Bugzilla #1067 - DKIM: Fix relaxed header canon for headers ending with whitespace.
[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 Ustrncpy(buffer, buffer2, sizeof(buffer));
1082 if (errno != 0 || buffer2[0] == 0 ||
1083 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
1084 goto RESPONSE_FAILED;
1085 }
1086
1087 /* STARTTLS accepted: try to negotiate a TLS session. */
1088
1089 else
1090 {
1091 int rc = tls_client_start(inblock.sock,
1092 host,
1093 addrlist,
1094 NULL, /* No DH param */
1095 ob->tls_certificate,
1096 ob->tls_privatekey,
1097 ob->tls_verify_certificates,
1098 ob->tls_crl,
1099 ob->tls_require_ciphers,
1100 ob->gnutls_require_mac,
1101 ob->gnutls_require_kx,
1102 ob->gnutls_require_proto,
1103 ob->command_timeout);
1104
1105 /* TLS negotiation failed; give an error. From outside, this function may
1106 be called again to try in clear on a new connection, if the options permit
1107 it for this host. */
1108
1109 if (rc != OK)
1110 {
1111 save_errno = ERRNO_TLSFAILURE;
1112 message = US"failure while setting up TLS session";
1113 send_quit = FALSE;
1114 goto TLS_FAILED;
1115 }
1116
1117 /* TLS session is set up */
1118
1119 for (addr = addrlist; addr != NULL; addr = addr->next)
1120 {
1121 if (addr->transport_return == PENDING_DEFER)
1122 {
1123 addr->cipher = tls_cipher;
1124 addr->peerdn = tls_peerdn;
1125 }
1126 }
1127 }
1128 }
1129
1130 /* If we started TLS, redo the EHLO/LHLO exchange over the secure channel. If
1131 helo_data is null, we are dealing with a connection that was passed from
1132 another process, and so we won't have expanded helo_data above. We have to
1133 expand it here. $sending_ip_address and $sending_port are set up right at the
1134 start of the Exim process (in exim.c). */
1135
1136 if (tls_active >= 0)
1137 {
1138 if (helo_data == NULL)
1139 {
1140 helo_data = expand_string(ob->helo_data);
1141 if (helo_data == NULL)
1142 {
1143 uschar *message = string_sprintf("failed to expand helo_data: %s",
1144 expand_string_message);
1145 set_errno(addrlist, 0, message, DEFER, FALSE);
1146 yield = DEFER;
1147 goto SEND_QUIT;
1148 }
1149 }
1150
1151 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n", lmtp? "LHLO" : "EHLO",
1152 helo_data) < 0)
1153 goto SEND_FAILED;
1154 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1155 ob->command_timeout))
1156 goto RESPONSE_FAILED;
1157 }
1158
1159 /* If the host is required to use a secure channel, ensure that we
1160 have one. */
1161
1162 else if (verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
1163 host->address, NULL) == OK)
1164 {
1165 save_errno = ERRNO_TLSREQUIRED;
1166 message = string_sprintf("a TLS session is required for %s [%s], but %s",
1167 host->name, host->address,
1168 tls_offered? "an attempt to start TLS failed" :
1169 "the server did not offer TLS support");
1170 goto TLS_FAILED;
1171 }
1172 #endif
1173
1174 /* If TLS is active, we have just started it up and re-done the EHLO command,
1175 so its response needs to be analyzed. If TLS is not active and this is a
1176 continued session down a previously-used socket, we haven't just done EHLO, so
1177 we skip this. */
1178
1179 if (continue_hostname == NULL
1180 #ifdef SUPPORT_TLS
1181 || tls_active >= 0
1182 #endif
1183 )
1184 {
1185 int require_auth;
1186 uschar *fail_reason = US"server did not advertise AUTH support";
1187
1188 /* Set for IGNOREQUOTA if the response to LHLO specifies support and the
1189 lmtp_ignore_quota option was set. */
1190
1191 igquotstr = (lmtp && ob->lmtp_ignore_quota &&
1192 pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer, Ustrlen(CS buffer), 0,
1193 PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
1194
1195 /* If the response to EHLO specified support for the SIZE parameter, note
1196 this, provided size_addition is non-negative. */
1197
1198 smtp_use_size = esmtp && ob->size_addition >= 0 &&
1199 pcre_exec(regex_SIZE, NULL, CS buffer, Ustrlen(CS buffer), 0,
1200 PCRE_EOPT, NULL, 0) >= 0;
1201
1202 /* Note whether the server supports PIPELINING. If hosts_avoid_esmtp matched
1203 the current host, esmtp will be false, so PIPELINING can never be used. If
1204 the current host matches hosts_avoid_pipelining, don't do it. */
1205
1206 smtp_use_pipelining = esmtp &&
1207 verify_check_this_host(&(ob->hosts_avoid_pipelining), NULL, host->name,
1208 host->address, NULL) != OK &&
1209 pcre_exec(regex_PIPELINING, NULL, CS buffer, Ustrlen(CS buffer), 0,
1210 PCRE_EOPT, NULL, 0) >= 0;
1211
1212 DEBUG(D_transport) debug_printf("%susing PIPELINING\n",
1213 smtp_use_pipelining? "" : "not ");
1214
1215 /* Note if the response to EHLO specifies support for the AUTH extension.
1216 If it has, check that this host is one we want to authenticate to, and do
1217 the business. The host name and address must be available when the
1218 authenticator's client driver is running. */
1219
1220 smtp_authenticated = FALSE;
1221 require_auth = verify_check_this_host(&(ob->hosts_require_auth), NULL,
1222 host->name, host->address, NULL);
1223
1224 if (esmtp && regex_match_and_setup(regex_AUTH, buffer, 0, -1))
1225 {
1226 uschar *names = string_copyn(expand_nstring[1], expand_nlength[1]);
1227 expand_nmax = -1; /* reset */
1228
1229 /* Must not do this check until after we have saved the result of the
1230 regex match above. */
1231
1232 if (require_auth == OK ||
1233 verify_check_this_host(&(ob->hosts_try_auth), NULL, host->name,
1234 host->address, NULL) == OK)
1235 {
1236 auth_instance *au;
1237 fail_reason = US"no common mechanisms were found";
1238
1239 DEBUG(D_transport) debug_printf("scanning authentication mechanisms\n");
1240
1241 /* Scan the configured authenticators looking for one which is configured
1242 for use as a client, which is not suppressed by client_condition, and
1243 whose name matches an authentication mechanism supported by the server.
1244 If one is found, attempt to authenticate by calling its client function.
1245 */
1246
1247 for (au = auths; !smtp_authenticated && au != NULL; au = au->next)
1248 {
1249 uschar *p = names;
1250 if (!au->client ||
1251 (au->client_condition != NULL &&
1252 !expand_check_condition(au->client_condition, au->name,
1253 US"client authenticator")))
1254 {
1255 DEBUG(D_transport) debug_printf("skipping %s authenticator: %s\n",
1256 au->name,
1257 (au->client)? "client_condition is false" :
1258 "not configured as a client");
1259 continue;
1260 }
1261
1262 /* Loop to scan supported server mechanisms */
1263
1264 while (*p != 0)
1265 {
1266 int rc;
1267 int len = Ustrlen(au->public_name);
1268 while (isspace(*p)) p++;
1269
1270 if (strncmpic(au->public_name, p, len) != 0 ||
1271 (p[len] != 0 && !isspace(p[len])))
1272 {
1273 while (*p != 0 && !isspace(*p)) p++;
1274 continue;
1275 }
1276
1277 /* Found data for a listed mechanism. Call its client entry. Set
1278 a flag in the outblock so that data is overwritten after sending so
1279 that reflections don't show it. */
1280
1281 fail_reason = US"authentication attempt(s) failed";
1282 outblock.authenticating = TRUE;
1283 rc = (au->info->clientcode)(au, &inblock, &outblock,
1284 ob->command_timeout, buffer, sizeof(buffer));
1285 outblock.authenticating = FALSE;
1286 DEBUG(D_transport) debug_printf("%s authenticator yielded %d\n",
1287 au->name, rc);
1288
1289 /* A temporary authentication failure must hold up delivery to
1290 this host. After a permanent authentication failure, we carry on
1291 to try other authentication methods. If all fail hard, try to
1292 deliver the message unauthenticated unless require_auth was set. */
1293
1294 switch(rc)
1295 {
1296 case OK:
1297 smtp_authenticated = TRUE; /* stops the outer loop */
1298 break;
1299
1300 /* Failure after writing a command */
1301
1302 case FAIL_SEND:
1303 goto SEND_FAILED;
1304
1305 /* Failure after reading a response */
1306
1307 case FAIL:
1308 if (errno != 0 || buffer[0] != '5') goto RESPONSE_FAILED;
1309 log_write(0, LOG_MAIN, "%s authenticator failed H=%s [%s] %s",
1310 au->name, host->name, host->address, buffer);
1311 break;
1312
1313 /* Failure by some other means. In effect, the authenticator
1314 decided it wasn't prepared to handle this case. Typically this
1315 is the result of "fail" in an expansion string. Do we need to
1316 log anything here? Feb 2006: a message is now put in the buffer
1317 if logging is required. */
1318
1319 case CANCELLED:
1320 if (*buffer != 0)
1321 log_write(0, LOG_MAIN, "%s authenticator cancelled "
1322 "authentication H=%s [%s] %s", au->name, host->name,
1323 host->address, buffer);
1324 break;
1325
1326 /* Internal problem, message in buffer. */
1327
1328 case ERROR:
1329 yield = ERROR;
1330 set_errno(addrlist, 0, string_copy(buffer), DEFER, FALSE);
1331 goto SEND_QUIT;
1332 }
1333
1334 break; /* If not authenticated, try next authenticator */
1335 } /* Loop for scanning supported server mechanisms */
1336 } /* Loop for further authenticators */
1337 }
1338 }
1339
1340 /* If we haven't authenticated, but are required to, give up. */
1341
1342 if (require_auth == OK && !smtp_authenticated)
1343 {
1344 yield = DEFER;
1345 set_errno(addrlist, ERRNO_AUTHFAIL,
1346 string_sprintf("authentication required but %s", fail_reason), DEFER,
1347 FALSE);
1348 goto SEND_QUIT;
1349 }
1350 }
1351
1352 /* The setting up of the SMTP call is now complete. Any subsequent errors are
1353 message-specific. */
1354
1355 setting_up = FALSE;
1356
1357 /* If there is a filter command specified for this transport, we can now
1358 set it up. This cannot be done until the identify of the host is known. */
1359
1360 if (tblock->filter_command != NULL)
1361 {
1362 BOOL rc;
1363 uschar buffer[64];
1364 sprintf(CS buffer, "%.50s transport", tblock->name);
1365 rc = transport_set_up_command(&transport_filter_argv, tblock->filter_command,
1366 TRUE, DEFER, addrlist, buffer, NULL);
1367 transport_filter_timeout = tblock->filter_timeout;
1368
1369 /* On failure, copy the error to all addresses, abandon the SMTP call, and
1370 yield ERROR. */
1371
1372 if (!rc)
1373 {
1374 set_errno(addrlist->next, addrlist->basic_errno, addrlist->message, DEFER,
1375 FALSE);
1376 yield = ERROR;
1377 goto SEND_QUIT;
1378 }
1379 }
1380
1381
1382 /* For messages that have more than the maximum number of envelope recipients,
1383 we want to send several transactions down the same SMTP connection. (See
1384 comments in deliver.c as to how this reconciles, heuristically, with
1385 remote_max_parallel.) This optimization was added to Exim after the following
1386 code was already working. The simplest way to put it in without disturbing the
1387 code was to use a goto to jump back to this point when there is another
1388 transaction to handle. */
1389
1390 SEND_MESSAGE:
1391 sync_addr = first_addr;
1392 address_count = 0;
1393 ok = FALSE;
1394 send_rset = TRUE;
1395 completed_address = FALSE;
1396
1397
1398 /* Initiate a message transfer. If we know the receiving MTA supports the SIZE
1399 qualification, send it, adding something to the message size to allow for
1400 imprecision and things that get added en route. Exim keeps the number of lines
1401 in a message, so we can give an accurate value for the original message, but we
1402 need some additional to handle added headers. (Double "." characters don't get
1403 included in the count.) */
1404
1405 p = buffer;
1406 *p = 0;
1407
1408 if (smtp_use_size)
1409 {
1410 sprintf(CS p, " SIZE=%d", message_size+message_linecount+ob->size_addition);
1411 while (*p) p++;
1412 }
1413
1414 /* Add the authenticated sender address if present */
1415
1416 if ((smtp_authenticated || ob->authenticated_sender_force) &&
1417 local_authenticated_sender != NULL)
1418 {
1419 string_format(p, sizeof(buffer) - (p-buffer), " AUTH=%s",
1420 auth_xtextencode(local_authenticated_sender,
1421 Ustrlen(local_authenticated_sender)));
1422 }
1423
1424 /* From here until we send the DATA command, we can make use of PIPELINING
1425 if the server host supports it. The code has to be able to check the responses
1426 at any point, for when the buffer fills up, so we write it totally generally.
1427 When PIPELINING is off, each command written reports that it has flushed the
1428 buffer. */
1429
1430 pending_MAIL = TRUE; /* The block starts with MAIL */
1431
1432 rc = smtp_write_command(&outblock, smtp_use_pipelining,
1433 "MAIL FROM:<%s>%s\r\n", return_path, buffer);
1434 mail_command = string_copy(big_buffer); /* Save for later error message */
1435
1436 switch(rc)
1437 {
1438 case -1: /* Transmission error */
1439 goto SEND_FAILED;
1440
1441 case +1: /* Block was sent */
1442 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1443 ob->command_timeout))
1444 {
1445 if (errno == 0 && buffer[0] == '4')
1446 {
1447 errno = ERRNO_MAIL4XX;
1448 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1449 }
1450 goto RESPONSE_FAILED;
1451 }
1452 pending_MAIL = FALSE;
1453 break;
1454 }
1455
1456 /* Pass over all the relevant recipient addresses for this host, which are the
1457 ones that have status PENDING_DEFER. If we are using PIPELINING, we can send
1458 several before we have to read the responses for those seen so far. This
1459 checking is done by a subroutine because it also needs to be done at the end.
1460 Send only up to max_rcpt addresses at a time, leaving first_addr pointing to
1461 the next one if not all are sent.
1462
1463 In the MUA wrapper situation, we want to flush the PIPELINING buffer for the
1464 last address because we want to abort if any recipients have any kind of
1465 problem, temporary or permanent. We know that all recipient addresses will have
1466 the PENDING_DEFER status, because only one attempt is ever made, and we know
1467 that max_rcpt will be large, so all addresses will be done at once. */
1468
1469 for (addr = first_addr;
1470 address_count < max_rcpt && addr != NULL;
1471 addr = addr->next)
1472 {
1473 int count;
1474 BOOL no_flush;
1475
1476 if (addr->transport_return != PENDING_DEFER) continue;
1477
1478 address_count++;
1479 no_flush = smtp_use_pipelining && (!mua_wrapper || addr->next != NULL);
1480
1481 /* Now send the RCPT command, and process outstanding responses when
1482 necessary. After a timeout on RCPT, we just end the function, leaving the
1483 yield as OK, because this error can often mean that there is a problem with
1484 just one address, so we don't want to delay the host. */
1485
1486 count = smtp_write_command(&outblock, no_flush, "RCPT TO:<%s>%s\r\n",
1487 transport_rcpt_address(addr, tblock->rcpt_include_affixes), igquotstr);
1488 if (count < 0) goto SEND_FAILED;
1489 if (count > 0)
1490 {
1491 switch(sync_responses(first_addr, tblock->rcpt_include_affixes,
1492 &sync_addr, host, count, ob->address_retry_include_sender,
1493 pending_MAIL, 0, &inblock, ob->command_timeout, buffer,
1494 sizeof(buffer)))
1495 {
1496 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1497 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1498 break;
1499
1500 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1501 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1502 case 0: /* No 2xx or 5xx, but no probs */
1503 break;
1504
1505 case -1: goto END_OFF; /* Timeout on RCPT */
1506 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL error */
1507 }
1508 pending_MAIL = FALSE; /* Dealt with MAIL */
1509 }
1510 } /* Loop for next address */
1511
1512 /* If we are an MUA wrapper, abort if any RCPTs were rejected, either
1513 permanently or temporarily. We should have flushed and synced after the last
1514 RCPT. */
1515
1516 if (mua_wrapper)
1517 {
1518 address_item *badaddr;
1519 for (badaddr = first_addr; badaddr != NULL; badaddr = badaddr->next)
1520 {
1521 if (badaddr->transport_return != PENDING_OK) break;
1522 }
1523 if (badaddr != NULL)
1524 {
1525 set_errno(addrlist, 0, badaddr->message, FAIL,
1526 testflag(badaddr, af_pass_message));
1527 ok = FALSE;
1528 }
1529 }
1530
1531 /* If ok is TRUE, we know we have got at least one good recipient, and must now
1532 send DATA, but if it is FALSE (in the normal, non-wrapper case), we may still
1533 have a good recipient buffered up if we are pipelining. We don't want to waste
1534 time sending DATA needlessly, so we only send it if either ok is TRUE or if we
1535 are pipelining. The responses are all handled by sync_responses(). */
1536
1537 if (ok || (smtp_use_pipelining && !mua_wrapper))
1538 {
1539 int count = smtp_write_command(&outblock, FALSE, "DATA\r\n");
1540 if (count < 0) goto SEND_FAILED;
1541 switch(sync_responses(first_addr, tblock->rcpt_include_affixes, &sync_addr,
1542 host, count, ob->address_retry_include_sender, pending_MAIL,
1543 ok? +1 : -1, &inblock, ob->command_timeout, buffer, sizeof(buffer)))
1544 {
1545 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1546 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1547 break;
1548
1549 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1550 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1551 case 0: break; /* No 2xx or 5xx, but no probs */
1552
1553 case -1: goto END_OFF; /* Timeout on RCPT */
1554 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */
1555 }
1556 }
1557
1558 /* Save the first address of the next batch. */
1559
1560 first_addr = addr;
1561
1562 /* If there were no good recipients (but otherwise there have been no
1563 problems), just set ok TRUE, since we have handled address-specific errors
1564 already. Otherwise, it's OK to send the message. Use the check/escape mechanism
1565 for handling the SMTP dot-handling protocol, flagging to apply to headers as
1566 well as body. Set the appropriate timeout value to be used for each chunk.
1567 (Haven't been able to make it work using select() for writing yet.) */
1568
1569 if (!ok) ok = TRUE; else
1570 {
1571 sigalrm_seen = FALSE;
1572 transport_write_timeout = ob->data_timeout;
1573 smtp_command = US"sending data block"; /* For error messages */
1574 DEBUG(D_transport|D_v)
1575 debug_printf(" SMTP>> writing message and terminating \".\"\n");
1576 transport_count = 0;
1577 #ifndef DISABLE_DKIM
1578 ok = dkim_transport_write_message(addrlist, inblock.sock,
1579 topt_use_crlf | topt_end_dot | topt_escape_headers |
1580 (tblock->body_only? topt_no_headers : 0) |
1581 (tblock->headers_only? topt_no_body : 0) |
1582 (tblock->return_path_add? topt_add_return_path : 0) |
1583 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1584 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1585 0, /* No size limit */
1586 tblock->add_headers, tblock->remove_headers,
1587 US".", US"..", /* Escaping strings */
1588 tblock->rewrite_rules, tblock->rewrite_existflags,
1589 ob->dkim_private_key, ob->dkim_domain, ob->dkim_selector,
1590 ob->dkim_canon, ob->dkim_strict, ob->dkim_sign_headers
1591 );
1592 #else
1593 ok = transport_write_message(addrlist, inblock.sock,
1594 topt_use_crlf | topt_end_dot | topt_escape_headers |
1595 (tblock->body_only? topt_no_headers : 0) |
1596 (tblock->headers_only? topt_no_body : 0) |
1597 (tblock->return_path_add? topt_add_return_path : 0) |
1598 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1599 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1600 0, /* No size limit */
1601 tblock->add_headers, tblock->remove_headers,
1602 US".", US"..", /* Escaping strings */
1603 tblock->rewrite_rules, tblock->rewrite_existflags);
1604 #endif
1605
1606 /* transport_write_message() uses write() because it is called from other
1607 places to write to non-sockets. This means that under some OS (e.g. Solaris)
1608 it can exit with "Broken pipe" as its error. This really means that the
1609 socket got closed at the far end. */
1610
1611 transport_write_timeout = 0; /* for subsequent transports */
1612
1613 /* Failure can either be some kind of I/O disaster (including timeout),
1614 or the failure of a transport filter or the expansion of added headers. */
1615
1616 if (!ok)
1617 {
1618 buffer[0] = 0; /* There hasn't been a response */
1619 goto RESPONSE_FAILED;
1620 }
1621
1622 /* We used to send the terminating "." explicitly here, but because of
1623 buffering effects at both ends of TCP/IP connections, you don't gain
1624 anything by keeping it separate, so it might as well go in the final
1625 data buffer for efficiency. This is now done by setting the topt_end_dot
1626 flag above. */
1627
1628 smtp_command = US"end of data";
1629
1630 /* For SMTP, we now read a single response that applies to the whole message.
1631 If it is OK, then all the addresses have been delivered. */
1632
1633 if (!lmtp)
1634 {
1635 ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1636 ob->final_timeout);
1637 if (!ok && errno == 0 && buffer[0] == '4')
1638 {
1639 errno = ERRNO_DATA4XX;
1640 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1641 }
1642 }
1643
1644 /* For LMTP, we get back a response for every RCPT command that we sent;
1645 some may be accepted and some rejected. For those that get a response, their
1646 status is fixed; any that are accepted have been handed over, even if later
1647 responses crash - at least, that's how I read RFC 2033.
1648
1649 If all went well, mark the recipient addresses as completed, record which
1650 host/IPaddress they were delivered to, and cut out RSET when sending another
1651 message down the same channel. Write the completed addresses to the journal
1652 now so that they are recorded in case there is a crash of hardware or
1653 software before the spool gets updated. Also record the final SMTP
1654 confirmation if needed (for SMTP only). */
1655
1656 if (ok)
1657 {
1658 int flag = '=';
1659 int delivery_time = (int)(time(NULL) - start_delivery_time);
1660 int len;
1661 host_item *thost;
1662 uschar *conf = NULL;
1663 send_rset = FALSE;
1664
1665 /* Make a copy of the host if it is local to this invocation
1666 of the transport. */
1667
1668 if (copy_host)
1669 {
1670 thost = store_get(sizeof(host_item));
1671 *thost = *host;
1672 thost->name = string_copy(host->name);
1673 thost->address = string_copy(host->address);
1674 }
1675 else thost = host;
1676
1677 /* Set up confirmation if needed - applies only to SMTP */
1678
1679 if ((log_extra_selector & LX_smtp_confirmation) != 0 && !lmtp)
1680 {
1681 uschar *s = string_printing(buffer);
1682 conf = (s == buffer)? (uschar *)string_copy(s) : s;
1683 }
1684
1685 /* Process all transported addresses - for LMTP, read a status for
1686 each one. */
1687
1688 for (addr = addrlist; addr != first_addr; addr = addr->next)
1689 {
1690 if (addr->transport_return != PENDING_OK) continue;
1691
1692 /* LMTP - if the response fails badly (e.g. timeout), use it for all the
1693 remaining addresses. Otherwise, it's a return code for just the one
1694 address. For temporary errors, add a retry item for the address so that
1695 it doesn't get tried again too soon. */
1696
1697 if (lmtp)
1698 {
1699 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1700 ob->final_timeout))
1701 {
1702 if (errno != 0 || buffer[0] == 0) goto RESPONSE_FAILED;
1703 addr->message = string_sprintf("LMTP error after %s: %s",
1704 big_buffer, string_printing(buffer));
1705 setflag(addr, af_pass_message); /* Allow message to go to user */
1706 if (buffer[0] == '5')
1707 addr->transport_return = FAIL;
1708 else
1709 {
1710 errno = ERRNO_DATA4XX;
1711 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1712 addr->transport_return = DEFER;
1713 retry_add_item(addr, addr->address_retry_key, 0);
1714 }
1715 continue;
1716 }
1717 completed_address = TRUE; /* NOW we can set this flag */
1718 conf = string_sprintf("LMTP Successful delivery:%s", string_printing(buffer));
1719 }
1720
1721 /* SMTP, or success return from LMTP for this address. Pass back the
1722 actual host that was used. */
1723
1724 addr->transport_return = OK;
1725 addr->more_errno = delivery_time;
1726 addr->host_used = thost;
1727 addr->special_action = flag;
1728 addr->message = conf;
1729 flag = '-';
1730
1731 /* Update the journal. For homonymic addresses, use the base address plus
1732 the transport name. See lots of comments in deliver.c about the reasons
1733 for the complications when homonyms are involved. Just carry on after
1734 write error, as it may prove possible to update the spool file later. */
1735
1736 if (testflag(addr, af_homonym))
1737 sprintf(CS buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
1738 else
1739 sprintf(CS buffer, "%.500s\n", addr->unique);
1740
1741 DEBUG(D_deliver) debug_printf("journalling %s", buffer);
1742 len = Ustrlen(CS buffer);
1743 if (write(journal_fd, buffer, len) != len)
1744 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
1745 "%s: %s", buffer, strerror(errno));
1746 }
1747
1748 /* Ensure the journal file is pushed out to disk. */
1749
1750 if (EXIMfsync(journal_fd) < 0)
1751 log_write(0, LOG_MAIN|LOG_PANIC, "failed to fsync journal: %s",
1752 strerror(errno));
1753 }
1754 }
1755
1756
1757 /* Handle general (not specific to one address) failures here. The value of ok
1758 is used to skip over this code on the falling through case. A timeout causes a
1759 deferral. Other errors may defer or fail according to the response code, and
1760 may set up a special errno value, e.g. after connection chopped, which is
1761 assumed if errno == 0 and there is no text in the buffer. If control reaches
1762 here during the setting up phase (i.e. before MAIL FROM) then always defer, as
1763 the problem is not related to this specific message. */
1764
1765 if (!ok)
1766 {
1767 int code;
1768
1769 RESPONSE_FAILED:
1770 save_errno = errno;
1771 message = NULL;
1772 send_quit = check_response(host, &save_errno, addrlist->more_errno,
1773 buffer, &code, &message, &pass_message);
1774 goto FAILED;
1775
1776 SEND_FAILED:
1777 save_errno = errno;
1778 code = '4';
1779 message = US string_sprintf("send() to %s [%s] failed: %s",
1780 host->name, host->address, strerror(save_errno));
1781 send_quit = FALSE;
1782 goto FAILED;
1783
1784 /* This label is jumped to directly when a TLS negotiation has failed,
1785 or was not done for a host for which it is required. Values will be set
1786 in message and save_errno, and setting_up will always be true. Treat as
1787 a temporary error. */
1788
1789 #ifdef SUPPORT_TLS
1790 TLS_FAILED:
1791 code = '4';
1792 #endif
1793
1794 /* If the failure happened while setting up the call, see if the failure was
1795 a 5xx response (this will either be on connection, or following HELO - a 5xx
1796 after EHLO causes it to try HELO). If so, fail all addresses, as this host is
1797 never going to accept them. For other errors during setting up (timeouts or
1798 whatever), defer all addresses, and yield DEFER, so that the host is not
1799 tried again for a while. */
1800
1801 FAILED:
1802 ok = FALSE; /* For when reached by GOTO */
1803
1804 if (setting_up)
1805 {
1806 if (code == '5')
1807 {
1808 set_errno(addrlist, save_errno, message, FAIL, pass_message);
1809 }
1810 else
1811 {
1812 set_errno(addrlist, save_errno, message, DEFER, pass_message);
1813 yield = DEFER;
1814 }
1815 }
1816
1817 /* We want to handle timeouts after MAIL or "." and loss of connection after
1818 "." specially. They can indicate a problem with the sender address or with
1819 the contents of the message rather than a real error on the connection. These
1820 cases are treated in the same way as a 4xx response. This next bit of code
1821 does the classification. */
1822
1823 else
1824 {
1825 BOOL message_error;
1826
1827 switch(save_errno)
1828 {
1829 case 0:
1830 case ERRNO_MAIL4XX:
1831 case ERRNO_DATA4XX:
1832 message_error = TRUE;
1833 break;
1834
1835 case ETIMEDOUT:
1836 message_error = Ustrncmp(smtp_command,"MAIL",4) == 0 ||
1837 Ustrncmp(smtp_command,"end ",4) == 0;
1838 break;
1839
1840 case ERRNO_SMTPCLOSED:
1841 message_error = Ustrncmp(smtp_command,"end ",4) == 0;
1842 break;
1843
1844 default:
1845 message_error = FALSE;
1846 break;
1847 }
1848
1849 /* Handle the cases that are treated as message errors. These are:
1850
1851 (a) negative response or timeout after MAIL
1852 (b) negative response after DATA
1853 (c) negative response or timeout or dropped connection after "."
1854
1855 It won't be a negative response or timeout after RCPT, as that is dealt
1856 with separately above. The action in all cases is to set an appropriate
1857 error code for all the addresses, but to leave yield set to OK because the
1858 host itself has not failed. Of course, it might in practice have failed
1859 when we've had a timeout, but if so, we'll discover that at the next
1860 delivery attempt. For a temporary error, set the message_defer flag, and
1861 write to the logs for information if this is not the last host. The error
1862 for the last host will be logged as part of the address's log line. */
1863
1864 if (message_error)
1865 {
1866 if (mua_wrapper) code = '5'; /* Force hard failure in wrapper mode */
1867 set_errno(addrlist, save_errno, message, (code == '5')? FAIL : DEFER,
1868 pass_message);
1869
1870 /* If there's an errno, the message contains just the identity of
1871 the host. */
1872
1873 if (code != '5') /* Anything other than 5 is treated as temporary */
1874 {
1875 if (save_errno > 0)
1876 message = US string_sprintf("%s: %s", message, strerror(save_errno));
1877 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", message);
1878 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
1879 *message_defer = TRUE;
1880 }
1881 }
1882
1883 /* Otherwise, we have an I/O error or a timeout other than after MAIL or
1884 ".", or some other transportation error. We defer all addresses and yield
1885 DEFER, except for the case of failed add_headers expansion, or a transport
1886 filter failure, when the yield should be ERROR, to stop it trying other
1887 hosts. */
1888
1889 else
1890 {
1891 yield = (save_errno == ERRNO_CHHEADER_FAIL ||
1892 save_errno == ERRNO_FILTER_FAIL)? ERROR : DEFER;
1893 set_errno(addrlist, save_errno, message, DEFER, pass_message);
1894 }
1895 }
1896 }
1897
1898
1899 /* If all has gone well, send_quit will be set TRUE, implying we can end the
1900 SMTP session tidily. However, if there were too many addresses to send in one
1901 message (indicated by first_addr being non-NULL) we want to carry on with the
1902 rest of them. Also, it is desirable to send more than one message down the SMTP
1903 connection if there are several waiting, provided we haven't already sent so
1904 many as to hit the configured limit. The function transport_check_waiting looks
1905 for a waiting message and returns its id. Then transport_pass_socket tries to
1906 set up a continued delivery by passing the socket on to another process. The
1907 variable send_rset is FALSE if a message has just been successfully transfered.
1908
1909 If we are already sending down a continued channel, there may be further
1910 addresses not yet delivered that are aimed at the same host, but which have not
1911 been passed in this run of the transport. In this case, continue_more will be
1912 true, and all we should do is send RSET if necessary, and return, leaving the
1913 channel open.
1914
1915 However, if no address was disposed of, i.e. all addresses got 4xx errors, we
1916 do not want to continue with other messages down the same channel, because that
1917 can lead to looping between two or more messages, all with the same,
1918 temporarily failing address(es). [The retry information isn't updated yet, so
1919 new processes keep on trying.] We probably also don't want to try more of this
1920 message's addresses either.
1921
1922 If we have started a TLS session, we have to end it before passing the
1923 connection to a new process. However, not all servers can handle this (Exim
1924 can), so we do not pass such a connection on if the host matches
1925 hosts_nopass_tls. */
1926
1927 DEBUG(D_transport)
1928 debug_printf("ok=%d send_quit=%d send_rset=%d continue_more=%d "
1929 "yield=%d first_address is %sNULL\n", ok, send_quit, send_rset,
1930 continue_more, yield, (first_addr == NULL)? "":"not ");
1931
1932 if (completed_address && ok && send_quit)
1933 {
1934 BOOL more;
1935 if (first_addr != NULL || continue_more ||
1936 (
1937 (tls_active < 0 ||
1938 verify_check_this_host(&(ob->hosts_nopass_tls), NULL, host->name,
1939 host->address, NULL) != OK)
1940 &&
1941 transport_check_waiting(tblock->name, host->name,
1942 tblock->connection_max_messages, new_message_id, &more)
1943 ))
1944 {
1945 uschar *msg;
1946 BOOL pass_message;
1947
1948 if (send_rset)
1949 {
1950 if (! (ok = smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0))
1951 {
1952 msg = US string_sprintf("send() to %s [%s] failed: %s", host->name,
1953 host->address, strerror(save_errno));
1954 send_quit = FALSE;
1955 }
1956 else if (! (ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1957 ob->command_timeout)))
1958 {
1959 int code;
1960 send_quit = check_response(host, &errno, 0, buffer, &code, &msg,
1961 &pass_message);
1962 if (!send_quit)
1963 {
1964 DEBUG(D_transport) debug_printf("%s\n", msg);
1965 }
1966 }
1967 }
1968
1969 /* Either RSET was not needed, or it succeeded */
1970
1971 if (ok)
1972 {
1973 if (first_addr != NULL) /* More addresses still to be sent */
1974 { /* in this run of the transport */
1975 continue_sequence++; /* Causes * in logging */
1976 goto SEND_MESSAGE;
1977 }
1978 if (continue_more) return yield; /* More addresses for another run */
1979
1980 /* Pass the socket to a new Exim process. Before doing so, we must shut
1981 down TLS. Not all MTAs allow for the continuation of the SMTP session
1982 when TLS is shut down. We test for this by sending a new EHLO. If we
1983 don't get a good response, we don't attempt to pass the socket on. */
1984
1985 #ifdef SUPPORT_TLS
1986 if (tls_active >= 0)
1987 {
1988 tls_close(TRUE);
1989 ok = smtp_write_command(&outblock,FALSE,"EHLO %s\r\n",helo_data) >= 0 &&
1990 smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1991 ob->command_timeout);
1992 }
1993 #endif
1994
1995 /* If the socket is successfully passed, we musn't send QUIT (or
1996 indeed anything!) from here. */
1997
1998 if (ok && transport_pass_socket(tblock->name, host->name, host->address,
1999 new_message_id, inblock.sock))
2000 {
2001 send_quit = FALSE;
2002 }
2003 }
2004
2005 /* If RSET failed and there are addresses left, they get deferred. */
2006
2007 else set_errno(first_addr, errno, msg, DEFER, FALSE);
2008 }
2009 }
2010
2011 /* End off tidily with QUIT unless the connection has died or the socket has
2012 been passed to another process. There has been discussion on the net about what
2013 to do after sending QUIT. The wording of the RFC suggests that it is necessary
2014 to wait for a response, but on the other hand, there isn't anything one can do
2015 with an error response, other than log it. Exim used to do that. However,
2016 further discussion suggested that it is positively advantageous not to wait for
2017 the response, but to close the session immediately. This is supposed to move
2018 the TCP/IP TIME_WAIT state from the server to the client, thereby removing some
2019 load from the server. (Hosts that are both servers and clients may not see much
2020 difference, of course.) Further discussion indicated that this was safe to do
2021 on Unix systems which have decent implementations of TCP/IP that leave the
2022 connection around for a while (TIME_WAIT) after the application has gone away.
2023 This enables the response sent by the server to be properly ACKed rather than
2024 timed out, as can happen on broken TCP/IP implementations on other OS.
2025
2026 This change is being made on 31-Jul-98. After over a year of trouble-free
2027 operation, the old commented-out code was removed on 17-Sep-99. */
2028
2029 SEND_QUIT:
2030 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
2031
2032 END_OFF:
2033
2034 #ifdef SUPPORT_TLS
2035 tls_close(TRUE);
2036 #endif
2037
2038 /* Close the socket, and return the appropriate value, first setting
2039 continue_transport and continue_hostname NULL to prevent any other addresses
2040 that may include the host from trying to re-use a continuation socket. This
2041 works because the NULL setting is passed back to the calling process, and
2042 remote_max_parallel is forced to 1 when delivering over an existing connection,
2043
2044 If all went well and continue_more is set, we shouldn't actually get here if
2045 there are further addresses, as the return above will be taken. However,
2046 writing RSET might have failed, or there may be other addresses whose hosts are
2047 specified in the transports, and therefore not visible at top level, in which
2048 case continue_more won't get set. */
2049
2050 (void)close(inblock.sock);
2051 continue_transport = NULL;
2052 continue_hostname = NULL;
2053 return yield;
2054 }
2055
2056
2057
2058
2059 /*************************************************
2060 * Closedown entry point *
2061 *************************************************/
2062
2063 /* This function is called when exim is passed an open smtp channel
2064 from another incarnation, but the message which it has been asked
2065 to deliver no longer exists. The channel is on stdin.
2066
2067 We might do fancy things like looking for another message to send down
2068 the channel, but if the one we sought has gone, it has probably been
2069 delivered by some other process that itself will seek further messages,
2070 so just close down our connection.
2071
2072 Argument: pointer to the transport instance block
2073 Returns: nothing
2074 */
2075
2076 void
2077 smtp_transport_closedown(transport_instance *tblock)
2078 {
2079 smtp_transport_options_block *ob =
2080 (smtp_transport_options_block *)(tblock->options_block);
2081 smtp_inblock inblock;
2082 smtp_outblock outblock;
2083 uschar buffer[256];
2084 uschar inbuffer[4096];
2085 uschar outbuffer[16];
2086
2087 inblock.sock = fileno(stdin);
2088 inblock.buffer = inbuffer;
2089 inblock.buffersize = sizeof(inbuffer);
2090 inblock.ptr = inbuffer;
2091 inblock.ptrend = inbuffer;
2092
2093 outblock.sock = inblock.sock;
2094 outblock.buffersize = sizeof(outbuffer);
2095 outblock.buffer = outbuffer;
2096 outblock.ptr = outbuffer;
2097 outblock.cmd_count = 0;
2098 outblock.authenticating = FALSE;
2099
2100 (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
2101 (void)smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2102 ob->command_timeout);
2103 (void)close(inblock.sock);
2104 }
2105
2106
2107
2108 /*************************************************
2109 * Prepare addresses for delivery *
2110 *************************************************/
2111
2112 /* This function is called to flush out error settings from previous delivery
2113 attempts to other hosts. It also records whether we got here via an MX record
2114 or not in the more_errno field of the address. We are interested only in
2115 addresses that are still marked DEFER - others may have got delivered to a
2116 previously considered IP address. Set their status to PENDING_DEFER to indicate
2117 which ones are relevant this time.
2118
2119 Arguments:
2120 addrlist the list of addresses
2121 host the host we are delivering to
2122
2123 Returns: the first address for this delivery
2124 */
2125
2126 static address_item *
2127 prepare_addresses(address_item *addrlist, host_item *host)
2128 {
2129 address_item *first_addr = NULL;
2130 address_item *addr;
2131 for (addr = addrlist; addr != NULL; addr = addr->next)
2132 {
2133 if (addr->transport_return != DEFER) continue;
2134 if (first_addr == NULL) first_addr = addr;
2135 addr->transport_return = PENDING_DEFER;
2136 addr->basic_errno = 0;
2137 addr->more_errno = (host->mx >= 0)? 'M' : 'A';
2138 addr->message = NULL;
2139 #ifdef SUPPORT_TLS
2140 addr->cipher = NULL;
2141 addr->peerdn = NULL;
2142 #endif
2143 }
2144 return first_addr;
2145 }
2146
2147
2148
2149 /*************************************************
2150 * Main entry point *
2151 *************************************************/
2152
2153 /* See local README for interface details. As this is a remote transport, it is
2154 given a chain of addresses to be delivered in one connection, if possible. It
2155 always returns TRUE, indicating that each address has its own independent
2156 status set, except if there is a setting up problem, in which case it returns
2157 FALSE. */
2158
2159 BOOL
2160 smtp_transport_entry(
2161 transport_instance *tblock, /* data for this instantiation */
2162 address_item *addrlist) /* addresses we are working on */
2163 {
2164 int cutoff_retry;
2165 int port;
2166 int hosts_defer = 0;
2167 int hosts_fail = 0;
2168 int hosts_looked_up = 0;
2169 int hosts_retry = 0;
2170 int hosts_serial = 0;
2171 int hosts_total = 0;
2172 int total_hosts_tried = 0;
2173 address_item *addr;
2174 BOOL expired = TRUE;
2175 BOOL continuing = continue_hostname != NULL;
2176 uschar *expanded_hosts = NULL;
2177 uschar *pistring;
2178 uschar *tid = string_sprintf("%s transport", tblock->name);
2179 smtp_transport_options_block *ob =
2180 (smtp_transport_options_block *)(tblock->options_block);
2181 host_item *hostlist = addrlist->host_list;
2182 host_item *host = NULL;
2183
2184 DEBUG(D_transport)
2185 {
2186 debug_printf("%s transport entered\n", tblock->name);
2187 for (addr = addrlist; addr != NULL; addr = addr->next)
2188 debug_printf(" %s\n", addr->address);
2189 if (continuing) debug_printf("already connected to %s [%s]\n",
2190 continue_hostname, continue_host_address);
2191 }
2192
2193 /* Set the flag requesting that these hosts be added to the waiting
2194 database if the delivery fails temporarily or if we are running with
2195 queue_smtp or a 2-stage queue run. This gets unset for certain
2196 kinds of error, typically those that are specific to the message. */
2197
2198 update_waiting = TRUE;
2199
2200 /* If a host list is not defined for the addresses - they must all have the
2201 same one in order to be passed to a single transport - or if the transport has
2202 a host list with hosts_override set, use the host list supplied with the
2203 transport. It is an error for this not to exist. */
2204
2205 if (hostlist == NULL || (ob->hosts_override && ob->hosts != NULL))
2206 {
2207 if (ob->hosts == NULL)
2208 {
2209 addrlist->message = string_sprintf("%s transport called with no hosts set",
2210 tblock->name);
2211 addrlist->transport_return = PANIC;
2212 return FALSE; /* Only top address has status */
2213 }
2214
2215 DEBUG(D_transport) debug_printf("using the transport's hosts: %s\n",
2216 ob->hosts);
2217
2218 /* If the transport's host list contains no '$' characters, and we are not
2219 randomizing, it is fixed and therefore a chain of hosts can be built once
2220 and for all, and remembered for subsequent use by other calls to this
2221 transport. If, on the other hand, the host list does contain '$', or we are
2222 randomizing its order, we have to rebuild it each time. In the fixed case,
2223 as the hosts string will never be used again, it doesn't matter that we
2224 replace all the : characters with zeros. */
2225
2226 if (ob->hostlist == NULL)
2227 {
2228 uschar *s = ob->hosts;
2229
2230 if (Ustrchr(s, '$') != NULL)
2231 {
2232 expanded_hosts = expand_string(s);
2233 if (expanded_hosts == NULL)
2234 {
2235 addrlist->message = string_sprintf("failed to expand list of hosts "
2236 "\"%s\" in %s transport: %s", s, tblock->name, expand_string_message);
2237 addrlist->transport_return = search_find_defer? DEFER : PANIC;
2238 return FALSE; /* Only top address has status */
2239 }
2240 DEBUG(D_transport) debug_printf("expanded list of hosts \"%s\" to "
2241 "\"%s\"\n", s, expanded_hosts);
2242 s = expanded_hosts;
2243 }
2244 else
2245 if (ob->hosts_randomize) s = expanded_hosts = string_copy(s);
2246
2247 host_build_hostlist(&hostlist, s, ob->hosts_randomize);
2248
2249 /* Check that the expansion yielded something useful. */
2250 if (hostlist == NULL)
2251 {
2252 addrlist->message =
2253 string_sprintf("%s transport has empty hosts setting", tblock->name);
2254 addrlist->transport_return = PANIC;
2255 return FALSE; /* Only top address has status */
2256 }
2257
2258 /* If there was no expansion of hosts, save the host list for
2259 next time. */
2260
2261 if (expanded_hosts == NULL) ob->hostlist = hostlist;
2262 }
2263
2264 /* This is not the first time this transport has been run in this delivery;
2265 the host list was built previously. */
2266
2267 else hostlist = ob->hostlist;
2268 }
2269
2270 /* The host list was supplied with the address. If hosts_randomize is set, we
2271 must sort it into a random order if it did not come from MX records and has not
2272 already been randomized (but don't bother if continuing down an existing
2273 connection). */
2274
2275 else if (ob->hosts_randomize && hostlist->mx == MX_NONE && !continuing)
2276 {
2277 host_item *newlist = NULL;
2278 while (hostlist != NULL)
2279 {
2280 host_item *h = hostlist;
2281 hostlist = hostlist->next;
2282
2283 h->sort_key = random_number(100);
2284
2285 if (newlist == NULL)
2286 {
2287 h->next = NULL;
2288 newlist = h;
2289 }
2290 else if (h->sort_key < newlist->sort_key)
2291 {
2292 h->next = newlist;
2293 newlist = h;
2294 }
2295 else
2296 {
2297 host_item *hh = newlist;
2298 while (hh->next != NULL)
2299 {
2300 if (h->sort_key < hh->next->sort_key) break;
2301 hh = hh->next;
2302 }
2303 h->next = hh->next;
2304 hh->next = h;
2305 }
2306 }
2307
2308 hostlist = addrlist->host_list = newlist;
2309 }
2310
2311
2312 /* Sort out the default port. */
2313
2314 if (!smtp_get_port(ob->port, addrlist, &port, tid)) return FALSE;
2315
2316
2317 /* For each host-plus-IP-address on the list:
2318
2319 . If this is a continued delivery and the host isn't the one with the
2320 current connection, skip.
2321
2322 . If the status is unusable (i.e. previously failed or retry checked), skip.
2323
2324 . If no IP address set, get the address, either by turning the name into
2325 an address, calling gethostbyname if gethostbyname is on, or by calling
2326 the DNS. The DNS may yield multiple addresses, in which case insert the
2327 extra ones into the list.
2328
2329 . Get the retry data if not previously obtained for this address and set the
2330 field which remembers the state of this address. Skip if the retry time is
2331 not reached. If not, remember whether retry data was found. The retry string
2332 contains both the name and the IP address.
2333
2334 . Scan the list of addresses and mark those whose status is DEFER as
2335 PENDING_DEFER. These are the only ones that will be processed in this cycle
2336 of the hosts loop.
2337
2338 . Make a delivery attempt - addresses marked PENDING_DEFER will be tried.
2339 Some addresses may be successfully delivered, others may fail, and yet
2340 others may get temporary errors and so get marked DEFER.
2341
2342 . The return from the delivery attempt is OK if a connection was made and a
2343 valid SMTP dialogue was completed. Otherwise it is DEFER.
2344
2345 . If OK, add a "remove" retry item for this host/IPaddress, if any.
2346
2347 . If fail to connect, or other defer state, add a retry item.
2348
2349 . If there are any addresses whose status is still DEFER, carry on to the
2350 next host/IPaddress, unless we have tried the number of hosts given
2351 by hosts_max_try or hosts_max_try_hardlimit; otherwise return. Note that
2352 there is some fancy logic for hosts_max_try that means its limit can be
2353 overstepped in some circumstances.
2354
2355 If we get to the end of the list, all hosts have deferred at least one address,
2356 or not reached their retry times. If delay_after_cutoff is unset, it requests a
2357 delivery attempt to those hosts whose last try was before the arrival time of
2358 the current message. To cope with this, we have to go round the loop a second
2359 time. After that, set the status and error data for any addresses that haven't
2360 had it set already. */
2361
2362 for (cutoff_retry = 0; expired &&
2363 cutoff_retry < ((ob->delay_after_cutoff)? 1 : 2);
2364 cutoff_retry++)
2365 {
2366 host_item *nexthost = NULL;
2367 int unexpired_hosts_tried = 0;
2368
2369 for (host = hostlist;
2370 host != NULL &&
2371 unexpired_hosts_tried < ob->hosts_max_try &&
2372 total_hosts_tried < ob->hosts_max_try_hardlimit;
2373 host = nexthost)
2374 {
2375 int rc;
2376 int host_af;
2377 uschar *rs;
2378 BOOL serialized = FALSE;
2379 BOOL host_is_expired = FALSE;
2380 BOOL message_defer = FALSE;
2381 BOOL ifchanges = FALSE;
2382 BOOL some_deferred = FALSE;
2383 address_item *first_addr = NULL;
2384 uschar *interface = NULL;
2385 uschar *retry_host_key = NULL;
2386 uschar *retry_message_key = NULL;
2387 uschar *serialize_key = NULL;
2388
2389 /* Default next host is next host. :-) But this can vary if the
2390 hosts_max_try limit is hit (see below). It may also be reset if a host
2391 address is looked up here (in case the host was multihomed). */
2392
2393 nexthost = host->next;
2394
2395 /* If the address hasn't yet been obtained from the host name, look it up
2396 now, unless the host is already marked as unusable. If it is marked as
2397 unusable, it means that the router was unable to find its IP address (in
2398 the DNS or wherever) OR we are in the 2nd time round the cutoff loop, and
2399 the lookup failed last time. We don't get this far if *all* MX records
2400 point to non-existent hosts; that is treated as a hard error.
2401
2402 We can just skip this host entirely. When the hosts came from the router,
2403 the address will timeout based on the other host(s); when the address is
2404 looked up below, there is an explicit retry record added.
2405
2406 Note that we mustn't skip unusable hosts if the address is not unset; they
2407 may be needed as expired hosts on the 2nd time round the cutoff loop. */
2408
2409 if (host->address == NULL)
2410 {
2411 int new_port, flags;
2412 host_item *hh;
2413 uschar *canonical_name;
2414
2415 if (host->status >= hstatus_unusable)
2416 {
2417 DEBUG(D_transport) debug_printf("%s has no address and is unusable - skipping\n",
2418 host->name);
2419 continue;
2420 }
2421
2422 DEBUG(D_transport) debug_printf("getting address for %s\n", host->name);
2423
2424 /* The host name is permitted to have an attached port. Find it, and
2425 strip it from the name. Just remember it for now. */
2426
2427 new_port = host_item_get_port(host);
2428
2429 /* Count hosts looked up */
2430
2431 hosts_looked_up++;
2432
2433 /* Find by name if so configured, or if it's an IP address. We don't
2434 just copy the IP address, because we need the test-for-local to happen. */
2435
2436 flags = HOST_FIND_BY_A;
2437 if (ob->dns_qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
2438 if (ob->dns_search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
2439
2440 if (ob->gethostbyname || string_is_ip_address(host->name, NULL) != 0)
2441 rc = host_find_byname(host, NULL, flags, &canonical_name, TRUE);
2442 else
2443 rc = host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
2444 &canonical_name, NULL);
2445
2446 /* Update the host (and any additional blocks, resulting from
2447 multihoming) with a host-specific port, if any. */
2448
2449 for (hh = host; hh != nexthost; hh = hh->next) hh->port = new_port;
2450
2451 /* Failure to find the host at this time (usually DNS temporary failure)
2452 is really a kind of routing failure rather than a transport failure.
2453 Therefore we add a retry item of the routing kind, not to stop us trying
2454 to look this name up here again, but to ensure the address gets timed
2455 out if the failures go on long enough. A complete failure at this point
2456 commonly points to a configuration error, but the best action is still
2457 to carry on for the next host. */
2458
2459 if (rc == HOST_FIND_AGAIN || rc == HOST_FIND_FAILED)
2460 {
2461 retry_add_item(addrlist, string_sprintf("R:%s", host->name), 0);
2462 expired = FALSE;
2463 if (rc == HOST_FIND_AGAIN) hosts_defer++; else hosts_fail++;
2464 DEBUG(D_transport) debug_printf("rc = %s for %s\n", (rc == HOST_FIND_AGAIN)?
2465 "HOST_FIND_AGAIN" : "HOST_FIND_FAILED", host->name);
2466 host->status = hstatus_unusable;
2467
2468 for (addr = addrlist; addr != NULL; addr = addr->next)
2469 {
2470 if (addr->transport_return != DEFER) continue;
2471 addr->basic_errno = ERRNO_UNKNOWNHOST;
2472 addr->message =
2473 string_sprintf("failed to lookup IP address for %s", host->name);
2474 }
2475 continue;
2476 }
2477
2478 /* If the host is actually the local host, we may have a problem, or
2479 there may be some cunning configuration going on. In the problem case,
2480 log things and give up. The default transport status is already DEFER. */
2481
2482 if (rc == HOST_FOUND_LOCAL && !ob->allow_localhost)
2483 {
2484 for (addr = addrlist; addr != NULL; addr = addr->next)
2485 {
2486 addr->basic_errno = 0;
2487 addr->message = string_sprintf("%s transport found host %s to be "
2488 "local", tblock->name, host->name);
2489 }
2490 goto END_TRANSPORT;
2491 }
2492 } /* End of block for IP address lookup */
2493
2494 /* If this is a continued delivery, we are interested only in the host
2495 which matches the name of the existing open channel. The check is put
2496 here after the local host lookup, in case the name gets expanded as a
2497 result of the lookup. Set expired FALSE, to save the outer loop executing
2498 twice. */
2499
2500 if (continuing && (Ustrcmp(continue_hostname, host->name) != 0 ||
2501 Ustrcmp(continue_host_address, host->address) != 0))
2502 {
2503 expired = FALSE;
2504 continue; /* With next host */
2505 }
2506
2507 /* Reset the default next host in case a multihomed host whose addresses
2508 are not looked up till just above added to the host list. */
2509
2510 nexthost = host->next;
2511
2512 /* If queue_smtp is set (-odqs or the first part of a 2-stage run), or the
2513 domain is in queue_smtp_domains, we don't actually want to attempt any
2514 deliveries. When doing a queue run, queue_smtp_domains is always unset. If
2515 there is a lookup defer in queue_smtp_domains, proceed as if the domain
2516 were not in it. We don't want to hold up all SMTP deliveries! Except when
2517 doing a two-stage queue run, don't do this if forcing. */
2518
2519 if ((!deliver_force || queue_2stage) && (queue_smtp ||
2520 match_isinlist(addrlist->domain, &queue_smtp_domains, 0,
2521 &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL) == OK))
2522 {
2523 expired = FALSE;
2524 for (addr = addrlist; addr != NULL; addr = addr->next)
2525 {
2526 if (addr->transport_return != DEFER) continue;
2527 addr->message = US"domain matches queue_smtp_domains, or -odqs set";
2528 }
2529 continue; /* With next host */
2530 }
2531
2532 /* Count hosts being considered - purely for an intelligent comment
2533 if none are usable. */
2534
2535 hosts_total++;
2536
2537 /* Set $host and $host address now in case they are needed for the
2538 interface expansion or the serialize_hosts check; they remain set if an
2539 actual delivery happens. */
2540
2541 deliver_host = host->name;
2542 deliver_host_address = host->address;
2543
2544 /* Set up a string for adding to the retry key if the port number is not
2545 the standard SMTP port. A host may have its own port setting that overrides
2546 the default. */
2547
2548 pistring = string_sprintf(":%d", (host->port == PORT_NONE)?
2549 port : host->port);
2550 if (Ustrcmp(pistring, ":25") == 0) pistring = US"";
2551
2552 /* Select IPv4 or IPv6, and choose an outgoing interface. If the interface
2553 string changes upon expansion, we must add it to the key that is used for
2554 retries, because connections to the same host from a different interface
2555 should be treated separately. */
2556
2557 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET : AF_INET6;
2558 if (!smtp_get_interface(ob->interface, host_af, addrlist, &ifchanges,
2559 &interface, tid))
2560 return FALSE;
2561 if (ifchanges) pistring = string_sprintf("%s/%s", pistring, interface);
2562
2563 /* The first time round the outer loop, check the status of the host by
2564 inspecting the retry data. The second time round, we are interested only
2565 in expired hosts that haven't been tried since this message arrived. */
2566
2567 if (cutoff_retry == 0)
2568 {
2569 /* Ensure the status of the address is set by checking retry data if
2570 necessary. There maybe host-specific retry data (applicable to all
2571 messages) and also data for retries of a specific message at this host.
2572 If either of these retry records are actually read, the keys used are
2573 returned to save recomputing them later. */
2574
2575 host_is_expired = retry_check_address(addrlist->domain, host, pistring,
2576 ob->retry_include_ip_address, &retry_host_key, &retry_message_key);
2577
2578 DEBUG(D_transport) debug_printf("%s [%s]%s status = %s\n", host->name,
2579 (host->address == NULL)? US"" : host->address, pistring,
2580 (host->status == hstatus_usable)? "usable" :
2581 (host->status == hstatus_unusable)? "unusable" :
2582 (host->status == hstatus_unusable_expired)? "unusable (expired)" : "?");
2583
2584 /* Skip this address if not usable at this time, noting if it wasn't
2585 actually expired, both locally and in the address. */
2586
2587 switch (host->status)
2588 {
2589 case hstatus_unusable:
2590 expired = FALSE;
2591 setflag(addrlist, af_retry_skipped);
2592 /* Fall through */
2593
2594 case hstatus_unusable_expired:
2595 switch (host->why)
2596 {
2597 case hwhy_retry: hosts_retry++; break;
2598 case hwhy_failed: hosts_fail++; break;
2599 case hwhy_deferred: hosts_defer++; break;
2600 }
2601
2602 /* If there was a retry message key, implying that previously there
2603 was a message-specific defer, we don't want to update the list of
2604 messages waiting for these hosts. */
2605
2606 if (retry_message_key != NULL) update_waiting = FALSE;
2607 continue; /* With the next host or IP address */
2608 }
2609 }
2610
2611 /* Second time round the loop: if the address is set but expired, and
2612 the message is newer than the last try, let it through. */
2613
2614 else
2615 {
2616 if (host->address == NULL ||
2617 host->status != hstatus_unusable_expired ||
2618 host->last_try > received_time)
2619 continue;
2620 DEBUG(D_transport)
2621 debug_printf("trying expired host %s [%s]%s\n",
2622 host->name, host->address, pistring);
2623 host_is_expired = TRUE;
2624 }
2625
2626 /* Setting "expired=FALSE" doesn't actually mean not all hosts are expired;
2627 it remains TRUE only if all hosts are expired and none are actually tried.
2628 */
2629
2630 expired = FALSE;
2631
2632 /* If this host is listed as one to which access must be serialized,
2633 see if another Exim process has a connection to it, and if so, skip
2634 this host. If not, update the database to record our connection to it
2635 and remember this for later deletion. Do not do any of this if we are
2636 sending the message down a pre-existing connection. */
2637
2638 if (!continuing &&
2639 verify_check_this_host(&(ob->serialize_hosts), NULL, host->name,
2640 host->address, NULL) == OK)
2641 {
2642 serialize_key = string_sprintf("host-serialize-%s", host->name);
2643 if (!enq_start(serialize_key))
2644 {
2645 DEBUG(D_transport)
2646 debug_printf("skipping host %s because another Exim process "
2647 "is connected to it\n", host->name);
2648 hosts_serial++;
2649 continue;
2650 }
2651 serialized = TRUE;
2652 }
2653
2654 /* OK, we have an IP address that is not waiting for its retry time to
2655 arrive (it might be expired) OR (second time round the loop) we have an
2656 expired host that hasn't been tried since the message arrived. Have a go
2657 at delivering the message to it. First prepare the addresses by flushing
2658 out the result of previous attempts, and finding the first address that
2659 is still to be delivered. */
2660
2661 first_addr = prepare_addresses(addrlist, host);
2662
2663 DEBUG(D_transport) debug_printf("delivering %s to %s [%s] (%s%s)\n",
2664 message_id, host->name, host->address, addrlist->address,
2665 (addrlist->next == NULL)? "" : ", ...");
2666
2667 set_process_info("delivering %s to %s [%s] (%s%s)",
2668 message_id, host->name, host->address, addrlist->address,
2669 (addrlist->next == NULL)? "" : ", ...");
2670
2671 /* This is not for real; don't do the delivery. If there are
2672 any remaining hosts, list them. */
2673
2674 if (dont_deliver)
2675 {
2676 host_item *host2;
2677 set_errno(addrlist, 0, NULL, OK, FALSE);
2678 for (addr = addrlist; addr != NULL; addr = addr->next)
2679 {
2680 addr->host_used = host;
2681 addr->special_action = '*';
2682 addr->message = US"delivery bypassed by -N option";
2683 }
2684 DEBUG(D_transport)
2685 {
2686 debug_printf("*** delivery by %s transport bypassed by -N option\n"
2687 "*** host and remaining hosts:\n", tblock->name);
2688 for (host2 = host; host2 != NULL; host2 = host2->next)
2689 debug_printf(" %s [%s]\n", host2->name,
2690 (host2->address == NULL)? US"unset" : host2->address);
2691 }
2692 rc = OK;
2693 }
2694
2695 /* This is for real. If the host is expired, we don't count it for
2696 hosts_max_retry. This ensures that all hosts must expire before an address
2697 is timed out, unless hosts_max_try_hardlimit (which protects against
2698 lunatic DNS configurations) is reached.
2699
2700 If the host is not expired and we are about to hit the hosts_max_retry
2701 limit, check to see if there is a subsequent hosts with a different MX
2702 value. If so, make that the next host, and don't count this one. This is a
2703 heuristic to make sure that different MXs do get tried. With a normal kind
2704 of retry rule, they would get tried anyway when the earlier hosts were
2705 delayed, but if the domain has a "retry every time" type of rule - as is
2706 often used for the the very large ISPs, that won't happen. */
2707
2708 else
2709 {
2710 if (!host_is_expired && ++unexpired_hosts_tried >= ob->hosts_max_try)
2711 {
2712 host_item *h;
2713 DEBUG(D_transport)
2714 debug_printf("hosts_max_try limit reached with this host\n");
2715 for (h = host; h != NULL; h = h->next)
2716 if (h->mx != host->mx) break;
2717 if (h != NULL)
2718 {
2719 nexthost = h;
2720 unexpired_hosts_tried--;
2721 DEBUG(D_transport) debug_printf("however, a higher MX host exists "
2722 "and will be tried\n");
2723 }
2724 }
2725
2726 /* Attempt the delivery. */
2727
2728 total_hosts_tried++;
2729 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2730 expanded_hosts != NULL, &message_defer, FALSE);
2731
2732 /* Yield is one of:
2733 OK => connection made, each address contains its result;
2734 message_defer is set for message-specific defers (when all
2735 recipients are marked defer)
2736 DEFER => there was a non-message-specific delivery problem;
2737 ERROR => there was a problem setting up the arguments for a filter,
2738 or there was a problem with expanding added headers
2739 */
2740
2741 /* If the result is not OK, there was a non-message-specific problem.
2742 If the result is DEFER, we need to write to the logs saying what happened
2743 for this particular host, except in the case of authentication and TLS
2744 failures, where the log has already been written. If all hosts defer a
2745 general message is written at the end. */
2746
2747 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL &&
2748 first_addr->basic_errno != ERRNO_TLSFAILURE)
2749 write_logs(first_addr, host);
2750
2751 /* If STARTTLS was accepted, but there was a failure in setting up the
2752 TLS session (usually a certificate screwup), and the host is not in
2753 hosts_require_tls, and tls_tempfail_tryclear is true, try again, with
2754 TLS forcibly turned off. We have to start from scratch with a new SMTP
2755 connection. That's why the retry is done from here, not from within
2756 smtp_deliver(). [Rejections of STARTTLS itself don't screw up the
2757 session, so the in-clear transmission after those errors, if permitted,
2758 happens inside smtp_deliver().] */
2759
2760 #ifdef SUPPORT_TLS
2761 if (rc == DEFER && first_addr->basic_errno == ERRNO_TLSFAILURE &&
2762 ob->tls_tempfail_tryclear &&
2763 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
2764 host->address, NULL) != OK)
2765 {
2766 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
2767 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
2768 first_addr = prepare_addresses(addrlist, host);
2769 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2770 expanded_hosts != NULL, &message_defer, TRUE);
2771 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL)
2772 write_logs(first_addr, host);
2773 }
2774 #endif
2775 }
2776
2777 /* Delivery attempt finished */
2778
2779 rs = (rc == OK)? US"OK" : (rc == DEFER)? US"DEFER" : (rc == ERROR)?
2780 US"ERROR" : US"?";
2781
2782 set_process_info("delivering %s: just tried %s [%s] for %s%s: result %s",
2783 message_id, host->name, host->address, addrlist->address,
2784 (addrlist->next == NULL)? "" : " (& others)", rs);
2785
2786 /* Release serialization if set up */
2787
2788 if (serialized) enq_end(serialize_key);
2789
2790 /* If the result is DEFER, or if a host retry record is known to exist, we
2791 need to add an item to the retry chain for updating the retry database
2792 at the end of delivery. We only need to add the item to the top address,
2793 of course. Also, if DEFER, we mark the IP address unusable so as to skip it
2794 for any other delivery attempts using the same address. (It is copied into
2795 the unusable tree at the outer level, so even if different address blocks
2796 contain the same address, it still won't get tried again.) */
2797
2798 if (rc == DEFER || retry_host_key != NULL)
2799 {
2800 int delete_flag = (rc != DEFER)? rf_delete : 0;
2801 if (retry_host_key == NULL)
2802 {
2803 retry_host_key = ob->retry_include_ip_address?
2804 string_sprintf("T:%S:%s%s", host->name, host->address, pistring) :
2805 string_sprintf("T:%S%s", host->name, pistring);
2806 }
2807
2808 /* If a delivery of another message over an existing SMTP connection
2809 yields DEFER, we do NOT set up retry data for the host. This covers the
2810 case when there are delays in routing the addresses in the second message
2811 that are so long that the server times out. This is alleviated by not
2812 routing addresses that previously had routing defers when handling an
2813 existing connection, but even so, this case may occur (e.g. if a
2814 previously happily routed address starts giving routing defers). If the
2815 host is genuinely down, another non-continued message delivery will
2816 notice it soon enough. */
2817
2818 if (delete_flag != 0 || !continuing)
2819 retry_add_item(first_addr, retry_host_key, rf_host | delete_flag);
2820
2821 /* We may have tried an expired host, if its retry time has come; ensure
2822 the status reflects the expiry for the benefit of any other addresses. */
2823
2824 if (rc == DEFER)
2825 {
2826 host->status = (host_is_expired)?
2827 hstatus_unusable_expired : hstatus_unusable;
2828 host->why = hwhy_deferred;
2829 }
2830 }
2831
2832 /* If message_defer is set (host was OK, but every recipient got deferred
2833 because of some message-specific problem), or if that had happened
2834 previously so that a message retry key exists, add an appropriate item
2835 to the retry chain. Note that if there was a message defer but now there is
2836 a host defer, the message defer record gets deleted. That seems perfectly
2837 reasonable. Also, stop the message from being remembered as waiting
2838 for specific hosts. */
2839
2840 if (message_defer || retry_message_key != NULL)
2841 {
2842 int delete_flag = message_defer? 0 : rf_delete;
2843 if (retry_message_key == NULL)
2844 {
2845 retry_message_key = ob->retry_include_ip_address?
2846 string_sprintf("T:%S:%s%s:%s", host->name, host->address, pistring,
2847 message_id) :
2848 string_sprintf("T:%S%s:%s", host->name, pistring, message_id);
2849 }
2850 retry_add_item(addrlist, retry_message_key,
2851 rf_message | rf_host | delete_flag);
2852 update_waiting = FALSE;
2853 }
2854
2855 /* Any return other than DEFER (that is, OK or ERROR) means that the
2856 addresses have got their final statuses filled in for this host. In the OK
2857 case, see if any of them are deferred. */
2858
2859 if (rc == OK)
2860 {
2861 for (addr = addrlist; addr != NULL; addr = addr->next)
2862 {
2863 if (addr->transport_return == DEFER)
2864 {
2865 some_deferred = TRUE;
2866 break;
2867 }
2868 }
2869 }
2870
2871 /* If no addresses deferred or the result was ERROR, return. We do this for
2872 ERROR because a failing filter set-up or add_headers expansion is likely to
2873 fail for any host we try. */
2874
2875 if (rc == ERROR || (rc == OK && !some_deferred))
2876 {
2877 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2878 return TRUE; /* Each address has its status */
2879 }
2880
2881 /* If the result was DEFER or some individual addresses deferred, let
2882 the loop run to try other hosts with the deferred addresses, except for the
2883 case when we were trying to deliver down an existing channel and failed.
2884 Don't try any other hosts in this case. */
2885
2886 if (continuing) break;
2887
2888 /* If the whole delivery, or some individual addresses, were deferred and
2889 there are more hosts that could be tried, do not count this host towards
2890 the hosts_max_try limit if the age of the message is greater than the
2891 maximum retry time for this host. This means we may try try all hosts,
2892 ignoring the limit, when messages have been around for some time. This is
2893 important because if we don't try all hosts, the address will never time
2894 out. NOTE: this does not apply to hosts_max_try_hardlimit. */
2895
2896 if ((rc == DEFER || some_deferred) && nexthost != NULL)
2897 {
2898 BOOL timedout;
2899 retry_config *retry = retry_find_config(host->name, NULL, 0, 0);
2900
2901 if (retry != NULL && retry->rules != NULL)
2902 {
2903 retry_rule *last_rule;
2904 for (last_rule = retry->rules;
2905 last_rule->next != NULL;
2906 last_rule = last_rule->next);
2907 timedout = time(NULL) - received_time > last_rule->timeout;
2908 }
2909 else timedout = TRUE; /* No rule => timed out */
2910
2911 if (timedout)
2912 {
2913 unexpired_hosts_tried--;
2914 DEBUG(D_transport) debug_printf("temporary delivery error(s) override "
2915 "hosts_max_try (message older than host's retry time)\n");
2916 }
2917 }
2918 } /* End of loop for trying multiple hosts. */
2919
2920 /* This is the end of the loop that repeats iff expired is TRUE and
2921 ob->delay_after_cutoff is FALSE. The second time round we will
2922 try those hosts that haven't been tried since the message arrived. */
2923
2924 DEBUG(D_transport)
2925 {
2926 debug_printf("all IP addresses skipped or deferred at least one address\n");
2927 if (expired && !ob->delay_after_cutoff && cutoff_retry == 0)
2928 debug_printf("retrying IP addresses not tried since message arrived\n");
2929 }
2930 }
2931
2932
2933 /* Get here if all IP addresses are skipped or defer at least one address. In
2934 MUA wrapper mode, this will happen only for connection or other non-message-
2935 specific failures. Force the delivery status for all addresses to FAIL. */
2936
2937 if (mua_wrapper)
2938 {
2939 for (addr = addrlist; addr != NULL; addr = addr->next)
2940 addr->transport_return = FAIL;
2941 goto END_TRANSPORT;
2942 }
2943
2944 /* In the normal, non-wrapper case, add a standard message to each deferred
2945 address if there hasn't been an error, that is, if it hasn't actually been
2946 tried this time. The variable "expired" will be FALSE if any deliveries were
2947 actually tried, or if there was at least one host that was not expired. That
2948 is, it is TRUE only if no deliveries were tried and all hosts were expired. If
2949 a delivery has been tried, an error code will be set, and the failing of the
2950 message is handled by the retry code later.
2951
2952 If queue_smtp is set, or this transport was called to send a subsequent message
2953 down an existing TCP/IP connection, and something caused the host not to be
2954 found, we end up here, but can detect these cases and handle them specially. */
2955
2956 for (addr = addrlist; addr != NULL; addr = addr->next)
2957 {
2958 /* If host is not NULL, it means that we stopped processing the host list
2959 because of hosts_max_try or hosts_max_try_hardlimit. In the former case, this
2960 means we need to behave as if some hosts were skipped because their retry
2961 time had not come. Specifically, this prevents the address from timing out.
2962 However, if we have hit hosts_max_try_hardlimit, we want to behave as if all
2963 hosts were tried. */
2964
2965 if (host != NULL)
2966 {
2967 if (total_hosts_tried >= ob->hosts_max_try_hardlimit)
2968 {
2969 DEBUG(D_transport)
2970 debug_printf("hosts_max_try_hardlimit reached: behave as if all "
2971 "hosts were tried\n");
2972 }
2973 else
2974 {
2975 DEBUG(D_transport)
2976 debug_printf("hosts_max_try limit caused some hosts to be skipped\n");
2977 setflag(addr, af_retry_skipped);
2978 }
2979 }
2980
2981 if (queue_smtp) /* no deliveries attempted */
2982 {
2983 addr->transport_return = DEFER;
2984 addr->basic_errno = 0;
2985 addr->message = US"SMTP delivery explicitly queued";
2986 }
2987
2988 else if (addr->transport_return == DEFER &&
2989 (addr->basic_errno == ERRNO_UNKNOWNERROR || addr->basic_errno == 0) &&
2990 addr->message == NULL)
2991 {
2992 addr->basic_errno = ERRNO_HRETRY;
2993 if (continue_hostname != NULL)
2994 {
2995 addr->message = US"no host found for existing SMTP connection";
2996 }
2997 else if (expired)
2998 {
2999 setflag(addr, af_pass_message); /* This is not a security risk */
3000 addr->message = (ob->delay_after_cutoff)?
3001 US"retry time not reached for any host after a long failure period" :
3002 US"all hosts have been failing for a long time and were last tried "
3003 "after this message arrived";
3004
3005 /* If we are already using fallback hosts, or there are no fallback hosts
3006 defined, convert the result to FAIL to cause a bounce. */
3007
3008 if (addr->host_list == addr->fallback_hosts ||
3009 addr->fallback_hosts == NULL)
3010 addr->transport_return = FAIL;
3011 }
3012 else
3013 {
3014 if (hosts_retry == hosts_total)
3015 addr->message = US"retry time not reached for any host";
3016 else if (hosts_fail == hosts_total)
3017 addr->message = US"all host address lookups failed permanently";
3018 else if (hosts_defer == hosts_total)
3019 addr->message = US"all host address lookups failed temporarily";
3020 else if (hosts_serial == hosts_total)
3021 addr->message = US"connection limit reached for all hosts";
3022 else if (hosts_fail+hosts_defer == hosts_total)
3023 addr->message = US"all host address lookups failed";
3024 else addr->message = US"some host address lookups failed and retry time "
3025 "not reached for other hosts or connection limit reached";
3026 }
3027 }
3028 }
3029
3030 /* Update the database which keeps information about which messages are waiting
3031 for which hosts to become available. For some message-specific errors, the
3032 update_waiting flag is turned off because we don't want follow-on deliveries in
3033 those cases. */
3034
3035 if (update_waiting) transport_update_waiting(hostlist, tblock->name);
3036
3037 END_TRANSPORT:
3038
3039 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
3040
3041 return TRUE; /* Each address has its status */
3042 }
3043
3044 /* End of transport/smtp.c */