Added the hosts_max_try_hardlimit option. (The removed file is left over
[exim.git] / src / src / transports / smtp.c
1 /* $Cambridge: exim/src/src/transports/smtp.c,v 1.4 2005/01/04 16:36:28 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 { "hosts_max_try_hardlimit", opt_int,
61 (void *)offsetof(smtp_transport_options_block, hosts_max_try_hardlimit) },
62 #ifdef SUPPORT_TLS
63 { "hosts_nopass_tls", opt_stringptr,
64 (void *)offsetof(smtp_transport_options_block, hosts_nopass_tls) },
65 #endif
66 { "hosts_override", opt_bool,
67 (void *)offsetof(smtp_transport_options_block, hosts_override) },
68 { "hosts_randomize", opt_bool,
69 (void *)offsetof(smtp_transport_options_block, hosts_randomize) },
70 { "hosts_require_auth", opt_stringptr,
71 (void *)offsetof(smtp_transport_options_block, hosts_require_auth) },
72 #ifdef SUPPORT_TLS
73 { "hosts_require_tls", opt_stringptr,
74 (void *)offsetof(smtp_transport_options_block, hosts_require_tls) },
75 #endif
76 { "hosts_try_auth", opt_stringptr,
77 (void *)offsetof(smtp_transport_options_block, hosts_try_auth) },
78 { "interface", opt_stringptr,
79 (void *)offsetof(smtp_transport_options_block, interface) },
80 { "keepalive", opt_bool,
81 (void *)offsetof(smtp_transport_options_block, keepalive) },
82 { "max_rcpt", opt_int | opt_public,
83 (void *)offsetof(transport_instance, max_addresses) },
84 { "multi_domain", opt_bool | opt_public,
85 (void *)offsetof(transport_instance, multi_domain) },
86 { "port", opt_stringptr,
87 (void *)offsetof(smtp_transport_options_block, port) },
88 { "protocol", opt_stringptr,
89 (void *)offsetof(smtp_transport_options_block, protocol) },
90 { "retry_include_ip_address", opt_bool,
91 (void *)offsetof(smtp_transport_options_block, retry_include_ip_address) },
92 { "serialize_hosts", opt_stringptr,
93 (void *)offsetof(smtp_transport_options_block, serialize_hosts) },
94 { "size_addition", opt_int,
95 (void *)offsetof(smtp_transport_options_block, size_addition) }
96 #ifdef SUPPORT_TLS
97 ,{ "tls_certificate", opt_stringptr,
98 (void *)offsetof(smtp_transport_options_block, tls_certificate) },
99 { "tls_crl", opt_stringptr,
100 (void *)offsetof(smtp_transport_options_block, tls_crl) },
101 { "tls_privatekey", opt_stringptr,
102 (void *)offsetof(smtp_transport_options_block, tls_privatekey) },
103 { "tls_require_ciphers", opt_stringptr,
104 (void *)offsetof(smtp_transport_options_block, tls_require_ciphers) },
105 { "tls_tempfail_tryclear", opt_bool,
106 (void *)offsetof(smtp_transport_options_block, tls_tempfail_tryclear) },
107 { "tls_verify_certificates", opt_stringptr,
108 (void *)offsetof(smtp_transport_options_block, tls_verify_certificates) }
109 #endif
110 };
111
112 /* Size of the options list. An extern variable has to be used so that its
113 address can appear in the tables drtables.c. */
114
115 int smtp_transport_options_count =
116 sizeof(smtp_transport_options)/sizeof(optionlist);
117
118 /* Default private options block for the smtp transport. */
119
120 smtp_transport_options_block smtp_transport_option_defaults = {
121 NULL, /* hosts */
122 NULL, /* fallback_hosts */
123 NULL, /* hostlist */
124 NULL, /* fallback_hostlist */
125 NULL, /* authenticated_sender */
126 US"$primary_hostname", /* helo_data */
127 NULL, /* interface */
128 NULL, /* port */
129 US"smtp", /* protocol */
130 NULL, /* serialize_hosts */
131 NULL, /* hosts_try_auth */
132 NULL, /* hosts_require_auth */
133 NULL, /* hosts_require_tls */
134 NULL, /* hosts_avoid_tls */
135 NULL, /* hosts_avoid_esmtp */
136 NULL, /* hosts_nopass_tls */
137 5*60, /* command_timeout */
138 5*60, /* connect_timeout; shorter system default overrides */
139 5*60, /* data timeout */
140 10*60, /* final timeout */
141 1024, /* size_addition */
142 5, /* hosts_max_try */
143 50, /* hosts_max_try_hardlimit */
144 FALSE, /* allow_localhost */
145 FALSE, /* gethostbyname */
146 TRUE, /* dns_qualify_single */
147 FALSE, /* dns_search_parents */
148 TRUE, /* delay_after_cutoff */
149 FALSE, /* hosts_override */
150 FALSE, /* hosts_randomize */
151 TRUE, /* keepalive */
152 TRUE /* retry_include_ip_address */
153 #ifdef SUPPORT_TLS
154 ,NULL, /* tls_certificate */
155 NULL, /* tls_crl */
156 NULL, /* tls_privatekey */
157 NULL, /* tls_require_ciphers */
158 NULL, /* tls_verify_certificates */
159 TRUE /* tls_tempfail_tryclear */
160 #endif
161 };
162
163
164 /* Local statics */
165
166 static uschar *smtp_command; /* Points to last cmd for error messages */
167 static uschar *mail_command; /* Points to MAIL cmd for error messages */
168
169
170 /*************************************************
171 * Setup entry point *
172 *************************************************/
173
174 /* This function is called when the transport is about to be used,
175 but before running it in a sub-process. It is used for two things:
176
177 (1) To set the fallback host list in addresses, when delivering.
178 (2) To pass back the interface, port, and protocol options, for use during
179 callout verification.
180
181 Arguments:
182 tblock pointer to the transport instance block
183 addrlist list of addresses about to be transported
184 tf if not NULL, pointer to block in which to return options
185 errmsg place for error message (not used)
186
187 Returns: OK always (FAIL, DEFER not used)
188 */
189
190 static int
191 smtp_transport_setup(transport_instance *tblock, address_item *addrlist,
192 transport_feedback *tf, uschar **errmsg)
193 {
194 smtp_transport_options_block *ob =
195 (smtp_transport_options_block *)(tblock->options_block);
196
197 errmsg = errmsg; /* Keep picky compilers happy */
198
199 /* Pass back options if required. This interface is getting very messy. */
200
201 if (tf != NULL)
202 {
203 tf->interface = ob->interface;
204 tf->port = ob->port;
205 tf->protocol = ob->protocol;
206 tf->hosts = ob->hosts;
207 tf->hosts_override = ob->hosts_override;
208 tf->hosts_randomize = ob->hosts_randomize;
209 tf->gethostbyname = ob->gethostbyname;
210 tf->qualify_single = ob->dns_qualify_single;
211 tf->search_parents = ob->dns_search_parents;
212 }
213
214 /* Set the fallback host list for all the addresses that don't have fallback
215 host lists, provided that the local host wasn't present in the original host
216 list. */
217
218 if (!testflag(addrlist, af_local_host_removed))
219 {
220 for (; addrlist != NULL; addrlist = addrlist->next)
221 if (addrlist->fallback_hosts == NULL)
222 addrlist->fallback_hosts = ob->fallback_hostlist;
223 }
224
225 return OK;
226 }
227
228
229
230 /*************************************************
231 * Initialization entry point *
232 *************************************************/
233
234 /* Called for each instance, after its options have been read, to
235 enable consistency checks to be done, or anything else that needs
236 to be set up.
237
238 Argument: pointer to the transport instance block
239 Returns: nothing
240 */
241
242 void
243 smtp_transport_init(transport_instance *tblock)
244 {
245 smtp_transport_options_block *ob =
246 (smtp_transport_options_block *)(tblock->options_block);
247
248 /* Retry_use_local_part defaults FALSE if unset */
249
250 if (tblock->retry_use_local_part == TRUE_UNSET)
251 tblock->retry_use_local_part = FALSE;
252
253 /* Set the default port according to the protocol */
254
255 if (ob->port == NULL)
256 ob->port = (strcmpic(ob->protocol, US"lmtp") == 0)? US"lmtp" : US"smtp";
257
258 /* Set up the setup entry point, to be called before subprocesses for this
259 transport. */
260
261 tblock->setup = smtp_transport_setup;
262
263 /* Complain if any of the timeouts are zero. */
264
265 if (ob->command_timeout <= 0 || ob->data_timeout <= 0 ||
266 ob->final_timeout <= 0)
267 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
268 "command, data, or final timeout value is zero for %s transport",
269 tblock->name);
270
271 /* If hosts_override is set and there are local hosts, set the global
272 flag that stops verify from showing router hosts. */
273
274 if (ob->hosts_override && ob->hosts != NULL) tblock->overrides_hosts = TRUE;
275
276 /* If there are any fallback hosts listed, build a chain of host items
277 for them, but do not do any lookups at this time. */
278
279 host_build_hostlist(&(ob->fallback_hostlist), ob->fallback_hosts, FALSE);
280 }
281
282
283
284
285
286 /*************************************************
287 * Set delivery info into all active addresses *
288 *************************************************/
289
290 /* Only addresses whose status is >= PENDING are relevant. A lesser
291 status means that an address is not currently being processed.
292
293 Arguments:
294 addrlist points to a chain of addresses
295 errno_value to put in each address's errno field
296 msg to put in each address's message field
297 rc to put in each address's transport_return field
298
299 If errno_value has the special value ERRNO_CONNECTTIMEOUT, ETIMEDOUT is put in
300 the errno field, and RTEF_CTOUT is ORed into the more_errno field, to indicate
301 this particular type of timeout.
302
303 Returns: nothing
304 */
305
306 static
307 void set_errno(address_item *addrlist, int errno_value, uschar *msg, int rc)
308 {
309 address_item *addr;
310 int orvalue = 0;
311 if (errno_value == ERRNO_CONNECTTIMEOUT)
312 {
313 errno_value = ETIMEDOUT;
314 orvalue = RTEF_CTOUT;
315 }
316 for (addr = addrlist; addr != NULL; addr = addr->next)
317 {
318 if (addr->transport_return < PENDING) continue;
319 addr->basic_errno = errno_value;
320 addr->more_errno |= orvalue;
321 if (msg != NULL) addr->message = msg;
322 addr->transport_return = rc;
323 }
324 }
325
326
327
328 /*************************************************
329 * Check an SMTP response *
330 *************************************************/
331
332 /* This function is given an errno code and the SMTP response buffer
333 to analyse, together with the host identification for generating messages. It
334 sets an appropriate message and puts the first digit of the response code into
335 the yield variable. If no response was actually read, a suitable digit is
336 chosen.
337
338 Arguments:
339 host the current host, to get its name for messages
340 errno_value pointer to the errno value
341 more_errno from the top address for use with ERRNO_FILTER_FAIL
342 buffer the SMTP response buffer
343 yield where to put a one-digit SMTP response code
344 message where to put an errror message
345
346 Returns: TRUE if an SMTP "QUIT" command should be sent, else FALSE
347 */
348
349 static BOOL check_response(host_item *host, int *errno_value, int more_errno,
350 uschar *buffer, int *yield, uschar **message)
351 {
352 uschar *pl = US"";
353
354 if (smtp_use_pipelining &&
355 (Ustrcmp(smtp_command, "MAIL") == 0 ||
356 Ustrcmp(smtp_command, "RCPT") == 0 ||
357 Ustrcmp(smtp_command, "DATA") == 0))
358 pl = US"pipelined ";
359
360 *yield = '4'; /* Default setting is to give a temporary error */
361
362 /* Handle response timeout */
363
364 if (*errno_value == ETIMEDOUT)
365 {
366 *message = US string_sprintf("SMTP timeout while connected to %s [%s] "
367 "after %s%s", host->name, host->address, pl, smtp_command);
368 if (transport_count > 0)
369 *message = US string_sprintf("%s (%d bytes written)", *message,
370 transport_count);
371 return FALSE;
372 }
373
374 /* Handle malformed SMTP response */
375
376 if (*errno_value == ERRNO_SMTPFORMAT)
377 {
378 uschar *malfresp = string_printing(buffer);
379 while (isspace(*malfresp)) malfresp++;
380 if (*malfresp == 0)
381 *message = string_sprintf("Malformed SMTP reply (an empty line) from "
382 "%s [%s] in response to %s%s", host->name, host->address, pl,
383 smtp_command);
384 else
385 *message = string_sprintf("Malformed SMTP reply from %s [%s] in response "
386 "to %s%s: %s", host->name, host->address, pl, smtp_command, malfresp);
387 return FALSE;
388 }
389
390 /* Handle a failed filter process error; can't send QUIT as we mustn't
391 end the DATA. */
392
393 if (*errno_value == ERRNO_FILTER_FAIL)
394 {
395 *message = US string_sprintf("transport filter process failed (%d)%s",
396 more_errno,
397 (more_errno == EX_EXECFAILED)? ": unable to execute command" : "");
398 return FALSE;
399 }
400
401 /* Handle a failed add_headers expansion; can't send QUIT as we mustn't
402 end the DATA. */
403
404 if (*errno_value == ERRNO_CHHEADER_FAIL)
405 {
406 *message =
407 US string_sprintf("failed to expand headers_add or headers_remove: %s",
408 expand_string_message);
409 return FALSE;
410 }
411
412 /* Handle failure to write a complete data block */
413
414 if (*errno_value == ERRNO_WRITEINCOMPLETE)
415 {
416 *message = US string_sprintf("failed to write a data block");
417 return FALSE;
418 }
419
420 /* Handle error responses from the remote mailer. */
421
422 if (buffer[0] != 0)
423 {
424 uschar *s = string_printing(buffer);
425 *message = US string_sprintf("SMTP error from remote mailer after %s%s: "
426 "host %s [%s]: %s", pl, smtp_command, host->name, host->address, s);
427 *yield = buffer[0];
428 return TRUE;
429 }
430
431 /* No data was read. If there is no errno, this must be the EOF (i.e.
432 connection closed) case, which causes deferral. Otherwise, put the host's
433 identity in the message, leaving the errno value to be interpreted as well. In
434 all cases, we have to assume the connection is now dead. */
435
436 if (*errno_value == 0)
437 {
438 *errno_value = ERRNO_SMTPCLOSED;
439 *message = US string_sprintf("Remote host %s [%s] closed connection "
440 "in response to %s%s", host->name, host->address, pl, smtp_command);
441 }
442 else *message = US string_sprintf("%s [%s]", host->name, host->address);
443
444 return FALSE;
445 }
446
447
448
449 /*************************************************
450 * Write error message to logs *
451 *************************************************/
452
453 /* This writes to the main log and to the message log.
454
455 Arguments:
456 addr the address item containing error information
457 host the current host
458
459 Returns: nothing
460 */
461
462 static void
463 write_logs(address_item *addr, host_item *host)
464 {
465 if (addr->message != NULL)
466 {
467 uschar *message = addr->message;
468 if (addr->basic_errno > 0)
469 message = string_sprintf("%s: %s", message, strerror(addr->basic_errno));
470 log_write(0, LOG_MAIN, "%s", message);
471 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
472 }
473 else
474 {
475 log_write(0, LOG_MAIN, "%s [%s]: %s",
476 host->name,
477 host->address,
478 strerror(addr->basic_errno));
479 deliver_msglog("%s %s [%s]: %s\n",
480 tod_stamp(tod_log),
481 host->name,
482 host->address,
483 strerror(addr->basic_errno));
484 }
485 }
486
487
488
489 /*************************************************
490 * Synchronize SMTP responses *
491 *************************************************/
492
493 /* This function is called from smtp_deliver() to receive SMTP responses from
494 the server, and match them up with the commands to which they relate. When
495 PIPELINING is not in use, this function is called after every command, and is
496 therefore somewhat over-engineered, but it is simpler to use a single scheme
497 that works both with and without PIPELINING instead of having two separate sets
498 of code.
499
500 The set of commands that are buffered up with pipelining may start with MAIL
501 and may end with DATA; in between are RCPT commands that correspond to the
502 addresses whose status is PENDING_DEFER. All other commands (STARTTLS, AUTH,
503 etc.) are never buffered.
504
505 Errors after MAIL or DATA abort the whole process leaving the response in the
506 buffer. After MAIL, pending responses are flushed, and the original command is
507 re-instated in big_buffer for error messages. For RCPT commands, the remote is
508 permitted to reject some recipient addresses while accepting others. However
509 certain errors clearly abort the whole process. Set the value in
510 transport_return to PENDING_OK if the address is accepted. If there is a
511 subsequent general error, it will get reset accordingly. If not, it will get
512 converted to OK at the end.
513
514 Arguments:
515 addrlist the complete address list
516 include_affixes TRUE if affixes include in RCPT
517 sync_addr ptr to the ptr of the one to start scanning at (updated)
518 host the host we are connected to
519 count the number of responses to read
520 pending_MAIL true if the first response is for MAIL
521 pending_DATA 0 if last command sent was not DATA
522 +1 if previously had a good recipient
523 -1 if not previously had a good recipient
524 inblock incoming SMTP block
525 timeout timeout value
526 buffer buffer for reading response
527 buffsize size of buffer
528
529 Returns: 3 if at least one address had 2xx and one had 5xx
530 2 if at least one address had 5xx but none had 2xx
531 1 if at least one host had a 2xx response, but none had 5xx
532 0 no address had 2xx or 5xx but no errors (all 4xx, or just DATA)
533 -1 timeout while reading RCPT response
534 -2 I/O or other non-response error for RCPT
535 -3 DATA or MAIL failed - errno and buffer set
536 */
537
538 static int
539 sync_responses(address_item *addrlist, BOOL include_affixes,
540 address_item **sync_addr, host_item *host, int count, BOOL pending_MAIL,
541 int pending_DATA, smtp_inblock *inblock, int timeout, uschar *buffer,
542 int buffsize)
543 {
544 address_item *addr = *sync_addr;
545 int yield = 0;
546
547 /* Handle the response for a MAIL command. On error, reinstate the original
548 command in big_buffer for error message use, and flush any further pending
549 responses before returning, except after I/O errors and timeouts. */
550
551 if (pending_MAIL)
552 {
553 count--;
554 if (!smtp_read_response(inblock, buffer, buffsize, '2', timeout))
555 {
556 Ustrcpy(big_buffer, mail_command); /* Fits, because it came from there! */
557 if (errno == 0 && buffer[0] != 0)
558 {
559 uschar flushbuffer[4096];
560 while (count-- > 0)
561 {
562 if (!smtp_read_response(inblock, flushbuffer, sizeof(flushbuffer),
563 '2', timeout)
564 && (errno != 0 || flushbuffer[0] == 0))
565 break;
566 }
567 }
568 return -3;
569 }
570 }
571
572 if (pending_DATA) count--; /* Number of RCPT responses to come */
573
574 /* Read and handle the required number of RCPT responses, matching each one up
575 with an address by scanning for the next address whose status is PENDING_DEFER.
576 */
577
578 while (count-- > 0)
579 {
580 while (addr->transport_return != PENDING_DEFER) addr = addr->next;
581
582 /* The address was accepted */
583
584 if (smtp_read_response(inblock, buffer, buffsize, '2', timeout))
585 {
586 yield |= 1;
587 addr->transport_return = PENDING_OK;
588
589 /* If af_dr_retry_exists is set, there was a routing delay on this address;
590 ensure that any address-specific retry record is expunged. */
591
592 if (testflag(addr, af_dr_retry_exists))
593 retry_add_item(addr, addr->address_retry_key, rf_delete);
594 }
595
596 /* Timeout while reading the response */
597
598 else if (errno == ETIMEDOUT)
599 {
600 int save_errno = errno;
601 uschar *message = string_sprintf("SMTP timeout while connected to %s [%s] "
602 "after RCPT TO:<%s>", host->name, host->address,
603 transport_rcpt_address(addr, include_affixes));
604 set_errno(addrlist, save_errno, message, DEFER);
605 retry_add_item(addr, addr->address_retry_key, 0);
606 host->update_waiting = FALSE;
607 return -1;
608 }
609
610 /* Handle other errors in obtaining an SMTP response by returning -1. This
611 will cause all the addresses to be deferred. Restore the SMTP command in
612 big_buffer for which we are checking the response, so the error message
613 makes sense. */
614
615 else if (errno != 0 || buffer[0] == 0)
616 {
617 string_format(big_buffer, big_buffer_size, "RCPT TO:<%s>",
618 transport_rcpt_address(addr, include_affixes));
619 return -2;
620 }
621
622 /* Handle SMTP permanent and temporary response codes. */
623
624 else
625 {
626 addr->message =
627 string_sprintf("SMTP error from remote mailer after RCPT TO:<%s>: "
628 "host %s [%s]: %s", transport_rcpt_address(addr, include_affixes),
629 host->name, host->address, string_printing(buffer));
630 deliver_msglog("%s %s\n", tod_stamp(tod_log), addr->message);
631
632 /* The response was 5xx */
633
634 if (buffer[0] == '5')
635 {
636 addr->transport_return = FAIL;
637 yield |= 2;
638 }
639
640 /* The response was 4xx */
641
642 else
643 {
644 int bincode = (buffer[1] - '0')*10 + buffer[2] - '0';
645
646 addr->transport_return = DEFER;
647 addr->basic_errno = ERRNO_RCPT4XX;
648 addr->more_errno |= bincode << 8;
649
650 /* Log temporary errors if there are more hosts to be tried. */
651
652 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", addr->message);
653
654 /* Do not put this message on the list of those waiting for this host,
655 as otherwise it is likely to be tried too often. */
656
657 host->update_waiting = FALSE;
658
659 /* Add a retry item for the address so that it doesn't get tried
660 again too soon. */
661
662 retry_add_item(addr, addr->address_retry_key, 0);
663 }
664 }
665 } /* Loop for next RCPT response */
666
667 /* Update where to start at for the next block of responses, unless we
668 have already handled all the addresses. */
669
670 if (addr != NULL) *sync_addr = addr->next;
671
672 /* Handle a response to DATA. If we have not had any good recipients, either
673 previously or in this block, the response is ignored. */
674
675 if (pending_DATA != 0 &&
676 !smtp_read_response(inblock, buffer, buffsize, '3', timeout))
677 {
678 int code;
679 uschar *msg;
680 if (pending_DATA > 0 || (yield & 1) != 0) return -3;
681 (void)check_response(host, &errno, 0, buffer, &code, &msg);
682 DEBUG(D_transport) debug_printf("%s\nerror for DATA ignored: pipelining "
683 "is in use and there were no good recipients\n", msg);
684 }
685
686 /* All responses read and handled; MAIL (if present) received 2xx and DATA (if
687 present) received 3xx. If any RCPTs were handled and yielded anything other
688 than 4xx, yield will be set non-zero. */
689
690 return yield;
691 }
692
693
694
695 /*************************************************
696 * Deliver address list to given host *
697 *************************************************/
698
699 /* If continue_hostname is not null, we get here only when continuing to
700 deliver down an existing channel. The channel was passed as the standard
701 input.
702
703 Otherwise, we have to make a connection to the remote host, and do the
704 initial protocol exchange.
705
706 When running as an MUA wrapper, if the sender or any recipient is rejected,
707 temporarily or permanently, we force failure for all recipients.
708
709 Arguments:
710 addrlist chain of potential addresses to deliver; only those whose
711 transport_return field is set to PENDING_DEFER are currently
712 being processed; others should be skipped - they have either
713 been delivered to an earlier host or IP address, or been
714 failed by one of them.
715 host host to deliver to
716 host_af AF_INET or AF_INET6
717 port TCP/IP port to use, in host byte order
718 interface interface to bind to, or NULL
719 tblock transport instance block
720 copy_host TRUE if host set in addr->host_used must be copied, because
721 it is specific to this call of the transport
722 message_defer set TRUE if yield is OK, but all addresses were deferred
723 because of a non-recipient, non-host failure, that is, a
724 4xx response to MAIL FROM, DATA, or ".". This is a defer
725 that is specific to the message.
726 suppress_tls if TRUE, don't attempt a TLS connection - this is set for
727 a second attempt after TLS initialization fails
728
729 Returns: OK - the connection was made and the delivery attempted;
730 the result for each address is in its data block.
731 DEFER - the connection could not be made, or something failed
732 while setting up the SMTP session, or there was a
733 non-message-specific error, such as a timeout.
734 ERROR - a filter command is specified for this transport,
735 and there was a problem setting it up; OR helo_data
736 or add_headers or authenticated_sender is specified
737 for this transport, and the string failed to expand
738 */
739
740 static int
741 smtp_deliver(address_item *addrlist, host_item *host, int host_af, int port,
742 uschar *interface, transport_instance *tblock, BOOL copy_host,
743 BOOL *message_defer, BOOL suppress_tls)
744 {
745 address_item *addr;
746 address_item *sync_addr;
747 address_item *first_addr = addrlist;
748 int yield = OK;
749 int address_count;
750 int save_errno;
751 int rc;
752 time_t start_delivery_time = time(NULL);
753 smtp_transport_options_block *ob =
754 (smtp_transport_options_block *)(tblock->options_block);
755 BOOL lmtp = strcmpic(ob->protocol, US"lmtp") == 0;
756 BOOL ok = FALSE;
757 BOOL send_rset = TRUE;
758 BOOL send_quit = TRUE;
759 BOOL setting_up = TRUE;
760 BOOL completed_address = FALSE;
761 BOOL esmtp = TRUE;
762 BOOL pending_MAIL;
763 smtp_inblock inblock;
764 smtp_outblock outblock;
765 int max_rcpt = tblock->max_addresses;
766 uschar *local_authenticated_sender = authenticated_sender;
767 uschar *helo_data;
768 uschar *message = NULL;
769 uschar new_message_id[MESSAGE_ID_LENGTH + 1];
770 uschar *p;
771 uschar buffer[4096];
772 uschar inbuffer[4096];
773 uschar outbuffer[1024];
774
775 suppress_tls = suppress_tls; /* stop compiler warning when no TLS support */
776
777 *message_defer = FALSE;
778 smtp_command = US"initial connection";
779 if (max_rcpt == 0) max_rcpt = 999999;
780
781 /* Set up the buffer for reading SMTP response packets. */
782
783 inblock.buffer = inbuffer;
784 inblock.buffersize = sizeof(inbuffer);
785 inblock.ptr = inbuffer;
786 inblock.ptrend = inbuffer;
787
788 /* Set up the buffer for holding SMTP commands while pipelining */
789
790 outblock.buffer = outbuffer;
791 outblock.buffersize = sizeof(outbuffer);
792 outblock.ptr = outbuffer;
793 outblock.cmd_count = 0;
794 outblock.authenticating = FALSE;
795
796 /* Expand the greeting message */
797
798 helo_data = expand_string(ob->helo_data);
799 if (helo_data == NULL)
800 {
801 uschar *message = string_sprintf("failed to expand helo_data: %s",
802 expand_string_message);
803 set_errno(addrlist, 0, message, DEFER);
804 return ERROR;
805 }
806
807 /* If an authenticated_sender override has been specified for this transport
808 instance, expand it. If the expansion is forced to fail, and there was already
809 an authenticated_sender for this message, the original value will be used.
810 Other expansion failures are serious. An empty result is ignored, but there is
811 otherwise no check - this feature is expected to be used with LMTP and other
812 cases where non-standard addresses (e.g. without domains) might be required. */
813
814 if (ob->authenticated_sender != NULL)
815 {
816 uschar *new = expand_string(ob->authenticated_sender);
817 if (new == NULL)
818 {
819 if (!expand_string_forcedfail)
820 {
821 uschar *message = string_sprintf("failed to expand "
822 "authenticated_sender: %s", expand_string_message);
823 set_errno(addrlist, 0, message, DEFER);
824 return ERROR;
825 }
826 }
827 else if (new[0] != 0) local_authenticated_sender = new;
828 }
829
830 /* Make a connection to the host if this isn't a continued delivery, and handle
831 the initial interaction and HELO/EHLO/LHLO. Connect timeout errors are handled
832 specially so they can be identified for retries. */
833
834 if (continue_hostname == NULL)
835 {
836 inblock.sock = outblock.sock =
837 smtp_connect(host, host_af, port, interface, ob->connect_timeout,
838 ob->keepalive);
839 if (inblock.sock < 0)
840 {
841 set_errno(addrlist, (errno == ETIMEDOUT)? ERRNO_CONNECTTIMEOUT : errno,
842 NULL, DEFER);
843 return DEFER;
844 }
845
846 /* The first thing is to wait for an initial OK response. The dreaded "goto"
847 is nevertheless a reasonably clean way of programming this kind of logic,
848 where you want to escape on any error. */
849
850 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
851 ob->command_timeout)) goto RESPONSE_FAILED;
852
853 /** Debugging without sending a message
854 addrlist->transport_return = DEFER;
855 goto SEND_QUIT;
856 **/
857
858 /* Errors that occur after this point follow an SMTP command, which is
859 left in big_buffer by smtp_write_command() for use in error messages. */
860
861 smtp_command = big_buffer;
862
863 /* Tell the remote who we are...
864
865 February 1998: A convention has evolved that ESMTP-speaking MTAs include the
866 string "ESMTP" in their greeting lines, so make Exim send EHLO if the
867 greeting is of this form. The assumption was that the far end supports it
868 properly... but experience shows that there are some that give 5xx responses,
869 even though the banner includes "ESMTP" (there's a bloody-minded one that
870 says "ESMTP not spoken here"). Cope with that case.
871
872 September 2000: Time has passed, and it seems reasonable now to always send
873 EHLO at the start. It is also convenient to make the change while installing
874 the TLS stuff.
875
876 July 2003: Joachim Wieland met a broken server that advertises "PIPELINING"
877 but times out after sending MAIL FROM, RCPT TO and DATA all together. There
878 would be no way to send out the mails, so there is now a host list
879 "hosts_avoid_esmtp" that disables ESMTP for special hosts and solves the
880 PIPELINING problem as well. Maybe it can also be useful to cure other
881 problems with broken servers.
882
883 Exim originally sent "Helo" at this point and ran for nearly a year that way.
884 Then somebody tried it with a Microsoft mailer... It seems that all other
885 mailers use upper case for some reason (the RFC is quite clear about case
886 independence) so, for peace of mind, I gave in. */
887
888 esmtp = verify_check_this_host(&(ob->hosts_avoid_esmtp), NULL,
889 host->name, host->address, NULL) != OK;
890
891 if (esmtp)
892 {
893 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n",
894 lmtp? "LHLO" : "EHLO", helo_data) < 0)
895 goto SEND_FAILED;
896 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
897 ob->command_timeout))
898 {
899 if (errno != 0 || buffer[0] == 0 || lmtp) goto RESPONSE_FAILED;
900 esmtp = FALSE;
901 }
902 }
903 else
904 {
905 DEBUG(D_transport)
906 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
907 }
908
909 if (!esmtp)
910 {
911 if (smtp_write_command(&outblock, FALSE, "HELO %s\r\n", helo_data) < 0)
912 goto SEND_FAILED;
913 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
914 ob->command_timeout)) goto RESPONSE_FAILED;
915 }
916
917 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
918
919 #ifdef SUPPORT_TLS
920 tls_offered = esmtp &&
921 pcre_exec(regex_STARTTLS, NULL, CS buffer, Ustrlen(buffer), 0,
922 PCRE_EOPT, NULL, 0) >= 0;
923 #endif
924 }
925
926 /* For continuing deliveries down the same channel, the socket is the standard
927 input, and we don't need to redo EHLO here (but may need to do so for TLS - see
928 below). Set up the pointer to where subsequent commands will be left, for
929 error messages. Note that smtp_use_size and smtp_use_pipelining will have been
930 set from the command line if they were set in the process that passed the
931 connection on. */
932
933 else
934 {
935 inblock.sock = outblock.sock = fileno(stdin);
936 smtp_command = big_buffer;
937 }
938
939 /* If TLS is available on this connection, whether continued or not, attempt to
940 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
941 send another EHLO - the server may give a different answer in secure mode. We
942 use a separate buffer for reading the response to STARTTLS so that if it is
943 negative, the original EHLO data is available for subsequent analysis, should
944 the client not be required to use TLS. If the response is bad, copy the buffer
945 for error analysis. */
946
947 #ifdef SUPPORT_TLS
948 if (tls_offered && !suppress_tls &&
949 verify_check_this_host(&(ob->hosts_avoid_tls), NULL, host->name,
950 host->address, NULL) != OK)
951 {
952 uschar buffer2[4096];
953 if (smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") < 0)
954 goto SEND_FAILED;
955
956 /* If there is an I/O error, transmission of this message is deferred. If
957 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
958 false, we also defer. However, if there is a temporary rejection of STARTTLS
959 and tls_tempfail_tryclear is true, or if there is an outright rejection of
960 STARTTLS, we carry on. This means we will try to send the message in clear,
961 unless the host is in hosts_require_tls (tested below). */
962
963 if (!smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
964 ob->command_timeout))
965 {
966 Ustrncpy(buffer, buffer2, sizeof(buffer));
967 if (errno != 0 || buffer2[0] == 0 ||
968 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
969 goto RESPONSE_FAILED;
970 }
971
972 /* STARTTLS accepted: try to negotiate a TLS session. */
973
974 else
975 {
976 int rc = tls_client_start(inblock.sock, host, addrlist,
977 NULL, /* No DH param */
978 ob->tls_certificate,
979 ob->tls_privatekey,
980 ob->tls_verify_certificates,
981 ob->tls_crl,
982 ob->tls_require_ciphers,
983 ob->command_timeout);
984
985 /* TLS negotiation failed; give an error. From outside, this function may
986 be called again to try in clear on a new connection, if the options permit
987 it for this host. */
988
989 if (rc != OK)
990 {
991 save_errno = ERRNO_TLSFAILURE;
992 message = US"failure while setting up TLS session";
993 send_quit = FALSE;
994 goto TLS_FAILED;
995 }
996
997 /* TLS session is set up */
998
999 for (addr = addrlist; addr != NULL; addr = addr->next)
1000 {
1001 addr->cipher = tls_cipher;
1002 addr->peerdn = tls_peerdn;
1003 }
1004 }
1005 }
1006
1007 /* If we started TLS, redo the EHLO/LHLO exchange over the secure channel. */
1008
1009 if (tls_active >= 0)
1010 {
1011 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n", lmtp? "LHLO" : "EHLO",
1012 helo_data) < 0)
1013 goto SEND_FAILED;
1014 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1015 ob->command_timeout))
1016 goto RESPONSE_FAILED;
1017 }
1018
1019 /* If the host is required to use a secure channel, ensure that we
1020 have one. */
1021
1022 else if (verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
1023 host->address, NULL) == OK)
1024 {
1025 save_errno = ERRNO_TLSREQUIRED;
1026 message = string_sprintf("a TLS session is required for %s [%s], but %s",
1027 host->name, host->address,
1028 tls_offered? "an attempt to start TLS failed" :
1029 "the server did not offer TLS support");
1030 goto TLS_FAILED;
1031 }
1032 #endif
1033
1034 /* If TLS is active, we have just started it up and re-done the EHLO command,
1035 so its response needs to be analyzed. If TLS is not active and this is a
1036 continued session down a previously-used socket, we haven't just done EHLO, so
1037 we skip this. */
1038
1039 if (continue_hostname == NULL
1040 #ifdef SUPPORT_TLS
1041 || tls_active >= 0
1042 #endif
1043 )
1044 {
1045 int require_auth;
1046 uschar *fail_reason = US"server did not advertise AUTH support";
1047
1048 /* If the response to EHLO specified support for the SIZE parameter, note
1049 this, provided size_addition is non-negative. */
1050
1051 smtp_use_size = esmtp && ob->size_addition >= 0 &&
1052 pcre_exec(regex_SIZE, NULL, CS buffer, Ustrlen(CS buffer), 0,
1053 PCRE_EOPT, NULL, 0) >= 0;
1054
1055 /* Note whether the server supports PIPELINING. If hosts_avoid_esmtp matched
1056 the current host, esmtp will be false, so PIPELINING can never be used. */
1057
1058 smtp_use_pipelining = esmtp &&
1059 pcre_exec(regex_PIPELINING, NULL, CS buffer, Ustrlen(CS buffer), 0,
1060 PCRE_EOPT, NULL, 0) >= 0;
1061
1062 DEBUG(D_transport) debug_printf("%susing PIPELINING\n",
1063 smtp_use_pipelining? "" : "not ");
1064
1065 /* Note if the response to EHLO specifies support for the AUTH extension.
1066 If it has, check that this host is one we want to authenticate to, and do
1067 the business. The host name and address must be available when the
1068 authenticator's client driver is running. */
1069
1070 smtp_authenticated = FALSE;
1071 require_auth = verify_check_this_host(&(ob->hosts_require_auth), NULL,
1072 host->name, host->address, NULL);
1073
1074 if (esmtp && regex_match_and_setup(regex_AUTH, buffer, 0, -1))
1075 {
1076 uschar *names = string_copyn(expand_nstring[1], expand_nlength[1]);
1077 expand_nmax = -1; /* reset */
1078
1079 /* Must not do this check until after we have saved the result of the
1080 regex match above. */
1081
1082 if (require_auth == OK ||
1083 verify_check_this_host(&(ob->hosts_try_auth), NULL, host->name,
1084 host->address, NULL) == OK)
1085 {
1086 auth_instance *au;
1087 fail_reason = US"no common mechanisms were found";
1088
1089 DEBUG(D_transport) debug_printf("scanning authentication mechanisms\n");
1090
1091 /* Scan the configured authenticators looking for one which is configured
1092 for use as a client and whose name matches an authentication mechanism
1093 supported by the server. If one is found, attempt to authenticate by
1094 calling its client function. */
1095
1096 for (au = auths; !smtp_authenticated && au != NULL; au = au->next)
1097 {
1098 uschar *p = names;
1099 if (!au->client) continue;
1100
1101 /* Loop to scan supported server mechanisms */
1102
1103 while (*p != 0)
1104 {
1105 int rc;
1106 int len = Ustrlen(au->public_name);
1107 while (isspace(*p)) p++;
1108
1109 if (strncmpic(au->public_name, p, len) != 0 ||
1110 (p[len] != 0 && !isspace(p[len])))
1111 {
1112 while (*p != 0 && !isspace(*p)) p++;
1113 continue;
1114 }
1115
1116 /* Found data for a listed mechanism. Call its client entry. Set
1117 a flag in the outblock so that data is overwritten after sending so
1118 that reflections don't show it. */
1119
1120 fail_reason = US"authentication attempt(s) failed";
1121 outblock.authenticating = TRUE;
1122 rc = (au->info->clientcode)(au, &inblock, &outblock,
1123 ob->command_timeout, buffer, sizeof(buffer));
1124 outblock.authenticating = FALSE;
1125 DEBUG(D_transport) debug_printf("%s authenticator yielded %d\n",
1126 au->name, rc);
1127
1128 /* A temporary authentication failure must hold up delivery to
1129 this host. After a permanent authentication failure, we carry on
1130 to try other authentication methods. If all fail hard, try to
1131 deliver the message unauthenticated unless require_auth was set. */
1132
1133 switch(rc)
1134 {
1135 case OK:
1136 smtp_authenticated = TRUE; /* stops the outer loop */
1137 break;
1138
1139 /* Failure after writing a command */
1140
1141 case FAIL_SEND:
1142 goto SEND_FAILED;
1143
1144 /* Failure after reading a response */
1145
1146 case FAIL:
1147 if (errno != 0 || buffer[0] != '5') goto RESPONSE_FAILED;
1148 log_write(0, LOG_MAIN, "%s authenticator failed H=%s [%s] %s",
1149 au->name, host->name, host->address, buffer);
1150 break;
1151
1152 /* Failure by some other means. In effect, the authenticator
1153 decided it wasn't prepared to handle this case. Typically this
1154 is the result of "fail" in an expansion string. Do we need to
1155 log anything here? */
1156
1157 case CANCELLED:
1158 break;
1159
1160 /* Internal problem, message in buffer. */
1161
1162 case ERROR:
1163 yield = ERROR;
1164 set_errno(addrlist, 0, string_copy(buffer), DEFER);
1165 goto SEND_QUIT;
1166 }
1167
1168 break; /* If not authenticated, try next authenticator */
1169 } /* Loop for scanning supported server mechanisms */
1170 } /* Loop for further authenticators */
1171 }
1172 }
1173
1174 /* If we haven't authenticated, but are required to, give up. */
1175
1176 if (require_auth == OK && !smtp_authenticated)
1177 {
1178 yield = DEFER;
1179 set_errno(addrlist, ERRNO_AUTHFAIL,
1180 string_sprintf("authentication required but %s", fail_reason), DEFER);
1181 goto SEND_QUIT;
1182 }
1183 }
1184
1185 /* The setting up of the SMTP call is now complete. Any subsequent errors are
1186 message-specific. */
1187
1188 setting_up = FALSE;
1189
1190 /* If there is a filter command specified for this transport, we can now
1191 set it up. This cannot be done until the identify of the host is known. */
1192
1193 if (tblock->filter_command != NULL)
1194 {
1195 BOOL rc;
1196 uschar buffer[64];
1197 sprintf(CS buffer, "%.50s transport", tblock->name);
1198 rc = transport_set_up_command(&transport_filter_argv, tblock->filter_command,
1199 TRUE, DEFER, addrlist, buffer, NULL);
1200
1201 /* On failure, copy the error to all addresses, abandon the SMTP call, and
1202 yield ERROR. */
1203
1204 if (!rc)
1205 {
1206 set_errno(addrlist->next, addrlist->basic_errno, addrlist->message, DEFER);
1207 yield = ERROR;
1208 goto SEND_QUIT;
1209 }
1210 }
1211
1212
1213 /* For messages that have more than the maximum number of envelope recipients,
1214 we want to send several transactions down the same SMTP connection. (See
1215 comments in deliver.c as to how this reconciles, heuristically, with
1216 remote_max_parallel.) This optimization was added to Exim after the following
1217 code was already working. The simplest way to put it in without disturbing the
1218 code was to use a goto to jump back to this point when there is another
1219 transaction to handle. */
1220
1221 SEND_MESSAGE:
1222 sync_addr = first_addr;
1223 address_count = 0;
1224 ok = FALSE;
1225 send_rset = TRUE;
1226 completed_address = FALSE;
1227
1228
1229 /* Initiate a message transfer. If we know the receiving MTA supports the SIZE
1230 qualification, send it, adding something to the message size to allow for
1231 imprecision and things that get added en route. Exim keeps the number of lines
1232 in a message, so we can give an accurate value for the original message, but we
1233 need some additional to handle added headers. (Double "." characters don't get
1234 included in the count.) */
1235
1236 p = buffer;
1237 *p = 0;
1238
1239 if (smtp_use_size)
1240 {
1241 sprintf(CS p, " SIZE=%d", message_size+message_linecount+ob->size_addition);
1242 while (*p) p++;
1243 }
1244
1245 /* Add the authenticated sender address if present */
1246
1247 if (smtp_authenticated && local_authenticated_sender != NULL)
1248 {
1249 string_format(p, sizeof(buffer) - (p-buffer), " AUTH=%s",
1250 auth_xtextencode(local_authenticated_sender,
1251 Ustrlen(local_authenticated_sender)));
1252 }
1253
1254 /* From here until we send the DATA command, we can make use of PIPELINING
1255 if the server host supports it. The code has to be able to check the responses
1256 at any point, for when the buffer fills up, so we write it totally generally.
1257 When PIPELINING is off, each command written reports that it has flushed the
1258 buffer. */
1259
1260 pending_MAIL = TRUE; /* The block starts with MAIL */
1261
1262 rc = smtp_write_command(&outblock, smtp_use_pipelining,
1263 "MAIL FROM:<%s>%s\r\n", return_path, buffer);
1264 mail_command = string_copy(big_buffer); /* Save for later error message */
1265
1266 switch(rc)
1267 {
1268 case -1: /* Transmission error */
1269 goto SEND_FAILED;
1270
1271 case +1: /* Block was sent */
1272 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1273 ob->command_timeout)) goto RESPONSE_FAILED;
1274 pending_MAIL = FALSE;
1275 break;
1276 }
1277
1278 /* Pass over all the relevant recipient addresses for this host, which are the
1279 ones that have status PENDING_DEFER. If we are using PIPELINING, we can send
1280 several before we have to read the responses for those seen so far. This
1281 checking is done by a subroutine because it also needs to be done at the end.
1282 Send only up to max_rcpt addresses at a time, leaving first_addr pointing to
1283 the next one if not all are sent.
1284
1285 In the MUA wrapper situation, we want to flush the PIPELINING buffer for the
1286 last address because we want to abort if any recipients have any kind of
1287 problem, temporary or permanent. We know that all recipient addresses will have
1288 the PENDING_DEFER status, because only one attempt is ever made, and we know
1289 that max_rcpt will be large, so all addresses will be done at once. */
1290
1291 for (addr = first_addr;
1292 address_count < max_rcpt && addr != NULL;
1293 addr = addr->next)
1294 {
1295 int count;
1296 BOOL no_flush;
1297
1298 if (addr->transport_return != PENDING_DEFER) continue;
1299
1300 address_count++;
1301 no_flush = smtp_use_pipelining && (!mua_wrapper || addr->next != NULL);
1302
1303 /* Now send the RCPT command, and process outstanding responses when
1304 necessary. After a timeout on RCPT, we just end the function, leaving the
1305 yield as OK, because this error can often mean that there is a problem with
1306 just one address, so we don't want to delay the host. */
1307
1308 count = smtp_write_command(&outblock, no_flush, "RCPT TO:<%s>\r\n",
1309 transport_rcpt_address(addr, tblock->rcpt_include_affixes));
1310 if (count < 0) goto SEND_FAILED;
1311 if (count > 0)
1312 {
1313 switch(sync_responses(first_addr, tblock->rcpt_include_affixes,
1314 &sync_addr, host, count, pending_MAIL, 0, &inblock,
1315 ob->command_timeout, buffer, sizeof(buffer)))
1316 {
1317 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1318 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1319 break;
1320
1321 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1322 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1323 case 0: /* No 2xx or 5xx, but no probs */
1324 break;
1325
1326 case -1: goto END_OFF; /* Timeout on RCPT */
1327 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL error */
1328 }
1329 pending_MAIL = FALSE; /* Dealt with MAIL */
1330 }
1331 } /* Loop for next address */
1332
1333 /* If we are an MUA wrapper, abort if any RCPTs were rejected, either
1334 permanently or temporarily. We should have flushed and synced after the last
1335 RCPT. */
1336
1337 if (mua_wrapper)
1338 {
1339 address_item *badaddr;
1340 for (badaddr = first_addr; badaddr != NULL; badaddr = badaddr->next)
1341 {
1342 if (badaddr->transport_return != PENDING_OK) break;
1343 }
1344 if (badaddr != NULL)
1345 {
1346 set_errno(addrlist, 0, badaddr->message, FAIL);
1347 ok = FALSE;
1348 }
1349 }
1350
1351 /* If ok is TRUE, we know we have got at least one good recipient, and must now
1352 send DATA, but if it is FALSE (in the normal, non-wrapper case), we may still
1353 have a good recipient buffered up if we are pipelining. We don't want to waste
1354 time sending DATA needlessly, so we only send it if either ok is TRUE or if we
1355 are pipelining. The responses are all handled by sync_responses(). */
1356
1357 if (ok || (smtp_use_pipelining && !mua_wrapper))
1358 {
1359 int count = smtp_write_command(&outblock, FALSE, "DATA\r\n");
1360 if (count < 0) goto SEND_FAILED;
1361 switch(sync_responses(first_addr, tblock->rcpt_include_affixes, &sync_addr,
1362 host, count, pending_MAIL, ok? +1 : -1, &inblock,
1363 ob->command_timeout, buffer, sizeof(buffer)))
1364 {
1365 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1366 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1367 break;
1368
1369 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1370 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1371 case 0: break; /* No 2xx or 5xx, but no probs */
1372
1373 case -1: goto END_OFF; /* Timeout on RCPT */
1374 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */
1375 }
1376 }
1377
1378 /* Save the first address of the next batch. */
1379
1380 first_addr = addr;
1381
1382 /* If there were no good recipients (but otherwise there have been no
1383 problems), just set ok TRUE, since we have handled address-specific errors
1384 already. Otherwise, it's OK to send the message. Use the check/escape mechanism
1385 for handling the SMTP dot-handling protocol, flagging to apply to headers as
1386 well as body. Set the appropriate timeout value to be used for each chunk.
1387 (Haven't been able to make it work using select() for writing yet.) */
1388
1389 if (!ok) ok = TRUE; else
1390 {
1391 sigalrm_seen = FALSE;
1392 transport_write_timeout = ob->data_timeout;
1393 smtp_command = US"sending data block"; /* For error messages */
1394 DEBUG(D_transport|D_v)
1395 debug_printf(" SMTP>> writing message and terminating \".\"\n");
1396 transport_count = 0;
1397 ok = transport_write_message(addrlist, inblock.sock,
1398 topt_use_crlf | topt_end_dot | topt_escape_headers |
1399 (tblock->body_only? topt_no_headers : 0) |
1400 (tblock->headers_only? topt_no_body : 0) |
1401 (tblock->return_path_add? topt_add_return_path : 0) |
1402 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1403 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1404 0, /* No size limit */
1405 tblock->add_headers, tblock->remove_headers,
1406 US".", US"..", /* Escaping strings */
1407 tblock->rewrite_rules, tblock->rewrite_existflags);
1408
1409 /* transport_write_message() uses write() because it is called from other
1410 places to write to non-sockets. This means that under some OS (e.g. Solaris)
1411 it can exit with "Broken pipe" as its error. This really means that the
1412 socket got closed at the far end. */
1413
1414 transport_write_timeout = 0; /* for subsequent transports */
1415
1416 /* Failure can either be some kind of I/O disaster (including timeout),
1417 or the failure of a transport filter or the expansion of added headers. */
1418
1419 if (!ok)
1420 {
1421 buffer[0] = 0; /* There hasn't been a response */
1422 goto RESPONSE_FAILED;
1423 }
1424
1425 /* We used to send the terminating "." explicitly here, but because of
1426 buffering effects at both ends of TCP/IP connections, you don't gain
1427 anything by keeping it separate, so it might as well go in the final
1428 data buffer for efficiency. This is now done by setting the topt_end_dot
1429 flag above. */
1430
1431 smtp_command = US"end of data";
1432
1433 /* For SMTP, we now read a single response that applies to the whole message.
1434 If it is OK, then all the addresses have been delivered. */
1435
1436 if (!lmtp) ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1437 ob->final_timeout);
1438
1439 /* For LMTP, we get back a response for every RCPT command that we sent;
1440 some may be accepted and some rejected. For those that get a response, their
1441 status is fixed; any that are accepted have been handed over, even if later
1442 responses crash - at least, that's how I read RFC 2033.
1443
1444 If all went well, mark the recipient addresses as completed, record which
1445 host/IPaddress they were delivered to, and cut out RSET when sending another
1446 message down the same channel. Write the completed addresses to the journal
1447 now so that they are recorded in case there is a crash of hardware or
1448 software before the spool gets updated. Also record the final SMTP
1449 confirmation if needed (for SMTP only). */
1450
1451 if (ok)
1452 {
1453 int flag = '=';
1454 int delivery_time = (int)(time(NULL) - start_delivery_time);
1455 int len;
1456 host_item *thost;
1457 uschar *conf = NULL;
1458 send_rset = FALSE;
1459
1460 /* Make a copy of the host if it is local to this invocation
1461 of the transport. */
1462
1463 if (copy_host)
1464 {
1465 thost = store_get(sizeof(host_item));
1466 *thost = *host;
1467 thost->name = string_copy(host->name);
1468 thost->address = string_copy(host->address);
1469 }
1470 else thost = host;
1471
1472 /* Set up confirmation if needed - applies only to SMTP */
1473
1474 if ((log_extra_selector & LX_smtp_confirmation) != 0 && !lmtp)
1475 {
1476 uschar *s = string_printing(buffer);
1477 conf = (s == buffer)? (uschar *)string_copy(s) : s;
1478 }
1479
1480 /* Process all transported addresses - for LMTP, read a status for
1481 each one. */
1482
1483 for (addr = addrlist; addr != first_addr; addr = addr->next)
1484 {
1485 if (addr->transport_return != PENDING_OK) continue;
1486
1487 /* LMTP - if the response fails badly (e.g. timeout), use it for all the
1488 remaining addresses. Otherwise, it's a return code for just the one
1489 address. */
1490
1491 if (lmtp)
1492 {
1493 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1494 ob->final_timeout))
1495 {
1496 if (errno != 0 || buffer[0] == 0) goto RESPONSE_FAILED;
1497 addr->message = string_sprintf("LMTP error after %s: %s",
1498 big_buffer, string_printing(buffer));
1499 addr->transport_return = (buffer[0] == '5')? FAIL : DEFER;
1500 continue;
1501 }
1502 completed_address = TRUE; /* NOW we can set this flag */
1503 }
1504
1505 /* SMTP, or success return from LMTP for this address. Pass back the
1506 actual port used. */
1507
1508 addr->transport_return = OK;
1509 addr->more_errno = delivery_time;
1510 thost->port = port;
1511 addr->host_used = thost;
1512 addr->special_action = flag;
1513 addr->message = conf;
1514 flag = '-';
1515
1516 /* Update the journal. For homonymic addresses, use the base address plus
1517 the transport name. See lots of comments in deliver.c about the reasons
1518 for the complications when homonyms are involved. Just carry on after
1519 write error, as it may prove possible to update the spool file later. */
1520
1521 if (testflag(addr, af_homonym))
1522 sprintf(CS buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
1523 else
1524 sprintf(CS buffer, "%.500s\n", addr->unique);
1525
1526 DEBUG(D_deliver) debug_printf("journalling %s", buffer);
1527 len = Ustrlen(CS buffer);
1528 if (write(journal_fd, buffer, len) != len)
1529 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
1530 "%s: %s", buffer, strerror(errno));
1531 }
1532
1533 /* Ensure the journal file is pushed out to disk. */
1534
1535 if (fsync(journal_fd) < 0)
1536 log_write(0, LOG_MAIN|LOG_PANIC, "failed to fsync journal: %s",
1537 strerror(errno));
1538 }
1539 }
1540
1541
1542 /* Handle general (not specific to one address) failures here. The value of ok
1543 is used to skip over this code on the falling through case. A timeout causes a
1544 deferral. Other errors may defer or fail according to the response code, and
1545 may set up a special errno value, e.g. after connection chopped, which is
1546 assumed if errno == 0 and there is no text in the buffer. If control reaches
1547 here during the setting up phase (i.e. before MAIL FROM) then always defer, as
1548 the problem is not related to this specific message. */
1549
1550 if (!ok)
1551 {
1552 int code;
1553
1554 RESPONSE_FAILED:
1555 save_errno = errno;
1556 message = NULL;
1557 send_quit = check_response(host, &save_errno, addrlist->more_errno,
1558 buffer, &code, &message);
1559 goto FAILED;
1560
1561 SEND_FAILED:
1562 save_errno = errno;
1563 code = '4';
1564 message = US string_sprintf("send() to %s [%s] failed: %s",
1565 host->name, host->address, strerror(save_errno));
1566 send_quit = FALSE;
1567 goto FAILED;
1568
1569 /* This label is jumped to directly when a TLS negotiation has failed,
1570 or was not done for a host for which it is required. Values will be set
1571 in message and save_errno, and setting_up will always be true. Treat as
1572 a temporary error. */
1573
1574 #ifdef SUPPORT_TLS
1575 TLS_FAILED:
1576 code = '4';
1577 #endif
1578
1579 /* If the failure happened while setting up the call, see if the failure was
1580 a 5xx response (this will either be on connection, or following HELO - a 5xx
1581 after EHLO causes it to try HELO). If so, fail all addresses, as this host is
1582 never going to accept them. For other errors during setting up (timeouts or
1583 whatever), defer all addresses, and yield DEFER, so that the host is not
1584 tried again for a while. */
1585
1586 FAILED:
1587 ok = FALSE; /* For when reached by GOTO */
1588
1589 if (setting_up)
1590 {
1591 if (code == '5')
1592 {
1593 set_errno(addrlist, save_errno, message, FAIL);
1594 }
1595 else
1596 {
1597 set_errno(addrlist, save_errno, message, DEFER);
1598 yield = DEFER;
1599 }
1600 }
1601
1602 /* If there was an I/O error or timeout or other transportation error,
1603 indicated by errno being non-zero, defer all addresses and yield DEFER,
1604 except for the case of failed add_headers expansion, or a transport filter
1605 failure, when the yield should be ERROR, to stop it trying other hosts.
1606
1607 However, handle timeouts after MAIL FROM or "." and loss of connection after
1608 "." specially. They can indicate a problem with the sender address or with
1609 the contents of the message rather than a real error on the connection.
1610 Therefore, treat these cases in the same way as a 4xx response.
1611
1612 The following condition tests for NOT these special cases. */
1613
1614 else if (save_errno != 0 &&
1615 (save_errno != ETIMEDOUT ||
1616 (Ustrncmp(smtp_command,"MAIL",4) != 0 &&
1617 Ustrncmp(smtp_command,"end ",4) != 0)) &&
1618 (save_errno != ERRNO_SMTPCLOSED ||
1619 Ustrncmp(smtp_command,"end ",4) != 0))
1620 {
1621 yield = (save_errno == ERRNO_CHHEADER_FAIL ||
1622 save_errno == ERRNO_FILTER_FAIL)? ERROR : DEFER;
1623 set_errno(addrlist, save_errno, message, DEFER);
1624 }
1625
1626 /* Otherwise we have a message-specific error response from the remote
1627 host. This is one of
1628 (a) negative response or timeout after "mail from"
1629 (b) negative response after "data"
1630 (c) negative response or timeout or dropped connection after "."
1631 It won't be a negative response or timeout after "rcpt to", as that is dealt
1632 with separately above. The action in all cases is to set an appropriate
1633 error code for all the addresses, but to leave yield set to OK because
1634 the host itself has not failed. [It might in practice have failed for a
1635 timeout after MAIL FROM, or "." but if so, we'll discover that at the next
1636 delivery attempt.] For a temporary error, set the message_defer flag, and
1637 write to the logs for information if this is not the last host. The error for
1638 the last host will be logged as part of the address's log line. */
1639
1640 else
1641 {
1642 if (mua_wrapper) code = '5'; /* Force hard failure in wrapper mode */
1643
1644 set_errno(addrlist, save_errno, message, (code == '5')? FAIL : DEFER);
1645
1646 /* If there's an errno, the message contains just the identity of
1647 the host. */
1648
1649 if (code != '5') /* Anything other than 5 is treated as temporary */
1650 {
1651 if (save_errno > 0)
1652 message = US string_sprintf("%s: %s", message, strerror(save_errno));
1653 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", message);
1654 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
1655 *message_defer = TRUE;
1656 }
1657 }
1658 }
1659
1660
1661 /* If all has gone well, send_quit will be set TRUE, implying we can end the
1662 SMTP session tidily. However, if there were too many addresses to send in one
1663 message (indicated by first_addr being non-NULL) we want to carry on with the
1664 rest of them. Also, it is desirable to send more than one message down the SMTP
1665 connection if there are several waiting, provided we haven't already sent so
1666 many as to hit the configured limit. The function transport_check_waiting looks
1667 for a waiting message and returns its id. Then transport_pass_socket tries to
1668 set up a continued delivery by passing the socket on to another process. The
1669 variable send_rset is FALSE if a message has just been successfully transfered.
1670
1671 If we are already sending down a continued channel, there may be further
1672 addresses not yet delivered that are aimed at the same host, but which have not
1673 been passed in this run of the transport. In this case, continue_more will be
1674 true, and all we should do is send RSET if necessary, and return, leaving the
1675 channel open.
1676
1677 However, if no address was disposed of, i.e. all addresses got 4xx errors, we
1678 do not want to continue with other messages down the same channel, because that
1679 can lead to looping between two or more messages, all with the same,
1680 temporarily failing address(es). [The retry information isn't updated yet, so
1681 new processes keep on trying.] We probably also don't want to try more of this
1682 message's addresses either.
1683
1684 If we have started a TLS session, we have to end it before passing the
1685 connection to a new process. However, not all servers can handle this (Exim
1686 can), so we do not pass such a connection on if the host matches
1687 hosts_nopass_tls. */
1688
1689 DEBUG(D_transport)
1690 debug_printf("ok=%d send_quit=%d send_rset=%d continue_more=%d "
1691 "yield=%d first_address is %sNULL\n", ok, send_quit, send_rset,
1692 continue_more, yield, (first_addr == NULL)? "":"not ");
1693
1694 if (completed_address && ok && send_quit)
1695 {
1696 BOOL more;
1697 if (first_addr != NULL || continue_more ||
1698 (
1699 (tls_active < 0 ||
1700 verify_check_this_host(&(ob->hosts_nopass_tls), NULL, host->name,
1701 host->address, NULL) != OK)
1702 &&
1703 transport_check_waiting(tblock->name, host->name,
1704 tblock->connection_max_messages, new_message_id, &more)
1705 ))
1706 {
1707 uschar *msg;
1708
1709 if (send_rset)
1710 {
1711 if (! (ok = smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0))
1712 {
1713 msg = US string_sprintf("send() to %s [%s] failed: %s", host->name,
1714 host->address, strerror(save_errno));
1715 send_quit = FALSE;
1716 }
1717 else if (! (ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1718 ob->command_timeout)))
1719 {
1720 int code;
1721 send_quit = check_response(host, &errno, 0, buffer, &code, &msg);
1722 if (!send_quit)
1723 {
1724 DEBUG(D_transport) debug_printf("%s\n", msg);
1725 }
1726 }
1727 }
1728
1729 /* Either RSET was not needed, or it succeeded */
1730
1731 if (ok)
1732 {
1733 if (first_addr != NULL) /* More addresses still to be sent */
1734 { /* in this run of the transport */
1735 continue_sequence++; /* Causes * in logging */
1736 goto SEND_MESSAGE;
1737 }
1738 if (continue_more) return yield; /* More addresses for another run */
1739
1740 /* Pass the socket to a new Exim process. Before doing so, we must shut
1741 down TLS. Not all MTAs allow for the continuation of the SMTP session
1742 when TLS is shut down. We test for this by sending a new EHLO. If we
1743 don't get a good response, we don't attempt to pass the socket on. */
1744
1745 #ifdef SUPPORT_TLS
1746 if (tls_active >= 0)
1747 {
1748 tls_close(TRUE);
1749 ok = smtp_write_command(&outblock,FALSE,"EHLO %s\r\n",helo_data) >= 0 &&
1750 smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1751 ob->command_timeout);
1752 }
1753 #endif
1754
1755 /* If the socket is successfully passed, we musn't send QUIT (or
1756 indeed anything!) from here. */
1757
1758 if (ok && transport_pass_socket(tblock->name, host->name, host->address,
1759 new_message_id, inblock.sock))
1760 {
1761 send_quit = FALSE;
1762 }
1763 }
1764
1765 /* If RSET failed and there are addresses left, they get deferred. */
1766
1767 else set_errno(first_addr, errno, msg, DEFER);
1768 }
1769 }
1770
1771 /* End off tidily with QUIT unless the connection has died or the socket has
1772 been passed to another process. There has been discussion on the net about what
1773 to do after sending QUIT. The wording of the RFC suggests that it is necessary
1774 to wait for a response, but on the other hand, there isn't anything one can do
1775 with an error response, other than log it. Exim used to do that. However,
1776 further discussion suggested that it is positively advantageous not to wait for
1777 the response, but to close the session immediately. This is supposed to move
1778 the TCP/IP TIME_WAIT state from the server to the client, thereby removing some
1779 load from the server. (Hosts that are both servers and clients may not see much
1780 difference, of course.) Further discussion indicated that this was safe to do
1781 on Unix systems which have decent implementations of TCP/IP that leave the
1782 connection around for a while (TIME_WAIT) after the application has gone away.
1783 This enables the response sent by the server to be properly ACKed rather than
1784 timed out, as can happen on broken TCP/IP implementations on other OS.
1785
1786 This change is being made on 31-Jul-98. After over a year of trouble-free
1787 operation, the old commented-out code was removed on 17-Sep-99. */
1788
1789 SEND_QUIT:
1790 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1791
1792 END_OFF:
1793
1794 #ifdef SUPPORT_TLS
1795 tls_close(TRUE);
1796 #endif
1797
1798 /* Close the socket, and return the appropriate value, first setting
1799 continue_transport and continue_hostname NULL to prevent any other addresses
1800 that may include the host from trying to re-use a continuation socket. This
1801 works because the NULL setting is passed back to the calling process, and
1802 remote_max_parallel is forced to 1 when delivering over an existing connection,
1803
1804 If all went well and continue_more is set, we shouldn't actually get here if
1805 there are further addresses, as the return above will be taken. However,
1806 writing RSET might have failed, or there may be other addresses whose hosts are
1807 specified in the transports, and therefore not visible at top level, in which
1808 case continue_more won't get set. */
1809
1810 close(inblock.sock);
1811 continue_transport = NULL;
1812 continue_hostname = NULL;
1813 return yield;
1814 }
1815
1816
1817
1818
1819 /*************************************************
1820 * Closedown entry point *
1821 *************************************************/
1822
1823 /* This function is called when exim is passed an open smtp channel
1824 from another incarnation, but the message which it has been asked
1825 to deliver no longer exists. The channel is on stdin.
1826
1827 We might do fancy things like looking for another message to send down
1828 the channel, but if the one we sought has gone, it has probably been
1829 delivered by some other process that itself will seek further messages,
1830 so just close down our connection.
1831
1832 Argument: pointer to the transport instance block
1833 Returns: nothing
1834 */
1835
1836 void
1837 smtp_transport_closedown(transport_instance *tblock)
1838 {
1839 smtp_transport_options_block *ob =
1840 (smtp_transport_options_block *)(tblock->options_block);
1841 smtp_inblock inblock;
1842 smtp_outblock outblock;
1843 uschar buffer[256];
1844 uschar inbuffer[4096];
1845 uschar outbuffer[16];
1846
1847 inblock.sock = fileno(stdin);
1848 inblock.buffer = inbuffer;
1849 inblock.buffersize = sizeof(inbuffer);
1850 inblock.ptr = inbuffer;
1851 inblock.ptrend = inbuffer;
1852
1853 outblock.sock = inblock.sock;
1854 outblock.buffersize = sizeof(outbuffer);
1855 outblock.buffer = outbuffer;
1856 outblock.ptr = outbuffer;
1857 outblock.cmd_count = 0;
1858 outblock.authenticating = FALSE;
1859
1860 (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1861 (void)smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1862 ob->command_timeout);
1863 close(inblock.sock);
1864 }
1865
1866
1867
1868 /*************************************************
1869 * Prepare addresses for delivery *
1870 *************************************************/
1871
1872 /* This function is called to flush out error settings from previous delivery
1873 attempts to other hosts. It also records whether we got here via an MX record
1874 or not in the more_errno field of the address. We are interested only in
1875 addresses that are still marked DEFER - others may have got delivered to a
1876 previously considered IP address. Set their status to PENDING_DEFER to indicate
1877 which ones are relevant this time.
1878
1879 Arguments:
1880 addrlist the list of addresses
1881 host the host we are delivering to
1882
1883 Returns: the first address for this delivery
1884 */
1885
1886 static address_item *
1887 prepare_addresses(address_item *addrlist, host_item *host)
1888 {
1889 address_item *first_addr = NULL;
1890 address_item *addr;
1891 for (addr = addrlist; addr != NULL; addr = addr->next)
1892 {
1893 if (addr->transport_return != DEFER) continue;
1894 if (first_addr == NULL) first_addr = addr;
1895 addr->transport_return = PENDING_DEFER;
1896 addr->basic_errno = 0;
1897 addr->more_errno = (host->mx >= 0)? 'M' : 'A';
1898 addr->message = NULL;
1899 #ifdef SUPPORT_TLS
1900 addr->cipher = NULL;
1901 addr->peerdn = NULL;
1902 #endif
1903 }
1904 return first_addr;
1905 }
1906
1907
1908
1909 /*************************************************
1910 * Main entry point *
1911 *************************************************/
1912
1913 /* See local README for interface details. As this is a remote transport, it is
1914 given a chain of addresses to be delivered in one connection, if possible. It
1915 always returns TRUE, indicating that each address has its own independent
1916 status set, except if there is a setting up problem, in which case it returns
1917 FALSE. */
1918
1919 BOOL
1920 smtp_transport_entry(
1921 transport_instance *tblock, /* data for this instantiation */
1922 address_item *addrlist) /* addresses we are working on */
1923 {
1924 int cutoff_retry;
1925 int port;
1926 int hosts_defer = 0;
1927 int hosts_fail = 0;
1928 int hosts_looked_up = 0;
1929 int hosts_retry = 0;
1930 int hosts_serial = 0;
1931 int hosts_total = 0;
1932 int total_hosts_tried = 0;
1933 address_item *addr;
1934 BOOL expired = TRUE;
1935 BOOL continuing = continue_hostname != NULL;
1936 uschar *expanded_hosts = NULL;
1937 uschar *pistring;
1938 uschar *tid = string_sprintf("%s transport", tblock->name);
1939 smtp_transport_options_block *ob =
1940 (smtp_transport_options_block *)(tblock->options_block);
1941 host_item *hostlist = addrlist->host_list;
1942 host_item *host = NULL;
1943
1944 DEBUG(D_transport)
1945 {
1946 debug_printf("%s transport entered\n", tblock->name);
1947 for (addr = addrlist; addr != NULL; addr = addr->next)
1948 debug_printf(" %s\n", addr->address);
1949 if (continuing) debug_printf("already connected to %s [%s]\n",
1950 continue_hostname, continue_host_address);
1951 }
1952
1953 /* If a host list is not defined for the addresses - they must all have the
1954 same one in order to be passed to a single transport - or if the transport has
1955 a host list with hosts_override set, use the host list supplied with the
1956 transport. It is an error for this not to exist. */
1957
1958 if (hostlist == NULL || (ob->hosts_override && ob->hosts != NULL))
1959 {
1960 if (ob->hosts == NULL)
1961 {
1962 addrlist->message = string_sprintf("%s transport called with no hosts set",
1963 tblock->name);
1964 addrlist->transport_return = PANIC;
1965 return FALSE; /* Only top address has status */
1966 }
1967
1968 DEBUG(D_transport) debug_printf("using the transport's hosts: %s\n",
1969 ob->hosts);
1970
1971 /* If the transport's host list contains no '$' characters, and we are not
1972 randomizing, it is fixed and therefore a chain of hosts can be built once
1973 and for all, and remembered for subsequent use by other calls to this
1974 transport. If, on the other hand, the host list does contain '$', or we are
1975 randomizing its order, we have to rebuild it each time. In the fixed case,
1976 as the hosts string will never be used again, it doesn't matter that we
1977 replace all the : characters with zeros. */
1978
1979 if (ob->hostlist == NULL)
1980 {
1981 uschar *s = ob->hosts;
1982
1983 if (Ustrchr(s, '$') != NULL)
1984 {
1985 expanded_hosts = expand_string(s);
1986 if (expanded_hosts == NULL)
1987 {
1988 addrlist->message = string_sprintf("failed to expand list of hosts "
1989 "\"%s\" in %s transport: %s", s, tblock->name, expand_string_message);
1990 addrlist->transport_return = search_find_defer? DEFER : PANIC;
1991 return FALSE; /* Only top address has status */
1992 }
1993 DEBUG(D_transport) debug_printf("expanded list of hosts \"%s\" to "
1994 "\"%s\"\n", s, expanded_hosts);
1995 s = expanded_hosts;
1996 }
1997 else
1998 if (ob->hosts_randomize) s = expanded_hosts = string_copy(s);
1999
2000 host_build_hostlist(&hostlist, s, ob->hosts_randomize);
2001
2002 /* If there was no expansion of hosts, save the host list for
2003 next time. */
2004
2005 if (expanded_hosts == NULL) ob->hostlist = hostlist;
2006 }
2007
2008 /* This is not the first time this transport has been run in this delivery;
2009 the host list was built previously. */
2010
2011 else hostlist = ob->hostlist;
2012 }
2013
2014 /* The host list was supplied with the address. If hosts_randomize is set, we
2015 must sort it into a random order if it did not come from MX records and has not
2016 already been randomized (but don't bother if continuing down an existing
2017 connection). */
2018
2019 else if (ob->hosts_randomize && hostlist->mx == MX_NONE && !continuing)
2020 {
2021 host_item *newlist = NULL;
2022 while (hostlist != NULL)
2023 {
2024 host_item *h = hostlist;
2025 hostlist = hostlist->next;
2026
2027 h->sort_key = random_number(100);
2028
2029 if (newlist == NULL)
2030 {
2031 h->next = NULL;
2032 newlist = h;
2033 }
2034 else if (h->sort_key < newlist->sort_key)
2035 {
2036 h->next = newlist;
2037 newlist = h;
2038 }
2039 else
2040 {
2041 host_item *hh = newlist;
2042 while (hh->next != NULL)
2043 {
2044 if (h->sort_key < hh->next->sort_key) break;
2045 hh = hh->next;
2046 }
2047 h->next = hh->next;
2048 hh->next = h;
2049 }
2050 }
2051
2052 hostlist = addrlist->host_list = newlist;
2053 }
2054
2055
2056 /* Sort out the port. Set up a string for adding to the retry key if the port
2057 number is not the standard SMTP port. */
2058
2059 if (!smtp_get_port(ob->port, addrlist, &port, tid)) return FALSE;
2060 pistring = string_sprintf(":%d", port);
2061 if (Ustrcmp(pistring, ":25") == 0) pistring = US"";
2062
2063
2064 /* For each host-plus-IP-address on the list:
2065
2066 . If this is a continued delivery and the host isn't the one with the
2067 current connection, skip.
2068
2069 . If the status is unusable (i.e. previously failed or retry checked), skip.
2070
2071 . If no IP address set, get the address, either by turning the name into
2072 an address, calling gethostbyname if gethostbyname is on, or by calling
2073 the DNS. The DNS may yield multiple addresses, in which case insert the
2074 extra ones into the list.
2075
2076 . Get the retry data if not previously obtained for this address and set the
2077 field which remembers the state of this address. Skip if the retry time is
2078 not reached. If not, remember whether retry data was found. The retry string
2079 contains both the name and the IP address.
2080
2081 . Scan the list of addresses and mark those whose status is DEFER as
2082 PENDING_DEFER. These are the only ones that will be processed in this cycle
2083 of the hosts loop.
2084
2085 . Make a delivery attempt - addresses marked PENDING_DEFER will be tried.
2086 Some addresses may be successfully delivered, others may fail, and yet
2087 others may get temporary errors and so get marked DEFER.
2088
2089 . The return from the delivery attempt is OK if a connection was made and a
2090 valid SMTP dialogue was completed. Otherwise it is DEFER.
2091
2092 . If OK, add a "remove" retry item for this host/IPaddress, if any.
2093
2094 . If fail to connect, or other defer state, add a retry item.
2095
2096 . If there are any addresses whose status is still DEFER, carry on to the
2097 next host/IPaddress, unless we have tried the number of hosts given
2098 by hosts_max_try or hosts_max_try_hardlimit; otherwise return. Note that
2099 there is some fancy logic for hosts_max_try that means its limit can be
2100 overstepped in some circumstances.
2101
2102 If we get to the end of the list, all hosts have deferred at least one address,
2103 or not reached their retry times. If delay_after_cutoff is unset, it requests a
2104 delivery attempt to those hosts whose last try was before the arrival time of
2105 the current message. To cope with this, we have to go round the loop a second
2106 time. After that, set the status and error data for any addresses that haven't
2107 had it set already. */
2108
2109 for (cutoff_retry = 0; expired &&
2110 cutoff_retry < ((ob->delay_after_cutoff)? 1 : 2);
2111 cutoff_retry++)
2112 {
2113 host_item *nexthost = NULL;
2114 int unexpired_hosts_tried = 0;
2115
2116 for (host = hostlist;
2117 host != NULL &&
2118 unexpired_hosts_tried < ob->hosts_max_try &&
2119 total_hosts_tried < ob->hosts_max_try_hardlimit;
2120 host = nexthost)
2121 {
2122 int rc;
2123 int host_af;
2124 uschar *rs;
2125 BOOL serialized = FALSE;
2126 BOOL host_is_expired = FALSE;
2127 BOOL message_defer = FALSE;
2128 BOOL ifchanges = FALSE;
2129 BOOL some_deferred = FALSE;
2130 address_item *first_addr = NULL;
2131 uschar *interface = NULL;
2132 uschar *retry_host_key = NULL;
2133 uschar *retry_message_key = NULL;
2134 uschar *serialize_key = NULL;
2135
2136 /* Default next host is next host. :-) But this can vary if the
2137 hosts_max_try limit is hit (see below). */
2138
2139 nexthost = host->next;
2140
2141 /* Set the flag requesting that this host be added to the waiting
2142 database if the delivery fails temporarily or if we are running with
2143 queue_smtp or a 2-stage queue run. This gets unset for certain
2144 kinds of error, typically those that are specific to the message. */
2145
2146 host->update_waiting = TRUE;
2147
2148 /* If the address hasn't yet been obtained from the host name, look it up
2149 now, unless the host is already marked as unusable. If it is marked as
2150 unusable, it means that the router was unable to find its IP address (in
2151 the DNS or wherever) OR we are in the 2nd time round the cutoff loop, and
2152 the lookup failed last time. We don't get this far if *all* MX records
2153 point to non-existent hosts; that is treated as a hard error.
2154
2155 We can just skip this host entirely. When the hosts came from the router,
2156 the address will timeout based on the other host(s); when the address is
2157 looked up below, there is an explicit retry record added.
2158
2159 Note that we mustn't skip unusable hosts if the address is not unset; they
2160 may be needed as expired hosts on the 2nd time round the cutoff loop. */
2161
2162 if (host->address == NULL)
2163 {
2164 uschar *canonical_name;
2165
2166 if (host->status >= hstatus_unusable)
2167 {
2168 DEBUG(D_transport) debug_printf("%s has no address and is unusable - skipping\n",
2169 host->name);
2170 continue;
2171 }
2172
2173 DEBUG(D_transport) debug_printf("getting address for %s\n", host->name);
2174
2175 hosts_looked_up++;
2176
2177 /* Find by name if so configured, or if it's an IP address. We don't
2178 just copy the IP address, because we need the test-for-local to happen. */
2179
2180 if (ob->gethostbyname || string_is_ip_address(host->name, NULL))
2181 rc = host_find_byname(host, NULL, &canonical_name, TRUE);
2182 else
2183 {
2184 int flags = HOST_FIND_BY_A;
2185 if (ob->dns_qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
2186 if (ob->dns_search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
2187 rc = host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
2188 &canonical_name, NULL);
2189 }
2190
2191 /* Failure to find the host at this time (usually DNS temporary failure)
2192 is really a kind of routing failure rather than a transport failure.
2193 Therefore we add a retry item of the routing kind, not to stop us trying
2194 to look this name up here again, but to ensure the address gets timed
2195 out if the failures go on long enough. A complete failure at this point
2196 commonly points to a configuration error, but the best action is still
2197 to carry on for the next host. */
2198
2199 if (rc == HOST_FIND_AGAIN || rc == HOST_FIND_FAILED)
2200 {
2201 retry_add_item(addrlist, string_sprintf("R:%s", host->name), 0);
2202 expired = FALSE;
2203 if (rc == HOST_FIND_AGAIN) hosts_defer++; else hosts_fail++;
2204 DEBUG(D_transport) debug_printf("rc = %s for %s\n", (rc == HOST_FIND_AGAIN)?
2205 "HOST_FIND_AGAIN" : "HOST_FIND_FAILED", host->name);
2206 host->status = hstatus_unusable;
2207
2208 for (addr = addrlist; addr != NULL; addr = addr->next)
2209 {
2210 if (addr->transport_return != DEFER) continue;
2211 addr->basic_errno = ERRNO_UNKNOWNHOST;
2212 addr->message =
2213 string_sprintf("failed to lookup IP address for %s", host->name);
2214 }
2215 continue;
2216 }
2217
2218 /* If the host is actually the local host, we may have a problem, or
2219 there may be some cunning configuration going on. In the problem case,
2220 log things and give up. The default transport status is already DEFER. */
2221
2222 if (rc == HOST_FOUND_LOCAL && !ob->allow_localhost)
2223 {
2224 for (addr = addrlist; addr != NULL; addr = addr->next)
2225 {
2226 addr->basic_errno = 0;
2227 addr->message = string_sprintf("%s transport found host %s to be "
2228 "local", tblock->name, host->name);
2229 }
2230 goto END_TRANSPORT;
2231 }
2232 } /* End of block for IP address lookup */
2233
2234 /* If this is a continued delivery, we are interested only in the host
2235 which matches the name of the existing open channel. The check is put
2236 here after the local host lookup, in case the name gets expanded as a
2237 result of the lookup. Set expired FALSE, to save the outer loop executing
2238 twice. */
2239
2240 if (continuing && (Ustrcmp(continue_hostname, host->name) != 0 ||
2241 Ustrcmp(continue_host_address, host->address) != 0))
2242 {
2243 expired = FALSE;
2244 continue; /* With next host */
2245 }
2246
2247 /* If queue_smtp is set (-odqs or the first part of a 2-stage run), or the
2248 domain is in queue_smtp_domains, we don't actually want to attempt any
2249 deliveries. When doing a queue run, queue_smtp_domains is always unset. If
2250 there is a lookup defer in queue_smtp_domains, proceed as if the domain
2251 were not in it. We don't want to hold up all SMTP deliveries! Except when
2252 doing a two-stage queue run, don't do this if forcing. */
2253
2254 if ((!deliver_force || queue_2stage) && (queue_smtp ||
2255 match_isinlist(addrlist->domain, &queue_smtp_domains, 0, NULL, NULL,
2256 MCL_DOMAIN, TRUE, NULL) == OK))
2257 {
2258 expired = FALSE;
2259 for (addr = addrlist; addr != NULL; addr = addr->next)
2260 {
2261 if (addr->transport_return != DEFER) continue;
2262 addr->message = US"domain matches queue_smtp_domains, or -odqs set";
2263 }
2264 continue; /* With next host */
2265 }
2266
2267 /* Count hosts being considered - purely for an intelligent comment
2268 if none are usable. */
2269
2270 hosts_total++;
2271
2272 /* Set $host and $host address now in case they are needed for the
2273 interface expansion or the serialize_hosts check; they remain set if an
2274 actual delivery happens. */
2275
2276 deliver_host = host->name;
2277 deliver_host_address = host->address;
2278
2279 /* Select IPv4 or IPv6, and choose an outgoing interface. If the interface
2280 string changes upon expansion, we must add it to the key that is used for
2281 retries, because connections to the same host from a different interface
2282 should be treated separately. */
2283
2284 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET : AF_INET6;
2285 if (!smtp_get_interface(ob->interface, host_af, addrlist, &ifchanges,
2286 &interface, tid))
2287 return FALSE;
2288 if (ifchanges) pistring = string_sprintf("%s/%s", pistring, interface);
2289
2290 /* The first time round the outer loop, check the status of the host by
2291 inspecting the retry data. The second time round, we are interested only
2292 in expired hosts that haven't been tried since this message arrived. */
2293
2294 if (cutoff_retry == 0)
2295 {
2296 /* Ensure the status of the address is set by checking retry data if
2297 necessary. There maybe host-specific retry data (applicable to all
2298 messages) and also data for retries of a specific message at this host.
2299 If either of these retry records are actually read, the keys used are
2300 returned to save recomputing them later. */
2301
2302 host_is_expired = retry_check_address(addrlist->domain, host, pistring,
2303 ob->retry_include_ip_address, &retry_host_key, &retry_message_key);
2304
2305 DEBUG(D_transport) debug_printf("%s [%s]%s status = %s\n", host->name,
2306 (host->address == NULL)? US"" : host->address, pistring,
2307 (host->status == hstatus_usable)? "usable" :
2308 (host->status == hstatus_unusable)? "unusable" :
2309 (host->status == hstatus_unusable_expired)? "unusable (expired)" : "?");
2310
2311 /* Skip this address if not usable at this time, noting if it wasn't
2312 actually expired, both locally and in the address. */
2313
2314 switch (host->status)
2315 {
2316 case hstatus_unusable:
2317 expired = FALSE;
2318 setflag(addrlist, af_retry_skipped);
2319 /* Fall through */
2320
2321 case hstatus_unusable_expired:
2322 switch (host->why)
2323 {
2324 case hwhy_retry: hosts_retry++; break;
2325 case hwhy_failed: hosts_fail++; break;
2326 case hwhy_deferred: hosts_defer++; break;
2327 }
2328
2329 /* If there was a retry message key, implying that previously there
2330 was a message-specific defer, we don't want to update the list of
2331 messages waiting for this host. */
2332
2333 if (retry_message_key != NULL) host->update_waiting = FALSE;
2334 continue; /* With the next host or IP address */
2335 }
2336 }
2337
2338 /* Second time round the loop: if the address is set but expired, and
2339 the message is newer than the last try, let it through. */
2340
2341 else
2342 {
2343 if (host->address == NULL ||
2344 host->status != hstatus_unusable_expired ||
2345 host->last_try > received_time)
2346 continue;
2347 DEBUG(D_transport)
2348 debug_printf("trying expired host %s [%s]%s\n",
2349 host->name, host->address, pistring);
2350 host_is_expired = TRUE;
2351 }
2352
2353 /* Setting "expired=FALSE" doesn't actually mean not all hosts are expired;
2354 it remains TRUE only if all hosts are expired and none are actually tried.
2355 */
2356
2357 expired = FALSE;
2358
2359 /* If this host is listed as one to which access must be serialized,
2360 see if another Exim process has a connection to it, and if so, skip
2361 this host. If not, update the database to record our connection to it
2362 and remember this for later deletion. Do not do any of this if we are
2363 sending the message down a pre-existing connection. */
2364
2365 if (!continuing &&
2366 verify_check_this_host(&(ob->serialize_hosts), NULL, host->name,
2367 host->address, NULL) == OK)
2368 {
2369 serialize_key = string_sprintf("host-serialize-%s", host->name);
2370 if (!enq_start(serialize_key))
2371 {
2372 DEBUG(D_transport)
2373 debug_printf("skipping host %s because another Exim process "
2374 "is connected to it\n", host->name);
2375 hosts_serial++;
2376 continue;
2377 }
2378 serialized = TRUE;
2379 }
2380
2381 /* OK, we have an IP address that is not waiting for its retry time to
2382 arrive (it might be expired) OR (second time round the loop) we have an
2383 expired host that hasn't been tried since the message arrived. Have a go
2384 at delivering the message to it. First prepare the addresses by flushing
2385 out the result of previous attempts, and finding the first address that
2386 is still to be delivered. */
2387
2388 first_addr = prepare_addresses(addrlist, host);
2389
2390 DEBUG(D_transport) debug_printf("delivering %s to %s [%s] (%s%s)\n",
2391 message_id, host->name, host->address, addrlist->address,
2392 (addrlist->next == NULL)? "" : ", ...");
2393
2394 set_process_info("delivering %s to %s [%s] (%s%s)",
2395 message_id, host->name, host->address, addrlist->address,
2396 (addrlist->next == NULL)? "" : ", ...");
2397
2398 /* This is not for real; don't do the delivery. If there are
2399 any remaining hosts, list them. */
2400
2401 if (dont_deliver)
2402 {
2403 host_item *host2;
2404 set_errno(addrlist, 0, NULL, OK);
2405 for (addr = addrlist; addr != NULL; addr = addr->next)
2406 {
2407 addr->host_used = host;
2408 addr->special_action = '*';
2409 addr->message = US"delivery bypassed by -N option";
2410 }
2411 DEBUG(D_transport)
2412 {
2413 debug_printf("*** delivery by %s transport bypassed by -N option\n"
2414 "*** host and remaining hosts:\n", tblock->name);
2415 for (host2 = host; host2 != NULL; host2 = host2->next)
2416 debug_printf(" %s [%s]\n", host2->name,
2417 (host2->address == NULL)? US"unset" : host2->address);
2418 }
2419 rc = OK;
2420 }
2421
2422 /* This is for real. If the host is expired, we don't count it for
2423 hosts_max_retry. This ensures that all hosts must expire before an address
2424 is timed out, unless hosts_max_try_hardlimit (which protects against
2425 lunatic DNS configurations) is reached.
2426
2427 If the host is not expired and we are about to hit the hosts_max_retry
2428 limit, check to see if there is a subsequent hosts with a different MX
2429 value. If so, make that the next host, and don't count this one. This is a
2430 heuristic to make sure that different MXs do get tried. With a normal kind
2431 of retry rule, they would get tried anyway when the earlier hosts were
2432 delayed, but if the domain has a "retry every time" type of rule - as is
2433 often used for the the very large ISPs, that won't happen. */
2434
2435 else
2436 {
2437 if (!host_is_expired && ++unexpired_hosts_tried >= ob->hosts_max_try)
2438 {
2439 host_item *h;
2440 DEBUG(D_transport)
2441 debug_printf("hosts_max_try limit reached with this host\n");
2442 for (h = host; h != NULL; h = h->next)
2443 if (h->mx != host->mx) break;
2444 if (h != NULL)
2445 {
2446 nexthost = h;
2447 unexpired_hosts_tried--;
2448 DEBUG(D_transport) debug_printf("however, a higher MX host exists "
2449 "and will be tried\n");
2450 }
2451 }
2452
2453 /* Attempt the delivery. */
2454
2455 total_hosts_tried++;
2456 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2457 expanded_hosts != NULL, &message_defer, FALSE);
2458
2459 /* Yield is one of:
2460 OK => connection made, each address contains its result;
2461 message_defer is set for message-specific defers (when all
2462 recipients are marked defer)
2463 DEFER => there was a non-message-specific delivery problem;
2464 ERROR => there was a problem setting up the arguments for a filter,
2465 or there was a problem with expanding added headers
2466 */
2467
2468 /* If the result is not OK, there was a non-message-specific problem.
2469 If the result is DEFER, we need to write to the logs saying what happened
2470 for this particular host, except in the case of authentication and TLS
2471 failures, where the log has already been written. If all hosts defer a
2472 general message is written at the end. */
2473
2474 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL &&
2475 first_addr->basic_errno != ERRNO_TLSFAILURE)
2476 write_logs(first_addr, host);
2477
2478 /* If STARTTLS was accepted, but there was a failure in setting up the
2479 TLS session (usually a certificate screwup), and the host is not in
2480 hosts_require_tls, and tls_tempfail_tryclear is true, try again, with
2481 TLS forcibly turned off. We have to start from scratch with a new SMTP
2482 connection. That's why the retry is done from here, not from within
2483 smtp_deliver(). [Rejections of STARTTLS itself don't screw up the
2484 session, so the in-clear transmission after those errors, if permitted,
2485 happens inside smtp_deliver().] */
2486
2487 #ifdef SUPPORT_TLS
2488 if (rc == DEFER && first_addr->basic_errno == ERRNO_TLSFAILURE &&
2489 ob->tls_tempfail_tryclear &&
2490 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
2491 host->address, NULL) != OK)
2492 {
2493 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
2494 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
2495 first_addr = prepare_addresses(addrlist, host);
2496 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2497 expanded_hosts != NULL, &message_defer, TRUE);
2498 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL)
2499 write_logs(first_addr, host);
2500 }
2501 #endif
2502 }
2503
2504 /* Delivery attempt finished */
2505
2506 rs = (rc == OK)? US"OK" : (rc == DEFER)? US"DEFER" : (rc == ERROR)?
2507 US"ERROR" : US"?";
2508
2509 set_process_info("delivering %s: just tried %s [%s] for %s%s: result %s",
2510 message_id, host->name, host->address, addrlist->address,
2511 (addrlist->next == NULL)? "" : " (& others)", rs);
2512
2513 /* Release serialization if set up */
2514
2515 if (serialized) enq_end(serialize_key);
2516
2517 /* If the result is DEFER, or if a host retry record is known to exist, we
2518 need to add an item to the retry chain for updating the retry database
2519 at the end of delivery. We only need to add the item to the top address,
2520 of course. Also, if DEFER, we mark the IP address unusable so as to skip it
2521 for any other delivery attempts using the same address. (It is copied into
2522 the unusable tree at the outer level, so even if different address blocks
2523 contain the same address, it still won't get tried again.) */
2524
2525 if (rc == DEFER || retry_host_key != NULL)
2526 {
2527 int delete_flag = (rc != DEFER)? rf_delete : 0;
2528 if (retry_host_key == NULL)
2529 {
2530 retry_host_key = ob->retry_include_ip_address?
2531 string_sprintf("T:%S:%s%s", host->name, host->address, pistring) :
2532 string_sprintf("T:%S%s", host->name, pistring);
2533 }
2534
2535 /* If a delivery of another message over an existing SMTP connection
2536 yields DEFER, we do NOT set up retry data for the host. This covers the
2537 case when there are delays in routing the addresses in the second message
2538 that are so long that the server times out. This is alleviated by not
2539 routing addresses that previously had routing defers when handling an
2540 existing connection, but even so, this case may occur (e.g. if a
2541 previously happily routed address starts giving routing defers). If the
2542 host is genuinely down, another non-continued message delivery will
2543 notice it soon enough. */
2544
2545 if (delete_flag != 0 || !continuing)
2546 retry_add_item(first_addr, retry_host_key, rf_host | delete_flag);
2547
2548 /* We may have tried an expired host, if its retry time has come; ensure
2549 the status reflects the expiry for the benefit of any other addresses. */
2550
2551 if (rc == DEFER)
2552 {
2553 host->status = (host_is_expired)?
2554 hstatus_unusable_expired : hstatus_unusable;
2555 host->why = hwhy_deferred;
2556 }
2557 }
2558
2559 /* If message_defer is set (host was OK, but every recipient got deferred
2560 because of some message-specific problem), or if that had happened
2561 previously so that a message retry key exists, add an appropriate item
2562 to the retry chain. Note that if there was a message defer but now there is
2563 a host defer, the message defer record gets deleted. That seems perfectly
2564 reasonable. Also, stop the message from being remembered as waiting
2565 for this host. */
2566
2567 if (message_defer || retry_message_key != NULL)
2568 {
2569 int delete_flag = message_defer? 0 : rf_delete;
2570 if (retry_message_key == NULL)
2571 {
2572 retry_message_key = ob->retry_include_ip_address?
2573 string_sprintf("T:%S:%s%s:%s", host->name, host->address, pistring,
2574 message_id) :
2575 string_sprintf("T:%S%s:%s", host->name, pistring, message_id);
2576 }
2577 retry_add_item(addrlist, retry_message_key,
2578 rf_message | rf_host | delete_flag);
2579 host->update_waiting = FALSE;
2580 }
2581
2582 /* Any return other than DEFER (that is, OK or ERROR) means that the
2583 addresses have got their final statuses filled in for this host. In the OK
2584 case, see if any of them are deferred. */
2585
2586 if (rc == OK)
2587 {
2588 for (addr = addrlist; addr != NULL; addr = addr->next)
2589 {
2590 if (addr->transport_return == DEFER)
2591 {
2592 some_deferred = TRUE;
2593 break;
2594 }
2595 }
2596 }
2597
2598 /* If no addresses deferred or the result was ERROR, return. We do this for
2599 ERROR because a failing filter set-up or add_headers expansion is likely to
2600 fail for any host we try. */
2601
2602 if (rc == ERROR || (rc == OK && !some_deferred))
2603 {
2604 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2605 return TRUE; /* Each address has its status */
2606 }
2607
2608 /* If the result was DEFER or some individual addresses deferred, let
2609 the loop run to try other hosts with the deferred addresses, except for the
2610 case when we were trying to deliver down an existing channel and failed.
2611 Don't try any other hosts in this case. */
2612
2613 if (continuing) break;
2614
2615 /* If the whole delivery, or some individual addresses, were deferred and
2616 there are more hosts that could be tried, do not count this host towards
2617 the hosts_max_try limit if the age of the message is greater than the
2618 maximum retry time for this host. This means we may try try all hosts,
2619 ignoring the limit, when messages have been around for some time. This is
2620 important because if we don't try all hosts, the address will never time
2621 out. NOTE: this does not apply to hosts_max_try_hardlimit. */
2622
2623 if ((rc == DEFER || some_deferred) && nexthost != NULL)
2624 {
2625 BOOL timedout;
2626 retry_config *retry = retry_find_config(host->name, NULL, 0, 0);
2627
2628 if (retry != NULL && retry->rules != NULL)
2629 {
2630 retry_rule *last_rule;
2631 for (last_rule = retry->rules;
2632 last_rule->next != NULL;
2633 last_rule = last_rule->next);
2634 timedout = time(NULL) - received_time > last_rule->timeout;
2635 }
2636 else timedout = TRUE; /* No rule => timed out */
2637
2638 if (timedout)
2639 {
2640 unexpired_hosts_tried--;
2641 DEBUG(D_transport) debug_printf("temporary delivery error(s) override "
2642 "hosts_max_try (message older than host's retry time)\n");
2643 }
2644 }
2645 } /* End of loop for trying multiple hosts. */
2646
2647 /* This is the end of the loop that repeats iff expired is TRUE and
2648 ob->delay_after_cutoff is FALSE. The second time round we will
2649 try those hosts that haven't been tried since the message arrived. */
2650
2651 DEBUG(D_transport)
2652 {
2653 debug_printf("all IP addresses skipped or deferred at least one address\n");
2654 if (expired && !ob->delay_after_cutoff && cutoff_retry == 0)
2655 debug_printf("retrying IP addresses not tried since message arrived\n");
2656 }
2657 }
2658
2659
2660 /* Get here if all IP addresses are skipped or defer at least one address. In
2661 MUA wrapper mode, this will happen only for connection or other non-message-
2662 specific failures. Force the delivery status for all addresses to FAIL. */
2663
2664 if (mua_wrapper)
2665 {
2666 for (addr = addrlist; addr != NULL; addr = addr->next)
2667 addr->transport_return = FAIL;
2668 goto END_TRANSPORT;
2669 }
2670
2671 /* In the normal, non-wrapper case, add a standard message to each deferred
2672 address if there hasn't been an error, that is, if it hasn't actually been
2673 tried this time. The variable "expired" will be FALSE if any deliveries were
2674 actually tried, or if there was at least one host that was not expired. That
2675 is, it is TRUE only if no deliveries were tried and all hosts were expired. If
2676 a delivery has been tried, an error code will be set, and the failing of the
2677 message is handled by the retry code later.
2678
2679 If queue_smtp is set, or this transport was called to send a subsequent message
2680 down an existing TCP/IP connection, and something caused the host not to be
2681 found, we end up here, but can detect these cases and handle them specially. */
2682
2683 for (addr = addrlist; addr != NULL; addr = addr->next)
2684 {
2685 /* If host is not NULL, it means that we stopped processing the host list
2686 because of hosts_max_try or hosts_max_try_hardlimit. In the former case, this
2687 means we need to behave as if some hosts were skipped because their retry
2688 time had not come. Specifically, this prevents the address from timing out.
2689 However, if we have hit hosts_max_try_hardlimit, we want to behave as if all
2690 hosts were tried. */
2691
2692 if (host != NULL)
2693 {
2694 if (total_hosts_tried >= ob->hosts_max_try_hardlimit)
2695 {
2696 DEBUG(D_transport)
2697 debug_printf("hosts_max_try_hardlimit reached: behave as if all "
2698 "hosts were tried\n");
2699 }
2700 else
2701 {
2702 DEBUG(D_transport)
2703 debug_printf("hosts_max_try limit caused some hosts to be skipped\n");
2704 setflag(addr, af_retry_skipped);
2705 }
2706 }
2707
2708 if (queue_smtp) /* no deliveries attempted */
2709 {
2710 addr->transport_return = DEFER;
2711 addr->basic_errno = 0;
2712 addr->message = US"SMTP delivery explicitly queued";
2713 }
2714
2715 else if (addr->transport_return == DEFER &&
2716 (addr->basic_errno == ERRNO_UNKNOWNERROR || addr->basic_errno == 0) &&
2717 addr->message == NULL)
2718 {
2719 addr->basic_errno = ERRNO_HRETRY;
2720 if (continue_hostname != NULL)
2721 {
2722 addr->message = US"no host found for existing SMTP connection";
2723 }
2724 else if (expired)
2725 {
2726 addr->message = (ob->delay_after_cutoff)?
2727 US"retry time not reached for any host after a long failure period" :
2728 US"all hosts have been failing for a long time and were last tried "
2729 "after this message arrived";
2730
2731 /* If we are already using fallback hosts, or there are no fallback hosts
2732 defined, convert the result to FAIL to cause a bounce. */
2733
2734 if (addr->host_list == addr->fallback_hosts ||
2735 addr->fallback_hosts == NULL)
2736 addr->transport_return = FAIL;
2737 }
2738 else
2739 {
2740 if (hosts_retry == hosts_total)
2741 addr->message = US"retry time not reached for any host";
2742 else if (hosts_fail == hosts_total)
2743 addr->message = US"all host address lookups failed permanently";
2744 else if (hosts_defer == hosts_total)
2745 addr->message = US"all host address lookups failed temporarily";
2746 else if (hosts_serial == hosts_total)
2747 addr->message = US"connection limit reached for all hosts";
2748 else if (hosts_fail+hosts_defer == hosts_total)
2749 addr->message = US"all host address lookups failed";
2750 else addr->message = US"some host address lookups failed and retry time "
2751 "not reached for other hosts or connection limit reached";
2752 }
2753 }
2754 }
2755
2756 /* Update the database which keeps information about which messages are waiting
2757 for which hosts to become available. Each host in the list has a flag which is
2758 set if the data is to be updated. For some message-specific errors, the flag is
2759 turned off because we don't want follow-on deliveries in those cases. */
2760
2761 transport_update_waiting(hostlist, tblock->name);
2762
2763 END_TRANSPORT:
2764
2765 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2766
2767 return TRUE; /* Each address has its status */
2768 }
2769
2770 /* End of transport/smtp.c */