41796a4d9d5d9d869a23748ea81afc189ac416cd
[exim.git] / src / src / transports / smtp.c
1 /* $Cambridge: exim/src/src/transports/smtp.c,v 1.44 2009/11/16 19:56:54 nm4 Exp $ */
2
3 /*************************************************
4 * Exim - an Internet mail transport agent *
5 *************************************************/
6
7 /* Copyright (c) University of Cambridge 1995 - 2009 */
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 { "address_retry_include_sender", opt_bool,
25 (void *)offsetof(smtp_transport_options_block, address_retry_include_sender) },
26 { "allow_localhost", opt_bool,
27 (void *)offsetof(smtp_transport_options_block, allow_localhost) },
28 { "authenticated_sender", opt_stringptr,
29 (void *)offsetof(smtp_transport_options_block, authenticated_sender) },
30 { "authenticated_sender_force", opt_bool,
31 (void *)offsetof(smtp_transport_options_block, authenticated_sender_force) },
32 { "command_timeout", opt_time,
33 (void *)offsetof(smtp_transport_options_block, command_timeout) },
34 { "connect_timeout", opt_time,
35 (void *)offsetof(smtp_transport_options_block, connect_timeout) },
36 { "connection_max_messages", opt_int | opt_public,
37 (void *)offsetof(transport_instance, connection_max_messages) },
38 { "data_timeout", opt_time,
39 (void *)offsetof(smtp_transport_options_block, data_timeout) },
40 { "delay_after_cutoff", opt_bool,
41 (void *)offsetof(smtp_transport_options_block, delay_after_cutoff) },
42 #ifndef DISABLE_DKIM
43 { "dkim_canon", opt_stringptr,
44 (void *)offsetof(smtp_transport_options_block, dkim_canon) },
45 { "dkim_domain", opt_stringptr,
46 (void *)offsetof(smtp_transport_options_block, dkim_domain) },
47 { "dkim_private_key", opt_stringptr,
48 (void *)offsetof(smtp_transport_options_block, dkim_private_key) },
49 { "dkim_selector", opt_stringptr,
50 (void *)offsetof(smtp_transport_options_block, dkim_selector) },
51 { "dkim_sign_headers", opt_stringptr,
52 (void *)offsetof(smtp_transport_options_block, dkim_sign_headers) },
53 { "dkim_strict", opt_stringptr,
54 (void *)offsetof(smtp_transport_options_block, dkim_strict) },
55 #endif
56 { "dns_qualify_single", opt_bool,
57 (void *)offsetof(smtp_transport_options_block, dns_qualify_single) },
58 { "dns_search_parents", opt_bool,
59 (void *)offsetof(smtp_transport_options_block, dns_search_parents) },
60 { "fallback_hosts", opt_stringptr,
61 (void *)offsetof(smtp_transport_options_block, fallback_hosts) },
62 { "final_timeout", opt_time,
63 (void *)offsetof(smtp_transport_options_block, final_timeout) },
64 { "gethostbyname", opt_bool,
65 (void *)offsetof(smtp_transport_options_block, gethostbyname) },
66 #ifdef SUPPORT_TLS
67 { "gnutls_require_kx", opt_stringptr,
68 (void *)offsetof(smtp_transport_options_block, gnutls_require_kx) },
69 { "gnutls_require_mac", opt_stringptr,
70 (void *)offsetof(smtp_transport_options_block, gnutls_require_mac) },
71 { "gnutls_require_protocols", opt_stringptr,
72 (void *)offsetof(smtp_transport_options_block, gnutls_require_proto) },
73 #endif
74 { "helo_data", opt_stringptr,
75 (void *)offsetof(smtp_transport_options_block, helo_data) },
76 { "hosts", opt_stringptr,
77 (void *)offsetof(smtp_transport_options_block, hosts) },
78 { "hosts_avoid_esmtp", opt_stringptr,
79 (void *)offsetof(smtp_transport_options_block, hosts_avoid_esmtp) },
80 { "hosts_avoid_pipelining", opt_stringptr,
81 (void *)offsetof(smtp_transport_options_block, hosts_avoid_pipelining) },
82 #ifdef SUPPORT_TLS
83 { "hosts_avoid_tls", opt_stringptr,
84 (void *)offsetof(smtp_transport_options_block, hosts_avoid_tls) },
85 #endif
86 { "hosts_max_try", opt_int,
87 (void *)offsetof(smtp_transport_options_block, hosts_max_try) },
88 { "hosts_max_try_hardlimit", opt_int,
89 (void *)offsetof(smtp_transport_options_block, hosts_max_try_hardlimit) },
90 #ifdef SUPPORT_TLS
91 { "hosts_nopass_tls", opt_stringptr,
92 (void *)offsetof(smtp_transport_options_block, hosts_nopass_tls) },
93 #endif
94 { "hosts_override", opt_bool,
95 (void *)offsetof(smtp_transport_options_block, hosts_override) },
96 { "hosts_randomize", opt_bool,
97 (void *)offsetof(smtp_transport_options_block, hosts_randomize) },
98 { "hosts_require_auth", opt_stringptr,
99 (void *)offsetof(smtp_transport_options_block, hosts_require_auth) },
100 #ifdef SUPPORT_TLS
101 { "hosts_require_tls", opt_stringptr,
102 (void *)offsetof(smtp_transport_options_block, hosts_require_tls) },
103 #endif
104 { "hosts_try_auth", opt_stringptr,
105 (void *)offsetof(smtp_transport_options_block, hosts_try_auth) },
106 { "interface", opt_stringptr,
107 (void *)offsetof(smtp_transport_options_block, interface) },
108 { "keepalive", opt_bool,
109 (void *)offsetof(smtp_transport_options_block, keepalive) },
110 { "lmtp_ignore_quota", opt_bool,
111 (void *)offsetof(smtp_transport_options_block, lmtp_ignore_quota) },
112 { "max_rcpt", opt_int | opt_public,
113 (void *)offsetof(transport_instance, max_addresses) },
114 { "multi_domain", opt_bool | opt_public,
115 (void *)offsetof(transport_instance, multi_domain) },
116 { "port", opt_stringptr,
117 (void *)offsetof(smtp_transport_options_block, port) },
118 { "protocol", opt_stringptr,
119 (void *)offsetof(smtp_transport_options_block, protocol) },
120 { "retry_include_ip_address", opt_bool,
121 (void *)offsetof(smtp_transport_options_block, retry_include_ip_address) },
122 { "serialize_hosts", opt_stringptr,
123 (void *)offsetof(smtp_transport_options_block, serialize_hosts) },
124 { "size_addition", opt_int,
125 (void *)offsetof(smtp_transport_options_block, size_addition) }
126 #ifdef SUPPORT_TLS
127 ,{ "tls_certificate", opt_stringptr,
128 (void *)offsetof(smtp_transport_options_block, tls_certificate) },
129 { "tls_crl", opt_stringptr,
130 (void *)offsetof(smtp_transport_options_block, tls_crl) },
131 { "tls_privatekey", opt_stringptr,
132 (void *)offsetof(smtp_transport_options_block, tls_privatekey) },
133 { "tls_require_ciphers", opt_stringptr,
134 (void *)offsetof(smtp_transport_options_block, tls_require_ciphers) },
135 { "tls_tempfail_tryclear", opt_bool,
136 (void *)offsetof(smtp_transport_options_block, tls_tempfail_tryclear) },
137 { "tls_verify_certificates", opt_stringptr,
138 (void *)offsetof(smtp_transport_options_block, tls_verify_certificates) }
139 #endif
140 };
141
142 /* Size of the options list. An extern variable has to be used so that its
143 address can appear in the tables drtables.c. */
144
145 int smtp_transport_options_count =
146 sizeof(smtp_transport_options)/sizeof(optionlist);
147
148 /* Default private options block for the smtp transport. */
149
150 smtp_transport_options_block smtp_transport_option_defaults = {
151 NULL, /* hosts */
152 NULL, /* fallback_hosts */
153 NULL, /* hostlist */
154 NULL, /* fallback_hostlist */
155 NULL, /* authenticated_sender */
156 US"$primary_hostname", /* helo_data */
157 NULL, /* interface */
158 NULL, /* port */
159 US"smtp", /* protocol */
160 NULL, /* serialize_hosts */
161 NULL, /* hosts_try_auth */
162 NULL, /* hosts_require_auth */
163 NULL, /* hosts_require_tls */
164 NULL, /* hosts_avoid_tls */
165 NULL, /* hosts_avoid_pipelining */
166 NULL, /* hosts_avoid_esmtp */
167 NULL, /* hosts_nopass_tls */
168 5*60, /* command_timeout */
169 5*60, /* connect_timeout; shorter system default overrides */
170 5*60, /* data timeout */
171 10*60, /* final timeout */
172 1024, /* size_addition */
173 5, /* hosts_max_try */
174 50, /* hosts_max_try_hardlimit */
175 TRUE, /* address_retry_include_sender */
176 FALSE, /* allow_localhost */
177 FALSE, /* authenticated_sender_force */
178 FALSE, /* gethostbyname */
179 TRUE, /* dns_qualify_single */
180 FALSE, /* dns_search_parents */
181 TRUE, /* delay_after_cutoff */
182 FALSE, /* hosts_override */
183 FALSE, /* hosts_randomize */
184 TRUE, /* keepalive */
185 FALSE, /* lmtp_ignore_quota */
186 TRUE /* retry_include_ip_address */
187 #ifdef SUPPORT_TLS
188 ,NULL, /* tls_certificate */
189 NULL, /* tls_crl */
190 NULL, /* tls_privatekey */
191 NULL, /* tls_require_ciphers */
192 NULL, /* gnutls_require_kx */
193 NULL, /* gnutls_require_mac */
194 NULL, /* gnutls_require_proto */
195 NULL, /* tls_verify_certificates */
196 TRUE /* tls_tempfail_tryclear */
197 #endif
198 #ifndef DISABLE_DKIM
199 ,NULL, /* dkim_canon */
200 NULL, /* dkim_domain */
201 NULL, /* dkim_private_key */
202 NULL, /* dkim_selector */
203 NULL, /* dkim_sign_headers */
204 NULL /* dkim_strict */
205 #endif
206 };
207
208
209 /* Local statics */
210
211 static uschar *smtp_command; /* Points to last cmd for error messages */
212 static uschar *mail_command; /* Points to MAIL cmd for error messages */
213 static BOOL update_waiting; /* TRUE to update the "wait" database */
214
215
216 /*************************************************
217 * Setup entry point *
218 *************************************************/
219
220 /* This function is called when the transport is about to be used,
221 but before running it in a sub-process. It is used for two things:
222
223 (1) To set the fallback host list in addresses, when delivering.
224 (2) To pass back the interface, port, protocol, and other options, for use
225 during callout verification.
226
227 Arguments:
228 tblock pointer to the transport instance block
229 addrlist list of addresses about to be transported
230 tf if not NULL, pointer to block in which to return options
231 uid the uid that will be set (not used)
232 gid the gid that will be set (not used)
233 errmsg place for error message (not used)
234
235 Returns: OK always (FAIL, DEFER not used)
236 */
237
238 static int
239 smtp_transport_setup(transport_instance *tblock, address_item *addrlist,
240 transport_feedback *tf, uid_t uid, gid_t gid, uschar **errmsg)
241 {
242 smtp_transport_options_block *ob =
243 (smtp_transport_options_block *)(tblock->options_block);
244
245 errmsg = errmsg; /* Keep picky compilers happy */
246 uid = uid;
247 gid = gid;
248
249 /* Pass back options if required. This interface is getting very messy. */
250
251 if (tf != NULL)
252 {
253 tf->interface = ob->interface;
254 tf->port = ob->port;
255 tf->protocol = ob->protocol;
256 tf->hosts = ob->hosts;
257 tf->hosts_override = ob->hosts_override;
258 tf->hosts_randomize = ob->hosts_randomize;
259 tf->gethostbyname = ob->gethostbyname;
260 tf->qualify_single = ob->dns_qualify_single;
261 tf->search_parents = ob->dns_search_parents;
262 tf->helo_data = ob->helo_data;
263 }
264
265 /* Set the fallback host list for all the addresses that don't have fallback
266 host lists, provided that the local host wasn't present in the original host
267 list. */
268
269 if (!testflag(addrlist, af_local_host_removed))
270 {
271 for (; addrlist != NULL; addrlist = addrlist->next)
272 if (addrlist->fallback_hosts == NULL)
273 addrlist->fallback_hosts = ob->fallback_hostlist;
274 }
275
276 return OK;
277 }
278
279
280
281 /*************************************************
282 * Initialization entry point *
283 *************************************************/
284
285 /* Called for each instance, after its options have been read, to
286 enable consistency checks to be done, or anything else that needs
287 to be set up.
288
289 Argument: pointer to the transport instance block
290 Returns: nothing
291 */
292
293 void
294 smtp_transport_init(transport_instance *tblock)
295 {
296 smtp_transport_options_block *ob =
297 (smtp_transport_options_block *)(tblock->options_block);
298
299 /* Retry_use_local_part defaults FALSE if unset */
300
301 if (tblock->retry_use_local_part == TRUE_UNSET)
302 tblock->retry_use_local_part = FALSE;
303
304 /* Set the default port according to the protocol */
305
306 if (ob->port == NULL)
307 ob->port = (strcmpic(ob->protocol, US"lmtp") == 0)? US"lmtp" : US"smtp";
308
309 /* Set up the setup entry point, to be called before subprocesses for this
310 transport. */
311
312 tblock->setup = smtp_transport_setup;
313
314 /* Complain if any of the timeouts are zero. */
315
316 if (ob->command_timeout <= 0 || ob->data_timeout <= 0 ||
317 ob->final_timeout <= 0)
318 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
319 "command, data, or final timeout value is zero for %s transport",
320 tblock->name);
321
322 /* If hosts_override is set and there are local hosts, set the global
323 flag that stops verify from showing router hosts. */
324
325 if (ob->hosts_override && ob->hosts != NULL) tblock->overrides_hosts = TRUE;
326
327 /* If there are any fallback hosts listed, build a chain of host items
328 for them, but do not do any lookups at this time. */
329
330 host_build_hostlist(&(ob->fallback_hostlist), ob->fallback_hosts, FALSE);
331 }
332
333
334
335
336
337 /*************************************************
338 * Set delivery info into all active addresses *
339 *************************************************/
340
341 /* Only addresses whose status is >= PENDING are relevant. A lesser
342 status means that an address is not currently being processed.
343
344 Arguments:
345 addrlist points to a chain of addresses
346 errno_value to put in each address's errno field
347 msg to put in each address's message field
348 rc to put in each address's transport_return field
349 pass_message if TRUE, set the "pass message" flag in the address
350
351 If errno_value has the special value ERRNO_CONNECTTIMEOUT, ETIMEDOUT is put in
352 the errno field, and RTEF_CTOUT is ORed into the more_errno field, to indicate
353 this particular type of timeout.
354
355 Returns: nothing
356 */
357
358 static void
359 set_errno(address_item *addrlist, int errno_value, uschar *msg, int rc,
360 BOOL pass_message)
361 {
362 address_item *addr;
363 int orvalue = 0;
364 if (errno_value == ERRNO_CONNECTTIMEOUT)
365 {
366 errno_value = ETIMEDOUT;
367 orvalue = RTEF_CTOUT;
368 }
369 for (addr = addrlist; addr != NULL; addr = addr->next)
370 {
371 if (addr->transport_return < PENDING) continue;
372 addr->basic_errno = errno_value;
373 addr->more_errno |= orvalue;
374 if (msg != NULL)
375 {
376 addr->message = msg;
377 if (pass_message) setflag(addr, af_pass_message);
378 }
379 addr->transport_return = rc;
380 }
381 }
382
383
384
385 /*************************************************
386 * Check an SMTP response *
387 *************************************************/
388
389 /* This function is given an errno code and the SMTP response buffer
390 to analyse, together with the host identification for generating messages. It
391 sets an appropriate message and puts the first digit of the response code into
392 the yield variable. If no response was actually read, a suitable digit is
393 chosen.
394
395 Arguments:
396 host the current host, to get its name for messages
397 errno_value pointer to the errno value
398 more_errno from the top address for use with ERRNO_FILTER_FAIL
399 buffer the SMTP response buffer
400 yield where to put a one-digit SMTP response code
401 message where to put an errror message
402 pass_message set TRUE if message is an SMTP response
403
404 Returns: TRUE if an SMTP "QUIT" command should be sent, else FALSE
405 */
406
407 static BOOL check_response(host_item *host, int *errno_value, int more_errno,
408 uschar *buffer, int *yield, uschar **message, BOOL *pass_message)
409 {
410 uschar *pl = US"";
411
412 if (smtp_use_pipelining &&
413 (Ustrcmp(smtp_command, "MAIL") == 0 ||
414 Ustrcmp(smtp_command, "RCPT") == 0 ||
415 Ustrcmp(smtp_command, "DATA") == 0))
416 pl = US"pipelined ";
417
418 *yield = '4'; /* Default setting is to give a temporary error */
419
420 /* Handle response timeout */
421
422 if (*errno_value == ETIMEDOUT)
423 {
424 *message = US string_sprintf("SMTP timeout while connected to %s [%s] "
425 "after %s%s", host->name, host->address, pl, smtp_command);
426 if (transport_count > 0)
427 *message = US string_sprintf("%s (%d bytes written)", *message,
428 transport_count);
429 return FALSE;
430 }
431
432 /* Handle malformed SMTP response */
433
434 if (*errno_value == ERRNO_SMTPFORMAT)
435 {
436 uschar *malfresp = string_printing(buffer);
437 while (isspace(*malfresp)) malfresp++;
438 if (*malfresp == 0)
439 *message = string_sprintf("Malformed SMTP reply (an empty line) from "
440 "%s [%s] in response to %s%s", host->name, host->address, pl,
441 smtp_command);
442 else
443 *message = string_sprintf("Malformed SMTP reply from %s [%s] in response "
444 "to %s%s: %s", host->name, host->address, pl, smtp_command, malfresp);
445 return FALSE;
446 }
447
448 /* Handle a failed filter process error; can't send QUIT as we mustn't
449 end the DATA. */
450
451 if (*errno_value == ERRNO_FILTER_FAIL)
452 {
453 *message = US string_sprintf("transport filter process failed (%d)%s",
454 more_errno,
455 (more_errno == EX_EXECFAILED)? ": unable to execute command" : "");
456 return FALSE;
457 }
458
459 /* Handle a failed add_headers expansion; can't send QUIT as we mustn't
460 end the DATA. */
461
462 if (*errno_value == ERRNO_CHHEADER_FAIL)
463 {
464 *message =
465 US string_sprintf("failed to expand headers_add or headers_remove: %s",
466 expand_string_message);
467 return FALSE;
468 }
469
470 /* Handle failure to write a complete data block */
471
472 if (*errno_value == ERRNO_WRITEINCOMPLETE)
473 {
474 *message = US string_sprintf("failed to write a data block");
475 return FALSE;
476 }
477
478 /* Handle error responses from the remote mailer. */
479
480 if (buffer[0] != 0)
481 {
482 uschar *s = string_printing(buffer);
483 *message = US string_sprintf("SMTP error from remote mail server after %s%s: "
484 "host %s [%s]: %s", pl, smtp_command, host->name, host->address, s);
485 *pass_message = TRUE;
486 *yield = buffer[0];
487 return TRUE;
488 }
489
490 /* No data was read. If there is no errno, this must be the EOF (i.e.
491 connection closed) case, which causes deferral. An explicit connection reset
492 error has the same effect. Otherwise, put the host's identity in the message,
493 leaving the errno value to be interpreted as well. In all cases, we have to
494 assume the connection is now dead. */
495
496 if (*errno_value == 0 || *errno_value == ECONNRESET)
497 {
498 *errno_value = ERRNO_SMTPCLOSED;
499 *message = US string_sprintf("Remote host %s [%s] closed connection "
500 "in response to %s%s", host->name, host->address, pl, smtp_command);
501 }
502 else *message = US string_sprintf("%s [%s]", host->name, host->address);
503
504 return FALSE;
505 }
506
507
508
509 /*************************************************
510 * Write error message to logs *
511 *************************************************/
512
513 /* This writes to the main log and to the message log.
514
515 Arguments:
516 addr the address item containing error information
517 host the current host
518
519 Returns: nothing
520 */
521
522 static void
523 write_logs(address_item *addr, host_item *host)
524 {
525 if (addr->message != NULL)
526 {
527 uschar *message = addr->message;
528 if (addr->basic_errno > 0)
529 message = string_sprintf("%s: %s", message, strerror(addr->basic_errno));
530 log_write(0, LOG_MAIN, "%s", message);
531 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
532 }
533 else
534 {
535 uschar *msg =
536 ((log_extra_selector & LX_outgoing_port) != 0)?
537 string_sprintf("%s [%s]:%d", host->name, host->address,
538 (host->port == PORT_NONE)? 25 : host->port)
539 :
540 string_sprintf("%s [%s]", host->name, host->address);
541 log_write(0, LOG_MAIN, "%s %s", msg, strerror(addr->basic_errno));
542 deliver_msglog("%s %s %s\n", tod_stamp(tod_log), msg,
543 strerror(addr->basic_errno));
544 }
545 }
546
547
548
549 /*************************************************
550 * Synchronize SMTP responses *
551 *************************************************/
552
553 /* This function is called from smtp_deliver() to receive SMTP responses from
554 the server, and match them up with the commands to which they relate. When
555 PIPELINING is not in use, this function is called after every command, and is
556 therefore somewhat over-engineered, but it is simpler to use a single scheme
557 that works both with and without PIPELINING instead of having two separate sets
558 of code.
559
560 The set of commands that are buffered up with pipelining may start with MAIL
561 and may end with DATA; in between are RCPT commands that correspond to the
562 addresses whose status is PENDING_DEFER. All other commands (STARTTLS, AUTH,
563 etc.) are never buffered.
564
565 Errors after MAIL or DATA abort the whole process leaving the response in the
566 buffer. After MAIL, pending responses are flushed, and the original command is
567 re-instated in big_buffer for error messages. For RCPT commands, the remote is
568 permitted to reject some recipient addresses while accepting others. However
569 certain errors clearly abort the whole process. Set the value in
570 transport_return to PENDING_OK if the address is accepted. If there is a
571 subsequent general error, it will get reset accordingly. If not, it will get
572 converted to OK at the end.
573
574 Arguments:
575 addrlist the complete address list
576 include_affixes TRUE if affixes include in RCPT
577 sync_addr ptr to the ptr of the one to start scanning at (updated)
578 host the host we are connected to
579 count the number of responses to read
580 address_retry_
581 include_sender true if 4xx retry is to include the sender it its key
582 pending_MAIL true if the first response is for MAIL
583 pending_DATA 0 if last command sent was not DATA
584 +1 if previously had a good recipient
585 -1 if not previously had a good recipient
586 inblock incoming SMTP block
587 timeout timeout value
588 buffer buffer for reading response
589 buffsize size of buffer
590
591 Returns: 3 if at least one address had 2xx and one had 5xx
592 2 if at least one address had 5xx but none had 2xx
593 1 if at least one host had a 2xx response, but none had 5xx
594 0 no address had 2xx or 5xx but no errors (all 4xx, or just DATA)
595 -1 timeout while reading RCPT response
596 -2 I/O or other non-response error for RCPT
597 -3 DATA or MAIL failed - errno and buffer set
598 */
599
600 static int
601 sync_responses(address_item *addrlist, BOOL include_affixes,
602 address_item **sync_addr, host_item *host, int count,
603 BOOL address_retry_include_sender, BOOL pending_MAIL,
604 int pending_DATA, smtp_inblock *inblock, int timeout, uschar *buffer,
605 int buffsize)
606 {
607 address_item *addr = *sync_addr;
608 int yield = 0;
609
610 /* Handle the response for a MAIL command. On error, reinstate the original
611 command in big_buffer for error message use, and flush any further pending
612 responses before returning, except after I/O errors and timeouts. */
613
614 if (pending_MAIL)
615 {
616 count--;
617 if (!smtp_read_response(inblock, buffer, buffsize, '2', timeout))
618 {
619 Ustrcpy(big_buffer, mail_command); /* Fits, because it came from there! */
620 if (errno == 0 && buffer[0] != 0)
621 {
622 uschar flushbuffer[4096];
623 int save_errno = 0;
624 if (buffer[0] == '4')
625 {
626 save_errno = ERRNO_MAIL4XX;
627 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
628 }
629 while (count-- > 0)
630 {
631 if (!smtp_read_response(inblock, flushbuffer, sizeof(flushbuffer),
632 '2', timeout)
633 && (errno != 0 || flushbuffer[0] == 0))
634 break;
635 }
636 errno = save_errno;
637 }
638 return -3;
639 }
640 }
641
642 if (pending_DATA) count--; /* Number of RCPT responses to come */
643
644 /* Read and handle the required number of RCPT responses, matching each one up
645 with an address by scanning for the next address whose status is PENDING_DEFER.
646 */
647
648 while (count-- > 0)
649 {
650 while (addr->transport_return != PENDING_DEFER) addr = addr->next;
651
652 /* The address was accepted */
653
654 if (smtp_read_response(inblock, buffer, buffsize, '2', timeout))
655 {
656 yield |= 1;
657 addr->transport_return = PENDING_OK;
658
659 /* If af_dr_retry_exists is set, there was a routing delay on this address;
660 ensure that any address-specific retry record is expunged. We do this both
661 for the basic key and for the version that also includes the sender. */
662
663 if (testflag(addr, af_dr_retry_exists))
664 {
665 uschar *altkey = string_sprintf("%s:<%s>", addr->address_retry_key,
666 sender_address);
667 retry_add_item(addr, altkey, rf_delete);
668 retry_add_item(addr, addr->address_retry_key, rf_delete);
669 }
670 }
671
672 /* Timeout while reading the response */
673
674 else if (errno == ETIMEDOUT)
675 {
676 int save_errno = errno;
677 uschar *message = string_sprintf("SMTP timeout while connected to %s [%s] "
678 "after RCPT TO:<%s>", host->name, host->address,
679 transport_rcpt_address(addr, include_affixes));
680 set_errno(addrlist, save_errno, message, DEFER, FALSE);
681 retry_add_item(addr, addr->address_retry_key, 0);
682 update_waiting = FALSE;
683 return -1;
684 }
685
686 /* Handle other errors in obtaining an SMTP response by returning -1. This
687 will cause all the addresses to be deferred. Restore the SMTP command in
688 big_buffer for which we are checking the response, so the error message
689 makes sense. */
690
691 else if (errno != 0 || buffer[0] == 0)
692 {
693 string_format(big_buffer, big_buffer_size, "RCPT TO:<%s>",
694 transport_rcpt_address(addr, include_affixes));
695 return -2;
696 }
697
698 /* Handle SMTP permanent and temporary response codes. */
699
700 else
701 {
702 addr->message =
703 string_sprintf("SMTP error from remote mail server after RCPT TO:<%s>: "
704 "host %s [%s]: %s", transport_rcpt_address(addr, include_affixes),
705 host->name, host->address, string_printing(buffer));
706 setflag(addr, af_pass_message);
707 deliver_msglog("%s %s\n", tod_stamp(tod_log), addr->message);
708
709 /* The response was 5xx */
710
711 if (buffer[0] == '5')
712 {
713 addr->transport_return = FAIL;
714 yield |= 2;
715 }
716
717 /* The response was 4xx */
718
719 else
720 {
721 addr->transport_return = DEFER;
722 addr->basic_errno = ERRNO_RCPT4XX;
723 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
724
725 /* Log temporary errors if there are more hosts to be tried. */
726
727 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", addr->message);
728
729 /* Do not put this message on the list of those waiting for specific
730 hosts, as otherwise it is likely to be tried too often. */
731
732 update_waiting = FALSE;
733
734 /* Add a retry item for the address so that it doesn't get tried again
735 too soon. If address_retry_include_sender is true, add the sender address
736 to the retry key. */
737
738 if (address_retry_include_sender)
739 {
740 uschar *altkey = string_sprintf("%s:<%s>", addr->address_retry_key,
741 sender_address);
742 retry_add_item(addr, altkey, 0);
743 }
744 else retry_add_item(addr, addr->address_retry_key, 0);
745 }
746 }
747 } /* Loop for next RCPT response */
748
749 /* Update where to start at for the next block of responses, unless we
750 have already handled all the addresses. */
751
752 if (addr != NULL) *sync_addr = addr->next;
753
754 /* Handle a response to DATA. If we have not had any good recipients, either
755 previously or in this block, the response is ignored. */
756
757 if (pending_DATA != 0 &&
758 !smtp_read_response(inblock, buffer, buffsize, '3', timeout))
759 {
760 int code;
761 uschar *msg;
762 BOOL pass_message;
763 if (pending_DATA > 0 || (yield & 1) != 0)
764 {
765 if (errno == 0 && buffer[0] == '4')
766 {
767 errno = ERRNO_DATA4XX;
768 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
769 }
770 return -3;
771 }
772 (void)check_response(host, &errno, 0, buffer, &code, &msg, &pass_message);
773 DEBUG(D_transport) debug_printf("%s\nerror for DATA ignored: pipelining "
774 "is in use and there were no good recipients\n", msg);
775 }
776
777 /* All responses read and handled; MAIL (if present) received 2xx and DATA (if
778 present) received 3xx. If any RCPTs were handled and yielded anything other
779 than 4xx, yield will be set non-zero. */
780
781 return yield;
782 }
783
784
785
786 /*************************************************
787 * Deliver address list to given host *
788 *************************************************/
789
790 /* If continue_hostname is not null, we get here only when continuing to
791 deliver down an existing channel. The channel was passed as the standard
792 input. TLS is never active on a passed channel; the previous process always
793 closes it down before passing the connection on.
794
795 Otherwise, we have to make a connection to the remote host, and do the
796 initial protocol exchange.
797
798 When running as an MUA wrapper, if the sender or any recipient is rejected,
799 temporarily or permanently, we force failure for all recipients.
800
801 Arguments:
802 addrlist chain of potential addresses to deliver; only those whose
803 transport_return field is set to PENDING_DEFER are currently
804 being processed; others should be skipped - they have either
805 been delivered to an earlier host or IP address, or been
806 failed by one of them.
807 host host to deliver to
808 host_af AF_INET or AF_INET6
809 port default TCP/IP port to use, in host byte order
810 interface interface to bind to, or NULL
811 tblock transport instance block
812 copy_host TRUE if host set in addr->host_used must be copied, because
813 it is specific to this call of the transport
814 message_defer set TRUE if yield is OK, but all addresses were deferred
815 because of a non-recipient, non-host failure, that is, a
816 4xx response to MAIL FROM, DATA, or ".". This is a defer
817 that is specific to the message.
818 suppress_tls if TRUE, don't attempt a TLS connection - this is set for
819 a second attempt after TLS initialization fails
820
821 Returns: OK - the connection was made and the delivery attempted;
822 the result for each address is in its data block.
823 DEFER - the connection could not be made, or something failed
824 while setting up the SMTP session, or there was a
825 non-message-specific error, such as a timeout.
826 ERROR - a filter command is specified for this transport,
827 and there was a problem setting it up; OR helo_data
828 or add_headers or authenticated_sender is specified
829 for this transport, and the string failed to expand
830 */
831
832 static int
833 smtp_deliver(address_item *addrlist, host_item *host, int host_af, int port,
834 uschar *interface, transport_instance *tblock, BOOL copy_host,
835 BOOL *message_defer, BOOL suppress_tls)
836 {
837 address_item *addr;
838 address_item *sync_addr;
839 address_item *first_addr = addrlist;
840 int yield = OK;
841 int address_count;
842 int save_errno;
843 int rc;
844 time_t start_delivery_time = time(NULL);
845 smtp_transport_options_block *ob =
846 (smtp_transport_options_block *)(tblock->options_block);
847 BOOL lmtp = strcmpic(ob->protocol, US"lmtp") == 0;
848 BOOL ok = FALSE;
849 BOOL send_rset = TRUE;
850 BOOL send_quit = TRUE;
851 BOOL setting_up = TRUE;
852 BOOL completed_address = FALSE;
853 BOOL esmtp = TRUE;
854 BOOL pending_MAIL;
855 BOOL pass_message = FALSE;
856 smtp_inblock inblock;
857 smtp_outblock outblock;
858 int max_rcpt = tblock->max_addresses;
859 uschar *igquotstr = US"";
860 uschar *local_authenticated_sender = authenticated_sender;
861 uschar *helo_data = NULL;
862 uschar *message = NULL;
863 uschar new_message_id[MESSAGE_ID_LENGTH + 1];
864 uschar *p;
865 uschar buffer[4096];
866 uschar inbuffer[4096];
867 uschar outbuffer[1024];
868
869 suppress_tls = suppress_tls; /* stop compiler warning when no TLS support */
870
871 *message_defer = FALSE;
872 smtp_command = US"initial connection";
873 if (max_rcpt == 0) max_rcpt = 999999;
874
875 /* Set up the buffer for reading SMTP response packets. */
876
877 inblock.buffer = inbuffer;
878 inblock.buffersize = sizeof(inbuffer);
879 inblock.ptr = inbuffer;
880 inblock.ptrend = inbuffer;
881
882 /* Set up the buffer for holding SMTP commands while pipelining */
883
884 outblock.buffer = outbuffer;
885 outblock.buffersize = sizeof(outbuffer);
886 outblock.ptr = outbuffer;
887 outblock.cmd_count = 0;
888 outblock.authenticating = FALSE;
889
890 /* Reset the parameters of a TLS session. */
891
892 tls_cipher = NULL;
893 tls_peerdn = NULL;
894
895 /* If an authenticated_sender override has been specified for this transport
896 instance, expand it. If the expansion is forced to fail, and there was already
897 an authenticated_sender for this message, the original value will be used.
898 Other expansion failures are serious. An empty result is ignored, but there is
899 otherwise no check - this feature is expected to be used with LMTP and other
900 cases where non-standard addresses (e.g. without domains) might be required. */
901
902 if (ob->authenticated_sender != NULL)
903 {
904 uschar *new = expand_string(ob->authenticated_sender);
905 if (new == NULL)
906 {
907 if (!expand_string_forcedfail)
908 {
909 uschar *message = string_sprintf("failed to expand "
910 "authenticated_sender: %s", expand_string_message);
911 set_errno(addrlist, 0, message, DEFER, FALSE);
912 return ERROR;
913 }
914 }
915 else if (new[0] != 0) local_authenticated_sender = new;
916 }
917
918 /* Make a connection to the host if this isn't a continued delivery, and handle
919 the initial interaction and HELO/EHLO/LHLO. Connect timeout errors are handled
920 specially so they can be identified for retries. */
921
922 if (continue_hostname == NULL)
923 {
924 inblock.sock = outblock.sock =
925 smtp_connect(host, host_af, port, interface, ob->connect_timeout,
926 ob->keepalive); /* This puts port into host->port */
927
928 if (inblock.sock < 0)
929 {
930 set_errno(addrlist, (errno == ETIMEDOUT)? ERRNO_CONNECTTIMEOUT : errno,
931 NULL, DEFER, FALSE);
932 return DEFER;
933 }
934
935 /* Expand the greeting message while waiting for the initial response. (Makes
936 sense if helo_data contains ${lookup dnsdb ...} stuff). The expansion is
937 delayed till here so that $sending_interface and $sending_port are set. */
938
939 helo_data = expand_string(ob->helo_data);
940
941 /* The first thing is to wait for an initial OK response. The dreaded "goto"
942 is nevertheless a reasonably clean way of programming this kind of logic,
943 where you want to escape on any error. */
944
945 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
946 ob->command_timeout)) goto RESPONSE_FAILED;
947
948 /* Now check if the helo_data expansion went well, and sign off cleanly if it
949 didn't. */
950
951 if (helo_data == NULL)
952 {
953 uschar *message = string_sprintf("failed to expand helo_data: %s",
954 expand_string_message);
955 set_errno(addrlist, 0, message, DEFER, FALSE);
956 yield = DEFER;
957 goto SEND_QUIT;
958 }
959
960 /** Debugging without sending a message
961 addrlist->transport_return = DEFER;
962 goto SEND_QUIT;
963 **/
964
965 /* Errors that occur after this point follow an SMTP command, which is
966 left in big_buffer by smtp_write_command() for use in error messages. */
967
968 smtp_command = big_buffer;
969
970 /* Tell the remote who we are...
971
972 February 1998: A convention has evolved that ESMTP-speaking MTAs include the
973 string "ESMTP" in their greeting lines, so make Exim send EHLO if the
974 greeting is of this form. The assumption was that the far end supports it
975 properly... but experience shows that there are some that give 5xx responses,
976 even though the banner includes "ESMTP" (there's a bloody-minded one that
977 says "ESMTP not spoken here"). Cope with that case.
978
979 September 2000: Time has passed, and it seems reasonable now to always send
980 EHLO at the start. It is also convenient to make the change while installing
981 the TLS stuff.
982
983 July 2003: Joachim Wieland met a broken server that advertises "PIPELINING"
984 but times out after sending MAIL FROM, RCPT TO and DATA all together. There
985 would be no way to send out the mails, so there is now a host list
986 "hosts_avoid_esmtp" that disables ESMTP for special hosts and solves the
987 PIPELINING problem as well. Maybe it can also be useful to cure other
988 problems with broken servers.
989
990 Exim originally sent "Helo" at this point and ran for nearly a year that way.
991 Then somebody tried it with a Microsoft mailer... It seems that all other
992 mailers use upper case for some reason (the RFC is quite clear about case
993 independence) so, for peace of mind, I gave in. */
994
995 esmtp = verify_check_this_host(&(ob->hosts_avoid_esmtp), NULL,
996 host->name, host->address, NULL) != OK;
997
998 if (esmtp)
999 {
1000 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n",
1001 lmtp? "LHLO" : "EHLO", helo_data) < 0)
1002 goto SEND_FAILED;
1003 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1004 ob->command_timeout))
1005 {
1006 if (errno != 0 || buffer[0] == 0 || lmtp) goto RESPONSE_FAILED;
1007 esmtp = FALSE;
1008 }
1009 }
1010 else
1011 {
1012 DEBUG(D_transport)
1013 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
1014 }
1015
1016 if (!esmtp)
1017 {
1018 if (smtp_write_command(&outblock, FALSE, "HELO %s\r\n", helo_data) < 0)
1019 goto SEND_FAILED;
1020 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1021 ob->command_timeout)) goto RESPONSE_FAILED;
1022 }
1023
1024 /* Set IGNOREQUOTA if the response to LHLO specifies support and the
1025 lmtp_ignore_quota option was set. */
1026
1027 igquotstr = (lmtp && ob->lmtp_ignore_quota &&
1028 pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer, Ustrlen(CS buffer), 0,
1029 PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
1030
1031 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
1032
1033 #ifdef SUPPORT_TLS
1034 tls_offered = esmtp &&
1035 pcre_exec(regex_STARTTLS, NULL, CS buffer, Ustrlen(buffer), 0,
1036 PCRE_EOPT, NULL, 0) >= 0;
1037 #endif
1038 }
1039
1040 /* For continuing deliveries down the same channel, the socket is the standard
1041 input, and we don't need to redo EHLO here (but may need to do so for TLS - see
1042 below). Set up the pointer to where subsequent commands will be left, for
1043 error messages. Note that smtp_use_size and smtp_use_pipelining will have been
1044 set from the command line if they were set in the process that passed the
1045 connection on. */
1046
1047 else
1048 {
1049 inblock.sock = outblock.sock = fileno(stdin);
1050 smtp_command = big_buffer;
1051 host->port = port; /* Record the port that was used */
1052 }
1053
1054 /* If TLS is available on this connection, whether continued or not, attempt to
1055 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
1056 send another EHLO - the server may give a different answer in secure mode. We
1057 use a separate buffer for reading the response to STARTTLS so that if it is
1058 negative, the original EHLO data is available for subsequent analysis, should
1059 the client not be required to use TLS. If the response is bad, copy the buffer
1060 for error analysis. */
1061
1062 #ifdef SUPPORT_TLS
1063 if (tls_offered && !suppress_tls &&
1064 verify_check_this_host(&(ob->hosts_avoid_tls), NULL, host->name,
1065 host->address, NULL) != OK)
1066 {
1067 uschar buffer2[4096];
1068 if (smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") < 0)
1069 goto SEND_FAILED;
1070
1071 /* If there is an I/O error, transmission of this message is deferred. If
1072 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
1073 false, we also defer. However, if there is a temporary rejection of STARTTLS
1074 and tls_tempfail_tryclear is true, or if there is an outright rejection of
1075 STARTTLS, we carry on. This means we will try to send the message in clear,
1076 unless the host is in hosts_require_tls (tested below). */
1077
1078 if (!smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
1079 ob->command_timeout))
1080 {
1081 if (errno != 0 || buffer2[0] == 0 ||
1082 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
1083 {
1084 Ustrncpy(buffer, buffer2, sizeof(buffer));
1085 goto RESPONSE_FAILED;
1086 }
1087 }
1088
1089 /* STARTTLS accepted: try to negotiate a TLS session. */
1090
1091 else
1092 {
1093 int rc = tls_client_start(inblock.sock,
1094 host,
1095 addrlist,
1096 NULL, /* No DH param */
1097 ob->tls_certificate,
1098 ob->tls_privatekey,
1099 ob->tls_verify_certificates,
1100 ob->tls_crl,
1101 ob->tls_require_ciphers,
1102 ob->gnutls_require_mac,
1103 ob->gnutls_require_kx,
1104 ob->gnutls_require_proto,
1105 ob->command_timeout);
1106
1107 /* TLS negotiation failed; give an error. From outside, this function may
1108 be called again to try in clear on a new connection, if the options permit
1109 it for this host. */
1110
1111 if (rc != OK)
1112 {
1113 save_errno = ERRNO_TLSFAILURE;
1114 message = US"failure while setting up TLS session";
1115 send_quit = FALSE;
1116 goto TLS_FAILED;
1117 }
1118
1119 /* TLS session is set up */
1120
1121 for (addr = addrlist; addr != NULL; addr = addr->next)
1122 {
1123 if (addr->transport_return == PENDING_DEFER)
1124 {
1125 addr->cipher = tls_cipher;
1126 addr->peerdn = tls_peerdn;
1127 }
1128 }
1129 }
1130 }
1131
1132 /* If we started TLS, redo the EHLO/LHLO exchange over the secure channel. If
1133 helo_data is null, we are dealing with a connection that was passed from
1134 another process, and so we won't have expanded helo_data above. We have to
1135 expand it here. $sending_ip_address and $sending_port are set up right at the
1136 start of the Exim process (in exim.c). */
1137
1138 if (tls_active >= 0)
1139 {
1140 if (helo_data == NULL)
1141 {
1142 helo_data = expand_string(ob->helo_data);
1143 if (helo_data == NULL)
1144 {
1145 uschar *message = string_sprintf("failed to expand helo_data: %s",
1146 expand_string_message);
1147 set_errno(addrlist, 0, message, DEFER, FALSE);
1148 yield = DEFER;
1149 goto SEND_QUIT;
1150 }
1151 }
1152
1153 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n", lmtp? "LHLO" : "EHLO",
1154 helo_data) < 0)
1155 goto SEND_FAILED;
1156 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1157 ob->command_timeout))
1158 goto RESPONSE_FAILED;
1159 }
1160
1161 /* If the host is required to use a secure channel, ensure that we
1162 have one. */
1163
1164 else if (verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
1165 host->address, NULL) == OK)
1166 {
1167 save_errno = ERRNO_TLSREQUIRED;
1168 message = string_sprintf("a TLS session is required for %s [%s], but %s",
1169 host->name, host->address,
1170 tls_offered? "an attempt to start TLS failed" :
1171 "the server did not offer TLS support");
1172 goto TLS_FAILED;
1173 }
1174 #endif
1175
1176 /* If TLS is active, we have just started it up and re-done the EHLO command,
1177 so its response needs to be analyzed. If TLS is not active and this is a
1178 continued session down a previously-used socket, we haven't just done EHLO, so
1179 we skip this. */
1180
1181 if (continue_hostname == NULL
1182 #ifdef SUPPORT_TLS
1183 || tls_active >= 0
1184 #endif
1185 )
1186 {
1187 int require_auth;
1188 uschar *fail_reason = US"server did not advertise AUTH support";
1189
1190 /* Set for IGNOREQUOTA if the response to LHLO specifies support and the
1191 lmtp_ignore_quota option was set. */
1192
1193 igquotstr = (lmtp && ob->lmtp_ignore_quota &&
1194 pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer, Ustrlen(CS buffer), 0,
1195 PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
1196
1197 /* If the response to EHLO specified support for the SIZE parameter, note
1198 this, provided size_addition is non-negative. */
1199
1200 smtp_use_size = esmtp && ob->size_addition >= 0 &&
1201 pcre_exec(regex_SIZE, NULL, CS buffer, Ustrlen(CS buffer), 0,
1202 PCRE_EOPT, NULL, 0) >= 0;
1203
1204 /* Note whether the server supports PIPELINING. If hosts_avoid_esmtp matched
1205 the current host, esmtp will be false, so PIPELINING can never be used. If
1206 the current host matches hosts_avoid_pipelining, don't do it. */
1207
1208 smtp_use_pipelining = esmtp &&
1209 verify_check_this_host(&(ob->hosts_avoid_pipelining), NULL, host->name,
1210 host->address, NULL) != OK &&
1211 pcre_exec(regex_PIPELINING, NULL, CS buffer, Ustrlen(CS buffer), 0,
1212 PCRE_EOPT, NULL, 0) >= 0;
1213
1214 DEBUG(D_transport) debug_printf("%susing PIPELINING\n",
1215 smtp_use_pipelining? "" : "not ");
1216
1217 /* Note if the response to EHLO specifies support for the AUTH extension.
1218 If it has, check that this host is one we want to authenticate to, and do
1219 the business. The host name and address must be available when the
1220 authenticator's client driver is running. */
1221
1222 smtp_authenticated = FALSE;
1223 require_auth = verify_check_this_host(&(ob->hosts_require_auth), NULL,
1224 host->name, host->address, NULL);
1225
1226 if (esmtp && regex_match_and_setup(regex_AUTH, buffer, 0, -1))
1227 {
1228 uschar *names = string_copyn(expand_nstring[1], expand_nlength[1]);
1229 expand_nmax = -1; /* reset */
1230
1231 /* Must not do this check until after we have saved the result of the
1232 regex match above. */
1233
1234 if (require_auth == OK ||
1235 verify_check_this_host(&(ob->hosts_try_auth), NULL, host->name,
1236 host->address, NULL) == OK)
1237 {
1238 auth_instance *au;
1239 fail_reason = US"no common mechanisms were found";
1240
1241 DEBUG(D_transport) debug_printf("scanning authentication mechanisms\n");
1242
1243 /* Scan the configured authenticators looking for one which is configured
1244 for use as a client, which is not suppressed by client_condition, and
1245 whose name matches an authentication mechanism supported by the server.
1246 If one is found, attempt to authenticate by calling its client function.
1247 */
1248
1249 for (au = auths; !smtp_authenticated && au != NULL; au = au->next)
1250 {
1251 uschar *p = names;
1252 if (!au->client ||
1253 (au->client_condition != NULL &&
1254 !expand_check_condition(au->client_condition, au->name,
1255 US"client authenticator")))
1256 {
1257 DEBUG(D_transport) debug_printf("skipping %s authenticator: %s\n",
1258 au->name,
1259 (au->client)? "client_condition is false" :
1260 "not configured as a client");
1261 continue;
1262 }
1263
1264 /* Loop to scan supported server mechanisms */
1265
1266 while (*p != 0)
1267 {
1268 int rc;
1269 int len = Ustrlen(au->public_name);
1270 while (isspace(*p)) p++;
1271
1272 if (strncmpic(au->public_name, p, len) != 0 ||
1273 (p[len] != 0 && !isspace(p[len])))
1274 {
1275 while (*p != 0 && !isspace(*p)) p++;
1276 continue;
1277 }
1278
1279 /* Found data for a listed mechanism. Call its client entry. Set
1280 a flag in the outblock so that data is overwritten after sending so
1281 that reflections don't show it. */
1282
1283 fail_reason = US"authentication attempt(s) failed";
1284 outblock.authenticating = TRUE;
1285 rc = (au->info->clientcode)(au, &inblock, &outblock,
1286 ob->command_timeout, buffer, sizeof(buffer));
1287 outblock.authenticating = FALSE;
1288 DEBUG(D_transport) debug_printf("%s authenticator yielded %d\n",
1289 au->name, rc);
1290
1291 /* A temporary authentication failure must hold up delivery to
1292 this host. After a permanent authentication failure, we carry on
1293 to try other authentication methods. If all fail hard, try to
1294 deliver the message unauthenticated unless require_auth was set. */
1295
1296 switch(rc)
1297 {
1298 case OK:
1299 smtp_authenticated = TRUE; /* stops the outer loop */
1300 break;
1301
1302 /* Failure after writing a command */
1303
1304 case FAIL_SEND:
1305 goto SEND_FAILED;
1306
1307 /* Failure after reading a response */
1308
1309 case FAIL:
1310 if (errno != 0 || buffer[0] != '5') goto RESPONSE_FAILED;
1311 log_write(0, LOG_MAIN, "%s authenticator failed H=%s [%s] %s",
1312 au->name, host->name, host->address, buffer);
1313 break;
1314
1315 /* Failure by some other means. In effect, the authenticator
1316 decided it wasn't prepared to handle this case. Typically this
1317 is the result of "fail" in an expansion string. Do we need to
1318 log anything here? Feb 2006: a message is now put in the buffer
1319 if logging is required. */
1320
1321 case CANCELLED:
1322 if (*buffer != 0)
1323 log_write(0, LOG_MAIN, "%s authenticator cancelled "
1324 "authentication H=%s [%s] %s", au->name, host->name,
1325 host->address, buffer);
1326 break;
1327
1328 /* Internal problem, message in buffer. */
1329
1330 case ERROR:
1331 yield = ERROR;
1332 set_errno(addrlist, 0, string_copy(buffer), DEFER, FALSE);
1333 goto SEND_QUIT;
1334 }
1335
1336 break; /* If not authenticated, try next authenticator */
1337 } /* Loop for scanning supported server mechanisms */
1338 } /* Loop for further authenticators */
1339 }
1340 }
1341
1342 /* If we haven't authenticated, but are required to, give up. */
1343
1344 if (require_auth == OK && !smtp_authenticated)
1345 {
1346 yield = DEFER;
1347 set_errno(addrlist, ERRNO_AUTHFAIL,
1348 string_sprintf("authentication required but %s", fail_reason), DEFER,
1349 FALSE);
1350 goto SEND_QUIT;
1351 }
1352 }
1353
1354 /* The setting up of the SMTP call is now complete. Any subsequent errors are
1355 message-specific. */
1356
1357 setting_up = FALSE;
1358
1359 /* If there is a filter command specified for this transport, we can now
1360 set it up. This cannot be done until the identify of the host is known. */
1361
1362 if (tblock->filter_command != NULL)
1363 {
1364 BOOL rc;
1365 uschar buffer[64];
1366 sprintf(CS buffer, "%.50s transport", tblock->name);
1367 rc = transport_set_up_command(&transport_filter_argv, tblock->filter_command,
1368 TRUE, DEFER, addrlist, buffer, NULL);
1369 transport_filter_timeout = tblock->filter_timeout;
1370
1371 /* On failure, copy the error to all addresses, abandon the SMTP call, and
1372 yield ERROR. */
1373
1374 if (!rc)
1375 {
1376 set_errno(addrlist->next, addrlist->basic_errno, addrlist->message, DEFER,
1377 FALSE);
1378 yield = ERROR;
1379 goto SEND_QUIT;
1380 }
1381 }
1382
1383
1384 /* For messages that have more than the maximum number of envelope recipients,
1385 we want to send several transactions down the same SMTP connection. (See
1386 comments in deliver.c as to how this reconciles, heuristically, with
1387 remote_max_parallel.) This optimization was added to Exim after the following
1388 code was already working. The simplest way to put it in without disturbing the
1389 code was to use a goto to jump back to this point when there is another
1390 transaction to handle. */
1391
1392 SEND_MESSAGE:
1393 sync_addr = first_addr;
1394 address_count = 0;
1395 ok = FALSE;
1396 send_rset = TRUE;
1397 completed_address = FALSE;
1398
1399
1400 /* Initiate a message transfer. If we know the receiving MTA supports the SIZE
1401 qualification, send it, adding something to the message size to allow for
1402 imprecision and things that get added en route. Exim keeps the number of lines
1403 in a message, so we can give an accurate value for the original message, but we
1404 need some additional to handle added headers. (Double "." characters don't get
1405 included in the count.) */
1406
1407 p = buffer;
1408 *p = 0;
1409
1410 if (smtp_use_size)
1411 {
1412 sprintf(CS p, " SIZE=%d", message_size+message_linecount+ob->size_addition);
1413 while (*p) p++;
1414 }
1415
1416 /* Add the authenticated sender address if present */
1417
1418 if ((smtp_authenticated || ob->authenticated_sender_force) &&
1419 local_authenticated_sender != NULL)
1420 {
1421 string_format(p, sizeof(buffer) - (p-buffer), " AUTH=%s",
1422 auth_xtextencode(local_authenticated_sender,
1423 Ustrlen(local_authenticated_sender)));
1424 }
1425
1426 /* From here until we send the DATA command, we can make use of PIPELINING
1427 if the server host supports it. The code has to be able to check the responses
1428 at any point, for when the buffer fills up, so we write it totally generally.
1429 When PIPELINING is off, each command written reports that it has flushed the
1430 buffer. */
1431
1432 pending_MAIL = TRUE; /* The block starts with MAIL */
1433
1434 rc = smtp_write_command(&outblock, smtp_use_pipelining,
1435 "MAIL FROM:<%s>%s\r\n", return_path, buffer);
1436 mail_command = string_copy(big_buffer); /* Save for later error message */
1437
1438 switch(rc)
1439 {
1440 case -1: /* Transmission error */
1441 goto SEND_FAILED;
1442
1443 case +1: /* Block was sent */
1444 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1445 ob->command_timeout))
1446 {
1447 if (errno == 0 && buffer[0] == '4')
1448 {
1449 errno = ERRNO_MAIL4XX;
1450 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1451 }
1452 goto RESPONSE_FAILED;
1453 }
1454 pending_MAIL = FALSE;
1455 break;
1456 }
1457
1458 /* Pass over all the relevant recipient addresses for this host, which are the
1459 ones that have status PENDING_DEFER. If we are using PIPELINING, we can send
1460 several before we have to read the responses for those seen so far. This
1461 checking is done by a subroutine because it also needs to be done at the end.
1462 Send only up to max_rcpt addresses at a time, leaving first_addr pointing to
1463 the next one if not all are sent.
1464
1465 In the MUA wrapper situation, we want to flush the PIPELINING buffer for the
1466 last address because we want to abort if any recipients have any kind of
1467 problem, temporary or permanent. We know that all recipient addresses will have
1468 the PENDING_DEFER status, because only one attempt is ever made, and we know
1469 that max_rcpt will be large, so all addresses will be done at once. */
1470
1471 for (addr = first_addr;
1472 address_count < max_rcpt && addr != NULL;
1473 addr = addr->next)
1474 {
1475 int count;
1476 BOOL no_flush;
1477
1478 if (addr->transport_return != PENDING_DEFER) continue;
1479
1480 address_count++;
1481 no_flush = smtp_use_pipelining && (!mua_wrapper || addr->next != NULL);
1482
1483 /* Now send the RCPT command, and process outstanding responses when
1484 necessary. After a timeout on RCPT, we just end the function, leaving the
1485 yield as OK, because this error can often mean that there is a problem with
1486 just one address, so we don't want to delay the host. */
1487
1488 count = smtp_write_command(&outblock, no_flush, "RCPT TO:<%s>%s\r\n",
1489 transport_rcpt_address(addr, tblock->rcpt_include_affixes), igquotstr);
1490 if (count < 0) goto SEND_FAILED;
1491 if (count > 0)
1492 {
1493 switch(sync_responses(first_addr, tblock->rcpt_include_affixes,
1494 &sync_addr, host, count, ob->address_retry_include_sender,
1495 pending_MAIL, 0, &inblock, ob->command_timeout, buffer,
1496 sizeof(buffer)))
1497 {
1498 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1499 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1500 break;
1501
1502 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1503 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1504 case 0: /* No 2xx or 5xx, but no probs */
1505 break;
1506
1507 case -1: goto END_OFF; /* Timeout on RCPT */
1508 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL error */
1509 }
1510 pending_MAIL = FALSE; /* Dealt with MAIL */
1511 }
1512 } /* Loop for next address */
1513
1514 /* If we are an MUA wrapper, abort if any RCPTs were rejected, either
1515 permanently or temporarily. We should have flushed and synced after the last
1516 RCPT. */
1517
1518 if (mua_wrapper)
1519 {
1520 address_item *badaddr;
1521 for (badaddr = first_addr; badaddr != NULL; badaddr = badaddr->next)
1522 {
1523 if (badaddr->transport_return != PENDING_OK) break;
1524 }
1525 if (badaddr != NULL)
1526 {
1527 set_errno(addrlist, 0, badaddr->message, FAIL,
1528 testflag(badaddr, af_pass_message));
1529 ok = FALSE;
1530 }
1531 }
1532
1533 /* If ok is TRUE, we know we have got at least one good recipient, and must now
1534 send DATA, but if it is FALSE (in the normal, non-wrapper case), we may still
1535 have a good recipient buffered up if we are pipelining. We don't want to waste
1536 time sending DATA needlessly, so we only send it if either ok is TRUE or if we
1537 are pipelining. The responses are all handled by sync_responses(). */
1538
1539 if (ok || (smtp_use_pipelining && !mua_wrapper))
1540 {
1541 int count = smtp_write_command(&outblock, FALSE, "DATA\r\n");
1542 if (count < 0) goto SEND_FAILED;
1543 switch(sync_responses(first_addr, tblock->rcpt_include_affixes, &sync_addr,
1544 host, count, ob->address_retry_include_sender, pending_MAIL,
1545 ok? +1 : -1, &inblock, ob->command_timeout, buffer, sizeof(buffer)))
1546 {
1547 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1548 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1549 break;
1550
1551 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1552 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1553 case 0: break; /* No 2xx or 5xx, but no probs */
1554
1555 case -1: goto END_OFF; /* Timeout on RCPT */
1556 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */
1557 }
1558 }
1559
1560 /* Save the first address of the next batch. */
1561
1562 first_addr = addr;
1563
1564 /* If there were no good recipients (but otherwise there have been no
1565 problems), just set ok TRUE, since we have handled address-specific errors
1566 already. Otherwise, it's OK to send the message. Use the check/escape mechanism
1567 for handling the SMTP dot-handling protocol, flagging to apply to headers as
1568 well as body. Set the appropriate timeout value to be used for each chunk.
1569 (Haven't been able to make it work using select() for writing yet.) */
1570
1571 if (!ok) ok = TRUE; else
1572 {
1573 sigalrm_seen = FALSE;
1574 transport_write_timeout = ob->data_timeout;
1575 smtp_command = US"sending data block"; /* For error messages */
1576 DEBUG(D_transport|D_v)
1577 debug_printf(" SMTP>> writing message and terminating \".\"\n");
1578 transport_count = 0;
1579 #ifndef DISABLE_DKIM
1580 ok = dkim_transport_write_message(addrlist, inblock.sock,
1581 topt_use_crlf | topt_end_dot | topt_escape_headers |
1582 (tblock->body_only? topt_no_headers : 0) |
1583 (tblock->headers_only? topt_no_body : 0) |
1584 (tblock->return_path_add? topt_add_return_path : 0) |
1585 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1586 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1587 0, /* No size limit */
1588 tblock->add_headers, tblock->remove_headers,
1589 US".", US"..", /* Escaping strings */
1590 tblock->rewrite_rules, tblock->rewrite_existflags,
1591 ob->dkim_private_key, ob->dkim_domain, ob->dkim_selector,
1592 ob->dkim_canon, ob->dkim_strict, ob->dkim_sign_headers
1593 );
1594 #else
1595 ok = transport_write_message(addrlist, inblock.sock,
1596 topt_use_crlf | topt_end_dot | topt_escape_headers |
1597 (tblock->body_only? topt_no_headers : 0) |
1598 (tblock->headers_only? topt_no_body : 0) |
1599 (tblock->return_path_add? topt_add_return_path : 0) |
1600 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1601 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1602 0, /* No size limit */
1603 tblock->add_headers, tblock->remove_headers,
1604 US".", US"..", /* Escaping strings */
1605 tblock->rewrite_rules, tblock->rewrite_existflags);
1606 #endif
1607
1608 /* transport_write_message() uses write() because it is called from other
1609 places to write to non-sockets. This means that under some OS (e.g. Solaris)
1610 it can exit with "Broken pipe" as its error. This really means that the
1611 socket got closed at the far end. */
1612
1613 transport_write_timeout = 0; /* for subsequent transports */
1614
1615 /* Failure can either be some kind of I/O disaster (including timeout),
1616 or the failure of a transport filter or the expansion of added headers. */
1617
1618 if (!ok)
1619 {
1620 buffer[0] = 0; /* There hasn't been a response */
1621 goto RESPONSE_FAILED;
1622 }
1623
1624 /* We used to send the terminating "." explicitly here, but because of
1625 buffering effects at both ends of TCP/IP connections, you don't gain
1626 anything by keeping it separate, so it might as well go in the final
1627 data buffer for efficiency. This is now done by setting the topt_end_dot
1628 flag above. */
1629
1630 smtp_command = US"end of data";
1631
1632 /* For SMTP, we now read a single response that applies to the whole message.
1633 If it is OK, then all the addresses have been delivered. */
1634
1635 if (!lmtp)
1636 {
1637 ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1638 ob->final_timeout);
1639 if (!ok && errno == 0 && buffer[0] == '4')
1640 {
1641 errno = ERRNO_DATA4XX;
1642 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1643 }
1644 }
1645
1646 /* For LMTP, we get back a response for every RCPT command that we sent;
1647 some may be accepted and some rejected. For those that get a response, their
1648 status is fixed; any that are accepted have been handed over, even if later
1649 responses crash - at least, that's how I read RFC 2033.
1650
1651 If all went well, mark the recipient addresses as completed, record which
1652 host/IPaddress they were delivered to, and cut out RSET when sending another
1653 message down the same channel. Write the completed addresses to the journal
1654 now so that they are recorded in case there is a crash of hardware or
1655 software before the spool gets updated. Also record the final SMTP
1656 confirmation if needed (for SMTP only). */
1657
1658 if (ok)
1659 {
1660 int flag = '=';
1661 int delivery_time = (int)(time(NULL) - start_delivery_time);
1662 int len;
1663 host_item *thost;
1664 uschar *conf = NULL;
1665 send_rset = FALSE;
1666
1667 /* Make a copy of the host if it is local to this invocation
1668 of the transport. */
1669
1670 if (copy_host)
1671 {
1672 thost = store_get(sizeof(host_item));
1673 *thost = *host;
1674 thost->name = string_copy(host->name);
1675 thost->address = string_copy(host->address);
1676 }
1677 else thost = host;
1678
1679 /* Set up confirmation if needed - applies only to SMTP */
1680
1681 if ((log_extra_selector & LX_smtp_confirmation) != 0 && !lmtp)
1682 {
1683 uschar *s = string_printing(buffer);
1684 conf = (s == buffer)? (uschar *)string_copy(s) : s;
1685 }
1686
1687 /* Process all transported addresses - for LMTP, read a status for
1688 each one. */
1689
1690 for (addr = addrlist; addr != first_addr; addr = addr->next)
1691 {
1692 if (addr->transport_return != PENDING_OK) continue;
1693
1694 /* LMTP - if the response fails badly (e.g. timeout), use it for all the
1695 remaining addresses. Otherwise, it's a return code for just the one
1696 address. For temporary errors, add a retry item for the address so that
1697 it doesn't get tried again too soon. */
1698
1699 if (lmtp)
1700 {
1701 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1702 ob->final_timeout))
1703 {
1704 if (errno != 0 || buffer[0] == 0) goto RESPONSE_FAILED;
1705 addr->message = string_sprintf("LMTP error after %s: %s",
1706 big_buffer, string_printing(buffer));
1707 setflag(addr, af_pass_message); /* Allow message to go to user */
1708 if (buffer[0] == '5')
1709 addr->transport_return = FAIL;
1710 else
1711 {
1712 errno = ERRNO_DATA4XX;
1713 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1714 addr->transport_return = DEFER;
1715 retry_add_item(addr, addr->address_retry_key, 0);
1716 }
1717 continue;
1718 }
1719 completed_address = TRUE; /* NOW we can set this flag */
1720 conf = string_sprintf("LMTP Successful delivery:%s", string_printing(buffer));
1721 }
1722
1723 /* SMTP, or success return from LMTP for this address. Pass back the
1724 actual host that was used. */
1725
1726 addr->transport_return = OK;
1727 addr->more_errno = delivery_time;
1728 addr->host_used = thost;
1729 addr->special_action = flag;
1730 addr->message = conf;
1731 flag = '-';
1732
1733 /* Update the journal. For homonymic addresses, use the base address plus
1734 the transport name. See lots of comments in deliver.c about the reasons
1735 for the complications when homonyms are involved. Just carry on after
1736 write error, as it may prove possible to update the spool file later. */
1737
1738 if (testflag(addr, af_homonym))
1739 sprintf(CS buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
1740 else
1741 sprintf(CS buffer, "%.500s\n", addr->unique);
1742
1743 DEBUG(D_deliver) debug_printf("journalling %s", buffer);
1744 len = Ustrlen(CS buffer);
1745 if (write(journal_fd, buffer, len) != len)
1746 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
1747 "%s: %s", buffer, strerror(errno));
1748 }
1749
1750 /* Ensure the journal file is pushed out to disk. */
1751
1752 if (EXIMfsync(journal_fd) < 0)
1753 log_write(0, LOG_MAIN|LOG_PANIC, "failed to fsync journal: %s",
1754 strerror(errno));
1755 }
1756 }
1757
1758
1759 /* Handle general (not specific to one address) failures here. The value of ok
1760 is used to skip over this code on the falling through case. A timeout causes a
1761 deferral. Other errors may defer or fail according to the response code, and
1762 may set up a special errno value, e.g. after connection chopped, which is
1763 assumed if errno == 0 and there is no text in the buffer. If control reaches
1764 here during the setting up phase (i.e. before MAIL FROM) then always defer, as
1765 the problem is not related to this specific message. */
1766
1767 if (!ok)
1768 {
1769 int code;
1770
1771 RESPONSE_FAILED:
1772 save_errno = errno;
1773 message = NULL;
1774 send_quit = check_response(host, &save_errno, addrlist->more_errno,
1775 buffer, &code, &message, &pass_message);
1776 goto FAILED;
1777
1778 SEND_FAILED:
1779 save_errno = errno;
1780 code = '4';
1781 message = US string_sprintf("send() to %s [%s] failed: %s",
1782 host->name, host->address, strerror(save_errno));
1783 send_quit = FALSE;
1784 goto FAILED;
1785
1786 /* This label is jumped to directly when a TLS negotiation has failed,
1787 or was not done for a host for which it is required. Values will be set
1788 in message and save_errno, and setting_up will always be true. Treat as
1789 a temporary error. */
1790
1791 #ifdef SUPPORT_TLS
1792 TLS_FAILED:
1793 code = '4';
1794 #endif
1795
1796 /* If the failure happened while setting up the call, see if the failure was
1797 a 5xx response (this will either be on connection, or following HELO - a 5xx
1798 after EHLO causes it to try HELO). If so, fail all addresses, as this host is
1799 never going to accept them. For other errors during setting up (timeouts or
1800 whatever), defer all addresses, and yield DEFER, so that the host is not
1801 tried again for a while. */
1802
1803 FAILED:
1804 ok = FALSE; /* For when reached by GOTO */
1805
1806 if (setting_up)
1807 {
1808 if (code == '5')
1809 {
1810 set_errno(addrlist, save_errno, message, FAIL, pass_message);
1811 }
1812 else
1813 {
1814 set_errno(addrlist, save_errno, message, DEFER, pass_message);
1815 yield = DEFER;
1816 }
1817 }
1818
1819 /* We want to handle timeouts after MAIL or "." and loss of connection after
1820 "." specially. They can indicate a problem with the sender address or with
1821 the contents of the message rather than a real error on the connection. These
1822 cases are treated in the same way as a 4xx response. This next bit of code
1823 does the classification. */
1824
1825 else
1826 {
1827 BOOL message_error;
1828
1829 switch(save_errno)
1830 {
1831 case 0:
1832 case ERRNO_MAIL4XX:
1833 case ERRNO_DATA4XX:
1834 message_error = TRUE;
1835 break;
1836
1837 case ETIMEDOUT:
1838 message_error = Ustrncmp(smtp_command,"MAIL",4) == 0 ||
1839 Ustrncmp(smtp_command,"end ",4) == 0;
1840 break;
1841
1842 case ERRNO_SMTPCLOSED:
1843 message_error = Ustrncmp(smtp_command,"end ",4) == 0;
1844 break;
1845
1846 default:
1847 message_error = FALSE;
1848 break;
1849 }
1850
1851 /* Handle the cases that are treated as message errors. These are:
1852
1853 (a) negative response or timeout after MAIL
1854 (b) negative response after DATA
1855 (c) negative response or timeout or dropped connection after "."
1856
1857 It won't be a negative response or timeout after RCPT, as that is dealt
1858 with separately above. The action in all cases is to set an appropriate
1859 error code for all the addresses, but to leave yield set to OK because the
1860 host itself has not failed. Of course, it might in practice have failed
1861 when we've had a timeout, but if so, we'll discover that at the next
1862 delivery attempt. For a temporary error, set the message_defer flag, and
1863 write to the logs for information if this is not the last host. The error
1864 for the last host will be logged as part of the address's log line. */
1865
1866 if (message_error)
1867 {
1868 if (mua_wrapper) code = '5'; /* Force hard failure in wrapper mode */
1869 set_errno(addrlist, save_errno, message, (code == '5')? FAIL : DEFER,
1870 pass_message);
1871
1872 /* If there's an errno, the message contains just the identity of
1873 the host. */
1874
1875 if (code != '5') /* Anything other than 5 is treated as temporary */
1876 {
1877 if (save_errno > 0)
1878 message = US string_sprintf("%s: %s", message, strerror(save_errno));
1879 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", message);
1880 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
1881 *message_defer = TRUE;
1882 }
1883 }
1884
1885 /* Otherwise, we have an I/O error or a timeout other than after MAIL or
1886 ".", or some other transportation error. We defer all addresses and yield
1887 DEFER, except for the case of failed add_headers expansion, or a transport
1888 filter failure, when the yield should be ERROR, to stop it trying other
1889 hosts. */
1890
1891 else
1892 {
1893 yield = (save_errno == ERRNO_CHHEADER_FAIL ||
1894 save_errno == ERRNO_FILTER_FAIL)? ERROR : DEFER;
1895 set_errno(addrlist, save_errno, message, DEFER, pass_message);
1896 }
1897 }
1898 }
1899
1900
1901 /* If all has gone well, send_quit will be set TRUE, implying we can end the
1902 SMTP session tidily. However, if there were too many addresses to send in one
1903 message (indicated by first_addr being non-NULL) we want to carry on with the
1904 rest of them. Also, it is desirable to send more than one message down the SMTP
1905 connection if there are several waiting, provided we haven't already sent so
1906 many as to hit the configured limit. The function transport_check_waiting looks
1907 for a waiting message and returns its id. Then transport_pass_socket tries to
1908 set up a continued delivery by passing the socket on to another process. The
1909 variable send_rset is FALSE if a message has just been successfully transfered.
1910
1911 If we are already sending down a continued channel, there may be further
1912 addresses not yet delivered that are aimed at the same host, but which have not
1913 been passed in this run of the transport. In this case, continue_more will be
1914 true, and all we should do is send RSET if necessary, and return, leaving the
1915 channel open.
1916
1917 However, if no address was disposed of, i.e. all addresses got 4xx errors, we
1918 do not want to continue with other messages down the same channel, because that
1919 can lead to looping between two or more messages, all with the same,
1920 temporarily failing address(es). [The retry information isn't updated yet, so
1921 new processes keep on trying.] We probably also don't want to try more of this
1922 message's addresses either.
1923
1924 If we have started a TLS session, we have to end it before passing the
1925 connection to a new process. However, not all servers can handle this (Exim
1926 can), so we do not pass such a connection on if the host matches
1927 hosts_nopass_tls. */
1928
1929 DEBUG(D_transport)
1930 debug_printf("ok=%d send_quit=%d send_rset=%d continue_more=%d "
1931 "yield=%d first_address is %sNULL\n", ok, send_quit, send_rset,
1932 continue_more, yield, (first_addr == NULL)? "":"not ");
1933
1934 if (completed_address && ok && send_quit)
1935 {
1936 BOOL more;
1937 if (first_addr != NULL || continue_more ||
1938 (
1939 (tls_active < 0 ||
1940 verify_check_this_host(&(ob->hosts_nopass_tls), NULL, host->name,
1941 host->address, NULL) != OK)
1942 &&
1943 transport_check_waiting(tblock->name, host->name,
1944 tblock->connection_max_messages, new_message_id, &more)
1945 ))
1946 {
1947 uschar *msg;
1948 BOOL pass_message;
1949
1950 if (send_rset)
1951 {
1952 if (! (ok = smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0))
1953 {
1954 msg = US string_sprintf("send() to %s [%s] failed: %s", host->name,
1955 host->address, strerror(save_errno));
1956 send_quit = FALSE;
1957 }
1958 else if (! (ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1959 ob->command_timeout)))
1960 {
1961 int code;
1962 send_quit = check_response(host, &errno, 0, buffer, &code, &msg,
1963 &pass_message);
1964 if (!send_quit)
1965 {
1966 DEBUG(D_transport) debug_printf("%s\n", msg);
1967 }
1968 }
1969 }
1970
1971 /* Either RSET was not needed, or it succeeded */
1972
1973 if (ok)
1974 {
1975 if (first_addr != NULL) /* More addresses still to be sent */
1976 { /* in this run of the transport */
1977 continue_sequence++; /* Causes * in logging */
1978 goto SEND_MESSAGE;
1979 }
1980 if (continue_more) return yield; /* More addresses for another run */
1981
1982 /* Pass the socket to a new Exim process. Before doing so, we must shut
1983 down TLS. Not all MTAs allow for the continuation of the SMTP session
1984 when TLS is shut down. We test for this by sending a new EHLO. If we
1985 don't get a good response, we don't attempt to pass the socket on. */
1986
1987 #ifdef SUPPORT_TLS
1988 if (tls_active >= 0)
1989 {
1990 tls_close(TRUE);
1991 ok = smtp_write_command(&outblock,FALSE,"EHLO %s\r\n",helo_data) >= 0 &&
1992 smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1993 ob->command_timeout);
1994 }
1995 #endif
1996
1997 /* If the socket is successfully passed, we musn't send QUIT (or
1998 indeed anything!) from here. */
1999
2000 if (ok && transport_pass_socket(tblock->name, host->name, host->address,
2001 new_message_id, inblock.sock))
2002 {
2003 send_quit = FALSE;
2004 }
2005 }
2006
2007 /* If RSET failed and there are addresses left, they get deferred. */
2008
2009 else set_errno(first_addr, errno, msg, DEFER, FALSE);
2010 }
2011 }
2012
2013 /* End off tidily with QUIT unless the connection has died or the socket has
2014 been passed to another process. There has been discussion on the net about what
2015 to do after sending QUIT. The wording of the RFC suggests that it is necessary
2016 to wait for a response, but on the other hand, there isn't anything one can do
2017 with an error response, other than log it. Exim used to do that. However,
2018 further discussion suggested that it is positively advantageous not to wait for
2019 the response, but to close the session immediately. This is supposed to move
2020 the TCP/IP TIME_WAIT state from the server to the client, thereby removing some
2021 load from the server. (Hosts that are both servers and clients may not see much
2022 difference, of course.) Further discussion indicated that this was safe to do
2023 on Unix systems which have decent implementations of TCP/IP that leave the
2024 connection around for a while (TIME_WAIT) after the application has gone away.
2025 This enables the response sent by the server to be properly ACKed rather than
2026 timed out, as can happen on broken TCP/IP implementations on other OS.
2027
2028 This change is being made on 31-Jul-98. After over a year of trouble-free
2029 operation, the old commented-out code was removed on 17-Sep-99. */
2030
2031 SEND_QUIT:
2032 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
2033
2034 END_OFF:
2035
2036 #ifdef SUPPORT_TLS
2037 tls_close(TRUE);
2038 #endif
2039
2040 /* Close the socket, and return the appropriate value, first setting
2041 continue_transport and continue_hostname NULL to prevent any other addresses
2042 that may include the host from trying to re-use a continuation socket. This
2043 works because the NULL setting is passed back to the calling process, and
2044 remote_max_parallel is forced to 1 when delivering over an existing connection,
2045
2046 If all went well and continue_more is set, we shouldn't actually get here if
2047 there are further addresses, as the return above will be taken. However,
2048 writing RSET might have failed, or there may be other addresses whose hosts are
2049 specified in the transports, and therefore not visible at top level, in which
2050 case continue_more won't get set. */
2051
2052 (void)close(inblock.sock);
2053 continue_transport = NULL;
2054 continue_hostname = NULL;
2055 return yield;
2056 }
2057
2058
2059
2060
2061 /*************************************************
2062 * Closedown entry point *
2063 *************************************************/
2064
2065 /* This function is called when exim is passed an open smtp channel
2066 from another incarnation, but the message which it has been asked
2067 to deliver no longer exists. The channel is on stdin.
2068
2069 We might do fancy things like looking for another message to send down
2070 the channel, but if the one we sought has gone, it has probably been
2071 delivered by some other process that itself will seek further messages,
2072 so just close down our connection.
2073
2074 Argument: pointer to the transport instance block
2075 Returns: nothing
2076 */
2077
2078 void
2079 smtp_transport_closedown(transport_instance *tblock)
2080 {
2081 smtp_transport_options_block *ob =
2082 (smtp_transport_options_block *)(tblock->options_block);
2083 smtp_inblock inblock;
2084 smtp_outblock outblock;
2085 uschar buffer[256];
2086 uschar inbuffer[4096];
2087 uschar outbuffer[16];
2088
2089 inblock.sock = fileno(stdin);
2090 inblock.buffer = inbuffer;
2091 inblock.buffersize = sizeof(inbuffer);
2092 inblock.ptr = inbuffer;
2093 inblock.ptrend = inbuffer;
2094
2095 outblock.sock = inblock.sock;
2096 outblock.buffersize = sizeof(outbuffer);
2097 outblock.buffer = outbuffer;
2098 outblock.ptr = outbuffer;
2099 outblock.cmd_count = 0;
2100 outblock.authenticating = FALSE;
2101
2102 (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
2103 (void)smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2104 ob->command_timeout);
2105 (void)close(inblock.sock);
2106 }
2107
2108
2109
2110 /*************************************************
2111 * Prepare addresses for delivery *
2112 *************************************************/
2113
2114 /* This function is called to flush out error settings from previous delivery
2115 attempts to other hosts. It also records whether we got here via an MX record
2116 or not in the more_errno field of the address. We are interested only in
2117 addresses that are still marked DEFER - others may have got delivered to a
2118 previously considered IP address. Set their status to PENDING_DEFER to indicate
2119 which ones are relevant this time.
2120
2121 Arguments:
2122 addrlist the list of addresses
2123 host the host we are delivering to
2124
2125 Returns: the first address for this delivery
2126 */
2127
2128 static address_item *
2129 prepare_addresses(address_item *addrlist, host_item *host)
2130 {
2131 address_item *first_addr = NULL;
2132 address_item *addr;
2133 for (addr = addrlist; addr != NULL; addr = addr->next)
2134 {
2135 if (addr->transport_return != DEFER) continue;
2136 if (first_addr == NULL) first_addr = addr;
2137 addr->transport_return = PENDING_DEFER;
2138 addr->basic_errno = 0;
2139 addr->more_errno = (host->mx >= 0)? 'M' : 'A';
2140 addr->message = NULL;
2141 #ifdef SUPPORT_TLS
2142 addr->cipher = NULL;
2143 addr->peerdn = NULL;
2144 #endif
2145 }
2146 return first_addr;
2147 }
2148
2149
2150
2151 /*************************************************
2152 * Main entry point *
2153 *************************************************/
2154
2155 /* See local README for interface details. As this is a remote transport, it is
2156 given a chain of addresses to be delivered in one connection, if possible. It
2157 always returns TRUE, indicating that each address has its own independent
2158 status set, except if there is a setting up problem, in which case it returns
2159 FALSE. */
2160
2161 BOOL
2162 smtp_transport_entry(
2163 transport_instance *tblock, /* data for this instantiation */
2164 address_item *addrlist) /* addresses we are working on */
2165 {
2166 int cutoff_retry;
2167 int port;
2168 int hosts_defer = 0;
2169 int hosts_fail = 0;
2170 int hosts_looked_up = 0;
2171 int hosts_retry = 0;
2172 int hosts_serial = 0;
2173 int hosts_total = 0;
2174 int total_hosts_tried = 0;
2175 address_item *addr;
2176 BOOL expired = TRUE;
2177 BOOL continuing = continue_hostname != NULL;
2178 uschar *expanded_hosts = NULL;
2179 uschar *pistring;
2180 uschar *tid = string_sprintf("%s transport", tblock->name);
2181 smtp_transport_options_block *ob =
2182 (smtp_transport_options_block *)(tblock->options_block);
2183 host_item *hostlist = addrlist->host_list;
2184 host_item *host = NULL;
2185
2186 DEBUG(D_transport)
2187 {
2188 debug_printf("%s transport entered\n", tblock->name);
2189 for (addr = addrlist; addr != NULL; addr = addr->next)
2190 debug_printf(" %s\n", addr->address);
2191 if (continuing) debug_printf("already connected to %s [%s]\n",
2192 continue_hostname, continue_host_address);
2193 }
2194
2195 /* Set the flag requesting that these hosts be added to the waiting
2196 database if the delivery fails temporarily or if we are running with
2197 queue_smtp or a 2-stage queue run. This gets unset for certain
2198 kinds of error, typically those that are specific to the message. */
2199
2200 update_waiting = TRUE;
2201
2202 /* If a host list is not defined for the addresses - they must all have the
2203 same one in order to be passed to a single transport - or if the transport has
2204 a host list with hosts_override set, use the host list supplied with the
2205 transport. It is an error for this not to exist. */
2206
2207 if (hostlist == NULL || (ob->hosts_override && ob->hosts != NULL))
2208 {
2209 if (ob->hosts == NULL)
2210 {
2211 addrlist->message = string_sprintf("%s transport called with no hosts set",
2212 tblock->name);
2213 addrlist->transport_return = PANIC;
2214 return FALSE; /* Only top address has status */
2215 }
2216
2217 DEBUG(D_transport) debug_printf("using the transport's hosts: %s\n",
2218 ob->hosts);
2219
2220 /* If the transport's host list contains no '$' characters, and we are not
2221 randomizing, it is fixed and therefore a chain of hosts can be built once
2222 and for all, and remembered for subsequent use by other calls to this
2223 transport. If, on the other hand, the host list does contain '$', or we are
2224 randomizing its order, we have to rebuild it each time. In the fixed case,
2225 as the hosts string will never be used again, it doesn't matter that we
2226 replace all the : characters with zeros. */
2227
2228 if (ob->hostlist == NULL)
2229 {
2230 uschar *s = ob->hosts;
2231
2232 if (Ustrchr(s, '$') != NULL)
2233 {
2234 expanded_hosts = expand_string(s);
2235 if (expanded_hosts == NULL)
2236 {
2237 addrlist->message = string_sprintf("failed to expand list of hosts "
2238 "\"%s\" in %s transport: %s", s, tblock->name, expand_string_message);
2239 addrlist->transport_return = search_find_defer? DEFER : PANIC;
2240 return FALSE; /* Only top address has status */
2241 }
2242 DEBUG(D_transport) debug_printf("expanded list of hosts \"%s\" to "
2243 "\"%s\"\n", s, expanded_hosts);
2244 s = expanded_hosts;
2245 }
2246 else
2247 if (ob->hosts_randomize) s = expanded_hosts = string_copy(s);
2248
2249 host_build_hostlist(&hostlist, s, ob->hosts_randomize);
2250
2251 /* Check that the expansion yielded something useful. */
2252 if (hostlist == NULL)
2253 {
2254 addrlist->message =
2255 string_sprintf("%s transport has empty hosts setting", tblock->name);
2256 addrlist->transport_return = PANIC;
2257 return FALSE; /* Only top address has status */
2258 }
2259
2260 /* If there was no expansion of hosts, save the host list for
2261 next time. */
2262
2263 if (expanded_hosts == NULL) ob->hostlist = hostlist;
2264 }
2265
2266 /* This is not the first time this transport has been run in this delivery;
2267 the host list was built previously. */
2268
2269 else hostlist = ob->hostlist;
2270 }
2271
2272 /* The host list was supplied with the address. If hosts_randomize is set, we
2273 must sort it into a random order if it did not come from MX records and has not
2274 already been randomized (but don't bother if continuing down an existing
2275 connection). */
2276
2277 else if (ob->hosts_randomize && hostlist->mx == MX_NONE && !continuing)
2278 {
2279 host_item *newlist = NULL;
2280 while (hostlist != NULL)
2281 {
2282 host_item *h = hostlist;
2283 hostlist = hostlist->next;
2284
2285 h->sort_key = random_number(100);
2286
2287 if (newlist == NULL)
2288 {
2289 h->next = NULL;
2290 newlist = h;
2291 }
2292 else if (h->sort_key < newlist->sort_key)
2293 {
2294 h->next = newlist;
2295 newlist = h;
2296 }
2297 else
2298 {
2299 host_item *hh = newlist;
2300 while (hh->next != NULL)
2301 {
2302 if (h->sort_key < hh->next->sort_key) break;
2303 hh = hh->next;
2304 }
2305 h->next = hh->next;
2306 hh->next = h;
2307 }
2308 }
2309
2310 hostlist = addrlist->host_list = newlist;
2311 }
2312
2313
2314 /* Sort out the default port. */
2315
2316 if (!smtp_get_port(ob->port, addrlist, &port, tid)) return FALSE;
2317
2318
2319 /* For each host-plus-IP-address on the list:
2320
2321 . If this is a continued delivery and the host isn't the one with the
2322 current connection, skip.
2323
2324 . If the status is unusable (i.e. previously failed or retry checked), skip.
2325
2326 . If no IP address set, get the address, either by turning the name into
2327 an address, calling gethostbyname if gethostbyname is on, or by calling
2328 the DNS. The DNS may yield multiple addresses, in which case insert the
2329 extra ones into the list.
2330
2331 . Get the retry data if not previously obtained for this address and set the
2332 field which remembers the state of this address. Skip if the retry time is
2333 not reached. If not, remember whether retry data was found. The retry string
2334 contains both the name and the IP address.
2335
2336 . Scan the list of addresses and mark those whose status is DEFER as
2337 PENDING_DEFER. These are the only ones that will be processed in this cycle
2338 of the hosts loop.
2339
2340 . Make a delivery attempt - addresses marked PENDING_DEFER will be tried.
2341 Some addresses may be successfully delivered, others may fail, and yet
2342 others may get temporary errors and so get marked DEFER.
2343
2344 . The return from the delivery attempt is OK if a connection was made and a
2345 valid SMTP dialogue was completed. Otherwise it is DEFER.
2346
2347 . If OK, add a "remove" retry item for this host/IPaddress, if any.
2348
2349 . If fail to connect, or other defer state, add a retry item.
2350
2351 . If there are any addresses whose status is still DEFER, carry on to the
2352 next host/IPaddress, unless we have tried the number of hosts given
2353 by hosts_max_try or hosts_max_try_hardlimit; otherwise return. Note that
2354 there is some fancy logic for hosts_max_try that means its limit can be
2355 overstepped in some circumstances.
2356
2357 If we get to the end of the list, all hosts have deferred at least one address,
2358 or not reached their retry times. If delay_after_cutoff is unset, it requests a
2359 delivery attempt to those hosts whose last try was before the arrival time of
2360 the current message. To cope with this, we have to go round the loop a second
2361 time. After that, set the status and error data for any addresses that haven't
2362 had it set already. */
2363
2364 for (cutoff_retry = 0; expired &&
2365 cutoff_retry < ((ob->delay_after_cutoff)? 1 : 2);
2366 cutoff_retry++)
2367 {
2368 host_item *nexthost = NULL;
2369 int unexpired_hosts_tried = 0;
2370
2371 for (host = hostlist;
2372 host != NULL &&
2373 unexpired_hosts_tried < ob->hosts_max_try &&
2374 total_hosts_tried < ob->hosts_max_try_hardlimit;
2375 host = nexthost)
2376 {
2377 int rc;
2378 int host_af;
2379 uschar *rs;
2380 BOOL serialized = FALSE;
2381 BOOL host_is_expired = FALSE;
2382 BOOL message_defer = FALSE;
2383 BOOL ifchanges = FALSE;
2384 BOOL some_deferred = FALSE;
2385 address_item *first_addr = NULL;
2386 uschar *interface = NULL;
2387 uschar *retry_host_key = NULL;
2388 uschar *retry_message_key = NULL;
2389 uschar *serialize_key = NULL;
2390
2391 /* Default next host is next host. :-) But this can vary if the
2392 hosts_max_try limit is hit (see below). It may also be reset if a host
2393 address is looked up here (in case the host was multihomed). */
2394
2395 nexthost = host->next;
2396
2397 /* If the address hasn't yet been obtained from the host name, look it up
2398 now, unless the host is already marked as unusable. If it is marked as
2399 unusable, it means that the router was unable to find its IP address (in
2400 the DNS or wherever) OR we are in the 2nd time round the cutoff loop, and
2401 the lookup failed last time. We don't get this far if *all* MX records
2402 point to non-existent hosts; that is treated as a hard error.
2403
2404 We can just skip this host entirely. When the hosts came from the router,
2405 the address will timeout based on the other host(s); when the address is
2406 looked up below, there is an explicit retry record added.
2407
2408 Note that we mustn't skip unusable hosts if the address is not unset; they
2409 may be needed as expired hosts on the 2nd time round the cutoff loop. */
2410
2411 if (host->address == NULL)
2412 {
2413 int new_port, flags;
2414 host_item *hh;
2415 uschar *canonical_name;
2416
2417 if (host->status >= hstatus_unusable)
2418 {
2419 DEBUG(D_transport) debug_printf("%s has no address and is unusable - skipping\n",
2420 host->name);
2421 continue;
2422 }
2423
2424 DEBUG(D_transport) debug_printf("getting address for %s\n", host->name);
2425
2426 /* The host name is permitted to have an attached port. Find it, and
2427 strip it from the name. Just remember it for now. */
2428
2429 new_port = host_item_get_port(host);
2430
2431 /* Count hosts looked up */
2432
2433 hosts_looked_up++;
2434
2435 /* Find by name if so configured, or if it's an IP address. We don't
2436 just copy the IP address, because we need the test-for-local to happen. */
2437
2438 flags = HOST_FIND_BY_A;
2439 if (ob->dns_qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
2440 if (ob->dns_search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
2441
2442 if (ob->gethostbyname || string_is_ip_address(host->name, NULL) != 0)
2443 rc = host_find_byname(host, NULL, flags, &canonical_name, TRUE);
2444 else
2445 rc = host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
2446 &canonical_name, NULL);
2447
2448 /* Update the host (and any additional blocks, resulting from
2449 multihoming) with a host-specific port, if any. */
2450
2451 for (hh = host; hh != nexthost; hh = hh->next) hh->port = new_port;
2452
2453 /* Failure to find the host at this time (usually DNS temporary failure)
2454 is really a kind of routing failure rather than a transport failure.
2455 Therefore we add a retry item of the routing kind, not to stop us trying
2456 to look this name up here again, but to ensure the address gets timed
2457 out if the failures go on long enough. A complete failure at this point
2458 commonly points to a configuration error, but the best action is still
2459 to carry on for the next host. */
2460
2461 if (rc == HOST_FIND_AGAIN || rc == HOST_FIND_FAILED)
2462 {
2463 retry_add_item(addrlist, string_sprintf("R:%s", host->name), 0);
2464 expired = FALSE;
2465 if (rc == HOST_FIND_AGAIN) hosts_defer++; else hosts_fail++;
2466 DEBUG(D_transport) debug_printf("rc = %s for %s\n", (rc == HOST_FIND_AGAIN)?
2467 "HOST_FIND_AGAIN" : "HOST_FIND_FAILED", host->name);
2468 host->status = hstatus_unusable;
2469
2470 for (addr = addrlist; addr != NULL; addr = addr->next)
2471 {
2472 if (addr->transport_return != DEFER) continue;
2473 addr->basic_errno = ERRNO_UNKNOWNHOST;
2474 addr->message =
2475 string_sprintf("failed to lookup IP address for %s", host->name);
2476 }
2477 continue;
2478 }
2479
2480 /* If the host is actually the local host, we may have a problem, or
2481 there may be some cunning configuration going on. In the problem case,
2482 log things and give up. The default transport status is already DEFER. */
2483
2484 if (rc == HOST_FOUND_LOCAL && !ob->allow_localhost)
2485 {
2486 for (addr = addrlist; addr != NULL; addr = addr->next)
2487 {
2488 addr->basic_errno = 0;
2489 addr->message = string_sprintf("%s transport found host %s to be "
2490 "local", tblock->name, host->name);
2491 }
2492 goto END_TRANSPORT;
2493 }
2494 } /* End of block for IP address lookup */
2495
2496 /* If this is a continued delivery, we are interested only in the host
2497 which matches the name of the existing open channel. The check is put
2498 here after the local host lookup, in case the name gets expanded as a
2499 result of the lookup. Set expired FALSE, to save the outer loop executing
2500 twice. */
2501
2502 if (continuing && (Ustrcmp(continue_hostname, host->name) != 0 ||
2503 Ustrcmp(continue_host_address, host->address) != 0))
2504 {
2505 expired = FALSE;
2506 continue; /* With next host */
2507 }
2508
2509 /* Reset the default next host in case a multihomed host whose addresses
2510 are not looked up till just above added to the host list. */
2511
2512 nexthost = host->next;
2513
2514 /* If queue_smtp is set (-odqs or the first part of a 2-stage run), or the
2515 domain is in queue_smtp_domains, we don't actually want to attempt any
2516 deliveries. When doing a queue run, queue_smtp_domains is always unset. If
2517 there is a lookup defer in queue_smtp_domains, proceed as if the domain
2518 were not in it. We don't want to hold up all SMTP deliveries! Except when
2519 doing a two-stage queue run, don't do this if forcing. */
2520
2521 if ((!deliver_force || queue_2stage) && (queue_smtp ||
2522 match_isinlist(addrlist->domain, &queue_smtp_domains, 0,
2523 &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL) == OK))
2524 {
2525 expired = FALSE;
2526 for (addr = addrlist; addr != NULL; addr = addr->next)
2527 {
2528 if (addr->transport_return != DEFER) continue;
2529 addr->message = US"domain matches queue_smtp_domains, or -odqs set";
2530 }
2531 continue; /* With next host */
2532 }
2533
2534 /* Count hosts being considered - purely for an intelligent comment
2535 if none are usable. */
2536
2537 hosts_total++;
2538
2539 /* Set $host and $host address now in case they are needed for the
2540 interface expansion or the serialize_hosts check; they remain set if an
2541 actual delivery happens. */
2542
2543 deliver_host = host->name;
2544 deliver_host_address = host->address;
2545
2546 /* Set up a string for adding to the retry key if the port number is not
2547 the standard SMTP port. A host may have its own port setting that overrides
2548 the default. */
2549
2550 pistring = string_sprintf(":%d", (host->port == PORT_NONE)?
2551 port : host->port);
2552 if (Ustrcmp(pistring, ":25") == 0) pistring = US"";
2553
2554 /* Select IPv4 or IPv6, and choose an outgoing interface. If the interface
2555 string changes upon expansion, we must add it to the key that is used for
2556 retries, because connections to the same host from a different interface
2557 should be treated separately. */
2558
2559 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET : AF_INET6;
2560 if (!smtp_get_interface(ob->interface, host_af, addrlist, &ifchanges,
2561 &interface, tid))
2562 return FALSE;
2563 if (ifchanges) pistring = string_sprintf("%s/%s", pistring, interface);
2564
2565 /* The first time round the outer loop, check the status of the host by
2566 inspecting the retry data. The second time round, we are interested only
2567 in expired hosts that haven't been tried since this message arrived. */
2568
2569 if (cutoff_retry == 0)
2570 {
2571 /* Ensure the status of the address is set by checking retry data if
2572 necessary. There maybe host-specific retry data (applicable to all
2573 messages) and also data for retries of a specific message at this host.
2574 If either of these retry records are actually read, the keys used are
2575 returned to save recomputing them later. */
2576
2577 host_is_expired = retry_check_address(addrlist->domain, host, pistring,
2578 ob->retry_include_ip_address, &retry_host_key, &retry_message_key);
2579
2580 DEBUG(D_transport) debug_printf("%s [%s]%s status = %s\n", host->name,
2581 (host->address == NULL)? US"" : host->address, pistring,
2582 (host->status == hstatus_usable)? "usable" :
2583 (host->status == hstatus_unusable)? "unusable" :
2584 (host->status == hstatus_unusable_expired)? "unusable (expired)" : "?");
2585
2586 /* Skip this address if not usable at this time, noting if it wasn't
2587 actually expired, both locally and in the address. */
2588
2589 switch (host->status)
2590 {
2591 case hstatus_unusable:
2592 expired = FALSE;
2593 setflag(addrlist, af_retry_skipped);
2594 /* Fall through */
2595
2596 case hstatus_unusable_expired:
2597 switch (host->why)
2598 {
2599 case hwhy_retry: hosts_retry++; break;
2600 case hwhy_failed: hosts_fail++; break;
2601 case hwhy_deferred: hosts_defer++; break;
2602 }
2603
2604 /* If there was a retry message key, implying that previously there
2605 was a message-specific defer, we don't want to update the list of
2606 messages waiting for these hosts. */
2607
2608 if (retry_message_key != NULL) update_waiting = FALSE;
2609 continue; /* With the next host or IP address */
2610 }
2611 }
2612
2613 /* Second time round the loop: if the address is set but expired, and
2614 the message is newer than the last try, let it through. */
2615
2616 else
2617 {
2618 if (host->address == NULL ||
2619 host->status != hstatus_unusable_expired ||
2620 host->last_try > received_time)
2621 continue;
2622 DEBUG(D_transport)
2623 debug_printf("trying expired host %s [%s]%s\n",
2624 host->name, host->address, pistring);
2625 host_is_expired = TRUE;
2626 }
2627
2628 /* Setting "expired=FALSE" doesn't actually mean not all hosts are expired;
2629 it remains TRUE only if all hosts are expired and none are actually tried.
2630 */
2631
2632 expired = FALSE;
2633
2634 /* If this host is listed as one to which access must be serialized,
2635 see if another Exim process has a connection to it, and if so, skip
2636 this host. If not, update the database to record our connection to it
2637 and remember this for later deletion. Do not do any of this if we are
2638 sending the message down a pre-existing connection. */
2639
2640 if (!continuing &&
2641 verify_check_this_host(&(ob->serialize_hosts), NULL, host->name,
2642 host->address, NULL) == OK)
2643 {
2644 serialize_key = string_sprintf("host-serialize-%s", host->name);
2645 if (!enq_start(serialize_key))
2646 {
2647 DEBUG(D_transport)
2648 debug_printf("skipping host %s because another Exim process "
2649 "is connected to it\n", host->name);
2650 hosts_serial++;
2651 continue;
2652 }
2653 serialized = TRUE;
2654 }
2655
2656 /* OK, we have an IP address that is not waiting for its retry time to
2657 arrive (it might be expired) OR (second time round the loop) we have an
2658 expired host that hasn't been tried since the message arrived. Have a go
2659 at delivering the message to it. First prepare the addresses by flushing
2660 out the result of previous attempts, and finding the first address that
2661 is still to be delivered. */
2662
2663 first_addr = prepare_addresses(addrlist, host);
2664
2665 DEBUG(D_transport) debug_printf("delivering %s to %s [%s] (%s%s)\n",
2666 message_id, host->name, host->address, addrlist->address,
2667 (addrlist->next == NULL)? "" : ", ...");
2668
2669 set_process_info("delivering %s to %s [%s] (%s%s)",
2670 message_id, host->name, host->address, addrlist->address,
2671 (addrlist->next == NULL)? "" : ", ...");
2672
2673 /* This is not for real; don't do the delivery. If there are
2674 any remaining hosts, list them. */
2675
2676 if (dont_deliver)
2677 {
2678 host_item *host2;
2679 set_errno(addrlist, 0, NULL, OK, FALSE);
2680 for (addr = addrlist; addr != NULL; addr = addr->next)
2681 {
2682 addr->host_used = host;
2683 addr->special_action = '*';
2684 addr->message = US"delivery bypassed by -N option";
2685 }
2686 DEBUG(D_transport)
2687 {
2688 debug_printf("*** delivery by %s transport bypassed by -N option\n"
2689 "*** host and remaining hosts:\n", tblock->name);
2690 for (host2 = host; host2 != NULL; host2 = host2->next)
2691 debug_printf(" %s [%s]\n", host2->name,
2692 (host2->address == NULL)? US"unset" : host2->address);
2693 }
2694 rc = OK;
2695 }
2696
2697 /* This is for real. If the host is expired, we don't count it for
2698 hosts_max_retry. This ensures that all hosts must expire before an address
2699 is timed out, unless hosts_max_try_hardlimit (which protects against
2700 lunatic DNS configurations) is reached.
2701
2702 If the host is not expired and we are about to hit the hosts_max_retry
2703 limit, check to see if there is a subsequent hosts with a different MX
2704 value. If so, make that the next host, and don't count this one. This is a
2705 heuristic to make sure that different MXs do get tried. With a normal kind
2706 of retry rule, they would get tried anyway when the earlier hosts were
2707 delayed, but if the domain has a "retry every time" type of rule - as is
2708 often used for the the very large ISPs, that won't happen. */
2709
2710 else
2711 {
2712 if (!host_is_expired && ++unexpired_hosts_tried >= ob->hosts_max_try)
2713 {
2714 host_item *h;
2715 DEBUG(D_transport)
2716 debug_printf("hosts_max_try limit reached with this host\n");
2717 for (h = host; h != NULL; h = h->next)
2718 if (h->mx != host->mx) break;
2719 if (h != NULL)
2720 {
2721 nexthost = h;
2722 unexpired_hosts_tried--;
2723 DEBUG(D_transport) debug_printf("however, a higher MX host exists "
2724 "and will be tried\n");
2725 }
2726 }
2727
2728 /* Attempt the delivery. */
2729
2730 total_hosts_tried++;
2731 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2732 expanded_hosts != NULL, &message_defer, FALSE);
2733
2734 /* Yield is one of:
2735 OK => connection made, each address contains its result;
2736 message_defer is set for message-specific defers (when all
2737 recipients are marked defer)
2738 DEFER => there was a non-message-specific delivery problem;
2739 ERROR => there was a problem setting up the arguments for a filter,
2740 or there was a problem with expanding added headers
2741 */
2742
2743 /* If the result is not OK, there was a non-message-specific problem.
2744 If the result is DEFER, we need to write to the logs saying what happened
2745 for this particular host, except in the case of authentication and TLS
2746 failures, where the log has already been written. If all hosts defer a
2747 general message is written at the end. */
2748
2749 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL &&
2750 first_addr->basic_errno != ERRNO_TLSFAILURE)
2751 write_logs(first_addr, host);
2752
2753 /* If STARTTLS was accepted, but there was a failure in setting up the
2754 TLS session (usually a certificate screwup), and the host is not in
2755 hosts_require_tls, and tls_tempfail_tryclear is true, try again, with
2756 TLS forcibly turned off. We have to start from scratch with a new SMTP
2757 connection. That's why the retry is done from here, not from within
2758 smtp_deliver(). [Rejections of STARTTLS itself don't screw up the
2759 session, so the in-clear transmission after those errors, if permitted,
2760 happens inside smtp_deliver().] */
2761
2762 #ifdef SUPPORT_TLS
2763 if (rc == DEFER && first_addr->basic_errno == ERRNO_TLSFAILURE &&
2764 ob->tls_tempfail_tryclear &&
2765 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
2766 host->address, NULL) != OK)
2767 {
2768 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
2769 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
2770 first_addr = prepare_addresses(addrlist, host);
2771 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2772 expanded_hosts != NULL, &message_defer, TRUE);
2773 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL)
2774 write_logs(first_addr, host);
2775 }
2776 #endif
2777 }
2778
2779 /* Delivery attempt finished */
2780
2781 rs = (rc == OK)? US"OK" : (rc == DEFER)? US"DEFER" : (rc == ERROR)?
2782 US"ERROR" : US"?";
2783
2784 set_process_info("delivering %s: just tried %s [%s] for %s%s: result %s",
2785 message_id, host->name, host->address, addrlist->address,
2786 (addrlist->next == NULL)? "" : " (& others)", rs);
2787
2788 /* Release serialization if set up */
2789
2790 if (serialized) enq_end(serialize_key);
2791
2792 /* If the result is DEFER, or if a host retry record is known to exist, we
2793 need to add an item to the retry chain for updating the retry database
2794 at the end of delivery. We only need to add the item to the top address,
2795 of course. Also, if DEFER, we mark the IP address unusable so as to skip it
2796 for any other delivery attempts using the same address. (It is copied into
2797 the unusable tree at the outer level, so even if different address blocks
2798 contain the same address, it still won't get tried again.) */
2799
2800 if (rc == DEFER || retry_host_key != NULL)
2801 {
2802 int delete_flag = (rc != DEFER)? rf_delete : 0;
2803 if (retry_host_key == NULL)
2804 {
2805 retry_host_key = ob->retry_include_ip_address?
2806 string_sprintf("T:%S:%s%s", host->name, host->address, pistring) :
2807 string_sprintf("T:%S%s", host->name, pistring);
2808 }
2809
2810 /* If a delivery of another message over an existing SMTP connection
2811 yields DEFER, we do NOT set up retry data for the host. This covers the
2812 case when there are delays in routing the addresses in the second message
2813 that are so long that the server times out. This is alleviated by not
2814 routing addresses that previously had routing defers when handling an
2815 existing connection, but even so, this case may occur (e.g. if a
2816 previously happily routed address starts giving routing defers). If the
2817 host is genuinely down, another non-continued message delivery will
2818 notice it soon enough. */
2819
2820 if (delete_flag != 0 || !continuing)
2821 retry_add_item(first_addr, retry_host_key, rf_host | delete_flag);
2822
2823 /* We may have tried an expired host, if its retry time has come; ensure
2824 the status reflects the expiry for the benefit of any other addresses. */
2825
2826 if (rc == DEFER)
2827 {
2828 host->status = (host_is_expired)?
2829 hstatus_unusable_expired : hstatus_unusable;
2830 host->why = hwhy_deferred;
2831 }
2832 }
2833
2834 /* If message_defer is set (host was OK, but every recipient got deferred
2835 because of some message-specific problem), or if that had happened
2836 previously so that a message retry key exists, add an appropriate item
2837 to the retry chain. Note that if there was a message defer but now there is
2838 a host defer, the message defer record gets deleted. That seems perfectly
2839 reasonable. Also, stop the message from being remembered as waiting
2840 for specific hosts. */
2841
2842 if (message_defer || retry_message_key != NULL)
2843 {
2844 int delete_flag = message_defer? 0 : rf_delete;
2845 if (retry_message_key == NULL)
2846 {
2847 retry_message_key = ob->retry_include_ip_address?
2848 string_sprintf("T:%S:%s%s:%s", host->name, host->address, pistring,
2849 message_id) :
2850 string_sprintf("T:%S%s:%s", host->name, pistring, message_id);
2851 }
2852 retry_add_item(addrlist, retry_message_key,
2853 rf_message | rf_host | delete_flag);
2854 update_waiting = FALSE;
2855 }
2856
2857 /* Any return other than DEFER (that is, OK or ERROR) means that the
2858 addresses have got their final statuses filled in for this host. In the OK
2859 case, see if any of them are deferred. */
2860
2861 if (rc == OK)
2862 {
2863 for (addr = addrlist; addr != NULL; addr = addr->next)
2864 {
2865 if (addr->transport_return == DEFER)
2866 {
2867 some_deferred = TRUE;
2868 break;
2869 }
2870 }
2871 }
2872
2873 /* If no addresses deferred or the result was ERROR, return. We do this for
2874 ERROR because a failing filter set-up or add_headers expansion is likely to
2875 fail for any host we try. */
2876
2877 if (rc == ERROR || (rc == OK && !some_deferred))
2878 {
2879 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2880 return TRUE; /* Each address has its status */
2881 }
2882
2883 /* If the result was DEFER or some individual addresses deferred, let
2884 the loop run to try other hosts with the deferred addresses, except for the
2885 case when we were trying to deliver down an existing channel and failed.
2886 Don't try any other hosts in this case. */
2887
2888 if (continuing) break;
2889
2890 /* If the whole delivery, or some individual addresses, were deferred and
2891 there are more hosts that could be tried, do not count this host towards
2892 the hosts_max_try limit if the age of the message is greater than the
2893 maximum retry time for this host. This means we may try try all hosts,
2894 ignoring the limit, when messages have been around for some time. This is
2895 important because if we don't try all hosts, the address will never time
2896 out. NOTE: this does not apply to hosts_max_try_hardlimit. */
2897
2898 if ((rc == DEFER || some_deferred) && nexthost != NULL)
2899 {
2900 BOOL timedout;
2901 retry_config *retry = retry_find_config(host->name, NULL, 0, 0);
2902
2903 if (retry != NULL && retry->rules != NULL)
2904 {
2905 retry_rule *last_rule;
2906 for (last_rule = retry->rules;
2907 last_rule->next != NULL;
2908 last_rule = last_rule->next);
2909 timedout = time(NULL) - received_time > last_rule->timeout;
2910 }
2911 else timedout = TRUE; /* No rule => timed out */
2912
2913 if (timedout)
2914 {
2915 unexpired_hosts_tried--;
2916 DEBUG(D_transport) debug_printf("temporary delivery error(s) override "
2917 "hosts_max_try (message older than host's retry time)\n");
2918 }
2919 }
2920 } /* End of loop for trying multiple hosts. */
2921
2922 /* This is the end of the loop that repeats iff expired is TRUE and
2923 ob->delay_after_cutoff is FALSE. The second time round we will
2924 try those hosts that haven't been tried since the message arrived. */
2925
2926 DEBUG(D_transport)
2927 {
2928 debug_printf("all IP addresses skipped or deferred at least one address\n");
2929 if (expired && !ob->delay_after_cutoff && cutoff_retry == 0)
2930 debug_printf("retrying IP addresses not tried since message arrived\n");
2931 }
2932 }
2933
2934
2935 /* Get here if all IP addresses are skipped or defer at least one address. In
2936 MUA wrapper mode, this will happen only for connection or other non-message-
2937 specific failures. Force the delivery status for all addresses to FAIL. */
2938
2939 if (mua_wrapper)
2940 {
2941 for (addr = addrlist; addr != NULL; addr = addr->next)
2942 addr->transport_return = FAIL;
2943 goto END_TRANSPORT;
2944 }
2945
2946 /* In the normal, non-wrapper case, add a standard message to each deferred
2947 address if there hasn't been an error, that is, if it hasn't actually been
2948 tried this time. The variable "expired" will be FALSE if any deliveries were
2949 actually tried, or if there was at least one host that was not expired. That
2950 is, it is TRUE only if no deliveries were tried and all hosts were expired. If
2951 a delivery has been tried, an error code will be set, and the failing of the
2952 message is handled by the retry code later.
2953
2954 If queue_smtp is set, or this transport was called to send a subsequent message
2955 down an existing TCP/IP connection, and something caused the host not to be
2956 found, we end up here, but can detect these cases and handle them specially. */
2957
2958 for (addr = addrlist; addr != NULL; addr = addr->next)
2959 {
2960 /* If host is not NULL, it means that we stopped processing the host list
2961 because of hosts_max_try or hosts_max_try_hardlimit. In the former case, this
2962 means we need to behave as if some hosts were skipped because their retry
2963 time had not come. Specifically, this prevents the address from timing out.
2964 However, if we have hit hosts_max_try_hardlimit, we want to behave as if all
2965 hosts were tried. */
2966
2967 if (host != NULL)
2968 {
2969 if (total_hosts_tried >= ob->hosts_max_try_hardlimit)
2970 {
2971 DEBUG(D_transport)
2972 debug_printf("hosts_max_try_hardlimit reached: behave as if all "
2973 "hosts were tried\n");
2974 }
2975 else
2976 {
2977 DEBUG(D_transport)
2978 debug_printf("hosts_max_try limit caused some hosts to be skipped\n");
2979 setflag(addr, af_retry_skipped);
2980 }
2981 }
2982
2983 if (queue_smtp) /* no deliveries attempted */
2984 {
2985 addr->transport_return = DEFER;
2986 addr->basic_errno = 0;
2987 addr->message = US"SMTP delivery explicitly queued";
2988 }
2989
2990 else if (addr->transport_return == DEFER &&
2991 (addr->basic_errno == ERRNO_UNKNOWNERROR || addr->basic_errno == 0) &&
2992 addr->message == NULL)
2993 {
2994 addr->basic_errno = ERRNO_HRETRY;
2995 if (continue_hostname != NULL)
2996 {
2997 addr->message = US"no host found for existing SMTP connection";
2998 }
2999 else if (expired)
3000 {
3001 setflag(addr, af_pass_message); /* This is not a security risk */
3002 addr->message = (ob->delay_after_cutoff)?
3003 US"retry time not reached for any host after a long failure period" :
3004 US"all hosts have been failing for a long time and were last tried "
3005 "after this message arrived";
3006
3007 /* If we are already using fallback hosts, or there are no fallback hosts
3008 defined, convert the result to FAIL to cause a bounce. */
3009
3010 if (addr->host_list == addr->fallback_hosts ||
3011 addr->fallback_hosts == NULL)
3012 addr->transport_return = FAIL;
3013 }
3014 else
3015 {
3016 if (hosts_retry == hosts_total)
3017 addr->message = US"retry time not reached for any host";
3018 else if (hosts_fail == hosts_total)
3019 addr->message = US"all host address lookups failed permanently";
3020 else if (hosts_defer == hosts_total)
3021 addr->message = US"all host address lookups failed temporarily";
3022 else if (hosts_serial == hosts_total)
3023 addr->message = US"connection limit reached for all hosts";
3024 else if (hosts_fail+hosts_defer == hosts_total)
3025 addr->message = US"all host address lookups failed";
3026 else addr->message = US"some host address lookups failed and retry time "
3027 "not reached for other hosts or connection limit reached";
3028 }
3029 }
3030 }
3031
3032 /* Update the database which keeps information about which messages are waiting
3033 for which hosts to become available. For some message-specific errors, the
3034 update_waiting flag is turned off because we don't want follow-on deliveries in
3035 those cases. */
3036
3037 if (update_waiting) transport_update_waiting(hostlist, tblock->name);
3038
3039 END_TRANSPORT:
3040
3041 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
3042
3043 return TRUE; /* Each address has its status */
3044 }
3045
3046 /* End of transport/smtp.c */