transport_return = DEFER;
895 /* Errors that occur after this point follow an SMTP command, which is
896 left in big_buffer by smtp_write_command() for use in error messages. */
898 smtp_command = big_buffer;
900 /* Tell the remote who we are...
902 February 1998: A convention has evolved that ESMTP-speaking MTAs include the
903 string "ESMTP" in their greeting lines, so make Exim send EHLO if the
904 greeting is of this form. The assumption was that the far end supports it
905 properly... but experience shows that there are some that give 5xx responses,
906 even though the banner includes "ESMTP" (there's a bloody-minded one that
907 says "ESMTP not spoken here"). Cope with that case.
909 September 2000: Time has passed, and it seems reasonable now to always send
910 EHLO at the start. It is also convenient to make the change while installing
913 July 2003: Joachim Wieland met a broken server that advertises "PIPELINING"
914 but times out after sending MAIL FROM, RCPT TO and DATA all together. There
915 would be no way to send out the mails, so there is now a host list
916 "hosts_avoid_esmtp" that disables ESMTP for special hosts and solves the
917 PIPELINING problem as well. Maybe it can also be useful to cure other
918 problems with broken servers.
920 Exim originally sent "Helo" at this point and ran for nearly a year that way.
921 Then somebody tried it with a Microsoft mailer... It seems that all other
922 mailers use upper case for some reason (the RFC is quite clear about case
923 independence) so, for peace of mind, I gave in. */
925 esmtp = verify_check_this_host(&(ob->hosts_avoid_esmtp), NULL,
926 host->name, host->address, NULL) != OK;
930 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n",
931 lmtp? "LHLO" : "EHLO", helo_data) < 0)
933 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
934 ob->command_timeout))
936 if (errno != 0 || buffer[0] == 0 || lmtp) goto RESPONSE_FAILED;
943 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
948 if (smtp_write_command(&outblock, FALSE, "HELO %s\r\n", helo_data) < 0)
950 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
951 ob->command_timeout)) goto RESPONSE_FAILED;
954 /* Set IGNOREQUOTA if the response to LHLO specifies support and the
955 lmtp_ignore_quota option was set. */
957 igquotstr = (lmtp && ob->lmtp_ignore_quota &&
958 pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer, Ustrlen(CS buffer), 0,
959 PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
961 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
964 tls_offered = esmtp &&
965 pcre_exec(regex_STARTTLS, NULL, CS buffer, Ustrlen(buffer), 0,
966 PCRE_EOPT, NULL, 0) >= 0;
970 /* For continuing deliveries down the same channel, the socket is the standard
971 input, and we don't need to redo EHLO here (but may need to do so for TLS - see
972 below). Set up the pointer to where subsequent commands will be left, for
973 error messages. Note that smtp_use_size and smtp_use_pipelining will have been
974 set from the command line if they were set in the process that passed the
979 inblock.sock = outblock.sock = fileno(stdin);
980 smtp_command = big_buffer;
983 /* If TLS is available on this connection, whether continued or not, attempt to
984 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
985 send another EHLO - the server may give a different answer in secure mode. We
986 use a separate buffer for reading the response to STARTTLS so that if it is
987 negative, the original EHLO data is available for subsequent analysis, should
988 the client not be required to use TLS. If the response is bad, copy the buffer
989 for error analysis. */
992 if (tls_offered && !suppress_tls &&
993 verify_check_this_host(&(ob->hosts_avoid_tls), NULL, host->name,
994 host->address, NULL) != OK)
996 uschar buffer2[4096];
997 if (smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") < 0)
1000 /* If there is an I/O error, transmission of this message is deferred. If
1001 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
1002 false, we also defer. However, if there is a temporary rejection of STARTTLS
1003 and tls_tempfail_tryclear is true, or if there is an outright rejection of
1004 STARTTLS, we carry on. This means we will try to send the message in clear,
1005 unless the host is in hosts_require_tls (tested below). */
1007 if (!smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
1008 ob->command_timeout))
1010 Ustrncpy(buffer, buffer2, sizeof(buffer));
1011 if (errno != 0 || buffer2[0] == 0 ||
1012 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
1013 goto RESPONSE_FAILED;
1016 /* STARTTLS accepted: try to negotiate a TLS session. */
1020 int rc = tls_client_start(inblock.sock, host, addrlist,
1021 NULL, /* No DH param */
1022 ob->tls_certificate,
1024 ob->tls_verify_certificates,
1026 ob->tls_require_ciphers,
1027 ob->command_timeout);
1029 /* TLS negotiation failed; give an error. From outside, this function may
1030 be called again to try in clear on a new connection, if the options permit
1031 it for this host. */
1035 save_errno = ERRNO_TLSFAILURE;
1036 message = US"failure while setting up TLS session";
1041 /* TLS session is set up */
1043 for (addr = addrlist; addr != NULL; addr = addr->next)
1045 if (addr->transport_return == PENDING_DEFER)
1047 addr->cipher = tls_cipher;
1048 addr->peerdn = tls_peerdn;
1054 /* If we started TLS, redo the EHLO/LHLO exchange over the secure channel. */
1056 if (tls_active >= 0)
1058 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n", lmtp? "LHLO" : "EHLO",
1061 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1062 ob->command_timeout))
1063 goto RESPONSE_FAILED;
1066 /* If the host is required to use a secure channel, ensure that we
1069 else if (verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
1070 host->address, NULL) == OK)
1072 save_errno = ERRNO_TLSREQUIRED;
1073 message = string_sprintf("a TLS session is required for %s [%s], but %s",
1074 host->name, host->address,
1075 tls_offered? "an attempt to start TLS failed" :
1076 "the server did not offer TLS support");
1081 /* If TLS is active, we have just started it up and re-done the EHLO command,
1082 so its response needs to be analyzed. If TLS is not active and this is a
1083 continued session down a previously-used socket, we haven't just done EHLO, so
1086 if (continue_hostname == NULL
1093 uschar *fail_reason = US"server did not advertise AUTH support";
1095 /* Set for IGNOREQUOTA if the response to LHLO specifies support and the
1096 lmtp_ignore_quota option was set. */
1098 igquotstr = (lmtp && ob->lmtp_ignore_quota &&
1099 pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer, Ustrlen(CS buffer), 0,
1100 PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
1102 /* If the response to EHLO specified support for the SIZE parameter, note
1103 this, provided size_addition is non-negative. */
1105 smtp_use_size = esmtp && ob->size_addition >= 0 &&
1106 pcre_exec(regex_SIZE, NULL, CS buffer, Ustrlen(CS buffer), 0,
1107 PCRE_EOPT, NULL, 0) >= 0;
1109 /* Note whether the server supports PIPELINING. If hosts_avoid_esmtp matched
1110 the current host, esmtp will be false, so PIPELINING can never be used. */
1112 smtp_use_pipelining = esmtp &&
1113 pcre_exec(regex_PIPELINING, NULL, CS buffer, Ustrlen(CS buffer), 0,
1114 PCRE_EOPT, NULL, 0) >= 0;
1116 DEBUG(D_transport) debug_printf("%susing PIPELINING\n",
1117 smtp_use_pipelining? "" : "not ");
1119 /* Note if the response to EHLO specifies support for the AUTH extension.
1120 If it has, check that this host is one we want to authenticate to, and do
1121 the business. The host name and address must be available when the
1122 authenticator's client driver is running. */
1124 smtp_authenticated = FALSE;
1125 require_auth = verify_check_this_host(&(ob->hosts_require_auth), NULL,
1126 host->name, host->address, NULL);
1128 if (esmtp && regex_match_and_setup(regex_AUTH, buffer, 0, -1))
1130 uschar *names = string_copyn(expand_nstring[1], expand_nlength[1]);
1131 expand_nmax = -1; /* reset */
1133 /* Must not do this check until after we have saved the result of the
1134 regex match above. */
1136 if (require_auth == OK ||
1137 verify_check_this_host(&(ob->hosts_try_auth), NULL, host->name,
1138 host->address, NULL) == OK)
1141 fail_reason = US"no common mechanisms were found";
1143 DEBUG(D_transport) debug_printf("scanning authentication mechanisms\n");
1145 /* Scan the configured authenticators looking for one which is configured
1146 for use as a client and whose name matches an authentication mechanism
1147 supported by the server. If one is found, attempt to authenticate by
1148 calling its client function. */
1150 for (au = auths; !smtp_authenticated && au != NULL; au = au->next)
1153 if (!au->client) continue;
1155 /* Loop to scan supported server mechanisms */
1160 int len = Ustrlen(au->public_name);
1161 while (isspace(*p)) p++;
1163 if (strncmpic(au->public_name, p, len) != 0 ||
1164 (p[len] != 0 && !isspace(p[len])))
1166 while (*p != 0 && !isspace(*p)) p++;
1170 /* Found data for a listed mechanism. Call its client entry. Set
1171 a flag in the outblock so that data is overwritten after sending so
1172 that reflections don't show it. */
1174 fail_reason = US"authentication attempt(s) failed";
1175 outblock.authenticating = TRUE;
1176 rc = (au->info->clientcode)(au, &inblock, &outblock,
1177 ob->command_timeout, buffer, sizeof(buffer));
1178 outblock.authenticating = FALSE;
1179 DEBUG(D_transport) debug_printf("%s authenticator yielded %d\n",
1182 /* A temporary authentication failure must hold up delivery to
1183 this host. After a permanent authentication failure, we carry on
1184 to try other authentication methods. If all fail hard, try to
1185 deliver the message unauthenticated unless require_auth was set. */
1190 smtp_authenticated = TRUE; /* stops the outer loop */
1193 /* Failure after writing a command */
1198 /* Failure after reading a response */
1201 if (errno != 0 || buffer[0] != '5') goto RESPONSE_FAILED;
1202 log_write(0, LOG_MAIN, "%s authenticator failed H=%s [%s] %s",
1203 au->name, host->name, host->address, buffer);
1206 /* Failure by some other means. In effect, the authenticator
1207 decided it wasn't prepared to handle this case. Typically this
1208 is the result of "fail" in an expansion string. Do we need to
1209 log anything here? */
1214 /* Internal problem, message in buffer. */
1218 set_errno(addrlist, 0, string_copy(buffer), DEFER, FALSE);
1222 break; /* If not authenticated, try next authenticator */
1223 } /* Loop for scanning supported server mechanisms */
1224 } /* Loop for further authenticators */
1228 /* If we haven't authenticated, but are required to, give up. */
1230 if (require_auth == OK && !smtp_authenticated)
1233 set_errno(addrlist, ERRNO_AUTHFAIL,
1234 string_sprintf("authentication required but %s", fail_reason), DEFER,
1240 /* The setting up of the SMTP call is now complete. Any subsequent errors are
1241 message-specific. */
1245 /* If there is a filter command specified for this transport, we can now
1246 set it up. This cannot be done until the identify of the host is known. */
1248 if (tblock->filter_command != NULL)
1252 sprintf(CS buffer, "%.50s transport", tblock->name);
1253 rc = transport_set_up_command(&transport_filter_argv, tblock->filter_command,
1254 TRUE, DEFER, addrlist, buffer, NULL);
1256 /* On failure, copy the error to all addresses, abandon the SMTP call, and
1261 set_errno(addrlist->next, addrlist->basic_errno, addrlist->message, DEFER,
1269 /* For messages that have more than the maximum number of envelope recipients,
1270 we want to send several transactions down the same SMTP connection. (See
1271 comments in deliver.c as to how this reconciles, heuristically, with
1272 remote_max_parallel.) This optimization was added to Exim after the following
1273 code was already working. The simplest way to put it in without disturbing the
1274 code was to use a goto to jump back to this point when there is another
1275 transaction to handle. */
1278 sync_addr = first_addr;
1282 completed_address = FALSE;
1285 /* Initiate a message transfer. If we know the receiving MTA supports the SIZE
1286 qualification, send it, adding something to the message size to allow for
1287 imprecision and things that get added en route. Exim keeps the number of lines
1288 in a message, so we can give an accurate value for the original message, but we
1289 need some additional to handle added headers. (Double "." characters don't get
1290 included in the count.) */
1297 sprintf(CS p, " SIZE=%d", message_size+message_linecount+ob->size_addition);
1301 /* Add the authenticated sender address if present */
1303 if (smtp_authenticated && local_authenticated_sender != NULL)
1305 string_format(p, sizeof(buffer) - (p-buffer), " AUTH=%s",
1306 auth_xtextencode(local_authenticated_sender,
1307 Ustrlen(local_authenticated_sender)));
1310 /* From here until we send the DATA command, we can make use of PIPELINING
1311 if the server host supports it. The code has to be able to check the responses
1312 at any point, for when the buffer fills up, so we write it totally generally.
1313 When PIPELINING is off, each command written reports that it has flushed the
1316 pending_MAIL = TRUE; /* The block starts with MAIL */
1318 rc = smtp_write_command(&outblock, smtp_use_pipelining,
1319 "MAIL FROM:<%s>%s\r\n", return_path, buffer);
1320 mail_command = string_copy(big_buffer); /* Save for later error message */
1324 case -1: /* Transmission error */
1327 case +1: /* Block was sent */
1328 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1329 ob->command_timeout)) goto RESPONSE_FAILED;
1330 pending_MAIL = FALSE;
1334 /* Pass over all the relevant recipient addresses for this host, which are the
1335 ones that have status PENDING_DEFER. If we are using PIPELINING, we can send
1336 several before we have to read the responses for those seen so far. This
1337 checking is done by a subroutine because it also needs to be done at the end.
1338 Send only up to max_rcpt addresses at a time, leaving first_addr pointing to
1339 the next one if not all are sent.
1341 In the MUA wrapper situation, we want to flush the PIPELINING buffer for the
1342 last address because we want to abort if any recipients have any kind of
1343 problem, temporary or permanent. We know that all recipient addresses will have
1344 the PENDING_DEFER status, because only one attempt is ever made, and we know
1345 that max_rcpt will be large, so all addresses will be done at once. */
1347 for (addr = first_addr;
1348 address_count < max_rcpt && addr != NULL;
1354 if (addr->transport_return != PENDING_DEFER) continue;
1357 no_flush = smtp_use_pipelining && (!mua_wrapper || addr->next != NULL);
1359 /* Now send the RCPT command, and process outstanding responses when
1360 necessary. After a timeout on RCPT, we just end the function, leaving the
1361 yield as OK, because this error can often mean that there is a problem with
1362 just one address, so we don't want to delay the host. */
1364 count = smtp_write_command(&outblock, no_flush, "RCPT TO:<%s>%s\r\n",
1365 transport_rcpt_address(addr, tblock->rcpt_include_affixes), igquotstr);
1366 if (count < 0) goto SEND_FAILED;
1369 switch(sync_responses(first_addr, tblock->rcpt_include_affixes,
1370 &sync_addr, host, count, pending_MAIL, 0, &inblock,
1371 ob->command_timeout, buffer, sizeof(buffer)))
1373 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1374 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1377 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1378 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1379 case 0: /* No 2xx or 5xx, but no probs */
1382 case -1: goto END_OFF; /* Timeout on RCPT */
1383 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL error */
1385 pending_MAIL = FALSE; /* Dealt with MAIL */
1387 } /* Loop for next address */
1389 /* If we are an MUA wrapper, abort if any RCPTs were rejected, either
1390 permanently or temporarily. We should have flushed and synced after the last
1395 address_item *badaddr;
1396 for (badaddr = first_addr; badaddr != NULL; badaddr = badaddr->next)
1398 if (badaddr->transport_return != PENDING_OK) break;
1400 if (badaddr != NULL)
1402 set_errno(addrlist, 0, badaddr->message, FAIL,
1403 testflag(badaddr, af_pass_message));
1408 /* If ok is TRUE, we know we have got at least one good recipient, and must now
1409 send DATA, but if it is FALSE (in the normal, non-wrapper case), we may still
1410 have a good recipient buffered up if we are pipelining. We don't want to waste
1411 time sending DATA needlessly, so we only send it if either ok is TRUE or if we
1412 are pipelining. The responses are all handled by sync_responses(). */
1414 if (ok || (smtp_use_pipelining && !mua_wrapper))
1416 int count = smtp_write_command(&outblock, FALSE, "DATA\r\n");
1417 if (count < 0) goto SEND_FAILED;
1418 switch(sync_responses(first_addr, tblock->rcpt_include_affixes, &sync_addr,
1419 host, count, pending_MAIL, ok? +1 : -1, &inblock,
1420 ob->command_timeout, buffer, sizeof(buffer)))
1422 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1423 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1426 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1427 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1428 case 0: break; /* No 2xx or 5xx, but no probs */
1430 case -1: goto END_OFF; /* Timeout on RCPT */
1431 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */
1435 /* Save the first address of the next batch. */
1439 /* If there were no good recipients (but otherwise there have been no
1440 problems), just set ok TRUE, since we have handled address-specific errors
1441 already. Otherwise, it's OK to send the message. Use the check/escape mechanism
1442 for handling the SMTP dot-handling protocol, flagging to apply to headers as
1443 well as body. Set the appropriate timeout value to be used for each chunk.
1444 (Haven't been able to make it work using select() for writing yet.) */
1446 if (!ok) ok = TRUE; else
1448 sigalrm_seen = FALSE;
1449 transport_write_timeout = ob->data_timeout;
1450 smtp_command = US"sending data block"; /* For error messages */
1451 DEBUG(D_transport|D_v)
1452 debug_printf(" SMTP>> writing message and terminating \".\"\n");
1453 transport_count = 0;
1454 #ifdef EXPERIMENTAL_DOMAINKEYS
1455 if ( (ob->dk_private_key != NULL) && (ob->dk_selector != NULL) )
1456 ok = dk_transport_write_message(addrlist, inblock.sock,
1457 topt_use_crlf | topt_end_dot | topt_escape_headers |
1458 (tblock->body_only? topt_no_headers : 0) |
1459 (tblock->headers_only? topt_no_body : 0) |
1460 (tblock->return_path_add? topt_add_return_path : 0) |
1461 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1462 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1463 0, /* No size limit */
1464 tblock->add_headers, tblock->remove_headers,
1465 US".", US"..", /* Escaping strings */
1466 tblock->rewrite_rules, tblock->rewrite_existflags,
1467 ob->dk_private_key, ob->dk_domain, ob->dk_selector,
1468 ob->dk_canon, ob->dk_headers, ob->dk_strict);
1471 ok = transport_write_message(addrlist, inblock.sock,
1472 topt_use_crlf | topt_end_dot | topt_escape_headers |
1473 (tblock->body_only? topt_no_headers : 0) |
1474 (tblock->headers_only? topt_no_body : 0) |
1475 (tblock->return_path_add? topt_add_return_path : 0) |
1476 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1477 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1478 0, /* No size limit */
1479 tblock->add_headers, tblock->remove_headers,
1480 US".", US"..", /* Escaping strings */
1481 tblock->rewrite_rules, tblock->rewrite_existflags);
1483 /* transport_write_message() uses write() because it is called from other
1484 places to write to non-sockets. This means that under some OS (e.g. Solaris)
1485 it can exit with "Broken pipe" as its error. This really means that the
1486 socket got closed at the far end. */
1488 transport_write_timeout = 0; /* for subsequent transports */
1490 /* Failure can either be some kind of I/O disaster (including timeout),
1491 or the failure of a transport filter or the expansion of added headers. */
1495 buffer[0] = 0; /* There hasn't been a response */
1496 goto RESPONSE_FAILED;
1499 /* We used to send the terminating "." explicitly here, but because of
1500 buffering effects at both ends of TCP/IP connections, you don't gain
1501 anything by keeping it separate, so it might as well go in the final
1502 data buffer for efficiency. This is now done by setting the topt_end_dot
1505 smtp_command = US"end of data";
1507 /* For SMTP, we now read a single response that applies to the whole message.
1508 If it is OK, then all the addresses have been delivered. */
1510 if (!lmtp) ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1513 /* For LMTP, we get back a response for every RCPT command that we sent;
1514 some may be accepted and some rejected. For those that get a response, their
1515 status is fixed; any that are accepted have been handed over, even if later
1516 responses crash - at least, that's how I read RFC 2033.
1518 If all went well, mark the recipient addresses as completed, record which
1519 host/IPaddress they were delivered to, and cut out RSET when sending another
1520 message down the same channel. Write the completed addresses to the journal
1521 now so that they are recorded in case there is a crash of hardware or
1522 software before the spool gets updated. Also record the final SMTP
1523 confirmation if needed (for SMTP only). */
1528 int delivery_time = (int)(time(NULL) - start_delivery_time);
1531 uschar *conf = NULL;
1534 /* Make a copy of the host if it is local to this invocation
1535 of the transport. */
1539 thost = store_get(sizeof(host_item));
1541 thost->name = string_copy(host->name);
1542 thost->address = string_copy(host->address);
1546 /* Set up confirmation if needed - applies only to SMTP */
1548 if ((log_extra_selector & LX_smtp_confirmation) != 0 && !lmtp)
1550 uschar *s = string_printing(buffer);
1551 conf = (s == buffer)? (uschar *)string_copy(s) : s;
1554 /* Process all transported addresses - for LMTP, read a status for
1557 for (addr = addrlist; addr != first_addr; addr = addr->next)
1559 if (addr->transport_return != PENDING_OK) continue;
1561 /* LMTP - if the response fails badly (e.g. timeout), use it for all the
1562 remaining addresses. Otherwise, it's a return code for just the one
1567 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1570 if (errno != 0 || buffer[0] == 0) goto RESPONSE_FAILED;
1571 addr->message = string_sprintf("LMTP error after %s: %s",
1572 big_buffer, string_printing(buffer));
1573 addr->transport_return = (buffer[0] == '5')? FAIL : DEFER;
1576 completed_address = TRUE; /* NOW we can set this flag */
1579 /* SMTP, or success return from LMTP for this address. Pass back the
1580 actual host that was used. */
1582 addr->transport_return = OK;
1583 addr->more_errno = delivery_time;
1584 addr->host_used = thost;
1585 addr->special_action = flag;
1586 addr->message = conf;
1589 /* Update the journal. For homonymic addresses, use the base address plus
1590 the transport name. See lots of comments in deliver.c about the reasons
1591 for the complications when homonyms are involved. Just carry on after
1592 write error, as it may prove possible to update the spool file later. */
1594 if (testflag(addr, af_homonym))
1595 sprintf(CS buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
1597 sprintf(CS buffer, "%.500s\n", addr->unique);
1599 DEBUG(D_deliver) debug_printf("journalling %s", buffer);
1600 len = Ustrlen(CS buffer);
1601 if (write(journal_fd, buffer, len) != len)
1602 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
1603 "%s: %s", buffer, strerror(errno));
1606 /* Ensure the journal file is pushed out to disk. */
1608 if (fsync(journal_fd) < 0)
1609 log_write(0, LOG_MAIN|LOG_PANIC, "failed to fsync journal: %s",
1615 /* Handle general (not specific to one address) failures here. The value of ok
1616 is used to skip over this code on the falling through case. A timeout causes a
1617 deferral. Other errors may defer or fail according to the response code, and
1618 may set up a special errno value, e.g. after connection chopped, which is
1619 assumed if errno == 0 and there is no text in the buffer. If control reaches
1620 here during the setting up phase (i.e. before MAIL FROM) then always defer, as
1621 the problem is not related to this specific message. */
1630 send_quit = check_response(host, &save_errno, addrlist->more_errno,
1631 buffer, &code, &message, &pass_message);
1637 message = US string_sprintf("send() to %s [%s] failed: %s",
1638 host->name, host->address, strerror(save_errno));
1642 /* This label is jumped to directly when a TLS negotiation has failed,
1643 or was not done for a host for which it is required. Values will be set
1644 in message and save_errno, and setting_up will always be true. Treat as
1645 a temporary error. */
1652 /* If the failure happened while setting up the call, see if the failure was
1653 a 5xx response (this will either be on connection, or following HELO - a 5xx
1654 after EHLO causes it to try HELO). If so, fail all addresses, as this host is
1655 never going to accept them. For other errors during setting up (timeouts or
1656 whatever), defer all addresses, and yield DEFER, so that the host is not
1657 tried again for a while. */
1660 ok = FALSE; /* For when reached by GOTO */
1666 set_errno(addrlist, save_errno, message, FAIL, pass_message);
1670 set_errno(addrlist, save_errno, message, DEFER, pass_message);
1675 /* If there was an I/O error or timeout or other transportation error,
1676 indicated by errno being non-zero, defer all addresses and yield DEFER,
1677 except for the case of failed add_headers expansion, or a transport filter
1678 failure, when the yield should be ERROR, to stop it trying other hosts.
1680 However, handle timeouts after MAIL FROM or "." and loss of connection after
1681 "." specially. They can indicate a problem with the sender address or with
1682 the contents of the message rather than a real error on the connection.
1683 Therefore, treat these cases in the same way as a 4xx response.
1685 The following condition tests for NOT these special cases. */
1687 else if (save_errno != 0 &&
1688 (save_errno != ETIMEDOUT ||
1689 (Ustrncmp(smtp_command,"MAIL",4) != 0 &&
1690 Ustrncmp(smtp_command,"end ",4) != 0)) &&
1691 (save_errno != ERRNO_SMTPCLOSED ||
1692 Ustrncmp(smtp_command,"end ",4) != 0))
1694 yield = (save_errno == ERRNO_CHHEADER_FAIL ||
1695 save_errno == ERRNO_FILTER_FAIL)? ERROR : DEFER;
1696 set_errno(addrlist, save_errno, message, DEFER, pass_message);
1699 /* Otherwise we have a message-specific error response from the remote
1700 host. This is one of
1701 (a) negative response or timeout after "mail from"
1702 (b) negative response after "data"
1703 (c) negative response or timeout or dropped connection after "."
1704 It won't be a negative response or timeout after "rcpt to", as that is dealt
1705 with separately above. The action in all cases is to set an appropriate
1706 error code for all the addresses, but to leave yield set to OK because
1707 the host itself has not failed. [It might in practice have failed for a
1708 timeout after MAIL FROM, or "." but if so, we'll discover that at the next
1709 delivery attempt.] For a temporary error, set the message_defer flag, and
1710 write to the logs for information if this is not the last host. The error for
1711 the last host will be logged as part of the address's log line. */
1715 if (mua_wrapper) code = '5'; /* Force hard failure in wrapper mode */
1717 set_errno(addrlist, save_errno, message, (code == '5')? FAIL : DEFER,
1720 /* If there's an errno, the message contains just the identity of
1723 if (code != '5') /* Anything other than 5 is treated as temporary */
1726 message = US string_sprintf("%s: %s", message, strerror(save_errno));
1727 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", message);
1728 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
1729 *message_defer = TRUE;
1735 /* If all has gone well, send_quit will be set TRUE, implying we can end the
1736 SMTP session tidily. However, if there were too many addresses to send in one
1737 message (indicated by first_addr being non-NULL) we want to carry on with the
1738 rest of them. Also, it is desirable to send more than one message down the SMTP
1739 connection if there are several waiting, provided we haven't already sent so
1740 many as to hit the configured limit. The function transport_check_waiting looks
1741 for a waiting message and returns its id. Then transport_pass_socket tries to
1742 set up a continued delivery by passing the socket on to another process. The
1743 variable send_rset is FALSE if a message has just been successfully transfered.
1745 If we are already sending down a continued channel, there may be further
1746 addresses not yet delivered that are aimed at the same host, but which have not
1747 been passed in this run of the transport. In this case, continue_more will be
1748 true, and all we should do is send RSET if necessary, and return, leaving the
1751 However, if no address was disposed of, i.e. all addresses got 4xx errors, we
1752 do not want to continue with other messages down the same channel, because that
1753 can lead to looping between two or more messages, all with the same,
1754 temporarily failing address(es). [The retry information isn't updated yet, so
1755 new processes keep on trying.] We probably also don't want to try more of this
1756 message's addresses either.
1758 If we have started a TLS session, we have to end it before passing the
1759 connection to a new process. However, not all servers can handle this (Exim
1760 can), so we do not pass such a connection on if the host matches
1761 hosts_nopass_tls. */
1764 debug_printf("ok=%d send_quit=%d send_rset=%d continue_more=%d "
1765 "yield=%d first_address is %sNULL\n", ok, send_quit, send_rset,
1766 continue_more, yield, (first_addr == NULL)? "":"not ");
1768 if (completed_address && ok && send_quit)
1771 if (first_addr != NULL || continue_more ||
1774 verify_check_this_host(&(ob->hosts_nopass_tls), NULL, host->name,
1775 host->address, NULL) != OK)
1777 transport_check_waiting(tblock->name, host->name,
1778 tblock->connection_max_messages, new_message_id, &more)
1786 if (! (ok = smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0))
1788 msg = US string_sprintf("send() to %s [%s] failed: %s", host->name,
1789 host->address, strerror(save_errno));
1792 else if (! (ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1793 ob->command_timeout)))
1796 send_quit = check_response(host, &errno, 0, buffer, &code, &msg,
1800 DEBUG(D_transport) debug_printf("%s\n", msg);
1805 /* Either RSET was not needed, or it succeeded */
1809 if (first_addr != NULL) /* More addresses still to be sent */
1810 { /* in this run of the transport */
1811 continue_sequence++; /* Causes * in logging */
1814 if (continue_more) return yield; /* More addresses for another run */
1816 /* Pass the socket to a new Exim process. Before doing so, we must shut
1817 down TLS. Not all MTAs allow for the continuation of the SMTP session
1818 when TLS is shut down. We test for this by sending a new EHLO. If we
1819 don't get a good response, we don't attempt to pass the socket on. */
1822 if (tls_active >= 0)
1825 ok = smtp_write_command(&outblock,FALSE,"EHLO %s\r\n",helo_data) >= 0 &&
1826 smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1827 ob->command_timeout);
1831 /* If the socket is successfully passed, we musn't send QUIT (or
1832 indeed anything!) from here. */
1834 if (ok && transport_pass_socket(tblock->name, host->name, host->address,
1835 new_message_id, inblock.sock))
1841 /* If RSET failed and there are addresses left, they get deferred. */
1843 else set_errno(first_addr, errno, msg, DEFER, FALSE);
1847 /* End off tidily with QUIT unless the connection has died or the socket has
1848 been passed to another process. There has been discussion on the net about what
1849 to do after sending QUIT. The wording of the RFC suggests that it is necessary
1850 to wait for a response, but on the other hand, there isn't anything one can do
1851 with an error response, other than log it. Exim used to do that. However,
1852 further discussion suggested that it is positively advantageous not to wait for
1853 the response, but to close the session immediately. This is supposed to move
1854 the TCP/IP TIME_WAIT state from the server to the client, thereby removing some
1855 load from the server. (Hosts that are both servers and clients may not see much
1856 difference, of course.) Further discussion indicated that this was safe to do
1857 on Unix systems which have decent implementations of TCP/IP that leave the
1858 connection around for a while (TIME_WAIT) after the application has gone away.
1859 This enables the response sent by the server to be properly ACKed rather than
1860 timed out, as can happen on broken TCP/IP implementations on other OS.
1862 This change is being made on 31-Jul-98. After over a year of trouble-free
1863 operation, the old commented-out code was removed on 17-Sep-99. */
1866 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1874 /* Close the socket, and return the appropriate value, first setting
1875 continue_transport and continue_hostname NULL to prevent any other addresses
1876 that may include the host from trying to re-use a continuation socket. This
1877 works because the NULL setting is passed back to the calling process, and
1878 remote_max_parallel is forced to 1 when delivering over an existing connection,
1880 If all went well and continue_more is set, we shouldn't actually get here if
1881 there are further addresses, as the return above will be taken. However,
1882 writing RSET might have failed, or there may be other addresses whose hosts are
1883 specified in the transports, and therefore not visible at top level, in which
1884 case continue_more won't get set. */
1886 (void)close(inblock.sock);
1887 continue_transport = NULL;
1888 continue_hostname = NULL;
1895 /*************************************************
1896 * Closedown entry point *
1897 *************************************************/
1899 /* This function is called when exim is passed an open smtp channel
1900 from another incarnation, but the message which it has been asked
1901 to deliver no longer exists. The channel is on stdin.
1903 We might do fancy things like looking for another message to send down
1904 the channel, but if the one we sought has gone, it has probably been
1905 delivered by some other process that itself will seek further messages,
1906 so just close down our connection.
1908 Argument: pointer to the transport instance block
1913 smtp_transport_closedown(transport_instance *tblock)
1915 smtp_transport_options_block *ob =
1916 (smtp_transport_options_block *)(tblock->options_block);
1917 smtp_inblock inblock;
1918 smtp_outblock outblock;
1920 uschar inbuffer[4096];
1921 uschar outbuffer[16];
1923 inblock.sock = fileno(stdin);
1924 inblock.buffer = inbuffer;
1925 inblock.buffersize = sizeof(inbuffer);
1926 inblock.ptr = inbuffer;
1927 inblock.ptrend = inbuffer;
1929 outblock.sock = inblock.sock;
1930 outblock.buffersize = sizeof(outbuffer);
1931 outblock.buffer = outbuffer;
1932 outblock.ptr = outbuffer;
1933 outblock.cmd_count = 0;
1934 outblock.authenticating = FALSE;
1936 (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1937 (void)smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1938 ob->command_timeout);
1939 (void)close(inblock.sock);
1944 /*************************************************
1945 * Prepare addresses for delivery *
1946 *************************************************/
1948 /* This function is called to flush out error settings from previous delivery
1949 attempts to other hosts. It also records whether we got here via an MX record
1950 or not in the more_errno field of the address. We are interested only in
1951 addresses that are still marked DEFER - others may have got delivered to a
1952 previously considered IP address. Set their status to PENDING_DEFER to indicate
1953 which ones are relevant this time.
1956 addrlist the list of addresses
1957 host the host we are delivering to
1959 Returns: the first address for this delivery
1962 static address_item *
1963 prepare_addresses(address_item *addrlist, host_item *host)
1965 address_item *first_addr = NULL;
1967 for (addr = addrlist; addr != NULL; addr = addr->next)
1969 if (addr->transport_return != DEFER) continue;
1970 if (first_addr == NULL) first_addr = addr;
1971 addr->transport_return = PENDING_DEFER;
1972 addr->basic_errno = 0;
1973 addr->more_errno = (host->mx >= 0)? 'M' : 'A';
1974 addr->message = NULL;
1976 addr->cipher = NULL;
1977 addr->peerdn = NULL;
1985 /*************************************************
1986 * Main entry point *
1987 *************************************************/
1989 /* See local README for interface details. As this is a remote transport, it is
1990 given a chain of addresses to be delivered in one connection, if possible. It
1991 always returns TRUE, indicating that each address has its own independent
1992 status set, except if there is a setting up problem, in which case it returns
1996 smtp_transport_entry(
1997 transport_instance *tblock, /* data for this instantiation */
1998 address_item *addrlist) /* addresses we are working on */
2002 int hosts_defer = 0;
2004 int hosts_looked_up = 0;
2005 int hosts_retry = 0;
2006 int hosts_serial = 0;
2007 int hosts_total = 0;
2008 int total_hosts_tried = 0;
2010 BOOL expired = TRUE;
2011 BOOL continuing = continue_hostname != NULL;
2012 uschar *expanded_hosts = NULL;
2014 uschar *tid = string_sprintf("%s transport", tblock->name);
2015 smtp_transport_options_block *ob =
2016 (smtp_transport_options_block *)(tblock->options_block);
2017 host_item *hostlist = addrlist->host_list;
2018 host_item *host = NULL;
2022 debug_printf("%s transport entered\n", tblock->name);
2023 for (addr = addrlist; addr != NULL; addr = addr->next)
2024 debug_printf(" %s\n", addr->address);
2025 if (continuing) debug_printf("already connected to %s [%s]\n",
2026 continue_hostname, continue_host_address);
2029 /* If a host list is not defined for the addresses - they must all have the
2030 same one in order to be passed to a single transport - or if the transport has
2031 a host list with hosts_override set, use the host list supplied with the
2032 transport. It is an error for this not to exist. */
2034 if (hostlist == NULL || (ob->hosts_override && ob->hosts != NULL))
2036 if (ob->hosts == NULL)
2038 addrlist->message = string_sprintf("%s transport called with no hosts set",
2040 addrlist->transport_return = PANIC;
2041 return FALSE; /* Only top address has status */
2044 DEBUG(D_transport) debug_printf("using the transport's hosts: %s\n",
2047 /* If the transport's host list contains no '$' characters, and we are not
2048 randomizing, it is fixed and therefore a chain of hosts can be built once
2049 and for all, and remembered for subsequent use by other calls to this
2050 transport. If, on the other hand, the host list does contain '$', or we are
2051 randomizing its order, we have to rebuild it each time. In the fixed case,
2052 as the hosts string will never be used again, it doesn't matter that we
2053 replace all the : characters with zeros. */
2055 if (ob->hostlist == NULL)
2057 uschar *s = ob->hosts;
2059 if (Ustrchr(s, '$') != NULL)
2061 expanded_hosts = expand_string(s);
2062 if (expanded_hosts == NULL)
2064 addrlist->message = string_sprintf("failed to expand list of hosts "
2065 "\"%s\" in %s transport: %s", s, tblock->name, expand_string_message);
2066 addrlist->transport_return = search_find_defer? DEFER : PANIC;
2067 return FALSE; /* Only top address has status */
2069 DEBUG(D_transport) debug_printf("expanded list of hosts \"%s\" to "
2070 "\"%s\"\n", s, expanded_hosts);
2074 if (ob->hosts_randomize) s = expanded_hosts = string_copy(s);
2076 host_build_hostlist(&hostlist, s, ob->hosts_randomize);
2078 /* If there was no expansion of hosts, save the host list for
2081 if (expanded_hosts == NULL) ob->hostlist = hostlist;
2084 /* This is not the first time this transport has been run in this delivery;
2085 the host list was built previously. */
2087 else hostlist = ob->hostlist;
2090 /* The host list was supplied with the address. If hosts_randomize is set, we
2091 must sort it into a random order if it did not come from MX records and has not
2092 already been randomized (but don't bother if continuing down an existing
2095 else if (ob->hosts_randomize && hostlist->mx == MX_NONE && !continuing)
2097 host_item *newlist = NULL;
2098 while (hostlist != NULL)
2100 host_item *h = hostlist;
2101 hostlist = hostlist->next;
2103 h->sort_key = random_number(100);
2105 if (newlist == NULL)
2110 else if (h->sort_key < newlist->sort_key)
2117 host_item *hh = newlist;
2118 while (hh->next != NULL)
2120 if (h->sort_key < hh->next->sort_key) break;
2128 hostlist = addrlist->host_list = newlist;
2132 /* Sort out the default port. */
2134 if (!smtp_get_port(ob->port, addrlist, &port, tid)) return FALSE;
2137 /* For each host-plus-IP-address on the list:
2139 . If this is a continued delivery and the host isn't the one with the
2140 current connection, skip.
2142 . If the status is unusable (i.e. previously failed or retry checked), skip.
2144 . If no IP address set, get the address, either by turning the name into
2145 an address, calling gethostbyname if gethostbyname is on, or by calling
2146 the DNS. The DNS may yield multiple addresses, in which case insert the
2147 extra ones into the list.
2149 . Get the retry data if not previously obtained for this address and set the
2150 field which remembers the state of this address. Skip if the retry time is
2151 not reached. If not, remember whether retry data was found. The retry string
2152 contains both the name and the IP address.
2154 . Scan the list of addresses and mark those whose status is DEFER as
2155 PENDING_DEFER. These are the only ones that will be processed in this cycle
2158 . Make a delivery attempt - addresses marked PENDING_DEFER will be tried.
2159 Some addresses may be successfully delivered, others may fail, and yet
2160 others may get temporary errors and so get marked DEFER.
2162 . The return from the delivery attempt is OK if a connection was made and a
2163 valid SMTP dialogue was completed. Otherwise it is DEFER.
2165 . If OK, add a "remove" retry item for this host/IPaddress, if any.
2167 . If fail to connect, or other defer state, add a retry item.
2169 . If there are any addresses whose status is still DEFER, carry on to the
2170 next host/IPaddress, unless we have tried the number of hosts given
2171 by hosts_max_try or hosts_max_try_hardlimit; otherwise return. Note that
2172 there is some fancy logic for hosts_max_try that means its limit can be
2173 overstepped in some circumstances.
2175 If we get to the end of the list, all hosts have deferred at least one address,
2176 or not reached their retry times. If delay_after_cutoff is unset, it requests a
2177 delivery attempt to those hosts whose last try was before the arrival time of
2178 the current message. To cope with this, we have to go round the loop a second
2179 time. After that, set the status and error data for any addresses that haven't
2180 had it set already. */
2182 for (cutoff_retry = 0; expired &&
2183 cutoff_retry < ((ob->delay_after_cutoff)? 1 : 2);
2186 host_item *nexthost = NULL;
2187 int unexpired_hosts_tried = 0;
2189 for (host = hostlist;
2191 unexpired_hosts_tried < ob->hosts_max_try &&
2192 total_hosts_tried < ob->hosts_max_try_hardlimit;
2198 BOOL serialized = FALSE;
2199 BOOL host_is_expired = FALSE;
2200 BOOL message_defer = FALSE;
2201 BOOL ifchanges = FALSE;
2202 BOOL some_deferred = FALSE;
2203 address_item *first_addr = NULL;
2204 uschar *interface = NULL;
2205 uschar *retry_host_key = NULL;
2206 uschar *retry_message_key = NULL;
2207 uschar *serialize_key = NULL;
2209 /* Default next host is next host. :-) But this can vary if the
2210 hosts_max_try limit is hit (see below). It may also be reset if a host
2211 address is looked up here (in case the host was multihomed). */
2213 nexthost = host->next;
2215 /* Set the flag requesting that this host be added to the waiting
2216 database if the delivery fails temporarily or if we are running with
2217 queue_smtp or a 2-stage queue run. This gets unset for certain
2218 kinds of error, typically those that are specific to the message. */
2220 host->update_waiting = TRUE;
2222 /* If the address hasn't yet been obtained from the host name, look it up
2223 now, unless the host is already marked as unusable. If it is marked as
2224 unusable, it means that the router was unable to find its IP address (in
2225 the DNS or wherever) OR we are in the 2nd time round the cutoff loop, and
2226 the lookup failed last time. We don't get this far if *all* MX records
2227 point to non-existent hosts; that is treated as a hard error.
2229 We can just skip this host entirely. When the hosts came from the router,
2230 the address will timeout based on the other host(s); when the address is
2231 looked up below, there is an explicit retry record added.
2233 Note that we mustn't skip unusable hosts if the address is not unset; they
2234 may be needed as expired hosts on the 2nd time round the cutoff loop. */
2236 if (host->address == NULL)
2240 uschar *canonical_name;
2242 if (host->status >= hstatus_unusable)
2244 DEBUG(D_transport) debug_printf("%s has no address and is unusable - skipping\n",
2249 DEBUG(D_transport) debug_printf("getting address for %s\n", host->name);
2251 /* The host name is permitted to have an attached port. Find it, and
2252 strip it from the name. Just remember it for now. */
2254 new_port = host_item_get_port(host);
2256 /* Count hosts looked up */
2260 /* Find by name if so configured, or if it's an IP address. We don't
2261 just copy the IP address, because we need the test-for-local to happen. */
2263 if (ob->gethostbyname || string_is_ip_address(host->name, NULL) > 0)
2264 rc = host_find_byname(host, NULL, &canonical_name, TRUE);
2267 int flags = HOST_FIND_BY_A;
2268 if (ob->dns_qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
2269 if (ob->dns_search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
2270 rc = host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
2271 &canonical_name, NULL);
2274 /* Update the host (and any additional blocks, resulting from
2275 multihoming) with a host-specific port, if any. */
2277 for (hh = host; hh != nexthost; hh = hh->next) hh->port = new_port;
2279 /* Failure to find the host at this time (usually DNS temporary failure)
2280 is really a kind of routing failure rather than a transport failure.
2281 Therefore we add a retry item of the routing kind, not to stop us trying
2282 to look this name up here again, but to ensure the address gets timed
2283 out if the failures go on long enough. A complete failure at this point
2284 commonly points to a configuration error, but the best action is still
2285 to carry on for the next host. */
2287 if (rc == HOST_FIND_AGAIN || rc == HOST_FIND_FAILED)
2289 retry_add_item(addrlist, string_sprintf("R:%s", host->name), 0);
2291 if (rc == HOST_FIND_AGAIN) hosts_defer++; else hosts_fail++;
2292 DEBUG(D_transport) debug_printf("rc = %s for %s\n", (rc == HOST_FIND_AGAIN)?
2293 "HOST_FIND_AGAIN" : "HOST_FIND_FAILED", host->name);
2294 host->status = hstatus_unusable;
2296 for (addr = addrlist; addr != NULL; addr = addr->next)
2298 if (addr->transport_return != DEFER) continue;
2299 addr->basic_errno = ERRNO_UNKNOWNHOST;
2301 string_sprintf("failed to lookup IP address for %s", host->name);
2306 /* If the host is actually the local host, we may have a problem, or
2307 there may be some cunning configuration going on. In the problem case,
2308 log things and give up. The default transport status is already DEFER. */
2310 if (rc == HOST_FOUND_LOCAL && !ob->allow_localhost)
2312 for (addr = addrlist; addr != NULL; addr = addr->next)
2314 addr->basic_errno = 0;
2315 addr->message = string_sprintf("%s transport found host %s to be "
2316 "local", tblock->name, host->name);
2320 } /* End of block for IP address lookup */
2322 /* If this is a continued delivery, we are interested only in the host
2323 which matches the name of the existing open channel. The check is put
2324 here after the local host lookup, in case the name gets expanded as a
2325 result of the lookup. Set expired FALSE, to save the outer loop executing
2328 if (continuing && (Ustrcmp(continue_hostname, host->name) != 0 ||
2329 Ustrcmp(continue_host_address, host->address) != 0))
2332 continue; /* With next host */
2335 /* Reset the default next host in case a multihomed host whose addresses
2336 are not looked up till just above added to the host list. */
2338 nexthost = host->next;
2340 /* If queue_smtp is set (-odqs or the first part of a 2-stage run), or the
2341 domain is in queue_smtp_domains, we don't actually want to attempt any
2342 deliveries. When doing a queue run, queue_smtp_domains is always unset. If
2343 there is a lookup defer in queue_smtp_domains, proceed as if the domain
2344 were not in it. We don't want to hold up all SMTP deliveries! Except when
2345 doing a two-stage queue run, don't do this if forcing. */
2347 if ((!deliver_force || queue_2stage) && (queue_smtp ||
2348 match_isinlist(addrlist->domain, &queue_smtp_domains, 0,
2349 &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL) == OK))
2352 for (addr = addrlist; addr != NULL; addr = addr->next)
2354 if (addr->transport_return != DEFER) continue;
2355 addr->message = US"domain matches queue_smtp_domains, or -odqs set";
2357 continue; /* With next host */
2360 /* Count hosts being considered - purely for an intelligent comment
2361 if none are usable. */
2365 /* Set $host and $host address now in case they are needed for the
2366 interface expansion or the serialize_hosts check; they remain set if an
2367 actual delivery happens. */
2369 deliver_host = host->name;
2370 deliver_host_address = host->address;
2372 /* Set up a string for adding to the retry key if the port number is not
2373 the standard SMTP port. A host may have its own port setting that overrides
2376 pistring = string_sprintf(":%d", (host->port == PORT_NONE)?
2378 if (Ustrcmp(pistring, ":25") == 0) pistring = US"";
2380 /* Select IPv4 or IPv6, and choose an outgoing interface. If the interface
2381 string changes upon expansion, we must add it to the key that is used for
2382 retries, because connections to the same host from a different interface
2383 should be treated separately. */
2385 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET : AF_INET6;
2386 if (!smtp_get_interface(ob->interface, host_af, addrlist, &ifchanges,
2389 if (ifchanges) pistring = string_sprintf("%s/%s", pistring, interface);
2391 /* The first time round the outer loop, check the status of the host by
2392 inspecting the retry data. The second time round, we are interested only
2393 in expired hosts that haven't been tried since this message arrived. */
2395 if (cutoff_retry == 0)
2397 /* Ensure the status of the address is set by checking retry data if
2398 necessary. There maybe host-specific retry data (applicable to all
2399 messages) and also data for retries of a specific message at this host.
2400 If either of these retry records are actually read, the keys used are
2401 returned to save recomputing them later. */
2403 host_is_expired = retry_check_address(addrlist->domain, host, pistring,
2404 ob->retry_include_ip_address, &retry_host_key, &retry_message_key);
2406 DEBUG(D_transport) debug_printf("%s [%s]%s status = %s\n", host->name,
2407 (host->address == NULL)? US"" : host->address, pistring,
2408 (host->status == hstatus_usable)? "usable" :
2409 (host->status == hstatus_unusable)? "unusable" :
2410 (host->status == hstatus_unusable_expired)? "unusable (expired)" : "?");
2412 /* Skip this address if not usable at this time, noting if it wasn't
2413 actually expired, both locally and in the address. */
2415 switch (host->status)
2417 case hstatus_unusable:
2419 setflag(addrlist, af_retry_skipped);
2422 case hstatus_unusable_expired:
2425 case hwhy_retry: hosts_retry++; break;
2426 case hwhy_failed: hosts_fail++; break;
2427 case hwhy_deferred: hosts_defer++; break;
2430 /* If there was a retry message key, implying that previously there
2431 was a message-specific defer, we don't want to update the list of
2432 messages waiting for this host. */
2434 if (retry_message_key != NULL) host->update_waiting = FALSE;
2435 continue; /* With the next host or IP address */
2439 /* Second time round the loop: if the address is set but expired, and
2440 the message is newer than the last try, let it through. */
2444 if (host->address == NULL ||
2445 host->status != hstatus_unusable_expired ||
2446 host->last_try > received_time)
2449 debug_printf("trying expired host %s [%s]%s\n",
2450 host->name, host->address, pistring);
2451 host_is_expired = TRUE;
2454 /* Setting "expired=FALSE" doesn't actually mean not all hosts are expired;
2455 it remains TRUE only if all hosts are expired and none are actually tried.
2460 /* If this host is listed as one to which access must be serialized,
2461 see if another Exim process has a connection to it, and if so, skip
2462 this host. If not, update the database to record our connection to it
2463 and remember this for later deletion. Do not do any of this if we are
2464 sending the message down a pre-existing connection. */
2467 verify_check_this_host(&(ob->serialize_hosts), NULL, host->name,
2468 host->address, NULL) == OK)
2470 serialize_key = string_sprintf("host-serialize-%s", host->name);
2471 if (!enq_start(serialize_key))
2474 debug_printf("skipping host %s because another Exim process "
2475 "is connected to it\n", host->name);
2482 /* OK, we have an IP address that is not waiting for its retry time to
2483 arrive (it might be expired) OR (second time round the loop) we have an
2484 expired host that hasn't been tried since the message arrived. Have a go
2485 at delivering the message to it. First prepare the addresses by flushing
2486 out the result of previous attempts, and finding the first address that
2487 is still to be delivered. */
2489 first_addr = prepare_addresses(addrlist, host);
2491 DEBUG(D_transport) debug_printf("delivering %s to %s [%s] (%s%s)\n",
2492 message_id, host->name, host->address, addrlist->address,
2493 (addrlist->next == NULL)? "" : ", ...");
2495 set_process_info("delivering %s to %s [%s] (%s%s)",
2496 message_id, host->name, host->address, addrlist->address,
2497 (addrlist->next == NULL)? "" : ", ...");
2499 /* This is not for real; don't do the delivery. If there are
2500 any remaining hosts, list them. */
2505 set_errno(addrlist, 0, NULL, OK, FALSE);
2506 for (addr = addrlist; addr != NULL; addr = addr->next)
2508 addr->host_used = host;
2509 addr->special_action = '*';
2510 addr->message = US"delivery bypassed by -N option";
2514 debug_printf("*** delivery by %s transport bypassed by -N option\n"
2515 "*** host and remaining hosts:\n", tblock->name);
2516 for (host2 = host; host2 != NULL; host2 = host2->next)
2517 debug_printf(" %s [%s]\n", host2->name,
2518 (host2->address == NULL)? US"unset" : host2->address);
2523 /* This is for real. If the host is expired, we don't count it for
2524 hosts_max_retry. This ensures that all hosts must expire before an address
2525 is timed out, unless hosts_max_try_hardlimit (which protects against
2526 lunatic DNS configurations) is reached.
2528 If the host is not expired and we are about to hit the hosts_max_retry
2529 limit, check to see if there is a subsequent hosts with a different MX
2530 value. If so, make that the next host, and don't count this one. This is a
2531 heuristic to make sure that different MXs do get tried. With a normal kind
2532 of retry rule, they would get tried anyway when the earlier hosts were
2533 delayed, but if the domain has a "retry every time" type of rule - as is
2534 often used for the the very large ISPs, that won't happen. */
2538 if (!host_is_expired && ++unexpired_hosts_tried >= ob->hosts_max_try)
2542 debug_printf("hosts_max_try limit reached with this host\n");
2543 for (h = host; h != NULL; h = h->next)
2544 if (h->mx != host->mx) break;
2548 unexpired_hosts_tried--;
2549 DEBUG(D_transport) debug_printf("however, a higher MX host exists "
2550 "and will be tried\n");
2554 /* Attempt the delivery. */
2556 total_hosts_tried++;
2557 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2558 expanded_hosts != NULL, &message_defer, FALSE);
2561 OK => connection made, each address contains its result;
2562 message_defer is set for message-specific defers (when all
2563 recipients are marked defer)
2564 DEFER => there was a non-message-specific delivery problem;
2565 ERROR => there was a problem setting up the arguments for a filter,
2566 or there was a problem with expanding added headers
2569 /* If the result is not OK, there was a non-message-specific problem.
2570 If the result is DEFER, we need to write to the logs saying what happened
2571 for this particular host, except in the case of authentication and TLS
2572 failures, where the log has already been written. If all hosts defer a
2573 general message is written at the end. */
2575 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL &&
2576 first_addr->basic_errno != ERRNO_TLSFAILURE)
2577 write_logs(first_addr, host);
2579 /* If STARTTLS was accepted, but there was a failure in setting up the
2580 TLS session (usually a certificate screwup), and the host is not in
2581 hosts_require_tls, and tls_tempfail_tryclear is true, try again, with
2582 TLS forcibly turned off. We have to start from scratch with a new SMTP
2583 connection. That's why the retry is done from here, not from within
2584 smtp_deliver(). [Rejections of STARTTLS itself don't screw up the
2585 session, so the in-clear transmission after those errors, if permitted,
2586 happens inside smtp_deliver().] */
2589 if (rc == DEFER && first_addr->basic_errno == ERRNO_TLSFAILURE &&
2590 ob->tls_tempfail_tryclear &&
2591 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
2592 host->address, NULL) != OK)
2594 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
2595 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
2596 first_addr = prepare_addresses(addrlist, host);
2597 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2598 expanded_hosts != NULL, &message_defer, TRUE);
2599 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL)
2600 write_logs(first_addr, host);
2605 /* Delivery attempt finished */
2607 rs = (rc == OK)? US"OK" : (rc == DEFER)? US"DEFER" : (rc == ERROR)?
2610 set_process_info("delivering %s: just tried %s [%s] for %s%s: result %s",
2611 message_id, host->name, host->address, addrlist->address,
2612 (addrlist->next == NULL)? "" : " (& others)", rs);
2614 /* Release serialization if set up */
2616 if (serialized) enq_end(serialize_key);
2618 /* If the result is DEFER, or if a host retry record is known to exist, we
2619 need to add an item to the retry chain for updating the retry database
2620 at the end of delivery. We only need to add the item to the top address,
2621 of course. Also, if DEFER, we mark the IP address unusable so as to skip it
2622 for any other delivery attempts using the same address. (It is copied into
2623 the unusable tree at the outer level, so even if different address blocks
2624 contain the same address, it still won't get tried again.) */
2626 if (rc == DEFER || retry_host_key != NULL)
2628 int delete_flag = (rc != DEFER)? rf_delete : 0;
2629 if (retry_host_key == NULL)
2631 retry_host_key = ob->retry_include_ip_address?
2632 string_sprintf("T:%S:%s%s", host->name, host->address, pistring) :
2633 string_sprintf("T:%S%s", host->name, pistring);
2636 /* If a delivery of another message over an existing SMTP connection
2637 yields DEFER, we do NOT set up retry data for the host. This covers the
2638 case when there are delays in routing the addresses in the second message
2639 that are so long that the server times out. This is alleviated by not
2640 routing addresses that previously had routing defers when handling an
2641 existing connection, but even so, this case may occur (e.g. if a
2642 previously happily routed address starts giving routing defers). If the
2643 host is genuinely down, another non-continued message delivery will
2644 notice it soon enough. */
2646 if (delete_flag != 0 || !continuing)
2647 retry_add_item(first_addr, retry_host_key, rf_host | delete_flag);
2649 /* We may have tried an expired host, if its retry time has come; ensure
2650 the status reflects the expiry for the benefit of any other addresses. */
2654 host->status = (host_is_expired)?
2655 hstatus_unusable_expired : hstatus_unusable;
2656 host->why = hwhy_deferred;
2660 /* If message_defer is set (host was OK, but every recipient got deferred
2661 because of some message-specific problem), or if that had happened
2662 previously so that a message retry key exists, add an appropriate item
2663 to the retry chain. Note that if there was a message defer but now there is
2664 a host defer, the message defer record gets deleted. That seems perfectly
2665 reasonable. Also, stop the message from being remembered as waiting
2668 if (message_defer || retry_message_key != NULL)
2670 int delete_flag = message_defer? 0 : rf_delete;
2671 if (retry_message_key == NULL)
2673 retry_message_key = ob->retry_include_ip_address?
2674 string_sprintf("T:%S:%s%s:%s", host->name, host->address, pistring,
2676 string_sprintf("T:%S%s:%s", host->name, pistring, message_id);
2678 retry_add_item(addrlist, retry_message_key,
2679 rf_message | rf_host | delete_flag);
2680 host->update_waiting = FALSE;
2683 /* Any return other than DEFER (that is, OK or ERROR) means that the
2684 addresses have got their final statuses filled in for this host. In the OK
2685 case, see if any of them are deferred. */
2689 for (addr = addrlist; addr != NULL; addr = addr->next)
2691 if (addr->transport_return == DEFER)
2693 some_deferred = TRUE;
2699 /* If no addresses deferred or the result was ERROR, return. We do this for
2700 ERROR because a failing filter set-up or add_headers expansion is likely to
2701 fail for any host we try. */
2703 if (rc == ERROR || (rc == OK && !some_deferred))
2705 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2706 return TRUE; /* Each address has its status */
2709 /* If the result was DEFER or some individual addresses deferred, let
2710 the loop run to try other hosts with the deferred addresses, except for the
2711 case when we were trying to deliver down an existing channel and failed.
2712 Don't try any other hosts in this case. */
2714 if (continuing) break;
2716 /* If the whole delivery, or some individual addresses, were deferred and
2717 there are more hosts that could be tried, do not count this host towards
2718 the hosts_max_try limit if the age of the message is greater than the
2719 maximum retry time for this host. This means we may try try all hosts,
2720 ignoring the limit, when messages have been around for some time. This is
2721 important because if we don't try all hosts, the address will never time
2722 out. NOTE: this does not apply to hosts_max_try_hardlimit. */
2724 if ((rc == DEFER || some_deferred) && nexthost != NULL)
2727 retry_config *retry = retry_find_config(host->name, NULL, 0, 0);
2729 if (retry != NULL && retry->rules != NULL)
2731 retry_rule *last_rule;
2732 for (last_rule = retry->rules;
2733 last_rule->next != NULL;
2734 last_rule = last_rule->next);
2735 timedout = time(NULL) - received_time > last_rule->timeout;
2737 else timedout = TRUE; /* No rule => timed out */
2741 unexpired_hosts_tried--;
2742 DEBUG(D_transport) debug_printf("temporary delivery error(s) override "
2743 "hosts_max_try (message older than host's retry time)\n");
2746 } /* End of loop for trying multiple hosts. */
2748 /* This is the end of the loop that repeats iff expired is TRUE and
2749 ob->delay_after_cutoff is FALSE. The second time round we will
2750 try those hosts that haven't been tried since the message arrived. */
2754 debug_printf("all IP addresses skipped or deferred at least one address\n");
2755 if (expired && !ob->delay_after_cutoff && cutoff_retry == 0)
2756 debug_printf("retrying IP addresses not tried since message arrived\n");
2761 /* Get here if all IP addresses are skipped or defer at least one address. In
2762 MUA wrapper mode, this will happen only for connection or other non-message-
2763 specific failures. Force the delivery status for all addresses to FAIL. */
2767 for (addr = addrlist; addr != NULL; addr = addr->next)
2768 addr->transport_return = FAIL;
2772 /* In the normal, non-wrapper case, add a standard message to each deferred
2773 address if there hasn't been an error, that is, if it hasn't actually been
2774 tried this time. The variable "expired" will be FALSE if any deliveries were
2775 actually tried, or if there was at least one host that was not expired. That
2776 is, it is TRUE only if no deliveries were tried and all hosts were expired. If
2777 a delivery has been tried, an error code will be set, and the failing of the
2778 message is handled by the retry code later.
2780 If queue_smtp is set, or this transport was called to send a subsequent message
2781 down an existing TCP/IP connection, and something caused the host not to be
2782 found, we end up here, but can detect these cases and handle them specially. */
2784 for (addr = addrlist; addr != NULL; addr = addr->next)
2786 /* If host is not NULL, it means that we stopped processing the host list
2787 because of hosts_max_try or hosts_max_try_hardlimit. In the former case, this
2788 means we need to behave as if some hosts were skipped because their retry
2789 time had not come. Specifically, this prevents the address from timing out.
2790 However, if we have hit hosts_max_try_hardlimit, we want to behave as if all
2791 hosts were tried. */
2795 if (total_hosts_tried >= ob->hosts_max_try_hardlimit)
2798 debug_printf("hosts_max_try_hardlimit reached: behave as if all "
2799 "hosts were tried\n");
2804 debug_printf("hosts_max_try limit caused some hosts to be skipped\n");
2805 setflag(addr, af_retry_skipped);
2809 if (queue_smtp) /* no deliveries attempted */
2811 addr->transport_return = DEFER;
2812 addr->basic_errno = 0;
2813 addr->message = US"SMTP delivery explicitly queued";
2816 else if (addr->transport_return == DEFER &&
2817 (addr->basic_errno == ERRNO_UNKNOWNERROR || addr->basic_errno == 0) &&
2818 addr->message == NULL)
2820 addr->basic_errno = ERRNO_HRETRY;
2821 if (continue_hostname != NULL)
2823 addr->message = US"no host found for existing SMTP connection";
2827 setflag(addr, af_pass_message); /* This is not a security risk */
2828 addr->message = (ob->delay_after_cutoff)?
2829 US"retry time not reached for any host after a long failure period" :
2830 US"all hosts have been failing for a long time and were last tried "
2831 "after this message arrived";
2833 /* If we are already using fallback hosts, or there are no fallback hosts
2834 defined, convert the result to FAIL to cause a bounce. */
2836 if (addr->host_list == addr->fallback_hosts ||
2837 addr->fallback_hosts == NULL)
2838 addr->transport_return = FAIL;
2842 if (hosts_retry == hosts_total)
2843 addr->message = US"retry time not reached for any host";
2844 else if (hosts_fail == hosts_total)
2845 addr->message = US"all host address lookups failed permanently";
2846 else if (hosts_defer == hosts_total)
2847 addr->message = US"all host address lookups failed temporarily";
2848 else if (hosts_serial == hosts_total)
2849 addr->message = US"connection limit reached for all hosts";
2850 else if (hosts_fail+hosts_defer == hosts_total)
2851 addr->message = US"all host address lookups failed";
2852 else addr->message = US"some host address lookups failed and retry time "
2853 "not reached for other hosts or connection limit reached";
2858 /* Update the database which keeps information about which messages are waiting
2859 for which hosts to become available. Each host in the list has a flag which is
2860 set if the data is to be updated. For some message-specific errors, the flag is
2861 turned off because we don't want follow-on deliveries in those cases. */
2863 transport_update_waiting(hostlist, tblock->name);
2867 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2869 return TRUE; /* Each address has its status */
2872 /* End of transport/smtp.c */
git://git.exim.org / exim.git / blob