1 /* $Cambridge: exim/src/src/transports/smtp.c,v 1.30 2007/01/08 10:50:20 ph10 Exp $ */
3 /*************************************************
4 * Exim - an Internet mail transport agent *
5 *************************************************/
7 /* Copyright (c) University of Cambridge 1995 - 2007 */
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 { "address_retry_include_sender", opt_bool,
25 (void *)offsetof(smtp_transport_options_block, address_retry_include_sender) },
26 { "allow_localhost", opt_bool,
27 (void *)offsetof(smtp_transport_options_block, allow_localhost) },
28 { "authenticated_sender", opt_stringptr,
29 (void *)offsetof(smtp_transport_options_block, authenticated_sender) },
30 { "authenticated_sender_force", opt_bool,
31 (void *)offsetof(smtp_transport_options_block, authenticated_sender_force) },
32 { "command_timeout", opt_time,
33 (void *)offsetof(smtp_transport_options_block, command_timeout) },
34 { "connect_timeout", opt_time,
35 (void *)offsetof(smtp_transport_options_block, connect_timeout) },
36 { "connection_max_messages", opt_int | opt_public,
37 (void *)offsetof(transport_instance, connection_max_messages) },
38 { "data_timeout", opt_time,
39 (void *)offsetof(smtp_transport_options_block, data_timeout) },
40 { "delay_after_cutoff", opt_bool,
41 (void *)offsetof(smtp_transport_options_block, delay_after_cutoff) },
42 #ifdef EXPERIMENTAL_DOMAINKEYS
43 { "dk_canon", opt_stringptr,
44 (void *)offsetof(smtp_transport_options_block, dk_canon) },
45 { "dk_domain", opt_stringptr,
46 (void *)offsetof(smtp_transport_options_block, dk_domain) },
47 { "dk_headers", opt_stringptr,
48 (void *)offsetof(smtp_transport_options_block, dk_headers) },
49 { "dk_private_key", opt_stringptr,
50 (void *)offsetof(smtp_transport_options_block, dk_private_key) },
51 { "dk_selector", opt_stringptr,
52 (void *)offsetof(smtp_transport_options_block, dk_selector) },
53 { "dk_strict", opt_stringptr,
54 (void *)offsetof(smtp_transport_options_block, dk_strict) },
56 { "dns_qualify_single", opt_bool,
57 (void *)offsetof(smtp_transport_options_block, dns_qualify_single) },
58 { "dns_search_parents", opt_bool,
59 (void *)offsetof(smtp_transport_options_block, dns_search_parents) },
60 { "fallback_hosts", opt_stringptr,
61 (void *)offsetof(smtp_transport_options_block, fallback_hosts) },
62 { "final_timeout", opt_time,
63 (void *)offsetof(smtp_transport_options_block, final_timeout) },
64 { "gethostbyname", opt_bool,
65 (void *)offsetof(smtp_transport_options_block, gethostbyname) },
66 { "helo_data", opt_stringptr,
67 (void *)offsetof(smtp_transport_options_block, helo_data) },
68 { "hosts", opt_stringptr,
69 (void *)offsetof(smtp_transport_options_block, hosts) },
70 { "hosts_avoid_esmtp", opt_stringptr,
71 (void *)offsetof(smtp_transport_options_block, hosts_avoid_esmtp) },
73 { "hosts_avoid_tls", opt_stringptr,
74 (void *)offsetof(smtp_transport_options_block, hosts_avoid_tls) },
76 { "hosts_max_try", opt_int,
77 (void *)offsetof(smtp_transport_options_block, hosts_max_try) },
78 { "hosts_max_try_hardlimit", opt_int,
79 (void *)offsetof(smtp_transport_options_block, hosts_max_try_hardlimit) },
81 { "hosts_nopass_tls", opt_stringptr,
82 (void *)offsetof(smtp_transport_options_block, hosts_nopass_tls) },
84 { "hosts_override", opt_bool,
85 (void *)offsetof(smtp_transport_options_block, hosts_override) },
86 { "hosts_randomize", opt_bool,
87 (void *)offsetof(smtp_transport_options_block, hosts_randomize) },
88 { "hosts_require_auth", opt_stringptr,
89 (void *)offsetof(smtp_transport_options_block, hosts_require_auth) },
91 { "hosts_require_tls", opt_stringptr,
92 (void *)offsetof(smtp_transport_options_block, hosts_require_tls) },
94 { "hosts_try_auth", opt_stringptr,
95 (void *)offsetof(smtp_transport_options_block, hosts_try_auth) },
96 { "interface", opt_stringptr,
97 (void *)offsetof(smtp_transport_options_block, interface) },
98 { "keepalive", opt_bool,
99 (void *)offsetof(smtp_transport_options_block, keepalive) },
100 { "lmtp_ignore_quota", opt_bool,
101 (void *)offsetof(smtp_transport_options_block, lmtp_ignore_quota) },
102 { "max_rcpt", opt_int | opt_public,
103 (void *)offsetof(transport_instance, max_addresses) },
104 { "multi_domain", opt_bool | opt_public,
105 (void *)offsetof(transport_instance, multi_domain) },
106 { "port", opt_stringptr,
107 (void *)offsetof(smtp_transport_options_block, port) },
108 { "protocol", opt_stringptr,
109 (void *)offsetof(smtp_transport_options_block, protocol) },
110 { "retry_include_ip_address", opt_bool,
111 (void *)offsetof(smtp_transport_options_block, retry_include_ip_address) },
112 { "serialize_hosts", opt_stringptr,
113 (void *)offsetof(smtp_transport_options_block, serialize_hosts) },
114 { "size_addition", opt_int,
115 (void *)offsetof(smtp_transport_options_block, size_addition) }
117 ,{ "tls_certificate", opt_stringptr,
118 (void *)offsetof(smtp_transport_options_block, tls_certificate) },
119 { "tls_crl", opt_stringptr,
120 (void *)offsetof(smtp_transport_options_block, tls_crl) },
121 { "tls_privatekey", opt_stringptr,
122 (void *)offsetof(smtp_transport_options_block, tls_privatekey) },
123 { "tls_require_ciphers", opt_stringptr,
124 (void *)offsetof(smtp_transport_options_block, tls_require_ciphers) },
125 { "tls_tempfail_tryclear", opt_bool,
126 (void *)offsetof(smtp_transport_options_block, tls_tempfail_tryclear) },
127 { "tls_verify_certificates", opt_stringptr,
128 (void *)offsetof(smtp_transport_options_block, tls_verify_certificates) }
132 /* Size of the options list. An extern variable has to be used so that its
133 address can appear in the tables drtables.c. */
135 int smtp_transport_options_count =
136 sizeof(smtp_transport_options)/sizeof(optionlist);
138 /* Default private options block for the smtp transport. */
140 smtp_transport_options_block smtp_transport_option_defaults = {
142 NULL, /* fallback_hosts */
144 NULL, /* fallback_hostlist */
145 NULL, /* authenticated_sender */
146 US"$primary_hostname", /* helo_data */
147 NULL, /* interface */
149 US"smtp", /* protocol */
150 NULL, /* serialize_hosts */
151 NULL, /* hosts_try_auth */
152 NULL, /* hosts_require_auth */
153 NULL, /* hosts_require_tls */
154 NULL, /* hosts_avoid_tls */
155 NULL, /* hosts_avoid_esmtp */
156 NULL, /* hosts_nopass_tls */
157 5*60, /* command_timeout */
158 5*60, /* connect_timeout; shorter system default overrides */
159 5*60, /* data timeout */
160 10*60, /* final timeout */
161 1024, /* size_addition */
162 5, /* hosts_max_try */
163 50, /* hosts_max_try_hardlimit */
164 TRUE, /* address_retry_include_sender */
165 FALSE, /* allow_localhost */
166 FALSE, /* authenticated_sender_force */
167 FALSE, /* gethostbyname */
168 TRUE, /* dns_qualify_single */
169 FALSE, /* dns_search_parents */
170 TRUE, /* delay_after_cutoff */
171 FALSE, /* hosts_override */
172 FALSE, /* hosts_randomize */
173 TRUE, /* keepalive */
174 FALSE, /* lmtp_ignore_quota */
175 TRUE /* retry_include_ip_address */
177 ,NULL, /* tls_certificate */
179 NULL, /* tls_privatekey */
180 NULL, /* tls_require_ciphers */
181 NULL, /* tls_verify_certificates */
182 TRUE /* tls_tempfail_tryclear */
184 #ifdef EXPERIMENTAL_DOMAINKEYS
185 ,NULL, /* dk_canon */
186 NULL, /* dk_domain */
187 NULL, /* dk_headers */
188 NULL, /* dk_private_key */
189 NULL, /* dk_selector */
197 static uschar *smtp_command; /* Points to last cmd for error messages */
198 static uschar *mail_command; /* Points to MAIL cmd for error messages */
199 static BOOL update_waiting; /* TRUE to update the "wait" database */
202 /*************************************************
203 * Setup entry point *
204 *************************************************/
206 /* This function is called when the transport is about to be used,
207 but before running it in a sub-process. It is used for two things:
209 (1) To set the fallback host list in addresses, when delivering.
210 (2) To pass back the interface, port, protocol, and other options, for use
211 during callout verification.
214 tblock pointer to the transport instance block
215 addrlist list of addresses about to be transported
216 tf if not NULL, pointer to block in which to return options
217 uid the uid that will be set (not used)
218 gid the gid that will be set (not used)
219 errmsg place for error message (not used)
221 Returns: OK always (FAIL, DEFER not used)
225 smtp_transport_setup(transport_instance *tblock, address_item *addrlist,
226 transport_feedback *tf, uid_t uid, gid_t gid, uschar **errmsg)
228 smtp_transport_options_block *ob =
229 (smtp_transport_options_block *)(tblock->options_block);
231 errmsg = errmsg; /* Keep picky compilers happy */
235 /* Pass back options if required. This interface is getting very messy. */
239 tf->interface = ob->interface;
241 tf->protocol = ob->protocol;
242 tf->hosts = ob->hosts;
243 tf->hosts_override = ob->hosts_override;
244 tf->hosts_randomize = ob->hosts_randomize;
245 tf->gethostbyname = ob->gethostbyname;
246 tf->qualify_single = ob->dns_qualify_single;
247 tf->search_parents = ob->dns_search_parents;
248 tf->helo_data = ob->helo_data;
251 /* Set the fallback host list for all the addresses that don't have fallback
252 host lists, provided that the local host wasn't present in the original host
255 if (!testflag(addrlist, af_local_host_removed))
257 for (; addrlist != NULL; addrlist = addrlist->next)
258 if (addrlist->fallback_hosts == NULL)
259 addrlist->fallback_hosts = ob->fallback_hostlist;
267 /*************************************************
268 * Initialization entry point *
269 *************************************************/
271 /* Called for each instance, after its options have been read, to
272 enable consistency checks to be done, or anything else that needs
275 Argument: pointer to the transport instance block
280 smtp_transport_init(transport_instance *tblock)
282 smtp_transport_options_block *ob =
283 (smtp_transport_options_block *)(tblock->options_block);
285 /* Retry_use_local_part defaults FALSE if unset */
287 if (tblock->retry_use_local_part == TRUE_UNSET)
288 tblock->retry_use_local_part = FALSE;
290 /* Set the default port according to the protocol */
292 if (ob->port == NULL)
293 ob->port = (strcmpic(ob->protocol, US"lmtp") == 0)? US"lmtp" : US"smtp";
295 /* Set up the setup entry point, to be called before subprocesses for this
298 tblock->setup = smtp_transport_setup;
300 /* Complain if any of the timeouts are zero. */
302 if (ob->command_timeout <= 0 || ob->data_timeout <= 0 ||
303 ob->final_timeout <= 0)
304 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
305 "command, data, or final timeout value is zero for %s transport",
308 /* If hosts_override is set and there are local hosts, set the global
309 flag that stops verify from showing router hosts. */
311 if (ob->hosts_override && ob->hosts != NULL) tblock->overrides_hosts = TRUE;
313 /* If there are any fallback hosts listed, build a chain of host items
314 for them, but do not do any lookups at this time. */
316 host_build_hostlist(&(ob->fallback_hostlist), ob->fallback_hosts, FALSE);
323 /*************************************************
324 * Set delivery info into all active addresses *
325 *************************************************/
327 /* Only addresses whose status is >= PENDING are relevant. A lesser
328 status means that an address is not currently being processed.
331 addrlist points to a chain of addresses
332 errno_value to put in each address's errno field
333 msg to put in each address's message field
334 rc to put in each address's transport_return field
335 pass_message if TRUE, set the "pass message" flag in the address
337 If errno_value has the special value ERRNO_CONNECTTIMEOUT, ETIMEDOUT is put in
338 the errno field, and RTEF_CTOUT is ORed into the more_errno field, to indicate
339 this particular type of timeout.
345 set_errno(address_item *addrlist, int errno_value, uschar *msg, int rc,
350 if (errno_value == ERRNO_CONNECTTIMEOUT)
352 errno_value = ETIMEDOUT;
353 orvalue = RTEF_CTOUT;
355 for (addr = addrlist; addr != NULL; addr = addr->next)
357 if (addr->transport_return < PENDING) continue;
358 addr->basic_errno = errno_value;
359 addr->more_errno |= orvalue;
363 if (pass_message) setflag(addr, af_pass_message);
365 addr->transport_return = rc;
371 /*************************************************
372 * Check an SMTP response *
373 *************************************************/
375 /* This function is given an errno code and the SMTP response buffer
376 to analyse, together with the host identification for generating messages. It
377 sets an appropriate message and puts the first digit of the response code into
378 the yield variable. If no response was actually read, a suitable digit is
382 host the current host, to get its name for messages
383 errno_value pointer to the errno value
384 more_errno from the top address for use with ERRNO_FILTER_FAIL
385 buffer the SMTP response buffer
386 yield where to put a one-digit SMTP response code
387 message where to put an errror message
388 pass_message set TRUE if message is an SMTP response
390 Returns: TRUE if an SMTP "QUIT" command should be sent, else FALSE
393 static BOOL check_response(host_item *host, int *errno_value, int more_errno,
394 uschar *buffer, int *yield, uschar **message, BOOL *pass_message)
398 if (smtp_use_pipelining &&
399 (Ustrcmp(smtp_command, "MAIL") == 0 ||
400 Ustrcmp(smtp_command, "RCPT") == 0 ||
401 Ustrcmp(smtp_command, "DATA") == 0))
404 *yield = '4'; /* Default setting is to give a temporary error */
406 /* Handle response timeout */
408 if (*errno_value == ETIMEDOUT)
410 *message = US string_sprintf("SMTP timeout while connected to %s [%s] "
411 "after %s%s", host->name, host->address, pl, smtp_command);
412 if (transport_count > 0)
413 *message = US string_sprintf("%s (%d bytes written)", *message,
418 /* Handle malformed SMTP response */
420 if (*errno_value == ERRNO_SMTPFORMAT)
422 uschar *malfresp = string_printing(buffer);
423 while (isspace(*malfresp)) malfresp++;
425 *message = string_sprintf("Malformed SMTP reply (an empty line) from "
426 "%s [%s] in response to %s%s", host->name, host->address, pl,
429 *message = string_sprintf("Malformed SMTP reply from %s [%s] in response "
430 "to %s%s: %s", host->name, host->address, pl, smtp_command, malfresp);
434 /* Handle a failed filter process error; can't send QUIT as we mustn't
437 if (*errno_value == ERRNO_FILTER_FAIL)
439 *message = US string_sprintf("transport filter process failed (%d)%s",
441 (more_errno == EX_EXECFAILED)? ": unable to execute command" : "");
445 /* Handle a failed add_headers expansion; can't send QUIT as we mustn't
448 if (*errno_value == ERRNO_CHHEADER_FAIL)
451 US string_sprintf("failed to expand headers_add or headers_remove: %s",
452 expand_string_message);
456 /* Handle failure to write a complete data block */
458 if (*errno_value == ERRNO_WRITEINCOMPLETE)
460 *message = US string_sprintf("failed to write a data block");
464 /* Handle error responses from the remote mailer. */
468 uschar *s = string_printing(buffer);
469 *message = US string_sprintf("SMTP error from remote mail server after %s%s: "
470 "host %s [%s]: %s", pl, smtp_command, host->name, host->address, s);
471 *pass_message = TRUE;
476 /* No data was read. If there is no errno, this must be the EOF (i.e.
477 connection closed) case, which causes deferral. An explicit connection reset
478 error has the same effect. Otherwise, put the host's identity in the message,
479 leaving the errno value to be interpreted as well. In all cases, we have to
480 assume the connection is now dead. */
482 if (*errno_value == 0 || *errno_value == ECONNRESET)
484 *errno_value = ERRNO_SMTPCLOSED;
485 *message = US string_sprintf("Remote host %s [%s] closed connection "
486 "in response to %s%s", host->name, host->address, pl, smtp_command);
488 else *message = US string_sprintf("%s [%s]", host->name, host->address);
495 /*************************************************
496 * Write error message to logs *
497 *************************************************/
499 /* This writes to the main log and to the message log.
502 addr the address item containing error information
503 host the current host
509 write_logs(address_item *addr, host_item *host)
511 if (addr->message != NULL)
513 uschar *message = addr->message;
514 if (addr->basic_errno > 0)
515 message = string_sprintf("%s: %s", message, strerror(addr->basic_errno));
516 log_write(0, LOG_MAIN, "%s", message);
517 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
522 ((log_extra_selector & LX_outgoing_port) != 0)?
523 string_sprintf("%s [%s]:%d", host->name, host->address,
524 (host->port == PORT_NONE)? 25 : host->port)
526 string_sprintf("%s [%s]", host->name, host->address);
527 log_write(0, LOG_MAIN, "%s %s", msg, strerror(addr->basic_errno));
528 deliver_msglog("%s %s %s\n", tod_stamp(tod_log), msg,
529 strerror(addr->basic_errno));
535 /*************************************************
536 * Synchronize SMTP responses *
537 *************************************************/
539 /* This function is called from smtp_deliver() to receive SMTP responses from
540 the server, and match them up with the commands to which they relate. When
541 PIPELINING is not in use, this function is called after every command, and is
542 therefore somewhat over-engineered, but it is simpler to use a single scheme
543 that works both with and without PIPELINING instead of having two separate sets
546 The set of commands that are buffered up with pipelining may start with MAIL
547 and may end with DATA; in between are RCPT commands that correspond to the
548 addresses whose status is PENDING_DEFER. All other commands (STARTTLS, AUTH,
549 etc.) are never buffered.
551 Errors after MAIL or DATA abort the whole process leaving the response in the
552 buffer. After MAIL, pending responses are flushed, and the original command is
553 re-instated in big_buffer for error messages. For RCPT commands, the remote is
554 permitted to reject some recipient addresses while accepting others. However
555 certain errors clearly abort the whole process. Set the value in
556 transport_return to PENDING_OK if the address is accepted. If there is a
557 subsequent general error, it will get reset accordingly. If not, it will get
558 converted to OK at the end.
561 addrlist the complete address list
562 include_affixes TRUE if affixes include in RCPT
563 sync_addr ptr to the ptr of the one to start scanning at (updated)
564 host the host we are connected to
565 count the number of responses to read
567 include_sender true if 4xx retry is to include the sender it its key
568 pending_MAIL true if the first response is for MAIL
569 pending_DATA 0 if last command sent was not DATA
570 +1 if previously had a good recipient
571 -1 if not previously had a good recipient
572 inblock incoming SMTP block
573 timeout timeout value
574 buffer buffer for reading response
575 buffsize size of buffer
577 Returns: 3 if at least one address had 2xx and one had 5xx
578 2 if at least one address had 5xx but none had 2xx
579 1 if at least one host had a 2xx response, but none had 5xx
580 0 no address had 2xx or 5xx but no errors (all 4xx, or just DATA)
581 -1 timeout while reading RCPT response
582 -2 I/O or other non-response error for RCPT
583 -3 DATA or MAIL failed - errno and buffer set
587 sync_responses(address_item *addrlist, BOOL include_affixes,
588 address_item **sync_addr, host_item *host, int count,
589 BOOL address_retry_include_sender, BOOL pending_MAIL,
590 int pending_DATA, smtp_inblock *inblock, int timeout, uschar *buffer,
593 address_item *addr = *sync_addr;
596 /* Handle the response for a MAIL command. On error, reinstate the original
597 command in big_buffer for error message use, and flush any further pending
598 responses before returning, except after I/O errors and timeouts. */
603 if (!smtp_read_response(inblock, buffer, buffsize, '2', timeout))
605 Ustrcpy(big_buffer, mail_command); /* Fits, because it came from there! */
606 if (errno == 0 && buffer[0] != 0)
608 uschar flushbuffer[4096];
610 if (buffer[0] == '4')
612 save_errno = ERRNO_MAIL4XX;
613 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
617 if (!smtp_read_response(inblock, flushbuffer, sizeof(flushbuffer),
619 && (errno != 0 || flushbuffer[0] == 0))
628 if (pending_DATA) count--; /* Number of RCPT responses to come */
630 /* Read and handle the required number of RCPT responses, matching each one up
631 with an address by scanning for the next address whose status is PENDING_DEFER.
636 while (addr->transport_return != PENDING_DEFER) addr = addr->next;
638 /* The address was accepted */
640 if (smtp_read_response(inblock, buffer, buffsize, '2', timeout))
643 addr->transport_return = PENDING_OK;
645 /* If af_dr_retry_exists is set, there was a routing delay on this address;
646 ensure that any address-specific retry record is expunged. */
648 if (testflag(addr, af_dr_retry_exists))
649 retry_add_item(addr, addr->address_retry_key, rf_delete);
652 /* Timeout while reading the response */
654 else if (errno == ETIMEDOUT)
656 int save_errno = errno;
657 uschar *message = string_sprintf("SMTP timeout while connected to %s [%s] "
658 "after RCPT TO:<%s>", host->name, host->address,
659 transport_rcpt_address(addr, include_affixes));
660 set_errno(addrlist, save_errno, message, DEFER, FALSE);
661 retry_add_item(addr, addr->address_retry_key, 0);
662 update_waiting = FALSE;
666 /* Handle other errors in obtaining an SMTP response by returning -1. This
667 will cause all the addresses to be deferred. Restore the SMTP command in
668 big_buffer for which we are checking the response, so the error message
671 else if (errno != 0 || buffer[0] == 0)
673 string_format(big_buffer, big_buffer_size, "RCPT TO:<%s>",
674 transport_rcpt_address(addr, include_affixes));
678 /* Handle SMTP permanent and temporary response codes. */
683 string_sprintf("SMTP error from remote mail server after RCPT TO:<%s>: "
684 "host %s [%s]: %s", transport_rcpt_address(addr, include_affixes),
685 host->name, host->address, string_printing(buffer));
686 setflag(addr, af_pass_message);
687 deliver_msglog("%s %s\n", tod_stamp(tod_log), addr->message);
689 /* The response was 5xx */
691 if (buffer[0] == '5')
693 addr->transport_return = FAIL;
697 /* The response was 4xx */
701 addr->transport_return = DEFER;
702 addr->basic_errno = ERRNO_RCPT4XX;
703 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
705 /* Log temporary errors if there are more hosts to be tried. */
707 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", addr->message);
709 /* Do not put this message on the list of those waiting for specific
710 hosts, as otherwise it is likely to be tried too often. */
712 update_waiting = FALSE;
714 /* Add a retry item for the address so that it doesn't get tried again
715 too soon. If address_retry_include_sender is true, add the sender address
718 if (address_retry_include_sender)
720 uschar *altkey = string_sprintf("%s:<%s>", addr->address_retry_key,
722 retry_add_item(addr, altkey, 0);
724 else retry_add_item(addr, addr->address_retry_key, 0);
727 } /* Loop for next RCPT response */
729 /* Update where to start at for the next block of responses, unless we
730 have already handled all the addresses. */
732 if (addr != NULL) *sync_addr = addr->next;
734 /* Handle a response to DATA. If we have not had any good recipients, either
735 previously or in this block, the response is ignored. */
737 if (pending_DATA != 0 &&
738 !smtp_read_response(inblock, buffer, buffsize, '3', timeout))
743 if (pending_DATA > 0 || (yield & 1) != 0)
745 if (errno == 0 && buffer[0] == '4')
747 errno = ERRNO_DATA4XX;
748 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
752 (void)check_response(host, &errno, 0, buffer, &code, &msg, &pass_message);
753 DEBUG(D_transport) debug_printf("%s\nerror for DATA ignored: pipelining "
754 "is in use and there were no good recipients\n", msg);
757 /* All responses read and handled; MAIL (if present) received 2xx and DATA (if
758 present) received 3xx. If any RCPTs were handled and yielded anything other
759 than 4xx, yield will be set non-zero. */
766 /*************************************************
767 * Deliver address list to given host *
768 *************************************************/
770 /* If continue_hostname is not null, we get here only when continuing to
771 deliver down an existing channel. The channel was passed as the standard
774 Otherwise, we have to make a connection to the remote host, and do the
775 initial protocol exchange.
777 When running as an MUA wrapper, if the sender or any recipient is rejected,
778 temporarily or permanently, we force failure for all recipients.
781 addrlist chain of potential addresses to deliver; only those whose
782 transport_return field is set to PENDING_DEFER are currently
783 being processed; others should be skipped - they have either
784 been delivered to an earlier host or IP address, or been
785 failed by one of them.
786 host host to deliver to
787 host_af AF_INET or AF_INET6
788 port default TCP/IP port to use, in host byte order
789 interface interface to bind to, or NULL
790 tblock transport instance block
791 copy_host TRUE if host set in addr->host_used must be copied, because
792 it is specific to this call of the transport
793 message_defer set TRUE if yield is OK, but all addresses were deferred
794 because of a non-recipient, non-host failure, that is, a
795 4xx response to MAIL FROM, DATA, or ".". This is a defer
796 that is specific to the message.
797 suppress_tls if TRUE, don't attempt a TLS connection - this is set for
798 a second attempt after TLS initialization fails
800 Returns: OK - the connection was made and the delivery attempted;
801 the result for each address is in its data block.
802 DEFER - the connection could not be made, or something failed
803 while setting up the SMTP session, or there was a
804 non-message-specific error, such as a timeout.
805 ERROR - a filter command is specified for this transport,
806 and there was a problem setting it up; OR helo_data
807 or add_headers or authenticated_sender is specified
808 for this transport, and the string failed to expand
812 smtp_deliver(address_item *addrlist, host_item *host, int host_af, int port,
813 uschar *interface, transport_instance *tblock, BOOL copy_host,
814 BOOL *message_defer, BOOL suppress_tls)
817 address_item *sync_addr;
818 address_item *first_addr = addrlist;
823 time_t start_delivery_time = time(NULL);
824 smtp_transport_options_block *ob =
825 (smtp_transport_options_block *)(tblock->options_block);
826 BOOL lmtp = strcmpic(ob->protocol, US"lmtp") == 0;
828 BOOL send_rset = TRUE;
829 BOOL send_quit = TRUE;
830 BOOL setting_up = TRUE;
831 BOOL completed_address = FALSE;
834 BOOL pass_message = FALSE;
835 smtp_inblock inblock;
836 smtp_outblock outblock;
837 int max_rcpt = tblock->max_addresses;
838 uschar *igquotstr = US"";
839 uschar *local_authenticated_sender = authenticated_sender;
841 uschar *message = NULL;
842 uschar new_message_id[MESSAGE_ID_LENGTH + 1];
845 uschar inbuffer[4096];
846 uschar outbuffer[1024];
848 suppress_tls = suppress_tls; /* stop compiler warning when no TLS support */
850 *message_defer = FALSE;
851 smtp_command = US"initial connection";
852 if (max_rcpt == 0) max_rcpt = 999999;
854 /* Set up the buffer for reading SMTP response packets. */
856 inblock.buffer = inbuffer;
857 inblock.buffersize = sizeof(inbuffer);
858 inblock.ptr = inbuffer;
859 inblock.ptrend = inbuffer;
861 /* Set up the buffer for holding SMTP commands while pipelining */
863 outblock.buffer = outbuffer;
864 outblock.buffersize = sizeof(outbuffer);
865 outblock.ptr = outbuffer;
866 outblock.cmd_count = 0;
867 outblock.authenticating = FALSE;
869 /* Expand the greeting message */
871 helo_data = expand_string(ob->helo_data);
872 if (helo_data == NULL)
874 uschar *message = string_sprintf("failed to expand helo_data: %s",
875 expand_string_message);
876 set_errno(addrlist, 0, message, DEFER, FALSE);
880 /* If an authenticated_sender override has been specified for this transport
881 instance, expand it. If the expansion is forced to fail, and there was already
882 an authenticated_sender for this message, the original value will be used.
883 Other expansion failures are serious. An empty result is ignored, but there is
884 otherwise no check - this feature is expected to be used with LMTP and other
885 cases where non-standard addresses (e.g. without domains) might be required. */
887 if (ob->authenticated_sender != NULL)
889 uschar *new = expand_string(ob->authenticated_sender);
892 if (!expand_string_forcedfail)
894 uschar *message = string_sprintf("failed to expand "
895 "authenticated_sender: %s", expand_string_message);
896 set_errno(addrlist, 0, message, DEFER, FALSE);
900 else if (new[0] != 0) local_authenticated_sender = new;
903 /* Make a connection to the host if this isn't a continued delivery, and handle
904 the initial interaction and HELO/EHLO/LHLO. Connect timeout errors are handled
905 specially so they can be identified for retries. */
907 if (continue_hostname == NULL)
909 inblock.sock = outblock.sock =
910 smtp_connect(host, host_af, port, interface, ob->connect_timeout,
912 if (inblock.sock < 0)
914 set_errno(addrlist, (errno == ETIMEDOUT)? ERRNO_CONNECTTIMEOUT : errno,
919 /* The first thing is to wait for an initial OK response. The dreaded "goto"
920 is nevertheless a reasonably clean way of programming this kind of logic,
921 where you want to escape on any error. */
923 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
924 ob->command_timeout)) goto RESPONSE_FAILED;
926 /** Debugging without sending a message
927 addrlist->transport_return = DEFER;
931 /* Errors that occur after this point follow an SMTP command, which is
932 left in big_buffer by smtp_write_command() for use in error messages. */
934 smtp_command = big_buffer;
936 /* Tell the remote who we are...
938 February 1998: A convention has evolved that ESMTP-speaking MTAs include the
939 string "ESMTP" in their greeting lines, so make Exim send EHLO if the
940 greeting is of this form. The assumption was that the far end supports it
941 properly... but experience shows that there are some that give 5xx responses,
942 even though the banner includes "ESMTP" (there's a bloody-minded one that
943 says "ESMTP not spoken here"). Cope with that case.
945 September 2000: Time has passed, and it seems reasonable now to always send
946 EHLO at the start. It is also convenient to make the change while installing
949 July 2003: Joachim Wieland met a broken server that advertises "PIPELINING"
950 but times out after sending MAIL FROM, RCPT TO and DATA all together. There
951 would be no way to send out the mails, so there is now a host list
952 "hosts_avoid_esmtp" that disables ESMTP for special hosts and solves the
953 PIPELINING problem as well. Maybe it can also be useful to cure other
954 problems with broken servers.
956 Exim originally sent "Helo" at this point and ran for nearly a year that way.
957 Then somebody tried it with a Microsoft mailer... It seems that all other
958 mailers use upper case for some reason (the RFC is quite clear about case
959 independence) so, for peace of mind, I gave in. */
961 esmtp = verify_check_this_host(&(ob->hosts_avoid_esmtp), NULL,
962 host->name, host->address, NULL) != OK;
966 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n",
967 lmtp? "LHLO" : "EHLO", helo_data) < 0)
969 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
970 ob->command_timeout))
972 if (errno != 0 || buffer[0] == 0 || lmtp) goto RESPONSE_FAILED;
979 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
984 if (smtp_write_command(&outblock, FALSE, "HELO %s\r\n", helo_data) < 0)
986 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
987 ob->command_timeout)) goto RESPONSE_FAILED;
990 /* Set IGNOREQUOTA if the response to LHLO specifies support and the
991 lmtp_ignore_quota option was set. */
993 igquotstr = (lmtp && ob->lmtp_ignore_quota &&
994 pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer, Ustrlen(CS buffer), 0,
995 PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
997 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
1000 tls_offered = esmtp &&
1001 pcre_exec(regex_STARTTLS, NULL, CS buffer, Ustrlen(buffer), 0,
1002 PCRE_EOPT, NULL, 0) >= 0;
1006 /* For continuing deliveries down the same channel, the socket is the standard
1007 input, and we don't need to redo EHLO here (but may need to do so for TLS - see
1008 below). Set up the pointer to where subsequent commands will be left, for
1009 error messages. Note that smtp_use_size and smtp_use_pipelining will have been
1010 set from the command line if they were set in the process that passed the
1015 inblock.sock = outblock.sock = fileno(stdin);
1016 smtp_command = big_buffer;
1019 /* If TLS is available on this connection, whether continued or not, attempt to
1020 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
1021 send another EHLO - the server may give a different answer in secure mode. We
1022 use a separate buffer for reading the response to STARTTLS so that if it is
1023 negative, the original EHLO data is available for subsequent analysis, should
1024 the client not be required to use TLS. If the response is bad, copy the buffer
1025 for error analysis. */
1028 if (tls_offered && !suppress_tls &&
1029 verify_check_this_host(&(ob->hosts_avoid_tls), NULL, host->name,
1030 host->address, NULL) != OK)
1032 uschar buffer2[4096];
1033 if (smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") < 0)
1036 /* If there is an I/O error, transmission of this message is deferred. If
1037 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
1038 false, we also defer. However, if there is a temporary rejection of STARTTLS
1039 and tls_tempfail_tryclear is true, or if there is an outright rejection of
1040 STARTTLS, we carry on. This means we will try to send the message in clear,
1041 unless the host is in hosts_require_tls (tested below). */
1043 if (!smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
1044 ob->command_timeout))
1046 Ustrncpy(buffer, buffer2, sizeof(buffer));
1047 if (errno != 0 || buffer2[0] == 0 ||
1048 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
1049 goto RESPONSE_FAILED;
1052 /* STARTTLS accepted: try to negotiate a TLS session. */
1056 int rc = tls_client_start(inblock.sock, host, addrlist,
1057 NULL, /* No DH param */
1058 ob->tls_certificate,
1060 ob->tls_verify_certificates,
1062 ob->tls_require_ciphers,
1063 ob->command_timeout);
1065 /* TLS negotiation failed; give an error. From outside, this function may
1066 be called again to try in clear on a new connection, if the options permit
1067 it for this host. */
1071 save_errno = ERRNO_TLSFAILURE;
1072 message = US"failure while setting up TLS session";
1077 /* TLS session is set up */
1079 for (addr = addrlist; addr != NULL; addr = addr->next)
1081 if (addr->transport_return == PENDING_DEFER)
1083 addr->cipher = tls_cipher;
1084 addr->peerdn = tls_peerdn;
1090 /* If we started TLS, redo the EHLO/LHLO exchange over the secure channel. */
1092 if (tls_active >= 0)
1094 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n", lmtp? "LHLO" : "EHLO",
1097 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1098 ob->command_timeout))
1099 goto RESPONSE_FAILED;
1102 /* If the host is required to use a secure channel, ensure that we
1105 else if (verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
1106 host->address, NULL) == OK)
1108 save_errno = ERRNO_TLSREQUIRED;
1109 message = string_sprintf("a TLS session is required for %s [%s], but %s",
1110 host->name, host->address,
1111 tls_offered? "an attempt to start TLS failed" :
1112 "the server did not offer TLS support");
1117 /* If TLS is active, we have just started it up and re-done the EHLO command,
1118 so its response needs to be analyzed. If TLS is not active and this is a
1119 continued session down a previously-used socket, we haven't just done EHLO, so
1122 if (continue_hostname == NULL
1129 uschar *fail_reason = US"server did not advertise AUTH support";
1131 /* Set for IGNOREQUOTA if the response to LHLO specifies support and the
1132 lmtp_ignore_quota option was set. */
1134 igquotstr = (lmtp && ob->lmtp_ignore_quota &&
1135 pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer, Ustrlen(CS buffer), 0,
1136 PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
1138 /* If the response to EHLO specified support for the SIZE parameter, note
1139 this, provided size_addition is non-negative. */
1141 smtp_use_size = esmtp && ob->size_addition >= 0 &&
1142 pcre_exec(regex_SIZE, NULL, CS buffer, Ustrlen(CS buffer), 0,
1143 PCRE_EOPT, NULL, 0) >= 0;
1145 /* Note whether the server supports PIPELINING. If hosts_avoid_esmtp matched
1146 the current host, esmtp will be false, so PIPELINING can never be used. */
1148 smtp_use_pipelining = esmtp &&
1149 pcre_exec(regex_PIPELINING, NULL, CS buffer, Ustrlen(CS buffer), 0,
1150 PCRE_EOPT, NULL, 0) >= 0;
1152 DEBUG(D_transport) debug_printf("%susing PIPELINING\n",
1153 smtp_use_pipelining? "" : "not ");
1155 /* Note if the response to EHLO specifies support for the AUTH extension.
1156 If it has, check that this host is one we want to authenticate to, and do
1157 the business. The host name and address must be available when the
1158 authenticator's client driver is running. */
1160 smtp_authenticated = FALSE;
1161 require_auth = verify_check_this_host(&(ob->hosts_require_auth), NULL,
1162 host->name, host->address, NULL);
1164 if (esmtp && regex_match_and_setup(regex_AUTH, buffer, 0, -1))
1166 uschar *names = string_copyn(expand_nstring[1], expand_nlength[1]);
1167 expand_nmax = -1; /* reset */
1169 /* Must not do this check until after we have saved the result of the
1170 regex match above. */
1172 if (require_auth == OK ||
1173 verify_check_this_host(&(ob->hosts_try_auth), NULL, host->name,
1174 host->address, NULL) == OK)
1177 fail_reason = US"no common mechanisms were found";
1179 DEBUG(D_transport) debug_printf("scanning authentication mechanisms\n");
1181 /* Scan the configured authenticators looking for one which is configured
1182 for use as a client and whose name matches an authentication mechanism
1183 supported by the server. If one is found, attempt to authenticate by
1184 calling its client function. */
1186 for (au = auths; !smtp_authenticated && au != NULL; au = au->next)
1189 if (!au->client) continue;
1191 /* Loop to scan supported server mechanisms */
1196 int len = Ustrlen(au->public_name);
1197 while (isspace(*p)) p++;
1199 if (strncmpic(au->public_name, p, len) != 0 ||
1200 (p[len] != 0 && !isspace(p[len])))
1202 while (*p != 0 && !isspace(*p)) p++;
1206 /* Found data for a listed mechanism. Call its client entry. Set
1207 a flag in the outblock so that data is overwritten after sending so
1208 that reflections don't show it. */
1210 fail_reason = US"authentication attempt(s) failed";
1211 outblock.authenticating = TRUE;
1212 rc = (au->info->clientcode)(au, &inblock, &outblock,
1213 ob->command_timeout, buffer, sizeof(buffer));
1214 outblock.authenticating = FALSE;
1215 DEBUG(D_transport) debug_printf("%s authenticator yielded %d\n",
1218 /* A temporary authentication failure must hold up delivery to
1219 this host. After a permanent authentication failure, we carry on
1220 to try other authentication methods. If all fail hard, try to
1221 deliver the message unauthenticated unless require_auth was set. */
1226 smtp_authenticated = TRUE; /* stops the outer loop */
1229 /* Failure after writing a command */
1234 /* Failure after reading a response */
1237 if (errno != 0 || buffer[0] != '5') goto RESPONSE_FAILED;
1238 log_write(0, LOG_MAIN, "%s authenticator failed H=%s [%s] %s",
1239 au->name, host->name, host->address, buffer);
1242 /* Failure by some other means. In effect, the authenticator
1243 decided it wasn't prepared to handle this case. Typically this
1244 is the result of "fail" in an expansion string. Do we need to
1245 log anything here? Feb 2006: a message is now put in the buffer
1246 if logging is required. */
1250 log_write(0, LOG_MAIN, "%s authenticator cancelled "
1251 "authentication H=%s [%s] %s", au->name, host->name,
1252 host->address, buffer);
1255 /* Internal problem, message in buffer. */
1259 set_errno(addrlist, 0, string_copy(buffer), DEFER, FALSE);
1263 break; /* If not authenticated, try next authenticator */
1264 } /* Loop for scanning supported server mechanisms */
1265 } /* Loop for further authenticators */
1269 /* If we haven't authenticated, but are required to, give up. */
1271 if (require_auth == OK && !smtp_authenticated)
1274 set_errno(addrlist, ERRNO_AUTHFAIL,
1275 string_sprintf("authentication required but %s", fail_reason), DEFER,
1281 /* The setting up of the SMTP call is now complete. Any subsequent errors are
1282 message-specific. */
1286 /* If there is a filter command specified for this transport, we can now
1287 set it up. This cannot be done until the identify of the host is known. */
1289 if (tblock->filter_command != NULL)
1293 sprintf(CS buffer, "%.50s transport", tblock->name);
1294 rc = transport_set_up_command(&transport_filter_argv, tblock->filter_command,
1295 TRUE, DEFER, addrlist, buffer, NULL);
1297 /* On failure, copy the error to all addresses, abandon the SMTP call, and
1302 set_errno(addrlist->next, addrlist->basic_errno, addrlist->message, DEFER,
1310 /* For messages that have more than the maximum number of envelope recipients,
1311 we want to send several transactions down the same SMTP connection. (See
1312 comments in deliver.c as to how this reconciles, heuristically, with
1313 remote_max_parallel.) This optimization was added to Exim after the following
1314 code was already working. The simplest way to put it in without disturbing the
1315 code was to use a goto to jump back to this point when there is another
1316 transaction to handle. */
1319 sync_addr = first_addr;
1323 completed_address = FALSE;
1326 /* Initiate a message transfer. If we know the receiving MTA supports the SIZE
1327 qualification, send it, adding something to the message size to allow for
1328 imprecision and things that get added en route. Exim keeps the number of lines
1329 in a message, so we can give an accurate value for the original message, but we
1330 need some additional to handle added headers. (Double "." characters don't get
1331 included in the count.) */
1338 sprintf(CS p, " SIZE=%d", message_size+message_linecount+ob->size_addition);
1342 /* Add the authenticated sender address if present */
1344 if ((smtp_authenticated || ob->authenticated_sender_force) &&
1345 local_authenticated_sender != NULL)
1347 string_format(p, sizeof(buffer) - (p-buffer), " AUTH=%s",
1348 auth_xtextencode(local_authenticated_sender,
1349 Ustrlen(local_authenticated_sender)));
1352 /* From here until we send the DATA command, we can make use of PIPELINING
1353 if the server host supports it. The code has to be able to check the responses
1354 at any point, for when the buffer fills up, so we write it totally generally.
1355 When PIPELINING is off, each command written reports that it has flushed the
1358 pending_MAIL = TRUE; /* The block starts with MAIL */
1360 rc = smtp_write_command(&outblock, smtp_use_pipelining,
1361 "MAIL FROM:<%s>%s\r\n", return_path, buffer);
1362 mail_command = string_copy(big_buffer); /* Save for later error message */
1366 case -1: /* Transmission error */
1369 case +1: /* Block was sent */
1370 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1371 ob->command_timeout))
1373 if (errno == 0 && buffer[0] == '4')
1375 errno = ERRNO_MAIL4XX;
1376 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1378 goto RESPONSE_FAILED;
1380 pending_MAIL = FALSE;
1384 /* Pass over all the relevant recipient addresses for this host, which are the
1385 ones that have status PENDING_DEFER. If we are using PIPELINING, we can send
1386 several before we have to read the responses for those seen so far. This
1387 checking is done by a subroutine because it also needs to be done at the end.
1388 Send only up to max_rcpt addresses at a time, leaving first_addr pointing to
1389 the next one if not all are sent.
1391 In the MUA wrapper situation, we want to flush the PIPELINING buffer for the
1392 last address because we want to abort if any recipients have any kind of
1393 problem, temporary or permanent. We know that all recipient addresses will have
1394 the PENDING_DEFER status, because only one attempt is ever made, and we know
1395 that max_rcpt will be large, so all addresses will be done at once. */
1397 for (addr = first_addr;
1398 address_count < max_rcpt && addr != NULL;
1404 if (addr->transport_return != PENDING_DEFER) continue;
1407 no_flush = smtp_use_pipelining && (!mua_wrapper || addr->next != NULL);
1409 /* Now send the RCPT command, and process outstanding responses when
1410 necessary. After a timeout on RCPT, we just end the function, leaving the
1411 yield as OK, because this error can often mean that there is a problem with
1412 just one address, so we don't want to delay the host. */
1414 count = smtp_write_command(&outblock, no_flush, "RCPT TO:<%s>%s\r\n",
1415 transport_rcpt_address(addr, tblock->rcpt_include_affixes), igquotstr);
1416 if (count < 0) goto SEND_FAILED;
1419 switch(sync_responses(first_addr, tblock->rcpt_include_affixes,
1420 &sync_addr, host, count, ob->address_retry_include_sender,
1421 pending_MAIL, 0, &inblock, ob->command_timeout, buffer,
1424 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1425 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1428 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1429 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1430 case 0: /* No 2xx or 5xx, but no probs */
1433 case -1: goto END_OFF; /* Timeout on RCPT */
1434 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL error */
1436 pending_MAIL = FALSE; /* Dealt with MAIL */
1438 } /* Loop for next address */
1440 /* If we are an MUA wrapper, abort if any RCPTs were rejected, either
1441 permanently or temporarily. We should have flushed and synced after the last
1446 address_item *badaddr;
1447 for (badaddr = first_addr; badaddr != NULL; badaddr = badaddr->next)
1449 if (badaddr->transport_return != PENDING_OK) break;
1451 if (badaddr != NULL)
1453 set_errno(addrlist, 0, badaddr->message, FAIL,
1454 testflag(badaddr, af_pass_message));
1459 /* If ok is TRUE, we know we have got at least one good recipient, and must now
1460 send DATA, but if it is FALSE (in the normal, non-wrapper case), we may still
1461 have a good recipient buffered up if we are pipelining. We don't want to waste
1462 time sending DATA needlessly, so we only send it if either ok is TRUE or if we
1463 are pipelining. The responses are all handled by sync_responses(). */
1465 if (ok || (smtp_use_pipelining && !mua_wrapper))
1467 int count = smtp_write_command(&outblock, FALSE, "DATA\r\n");
1468 if (count < 0) goto SEND_FAILED;
1469 switch(sync_responses(first_addr, tblock->rcpt_include_affixes, &sync_addr,
1470 host, count, ob->address_retry_include_sender, pending_MAIL,
1471 ok? +1 : -1, &inblock, ob->command_timeout, buffer, sizeof(buffer)))
1473 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1474 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1477 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1478 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1479 case 0: break; /* No 2xx or 5xx, but no probs */
1481 case -1: goto END_OFF; /* Timeout on RCPT */
1482 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */
1486 /* Save the first address of the next batch. */
1490 /* If there were no good recipients (but otherwise there have been no
1491 problems), just set ok TRUE, since we have handled address-specific errors
1492 already. Otherwise, it's OK to send the message. Use the check/escape mechanism
1493 for handling the SMTP dot-handling protocol, flagging to apply to headers as
1494 well as body. Set the appropriate timeout value to be used for each chunk.
1495 (Haven't been able to make it work using select() for writing yet.) */
1497 if (!ok) ok = TRUE; else
1499 sigalrm_seen = FALSE;
1500 transport_write_timeout = ob->data_timeout;
1501 smtp_command = US"sending data block"; /* For error messages */
1502 DEBUG(D_transport|D_v)
1503 debug_printf(" SMTP>> writing message and terminating \".\"\n");
1504 transport_count = 0;
1505 #ifdef EXPERIMENTAL_DOMAINKEYS
1506 if ( (ob->dk_private_key != NULL) && (ob->dk_selector != NULL) )
1507 ok = dk_transport_write_message(addrlist, inblock.sock,
1508 topt_use_crlf | topt_end_dot | topt_escape_headers |
1509 (tblock->body_only? topt_no_headers : 0) |
1510 (tblock->headers_only? topt_no_body : 0) |
1511 (tblock->return_path_add? topt_add_return_path : 0) |
1512 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1513 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1514 0, /* No size limit */
1515 tblock->add_headers, tblock->remove_headers,
1516 US".", US"..", /* Escaping strings */
1517 tblock->rewrite_rules, tblock->rewrite_existflags,
1518 ob->dk_private_key, ob->dk_domain, ob->dk_selector,
1519 ob->dk_canon, ob->dk_headers, ob->dk_strict);
1522 ok = transport_write_message(addrlist, inblock.sock,
1523 topt_use_crlf | topt_end_dot | topt_escape_headers |
1524 (tblock->body_only? topt_no_headers : 0) |
1525 (tblock->headers_only? topt_no_body : 0) |
1526 (tblock->return_path_add? topt_add_return_path : 0) |
1527 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1528 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1529 0, /* No size limit */
1530 tblock->add_headers, tblock->remove_headers,
1531 US".", US"..", /* Escaping strings */
1532 tblock->rewrite_rules, tblock->rewrite_existflags);
1534 /* transport_write_message() uses write() because it is called from other
1535 places to write to non-sockets. This means that under some OS (e.g. Solaris)
1536 it can exit with "Broken pipe" as its error. This really means that the
1537 socket got closed at the far end. */
1539 transport_write_timeout = 0; /* for subsequent transports */
1541 /* Failure can either be some kind of I/O disaster (including timeout),
1542 or the failure of a transport filter or the expansion of added headers. */
1546 buffer[0] = 0; /* There hasn't been a response */
1547 goto RESPONSE_FAILED;
1550 /* We used to send the terminating "." explicitly here, but because of
1551 buffering effects at both ends of TCP/IP connections, you don't gain
1552 anything by keeping it separate, so it might as well go in the final
1553 data buffer for efficiency. This is now done by setting the topt_end_dot
1556 smtp_command = US"end of data";
1558 /* For SMTP, we now read a single response that applies to the whole message.
1559 If it is OK, then all the addresses have been delivered. */
1563 ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1565 if (!ok && errno == 0 && buffer[0] == '4')
1567 errno = ERRNO_DATA4XX;
1568 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1572 /* For LMTP, we get back a response for every RCPT command that we sent;
1573 some may be accepted and some rejected. For those that get a response, their
1574 status is fixed; any that are accepted have been handed over, even if later
1575 responses crash - at least, that's how I read RFC 2033.
1577 If all went well, mark the recipient addresses as completed, record which
1578 host/IPaddress they were delivered to, and cut out RSET when sending another
1579 message down the same channel. Write the completed addresses to the journal
1580 now so that they are recorded in case there is a crash of hardware or
1581 software before the spool gets updated. Also record the final SMTP
1582 confirmation if needed (for SMTP only). */
1587 int delivery_time = (int)(time(NULL) - start_delivery_time);
1590 uschar *conf = NULL;
1593 /* Make a copy of the host if it is local to this invocation
1594 of the transport. */
1598 thost = store_get(sizeof(host_item));
1600 thost->name = string_copy(host->name);
1601 thost->address = string_copy(host->address);
1605 /* Set up confirmation if needed - applies only to SMTP */
1607 if ((log_extra_selector & LX_smtp_confirmation) != 0 && !lmtp)
1609 uschar *s = string_printing(buffer);
1610 conf = (s == buffer)? (uschar *)string_copy(s) : s;
1613 /* Process all transported addresses - for LMTP, read a status for
1616 for (addr = addrlist; addr != first_addr; addr = addr->next)
1618 if (addr->transport_return != PENDING_OK) continue;
1620 /* LMTP - if the response fails badly (e.g. timeout), use it for all the
1621 remaining addresses. Otherwise, it's a return code for just the one
1622 address. For temporary errors, add a retry item for the address so that
1623 it doesn't get tried again too soon. */
1627 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1630 if (errno != 0 || buffer[0] == 0) goto RESPONSE_FAILED;
1631 addr->message = string_sprintf("LMTP error after %s: %s",
1632 big_buffer, string_printing(buffer));
1633 setflag(addr, af_pass_message); /* Allow message to go to user */
1634 if (buffer[0] == '5')
1635 addr->transport_return = FAIL;
1638 errno = ERRNO_DATA4XX;
1639 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1640 addr->transport_return = DEFER;
1641 retry_add_item(addr, addr->address_retry_key, 0);
1645 completed_address = TRUE; /* NOW we can set this flag */
1648 /* SMTP, or success return from LMTP for this address. Pass back the
1649 actual host that was used. */
1651 addr->transport_return = OK;
1652 addr->more_errno = delivery_time;
1653 addr->host_used = thost;
1654 addr->special_action = flag;
1655 addr->message = conf;
1658 /* Update the journal. For homonymic addresses, use the base address plus
1659 the transport name. See lots of comments in deliver.c about the reasons
1660 for the complications when homonyms are involved. Just carry on after
1661 write error, as it may prove possible to update the spool file later. */
1663 if (testflag(addr, af_homonym))
1664 sprintf(CS buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
1666 sprintf(CS buffer, "%.500s\n", addr->unique);
1668 DEBUG(D_deliver) debug_printf("journalling %s", buffer);
1669 len = Ustrlen(CS buffer);
1670 if (write(journal_fd, buffer, len) != len)
1671 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
1672 "%s: %s", buffer, strerror(errno));
1675 /* Ensure the journal file is pushed out to disk. */
1677 if (fsync(journal_fd) < 0)
1678 log_write(0, LOG_MAIN|LOG_PANIC, "failed to fsync journal: %s",
1684 /* Handle general (not specific to one address) failures here. The value of ok
1685 is used to skip over this code on the falling through case. A timeout causes a
1686 deferral. Other errors may defer or fail according to the response code, and
1687 may set up a special errno value, e.g. after connection chopped, which is
1688 assumed if errno == 0 and there is no text in the buffer. If control reaches
1689 here during the setting up phase (i.e. before MAIL FROM) then always defer, as
1690 the problem is not related to this specific message. */
1699 send_quit = check_response(host, &save_errno, addrlist->more_errno,
1700 buffer, &code, &message, &pass_message);
1706 message = US string_sprintf("send() to %s [%s] failed: %s",
1707 host->name, host->address, strerror(save_errno));
1711 /* This label is jumped to directly when a TLS negotiation has failed,
1712 or was not done for a host for which it is required. Values will be set
1713 in message and save_errno, and setting_up will always be true. Treat as
1714 a temporary error. */
1721 /* If the failure happened while setting up the call, see if the failure was
1722 a 5xx response (this will either be on connection, or following HELO - a 5xx
1723 after EHLO causes it to try HELO). If so, fail all addresses, as this host is
1724 never going to accept them. For other errors during setting up (timeouts or
1725 whatever), defer all addresses, and yield DEFER, so that the host is not
1726 tried again for a while. */
1729 ok = FALSE; /* For when reached by GOTO */
1735 set_errno(addrlist, save_errno, message, FAIL, pass_message);
1739 set_errno(addrlist, save_errno, message, DEFER, pass_message);
1744 /* We want to handle timeouts after MAIL or "." and loss of connection after
1745 "." specially. They can indicate a problem with the sender address or with
1746 the contents of the message rather than a real error on the connection. These
1747 cases are treated in the same way as a 4xx response. This next bit of code
1748 does the classification. */
1759 message_error = TRUE;
1763 message_error = Ustrncmp(smtp_command,"MAIL",4) == 0 ||
1764 Ustrncmp(smtp_command,"end ",4) == 0;
1767 case ERRNO_SMTPCLOSED:
1768 message_error = Ustrncmp(smtp_command,"end ",4) == 0;
1772 message_error = FALSE;
1776 /* Handle the cases that are treated as message errors. These are:
1778 (a) negative response or timeout after MAIL
1779 (b) negative response after DATA
1780 (c) negative response or timeout or dropped connection after "."
1782 It won't be a negative response or timeout after RCPT, as that is dealt
1783 with separately above. The action in all cases is to set an appropriate
1784 error code for all the addresses, but to leave yield set to OK because the
1785 host itself has not failed. Of course, it might in practice have failed
1786 when we've had a timeout, but if so, we'll discover that at the next
1787 delivery attempt. For a temporary error, set the message_defer flag, and
1788 write to the logs for information if this is not the last host. The error
1789 for the last host will be logged as part of the address's log line. */
1793 if (mua_wrapper) code = '5'; /* Force hard failure in wrapper mode */
1794 set_errno(addrlist, save_errno, message, (code == '5')? FAIL : DEFER,
1797 /* If there's an errno, the message contains just the identity of
1800 if (code != '5') /* Anything other than 5 is treated as temporary */
1803 message = US string_sprintf("%s: %s", message, strerror(save_errno));
1804 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", message);
1805 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
1806 *message_defer = TRUE;
1810 /* Otherwise, we have an I/O error or a timeout other than after MAIL or
1811 ".", or some other transportation error. We defer all addresses and yield
1812 DEFER, except for the case of failed add_headers expansion, or a transport
1813 filter failure, when the yield should be ERROR, to stop it trying other
1818 yield = (save_errno == ERRNO_CHHEADER_FAIL ||
1819 save_errno == ERRNO_FILTER_FAIL)? ERROR : DEFER;
1820 set_errno(addrlist, save_errno, message, DEFER, pass_message);
1826 /* If all has gone well, send_quit will be set TRUE, implying we can end the
1827 SMTP session tidily. However, if there were too many addresses to send in one
1828 message (indicated by first_addr being non-NULL) we want to carry on with the
1829 rest of them. Also, it is desirable to send more than one message down the SMTP
1830 connection if there are several waiting, provided we haven't already sent so
1831 many as to hit the configured limit. The function transport_check_waiting looks
1832 for a waiting message and returns its id. Then transport_pass_socket tries to
1833 set up a continued delivery by passing the socket on to another process. The
1834 variable send_rset is FALSE if a message has just been successfully transfered.
1836 If we are already sending down a continued channel, there may be further
1837 addresses not yet delivered that are aimed at the same host, but which have not
1838 been passed in this run of the transport. In this case, continue_more will be
1839 true, and all we should do is send RSET if necessary, and return, leaving the
1842 However, if no address was disposed of, i.e. all addresses got 4xx errors, we
1843 do not want to continue with other messages down the same channel, because that
1844 can lead to looping between two or more messages, all with the same,
1845 temporarily failing address(es). [The retry information isn't updated yet, so
1846 new processes keep on trying.] We probably also don't want to try more of this
1847 message's addresses either.
1849 If we have started a TLS session, we have to end it before passing the
1850 connection to a new process. However, not all servers can handle this (Exim
1851 can), so we do not pass such a connection on if the host matches
1852 hosts_nopass_tls. */
1855 debug_printf("ok=%d send_quit=%d send_rset=%d continue_more=%d "
1856 "yield=%d first_address is %sNULL\n", ok, send_quit, send_rset,
1857 continue_more, yield, (first_addr == NULL)? "":"not ");
1859 if (completed_address && ok && send_quit)
1862 if (first_addr != NULL || continue_more ||
1865 verify_check_this_host(&(ob->hosts_nopass_tls), NULL, host->name,
1866 host->address, NULL) != OK)
1868 transport_check_waiting(tblock->name, host->name,
1869 tblock->connection_max_messages, new_message_id, &more)
1877 if (! (ok = smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0))
1879 msg = US string_sprintf("send() to %s [%s] failed: %s", host->name,
1880 host->address, strerror(save_errno));
1883 else if (! (ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1884 ob->command_timeout)))
1887 send_quit = check_response(host, &errno, 0, buffer, &code, &msg,
1891 DEBUG(D_transport) debug_printf("%s\n", msg);
1896 /* Either RSET was not needed, or it succeeded */
1900 if (first_addr != NULL) /* More addresses still to be sent */
1901 { /* in this run of the transport */
1902 continue_sequence++; /* Causes * in logging */
1905 if (continue_more) return yield; /* More addresses for another run */
1907 /* Pass the socket to a new Exim process. Before doing so, we must shut
1908 down TLS. Not all MTAs allow for the continuation of the SMTP session
1909 when TLS is shut down. We test for this by sending a new EHLO. If we
1910 don't get a good response, we don't attempt to pass the socket on. */
1913 if (tls_active >= 0)
1916 ok = smtp_write_command(&outblock,FALSE,"EHLO %s\r\n",helo_data) >= 0 &&
1917 smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1918 ob->command_timeout);
1922 /* If the socket is successfully passed, we musn't send QUIT (or
1923 indeed anything!) from here. */
1925 if (ok && transport_pass_socket(tblock->name, host->name, host->address,
1926 new_message_id, inblock.sock))
1932 /* If RSET failed and there are addresses left, they get deferred. */
1934 else set_errno(first_addr, errno, msg, DEFER, FALSE);
1938 /* End off tidily with QUIT unless the connection has died or the socket has
1939 been passed to another process. There has been discussion on the net about what
1940 to do after sending QUIT. The wording of the RFC suggests that it is necessary
1941 to wait for a response, but on the other hand, there isn't anything one can do
1942 with an error response, other than log it. Exim used to do that. However,
1943 further discussion suggested that it is positively advantageous not to wait for
1944 the response, but to close the session immediately. This is supposed to move
1945 the TCP/IP TIME_WAIT state from the server to the client, thereby removing some
1946 load from the server. (Hosts that are both servers and clients may not see much
1947 difference, of course.) Further discussion indicated that this was safe to do
1948 on Unix systems which have decent implementations of TCP/IP that leave the
1949 connection around for a while (TIME_WAIT) after the application has gone away.
1950 This enables the response sent by the server to be properly ACKed rather than
1951 timed out, as can happen on broken TCP/IP implementations on other OS.
1953 This change is being made on 31-Jul-98. After over a year of trouble-free
1954 operation, the old commented-out code was removed on 17-Sep-99. */
1957 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1965 /* Close the socket, and return the appropriate value, first setting
1966 continue_transport and continue_hostname NULL to prevent any other addresses
1967 that may include the host from trying to re-use a continuation socket. This
1968 works because the NULL setting is passed back to the calling process, and
1969 remote_max_parallel is forced to 1 when delivering over an existing connection,
1971 If all went well and continue_more is set, we shouldn't actually get here if
1972 there are further addresses, as the return above will be taken. However,
1973 writing RSET might have failed, or there may be other addresses whose hosts are
1974 specified in the transports, and therefore not visible at top level, in which
1975 case continue_more won't get set. */
1977 (void)close(inblock.sock);
1978 continue_transport = NULL;
1979 continue_hostname = NULL;
1986 /*************************************************
1987 * Closedown entry point *
1988 *************************************************/
1990 /* This function is called when exim is passed an open smtp channel
1991 from another incarnation, but the message which it has been asked
1992 to deliver no longer exists. The channel is on stdin.
1994 We might do fancy things like looking for another message to send down
1995 the channel, but if the one we sought has gone, it has probably been
1996 delivered by some other process that itself will seek further messages,
1997 so just close down our connection.
1999 Argument: pointer to the transport instance block
2004 smtp_transport_closedown(transport_instance *tblock)
2006 smtp_transport_options_block *ob =
2007 (smtp_transport_options_block *)(tblock->options_block);
2008 smtp_inblock inblock;
2009 smtp_outblock outblock;
2011 uschar inbuffer[4096];
2012 uschar outbuffer[16];
2014 inblock.sock = fileno(stdin);
2015 inblock.buffer = inbuffer;
2016 inblock.buffersize = sizeof(inbuffer);
2017 inblock.ptr = inbuffer;
2018 inblock.ptrend = inbuffer;
2020 outblock.sock = inblock.sock;
2021 outblock.buffersize = sizeof(outbuffer);
2022 outblock.buffer = outbuffer;
2023 outblock.ptr = outbuffer;
2024 outblock.cmd_count = 0;
2025 outblock.authenticating = FALSE;
2027 (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
2028 (void)smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2029 ob->command_timeout);
2030 (void)close(inblock.sock);
2035 /*************************************************
2036 * Prepare addresses for delivery *
2037 *************************************************/
2039 /* This function is called to flush out error settings from previous delivery
2040 attempts to other hosts. It also records whether we got here via an MX record
2041 or not in the more_errno field of the address. We are interested only in
2042 addresses that are still marked DEFER - others may have got delivered to a
2043 previously considered IP address. Set their status to PENDING_DEFER to indicate
2044 which ones are relevant this time.
2047 addrlist the list of addresses
2048 host the host we are delivering to
2050 Returns: the first address for this delivery
2053 static address_item *
2054 prepare_addresses(address_item *addrlist, host_item *host)
2056 address_item *first_addr = NULL;
2058 for (addr = addrlist; addr != NULL; addr = addr->next)
2060 if (addr->transport_return != DEFER) continue;
2061 if (first_addr == NULL) first_addr = addr;
2062 addr->transport_return = PENDING_DEFER;
2063 addr->basic_errno = 0;
2064 addr->more_errno = (host->mx >= 0)? 'M' : 'A';
2065 addr->message = NULL;
2067 addr->cipher = NULL;
2068 addr->peerdn = NULL;
2076 /*************************************************
2077 * Main entry point *
2078 *************************************************/
2080 /* See local README for interface details. As this is a remote transport, it is
2081 given a chain of addresses to be delivered in one connection, if possible. It
2082 always returns TRUE, indicating that each address has its own independent
2083 status set, except if there is a setting up problem, in which case it returns
2087 smtp_transport_entry(
2088 transport_instance *tblock, /* data for this instantiation */
2089 address_item *addrlist) /* addresses we are working on */
2093 int hosts_defer = 0;
2095 int hosts_looked_up = 0;
2096 int hosts_retry = 0;
2097 int hosts_serial = 0;
2098 int hosts_total = 0;
2099 int total_hosts_tried = 0;
2101 BOOL expired = TRUE;
2102 BOOL continuing = continue_hostname != NULL;
2103 uschar *expanded_hosts = NULL;
2105 uschar *tid = string_sprintf("%s transport", tblock->name);
2106 smtp_transport_options_block *ob =
2107 (smtp_transport_options_block *)(tblock->options_block);
2108 host_item *hostlist = addrlist->host_list;
2109 host_item *host = NULL;
2113 debug_printf("%s transport entered\n", tblock->name);
2114 for (addr = addrlist; addr != NULL; addr = addr->next)
2115 debug_printf(" %s\n", addr->address);
2116 if (continuing) debug_printf("already connected to %s [%s]\n",
2117 continue_hostname, continue_host_address);
2120 /* Set the flag requesting that these hosts be added to the waiting
2121 database if the delivery fails temporarily or if we are running with
2122 queue_smtp or a 2-stage queue run. This gets unset for certain
2123 kinds of error, typically those that are specific to the message. */
2125 update_waiting = TRUE;
2127 /* If a host list is not defined for the addresses - they must all have the
2128 same one in order to be passed to a single transport - or if the transport has
2129 a host list with hosts_override set, use the host list supplied with the
2130 transport. It is an error for this not to exist. */
2132 if (hostlist == NULL || (ob->hosts_override && ob->hosts != NULL))
2134 if (ob->hosts == NULL)
2136 addrlist->message = string_sprintf("%s transport called with no hosts set",
2138 addrlist->transport_return = PANIC;
2139 return FALSE; /* Only top address has status */
2142 DEBUG(D_transport) debug_printf("using the transport's hosts: %s\n",
2145 /* If the transport's host list contains no '$' characters, and we are not
2146 randomizing, it is fixed and therefore a chain of hosts can be built once
2147 and for all, and remembered for subsequent use by other calls to this
2148 transport. If, on the other hand, the host list does contain '$', or we are
2149 randomizing its order, we have to rebuild it each time. In the fixed case,
2150 as the hosts string will never be used again, it doesn't matter that we
2151 replace all the : characters with zeros. */
2153 if (ob->hostlist == NULL)
2155 uschar *s = ob->hosts;
2157 if (Ustrchr(s, '$') != NULL)
2159 expanded_hosts = expand_string(s);
2160 if (expanded_hosts == NULL)
2162 addrlist->message = string_sprintf("failed to expand list of hosts "
2163 "\"%s\" in %s transport: %s", s, tblock->name, expand_string_message);
2164 addrlist->transport_return = search_find_defer? DEFER : PANIC;
2165 return FALSE; /* Only top address has status */
2167 DEBUG(D_transport) debug_printf("expanded list of hosts \"%s\" to "
2168 "\"%s\"\n", s, expanded_hosts);
2172 if (ob->hosts_randomize) s = expanded_hosts = string_copy(s);
2174 host_build_hostlist(&hostlist, s, ob->hosts_randomize);
2176 /* If there was no expansion of hosts, save the host list for
2179 if (expanded_hosts == NULL) ob->hostlist = hostlist;
2182 /* This is not the first time this transport has been run in this delivery;
2183 the host list was built previously. */
2185 else hostlist = ob->hostlist;
2188 /* The host list was supplied with the address. If hosts_randomize is set, we
2189 must sort it into a random order if it did not come from MX records and has not
2190 already been randomized (but don't bother if continuing down an existing
2193 else if (ob->hosts_randomize && hostlist->mx == MX_NONE && !continuing)
2195 host_item *newlist = NULL;
2196 while (hostlist != NULL)
2198 host_item *h = hostlist;
2199 hostlist = hostlist->next;
2201 h->sort_key = random_number(100);
2203 if (newlist == NULL)
2208 else if (h->sort_key < newlist->sort_key)
2215 host_item *hh = newlist;
2216 while (hh->next != NULL)
2218 if (h->sort_key < hh->next->sort_key) break;
2226 hostlist = addrlist->host_list = newlist;
2230 /* Sort out the default port. */
2232 if (!smtp_get_port(ob->port, addrlist, &port, tid)) return FALSE;
2235 /* For each host-plus-IP-address on the list:
2237 . If this is a continued delivery and the host isn't the one with the
2238 current connection, skip.
2240 . If the status is unusable (i.e. previously failed or retry checked), skip.
2242 . If no IP address set, get the address, either by turning the name into
2243 an address, calling gethostbyname if gethostbyname is on, or by calling
2244 the DNS. The DNS may yield multiple addresses, in which case insert the
2245 extra ones into the list.
2247 . Get the retry data if not previously obtained for this address and set the
2248 field which remembers the state of this address. Skip if the retry time is
2249 not reached. If not, remember whether retry data was found. The retry string
2250 contains both the name and the IP address.
2252 . Scan the list of addresses and mark those whose status is DEFER as
2253 PENDING_DEFER. These are the only ones that will be processed in this cycle
2256 . Make a delivery attempt - addresses marked PENDING_DEFER will be tried.
2257 Some addresses may be successfully delivered, others may fail, and yet
2258 others may get temporary errors and so get marked DEFER.
2260 . The return from the delivery attempt is OK if a connection was made and a
2261 valid SMTP dialogue was completed. Otherwise it is DEFER.
2263 . If OK, add a "remove" retry item for this host/IPaddress, if any.
2265 . If fail to connect, or other defer state, add a retry item.
2267 . If there are any addresses whose status is still DEFER, carry on to the
2268 next host/IPaddress, unless we have tried the number of hosts given
2269 by hosts_max_try or hosts_max_try_hardlimit; otherwise return. Note that
2270 there is some fancy logic for hosts_max_try that means its limit can be
2271 overstepped in some circumstances.
2273 If we get to the end of the list, all hosts have deferred at least one address,
2274 or not reached their retry times. If delay_after_cutoff is unset, it requests a
2275 delivery attempt to those hosts whose last try was before the arrival time of
2276 the current message. To cope with this, we have to go round the loop a second
2277 time. After that, set the status and error data for any addresses that haven't
2278 had it set already. */
2280 for (cutoff_retry = 0; expired &&
2281 cutoff_retry < ((ob->delay_after_cutoff)? 1 : 2);
2284 host_item *nexthost = NULL;
2285 int unexpired_hosts_tried = 0;
2287 for (host = hostlist;
2289 unexpired_hosts_tried < ob->hosts_max_try &&
2290 total_hosts_tried < ob->hosts_max_try_hardlimit;
2296 BOOL serialized = FALSE;
2297 BOOL host_is_expired = FALSE;
2298 BOOL message_defer = FALSE;
2299 BOOL ifchanges = FALSE;
2300 BOOL some_deferred = FALSE;
2301 address_item *first_addr = NULL;
2302 uschar *interface = NULL;
2303 uschar *retry_host_key = NULL;
2304 uschar *retry_message_key = NULL;
2305 uschar *serialize_key = NULL;
2307 /* Default next host is next host. :-) But this can vary if the
2308 hosts_max_try limit is hit (see below). It may also be reset if a host
2309 address is looked up here (in case the host was multihomed). */
2311 nexthost = host->next;
2313 /* If the address hasn't yet been obtained from the host name, look it up
2314 now, unless the host is already marked as unusable. If it is marked as
2315 unusable, it means that the router was unable to find its IP address (in
2316 the DNS or wherever) OR we are in the 2nd time round the cutoff loop, and
2317 the lookup failed last time. We don't get this far if *all* MX records
2318 point to non-existent hosts; that is treated as a hard error.
2320 We can just skip this host entirely. When the hosts came from the router,
2321 the address will timeout based on the other host(s); when the address is
2322 looked up below, there is an explicit retry record added.
2324 Note that we mustn't skip unusable hosts if the address is not unset; they
2325 may be needed as expired hosts on the 2nd time round the cutoff loop. */
2327 if (host->address == NULL)
2329 int new_port, flags;
2331 uschar *canonical_name;
2333 if (host->status >= hstatus_unusable)
2335 DEBUG(D_transport) debug_printf("%s has no address and is unusable - skipping\n",
2340 DEBUG(D_transport) debug_printf("getting address for %s\n", host->name);
2342 /* The host name is permitted to have an attached port. Find it, and
2343 strip it from the name. Just remember it for now. */
2345 new_port = host_item_get_port(host);
2347 /* Count hosts looked up */
2351 /* Find by name if so configured, or if it's an IP address. We don't
2352 just copy the IP address, because we need the test-for-local to happen. */
2354 flags = HOST_FIND_BY_A;
2355 if (ob->dns_qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
2356 if (ob->dns_search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
2358 if (ob->gethostbyname || string_is_ip_address(host->name, NULL) != 0)
2359 rc = host_find_byname(host, NULL, flags, &canonical_name, TRUE);
2361 rc = host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
2362 &canonical_name, NULL);
2364 /* Update the host (and any additional blocks, resulting from
2365 multihoming) with a host-specific port, if any. */
2367 for (hh = host; hh != nexthost; hh = hh->next) hh->port = new_port;
2369 /* Failure to find the host at this time (usually DNS temporary failure)
2370 is really a kind of routing failure rather than a transport failure.
2371 Therefore we add a retry item of the routing kind, not to stop us trying
2372 to look this name up here again, but to ensure the address gets timed
2373 out if the failures go on long enough. A complete failure at this point
2374 commonly points to a configuration error, but the best action is still
2375 to carry on for the next host. */
2377 if (rc == HOST_FIND_AGAIN || rc == HOST_FIND_FAILED)
2379 retry_add_item(addrlist, string_sprintf("R:%s", host->name), 0);
2381 if (rc == HOST_FIND_AGAIN) hosts_defer++; else hosts_fail++;
2382 DEBUG(D_transport) debug_printf("rc = %s for %s\n", (rc == HOST_FIND_AGAIN)?
2383 "HOST_FIND_AGAIN" : "HOST_FIND_FAILED", host->name);
2384 host->status = hstatus_unusable;
2386 for (addr = addrlist; addr != NULL; addr = addr->next)
2388 if (addr->transport_return != DEFER) continue;
2389 addr->basic_errno = ERRNO_UNKNOWNHOST;
2391 string_sprintf("failed to lookup IP address for %s", host->name);
2396 /* If the host is actually the local host, we may have a problem, or
2397 there may be some cunning configuration going on. In the problem case,
2398 log things and give up. The default transport status is already DEFER. */
2400 if (rc == HOST_FOUND_LOCAL && !ob->allow_localhost)
2402 for (addr = addrlist; addr != NULL; addr = addr->next)
2404 addr->basic_errno = 0;
2405 addr->message = string_sprintf("%s transport found host %s to be "
2406 "local", tblock->name, host->name);
2410 } /* End of block for IP address lookup */
2412 /* If this is a continued delivery, we are interested only in the host
2413 which matches the name of the existing open channel. The check is put
2414 here after the local host lookup, in case the name gets expanded as a
2415 result of the lookup. Set expired FALSE, to save the outer loop executing
2418 if (continuing && (Ustrcmp(continue_hostname, host->name) != 0 ||
2419 Ustrcmp(continue_host_address, host->address) != 0))
2422 continue; /* With next host */
2425 /* Reset the default next host in case a multihomed host whose addresses
2426 are not looked up till just above added to the host list. */
2428 nexthost = host->next;
2430 /* If queue_smtp is set (-odqs or the first part of a 2-stage run), or the
2431 domain is in queue_smtp_domains, we don't actually want to attempt any
2432 deliveries. When doing a queue run, queue_smtp_domains is always unset. If
2433 there is a lookup defer in queue_smtp_domains, proceed as if the domain
2434 were not in it. We don't want to hold up all SMTP deliveries! Except when
2435 doing a two-stage queue run, don't do this if forcing. */
2437 if ((!deliver_force || queue_2stage) && (queue_smtp ||
2438 match_isinlist(addrlist->domain, &queue_smtp_domains, 0,
2439 &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL) == OK))
2442 for (addr = addrlist; addr != NULL; addr = addr->next)
2444 if (addr->transport_return != DEFER) continue;
2445 addr->message = US"domain matches queue_smtp_domains, or -odqs set";
2447 continue; /* With next host */
2450 /* Count hosts being considered - purely for an intelligent comment
2451 if none are usable. */
2455 /* Set $host and $host address now in case they are needed for the
2456 interface expansion or the serialize_hosts check; they remain set if an
2457 actual delivery happens. */
2459 deliver_host = host->name;
2460 deliver_host_address = host->address;
2462 /* Set up a string for adding to the retry key if the port number is not
2463 the standard SMTP port. A host may have its own port setting that overrides
2466 pistring = string_sprintf(":%d", (host->port == PORT_NONE)?
2468 if (Ustrcmp(pistring, ":25") == 0) pistring = US"";
2470 /* Select IPv4 or IPv6, and choose an outgoing interface. If the interface
2471 string changes upon expansion, we must add it to the key that is used for
2472 retries, because connections to the same host from a different interface
2473 should be treated separately. */
2475 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET : AF_INET6;
2476 if (!smtp_get_interface(ob->interface, host_af, addrlist, &ifchanges,
2479 if (ifchanges) pistring = string_sprintf("%s/%s", pistring, interface);
2481 /* The first time round the outer loop, check the status of the host by
2482 inspecting the retry data. The second time round, we are interested only
2483 in expired hosts that haven't been tried since this message arrived. */
2485 if (cutoff_retry == 0)
2487 /* Ensure the status of the address is set by checking retry data if
2488 necessary. There maybe host-specific retry data (applicable to all
2489 messages) and also data for retries of a specific message at this host.
2490 If either of these retry records are actually read, the keys used are
2491 returned to save recomputing them later. */
2493 host_is_expired = retry_check_address(addrlist->domain, host, pistring,
2494 ob->retry_include_ip_address, &retry_host_key, &retry_message_key);
2496 DEBUG(D_transport) debug_printf("%s [%s]%s status = %s\n", host->name,
2497 (host->address == NULL)? US"" : host->address, pistring,
2498 (host->status == hstatus_usable)? "usable" :
2499 (host->status == hstatus_unusable)? "unusable" :
2500 (host->status == hstatus_unusable_expired)? "unusable (expired)" : "?");
2502 /* Skip this address if not usable at this time, noting if it wasn't
2503 actually expired, both locally and in the address. */
2505 switch (host->status)
2507 case hstatus_unusable:
2509 setflag(addrlist, af_retry_skipped);
2512 case hstatus_unusable_expired:
2515 case hwhy_retry: hosts_retry++; break;
2516 case hwhy_failed: hosts_fail++; break;
2517 case hwhy_deferred: hosts_defer++; break;
2520 /* If there was a retry message key, implying that previously there
2521 was a message-specific defer, we don't want to update the list of
2522 messages waiting for these hosts. */
2524 if (retry_message_key != NULL) update_waiting = FALSE;
2525 continue; /* With the next host or IP address */
2529 /* Second time round the loop: if the address is set but expired, and
2530 the message is newer than the last try, let it through. */
2534 if (host->address == NULL ||
2535 host->status != hstatus_unusable_expired ||
2536 host->last_try > received_time)
2539 debug_printf("trying expired host %s [%s]%s\n",
2540 host->name, host->address, pistring);
2541 host_is_expired = TRUE;
2544 /* Setting "expired=FALSE" doesn't actually mean not all hosts are expired;
2545 it remains TRUE only if all hosts are expired and none are actually tried.
2550 /* If this host is listed as one to which access must be serialized,
2551 see if another Exim process has a connection to it, and if so, skip
2552 this host. If not, update the database to record our connection to it
2553 and remember this for later deletion. Do not do any of this if we are
2554 sending the message down a pre-existing connection. */
2557 verify_check_this_host(&(ob->serialize_hosts), NULL, host->name,
2558 host->address, NULL) == OK)
2560 serialize_key = string_sprintf("host-serialize-%s", host->name);
2561 if (!enq_start(serialize_key))
2564 debug_printf("skipping host %s because another Exim process "
2565 "is connected to it\n", host->name);
2572 /* OK, we have an IP address that is not waiting for its retry time to
2573 arrive (it might be expired) OR (second time round the loop) we have an
2574 expired host that hasn't been tried since the message arrived. Have a go
2575 at delivering the message to it. First prepare the addresses by flushing
2576 out the result of previous attempts, and finding the first address that
2577 is still to be delivered. */
2579 first_addr = prepare_addresses(addrlist, host);
2581 DEBUG(D_transport) debug_printf("delivering %s to %s [%s] (%s%s)\n",
2582 message_id, host->name, host->address, addrlist->address,
2583 (addrlist->next == NULL)? "" : ", ...");
2585 set_process_info("delivering %s to %s [%s] (%s%s)",
2586 message_id, host->name, host->address, addrlist->address,
2587 (addrlist->next == NULL)? "" : ", ...");
2589 /* This is not for real; don't do the delivery. If there are
2590 any remaining hosts, list them. */
2595 set_errno(addrlist, 0, NULL, OK, FALSE);
2596 for (addr = addrlist; addr != NULL; addr = addr->next)
2598 addr->host_used = host;
2599 addr->special_action = '*';
2600 addr->message = US"delivery bypassed by -N option";
2604 debug_printf("*** delivery by %s transport bypassed by -N option\n"
2605 "*** host and remaining hosts:\n", tblock->name);
2606 for (host2 = host; host2 != NULL; host2 = host2->next)
2607 debug_printf(" %s [%s]\n", host2->name,
2608 (host2->address == NULL)? US"unset" : host2->address);
2613 /* This is for real. If the host is expired, we don't count it for
2614 hosts_max_retry. This ensures that all hosts must expire before an address
2615 is timed out, unless hosts_max_try_hardlimit (which protects against
2616 lunatic DNS configurations) is reached.
2618 If the host is not expired and we are about to hit the hosts_max_retry
2619 limit, check to see if there is a subsequent hosts with a different MX
2620 value. If so, make that the next host, and don't count this one. This is a
2621 heuristic to make sure that different MXs do get tried. With a normal kind
2622 of retry rule, they would get tried anyway when the earlier hosts were
2623 delayed, but if the domain has a "retry every time" type of rule - as is
2624 often used for the the very large ISPs, that won't happen. */
2628 if (!host_is_expired && ++unexpired_hosts_tried >= ob->hosts_max_try)
2632 debug_printf("hosts_max_try limit reached with this host\n");
2633 for (h = host; h != NULL; h = h->next)
2634 if (h->mx != host->mx) break;
2638 unexpired_hosts_tried--;
2639 DEBUG(D_transport) debug_printf("however, a higher MX host exists "
2640 "and will be tried\n");
2644 /* Attempt the delivery. */
2646 total_hosts_tried++;
2647 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2648 expanded_hosts != NULL, &message_defer, FALSE);
2651 OK => connection made, each address contains its result;
2652 message_defer is set for message-specific defers (when all
2653 recipients are marked defer)
2654 DEFER => there was a non-message-specific delivery problem;
2655 ERROR => there was a problem setting up the arguments for a filter,
2656 or there was a problem with expanding added headers
2659 /* If the result is not OK, there was a non-message-specific problem.
2660 If the result is DEFER, we need to write to the logs saying what happened
2661 for this particular host, except in the case of authentication and TLS
2662 failures, where the log has already been written. If all hosts defer a
2663 general message is written at the end. */
2665 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL &&
2666 first_addr->basic_errno != ERRNO_TLSFAILURE)
2667 write_logs(first_addr, host);
2669 /* If STARTTLS was accepted, but there was a failure in setting up the
2670 TLS session (usually a certificate screwup), and the host is not in
2671 hosts_require_tls, and tls_tempfail_tryclear is true, try again, with
2672 TLS forcibly turned off. We have to start from scratch with a new SMTP
2673 connection. That's why the retry is done from here, not from within
2674 smtp_deliver(). [Rejections of STARTTLS itself don't screw up the
2675 session, so the in-clear transmission after those errors, if permitted,
2676 happens inside smtp_deliver().] */
2679 if (rc == DEFER && first_addr->basic_errno == ERRNO_TLSFAILURE &&
2680 ob->tls_tempfail_tryclear &&
2681 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
2682 host->address, NULL) != OK)
2684 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
2685 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
2686 first_addr = prepare_addresses(addrlist, host);
2687 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2688 expanded_hosts != NULL, &message_defer, TRUE);
2689 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL)
2690 write_logs(first_addr, host);
2695 /* Delivery attempt finished */
2697 rs = (rc == OK)? US"OK" : (rc == DEFER)? US"DEFER" : (rc == ERROR)?
2700 set_process_info("delivering %s: just tried %s [%s] for %s%s: result %s",
2701 message_id, host->name, host->address, addrlist->address,
2702 (addrlist->next == NULL)? "" : " (& others)", rs);
2704 /* Release serialization if set up */
2706 if (serialized) enq_end(serialize_key);
2708 /* If the result is DEFER, or if a host retry record is known to exist, we
2709 need to add an item to the retry chain for updating the retry database
2710 at the end of delivery. We only need to add the item to the top address,
2711 of course. Also, if DEFER, we mark the IP address unusable so as to skip it
2712 for any other delivery attempts using the same address. (It is copied into
2713 the unusable tree at the outer level, so even if different address blocks
2714 contain the same address, it still won't get tried again.) */
2716 if (rc == DEFER || retry_host_key != NULL)
2718 int delete_flag = (rc != DEFER)? rf_delete : 0;
2719 if (retry_host_key == NULL)
2721 retry_host_key = ob->retry_include_ip_address?
2722 string_sprintf("T:%S:%s%s", host->name, host->address, pistring) :
2723 string_sprintf("T:%S%s", host->name, pistring);
2726 /* If a delivery of another message over an existing SMTP connection
2727 yields DEFER, we do NOT set up retry data for the host. This covers the
2728 case when there are delays in routing the addresses in the second message
2729 that are so long that the server times out. This is alleviated by not
2730 routing addresses that previously had routing defers when handling an
2731 existing connection, but even so, this case may occur (e.g. if a
2732 previously happily routed address starts giving routing defers). If the
2733 host is genuinely down, another non-continued message delivery will
2734 notice it soon enough. */
2736 if (delete_flag != 0 || !continuing)
2737 retry_add_item(first_addr, retry_host_key, rf_host | delete_flag);
2739 /* We may have tried an expired host, if its retry time has come; ensure
2740 the status reflects the expiry for the benefit of any other addresses. */
2744 host->status = (host_is_expired)?
2745 hstatus_unusable_expired : hstatus_unusable;
2746 host->why = hwhy_deferred;
2750 /* If message_defer is set (host was OK, but every recipient got deferred
2751 because of some message-specific problem), or if that had happened
2752 previously so that a message retry key exists, add an appropriate item
2753 to the retry chain. Note that if there was a message defer but now there is
2754 a host defer, the message defer record gets deleted. That seems perfectly
2755 reasonable. Also, stop the message from being remembered as waiting
2756 for specific hosts. */
2758 if (message_defer || retry_message_key != NULL)
2760 int delete_flag = message_defer? 0 : rf_delete;
2761 if (retry_message_key == NULL)
2763 retry_message_key = ob->retry_include_ip_address?
2764 string_sprintf("T:%S:%s%s:%s", host->name, host->address, pistring,
2766 string_sprintf("T:%S%s:%s", host->name, pistring, message_id);
2768 retry_add_item(addrlist, retry_message_key,
2769 rf_message | rf_host | delete_flag);
2770 update_waiting = FALSE;
2773 /* Any return other than DEFER (that is, OK or ERROR) means that the
2774 addresses have got their final statuses filled in for this host. In the OK
2775 case, see if any of them are deferred. */
2779 for (addr = addrlist; addr != NULL; addr = addr->next)
2781 if (addr->transport_return == DEFER)
2783 some_deferred = TRUE;
2789 /* If no addresses deferred or the result was ERROR, return. We do this for
2790 ERROR because a failing filter set-up or add_headers expansion is likely to
2791 fail for any host we try. */
2793 if (rc == ERROR || (rc == OK && !some_deferred))
2795 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2796 return TRUE; /* Each address has its status */
2799 /* If the result was DEFER or some individual addresses deferred, let
2800 the loop run to try other hosts with the deferred addresses, except for the
2801 case when we were trying to deliver down an existing channel and failed.
2802 Don't try any other hosts in this case. */
2804 if (continuing) break;
2806 /* If the whole delivery, or some individual addresses, were deferred and
2807 there are more hosts that could be tried, do not count this host towards
2808 the hosts_max_try limit if the age of the message is greater than the
2809 maximum retry time for this host. This means we may try try all hosts,
2810 ignoring the limit, when messages have been around for some time. This is
2811 important because if we don't try all hosts, the address will never time
2812 out. NOTE: this does not apply to hosts_max_try_hardlimit. */
2814 if ((rc == DEFER || some_deferred) && nexthost != NULL)
2817 retry_config *retry = retry_find_config(host->name, NULL, 0, 0);
2819 if (retry != NULL && retry->rules != NULL)
2821 retry_rule *last_rule;
2822 for (last_rule = retry->rules;
2823 last_rule->next != NULL;
2824 last_rule = last_rule->next);
2825 timedout = time(NULL) - received_time > last_rule->timeout;
2827 else timedout = TRUE; /* No rule => timed out */
2831 unexpired_hosts_tried--;
2832 DEBUG(D_transport) debug_printf("temporary delivery error(s) override "
2833 "hosts_max_try (message older than host's retry time)\n");
2836 } /* End of loop for trying multiple hosts. */
2838 /* This is the end of the loop that repeats iff expired is TRUE and
2839 ob->delay_after_cutoff is FALSE. The second time round we will
2840 try those hosts that haven't been tried since the message arrived. */
2844 debug_printf("all IP addresses skipped or deferred at least one address\n");
2845 if (expired && !ob->delay_after_cutoff && cutoff_retry == 0)
2846 debug_printf("retrying IP addresses not tried since message arrived\n");
2851 /* Get here if all IP addresses are skipped or defer at least one address. In
2852 MUA wrapper mode, this will happen only for connection or other non-message-
2853 specific failures. Force the delivery status for all addresses to FAIL. */
2857 for (addr = addrlist; addr != NULL; addr = addr->next)
2858 addr->transport_return = FAIL;
2862 /* In the normal, non-wrapper case, add a standard message to each deferred
2863 address if there hasn't been an error, that is, if it hasn't actually been
2864 tried this time. The variable "expired" will be FALSE if any deliveries were
2865 actually tried, or if there was at least one host that was not expired. That
2866 is, it is TRUE only if no deliveries were tried and all hosts were expired. If
2867 a delivery has been tried, an error code will be set, and the failing of the
2868 message is handled by the retry code later.
2870 If queue_smtp is set, or this transport was called to send a subsequent message
2871 down an existing TCP/IP connection, and something caused the host not to be
2872 found, we end up here, but can detect these cases and handle them specially. */
2874 for (addr = addrlist; addr != NULL; addr = addr->next)
2876 /* If host is not NULL, it means that we stopped processing the host list
2877 because of hosts_max_try or hosts_max_try_hardlimit. In the former case, this
2878 means we need to behave as if some hosts were skipped because their retry
2879 time had not come. Specifically, this prevents the address from timing out.
2880 However, if we have hit hosts_max_try_hardlimit, we want to behave as if all
2881 hosts were tried. */
2885 if (total_hosts_tried >= ob->hosts_max_try_hardlimit)
2888 debug_printf("hosts_max_try_hardlimit reached: behave as if all "
2889 "hosts were tried\n");
2894 debug_printf("hosts_max_try limit caused some hosts to be skipped\n");
2895 setflag(addr, af_retry_skipped);
2899 if (queue_smtp) /* no deliveries attempted */
2901 addr->transport_return = DEFER;
2902 addr->basic_errno = 0;
2903 addr->message = US"SMTP delivery explicitly queued";
2906 else if (addr->transport_return == DEFER &&
2907 (addr->basic_errno == ERRNO_UNKNOWNERROR || addr->basic_errno == 0) &&
2908 addr->message == NULL)
2910 addr->basic_errno = ERRNO_HRETRY;
2911 if (continue_hostname != NULL)
2913 addr->message = US"no host found for existing SMTP connection";
2917 setflag(addr, af_pass_message); /* This is not a security risk */
2918 addr->message = (ob->delay_after_cutoff)?
2919 US"retry time not reached for any host after a long failure period" :
2920 US"all hosts have been failing for a long time and were last tried "
2921 "after this message arrived";
2923 /* If we are already using fallback hosts, or there are no fallback hosts
2924 defined, convert the result to FAIL to cause a bounce. */
2926 if (addr->host_list == addr->fallback_hosts ||
2927 addr->fallback_hosts == NULL)
2928 addr->transport_return = FAIL;
2932 if (hosts_retry == hosts_total)
2933 addr->message = US"retry time not reached for any host";
2934 else if (hosts_fail == hosts_total)
2935 addr->message = US"all host address lookups failed permanently";
2936 else if (hosts_defer == hosts_total)
2937 addr->message = US"all host address lookups failed temporarily";
2938 else if (hosts_serial == hosts_total)
2939 addr->message = US"connection limit reached for all hosts";
2940 else if (hosts_fail+hosts_defer == hosts_total)
2941 addr->message = US"all host address lookups failed";
2942 else addr->message = US"some host address lookups failed and retry time "
2943 "not reached for other hosts or connection limit reached";
2948 /* Update the database which keeps information about which messages are waiting
2949 for which hosts to become available. For some message-specific errors, the
2950 update_waiting flag is turned off because we don't want follow-on deliveries in
2953 if (update_waiting) transport_update_waiting(hostlist, tblock->name);
2957 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2959 return TRUE; /* Each address has its status */
2962 /* End of transport/smtp.c */