1 /* $Cambridge: exim/src/src/transports/smtp.c,v 1.31 2007/01/18 15:35:43 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) },
67 { "gnutls_require_kx", opt_stringptr,
68 (void *)offsetof(smtp_transport_options_block, gnutls_require_kx) },
69 { "gnutls_require_mac", opt_stringptr,
70 (void *)offsetof(smtp_transport_options_block, gnutls_require_mac) },
71 { "gnutls_require_protocols", opt_stringptr,
72 (void *)offsetof(smtp_transport_options_block, gnutls_require_proto) },
74 { "helo_data", opt_stringptr,
75 (void *)offsetof(smtp_transport_options_block, helo_data) },
76 { "hosts", opt_stringptr,
77 (void *)offsetof(smtp_transport_options_block, hosts) },
78 { "hosts_avoid_esmtp", opt_stringptr,
79 (void *)offsetof(smtp_transport_options_block, hosts_avoid_esmtp) },
81 { "hosts_avoid_tls", opt_stringptr,
82 (void *)offsetof(smtp_transport_options_block, hosts_avoid_tls) },
84 { "hosts_max_try", opt_int,
85 (void *)offsetof(smtp_transport_options_block, hosts_max_try) },
86 { "hosts_max_try_hardlimit", opt_int,
87 (void *)offsetof(smtp_transport_options_block, hosts_max_try_hardlimit) },
89 { "hosts_nopass_tls", opt_stringptr,
90 (void *)offsetof(smtp_transport_options_block, hosts_nopass_tls) },
92 { "hosts_override", opt_bool,
93 (void *)offsetof(smtp_transport_options_block, hosts_override) },
94 { "hosts_randomize", opt_bool,
95 (void *)offsetof(smtp_transport_options_block, hosts_randomize) },
96 { "hosts_require_auth", opt_stringptr,
97 (void *)offsetof(smtp_transport_options_block, hosts_require_auth) },
99 { "hosts_require_tls", opt_stringptr,
100 (void *)offsetof(smtp_transport_options_block, hosts_require_tls) },
102 { "hosts_try_auth", opt_stringptr,
103 (void *)offsetof(smtp_transport_options_block, hosts_try_auth) },
104 { "interface", opt_stringptr,
105 (void *)offsetof(smtp_transport_options_block, interface) },
106 { "keepalive", opt_bool,
107 (void *)offsetof(smtp_transport_options_block, keepalive) },
108 { "lmtp_ignore_quota", opt_bool,
109 (void *)offsetof(smtp_transport_options_block, lmtp_ignore_quota) },
110 { "max_rcpt", opt_int | opt_public,
111 (void *)offsetof(transport_instance, max_addresses) },
112 { "multi_domain", opt_bool | opt_public,
113 (void *)offsetof(transport_instance, multi_domain) },
114 { "port", opt_stringptr,
115 (void *)offsetof(smtp_transport_options_block, port) },
116 { "protocol", opt_stringptr,
117 (void *)offsetof(smtp_transport_options_block, protocol) },
118 { "retry_include_ip_address", opt_bool,
119 (void *)offsetof(smtp_transport_options_block, retry_include_ip_address) },
120 { "serialize_hosts", opt_stringptr,
121 (void *)offsetof(smtp_transport_options_block, serialize_hosts) },
122 { "size_addition", opt_int,
123 (void *)offsetof(smtp_transport_options_block, size_addition) }
125 ,{ "tls_certificate", opt_stringptr,
126 (void *)offsetof(smtp_transport_options_block, tls_certificate) },
127 { "tls_crl", opt_stringptr,
128 (void *)offsetof(smtp_transport_options_block, tls_crl) },
129 { "tls_privatekey", opt_stringptr,
130 (void *)offsetof(smtp_transport_options_block, tls_privatekey) },
131 { "tls_require_ciphers", opt_stringptr,
132 (void *)offsetof(smtp_transport_options_block, tls_require_ciphers) },
133 { "tls_tempfail_tryclear", opt_bool,
134 (void *)offsetof(smtp_transport_options_block, tls_tempfail_tryclear) },
135 { "tls_verify_certificates", opt_stringptr,
136 (void *)offsetof(smtp_transport_options_block, tls_verify_certificates) }
140 /* Size of the options list. An extern variable has to be used so that its
141 address can appear in the tables drtables.c. */
143 int smtp_transport_options_count =
144 sizeof(smtp_transport_options)/sizeof(optionlist);
146 /* Default private options block for the smtp transport. */
148 smtp_transport_options_block smtp_transport_option_defaults = {
150 NULL, /* fallback_hosts */
152 NULL, /* fallback_hostlist */
153 NULL, /* authenticated_sender */
154 US"$primary_hostname", /* helo_data */
155 NULL, /* interface */
157 US"smtp", /* protocol */
158 NULL, /* serialize_hosts */
159 NULL, /* hosts_try_auth */
160 NULL, /* hosts_require_auth */
161 NULL, /* hosts_require_tls */
162 NULL, /* hosts_avoid_tls */
163 NULL, /* hosts_avoid_esmtp */
164 NULL, /* hosts_nopass_tls */
165 5*60, /* command_timeout */
166 5*60, /* connect_timeout; shorter system default overrides */
167 5*60, /* data timeout */
168 10*60, /* final timeout */
169 1024, /* size_addition */
170 5, /* hosts_max_try */
171 50, /* hosts_max_try_hardlimit */
172 TRUE, /* address_retry_include_sender */
173 FALSE, /* allow_localhost */
174 FALSE, /* authenticated_sender_force */
175 FALSE, /* gethostbyname */
176 TRUE, /* dns_qualify_single */
177 FALSE, /* dns_search_parents */
178 TRUE, /* delay_after_cutoff */
179 FALSE, /* hosts_override */
180 FALSE, /* hosts_randomize */
181 TRUE, /* keepalive */
182 FALSE, /* lmtp_ignore_quota */
183 TRUE /* retry_include_ip_address */
185 ,NULL, /* tls_certificate */
187 NULL, /* tls_privatekey */
188 NULL, /* tls_require_ciphers */
189 NULL, /* gnutls_require_kx */
190 NULL, /* gnutls_require_mac */
191 NULL, /* gnutls_require_proto */
192 NULL, /* tls_verify_certificates */
193 TRUE /* tls_tempfail_tryclear */
195 #ifdef EXPERIMENTAL_DOMAINKEYS
196 ,NULL, /* dk_canon */
197 NULL, /* dk_domain */
198 NULL, /* dk_headers */
199 NULL, /* dk_private_key */
200 NULL, /* dk_selector */
208 static uschar *smtp_command; /* Points to last cmd for error messages */
209 static uschar *mail_command; /* Points to MAIL cmd for error messages */
210 static BOOL update_waiting; /* TRUE to update the "wait" database */
213 /*************************************************
214 * Setup entry point *
215 *************************************************/
217 /* This function is called when the transport is about to be used,
218 but before running it in a sub-process. It is used for two things:
220 (1) To set the fallback host list in addresses, when delivering.
221 (2) To pass back the interface, port, protocol, and other options, for use
222 during callout verification.
225 tblock pointer to the transport instance block
226 addrlist list of addresses about to be transported
227 tf if not NULL, pointer to block in which to return options
228 uid the uid that will be set (not used)
229 gid the gid that will be set (not used)
230 errmsg place for error message (not used)
232 Returns: OK always (FAIL, DEFER not used)
236 smtp_transport_setup(transport_instance *tblock, address_item *addrlist,
237 transport_feedback *tf, uid_t uid, gid_t gid, uschar **errmsg)
239 smtp_transport_options_block *ob =
240 (smtp_transport_options_block *)(tblock->options_block);
242 errmsg = errmsg; /* Keep picky compilers happy */
246 /* Pass back options if required. This interface is getting very messy. */
250 tf->interface = ob->interface;
252 tf->protocol = ob->protocol;
253 tf->hosts = ob->hosts;
254 tf->hosts_override = ob->hosts_override;
255 tf->hosts_randomize = ob->hosts_randomize;
256 tf->gethostbyname = ob->gethostbyname;
257 tf->qualify_single = ob->dns_qualify_single;
258 tf->search_parents = ob->dns_search_parents;
259 tf->helo_data = ob->helo_data;
262 /* Set the fallback host list for all the addresses that don't have fallback
263 host lists, provided that the local host wasn't present in the original host
266 if (!testflag(addrlist, af_local_host_removed))
268 for (; addrlist != NULL; addrlist = addrlist->next)
269 if (addrlist->fallback_hosts == NULL)
270 addrlist->fallback_hosts = ob->fallback_hostlist;
278 /*************************************************
279 * Initialization entry point *
280 *************************************************/
282 /* Called for each instance, after its options have been read, to
283 enable consistency checks to be done, or anything else that needs
286 Argument: pointer to the transport instance block
291 smtp_transport_init(transport_instance *tblock)
293 smtp_transport_options_block *ob =
294 (smtp_transport_options_block *)(tblock->options_block);
296 /* Retry_use_local_part defaults FALSE if unset */
298 if (tblock->retry_use_local_part == TRUE_UNSET)
299 tblock->retry_use_local_part = FALSE;
301 /* Set the default port according to the protocol */
303 if (ob->port == NULL)
304 ob->port = (strcmpic(ob->protocol, US"lmtp") == 0)? US"lmtp" : US"smtp";
306 /* Set up the setup entry point, to be called before subprocesses for this
309 tblock->setup = smtp_transport_setup;
311 /* Complain if any of the timeouts are zero. */
313 if (ob->command_timeout <= 0 || ob->data_timeout <= 0 ||
314 ob->final_timeout <= 0)
315 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
316 "command, data, or final timeout value is zero for %s transport",
319 /* If hosts_override is set and there are local hosts, set the global
320 flag that stops verify from showing router hosts. */
322 if (ob->hosts_override && ob->hosts != NULL) tblock->overrides_hosts = TRUE;
324 /* If there are any fallback hosts listed, build a chain of host items
325 for them, but do not do any lookups at this time. */
327 host_build_hostlist(&(ob->fallback_hostlist), ob->fallback_hosts, FALSE);
334 /*************************************************
335 * Set delivery info into all active addresses *
336 *************************************************/
338 /* Only addresses whose status is >= PENDING are relevant. A lesser
339 status means that an address is not currently being processed.
342 addrlist points to a chain of addresses
343 errno_value to put in each address's errno field
344 msg to put in each address's message field
345 rc to put in each address's transport_return field
346 pass_message if TRUE, set the "pass message" flag in the address
348 If errno_value has the special value ERRNO_CONNECTTIMEOUT, ETIMEDOUT is put in
349 the errno field, and RTEF_CTOUT is ORed into the more_errno field, to indicate
350 this particular type of timeout.
356 set_errno(address_item *addrlist, int errno_value, uschar *msg, int rc,
361 if (errno_value == ERRNO_CONNECTTIMEOUT)
363 errno_value = ETIMEDOUT;
364 orvalue = RTEF_CTOUT;
366 for (addr = addrlist; addr != NULL; addr = addr->next)
368 if (addr->transport_return < PENDING) continue;
369 addr->basic_errno = errno_value;
370 addr->more_errno |= orvalue;
374 if (pass_message) setflag(addr, af_pass_message);
376 addr->transport_return = rc;
382 /*************************************************
383 * Check an SMTP response *
384 *************************************************/
386 /* This function is given an errno code and the SMTP response buffer
387 to analyse, together with the host identification for generating messages. It
388 sets an appropriate message and puts the first digit of the response code into
389 the yield variable. If no response was actually read, a suitable digit is
393 host the current host, to get its name for messages
394 errno_value pointer to the errno value
395 more_errno from the top address for use with ERRNO_FILTER_FAIL
396 buffer the SMTP response buffer
397 yield where to put a one-digit SMTP response code
398 message where to put an errror message
399 pass_message set TRUE if message is an SMTP response
401 Returns: TRUE if an SMTP "QUIT" command should be sent, else FALSE
404 static BOOL check_response(host_item *host, int *errno_value, int more_errno,
405 uschar *buffer, int *yield, uschar **message, BOOL *pass_message)
409 if (smtp_use_pipelining &&
410 (Ustrcmp(smtp_command, "MAIL") == 0 ||
411 Ustrcmp(smtp_command, "RCPT") == 0 ||
412 Ustrcmp(smtp_command, "DATA") == 0))
415 *yield = '4'; /* Default setting is to give a temporary error */
417 /* Handle response timeout */
419 if (*errno_value == ETIMEDOUT)
421 *message = US string_sprintf("SMTP timeout while connected to %s [%s] "
422 "after %s%s", host->name, host->address, pl, smtp_command);
423 if (transport_count > 0)
424 *message = US string_sprintf("%s (%d bytes written)", *message,
429 /* Handle malformed SMTP response */
431 if (*errno_value == ERRNO_SMTPFORMAT)
433 uschar *malfresp = string_printing(buffer);
434 while (isspace(*malfresp)) malfresp++;
436 *message = string_sprintf("Malformed SMTP reply (an empty line) from "
437 "%s [%s] in response to %s%s", host->name, host->address, pl,
440 *message = string_sprintf("Malformed SMTP reply from %s [%s] in response "
441 "to %s%s: %s", host->name, host->address, pl, smtp_command, malfresp);
445 /* Handle a failed filter process error; can't send QUIT as we mustn't
448 if (*errno_value == ERRNO_FILTER_FAIL)
450 *message = US string_sprintf("transport filter process failed (%d)%s",
452 (more_errno == EX_EXECFAILED)? ": unable to execute command" : "");
456 /* Handle a failed add_headers expansion; can't send QUIT as we mustn't
459 if (*errno_value == ERRNO_CHHEADER_FAIL)
462 US string_sprintf("failed to expand headers_add or headers_remove: %s",
463 expand_string_message);
467 /* Handle failure to write a complete data block */
469 if (*errno_value == ERRNO_WRITEINCOMPLETE)
471 *message = US string_sprintf("failed to write a data block");
475 /* Handle error responses from the remote mailer. */
479 uschar *s = string_printing(buffer);
480 *message = US string_sprintf("SMTP error from remote mail server after %s%s: "
481 "host %s [%s]: %s", pl, smtp_command, host->name, host->address, s);
482 *pass_message = TRUE;
487 /* No data was read. If there is no errno, this must be the EOF (i.e.
488 connection closed) case, which causes deferral. An explicit connection reset
489 error has the same effect. Otherwise, put the host's identity in the message,
490 leaving the errno value to be interpreted as well. In all cases, we have to
491 assume the connection is now dead. */
493 if (*errno_value == 0 || *errno_value == ECONNRESET)
495 *errno_value = ERRNO_SMTPCLOSED;
496 *message = US string_sprintf("Remote host %s [%s] closed connection "
497 "in response to %s%s", host->name, host->address, pl, smtp_command);
499 else *message = US string_sprintf("%s [%s]", host->name, host->address);
506 /*************************************************
507 * Write error message to logs *
508 *************************************************/
510 /* This writes to the main log and to the message log.
513 addr the address item containing error information
514 host the current host
520 write_logs(address_item *addr, host_item *host)
522 if (addr->message != NULL)
524 uschar *message = addr->message;
525 if (addr->basic_errno > 0)
526 message = string_sprintf("%s: %s", message, strerror(addr->basic_errno));
527 log_write(0, LOG_MAIN, "%s", message);
528 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
533 ((log_extra_selector & LX_outgoing_port) != 0)?
534 string_sprintf("%s [%s]:%d", host->name, host->address,
535 (host->port == PORT_NONE)? 25 : host->port)
537 string_sprintf("%s [%s]", host->name, host->address);
538 log_write(0, LOG_MAIN, "%s %s", msg, strerror(addr->basic_errno));
539 deliver_msglog("%s %s %s\n", tod_stamp(tod_log), msg,
540 strerror(addr->basic_errno));
546 /*************************************************
547 * Synchronize SMTP responses *
548 *************************************************/
550 /* This function is called from smtp_deliver() to receive SMTP responses from
551 the server, and match them up with the commands to which they relate. When
552 PIPELINING is not in use, this function is called after every command, and is
553 therefore somewhat over-engineered, but it is simpler to use a single scheme
554 that works both with and without PIPELINING instead of having two separate sets
557 The set of commands that are buffered up with pipelining may start with MAIL
558 and may end with DATA; in between are RCPT commands that correspond to the
559 addresses whose status is PENDING_DEFER. All other commands (STARTTLS, AUTH,
560 etc.) are never buffered.
562 Errors after MAIL or DATA abort the whole process leaving the response in the
563 buffer. After MAIL, pending responses are flushed, and the original command is
564 re-instated in big_buffer for error messages. For RCPT commands, the remote is
565 permitted to reject some recipient addresses while accepting others. However
566 certain errors clearly abort the whole process. Set the value in
567 transport_return to PENDING_OK if the address is accepted. If there is a
568 subsequent general error, it will get reset accordingly. If not, it will get
569 converted to OK at the end.
572 addrlist the complete address list
573 include_affixes TRUE if affixes include in RCPT
574 sync_addr ptr to the ptr of the one to start scanning at (updated)
575 host the host we are connected to
576 count the number of responses to read
578 include_sender true if 4xx retry is to include the sender it its key
579 pending_MAIL true if the first response is for MAIL
580 pending_DATA 0 if last command sent was not DATA
581 +1 if previously had a good recipient
582 -1 if not previously had a good recipient
583 inblock incoming SMTP block
584 timeout timeout value
585 buffer buffer for reading response
586 buffsize size of buffer
588 Returns: 3 if at least one address had 2xx and one had 5xx
589 2 if at least one address had 5xx but none had 2xx
590 1 if at least one host had a 2xx response, but none had 5xx
591 0 no address had 2xx or 5xx but no errors (all 4xx, or just DATA)
592 -1 timeout while reading RCPT response
593 -2 I/O or other non-response error for RCPT
594 -3 DATA or MAIL failed - errno and buffer set
598 sync_responses(address_item *addrlist, BOOL include_affixes,
599 address_item **sync_addr, host_item *host, int count,
600 BOOL address_retry_include_sender, BOOL pending_MAIL,
601 int pending_DATA, smtp_inblock *inblock, int timeout, uschar *buffer,
604 address_item *addr = *sync_addr;
607 /* Handle the response for a MAIL command. On error, reinstate the original
608 command in big_buffer for error message use, and flush any further pending
609 responses before returning, except after I/O errors and timeouts. */
614 if (!smtp_read_response(inblock, buffer, buffsize, '2', timeout))
616 Ustrcpy(big_buffer, mail_command); /* Fits, because it came from there! */
617 if (errno == 0 && buffer[0] != 0)
619 uschar flushbuffer[4096];
621 if (buffer[0] == '4')
623 save_errno = ERRNO_MAIL4XX;
624 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
628 if (!smtp_read_response(inblock, flushbuffer, sizeof(flushbuffer),
630 && (errno != 0 || flushbuffer[0] == 0))
639 if (pending_DATA) count--; /* Number of RCPT responses to come */
641 /* Read and handle the required number of RCPT responses, matching each one up
642 with an address by scanning for the next address whose status is PENDING_DEFER.
647 while (addr->transport_return != PENDING_DEFER) addr = addr->next;
649 /* The address was accepted */
651 if (smtp_read_response(inblock, buffer, buffsize, '2', timeout))
654 addr->transport_return = PENDING_OK;
656 /* If af_dr_retry_exists is set, there was a routing delay on this address;
657 ensure that any address-specific retry record is expunged. */
659 if (testflag(addr, af_dr_retry_exists))
660 retry_add_item(addr, addr->address_retry_key, rf_delete);
663 /* Timeout while reading the response */
665 else if (errno == ETIMEDOUT)
667 int save_errno = errno;
668 uschar *message = string_sprintf("SMTP timeout while connected to %s [%s] "
669 "after RCPT TO:<%s>", host->name, host->address,
670 transport_rcpt_address(addr, include_affixes));
671 set_errno(addrlist, save_errno, message, DEFER, FALSE);
672 retry_add_item(addr, addr->address_retry_key, 0);
673 update_waiting = FALSE;
677 /* Handle other errors in obtaining an SMTP response by returning -1. This
678 will cause all the addresses to be deferred. Restore the SMTP command in
679 big_buffer for which we are checking the response, so the error message
682 else if (errno != 0 || buffer[0] == 0)
684 string_format(big_buffer, big_buffer_size, "RCPT TO:<%s>",
685 transport_rcpt_address(addr, include_affixes));
689 /* Handle SMTP permanent and temporary response codes. */
694 string_sprintf("SMTP error from remote mail server after RCPT TO:<%s>: "
695 "host %s [%s]: %s", transport_rcpt_address(addr, include_affixes),
696 host->name, host->address, string_printing(buffer));
697 setflag(addr, af_pass_message);
698 deliver_msglog("%s %s\n", tod_stamp(tod_log), addr->message);
700 /* The response was 5xx */
702 if (buffer[0] == '5')
704 addr->transport_return = FAIL;
708 /* The response was 4xx */
712 addr->transport_return = DEFER;
713 addr->basic_errno = ERRNO_RCPT4XX;
714 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
716 /* Log temporary errors if there are more hosts to be tried. */
718 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", addr->message);
720 /* Do not put this message on the list of those waiting for specific
721 hosts, as otherwise it is likely to be tried too often. */
723 update_waiting = FALSE;
725 /* Add a retry item for the address so that it doesn't get tried again
726 too soon. If address_retry_include_sender is true, add the sender address
729 if (address_retry_include_sender)
731 uschar *altkey = string_sprintf("%s:<%s>", addr->address_retry_key,
733 retry_add_item(addr, altkey, 0);
735 else retry_add_item(addr, addr->address_retry_key, 0);
738 } /* Loop for next RCPT response */
740 /* Update where to start at for the next block of responses, unless we
741 have already handled all the addresses. */
743 if (addr != NULL) *sync_addr = addr->next;
745 /* Handle a response to DATA. If we have not had any good recipients, either
746 previously or in this block, the response is ignored. */
748 if (pending_DATA != 0 &&
749 !smtp_read_response(inblock, buffer, buffsize, '3', timeout))
754 if (pending_DATA > 0 || (yield & 1) != 0)
756 if (errno == 0 && buffer[0] == '4')
758 errno = ERRNO_DATA4XX;
759 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
763 (void)check_response(host, &errno, 0, buffer, &code, &msg, &pass_message);
764 DEBUG(D_transport) debug_printf("%s\nerror for DATA ignored: pipelining "
765 "is in use and there were no good recipients\n", msg);
768 /* All responses read and handled; MAIL (if present) received 2xx and DATA (if
769 present) received 3xx. If any RCPTs were handled and yielded anything other
770 than 4xx, yield will be set non-zero. */
777 /*************************************************
778 * Deliver address list to given host *
779 *************************************************/
781 /* If continue_hostname is not null, we get here only when continuing to
782 deliver down an existing channel. The channel was passed as the standard
785 Otherwise, we have to make a connection to the remote host, and do the
786 initial protocol exchange.
788 When running as an MUA wrapper, if the sender or any recipient is rejected,
789 temporarily or permanently, we force failure for all recipients.
792 addrlist chain of potential addresses to deliver; only those whose
793 transport_return field is set to PENDING_DEFER are currently
794 being processed; others should be skipped - they have either
795 been delivered to an earlier host or IP address, or been
796 failed by one of them.
797 host host to deliver to
798 host_af AF_INET or AF_INET6
799 port default TCP/IP port to use, in host byte order
800 interface interface to bind to, or NULL
801 tblock transport instance block
802 copy_host TRUE if host set in addr->host_used must be copied, because
803 it is specific to this call of the transport
804 message_defer set TRUE if yield is OK, but all addresses were deferred
805 because of a non-recipient, non-host failure, that is, a
806 4xx response to MAIL FROM, DATA, or ".". This is a defer
807 that is specific to the message.
808 suppress_tls if TRUE, don't attempt a TLS connection - this is set for
809 a second attempt after TLS initialization fails
811 Returns: OK - the connection was made and the delivery attempted;
812 the result for each address is in its data block.
813 DEFER - the connection could not be made, or something failed
814 while setting up the SMTP session, or there was a
815 non-message-specific error, such as a timeout.
816 ERROR - a filter command is specified for this transport,
817 and there was a problem setting it up; OR helo_data
818 or add_headers or authenticated_sender is specified
819 for this transport, and the string failed to expand
823 smtp_deliver(address_item *addrlist, host_item *host, int host_af, int port,
824 uschar *interface, transport_instance *tblock, BOOL copy_host,
825 BOOL *message_defer, BOOL suppress_tls)
828 address_item *sync_addr;
829 address_item *first_addr = addrlist;
834 time_t start_delivery_time = time(NULL);
835 smtp_transport_options_block *ob =
836 (smtp_transport_options_block *)(tblock->options_block);
837 BOOL lmtp = strcmpic(ob->protocol, US"lmtp") == 0;
839 BOOL send_rset = TRUE;
840 BOOL send_quit = TRUE;
841 BOOL setting_up = TRUE;
842 BOOL completed_address = FALSE;
845 BOOL pass_message = FALSE;
846 smtp_inblock inblock;
847 smtp_outblock outblock;
848 int max_rcpt = tblock->max_addresses;
849 uschar *igquotstr = US"";
850 uschar *local_authenticated_sender = authenticated_sender;
852 uschar *message = NULL;
853 uschar new_message_id[MESSAGE_ID_LENGTH + 1];
856 uschar inbuffer[4096];
857 uschar outbuffer[1024];
859 suppress_tls = suppress_tls; /* stop compiler warning when no TLS support */
861 *message_defer = FALSE;
862 smtp_command = US"initial connection";
863 if (max_rcpt == 0) max_rcpt = 999999;
865 /* Set up the buffer for reading SMTP response packets. */
867 inblock.buffer = inbuffer;
868 inblock.buffersize = sizeof(inbuffer);
869 inblock.ptr = inbuffer;
870 inblock.ptrend = inbuffer;
872 /* Set up the buffer for holding SMTP commands while pipelining */
874 outblock.buffer = outbuffer;
875 outblock.buffersize = sizeof(outbuffer);
876 outblock.ptr = outbuffer;
877 outblock.cmd_count = 0;
878 outblock.authenticating = FALSE;
880 /* Expand the greeting message */
882 helo_data = expand_string(ob->helo_data);
883 if (helo_data == NULL)
885 uschar *message = string_sprintf("failed to expand helo_data: %s",
886 expand_string_message);
887 set_errno(addrlist, 0, message, DEFER, FALSE);
891 /* If an authenticated_sender override has been specified for this transport
892 instance, expand it. If the expansion is forced to fail, and there was already
893 an authenticated_sender for this message, the original value will be used.
894 Other expansion failures are serious. An empty result is ignored, but there is
895 otherwise no check - this feature is expected to be used with LMTP and other
896 cases where non-standard addresses (e.g. without domains) might be required. */
898 if (ob->authenticated_sender != NULL)
900 uschar *new = expand_string(ob->authenticated_sender);
903 if (!expand_string_forcedfail)
905 uschar *message = string_sprintf("failed to expand "
906 "authenticated_sender: %s", expand_string_message);
907 set_errno(addrlist, 0, message, DEFER, FALSE);
911 else if (new[0] != 0) local_authenticated_sender = new;
914 /* Make a connection to the host if this isn't a continued delivery, and handle
915 the initial interaction and HELO/EHLO/LHLO. Connect timeout errors are handled
916 specially so they can be identified for retries. */
918 if (continue_hostname == NULL)
920 inblock.sock = outblock.sock =
921 smtp_connect(host, host_af, port, interface, ob->connect_timeout,
923 if (inblock.sock < 0)
925 set_errno(addrlist, (errno == ETIMEDOUT)? ERRNO_CONNECTTIMEOUT : errno,
930 /* The first thing is to wait for an initial OK response. The dreaded "goto"
931 is nevertheless a reasonably clean way of programming this kind of logic,
932 where you want to escape on any error. */
934 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
935 ob->command_timeout)) goto RESPONSE_FAILED;
937 /** Debugging without sending a message
938 addrlist->transport_return = DEFER;
942 /* Errors that occur after this point follow an SMTP command, which is
943 left in big_buffer by smtp_write_command() for use in error messages. */
945 smtp_command = big_buffer;
947 /* Tell the remote who we are...
949 February 1998: A convention has evolved that ESMTP-speaking MTAs include the
950 string "ESMTP" in their greeting lines, so make Exim send EHLO if the
951 greeting is of this form. The assumption was that the far end supports it
952 properly... but experience shows that there are some that give 5xx responses,
953 even though the banner includes "ESMTP" (there's a bloody-minded one that
954 says "ESMTP not spoken here"). Cope with that case.
956 September 2000: Time has passed, and it seems reasonable now to always send
957 EHLO at the start. It is also convenient to make the change while installing
960 July 2003: Joachim Wieland met a broken server that advertises "PIPELINING"
961 but times out after sending MAIL FROM, RCPT TO and DATA all together. There
962 would be no way to send out the mails, so there is now a host list
963 "hosts_avoid_esmtp" that disables ESMTP for special hosts and solves the
964 PIPELINING problem as well. Maybe it can also be useful to cure other
965 problems with broken servers.
967 Exim originally sent "Helo" at this point and ran for nearly a year that way.
968 Then somebody tried it with a Microsoft mailer... It seems that all other
969 mailers use upper case for some reason (the RFC is quite clear about case
970 independence) so, for peace of mind, I gave in. */
972 esmtp = verify_check_this_host(&(ob->hosts_avoid_esmtp), NULL,
973 host->name, host->address, NULL) != OK;
977 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n",
978 lmtp? "LHLO" : "EHLO", helo_data) < 0)
980 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
981 ob->command_timeout))
983 if (errno != 0 || buffer[0] == 0 || lmtp) goto RESPONSE_FAILED;
990 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
995 if (smtp_write_command(&outblock, FALSE, "HELO %s\r\n", helo_data) < 0)
997 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
998 ob->command_timeout)) goto RESPONSE_FAILED;
1001 /* Set IGNOREQUOTA if the response to LHLO specifies support and the
1002 lmtp_ignore_quota option was set. */
1004 igquotstr = (lmtp && ob->lmtp_ignore_quota &&
1005 pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer, Ustrlen(CS buffer), 0,
1006 PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
1008 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
1011 tls_offered = esmtp &&
1012 pcre_exec(regex_STARTTLS, NULL, CS buffer, Ustrlen(buffer), 0,
1013 PCRE_EOPT, NULL, 0) >= 0;
1017 /* For continuing deliveries down the same channel, the socket is the standard
1018 input, and we don't need to redo EHLO here (but may need to do so for TLS - see
1019 below). Set up the pointer to where subsequent commands will be left, for
1020 error messages. Note that smtp_use_size and smtp_use_pipelining will have been
1021 set from the command line if they were set in the process that passed the
1026 inblock.sock = outblock.sock = fileno(stdin);
1027 smtp_command = big_buffer;
1030 /* If TLS is available on this connection, whether continued or not, attempt to
1031 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
1032 send another EHLO - the server may give a different answer in secure mode. We
1033 use a separate buffer for reading the response to STARTTLS so that if it is
1034 negative, the original EHLO data is available for subsequent analysis, should
1035 the client not be required to use TLS. If the response is bad, copy the buffer
1036 for error analysis. */
1039 if (tls_offered && !suppress_tls &&
1040 verify_check_this_host(&(ob->hosts_avoid_tls), NULL, host->name,
1041 host->address, NULL) != OK)
1043 uschar buffer2[4096];
1044 if (smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") < 0)
1047 /* If there is an I/O error, transmission of this message is deferred. If
1048 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
1049 false, we also defer. However, if there is a temporary rejection of STARTTLS
1050 and tls_tempfail_tryclear is true, or if there is an outright rejection of
1051 STARTTLS, we carry on. This means we will try to send the message in clear,
1052 unless the host is in hosts_require_tls (tested below). */
1054 if (!smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
1055 ob->command_timeout))
1057 Ustrncpy(buffer, buffer2, sizeof(buffer));
1058 if (errno != 0 || buffer2[0] == 0 ||
1059 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
1060 goto RESPONSE_FAILED;
1063 /* STARTTLS accepted: try to negotiate a TLS session. */
1067 int rc = tls_client_start(inblock.sock,
1070 NULL, /* No DH param */
1071 ob->tls_certificate,
1073 ob->tls_verify_certificates,
1075 ob->tls_require_ciphers,
1076 ob->gnutls_require_mac,
1077 ob->gnutls_require_kx,
1078 ob->gnutls_require_proto,
1079 ob->command_timeout);
1081 /* TLS negotiation failed; give an error. From outside, this function may
1082 be called again to try in clear on a new connection, if the options permit
1083 it for this host. */
1087 save_errno = ERRNO_TLSFAILURE;
1088 message = US"failure while setting up TLS session";
1093 /* TLS session is set up */
1095 for (addr = addrlist; addr != NULL; addr = addr->next)
1097 if (addr->transport_return == PENDING_DEFER)
1099 addr->cipher = tls_cipher;
1100 addr->peerdn = tls_peerdn;
1106 /* If we started TLS, redo the EHLO/LHLO exchange over the secure channel. */
1108 if (tls_active >= 0)
1110 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n", lmtp? "LHLO" : "EHLO",
1113 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1114 ob->command_timeout))
1115 goto RESPONSE_FAILED;
1118 /* If the host is required to use a secure channel, ensure that we
1121 else if (verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
1122 host->address, NULL) == OK)
1124 save_errno = ERRNO_TLSREQUIRED;
1125 message = string_sprintf("a TLS session is required for %s [%s], but %s",
1126 host->name, host->address,
1127 tls_offered? "an attempt to start TLS failed" :
1128 "the server did not offer TLS support");
1133 /* If TLS is active, we have just started it up and re-done the EHLO command,
1134 so its response needs to be analyzed. If TLS is not active and this is a
1135 continued session down a previously-used socket, we haven't just done EHLO, so
1138 if (continue_hostname == NULL
1145 uschar *fail_reason = US"server did not advertise AUTH support";
1147 /* Set for IGNOREQUOTA if the response to LHLO specifies support and the
1148 lmtp_ignore_quota option was set. */
1150 igquotstr = (lmtp && ob->lmtp_ignore_quota &&
1151 pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer, Ustrlen(CS buffer), 0,
1152 PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
1154 /* If the response to EHLO specified support for the SIZE parameter, note
1155 this, provided size_addition is non-negative. */
1157 smtp_use_size = esmtp && ob->size_addition >= 0 &&
1158 pcre_exec(regex_SIZE, NULL, CS buffer, Ustrlen(CS buffer), 0,
1159 PCRE_EOPT, NULL, 0) >= 0;
1161 /* Note whether the server supports PIPELINING. If hosts_avoid_esmtp matched
1162 the current host, esmtp will be false, so PIPELINING can never be used. */
1164 smtp_use_pipelining = esmtp &&
1165 pcre_exec(regex_PIPELINING, NULL, CS buffer, Ustrlen(CS buffer), 0,
1166 PCRE_EOPT, NULL, 0) >= 0;
1168 DEBUG(D_transport) debug_printf("%susing PIPELINING\n",
1169 smtp_use_pipelining? "" : "not ");
1171 /* Note if the response to EHLO specifies support for the AUTH extension.
1172 If it has, check that this host is one we want to authenticate to, and do
1173 the business. The host name and address must be available when the
1174 authenticator's client driver is running. */
1176 smtp_authenticated = FALSE;
1177 require_auth = verify_check_this_host(&(ob->hosts_require_auth), NULL,
1178 host->name, host->address, NULL);
1180 if (esmtp && regex_match_and_setup(regex_AUTH, buffer, 0, -1))
1182 uschar *names = string_copyn(expand_nstring[1], expand_nlength[1]);
1183 expand_nmax = -1; /* reset */
1185 /* Must not do this check until after we have saved the result of the
1186 regex match above. */
1188 if (require_auth == OK ||
1189 verify_check_this_host(&(ob->hosts_try_auth), NULL, host->name,
1190 host->address, NULL) == OK)
1193 fail_reason = US"no common mechanisms were found";
1195 DEBUG(D_transport) debug_printf("scanning authentication mechanisms\n");
1197 /* Scan the configured authenticators looking for one which is configured
1198 for use as a client and whose name matches an authentication mechanism
1199 supported by the server. If one is found, attempt to authenticate by
1200 calling its client function. */
1202 for (au = auths; !smtp_authenticated && au != NULL; au = au->next)
1205 if (!au->client) continue;
1207 /* Loop to scan supported server mechanisms */
1212 int len = Ustrlen(au->public_name);
1213 while (isspace(*p)) p++;
1215 if (strncmpic(au->public_name, p, len) != 0 ||
1216 (p[len] != 0 && !isspace(p[len])))
1218 while (*p != 0 && !isspace(*p)) p++;
1222 /* Found data for a listed mechanism. Call its client entry. Set
1223 a flag in the outblock so that data is overwritten after sending so
1224 that reflections don't show it. */
1226 fail_reason = US"authentication attempt(s) failed";
1227 outblock.authenticating = TRUE;
1228 rc = (au->info->clientcode)(au, &inblock, &outblock,
1229 ob->command_timeout, buffer, sizeof(buffer));
1230 outblock.authenticating = FALSE;
1231 DEBUG(D_transport) debug_printf("%s authenticator yielded %d\n",
1234 /* A temporary authentication failure must hold up delivery to
1235 this host. After a permanent authentication failure, we carry on
1236 to try other authentication methods. If all fail hard, try to
1237 deliver the message unauthenticated unless require_auth was set. */
1242 smtp_authenticated = TRUE; /* stops the outer loop */
1245 /* Failure after writing a command */
1250 /* Failure after reading a response */
1253 if (errno != 0 || buffer[0] != '5') goto RESPONSE_FAILED;
1254 log_write(0, LOG_MAIN, "%s authenticator failed H=%s [%s] %s",
1255 au->name, host->name, host->address, buffer);
1258 /* Failure by some other means. In effect, the authenticator
1259 decided it wasn't prepared to handle this case. Typically this
1260 is the result of "fail" in an expansion string. Do we need to
1261 log anything here? Feb 2006: a message is now put in the buffer
1262 if logging is required. */
1266 log_write(0, LOG_MAIN, "%s authenticator cancelled "
1267 "authentication H=%s [%s] %s", au->name, host->name,
1268 host->address, buffer);
1271 /* Internal problem, message in buffer. */
1275 set_errno(addrlist, 0, string_copy(buffer), DEFER, FALSE);
1279 break; /* If not authenticated, try next authenticator */
1280 } /* Loop for scanning supported server mechanisms */
1281 } /* Loop for further authenticators */
1285 /* If we haven't authenticated, but are required to, give up. */
1287 if (require_auth == OK && !smtp_authenticated)
1290 set_errno(addrlist, ERRNO_AUTHFAIL,
1291 string_sprintf("authentication required but %s", fail_reason), DEFER,
1297 /* The setting up of the SMTP call is now complete. Any subsequent errors are
1298 message-specific. */
1302 /* If there is a filter command specified for this transport, we can now
1303 set it up. This cannot be done until the identify of the host is known. */
1305 if (tblock->filter_command != NULL)
1309 sprintf(CS buffer, "%.50s transport", tblock->name);
1310 rc = transport_set_up_command(&transport_filter_argv, tblock->filter_command,
1311 TRUE, DEFER, addrlist, buffer, NULL);
1313 /* On failure, copy the error to all addresses, abandon the SMTP call, and
1318 set_errno(addrlist->next, addrlist->basic_errno, addrlist->message, DEFER,
1326 /* For messages that have more than the maximum number of envelope recipients,
1327 we want to send several transactions down the same SMTP connection. (See
1328 comments in deliver.c as to how this reconciles, heuristically, with
1329 remote_max_parallel.) This optimization was added to Exim after the following
1330 code was already working. The simplest way to put it in without disturbing the
1331 code was to use a goto to jump back to this point when there is another
1332 transaction to handle. */
1335 sync_addr = first_addr;
1339 completed_address = FALSE;
1342 /* Initiate a message transfer. If we know the receiving MTA supports the SIZE
1343 qualification, send it, adding something to the message size to allow for
1344 imprecision and things that get added en route. Exim keeps the number of lines
1345 in a message, so we can give an accurate value for the original message, but we
1346 need some additional to handle added headers. (Double "." characters don't get
1347 included in the count.) */
1354 sprintf(CS p, " SIZE=%d", message_size+message_linecount+ob->size_addition);
1358 /* Add the authenticated sender address if present */
1360 if ((smtp_authenticated || ob->authenticated_sender_force) &&
1361 local_authenticated_sender != NULL)
1363 string_format(p, sizeof(buffer) - (p-buffer), " AUTH=%s",
1364 auth_xtextencode(local_authenticated_sender,
1365 Ustrlen(local_authenticated_sender)));
1368 /* From here until we send the DATA command, we can make use of PIPELINING
1369 if the server host supports it. The code has to be able to check the responses
1370 at any point, for when the buffer fills up, so we write it totally generally.
1371 When PIPELINING is off, each command written reports that it has flushed the
1374 pending_MAIL = TRUE; /* The block starts with MAIL */
1376 rc = smtp_write_command(&outblock, smtp_use_pipelining,
1377 "MAIL FROM:<%s>%s\r\n", return_path, buffer);
1378 mail_command = string_copy(big_buffer); /* Save for later error message */
1382 case -1: /* Transmission error */
1385 case +1: /* Block was sent */
1386 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1387 ob->command_timeout))
1389 if (errno == 0 && buffer[0] == '4')
1391 errno = ERRNO_MAIL4XX;
1392 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1394 goto RESPONSE_FAILED;
1396 pending_MAIL = FALSE;
1400 /* Pass over all the relevant recipient addresses for this host, which are the
1401 ones that have status PENDING_DEFER. If we are using PIPELINING, we can send
1402 several before we have to read the responses for those seen so far. This
1403 checking is done by a subroutine because it also needs to be done at the end.
1404 Send only up to max_rcpt addresses at a time, leaving first_addr pointing to
1405 the next one if not all are sent.
1407 In the MUA wrapper situation, we want to flush the PIPELINING buffer for the
1408 last address because we want to abort if any recipients have any kind of
1409 problem, temporary or permanent. We know that all recipient addresses will have
1410 the PENDING_DEFER status, because only one attempt is ever made, and we know
1411 that max_rcpt will be large, so all addresses will be done at once. */
1413 for (addr = first_addr;
1414 address_count < max_rcpt && addr != NULL;
1420 if (addr->transport_return != PENDING_DEFER) continue;
1423 no_flush = smtp_use_pipelining && (!mua_wrapper || addr->next != NULL);
1425 /* Now send the RCPT command, and process outstanding responses when
1426 necessary. After a timeout on RCPT, we just end the function, leaving the
1427 yield as OK, because this error can often mean that there is a problem with
1428 just one address, so we don't want to delay the host. */
1430 count = smtp_write_command(&outblock, no_flush, "RCPT TO:<%s>%s\r\n",
1431 transport_rcpt_address(addr, tblock->rcpt_include_affixes), igquotstr);
1432 if (count < 0) goto SEND_FAILED;
1435 switch(sync_responses(first_addr, tblock->rcpt_include_affixes,
1436 &sync_addr, host, count, ob->address_retry_include_sender,
1437 pending_MAIL, 0, &inblock, ob->command_timeout, buffer,
1440 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1441 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1444 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1445 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1446 case 0: /* No 2xx or 5xx, but no probs */
1449 case -1: goto END_OFF; /* Timeout on RCPT */
1450 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL error */
1452 pending_MAIL = FALSE; /* Dealt with MAIL */
1454 } /* Loop for next address */
1456 /* If we are an MUA wrapper, abort if any RCPTs were rejected, either
1457 permanently or temporarily. We should have flushed and synced after the last
1462 address_item *badaddr;
1463 for (badaddr = first_addr; badaddr != NULL; badaddr = badaddr->next)
1465 if (badaddr->transport_return != PENDING_OK) break;
1467 if (badaddr != NULL)
1469 set_errno(addrlist, 0, badaddr->message, FAIL,
1470 testflag(badaddr, af_pass_message));
1475 /* If ok is TRUE, we know we have got at least one good recipient, and must now
1476 send DATA, but if it is FALSE (in the normal, non-wrapper case), we may still
1477 have a good recipient buffered up if we are pipelining. We don't want to waste
1478 time sending DATA needlessly, so we only send it if either ok is TRUE or if we
1479 are pipelining. The responses are all handled by sync_responses(). */
1481 if (ok || (smtp_use_pipelining && !mua_wrapper))
1483 int count = smtp_write_command(&outblock, FALSE, "DATA\r\n");
1484 if (count < 0) goto SEND_FAILED;
1485 switch(sync_responses(first_addr, tblock->rcpt_include_affixes, &sync_addr,
1486 host, count, ob->address_retry_include_sender, pending_MAIL,
1487 ok? +1 : -1, &inblock, ob->command_timeout, buffer, sizeof(buffer)))
1489 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1490 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1493 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1494 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1495 case 0: break; /* No 2xx or 5xx, but no probs */
1497 case -1: goto END_OFF; /* Timeout on RCPT */
1498 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */
1502 /* Save the first address of the next batch. */
1506 /* If there were no good recipients (but otherwise there have been no
1507 problems), just set ok TRUE, since we have handled address-specific errors
1508 already. Otherwise, it's OK to send the message. Use the check/escape mechanism
1509 for handling the SMTP dot-handling protocol, flagging to apply to headers as
1510 well as body. Set the appropriate timeout value to be used for each chunk.
1511 (Haven't been able to make it work using select() for writing yet.) */
1513 if (!ok) ok = TRUE; else
1515 sigalrm_seen = FALSE;
1516 transport_write_timeout = ob->data_timeout;
1517 smtp_command = US"sending data block"; /* For error messages */
1518 DEBUG(D_transport|D_v)
1519 debug_printf(" SMTP>> writing message and terminating \".\"\n");
1520 transport_count = 0;
1521 #ifdef EXPERIMENTAL_DOMAINKEYS
1522 if ( (ob->dk_private_key != NULL) && (ob->dk_selector != NULL) )
1523 ok = dk_transport_write_message(addrlist, inblock.sock,
1524 topt_use_crlf | topt_end_dot | topt_escape_headers |
1525 (tblock->body_only? topt_no_headers : 0) |
1526 (tblock->headers_only? topt_no_body : 0) |
1527 (tblock->return_path_add? topt_add_return_path : 0) |
1528 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1529 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1530 0, /* No size limit */
1531 tblock->add_headers, tblock->remove_headers,
1532 US".", US"..", /* Escaping strings */
1533 tblock->rewrite_rules, tblock->rewrite_existflags,
1534 ob->dk_private_key, ob->dk_domain, ob->dk_selector,
1535 ob->dk_canon, ob->dk_headers, ob->dk_strict);
1538 ok = transport_write_message(addrlist, inblock.sock,
1539 topt_use_crlf | topt_end_dot | topt_escape_headers |
1540 (tblock->body_only? topt_no_headers : 0) |
1541 (tblock->headers_only? topt_no_body : 0) |
1542 (tblock->return_path_add? topt_add_return_path : 0) |
1543 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1544 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1545 0, /* No size limit */
1546 tblock->add_headers, tblock->remove_headers,
1547 US".", US"..", /* Escaping strings */
1548 tblock->rewrite_rules, tblock->rewrite_existflags);
1550 /* transport_write_message() uses write() because it is called from other
1551 places to write to non-sockets. This means that under some OS (e.g. Solaris)
1552 it can exit with "Broken pipe" as its error. This really means that the
1553 socket got closed at the far end. */
1555 transport_write_timeout = 0; /* for subsequent transports */
1557 /* Failure can either be some kind of I/O disaster (including timeout),
1558 or the failure of a transport filter or the expansion of added headers. */
1562 buffer[0] = 0; /* There hasn't been a response */
1563 goto RESPONSE_FAILED;
1566 /* We used to send the terminating "." explicitly here, but because of
1567 buffering effects at both ends of TCP/IP connections, you don't gain
1568 anything by keeping it separate, so it might as well go in the final
1569 data buffer for efficiency. This is now done by setting the topt_end_dot
1572 smtp_command = US"end of data";
1574 /* For SMTP, we now read a single response that applies to the whole message.
1575 If it is OK, then all the addresses have been delivered. */
1579 ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1581 if (!ok && errno == 0 && buffer[0] == '4')
1583 errno = ERRNO_DATA4XX;
1584 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1588 /* For LMTP, we get back a response for every RCPT command that we sent;
1589 some may be accepted and some rejected. For those that get a response, their
1590 status is fixed; any that are accepted have been handed over, even if later
1591 responses crash - at least, that's how I read RFC 2033.
1593 If all went well, mark the recipient addresses as completed, record which
1594 host/IPaddress they were delivered to, and cut out RSET when sending another
1595 message down the same channel. Write the completed addresses to the journal
1596 now so that they are recorded in case there is a crash of hardware or
1597 software before the spool gets updated. Also record the final SMTP
1598 confirmation if needed (for SMTP only). */
1603 int delivery_time = (int)(time(NULL) - start_delivery_time);
1606 uschar *conf = NULL;
1609 /* Make a copy of the host if it is local to this invocation
1610 of the transport. */
1614 thost = store_get(sizeof(host_item));
1616 thost->name = string_copy(host->name);
1617 thost->address = string_copy(host->address);
1621 /* Set up confirmation if needed - applies only to SMTP */
1623 if ((log_extra_selector & LX_smtp_confirmation) != 0 && !lmtp)
1625 uschar *s = string_printing(buffer);
1626 conf = (s == buffer)? (uschar *)string_copy(s) : s;
1629 /* Process all transported addresses - for LMTP, read a status for
1632 for (addr = addrlist; addr != first_addr; addr = addr->next)
1634 if (addr->transport_return != PENDING_OK) continue;
1636 /* LMTP - if the response fails badly (e.g. timeout), use it for all the
1637 remaining addresses. Otherwise, it's a return code for just the one
1638 address. For temporary errors, add a retry item for the address so that
1639 it doesn't get tried again too soon. */
1643 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1646 if (errno != 0 || buffer[0] == 0) goto RESPONSE_FAILED;
1647 addr->message = string_sprintf("LMTP error after %s: %s",
1648 big_buffer, string_printing(buffer));
1649 setflag(addr, af_pass_message); /* Allow message to go to user */
1650 if (buffer[0] == '5')
1651 addr->transport_return = FAIL;
1654 errno = ERRNO_DATA4XX;
1655 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1656 addr->transport_return = DEFER;
1657 retry_add_item(addr, addr->address_retry_key, 0);
1661 completed_address = TRUE; /* NOW we can set this flag */
1664 /* SMTP, or success return from LMTP for this address. Pass back the
1665 actual host that was used. */
1667 addr->transport_return = OK;
1668 addr->more_errno = delivery_time;
1669 addr->host_used = thost;
1670 addr->special_action = flag;
1671 addr->message = conf;
1674 /* Update the journal. For homonymic addresses, use the base address plus
1675 the transport name. See lots of comments in deliver.c about the reasons
1676 for the complications when homonyms are involved. Just carry on after
1677 write error, as it may prove possible to update the spool file later. */
1679 if (testflag(addr, af_homonym))
1680 sprintf(CS buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
1682 sprintf(CS buffer, "%.500s\n", addr->unique);
1684 DEBUG(D_deliver) debug_printf("journalling %s", buffer);
1685 len = Ustrlen(CS buffer);
1686 if (write(journal_fd, buffer, len) != len)
1687 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
1688 "%s: %s", buffer, strerror(errno));
1691 /* Ensure the journal file is pushed out to disk. */
1693 if (fsync(journal_fd) < 0)
1694 log_write(0, LOG_MAIN|LOG_PANIC, "failed to fsync journal: %s",
1700 /* Handle general (not specific to one address) failures here. The value of ok
1701 is used to skip over this code on the falling through case. A timeout causes a
1702 deferral. Other errors may defer or fail according to the response code, and
1703 may set up a special errno value, e.g. after connection chopped, which is
1704 assumed if errno == 0 and there is no text in the buffer. If control reaches
1705 here during the setting up phase (i.e. before MAIL FROM) then always defer, as
1706 the problem is not related to this specific message. */
1715 send_quit = check_response(host, &save_errno, addrlist->more_errno,
1716 buffer, &code, &message, &pass_message);
1722 message = US string_sprintf("send() to %s [%s] failed: %s",
1723 host->name, host->address, strerror(save_errno));
1727 /* This label is jumped to directly when a TLS negotiation has failed,
1728 or was not done for a host for which it is required. Values will be set
1729 in message and save_errno, and setting_up will always be true. Treat as
1730 a temporary error. */
1737 /* If the failure happened while setting up the call, see if the failure was
1738 a 5xx response (this will either be on connection, or following HELO - a 5xx
1739 after EHLO causes it to try HELO). If so, fail all addresses, as this host is
1740 never going to accept them. For other errors during setting up (timeouts or
1741 whatever), defer all addresses, and yield DEFER, so that the host is not
1742 tried again for a while. */
1745 ok = FALSE; /* For when reached by GOTO */
1751 set_errno(addrlist, save_errno, message, FAIL, pass_message);
1755 set_errno(addrlist, save_errno, message, DEFER, pass_message);
1760 /* We want to handle timeouts after MAIL or "." and loss of connection after
1761 "." specially. They can indicate a problem with the sender address or with
1762 the contents of the message rather than a real error on the connection. These
1763 cases are treated in the same way as a 4xx response. This next bit of code
1764 does the classification. */
1775 message_error = TRUE;
1779 message_error = Ustrncmp(smtp_command,"MAIL",4) == 0 ||
1780 Ustrncmp(smtp_command,"end ",4) == 0;
1783 case ERRNO_SMTPCLOSED:
1784 message_error = Ustrncmp(smtp_command,"end ",4) == 0;
1788 message_error = FALSE;
1792 /* Handle the cases that are treated as message errors. These are:
1794 (a) negative response or timeout after MAIL
1795 (b) negative response after DATA
1796 (c) negative response or timeout or dropped connection after "."
1798 It won't be a negative response or timeout after RCPT, as that is dealt
1799 with separately above. The action in all cases is to set an appropriate
1800 error code for all the addresses, but to leave yield set to OK because the
1801 host itself has not failed. Of course, it might in practice have failed
1802 when we've had a timeout, but if so, we'll discover that at the next
1803 delivery attempt. For a temporary error, set the message_defer flag, and
1804 write to the logs for information if this is not the last host. The error
1805 for the last host will be logged as part of the address's log line. */
1809 if (mua_wrapper) code = '5'; /* Force hard failure in wrapper mode */
1810 set_errno(addrlist, save_errno, message, (code == '5')? FAIL : DEFER,
1813 /* If there's an errno, the message contains just the identity of
1816 if (code != '5') /* Anything other than 5 is treated as temporary */
1819 message = US string_sprintf("%s: %s", message, strerror(save_errno));
1820 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", message);
1821 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
1822 *message_defer = TRUE;
1826 /* Otherwise, we have an I/O error or a timeout other than after MAIL or
1827 ".", or some other transportation error. We defer all addresses and yield
1828 DEFER, except for the case of failed add_headers expansion, or a transport
1829 filter failure, when the yield should be ERROR, to stop it trying other
1834 yield = (save_errno == ERRNO_CHHEADER_FAIL ||
1835 save_errno == ERRNO_FILTER_FAIL)? ERROR : DEFER;
1836 set_errno(addrlist, save_errno, message, DEFER, pass_message);
1842 /* If all has gone well, send_quit will be set TRUE, implying we can end the
1843 SMTP session tidily. However, if there were too many addresses to send in one
1844 message (indicated by first_addr being non-NULL) we want to carry on with the
1845 rest of them. Also, it is desirable to send more than one message down the SMTP
1846 connection if there are several waiting, provided we haven't already sent so
1847 many as to hit the configured limit. The function transport_check_waiting looks
1848 for a waiting message and returns its id. Then transport_pass_socket tries to
1849 set up a continued delivery by passing the socket on to another process. The
1850 variable send_rset is FALSE if a message has just been successfully transfered.
1852 If we are already sending down a continued channel, there may be further
1853 addresses not yet delivered that are aimed at the same host, but which have not
1854 been passed in this run of the transport. In this case, continue_more will be
1855 true, and all we should do is send RSET if necessary, and return, leaving the
1858 However, if no address was disposed of, i.e. all addresses got 4xx errors, we
1859 do not want to continue with other messages down the same channel, because that
1860 can lead to looping between two or more messages, all with the same,
1861 temporarily failing address(es). [The retry information isn't updated yet, so
1862 new processes keep on trying.] We probably also don't want to try more of this
1863 message's addresses either.
1865 If we have started a TLS session, we have to end it before passing the
1866 connection to a new process. However, not all servers can handle this (Exim
1867 can), so we do not pass such a connection on if the host matches
1868 hosts_nopass_tls. */
1871 debug_printf("ok=%d send_quit=%d send_rset=%d continue_more=%d "
1872 "yield=%d first_address is %sNULL\n", ok, send_quit, send_rset,
1873 continue_more, yield, (first_addr == NULL)? "":"not ");
1875 if (completed_address && ok && send_quit)
1878 if (first_addr != NULL || continue_more ||
1881 verify_check_this_host(&(ob->hosts_nopass_tls), NULL, host->name,
1882 host->address, NULL) != OK)
1884 transport_check_waiting(tblock->name, host->name,
1885 tblock->connection_max_messages, new_message_id, &more)
1893 if (! (ok = smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0))
1895 msg = US string_sprintf("send() to %s [%s] failed: %s", host->name,
1896 host->address, strerror(save_errno));
1899 else if (! (ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1900 ob->command_timeout)))
1903 send_quit = check_response(host, &errno, 0, buffer, &code, &msg,
1907 DEBUG(D_transport) debug_printf("%s\n", msg);
1912 /* Either RSET was not needed, or it succeeded */
1916 if (first_addr != NULL) /* More addresses still to be sent */
1917 { /* in this run of the transport */
1918 continue_sequence++; /* Causes * in logging */
1921 if (continue_more) return yield; /* More addresses for another run */
1923 /* Pass the socket to a new Exim process. Before doing so, we must shut
1924 down TLS. Not all MTAs allow for the continuation of the SMTP session
1925 when TLS is shut down. We test for this by sending a new EHLO. If we
1926 don't get a good response, we don't attempt to pass the socket on. */
1929 if (tls_active >= 0)
1932 ok = smtp_write_command(&outblock,FALSE,"EHLO %s\r\n",helo_data) >= 0 &&
1933 smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1934 ob->command_timeout);
1938 /* If the socket is successfully passed, we musn't send QUIT (or
1939 indeed anything!) from here. */
1941 if (ok && transport_pass_socket(tblock->name, host->name, host->address,
1942 new_message_id, inblock.sock))
1948 /* If RSET failed and there are addresses left, they get deferred. */
1950 else set_errno(first_addr, errno, msg, DEFER, FALSE);
1954 /* End off tidily with QUIT unless the connection has died or the socket has
1955 been passed to another process. There has been discussion on the net about what
1956 to do after sending QUIT. The wording of the RFC suggests that it is necessary
1957 to wait for a response, but on the other hand, there isn't anything one can do
1958 with an error response, other than log it. Exim used to do that. However,
1959 further discussion suggested that it is positively advantageous not to wait for
1960 the response, but to close the session immediately. This is supposed to move
1961 the TCP/IP TIME_WAIT state from the server to the client, thereby removing some
1962 load from the server. (Hosts that are both servers and clients may not see much
1963 difference, of course.) Further discussion indicated that this was safe to do
1964 on Unix systems which have decent implementations of TCP/IP that leave the
1965 connection around for a while (TIME_WAIT) after the application has gone away.
1966 This enables the response sent by the server to be properly ACKed rather than
1967 timed out, as can happen on broken TCP/IP implementations on other OS.
1969 This change is being made on 31-Jul-98. After over a year of trouble-free
1970 operation, the old commented-out code was removed on 17-Sep-99. */
1973 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1981 /* Close the socket, and return the appropriate value, first setting
1982 continue_transport and continue_hostname NULL to prevent any other addresses
1983 that may include the host from trying to re-use a continuation socket. This
1984 works because the NULL setting is passed back to the calling process, and
1985 remote_max_parallel is forced to 1 when delivering over an existing connection,
1987 If all went well and continue_more is set, we shouldn't actually get here if
1988 there are further addresses, as the return above will be taken. However,
1989 writing RSET might have failed, or there may be other addresses whose hosts are
1990 specified in the transports, and therefore not visible at top level, in which
1991 case continue_more won't get set. */
1993 (void)close(inblock.sock);
1994 continue_transport = NULL;
1995 continue_hostname = NULL;
2002 /*************************************************
2003 * Closedown entry point *
2004 *************************************************/
2006 /* This function is called when exim is passed an open smtp channel
2007 from another incarnation, but the message which it has been asked
2008 to deliver no longer exists. The channel is on stdin.
2010 We might do fancy things like looking for another message to send down
2011 the channel, but if the one we sought has gone, it has probably been
2012 delivered by some other process that itself will seek further messages,
2013 so just close down our connection.
2015 Argument: pointer to the transport instance block
2020 smtp_transport_closedown(transport_instance *tblock)
2022 smtp_transport_options_block *ob =
2023 (smtp_transport_options_block *)(tblock->options_block);
2024 smtp_inblock inblock;
2025 smtp_outblock outblock;
2027 uschar inbuffer[4096];
2028 uschar outbuffer[16];
2030 inblock.sock = fileno(stdin);
2031 inblock.buffer = inbuffer;
2032 inblock.buffersize = sizeof(inbuffer);
2033 inblock.ptr = inbuffer;
2034 inblock.ptrend = inbuffer;
2036 outblock.sock = inblock.sock;
2037 outblock.buffersize = sizeof(outbuffer);
2038 outblock.buffer = outbuffer;
2039 outblock.ptr = outbuffer;
2040 outblock.cmd_count = 0;
2041 outblock.authenticating = FALSE;
2043 (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
2044 (void)smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2045 ob->command_timeout);
2046 (void)close(inblock.sock);
2051 /*************************************************
2052 * Prepare addresses for delivery *
2053 *************************************************/
2055 /* This function is called to flush out error settings from previous delivery
2056 attempts to other hosts. It also records whether we got here via an MX record
2057 or not in the more_errno field of the address. We are interested only in
2058 addresses that are still marked DEFER - others may have got delivered to a
2059 previously considered IP address. Set their status to PENDING_DEFER to indicate
2060 which ones are relevant this time.
2063 addrlist the list of addresses
2064 host the host we are delivering to
2066 Returns: the first address for this delivery
2069 static address_item *
2070 prepare_addresses(address_item *addrlist, host_item *host)
2072 address_item *first_addr = NULL;
2074 for (addr = addrlist; addr != NULL; addr = addr->next)
2076 if (addr->transport_return != DEFER) continue;
2077 if (first_addr == NULL) first_addr = addr;
2078 addr->transport_return = PENDING_DEFER;
2079 addr->basic_errno = 0;
2080 addr->more_errno = (host->mx >= 0)? 'M' : 'A';
2081 addr->message = NULL;
2083 addr->cipher = NULL;
2084 addr->peerdn = NULL;
2092 /*************************************************
2093 * Main entry point *
2094 *************************************************/
2096 /* See local README for interface details. As this is a remote transport, it is
2097 given a chain of addresses to be delivered in one connection, if possible. It
2098 always returns TRUE, indicating that each address has its own independent
2099 status set, except if there is a setting up problem, in which case it returns
2103 smtp_transport_entry(
2104 transport_instance *tblock, /* data for this instantiation */
2105 address_item *addrlist) /* addresses we are working on */
2109 int hosts_defer = 0;
2111 int hosts_looked_up = 0;
2112 int hosts_retry = 0;
2113 int hosts_serial = 0;
2114 int hosts_total = 0;
2115 int total_hosts_tried = 0;
2117 BOOL expired = TRUE;
2118 BOOL continuing = continue_hostname != NULL;
2119 uschar *expanded_hosts = NULL;
2121 uschar *tid = string_sprintf("%s transport", tblock->name);
2122 smtp_transport_options_block *ob =
2123 (smtp_transport_options_block *)(tblock->options_block);
2124 host_item *hostlist = addrlist->host_list;
2125 host_item *host = NULL;
2129 debug_printf("%s transport entered\n", tblock->name);
2130 for (addr = addrlist; addr != NULL; addr = addr->next)
2131 debug_printf(" %s\n", addr->address);
2132 if (continuing) debug_printf("already connected to %s [%s]\n",
2133 continue_hostname, continue_host_address);
2136 /* Set the flag requesting that these hosts be added to the waiting
2137 database if the delivery fails temporarily or if we are running with
2138 queue_smtp or a 2-stage queue run. This gets unset for certain
2139 kinds of error, typically those that are specific to the message. */
2141 update_waiting = TRUE;
2143 /* If a host list is not defined for the addresses - they must all have the
2144 same one in order to be passed to a single transport - or if the transport has
2145 a host list with hosts_override set, use the host list supplied with the
2146 transport. It is an error for this not to exist. */
2148 if (hostlist == NULL || (ob->hosts_override && ob->hosts != NULL))
2150 if (ob->hosts == NULL)
2152 addrlist->message = string_sprintf("%s transport called with no hosts set",
2154 addrlist->transport_return = PANIC;
2155 return FALSE; /* Only top address has status */
2158 DEBUG(D_transport) debug_printf("using the transport's hosts: %s\n",
2161 /* If the transport's host list contains no '$' characters, and we are not
2162 randomizing, it is fixed and therefore a chain of hosts can be built once
2163 and for all, and remembered for subsequent use by other calls to this
2164 transport. If, on the other hand, the host list does contain '$', or we are
2165 randomizing its order, we have to rebuild it each time. In the fixed case,
2166 as the hosts string will never be used again, it doesn't matter that we
2167 replace all the : characters with zeros. */
2169 if (ob->hostlist == NULL)
2171 uschar *s = ob->hosts;
2173 if (Ustrchr(s, '$') != NULL)
2175 expanded_hosts = expand_string(s);
2176 if (expanded_hosts == NULL)
2178 addrlist->message = string_sprintf("failed to expand list of hosts "
2179 "\"%s\" in %s transport: %s", s, tblock->name, expand_string_message);
2180 addrlist->transport_return = search_find_defer? DEFER : PANIC;
2181 return FALSE; /* Only top address has status */
2183 DEBUG(D_transport) debug_printf("expanded list of hosts \"%s\" to "
2184 "\"%s\"\n", s, expanded_hosts);
2188 if (ob->hosts_randomize) s = expanded_hosts = string_copy(s);
2190 host_build_hostlist(&hostlist, s, ob->hosts_randomize);
2192 /* If there was no expansion of hosts, save the host list for
2195 if (expanded_hosts == NULL) ob->hostlist = hostlist;
2198 /* This is not the first time this transport has been run in this delivery;
2199 the host list was built previously. */
2201 else hostlist = ob->hostlist;
2204 /* The host list was supplied with the address. If hosts_randomize is set, we
2205 must sort it into a random order if it did not come from MX records and has not
2206 already been randomized (but don't bother if continuing down an existing
2209 else if (ob->hosts_randomize && hostlist->mx == MX_NONE && !continuing)
2211 host_item *newlist = NULL;
2212 while (hostlist != NULL)
2214 host_item *h = hostlist;
2215 hostlist = hostlist->next;
2217 h->sort_key = random_number(100);
2219 if (newlist == NULL)
2224 else if (h->sort_key < newlist->sort_key)
2231 host_item *hh = newlist;
2232 while (hh->next != NULL)
2234 if (h->sort_key < hh->next->sort_key) break;
2242 hostlist = addrlist->host_list = newlist;
2246 /* Sort out the default port. */
2248 if (!smtp_get_port(ob->port, addrlist, &port, tid)) return FALSE;
2251 /* For each host-plus-IP-address on the list:
2253 . If this is a continued delivery and the host isn't the one with the
2254 current connection, skip.
2256 . If the status is unusable (i.e. previously failed or retry checked), skip.
2258 . If no IP address set, get the address, either by turning the name into
2259 an address, calling gethostbyname if gethostbyname is on, or by calling
2260 the DNS. The DNS may yield multiple addresses, in which case insert the
2261 extra ones into the list.
2263 . Get the retry data if not previously obtained for this address and set the
2264 field which remembers the state of this address. Skip if the retry time is
2265 not reached. If not, remember whether retry data was found. The retry string
2266 contains both the name and the IP address.
2268 . Scan the list of addresses and mark those whose status is DEFER as
2269 PENDING_DEFER. These are the only ones that will be processed in this cycle
2272 . Make a delivery attempt - addresses marked PENDING_DEFER will be tried.
2273 Some addresses may be successfully delivered, others may fail, and yet
2274 others may get temporary errors and so get marked DEFER.
2276 . The return from the delivery attempt is OK if a connection was made and a
2277 valid SMTP dialogue was completed. Otherwise it is DEFER.
2279 . If OK, add a "remove" retry item for this host/IPaddress, if any.
2281 . If fail to connect, or other defer state, add a retry item.
2283 . If there are any addresses whose status is still DEFER, carry on to the
2284 next host/IPaddress, unless we have tried the number of hosts given
2285 by hosts_max_try or hosts_max_try_hardlimit; otherwise return. Note that
2286 there is some fancy logic for hosts_max_try that means its limit can be
2287 overstepped in some circumstances.
2289 If we get to the end of the list, all hosts have deferred at least one address,
2290 or not reached their retry times. If delay_after_cutoff is unset, it requests a
2291 delivery attempt to those hosts whose last try was before the arrival time of
2292 the current message. To cope with this, we have to go round the loop a second
2293 time. After that, set the status and error data for any addresses that haven't
2294 had it set already. */
2296 for (cutoff_retry = 0; expired &&
2297 cutoff_retry < ((ob->delay_after_cutoff)? 1 : 2);
2300 host_item *nexthost = NULL;
2301 int unexpired_hosts_tried = 0;
2303 for (host = hostlist;
2305 unexpired_hosts_tried < ob->hosts_max_try &&
2306 total_hosts_tried < ob->hosts_max_try_hardlimit;
2312 BOOL serialized = FALSE;
2313 BOOL host_is_expired = FALSE;
2314 BOOL message_defer = FALSE;
2315 BOOL ifchanges = FALSE;
2316 BOOL some_deferred = FALSE;
2317 address_item *first_addr = NULL;
2318 uschar *interface = NULL;
2319 uschar *retry_host_key = NULL;
2320 uschar *retry_message_key = NULL;
2321 uschar *serialize_key = NULL;
2323 /* Default next host is next host. :-) But this can vary if the
2324 hosts_max_try limit is hit (see below). It may also be reset if a host
2325 address is looked up here (in case the host was multihomed). */
2327 nexthost = host->next;
2329 /* If the address hasn't yet been obtained from the host name, look it up
2330 now, unless the host is already marked as unusable. If it is marked as
2331 unusable, it means that the router was unable to find its IP address (in
2332 the DNS or wherever) OR we are in the 2nd time round the cutoff loop, and
2333 the lookup failed last time. We don't get this far if *all* MX records
2334 point to non-existent hosts; that is treated as a hard error.
2336 We can just skip this host entirely. When the hosts came from the router,
2337 the address will timeout based on the other host(s); when the address is
2338 looked up below, there is an explicit retry record added.
2340 Note that we mustn't skip unusable hosts if the address is not unset; they
2341 may be needed as expired hosts on the 2nd time round the cutoff loop. */
2343 if (host->address == NULL)
2345 int new_port, flags;
2347 uschar *canonical_name;
2349 if (host->status >= hstatus_unusable)
2351 DEBUG(D_transport) debug_printf("%s has no address and is unusable - skipping\n",
2356 DEBUG(D_transport) debug_printf("getting address for %s\n", host->name);
2358 /* The host name is permitted to have an attached port. Find it, and
2359 strip it from the name. Just remember it for now. */
2361 new_port = host_item_get_port(host);
2363 /* Count hosts looked up */
2367 /* Find by name if so configured, or if it's an IP address. We don't
2368 just copy the IP address, because we need the test-for-local to happen. */
2370 flags = HOST_FIND_BY_A;
2371 if (ob->dns_qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
2372 if (ob->dns_search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
2374 if (ob->gethostbyname || string_is_ip_address(host->name, NULL) != 0)
2375 rc = host_find_byname(host, NULL, flags, &canonical_name, TRUE);
2377 rc = host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
2378 &canonical_name, NULL);
2380 /* Update the host (and any additional blocks, resulting from
2381 multihoming) with a host-specific port, if any. */
2383 for (hh = host; hh != nexthost; hh = hh->next) hh->port = new_port;
2385 /* Failure to find the host at this time (usually DNS temporary failure)
2386 is really a kind of routing failure rather than a transport failure.
2387 Therefore we add a retry item of the routing kind, not to stop us trying
2388 to look this name up here again, but to ensure the address gets timed
2389 out if the failures go on long enough. A complete failure at this point
2390 commonly points to a configuration error, but the best action is still
2391 to carry on for the next host. */
2393 if (rc == HOST_FIND_AGAIN || rc == HOST_FIND_FAILED)
2395 retry_add_item(addrlist, string_sprintf("R:%s", host->name), 0);
2397 if (rc == HOST_FIND_AGAIN) hosts_defer++; else hosts_fail++;
2398 DEBUG(D_transport) debug_printf("rc = %s for %s\n", (rc == HOST_FIND_AGAIN)?
2399 "HOST_FIND_AGAIN" : "HOST_FIND_FAILED", host->name);
2400 host->status = hstatus_unusable;
2402 for (addr = addrlist; addr != NULL; addr = addr->next)
2404 if (addr->transport_return != DEFER) continue;
2405 addr->basic_errno = ERRNO_UNKNOWNHOST;
2407 string_sprintf("failed to lookup IP address for %s", host->name);
2412 /* If the host is actually the local host, we may have a problem, or
2413 there may be some cunning configuration going on. In the problem case,
2414 log things and give up. The default transport status is already DEFER. */
2416 if (rc == HOST_FOUND_LOCAL && !ob->allow_localhost)
2418 for (addr = addrlist; addr != NULL; addr = addr->next)
2420 addr->basic_errno = 0;
2421 addr->message = string_sprintf("%s transport found host %s to be "
2422 "local", tblock->name, host->name);
2426 } /* End of block for IP address lookup */
2428 /* If this is a continued delivery, we are interested only in the host
2429 which matches the name of the existing open channel. The check is put
2430 here after the local host lookup, in case the name gets expanded as a
2431 result of the lookup. Set expired FALSE, to save the outer loop executing
2434 if (continuing && (Ustrcmp(continue_hostname, host->name) != 0 ||
2435 Ustrcmp(continue_host_address, host->address) != 0))
2438 continue; /* With next host */
2441 /* Reset the default next host in case a multihomed host whose addresses
2442 are not looked up till just above added to the host list. */
2444 nexthost = host->next;
2446 /* If queue_smtp is set (-odqs or the first part of a 2-stage run), or the
2447 domain is in queue_smtp_domains, we don't actually want to attempt any
2448 deliveries. When doing a queue run, queue_smtp_domains is always unset. If
2449 there is a lookup defer in queue_smtp_domains, proceed as if the domain
2450 were not in it. We don't want to hold up all SMTP deliveries! Except when
2451 doing a two-stage queue run, don't do this if forcing. */
2453 if ((!deliver_force || queue_2stage) && (queue_smtp ||
2454 match_isinlist(addrlist->domain, &queue_smtp_domains, 0,
2455 &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL) == OK))
2458 for (addr = addrlist; addr != NULL; addr = addr->next)
2460 if (addr->transport_return != DEFER) continue;
2461 addr->message = US"domain matches queue_smtp_domains, or -odqs set";
2463 continue; /* With next host */
2466 /* Count hosts being considered - purely for an intelligent comment
2467 if none are usable. */
2471 /* Set $host and $host address now in case they are needed for the
2472 interface expansion or the serialize_hosts check; they remain set if an
2473 actual delivery happens. */
2475 deliver_host = host->name;
2476 deliver_host_address = host->address;
2478 /* Set up a string for adding to the retry key if the port number is not
2479 the standard SMTP port. A host may have its own port setting that overrides
2482 pistring = string_sprintf(":%d", (host->port == PORT_NONE)?
2484 if (Ustrcmp(pistring, ":25") == 0) pistring = US"";
2486 /* Select IPv4 or IPv6, and choose an outgoing interface. If the interface
2487 string changes upon expansion, we must add it to the key that is used for
2488 retries, because connections to the same host from a different interface
2489 should be treated separately. */
2491 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET : AF_INET6;
2492 if (!smtp_get_interface(ob->interface, host_af, addrlist, &ifchanges,
2495 if (ifchanges) pistring = string_sprintf("%s/%s", pistring, interface);
2497 /* The first time round the outer loop, check the status of the host by
2498 inspecting the retry data. The second time round, we are interested only
2499 in expired hosts that haven't been tried since this message arrived. */
2501 if (cutoff_retry == 0)
2503 /* Ensure the status of the address is set by checking retry data if
2504 necessary. There maybe host-specific retry data (applicable to all
2505 messages) and also data for retries of a specific message at this host.
2506 If either of these retry records are actually read, the keys used are
2507 returned to save recomputing them later. */
2509 host_is_expired = retry_check_address(addrlist->domain, host, pistring,
2510 ob->retry_include_ip_address, &retry_host_key, &retry_message_key);
2512 DEBUG(D_transport) debug_printf("%s [%s]%s status = %s\n", host->name,
2513 (host->address == NULL)? US"" : host->address, pistring,
2514 (host->status == hstatus_usable)? "usable" :
2515 (host->status == hstatus_unusable)? "unusable" :
2516 (host->status == hstatus_unusable_expired)? "unusable (expired)" : "?");
2518 /* Skip this address if not usable at this time, noting if it wasn't
2519 actually expired, both locally and in the address. */
2521 switch (host->status)
2523 case hstatus_unusable:
2525 setflag(addrlist, af_retry_skipped);
2528 case hstatus_unusable_expired:
2531 case hwhy_retry: hosts_retry++; break;
2532 case hwhy_failed: hosts_fail++; break;
2533 case hwhy_deferred: hosts_defer++; break;
2536 /* If there was a retry message key, implying that previously there
2537 was a message-specific defer, we don't want to update the list of
2538 messages waiting for these hosts. */
2540 if (retry_message_key != NULL) update_waiting = FALSE;
2541 continue; /* With the next host or IP address */
2545 /* Second time round the loop: if the address is set but expired, and
2546 the message is newer than the last try, let it through. */
2550 if (host->address == NULL ||
2551 host->status != hstatus_unusable_expired ||
2552 host->last_try > received_time)
2555 debug_printf("trying expired host %s [%s]%s\n",
2556 host->name, host->address, pistring);
2557 host_is_expired = TRUE;
2560 /* Setting "expired=FALSE" doesn't actually mean not all hosts are expired;
2561 it remains TRUE only if all hosts are expired and none are actually tried.
2566 /* If this host is listed as one to which access must be serialized,
2567 see if another Exim process has a connection to it, and if so, skip
2568 this host. If not, update the database to record our connection to it
2569 and remember this for later deletion. Do not do any of this if we are
2570 sending the message down a pre-existing connection. */
2573 verify_check_this_host(&(ob->serialize_hosts), NULL, host->name,
2574 host->address, NULL) == OK)
2576 serialize_key = string_sprintf("host-serialize-%s", host->name);
2577 if (!enq_start(serialize_key))
2580 debug_printf("skipping host %s because another Exim process "
2581 "is connected to it\n", host->name);
2588 /* OK, we have an IP address that is not waiting for its retry time to
2589 arrive (it might be expired) OR (second time round the loop) we have an
2590 expired host that hasn't been tried since the message arrived. Have a go
2591 at delivering the message to it. First prepare the addresses by flushing
2592 out the result of previous attempts, and finding the first address that
2593 is still to be delivered. */
2595 first_addr = prepare_addresses(addrlist, host);
2597 DEBUG(D_transport) debug_printf("delivering %s to %s [%s] (%s%s)\n",
2598 message_id, host->name, host->address, addrlist->address,
2599 (addrlist->next == NULL)? "" : ", ...");
2601 set_process_info("delivering %s to %s [%s] (%s%s)",
2602 message_id, host->name, host->address, addrlist->address,
2603 (addrlist->next == NULL)? "" : ", ...");
2605 /* This is not for real; don't do the delivery. If there are
2606 any remaining hosts, list them. */
2611 set_errno(addrlist, 0, NULL, OK, FALSE);
2612 for (addr = addrlist; addr != NULL; addr = addr->next)
2614 addr->host_used = host;
2615 addr->special_action = '*';
2616 addr->message = US"delivery bypassed by -N option";
2620 debug_printf("*** delivery by %s transport bypassed by -N option\n"
2621 "*** host and remaining hosts:\n", tblock->name);
2622 for (host2 = host; host2 != NULL; host2 = host2->next)
2623 debug_printf(" %s [%s]\n", host2->name,
2624 (host2->address == NULL)? US"unset" : host2->address);
2629 /* This is for real. If the host is expired, we don't count it for
2630 hosts_max_retry. This ensures that all hosts must expire before an address
2631 is timed out, unless hosts_max_try_hardlimit (which protects against
2632 lunatic DNS configurations) is reached.
2634 If the host is not expired and we are about to hit the hosts_max_retry
2635 limit, check to see if there is a subsequent hosts with a different MX
2636 value. If so, make that the next host, and don't count this one. This is a
2637 heuristic to make sure that different MXs do get tried. With a normal kind
2638 of retry rule, they would get tried anyway when the earlier hosts were
2639 delayed, but if the domain has a "retry every time" type of rule - as is
2640 often used for the the very large ISPs, that won't happen. */
2644 if (!host_is_expired && ++unexpired_hosts_tried >= ob->hosts_max_try)
2648 debug_printf("hosts_max_try limit reached with this host\n");
2649 for (h = host; h != NULL; h = h->next)
2650 if (h->mx != host->mx) break;
2654 unexpired_hosts_tried--;
2655 DEBUG(D_transport) debug_printf("however, a higher MX host exists "
2656 "and will be tried\n");
2660 /* Attempt the delivery. */
2662 total_hosts_tried++;
2663 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2664 expanded_hosts != NULL, &message_defer, FALSE);
2667 OK => connection made, each address contains its result;
2668 message_defer is set for message-specific defers (when all
2669 recipients are marked defer)
2670 DEFER => there was a non-message-specific delivery problem;
2671 ERROR => there was a problem setting up the arguments for a filter,
2672 or there was a problem with expanding added headers
2675 /* If the result is not OK, there was a non-message-specific problem.
2676 If the result is DEFER, we need to write to the logs saying what happened
2677 for this particular host, except in the case of authentication and TLS
2678 failures, where the log has already been written. If all hosts defer a
2679 general message is written at the end. */
2681 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL &&
2682 first_addr->basic_errno != ERRNO_TLSFAILURE)
2683 write_logs(first_addr, host);
2685 /* If STARTTLS was accepted, but there was a failure in setting up the
2686 TLS session (usually a certificate screwup), and the host is not in
2687 hosts_require_tls, and tls_tempfail_tryclear is true, try again, with
2688 TLS forcibly turned off. We have to start from scratch with a new SMTP
2689 connection. That's why the retry is done from here, not from within
2690 smtp_deliver(). [Rejections of STARTTLS itself don't screw up the
2691 session, so the in-clear transmission after those errors, if permitted,
2692 happens inside smtp_deliver().] */
2695 if (rc == DEFER && first_addr->basic_errno == ERRNO_TLSFAILURE &&
2696 ob->tls_tempfail_tryclear &&
2697 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
2698 host->address, NULL) != OK)
2700 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
2701 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
2702 first_addr = prepare_addresses(addrlist, host);
2703 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2704 expanded_hosts != NULL, &message_defer, TRUE);
2705 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL)
2706 write_logs(first_addr, host);
2711 /* Delivery attempt finished */
2713 rs = (rc == OK)? US"OK" : (rc == DEFER)? US"DEFER" : (rc == ERROR)?
2716 set_process_info("delivering %s: just tried %s [%s] for %s%s: result %s",
2717 message_id, host->name, host->address, addrlist->address,
2718 (addrlist->next == NULL)? "" : " (& others)", rs);
2720 /* Release serialization if set up */
2722 if (serialized) enq_end(serialize_key);
2724 /* If the result is DEFER, or if a host retry record is known to exist, we
2725 need to add an item to the retry chain for updating the retry database
2726 at the end of delivery. We only need to add the item to the top address,
2727 of course. Also, if DEFER, we mark the IP address unusable so as to skip it
2728 for any other delivery attempts using the same address. (It is copied into
2729 the unusable tree at the outer level, so even if different address blocks
2730 contain the same address, it still won't get tried again.) */
2732 if (rc == DEFER || retry_host_key != NULL)
2734 int delete_flag = (rc != DEFER)? rf_delete : 0;
2735 if (retry_host_key == NULL)
2737 retry_host_key = ob->retry_include_ip_address?
2738 string_sprintf("T:%S:%s%s", host->name, host->address, pistring) :
2739 string_sprintf("T:%S%s", host->name, pistring);
2742 /* If a delivery of another message over an existing SMTP connection
2743 yields DEFER, we do NOT set up retry data for the host. This covers the
2744 case when there are delays in routing the addresses in the second message
2745 that are so long that the server times out. This is alleviated by not
2746 routing addresses that previously had routing defers when handling an
2747 existing connection, but even so, this case may occur (e.g. if a
2748 previously happily routed address starts giving routing defers). If the
2749 host is genuinely down, another non-continued message delivery will
2750 notice it soon enough. */
2752 if (delete_flag != 0 || !continuing)
2753 retry_add_item(first_addr, retry_host_key, rf_host | delete_flag);
2755 /* We may have tried an expired host, if its retry time has come; ensure
2756 the status reflects the expiry for the benefit of any other addresses. */
2760 host->status = (host_is_expired)?
2761 hstatus_unusable_expired : hstatus_unusable;
2762 host->why = hwhy_deferred;
2766 /* If message_defer is set (host was OK, but every recipient got deferred
2767 because of some message-specific problem), or if that had happened
2768 previously so that a message retry key exists, add an appropriate item
2769 to the retry chain. Note that if there was a message defer but now there is
2770 a host defer, the message defer record gets deleted. That seems perfectly
2771 reasonable. Also, stop the message from being remembered as waiting
2772 for specific hosts. */
2774 if (message_defer || retry_message_key != NULL)
2776 int delete_flag = message_defer? 0 : rf_delete;
2777 if (retry_message_key == NULL)
2779 retry_message_key = ob->retry_include_ip_address?
2780 string_sprintf("T:%S:%s%s:%s", host->name, host->address, pistring,
2782 string_sprintf("T:%S%s:%s", host->name, pistring, message_id);
2784 retry_add_item(addrlist, retry_message_key,
2785 rf_message | rf_host | delete_flag);
2786 update_waiting = FALSE;
2789 /* Any return other than DEFER (that is, OK or ERROR) means that the
2790 addresses have got their final statuses filled in for this host. In the OK
2791 case, see if any of them are deferred. */
2795 for (addr = addrlist; addr != NULL; addr = addr->next)
2797 if (addr->transport_return == DEFER)
2799 some_deferred = TRUE;
2805 /* If no addresses deferred or the result was ERROR, return. We do this for
2806 ERROR because a failing filter set-up or add_headers expansion is likely to
2807 fail for any host we try. */
2809 if (rc == ERROR || (rc == OK && !some_deferred))
2811 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2812 return TRUE; /* Each address has its status */
2815 /* If the result was DEFER or some individual addresses deferred, let
2816 the loop run to try other hosts with the deferred addresses, except for the
2817 case when we were trying to deliver down an existing channel and failed.
2818 Don't try any other hosts in this case. */
2820 if (continuing) break;
2822 /* If the whole delivery, or some individual addresses, were deferred and
2823 there are more hosts that could be tried, do not count this host towards
2824 the hosts_max_try limit if the age of the message is greater than the
2825 maximum retry time for this host. This means we may try try all hosts,
2826 ignoring the limit, when messages have been around for some time. This is
2827 important because if we don't try all hosts, the address will never time
2828 out. NOTE: this does not apply to hosts_max_try_hardlimit. */
2830 if ((rc == DEFER || some_deferred) && nexthost != NULL)
2833 retry_config *retry = retry_find_config(host->name, NULL, 0, 0);
2835 if (retry != NULL && retry->rules != NULL)
2837 retry_rule *last_rule;
2838 for (last_rule = retry->rules;
2839 last_rule->next != NULL;
2840 last_rule = last_rule->next);
2841 timedout = time(NULL) - received_time > last_rule->timeout;
2843 else timedout = TRUE; /* No rule => timed out */
2847 unexpired_hosts_tried--;
2848 DEBUG(D_transport) debug_printf("temporary delivery error(s) override "
2849 "hosts_max_try (message older than host's retry time)\n");
2852 } /* End of loop for trying multiple hosts. */
2854 /* This is the end of the loop that repeats iff expired is TRUE and
2855 ob->delay_after_cutoff is FALSE. The second time round we will
2856 try those hosts that haven't been tried since the message arrived. */
2860 debug_printf("all IP addresses skipped or deferred at least one address\n");
2861 if (expired && !ob->delay_after_cutoff && cutoff_retry == 0)
2862 debug_printf("retrying IP addresses not tried since message arrived\n");
2867 /* Get here if all IP addresses are skipped or defer at least one address. In
2868 MUA wrapper mode, this will happen only for connection or other non-message-
2869 specific failures. Force the delivery status for all addresses to FAIL. */
2873 for (addr = addrlist; addr != NULL; addr = addr->next)
2874 addr->transport_return = FAIL;
2878 /* In the normal, non-wrapper case, add a standard message to each deferred
2879 address if there hasn't been an error, that is, if it hasn't actually been
2880 tried this time. The variable "expired" will be FALSE if any deliveries were
2881 actually tried, or if there was at least one host that was not expired. That
2882 is, it is TRUE only if no deliveries were tried and all hosts were expired. If
2883 a delivery has been tried, an error code will be set, and the failing of the
2884 message is handled by the retry code later.
2886 If queue_smtp is set, or this transport was called to send a subsequent message
2887 down an existing TCP/IP connection, and something caused the host not to be
2888 found, we end up here, but can detect these cases and handle them specially. */
2890 for (addr = addrlist; addr != NULL; addr = addr->next)
2892 /* If host is not NULL, it means that we stopped processing the host list
2893 because of hosts_max_try or hosts_max_try_hardlimit. In the former case, this
2894 means we need to behave as if some hosts were skipped because their retry
2895 time had not come. Specifically, this prevents the address from timing out.
2896 However, if we have hit hosts_max_try_hardlimit, we want to behave as if all
2897 hosts were tried. */
2901 if (total_hosts_tried >= ob->hosts_max_try_hardlimit)
2904 debug_printf("hosts_max_try_hardlimit reached: behave as if all "
2905 "hosts were tried\n");
2910 debug_printf("hosts_max_try limit caused some hosts to be skipped\n");
2911 setflag(addr, af_retry_skipped);
2915 if (queue_smtp) /* no deliveries attempted */
2917 addr->transport_return = DEFER;
2918 addr->basic_errno = 0;
2919 addr->message = US"SMTP delivery explicitly queued";
2922 else if (addr->transport_return == DEFER &&
2923 (addr->basic_errno == ERRNO_UNKNOWNERROR || addr->basic_errno == 0) &&
2924 addr->message == NULL)
2926 addr->basic_errno = ERRNO_HRETRY;
2927 if (continue_hostname != NULL)
2929 addr->message = US"no host found for existing SMTP connection";
2933 setflag(addr, af_pass_message); /* This is not a security risk */
2934 addr->message = (ob->delay_after_cutoff)?
2935 US"retry time not reached for any host after a long failure period" :
2936 US"all hosts have been failing for a long time and were last tried "
2937 "after this message arrived";
2939 /* If we are already using fallback hosts, or there are no fallback hosts
2940 defined, convert the result to FAIL to cause a bounce. */
2942 if (addr->host_list == addr->fallback_hosts ||
2943 addr->fallback_hosts == NULL)
2944 addr->transport_return = FAIL;
2948 if (hosts_retry == hosts_total)
2949 addr->message = US"retry time not reached for any host";
2950 else if (hosts_fail == hosts_total)
2951 addr->message = US"all host address lookups failed permanently";
2952 else if (hosts_defer == hosts_total)
2953 addr->message = US"all host address lookups failed temporarily";
2954 else if (hosts_serial == hosts_total)
2955 addr->message = US"connection limit reached for all hosts";
2956 else if (hosts_fail+hosts_defer == hosts_total)
2957 addr->message = US"all host address lookups failed";
2958 else addr->message = US"some host address lookups failed and retry time "
2959 "not reached for other hosts or connection limit reached";
2964 /* Update the database which keeps information about which messages are waiting
2965 for which hosts to become available. For some message-specific errors, the
2966 update_waiting flag is turned off because we don't want follow-on deliveries in
2969 if (update_waiting) transport_update_waiting(hostlist, tblock->name);
2973 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2975 return TRUE; /* Each address has its status */
2978 /* End of transport/smtp.c */