edcdc409d799fe0482ae8059c572d3e23fdf0aec
[exim.git] / src / src / transports / smtp.c
1 /* $Cambridge: exim/src/src/transports/smtp.c,v 1.8 2005/03/22 15:45:35 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 #ifdef EXPERIMENTAL_DOMAINKEYS
39 { "dk_canon", opt_stringptr,
40 (void *)offsetof(smtp_transport_options_block, dk_canon) },
41 { "dk_domain", opt_stringptr,
42 (void *)offsetof(smtp_transport_options_block, dk_domain) },
43 { "dk_headers", opt_stringptr,
44 (void *)offsetof(smtp_transport_options_block, dk_headers) },
45 { "dk_private_key", opt_stringptr,
46 (void *)offsetof(smtp_transport_options_block, dk_private_key) },
47 { "dk_selector", opt_stringptr,
48 (void *)offsetof(smtp_transport_options_block, dk_selector) },
49 { "dk_strict", opt_stringptr,
50 (void *)offsetof(smtp_transport_options_block, dk_strict) },
51 #endif
52 { "dns_qualify_single", opt_bool,
53 (void *)offsetof(smtp_transport_options_block, dns_qualify_single) },
54 { "dns_search_parents", opt_bool,
55 (void *)offsetof(smtp_transport_options_block, dns_search_parents) },
56 { "fallback_hosts", opt_stringptr,
57 (void *)offsetof(smtp_transport_options_block, fallback_hosts) },
58 { "final_timeout", opt_time,
59 (void *)offsetof(smtp_transport_options_block, final_timeout) },
60 { "gethostbyname", opt_bool,
61 (void *)offsetof(smtp_transport_options_block, gethostbyname) },
62 { "helo_data", opt_stringptr,
63 (void *)offsetof(smtp_transport_options_block, helo_data) },
64 { "hosts", opt_stringptr,
65 (void *)offsetof(smtp_transport_options_block, hosts) },
66 { "hosts_avoid_esmtp", opt_stringptr,
67 (void *)offsetof(smtp_transport_options_block, hosts_avoid_esmtp) },
68 #ifdef SUPPORT_TLS
69 { "hosts_avoid_tls", opt_stringptr,
70 (void *)offsetof(smtp_transport_options_block, hosts_avoid_tls) },
71 #endif
72 { "hosts_max_try", opt_int,
73 (void *)offsetof(smtp_transport_options_block, hosts_max_try) },
74 { "hosts_max_try_hardlimit", opt_int,
75 (void *)offsetof(smtp_transport_options_block, hosts_max_try_hardlimit) },
76 #ifdef SUPPORT_TLS
77 { "hosts_nopass_tls", opt_stringptr,
78 (void *)offsetof(smtp_transport_options_block, hosts_nopass_tls) },
79 #endif
80 { "hosts_override", opt_bool,
81 (void *)offsetof(smtp_transport_options_block, hosts_override) },
82 { "hosts_randomize", opt_bool,
83 (void *)offsetof(smtp_transport_options_block, hosts_randomize) },
84 { "hosts_require_auth", opt_stringptr,
85 (void *)offsetof(smtp_transport_options_block, hosts_require_auth) },
86 #ifdef SUPPORT_TLS
87 { "hosts_require_tls", opt_stringptr,
88 (void *)offsetof(smtp_transport_options_block, hosts_require_tls) },
89 #endif
90 { "hosts_try_auth", opt_stringptr,
91 (void *)offsetof(smtp_transport_options_block, hosts_try_auth) },
92 { "interface", opt_stringptr,
93 (void *)offsetof(smtp_transport_options_block, interface) },
94 { "keepalive", opt_bool,
95 (void *)offsetof(smtp_transport_options_block, keepalive) },
96 { "max_rcpt", opt_int | opt_public,
97 (void *)offsetof(transport_instance, max_addresses) },
98 { "multi_domain", opt_bool | opt_public,
99 (void *)offsetof(transport_instance, multi_domain) },
100 { "port", opt_stringptr,
101 (void *)offsetof(smtp_transport_options_block, port) },
102 { "protocol", opt_stringptr,
103 (void *)offsetof(smtp_transport_options_block, protocol) },
104 { "retry_include_ip_address", opt_bool,
105 (void *)offsetof(smtp_transport_options_block, retry_include_ip_address) },
106 { "serialize_hosts", opt_stringptr,
107 (void *)offsetof(smtp_transport_options_block, serialize_hosts) },
108 { "size_addition", opt_int,
109 (void *)offsetof(smtp_transport_options_block, size_addition) }
110 #ifdef SUPPORT_TLS
111 ,{ "tls_certificate", opt_stringptr,
112 (void *)offsetof(smtp_transport_options_block, tls_certificate) },
113 { "tls_crl", opt_stringptr,
114 (void *)offsetof(smtp_transport_options_block, tls_crl) },
115 { "tls_privatekey", opt_stringptr,
116 (void *)offsetof(smtp_transport_options_block, tls_privatekey) },
117 { "tls_require_ciphers", opt_stringptr,
118 (void *)offsetof(smtp_transport_options_block, tls_require_ciphers) },
119 { "tls_tempfail_tryclear", opt_bool,
120 (void *)offsetof(smtp_transport_options_block, tls_tempfail_tryclear) },
121 { "tls_verify_certificates", opt_stringptr,
122 (void *)offsetof(smtp_transport_options_block, tls_verify_certificates) }
123 #endif
124 };
125
126 /* Size of the options list. An extern variable has to be used so that its
127 address can appear in the tables drtables.c. */
128
129 int smtp_transport_options_count =
130 sizeof(smtp_transport_options)/sizeof(optionlist);
131
132 /* Default private options block for the smtp transport. */
133
134 smtp_transport_options_block smtp_transport_option_defaults = {
135 NULL, /* hosts */
136 NULL, /* fallback_hosts */
137 NULL, /* hostlist */
138 NULL, /* fallback_hostlist */
139 NULL, /* authenticated_sender */
140 US"$primary_hostname", /* helo_data */
141 NULL, /* interface */
142 NULL, /* port */
143 US"smtp", /* protocol */
144 NULL, /* serialize_hosts */
145 NULL, /* hosts_try_auth */
146 NULL, /* hosts_require_auth */
147 NULL, /* hosts_require_tls */
148 NULL, /* hosts_avoid_tls */
149 NULL, /* hosts_avoid_esmtp */
150 NULL, /* hosts_nopass_tls */
151 5*60, /* command_timeout */
152 5*60, /* connect_timeout; shorter system default overrides */
153 5*60, /* data timeout */
154 10*60, /* final timeout */
155 1024, /* size_addition */
156 5, /* hosts_max_try */
157 50, /* hosts_max_try_hardlimit */
158 FALSE, /* allow_localhost */
159 FALSE, /* gethostbyname */
160 TRUE, /* dns_qualify_single */
161 FALSE, /* dns_search_parents */
162 TRUE, /* delay_after_cutoff */
163 FALSE, /* hosts_override */
164 FALSE, /* hosts_randomize */
165 TRUE, /* keepalive */
166 TRUE /* retry_include_ip_address */
167 #ifdef SUPPORT_TLS
168 ,NULL, /* tls_certificate */
169 NULL, /* tls_crl */
170 NULL, /* tls_privatekey */
171 NULL, /* tls_require_ciphers */
172 NULL, /* tls_verify_certificates */
173 TRUE /* tls_tempfail_tryclear */
174 #endif
175 #ifdef EXPERIMENTAL_DOMAINKEYS
176 ,NULL, /* dk_canon */
177 NULL, /* dk_domain */
178 NULL, /* dk_headers */
179 NULL, /* dk_private_key */
180 NULL, /* dk_selector */
181 NULL /* dk_strict */
182 #endif
183 };
184
185
186 /* Local statics */
187
188 static uschar *smtp_command; /* Points to last cmd for error messages */
189 static uschar *mail_command; /* Points to MAIL cmd for error messages */
190
191
192 /*************************************************
193 * Setup entry point *
194 *************************************************/
195
196 /* This function is called when the transport is about to be used,
197 but before running it in a sub-process. It is used for two things:
198
199 (1) To set the fallback host list in addresses, when delivering.
200 (2) To pass back the interface, port, and protocol options, for use during
201 callout verification.
202
203 Arguments:
204 tblock pointer to the transport instance block
205 addrlist list of addresses about to be transported
206 tf if not NULL, pointer to block in which to return options
207 errmsg place for error message (not used)
208
209 Returns: OK always (FAIL, DEFER not used)
210 */
211
212 static int
213 smtp_transport_setup(transport_instance *tblock, address_item *addrlist,
214 transport_feedback *tf, uschar **errmsg)
215 {
216 smtp_transport_options_block *ob =
217 (smtp_transport_options_block *)(tblock->options_block);
218
219 errmsg = errmsg; /* Keep picky compilers happy */
220
221 /* Pass back options if required. This interface is getting very messy. */
222
223 if (tf != NULL)
224 {
225 tf->interface = ob->interface;
226 tf->port = ob->port;
227 tf->protocol = ob->protocol;
228 tf->hosts = ob->hosts;
229 tf->hosts_override = ob->hosts_override;
230 tf->hosts_randomize = ob->hosts_randomize;
231 tf->gethostbyname = ob->gethostbyname;
232 tf->qualify_single = ob->dns_qualify_single;
233 tf->search_parents = ob->dns_search_parents;
234 }
235
236 /* Set the fallback host list for all the addresses that don't have fallback
237 host lists, provided that the local host wasn't present in the original host
238 list. */
239
240 if (!testflag(addrlist, af_local_host_removed))
241 {
242 for (; addrlist != NULL; addrlist = addrlist->next)
243 if (addrlist->fallback_hosts == NULL)
244 addrlist->fallback_hosts = ob->fallback_hostlist;
245 }
246
247 return OK;
248 }
249
250
251
252 /*************************************************
253 * Initialization entry point *
254 *************************************************/
255
256 /* Called for each instance, after its options have been read, to
257 enable consistency checks to be done, or anything else that needs
258 to be set up.
259
260 Argument: pointer to the transport instance block
261 Returns: nothing
262 */
263
264 void
265 smtp_transport_init(transport_instance *tblock)
266 {
267 smtp_transport_options_block *ob =
268 (smtp_transport_options_block *)(tblock->options_block);
269
270 /* Retry_use_local_part defaults FALSE if unset */
271
272 if (tblock->retry_use_local_part == TRUE_UNSET)
273 tblock->retry_use_local_part = FALSE;
274
275 /* Set the default port according to the protocol */
276
277 if (ob->port == NULL)
278 ob->port = (strcmpic(ob->protocol, US"lmtp") == 0)? US"lmtp" : US"smtp";
279
280 /* Set up the setup entry point, to be called before subprocesses for this
281 transport. */
282
283 tblock->setup = smtp_transport_setup;
284
285 /* Complain if any of the timeouts are zero. */
286
287 if (ob->command_timeout <= 0 || ob->data_timeout <= 0 ||
288 ob->final_timeout <= 0)
289 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
290 "command, data, or final timeout value is zero for %s transport",
291 tblock->name);
292
293 /* If hosts_override is set and there are local hosts, set the global
294 flag that stops verify from showing router hosts. */
295
296 if (ob->hosts_override && ob->hosts != NULL) tblock->overrides_hosts = TRUE;
297
298 /* If there are any fallback hosts listed, build a chain of host items
299 for them, but do not do any lookups at this time. */
300
301 host_build_hostlist(&(ob->fallback_hostlist), ob->fallback_hosts, FALSE);
302 }
303
304
305
306
307
308 /*************************************************
309 * Set delivery info into all active addresses *
310 *************************************************/
311
312 /* Only addresses whose status is >= PENDING are relevant. A lesser
313 status means that an address is not currently being processed.
314
315 Arguments:
316 addrlist points to a chain of addresses
317 errno_value to put in each address's errno field
318 msg to put in each address's message field
319 rc to put in each address's transport_return field
320
321 If errno_value has the special value ERRNO_CONNECTTIMEOUT, ETIMEDOUT is put in
322 the errno field, and RTEF_CTOUT is ORed into the more_errno field, to indicate
323 this particular type of timeout.
324
325 Returns: nothing
326 */
327
328 static
329 void set_errno(address_item *addrlist, int errno_value, uschar *msg, int rc)
330 {
331 address_item *addr;
332 int orvalue = 0;
333 if (errno_value == ERRNO_CONNECTTIMEOUT)
334 {
335 errno_value = ETIMEDOUT;
336 orvalue = RTEF_CTOUT;
337 }
338 for (addr = addrlist; addr != NULL; addr = addr->next)
339 {
340 if (addr->transport_return < PENDING) continue;
341 addr->basic_errno = errno_value;
342 addr->more_errno |= orvalue;
343 if (msg != NULL) addr->message = msg;
344 addr->transport_return = rc;
345 }
346 }
347
348
349
350 /*************************************************
351 * Check an SMTP response *
352 *************************************************/
353
354 /* This function is given an errno code and the SMTP response buffer
355 to analyse, together with the host identification for generating messages. It
356 sets an appropriate message and puts the first digit of the response code into
357 the yield variable. If no response was actually read, a suitable digit is
358 chosen.
359
360 Arguments:
361 host the current host, to get its name for messages
362 errno_value pointer to the errno value
363 more_errno from the top address for use with ERRNO_FILTER_FAIL
364 buffer the SMTP response buffer
365 yield where to put a one-digit SMTP response code
366 message where to put an errror message
367
368 Returns: TRUE if an SMTP "QUIT" command should be sent, else FALSE
369 */
370
371 static BOOL check_response(host_item *host, int *errno_value, int more_errno,
372 uschar *buffer, int *yield, uschar **message)
373 {
374 uschar *pl = US"";
375
376 if (smtp_use_pipelining &&
377 (Ustrcmp(smtp_command, "MAIL") == 0 ||
378 Ustrcmp(smtp_command, "RCPT") == 0 ||
379 Ustrcmp(smtp_command, "DATA") == 0))
380 pl = US"pipelined ";
381
382 *yield = '4'; /* Default setting is to give a temporary error */
383
384 /* Handle response timeout */
385
386 if (*errno_value == ETIMEDOUT)
387 {
388 *message = US string_sprintf("SMTP timeout while connected to %s [%s] "
389 "after %s%s", host->name, host->address, pl, smtp_command);
390 if (transport_count > 0)
391 *message = US string_sprintf("%s (%d bytes written)", *message,
392 transport_count);
393 return FALSE;
394 }
395
396 /* Handle malformed SMTP response */
397
398 if (*errno_value == ERRNO_SMTPFORMAT)
399 {
400 uschar *malfresp = string_printing(buffer);
401 while (isspace(*malfresp)) malfresp++;
402 if (*malfresp == 0)
403 *message = string_sprintf("Malformed SMTP reply (an empty line) from "
404 "%s [%s] in response to %s%s", host->name, host->address, pl,
405 smtp_command);
406 else
407 *message = string_sprintf("Malformed SMTP reply from %s [%s] in response "
408 "to %s%s: %s", host->name, host->address, pl, smtp_command, malfresp);
409 return FALSE;
410 }
411
412 /* Handle a failed filter process error; can't send QUIT as we mustn't
413 end the DATA. */
414
415 if (*errno_value == ERRNO_FILTER_FAIL)
416 {
417 *message = US string_sprintf("transport filter process failed (%d)%s",
418 more_errno,
419 (more_errno == EX_EXECFAILED)? ": unable to execute command" : "");
420 return FALSE;
421 }
422
423 /* Handle a failed add_headers expansion; can't send QUIT as we mustn't
424 end the DATA. */
425
426 if (*errno_value == ERRNO_CHHEADER_FAIL)
427 {
428 *message =
429 US string_sprintf("failed to expand headers_add or headers_remove: %s",
430 expand_string_message);
431 return FALSE;
432 }
433
434 /* Handle failure to write a complete data block */
435
436 if (*errno_value == ERRNO_WRITEINCOMPLETE)
437 {
438 *message = US string_sprintf("failed to write a data block");
439 return FALSE;
440 }
441
442 /* Handle error responses from the remote mailer. */
443
444 if (buffer[0] != 0)
445 {
446 uschar *s = string_printing(buffer);
447 *message = US string_sprintf("SMTP error from remote mailer after %s%s: "
448 "host %s [%s]: %s", pl, smtp_command, host->name, host->address, s);
449 *yield = buffer[0];
450 return TRUE;
451 }
452
453 /* No data was read. If there is no errno, this must be the EOF (i.e.
454 connection closed) case, which causes deferral. Otherwise, put the host's
455 identity in the message, leaving the errno value to be interpreted as well. In
456 all cases, we have to assume the connection is now dead. */
457
458 if (*errno_value == 0)
459 {
460 *errno_value = ERRNO_SMTPCLOSED;
461 *message = US string_sprintf("Remote host %s [%s] closed connection "
462 "in response to %s%s", host->name, host->address, pl, smtp_command);
463 }
464 else *message = US string_sprintf("%s [%s]", host->name, host->address);
465
466 return FALSE;
467 }
468
469
470
471 /*************************************************
472 * Write error message to logs *
473 *************************************************/
474
475 /* This writes to the main log and to the message log.
476
477 Arguments:
478 addr the address item containing error information
479 host the current host
480
481 Returns: nothing
482 */
483
484 static void
485 write_logs(address_item *addr, host_item *host)
486 {
487 if (addr->message != NULL)
488 {
489 uschar *message = addr->message;
490 if (addr->basic_errno > 0)
491 message = string_sprintf("%s: %s", message, strerror(addr->basic_errno));
492 log_write(0, LOG_MAIN, "%s", message);
493 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
494 }
495 else
496 {
497 log_write(0, LOG_MAIN, "%s [%s]: %s",
498 host->name,
499 host->address,
500 strerror(addr->basic_errno));
501 deliver_msglog("%s %s [%s]: %s\n",
502 tod_stamp(tod_log),
503 host->name,
504 host->address,
505 strerror(addr->basic_errno));
506 }
507 }
508
509
510
511 /*************************************************
512 * Synchronize SMTP responses *
513 *************************************************/
514
515 /* This function is called from smtp_deliver() to receive SMTP responses from
516 the server, and match them up with the commands to which they relate. When
517 PIPELINING is not in use, this function is called after every command, and is
518 therefore somewhat over-engineered, but it is simpler to use a single scheme
519 that works both with and without PIPELINING instead of having two separate sets
520 of code.
521
522 The set of commands that are buffered up with pipelining may start with MAIL
523 and may end with DATA; in between are RCPT commands that correspond to the
524 addresses whose status is PENDING_DEFER. All other commands (STARTTLS, AUTH,
525 etc.) are never buffered.
526
527 Errors after MAIL or DATA abort the whole process leaving the response in the
528 buffer. After MAIL, pending responses are flushed, and the original command is
529 re-instated in big_buffer for error messages. For RCPT commands, the remote is
530 permitted to reject some recipient addresses while accepting others. However
531 certain errors clearly abort the whole process. Set the value in
532 transport_return to PENDING_OK if the address is accepted. If there is a
533 subsequent general error, it will get reset accordingly. If not, it will get
534 converted to OK at the end.
535
536 Arguments:
537 addrlist the complete address list
538 include_affixes TRUE if affixes include in RCPT
539 sync_addr ptr to the ptr of the one to start scanning at (updated)
540 host the host we are connected to
541 count the number of responses to read
542 pending_MAIL true if the first response is for MAIL
543 pending_DATA 0 if last command sent was not DATA
544 +1 if previously had a good recipient
545 -1 if not previously had a good recipient
546 inblock incoming SMTP block
547 timeout timeout value
548 buffer buffer for reading response
549 buffsize size of buffer
550
551 Returns: 3 if at least one address had 2xx and one had 5xx
552 2 if at least one address had 5xx but none had 2xx
553 1 if at least one host had a 2xx response, but none had 5xx
554 0 no address had 2xx or 5xx but no errors (all 4xx, or just DATA)
555 -1 timeout while reading RCPT response
556 -2 I/O or other non-response error for RCPT
557 -3 DATA or MAIL failed - errno and buffer set
558 */
559
560 static int
561 sync_responses(address_item *addrlist, BOOL include_affixes,
562 address_item **sync_addr, host_item *host, int count, BOOL pending_MAIL,
563 int pending_DATA, smtp_inblock *inblock, int timeout, uschar *buffer,
564 int buffsize)
565 {
566 address_item *addr = *sync_addr;
567 int yield = 0;
568
569 /* Handle the response for a MAIL command. On error, reinstate the original
570 command in big_buffer for error message use, and flush any further pending
571 responses before returning, except after I/O errors and timeouts. */
572
573 if (pending_MAIL)
574 {
575 count--;
576 if (!smtp_read_response(inblock, buffer, buffsize, '2', timeout))
577 {
578 Ustrcpy(big_buffer, mail_command); /* Fits, because it came from there! */
579 if (errno == 0 && buffer[0] != 0)
580 {
581 uschar flushbuffer[4096];
582 while (count-- > 0)
583 {
584 if (!smtp_read_response(inblock, flushbuffer, sizeof(flushbuffer),
585 '2', timeout)
586 && (errno != 0 || flushbuffer[0] == 0))
587 break;
588 }
589 }
590 return -3;
591 }
592 }
593
594 if (pending_DATA) count--; /* Number of RCPT responses to come */
595
596 /* Read and handle the required number of RCPT responses, matching each one up
597 with an address by scanning for the next address whose status is PENDING_DEFER.
598 */
599
600 while (count-- > 0)
601 {
602 while (addr->transport_return != PENDING_DEFER) addr = addr->next;
603
604 /* The address was accepted */
605
606 if (smtp_read_response(inblock, buffer, buffsize, '2', timeout))
607 {
608 yield |= 1;
609 addr->transport_return = PENDING_OK;
610
611 /* If af_dr_retry_exists is set, there was a routing delay on this address;
612 ensure that any address-specific retry record is expunged. */
613
614 if (testflag(addr, af_dr_retry_exists))
615 retry_add_item(addr, addr->address_retry_key, rf_delete);
616 }
617
618 /* Timeout while reading the response */
619
620 else if (errno == ETIMEDOUT)
621 {
622 int save_errno = errno;
623 uschar *message = string_sprintf("SMTP timeout while connected to %s [%s] "
624 "after RCPT TO:<%s>", host->name, host->address,
625 transport_rcpt_address(addr, include_affixes));
626 set_errno(addrlist, save_errno, message, DEFER);
627 retry_add_item(addr, addr->address_retry_key, 0);
628 host->update_waiting = FALSE;
629 return -1;
630 }
631
632 /* Handle other errors in obtaining an SMTP response by returning -1. This
633 will cause all the addresses to be deferred. Restore the SMTP command in
634 big_buffer for which we are checking the response, so the error message
635 makes sense. */
636
637 else if (errno != 0 || buffer[0] == 0)
638 {
639 string_format(big_buffer, big_buffer_size, "RCPT TO:<%s>",
640 transport_rcpt_address(addr, include_affixes));
641 return -2;
642 }
643
644 /* Handle SMTP permanent and temporary response codes. */
645
646 else
647 {
648 addr->message =
649 string_sprintf("SMTP error from remote mailer after RCPT TO:<%s>: "
650 "host %s [%s]: %s", transport_rcpt_address(addr, include_affixes),
651 host->name, host->address, string_printing(buffer));
652 deliver_msglog("%s %s\n", tod_stamp(tod_log), addr->message);
653
654 /* The response was 5xx */
655
656 if (buffer[0] == '5')
657 {
658 addr->transport_return = FAIL;
659 yield |= 2;
660 }
661
662 /* The response was 4xx */
663
664 else
665 {
666 int bincode = (buffer[1] - '0')*10 + buffer[2] - '0';
667
668 addr->transport_return = DEFER;
669 addr->basic_errno = ERRNO_RCPT4XX;
670 addr->more_errno |= bincode << 8;
671
672 /* Log temporary errors if there are more hosts to be tried. */
673
674 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", addr->message);
675
676 /* Do not put this message on the list of those waiting for this host,
677 as otherwise it is likely to be tried too often. */
678
679 host->update_waiting = FALSE;
680
681 /* Add a retry item for the address so that it doesn't get tried
682 again too soon. */
683
684 retry_add_item(addr, addr->address_retry_key, 0);
685 }
686 }
687 } /* Loop for next RCPT response */
688
689 /* Update where to start at for the next block of responses, unless we
690 have already handled all the addresses. */
691
692 if (addr != NULL) *sync_addr = addr->next;
693
694 /* Handle a response to DATA. If we have not had any good recipients, either
695 previously or in this block, the response is ignored. */
696
697 if (pending_DATA != 0 &&
698 !smtp_read_response(inblock, buffer, buffsize, '3', timeout))
699 {
700 int code;
701 uschar *msg;
702 if (pending_DATA > 0 || (yield & 1) != 0) return -3;
703 (void)check_response(host, &errno, 0, buffer, &code, &msg);
704 DEBUG(D_transport) debug_printf("%s\nerror for DATA ignored: pipelining "
705 "is in use and there were no good recipients\n", msg);
706 }
707
708 /* All responses read and handled; MAIL (if present) received 2xx and DATA (if
709 present) received 3xx. If any RCPTs were handled and yielded anything other
710 than 4xx, yield will be set non-zero. */
711
712 return yield;
713 }
714
715
716
717 /*************************************************
718 * Deliver address list to given host *
719 *************************************************/
720
721 /* If continue_hostname is not null, we get here only when continuing to
722 deliver down an existing channel. The channel was passed as the standard
723 input.
724
725 Otherwise, we have to make a connection to the remote host, and do the
726 initial protocol exchange.
727
728 When running as an MUA wrapper, if the sender or any recipient is rejected,
729 temporarily or permanently, we force failure for all recipients.
730
731 Arguments:
732 addrlist chain of potential addresses to deliver; only those whose
733 transport_return field is set to PENDING_DEFER are currently
734 being processed; others should be skipped - they have either
735 been delivered to an earlier host or IP address, or been
736 failed by one of them.
737 host host to deliver to
738 host_af AF_INET or AF_INET6
739 port TCP/IP port to use, in host byte order
740 interface interface to bind to, or NULL
741 tblock transport instance block
742 copy_host TRUE if host set in addr->host_used must be copied, because
743 it is specific to this call of the transport
744 message_defer set TRUE if yield is OK, but all addresses were deferred
745 because of a non-recipient, non-host failure, that is, a
746 4xx response to MAIL FROM, DATA, or ".". This is a defer
747 that is specific to the message.
748 suppress_tls if TRUE, don't attempt a TLS connection - this is set for
749 a second attempt after TLS initialization fails
750
751 Returns: OK - the connection was made and the delivery attempted;
752 the result for each address is in its data block.
753 DEFER - the connection could not be made, or something failed
754 while setting up the SMTP session, or there was a
755 non-message-specific error, such as a timeout.
756 ERROR - a filter command is specified for this transport,
757 and there was a problem setting it up; OR helo_data
758 or add_headers or authenticated_sender is specified
759 for this transport, and the string failed to expand
760 */
761
762 static int
763 smtp_deliver(address_item *addrlist, host_item *host, int host_af, int port,
764 uschar *interface, transport_instance *tblock, BOOL copy_host,
765 BOOL *message_defer, BOOL suppress_tls)
766 {
767 address_item *addr;
768 address_item *sync_addr;
769 address_item *first_addr = addrlist;
770 int yield = OK;
771 int address_count;
772 int save_errno;
773 int rc;
774 time_t start_delivery_time = time(NULL);
775 smtp_transport_options_block *ob =
776 (smtp_transport_options_block *)(tblock->options_block);
777 BOOL lmtp = strcmpic(ob->protocol, US"lmtp") == 0;
778 BOOL ok = FALSE;
779 BOOL send_rset = TRUE;
780 BOOL send_quit = TRUE;
781 BOOL setting_up = TRUE;
782 BOOL completed_address = FALSE;
783 BOOL esmtp = TRUE;
784 BOOL pending_MAIL;
785 smtp_inblock inblock;
786 smtp_outblock outblock;
787 int max_rcpt = tblock->max_addresses;
788 uschar *local_authenticated_sender = authenticated_sender;
789 uschar *helo_data;
790 uschar *message = NULL;
791 uschar new_message_id[MESSAGE_ID_LENGTH + 1];
792 uschar *p;
793 uschar buffer[4096];
794 uschar inbuffer[4096];
795 uschar outbuffer[1024];
796
797 suppress_tls = suppress_tls; /* stop compiler warning when no TLS support */
798
799 *message_defer = FALSE;
800 smtp_command = US"initial connection";
801 if (max_rcpt == 0) max_rcpt = 999999;
802
803 /* Set up the buffer for reading SMTP response packets. */
804
805 inblock.buffer = inbuffer;
806 inblock.buffersize = sizeof(inbuffer);
807 inblock.ptr = inbuffer;
808 inblock.ptrend = inbuffer;
809
810 /* Set up the buffer for holding SMTP commands while pipelining */
811
812 outblock.buffer = outbuffer;
813 outblock.buffersize = sizeof(outbuffer);
814 outblock.ptr = outbuffer;
815 outblock.cmd_count = 0;
816 outblock.authenticating = FALSE;
817
818 /* Expand the greeting message */
819
820 helo_data = expand_string(ob->helo_data);
821 if (helo_data == NULL)
822 {
823 uschar *message = string_sprintf("failed to expand helo_data: %s",
824 expand_string_message);
825 set_errno(addrlist, 0, message, DEFER);
826 return ERROR;
827 }
828
829 /* If an authenticated_sender override has been specified for this transport
830 instance, expand it. If the expansion is forced to fail, and there was already
831 an authenticated_sender for this message, the original value will be used.
832 Other expansion failures are serious. An empty result is ignored, but there is
833 otherwise no check - this feature is expected to be used with LMTP and other
834 cases where non-standard addresses (e.g. without domains) might be required. */
835
836 if (ob->authenticated_sender != NULL)
837 {
838 uschar *new = expand_string(ob->authenticated_sender);
839 if (new == NULL)
840 {
841 if (!expand_string_forcedfail)
842 {
843 uschar *message = string_sprintf("failed to expand "
844 "authenticated_sender: %s", expand_string_message);
845 set_errno(addrlist, 0, message, DEFER);
846 return ERROR;
847 }
848 }
849 else if (new[0] != 0) local_authenticated_sender = new;
850 }
851
852 /* Make a connection to the host if this isn't a continued delivery, and handle
853 the initial interaction and HELO/EHLO/LHLO. Connect timeout errors are handled
854 specially so they can be identified for retries. */
855
856 if (continue_hostname == NULL)
857 {
858 inblock.sock = outblock.sock =
859 smtp_connect(host, host_af, port, interface, ob->connect_timeout,
860 ob->keepalive);
861 if (inblock.sock < 0)
862 {
863 set_errno(addrlist, (errno == ETIMEDOUT)? ERRNO_CONNECTTIMEOUT : errno,
864 NULL, DEFER);
865 return DEFER;
866 }
867
868 /* The first thing is to wait for an initial OK response. The dreaded "goto"
869 is nevertheless a reasonably clean way of programming this kind of logic,
870 where you want to escape on any error. */
871
872 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
873 ob->command_timeout)) goto RESPONSE_FAILED;
874
875 /** Debugging without sending a message
876 addrlist->transport_return = DEFER;
877 goto SEND_QUIT;
878 **/
879
880 /* Errors that occur after this point follow an SMTP command, which is
881 left in big_buffer by smtp_write_command() for use in error messages. */
882
883 smtp_command = big_buffer;
884
885 /* Tell the remote who we are...
886
887 February 1998: A convention has evolved that ESMTP-speaking MTAs include the
888 string "ESMTP" in their greeting lines, so make Exim send EHLO if the
889 greeting is of this form. The assumption was that the far end supports it
890 properly... but experience shows that there are some that give 5xx responses,
891 even though the banner includes "ESMTP" (there's a bloody-minded one that
892 says "ESMTP not spoken here"). Cope with that case.
893
894 September 2000: Time has passed, and it seems reasonable now to always send
895 EHLO at the start. It is also convenient to make the change while installing
896 the TLS stuff.
897
898 July 2003: Joachim Wieland met a broken server that advertises "PIPELINING"
899 but times out after sending MAIL FROM, RCPT TO and DATA all together. There
900 would be no way to send out the mails, so there is now a host list
901 "hosts_avoid_esmtp" that disables ESMTP for special hosts and solves the
902 PIPELINING problem as well. Maybe it can also be useful to cure other
903 problems with broken servers.
904
905 Exim originally sent "Helo" at this point and ran for nearly a year that way.
906 Then somebody tried it with a Microsoft mailer... It seems that all other
907 mailers use upper case for some reason (the RFC is quite clear about case
908 independence) so, for peace of mind, I gave in. */
909
910 esmtp = verify_check_this_host(&(ob->hosts_avoid_esmtp), NULL,
911 host->name, host->address, NULL) != OK;
912
913 if (esmtp)
914 {
915 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n",
916 lmtp? "LHLO" : "EHLO", helo_data) < 0)
917 goto SEND_FAILED;
918 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
919 ob->command_timeout))
920 {
921 if (errno != 0 || buffer[0] == 0 || lmtp) goto RESPONSE_FAILED;
922 esmtp = FALSE;
923 }
924 }
925 else
926 {
927 DEBUG(D_transport)
928 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
929 }
930
931 if (!esmtp)
932 {
933 if (smtp_write_command(&outblock, FALSE, "HELO %s\r\n", helo_data) < 0)
934 goto SEND_FAILED;
935 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
936 ob->command_timeout)) goto RESPONSE_FAILED;
937 }
938
939 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
940
941 #ifdef SUPPORT_TLS
942 tls_offered = esmtp &&
943 pcre_exec(regex_STARTTLS, NULL, CS buffer, Ustrlen(buffer), 0,
944 PCRE_EOPT, NULL, 0) >= 0;
945 #endif
946 }
947
948 /* For continuing deliveries down the same channel, the socket is the standard
949 input, and we don't need to redo EHLO here (but may need to do so for TLS - see
950 below). Set up the pointer to where subsequent commands will be left, for
951 error messages. Note that smtp_use_size and smtp_use_pipelining will have been
952 set from the command line if they were set in the process that passed the
953 connection on. */
954
955 else
956 {
957 inblock.sock = outblock.sock = fileno(stdin);
958 smtp_command = big_buffer;
959 }
960
961 /* If TLS is available on this connection, whether continued or not, attempt to
962 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
963 send another EHLO - the server may give a different answer in secure mode. We
964 use a separate buffer for reading the response to STARTTLS so that if it is
965 negative, the original EHLO data is available for subsequent analysis, should
966 the client not be required to use TLS. If the response is bad, copy the buffer
967 for error analysis. */
968
969 #ifdef SUPPORT_TLS
970 if (tls_offered && !suppress_tls &&
971 verify_check_this_host(&(ob->hosts_avoid_tls), NULL, host->name,
972 host->address, NULL) != OK)
973 {
974 uschar buffer2[4096];
975 if (smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") < 0)
976 goto SEND_FAILED;
977
978 /* If there is an I/O error, transmission of this message is deferred. If
979 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
980 false, we also defer. However, if there is a temporary rejection of STARTTLS
981 and tls_tempfail_tryclear is true, or if there is an outright rejection of
982 STARTTLS, we carry on. This means we will try to send the message in clear,
983 unless the host is in hosts_require_tls (tested below). */
984
985 if (!smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
986 ob->command_timeout))
987 {
988 Ustrncpy(buffer, buffer2, sizeof(buffer));
989 if (errno != 0 || buffer2[0] == 0 ||
990 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
991 goto RESPONSE_FAILED;
992 }
993
994 /* STARTTLS accepted: try to negotiate a TLS session. */
995
996 else
997 {
998 int rc = tls_client_start(inblock.sock, host, addrlist,
999 NULL, /* No DH param */
1000 ob->tls_certificate,
1001 ob->tls_privatekey,
1002 ob->tls_verify_certificates,
1003 ob->tls_crl,
1004 ob->tls_require_ciphers,
1005 ob->command_timeout);
1006
1007 /* TLS negotiation failed; give an error. From outside, this function may
1008 be called again to try in clear on a new connection, if the options permit
1009 it for this host. */
1010
1011 if (rc != OK)
1012 {
1013 save_errno = ERRNO_TLSFAILURE;
1014 message = US"failure while setting up TLS session";
1015 send_quit = FALSE;
1016 goto TLS_FAILED;
1017 }
1018
1019 /* TLS session is set up */
1020
1021 for (addr = addrlist; addr != NULL; addr = addr->next)
1022 {
1023 addr->cipher = tls_cipher;
1024 addr->peerdn = tls_peerdn;
1025 }
1026 }
1027 }
1028
1029 /* If we started TLS, redo the EHLO/LHLO exchange over the secure channel. */
1030
1031 if (tls_active >= 0)
1032 {
1033 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n", lmtp? "LHLO" : "EHLO",
1034 helo_data) < 0)
1035 goto SEND_FAILED;
1036 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1037 ob->command_timeout))
1038 goto RESPONSE_FAILED;
1039 }
1040
1041 /* If the host is required to use a secure channel, ensure that we
1042 have one. */
1043
1044 else if (verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
1045 host->address, NULL) == OK)
1046 {
1047 save_errno = ERRNO_TLSREQUIRED;
1048 message = string_sprintf("a TLS session is required for %s [%s], but %s",
1049 host->name, host->address,
1050 tls_offered? "an attempt to start TLS failed" :
1051 "the server did not offer TLS support");
1052 goto TLS_FAILED;
1053 }
1054 #endif
1055
1056 /* If TLS is active, we have just started it up and re-done the EHLO command,
1057 so its response needs to be analyzed. If TLS is not active and this is a
1058 continued session down a previously-used socket, we haven't just done EHLO, so
1059 we skip this. */
1060
1061 if (continue_hostname == NULL
1062 #ifdef SUPPORT_TLS
1063 || tls_active >= 0
1064 #endif
1065 )
1066 {
1067 int require_auth;
1068 uschar *fail_reason = US"server did not advertise AUTH support";
1069
1070 /* If the response to EHLO specified support for the SIZE parameter, note
1071 this, provided size_addition is non-negative. */
1072
1073 smtp_use_size = esmtp && ob->size_addition >= 0 &&
1074 pcre_exec(regex_SIZE, NULL, CS buffer, Ustrlen(CS buffer), 0,
1075 PCRE_EOPT, NULL, 0) >= 0;
1076
1077 /* Note whether the server supports PIPELINING. If hosts_avoid_esmtp matched
1078 the current host, esmtp will be false, so PIPELINING can never be used. */
1079
1080 smtp_use_pipelining = esmtp &&
1081 pcre_exec(regex_PIPELINING, NULL, CS buffer, Ustrlen(CS buffer), 0,
1082 PCRE_EOPT, NULL, 0) >= 0;
1083
1084 DEBUG(D_transport) debug_printf("%susing PIPELINING\n",
1085 smtp_use_pipelining? "" : "not ");
1086
1087 /* Note if the response to EHLO specifies support for the AUTH extension.
1088 If it has, check that this host is one we want to authenticate to, and do
1089 the business. The host name and address must be available when the
1090 authenticator's client driver is running. */
1091
1092 smtp_authenticated = FALSE;
1093 require_auth = verify_check_this_host(&(ob->hosts_require_auth), NULL,
1094 host->name, host->address, NULL);
1095
1096 if (esmtp && regex_match_and_setup(regex_AUTH, buffer, 0, -1))
1097 {
1098 uschar *names = string_copyn(expand_nstring[1], expand_nlength[1]);
1099 expand_nmax = -1; /* reset */
1100
1101 /* Must not do this check until after we have saved the result of the
1102 regex match above. */
1103
1104 if (require_auth == OK ||
1105 verify_check_this_host(&(ob->hosts_try_auth), NULL, host->name,
1106 host->address, NULL) == OK)
1107 {
1108 auth_instance *au;
1109 fail_reason = US"no common mechanisms were found";
1110
1111 DEBUG(D_transport) debug_printf("scanning authentication mechanisms\n");
1112
1113 /* Scan the configured authenticators looking for one which is configured
1114 for use as a client and whose name matches an authentication mechanism
1115 supported by the server. If one is found, attempt to authenticate by
1116 calling its client function. */
1117
1118 for (au = auths; !smtp_authenticated && au != NULL; au = au->next)
1119 {
1120 uschar *p = names;
1121 if (!au->client) continue;
1122
1123 /* Loop to scan supported server mechanisms */
1124
1125 while (*p != 0)
1126 {
1127 int rc;
1128 int len = Ustrlen(au->public_name);
1129 while (isspace(*p)) p++;
1130
1131 if (strncmpic(au->public_name, p, len) != 0 ||
1132 (p[len] != 0 && !isspace(p[len])))
1133 {
1134 while (*p != 0 && !isspace(*p)) p++;
1135 continue;
1136 }
1137
1138 /* Found data for a listed mechanism. Call its client entry. Set
1139 a flag in the outblock so that data is overwritten after sending so
1140 that reflections don't show it. */
1141
1142 fail_reason = US"authentication attempt(s) failed";
1143 outblock.authenticating = TRUE;
1144 rc = (au->info->clientcode)(au, &inblock, &outblock,
1145 ob->command_timeout, buffer, sizeof(buffer));
1146 outblock.authenticating = FALSE;
1147 DEBUG(D_transport) debug_printf("%s authenticator yielded %d\n",
1148 au->name, rc);
1149
1150 /* A temporary authentication failure must hold up delivery to
1151 this host. After a permanent authentication failure, we carry on
1152 to try other authentication methods. If all fail hard, try to
1153 deliver the message unauthenticated unless require_auth was set. */
1154
1155 switch(rc)
1156 {
1157 case OK:
1158 smtp_authenticated = TRUE; /* stops the outer loop */
1159 break;
1160
1161 /* Failure after writing a command */
1162
1163 case FAIL_SEND:
1164 goto SEND_FAILED;
1165
1166 /* Failure after reading a response */
1167
1168 case FAIL:
1169 if (errno != 0 || buffer[0] != '5') goto RESPONSE_FAILED;
1170 log_write(0, LOG_MAIN, "%s authenticator failed H=%s [%s] %s",
1171 au->name, host->name, host->address, buffer);
1172 break;
1173
1174 /* Failure by some other means. In effect, the authenticator
1175 decided it wasn't prepared to handle this case. Typically this
1176 is the result of "fail" in an expansion string. Do we need to
1177 log anything here? */
1178
1179 case CANCELLED:
1180 break;
1181
1182 /* Internal problem, message in buffer. */
1183
1184 case ERROR:
1185 yield = ERROR;
1186 set_errno(addrlist, 0, string_copy(buffer), DEFER);
1187 goto SEND_QUIT;
1188 }
1189
1190 break; /* If not authenticated, try next authenticator */
1191 } /* Loop for scanning supported server mechanisms */
1192 } /* Loop for further authenticators */
1193 }
1194 }
1195
1196 /* If we haven't authenticated, but are required to, give up. */
1197
1198 if (require_auth == OK && !smtp_authenticated)
1199 {
1200 yield = DEFER;
1201 set_errno(addrlist, ERRNO_AUTHFAIL,
1202 string_sprintf("authentication required but %s", fail_reason), DEFER);
1203 goto SEND_QUIT;
1204 }
1205 }
1206
1207 /* The setting up of the SMTP call is now complete. Any subsequent errors are
1208 message-specific. */
1209
1210 setting_up = FALSE;
1211
1212 /* If there is a filter command specified for this transport, we can now
1213 set it up. This cannot be done until the identify of the host is known. */
1214
1215 if (tblock->filter_command != NULL)
1216 {
1217 BOOL rc;
1218 uschar buffer[64];
1219 sprintf(CS buffer, "%.50s transport", tblock->name);
1220 rc = transport_set_up_command(&transport_filter_argv, tblock->filter_command,
1221 TRUE, DEFER, addrlist, buffer, NULL);
1222
1223 /* On failure, copy the error to all addresses, abandon the SMTP call, and
1224 yield ERROR. */
1225
1226 if (!rc)
1227 {
1228 set_errno(addrlist->next, addrlist->basic_errno, addrlist->message, DEFER);
1229 yield = ERROR;
1230 goto SEND_QUIT;
1231 }
1232 }
1233
1234
1235 /* For messages that have more than the maximum number of envelope recipients,
1236 we want to send several transactions down the same SMTP connection. (See
1237 comments in deliver.c as to how this reconciles, heuristically, with
1238 remote_max_parallel.) This optimization was added to Exim after the following
1239 code was already working. The simplest way to put it in without disturbing the
1240 code was to use a goto to jump back to this point when there is another
1241 transaction to handle. */
1242
1243 SEND_MESSAGE:
1244 sync_addr = first_addr;
1245 address_count = 0;
1246 ok = FALSE;
1247 send_rset = TRUE;
1248 completed_address = FALSE;
1249
1250
1251 /* Initiate a message transfer. If we know the receiving MTA supports the SIZE
1252 qualification, send it, adding something to the message size to allow for
1253 imprecision and things that get added en route. Exim keeps the number of lines
1254 in a message, so we can give an accurate value for the original message, but we
1255 need some additional to handle added headers. (Double "." characters don't get
1256 included in the count.) */
1257
1258 p = buffer;
1259 *p = 0;
1260
1261 if (smtp_use_size)
1262 {
1263 sprintf(CS p, " SIZE=%d", message_size+message_linecount+ob->size_addition);
1264 while (*p) p++;
1265 }
1266
1267 /* Add the authenticated sender address if present */
1268
1269 if (smtp_authenticated && local_authenticated_sender != NULL)
1270 {
1271 string_format(p, sizeof(buffer) - (p-buffer), " AUTH=%s",
1272 auth_xtextencode(local_authenticated_sender,
1273 Ustrlen(local_authenticated_sender)));
1274 }
1275
1276 /* From here until we send the DATA command, we can make use of PIPELINING
1277 if the server host supports it. The code has to be able to check the responses
1278 at any point, for when the buffer fills up, so we write it totally generally.
1279 When PIPELINING is off, each command written reports that it has flushed the
1280 buffer. */
1281
1282 pending_MAIL = TRUE; /* The block starts with MAIL */
1283
1284 rc = smtp_write_command(&outblock, smtp_use_pipelining,
1285 "MAIL FROM:<%s>%s\r\n", return_path, buffer);
1286 mail_command = string_copy(big_buffer); /* Save for later error message */
1287
1288 switch(rc)
1289 {
1290 case -1: /* Transmission error */
1291 goto SEND_FAILED;
1292
1293 case +1: /* Block was sent */
1294 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1295 ob->command_timeout)) goto RESPONSE_FAILED;
1296 pending_MAIL = FALSE;
1297 break;
1298 }
1299
1300 /* Pass over all the relevant recipient addresses for this host, which are the
1301 ones that have status PENDING_DEFER. If we are using PIPELINING, we can send
1302 several before we have to read the responses for those seen so far. This
1303 checking is done by a subroutine because it also needs to be done at the end.
1304 Send only up to max_rcpt addresses at a time, leaving first_addr pointing to
1305 the next one if not all are sent.
1306
1307 In the MUA wrapper situation, we want to flush the PIPELINING buffer for the
1308 last address because we want to abort if any recipients have any kind of
1309 problem, temporary or permanent. We know that all recipient addresses will have
1310 the PENDING_DEFER status, because only one attempt is ever made, and we know
1311 that max_rcpt will be large, so all addresses will be done at once. */
1312
1313 for (addr = first_addr;
1314 address_count < max_rcpt && addr != NULL;
1315 addr = addr->next)
1316 {
1317 int count;
1318 BOOL no_flush;
1319
1320 if (addr->transport_return != PENDING_DEFER) continue;
1321
1322 address_count++;
1323 no_flush = smtp_use_pipelining && (!mua_wrapper || addr->next != NULL);
1324
1325 /* Now send the RCPT command, and process outstanding responses when
1326 necessary. After a timeout on RCPT, we just end the function, leaving the
1327 yield as OK, because this error can often mean that there is a problem with
1328 just one address, so we don't want to delay the host. */
1329
1330 count = smtp_write_command(&outblock, no_flush, "RCPT TO:<%s>\r\n",
1331 transport_rcpt_address(addr, tblock->rcpt_include_affixes));
1332 if (count < 0) goto SEND_FAILED;
1333 if (count > 0)
1334 {
1335 switch(sync_responses(first_addr, tblock->rcpt_include_affixes,
1336 &sync_addr, host, count, pending_MAIL, 0, &inblock,
1337 ob->command_timeout, buffer, sizeof(buffer)))
1338 {
1339 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1340 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1341 break;
1342
1343 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1344 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1345 case 0: /* No 2xx or 5xx, but no probs */
1346 break;
1347
1348 case -1: goto END_OFF; /* Timeout on RCPT */
1349 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL error */
1350 }
1351 pending_MAIL = FALSE; /* Dealt with MAIL */
1352 }
1353 } /* Loop for next address */
1354
1355 /* If we are an MUA wrapper, abort if any RCPTs were rejected, either
1356 permanently or temporarily. We should have flushed and synced after the last
1357 RCPT. */
1358
1359 if (mua_wrapper)
1360 {
1361 address_item *badaddr;
1362 for (badaddr = first_addr; badaddr != NULL; badaddr = badaddr->next)
1363 {
1364 if (badaddr->transport_return != PENDING_OK) break;
1365 }
1366 if (badaddr != NULL)
1367 {
1368 set_errno(addrlist, 0, badaddr->message, FAIL);
1369 ok = FALSE;
1370 }
1371 }
1372
1373 /* If ok is TRUE, we know we have got at least one good recipient, and must now
1374 send DATA, but if it is FALSE (in the normal, non-wrapper case), we may still
1375 have a good recipient buffered up if we are pipelining. We don't want to waste
1376 time sending DATA needlessly, so we only send it if either ok is TRUE or if we
1377 are pipelining. The responses are all handled by sync_responses(). */
1378
1379 if (ok || (smtp_use_pipelining && !mua_wrapper))
1380 {
1381 int count = smtp_write_command(&outblock, FALSE, "DATA\r\n");
1382 if (count < 0) goto SEND_FAILED;
1383 switch(sync_responses(first_addr, tblock->rcpt_include_affixes, &sync_addr,
1384 host, count, pending_MAIL, ok? +1 : -1, &inblock,
1385 ob->command_timeout, buffer, sizeof(buffer)))
1386 {
1387 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1388 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1389 break;
1390
1391 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1392 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1393 case 0: break; /* No 2xx or 5xx, but no probs */
1394
1395 case -1: goto END_OFF; /* Timeout on RCPT */
1396 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */
1397 }
1398 }
1399
1400 /* Save the first address of the next batch. */
1401
1402 first_addr = addr;
1403
1404 /* If there were no good recipients (but otherwise there have been no
1405 problems), just set ok TRUE, since we have handled address-specific errors
1406 already. Otherwise, it's OK to send the message. Use the check/escape mechanism
1407 for handling the SMTP dot-handling protocol, flagging to apply to headers as
1408 well as body. Set the appropriate timeout value to be used for each chunk.
1409 (Haven't been able to make it work using select() for writing yet.) */
1410
1411 if (!ok) ok = TRUE; else
1412 {
1413 sigalrm_seen = FALSE;
1414 transport_write_timeout = ob->data_timeout;
1415 smtp_command = US"sending data block"; /* For error messages */
1416 DEBUG(D_transport|D_v)
1417 debug_printf(" SMTP>> writing message and terminating \".\"\n");
1418 transport_count = 0;
1419 #ifdef EXPERIMENTAL_DOMAINKEYS
1420 if ( (ob->dk_private_key != NULL) && (ob->dk_selector != NULL) )
1421 ok = dk_transport_write_message(addrlist, inblock.sock,
1422 topt_use_crlf | topt_end_dot | topt_escape_headers |
1423 (tblock->body_only? topt_no_headers : 0) |
1424 (tblock->headers_only? topt_no_body : 0) |
1425 (tblock->return_path_add? topt_add_return_path : 0) |
1426 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1427 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1428 0, /* No size limit */
1429 tblock->add_headers, tblock->remove_headers,
1430 US".", US"..", /* Escaping strings */
1431 tblock->rewrite_rules, tblock->rewrite_existflags,
1432 ob->dk_private_key, ob->dk_domain, ob->dk_selector,
1433 ob->dk_canon, ob->dk_headers, ob->dk_strict);
1434 else
1435 #endif
1436 ok = transport_write_message(addrlist, inblock.sock,
1437 topt_use_crlf | topt_end_dot | topt_escape_headers |
1438 (tblock->body_only? topt_no_headers : 0) |
1439 (tblock->headers_only? topt_no_body : 0) |
1440 (tblock->return_path_add? topt_add_return_path : 0) |
1441 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1442 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1443 0, /* No size limit */
1444 tblock->add_headers, tblock->remove_headers,
1445 US".", US"..", /* Escaping strings */
1446 tblock->rewrite_rules, tblock->rewrite_existflags);
1447
1448 /* transport_write_message() uses write() because it is called from other
1449 places to write to non-sockets. This means that under some OS (e.g. Solaris)
1450 it can exit with "Broken pipe" as its error. This really means that the
1451 socket got closed at the far end. */
1452
1453 transport_write_timeout = 0; /* for subsequent transports */
1454
1455 /* Failure can either be some kind of I/O disaster (including timeout),
1456 or the failure of a transport filter or the expansion of added headers. */
1457
1458 if (!ok)
1459 {
1460 buffer[0] = 0; /* There hasn't been a response */
1461 goto RESPONSE_FAILED;
1462 }
1463
1464 /* We used to send the terminating "." explicitly here, but because of
1465 buffering effects at both ends of TCP/IP connections, you don't gain
1466 anything by keeping it separate, so it might as well go in the final
1467 data buffer for efficiency. This is now done by setting the topt_end_dot
1468 flag above. */
1469
1470 smtp_command = US"end of data";
1471
1472 /* For SMTP, we now read a single response that applies to the whole message.
1473 If it is OK, then all the addresses have been delivered. */
1474
1475 if (!lmtp) ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1476 ob->final_timeout);
1477
1478 /* For LMTP, we get back a response for every RCPT command that we sent;
1479 some may be accepted and some rejected. For those that get a response, their
1480 status is fixed; any that are accepted have been handed over, even if later
1481 responses crash - at least, that's how I read RFC 2033.
1482
1483 If all went well, mark the recipient addresses as completed, record which
1484 host/IPaddress they were delivered to, and cut out RSET when sending another
1485 message down the same channel. Write the completed addresses to the journal
1486 now so that they are recorded in case there is a crash of hardware or
1487 software before the spool gets updated. Also record the final SMTP
1488 confirmation if needed (for SMTP only). */
1489
1490 if (ok)
1491 {
1492 int flag = '=';
1493 int delivery_time = (int)(time(NULL) - start_delivery_time);
1494 int len;
1495 host_item *thost;
1496 uschar *conf = NULL;
1497 send_rset = FALSE;
1498
1499 /* Make a copy of the host if it is local to this invocation
1500 of the transport. */
1501
1502 if (copy_host)
1503 {
1504 thost = store_get(sizeof(host_item));
1505 *thost = *host;
1506 thost->name = string_copy(host->name);
1507 thost->address = string_copy(host->address);
1508 }
1509 else thost = host;
1510
1511 /* Set up confirmation if needed - applies only to SMTP */
1512
1513 if ((log_extra_selector & LX_smtp_confirmation) != 0 && !lmtp)
1514 {
1515 uschar *s = string_printing(buffer);
1516 conf = (s == buffer)? (uschar *)string_copy(s) : s;
1517 }
1518
1519 /* Process all transported addresses - for LMTP, read a status for
1520 each one. */
1521
1522 for (addr = addrlist; addr != first_addr; addr = addr->next)
1523 {
1524 if (addr->transport_return != PENDING_OK) continue;
1525
1526 /* LMTP - if the response fails badly (e.g. timeout), use it for all the
1527 remaining addresses. Otherwise, it's a return code for just the one
1528 address. */
1529
1530 if (lmtp)
1531 {
1532 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1533 ob->final_timeout))
1534 {
1535 if (errno != 0 || buffer[0] == 0) goto RESPONSE_FAILED;
1536 addr->message = string_sprintf("LMTP error after %s: %s",
1537 big_buffer, string_printing(buffer));
1538 addr->transport_return = (buffer[0] == '5')? FAIL : DEFER;
1539 continue;
1540 }
1541 completed_address = TRUE; /* NOW we can set this flag */
1542 }
1543
1544 /* SMTP, or success return from LMTP for this address. Pass back the
1545 actual port used. */
1546
1547 addr->transport_return = OK;
1548 addr->more_errno = delivery_time;
1549 thost->port = port;
1550 addr->host_used = thost;
1551 addr->special_action = flag;
1552 addr->message = conf;
1553 flag = '-';
1554
1555 /* Update the journal. For homonymic addresses, use the base address plus
1556 the transport name. See lots of comments in deliver.c about the reasons
1557 for the complications when homonyms are involved. Just carry on after
1558 write error, as it may prove possible to update the spool file later. */
1559
1560 if (testflag(addr, af_homonym))
1561 sprintf(CS buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
1562 else
1563 sprintf(CS buffer, "%.500s\n", addr->unique);
1564
1565 DEBUG(D_deliver) debug_printf("journalling %s", buffer);
1566 len = Ustrlen(CS buffer);
1567 if (write(journal_fd, buffer, len) != len)
1568 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
1569 "%s: %s", buffer, strerror(errno));
1570 }
1571
1572 /* Ensure the journal file is pushed out to disk. */
1573
1574 if (fsync(journal_fd) < 0)
1575 log_write(0, LOG_MAIN|LOG_PANIC, "failed to fsync journal: %s",
1576 strerror(errno));
1577 }
1578 }
1579
1580
1581 /* Handle general (not specific to one address) failures here. The value of ok
1582 is used to skip over this code on the falling through case. A timeout causes a
1583 deferral. Other errors may defer or fail according to the response code, and
1584 may set up a special errno value, e.g. after connection chopped, which is
1585 assumed if errno == 0 and there is no text in the buffer. If control reaches
1586 here during the setting up phase (i.e. before MAIL FROM) then always defer, as
1587 the problem is not related to this specific message. */
1588
1589 if (!ok)
1590 {
1591 int code;
1592
1593 RESPONSE_FAILED:
1594 save_errno = errno;
1595 message = NULL;
1596 send_quit = check_response(host, &save_errno, addrlist->more_errno,
1597 buffer, &code, &message);
1598 goto FAILED;
1599
1600 SEND_FAILED:
1601 save_errno = errno;
1602 code = '4';
1603 message = US string_sprintf("send() to %s [%s] failed: %s",
1604 host->name, host->address, strerror(save_errno));
1605 send_quit = FALSE;
1606 goto FAILED;
1607
1608 /* This label is jumped to directly when a TLS negotiation has failed,
1609 or was not done for a host for which it is required. Values will be set
1610 in message and save_errno, and setting_up will always be true. Treat as
1611 a temporary error. */
1612
1613 #ifdef SUPPORT_TLS
1614 TLS_FAILED:
1615 code = '4';
1616 #endif
1617
1618 /* If the failure happened while setting up the call, see if the failure was
1619 a 5xx response (this will either be on connection, or following HELO - a 5xx
1620 after EHLO causes it to try HELO). If so, fail all addresses, as this host is
1621 never going to accept them. For other errors during setting up (timeouts or
1622 whatever), defer all addresses, and yield DEFER, so that the host is not
1623 tried again for a while. */
1624
1625 FAILED:
1626 ok = FALSE; /* For when reached by GOTO */
1627
1628 if (setting_up)
1629 {
1630 if (code == '5')
1631 {
1632 set_errno(addrlist, save_errno, message, FAIL);
1633 }
1634 else
1635 {
1636 set_errno(addrlist, save_errno, message, DEFER);
1637 yield = DEFER;
1638 }
1639 }
1640
1641 /* If there was an I/O error or timeout or other transportation error,
1642 indicated by errno being non-zero, defer all addresses and yield DEFER,
1643 except for the case of failed add_headers expansion, or a transport filter
1644 failure, when the yield should be ERROR, to stop it trying other hosts.
1645
1646 However, handle timeouts after MAIL FROM or "." and loss of connection after
1647 "." specially. They can indicate a problem with the sender address or with
1648 the contents of the message rather than a real error on the connection.
1649 Therefore, treat these cases in the same way as a 4xx response.
1650
1651 The following condition tests for NOT these special cases. */
1652
1653 else if (save_errno != 0 &&
1654 (save_errno != ETIMEDOUT ||
1655 (Ustrncmp(smtp_command,"MAIL",4) != 0 &&
1656 Ustrncmp(smtp_command,"end ",4) != 0)) &&
1657 (save_errno != ERRNO_SMTPCLOSED ||
1658 Ustrncmp(smtp_command,"end ",4) != 0))
1659 {
1660 yield = (save_errno == ERRNO_CHHEADER_FAIL ||
1661 save_errno == ERRNO_FILTER_FAIL)? ERROR : DEFER;
1662 set_errno(addrlist, save_errno, message, DEFER);
1663 }
1664
1665 /* Otherwise we have a message-specific error response from the remote
1666 host. This is one of
1667 (a) negative response or timeout after "mail from"
1668 (b) negative response after "data"
1669 (c) negative response or timeout or dropped connection after "."
1670 It won't be a negative response or timeout after "rcpt to", as that is dealt
1671 with separately above. The action in all cases is to set an appropriate
1672 error code for all the addresses, but to leave yield set to OK because
1673 the host itself has not failed. [It might in practice have failed for a
1674 timeout after MAIL FROM, or "." but if so, we'll discover that at the next
1675 delivery attempt.] For a temporary error, set the message_defer flag, and
1676 write to the logs for information if this is not the last host. The error for
1677 the last host will be logged as part of the address's log line. */
1678
1679 else
1680 {
1681 if (mua_wrapper) code = '5'; /* Force hard failure in wrapper mode */
1682
1683 set_errno(addrlist, save_errno, message, (code == '5')? FAIL : DEFER);
1684
1685 /* If there's an errno, the message contains just the identity of
1686 the host. */
1687
1688 if (code != '5') /* Anything other than 5 is treated as temporary */
1689 {
1690 if (save_errno > 0)
1691 message = US string_sprintf("%s: %s", message, strerror(save_errno));
1692 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", message);
1693 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
1694 *message_defer = TRUE;
1695 }
1696 }
1697 }
1698
1699
1700 /* If all has gone well, send_quit will be set TRUE, implying we can end the
1701 SMTP session tidily. However, if there were too many addresses to send in one
1702 message (indicated by first_addr being non-NULL) we want to carry on with the
1703 rest of them. Also, it is desirable to send more than one message down the SMTP
1704 connection if there are several waiting, provided we haven't already sent so
1705 many as to hit the configured limit. The function transport_check_waiting looks
1706 for a waiting message and returns its id. Then transport_pass_socket tries to
1707 set up a continued delivery by passing the socket on to another process. The
1708 variable send_rset is FALSE if a message has just been successfully transfered.
1709
1710 If we are already sending down a continued channel, there may be further
1711 addresses not yet delivered that are aimed at the same host, but which have not
1712 been passed in this run of the transport. In this case, continue_more will be
1713 true, and all we should do is send RSET if necessary, and return, leaving the
1714 channel open.
1715
1716 However, if no address was disposed of, i.e. all addresses got 4xx errors, we
1717 do not want to continue with other messages down the same channel, because that
1718 can lead to looping between two or more messages, all with the same,
1719 temporarily failing address(es). [The retry information isn't updated yet, so
1720 new processes keep on trying.] We probably also don't want to try more of this
1721 message's addresses either.
1722
1723 If we have started a TLS session, we have to end it before passing the
1724 connection to a new process. However, not all servers can handle this (Exim
1725 can), so we do not pass such a connection on if the host matches
1726 hosts_nopass_tls. */
1727
1728 DEBUG(D_transport)
1729 debug_printf("ok=%d send_quit=%d send_rset=%d continue_more=%d "
1730 "yield=%d first_address is %sNULL\n", ok, send_quit, send_rset,
1731 continue_more, yield, (first_addr == NULL)? "":"not ");
1732
1733 if (completed_address && ok && send_quit)
1734 {
1735 BOOL more;
1736 if (first_addr != NULL || continue_more ||
1737 (
1738 (tls_active < 0 ||
1739 verify_check_this_host(&(ob->hosts_nopass_tls), NULL, host->name,
1740 host->address, NULL) != OK)
1741 &&
1742 transport_check_waiting(tblock->name, host->name,
1743 tblock->connection_max_messages, new_message_id, &more)
1744 ))
1745 {
1746 uschar *msg;
1747
1748 if (send_rset)
1749 {
1750 if (! (ok = smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0))
1751 {
1752 msg = US string_sprintf("send() to %s [%s] failed: %s", host->name,
1753 host->address, strerror(save_errno));
1754 send_quit = FALSE;
1755 }
1756 else if (! (ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1757 ob->command_timeout)))
1758 {
1759 int code;
1760 send_quit = check_response(host, &errno, 0, buffer, &code, &msg);
1761 if (!send_quit)
1762 {
1763 DEBUG(D_transport) debug_printf("%s\n", msg);
1764 }
1765 }
1766 }
1767
1768 /* Either RSET was not needed, or it succeeded */
1769
1770 if (ok)
1771 {
1772 if (first_addr != NULL) /* More addresses still to be sent */
1773 { /* in this run of the transport */
1774 continue_sequence++; /* Causes * in logging */
1775 goto SEND_MESSAGE;
1776 }
1777 if (continue_more) return yield; /* More addresses for another run */
1778
1779 /* Pass the socket to a new Exim process. Before doing so, we must shut
1780 down TLS. Not all MTAs allow for the continuation of the SMTP session
1781 when TLS is shut down. We test for this by sending a new EHLO. If we
1782 don't get a good response, we don't attempt to pass the socket on. */
1783
1784 #ifdef SUPPORT_TLS
1785 if (tls_active >= 0)
1786 {
1787 tls_close(TRUE);
1788 ok = smtp_write_command(&outblock,FALSE,"EHLO %s\r\n",helo_data) >= 0 &&
1789 smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1790 ob->command_timeout);
1791 }
1792 #endif
1793
1794 /* If the socket is successfully passed, we musn't send QUIT (or
1795 indeed anything!) from here. */
1796
1797 if (ok && transport_pass_socket(tblock->name, host->name, host->address,
1798 new_message_id, inblock.sock))
1799 {
1800 send_quit = FALSE;
1801 }
1802 }
1803
1804 /* If RSET failed and there are addresses left, they get deferred. */
1805
1806 else set_errno(first_addr, errno, msg, DEFER);
1807 }
1808 }
1809
1810 /* End off tidily with QUIT unless the connection has died or the socket has
1811 been passed to another process. There has been discussion on the net about what
1812 to do after sending QUIT. The wording of the RFC suggests that it is necessary
1813 to wait for a response, but on the other hand, there isn't anything one can do
1814 with an error response, other than log it. Exim used to do that. However,
1815 further discussion suggested that it is positively advantageous not to wait for
1816 the response, but to close the session immediately. This is supposed to move
1817 the TCP/IP TIME_WAIT state from the server to the client, thereby removing some
1818 load from the server. (Hosts that are both servers and clients may not see much
1819 difference, of course.) Further discussion indicated that this was safe to do
1820 on Unix systems which have decent implementations of TCP/IP that leave the
1821 connection around for a while (TIME_WAIT) after the application has gone away.
1822 This enables the response sent by the server to be properly ACKed rather than
1823 timed out, as can happen on broken TCP/IP implementations on other OS.
1824
1825 This change is being made on 31-Jul-98. After over a year of trouble-free
1826 operation, the old commented-out code was removed on 17-Sep-99. */
1827
1828 SEND_QUIT:
1829 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1830
1831 END_OFF:
1832
1833 #ifdef SUPPORT_TLS
1834 tls_close(TRUE);
1835 #endif
1836
1837 /* Close the socket, and return the appropriate value, first setting
1838 continue_transport and continue_hostname NULL to prevent any other addresses
1839 that may include the host from trying to re-use a continuation socket. This
1840 works because the NULL setting is passed back to the calling process, and
1841 remote_max_parallel is forced to 1 when delivering over an existing connection,
1842
1843 If all went well and continue_more is set, we shouldn't actually get here if
1844 there are further addresses, as the return above will be taken. However,
1845 writing RSET might have failed, or there may be other addresses whose hosts are
1846 specified in the transports, and therefore not visible at top level, in which
1847 case continue_more won't get set. */
1848
1849 close(inblock.sock);
1850 continue_transport = NULL;
1851 continue_hostname = NULL;
1852 return yield;
1853 }
1854
1855
1856
1857
1858 /*************************************************
1859 * Closedown entry point *
1860 *************************************************/
1861
1862 /* This function is called when exim is passed an open smtp channel
1863 from another incarnation, but the message which it has been asked
1864 to deliver no longer exists. The channel is on stdin.
1865
1866 We might do fancy things like looking for another message to send down
1867 the channel, but if the one we sought has gone, it has probably been
1868 delivered by some other process that itself will seek further messages,
1869 so just close down our connection.
1870
1871 Argument: pointer to the transport instance block
1872 Returns: nothing
1873 */
1874
1875 void
1876 smtp_transport_closedown(transport_instance *tblock)
1877 {
1878 smtp_transport_options_block *ob =
1879 (smtp_transport_options_block *)(tblock->options_block);
1880 smtp_inblock inblock;
1881 smtp_outblock outblock;
1882 uschar buffer[256];
1883 uschar inbuffer[4096];
1884 uschar outbuffer[16];
1885
1886 inblock.sock = fileno(stdin);
1887 inblock.buffer = inbuffer;
1888 inblock.buffersize = sizeof(inbuffer);
1889 inblock.ptr = inbuffer;
1890 inblock.ptrend = inbuffer;
1891
1892 outblock.sock = inblock.sock;
1893 outblock.buffersize = sizeof(outbuffer);
1894 outblock.buffer = outbuffer;
1895 outblock.ptr = outbuffer;
1896 outblock.cmd_count = 0;
1897 outblock.authenticating = FALSE;
1898
1899 (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1900 (void)smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1901 ob->command_timeout);
1902 close(inblock.sock);
1903 }
1904
1905
1906
1907 /*************************************************
1908 * Prepare addresses for delivery *
1909 *************************************************/
1910
1911 /* This function is called to flush out error settings from previous delivery
1912 attempts to other hosts. It also records whether we got here via an MX record
1913 or not in the more_errno field of the address. We are interested only in
1914 addresses that are still marked DEFER - others may have got delivered to a
1915 previously considered IP address. Set their status to PENDING_DEFER to indicate
1916 which ones are relevant this time.
1917
1918 Arguments:
1919 addrlist the list of addresses
1920 host the host we are delivering to
1921
1922 Returns: the first address for this delivery
1923 */
1924
1925 static address_item *
1926 prepare_addresses(address_item *addrlist, host_item *host)
1927 {
1928 address_item *first_addr = NULL;
1929 address_item *addr;
1930 for (addr = addrlist; addr != NULL; addr = addr->next)
1931 {
1932 if (addr->transport_return != DEFER) continue;
1933 if (first_addr == NULL) first_addr = addr;
1934 addr->transport_return = PENDING_DEFER;
1935 addr->basic_errno = 0;
1936 addr->more_errno = (host->mx >= 0)? 'M' : 'A';
1937 addr->message = NULL;
1938 #ifdef SUPPORT_TLS
1939 addr->cipher = NULL;
1940 addr->peerdn = NULL;
1941 #endif
1942 }
1943 return first_addr;
1944 }
1945
1946
1947
1948 /*************************************************
1949 * Main entry point *
1950 *************************************************/
1951
1952 /* See local README for interface details. As this is a remote transport, it is
1953 given a chain of addresses to be delivered in one connection, if possible. It
1954 always returns TRUE, indicating that each address has its own independent
1955 status set, except if there is a setting up problem, in which case it returns
1956 FALSE. */
1957
1958 BOOL
1959 smtp_transport_entry(
1960 transport_instance *tblock, /* data for this instantiation */
1961 address_item *addrlist) /* addresses we are working on */
1962 {
1963 int cutoff_retry;
1964 int port;
1965 int hosts_defer = 0;
1966 int hosts_fail = 0;
1967 int hosts_looked_up = 0;
1968 int hosts_retry = 0;
1969 int hosts_serial = 0;
1970 int hosts_total = 0;
1971 int total_hosts_tried = 0;
1972 address_item *addr;
1973 BOOL expired = TRUE;
1974 BOOL continuing = continue_hostname != NULL;
1975 uschar *expanded_hosts = NULL;
1976 uschar *pistring;
1977 uschar *tid = string_sprintf("%s transport", tblock->name);
1978 smtp_transport_options_block *ob =
1979 (smtp_transport_options_block *)(tblock->options_block);
1980 host_item *hostlist = addrlist->host_list;
1981 host_item *host = NULL;
1982
1983 DEBUG(D_transport)
1984 {
1985 debug_printf("%s transport entered\n", tblock->name);
1986 for (addr = addrlist; addr != NULL; addr = addr->next)
1987 debug_printf(" %s\n", addr->address);
1988 if (continuing) debug_printf("already connected to %s [%s]\n",
1989 continue_hostname, continue_host_address);
1990 }
1991
1992 /* If a host list is not defined for the addresses - they must all have the
1993 same one in order to be passed to a single transport - or if the transport has
1994 a host list with hosts_override set, use the host list supplied with the
1995 transport. It is an error for this not to exist. */
1996
1997 if (hostlist == NULL || (ob->hosts_override && ob->hosts != NULL))
1998 {
1999 if (ob->hosts == NULL)
2000 {
2001 addrlist->message = string_sprintf("%s transport called with no hosts set",
2002 tblock->name);
2003 addrlist->transport_return = PANIC;
2004 return FALSE; /* Only top address has status */
2005 }
2006
2007 DEBUG(D_transport) debug_printf("using the transport's hosts: %s\n",
2008 ob->hosts);
2009
2010 /* If the transport's host list contains no '$' characters, and we are not
2011 randomizing, it is fixed and therefore a chain of hosts can be built once
2012 and for all, and remembered for subsequent use by other calls to this
2013 transport. If, on the other hand, the host list does contain '$', or we are
2014 randomizing its order, we have to rebuild it each time. In the fixed case,
2015 as the hosts string will never be used again, it doesn't matter that we
2016 replace all the : characters with zeros. */
2017
2018 if (ob->hostlist == NULL)
2019 {
2020 uschar *s = ob->hosts;
2021
2022 if (Ustrchr(s, '$') != NULL)
2023 {
2024 expanded_hosts = expand_string(s);
2025 if (expanded_hosts == NULL)
2026 {
2027 addrlist->message = string_sprintf("failed to expand list of hosts "
2028 "\"%s\" in %s transport: %s", s, tblock->name, expand_string_message);
2029 addrlist->transport_return = search_find_defer? DEFER : PANIC;
2030 return FALSE; /* Only top address has status */
2031 }
2032 DEBUG(D_transport) debug_printf("expanded list of hosts \"%s\" to "
2033 "\"%s\"\n", s, expanded_hosts);
2034 s = expanded_hosts;
2035 }
2036 else
2037 if (ob->hosts_randomize) s = expanded_hosts = string_copy(s);
2038
2039 host_build_hostlist(&hostlist, s, ob->hosts_randomize);
2040
2041 /* If there was no expansion of hosts, save the host list for
2042 next time. */
2043
2044 if (expanded_hosts == NULL) ob->hostlist = hostlist;
2045 }
2046
2047 /* This is not the first time this transport has been run in this delivery;
2048 the host list was built previously. */
2049
2050 else hostlist = ob->hostlist;
2051 }
2052
2053 /* The host list was supplied with the address. If hosts_randomize is set, we
2054 must sort it into a random order if it did not come from MX records and has not
2055 already been randomized (but don't bother if continuing down an existing
2056 connection). */
2057
2058 else if (ob->hosts_randomize && hostlist->mx == MX_NONE && !continuing)
2059 {
2060 host_item *newlist = NULL;
2061 while (hostlist != NULL)
2062 {
2063 host_item *h = hostlist;
2064 hostlist = hostlist->next;
2065
2066 h->sort_key = random_number(100);
2067
2068 if (newlist == NULL)
2069 {
2070 h->next = NULL;
2071 newlist = h;
2072 }
2073 else if (h->sort_key < newlist->sort_key)
2074 {
2075 h->next = newlist;
2076 newlist = h;
2077 }
2078 else
2079 {
2080 host_item *hh = newlist;
2081 while (hh->next != NULL)
2082 {
2083 if (h->sort_key < hh->next->sort_key) break;
2084 hh = hh->next;
2085 }
2086 h->next = hh->next;
2087 hh->next = h;
2088 }
2089 }
2090
2091 hostlist = addrlist->host_list = newlist;
2092 }
2093
2094
2095 /* Sort out the port. Set up a string for adding to the retry key if the port
2096 number is not the standard SMTP port. */
2097
2098 if (!smtp_get_port(ob->port, addrlist, &port, tid)) return FALSE;
2099 pistring = string_sprintf(":%d", port);
2100 if (Ustrcmp(pistring, ":25") == 0) pistring = US"";
2101
2102
2103 /* For each host-plus-IP-address on the list:
2104
2105 . If this is a continued delivery and the host isn't the one with the
2106 current connection, skip.
2107
2108 . If the status is unusable (i.e. previously failed or retry checked), skip.
2109
2110 . If no IP address set, get the address, either by turning the name into
2111 an address, calling gethostbyname if gethostbyname is on, or by calling
2112 the DNS. The DNS may yield multiple addresses, in which case insert the
2113 extra ones into the list.
2114
2115 . Get the retry data if not previously obtained for this address and set the
2116 field which remembers the state of this address. Skip if the retry time is
2117 not reached. If not, remember whether retry data was found. The retry string
2118 contains both the name and the IP address.
2119
2120 . Scan the list of addresses and mark those whose status is DEFER as
2121 PENDING_DEFER. These are the only ones that will be processed in this cycle
2122 of the hosts loop.
2123
2124 . Make a delivery attempt - addresses marked PENDING_DEFER will be tried.
2125 Some addresses may be successfully delivered, others may fail, and yet
2126 others may get temporary errors and so get marked DEFER.
2127
2128 . The return from the delivery attempt is OK if a connection was made and a
2129 valid SMTP dialogue was completed. Otherwise it is DEFER.
2130
2131 . If OK, add a "remove" retry item for this host/IPaddress, if any.
2132
2133 . If fail to connect, or other defer state, add a retry item.
2134
2135 . If there are any addresses whose status is still DEFER, carry on to the
2136 next host/IPaddress, unless we have tried the number of hosts given
2137 by hosts_max_try or hosts_max_try_hardlimit; otherwise return. Note that
2138 there is some fancy logic for hosts_max_try that means its limit can be
2139 overstepped in some circumstances.
2140
2141 If we get to the end of the list, all hosts have deferred at least one address,
2142 or not reached their retry times. If delay_after_cutoff is unset, it requests a
2143 delivery attempt to those hosts whose last try was before the arrival time of
2144 the current message. To cope with this, we have to go round the loop a second
2145 time. After that, set the status and error data for any addresses that haven't
2146 had it set already. */
2147
2148 for (cutoff_retry = 0; expired &&
2149 cutoff_retry < ((ob->delay_after_cutoff)? 1 : 2);
2150 cutoff_retry++)
2151 {
2152 host_item *nexthost = NULL;
2153 int unexpired_hosts_tried = 0;
2154
2155 for (host = hostlist;
2156 host != NULL &&
2157 unexpired_hosts_tried < ob->hosts_max_try &&
2158 total_hosts_tried < ob->hosts_max_try_hardlimit;
2159 host = nexthost)
2160 {
2161 int rc;
2162 int host_af;
2163 uschar *rs;
2164 BOOL serialized = FALSE;
2165 BOOL host_is_expired = FALSE;
2166 BOOL message_defer = FALSE;
2167 BOOL ifchanges = FALSE;
2168 BOOL some_deferred = FALSE;
2169 address_item *first_addr = NULL;
2170 uschar *interface = NULL;
2171 uschar *retry_host_key = NULL;
2172 uschar *retry_message_key = NULL;
2173 uschar *serialize_key = NULL;
2174
2175 /* Set the flag requesting that this host be added to the waiting
2176 database if the delivery fails temporarily or if we are running with
2177 queue_smtp or a 2-stage queue run. This gets unset for certain
2178 kinds of error, typically those that are specific to the message. */
2179
2180 host->update_waiting = TRUE;
2181
2182 /* If the address hasn't yet been obtained from the host name, look it up
2183 now, unless the host is already marked as unusable. If it is marked as
2184 unusable, it means that the router was unable to find its IP address (in
2185 the DNS or wherever) OR we are in the 2nd time round the cutoff loop, and
2186 the lookup failed last time. We don't get this far if *all* MX records
2187 point to non-existent hosts; that is treated as a hard error.
2188
2189 We can just skip this host entirely. When the hosts came from the router,
2190 the address will timeout based on the other host(s); when the address is
2191 looked up below, there is an explicit retry record added.
2192
2193 Note that we mustn't skip unusable hosts if the address is not unset; they
2194 may be needed as expired hosts on the 2nd time round the cutoff loop. */
2195
2196 if (host->address == NULL)
2197 {
2198 uschar *canonical_name;
2199
2200 if (host->status >= hstatus_unusable)
2201 {
2202 DEBUG(D_transport) debug_printf("%s has no address and is unusable - skipping\n",
2203 host->name);
2204 continue;
2205 }
2206
2207 DEBUG(D_transport) debug_printf("getting address for %s\n", host->name);
2208
2209 hosts_looked_up++;
2210
2211 /* Find by name if so configured, or if it's an IP address. We don't
2212 just copy the IP address, because we need the test-for-local to happen. */
2213
2214 if (ob->gethostbyname || string_is_ip_address(host->name, NULL) > 0)
2215 rc = host_find_byname(host, NULL, &canonical_name, TRUE);
2216 else
2217 {
2218 int flags = HOST_FIND_BY_A;
2219 if (ob->dns_qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
2220 if (ob->dns_search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
2221 rc = host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
2222 &canonical_name, NULL);
2223 }
2224
2225 /* Failure to find the host at this time (usually DNS temporary failure)
2226 is really a kind of routing failure rather than a transport failure.
2227 Therefore we add a retry item of the routing kind, not to stop us trying
2228 to look this name up here again, but to ensure the address gets timed
2229 out if the failures go on long enough. A complete failure at this point
2230 commonly points to a configuration error, but the best action is still
2231 to carry on for the next host. */
2232
2233 if (rc == HOST_FIND_AGAIN || rc == HOST_FIND_FAILED)
2234 {
2235 retry_add_item(addrlist, string_sprintf("R:%s", host->name), 0);
2236 expired = FALSE;
2237 if (rc == HOST_FIND_AGAIN) hosts_defer++; else hosts_fail++;
2238 DEBUG(D_transport) debug_printf("rc = %s for %s\n", (rc == HOST_FIND_AGAIN)?
2239 "HOST_FIND_AGAIN" : "HOST_FIND_FAILED", host->name);
2240 host->status = hstatus_unusable;
2241
2242 for (addr = addrlist; addr != NULL; addr = addr->next)
2243 {
2244 if (addr->transport_return != DEFER) continue;
2245 addr->basic_errno = ERRNO_UNKNOWNHOST;
2246 addr->message =
2247 string_sprintf("failed to lookup IP address for %s", host->name);
2248 }
2249 continue;
2250 }
2251
2252 /* If the host is actually the local host, we may have a problem, or
2253 there may be some cunning configuration going on. In the problem case,
2254 log things and give up. The default transport status is already DEFER. */
2255
2256 if (rc == HOST_FOUND_LOCAL && !ob->allow_localhost)
2257 {
2258 for (addr = addrlist; addr != NULL; addr = addr->next)
2259 {
2260 addr->basic_errno = 0;
2261 addr->message = string_sprintf("%s transport found host %s to be "
2262 "local", tblock->name, host->name);
2263 }
2264 goto END_TRANSPORT;
2265 }
2266 } /* End of block for IP address lookup */
2267
2268 /* If this is a continued delivery, we are interested only in the host
2269 which matches the name of the existing open channel. The check is put
2270 here after the local host lookup, in case the name gets expanded as a
2271 result of the lookup. Set expired FALSE, to save the outer loop executing
2272 twice. */
2273
2274 if (continuing && (Ustrcmp(continue_hostname, host->name) != 0 ||
2275 Ustrcmp(continue_host_address, host->address) != 0))
2276 {
2277 expired = FALSE;
2278 continue; /* With next host */
2279 }
2280
2281 /* The default next host is the next host. :-) But this can vary if the
2282 hosts_max_try limit is hit (see below). NOTE: we cannot put this setting
2283 earlier than this, because a multihomed host whose addresses are not looked
2284 up till just above will add to the host list. */
2285
2286 nexthost = host->next;
2287
2288 /* If queue_smtp is set (-odqs or the first part of a 2-stage run), or the
2289 domain is in queue_smtp_domains, we don't actually want to attempt any
2290 deliveries. When doing a queue run, queue_smtp_domains is always unset. If
2291 there is a lookup defer in queue_smtp_domains, proceed as if the domain
2292 were not in it. We don't want to hold up all SMTP deliveries! Except when
2293 doing a two-stage queue run, don't do this if forcing. */
2294
2295 if ((!deliver_force || queue_2stage) && (queue_smtp ||
2296 match_isinlist(addrlist->domain, &queue_smtp_domains, 0, NULL, NULL,
2297 MCL_DOMAIN, TRUE, NULL) == OK))
2298 {
2299 expired = FALSE;
2300 for (addr = addrlist; addr != NULL; addr = addr->next)
2301 {
2302 if (addr->transport_return != DEFER) continue;
2303 addr->message = US"domain matches queue_smtp_domains, or -odqs set";
2304 }
2305 continue; /* With next host */
2306 }
2307
2308 /* Count hosts being considered - purely for an intelligent comment
2309 if none are usable. */
2310
2311 hosts_total++;
2312
2313 /* Set $host and $host address now in case they are needed for the
2314 interface expansion or the serialize_hosts check; they remain set if an
2315 actual delivery happens. */
2316
2317 deliver_host = host->name;
2318 deliver_host_address = host->address;
2319
2320 /* Select IPv4 or IPv6, and choose an outgoing interface. If the interface
2321 string changes upon expansion, we must add it to the key that is used for
2322 retries, because connections to the same host from a different interface
2323 should be treated separately. */
2324
2325 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET : AF_INET6;
2326 if (!smtp_get_interface(ob->interface, host_af, addrlist, &ifchanges,
2327 &interface, tid))
2328 return FALSE;
2329 if (ifchanges) pistring = string_sprintf("%s/%s", pistring, interface);
2330
2331 /* The first time round the outer loop, check the status of the host by
2332 inspecting the retry data. The second time round, we are interested only
2333 in expired hosts that haven't been tried since this message arrived. */
2334
2335 if (cutoff_retry == 0)
2336 {
2337 /* Ensure the status of the address is set by checking retry data if
2338 necessary. There maybe host-specific retry data (applicable to all
2339 messages) and also data for retries of a specific message at this host.
2340 If either of these retry records are actually read, the keys used are
2341 returned to save recomputing them later. */
2342
2343 host_is_expired = retry_check_address(addrlist->domain, host, pistring,
2344 ob->retry_include_ip_address, &retry_host_key, &retry_message_key);
2345
2346 DEBUG(D_transport) debug_printf("%s [%s]%s status = %s\n", host->name,
2347 (host->address == NULL)? US"" : host->address, pistring,
2348 (host->status == hstatus_usable)? "usable" :
2349 (host->status == hstatus_unusable)? "unusable" :
2350 (host->status == hstatus_unusable_expired)? "unusable (expired)" : "?");
2351
2352 /* Skip this address if not usable at this time, noting if it wasn't
2353 actually expired, both locally and in the address. */
2354
2355 switch (host->status)
2356 {
2357 case hstatus_unusable:
2358 expired = FALSE;
2359 setflag(addrlist, af_retry_skipped);
2360 /* Fall through */
2361
2362 case hstatus_unusable_expired:
2363 switch (host->why)
2364 {
2365 case hwhy_retry: hosts_retry++; break;
2366 case hwhy_failed: hosts_fail++; break;
2367 case hwhy_deferred: hosts_defer++; break;
2368 }
2369
2370 /* If there was a retry message key, implying that previously there
2371 was a message-specific defer, we don't want to update the list of
2372 messages waiting for this host. */
2373
2374 if (retry_message_key != NULL) host->update_waiting = FALSE;
2375 continue; /* With the next host or IP address */
2376 }
2377 }
2378
2379 /* Second time round the loop: if the address is set but expired, and
2380 the message is newer than the last try, let it through. */
2381
2382 else
2383 {
2384 if (host->address == NULL ||
2385 host->status != hstatus_unusable_expired ||
2386 host->last_try > received_time)
2387 continue;
2388 DEBUG(D_transport)
2389 debug_printf("trying expired host %s [%s]%s\n",
2390 host->name, host->address, pistring);
2391 host_is_expired = TRUE;
2392 }
2393
2394 /* Setting "expired=FALSE" doesn't actually mean not all hosts are expired;
2395 it remains TRUE only if all hosts are expired and none are actually tried.
2396 */
2397
2398 expired = FALSE;
2399
2400 /* If this host is listed as one to which access must be serialized,
2401 see if another Exim process has a connection to it, and if so, skip
2402 this host. If not, update the database to record our connection to it
2403 and remember this for later deletion. Do not do any of this if we are
2404 sending the message down a pre-existing connection. */
2405
2406 if (!continuing &&
2407 verify_check_this_host(&(ob->serialize_hosts), NULL, host->name,
2408 host->address, NULL) == OK)
2409 {
2410 serialize_key = string_sprintf("host-serialize-%s", host->name);
2411 if (!enq_start(serialize_key))
2412 {
2413 DEBUG(D_transport)
2414 debug_printf("skipping host %s because another Exim process "
2415 "is connected to it\n", host->name);
2416 hosts_serial++;
2417 continue;
2418 }
2419 serialized = TRUE;
2420 }
2421
2422 /* OK, we have an IP address that is not waiting for its retry time to
2423 arrive (it might be expired) OR (second time round the loop) we have an
2424 expired host that hasn't been tried since the message arrived. Have a go
2425 at delivering the message to it. First prepare the addresses by flushing
2426 out the result of previous attempts, and finding the first address that
2427 is still to be delivered. */
2428
2429 first_addr = prepare_addresses(addrlist, host);
2430
2431 DEBUG(D_transport) debug_printf("delivering %s to %s [%s] (%s%s)\n",
2432 message_id, host->name, host->address, addrlist->address,
2433 (addrlist->next == NULL)? "" : ", ...");
2434
2435 set_process_info("delivering %s to %s [%s] (%s%s)",
2436 message_id, host->name, host->address, addrlist->address,
2437 (addrlist->next == NULL)? "" : ", ...");
2438
2439 /* This is not for real; don't do the delivery. If there are
2440 any remaining hosts, list them. */
2441
2442 if (dont_deliver)
2443 {
2444 host_item *host2;
2445 set_errno(addrlist, 0, NULL, OK);
2446 for (addr = addrlist; addr != NULL; addr = addr->next)
2447 {
2448 addr->host_used = host;
2449 addr->special_action = '*';
2450 addr->message = US"delivery bypassed by -N option";
2451 }
2452 DEBUG(D_transport)
2453 {
2454 debug_printf("*** delivery by %s transport bypassed by -N option\n"
2455 "*** host and remaining hosts:\n", tblock->name);
2456 for (host2 = host; host2 != NULL; host2 = host2->next)
2457 debug_printf(" %s [%s]\n", host2->name,
2458 (host2->address == NULL)? US"unset" : host2->address);
2459 }
2460 rc = OK;
2461 }
2462
2463 /* This is for real. If the host is expired, we don't count it for
2464 hosts_max_retry. This ensures that all hosts must expire before an address
2465 is timed out, unless hosts_max_try_hardlimit (which protects against
2466 lunatic DNS configurations) is reached.
2467
2468 If the host is not expired and we are about to hit the hosts_max_retry
2469 limit, check to see if there is a subsequent hosts with a different MX
2470 value. If so, make that the next host, and don't count this one. This is a
2471 heuristic to make sure that different MXs do get tried. With a normal kind
2472 of retry rule, they would get tried anyway when the earlier hosts were
2473 delayed, but if the domain has a "retry every time" type of rule - as is
2474 often used for the the very large ISPs, that won't happen. */
2475
2476 else
2477 {
2478 if (!host_is_expired && ++unexpired_hosts_tried >= ob->hosts_max_try)
2479 {
2480 host_item *h;
2481 DEBUG(D_transport)
2482 debug_printf("hosts_max_try limit reached with this host\n");
2483 for (h = host; h != NULL; h = h->next)
2484 if (h->mx != host->mx) break;
2485 if (h != NULL)
2486 {
2487 nexthost = h;
2488 unexpired_hosts_tried--;
2489 DEBUG(D_transport) debug_printf("however, a higher MX host exists "
2490 "and will be tried\n");
2491 }
2492 }
2493
2494 /* Attempt the delivery. */
2495
2496 total_hosts_tried++;
2497 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2498 expanded_hosts != NULL, &message_defer, FALSE);
2499
2500 /* Yield is one of:
2501 OK => connection made, each address contains its result;
2502 message_defer is set for message-specific defers (when all
2503 recipients are marked defer)
2504 DEFER => there was a non-message-specific delivery problem;
2505 ERROR => there was a problem setting up the arguments for a filter,
2506 or there was a problem with expanding added headers
2507 */
2508
2509 /* If the result is not OK, there was a non-message-specific problem.
2510 If the result is DEFER, we need to write to the logs saying what happened
2511 for this particular host, except in the case of authentication and TLS
2512 failures, where the log has already been written. If all hosts defer a
2513 general message is written at the end. */
2514
2515 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL &&
2516 first_addr->basic_errno != ERRNO_TLSFAILURE)
2517 write_logs(first_addr, host);
2518
2519 /* If STARTTLS was accepted, but there was a failure in setting up the
2520 TLS session (usually a certificate screwup), and the host is not in
2521 hosts_require_tls, and tls_tempfail_tryclear is true, try again, with
2522 TLS forcibly turned off. We have to start from scratch with a new SMTP
2523 connection. That's why the retry is done from here, not from within
2524 smtp_deliver(). [Rejections of STARTTLS itself don't screw up the
2525 session, so the in-clear transmission after those errors, if permitted,
2526 happens inside smtp_deliver().] */
2527
2528 #ifdef SUPPORT_TLS
2529 if (rc == DEFER && first_addr->basic_errno == ERRNO_TLSFAILURE &&
2530 ob->tls_tempfail_tryclear &&
2531 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
2532 host->address, NULL) != OK)
2533 {
2534 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
2535 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
2536 first_addr = prepare_addresses(addrlist, host);
2537 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2538 expanded_hosts != NULL, &message_defer, TRUE);
2539 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL)
2540 write_logs(first_addr, host);
2541 }
2542 #endif
2543 }
2544
2545 /* Delivery attempt finished */
2546
2547 rs = (rc == OK)? US"OK" : (rc == DEFER)? US"DEFER" : (rc == ERROR)?
2548 US"ERROR" : US"?";
2549
2550 set_process_info("delivering %s: just tried %s [%s] for %s%s: result %s",
2551 message_id, host->name, host->address, addrlist->address,
2552 (addrlist->next == NULL)? "" : " (& others)", rs);
2553
2554 /* Release serialization if set up */
2555
2556 if (serialized) enq_end(serialize_key);
2557
2558 /* If the result is DEFER, or if a host retry record is known to exist, we
2559 need to add an item to the retry chain for updating the retry database
2560 at the end of delivery. We only need to add the item to the top address,
2561 of course. Also, if DEFER, we mark the IP address unusable so as to skip it
2562 for any other delivery attempts using the same address. (It is copied into
2563 the unusable tree at the outer level, so even if different address blocks
2564 contain the same address, it still won't get tried again.) */
2565
2566 if (rc == DEFER || retry_host_key != NULL)
2567 {
2568 int delete_flag = (rc != DEFER)? rf_delete : 0;
2569 if (retry_host_key == NULL)
2570 {
2571 retry_host_key = ob->retry_include_ip_address?
2572 string_sprintf("T:%S:%s%s", host->name, host->address, pistring) :
2573 string_sprintf("T:%S%s", host->name, pistring);
2574 }
2575
2576 /* If a delivery of another message over an existing SMTP connection
2577 yields DEFER, we do NOT set up retry data for the host. This covers the
2578 case when there are delays in routing the addresses in the second message
2579 that are so long that the server times out. This is alleviated by not
2580 routing addresses that previously had routing defers when handling an
2581 existing connection, but even so, this case may occur (e.g. if a
2582 previously happily routed address starts giving routing defers). If the
2583 host is genuinely down, another non-continued message delivery will
2584 notice it soon enough. */
2585
2586 if (delete_flag != 0 || !continuing)
2587 retry_add_item(first_addr, retry_host_key, rf_host | delete_flag);
2588
2589 /* We may have tried an expired host, if its retry time has come; ensure
2590 the status reflects the expiry for the benefit of any other addresses. */
2591
2592 if (rc == DEFER)
2593 {
2594 host->status = (host_is_expired)?
2595 hstatus_unusable_expired : hstatus_unusable;
2596 host->why = hwhy_deferred;
2597 }
2598 }
2599
2600 /* If message_defer is set (host was OK, but every recipient got deferred
2601 because of some message-specific problem), or if that had happened
2602 previously so that a message retry key exists, add an appropriate item
2603 to the retry chain. Note that if there was a message defer but now there is
2604 a host defer, the message defer record gets deleted. That seems perfectly
2605 reasonable. Also, stop the message from being remembered as waiting
2606 for this host. */
2607
2608 if (message_defer || retry_message_key != NULL)
2609 {
2610 int delete_flag = message_defer? 0 : rf_delete;
2611 if (retry_message_key == NULL)
2612 {
2613 retry_message_key = ob->retry_include_ip_address?
2614 string_sprintf("T:%S:%s%s:%s", host->name, host->address, pistring,
2615 message_id) :
2616 string_sprintf("T:%S%s:%s", host->name, pistring, message_id);
2617 }
2618 retry_add_item(addrlist, retry_message_key,
2619 rf_message | rf_host | delete_flag);
2620 host->update_waiting = FALSE;
2621 }
2622
2623 /* Any return other than DEFER (that is, OK or ERROR) means that the
2624 addresses have got their final statuses filled in for this host. In the OK
2625 case, see if any of them are deferred. */
2626
2627 if (rc == OK)
2628 {
2629 for (addr = addrlist; addr != NULL; addr = addr->next)
2630 {
2631 if (addr->transport_return == DEFER)
2632 {
2633 some_deferred = TRUE;
2634 break;
2635 }
2636 }
2637 }
2638
2639 /* If no addresses deferred or the result was ERROR, return. We do this for
2640 ERROR because a failing filter set-up or add_headers expansion is likely to
2641 fail for any host we try. */
2642
2643 if (rc == ERROR || (rc == OK && !some_deferred))
2644 {
2645 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2646 return TRUE; /* Each address has its status */
2647 }
2648
2649 /* If the result was DEFER or some individual addresses deferred, let
2650 the loop run to try other hosts with the deferred addresses, except for the
2651 case when we were trying to deliver down an existing channel and failed.
2652 Don't try any other hosts in this case. */
2653
2654 if (continuing) break;
2655
2656 /* If the whole delivery, or some individual addresses, were deferred and
2657 there are more hosts that could be tried, do not count this host towards
2658 the hosts_max_try limit if the age of the message is greater than the
2659 maximum retry time for this host. This means we may try try all hosts,
2660 ignoring the limit, when messages have been around for some time. This is
2661 important because if we don't try all hosts, the address will never time
2662 out. NOTE: this does not apply to hosts_max_try_hardlimit. */
2663
2664 if ((rc == DEFER || some_deferred) && nexthost != NULL)
2665 {
2666 BOOL timedout;
2667 retry_config *retry = retry_find_config(host->name, NULL, 0, 0);
2668
2669 if (retry != NULL && retry->rules != NULL)
2670 {
2671 retry_rule *last_rule;
2672 for (last_rule = retry->rules;
2673 last_rule->next != NULL;
2674 last_rule = last_rule->next);
2675 timedout = time(NULL) - received_time > last_rule->timeout;
2676 }
2677 else timedout = TRUE; /* No rule => timed out */
2678
2679 if (timedout)
2680 {
2681 unexpired_hosts_tried--;
2682 DEBUG(D_transport) debug_printf("temporary delivery error(s) override "
2683 "hosts_max_try (message older than host's retry time)\n");
2684 }
2685 }
2686 } /* End of loop for trying multiple hosts. */
2687
2688 /* This is the end of the loop that repeats iff expired is TRUE and
2689 ob->delay_after_cutoff is FALSE. The second time round we will
2690 try those hosts that haven't been tried since the message arrived. */
2691
2692 DEBUG(D_transport)
2693 {
2694 debug_printf("all IP addresses skipped or deferred at least one address\n");
2695 if (expired && !ob->delay_after_cutoff && cutoff_retry == 0)
2696 debug_printf("retrying IP addresses not tried since message arrived\n");
2697 }
2698 }
2699
2700
2701 /* Get here if all IP addresses are skipped or defer at least one address. In
2702 MUA wrapper mode, this will happen only for connection or other non-message-
2703 specific failures. Force the delivery status for all addresses to FAIL. */
2704
2705 if (mua_wrapper)
2706 {
2707 for (addr = addrlist; addr != NULL; addr = addr->next)
2708 addr->transport_return = FAIL;
2709 goto END_TRANSPORT;
2710 }
2711
2712 /* In the normal, non-wrapper case, add a standard message to each deferred
2713 address if there hasn't been an error, that is, if it hasn't actually been
2714 tried this time. The variable "expired" will be FALSE if any deliveries were
2715 actually tried, or if there was at least one host that was not expired. That
2716 is, it is TRUE only if no deliveries were tried and all hosts were expired. If
2717 a delivery has been tried, an error code will be set, and the failing of the
2718 message is handled by the retry code later.
2719
2720 If queue_smtp is set, or this transport was called to send a subsequent message
2721 down an existing TCP/IP connection, and something caused the host not to be
2722 found, we end up here, but can detect these cases and handle them specially. */
2723
2724 for (addr = addrlist; addr != NULL; addr = addr->next)
2725 {
2726 /* If host is not NULL, it means that we stopped processing the host list
2727 because of hosts_max_try or hosts_max_try_hardlimit. In the former case, this
2728 means we need to behave as if some hosts were skipped because their retry
2729 time had not come. Specifically, this prevents the address from timing out.
2730 However, if we have hit hosts_max_try_hardlimit, we want to behave as if all
2731 hosts were tried. */
2732
2733 if (host != NULL)
2734 {
2735 if (total_hosts_tried >= ob->hosts_max_try_hardlimit)
2736 {
2737 DEBUG(D_transport)
2738 debug_printf("hosts_max_try_hardlimit reached: behave as if all "
2739 "hosts were tried\n");
2740 }
2741 else
2742 {
2743 DEBUG(D_transport)
2744 debug_printf("hosts_max_try limit caused some hosts to be skipped\n");
2745 setflag(addr, af_retry_skipped);
2746 }
2747 }
2748
2749 if (queue_smtp) /* no deliveries attempted */
2750 {
2751 addr->transport_return = DEFER;
2752 addr->basic_errno = 0;
2753 addr->message = US"SMTP delivery explicitly queued";
2754 }
2755
2756 else if (addr->transport_return == DEFER &&
2757 (addr->basic_errno == ERRNO_UNKNOWNERROR || addr->basic_errno == 0) &&
2758 addr->message == NULL)
2759 {
2760 addr->basic_errno = ERRNO_HRETRY;
2761 if (continue_hostname != NULL)
2762 {
2763 addr->message = US"no host found for existing SMTP connection";
2764 }
2765 else if (expired)
2766 {
2767 addr->message = (ob->delay_after_cutoff)?
2768 US"retry time not reached for any host after a long failure period" :
2769 US"all hosts have been failing for a long time and were last tried "
2770 "after this message arrived";
2771
2772 /* If we are already using fallback hosts, or there are no fallback hosts
2773 defined, convert the result to FAIL to cause a bounce. */
2774
2775 if (addr->host_list == addr->fallback_hosts ||
2776 addr->fallback_hosts == NULL)
2777 addr->transport_return = FAIL;
2778 }
2779 else
2780 {
2781 if (hosts_retry == hosts_total)
2782 addr->message = US"retry time not reached for any host";
2783 else if (hosts_fail == hosts_total)
2784 addr->message = US"all host address lookups failed permanently";
2785 else if (hosts_defer == hosts_total)
2786 addr->message = US"all host address lookups failed temporarily";
2787 else if (hosts_serial == hosts_total)
2788 addr->message = US"connection limit reached for all hosts";
2789 else if (hosts_fail+hosts_defer == hosts_total)
2790 addr->message = US"all host address lookups failed";
2791 else addr->message = US"some host address lookups failed and retry time "
2792 "not reached for other hosts or connection limit reached";
2793 }
2794 }
2795 }
2796
2797 /* Update the database which keeps information about which messages are waiting
2798 for which hosts to become available. Each host in the list has a flag which is
2799 set if the data is to be updated. For some message-specific errors, the flag is
2800 turned off because we don't want follow-on deliveries in those cases. */
2801
2802 transport_update_waiting(hostlist, tblock->name);
2803
2804 END_TRANSPORT:
2805
2806 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2807
2808 return TRUE; /* Each address has its status */
2809 }
2810
2811 /* End of transport/smtp.c */