1 /* $Cambridge: exim/src/src/transports/smtp.c,v 1.1 2004/10/07 13:10:02 ph10 Exp $ */
3 /*************************************************
4 * Exim - an Internet mail transport agent *
5 *************************************************/
7 /* Copyright (c) University of Cambridge 1995 - 2004 */
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 { "dns_qualify_single", opt_bool,
39 (void *)offsetof(smtp_transport_options_block, dns_qualify_single) },
40 { "dns_search_parents", opt_bool,
41 (void *)offsetof(smtp_transport_options_block, dns_search_parents) },
42 { "fallback_hosts", opt_stringptr,
43 (void *)offsetof(smtp_transport_options_block, fallback_hosts) },
44 { "final_timeout", opt_time,
45 (void *)offsetof(smtp_transport_options_block, final_timeout) },
46 { "gethostbyname", opt_bool,
47 (void *)offsetof(smtp_transport_options_block, gethostbyname) },
48 { "helo_data", opt_stringptr,
49 (void *)offsetof(smtp_transport_options_block, helo_data) },
50 { "hosts", opt_stringptr,
51 (void *)offsetof(smtp_transport_options_block, hosts) },
52 { "hosts_avoid_esmtp", opt_stringptr,
53 (void *)offsetof(smtp_transport_options_block, hosts_avoid_esmtp) },
55 { "hosts_avoid_tls", opt_stringptr,
56 (void *)offsetof(smtp_transport_options_block, hosts_avoid_tls) },
58 { "hosts_max_try", opt_int,
59 (void *)offsetof(smtp_transport_options_block, hosts_max_try) },
61 { "hosts_nopass_tls", opt_stringptr,
62 (void *)offsetof(smtp_transport_options_block, hosts_nopass_tls) },
64 { "hosts_override", opt_bool,
65 (void *)offsetof(smtp_transport_options_block, hosts_override) },
66 { "hosts_randomize", opt_bool,
67 (void *)offsetof(smtp_transport_options_block, hosts_randomize) },
68 { "hosts_require_auth", opt_stringptr,
69 (void *)offsetof(smtp_transport_options_block, hosts_require_auth) },
71 { "hosts_require_tls", opt_stringptr,
72 (void *)offsetof(smtp_transport_options_block, hosts_require_tls) },
74 { "hosts_try_auth", opt_stringptr,
75 (void *)offsetof(smtp_transport_options_block, hosts_try_auth) },
76 { "interface", opt_stringptr,
77 (void *)offsetof(smtp_transport_options_block, interface) },
78 { "keepalive", opt_bool,
79 (void *)offsetof(smtp_transport_options_block, keepalive) },
80 { "max_rcpt", opt_int | opt_public,
81 (void *)offsetof(transport_instance, max_addresses) },
82 { "multi_domain", opt_bool | opt_public,
83 (void *)offsetof(transport_instance, multi_domain) },
84 { "port", opt_stringptr,
85 (void *)offsetof(smtp_transport_options_block, port) },
86 { "protocol", opt_stringptr,
87 (void *)offsetof(smtp_transport_options_block, protocol) },
88 { "retry_include_ip_address", opt_bool,
89 (void *)offsetof(smtp_transport_options_block, retry_include_ip_address) },
90 { "serialize_hosts", opt_stringptr,
91 (void *)offsetof(smtp_transport_options_block, serialize_hosts) },
92 { "size_addition", opt_int,
93 (void *)offsetof(smtp_transport_options_block, size_addition) }
95 ,{ "tls_certificate", opt_stringptr,
96 (void *)offsetof(smtp_transport_options_block, tls_certificate) },
97 { "tls_crl", opt_stringptr,
98 (void *)offsetof(smtp_transport_options_block, tls_crl) },
99 { "tls_privatekey", opt_stringptr,
100 (void *)offsetof(smtp_transport_options_block, tls_privatekey) },
101 { "tls_require_ciphers", opt_stringptr,
102 (void *)offsetof(smtp_transport_options_block, tls_require_ciphers) },
103 { "tls_tempfail_tryclear", opt_bool,
104 (void *)offsetof(smtp_transport_options_block, tls_tempfail_tryclear) },
105 { "tls_verify_certificates", opt_stringptr,
106 (void *)offsetof(smtp_transport_options_block, tls_verify_certificates) }
110 /* Size of the options list. An extern variable has to be used so that its
111 address can appear in the tables drtables.c. */
113 int smtp_transport_options_count =
114 sizeof(smtp_transport_options)/sizeof(optionlist);
116 /* Default private options block for the smtp transport. */
118 smtp_transport_options_block smtp_transport_option_defaults = {
120 NULL, /* fallback_hosts */
122 NULL, /* fallback_hostlist */
123 NULL, /* authenticated_sender */
124 US"$primary_hostname", /* helo_data */
125 NULL, /* interface */
127 US"smtp", /* protocol */
128 NULL, /* serialize_hosts */
129 NULL, /* hosts_try_auth */
130 NULL, /* hosts_require_auth */
131 NULL, /* hosts_require_tls */
132 NULL, /* hosts_avoid_tls */
133 NULL, /* hosts_avoid_esmtp */
134 NULL, /* hosts_nopass_tls */
135 5*60, /* command_timeout */
136 5*60, /* connect_timeout; shorter system default overrides */
137 5*60, /* data timeout */
138 10*60, /* final timeout */
139 1024, /* size_addition */
140 5, /* hosts_max_try */
141 FALSE, /* allow_localhost */
142 FALSE, /* gethostbyname */
143 TRUE, /* dns_qualify_single */
144 FALSE, /* dns_search_parents */
145 TRUE, /* delay_after_cutoff */
146 FALSE, /* hosts_override */
147 FALSE, /* hosts_randomize */
148 TRUE, /* keepalive */
149 TRUE /* retry_include_ip_address */
151 ,NULL, /* tls_certificate */
153 NULL, /* tls_privatekey */
154 NULL, /* tls_require_ciphers */
155 NULL, /* tls_verify_certificates */
156 TRUE /* tls_tempfail_tryclear */
163 static uschar *smtp_command; /* Points to last cmd for error messages */
164 static uschar *mail_command; /* Points to MAIL cmd for error messages */
167 /*************************************************
168 * Setup entry point *
169 *************************************************/
171 /* This function is called when the transport is about to be used,
172 but before running it in a sub-process. It is used for two things:
174 (1) To set the fallback host list in addresses, when delivering.
175 (2) To pass back the interface, port, and protocol options, for use during
176 callout verification.
179 tblock pointer to the transport instance block
180 addrlist list of addresses about to be transported
181 tf if not NULL, pointer to block in which to return options
182 errmsg place for error message (not used)
184 Returns: OK always (FAIL, DEFER not used)
188 smtp_transport_setup(transport_instance *tblock, address_item *addrlist,
189 transport_feedback *tf, uschar **errmsg)
191 smtp_transport_options_block *ob =
192 (smtp_transport_options_block *)(tblock->options_block);
194 errmsg = errmsg; /* Keep picky compilers happy */
196 /* Pass back options if required. This interface is getting very messy. */
200 tf->interface = ob->interface;
202 tf->protocol = ob->protocol;
203 tf->hosts = ob->hosts;
204 tf->hosts_override = ob->hosts_override;
205 tf->hosts_randomize = ob->hosts_randomize;
206 tf->gethostbyname = ob->gethostbyname;
207 tf->qualify_single = ob->dns_qualify_single;
208 tf->search_parents = ob->dns_search_parents;
211 /* Set the fallback host list for all the addresses that don't have fallback
212 host lists, provided that the local host wasn't present in the original host
215 if (!testflag(addrlist, af_local_host_removed))
217 for (; addrlist != NULL; addrlist = addrlist->next)
218 if (addrlist->fallback_hosts == NULL)
219 addrlist->fallback_hosts = ob->fallback_hostlist;
227 /*************************************************
228 * Initialization entry point *
229 *************************************************/
231 /* Called for each instance, after its options have been read, to
232 enable consistency checks to be done, or anything else that needs
235 Argument: pointer to the transport instance block
240 smtp_transport_init(transport_instance *tblock)
242 smtp_transport_options_block *ob =
243 (smtp_transport_options_block *)(tblock->options_block);
245 /* Retry_use_local_part defaults FALSE if unset */
247 if (tblock->retry_use_local_part == TRUE_UNSET)
248 tblock->retry_use_local_part = FALSE;
250 /* Set the default port according to the protocol */
252 if (ob->port == NULL)
253 ob->port = (strcmpic(ob->protocol, US"lmtp") == 0)? US"lmtp" : US"smtp";
255 /* Set up the setup entry point, to be called before subprocesses for this
258 tblock->setup = smtp_transport_setup;
260 /* Complain if any of the timeouts are zero. */
262 if (ob->command_timeout <= 0 || ob->data_timeout <= 0 ||
263 ob->final_timeout <= 0)
264 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
265 "command, data, or final timeout value is zero for %s transport",
268 /* If hosts_override is set and there are local hosts, set the global
269 flag that stops verify from showing router hosts. */
271 if (ob->hosts_override && ob->hosts != NULL) tblock->overrides_hosts = TRUE;
273 /* If there are any fallback hosts listed, build a chain of host items
274 for them, but do not do any lookups at this time. */
276 host_build_hostlist(&(ob->fallback_hostlist), ob->fallback_hosts, FALSE);
283 /*************************************************
284 * Set delivery info into all active addresses *
285 *************************************************/
287 /* Only addresses whose status is >= PENDING are relevant. A lesser
288 status means that an address is not currently being processed.
291 addrlist points to a chain of addresses
292 errno_value to put in each address's errno field
293 msg to put in each address's message field
294 rc to put in each address's transport_return field
296 If errno_value has the special value ERRNO_CONNECTTIMEOUT, ETIMEDOUT is put in
297 the errno field, and RTEF_CTOUT is ORed into the more_errno field, to indicate
298 this particular type of timeout.
304 void set_errno(address_item *addrlist, int errno_value, uschar *msg, int rc)
308 if (errno_value == ERRNO_CONNECTTIMEOUT)
310 errno_value = ETIMEDOUT;
311 orvalue = RTEF_CTOUT;
313 for (addr = addrlist; addr != NULL; addr = addr->next)
315 if (addr->transport_return < PENDING) continue;
316 addr->basic_errno = errno_value;
317 addr->more_errno |= orvalue;
318 if (msg != NULL) addr->message = msg;
319 addr->transport_return = rc;
325 /*************************************************
326 * Check an SMTP response *
327 *************************************************/
329 /* This function is given an errno code and the SMTP response buffer
330 to analyse, together with the host identification for generating messages. It
331 sets an appropriate message and puts the first digit of the response code into
332 the yield variable. If no response was actually read, a suitable digit is
336 host the current host, to get its name for messages
337 errno_value pointer to the errno value
338 more_errno from the top address for use with ERRNO_FILTER_FAIL
339 buffer the SMTP response buffer
340 yield where to put a one-digit SMTP response code
341 message where to put an errror message
343 Returns: TRUE if an SMTP "QUIT" command should be sent, else FALSE
346 static BOOL check_response(host_item *host, int *errno_value, int more_errno,
347 uschar *buffer, int *yield, uschar **message)
351 if (smtp_use_pipelining &&
352 (Ustrcmp(smtp_command, "MAIL") == 0 ||
353 Ustrcmp(smtp_command, "RCPT") == 0 ||
354 Ustrcmp(smtp_command, "DATA") == 0))
357 *yield = '4'; /* Default setting is to give a temporary error */
359 /* Handle response timeout */
361 if (*errno_value == ETIMEDOUT)
363 *message = US string_sprintf("SMTP timeout while connected to %s [%s] "
364 "after %s%s", host->name, host->address, pl, smtp_command);
365 if (transport_count > 0)
366 *message = US string_sprintf("%s (%d bytes written)", *message,
371 /* Handle malformed SMTP response */
373 if (*errno_value == ERRNO_SMTPFORMAT)
375 uschar *malfresp = string_printing(buffer);
376 while (isspace(*malfresp)) malfresp++;
378 *message = string_sprintf("Malformed SMTP reply (an empty line) from "
379 "%s [%s] in response to %s%s", host->name, host->address, pl,
382 *message = string_sprintf("Malformed SMTP reply from %s [%s] in response "
383 "to %s%s: %s", host->name, host->address, pl, smtp_command, malfresp);
387 /* Handle a failed filter process error; can't send QUIT as we mustn't
390 if (*errno_value == ERRNO_FILTER_FAIL)
392 *message = US string_sprintf("transport filter process failed (%d)",
397 /* Handle a failed add_headers expansion; can't send QUIT as we mustn't
400 if (*errno_value == ERRNO_CHHEADER_FAIL)
403 US string_sprintf("failed to expand headers_add or headers_remove: %s",
404 expand_string_message);
408 /* Handle failure to write a complete data block */
410 if (*errno_value == ERRNO_WRITEINCOMPLETE)
412 *message = US string_sprintf("failed to write a data block");
416 /* Handle error responses from the remote mailer. */
420 uschar *s = string_printing(buffer);
421 *message = US string_sprintf("SMTP error from remote mailer after %s%s: "
422 "host %s [%s]: %s", pl, smtp_command, host->name, host->address, s);
427 /* No data was read. If there is no errno, this must be the EOF (i.e.
428 connection closed) case, which causes deferral. Otherwise, put the host's
429 identity in the message, leaving the errno value to be interpreted as well. In
430 all cases, we have to assume the connection is now dead. */
432 if (*errno_value == 0)
434 *errno_value = ERRNO_SMTPCLOSED;
435 *message = US string_sprintf("Remote host %s [%s] closed connection "
436 "in response to %s%s", host->name, host->address, pl, smtp_command);
438 else *message = US string_sprintf("%s [%s]", host->name, host->address);
445 /*************************************************
446 * Write error message to logs *
447 *************************************************/
449 /* This writes to the main log and to the message log.
452 addr the address item containing error information
453 host the current host
459 write_logs(address_item *addr, host_item *host)
461 if (addr->message != NULL)
463 uschar *message = addr->message;
464 if (addr->basic_errno > 0)
465 message = string_sprintf("%s: %s", message, strerror(addr->basic_errno));
466 log_write(0, LOG_MAIN, "%s", message);
467 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
471 log_write(0, LOG_MAIN, "%s [%s]: %s",
474 strerror(addr->basic_errno));
475 deliver_msglog("%s %s [%s]: %s\n",
479 strerror(addr->basic_errno));
485 /*************************************************
486 * Synchronize SMTP responses *
487 *************************************************/
489 /* This function is called from smtp_deliver() to receive SMTP responses from
490 the server, and match them up with the commands to which they relate. When
491 PIPELINING is not in use, this function is called after every command, and is
492 therefore somewhat over-engineered, but it is simpler to use a single scheme
493 that works both with and without PIPELINING instead of having two separate sets
496 The set of commands that are buffered up with pipelining may start with MAIL
497 and may end with DATA; in between are RCPT commands that correspond to the
498 addresses whose status is PENDING_DEFER. All other commands (STARTTLS, AUTH,
499 etc.) are never buffered.
501 Errors after MAIL or DATA abort the whole process leaving the response in the
502 buffer. After MAIL, pending responses are flushed, and the original command is
503 re-instated in big_buffer for error messages. For RCPT commands, the remote is
504 permitted to reject some recipient addresses while accepting others. However
505 certain errors clearly abort the whole process. Set the value in
506 transport_return to PENDING_OK if the address is accepted. If there is a
507 subsequent general error, it will get reset accordingly. If not, it will get
508 converted to OK at the end.
511 addrlist the complete address list
512 include_affixes TRUE if affixes include in RCPT
513 sync_addr ptr to the ptr of the one to start scanning at (updated)
514 host the host we are connected to
515 count the number of responses to read
516 pending_MAIL true if the first response is for MAIL
517 pending_DATA 0 if last command sent was not DATA
518 +1 if previously had a good recipient
519 -1 if not previously had a good recipient
520 inblock incoming SMTP block
521 timeout timeout value
522 buffer buffer for reading response
523 buffsize size of buffer
525 Returns: 3 if at least one address had 2xx and one had 5xx
526 2 if at least one address had 5xx but none had 2xx
527 1 if at least one host had a 2xx response, but none had 5xx
528 0 no address had 2xx or 5xx but no errors (all 4xx, or just DATA)
529 -1 timeout while reading RCPT response
530 -2 I/O or other non-response error for RCPT
531 -3 DATA or MAIL failed - errno and buffer set
535 sync_responses(address_item *addrlist, BOOL include_affixes,
536 address_item **sync_addr, host_item *host, int count, BOOL pending_MAIL,
537 int pending_DATA, smtp_inblock *inblock, int timeout, uschar *buffer,
540 address_item *addr = *sync_addr;
543 /* Handle the response for a MAIL command. On error, reinstate the original
544 command in big_buffer for error message use, and flush any further pending
545 responses before returning, except after I/O errors and timeouts. */
550 if (!smtp_read_response(inblock, buffer, buffsize, '2', timeout))
552 Ustrcpy(big_buffer, mail_command); /* Fits, because it came from there! */
553 if (errno == 0 && buffer[0] != 0)
555 uschar flushbuffer[4096];
558 if (!smtp_read_response(inblock, flushbuffer, sizeof(flushbuffer),
560 && (errno != 0 || flushbuffer[0] == 0))
568 if (pending_DATA) count--; /* Number of RCPT responses to come */
570 /* Read and handle the required number of RCPT responses, matching each one up
571 with an address by scanning for the next address whose status is PENDING_DEFER.
576 while (addr->transport_return != PENDING_DEFER) addr = addr->next;
578 /* The address was accepted */
580 if (smtp_read_response(inblock, buffer, buffsize, '2', timeout))
583 addr->transport_return = PENDING_OK;
585 /* If af_dr_retry_exists is set, there was a routing delay on this address;
586 ensure that any address-specific retry record is expunged. */
588 if (testflag(addr, af_dr_retry_exists))
589 retry_add_item(addr, addr->address_retry_key, rf_delete);
592 /* Timeout while reading the response */
594 else if (errno == ETIMEDOUT)
596 int save_errno = errno;
597 uschar *message = string_sprintf("SMTP timeout while connected to %s [%s] "
598 "after RCPT TO:<%s>", host->name, host->address,
599 transport_rcpt_address(addr, include_affixes));
600 set_errno(addrlist, save_errno, message, DEFER);
601 retry_add_item(addr, addr->address_retry_key, 0);
602 host->update_waiting = FALSE;
606 /* Handle other errors in obtaining an SMTP response by returning -1. This
607 will cause all the addresses to be deferred. Restore the SMTP command in
608 big_buffer for which we are checking the response, so the error message
611 else if (errno != 0 || buffer[0] == 0)
613 string_format(big_buffer, big_buffer_size, "RCPT TO:<%s>",
614 transport_rcpt_address(addr, include_affixes));
618 /* Handle SMTP permanent and temporary response codes. */
623 string_sprintf("SMTP error from remote mailer after RCPT TO:<%s>: "
624 "host %s [%s]: %s", transport_rcpt_address(addr, include_affixes),
625 host->name, host->address, string_printing(buffer));
626 deliver_msglog("%s %s\n", tod_stamp(tod_log), addr->message);
628 /* The response was 5xx */
630 if (buffer[0] == '5')
632 addr->transport_return = FAIL;
636 /* The response was 4xx */
640 int bincode = (buffer[1] - '0')*10 + buffer[2] - '0';
642 addr->transport_return = DEFER;
643 addr->basic_errno = ERRNO_RCPT4XX;
644 addr->more_errno |= bincode << 8;
646 /* Log temporary errors if there are more hosts to be tried. */
648 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", addr->message);
650 /* Do not put this message on the list of those waiting for this host,
651 as otherwise it is likely to be tried too often. */
653 host->update_waiting = FALSE;
655 /* Add a retry item for the address so that it doesn't get tried
658 retry_add_item(addr, addr->address_retry_key, 0);
661 } /* Loop for next RCPT response */
663 /* Update where to start at for the next block of responses, unless we
664 have already handled all the addresses. */
666 if (addr != NULL) *sync_addr = addr->next;
668 /* Handle a response to DATA. If we have not had any good recipients, either
669 previously or in this block, the response is ignored. */
671 if (pending_DATA != 0 &&
672 !smtp_read_response(inblock, buffer, buffsize, '3', timeout))
676 if (pending_DATA > 0 || (yield & 1) != 0) return -3;
677 (void)check_response(host, &errno, 0, buffer, &code, &msg);
678 DEBUG(D_transport) debug_printf("%s\nerror for DATA ignored: pipelining "
679 "is in use and there were no good recipients\n", msg);
682 /* All responses read and handled; MAIL (if present) received 2xx and DATA (if
683 present) received 3xx. If any RCPTs were handled and yielded anything other
684 than 4xx, yield will be set non-zero. */
691 /*************************************************
692 * Deliver address list to given host *
693 *************************************************/
695 /* If continue_hostname is not null, we get here only when continuing to
696 deliver down an existing channel. The channel was passed as the standard
699 Otherwise, we have to make a connection to the remote host, and do the
700 initial protocol exchange.
702 When running as an MUA wrapper, if the sender or any recipient is rejected,
703 temporarily or permanently, we force failure for all recipients.
706 addrlist chain of potential addresses to deliver; only those whose
707 transport_return field is set to PENDING_DEFER are currently
708 being processed; others should be skipped - they have either
709 been delivered to an earlier host or IP address, or been
710 failed by one of them.
711 host host to deliver to
712 host_af AF_INET or AF_INET6
713 port TCP/IP port to use, in host byte order
714 interface interface to bind to, or NULL
715 tblock transport instance block
716 copy_host TRUE if host set in addr->host_used must be copied, because
717 it is specific to this call of the transport
718 message_defer set TRUE if yield is OK, but all addresses were deferred
719 because of a non-recipient, non-host failure, that is, a
720 4xx response to MAIL FROM, DATA, or ".". This is a defer
721 that is specific to the message.
722 suppress_tls if TRUE, don't attempt a TLS connection - this is set for
723 a second attempt after TLS initialization fails
725 Returns: OK - the connection was made and the delivery attempted;
726 the result for each address is in its data block.
727 DEFER - the connection could not be made, or something failed
728 while setting up the SMTP session, or there was a
729 non-message-specific error, such as a timeout.
730 ERROR - a filter command is specified for this transport,
731 and there was a problem setting it up; OR helo_data
732 or add_headers or authenticated_sender is specified
733 for this transport, and the string failed to expand
737 smtp_deliver(address_item *addrlist, host_item *host, int host_af, int port,
738 uschar *interface, transport_instance *tblock, BOOL copy_host,
739 BOOL *message_defer, BOOL suppress_tls)
742 address_item *sync_addr;
743 address_item *first_addr = addrlist;
748 time_t start_delivery_time = time(NULL);
749 smtp_transport_options_block *ob =
750 (smtp_transport_options_block *)(tblock->options_block);
751 BOOL lmtp = strcmpic(ob->protocol, US"lmtp") == 0;
753 BOOL send_rset = TRUE;
754 BOOL send_quit = TRUE;
755 BOOL setting_up = TRUE;
756 BOOL completed_address = FALSE;
759 smtp_inblock inblock;
760 smtp_outblock outblock;
761 int max_rcpt = tblock->max_addresses;
762 uschar *local_authenticated_sender = authenticated_sender;
764 uschar *message = NULL;
765 uschar new_message_id[MESSAGE_ID_LENGTH + 1];
768 uschar inbuffer[4096];
769 uschar outbuffer[1024];
771 suppress_tls = suppress_tls; /* stop compiler warning when no TLS support */
773 *message_defer = FALSE;
774 smtp_command = US"initial connection";
775 if (max_rcpt == 0) max_rcpt = 999999;
777 /* Set up the buffer for reading SMTP response packets. */
779 inblock.buffer = inbuffer;
780 inblock.buffersize = sizeof(inbuffer);
781 inblock.ptr = inbuffer;
782 inblock.ptrend = inbuffer;
784 /* Set up the buffer for holding SMTP commands while pipelining */
786 outblock.buffer = outbuffer;
787 outblock.buffersize = sizeof(outbuffer);
788 outblock.ptr = outbuffer;
789 outblock.cmd_count = 0;
790 outblock.authenticating = FALSE;
792 /* Expand the greeting message */
794 helo_data = expand_string(ob->helo_data);
795 if (helo_data == NULL)
797 uschar *message = string_sprintf("failed to expand helo_data: %s",
798 expand_string_message);
799 set_errno(addrlist, 0, message, DEFER);
803 /* If an authenticated_sender override has been specified for this transport
804 instance, expand it. If the expansion is forced to fail, and there was already
805 an authenticated_sender for this message, the original value will be used.
806 Other expansion failures are serious. An empty result is ignored, but there is
807 otherwise no check - this feature is expected to be used with LMTP and other
808 cases where non-standard addresses (e.g. without domains) might be required. */
810 if (ob->authenticated_sender != NULL)
812 uschar *new = expand_string(ob->authenticated_sender);
815 if (!expand_string_forcedfail)
817 uschar *message = string_sprintf("failed to expand "
818 "authenticated_sender: %s", expand_string_message);
819 set_errno(addrlist, 0, message, DEFER);
823 else if (new[0] != 0) local_authenticated_sender = new;
826 /* Make a connection to the host if this isn't a continued delivery, and handle
827 the initial interaction and HELO/EHLO/LHLO. Connect timeout errors are handled
828 specially so they can be identified for retries. */
830 if (continue_hostname == NULL)
832 inblock.sock = outblock.sock =
833 smtp_connect(host, host_af, port, interface, ob->connect_timeout,
835 if (inblock.sock < 0)
837 set_errno(addrlist, (errno == ETIMEDOUT)? ERRNO_CONNECTTIMEOUT : errno,
842 /* The first thing is to wait for an initial OK response. The dreaded "goto"
843 is nevertheless a reasonably clean way of programming this kind of logic,
844 where you want to escape on any error. */
846 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
847 ob->command_timeout)) goto RESPONSE_FAILED;
849 /** Debugging without sending a message
850 addrlist->transport_return = DEFER;
854 /* Errors that occur after this point follow an SMTP command, which is
855 left in big_buffer by smtp_write_command() for use in error messages. */
857 smtp_command = big_buffer;
859 /* Tell the remote who we are...
861 February 1998: A convention has evolved that ESMTP-speaking MTAs include the
862 string "ESMTP" in their greeting lines, so make Exim send EHLO if the
863 greeting is of this form. The assumption was that the far end supports it
864 properly... but experience shows that there are some that give 5xx responses,
865 even though the banner includes "ESMTP" (there's a bloody-minded one that
866 says "ESMTP not spoken here"). Cope with that case.
868 September 2000: Time has passed, and it seems reasonable now to always send
869 EHLO at the start. It is also convenient to make the change while installing
872 July 2003: Joachim Wieland met a broken server that advertises "PIPELINING"
873 but times out after sending MAIL FROM, RCPT TO and DATA all together. There
874 would be no way to send out the mails, so there is now a host list
875 "hosts_avoid_esmtp" that disables ESMTP for special hosts and solves the
876 PIPELINING problem as well. Maybe it can also be useful to cure other
877 problems with broken servers.
879 Exim originally sent "Helo" at this point and ran for nearly a year that way.
880 Then somebody tried it with a Microsoft mailer... It seems that all other
881 mailers use upper case for some reason (the RFC is quite clear about case
882 independence) so, for peace of mind, I gave in. */
884 esmtp = verify_check_this_host(&(ob->hosts_avoid_esmtp), NULL,
885 host->name, host->address, NULL) != OK;
889 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n",
890 lmtp? "LHLO" : "EHLO", helo_data) < 0)
892 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
893 ob->command_timeout))
895 if (errno != 0 || buffer[0] == 0 || lmtp) goto RESPONSE_FAILED;
902 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
907 if (smtp_write_command(&outblock, FALSE, "HELO %s\r\n", helo_data) < 0)
909 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
910 ob->command_timeout)) goto RESPONSE_FAILED;
913 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
916 tls_offered = esmtp &&
917 pcre_exec(regex_STARTTLS, NULL, CS buffer, Ustrlen(buffer), 0,
918 PCRE_EOPT, NULL, 0) >= 0;
922 /* For continuing deliveries down the same channel, the socket is the standard
923 input, and we don't need to redo EHLO here (but may need to do so for TLS - see
924 below). Set up the pointer to where subsequent commands will be left, for
925 error messages. Note that smtp_use_size and smtp_use_pipelining will have been
926 set from the command line if they were set in the process that passed the
931 inblock.sock = outblock.sock = fileno(stdin);
932 smtp_command = big_buffer;
935 /* If TLS is available on this connection, whether continued or not, attempt to
936 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
937 send another EHLO - the server may give a different answer in secure mode. We
938 use a separate buffer for reading the response to STARTTLS so that if it is
939 negative, the original EHLO data is available for subsequent analysis, should
940 the client not be required to use TLS. If the response is bad, copy the buffer
941 for error analysis. */
944 if (tls_offered && !suppress_tls &&
945 verify_check_this_host(&(ob->hosts_avoid_tls), NULL, host->name,
946 host->address, NULL) != OK)
948 uschar buffer2[4096];
949 if (smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") < 0)
952 /* If there is an I/O error, transmission of this message is deferred. If
953 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
954 false, we also defer. However, if there is a temporary rejection of STARTTLS
955 and tls_tempfail_tryclear is true, or if there is an outright rejection of
956 STARTTLS, we carry on. This means we will try to send the message in clear,
957 unless the host is in hosts_require_tls (tested below). */
959 if (!smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
960 ob->command_timeout))
962 Ustrncpy(buffer, buffer2, sizeof(buffer));
963 if (errno != 0 || buffer2[0] == 0 ||
964 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
965 goto RESPONSE_FAILED;
968 /* STARTTLS accepted: try to negotiate a TLS session. */
972 int rc = tls_client_start(inblock.sock, host, addrlist,
973 NULL, /* No DH param */
976 ob->tls_verify_certificates,
978 ob->tls_require_ciphers,
979 ob->command_timeout);
981 /* TLS negotiation failed; give an error. From outside, this function may
982 be called again to try in clear on a new connection, if the options permit
987 save_errno = ERRNO_TLSFAILURE;
988 message = US"failure while setting up TLS session";
993 /* TLS session is set up */
995 for (addr = addrlist; addr != NULL; addr = addr->next)
997 addr->cipher = tls_cipher;
998 addr->peerdn = tls_peerdn;
1003 /* If we started TLS, redo the EHLO/LHLO exchange over the secure channel. */
1005 if (tls_active >= 0)
1007 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n", lmtp? "LHLO" : "EHLO",
1010 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1011 ob->command_timeout))
1012 goto RESPONSE_FAILED;
1015 /* If the host is required to use a secure channel, ensure that we
1018 else if (verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
1019 host->address, NULL) == OK)
1021 save_errno = ERRNO_TLSREQUIRED;
1022 message = string_sprintf("a TLS session is required for %s [%s], but %s",
1023 host->name, host->address,
1024 tls_offered? "an attempt to start TLS failed" :
1025 "the server did not offer TLS support");
1030 /* If TLS is active, we have just started it up and re-done the EHLO command,
1031 so its response needs to be analyzed. If TLS is not active and this is a
1032 continued session down a previously-used socket, we haven't just done EHLO, so
1035 if (continue_hostname == NULL
1042 uschar *fail_reason = US"server did not advertise AUTH support";
1044 /* If the response to EHLO specified support for the SIZE parameter, note
1045 this, provided size_addition is non-negative. */
1047 smtp_use_size = esmtp && ob->size_addition >= 0 &&
1048 pcre_exec(regex_SIZE, NULL, CS buffer, Ustrlen(CS buffer), 0,
1049 PCRE_EOPT, NULL, 0) >= 0;
1051 /* Note whether the server supports PIPELINING. If hosts_avoid_esmtp matched
1052 the current host, esmtp will be false, so PIPELINING can never be used. */
1054 smtp_use_pipelining = esmtp &&
1055 pcre_exec(regex_PIPELINING, NULL, CS buffer, Ustrlen(CS buffer), 0,
1056 PCRE_EOPT, NULL, 0) >= 0;
1058 DEBUG(D_transport) debug_printf("%susing PIPELINING\n",
1059 smtp_use_pipelining? "" : "not ");
1061 /* Note if the response to EHLO specifies support for the AUTH extension.
1062 If it has, check that this host is one we want to authenticate to, and do
1063 the business. The host name and address must be available when the
1064 authenticator's client driver is running. */
1066 smtp_authenticated = FALSE;
1067 require_auth = verify_check_this_host(&(ob->hosts_require_auth), NULL,
1068 host->name, host->address, NULL);
1070 if (esmtp && regex_match_and_setup(regex_AUTH, buffer, 0, -1))
1072 uschar *names = string_copyn(expand_nstring[1], expand_nlength[1]);
1073 expand_nmax = -1; /* reset */
1075 /* Must not do this check until after we have saved the result of the
1076 regex match above. */
1078 if (require_auth == OK ||
1079 verify_check_this_host(&(ob->hosts_try_auth), NULL, host->name,
1080 host->address, NULL) == OK)
1083 fail_reason = US"no common mechanisms were found";
1085 DEBUG(D_transport) debug_printf("scanning authentication mechanisms\n");
1087 /* Scan the configured authenticators looking for one which is configured
1088 for use as a client and whose name matches an authentication mechanism
1089 supported by the server. If one is found, attempt to authenticate by
1090 calling its client function. */
1092 for (au = auths; !smtp_authenticated && au != NULL; au = au->next)
1095 if (!au->client) continue;
1097 /* Loop to scan supported server mechanisms */
1102 int len = Ustrlen(au->public_name);
1103 while (isspace(*p)) p++;
1105 if (strncmpic(au->public_name, p, len) != 0 ||
1106 (p[len] != 0 && !isspace(p[len])))
1108 while (*p != 0 && !isspace(*p)) p++;
1112 /* Found data for a listed mechanism. Call its client entry. Set
1113 a flag in the outblock so that data is overwritten after sending so
1114 that reflections don't show it. */
1116 fail_reason = US"authentication attempt(s) failed";
1117 outblock.authenticating = TRUE;
1118 rc = (au->info->clientcode)(au, &inblock, &outblock,
1119 ob->command_timeout, buffer, sizeof(buffer));
1120 outblock.authenticating = FALSE;
1121 DEBUG(D_transport) debug_printf("%s authenticator yielded %d\n",
1124 /* A temporary authentication failure must hold up delivery to
1125 this host. After a permanent authentication failure, we carry on
1126 to try other authentication methods. If all fail hard, try to
1127 deliver the message unauthenticated unless require_auth was set. */
1132 smtp_authenticated = TRUE; /* stops the outer loop */
1135 /* Failure after writing a command */
1140 /* Failure after reading a response */
1143 if (errno != 0 || buffer[0] != '5') goto RESPONSE_FAILED;
1144 log_write(0, LOG_MAIN, "%s authenticator failed H=%s [%s] %s",
1145 au->name, host->name, host->address, buffer);
1148 /* Failure by some other means. In effect, the authenticator
1149 decided it wasn't prepared to handle this case. Typically this
1150 is the result of "fail" in an expansion string. Do we need to
1151 log anything here? */
1156 /* Internal problem, message in buffer. */
1160 set_errno(addrlist, 0, string_copy(buffer), DEFER);
1164 break; /* If not authenticated, try next authenticator */
1165 } /* Loop for scanning supported server mechanisms */
1166 } /* Loop for further authenticators */
1170 /* If we haven't authenticated, but are required to, give up. */
1172 if (require_auth == OK && !smtp_authenticated)
1175 set_errno(addrlist, ERRNO_AUTHFAIL,
1176 string_sprintf("authentication required but %s", fail_reason), DEFER);
1181 /* The setting up of the SMTP call is now complete. Any subsequent errors are
1182 message-specific. */
1186 /* If there is a filter command specified for this transport, we can now
1187 set it up. This cannot be done until the identify of the host is known. */
1189 if (tblock->filter_command != NULL)
1193 sprintf(CS buffer, "%.50s transport", tblock->name);
1194 rc = transport_set_up_command(&transport_filter_argv, tblock->filter_command,
1195 TRUE, DEFER, addrlist, buffer, NULL);
1197 /* On failure, copy the error to all addresses, abandon the SMTP call, and
1202 set_errno(addrlist->next, addrlist->basic_errno, addrlist->message, DEFER);
1209 /* For messages that have more than the maximum number of envelope recipients,
1210 we want to send several transactions down the same SMTP connection. (See
1211 comments in deliver.c as to how this reconciles, heuristically, with
1212 remote_max_parallel.) This optimization was added to Exim after the following
1213 code was already working. The simplest way to put it in without disturbing the
1214 code was to use a goto to jump back to this point when there is another
1215 transaction to handle. */
1218 sync_addr = first_addr;
1222 completed_address = FALSE;
1225 /* Initiate a message transfer. If we know the receiving MTA supports the SIZE
1226 qualification, send it, adding something to the message size to allow for
1227 imprecision and things that get added en route. Exim keeps the number of lines
1228 in a message, so we can give an accurate value for the original message, but we
1229 need some additional to handle added headers. (Double "." characters don't get
1230 included in the count.) */
1237 sprintf(CS p, " SIZE=%d", message_size+message_linecount+ob->size_addition);
1241 /* Add the authenticated sender address if present */
1243 if (smtp_authenticated && local_authenticated_sender != NULL)
1245 string_format(p, sizeof(buffer) - (p-buffer), " AUTH=%s",
1246 auth_xtextencode(local_authenticated_sender,
1247 Ustrlen(local_authenticated_sender)));
1250 /* From here until we send the DATA command, we can make use of PIPELINING
1251 if the server host supports it. The code has to be able to check the responses
1252 at any point, for when the buffer fills up, so we write it totally generally.
1253 When PIPELINING is off, each command written reports that it has flushed the
1256 pending_MAIL = TRUE; /* The block starts with MAIL */
1258 rc = smtp_write_command(&outblock, smtp_use_pipelining,
1259 "MAIL FROM:<%s>%s\r\n", return_path, buffer);
1260 mail_command = string_copy(big_buffer); /* Save for later error message */
1264 case -1: /* Transmission error */
1267 case +1: /* Block was sent */
1268 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1269 ob->command_timeout)) goto RESPONSE_FAILED;
1270 pending_MAIL = FALSE;
1274 /* Pass over all the relevant recipient addresses for this host, which are the
1275 ones that have status PENDING_DEFER. If we are using PIPELINING, we can send
1276 several before we have to read the responses for those seen so far. This
1277 checking is done by a subroutine because it also needs to be done at the end.
1278 Send only up to max_rcpt addresses at a time, leaving first_addr pointing to
1279 the next one if not all are sent.
1281 In the MUA wrapper situation, we want to flush the PIPELINING buffer for the
1282 last address because we want to abort if any recipients have any kind of
1283 problem, temporary or permanent. We know that all recipient addresses will have
1284 the PENDING_DEFER status, because only one attempt is ever made, and we know
1285 that max_rcpt will be large, so all addresses will be done at once. */
1287 for (addr = first_addr;
1288 address_count < max_rcpt && addr != NULL;
1294 if (addr->transport_return != PENDING_DEFER) continue;
1297 no_flush = smtp_use_pipelining && (!mua_wrapper || addr->next != NULL);
1299 /* Now send the RCPT command, and process outstanding responses when
1300 necessary. After a timeout on RCPT, we just end the function, leaving the
1301 yield as OK, because this error can often mean that there is a problem with
1302 just one address, so we don't want to delay the host. */
1304 count = smtp_write_command(&outblock, no_flush, "RCPT TO:<%s>\r\n",
1305 transport_rcpt_address(addr, tblock->rcpt_include_affixes));
1306 if (count < 0) goto SEND_FAILED;
1309 switch(sync_responses(first_addr, tblock->rcpt_include_affixes,
1310 &sync_addr, host, count, pending_MAIL, 0, &inblock,
1311 ob->command_timeout, buffer, sizeof(buffer)))
1313 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1314 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1317 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1318 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1319 case 0: /* No 2xx or 5xx, but no probs */
1322 case -1: goto END_OFF; /* Timeout on RCPT */
1323 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL error */
1325 pending_MAIL = FALSE; /* Dealt with MAIL */
1327 } /* Loop for next address */
1329 /* If we are an MUA wrapper, abort if any RCPTs were rejected, either
1330 permanently or temporarily. We should have flushed and synced after the last
1335 address_item *badaddr;
1336 for (badaddr = first_addr; badaddr != NULL; badaddr = badaddr->next)
1338 if (badaddr->transport_return != PENDING_OK) break;
1340 if (badaddr != NULL)
1342 set_errno(addrlist, 0, badaddr->message, FAIL);
1347 /* If ok is TRUE, we know we have got at least one good recipient, and must now
1348 send DATA, but if it is FALSE (in the normal, non-wrapper case), we may still
1349 have a good recipient buffered up if we are pipelining. We don't want to waste
1350 time sending DATA needlessly, so we only send it if either ok is TRUE or if we
1351 are pipelining. The responses are all handled by sync_responses(). */
1353 if (ok || (smtp_use_pipelining && !mua_wrapper))
1355 int count = smtp_write_command(&outblock, FALSE, "DATA\r\n");
1356 if (count < 0) goto SEND_FAILED;
1357 switch(sync_responses(first_addr, tblock->rcpt_include_affixes, &sync_addr,
1358 host, count, pending_MAIL, ok? +1 : -1, &inblock,
1359 ob->command_timeout, buffer, sizeof(buffer)))
1361 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1362 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1365 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1366 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1367 case 0: break; /* No 2xx or 5xx, but no probs */
1369 case -1: goto END_OFF; /* Timeout on RCPT */
1370 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */
1374 /* Save the first address of the next batch. */
1378 /* If there were no good recipients (but otherwise there have been no
1379 problems), just set ok TRUE, since we have handled address-specific errors
1380 already. Otherwise, it's OK to send the message. Use the check/escape mechanism
1381 for handling the SMTP dot-handling protocol, flagging to apply to headers as
1382 well as body. Set the appropriate timeout value to be used for each chunk.
1383 (Haven't been able to make it work using select() for writing yet.) */
1385 if (!ok) ok = TRUE; else
1387 sigalrm_seen = FALSE;
1388 transport_write_timeout = ob->data_timeout;
1389 smtp_command = US"sending data block"; /* For error messages */
1390 DEBUG(D_transport|D_v)
1391 debug_printf(" SMTP>> writing message and terminating \".\"\n");
1392 transport_count = 0;
1393 ok = transport_write_message(addrlist, inblock.sock,
1394 topt_use_crlf | topt_end_dot | topt_escape_headers |
1395 (tblock->body_only? topt_no_headers : 0) |
1396 (tblock->headers_only? topt_no_body : 0) |
1397 (tblock->return_path_add? topt_add_return_path : 0) |
1398 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1399 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1400 0, /* No size limit */
1401 tblock->add_headers, tblock->remove_headers,
1402 US".", US"..", /* Escaping strings */
1403 tblock->rewrite_rules, tblock->rewrite_existflags);
1405 /* transport_write_message() uses write() because it is called from other
1406 places to write to non-sockets. This means that under some OS (e.g. Solaris)
1407 it can exit with "Broken pipe" as its error. This really means that the
1408 socket got closed at the far end. */
1410 transport_write_timeout = 0; /* for subsequent transports */
1412 /* Failure can either be some kind of I/O disaster (including timeout),
1413 or the failure of a transport filter or the expansion of added headers. */
1417 buffer[0] = 0; /* There hasn't been a response */
1418 goto RESPONSE_FAILED;
1421 /* We used to send the terminating "." explicitly here, but because of
1422 buffering effects at both ends of TCP/IP connections, you don't gain
1423 anything by keeping it separate, so it might as well go in the final
1424 data buffer for efficiency. This is now done by setting the topt_end_dot
1427 smtp_command = US"end of data";
1429 /* For SMTP, we now read a single response that applies to the whole message.
1430 If it is OK, then all the addresses have been delivered. */
1432 if (!lmtp) ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1435 /* For LMTP, we get back a response for every RCPT command that we sent;
1436 some may be accepted and some rejected. For those that get a response, their
1437 status is fixed; any that are accepted have been handed over, even if later
1438 responses crash - at least, that's how I read RFC 2033.
1440 If all went well, mark the recipient addresses as completed, record which
1441 host/IPaddress they were delivered to, and cut out RSET when sending another
1442 message down the same channel. Write the completed addresses to the journal
1443 now so that they are recorded in case there is a crash of hardware or
1444 software before the spool gets updated. Also record the final SMTP
1445 confirmation if needed (for SMTP only). */
1450 int delivery_time = (int)(time(NULL) - start_delivery_time);
1453 uschar *conf = NULL;
1456 /* Make a copy of the host if it is local to this invocation
1457 of the transport. */
1461 thost = store_get(sizeof(host_item));
1463 thost->name = string_copy(host->name);
1464 thost->address = string_copy(host->address);
1468 /* Set up confirmation if needed - applies only to SMTP */
1470 if ((log_extra_selector & LX_smtp_confirmation) != 0 && !lmtp)
1472 uschar *s = string_printing(buffer);
1473 conf = (s == buffer)? (uschar *)string_copy(s) : s;
1476 /* Process all transported addresses - for LMTP, read a status for
1479 for (addr = addrlist; addr != first_addr; addr = addr->next)
1481 if (addr->transport_return != PENDING_OK) continue;
1483 /* LMTP - if the response fails badly (e.g. timeout), use it for all the
1484 remaining addresses. Otherwise, it's a return code for just the one
1489 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1492 if (errno != 0 || buffer[0] == 0) goto RESPONSE_FAILED;
1493 addr->message = string_sprintf("LMTP error after %s: %s",
1494 big_buffer, string_printing(buffer));
1495 addr->transport_return = (buffer[0] == '5')? FAIL : DEFER;
1498 completed_address = TRUE; /* NOW we can set this flag */
1501 /* SMTP, or success return from LMTP for this address. Pass back the
1502 actual port used. */
1504 addr->transport_return = OK;
1505 addr->more_errno = delivery_time;
1507 addr->host_used = thost;
1508 addr->special_action = flag;
1509 addr->message = conf;
1512 /* Update the journal. For homonymic addresses, use the base address plus
1513 the transport name. See lots of comments in deliver.c about the reasons
1514 for the complications when homonyms are involved. Just carry on after
1515 write error, as it may prove possible to update the spool file later. */
1517 if (testflag(addr, af_homonym))
1518 sprintf(CS buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
1520 sprintf(CS buffer, "%.500s\n", addr->unique);
1522 DEBUG(D_deliver) debug_printf("journalling %s", buffer);
1523 len = Ustrlen(CS buffer);
1524 if (write(journal_fd, buffer, len) != len)
1525 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
1526 "%s: %s", buffer, strerror(errno));
1529 /* Ensure the journal file is pushed out to disk. */
1531 if (fsync(journal_fd) < 0)
1532 log_write(0, LOG_MAIN|LOG_PANIC, "failed to fsync journal: %s",
1538 /* Handle general (not specific to one address) failures here. The value of ok
1539 is used to skip over this code on the falling through case. A timeout causes a
1540 deferral. Other errors may defer or fail according to the response code, and
1541 may set up a special errno value, e.g. after connection chopped, which is
1542 assumed if errno == 0 and there is no text in the buffer. If control reaches
1543 here during the setting up phase (i.e. before MAIL FROM) then always defer, as
1544 the problem is not related to this specific message. */
1553 send_quit = check_response(host, &save_errno, addrlist->more_errno,
1554 buffer, &code, &message);
1560 message = US string_sprintf("send() to %s [%s] failed: %s",
1561 host->name, host->address, strerror(save_errno));
1565 /* This label is jumped to directly when a TLS negotiation has failed,
1566 or was not done for a host for which it is required. Values will be set
1567 in message and save_errno, and setting_up will always be true. Treat as
1568 a temporary error. */
1575 /* If the failure happened while setting up the call, see if the failure was
1576 a 5xx response (this will either be on connection, or following HELO - a 5xx
1577 after EHLO causes it to try HELO). If so, fail all addresses, as this host is
1578 never going to accept them. For other errors during setting up (timeouts or
1579 whatever), defer all addresses, and yield DEFER, so that the host is not
1580 tried again for a while. */
1583 ok = FALSE; /* For when reached by GOTO */
1589 set_errno(addrlist, save_errno, message, FAIL);
1593 set_errno(addrlist, save_errno, message, DEFER);
1598 /* If there was an I/O error or timeout or other transportation error,
1599 indicated by errno being non-zero, defer all addresses and yield DEFER,
1600 except for the case of failed add_headers expansion, or a transport filter
1601 failure, when the yield should be ERROR, to stop it trying other hosts.
1603 However, handle timeouts after MAIL FROM or "." and loss of connection after
1604 "." specially. They can indicate a problem with the sender address or with
1605 the contents of the message rather than a real error on the connection.
1606 Therefore, treat these cases in the same way as a 4xx response.
1608 The following condition tests for NOT these special cases. */
1610 else if (save_errno != 0 &&
1611 (save_errno != ETIMEDOUT ||
1612 (Ustrncmp(smtp_command,"MAIL",4) != 0 &&
1613 Ustrncmp(smtp_command,"end ",4) != 0)) &&
1614 (save_errno != ERRNO_SMTPCLOSED ||
1615 Ustrncmp(smtp_command,"end ",4) != 0))
1617 yield = (save_errno == ERRNO_CHHEADER_FAIL ||
1618 save_errno == ERRNO_FILTER_FAIL)? ERROR : DEFER;
1619 set_errno(addrlist, save_errno, message, DEFER);
1622 /* Otherwise we have a message-specific error response from the remote
1623 host. This is one of
1624 (a) negative response or timeout after "mail from"
1625 (b) negative response after "data"
1626 (c) negative response or timeout or dropped connection after "."
1627 It won't be a negative response or timeout after "rcpt to", as that is dealt
1628 with separately above. The action in all cases is to set an appropriate
1629 error code for all the addresses, but to leave yield set to OK because
1630 the host itself has not failed. [It might in practice have failed for a
1631 timeout after MAIL FROM, or "." but if so, we'll discover that at the next
1632 delivery attempt.] For a temporary error, set the message_defer flag, and
1633 write to the logs for information if this is not the last host. The error for
1634 the last host will be logged as part of the address's log line. */
1638 if (mua_wrapper) code = '5'; /* Force hard failure in wrapper mode */
1640 set_errno(addrlist, save_errno, message, (code == '5')? FAIL : DEFER);
1642 /* If there's an errno, the message contains just the identity of
1645 if (code != '5') /* Anything other than 5 is treated as temporary */
1648 message = US string_sprintf("%s: %s", message, strerror(save_errno));
1649 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", message);
1650 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
1651 *message_defer = TRUE;
1657 /* If all has gone well, send_quit will be set TRUE, implying we can end the
1658 SMTP session tidily. However, if there were too many addresses to send in one
1659 message (indicated by first_addr being non-NULL) we want to carry on with the
1660 rest of them. Also, it is desirable to send more than one message down the SMTP
1661 connection if there are several waiting, provided we haven't already sent so
1662 many as to hit the configured limit. The function transport_check_waiting looks
1663 for a waiting message and returns its id. Then transport_pass_socket tries to
1664 set up a continued delivery by passing the socket on to another process. The
1665 variable send_rset is FALSE if a message has just been successfully transfered.
1667 If we are already sending down a continued channel, there may be further
1668 addresses not yet delivered that are aimed at the same host, but which have not
1669 been passed in this run of the transport. In this case, continue_more will be
1670 true, and all we should do is send RSET if necessary, and return, leaving the
1673 However, if no address was disposed of, i.e. all addresses got 4xx errors, we
1674 do not want to continue with other messages down the same channel, because that
1675 can lead to looping between two or more messages, all with the same,
1676 temporarily failing address(es). [The retry information isn't updated yet, so
1677 new processes keep on trying.] We probably also don't want to try more of this
1678 message's addresses either.
1680 If we have started a TLS session, we have to end it before passing the
1681 connection to a new process. However, not all servers can handle this (Exim
1682 can), so we do not pass such a connection on if the host matches
1683 hosts_nopass_tls. */
1686 debug_printf("ok=%d send_quit=%d send_rset=%d continue_more=%d "
1687 "yield=%d first_address is %sNULL\n", ok, send_quit, send_rset,
1688 continue_more, yield, (first_addr == NULL)? "":"not ");
1690 if (completed_address && ok && send_quit)
1693 if (first_addr != NULL || continue_more ||
1696 verify_check_this_host(&(ob->hosts_nopass_tls), NULL, host->name,
1697 host->address, NULL) != OK)
1699 transport_check_waiting(tblock->name, host->name,
1700 tblock->connection_max_messages, new_message_id, &more)
1707 if (! (ok = smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0))
1709 msg = US string_sprintf("send() to %s [%s] failed: %s", host->name,
1710 host->address, strerror(save_errno));
1713 else if (! (ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1714 ob->command_timeout)))
1717 send_quit = check_response(host, &errno, 0, buffer, &code, &msg);
1720 DEBUG(D_transport) debug_printf("%s\n", msg);
1725 /* Either RSET was not needed, or it succeeded */
1729 if (first_addr != NULL) /* More addresses still to be sent */
1730 { /* in this run of the transport */
1731 continue_sequence++; /* Causes * in logging */
1734 if (continue_more) return yield; /* More addresses for another run */
1736 /* Pass the socket to a new Exim process. Before doing so, we must shut
1737 down TLS. Not all MTAs allow for the continuation of the SMTP session
1738 when TLS is shut down. We test for this by sending a new EHLO. If we
1739 don't get a good response, we don't attempt to pass the socket on. */
1742 if (tls_active >= 0)
1745 ok = smtp_write_command(&outblock,FALSE,"EHLO %s\r\n",helo_data) >= 0 &&
1746 smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1747 ob->command_timeout);
1751 /* If the socket is successfully passed, we musn't send QUIT (or
1752 indeed anything!) from here. */
1754 if (ok && transport_pass_socket(tblock->name, host->name, host->address,
1755 new_message_id, inblock.sock))
1761 /* If RSET failed and there are addresses left, they get deferred. */
1763 else set_errno(first_addr, errno, msg, DEFER);
1767 /* End off tidily with QUIT unless the connection has died or the socket has
1768 been passed to another process. There has been discussion on the net about what
1769 to do after sending QUIT. The wording of the RFC suggests that it is necessary
1770 to wait for a response, but on the other hand, there isn't anything one can do
1771 with an error response, other than log it. Exim used to do that. However,
1772 further discussion suggested that it is positively advantageous not to wait for
1773 the response, but to close the session immediately. This is supposed to move
1774 the TCP/IP TIME_WAIT state from the server to the client, thereby removing some
1775 load from the server. (Hosts that are both servers and clients may not see much
1776 difference, of course.) Further discussion indicated that this was safe to do
1777 on Unix systems which have decent implementations of TCP/IP that leave the
1778 connection around for a while (TIME_WAIT) after the application has gone away.
1779 This enables the response sent by the server to be properly ACKed rather than
1780 timed out, as can happen on broken TCP/IP implementations on other OS.
1782 This change is being made on 31-Jul-98. After over a year of trouble-free
1783 operation, the old commented-out code was removed on 17-Sep-99. */
1786 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1794 /* Close the socket, and return the appropriate value, first setting
1795 continue_transport and continue_hostname NULL to prevent any other addresses
1796 that may include the host from trying to re-use a continuation socket. This
1797 works because the NULL setting is passed back to the calling process, and
1798 remote_max_parallel is forced to 1 when delivering over an existing connection,
1800 If all went well and continue_more is set, we shouldn't actually get here if
1801 there are further addresses, as the return above will be taken. However,
1802 writing RSET might have failed, or there may be other addresses whose hosts are
1803 specified in the transports, and therefore not visible at top level, in which
1804 case continue_more won't get set. */
1806 close(inblock.sock);
1807 continue_transport = NULL;
1808 continue_hostname = NULL;
1815 /*************************************************
1816 * Closedown entry point *
1817 *************************************************/
1819 /* This function is called when exim is passed an open smtp channel
1820 from another incarnation, but the message which it has been asked
1821 to deliver no longer exists. The channel is on stdin.
1823 We might do fancy things like looking for another message to send down
1824 the channel, but if the one we sought has gone, it has probably been
1825 delivered by some other process that itself will seek further messages,
1826 so just close down our connection.
1828 Argument: pointer to the transport instance block
1833 smtp_transport_closedown(transport_instance *tblock)
1835 smtp_transport_options_block *ob =
1836 (smtp_transport_options_block *)(tblock->options_block);
1837 smtp_inblock inblock;
1838 smtp_outblock outblock;
1840 uschar inbuffer[4096];
1841 uschar outbuffer[16];
1843 inblock.sock = fileno(stdin);
1844 inblock.buffer = inbuffer;
1845 inblock.buffersize = sizeof(inbuffer);
1846 inblock.ptr = inbuffer;
1847 inblock.ptrend = inbuffer;
1849 outblock.sock = inblock.sock;
1850 outblock.buffersize = sizeof(outbuffer);
1851 outblock.buffer = outbuffer;
1852 outblock.ptr = outbuffer;
1853 outblock.cmd_count = 0;
1854 outblock.authenticating = FALSE;
1856 (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1857 (void)smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1858 ob->command_timeout);
1859 close(inblock.sock);
1864 /*************************************************
1865 * Prepare addresses for delivery *
1866 *************************************************/
1868 /* This function is called to flush out error settings from previous delivery
1869 attempts to other hosts. It also records whether we got here via an MX record
1870 or not in the more_errno field of the address. We are interested only in
1871 addresses that are still marked DEFER - others may have got delivered to a
1872 previously considered IP address. Set their status to PENDING_DEFER to indicate
1873 which ones are relevant this time.
1876 addrlist the list of addresses
1877 host the host we are delivering to
1879 Returns: the first address for this delivery
1882 static address_item *
1883 prepare_addresses(address_item *addrlist, host_item *host)
1885 address_item *first_addr = NULL;
1887 for (addr = addrlist; addr != NULL; addr = addr->next)
1889 if (addr->transport_return != DEFER) continue;
1890 if (first_addr == NULL) first_addr = addr;
1891 addr->transport_return = PENDING_DEFER;
1892 addr->basic_errno = 0;
1893 addr->more_errno = (host->mx >= 0)? 'M' : 'A';
1894 addr->message = NULL;
1896 addr->cipher = NULL;
1897 addr->peerdn = NULL;
1905 /*************************************************
1906 * Main entry point *
1907 *************************************************/
1909 /* See local README for interface details. As this is a remote transport, it is
1910 given a chain of addresses to be delivered in one connection, if possible. It
1911 always returns TRUE, indicating that each address has its own independent
1912 status set, except if there is a setting up problem, in which case it returns
1916 smtp_transport_entry(
1917 transport_instance *tblock, /* data for this instantiation */
1918 address_item *addrlist) /* addresses we are working on */
1922 int hosts_defer = 0;
1924 int hosts_looked_up = 0;
1925 int hosts_retry = 0;
1926 int hosts_serial = 0;
1927 int hosts_total = 0;
1929 BOOL expired = TRUE;
1930 BOOL continuing = continue_hostname != NULL;
1931 uschar *expanded_hosts = NULL;
1933 uschar *tid = string_sprintf("%s transport", tblock->name);
1934 smtp_transport_options_block *ob =
1935 (smtp_transport_options_block *)(tblock->options_block);
1936 host_item *hostlist = addrlist->host_list;
1937 host_item *host = NULL;
1941 debug_printf("%s transport entered\n", tblock->name);
1942 for (addr = addrlist; addr != NULL; addr = addr->next)
1943 debug_printf(" %s\n", addr->address);
1944 if (continuing) debug_printf("already connected to %s [%s]\n",
1945 continue_hostname, continue_host_address);
1948 /* If a host list is not defined for the addresses - they must all have the
1949 same one in order to be passed to a single transport - or if the transport has
1950 a host list with hosts_override set, use the host list supplied with the
1951 transport. It is an error for this not to exist. */
1953 if (hostlist == NULL || (ob->hosts_override && ob->hosts != NULL))
1955 if (ob->hosts == NULL)
1957 addrlist->message = string_sprintf("%s transport called with no hosts set",
1959 addrlist->transport_return = PANIC;
1960 return FALSE; /* Only top address has status */
1963 DEBUG(D_transport) debug_printf("using the transport's hosts: %s\n",
1966 /* If the transport's host list contains no '$' characters, and we are not
1967 randomizing, it is fixed and therefore a chain of hosts can be built once
1968 and for all, and remembered for subsequent use by other calls to this
1969 transport. If, on the other hand, the host list does contain '$', or we are
1970 randomizing its order, we have to rebuild it each time. In the fixed case,
1971 as the hosts string will never be used again, it doesn't matter that we
1972 replace all the : characters with zeros. */
1974 if (ob->hostlist == NULL)
1976 uschar *s = ob->hosts;
1978 if (Ustrchr(s, '$') != NULL)
1980 expanded_hosts = expand_string(s);
1981 if (expanded_hosts == NULL)
1983 addrlist->message = string_sprintf("failed to expand list of hosts "
1984 "\"%s\" in %s transport: %s", s, tblock->name, expand_string_message);
1985 addrlist->transport_return = search_find_defer? DEFER : PANIC;
1986 return FALSE; /* Only top address has status */
1988 DEBUG(D_transport) debug_printf("expanded list of hosts \"%s\" to "
1989 "\"%s\"\n", s, expanded_hosts);
1993 if (ob->hosts_randomize) s = expanded_hosts = string_copy(s);
1995 host_build_hostlist(&hostlist, s, ob->hosts_randomize);
1997 /* If there was no expansion of hosts, save the host list for
2000 if (expanded_hosts == NULL) ob->hostlist = hostlist;
2003 /* This is not the first time this transport has been run in this delivery;
2004 the host list was built previously. */
2006 else hostlist = ob->hostlist;
2009 /* The host list was supplied with the address. If hosts_randomize is set, we
2010 must sort it into a random order if it did not come from MX records and has not
2011 already been randomized (but don't bother if continuing down an existing
2014 else if (ob->hosts_randomize && hostlist->mx == MX_NONE && !continuing)
2016 host_item *newlist = NULL;
2017 while (hostlist != NULL)
2019 host_item *h = hostlist;
2020 hostlist = hostlist->next;
2022 h->sort_key = random_number(100);
2024 if (newlist == NULL)
2029 else if (h->sort_key < newlist->sort_key)
2036 host_item *hh = newlist;
2037 while (hh->next != NULL)
2039 if (h->sort_key < hh->next->sort_key) break;
2047 hostlist = addrlist->host_list = newlist;
2051 /* Sort out the port. Set up a string for adding to the retry key if the port
2052 number is not the standard SMTP port. */
2054 if (!smtp_get_port(ob->port, addrlist, &port, tid)) return FALSE;
2055 pistring = string_sprintf(":%d", port);
2056 if (Ustrcmp(pistring, ":25") == 0) pistring = US"";
2059 /* For each host-plus-IP-address on the list:
2061 . If this is a continued delivery and the host isn't the one with the
2062 current connection, skip.
2064 . If the status is unusable (i.e. previously failed or retry checked), skip.
2066 . If no IP address set, get the address, either by turning the name into
2067 an address, calling gethostbyname if gethostbyname is on, or by calling
2068 the DNS. The DNS may yield multiple addresses, in which case insert the
2069 extra ones into the list.
2071 . Get the retry data if not previously obtained for this address and set the
2072 field which remembers the state of this address. Skip if the retry time is
2073 not reached. If not, remember whether retry data was found. The retry string
2074 contains both the name and the IP address.
2076 . Scan the list of addresses and mark those whose status is DEFER as
2077 PENDING_DEFER. These are the only ones that will be processed in this cycle
2080 . Make a delivery attempt - addresses marked PENDING_DEFER will be tried.
2081 Some addresses may be successfully delivered, others may fail, and yet
2082 others may get temporary errors and so get marked DEFER.
2084 . The return from the delivery attempt is OK if a connection was made and a
2085 valid SMTP dialogue was completed. Otherwise it is DEFER.
2087 . If OK, add a "remove" retry item for this host/IPaddress, if any.
2089 . If fail to connect, or other defer state, add a retry item.
2091 . If there are any addresses whose status is still DEFER, carry on to the
2092 next host/IPaddress, unless we have tried the number of hosts given
2093 by hosts_max_try; otherwise return.
2095 If we get to the end of the list, all hosts have deferred at least one address,
2096 or not reached their retry times. If delay_after_cutoff is unset, it requests a
2097 delivery attempt to those hosts whose last try was before the arrival time of
2098 the current message. To cope with this, we have to go round the loop a second
2099 time. After that, set the status and error data for any addresses that haven't
2100 had it set already. */
2102 for (cutoff_retry = 0; expired &&
2103 cutoff_retry < ((ob->delay_after_cutoff)? 1 : 2);
2106 host_item *nexthost = NULL;
2107 int unexpired_hosts_tried = 0;
2109 for (host = hostlist;
2110 host != NULL && unexpired_hosts_tried < ob->hosts_max_try;
2116 BOOL serialized = FALSE;
2117 BOOL host_is_expired = FALSE;
2118 BOOL message_defer = FALSE;
2119 BOOL ifchanges = FALSE;
2120 BOOL some_deferred = FALSE;
2121 address_item *first_addr = NULL;
2122 uschar *interface = NULL;
2123 uschar *retry_host_key = NULL;
2124 uschar *retry_message_key = NULL;
2125 uschar *serialize_key = NULL;
2127 /* Default next host is next host. :-) But this can vary if the
2128 hosts_max_try limit is hit (see below). */
2130 nexthost = host->next;
2132 /* Set the flag requesting that this host be added to the waiting
2133 database if the delivery fails temporarily or if we are running with
2134 queue_smtp or a 2-stage queue run. This gets unset for certain
2135 kinds of error, typically those that are specific to the message. */
2137 host->update_waiting = TRUE;
2139 /* If the address hasn't yet been obtained from the host name, look it up
2140 now, unless the host is already marked as unusable. If it is marked as
2141 unusable, it means that the router was unable to find its IP address (in
2142 the DNS or wherever) OR we are in the 2nd time round the cutoff loop, and
2143 the lookup failed last time. We don't get this far if *all* MX records
2144 point to non-existent hosts; that is treated as a hard error.
2146 We can just skip this host entirely. When the hosts came from the router,
2147 the address will timeout based on the other host(s); when the address is
2148 looked up below, there is an explicit retry record added.
2150 Note that we mustn't skip unusable hosts if the address is not unset; they
2151 may be needed as expired hosts on the 2nd time round the cutoff loop. */
2153 if (host->address == NULL)
2155 uschar *canonical_name;
2157 if (host->status >= hstatus_unusable)
2159 DEBUG(D_transport) debug_printf("%s has no address and is unusable - skipping\n",
2164 DEBUG(D_transport) debug_printf("getting address for %s\n", host->name);
2168 /* Find by name if so configured, or if it's an IP address. We don't
2169 just copy the IP address, because we need the test-for-local to happen. */
2171 if (ob->gethostbyname || string_is_ip_address(host->name, NULL))
2172 rc = host_find_byname(host, NULL, &canonical_name, TRUE);
2175 int flags = HOST_FIND_BY_A;
2176 if (ob->dns_qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
2177 if (ob->dns_search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
2178 rc = host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
2179 &canonical_name, NULL);
2182 /* Failure to find the host at this time (usually DNS temporary failure)
2183 is really a kind of routing failure rather than a transport failure.
2184 Therefore we add a retry item of the routing kind, not to stop us trying
2185 to look this name up here again, but to ensure the address gets timed
2186 out if the failures go on long enough. A complete failure at this point
2187 commonly points to a configuration error, but the best action is still
2188 to carry on for the next host. */
2190 if (rc == HOST_FIND_AGAIN || rc == HOST_FIND_FAILED)
2192 retry_add_item(addrlist, string_sprintf("R:%s", host->name), 0);
2194 if (rc == HOST_FIND_AGAIN) hosts_defer++; else hosts_fail++;
2195 DEBUG(D_transport) debug_printf("rc = %s for %s\n", (rc == HOST_FIND_AGAIN)?
2196 "HOST_FIND_AGAIN" : "HOST_FIND_FAILED", host->name);
2197 host->status = hstatus_unusable;
2199 for (addr = addrlist; addr != NULL; addr = addr->next)
2201 if (addr->transport_return != DEFER) continue;
2202 addr->basic_errno = ERRNO_UNKNOWNHOST;
2204 string_sprintf("failed to lookup IP address for %s", host->name);
2209 /* If the host is actually the local host, we may have a problem, or
2210 there may be some cunning configuration going on. In the problem case,
2211 log things and give up. The default transport status is already DEFER. */
2213 if (rc == HOST_FOUND_LOCAL && !ob->allow_localhost)
2215 for (addr = addrlist; addr != NULL; addr = addr->next)
2217 addr->basic_errno = 0;
2218 addr->message = string_sprintf("%s transport found host %s to be "
2219 "local", tblock->name, host->name);
2223 } /* End of block for IP address lookup */
2225 /* If this is a continued delivery, we are interested only in the host
2226 which matches the name of the existing open channel. The check is put
2227 here after the local host lookup, in case the name gets expanded as a
2228 result of the lookup. Set expired FALSE, to save the outer loop executing
2231 if (continuing && (Ustrcmp(continue_hostname, host->name) != 0 ||
2232 Ustrcmp(continue_host_address, host->address) != 0))
2235 continue; /* With next host */
2238 /* If queue_smtp is set (-odqs or the first part of a 2-stage run), or the
2239 domain is in queue_smtp_domains, we don't actually want to attempt any
2240 deliveries. When doing a queue run, queue_smtp_domains is always unset. If
2241 there is a lookup defer in queue_smtp_domains, proceed as if the domain
2242 were not in it. We don't want to hold up all SMTP deliveries! Except when
2243 doing a two-stage queue run, don't do this if forcing. */
2245 if ((!deliver_force || queue_2stage) && (queue_smtp ||
2246 match_isinlist(addrlist->domain, &queue_smtp_domains, 0, NULL, NULL,
2247 MCL_DOMAIN, TRUE, NULL) == OK))
2250 for (addr = addrlist; addr != NULL; addr = addr->next)
2252 if (addr->transport_return != DEFER) continue;
2253 addr->message = US"domain matches queue_smtp_domains, or -odqs set";
2255 continue; /* With next host */
2258 /* Count hosts being considered - purely for an intelligent comment
2259 if none are usable. */
2263 /* Set $host and $host address now in case they are needed for the
2264 interface expansion or the serialize_hosts check; they remain set if an
2265 actual delivery happens. */
2267 deliver_host = host->name;
2268 deliver_host_address = host->address;
2270 /* Select IPv4 or IPv6, and choose an outgoing interface. If the interface
2271 string changes upon expansion, we must add it to the key that is used for
2272 retries, because connections to the same host from a different interface
2273 should be treated separately. */
2275 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET : AF_INET6;
2276 if (!smtp_get_interface(ob->interface, host_af, addrlist, &ifchanges,
2279 if (ifchanges) pistring = string_sprintf("%s/%s", pistring, interface);
2281 /* The first time round the outer loop, check the status of the host by
2282 inspecting the retry data. The second time round, we are interested only
2283 in expired hosts that haven't been tried since this message arrived. */
2285 if (cutoff_retry == 0)
2287 /* Ensure the status of the address is set by checking retry data if
2288 necessary. There maybe host-specific retry data (applicable to all
2289 messages) and also data for retries of a specific message at this host.
2290 If either of these retry records are actually read, the keys used are
2291 returned to save recomputing them later. */
2293 host_is_expired = retry_check_address(addrlist->domain, host, pistring,
2294 ob->retry_include_ip_address, &retry_host_key, &retry_message_key);
2296 DEBUG(D_transport) debug_printf("%s [%s]%s status = %s\n", host->name,
2297 (host->address == NULL)? US"" : host->address, pistring,
2298 (host->status == hstatus_usable)? "usable" :
2299 (host->status == hstatus_unusable)? "unusable" :
2300 (host->status == hstatus_unusable_expired)? "unusable (expired)" : "?");
2302 /* Skip this address if not usable at this time, noting if it wasn't
2303 actually expired, both locally and in the address. */
2305 switch (host->status)
2307 case hstatus_unusable:
2309 setflag(addrlist, af_retry_skipped);
2312 case hstatus_unusable_expired:
2315 case hwhy_retry: hosts_retry++; break;
2316 case hwhy_failed: hosts_fail++; break;
2317 case hwhy_deferred: hosts_defer++; break;
2320 /* If there was a retry message key, implying that previously there
2321 was a message-specific defer, we don't want to update the list of
2322 messages waiting for this host. */
2324 if (retry_message_key != NULL) host->update_waiting = FALSE;
2325 continue; /* With the next host or IP address */
2329 /* Second time round the loop: if the address is set but expired, and
2330 the message is newer than the last try, let it through. */
2334 if (host->address == NULL ||
2335 host->status != hstatus_unusable_expired ||
2336 host->last_try > received_time)
2339 debug_printf("trying expired host %s [%s]%s\n",
2340 host->name, host->address, pistring);
2341 host_is_expired = TRUE;
2344 /* Setting "expired=FALSE" doesn't actually mean not all hosts are expired;
2345 it remains TRUE only if all hosts are expired and none are actually tried.
2350 /* If this host is listed as one to which access must be serialized,
2351 see if another Exim process has a connection to it, and if so, skip
2352 this host. If not, update the database to record our connection to it
2353 and remember this for later deletion. Do not do any of this if we are
2354 sending the message down a pre-existing connection. */
2357 verify_check_this_host(&(ob->serialize_hosts), NULL, host->name,
2358 host->address, NULL) == OK)
2360 serialize_key = string_sprintf("host-serialize-%s", host->name);
2361 if (!enq_start(serialize_key))
2364 debug_printf("skipping host %s because another Exim process "
2365 "is connected to it\n", host->name);
2372 /* OK, we have an IP address that is not waiting for its retry time to
2373 arrive (it might be expired) OR (second time round the loop) we have an
2374 expired host that hasn't been tried since the message arrived. Have a go
2375 at delivering the message to it. First prepare the addresses by flushing
2376 out the result of previous attempts, and finding the first address that
2377 is still to be delivered. */
2379 first_addr = prepare_addresses(addrlist, host);
2381 DEBUG(D_transport) debug_printf("delivering %s to %s [%s] (%s%s)\n",
2382 message_id, host->name, host->address, addrlist->address,
2383 (addrlist->next == NULL)? "" : ", ...");
2385 set_process_info("delivering %s to %s [%s] (%s%s)",
2386 message_id, host->name, host->address, addrlist->address,
2387 (addrlist->next == NULL)? "" : ", ...");
2389 /* This is not for real; don't do the delivery. If there are
2390 any remaining hosts, list them. */
2395 set_errno(addrlist, 0, NULL, OK);
2396 for (addr = addrlist; addr != NULL; addr = addr->next)
2398 addr->host_used = host;
2399 addr->special_action = '*';
2400 addr->message = US"delivery bypassed by -N option";
2404 debug_printf("*** delivery by %s transport bypassed by -N option\n"
2405 "*** host and remaining hosts:\n", tblock->name);
2406 for (host2 = host; host2 != NULL; host2 = host2->next)
2407 debug_printf(" %s [%s]\n", host2->name,
2408 (host2->address == NULL)? US"unset" : host2->address);
2413 /* This is for real. If the host is expired, we don't count it for
2414 hosts_max_retry. This ensures that all hosts must expire before an address
2415 is timed out. Otherwise, if we are about to hit the hosts_max_retry limit,
2416 check to see if there is a subsequent hosts with a different MX value. If
2417 so, make that the next host, and don't count this one. This is a heuristic
2418 to make sure that different MXs do get tried. With a normal kind of retry
2419 rule, they would get tried anyway when the earlier hosts were delayed, but
2420 if the domain has a "retry every time" type of rule - as is often used for
2421 the the very large ISPs, that won't happen. */
2425 if (!host_is_expired && ++unexpired_hosts_tried >= ob->hosts_max_try)
2429 debug_printf("hosts_max_try limit reached with this host\n");
2430 for (h = host; h != NULL; h = h->next)
2431 if (h->mx != host->mx) break;
2435 unexpired_hosts_tried--;
2436 DEBUG(D_transport) debug_printf("however, a higher MX host exists "
2437 "and will be tried\n");
2441 /* Attempt the delivery. */
2443 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2444 expanded_hosts != NULL, &message_defer, FALSE);
2447 OK => connection made, each address contains its result;
2448 message_defer is set for message-specific defers (when all
2449 recipients are marked defer)
2450 DEFER => there was a non-message-specific delivery problem;
2451 ERROR => there was a problem setting up the arguments for a filter,
2452 or there was a problem with expanding added headers
2455 /* If the result is not OK, there was a non-message-specific problem.
2456 If the result is DEFER, we need to write to the logs saying what happened
2457 for this particular host, except in the case of authentication and TLS
2458 failures, where the log has already been written. If all hosts defer a
2459 general message is written at the end. */
2461 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL &&
2462 first_addr->basic_errno != ERRNO_TLSFAILURE)
2463 write_logs(first_addr, host);
2465 /* If STARTTLS was accepted, but there was a failure in setting up the
2466 TLS session (usually a certificate screwup), and the host is not in
2467 hosts_require_tls, and tls_tempfail_tryclear is true, try again, with
2468 TLS forcibly turned off. We have to start from scratch with a new SMTP
2469 connection. That's why the retry is done from here, not from within
2470 smtp_deliver(). [Rejections of STARTTLS itself don't screw up the
2471 session, so the in-clear transmission after those errors, if permitted,
2472 happens inside smtp_deliver().] */
2475 if (rc == DEFER && first_addr->basic_errno == ERRNO_TLSFAILURE &&
2476 ob->tls_tempfail_tryclear &&
2477 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
2478 host->address, NULL) != OK)
2480 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
2481 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
2482 first_addr = prepare_addresses(addrlist, host);
2483 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2484 expanded_hosts != NULL, &message_defer, TRUE);
2485 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL)
2486 write_logs(first_addr, host);
2491 /* Delivery attempt finished */
2493 rs = (rc == OK)? US"OK" : (rc == DEFER)? US"DEFER" : (rc == ERROR)?
2496 set_process_info("delivering %s: just tried %s [%s] for %s%s: result %s",
2497 message_id, host->name, host->address, addrlist->address,
2498 (addrlist->next == NULL)? "" : " (& others)", rs);
2500 /* Release serialization if set up */
2502 if (serialized) enq_end(serialize_key);
2504 /* If the result is DEFER, or if a host retry record is known to exist, we
2505 need to add an item to the retry chain for updating the retry database
2506 at the end of delivery. We only need to add the item to the top address,
2507 of course. Also, if DEFER, we mark the IP address unusable so as to skip it
2508 for any other delivery attempts using the same address. (It is copied into
2509 the unusable tree at the outer level, so even if different address blocks
2510 contain the same address, it still won't get tried again.) */
2512 if (rc == DEFER || retry_host_key != NULL)
2514 int delete_flag = (rc != DEFER)? rf_delete : 0;
2515 if (retry_host_key == NULL)
2517 retry_host_key = ob->retry_include_ip_address?
2518 string_sprintf("T:%S:%s%s", host->name, host->address, pistring) :
2519 string_sprintf("T:%S%s", host->name, pistring);
2522 /* If a delivery of another message over an existing SMTP connection
2523 yields DEFER, we do NOT set up retry data for the host. This covers the
2524 case when there are delays in routing the addresses in the second message
2525 that are so long that the server times out. This is alleviated by not
2526 routing addresses that previously had routing defers when handling an
2527 existing connection, but even so, this case may occur (e.g. if a
2528 previously happily routed address starts giving routing defers). If the
2529 host is genuinely down, another non-continued message delivery will
2530 notice it soon enough. */
2532 if (delete_flag != 0 || !continuing)
2533 retry_add_item(first_addr, retry_host_key, rf_host | delete_flag);
2535 /* We may have tried an expired host, if its retry time has come; ensure
2536 the status reflects the expiry for the benefit of any other addresses. */
2540 host->status = (host_is_expired)?
2541 hstatus_unusable_expired : hstatus_unusable;
2542 host->why = hwhy_deferred;
2546 /* If message_defer is set (host was OK, but every recipient got deferred
2547 because of some message-specific problem), or if that had happened
2548 previously so that a message retry key exists, add an appropriate item
2549 to the retry chain. Note that if there was a message defer but now there is
2550 a host defer, the message defer record gets deleted. That seems perfectly
2551 reasonable. Also, stop the message from being remembered as waiting
2554 if (message_defer || retry_message_key != NULL)
2556 int delete_flag = message_defer? 0 : rf_delete;
2557 if (retry_message_key == NULL)
2559 retry_message_key = ob->retry_include_ip_address?
2560 string_sprintf("T:%S:%s%s:%s", host->name, host->address, pistring,
2562 string_sprintf("T:%S%s:%s", host->name, pistring, message_id);
2564 retry_add_item(addrlist, retry_message_key,
2565 rf_message | rf_host | delete_flag);
2566 host->update_waiting = FALSE;
2569 /* Any return other than DEFER (that is, OK or ERROR) means that the
2570 addresses have got their final statuses filled in for this host. In the OK
2571 case, see if any of them are deferred. */
2575 for (addr = addrlist; addr != NULL; addr = addr->next)
2577 if (addr->transport_return == DEFER)
2579 some_deferred = TRUE;
2585 /* If no addresses deferred or the result was ERROR, return. We do this for
2586 ERROR because a failing filter set-up or add_headers expansion is likely to
2587 fail for any host we try. */
2589 if (rc == ERROR || (rc == OK && !some_deferred))
2591 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2592 return TRUE; /* Each address has its status */
2595 /* If the result was DEFER or some individual addresses deferred, let
2596 the loop run to try other hosts with the deferred addresses, except for the
2597 case when we were trying to deliver down an existing channel and failed.
2598 Don't try any other hosts in this case. */
2600 if (continuing) break;
2602 /* If the whole delivery, or some individual addresses, were deferred and
2603 there are more hosts that could be tried, do not count this host towards
2604 the hosts_max_try limit if the age of the message is greater than the
2605 maximum retry time for this host. This means we may try try all hosts,
2606 ignoring the limit, when messages have been around for some time. This is
2607 important because if we don't try all hosts, the address will never time
2610 if ((rc == DEFER || some_deferred) && nexthost != NULL)
2613 retry_config *retry = retry_find_config(host->name, NULL, 0, 0);
2615 if (retry != NULL && retry->rules != NULL)
2617 retry_rule *last_rule;
2618 for (last_rule = retry->rules;
2619 last_rule->next != NULL;
2620 last_rule = last_rule->next);
2621 timedout = time(NULL) - received_time > last_rule->timeout;
2623 else timedout = TRUE; /* No rule => timed out */
2627 unexpired_hosts_tried--;
2628 DEBUG(D_transport) debug_printf("temporary delivery error(s) override "
2629 "hosts_max_try (message older than host's retry time)\n");
2632 } /* End of loop for trying multiple hosts. */
2634 /* This is the end of the loop that repeats iff expired is TRUE and
2635 ob->delay_after_cutoff is FALSE. The second time round we will
2636 try those hosts that haven't been tried since the message arrived. */
2640 debug_printf("all IP addresses skipped or deferred at least one address\n");
2641 if (expired && !ob->delay_after_cutoff && cutoff_retry == 0)
2642 debug_printf("retrying IP addresses not tried since message arrived\n");
2647 /* Get here if all IP addresses are skipped or defer at least one address. In
2648 MUA wrapper mode, this will happen only for connection or other non-message-
2649 specific failures. Force the delivery status for all addresses to FAIL. */
2653 for (addr = addrlist; addr != NULL; addr = addr->next)
2654 addr->transport_return = FAIL;
2658 /* In the normal, non-wrapper case, add a standard message to each deferred
2659 address if there hasn't been an error, that is, if it hasn't actually been
2660 tried this time. The variable "expired" will be FALSE if any deliveries were
2661 actually tried, or if there was at least one host that was not expired. That
2662 is, it is TRUE only if no deliveries were tried and all hosts were expired. If
2663 a delivery has been tried, an error code will be set, and the failing of the
2664 message is handled by the retry code later.
2666 If queue_smtp is set, or this transport was called to send a subsequent message
2667 down an existing TCP/IP connection, and something caused the host not to be
2668 found, we end up here, but can detect these cases and handle them specially. */
2670 for (addr = addrlist; addr != NULL; addr = addr->next)
2672 /* If host is not NULL, it means that we stopped processing the host list
2673 because of hosts_max_try. This means we need to behave as if some hosts were
2674 skipped because their retry time had not come. Specifically, this prevents
2675 the address from timing out. */
2680 debug_printf("hosts_max_try limit caused some hosts to be skipped\n");
2681 setflag(addr, af_retry_skipped);
2684 if (queue_smtp) /* no deliveries attempted */
2686 addr->transport_return = DEFER;
2687 addr->basic_errno = 0;
2688 addr->message = US"SMTP delivery explicitly queued";
2691 else if (addr->transport_return == DEFER &&
2692 (addr->basic_errno == ERRNO_UNKNOWNERROR || addr->basic_errno == 0) &&
2693 addr->message == NULL)
2695 addr->basic_errno = ERRNO_HRETRY;
2696 if (continue_hostname != NULL)
2698 addr->message = US"no host found for existing SMTP connection";
2702 addr->message = (ob->delay_after_cutoff)?
2703 US"retry time not reached for any host after a long failure period" :
2704 US"all hosts have been failing for a long time and were last tried "
2705 "after this message arrived";
2707 /* If we are already using fallback hosts, or there are no fallback hosts
2708 defined, convert the result to FAIL to cause a bounce. */
2710 if (addr->host_list == addr->fallback_hosts ||
2711 addr->fallback_hosts == NULL)
2712 addr->transport_return = FAIL;
2716 if (hosts_retry == hosts_total)
2717 addr->message = US"retry time not reached for any host";
2718 else if (hosts_fail == hosts_total)
2719 addr->message = US"all host address lookups failed permanently";
2720 else if (hosts_defer == hosts_total)
2721 addr->message = US"all host address lookups failed temporarily";
2722 else if (hosts_serial == hosts_total)
2723 addr->message = US"connection limit reached for all hosts";
2724 else if (hosts_fail+hosts_defer == hosts_total)
2725 addr->message = US"all host address lookups failed";
2726 else addr->message = US"some host address lookups failed and retry time "
2727 "not reached for other hosts or connection limit reached";
2732 /* Update the database which keeps information about which messages are waiting
2733 for which hosts to become available. Each host in the list has a flag which is
2734 set if the data is to be updated. For some message-specific errors, the flag is
2735 turned off because we don't want follow-on deliveries in those cases. */
2737 transport_update_waiting(hostlist, tblock->name);
2741 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2743 return TRUE; /* Each address has its status */
2746 /* End of transport/smtp.c */