424f9afa92a394a604a5cd4fe3e5f285cd3385aa
[exim.git] / src / src / transports / smtp.c
1 /* $Cambridge: exim/src/src/transports/smtp.c,v 1.3 2005/01/04 10:00:45 ph10 Exp $ */
2
3 /*************************************************
4 * Exim - an Internet mail transport agent *
5 *************************************************/
6
7 /* Copyright (c) University of Cambridge 1995 - 2005 */
8 /* See the file NOTICE for conditions of use and distribution. */
9
10 #include "../exim.h"
11 #include "smtp.h"
12
13 #define PENDING 256
14 #define PENDING_DEFER (PENDING + DEFER)
15 #define PENDING_OK (PENDING + OK)
16
17
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. */
22
23 optionlist smtp_transport_options[] = {
24 { "allow_localhost", opt_bool,
25 (void *)offsetof(smtp_transport_options_block, allow_localhost) },
26 { "authenticated_sender", opt_stringptr,
27 (void *)offsetof(smtp_transport_options_block, authenticated_sender) },
28 { "command_timeout", opt_time,
29 (void *)offsetof(smtp_transport_options_block, command_timeout) },
30 { "connect_timeout", opt_time,
31 (void *)offsetof(smtp_transport_options_block, connect_timeout) },
32 { "connection_max_messages", opt_int | opt_public,
33 (void *)offsetof(transport_instance, connection_max_messages) },
34 { "data_timeout", opt_time,
35 (void *)offsetof(smtp_transport_options_block, data_timeout) },
36 { "delay_after_cutoff", opt_bool,
37 (void *)offsetof(smtp_transport_options_block, delay_after_cutoff) },
38 { "dns_qualify_single", opt_bool,
39 (void *)offsetof(smtp_transport_options_block, dns_qualify_single) },
40 { "dns_search_parents", opt_bool,
41 (void *)offsetof(smtp_transport_options_block, dns_search_parents) },
42 { "fallback_hosts", opt_stringptr,
43 (void *)offsetof(smtp_transport_options_block, fallback_hosts) },
44 { "final_timeout", opt_time,
45 (void *)offsetof(smtp_transport_options_block, final_timeout) },
46 { "gethostbyname", opt_bool,
47 (void *)offsetof(smtp_transport_options_block, gethostbyname) },
48 { "helo_data", opt_stringptr,
49 (void *)offsetof(smtp_transport_options_block, helo_data) },
50 { "hosts", opt_stringptr,
51 (void *)offsetof(smtp_transport_options_block, hosts) },
52 { "hosts_avoid_esmtp", opt_stringptr,
53 (void *)offsetof(smtp_transport_options_block, hosts_avoid_esmtp) },
54 #ifdef SUPPORT_TLS
55 { "hosts_avoid_tls", opt_stringptr,
56 (void *)offsetof(smtp_transport_options_block, hosts_avoid_tls) },
57 #endif
58 { "hosts_max_try", opt_int,
59 (void *)offsetof(smtp_transport_options_block, hosts_max_try) },
60 #ifdef SUPPORT_TLS
61 { "hosts_nopass_tls", opt_stringptr,
62 (void *)offsetof(smtp_transport_options_block, hosts_nopass_tls) },
63 #endif
64 { "hosts_override", opt_bool,
65 (void *)offsetof(smtp_transport_options_block, hosts_override) },
66 { "hosts_randomize", opt_bool,
67 (void *)offsetof(smtp_transport_options_block, hosts_randomize) },
68 { "hosts_require_auth", opt_stringptr,
69 (void *)offsetof(smtp_transport_options_block, hosts_require_auth) },
70 #ifdef SUPPORT_TLS
71 { "hosts_require_tls", opt_stringptr,
72 (void *)offsetof(smtp_transport_options_block, hosts_require_tls) },
73 #endif
74 { "hosts_try_auth", opt_stringptr,
75 (void *)offsetof(smtp_transport_options_block, hosts_try_auth) },
76 { "interface", opt_stringptr,
77 (void *)offsetof(smtp_transport_options_block, interface) },
78 { "keepalive", opt_bool,
79 (void *)offsetof(smtp_transport_options_block, keepalive) },
80 { "max_rcpt", opt_int | opt_public,
81 (void *)offsetof(transport_instance, max_addresses) },
82 { "multi_domain", opt_bool | opt_public,
83 (void *)offsetof(transport_instance, multi_domain) },
84 { "port", opt_stringptr,
85 (void *)offsetof(smtp_transport_options_block, port) },
86 { "protocol", opt_stringptr,
87 (void *)offsetof(smtp_transport_options_block, protocol) },
88 { "retry_include_ip_address", opt_bool,
89 (void *)offsetof(smtp_transport_options_block, retry_include_ip_address) },
90 { "serialize_hosts", opt_stringptr,
91 (void *)offsetof(smtp_transport_options_block, serialize_hosts) },
92 { "size_addition", opt_int,
93 (void *)offsetof(smtp_transport_options_block, size_addition) }
94 #ifdef SUPPORT_TLS
95 ,{ "tls_certificate", opt_stringptr,
96 (void *)offsetof(smtp_transport_options_block, tls_certificate) },
97 { "tls_crl", opt_stringptr,
98 (void *)offsetof(smtp_transport_options_block, tls_crl) },
99 { "tls_privatekey", opt_stringptr,
100 (void *)offsetof(smtp_transport_options_block, tls_privatekey) },
101 { "tls_require_ciphers", opt_stringptr,
102 (void *)offsetof(smtp_transport_options_block, tls_require_ciphers) },
103 { "tls_tempfail_tryclear", opt_bool,
104 (void *)offsetof(smtp_transport_options_block, tls_tempfail_tryclear) },
105 { "tls_verify_certificates", opt_stringptr,
106 (void *)offsetof(smtp_transport_options_block, tls_verify_certificates) }
107 #endif
108 };
109
110 /* Size of the options list. An extern variable has to be used so that its
111 address can appear in the tables drtables.c. */
112
113 int smtp_transport_options_count =
114 sizeof(smtp_transport_options)/sizeof(optionlist);
115
116 /* Default private options block for the smtp transport. */
117
118 smtp_transport_options_block smtp_transport_option_defaults = {
119 NULL, /* hosts */
120 NULL, /* fallback_hosts */
121 NULL, /* hostlist */
122 NULL, /* fallback_hostlist */
123 NULL, /* authenticated_sender */
124 US"$primary_hostname", /* helo_data */
125 NULL, /* interface */
126 NULL, /* port */
127 US"smtp", /* protocol */
128 NULL, /* serialize_hosts */
129 NULL, /* hosts_try_auth */
130 NULL, /* hosts_require_auth */
131 NULL, /* hosts_require_tls */
132 NULL, /* hosts_avoid_tls */
133 NULL, /* hosts_avoid_esmtp */
134 NULL, /* hosts_nopass_tls */
135 5*60, /* command_timeout */
136 5*60, /* connect_timeout; shorter system default overrides */
137 5*60, /* data timeout */
138 10*60, /* final timeout */
139 1024, /* size_addition */
140 5, /* hosts_max_try */
141 FALSE, /* allow_localhost */
142 FALSE, /* gethostbyname */
143 TRUE, /* dns_qualify_single */
144 FALSE, /* dns_search_parents */
145 TRUE, /* delay_after_cutoff */
146 FALSE, /* hosts_override */
147 FALSE, /* hosts_randomize */
148 TRUE, /* keepalive */
149 TRUE /* retry_include_ip_address */
150 #ifdef SUPPORT_TLS
151 ,NULL, /* tls_certificate */
152 NULL, /* tls_crl */
153 NULL, /* tls_privatekey */
154 NULL, /* tls_require_ciphers */
155 NULL, /* tls_verify_certificates */
156 TRUE /* tls_tempfail_tryclear */
157 #endif
158 };
159
160
161 /* Local statics */
162
163 static uschar *smtp_command; /* Points to last cmd for error messages */
164 static uschar *mail_command; /* Points to MAIL cmd for error messages */
165
166
167 /*************************************************
168 * Setup entry point *
169 *************************************************/
170
171 /* This function is called when the transport is about to be used,
172 but before running it in a sub-process. It is used for two things:
173
174 (1) To set the fallback host list in addresses, when delivering.
175 (2) To pass back the interface, port, and protocol options, for use during
176 callout verification.
177
178 Arguments:
179 tblock pointer to the transport instance block
180 addrlist list of addresses about to be transported
181 tf if not NULL, pointer to block in which to return options
182 errmsg place for error message (not used)
183
184 Returns: OK always (FAIL, DEFER not used)
185 */
186
187 static int
188 smtp_transport_setup(transport_instance *tblock, address_item *addrlist,
189 transport_feedback *tf, uschar **errmsg)
190 {
191 smtp_transport_options_block *ob =
192 (smtp_transport_options_block *)(tblock->options_block);
193
194 errmsg = errmsg; /* Keep picky compilers happy */
195
196 /* Pass back options if required. This interface is getting very messy. */
197
198 if (tf != NULL)
199 {
200 tf->interface = ob->interface;
201 tf->port = ob->port;
202 tf->protocol = ob->protocol;
203 tf->hosts = ob->hosts;
204 tf->hosts_override = ob->hosts_override;
205 tf->hosts_randomize = ob->hosts_randomize;
206 tf->gethostbyname = ob->gethostbyname;
207 tf->qualify_single = ob->dns_qualify_single;
208 tf->search_parents = ob->dns_search_parents;
209 }
210
211 /* Set the fallback host list for all the addresses that don't have fallback
212 host lists, provided that the local host wasn't present in the original host
213 list. */
214
215 if (!testflag(addrlist, af_local_host_removed))
216 {
217 for (; addrlist != NULL; addrlist = addrlist->next)
218 if (addrlist->fallback_hosts == NULL)
219 addrlist->fallback_hosts = ob->fallback_hostlist;
220 }
221
222 return OK;
223 }
224
225
226
227 /*************************************************
228 * Initialization entry point *
229 *************************************************/
230
231 /* Called for each instance, after its options have been read, to
232 enable consistency checks to be done, or anything else that needs
233 to be set up.
234
235 Argument: pointer to the transport instance block
236 Returns: nothing
237 */
238
239 void
240 smtp_transport_init(transport_instance *tblock)
241 {
242 smtp_transport_options_block *ob =
243 (smtp_transport_options_block *)(tblock->options_block);
244
245 /* Retry_use_local_part defaults FALSE if unset */
246
247 if (tblock->retry_use_local_part == TRUE_UNSET)
248 tblock->retry_use_local_part = FALSE;
249
250 /* Set the default port according to the protocol */
251
252 if (ob->port == NULL)
253 ob->port = (strcmpic(ob->protocol, US"lmtp") == 0)? US"lmtp" : US"smtp";
254
255 /* Set up the setup entry point, to be called before subprocesses for this
256 transport. */
257
258 tblock->setup = smtp_transport_setup;
259
260 /* Complain if any of the timeouts are zero. */
261
262 if (ob->command_timeout <= 0 || ob->data_timeout <= 0 ||
263 ob->final_timeout <= 0)
264 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
265 "command, data, or final timeout value is zero for %s transport",
266 tblock->name);
267
268 /* If hosts_override is set and there are local hosts, set the global
269 flag that stops verify from showing router hosts. */
270
271 if (ob->hosts_override && ob->hosts != NULL) tblock->overrides_hosts = TRUE;
272
273 /* If there are any fallback hosts listed, build a chain of host items
274 for them, but do not do any lookups at this time. */
275
276 host_build_hostlist(&(ob->fallback_hostlist), ob->fallback_hosts, FALSE);
277 }
278
279
280
281
282
283 /*************************************************
284 * Set delivery info into all active addresses *
285 *************************************************/
286
287 /* Only addresses whose status is >= PENDING are relevant. A lesser
288 status means that an address is not currently being processed.
289
290 Arguments:
291 addrlist points to a chain of addresses
292 errno_value to put in each address's errno field
293 msg to put in each address's message field
294 rc to put in each address's transport_return field
295
296 If errno_value has the special value ERRNO_CONNECTTIMEOUT, ETIMEDOUT is put in
297 the errno field, and RTEF_CTOUT is ORed into the more_errno field, to indicate
298 this particular type of timeout.
299
300 Returns: nothing
301 */
302
303 static
304 void set_errno(address_item *addrlist, int errno_value, uschar *msg, int rc)
305 {
306 address_item *addr;
307 int orvalue = 0;
308 if (errno_value == ERRNO_CONNECTTIMEOUT)
309 {
310 errno_value = ETIMEDOUT;
311 orvalue = RTEF_CTOUT;
312 }
313 for (addr = addrlist; addr != NULL; addr = addr->next)
314 {
315 if (addr->transport_return < PENDING) continue;
316 addr->basic_errno = errno_value;
317 addr->more_errno |= orvalue;
318 if (msg != NULL) addr->message = msg;
319 addr->transport_return = rc;
320 }
321 }
322
323
324
325 /*************************************************
326 * Check an SMTP response *
327 *************************************************/
328
329 /* This function is given an errno code and the SMTP response buffer
330 to analyse, together with the host identification for generating messages. It
331 sets an appropriate message and puts the first digit of the response code into
332 the yield variable. If no response was actually read, a suitable digit is
333 chosen.
334
335 Arguments:
336 host the current host, to get its name for messages
337 errno_value pointer to the errno value
338 more_errno from the top address for use with ERRNO_FILTER_FAIL
339 buffer the SMTP response buffer
340 yield where to put a one-digit SMTP response code
341 message where to put an errror message
342
343 Returns: TRUE if an SMTP "QUIT" command should be sent, else FALSE
344 */
345
346 static BOOL check_response(host_item *host, int *errno_value, int more_errno,
347 uschar *buffer, int *yield, uschar **message)
348 {
349 uschar *pl = US"";
350
351 if (smtp_use_pipelining &&
352 (Ustrcmp(smtp_command, "MAIL") == 0 ||
353 Ustrcmp(smtp_command, "RCPT") == 0 ||
354 Ustrcmp(smtp_command, "DATA") == 0))
355 pl = US"pipelined ";
356
357 *yield = '4'; /* Default setting is to give a temporary error */
358
359 /* Handle response timeout */
360
361 if (*errno_value == ETIMEDOUT)
362 {
363 *message = US string_sprintf("SMTP timeout while connected to %s [%s] "
364 "after %s%s", host->name, host->address, pl, smtp_command);
365 if (transport_count > 0)
366 *message = US string_sprintf("%s (%d bytes written)", *message,
367 transport_count);
368 return FALSE;
369 }
370
371 /* Handle malformed SMTP response */
372
373 if (*errno_value == ERRNO_SMTPFORMAT)
374 {
375 uschar *malfresp = string_printing(buffer);
376 while (isspace(*malfresp)) malfresp++;
377 if (*malfresp == 0)
378 *message = string_sprintf("Malformed SMTP reply (an empty line) from "
379 "%s [%s] in response to %s%s", host->name, host->address, pl,
380 smtp_command);
381 else
382 *message = string_sprintf("Malformed SMTP reply from %s [%s] in response "
383 "to %s%s: %s", host->name, host->address, pl, smtp_command, malfresp);
384 return FALSE;
385 }
386
387 /* Handle a failed filter process error; can't send QUIT as we mustn't
388 end the DATA. */
389
390 if (*errno_value == ERRNO_FILTER_FAIL)
391 {
392 *message = US string_sprintf("transport filter process failed (%d)%s",
393 more_errno,
394 (more_errno == EX_EXECFAILED)? ": unable to execute command" : "");
395 return FALSE;
396 }
397
398 /* Handle a failed add_headers expansion; can't send QUIT as we mustn't
399 end the DATA. */
400
401 if (*errno_value == ERRNO_CHHEADER_FAIL)
402 {
403 *message =
404 US string_sprintf("failed to expand headers_add or headers_remove: %s",
405 expand_string_message);
406 return FALSE;
407 }
408
409 /* Handle failure to write a complete data block */
410
411 if (*errno_value == ERRNO_WRITEINCOMPLETE)
412 {
413 *message = US string_sprintf("failed to write a data block");
414 return FALSE;
415 }
416
417 /* Handle error responses from the remote mailer. */
418
419 if (buffer[0] != 0)
420 {
421 uschar *s = string_printing(buffer);
422 *message = US string_sprintf("SMTP error from remote mailer after %s%s: "
423 "host %s [%s]: %s", pl, smtp_command, host->name, host->address, s);
424 *yield = buffer[0];
425 return TRUE;
426 }
427
428 /* No data was read. If there is no errno, this must be the EOF (i.e.
429 connection closed) case, which causes deferral. Otherwise, put the host's
430 identity in the message, leaving the errno value to be interpreted as well. In
431 all cases, we have to assume the connection is now dead. */
432
433 if (*errno_value == 0)
434 {
435 *errno_value = ERRNO_SMTPCLOSED;
436 *message = US string_sprintf("Remote host %s [%s] closed connection "
437 "in response to %s%s", host->name, host->address, pl, smtp_command);
438 }
439 else *message = US string_sprintf("%s [%s]", host->name, host->address);
440
441 return FALSE;
442 }
443
444
445
446 /*************************************************
447 * Write error message to logs *
448 *************************************************/
449
450 /* This writes to the main log and to the message log.
451
452 Arguments:
453 addr the address item containing error information
454 host the current host
455
456 Returns: nothing
457 */
458
459 static void
460 write_logs(address_item *addr, host_item *host)
461 {
462 if (addr->message != NULL)
463 {
464 uschar *message = addr->message;
465 if (addr->basic_errno > 0)
466 message = string_sprintf("%s: %s", message, strerror(addr->basic_errno));
467 log_write(0, LOG_MAIN, "%s", message);
468 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
469 }
470 else
471 {
472 log_write(0, LOG_MAIN, "%s [%s]: %s",
473 host->name,
474 host->address,
475 strerror(addr->basic_errno));
476 deliver_msglog("%s %s [%s]: %s\n",
477 tod_stamp(tod_log),
478 host->name,
479 host->address,
480 strerror(addr->basic_errno));
481 }
482 }
483
484
485
486 /*************************************************
487 * Synchronize SMTP responses *
488 *************************************************/
489
490 /* This function is called from smtp_deliver() to receive SMTP responses from
491 the server, and match them up with the commands to which they relate. When
492 PIPELINING is not in use, this function is called after every command, and is
493 therefore somewhat over-engineered, but it is simpler to use a single scheme
494 that works both with and without PIPELINING instead of having two separate sets
495 of code.
496
497 The set of commands that are buffered up with pipelining may start with MAIL
498 and may end with DATA; in between are RCPT commands that correspond to the
499 addresses whose status is PENDING_DEFER. All other commands (STARTTLS, AUTH,
500 etc.) are never buffered.
501
502 Errors after MAIL or DATA abort the whole process leaving the response in the
503 buffer. After MAIL, pending responses are flushed, and the original command is
504 re-instated in big_buffer for error messages. For RCPT commands, the remote is
505 permitted to reject some recipient addresses while accepting others. However
506 certain errors clearly abort the whole process. Set the value in
507 transport_return to PENDING_OK if the address is accepted. If there is a
508 subsequent general error, it will get reset accordingly. If not, it will get
509 converted to OK at the end.
510
511 Arguments:
512 addrlist the complete address list
513 include_affixes TRUE if affixes include in RCPT
514 sync_addr ptr to the ptr of the one to start scanning at (updated)
515 host the host we are connected to
516 count the number of responses to read
517 pending_MAIL true if the first response is for MAIL
518 pending_DATA 0 if last command sent was not DATA
519 +1 if previously had a good recipient
520 -1 if not previously had a good recipient
521 inblock incoming SMTP block
522 timeout timeout value
523 buffer buffer for reading response
524 buffsize size of buffer
525
526 Returns: 3 if at least one address had 2xx and one had 5xx
527 2 if at least one address had 5xx but none had 2xx
528 1 if at least one host had a 2xx response, but none had 5xx
529 0 no address had 2xx or 5xx but no errors (all 4xx, or just DATA)
530 -1 timeout while reading RCPT response
531 -2 I/O or other non-response error for RCPT
532 -3 DATA or MAIL failed - errno and buffer set
533 */
534
535 static int
536 sync_responses(address_item *addrlist, BOOL include_affixes,
537 address_item **sync_addr, host_item *host, int count, BOOL pending_MAIL,
538 int pending_DATA, smtp_inblock *inblock, int timeout, uschar *buffer,
539 int buffsize)
540 {
541 address_item *addr = *sync_addr;
542 int yield = 0;
543
544 /* Handle the response for a MAIL command. On error, reinstate the original
545 command in big_buffer for error message use, and flush any further pending
546 responses before returning, except after I/O errors and timeouts. */
547
548 if (pending_MAIL)
549 {
550 count--;
551 if (!smtp_read_response(inblock, buffer, buffsize, '2', timeout))
552 {
553 Ustrcpy(big_buffer, mail_command); /* Fits, because it came from there! */
554 if (errno == 0 && buffer[0] != 0)
555 {
556 uschar flushbuffer[4096];
557 while (count-- > 0)
558 {
559 if (!smtp_read_response(inblock, flushbuffer, sizeof(flushbuffer),
560 '2', timeout)
561 && (errno != 0 || flushbuffer[0] == 0))
562 break;
563 }
564 }
565 return -3;
566 }
567 }
568
569 if (pending_DATA) count--; /* Number of RCPT responses to come */
570
571 /* Read and handle the required number of RCPT responses, matching each one up
572 with an address by scanning for the next address whose status is PENDING_DEFER.
573 */
574
575 while (count-- > 0)
576 {
577 while (addr->transport_return != PENDING_DEFER) addr = addr->next;
578
579 /* The address was accepted */
580
581 if (smtp_read_response(inblock, buffer, buffsize, '2', timeout))
582 {
583 yield |= 1;
584 addr->transport_return = PENDING_OK;
585
586 /* If af_dr_retry_exists is set, there was a routing delay on this address;
587 ensure that any address-specific retry record is expunged. */
588
589 if (testflag(addr, af_dr_retry_exists))
590 retry_add_item(addr, addr->address_retry_key, rf_delete);
591 }
592
593 /* Timeout while reading the response */
594
595 else if (errno == ETIMEDOUT)
596 {
597 int save_errno = errno;
598 uschar *message = string_sprintf("SMTP timeout while connected to %s [%s] "
599 "after RCPT TO:<%s>", host->name, host->address,
600 transport_rcpt_address(addr, include_affixes));
601 set_errno(addrlist, save_errno, message, DEFER);
602 retry_add_item(addr, addr->address_retry_key, 0);
603 host->update_waiting = FALSE;
604 return -1;
605 }
606
607 /* Handle other errors in obtaining an SMTP response by returning -1. This
608 will cause all the addresses to be deferred. Restore the SMTP command in
609 big_buffer for which we are checking the response, so the error message
610 makes sense. */
611
612 else if (errno != 0 || buffer[0] == 0)
613 {
614 string_format(big_buffer, big_buffer_size, "RCPT TO:<%s>",
615 transport_rcpt_address(addr, include_affixes));
616 return -2;
617 }
618
619 /* Handle SMTP permanent and temporary response codes. */
620
621 else
622 {
623 addr->message =
624 string_sprintf("SMTP error from remote mailer after RCPT TO:<%s>: "
625 "host %s [%s]: %s", transport_rcpt_address(addr, include_affixes),
626 host->name, host->address, string_printing(buffer));
627 deliver_msglog("%s %s\n", tod_stamp(tod_log), addr->message);
628
629 /* The response was 5xx */
630
631 if (buffer[0] == '5')
632 {
633 addr->transport_return = FAIL;
634 yield |= 2;
635 }
636
637 /* The response was 4xx */
638
639 else
640 {
641 int bincode = (buffer[1] - '0')*10 + buffer[2] - '0';
642
643 addr->transport_return = DEFER;
644 addr->basic_errno = ERRNO_RCPT4XX;
645 addr->more_errno |= bincode << 8;
646
647 /* Log temporary errors if there are more hosts to be tried. */
648
649 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", addr->message);
650
651 /* Do not put this message on the list of those waiting for this host,
652 as otherwise it is likely to be tried too often. */
653
654 host->update_waiting = FALSE;
655
656 /* Add a retry item for the address so that it doesn't get tried
657 again too soon. */
658
659 retry_add_item(addr, addr->address_retry_key, 0);
660 }
661 }
662 } /* Loop for next RCPT response */
663
664 /* Update where to start at for the next block of responses, unless we
665 have already handled all the addresses. */
666
667 if (addr != NULL) *sync_addr = addr->next;
668
669 /* Handle a response to DATA. If we have not had any good recipients, either
670 previously or in this block, the response is ignored. */
671
672 if (pending_DATA != 0 &&
673 !smtp_read_response(inblock, buffer, buffsize, '3', timeout))
674 {
675 int code;
676 uschar *msg;
677 if (pending_DATA > 0 || (yield & 1) != 0) return -3;
678 (void)check_response(host, &errno, 0, buffer, &code, &msg);
679 DEBUG(D_transport) debug_printf("%s\nerror for DATA ignored: pipelining "
680 "is in use and there were no good recipients\n", msg);
681 }
682
683 /* All responses read and handled; MAIL (if present) received 2xx and DATA (if
684 present) received 3xx. If any RCPTs were handled and yielded anything other
685 than 4xx, yield will be set non-zero. */
686
687 return yield;
688 }
689
690
691
692 /*************************************************
693 * Deliver address list to given host *
694 *************************************************/
695
696 /* If continue_hostname is not null, we get here only when continuing to
697 deliver down an existing channel. The channel was passed as the standard
698 input.
699
700 Otherwise, we have to make a connection to the remote host, and do the
701 initial protocol exchange.
702
703 When running as an MUA wrapper, if the sender or any recipient is rejected,
704 temporarily or permanently, we force failure for all recipients.
705
706 Arguments:
707 addrlist chain of potential addresses to deliver; only those whose
708 transport_return field is set to PENDING_DEFER are currently
709 being processed; others should be skipped - they have either
710 been delivered to an earlier host or IP address, or been
711 failed by one of them.
712 host host to deliver to
713 host_af AF_INET or AF_INET6
714 port TCP/IP port to use, in host byte order
715 interface interface to bind to, or NULL
716 tblock transport instance block
717 copy_host TRUE if host set in addr->host_used must be copied, because
718 it is specific to this call of the transport
719 message_defer set TRUE if yield is OK, but all addresses were deferred
720 because of a non-recipient, non-host failure, that is, a
721 4xx response to MAIL FROM, DATA, or ".". This is a defer
722 that is specific to the message.
723 suppress_tls if TRUE, don't attempt a TLS connection - this is set for
724 a second attempt after TLS initialization fails
725
726 Returns: OK - the connection was made and the delivery attempted;
727 the result for each address is in its data block.
728 DEFER - the connection could not be made, or something failed
729 while setting up the SMTP session, or there was a
730 non-message-specific error, such as a timeout.
731 ERROR - a filter command is specified for this transport,
732 and there was a problem setting it up; OR helo_data
733 or add_headers or authenticated_sender is specified
734 for this transport, and the string failed to expand
735 */
736
737 static int
738 smtp_deliver(address_item *addrlist, host_item *host, int host_af, int port,
739 uschar *interface, transport_instance *tblock, BOOL copy_host,
740 BOOL *message_defer, BOOL suppress_tls)
741 {
742 address_item *addr;
743 address_item *sync_addr;
744 address_item *first_addr = addrlist;
745 int yield = OK;
746 int address_count;
747 int save_errno;
748 int rc;
749 time_t start_delivery_time = time(NULL);
750 smtp_transport_options_block *ob =
751 (smtp_transport_options_block *)(tblock->options_block);
752 BOOL lmtp = strcmpic(ob->protocol, US"lmtp") == 0;
753 BOOL ok = FALSE;
754 BOOL send_rset = TRUE;
755 BOOL send_quit = TRUE;
756 BOOL setting_up = TRUE;
757 BOOL completed_address = FALSE;
758 BOOL esmtp = TRUE;
759 BOOL pending_MAIL;
760 smtp_inblock inblock;
761 smtp_outblock outblock;
762 int max_rcpt = tblock->max_addresses;
763 uschar *local_authenticated_sender = authenticated_sender;
764 uschar *helo_data;
765 uschar *message = NULL;
766 uschar new_message_id[MESSAGE_ID_LENGTH + 1];
767 uschar *p;
768 uschar buffer[4096];
769 uschar inbuffer[4096];
770 uschar outbuffer[1024];
771
772 suppress_tls = suppress_tls; /* stop compiler warning when no TLS support */
773
774 *message_defer = FALSE;
775 smtp_command = US"initial connection";
776 if (max_rcpt == 0) max_rcpt = 999999;
777
778 /* Set up the buffer for reading SMTP response packets. */
779
780 inblock.buffer = inbuffer;
781 inblock.buffersize = sizeof(inbuffer);
782 inblock.ptr = inbuffer;
783 inblock.ptrend = inbuffer;
784
785 /* Set up the buffer for holding SMTP commands while pipelining */
786
787 outblock.buffer = outbuffer;
788 outblock.buffersize = sizeof(outbuffer);
789 outblock.ptr = outbuffer;
790 outblock.cmd_count = 0;
791 outblock.authenticating = FALSE;
792
793 /* Expand the greeting message */
794
795 helo_data = expand_string(ob->helo_data);
796 if (helo_data == NULL)
797 {
798 uschar *message = string_sprintf("failed to expand helo_data: %s",
799 expand_string_message);
800 set_errno(addrlist, 0, message, DEFER);
801 return ERROR;
802 }
803
804 /* If an authenticated_sender override has been specified for this transport
805 instance, expand it. If the expansion is forced to fail, and there was already
806 an authenticated_sender for this message, the original value will be used.
807 Other expansion failures are serious. An empty result is ignored, but there is
808 otherwise no check - this feature is expected to be used with LMTP and other
809 cases where non-standard addresses (e.g. without domains) might be required. */
810
811 if (ob->authenticated_sender != NULL)
812 {
813 uschar *new = expand_string(ob->authenticated_sender);
814 if (new == NULL)
815 {
816 if (!expand_string_forcedfail)
817 {
818 uschar *message = string_sprintf("failed to expand "
819 "authenticated_sender: %s", expand_string_message);
820 set_errno(addrlist, 0, message, DEFER);
821 return ERROR;
822 }
823 }
824 else if (new[0] != 0) local_authenticated_sender = new;
825 }
826
827 /* Make a connection to the host if this isn't a continued delivery, and handle
828 the initial interaction and HELO/EHLO/LHLO. Connect timeout errors are handled
829 specially so they can be identified for retries. */
830
831 if (continue_hostname == NULL)
832 {
833 inblock.sock = outblock.sock =
834 smtp_connect(host, host_af, port, interface, ob->connect_timeout,
835 ob->keepalive);
836 if (inblock.sock < 0)
837 {
838 set_errno(addrlist, (errno == ETIMEDOUT)? ERRNO_CONNECTTIMEOUT : errno,
839 NULL, DEFER);
840 return DEFER;
841 }
842
843 /* The first thing is to wait for an initial OK response. The dreaded "goto"
844 is nevertheless a reasonably clean way of programming this kind of logic,
845 where you want to escape on any error. */
846
847 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
848 ob->command_timeout)) goto RESPONSE_FAILED;
849
850 /** Debugging without sending a message
851 addrlist->transport_return = DEFER;
852 goto SEND_QUIT;
853 **/
854
855 /* Errors that occur after this point follow an SMTP command, which is
856 left in big_buffer by smtp_write_command() for use in error messages. */
857
858 smtp_command = big_buffer;
859
860 /* Tell the remote who we are...
861
862 February 1998: A convention has evolved that ESMTP-speaking MTAs include the
863 string "ESMTP" in their greeting lines, so make Exim send EHLO if the
864 greeting is of this form. The assumption was that the far end supports it
865 properly... but experience shows that there are some that give 5xx responses,
866 even though the banner includes "ESMTP" (there's a bloody-minded one that
867 says "ESMTP not spoken here"). Cope with that case.
868
869 September 2000: Time has passed, and it seems reasonable now to always send
870 EHLO at the start. It is also convenient to make the change while installing
871 the TLS stuff.
872
873 July 2003: Joachim Wieland met a broken server that advertises "PIPELINING"
874 but times out after sending MAIL FROM, RCPT TO and DATA all together. There
875 would be no way to send out the mails, so there is now a host list
876 "hosts_avoid_esmtp" that disables ESMTP for special hosts and solves the
877 PIPELINING problem as well. Maybe it can also be useful to cure other
878 problems with broken servers.
879
880 Exim originally sent "Helo" at this point and ran for nearly a year that way.
881 Then somebody tried it with a Microsoft mailer... It seems that all other
882 mailers use upper case for some reason (the RFC is quite clear about case
883 independence) so, for peace of mind, I gave in. */
884
885 esmtp = verify_check_this_host(&(ob->hosts_avoid_esmtp), NULL,
886 host->name, host->address, NULL) != OK;
887
888 if (esmtp)
889 {
890 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n",
891 lmtp? "LHLO" : "EHLO", helo_data) < 0)
892 goto SEND_FAILED;
893 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
894 ob->command_timeout))
895 {
896 if (errno != 0 || buffer[0] == 0 || lmtp) goto RESPONSE_FAILED;
897 esmtp = FALSE;
898 }
899 }
900 else
901 {
902 DEBUG(D_transport)
903 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
904 }
905
906 if (!esmtp)
907 {
908 if (smtp_write_command(&outblock, FALSE, "HELO %s\r\n", helo_data) < 0)
909 goto SEND_FAILED;
910 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
911 ob->command_timeout)) goto RESPONSE_FAILED;
912 }
913
914 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
915
916 #ifdef SUPPORT_TLS
917 tls_offered = esmtp &&
918 pcre_exec(regex_STARTTLS, NULL, CS buffer, Ustrlen(buffer), 0,
919 PCRE_EOPT, NULL, 0) >= 0;
920 #endif
921 }
922
923 /* For continuing deliveries down the same channel, the socket is the standard
924 input, and we don't need to redo EHLO here (but may need to do so for TLS - see
925 below). Set up the pointer to where subsequent commands will be left, for
926 error messages. Note that smtp_use_size and smtp_use_pipelining will have been
927 set from the command line if they were set in the process that passed the
928 connection on. */
929
930 else
931 {
932 inblock.sock = outblock.sock = fileno(stdin);
933 smtp_command = big_buffer;
934 }
935
936 /* If TLS is available on this connection, whether continued or not, attempt to
937 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
938 send another EHLO - the server may give a different answer in secure mode. We
939 use a separate buffer for reading the response to STARTTLS so that if it is
940 negative, the original EHLO data is available for subsequent analysis, should
941 the client not be required to use TLS. If the response is bad, copy the buffer
942 for error analysis. */
943
944 #ifdef SUPPORT_TLS
945 if (tls_offered && !suppress_tls &&
946 verify_check_this_host(&(ob->hosts_avoid_tls), NULL, host->name,
947 host->address, NULL) != OK)
948 {
949 uschar buffer2[4096];
950 if (smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") < 0)
951 goto SEND_FAILED;
952
953 /* If there is an I/O error, transmission of this message is deferred. If
954 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
955 false, we also defer. However, if there is a temporary rejection of STARTTLS
956 and tls_tempfail_tryclear is true, or if there is an outright rejection of
957 STARTTLS, we carry on. This means we will try to send the message in clear,
958 unless the host is in hosts_require_tls (tested below). */
959
960 if (!smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
961 ob->command_timeout))
962 {
963 Ustrncpy(buffer, buffer2, sizeof(buffer));
964 if (errno != 0 || buffer2[0] == 0 ||
965 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
966 goto RESPONSE_FAILED;
967 }
968
969 /* STARTTLS accepted: try to negotiate a TLS session. */
970
971 else
972 {
973 int rc = tls_client_start(inblock.sock, host, addrlist,
974 NULL, /* No DH param */
975 ob->tls_certificate,
976 ob->tls_privatekey,
977 ob->tls_verify_certificates,
978 ob->tls_crl,
979 ob->tls_require_ciphers,
980 ob->command_timeout);
981
982 /* TLS negotiation failed; give an error. From outside, this function may
983 be called again to try in clear on a new connection, if the options permit
984 it for this host. */
985
986 if (rc != OK)
987 {
988 save_errno = ERRNO_TLSFAILURE;
989 message = US"failure while setting up TLS session";
990 send_quit = FALSE;
991 goto TLS_FAILED;
992 }
993
994 /* TLS session is set up */
995
996 for (addr = addrlist; addr != NULL; addr = addr->next)
997 {
998 addr->cipher = tls_cipher;
999 addr->peerdn = tls_peerdn;
1000 }
1001 }
1002 }
1003
1004 /* If we started TLS, redo the EHLO/LHLO exchange over the secure channel. */
1005
1006 if (tls_active >= 0)
1007 {
1008 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n", lmtp? "LHLO" : "EHLO",
1009 helo_data) < 0)
1010 goto SEND_FAILED;
1011 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1012 ob->command_timeout))
1013 goto RESPONSE_FAILED;
1014 }
1015
1016 /* If the host is required to use a secure channel, ensure that we
1017 have one. */
1018
1019 else if (verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
1020 host->address, NULL) == OK)
1021 {
1022 save_errno = ERRNO_TLSREQUIRED;
1023 message = string_sprintf("a TLS session is required for %s [%s], but %s",
1024 host->name, host->address,
1025 tls_offered? "an attempt to start TLS failed" :
1026 "the server did not offer TLS support");
1027 goto TLS_FAILED;
1028 }
1029 #endif
1030
1031 /* If TLS is active, we have just started it up and re-done the EHLO command,
1032 so its response needs to be analyzed. If TLS is not active and this is a
1033 continued session down a previously-used socket, we haven't just done EHLO, so
1034 we skip this. */
1035
1036 if (continue_hostname == NULL
1037 #ifdef SUPPORT_TLS
1038 || tls_active >= 0
1039 #endif
1040 )
1041 {
1042 int require_auth;
1043 uschar *fail_reason = US"server did not advertise AUTH support";
1044
1045 /* If the response to EHLO specified support for the SIZE parameter, note
1046 this, provided size_addition is non-negative. */
1047
1048 smtp_use_size = esmtp && ob->size_addition >= 0 &&
1049 pcre_exec(regex_SIZE, NULL, CS buffer, Ustrlen(CS buffer), 0,
1050 PCRE_EOPT, NULL, 0) >= 0;
1051
1052 /* Note whether the server supports PIPELINING. If hosts_avoid_esmtp matched
1053 the current host, esmtp will be false, so PIPELINING can never be used. */
1054
1055 smtp_use_pipelining = esmtp &&
1056 pcre_exec(regex_PIPELINING, NULL, CS buffer, Ustrlen(CS buffer), 0,
1057 PCRE_EOPT, NULL, 0) >= 0;
1058
1059 DEBUG(D_transport) debug_printf("%susing PIPELINING\n",
1060 smtp_use_pipelining? "" : "not ");
1061
1062 /* Note if the response to EHLO specifies support for the AUTH extension.
1063 If it has, check that this host is one we want to authenticate to, and do
1064 the business. The host name and address must be available when the
1065 authenticator's client driver is running. */
1066
1067 smtp_authenticated = FALSE;
1068 require_auth = verify_check_this_host(&(ob->hosts_require_auth), NULL,
1069 host->name, host->address, NULL);
1070
1071 if (esmtp && regex_match_and_setup(regex_AUTH, buffer, 0, -1))
1072 {
1073 uschar *names = string_copyn(expand_nstring[1], expand_nlength[1]);
1074 expand_nmax = -1; /* reset */
1075
1076 /* Must not do this check until after we have saved the result of the
1077 regex match above. */
1078
1079 if (require_auth == OK ||
1080 verify_check_this_host(&(ob->hosts_try_auth), NULL, host->name,
1081 host->address, NULL) == OK)
1082 {
1083 auth_instance *au;
1084 fail_reason = US"no common mechanisms were found";
1085
1086 DEBUG(D_transport) debug_printf("scanning authentication mechanisms\n");
1087
1088 /* Scan the configured authenticators looking for one which is configured
1089 for use as a client and whose name matches an authentication mechanism
1090 supported by the server. If one is found, attempt to authenticate by
1091 calling its client function. */
1092
1093 for (au = auths; !smtp_authenticated && au != NULL; au = au->next)
1094 {
1095 uschar *p = names;
1096 if (!au->client) continue;
1097
1098 /* Loop to scan supported server mechanisms */
1099
1100 while (*p != 0)
1101 {
1102 int rc;
1103 int len = Ustrlen(au->public_name);
1104 while (isspace(*p)) p++;
1105
1106 if (strncmpic(au->public_name, p, len) != 0 ||
1107 (p[len] != 0 && !isspace(p[len])))
1108 {
1109 while (*p != 0 && !isspace(*p)) p++;
1110 continue;
1111 }
1112
1113 /* Found data for a listed mechanism. Call its client entry. Set
1114 a flag in the outblock so that data is overwritten after sending so
1115 that reflections don't show it. */
1116
1117 fail_reason = US"authentication attempt(s) failed";
1118 outblock.authenticating = TRUE;
1119 rc = (au->info->clientcode)(au, &inblock, &outblock,
1120 ob->command_timeout, buffer, sizeof(buffer));
1121 outblock.authenticating = FALSE;
1122 DEBUG(D_transport) debug_printf("%s authenticator yielded %d\n",
1123 au->name, rc);
1124
1125 /* A temporary authentication failure must hold up delivery to
1126 this host. After a permanent authentication failure, we carry on
1127 to try other authentication methods. If all fail hard, try to
1128 deliver the message unauthenticated unless require_auth was set. */
1129
1130 switch(rc)
1131 {
1132 case OK:
1133 smtp_authenticated = TRUE; /* stops the outer loop */
1134 break;
1135
1136 /* Failure after writing a command */
1137
1138 case FAIL_SEND:
1139 goto SEND_FAILED;
1140
1141 /* Failure after reading a response */
1142
1143 case FAIL:
1144 if (errno != 0 || buffer[0] != '5') goto RESPONSE_FAILED;
1145 log_write(0, LOG_MAIN, "%s authenticator failed H=%s [%s] %s",
1146 au->name, host->name, host->address, buffer);
1147 break;
1148
1149 /* Failure by some other means. In effect, the authenticator
1150 decided it wasn't prepared to handle this case. Typically this
1151 is the result of "fail" in an expansion string. Do we need to
1152 log anything here? */
1153
1154 case CANCELLED:
1155 break;
1156
1157 /* Internal problem, message in buffer. */
1158
1159 case ERROR:
1160 yield = ERROR;
1161 set_errno(addrlist, 0, string_copy(buffer), DEFER);
1162 goto SEND_QUIT;
1163 }
1164
1165 break; /* If not authenticated, try next authenticator */
1166 } /* Loop for scanning supported server mechanisms */
1167 } /* Loop for further authenticators */
1168 }
1169 }
1170
1171 /* If we haven't authenticated, but are required to, give up. */
1172
1173 if (require_auth == OK && !smtp_authenticated)
1174 {
1175 yield = DEFER;
1176 set_errno(addrlist, ERRNO_AUTHFAIL,
1177 string_sprintf("authentication required but %s", fail_reason), DEFER);
1178 goto SEND_QUIT;
1179 }
1180 }
1181
1182 /* The setting up of the SMTP call is now complete. Any subsequent errors are
1183 message-specific. */
1184
1185 setting_up = FALSE;
1186
1187 /* If there is a filter command specified for this transport, we can now
1188 set it up. This cannot be done until the identify of the host is known. */
1189
1190 if (tblock->filter_command != NULL)
1191 {
1192 BOOL rc;
1193 uschar buffer[64];
1194 sprintf(CS buffer, "%.50s transport", tblock->name);
1195 rc = transport_set_up_command(&transport_filter_argv, tblock->filter_command,
1196 TRUE, DEFER, addrlist, buffer, NULL);
1197
1198 /* On failure, copy the error to all addresses, abandon the SMTP call, and
1199 yield ERROR. */
1200
1201 if (!rc)
1202 {
1203 set_errno(addrlist->next, addrlist->basic_errno, addrlist->message, DEFER);
1204 yield = ERROR;
1205 goto SEND_QUIT;
1206 }
1207 }
1208
1209
1210 /* For messages that have more than the maximum number of envelope recipients,
1211 we want to send several transactions down the same SMTP connection. (See
1212 comments in deliver.c as to how this reconciles, heuristically, with
1213 remote_max_parallel.) This optimization was added to Exim after the following
1214 code was already working. The simplest way to put it in without disturbing the
1215 code was to use a goto to jump back to this point when there is another
1216 transaction to handle. */
1217
1218 SEND_MESSAGE:
1219 sync_addr = first_addr;
1220 address_count = 0;
1221 ok = FALSE;
1222 send_rset = TRUE;
1223 completed_address = FALSE;
1224
1225
1226 /* Initiate a message transfer. If we know the receiving MTA supports the SIZE
1227 qualification, send it, adding something to the message size to allow for
1228 imprecision and things that get added en route. Exim keeps the number of lines
1229 in a message, so we can give an accurate value for the original message, but we
1230 need some additional to handle added headers. (Double "." characters don't get
1231 included in the count.) */
1232
1233 p = buffer;
1234 *p = 0;
1235
1236 if (smtp_use_size)
1237 {
1238 sprintf(CS p, " SIZE=%d", message_size+message_linecount+ob->size_addition);
1239 while (*p) p++;
1240 }
1241
1242 /* Add the authenticated sender address if present */
1243
1244 if (smtp_authenticated && local_authenticated_sender != NULL)
1245 {
1246 string_format(p, sizeof(buffer) - (p-buffer), " AUTH=%s",
1247 auth_xtextencode(local_authenticated_sender,
1248 Ustrlen(local_authenticated_sender)));
1249 }
1250
1251 /* From here until we send the DATA command, we can make use of PIPELINING
1252 if the server host supports it. The code has to be able to check the responses
1253 at any point, for when the buffer fills up, so we write it totally generally.
1254 When PIPELINING is off, each command written reports that it has flushed the
1255 buffer. */
1256
1257 pending_MAIL = TRUE; /* The block starts with MAIL */
1258
1259 rc = smtp_write_command(&outblock, smtp_use_pipelining,
1260 "MAIL FROM:<%s>%s\r\n", return_path, buffer);
1261 mail_command = string_copy(big_buffer); /* Save for later error message */
1262
1263 switch(rc)
1264 {
1265 case -1: /* Transmission error */
1266 goto SEND_FAILED;
1267
1268 case +1: /* Block was sent */
1269 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1270 ob->command_timeout)) goto RESPONSE_FAILED;
1271 pending_MAIL = FALSE;
1272 break;
1273 }
1274
1275 /* Pass over all the relevant recipient addresses for this host, which are the
1276 ones that have status PENDING_DEFER. If we are using PIPELINING, we can send
1277 several before we have to read the responses for those seen so far. This
1278 checking is done by a subroutine because it also needs to be done at the end.
1279 Send only up to max_rcpt addresses at a time, leaving first_addr pointing to
1280 the next one if not all are sent.
1281
1282 In the MUA wrapper situation, we want to flush the PIPELINING buffer for the
1283 last address because we want to abort if any recipients have any kind of
1284 problem, temporary or permanent. We know that all recipient addresses will have
1285 the PENDING_DEFER status, because only one attempt is ever made, and we know
1286 that max_rcpt will be large, so all addresses will be done at once. */
1287
1288 for (addr = first_addr;
1289 address_count < max_rcpt && addr != NULL;
1290 addr = addr->next)
1291 {
1292 int count;
1293 BOOL no_flush;
1294
1295 if (addr->transport_return != PENDING_DEFER) continue;
1296
1297 address_count++;
1298 no_flush = smtp_use_pipelining && (!mua_wrapper || addr->next != NULL);
1299
1300 /* Now send the RCPT command, and process outstanding responses when
1301 necessary. After a timeout on RCPT, we just end the function, leaving the
1302 yield as OK, because this error can often mean that there is a problem with
1303 just one address, so we don't want to delay the host. */
1304
1305 count = smtp_write_command(&outblock, no_flush, "RCPT TO:<%s>\r\n",
1306 transport_rcpt_address(addr, tblock->rcpt_include_affixes));
1307 if (count < 0) goto SEND_FAILED;
1308 if (count > 0)
1309 {
1310 switch(sync_responses(first_addr, tblock->rcpt_include_affixes,
1311 &sync_addr, host, count, pending_MAIL, 0, &inblock,
1312 ob->command_timeout, buffer, sizeof(buffer)))
1313 {
1314 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1315 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1316 break;
1317
1318 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1319 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1320 case 0: /* No 2xx or 5xx, but no probs */
1321 break;
1322
1323 case -1: goto END_OFF; /* Timeout on RCPT */
1324 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL error */
1325 }
1326 pending_MAIL = FALSE; /* Dealt with MAIL */
1327 }
1328 } /* Loop for next address */
1329
1330 /* If we are an MUA wrapper, abort if any RCPTs were rejected, either
1331 permanently or temporarily. We should have flushed and synced after the last
1332 RCPT. */
1333
1334 if (mua_wrapper)
1335 {
1336 address_item *badaddr;
1337 for (badaddr = first_addr; badaddr != NULL; badaddr = badaddr->next)
1338 {
1339 if (badaddr->transport_return != PENDING_OK) break;
1340 }
1341 if (badaddr != NULL)
1342 {
1343 set_errno(addrlist, 0, badaddr->message, FAIL);
1344 ok = FALSE;
1345 }
1346 }
1347
1348 /* If ok is TRUE, we know we have got at least one good recipient, and must now
1349 send DATA, but if it is FALSE (in the normal, non-wrapper case), we may still
1350 have a good recipient buffered up if we are pipelining. We don't want to waste
1351 time sending DATA needlessly, so we only send it if either ok is TRUE or if we
1352 are pipelining. The responses are all handled by sync_responses(). */
1353
1354 if (ok || (smtp_use_pipelining && !mua_wrapper))
1355 {
1356 int count = smtp_write_command(&outblock, FALSE, "DATA\r\n");
1357 if (count < 0) goto SEND_FAILED;
1358 switch(sync_responses(first_addr, tblock->rcpt_include_affixes, &sync_addr,
1359 host, count, pending_MAIL, ok? +1 : -1, &inblock,
1360 ob->command_timeout, buffer, sizeof(buffer)))
1361 {
1362 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1363 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1364 break;
1365
1366 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1367 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1368 case 0: break; /* No 2xx or 5xx, but no probs */
1369
1370 case -1: goto END_OFF; /* Timeout on RCPT */
1371 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */
1372 }
1373 }
1374
1375 /* Save the first address of the next batch. */
1376
1377 first_addr = addr;
1378
1379 /* If there were no good recipients (but otherwise there have been no
1380 problems), just set ok TRUE, since we have handled address-specific errors
1381 already. Otherwise, it's OK to send the message. Use the check/escape mechanism
1382 for handling the SMTP dot-handling protocol, flagging to apply to headers as
1383 well as body. Set the appropriate timeout value to be used for each chunk.
1384 (Haven't been able to make it work using select() for writing yet.) */
1385
1386 if (!ok) ok = TRUE; else
1387 {
1388 sigalrm_seen = FALSE;
1389 transport_write_timeout = ob->data_timeout;
1390 smtp_command = US"sending data block"; /* For error messages */
1391 DEBUG(D_transport|D_v)
1392 debug_printf(" SMTP>> writing message and terminating \".\"\n");
1393 transport_count = 0;
1394 ok = transport_write_message(addrlist, inblock.sock,
1395 topt_use_crlf | topt_end_dot | topt_escape_headers |
1396 (tblock->body_only? topt_no_headers : 0) |
1397 (tblock->headers_only? topt_no_body : 0) |
1398 (tblock->return_path_add? topt_add_return_path : 0) |
1399 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1400 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1401 0, /* No size limit */
1402 tblock->add_headers, tblock->remove_headers,
1403 US".", US"..", /* Escaping strings */
1404 tblock->rewrite_rules, tblock->rewrite_existflags);
1405
1406 /* transport_write_message() uses write() because it is called from other
1407 places to write to non-sockets. This means that under some OS (e.g. Solaris)
1408 it can exit with "Broken pipe" as its error. This really means that the
1409 socket got closed at the far end. */
1410
1411 transport_write_timeout = 0; /* for subsequent transports */
1412
1413 /* Failure can either be some kind of I/O disaster (including timeout),
1414 or the failure of a transport filter or the expansion of added headers. */
1415
1416 if (!ok)
1417 {
1418 buffer[0] = 0; /* There hasn't been a response */
1419 goto RESPONSE_FAILED;
1420 }
1421
1422 /* We used to send the terminating "." explicitly here, but because of
1423 buffering effects at both ends of TCP/IP connections, you don't gain
1424 anything by keeping it separate, so it might as well go in the final
1425 data buffer for efficiency. This is now done by setting the topt_end_dot
1426 flag above. */
1427
1428 smtp_command = US"end of data";
1429
1430 /* For SMTP, we now read a single response that applies to the whole message.
1431 If it is OK, then all the addresses have been delivered. */
1432
1433 if (!lmtp) ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1434 ob->final_timeout);
1435
1436 /* For LMTP, we get back a response for every RCPT command that we sent;
1437 some may be accepted and some rejected. For those that get a response, their
1438 status is fixed; any that are accepted have been handed over, even if later
1439 responses crash - at least, that's how I read RFC 2033.
1440
1441 If all went well, mark the recipient addresses as completed, record which
1442 host/IPaddress they were delivered to, and cut out RSET when sending another
1443 message down the same channel. Write the completed addresses to the journal
1444 now so that they are recorded in case there is a crash of hardware or
1445 software before the spool gets updated. Also record the final SMTP
1446 confirmation if needed (for SMTP only). */
1447
1448 if (ok)
1449 {
1450 int flag = '=';
1451 int delivery_time = (int)(time(NULL) - start_delivery_time);
1452 int len;
1453 host_item *thost;
1454 uschar *conf = NULL;
1455 send_rset = FALSE;
1456
1457 /* Make a copy of the host if it is local to this invocation
1458 of the transport. */
1459
1460 if (copy_host)
1461 {
1462 thost = store_get(sizeof(host_item));
1463 *thost = *host;
1464 thost->name = string_copy(host->name);
1465 thost->address = string_copy(host->address);
1466 }
1467 else thost = host;
1468
1469 /* Set up confirmation if needed - applies only to SMTP */
1470
1471 if ((log_extra_selector & LX_smtp_confirmation) != 0 && !lmtp)
1472 {
1473 uschar *s = string_printing(buffer);
1474 conf = (s == buffer)? (uschar *)string_copy(s) : s;
1475 }
1476
1477 /* Process all transported addresses - for LMTP, read a status for
1478 each one. */
1479
1480 for (addr = addrlist; addr != first_addr; addr = addr->next)
1481 {
1482 if (addr->transport_return != PENDING_OK) continue;
1483
1484 /* LMTP - if the response fails badly (e.g. timeout), use it for all the
1485 remaining addresses. Otherwise, it's a return code for just the one
1486 address. */
1487
1488 if (lmtp)
1489 {
1490 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1491 ob->final_timeout))
1492 {
1493 if (errno != 0 || buffer[0] == 0) goto RESPONSE_FAILED;
1494 addr->message = string_sprintf("LMTP error after %s: %s",
1495 big_buffer, string_printing(buffer));
1496 addr->transport_return = (buffer[0] == '5')? FAIL : DEFER;
1497 continue;
1498 }
1499 completed_address = TRUE; /* NOW we can set this flag */
1500 }
1501
1502 /* SMTP, or success return from LMTP for this address. Pass back the
1503 actual port used. */
1504
1505 addr->transport_return = OK;
1506 addr->more_errno = delivery_time;
1507 thost->port = port;
1508 addr->host_used = thost;
1509 addr->special_action = flag;
1510 addr->message = conf;
1511 flag = '-';
1512
1513 /* Update the journal. For homonymic addresses, use the base address plus
1514 the transport name. See lots of comments in deliver.c about the reasons
1515 for the complications when homonyms are involved. Just carry on after
1516 write error, as it may prove possible to update the spool file later. */
1517
1518 if (testflag(addr, af_homonym))
1519 sprintf(CS buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
1520 else
1521 sprintf(CS buffer, "%.500s\n", addr->unique);
1522
1523 DEBUG(D_deliver) debug_printf("journalling %s", buffer);
1524 len = Ustrlen(CS buffer);
1525 if (write(journal_fd, buffer, len) != len)
1526 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
1527 "%s: %s", buffer, strerror(errno));
1528 }
1529
1530 /* Ensure the journal file is pushed out to disk. */
1531
1532 if (fsync(journal_fd) < 0)
1533 log_write(0, LOG_MAIN|LOG_PANIC, "failed to fsync journal: %s",
1534 strerror(errno));
1535 }
1536 }
1537
1538
1539 /* Handle general (not specific to one address) failures here. The value of ok
1540 is used to skip over this code on the falling through case. A timeout causes a
1541 deferral. Other errors may defer or fail according to the response code, and
1542 may set up a special errno value, e.g. after connection chopped, which is
1543 assumed if errno == 0 and there is no text in the buffer. If control reaches
1544 here during the setting up phase (i.e. before MAIL FROM) then always defer, as
1545 the problem is not related to this specific message. */
1546
1547 if (!ok)
1548 {
1549 int code;
1550
1551 RESPONSE_FAILED:
1552 save_errno = errno;
1553 message = NULL;
1554 send_quit = check_response(host, &save_errno, addrlist->more_errno,
1555 buffer, &code, &message);
1556 goto FAILED;
1557
1558 SEND_FAILED:
1559 save_errno = errno;
1560 code = '4';
1561 message = US string_sprintf("send() to %s [%s] failed: %s",
1562 host->name, host->address, strerror(save_errno));
1563 send_quit = FALSE;
1564 goto FAILED;
1565
1566 /* This label is jumped to directly when a TLS negotiation has failed,
1567 or was not done for a host for which it is required. Values will be set
1568 in message and save_errno, and setting_up will always be true. Treat as
1569 a temporary error. */
1570
1571 #ifdef SUPPORT_TLS
1572 TLS_FAILED:
1573 code = '4';
1574 #endif
1575
1576 /* If the failure happened while setting up the call, see if the failure was
1577 a 5xx response (this will either be on connection, or following HELO - a 5xx
1578 after EHLO causes it to try HELO). If so, fail all addresses, as this host is
1579 never going to accept them. For other errors during setting up (timeouts or
1580 whatever), defer all addresses, and yield DEFER, so that the host is not
1581 tried again for a while. */
1582
1583 FAILED:
1584 ok = FALSE; /* For when reached by GOTO */
1585
1586 if (setting_up)
1587 {
1588 if (code == '5')
1589 {
1590 set_errno(addrlist, save_errno, message, FAIL);
1591 }
1592 else
1593 {
1594 set_errno(addrlist, save_errno, message, DEFER);
1595 yield = DEFER;
1596 }
1597 }
1598
1599 /* If there was an I/O error or timeout or other transportation error,
1600 indicated by errno being non-zero, defer all addresses and yield DEFER,
1601 except for the case of failed add_headers expansion, or a transport filter
1602 failure, when the yield should be ERROR, to stop it trying other hosts.
1603
1604 However, handle timeouts after MAIL FROM or "." and loss of connection after
1605 "." specially. They can indicate a problem with the sender address or with
1606 the contents of the message rather than a real error on the connection.
1607 Therefore, treat these cases in the same way as a 4xx response.
1608
1609 The following condition tests for NOT these special cases. */
1610
1611 else if (save_errno != 0 &&
1612 (save_errno != ETIMEDOUT ||
1613 (Ustrncmp(smtp_command,"MAIL",4) != 0 &&
1614 Ustrncmp(smtp_command,"end ",4) != 0)) &&
1615 (save_errno != ERRNO_SMTPCLOSED ||
1616 Ustrncmp(smtp_command,"end ",4) != 0))
1617 {
1618 yield = (save_errno == ERRNO_CHHEADER_FAIL ||
1619 save_errno == ERRNO_FILTER_FAIL)? ERROR : DEFER;
1620 set_errno(addrlist, save_errno, message, DEFER);
1621 }
1622
1623 /* Otherwise we have a message-specific error response from the remote
1624 host. This is one of
1625 (a) negative response or timeout after "mail from"
1626 (b) negative response after "data"
1627 (c) negative response or timeout or dropped connection after "."
1628 It won't be a negative response or timeout after "rcpt to", as that is dealt
1629 with separately above. The action in all cases is to set an appropriate
1630 error code for all the addresses, but to leave yield set to OK because
1631 the host itself has not failed. [It might in practice have failed for a
1632 timeout after MAIL FROM, or "." but if so, we'll discover that at the next
1633 delivery attempt.] For a temporary error, set the message_defer flag, and
1634 write to the logs for information if this is not the last host. The error for
1635 the last host will be logged as part of the address's log line. */
1636
1637 else
1638 {
1639 if (mua_wrapper) code = '5'; /* Force hard failure in wrapper mode */
1640
1641 set_errno(addrlist, save_errno, message, (code == '5')? FAIL : DEFER);
1642
1643 /* If there's an errno, the message contains just the identity of
1644 the host. */
1645
1646 if (code != '5') /* Anything other than 5 is treated as temporary */
1647 {
1648 if (save_errno > 0)
1649 message = US string_sprintf("%s: %s", message, strerror(save_errno));
1650 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", message);
1651 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
1652 *message_defer = TRUE;
1653 }
1654 }
1655 }
1656
1657
1658 /* If all has gone well, send_quit will be set TRUE, implying we can end the
1659 SMTP session tidily. However, if there were too many addresses to send in one
1660 message (indicated by first_addr being non-NULL) we want to carry on with the
1661 rest of them. Also, it is desirable to send more than one message down the SMTP
1662 connection if there are several waiting, provided we haven't already sent so
1663 many as to hit the configured limit. The function transport_check_waiting looks
1664 for a waiting message and returns its id. Then transport_pass_socket tries to
1665 set up a continued delivery by passing the socket on to another process. The
1666 variable send_rset is FALSE if a message has just been successfully transfered.
1667
1668 If we are already sending down a continued channel, there may be further
1669 addresses not yet delivered that are aimed at the same host, but which have not
1670 been passed in this run of the transport. In this case, continue_more will be
1671 true, and all we should do is send RSET if necessary, and return, leaving the
1672 channel open.
1673
1674 However, if no address was disposed of, i.e. all addresses got 4xx errors, we
1675 do not want to continue with other messages down the same channel, because that
1676 can lead to looping between two or more messages, all with the same,
1677 temporarily failing address(es). [The retry information isn't updated yet, so
1678 new processes keep on trying.] We probably also don't want to try more of this
1679 message's addresses either.
1680
1681 If we have started a TLS session, we have to end it before passing the
1682 connection to a new process. However, not all servers can handle this (Exim
1683 can), so we do not pass such a connection on if the host matches
1684 hosts_nopass_tls. */
1685
1686 DEBUG(D_transport)
1687 debug_printf("ok=%d send_quit=%d send_rset=%d continue_more=%d "
1688 "yield=%d first_address is %sNULL\n", ok, send_quit, send_rset,
1689 continue_more, yield, (first_addr == NULL)? "":"not ");
1690
1691 if (completed_address && ok && send_quit)
1692 {
1693 BOOL more;
1694 if (first_addr != NULL || continue_more ||
1695 (
1696 (tls_active < 0 ||
1697 verify_check_this_host(&(ob->hosts_nopass_tls), NULL, host->name,
1698 host->address, NULL) != OK)
1699 &&
1700 transport_check_waiting(tblock->name, host->name,
1701 tblock->connection_max_messages, new_message_id, &more)
1702 ))
1703 {
1704 uschar *msg;
1705
1706 if (send_rset)
1707 {
1708 if (! (ok = smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0))
1709 {
1710 msg = US string_sprintf("send() to %s [%s] failed: %s", host->name,
1711 host->address, strerror(save_errno));
1712 send_quit = FALSE;
1713 }
1714 else if (! (ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1715 ob->command_timeout)))
1716 {
1717 int code;
1718 send_quit = check_response(host, &errno, 0, buffer, &code, &msg);
1719 if (!send_quit)
1720 {
1721 DEBUG(D_transport) debug_printf("%s\n", msg);
1722 }
1723 }
1724 }
1725
1726 /* Either RSET was not needed, or it succeeded */
1727
1728 if (ok)
1729 {
1730 if (first_addr != NULL) /* More addresses still to be sent */
1731 { /* in this run of the transport */
1732 continue_sequence++; /* Causes * in logging */
1733 goto SEND_MESSAGE;
1734 }
1735 if (continue_more) return yield; /* More addresses for another run */
1736
1737 /* Pass the socket to a new Exim process. Before doing so, we must shut
1738 down TLS. Not all MTAs allow for the continuation of the SMTP session
1739 when TLS is shut down. We test for this by sending a new EHLO. If we
1740 don't get a good response, we don't attempt to pass the socket on. */
1741
1742 #ifdef SUPPORT_TLS
1743 if (tls_active >= 0)
1744 {
1745 tls_close(TRUE);
1746 ok = smtp_write_command(&outblock,FALSE,"EHLO %s\r\n",helo_data) >= 0 &&
1747 smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1748 ob->command_timeout);
1749 }
1750 #endif
1751
1752 /* If the socket is successfully passed, we musn't send QUIT (or
1753 indeed anything!) from here. */
1754
1755 if (ok && transport_pass_socket(tblock->name, host->name, host->address,
1756 new_message_id, inblock.sock))
1757 {
1758 send_quit = FALSE;
1759 }
1760 }
1761
1762 /* If RSET failed and there are addresses left, they get deferred. */
1763
1764 else set_errno(first_addr, errno, msg, DEFER);
1765 }
1766 }
1767
1768 /* End off tidily with QUIT unless the connection has died or the socket has
1769 been passed to another process. There has been discussion on the net about what
1770 to do after sending QUIT. The wording of the RFC suggests that it is necessary
1771 to wait for a response, but on the other hand, there isn't anything one can do
1772 with an error response, other than log it. Exim used to do that. However,
1773 further discussion suggested that it is positively advantageous not to wait for
1774 the response, but to close the session immediately. This is supposed to move
1775 the TCP/IP TIME_WAIT state from the server to the client, thereby removing some
1776 load from the server. (Hosts that are both servers and clients may not see much
1777 difference, of course.) Further discussion indicated that this was safe to do
1778 on Unix systems which have decent implementations of TCP/IP that leave the
1779 connection around for a while (TIME_WAIT) after the application has gone away.
1780 This enables the response sent by the server to be properly ACKed rather than
1781 timed out, as can happen on broken TCP/IP implementations on other OS.
1782
1783 This change is being made on 31-Jul-98. After over a year of trouble-free
1784 operation, the old commented-out code was removed on 17-Sep-99. */
1785
1786 SEND_QUIT:
1787 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1788
1789 END_OFF:
1790
1791 #ifdef SUPPORT_TLS
1792 tls_close(TRUE);
1793 #endif
1794
1795 /* Close the socket, and return the appropriate value, first setting
1796 continue_transport and continue_hostname NULL to prevent any other addresses
1797 that may include the host from trying to re-use a continuation socket. This
1798 works because the NULL setting is passed back to the calling process, and
1799 remote_max_parallel is forced to 1 when delivering over an existing connection,
1800
1801 If all went well and continue_more is set, we shouldn't actually get here if
1802 there are further addresses, as the return above will be taken. However,
1803 writing RSET might have failed, or there may be other addresses whose hosts are
1804 specified in the transports, and therefore not visible at top level, in which
1805 case continue_more won't get set. */
1806
1807 close(inblock.sock);
1808 continue_transport = NULL;
1809 continue_hostname = NULL;
1810 return yield;
1811 }
1812
1813
1814
1815
1816 /*************************************************
1817 * Closedown entry point *
1818 *************************************************/
1819
1820 /* This function is called when exim is passed an open smtp channel
1821 from another incarnation, but the message which it has been asked
1822 to deliver no longer exists. The channel is on stdin.
1823
1824 We might do fancy things like looking for another message to send down
1825 the channel, but if the one we sought has gone, it has probably been
1826 delivered by some other process that itself will seek further messages,
1827 so just close down our connection.
1828
1829 Argument: pointer to the transport instance block
1830 Returns: nothing
1831 */
1832
1833 void
1834 smtp_transport_closedown(transport_instance *tblock)
1835 {
1836 smtp_transport_options_block *ob =
1837 (smtp_transport_options_block *)(tblock->options_block);
1838 smtp_inblock inblock;
1839 smtp_outblock outblock;
1840 uschar buffer[256];
1841 uschar inbuffer[4096];
1842 uschar outbuffer[16];
1843
1844 inblock.sock = fileno(stdin);
1845 inblock.buffer = inbuffer;
1846 inblock.buffersize = sizeof(inbuffer);
1847 inblock.ptr = inbuffer;
1848 inblock.ptrend = inbuffer;
1849
1850 outblock.sock = inblock.sock;
1851 outblock.buffersize = sizeof(outbuffer);
1852 outblock.buffer = outbuffer;
1853 outblock.ptr = outbuffer;
1854 outblock.cmd_count = 0;
1855 outblock.authenticating = FALSE;
1856
1857 (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1858 (void)smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1859 ob->command_timeout);
1860 close(inblock.sock);
1861 }
1862
1863
1864
1865 /*************************************************
1866 * Prepare addresses for delivery *
1867 *************************************************/
1868
1869 /* This function is called to flush out error settings from previous delivery
1870 attempts to other hosts. It also records whether we got here via an MX record
1871 or not in the more_errno field of the address. We are interested only in
1872 addresses that are still marked DEFER - others may have got delivered to a
1873 previously considered IP address. Set their status to PENDING_DEFER to indicate
1874 which ones are relevant this time.
1875
1876 Arguments:
1877 addrlist the list of addresses
1878 host the host we are delivering to
1879
1880 Returns: the first address for this delivery
1881 */
1882
1883 static address_item *
1884 prepare_addresses(address_item *addrlist, host_item *host)
1885 {
1886 address_item *first_addr = NULL;
1887 address_item *addr;
1888 for (addr = addrlist; addr != NULL; addr = addr->next)
1889 {
1890 if (addr->transport_return != DEFER) continue;
1891 if (first_addr == NULL) first_addr = addr;
1892 addr->transport_return = PENDING_DEFER;
1893 addr->basic_errno = 0;
1894 addr->more_errno = (host->mx >= 0)? 'M' : 'A';
1895 addr->message = NULL;
1896 #ifdef SUPPORT_TLS
1897 addr->cipher = NULL;
1898 addr->peerdn = NULL;
1899 #endif
1900 }
1901 return first_addr;
1902 }
1903
1904
1905
1906 /*************************************************
1907 * Main entry point *
1908 *************************************************/
1909
1910 /* See local README for interface details. As this is a remote transport, it is
1911 given a chain of addresses to be delivered in one connection, if possible. It
1912 always returns TRUE, indicating that each address has its own independent
1913 status set, except if there is a setting up problem, in which case it returns
1914 FALSE. */
1915
1916 BOOL
1917 smtp_transport_entry(
1918 transport_instance *tblock, /* data for this instantiation */
1919 address_item *addrlist) /* addresses we are working on */
1920 {
1921 int cutoff_retry;
1922 int port;
1923 int hosts_defer = 0;
1924 int hosts_fail = 0;
1925 int hosts_looked_up = 0;
1926 int hosts_retry = 0;
1927 int hosts_serial = 0;
1928 int hosts_total = 0;
1929 address_item *addr;
1930 BOOL expired = TRUE;
1931 BOOL continuing = continue_hostname != NULL;
1932 uschar *expanded_hosts = NULL;
1933 uschar *pistring;
1934 uschar *tid = string_sprintf("%s transport", tblock->name);
1935 smtp_transport_options_block *ob =
1936 (smtp_transport_options_block *)(tblock->options_block);
1937 host_item *hostlist = addrlist->host_list;
1938 host_item *host = NULL;
1939
1940 DEBUG(D_transport)
1941 {
1942 debug_printf("%s transport entered\n", tblock->name);
1943 for (addr = addrlist; addr != NULL; addr = addr->next)
1944 debug_printf(" %s\n", addr->address);
1945 if (continuing) debug_printf("already connected to %s [%s]\n",
1946 continue_hostname, continue_host_address);
1947 }
1948
1949 /* If a host list is not defined for the addresses - they must all have the
1950 same one in order to be passed to a single transport - or if the transport has
1951 a host list with hosts_override set, use the host list supplied with the
1952 transport. It is an error for this not to exist. */
1953
1954 if (hostlist == NULL || (ob->hosts_override && ob->hosts != NULL))
1955 {
1956 if (ob->hosts == NULL)
1957 {
1958 addrlist->message = string_sprintf("%s transport called with no hosts set",
1959 tblock->name);
1960 addrlist->transport_return = PANIC;
1961 return FALSE; /* Only top address has status */
1962 }
1963
1964 DEBUG(D_transport) debug_printf("using the transport's hosts: %s\n",
1965 ob->hosts);
1966
1967 /* If the transport's host list contains no '$' characters, and we are not
1968 randomizing, it is fixed and therefore a chain of hosts can be built once
1969 and for all, and remembered for subsequent use by other calls to this
1970 transport. If, on the other hand, the host list does contain '$', or we are
1971 randomizing its order, we have to rebuild it each time. In the fixed case,
1972 as the hosts string will never be used again, it doesn't matter that we
1973 replace all the : characters with zeros. */
1974
1975 if (ob->hostlist == NULL)
1976 {
1977 uschar *s = ob->hosts;
1978
1979 if (Ustrchr(s, '$') != NULL)
1980 {
1981 expanded_hosts = expand_string(s);
1982 if (expanded_hosts == NULL)
1983 {
1984 addrlist->message = string_sprintf("failed to expand list of hosts "
1985 "\"%s\" in %s transport: %s", s, tblock->name, expand_string_message);
1986 addrlist->transport_return = search_find_defer? DEFER : PANIC;
1987 return FALSE; /* Only top address has status */
1988 }
1989 DEBUG(D_transport) debug_printf("expanded list of hosts \"%s\" to "
1990 "\"%s\"\n", s, expanded_hosts);
1991 s = expanded_hosts;
1992 }
1993 else
1994 if (ob->hosts_randomize) s = expanded_hosts = string_copy(s);
1995
1996 host_build_hostlist(&hostlist, s, ob->hosts_randomize);
1997
1998 /* If there was no expansion of hosts, save the host list for
1999 next time. */
2000
2001 if (expanded_hosts == NULL) ob->hostlist = hostlist;
2002 }
2003
2004 /* This is not the first time this transport has been run in this delivery;
2005 the host list was built previously. */
2006
2007 else hostlist = ob->hostlist;
2008 }
2009
2010 /* The host list was supplied with the address. If hosts_randomize is set, we
2011 must sort it into a random order if it did not come from MX records and has not
2012 already been randomized (but don't bother if continuing down an existing
2013 connection). */
2014
2015 else if (ob->hosts_randomize && hostlist->mx == MX_NONE && !continuing)
2016 {
2017 host_item *newlist = NULL;
2018 while (hostlist != NULL)
2019 {
2020 host_item *h = hostlist;
2021 hostlist = hostlist->next;
2022
2023 h->sort_key = random_number(100);
2024
2025 if (newlist == NULL)
2026 {
2027 h->next = NULL;
2028 newlist = h;
2029 }
2030 else if (h->sort_key < newlist->sort_key)
2031 {
2032 h->next = newlist;
2033 newlist = h;
2034 }
2035 else
2036 {
2037 host_item *hh = newlist;
2038 while (hh->next != NULL)
2039 {
2040 if (h->sort_key < hh->next->sort_key) break;
2041 hh = hh->next;
2042 }
2043 h->next = hh->next;
2044 hh->next = h;
2045 }
2046 }
2047
2048 hostlist = addrlist->host_list = newlist;
2049 }
2050
2051
2052 /* Sort out the port. Set up a string for adding to the retry key if the port
2053 number is not the standard SMTP port. */
2054
2055 if (!smtp_get_port(ob->port, addrlist, &port, tid)) return FALSE;
2056 pistring = string_sprintf(":%d", port);
2057 if (Ustrcmp(pistring, ":25") == 0) pistring = US"";
2058
2059
2060 /* For each host-plus-IP-address on the list:
2061
2062 . If this is a continued delivery and the host isn't the one with the
2063 current connection, skip.
2064
2065 . If the status is unusable (i.e. previously failed or retry checked), skip.
2066
2067 . If no IP address set, get the address, either by turning the name into
2068 an address, calling gethostbyname if gethostbyname is on, or by calling
2069 the DNS. The DNS may yield multiple addresses, in which case insert the
2070 extra ones into the list.
2071
2072 . Get the retry data if not previously obtained for this address and set the
2073 field which remembers the state of this address. Skip if the retry time is
2074 not reached. If not, remember whether retry data was found. The retry string
2075 contains both the name and the IP address.
2076
2077 . Scan the list of addresses and mark those whose status is DEFER as
2078 PENDING_DEFER. These are the only ones that will be processed in this cycle
2079 of the hosts loop.
2080
2081 . Make a delivery attempt - addresses marked PENDING_DEFER will be tried.
2082 Some addresses may be successfully delivered, others may fail, and yet
2083 others may get temporary errors and so get marked DEFER.
2084
2085 . The return from the delivery attempt is OK if a connection was made and a
2086 valid SMTP dialogue was completed. Otherwise it is DEFER.
2087
2088 . If OK, add a "remove" retry item for this host/IPaddress, if any.
2089
2090 . If fail to connect, or other defer state, add a retry item.
2091
2092 . If there are any addresses whose status is still DEFER, carry on to the
2093 next host/IPaddress, unless we have tried the number of hosts given
2094 by hosts_max_try; otherwise return.
2095
2096 If we get to the end of the list, all hosts have deferred at least one address,
2097 or not reached their retry times. If delay_after_cutoff is unset, it requests a
2098 delivery attempt to those hosts whose last try was before the arrival time of
2099 the current message. To cope with this, we have to go round the loop a second
2100 time. After that, set the status and error data for any addresses that haven't
2101 had it set already. */
2102
2103 for (cutoff_retry = 0; expired &&
2104 cutoff_retry < ((ob->delay_after_cutoff)? 1 : 2);
2105 cutoff_retry++)
2106 {
2107 host_item *nexthost = NULL;
2108 int unexpired_hosts_tried = 0;
2109
2110 for (host = hostlist;
2111 host != NULL && unexpired_hosts_tried < ob->hosts_max_try;
2112 host = nexthost)
2113 {
2114 int rc;
2115 int host_af;
2116 uschar *rs;
2117 BOOL serialized = FALSE;
2118 BOOL host_is_expired = FALSE;
2119 BOOL message_defer = FALSE;
2120 BOOL ifchanges = FALSE;
2121 BOOL some_deferred = FALSE;
2122 address_item *first_addr = NULL;
2123 uschar *interface = NULL;
2124 uschar *retry_host_key = NULL;
2125 uschar *retry_message_key = NULL;
2126 uschar *serialize_key = NULL;
2127
2128 /* Default next host is next host. :-) But this can vary if the
2129 hosts_max_try limit is hit (see below). */
2130
2131 nexthost = host->next;
2132
2133 /* Set the flag requesting that this host be added to the waiting
2134 database if the delivery fails temporarily or if we are running with
2135 queue_smtp or a 2-stage queue run. This gets unset for certain
2136 kinds of error, typically those that are specific to the message. */
2137
2138 host->update_waiting = TRUE;
2139
2140 /* If the address hasn't yet been obtained from the host name, look it up
2141 now, unless the host is already marked as unusable. If it is marked as
2142 unusable, it means that the router was unable to find its IP address (in
2143 the DNS or wherever) OR we are in the 2nd time round the cutoff loop, and
2144 the lookup failed last time. We don't get this far if *all* MX records
2145 point to non-existent hosts; that is treated as a hard error.
2146
2147 We can just skip this host entirely. When the hosts came from the router,
2148 the address will timeout based on the other host(s); when the address is
2149 looked up below, there is an explicit retry record added.
2150
2151 Note that we mustn't skip unusable hosts if the address is not unset; they
2152 may be needed as expired hosts on the 2nd time round the cutoff loop. */
2153
2154 if (host->address == NULL)
2155 {
2156 uschar *canonical_name;
2157
2158 if (host->status >= hstatus_unusable)
2159 {
2160 DEBUG(D_transport) debug_printf("%s has no address and is unusable - skipping\n",
2161 host->name);
2162 continue;
2163 }
2164
2165 DEBUG(D_transport) debug_printf("getting address for %s\n", host->name);
2166
2167 hosts_looked_up++;
2168
2169 /* Find by name if so configured, or if it's an IP address. We don't
2170 just copy the IP address, because we need the test-for-local to happen. */
2171
2172 if (ob->gethostbyname || string_is_ip_address(host->name, NULL))
2173 rc = host_find_byname(host, NULL, &canonical_name, TRUE);
2174 else
2175 {
2176 int flags = HOST_FIND_BY_A;
2177 if (ob->dns_qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
2178 if (ob->dns_search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
2179 rc = host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
2180 &canonical_name, NULL);
2181 }
2182
2183 /* Failure to find the host at this time (usually DNS temporary failure)
2184 is really a kind of routing failure rather than a transport failure.
2185 Therefore we add a retry item of the routing kind, not to stop us trying
2186 to look this name up here again, but to ensure the address gets timed
2187 out if the failures go on long enough. A complete failure at this point
2188 commonly points to a configuration error, but the best action is still
2189 to carry on for the next host. */
2190
2191 if (rc == HOST_FIND_AGAIN || rc == HOST_FIND_FAILED)
2192 {
2193 retry_add_item(addrlist, string_sprintf("R:%s", host->name), 0);
2194 expired = FALSE;
2195 if (rc == HOST_FIND_AGAIN) hosts_defer++; else hosts_fail++;
2196 DEBUG(D_transport) debug_printf("rc = %s for %s\n", (rc == HOST_FIND_AGAIN)?
2197 "HOST_FIND_AGAIN" : "HOST_FIND_FAILED", host->name);
2198 host->status = hstatus_unusable;
2199
2200 for (addr = addrlist; addr != NULL; addr = addr->next)
2201 {
2202 if (addr->transport_return != DEFER) continue;
2203 addr->basic_errno = ERRNO_UNKNOWNHOST;
2204 addr->message =
2205 string_sprintf("failed to lookup IP address for %s", host->name);
2206 }
2207 continue;
2208 }
2209
2210 /* If the host is actually the local host, we may have a problem, or
2211 there may be some cunning configuration going on. In the problem case,
2212 log things and give up. The default transport status is already DEFER. */
2213
2214 if (rc == HOST_FOUND_LOCAL && !ob->allow_localhost)
2215 {
2216 for (addr = addrlist; addr != NULL; addr = addr->next)
2217 {
2218 addr->basic_errno = 0;
2219 addr->message = string_sprintf("%s transport found host %s to be "
2220 "local", tblock->name, host->name);
2221 }
2222 goto END_TRANSPORT;
2223 }
2224 } /* End of block for IP address lookup */
2225
2226 /* If this is a continued delivery, we are interested only in the host
2227 which matches the name of the existing open channel. The check is put
2228 here after the local host lookup, in case the name gets expanded as a
2229 result of the lookup. Set expired FALSE, to save the outer loop executing
2230 twice. */
2231
2232 if (continuing && (Ustrcmp(continue_hostname, host->name) != 0 ||
2233 Ustrcmp(continue_host_address, host->address) != 0))
2234 {
2235 expired = FALSE;
2236 continue; /* With next host */
2237 }
2238
2239 /* If queue_smtp is set (-odqs or the first part of a 2-stage run), or the
2240 domain is in queue_smtp_domains, we don't actually want to attempt any
2241 deliveries. When doing a queue run, queue_smtp_domains is always unset. If
2242 there is a lookup defer in queue_smtp_domains, proceed as if the domain
2243 were not in it. We don't want to hold up all SMTP deliveries! Except when
2244 doing a two-stage queue run, don't do this if forcing. */
2245
2246 if ((!deliver_force || queue_2stage) && (queue_smtp ||
2247 match_isinlist(addrlist->domain, &queue_smtp_domains, 0, NULL, NULL,
2248 MCL_DOMAIN, TRUE, NULL) == OK))
2249 {
2250 expired = FALSE;
2251 for (addr = addrlist; addr != NULL; addr = addr->next)
2252 {
2253 if (addr->transport_return != DEFER) continue;
2254 addr->message = US"domain matches queue_smtp_domains, or -odqs set";
2255 }
2256 continue; /* With next host */
2257 }
2258
2259 /* Count hosts being considered - purely for an intelligent comment
2260 if none are usable. */
2261
2262 hosts_total++;
2263
2264 /* Set $host and $host address now in case they are needed for the
2265 interface expansion or the serialize_hosts check; they remain set if an
2266 actual delivery happens. */
2267
2268 deliver_host = host->name;
2269 deliver_host_address = host->address;
2270
2271 /* Select IPv4 or IPv6, and choose an outgoing interface. If the interface
2272 string changes upon expansion, we must add it to the key that is used for
2273 retries, because connections to the same host from a different interface
2274 should be treated separately. */
2275
2276 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET : AF_INET6;
2277 if (!smtp_get_interface(ob->interface, host_af, addrlist, &ifchanges,
2278 &interface, tid))
2279 return FALSE;
2280 if (ifchanges) pistring = string_sprintf("%s/%s", pistring, interface);
2281
2282 /* The first time round the outer loop, check the status of the host by
2283 inspecting the retry data. The second time round, we are interested only
2284 in expired hosts that haven't been tried since this message arrived. */
2285
2286 if (cutoff_retry == 0)
2287 {
2288 /* Ensure the status of the address is set by checking retry data if
2289 necessary. There maybe host-specific retry data (applicable to all
2290 messages) and also data for retries of a specific message at this host.
2291 If either of these retry records are actually read, the keys used are
2292 returned to save recomputing them later. */
2293
2294 host_is_expired = retry_check_address(addrlist->domain, host, pistring,
2295 ob->retry_include_ip_address, &retry_host_key, &retry_message_key);
2296
2297 DEBUG(D_transport) debug_printf("%s [%s]%s status = %s\n", host->name,
2298 (host->address == NULL)? US"" : host->address, pistring,
2299 (host->status == hstatus_usable)? "usable" :
2300 (host->status == hstatus_unusable)? "unusable" :
2301 (host->status == hstatus_unusable_expired)? "unusable (expired)" : "?");
2302
2303 /* Skip this address if not usable at this time, noting if it wasn't
2304 actually expired, both locally and in the address. */
2305
2306 switch (host->status)
2307 {
2308 case hstatus_unusable:
2309 expired = FALSE;
2310 setflag(addrlist, af_retry_skipped);
2311 /* Fall through */
2312
2313 case hstatus_unusable_expired:
2314 switch (host->why)
2315 {
2316 case hwhy_retry: hosts_retry++; break;
2317 case hwhy_failed: hosts_fail++; break;
2318 case hwhy_deferred: hosts_defer++; break;
2319 }
2320
2321 /* If there was a retry message key, implying that previously there
2322 was a message-specific defer, we don't want to update the list of
2323 messages waiting for this host. */
2324
2325 if (retry_message_key != NULL) host->update_waiting = FALSE;
2326 continue; /* With the next host or IP address */
2327 }
2328 }
2329
2330 /* Second time round the loop: if the address is set but expired, and
2331 the message is newer than the last try, let it through. */
2332
2333 else
2334 {
2335 if (host->address == NULL ||
2336 host->status != hstatus_unusable_expired ||
2337 host->last_try > received_time)
2338 continue;
2339 DEBUG(D_transport)
2340 debug_printf("trying expired host %s [%s]%s\n",
2341 host->name, host->address, pistring);
2342 host_is_expired = TRUE;
2343 }
2344
2345 /* Setting "expired=FALSE" doesn't actually mean not all hosts are expired;
2346 it remains TRUE only if all hosts are expired and none are actually tried.
2347 */
2348
2349 expired = FALSE;
2350
2351 /* If this host is listed as one to which access must be serialized,
2352 see if another Exim process has a connection to it, and if so, skip
2353 this host. If not, update the database to record our connection to it
2354 and remember this for later deletion. Do not do any of this if we are
2355 sending the message down a pre-existing connection. */
2356
2357 if (!continuing &&
2358 verify_check_this_host(&(ob->serialize_hosts), NULL, host->name,
2359 host->address, NULL) == OK)
2360 {
2361 serialize_key = string_sprintf("host-serialize-%s", host->name);
2362 if (!enq_start(serialize_key))
2363 {
2364 DEBUG(D_transport)
2365 debug_printf("skipping host %s because another Exim process "
2366 "is connected to it\n", host->name);
2367 hosts_serial++;
2368 continue;
2369 }
2370 serialized = TRUE;
2371 }
2372
2373 /* OK, we have an IP address that is not waiting for its retry time to
2374 arrive (it might be expired) OR (second time round the loop) we have an
2375 expired host that hasn't been tried since the message arrived. Have a go
2376 at delivering the message to it. First prepare the addresses by flushing
2377 out the result of previous attempts, and finding the first address that
2378 is still to be delivered. */
2379
2380 first_addr = prepare_addresses(addrlist, host);
2381
2382 DEBUG(D_transport) debug_printf("delivering %s to %s [%s] (%s%s)\n",
2383 message_id, host->name, host->address, addrlist->address,
2384 (addrlist->next == NULL)? "" : ", ...");
2385
2386 set_process_info("delivering %s to %s [%s] (%s%s)",
2387 message_id, host->name, host->address, addrlist->address,
2388 (addrlist->next == NULL)? "" : ", ...");
2389
2390 /* This is not for real; don't do the delivery. If there are
2391 any remaining hosts, list them. */
2392
2393 if (dont_deliver)
2394 {
2395 host_item *host2;
2396 set_errno(addrlist, 0, NULL, OK);
2397 for (addr = addrlist; addr != NULL; addr = addr->next)
2398 {
2399 addr->host_used = host;
2400 addr->special_action = '*';
2401 addr->message = US"delivery bypassed by -N option";
2402 }
2403 DEBUG(D_transport)
2404 {
2405 debug_printf("*** delivery by %s transport bypassed by -N option\n"
2406 "*** host and remaining hosts:\n", tblock->name);
2407 for (host2 = host; host2 != NULL; host2 = host2->next)
2408 debug_printf(" %s [%s]\n", host2->name,
2409 (host2->address == NULL)? US"unset" : host2->address);
2410 }
2411 rc = OK;
2412 }
2413
2414 /* This is for real. If the host is expired, we don't count it for
2415 hosts_max_retry. This ensures that all hosts must expire before an address
2416 is timed out. Otherwise, if we are about to hit the hosts_max_retry limit,
2417 check to see if there is a subsequent hosts with a different MX value. If
2418 so, make that the next host, and don't count this one. This is a heuristic
2419 to make sure that different MXs do get tried. With a normal kind of retry
2420 rule, they would get tried anyway when the earlier hosts were delayed, but
2421 if the domain has a "retry every time" type of rule - as is often used for
2422 the the very large ISPs, that won't happen. */
2423
2424 else
2425 {
2426 if (!host_is_expired && ++unexpired_hosts_tried >= ob->hosts_max_try)
2427 {
2428 host_item *h;
2429 DEBUG(D_transport)
2430 debug_printf("hosts_max_try limit reached with this host\n");
2431 for (h = host; h != NULL; h = h->next)
2432 if (h->mx != host->mx) break;
2433 if (h != NULL)
2434 {
2435 nexthost = h;
2436 unexpired_hosts_tried--;
2437 DEBUG(D_transport) debug_printf("however, a higher MX host exists "
2438 "and will be tried\n");
2439 }
2440 }
2441
2442 /* Attempt the delivery. */
2443
2444 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2445 expanded_hosts != NULL, &message_defer, FALSE);
2446
2447 /* Yield is one of:
2448 OK => connection made, each address contains its result;
2449 message_defer is set for message-specific defers (when all
2450 recipients are marked defer)
2451 DEFER => there was a non-message-specific delivery problem;
2452 ERROR => there was a problem setting up the arguments for a filter,
2453 or there was a problem with expanding added headers
2454 */
2455
2456 /* If the result is not OK, there was a non-message-specific problem.
2457 If the result is DEFER, we need to write to the logs saying what happened
2458 for this particular host, except in the case of authentication and TLS
2459 failures, where the log has already been written. If all hosts defer a
2460 general message is written at the end. */
2461
2462 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL &&
2463 first_addr->basic_errno != ERRNO_TLSFAILURE)
2464 write_logs(first_addr, host);
2465
2466 /* If STARTTLS was accepted, but there was a failure in setting up the
2467 TLS session (usually a certificate screwup), and the host is not in
2468 hosts_require_tls, and tls_tempfail_tryclear is true, try again, with
2469 TLS forcibly turned off. We have to start from scratch with a new SMTP
2470 connection. That's why the retry is done from here, not from within
2471 smtp_deliver(). [Rejections of STARTTLS itself don't screw up the
2472 session, so the in-clear transmission after those errors, if permitted,
2473 happens inside smtp_deliver().] */
2474
2475 #ifdef SUPPORT_TLS
2476 if (rc == DEFER && first_addr->basic_errno == ERRNO_TLSFAILURE &&
2477 ob->tls_tempfail_tryclear &&
2478 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
2479 host->address, NULL) != OK)
2480 {
2481 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
2482 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
2483 first_addr = prepare_addresses(addrlist, host);
2484 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2485 expanded_hosts != NULL, &message_defer, TRUE);
2486 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL)
2487 write_logs(first_addr, host);
2488 }
2489 #endif
2490 }
2491
2492 /* Delivery attempt finished */
2493
2494 rs = (rc == OK)? US"OK" : (rc == DEFER)? US"DEFER" : (rc == ERROR)?
2495 US"ERROR" : US"?";
2496
2497 set_process_info("delivering %s: just tried %s [%s] for %s%s: result %s",
2498 message_id, host->name, host->address, addrlist->address,
2499 (addrlist->next == NULL)? "" : " (& others)", rs);
2500
2501 /* Release serialization if set up */
2502
2503 if (serialized) enq_end(serialize_key);
2504
2505 /* If the result is DEFER, or if a host retry record is known to exist, we
2506 need to add an item to the retry chain for updating the retry database
2507 at the end of delivery. We only need to add the item to the top address,
2508 of course. Also, if DEFER, we mark the IP address unusable so as to skip it
2509 for any other delivery attempts using the same address. (It is copied into
2510 the unusable tree at the outer level, so even if different address blocks
2511 contain the same address, it still won't get tried again.) */
2512
2513 if (rc == DEFER || retry_host_key != NULL)
2514 {
2515 int delete_flag = (rc != DEFER)? rf_delete : 0;
2516 if (retry_host_key == NULL)
2517 {
2518 retry_host_key = ob->retry_include_ip_address?
2519 string_sprintf("T:%S:%s%s", host->name, host->address, pistring) :
2520 string_sprintf("T:%S%s", host->name, pistring);
2521 }
2522
2523 /* If a delivery of another message over an existing SMTP connection
2524 yields DEFER, we do NOT set up retry data for the host. This covers the
2525 case when there are delays in routing the addresses in the second message
2526 that are so long that the server times out. This is alleviated by not
2527 routing addresses that previously had routing defers when handling an
2528 existing connection, but even so, this case may occur (e.g. if a
2529 previously happily routed address starts giving routing defers). If the
2530 host is genuinely down, another non-continued message delivery will
2531 notice it soon enough. */
2532
2533 if (delete_flag != 0 || !continuing)
2534 retry_add_item(first_addr, retry_host_key, rf_host | delete_flag);
2535
2536 /* We may have tried an expired host, if its retry time has come; ensure
2537 the status reflects the expiry for the benefit of any other addresses. */
2538
2539 if (rc == DEFER)
2540 {
2541 host->status = (host_is_expired)?
2542 hstatus_unusable_expired : hstatus_unusable;
2543 host->why = hwhy_deferred;
2544 }
2545 }
2546
2547 /* If message_defer is set (host was OK, but every recipient got deferred
2548 because of some message-specific problem), or if that had happened
2549 previously so that a message retry key exists, add an appropriate item
2550 to the retry chain. Note that if there was a message defer but now there is
2551 a host defer, the message defer record gets deleted. That seems perfectly
2552 reasonable. Also, stop the message from being remembered as waiting
2553 for this host. */
2554
2555 if (message_defer || retry_message_key != NULL)
2556 {
2557 int delete_flag = message_defer? 0 : rf_delete;
2558 if (retry_message_key == NULL)
2559 {
2560 retry_message_key = ob->retry_include_ip_address?
2561 string_sprintf("T:%S:%s%s:%s", host->name, host->address, pistring,
2562 message_id) :
2563 string_sprintf("T:%S%s:%s", host->name, pistring, message_id);
2564 }
2565 retry_add_item(addrlist, retry_message_key,
2566 rf_message | rf_host | delete_flag);
2567 host->update_waiting = FALSE;
2568 }
2569
2570 /* Any return other than DEFER (that is, OK or ERROR) means that the
2571 addresses have got their final statuses filled in for this host. In the OK
2572 case, see if any of them are deferred. */
2573
2574 if (rc == OK)
2575 {
2576 for (addr = addrlist; addr != NULL; addr = addr->next)
2577 {
2578 if (addr->transport_return == DEFER)
2579 {
2580 some_deferred = TRUE;
2581 break;
2582 }
2583 }
2584 }
2585
2586 /* If no addresses deferred or the result was ERROR, return. We do this for
2587 ERROR because a failing filter set-up or add_headers expansion is likely to
2588 fail for any host we try. */
2589
2590 if (rc == ERROR || (rc == OK && !some_deferred))
2591 {
2592 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2593 return TRUE; /* Each address has its status */
2594 }
2595
2596 /* If the result was DEFER or some individual addresses deferred, let
2597 the loop run to try other hosts with the deferred addresses, except for the
2598 case when we were trying to deliver down an existing channel and failed.
2599 Don't try any other hosts in this case. */
2600
2601 if (continuing) break;
2602
2603 /* If the whole delivery, or some individual addresses, were deferred and
2604 there are more hosts that could be tried, do not count this host towards
2605 the hosts_max_try limit if the age of the message is greater than the
2606 maximum retry time for this host. This means we may try try all hosts,
2607 ignoring the limit, when messages have been around for some time. This is
2608 important because if we don't try all hosts, the address will never time
2609 out. */
2610
2611 if ((rc == DEFER || some_deferred) && nexthost != NULL)
2612 {
2613 BOOL timedout;
2614 retry_config *retry = retry_find_config(host->name, NULL, 0, 0);
2615
2616 if (retry != NULL && retry->rules != NULL)
2617 {
2618 retry_rule *last_rule;
2619 for (last_rule = retry->rules;
2620 last_rule->next != NULL;
2621 last_rule = last_rule->next);
2622 timedout = time(NULL) - received_time > last_rule->timeout;
2623 }
2624 else timedout = TRUE; /* No rule => timed out */
2625
2626 if (timedout)
2627 {
2628 unexpired_hosts_tried--;
2629 DEBUG(D_transport) debug_printf("temporary delivery error(s) override "
2630 "hosts_max_try (message older than host's retry time)\n");
2631 }
2632 }
2633 } /* End of loop for trying multiple hosts. */
2634
2635 /* This is the end of the loop that repeats iff expired is TRUE and
2636 ob->delay_after_cutoff is FALSE. The second time round we will
2637 try those hosts that haven't been tried since the message arrived. */
2638
2639 DEBUG(D_transport)
2640 {
2641 debug_printf("all IP addresses skipped or deferred at least one address\n");
2642 if (expired && !ob->delay_after_cutoff && cutoff_retry == 0)
2643 debug_printf("retrying IP addresses not tried since message arrived\n");
2644 }
2645 }
2646
2647
2648 /* Get here if all IP addresses are skipped or defer at least one address. In
2649 MUA wrapper mode, this will happen only for connection or other non-message-
2650 specific failures. Force the delivery status for all addresses to FAIL. */
2651
2652 if (mua_wrapper)
2653 {
2654 for (addr = addrlist; addr != NULL; addr = addr->next)
2655 addr->transport_return = FAIL;
2656 goto END_TRANSPORT;
2657 }
2658
2659 /* In the normal, non-wrapper case, add a standard message to each deferred
2660 address if there hasn't been an error, that is, if it hasn't actually been
2661 tried this time. The variable "expired" will be FALSE if any deliveries were
2662 actually tried, or if there was at least one host that was not expired. That
2663 is, it is TRUE only if no deliveries were tried and all hosts were expired. If
2664 a delivery has been tried, an error code will be set, and the failing of the
2665 message is handled by the retry code later.
2666
2667 If queue_smtp is set, or this transport was called to send a subsequent message
2668 down an existing TCP/IP connection, and something caused the host not to be
2669 found, we end up here, but can detect these cases and handle them specially. */
2670
2671 for (addr = addrlist; addr != NULL; addr = addr->next)
2672 {
2673 /* If host is not NULL, it means that we stopped processing the host list
2674 because of hosts_max_try. This means we need to behave as if some hosts were
2675 skipped because their retry time had not come. Specifically, this prevents
2676 the address from timing out. */
2677
2678 if (host != NULL)
2679 {
2680 DEBUG(D_transport)
2681 debug_printf("hosts_max_try limit caused some hosts to be skipped\n");
2682 setflag(addr, af_retry_skipped);
2683 }
2684
2685 if (queue_smtp) /* no deliveries attempted */
2686 {
2687 addr->transport_return = DEFER;
2688 addr->basic_errno = 0;
2689 addr->message = US"SMTP delivery explicitly queued";
2690 }
2691
2692 else if (addr->transport_return == DEFER &&
2693 (addr->basic_errno == ERRNO_UNKNOWNERROR || addr->basic_errno == 0) &&
2694 addr->message == NULL)
2695 {
2696 addr->basic_errno = ERRNO_HRETRY;
2697 if (continue_hostname != NULL)
2698 {
2699 addr->message = US"no host found for existing SMTP connection";
2700 }
2701 else if (expired)
2702 {
2703 addr->message = (ob->delay_after_cutoff)?
2704 US"retry time not reached for any host after a long failure period" :
2705 US"all hosts have been failing for a long time and were last tried "
2706 "after this message arrived";
2707
2708 /* If we are already using fallback hosts, or there are no fallback hosts
2709 defined, convert the result to FAIL to cause a bounce. */
2710
2711 if (addr->host_list == addr->fallback_hosts ||
2712 addr->fallback_hosts == NULL)
2713 addr->transport_return = FAIL;
2714 }
2715 else
2716 {
2717 if (hosts_retry == hosts_total)
2718 addr->message = US"retry time not reached for any host";
2719 else if (hosts_fail == hosts_total)
2720 addr->message = US"all host address lookups failed permanently";
2721 else if (hosts_defer == hosts_total)
2722 addr->message = US"all host address lookups failed temporarily";
2723 else if (hosts_serial == hosts_total)
2724 addr->message = US"connection limit reached for all hosts";
2725 else if (hosts_fail+hosts_defer == hosts_total)
2726 addr->message = US"all host address lookups failed";
2727 else addr->message = US"some host address lookups failed and retry time "
2728 "not reached for other hosts or connection limit reached";
2729 }
2730 }
2731 }
2732
2733 /* Update the database which keeps information about which messages are waiting
2734 for which hosts to become available. Each host in the list has a flag which is
2735 set if the data is to be updated. For some message-specific errors, the flag is
2736 turned off because we don't want follow-on deliveries in those cases. */
2737
2738 transport_update_waiting(hostlist, tblock->name);
2739
2740 END_TRANSPORT:
2741
2742 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2743
2744 return TRUE; /* Each address has its status */
2745 }
2746
2747 /* End of transport/smtp.c */