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[exim.git] / src / src / transports / smtp.c
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) University of Cambridge 1995 - 2014 */
6 /* See the file NOTICE for conditions of use and distribution. */
7
8 #include "../exim.h"
9 #include "smtp.h"
10
11 #define PENDING 256
12 #define PENDING_DEFER (PENDING + DEFER)
13 #define PENDING_OK (PENDING + OK)
14
15
16 /* Options specific to the smtp transport. This transport also supports LMTP
17 over TCP/IP. The options must be in alphabetic order (note that "_" comes
18 before the lower case letters). Some live in the transport_instance block so as
19 to be publicly visible; these are flagged with opt_public. */
20
21 optionlist smtp_transport_options[] = {
22 { "*expand_multi_domain", opt_stringptr | opt_hidden | opt_public,
23 (void *)offsetof(transport_instance, expand_multi_domain) },
24 { "*expand_retry_include_ip_address", opt_stringptr | opt_hidden,
25 (void *)(offsetof(smtp_transport_options_block, expand_retry_include_ip_address)) },
26
27 { "address_retry_include_sender", opt_bool,
28 (void *)offsetof(smtp_transport_options_block, address_retry_include_sender) },
29 { "allow_localhost", opt_bool,
30 (void *)offsetof(smtp_transport_options_block, allow_localhost) },
31 { "authenticated_sender", opt_stringptr,
32 (void *)offsetof(smtp_transport_options_block, authenticated_sender) },
33 { "authenticated_sender_force", opt_bool,
34 (void *)offsetof(smtp_transport_options_block, authenticated_sender_force) },
35 { "command_timeout", opt_time,
36 (void *)offsetof(smtp_transport_options_block, command_timeout) },
37 { "connect_timeout", opt_time,
38 (void *)offsetof(smtp_transport_options_block, connect_timeout) },
39 { "connection_max_messages", opt_int | opt_public,
40 (void *)offsetof(transport_instance, connection_max_messages) },
41 { "data_timeout", opt_time,
42 (void *)offsetof(smtp_transport_options_block, data_timeout) },
43 { "delay_after_cutoff", opt_bool,
44 (void *)offsetof(smtp_transport_options_block, delay_after_cutoff) },
45 #ifndef DISABLE_DKIM
46 { "dkim_canon", opt_stringptr,
47 (void *)offsetof(smtp_transport_options_block, dkim_canon) },
48 { "dkim_domain", opt_stringptr,
49 (void *)offsetof(smtp_transport_options_block, dkim_domain) },
50 { "dkim_private_key", opt_stringptr,
51 (void *)offsetof(smtp_transport_options_block, dkim_private_key) },
52 { "dkim_selector", opt_stringptr,
53 (void *)offsetof(smtp_transport_options_block, dkim_selector) },
54 { "dkim_sign_headers", opt_stringptr,
55 (void *)offsetof(smtp_transport_options_block, dkim_sign_headers) },
56 { "dkim_strict", opt_stringptr,
57 (void *)offsetof(smtp_transport_options_block, dkim_strict) },
58 #endif
59 { "dns_qualify_single", opt_bool,
60 (void *)offsetof(smtp_transport_options_block, dns_qualify_single) },
61 { "dns_search_parents", opt_bool,
62 (void *)offsetof(smtp_transport_options_block, dns_search_parents) },
63 { "dnssec_request_domains", opt_stringptr,
64 (void *)offsetof(smtp_transport_options_block, dnssec_request_domains) },
65 { "dnssec_require_domains", opt_stringptr,
66 (void *)offsetof(smtp_transport_options_block, dnssec_require_domains) },
67 { "dscp", opt_stringptr,
68 (void *)offsetof(smtp_transport_options_block, dscp) },
69 { "fallback_hosts", opt_stringptr,
70 (void *)offsetof(smtp_transport_options_block, fallback_hosts) },
71 { "final_timeout", opt_time,
72 (void *)offsetof(smtp_transport_options_block, final_timeout) },
73 { "gethostbyname", opt_bool,
74 (void *)offsetof(smtp_transport_options_block, gethostbyname) },
75 #ifdef SUPPORT_TLS
76 /* These are no longer honoured, as of Exim 4.80; for now, we silently
77 ignore; 4.83 will warn, and a later-still release will remove
78 these options, so that using them becomes an error. */
79 { "gnutls_require_kx", opt_stringptr,
80 (void *)offsetof(smtp_transport_options_block, gnutls_require_kx) },
81 { "gnutls_require_mac", opt_stringptr,
82 (void *)offsetof(smtp_transport_options_block, gnutls_require_mac) },
83 { "gnutls_require_protocols", opt_stringptr,
84 (void *)offsetof(smtp_transport_options_block, gnutls_require_proto) },
85 #endif
86 { "helo_data", opt_stringptr,
87 (void *)offsetof(smtp_transport_options_block, helo_data) },
88 { "hosts", opt_stringptr,
89 (void *)offsetof(smtp_transport_options_block, hosts) },
90 { "hosts_avoid_esmtp", opt_stringptr,
91 (void *)offsetof(smtp_transport_options_block, hosts_avoid_esmtp) },
92 { "hosts_avoid_pipelining", opt_stringptr,
93 (void *)offsetof(smtp_transport_options_block, hosts_avoid_pipelining) },
94 #ifdef SUPPORT_TLS
95 { "hosts_avoid_tls", opt_stringptr,
96 (void *)offsetof(smtp_transport_options_block, hosts_avoid_tls) },
97 #endif
98 { "hosts_max_try", opt_int,
99 (void *)offsetof(smtp_transport_options_block, hosts_max_try) },
100 { "hosts_max_try_hardlimit", opt_int,
101 (void *)offsetof(smtp_transport_options_block, hosts_max_try_hardlimit) },
102 #ifdef SUPPORT_TLS
103 { "hosts_nopass_tls", opt_stringptr,
104 (void *)offsetof(smtp_transport_options_block, hosts_nopass_tls) },
105 #endif
106 { "hosts_override", opt_bool,
107 (void *)offsetof(smtp_transport_options_block, hosts_override) },
108 { "hosts_randomize", opt_bool,
109 (void *)offsetof(smtp_transport_options_block, hosts_randomize) },
110 #if defined(SUPPORT_TLS) && !defined(DISABLE_OCSP)
111 { "hosts_request_ocsp", opt_stringptr,
112 (void *)offsetof(smtp_transport_options_block, hosts_request_ocsp) },
113 #endif
114 { "hosts_require_auth", opt_stringptr,
115 (void *)offsetof(smtp_transport_options_block, hosts_require_auth) },
116 #ifdef SUPPORT_TLS
117 # ifdef EXPERIMENTAL_DANE
118 { "hosts_require_dane", opt_stringptr,
119 (void *)offsetof(smtp_transport_options_block, hosts_require_dane) },
120 # endif
121 # ifndef DISABLE_OCSP
122 { "hosts_require_ocsp", opt_stringptr,
123 (void *)offsetof(smtp_transport_options_block, hosts_require_ocsp) },
124 # endif
125 { "hosts_require_tls", opt_stringptr,
126 (void *)offsetof(smtp_transport_options_block, hosts_require_tls) },
127 #endif
128 { "hosts_try_auth", opt_stringptr,
129 (void *)offsetof(smtp_transport_options_block, hosts_try_auth) },
130 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
131 { "hosts_try_dane", opt_stringptr,
132 (void *)offsetof(smtp_transport_options_block, hosts_try_dane) },
133 #endif
134 #ifndef DISABLE_PRDR
135 { "hosts_try_prdr", opt_stringptr,
136 (void *)offsetof(smtp_transport_options_block, hosts_try_prdr) },
137 #endif
138 #ifdef SUPPORT_TLS
139 { "hosts_verify_avoid_tls", opt_stringptr,
140 (void *)offsetof(smtp_transport_options_block, hosts_verify_avoid_tls) },
141 #endif
142 { "interface", opt_stringptr,
143 (void *)offsetof(smtp_transport_options_block, interface) },
144 { "keepalive", opt_bool,
145 (void *)offsetof(smtp_transport_options_block, keepalive) },
146 { "lmtp_ignore_quota", opt_bool,
147 (void *)offsetof(smtp_transport_options_block, lmtp_ignore_quota) },
148 { "max_rcpt", opt_int | opt_public,
149 (void *)offsetof(transport_instance, max_addresses) },
150 { "multi_domain", opt_expand_bool | opt_public,
151 (void *)offsetof(transport_instance, multi_domain) },
152 { "port", opt_stringptr,
153 (void *)offsetof(smtp_transport_options_block, port) },
154 { "protocol", opt_stringptr,
155 (void *)offsetof(smtp_transport_options_block, protocol) },
156 { "retry_include_ip_address", opt_expand_bool,
157 (void *)offsetof(smtp_transport_options_block, retry_include_ip_address) },
158 { "serialize_hosts", opt_stringptr,
159 (void *)offsetof(smtp_transport_options_block, serialize_hosts) },
160 { "size_addition", opt_int,
161 (void *)offsetof(smtp_transport_options_block, size_addition) }
162 #ifdef SUPPORT_TLS
163 ,{ "tls_certificate", opt_stringptr,
164 (void *)offsetof(smtp_transport_options_block, tls_certificate) },
165 { "tls_crl", opt_stringptr,
166 (void *)offsetof(smtp_transport_options_block, tls_crl) },
167 { "tls_dh_min_bits", opt_int,
168 (void *)offsetof(smtp_transport_options_block, tls_dh_min_bits) },
169 { "tls_privatekey", opt_stringptr,
170 (void *)offsetof(smtp_transport_options_block, tls_privatekey) },
171 { "tls_require_ciphers", opt_stringptr,
172 (void *)offsetof(smtp_transport_options_block, tls_require_ciphers) },
173 { "tls_sni", opt_stringptr,
174 (void *)offsetof(smtp_transport_options_block, tls_sni) },
175 { "tls_tempfail_tryclear", opt_bool,
176 (void *)offsetof(smtp_transport_options_block, tls_tempfail_tryclear) },
177 { "tls_try_verify_hosts", opt_stringptr,
178 (void *)offsetof(smtp_transport_options_block, tls_try_verify_hosts) },
179 #ifdef EXPERIMENTAL_CERTNAMES
180 { "tls_verify_cert_hostnames", opt_stringptr,
181 (void *)offsetof(smtp_transport_options_block,tls_verify_cert_hostnames)},
182 #endif
183 { "tls_verify_certificates", opt_stringptr,
184 (void *)offsetof(smtp_transport_options_block, tls_verify_certificates) },
185 { "tls_verify_hosts", opt_stringptr,
186 (void *)offsetof(smtp_transport_options_block, tls_verify_hosts) }
187 #endif
188 };
189
190 /* Size of the options list. An extern variable has to be used so that its
191 address can appear in the tables drtables.c. */
192
193 int smtp_transport_options_count =
194 sizeof(smtp_transport_options)/sizeof(optionlist);
195
196 /* Default private options block for the smtp transport. */
197
198 smtp_transport_options_block smtp_transport_option_defaults = {
199 NULL, /* hosts */
200 NULL, /* fallback_hosts */
201 NULL, /* hostlist */
202 NULL, /* fallback_hostlist */
203 NULL, /* authenticated_sender */
204 US"$primary_hostname", /* helo_data */
205 NULL, /* interface */
206 NULL, /* port */
207 US"smtp", /* protocol */
208 NULL, /* DSCP */
209 NULL, /* serialize_hosts */
210 NULL, /* hosts_try_auth */
211 NULL, /* hosts_require_auth */
212 #ifdef EXPERIMENTAL_DANE
213 NULL, /* hosts_try_dane */
214 NULL, /* hosts_require_dane */
215 #endif
216 #ifndef DISABLE_PRDR
217 US"*", /* hosts_try_prdr */
218 #endif
219 #ifndef DISABLE_OCSP
220 US"*", /* hosts_request_ocsp (except under DANE; tls_client_start()) */
221 NULL, /* hosts_require_ocsp */
222 #endif
223 NULL, /* hosts_require_tls */
224 NULL, /* hosts_avoid_tls */
225 US"*", /* hosts_verify_avoid_tls */
226 NULL, /* hosts_avoid_pipelining */
227 NULL, /* hosts_avoid_esmtp */
228 NULL, /* hosts_nopass_tls */
229 5*60, /* command_timeout */
230 5*60, /* connect_timeout; shorter system default overrides */
231 5*60, /* data timeout */
232 10*60, /* final timeout */
233 1024, /* size_addition */
234 5, /* hosts_max_try */
235 50, /* hosts_max_try_hardlimit */
236 TRUE, /* address_retry_include_sender */
237 FALSE, /* allow_localhost */
238 FALSE, /* authenticated_sender_force */
239 FALSE, /* gethostbyname */
240 TRUE, /* dns_qualify_single */
241 FALSE, /* dns_search_parents */
242 NULL, /* dnssec_request_domains */
243 NULL, /* dnssec_require_domains */
244 TRUE, /* delay_after_cutoff */
245 FALSE, /* hosts_override */
246 FALSE, /* hosts_randomize */
247 TRUE, /* keepalive */
248 FALSE, /* lmtp_ignore_quota */
249 NULL, /* expand_retry_include_ip_address */
250 TRUE /* retry_include_ip_address */
251 #ifdef SUPPORT_TLS
252 ,NULL, /* tls_certificate */
253 NULL, /* tls_crl */
254 NULL, /* tls_privatekey */
255 NULL, /* tls_require_ciphers */
256 NULL, /* gnutls_require_kx */
257 NULL, /* gnutls_require_mac */
258 NULL, /* gnutls_require_proto */
259 NULL, /* tls_sni */
260 NULL, /* tls_verify_certificates */
261 EXIM_CLIENT_DH_DEFAULT_MIN_BITS,
262 /* tls_dh_min_bits */
263 TRUE, /* tls_tempfail_tryclear */
264 NULL, /* tls_verify_hosts */
265 NULL /* tls_try_verify_hosts */
266 # ifdef EXPERIMENTAL_CERTNAMES
267 ,NULL /* tls_verify_cert_hostnames */
268 # endif
269 #endif
270 #ifndef DISABLE_DKIM
271 ,NULL, /* dkim_canon */
272 NULL, /* dkim_domain */
273 NULL, /* dkim_private_key */
274 NULL, /* dkim_selector */
275 NULL, /* dkim_sign_headers */
276 NULL /* dkim_strict */
277 #endif
278 };
279
280 #ifdef EXPERIMENTAL_DSN
281 /* some DSN flags for use later */
282
283 static int rf_list[] = {rf_notify_never, rf_notify_success,
284 rf_notify_failure, rf_notify_delay };
285
286 static uschar *rf_names[] = { US"NEVER", US"SUCCESS", US"FAILURE", US"DELAY" };
287 #endif
288
289
290
291 /* Local statics */
292
293 static uschar *smtp_command; /* Points to last cmd for error messages */
294 static uschar *mail_command; /* Points to MAIL cmd for error messages */
295 static BOOL update_waiting; /* TRUE to update the "wait" database */
296
297
298 /*************************************************
299 * Setup entry point *
300 *************************************************/
301
302 /* This function is called when the transport is about to be used,
303 but before running it in a sub-process. It is used for two things:
304
305 (1) To set the fallback host list in addresses, when delivering.
306 (2) To pass back the interface, port, protocol, and other options, for use
307 during callout verification.
308
309 Arguments:
310 tblock pointer to the transport instance block
311 addrlist list of addresses about to be transported
312 tf if not NULL, pointer to block in which to return options
313 uid the uid that will be set (not used)
314 gid the gid that will be set (not used)
315 errmsg place for error message (not used)
316
317 Returns: OK always (FAIL, DEFER not used)
318 */
319
320 static int
321 smtp_transport_setup(transport_instance *tblock, address_item *addrlist,
322 transport_feedback *tf, uid_t uid, gid_t gid, uschar **errmsg)
323 {
324 smtp_transport_options_block *ob =
325 (smtp_transport_options_block *)(tblock->options_block);
326
327 errmsg = errmsg; /* Keep picky compilers happy */
328 uid = uid;
329 gid = gid;
330
331 /* Pass back options if required. This interface is getting very messy. */
332
333 if (tf != NULL)
334 {
335 tf->interface = ob->interface;
336 tf->port = ob->port;
337 tf->protocol = ob->protocol;
338 tf->hosts = ob->hosts;
339 tf->hosts_override = ob->hosts_override;
340 tf->hosts_randomize = ob->hosts_randomize;
341 tf->gethostbyname = ob->gethostbyname;
342 tf->qualify_single = ob->dns_qualify_single;
343 tf->search_parents = ob->dns_search_parents;
344 tf->helo_data = ob->helo_data;
345 }
346
347 /* Set the fallback host list for all the addresses that don't have fallback
348 host lists, provided that the local host wasn't present in the original host
349 list. */
350
351 if (!testflag(addrlist, af_local_host_removed))
352 {
353 for (; addrlist != NULL; addrlist = addrlist->next)
354 if (addrlist->fallback_hosts == NULL)
355 addrlist->fallback_hosts = ob->fallback_hostlist;
356 }
357
358 return OK;
359 }
360
361
362
363 /*************************************************
364 * Initialization entry point *
365 *************************************************/
366
367 /* Called for each instance, after its options have been read, to
368 enable consistency checks to be done, or anything else that needs
369 to be set up.
370
371 Argument: pointer to the transport instance block
372 Returns: nothing
373 */
374
375 void
376 smtp_transport_init(transport_instance *tblock)
377 {
378 smtp_transport_options_block *ob =
379 (smtp_transport_options_block *)(tblock->options_block);
380
381 /* Retry_use_local_part defaults FALSE if unset */
382
383 if (tblock->retry_use_local_part == TRUE_UNSET)
384 tblock->retry_use_local_part = FALSE;
385
386 /* Set the default port according to the protocol */
387
388 if (ob->port == NULL)
389 ob->port = (strcmpic(ob->protocol, US"lmtp") == 0)? US"lmtp" :
390 (strcmpic(ob->protocol, US"smtps") == 0)? US"smtps" : US"smtp";
391
392 /* Set up the setup entry point, to be called before subprocesses for this
393 transport. */
394
395 tblock->setup = smtp_transport_setup;
396
397 /* Complain if any of the timeouts are zero. */
398
399 if (ob->command_timeout <= 0 || ob->data_timeout <= 0 ||
400 ob->final_timeout <= 0)
401 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
402 "command, data, or final timeout value is zero for %s transport",
403 tblock->name);
404
405 /* If hosts_override is set and there are local hosts, set the global
406 flag that stops verify from showing router hosts. */
407
408 if (ob->hosts_override && ob->hosts != NULL) tblock->overrides_hosts = TRUE;
409
410 /* If there are any fallback hosts listed, build a chain of host items
411 for them, but do not do any lookups at this time. */
412
413 host_build_hostlist(&(ob->fallback_hostlist), ob->fallback_hosts, FALSE);
414
415 #ifdef SUPPORT_TLS
416 if ( ob->gnutls_require_kx
417 || ob->gnutls_require_mac
418 || ob->gnutls_require_proto)
419 log_write(0, LOG_MAIN, "WARNING: smtp transport options"
420 " gnutls_require_kx, gnutls_require_mac and gnutls_require_protocols"
421 " are obsolete\n");
422 #endif
423 }
424
425
426
427
428
429 /*************************************************
430 * Set delivery info into all active addresses *
431 *************************************************/
432
433 /* Only addresses whose status is >= PENDING are relevant. A lesser
434 status means that an address is not currently being processed.
435
436 Arguments:
437 addrlist points to a chain of addresses
438 errno_value to put in each address's errno field
439 msg to put in each address's message field
440 rc to put in each address's transport_return field
441 pass_message if TRUE, set the "pass message" flag in the address
442 host if set, mark addrs as having used this host
443
444 If errno_value has the special value ERRNO_CONNECTTIMEOUT, ETIMEDOUT is put in
445 the errno field, and RTEF_CTOUT is ORed into the more_errno field, to indicate
446 this particular type of timeout.
447
448 Returns: nothing
449 */
450
451 static void
452 set_errno(address_item *addrlist, int errno_value, uschar *msg, int rc,
453 BOOL pass_message, host_item * host)
454 {
455 address_item *addr;
456 int orvalue = 0;
457 if (errno_value == ERRNO_CONNECTTIMEOUT)
458 {
459 errno_value = ETIMEDOUT;
460 orvalue = RTEF_CTOUT;
461 }
462 for (addr = addrlist; addr != NULL; addr = addr->next)
463 {
464 if (addr->transport_return < PENDING) continue;
465 addr->basic_errno = errno_value;
466 addr->more_errno |= orvalue;
467 if (msg != NULL)
468 {
469 addr->message = msg;
470 if (pass_message) setflag(addr, af_pass_message);
471 }
472 addr->transport_return = rc;
473 if (host)
474 addr->host_used = host;
475 }
476 }
477
478
479
480 /*************************************************
481 * Check an SMTP response *
482 *************************************************/
483
484 /* This function is given an errno code and the SMTP response buffer
485 to analyse, together with the host identification for generating messages. It
486 sets an appropriate message and puts the first digit of the response code into
487 the yield variable. If no response was actually read, a suitable digit is
488 chosen.
489
490 Arguments:
491 host the current host, to get its name for messages
492 errno_value pointer to the errno value
493 more_errno from the top address for use with ERRNO_FILTER_FAIL
494 buffer the SMTP response buffer
495 yield where to put a one-digit SMTP response code
496 message where to put an errror message
497 pass_message set TRUE if message is an SMTP response
498
499 Returns: TRUE if an SMTP "QUIT" command should be sent, else FALSE
500 */
501
502 static BOOL
503 check_response(host_item *host, int *errno_value, int more_errno,
504 uschar *buffer, int *yield, uschar **message, BOOL *pass_message)
505 {
506 uschar *pl = US"";
507
508 if (smtp_use_pipelining &&
509 (Ustrcmp(smtp_command, "MAIL") == 0 ||
510 Ustrcmp(smtp_command, "RCPT") == 0 ||
511 Ustrcmp(smtp_command, "DATA") == 0))
512 pl = US"pipelined ";
513
514 *yield = '4'; /* Default setting is to give a temporary error */
515
516 /* Handle response timeout */
517
518 if (*errno_value == ETIMEDOUT)
519 {
520 *message = US string_sprintf("SMTP timeout after %s%s",
521 pl, smtp_command);
522 if (transport_count > 0)
523 *message = US string_sprintf("%s (%d bytes written)", *message,
524 transport_count);
525 return FALSE;
526 }
527
528 /* Handle malformed SMTP response */
529
530 if (*errno_value == ERRNO_SMTPFORMAT)
531 {
532 uschar *malfresp = string_printing(buffer);
533 while (isspace(*malfresp)) malfresp++;
534 *message = *malfresp == 0
535 ? string_sprintf("Malformed SMTP reply (an empty line) "
536 "in response to %s%s", pl, smtp_command)
537 : string_sprintf("Malformed SMTP reply in response to %s%s: %s",
538 pl, smtp_command, malfresp);
539 return FALSE;
540 }
541
542 /* Handle a failed filter process error; can't send QUIT as we mustn't
543 end the DATA. */
544
545 if (*errno_value == ERRNO_FILTER_FAIL)
546 {
547 *message = US string_sprintf("transport filter process failed (%d)%s",
548 more_errno,
549 (more_errno == EX_EXECFAILED)? ": unable to execute command" : "");
550 return FALSE;
551 }
552
553 /* Handle a failed add_headers expansion; can't send QUIT as we mustn't
554 end the DATA. */
555
556 if (*errno_value == ERRNO_CHHEADER_FAIL)
557 {
558 *message =
559 US string_sprintf("failed to expand headers_add or headers_remove: %s",
560 expand_string_message);
561 return FALSE;
562 }
563
564 /* Handle failure to write a complete data block */
565
566 if (*errno_value == ERRNO_WRITEINCOMPLETE)
567 {
568 *message = US string_sprintf("failed to write a data block");
569 return FALSE;
570 }
571
572 /* Handle error responses from the remote mailer. */
573
574 if (buffer[0] != 0)
575 {
576 uschar *s = string_printing(buffer);
577 *message = US string_sprintf("SMTP error from remote mail server after %s%s: "
578 "%s", pl, smtp_command, s);
579 *pass_message = TRUE;
580 *yield = buffer[0];
581 return TRUE;
582 }
583
584 /* No data was read. If there is no errno, this must be the EOF (i.e.
585 connection closed) case, which causes deferral. An explicit connection reset
586 error has the same effect. Otherwise, put the host's identity in the message,
587 leaving the errno value to be interpreted as well. In all cases, we have to
588 assume the connection is now dead. */
589
590 if (*errno_value == 0 || *errno_value == ECONNRESET)
591 {
592 *errno_value = ERRNO_SMTPCLOSED;
593 *message = US string_sprintf("Remote host closed connection "
594 "in response to %s%s", pl, smtp_command);
595 }
596 else *message = US string_sprintf("%s [%s]", host->name, host->address);
597
598 return FALSE;
599 }
600
601
602
603 /*************************************************
604 * Write error message to logs *
605 *************************************************/
606
607 /* This writes to the main log and to the message log.
608
609 Arguments:
610 addr the address item containing error information
611 host the current host
612
613 Returns: nothing
614 */
615
616 static void
617 write_logs(address_item *addr, host_item *host)
618 {
619 uschar * message = string_sprintf("H=%s [%s]", host->name, host->address);
620
621 if (addr->message)
622 {
623 message = string_sprintf("%s: %s", message, addr->message);
624 if (addr->basic_errno > 0)
625 message = string_sprintf("%s: %s", message, strerror(addr->basic_errno));
626 log_write(0, LOG_MAIN, "%s", message);
627 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
628 }
629 else
630 {
631 if (log_extra_selector & LX_outgoing_port)
632 message = string_sprintf("%s:%d", message,
633 host->port == PORT_NONE ? 25 : host->port);
634 log_write(0, LOG_MAIN, "%s %s", message, strerror(addr->basic_errno));
635 deliver_msglog("%s %s %s\n", tod_stamp(tod_log), message,
636 strerror(addr->basic_errno));
637 }
638 }
639
640 static void
641 msglog_line(host_item * host, uschar * message)
642 {
643 deliver_msglog("%s H=%s [%s] %s\n", tod_stamp(tod_log),
644 host->name, host->address, message);
645 }
646
647
648
649 #ifdef EXPERIMENTAL_EVENT
650 /*************************************************
651 * Post-defer action *
652 *************************************************/
653
654 /* This expands an arbitrary per-transport string.
655 It might, for example, be used to write to the database log.
656
657 Arguments:
658 addr the address item containing error information
659 host the current host
660
661 Returns: nothing
662 */
663
664 static void
665 deferred_event_raise(address_item *addr, host_item *host)
666 {
667 uschar * action = addr->transport->event_action;
668 uschar * save_domain;
669 uschar * save_local;
670
671 if (!action)
672 return;
673
674 save_domain = deliver_domain;
675 save_local = deliver_localpart;
676
677 /*XXX would ip & port already be set up? */
678 deliver_host_address = string_copy(host->address);
679 deliver_host_port = host->port == PORT_NONE ? 25 : host->port;
680 event_defer_errno = addr->basic_errno;
681
682 router_name = addr->router->name;
683 transport_name = addr->transport->name;
684 deliver_domain = addr->domain;
685 deliver_localpart = addr->local_part;
686
687 (void) event_raise(action, US"msg:host:defer",
688 addr->message
689 ? addr->basic_errno > 0
690 ? string_sprintf("%s: %s", addr->message, strerror(addr->basic_errno))
691 : string_copy(addr->message)
692 : addr->basic_errno > 0
693 ? string_copy(US strerror(addr->basic_errno))
694 : NULL);
695
696 deliver_localpart = save_local;
697 deliver_domain = save_domain;
698 router_name = transport_name = NULL;
699 }
700 #endif
701
702
703
704 /*************************************************
705 * Synchronize SMTP responses *
706 *************************************************/
707
708 /* This function is called from smtp_deliver() to receive SMTP responses from
709 the server, and match them up with the commands to which they relate. When
710 PIPELINING is not in use, this function is called after every command, and is
711 therefore somewhat over-engineered, but it is simpler to use a single scheme
712 that works both with and without PIPELINING instead of having two separate sets
713 of code.
714
715 The set of commands that are buffered up with pipelining may start with MAIL
716 and may end with DATA; in between are RCPT commands that correspond to the
717 addresses whose status is PENDING_DEFER. All other commands (STARTTLS, AUTH,
718 etc.) are never buffered.
719
720 Errors after MAIL or DATA abort the whole process leaving the response in the
721 buffer. After MAIL, pending responses are flushed, and the original command is
722 re-instated in big_buffer for error messages. For RCPT commands, the remote is
723 permitted to reject some recipient addresses while accepting others. However
724 certain errors clearly abort the whole process. Set the value in
725 transport_return to PENDING_OK if the address is accepted. If there is a
726 subsequent general error, it will get reset accordingly. If not, it will get
727 converted to OK at the end.
728
729 Arguments:
730 addrlist the complete address list
731 include_affixes TRUE if affixes include in RCPT
732 sync_addr ptr to the ptr of the one to start scanning at (updated)
733 host the host we are connected to
734 count the number of responses to read
735 address_retry_
736 include_sender true if 4xx retry is to include the sender it its key
737 pending_MAIL true if the first response is for MAIL
738 pending_DATA 0 if last command sent was not DATA
739 +1 if previously had a good recipient
740 -1 if not previously had a good recipient
741 inblock incoming SMTP block
742 timeout timeout value
743 buffer buffer for reading response
744 buffsize size of buffer
745
746 Returns: 3 if at least one address had 2xx and one had 5xx
747 2 if at least one address had 5xx but none had 2xx
748 1 if at least one host had a 2xx response, but none had 5xx
749 0 no address had 2xx or 5xx but no errors (all 4xx, or just DATA)
750 -1 timeout while reading RCPT response
751 -2 I/O or other non-response error for RCPT
752 -3 DATA or MAIL failed - errno and buffer set
753 */
754
755 static int
756 sync_responses(address_item *addrlist, BOOL include_affixes,
757 address_item **sync_addr, host_item *host, int count,
758 BOOL address_retry_include_sender, BOOL pending_MAIL,
759 int pending_DATA, smtp_inblock *inblock, int timeout, uschar *buffer,
760 int buffsize)
761 {
762 address_item *addr = *sync_addr;
763 int yield = 0;
764
765 /* Handle the response for a MAIL command. On error, reinstate the original
766 command in big_buffer for error message use, and flush any further pending
767 responses before returning, except after I/O errors and timeouts. */
768
769 if (pending_MAIL)
770 {
771 count--;
772 if (!smtp_read_response(inblock, buffer, buffsize, '2', timeout))
773 {
774 Ustrcpy(big_buffer, mail_command); /* Fits, because it came from there! */
775 if (errno == 0 && buffer[0] != 0)
776 {
777 uschar flushbuffer[4096];
778 int save_errno = 0;
779 if (buffer[0] == '4')
780 {
781 save_errno = ERRNO_MAIL4XX;
782 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
783 }
784 while (count-- > 0)
785 {
786 if (!smtp_read_response(inblock, flushbuffer, sizeof(flushbuffer),
787 '2', timeout)
788 && (errno != 0 || flushbuffer[0] == 0))
789 break;
790 }
791 errno = save_errno;
792 }
793
794 if (pending_DATA) count--; /* Number of RCPT responses to come */
795 while (count-- > 0) /* Mark any pending addrs with the host used */
796 {
797 while (addr->transport_return != PENDING_DEFER) addr = addr->next;
798 addr->host_used = host;
799 addr = addr->next;
800 }
801 return -3;
802 }
803 }
804
805 if (pending_DATA) count--; /* Number of RCPT responses to come */
806
807 /* Read and handle the required number of RCPT responses, matching each one up
808 with an address by scanning for the next address whose status is PENDING_DEFER.
809 */
810
811 while (count-- > 0)
812 {
813 while (addr->transport_return != PENDING_DEFER) addr = addr->next;
814
815 /* The address was accepted */
816 addr->host_used = host;
817
818 if (smtp_read_response(inblock, buffer, buffsize, '2', timeout))
819 {
820 yield |= 1;
821 addr->transport_return = PENDING_OK;
822
823 /* If af_dr_retry_exists is set, there was a routing delay on this address;
824 ensure that any address-specific retry record is expunged. We do this both
825 for the basic key and for the version that also includes the sender. */
826
827 if (testflag(addr, af_dr_retry_exists))
828 {
829 uschar *altkey = string_sprintf("%s:<%s>", addr->address_retry_key,
830 sender_address);
831 retry_add_item(addr, altkey, rf_delete);
832 retry_add_item(addr, addr->address_retry_key, rf_delete);
833 }
834 }
835
836 /* Timeout while reading the response */
837
838 else if (errno == ETIMEDOUT)
839 {
840 int save_errno = errno;
841 uschar *message = string_sprintf("SMTP timeout after RCPT TO:<%s>",
842 transport_rcpt_address(addr, include_affixes));
843 set_errno(addrlist, save_errno, message, DEFER, FALSE, NULL);
844 retry_add_item(addr, addr->address_retry_key, 0);
845 update_waiting = FALSE;
846 return -1;
847 }
848
849 /* Handle other errors in obtaining an SMTP response by returning -1. This
850 will cause all the addresses to be deferred. Restore the SMTP command in
851 big_buffer for which we are checking the response, so the error message
852 makes sense. */
853
854 else if (errno != 0 || buffer[0] == 0)
855 {
856 string_format(big_buffer, big_buffer_size, "RCPT TO:<%s>",
857 transport_rcpt_address(addr, include_affixes));
858 return -2;
859 }
860
861 /* Handle SMTP permanent and temporary response codes. */
862
863 else
864 {
865 addr->message =
866 string_sprintf("SMTP error from remote mail server after RCPT TO:<%s>: "
867 "%s", transport_rcpt_address(addr, include_affixes),
868 string_printing(buffer));
869 setflag(addr, af_pass_message);
870 msglog_line(host, addr->message);
871
872 /* The response was 5xx */
873
874 if (buffer[0] == '5')
875 {
876 addr->transport_return = FAIL;
877 yield |= 2;
878 }
879
880 /* The response was 4xx */
881
882 else
883 {
884 addr->transport_return = DEFER;
885 addr->basic_errno = ERRNO_RCPT4XX;
886 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
887
888 /* Log temporary errors if there are more hosts to be tried.
889 If not, log this last one in the == line. */
890
891 if (host->next)
892 log_write(0, LOG_MAIN, "H=%s [%s]: %s", host->name, host->address, addr->message);
893
894 /* Do not put this message on the list of those waiting for specific
895 hosts, as otherwise it is likely to be tried too often. */
896
897 update_waiting = FALSE;
898
899 /* Add a retry item for the address so that it doesn't get tried again
900 too soon. If address_retry_include_sender is true, add the sender address
901 to the retry key. */
902
903 if (address_retry_include_sender)
904 {
905 uschar *altkey = string_sprintf("%s:<%s>", addr->address_retry_key,
906 sender_address);
907 retry_add_item(addr, altkey, 0);
908 }
909 else retry_add_item(addr, addr->address_retry_key, 0);
910 }
911 }
912 } /* Loop for next RCPT response */
913
914 /* Update where to start at for the next block of responses, unless we
915 have already handled all the addresses. */
916
917 if (addr != NULL) *sync_addr = addr->next;
918
919 /* Handle a response to DATA. If we have not had any good recipients, either
920 previously or in this block, the response is ignored. */
921
922 if (pending_DATA != 0 &&
923 !smtp_read_response(inblock, buffer, buffsize, '3', timeout))
924 {
925 int code;
926 uschar *msg;
927 BOOL pass_message;
928 if (pending_DATA > 0 || (yield & 1) != 0)
929 {
930 if (errno == 0 && buffer[0] == '4')
931 {
932 errno = ERRNO_DATA4XX;
933 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
934 }
935 return -3;
936 }
937 (void)check_response(host, &errno, 0, buffer, &code, &msg, &pass_message);
938 DEBUG(D_transport) debug_printf("%s\nerror for DATA ignored: pipelining "
939 "is in use and there were no good recipients\n", msg);
940 }
941
942 /* All responses read and handled; MAIL (if present) received 2xx and DATA (if
943 present) received 3xx. If any RCPTs were handled and yielded anything other
944 than 4xx, yield will be set non-zero. */
945
946 return yield;
947 }
948
949
950
951 /* Do the client side of smtp-level authentication */
952 /*
953 Arguments:
954 buffer EHLO response from server (gets overwritten)
955 addrlist chain of potential addresses to deliver
956 host host to deliver to
957 ob transport options
958 ibp, obp comms channel control blocks
959
960 Returns:
961 OK Success, or failed (but not required): global "smtp_authenticated" set
962 DEFER Failed authentication (and was required)
963 ERROR Internal problem
964
965 FAIL_SEND Failed communications - transmit
966 FAIL - response
967 */
968
969 int
970 smtp_auth(uschar *buffer, unsigned bufsize, address_item *addrlist, host_item *host,
971 smtp_transport_options_block *ob, BOOL is_esmtp,
972 smtp_inblock *ibp, smtp_outblock *obp)
973 {
974 int require_auth;
975 uschar *fail_reason = US"server did not advertise AUTH support";
976
977 smtp_authenticated = FALSE;
978 client_authenticator = client_authenticated_id = client_authenticated_sender = NULL;
979 require_auth = verify_check_given_host(&ob->hosts_require_auth, host);
980
981 if (is_esmtp && !regex_AUTH) regex_AUTH =
982 regex_must_compile(US"\\n250[\\s\\-]AUTH\\s+([\\-\\w\\s]+)(?:\\n|$)",
983 FALSE, TRUE);
984
985 if (is_esmtp && regex_match_and_setup(regex_AUTH, buffer, 0, -1))
986 {
987 uschar *names = string_copyn(expand_nstring[1], expand_nlength[1]);
988 expand_nmax = -1; /* reset */
989
990 /* Must not do this check until after we have saved the result of the
991 regex match above. */
992
993 if (require_auth == OK ||
994 verify_check_given_host(&ob->hosts_try_auth, host) == OK)
995 {
996 auth_instance *au;
997 fail_reason = US"no common mechanisms were found";
998
999 DEBUG(D_transport) debug_printf("scanning authentication mechanisms\n");
1000
1001 /* Scan the configured authenticators looking for one which is configured
1002 for use as a client, which is not suppressed by client_condition, and
1003 whose name matches an authentication mechanism supported by the server.
1004 If one is found, attempt to authenticate by calling its client function.
1005 */
1006
1007 for (au = auths; !smtp_authenticated && au != NULL; au = au->next)
1008 {
1009 uschar *p = names;
1010 if (!au->client ||
1011 (au->client_condition != NULL &&
1012 !expand_check_condition(au->client_condition, au->name,
1013 US"client authenticator")))
1014 {
1015 DEBUG(D_transport) debug_printf("skipping %s authenticator: %s\n",
1016 au->name,
1017 (au->client)? "client_condition is false" :
1018 "not configured as a client");
1019 continue;
1020 }
1021
1022 /* Loop to scan supported server mechanisms */
1023
1024 while (*p != 0)
1025 {
1026 int rc;
1027 int len = Ustrlen(au->public_name);
1028 while (isspace(*p)) p++;
1029
1030 if (strncmpic(au->public_name, p, len) != 0 ||
1031 (p[len] != 0 && !isspace(p[len])))
1032 {
1033 while (*p != 0 && !isspace(*p)) p++;
1034 continue;
1035 }
1036
1037 /* Found data for a listed mechanism. Call its client entry. Set
1038 a flag in the outblock so that data is overwritten after sending so
1039 that reflections don't show it. */
1040
1041 fail_reason = US"authentication attempt(s) failed";
1042 obp->authenticating = TRUE;
1043 rc = (au->info->clientcode)(au, ibp, obp,
1044 ob->command_timeout, buffer, bufsize);
1045 obp->authenticating = FALSE;
1046 DEBUG(D_transport) debug_printf("%s authenticator yielded %d\n",
1047 au->name, rc);
1048
1049 /* A temporary authentication failure must hold up delivery to
1050 this host. After a permanent authentication failure, we carry on
1051 to try other authentication methods. If all fail hard, try to
1052 deliver the message unauthenticated unless require_auth was set. */
1053
1054 switch(rc)
1055 {
1056 case OK:
1057 smtp_authenticated = TRUE; /* stops the outer loop */
1058 client_authenticator = au->name;
1059 if (au->set_client_id != NULL)
1060 client_authenticated_id = expand_string(au->set_client_id);
1061 break;
1062
1063 /* Failure after writing a command */
1064
1065 case FAIL_SEND:
1066 return FAIL_SEND;
1067
1068 /* Failure after reading a response */
1069
1070 case FAIL:
1071 if (errno != 0 || buffer[0] != '5') return FAIL;
1072 log_write(0, LOG_MAIN, "%s authenticator failed H=%s [%s] %s",
1073 au->name, host->name, host->address, buffer);
1074 break;
1075
1076 /* Failure by some other means. In effect, the authenticator
1077 decided it wasn't prepared to handle this case. Typically this
1078 is the result of "fail" in an expansion string. Do we need to
1079 log anything here? Feb 2006: a message is now put in the buffer
1080 if logging is required. */
1081
1082 case CANCELLED:
1083 if (*buffer != 0)
1084 log_write(0, LOG_MAIN, "%s authenticator cancelled "
1085 "authentication H=%s [%s] %s", au->name, host->name,
1086 host->address, buffer);
1087 break;
1088
1089 /* Internal problem, message in buffer. */
1090
1091 case ERROR:
1092 set_errno(addrlist, 0, string_copy(buffer), DEFER, FALSE, NULL);
1093 return ERROR;
1094 }
1095
1096 break; /* If not authenticated, try next authenticator */
1097 } /* Loop for scanning supported server mechanisms */
1098 } /* Loop for further authenticators */
1099 }
1100 }
1101
1102 /* If we haven't authenticated, but are required to, give up. */
1103
1104 if (require_auth == OK && !smtp_authenticated)
1105 {
1106 set_errno(addrlist, ERRNO_AUTHFAIL,
1107 string_sprintf("authentication required but %s", fail_reason), DEFER,
1108 FALSE, NULL);
1109 return DEFER;
1110 }
1111
1112 return OK;
1113 }
1114
1115
1116 /* Construct AUTH appendix string for MAIL TO */
1117 /*
1118 Arguments
1119 buffer to build string
1120 addrlist chain of potential addresses to deliver
1121 ob transport options
1122
1123 Globals smtp_authenticated
1124 client_authenticated_sender
1125 Return True on error, otherwise buffer has (possibly empty) terminated string
1126 */
1127
1128 BOOL
1129 smtp_mail_auth_str(uschar *buffer, unsigned bufsize, address_item *addrlist,
1130 smtp_transport_options_block *ob)
1131 {
1132 uschar *local_authenticated_sender = authenticated_sender;
1133
1134 #ifdef notdef
1135 debug_printf("smtp_mail_auth_str: as<%s> os<%s> SA<%s>\n", authenticated_sender, ob->authenticated_sender, smtp_authenticated?"Y":"N");
1136 #endif
1137
1138 if (ob->authenticated_sender != NULL)
1139 {
1140 uschar *new = expand_string(ob->authenticated_sender);
1141 if (new == NULL)
1142 {
1143 if (!expand_string_forcedfail)
1144 {
1145 uschar *message = string_sprintf("failed to expand "
1146 "authenticated_sender: %s", expand_string_message);
1147 set_errno(addrlist, 0, message, DEFER, FALSE, NULL);
1148 return TRUE;
1149 }
1150 }
1151 else if (new[0] != 0) local_authenticated_sender = new;
1152 }
1153
1154 /* Add the authenticated sender address if present */
1155
1156 if ((smtp_authenticated || ob->authenticated_sender_force) &&
1157 local_authenticated_sender != NULL)
1158 {
1159 string_format(buffer, bufsize, " AUTH=%s",
1160 auth_xtextencode(local_authenticated_sender,
1161 Ustrlen(local_authenticated_sender)));
1162 client_authenticated_sender = string_copy(local_authenticated_sender);
1163 }
1164 else
1165 *buffer= 0;
1166
1167 return FALSE;
1168 }
1169
1170
1171
1172 #ifdef EXPERIMENTAL_DANE
1173 int
1174 tlsa_lookup(host_item * host, dns_answer * dnsa,
1175 BOOL dane_required, BOOL * dane)
1176 {
1177 /* move this out to host.c given the similarity to dns_lookup() ? */
1178 uschar buffer[300];
1179 uschar * fullname = buffer;
1180
1181 /* TLSA lookup string */
1182 (void)sprintf(CS buffer, "_%d._tcp.%.256s", host->port, host->name);
1183
1184 switch (dns_lookup(dnsa, buffer, T_TLSA, &fullname))
1185 {
1186 case DNS_AGAIN:
1187 return DEFER; /* just defer this TLS'd conn */
1188
1189 default:
1190 case DNS_FAIL:
1191 if (dane_required)
1192 {
1193 log_write(0, LOG_MAIN, "DANE error: TLSA lookup failed");
1194 return FAIL;
1195 }
1196 break;
1197
1198 case DNS_SUCCEED:
1199 if (!dns_is_secure(dnsa))
1200 {
1201 log_write(0, LOG_MAIN, "DANE error: TLSA lookup not DNSSEC");
1202 return DEFER;
1203 }
1204 *dane = TRUE;
1205 break;
1206 }
1207 return OK;
1208 }
1209 #endif
1210
1211
1212 /*************************************************
1213 * Deliver address list to given host *
1214 *************************************************/
1215
1216 /* If continue_hostname is not null, we get here only when continuing to
1217 deliver down an existing channel. The channel was passed as the standard
1218 input. TLS is never active on a passed channel; the previous process always
1219 closes it down before passing the connection on.
1220
1221 Otherwise, we have to make a connection to the remote host, and do the
1222 initial protocol exchange.
1223
1224 When running as an MUA wrapper, if the sender or any recipient is rejected,
1225 temporarily or permanently, we force failure for all recipients.
1226
1227 Arguments:
1228 addrlist chain of potential addresses to deliver; only those whose
1229 transport_return field is set to PENDING_DEFER are currently
1230 being processed; others should be skipped - they have either
1231 been delivered to an earlier host or IP address, or been
1232 failed by one of them.
1233 host host to deliver to
1234 host_af AF_INET or AF_INET6
1235 port default TCP/IP port to use, in host byte order
1236 interface interface to bind to, or NULL
1237 tblock transport instance block
1238 copy_host TRUE if host set in addr->host_used must be copied, because
1239 it is specific to this call of the transport
1240 message_defer set TRUE if yield is OK, but all addresses were deferred
1241 because of a non-recipient, non-host failure, that is, a
1242 4xx response to MAIL FROM, DATA, or ".". This is a defer
1243 that is specific to the message.
1244 suppress_tls if TRUE, don't attempt a TLS connection - this is set for
1245 a second attempt after TLS initialization fails
1246
1247 Returns: OK - the connection was made and the delivery attempted;
1248 the result for each address is in its data block.
1249 DEFER - the connection could not be made, or something failed
1250 while setting up the SMTP session, or there was a
1251 non-message-specific error, such as a timeout.
1252 ERROR - a filter command is specified for this transport,
1253 and there was a problem setting it up; OR helo_data
1254 or add_headers or authenticated_sender is specified
1255 for this transport, and the string failed to expand
1256 */
1257
1258 static int
1259 smtp_deliver(address_item *addrlist, host_item *host, int host_af, int port,
1260 uschar *interface, transport_instance *tblock, BOOL copy_host,
1261 BOOL *message_defer, BOOL suppress_tls)
1262 {
1263 address_item *addr;
1264 address_item *sync_addr;
1265 address_item *first_addr = addrlist;
1266 int yield = OK;
1267 int address_count;
1268 int save_errno;
1269 int rc;
1270 time_t start_delivery_time = time(NULL);
1271 smtp_transport_options_block *ob =
1272 (smtp_transport_options_block *)(tblock->options_block);
1273 BOOL lmtp = strcmpic(ob->protocol, US"lmtp") == 0;
1274 BOOL smtps = strcmpic(ob->protocol, US"smtps") == 0;
1275 BOOL ok = FALSE;
1276 BOOL send_rset = TRUE;
1277 BOOL send_quit = TRUE;
1278 BOOL setting_up = TRUE;
1279 BOOL completed_address = FALSE;
1280 BOOL esmtp = TRUE;
1281 BOOL pending_MAIL;
1282 BOOL pass_message = FALSE;
1283 #ifndef DISABLE_PRDR
1284 BOOL prdr_offered = FALSE;
1285 BOOL prdr_active;
1286 #endif
1287 #ifdef EXPERIMENTAL_DSN
1288 BOOL dsn_all_lasthop = TRUE;
1289 #endif
1290 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
1291 BOOL dane = FALSE;
1292 dns_answer tlsa_dnsa;
1293 #endif
1294 smtp_inblock inblock;
1295 smtp_outblock outblock;
1296 int max_rcpt = tblock->max_addresses;
1297 uschar *igquotstr = US"";
1298 uschar *helo_data = NULL;
1299 uschar *message = NULL;
1300 uschar new_message_id[MESSAGE_ID_LENGTH + 1];
1301 uschar *p;
1302 uschar buffer[4096];
1303 uschar inbuffer[4096];
1304 uschar outbuffer[4096];
1305
1306 suppress_tls = suppress_tls; /* stop compiler warning when no TLS support */
1307
1308 *message_defer = FALSE;
1309 smtp_command = US"initial connection";
1310 if (max_rcpt == 0) max_rcpt = 999999;
1311
1312 /* Set up the buffer for reading SMTP response packets. */
1313
1314 inblock.buffer = inbuffer;
1315 inblock.buffersize = sizeof(inbuffer);
1316 inblock.ptr = inbuffer;
1317 inblock.ptrend = inbuffer;
1318
1319 /* Set up the buffer for holding SMTP commands while pipelining */
1320
1321 outblock.buffer = outbuffer;
1322 outblock.buffersize = sizeof(outbuffer);
1323 outblock.ptr = outbuffer;
1324 outblock.cmd_count = 0;
1325 outblock.authenticating = FALSE;
1326
1327 /* Reset the parameters of a TLS session. */
1328
1329 tls_out.bits = 0;
1330 tls_out.cipher = NULL; /* the one we may use for this transport */
1331 tls_out.ourcert = NULL;
1332 tls_out.peercert = NULL;
1333 tls_out.peerdn = NULL;
1334 #if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
1335 tls_out.sni = NULL;
1336 #endif
1337 tls_out.ocsp = OCSP_NOT_REQ;
1338
1339 /* Flip the legacy TLS-related variables over to the outbound set in case
1340 they're used in the context of the transport. Don't bother resetting
1341 afterward as we're in a subprocess. */
1342
1343 tls_modify_variables(&tls_out);
1344
1345 #ifndef SUPPORT_TLS
1346 if (smtps)
1347 {
1348 set_errno(addrlist, 0, US"TLS support not available", DEFER, FALSE, NULL);
1349 return ERROR;
1350 }
1351 #endif
1352
1353 /* Make a connection to the host if this isn't a continued delivery, and handle
1354 the initial interaction and HELO/EHLO/LHLO. Connect timeout errors are handled
1355 specially so they can be identified for retries. */
1356
1357 if (continue_hostname == NULL)
1358 {
1359 /* This puts port into host->port */
1360 inblock.sock = outblock.sock =
1361 smtp_connect(host, host_af, port, interface, ob->connect_timeout,
1362 ob->keepalive, ob->dscp
1363 #ifdef EXPERIMENTAL_EVENT
1364 , tblock->event_action
1365 #endif
1366 );
1367
1368 if (inblock.sock < 0)
1369 {
1370 set_errno(addrlist, (errno == ETIMEDOUT)? ERRNO_CONNECTTIMEOUT : errno,
1371 NULL, DEFER, FALSE, NULL);
1372 return DEFER;
1373 }
1374
1375 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
1376 {
1377 BOOL dane_required;
1378
1379 tls_out.dane_verified = FALSE;
1380 tls_out.tlsa_usage = 0;
1381
1382 dane_required = verify_check_given_host(&ob->hosts_require_dane, host) == OK;
1383
1384 if (host->dnssec == DS_YES)
1385 {
1386 if( dane_required
1387 || verify_check_given_host(&ob->hosts_try_dane, host) == OK
1388 )
1389 if ((rc = tlsa_lookup(host, &tlsa_dnsa, dane_required, &dane)) != OK)
1390 return rc;
1391 }
1392 else if (dane_required)
1393 {
1394 log_write(0, LOG_MAIN, "DANE error: %s lookup not DNSSEC", host->name);
1395 return FAIL;
1396 }
1397
1398 if (dane)
1399 ob->tls_tempfail_tryclear = FALSE;
1400 }
1401 #endif /*DANE*/
1402
1403 /* Expand the greeting message while waiting for the initial response. (Makes
1404 sense if helo_data contains ${lookup dnsdb ...} stuff). The expansion is
1405 delayed till here so that $sending_interface and $sending_port are set. */
1406
1407 helo_data = expand_string(ob->helo_data);
1408
1409 /* The first thing is to wait for an initial OK response. The dreaded "goto"
1410 is nevertheless a reasonably clean way of programming this kind of logic,
1411 where you want to escape on any error. */
1412
1413 if (!smtps)
1414 {
1415 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1416 ob->command_timeout)) goto RESPONSE_FAILED;
1417
1418 #ifdef EXPERIMENTAL_EVENT
1419 {
1420 uschar * s;
1421 lookup_dnssec_authenticated = host->dnssec==DS_YES ? US"yes"
1422 : host->dnssec==DS_NO ? US"no" : NULL;
1423 s = event_raise(tblock->event_action, US"smtp:connect", buffer);
1424 if (s)
1425 {
1426 set_errno(addrlist, 0,
1427 string_sprintf("deferred by smtp:connect event expansion: %s", s),
1428 DEFER, FALSE, NULL);
1429 yield = DEFER;
1430 goto SEND_QUIT;
1431 }
1432 }
1433 #endif
1434
1435 /* Now check if the helo_data expansion went well, and sign off cleanly if
1436 it didn't. */
1437
1438 if (helo_data == NULL)
1439 {
1440 uschar *message = string_sprintf("failed to expand helo_data: %s",
1441 expand_string_message);
1442 set_errno(addrlist, 0, message, DEFER, FALSE, NULL);
1443 yield = DEFER;
1444 goto SEND_QUIT;
1445 }
1446 }
1447
1448 /** Debugging without sending a message
1449 addrlist->transport_return = DEFER;
1450 goto SEND_QUIT;
1451 **/
1452
1453 /* Errors that occur after this point follow an SMTP command, which is
1454 left in big_buffer by smtp_write_command() for use in error messages. */
1455
1456 smtp_command = big_buffer;
1457
1458 /* Tell the remote who we are...
1459
1460 February 1998: A convention has evolved that ESMTP-speaking MTAs include the
1461 string "ESMTP" in their greeting lines, so make Exim send EHLO if the
1462 greeting is of this form. The assumption was that the far end supports it
1463 properly... but experience shows that there are some that give 5xx responses,
1464 even though the banner includes "ESMTP" (there's a bloody-minded one that
1465 says "ESMTP not spoken here"). Cope with that case.
1466
1467 September 2000: Time has passed, and it seems reasonable now to always send
1468 EHLO at the start. It is also convenient to make the change while installing
1469 the TLS stuff.
1470
1471 July 2003: Joachim Wieland met a broken server that advertises "PIPELINING"
1472 but times out after sending MAIL FROM, RCPT TO and DATA all together. There
1473 would be no way to send out the mails, so there is now a host list
1474 "hosts_avoid_esmtp" that disables ESMTP for special hosts and solves the
1475 PIPELINING problem as well. Maybe it can also be useful to cure other
1476 problems with broken servers.
1477
1478 Exim originally sent "Helo" at this point and ran for nearly a year that way.
1479 Then somebody tried it with a Microsoft mailer... It seems that all other
1480 mailers use upper case for some reason (the RFC is quite clear about case
1481 independence) so, for peace of mind, I gave in. */
1482
1483 esmtp = verify_check_given_host(&ob->hosts_avoid_esmtp, host) != OK;
1484
1485 /* Alas; be careful, since this goto is not an error-out, so conceivably
1486 we might set data between here and the target which we assume to exist
1487 and be usable. I can see this coming back to bite us. */
1488 #ifdef SUPPORT_TLS
1489 if (smtps)
1490 {
1491 tls_offered = TRUE;
1492 suppress_tls = FALSE;
1493 ob->tls_tempfail_tryclear = FALSE;
1494 smtp_command = US"SSL-on-connect";
1495 goto TLS_NEGOTIATE;
1496 }
1497 #endif
1498
1499 if (esmtp)
1500 {
1501 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n",
1502 lmtp? "LHLO" : "EHLO", helo_data) < 0)
1503 goto SEND_FAILED;
1504 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1505 ob->command_timeout))
1506 {
1507 if (errno != 0 || buffer[0] == 0 || lmtp) goto RESPONSE_FAILED;
1508 esmtp = FALSE;
1509 }
1510 }
1511 else
1512 {
1513 DEBUG(D_transport)
1514 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
1515 }
1516
1517 if (!esmtp)
1518 {
1519 if (smtp_write_command(&outblock, FALSE, "HELO %s\r\n", helo_data) < 0)
1520 goto SEND_FAILED;
1521 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1522 ob->command_timeout)) goto RESPONSE_FAILED;
1523 }
1524
1525 /* Set IGNOREQUOTA if the response to LHLO specifies support and the
1526 lmtp_ignore_quota option was set. */
1527
1528 igquotstr = (lmtp && ob->lmtp_ignore_quota &&
1529 pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer, Ustrlen(CS buffer), 0,
1530 PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
1531
1532 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
1533
1534 #ifdef SUPPORT_TLS
1535 tls_offered = esmtp &&
1536 pcre_exec(regex_STARTTLS, NULL, CS buffer, Ustrlen(buffer), 0,
1537 PCRE_EOPT, NULL, 0) >= 0;
1538 #endif
1539
1540 #ifndef DISABLE_PRDR
1541 prdr_offered = esmtp
1542 && pcre_exec(regex_PRDR, NULL, CS buffer, Ustrlen(buffer), 0,
1543 PCRE_EOPT, NULL, 0) >= 0
1544 && verify_check_given_host(&ob->hosts_try_prdr, host) == OK;
1545
1546 if (prdr_offered)
1547 {DEBUG(D_transport) debug_printf("PRDR usable\n");}
1548 #endif
1549 }
1550
1551 /* For continuing deliveries down the same channel, the socket is the standard
1552 input, and we don't need to redo EHLO here (but may need to do so for TLS - see
1553 below). Set up the pointer to where subsequent commands will be left, for
1554 error messages. Note that smtp_use_size and smtp_use_pipelining will have been
1555 set from the command line if they were set in the process that passed the
1556 connection on. */
1557
1558 else
1559 {
1560 inblock.sock = outblock.sock = fileno(stdin);
1561 smtp_command = big_buffer;
1562 host->port = port; /* Record the port that was used */
1563 }
1564
1565 /* If TLS is available on this connection, whether continued or not, attempt to
1566 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
1567 send another EHLO - the server may give a different answer in secure mode. We
1568 use a separate buffer for reading the response to STARTTLS so that if it is
1569 negative, the original EHLO data is available for subsequent analysis, should
1570 the client not be required to use TLS. If the response is bad, copy the buffer
1571 for error analysis. */
1572
1573 #ifdef SUPPORT_TLS
1574 if ( tls_offered
1575 && !suppress_tls
1576 && verify_check_given_host(&ob->hosts_avoid_tls, host) != OK)
1577 {
1578 uschar buffer2[4096];
1579 if (smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") < 0)
1580 goto SEND_FAILED;
1581
1582 /* If there is an I/O error, transmission of this message is deferred. If
1583 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
1584 false, we also defer. However, if there is a temporary rejection of STARTTLS
1585 and tls_tempfail_tryclear is true, or if there is an outright rejection of
1586 STARTTLS, we carry on. This means we will try to send the message in clear,
1587 unless the host is in hosts_require_tls (tested below). */
1588
1589 if (!smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
1590 ob->command_timeout))
1591 {
1592 if (errno != 0 || buffer2[0] == 0 ||
1593 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
1594 {
1595 Ustrncpy(buffer, buffer2, sizeof(buffer));
1596 goto RESPONSE_FAILED;
1597 }
1598 }
1599
1600 /* STARTTLS accepted: try to negotiate a TLS session. */
1601
1602 else
1603 TLS_NEGOTIATE:
1604 {
1605 int rc = tls_client_start(inblock.sock, host, addrlist, tblock
1606 # ifdef EXPERIMENTAL_DANE
1607 , dane ? &tlsa_dnsa : NULL
1608 # endif
1609 );
1610
1611 /* TLS negotiation failed; give an error. From outside, this function may
1612 be called again to try in clear on a new connection, if the options permit
1613 it for this host. */
1614
1615 if (rc != OK)
1616 {
1617 save_errno = ERRNO_TLSFAILURE;
1618 message = US"failure while setting up TLS session";
1619 send_quit = FALSE;
1620 goto TLS_FAILED;
1621 }
1622
1623 /* TLS session is set up */
1624
1625 for (addr = addrlist; addr != NULL; addr = addr->next)
1626 if (addr->transport_return == PENDING_DEFER)
1627 {
1628 addr->cipher = tls_out.cipher;
1629 addr->ourcert = tls_out.ourcert;
1630 addr->peercert = tls_out.peercert;
1631 addr->peerdn = tls_out.peerdn;
1632 addr->ocsp = tls_out.ocsp;
1633 }
1634 }
1635 }
1636
1637 /* if smtps, we'll have smtp_command set to something else; always safe to
1638 reset it here. */
1639 smtp_command = big_buffer;
1640
1641 /* If we started TLS, redo the EHLO/LHLO exchange over the secure channel. If
1642 helo_data is null, we are dealing with a connection that was passed from
1643 another process, and so we won't have expanded helo_data above. We have to
1644 expand it here. $sending_ip_address and $sending_port are set up right at the
1645 start of the Exim process (in exim.c). */
1646
1647 if (tls_out.active >= 0)
1648 {
1649 char *greeting_cmd;
1650 if (helo_data == NULL)
1651 {
1652 helo_data = expand_string(ob->helo_data);
1653 if (helo_data == NULL)
1654 {
1655 uschar *message = string_sprintf("failed to expand helo_data: %s",
1656 expand_string_message);
1657 set_errno(addrlist, 0, message, DEFER, FALSE, NULL);
1658 yield = DEFER;
1659 goto SEND_QUIT;
1660 }
1661 }
1662
1663 /* For SMTPS we need to wait for the initial OK response. */
1664 if (smtps)
1665 {
1666 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1667 ob->command_timeout)) goto RESPONSE_FAILED;
1668 }
1669
1670 if (esmtp)
1671 greeting_cmd = "EHLO";
1672 else
1673 {
1674 greeting_cmd = "HELO";
1675 DEBUG(D_transport)
1676 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
1677 }
1678
1679 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n",
1680 lmtp? "LHLO" : greeting_cmd, helo_data) < 0)
1681 goto SEND_FAILED;
1682 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1683 ob->command_timeout))
1684 goto RESPONSE_FAILED;
1685 }
1686
1687 /* If the host is required to use a secure channel, ensure that we
1688 have one. */
1689
1690 else if (
1691 # ifdef EXPERIMENTAL_DANE
1692 dane ||
1693 # endif
1694 verify_check_given_host(&ob->hosts_require_tls, host) == OK
1695 )
1696 {
1697 save_errno = ERRNO_TLSREQUIRED;
1698 message = string_sprintf("a TLS session is required, but %s",
1699 tls_offered? "an attempt to start TLS failed" :
1700 "the server did not offer TLS support");
1701 goto TLS_FAILED;
1702 }
1703 #endif /*SUPPORT_TLS*/
1704
1705 /* If TLS is active, we have just started it up and re-done the EHLO command,
1706 so its response needs to be analyzed. If TLS is not active and this is a
1707 continued session down a previously-used socket, we haven't just done EHLO, so
1708 we skip this. */
1709
1710 if (continue_hostname == NULL
1711 #ifdef SUPPORT_TLS
1712 || tls_out.active >= 0
1713 #endif
1714 )
1715 {
1716 /* Set for IGNOREQUOTA if the response to LHLO specifies support and the
1717 lmtp_ignore_quota option was set. */
1718
1719 igquotstr = (lmtp && ob->lmtp_ignore_quota &&
1720 pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer, Ustrlen(CS buffer), 0,
1721 PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
1722
1723 /* If the response to EHLO specified support for the SIZE parameter, note
1724 this, provided size_addition is non-negative. */
1725
1726 smtp_use_size = esmtp && ob->size_addition >= 0 &&
1727 pcre_exec(regex_SIZE, NULL, CS buffer, Ustrlen(CS buffer), 0,
1728 PCRE_EOPT, NULL, 0) >= 0;
1729
1730 /* Note whether the server supports PIPELINING. If hosts_avoid_esmtp matched
1731 the current host, esmtp will be false, so PIPELINING can never be used. If
1732 the current host matches hosts_avoid_pipelining, don't do it. */
1733
1734 smtp_use_pipelining = esmtp
1735 && verify_check_given_host(&ob->hosts_avoid_pipelining, host) != OK
1736 && pcre_exec(regex_PIPELINING, NULL, CS buffer, Ustrlen(CS buffer), 0,
1737 PCRE_EOPT, NULL, 0) >= 0;
1738
1739 DEBUG(D_transport) debug_printf("%susing PIPELINING\n",
1740 smtp_use_pipelining? "" : "not ");
1741
1742 #ifndef DISABLE_PRDR
1743 prdr_offered = esmtp
1744 && pcre_exec(regex_PRDR, NULL, CS buffer, Ustrlen(CS buffer), 0,
1745 PCRE_EOPT, NULL, 0) >= 0
1746 && verify_check_given_host(&ob->hosts_try_prdr, host) == OK;
1747
1748 if (prdr_offered)
1749 {DEBUG(D_transport) debug_printf("PRDR usable\n");}
1750 #endif
1751
1752 #ifdef EXPERIMENTAL_DSN
1753 /* Note if the server supports DSN */
1754 smtp_use_dsn = esmtp && pcre_exec(regex_DSN, NULL, CS buffer, (int)Ustrlen(CS buffer), 0,
1755 PCRE_EOPT, NULL, 0) >= 0;
1756 DEBUG(D_transport) debug_printf("use_dsn=%d\n", smtp_use_dsn);
1757 #endif
1758
1759 /* Note if the response to EHLO specifies support for the AUTH extension.
1760 If it has, check that this host is one we want to authenticate to, and do
1761 the business. The host name and address must be available when the
1762 authenticator's client driver is running. */
1763
1764 switch (yield = smtp_auth(buffer, sizeof(buffer), addrlist, host,
1765 ob, esmtp, &inblock, &outblock))
1766 {
1767 default: goto SEND_QUIT;
1768 case OK: break;
1769 case FAIL_SEND: goto SEND_FAILED;
1770 case FAIL: goto RESPONSE_FAILED;
1771 }
1772 }
1773
1774 /* The setting up of the SMTP call is now complete. Any subsequent errors are
1775 message-specific. */
1776
1777 setting_up = FALSE;
1778
1779 /* If there is a filter command specified for this transport, we can now
1780 set it up. This cannot be done until the identify of the host is known. */
1781
1782 if (tblock->filter_command != NULL)
1783 {
1784 BOOL rc;
1785 uschar buffer[64];
1786 sprintf(CS buffer, "%.50s transport", tblock->name);
1787 rc = transport_set_up_command(&transport_filter_argv, tblock->filter_command,
1788 TRUE, DEFER, addrlist, buffer, NULL);
1789 transport_filter_timeout = tblock->filter_timeout;
1790
1791 /* On failure, copy the error to all addresses, abandon the SMTP call, and
1792 yield ERROR. */
1793
1794 if (!rc)
1795 {
1796 set_errno(addrlist->next, addrlist->basic_errno, addrlist->message, DEFER,
1797 FALSE, NULL);
1798 yield = ERROR;
1799 goto SEND_QUIT;
1800 }
1801 }
1802
1803
1804 /* For messages that have more than the maximum number of envelope recipients,
1805 we want to send several transactions down the same SMTP connection. (See
1806 comments in deliver.c as to how this reconciles, heuristically, with
1807 remote_max_parallel.) This optimization was added to Exim after the following
1808 code was already working. The simplest way to put it in without disturbing the
1809 code was to use a goto to jump back to this point when there is another
1810 transaction to handle. */
1811
1812 SEND_MESSAGE:
1813 sync_addr = first_addr;
1814 address_count = 0;
1815 ok = FALSE;
1816 send_rset = TRUE;
1817 completed_address = FALSE;
1818
1819
1820 /* Initiate a message transfer. If we know the receiving MTA supports the SIZE
1821 qualification, send it, adding something to the message size to allow for
1822 imprecision and things that get added en route. Exim keeps the number of lines
1823 in a message, so we can give an accurate value for the original message, but we
1824 need some additional to handle added headers. (Double "." characters don't get
1825 included in the count.) */
1826
1827 p = buffer;
1828 *p = 0;
1829
1830 if (smtp_use_size)
1831 {
1832 sprintf(CS p, " SIZE=%d", message_size+message_linecount+ob->size_addition);
1833 while (*p) p++;
1834 }
1835
1836 #ifndef DISABLE_PRDR
1837 prdr_active = FALSE;
1838 if (prdr_offered)
1839 {
1840 for (addr = first_addr; addr; addr = addr->next)
1841 if (addr->transport_return == PENDING_DEFER)
1842 {
1843 for (addr = addr->next; addr; addr = addr->next)
1844 if (addr->transport_return == PENDING_DEFER)
1845 { /* at least two recipients to send */
1846 prdr_active = TRUE;
1847 sprintf(CS p, " PRDR"); p += 5;
1848 break;
1849 }
1850 break;
1851 }
1852 }
1853 #endif
1854
1855 #ifdef EXPERIMENTAL_DSN
1856 /* check if all addresses have lasthop flag */
1857 /* do not send RET and ENVID if true */
1858 dsn_all_lasthop = TRUE;
1859 for (addr = first_addr;
1860 address_count < max_rcpt && addr != NULL;
1861 addr = addr->next)
1862 if ((addr->dsn_flags & rf_dsnlasthop) != 1)
1863 dsn_all_lasthop = FALSE;
1864
1865 /* Add any DSN flags to the mail command */
1866
1867 if ((smtp_use_dsn) && (dsn_all_lasthop == FALSE))
1868 {
1869 if (dsn_ret == dsn_ret_hdrs)
1870 {
1871 Ustrcpy(p, " RET=HDRS");
1872 while (*p) p++;
1873 }
1874 else if (dsn_ret == dsn_ret_full)
1875 {
1876 Ustrcpy(p, " RET=FULL");
1877 while (*p) p++;
1878 }
1879 if (dsn_envid != NULL)
1880 {
1881 string_format(p, sizeof(buffer) - (p-buffer), " ENVID=%s", dsn_envid);
1882 while (*p) p++;
1883 }
1884 }
1885 #endif
1886
1887 /* If an authenticated_sender override has been specified for this transport
1888 instance, expand it. If the expansion is forced to fail, and there was already
1889 an authenticated_sender for this message, the original value will be used.
1890 Other expansion failures are serious. An empty result is ignored, but there is
1891 otherwise no check - this feature is expected to be used with LMTP and other
1892 cases where non-standard addresses (e.g. without domains) might be required. */
1893
1894 if (smtp_mail_auth_str(p, sizeof(buffer) - (p-buffer), addrlist, ob))
1895 {
1896 yield = ERROR;
1897 goto SEND_QUIT;
1898 }
1899
1900 /* From here until we send the DATA command, we can make use of PIPELINING
1901 if the server host supports it. The code has to be able to check the responses
1902 at any point, for when the buffer fills up, so we write it totally generally.
1903 When PIPELINING is off, each command written reports that it has flushed the
1904 buffer. */
1905
1906 pending_MAIL = TRUE; /* The block starts with MAIL */
1907
1908 rc = smtp_write_command(&outblock, smtp_use_pipelining,
1909 "MAIL FROM:<%s>%s\r\n", return_path, buffer);
1910 mail_command = string_copy(big_buffer); /* Save for later error message */
1911
1912 switch(rc)
1913 {
1914 case -1: /* Transmission error */
1915 goto SEND_FAILED;
1916
1917 case +1: /* Block was sent */
1918 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1919 ob->command_timeout))
1920 {
1921 if (errno == 0 && buffer[0] == '4')
1922 {
1923 errno = ERRNO_MAIL4XX;
1924 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1925 }
1926 goto RESPONSE_FAILED;
1927 }
1928 pending_MAIL = FALSE;
1929 break;
1930 }
1931
1932 /* Pass over all the relevant recipient addresses for this host, which are the
1933 ones that have status PENDING_DEFER. If we are using PIPELINING, we can send
1934 several before we have to read the responses for those seen so far. This
1935 checking is done by a subroutine because it also needs to be done at the end.
1936 Send only up to max_rcpt addresses at a time, leaving first_addr pointing to
1937 the next one if not all are sent.
1938
1939 In the MUA wrapper situation, we want to flush the PIPELINING buffer for the
1940 last address because we want to abort if any recipients have any kind of
1941 problem, temporary or permanent. We know that all recipient addresses will have
1942 the PENDING_DEFER status, because only one attempt is ever made, and we know
1943 that max_rcpt will be large, so all addresses will be done at once. */
1944
1945 for (addr = first_addr;
1946 address_count < max_rcpt && addr != NULL;
1947 addr = addr->next)
1948 {
1949 int count;
1950 BOOL no_flush;
1951
1952 #ifdef EXPERIMENTAL_DSN
1953 addr->dsn_aware = smtp_use_dsn ? dsn_support_yes : dsn_support_no;
1954 #endif
1955
1956 if (addr->transport_return != PENDING_DEFER) continue;
1957
1958 address_count++;
1959 no_flush = smtp_use_pipelining && (!mua_wrapper || addr->next != NULL);
1960
1961 #ifdef EXPERIMENTAL_DSN
1962 /* Add any DSN flags to the rcpt command and add to the sent string */
1963
1964 p = buffer;
1965 *p = 0;
1966
1967 if (smtp_use_dsn && (addr->dsn_flags & rf_dsnlasthop) != 1)
1968 {
1969 if ((addr->dsn_flags & rf_dsnflags) != 0)
1970 {
1971 int i;
1972 BOOL first = TRUE;
1973 Ustrcpy(p, " NOTIFY=");
1974 while (*p) p++;
1975 for (i = 0; i < 4; i++)
1976 if ((addr->dsn_flags & rf_list[i]) != 0)
1977 {
1978 if (!first) *p++ = ',';
1979 first = FALSE;
1980 Ustrcpy(p, rf_names[i]);
1981 while (*p) p++;
1982 }
1983 }
1984
1985 if (addr->dsn_orcpt != NULL)
1986 {
1987 string_format(p, sizeof(buffer) - (p-buffer), " ORCPT=%s",
1988 addr->dsn_orcpt);
1989 while (*p) p++;
1990 }
1991 }
1992 #endif
1993
1994
1995 /* Now send the RCPT command, and process outstanding responses when
1996 necessary. After a timeout on RCPT, we just end the function, leaving the
1997 yield as OK, because this error can often mean that there is a problem with
1998 just one address, so we don't want to delay the host. */
1999
2000 #ifdef EXPERIMENTAL_DSN
2001 count = smtp_write_command(&outblock, no_flush, "RCPT TO:<%s>%s%s\r\n",
2002 transport_rcpt_address(addr, tblock->rcpt_include_affixes), igquotstr, buffer);
2003 #else
2004 count = smtp_write_command(&outblock, no_flush, "RCPT TO:<%s>%s\r\n",
2005 transport_rcpt_address(addr, tblock->rcpt_include_affixes), igquotstr);
2006 #endif
2007
2008 if (count < 0) goto SEND_FAILED;
2009 if (count > 0)
2010 {
2011 switch(sync_responses(first_addr, tblock->rcpt_include_affixes,
2012 &sync_addr, host, count, ob->address_retry_include_sender,
2013 pending_MAIL, 0, &inblock, ob->command_timeout, buffer,
2014 sizeof(buffer)))
2015 {
2016 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
2017 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
2018 break;
2019
2020 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
2021 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
2022 case 0: /* No 2xx or 5xx, but no probs */
2023 break;
2024
2025 case -1: goto END_OFF; /* Timeout on RCPT */
2026 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL error */
2027 }
2028 pending_MAIL = FALSE; /* Dealt with MAIL */
2029 }
2030 } /* Loop for next address */
2031
2032 /* If we are an MUA wrapper, abort if any RCPTs were rejected, either
2033 permanently or temporarily. We should have flushed and synced after the last
2034 RCPT. */
2035
2036 if (mua_wrapper)
2037 {
2038 address_item *badaddr;
2039 for (badaddr = first_addr; badaddr != NULL; badaddr = badaddr->next)
2040 {
2041 if (badaddr->transport_return != PENDING_OK) break;
2042 }
2043 if (badaddr != NULL)
2044 {
2045 set_errno(addrlist, 0, badaddr->message, FAIL,
2046 testflag(badaddr, af_pass_message), NULL);
2047 ok = FALSE;
2048 }
2049 }
2050
2051 /* If ok is TRUE, we know we have got at least one good recipient, and must now
2052 send DATA, but if it is FALSE (in the normal, non-wrapper case), we may still
2053 have a good recipient buffered up if we are pipelining. We don't want to waste
2054 time sending DATA needlessly, so we only send it if either ok is TRUE or if we
2055 are pipelining. The responses are all handled by sync_responses(). */
2056
2057 if (ok || (smtp_use_pipelining && !mua_wrapper))
2058 {
2059 int count = smtp_write_command(&outblock, FALSE, "DATA\r\n");
2060 if (count < 0) goto SEND_FAILED;
2061 switch(sync_responses(first_addr, tblock->rcpt_include_affixes, &sync_addr,
2062 host, count, ob->address_retry_include_sender, pending_MAIL,
2063 ok? +1 : -1, &inblock, ob->command_timeout, buffer, sizeof(buffer)))
2064 {
2065 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
2066 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
2067 break;
2068
2069 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
2070 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
2071 case 0: break; /* No 2xx or 5xx, but no probs */
2072
2073 case -1: goto END_OFF; /* Timeout on RCPT */
2074 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */
2075 }
2076 }
2077
2078 /* Save the first address of the next batch. */
2079
2080 first_addr = addr;
2081
2082 /* If there were no good recipients (but otherwise there have been no
2083 problems), just set ok TRUE, since we have handled address-specific errors
2084 already. Otherwise, it's OK to send the message. Use the check/escape mechanism
2085 for handling the SMTP dot-handling protocol, flagging to apply to headers as
2086 well as body. Set the appropriate timeout value to be used for each chunk.
2087 (Haven't been able to make it work using select() for writing yet.) */
2088
2089 if (!ok) ok = TRUE; else
2090 {
2091 sigalrm_seen = FALSE;
2092 transport_write_timeout = ob->data_timeout;
2093 smtp_command = US"sending data block"; /* For error messages */
2094 DEBUG(D_transport|D_v)
2095 debug_printf(" SMTP>> writing message and terminating \".\"\n");
2096 transport_count = 0;
2097
2098 #ifndef DISABLE_DKIM
2099 ok = dkim_transport_write_message(addrlist, inblock.sock,
2100 topt_use_crlf | topt_end_dot | topt_escape_headers |
2101 (tblock->body_only? topt_no_headers : 0) |
2102 (tblock->headers_only? topt_no_body : 0) |
2103 (tblock->return_path_add? topt_add_return_path : 0) |
2104 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
2105 (tblock->envelope_to_add? topt_add_envelope_to : 0),
2106 0, /* No size limit */
2107 tblock->add_headers, tblock->remove_headers,
2108 US".", US"..", /* Escaping strings */
2109 tblock->rewrite_rules, tblock->rewrite_existflags,
2110 ob->dkim_private_key, ob->dkim_domain, ob->dkim_selector,
2111 ob->dkim_canon, ob->dkim_strict, ob->dkim_sign_headers
2112 );
2113 #else
2114 ok = transport_write_message(addrlist, inblock.sock,
2115 topt_use_crlf | topt_end_dot | topt_escape_headers |
2116 (tblock->body_only? topt_no_headers : 0) |
2117 (tblock->headers_only? topt_no_body : 0) |
2118 (tblock->return_path_add? topt_add_return_path : 0) |
2119 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
2120 (tblock->envelope_to_add? topt_add_envelope_to : 0),
2121 0, /* No size limit */
2122 tblock->add_headers, tblock->remove_headers,
2123 US".", US"..", /* Escaping strings */
2124 tblock->rewrite_rules, tblock->rewrite_existflags);
2125 #endif
2126
2127 /* transport_write_message() uses write() because it is called from other
2128 places to write to non-sockets. This means that under some OS (e.g. Solaris)
2129 it can exit with "Broken pipe" as its error. This really means that the
2130 socket got closed at the far end. */
2131
2132 transport_write_timeout = 0; /* for subsequent transports */
2133
2134 /* Failure can either be some kind of I/O disaster (including timeout),
2135 or the failure of a transport filter or the expansion of added headers. */
2136
2137 if (!ok)
2138 {
2139 buffer[0] = 0; /* There hasn't been a response */
2140 goto RESPONSE_FAILED;
2141 }
2142
2143 /* We used to send the terminating "." explicitly here, but because of
2144 buffering effects at both ends of TCP/IP connections, you don't gain
2145 anything by keeping it separate, so it might as well go in the final
2146 data buffer for efficiency. This is now done by setting the topt_end_dot
2147 flag above. */
2148
2149 smtp_command = US"end of data";
2150
2151 #ifndef DISABLE_PRDR
2152 /* For PRDR we optionally get a partial-responses warning
2153 * followed by the individual responses, before going on with
2154 * the overall response. If we don't get the warning then deal
2155 * with per non-PRDR. */
2156 if(prdr_active)
2157 {
2158 ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '3',
2159 ob->final_timeout);
2160 if (!ok && errno == 0)
2161 switch(buffer[0])
2162 {
2163 case '2': prdr_active = FALSE;
2164 ok = TRUE;
2165 break;
2166 case '4': errno = ERRNO_DATA4XX;
2167 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
2168 break;
2169 }
2170 }
2171 else
2172 #endif
2173
2174 /* For non-PRDR SMTP, we now read a single response that applies to the
2175 whole message. If it is OK, then all the addresses have been delivered. */
2176
2177 if (!lmtp)
2178 {
2179 ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2180 ob->final_timeout);
2181 if (!ok && errno == 0 && buffer[0] == '4')
2182 {
2183 errno = ERRNO_DATA4XX;
2184 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
2185 }
2186 }
2187
2188 /* For LMTP, we get back a response for every RCPT command that we sent;
2189 some may be accepted and some rejected. For those that get a response, their
2190 status is fixed; any that are accepted have been handed over, even if later
2191 responses crash - at least, that's how I read RFC 2033.
2192
2193 If all went well, mark the recipient addresses as completed, record which
2194 host/IPaddress they were delivered to, and cut out RSET when sending another
2195 message down the same channel. Write the completed addresses to the journal
2196 now so that they are recorded in case there is a crash of hardware or
2197 software before the spool gets updated. Also record the final SMTP
2198 confirmation if needed (for SMTP only). */
2199
2200 if (ok)
2201 {
2202 int flag = '=';
2203 int delivery_time = (int)(time(NULL) - start_delivery_time);
2204 int len;
2205 host_item *thost;
2206 uschar *conf = NULL;
2207 send_rset = FALSE;
2208
2209 /* Make a copy of the host if it is local to this invocation
2210 of the transport. */
2211
2212 if (copy_host)
2213 {
2214 thost = store_get(sizeof(host_item));
2215 *thost = *host;
2216 thost->name = string_copy(host->name);
2217 thost->address = string_copy(host->address);
2218 }
2219 else thost = host;
2220
2221 /* Set up confirmation if needed - applies only to SMTP */
2222
2223 if (
2224 #ifndef EXPERIMENTAL_EVENT
2225 (log_extra_selector & LX_smtp_confirmation) != 0 &&
2226 #endif
2227 !lmtp
2228 )
2229 {
2230 uschar *s = string_printing(buffer);
2231 conf = (s == buffer)? (uschar *)string_copy(s) : s;
2232 }
2233
2234 /* Process all transported addresses - for LMTP or PRDR, read a status for
2235 each one. */
2236
2237 for (addr = addrlist; addr != first_addr; addr = addr->next)
2238 {
2239 if (addr->transport_return != PENDING_OK) continue;
2240
2241 /* LMTP - if the response fails badly (e.g. timeout), use it for all the
2242 remaining addresses. Otherwise, it's a return code for just the one
2243 address. For temporary errors, add a retry item for the address so that
2244 it doesn't get tried again too soon. */
2245
2246 #ifndef DISABLE_PRDR
2247 if (lmtp || prdr_active)
2248 #else
2249 if (lmtp)
2250 #endif
2251 {
2252 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2253 ob->final_timeout))
2254 {
2255 if (errno != 0 || buffer[0] == 0) goto RESPONSE_FAILED;
2256 addr->message = string_sprintf(
2257 #ifndef DISABLE_PRDR
2258 "%s error after %s: %s", prdr_active ? "PRDR":"LMTP",
2259 #else
2260 "LMTP error after %s: %s",
2261 #endif
2262 big_buffer, string_printing(buffer));
2263 setflag(addr, af_pass_message); /* Allow message to go to user */
2264 if (buffer[0] == '5')
2265 addr->transport_return = FAIL;
2266 else
2267 {
2268 errno = ERRNO_DATA4XX;
2269 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
2270 addr->transport_return = DEFER;
2271 #ifndef DISABLE_PRDR
2272 if (!prdr_active)
2273 #endif
2274 retry_add_item(addr, addr->address_retry_key, 0);
2275 }
2276 continue;
2277 }
2278 completed_address = TRUE; /* NOW we can set this flag */
2279 if ((log_extra_selector & LX_smtp_confirmation) != 0)
2280 {
2281 uschar *s = string_printing(buffer);
2282 conf = (s == buffer)? (uschar *)string_copy(s) : s;
2283 }
2284 }
2285
2286 /* SMTP, or success return from LMTP for this address. Pass back the
2287 actual host that was used. */
2288
2289 addr->transport_return = OK;
2290 addr->more_errno = delivery_time;
2291 addr->host_used = thost;
2292 addr->special_action = flag;
2293 addr->message = conf;
2294 #ifndef DISABLE_PRDR
2295 if (prdr_active) addr->flags |= af_prdr_used;
2296 #endif
2297 flag = '-';
2298
2299 #ifndef DISABLE_PRDR
2300 if (!prdr_active)
2301 #endif
2302 {
2303 /* Update the journal. For homonymic addresses, use the base address plus
2304 the transport name. See lots of comments in deliver.c about the reasons
2305 for the complications when homonyms are involved. Just carry on after
2306 write error, as it may prove possible to update the spool file later. */
2307
2308 if (testflag(addr, af_homonym))
2309 sprintf(CS buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
2310 else
2311 sprintf(CS buffer, "%.500s\n", addr->unique);
2312
2313 DEBUG(D_deliver) debug_printf("journalling %s", buffer);
2314 len = Ustrlen(CS buffer);
2315 if (write(journal_fd, buffer, len) != len)
2316 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
2317 "%s: %s", buffer, strerror(errno));
2318 }
2319 }
2320
2321 #ifndef DISABLE_PRDR
2322 if (prdr_active)
2323 {
2324 /* PRDR - get the final, overall response. For any non-success
2325 upgrade all the address statuses. */
2326 ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2327 ob->final_timeout);
2328 if (!ok)
2329 {
2330 if(errno == 0 && buffer[0] == '4')
2331 {
2332 errno = ERRNO_DATA4XX;
2333 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
2334 }
2335 for (addr = addrlist; addr != first_addr; addr = addr->next)
2336 if (buffer[0] == '5' || addr->transport_return == OK)
2337 addr->transport_return = PENDING_OK; /* allow set_errno action */
2338 goto RESPONSE_FAILED;
2339 }
2340
2341 /* Update the journal, or setup retry. */
2342 for (addr = addrlist; addr != first_addr; addr = addr->next)
2343 if (addr->transport_return == OK)
2344 {
2345 if (testflag(addr, af_homonym))
2346 sprintf(CS buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
2347 else
2348 sprintf(CS buffer, "%.500s\n", addr->unique);
2349
2350 DEBUG(D_deliver) debug_printf("journalling(PRDR) %s", buffer);
2351 len = Ustrlen(CS buffer);
2352 if (write(journal_fd, buffer, len) != len)
2353 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
2354 "%s: %s", buffer, strerror(errno));
2355 }
2356 else if (addr->transport_return == DEFER)
2357 retry_add_item(addr, addr->address_retry_key, -2);
2358 }
2359 #endif
2360
2361 /* Ensure the journal file is pushed out to disk. */
2362
2363 if (EXIMfsync(journal_fd) < 0)
2364 log_write(0, LOG_MAIN|LOG_PANIC, "failed to fsync journal: %s",
2365 strerror(errno));
2366 }
2367 }
2368
2369
2370 /* Handle general (not specific to one address) failures here. The value of ok
2371 is used to skip over this code on the falling through case. A timeout causes a
2372 deferral. Other errors may defer or fail according to the response code, and
2373 may set up a special errno value, e.g. after connection chopped, which is
2374 assumed if errno == 0 and there is no text in the buffer. If control reaches
2375 here during the setting up phase (i.e. before MAIL FROM) then always defer, as
2376 the problem is not related to this specific message. */
2377
2378 if (!ok)
2379 {
2380 int code;
2381
2382 RESPONSE_FAILED:
2383 save_errno = errno;
2384 message = NULL;
2385 send_quit = check_response(host, &save_errno, addrlist->more_errno,
2386 buffer, &code, &message, &pass_message);
2387 goto FAILED;
2388
2389 SEND_FAILED:
2390 save_errno = errno;
2391 code = '4';
2392 message = US string_sprintf("send() to %s [%s] failed: %s",
2393 host->name, host->address, strerror(save_errno));
2394 send_quit = FALSE;
2395 goto FAILED;
2396
2397 /* This label is jumped to directly when a TLS negotiation has failed,
2398 or was not done for a host for which it is required. Values will be set
2399 in message and save_errno, and setting_up will always be true. Treat as
2400 a temporary error. */
2401
2402 #ifdef SUPPORT_TLS
2403 TLS_FAILED:
2404 code = '4';
2405 #endif
2406
2407 /* If the failure happened while setting up the call, see if the failure was
2408 a 5xx response (this will either be on connection, or following HELO - a 5xx
2409 after EHLO causes it to try HELO). If so, fail all addresses, as this host is
2410 never going to accept them. For other errors during setting up (timeouts or
2411 whatever), defer all addresses, and yield DEFER, so that the host is not
2412 tried again for a while. */
2413
2414 FAILED:
2415 ok = FALSE; /* For when reached by GOTO */
2416
2417 if (setting_up)
2418 {
2419 if (code == '5')
2420 set_errno(addrlist, save_errno, message, FAIL, pass_message, host);
2421 else
2422 {
2423 set_errno(addrlist, save_errno, message, DEFER, pass_message, host);
2424 yield = DEFER;
2425 }
2426 }
2427
2428 /* We want to handle timeouts after MAIL or "." and loss of connection after
2429 "." specially. They can indicate a problem with the sender address or with
2430 the contents of the message rather than a real error on the connection. These
2431 cases are treated in the same way as a 4xx response. This next bit of code
2432 does the classification. */
2433
2434 else
2435 {
2436 BOOL message_error;
2437
2438 switch(save_errno)
2439 {
2440 case 0:
2441 case ERRNO_MAIL4XX:
2442 case ERRNO_DATA4XX:
2443 message_error = TRUE;
2444 break;
2445
2446 case ETIMEDOUT:
2447 message_error = Ustrncmp(smtp_command,"MAIL",4) == 0 ||
2448 Ustrncmp(smtp_command,"end ",4) == 0;
2449 break;
2450
2451 case ERRNO_SMTPCLOSED:
2452 message_error = Ustrncmp(smtp_command,"end ",4) == 0;
2453 break;
2454
2455 default:
2456 message_error = FALSE;
2457 break;
2458 }
2459
2460 /* Handle the cases that are treated as message errors. These are:
2461
2462 (a) negative response or timeout after MAIL
2463 (b) negative response after DATA
2464 (c) negative response or timeout or dropped connection after "."
2465
2466 It won't be a negative response or timeout after RCPT, as that is dealt
2467 with separately above. The action in all cases is to set an appropriate
2468 error code for all the addresses, but to leave yield set to OK because the
2469 host itself has not failed. Of course, it might in practice have failed
2470 when we've had a timeout, but if so, we'll discover that at the next
2471 delivery attempt. For a temporary error, set the message_defer flag, and
2472 write to the logs for information if this is not the last host. The error
2473 for the last host will be logged as part of the address's log line. */
2474
2475 if (message_error)
2476 {
2477 if (mua_wrapper) code = '5'; /* Force hard failure in wrapper mode */
2478 set_errno(addrlist, save_errno, message, (code == '5')? FAIL : DEFER,
2479 pass_message, host);
2480
2481 /* If there's an errno, the message contains just the identity of
2482 the host. */
2483
2484 if (code != '5') /* Anything other than 5 is treated as temporary */
2485 {
2486 if (save_errno > 0)
2487 message = US string_sprintf("%s: %s", message, strerror(save_errno));
2488 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", message);
2489 msglog_line(host, message);
2490 *message_defer = TRUE;
2491 }
2492 }
2493
2494 /* Otherwise, we have an I/O error or a timeout other than after MAIL or
2495 ".", or some other transportation error. We defer all addresses and yield
2496 DEFER, except for the case of failed add_headers expansion, or a transport
2497 filter failure, when the yield should be ERROR, to stop it trying other
2498 hosts. */
2499
2500 else
2501 {
2502 yield = (save_errno == ERRNO_CHHEADER_FAIL ||
2503 save_errno == ERRNO_FILTER_FAIL)? ERROR : DEFER;
2504 set_errno(addrlist, save_errno, message, DEFER, pass_message, host);
2505 }
2506 }
2507 }
2508
2509
2510 /* If all has gone well, send_quit will be set TRUE, implying we can end the
2511 SMTP session tidily. However, if there were too many addresses to send in one
2512 message (indicated by first_addr being non-NULL) we want to carry on with the
2513 rest of them. Also, it is desirable to send more than one message down the SMTP
2514 connection if there are several waiting, provided we haven't already sent so
2515 many as to hit the configured limit. The function transport_check_waiting looks
2516 for a waiting message and returns its id. Then transport_pass_socket tries to
2517 set up a continued delivery by passing the socket on to another process. The
2518 variable send_rset is FALSE if a message has just been successfully transfered.
2519
2520 If we are already sending down a continued channel, there may be further
2521 addresses not yet delivered that are aimed at the same host, but which have not
2522 been passed in this run of the transport. In this case, continue_more will be
2523 true, and all we should do is send RSET if necessary, and return, leaving the
2524 channel open.
2525
2526 However, if no address was disposed of, i.e. all addresses got 4xx errors, we
2527 do not want to continue with other messages down the same channel, because that
2528 can lead to looping between two or more messages, all with the same,
2529 temporarily failing address(es). [The retry information isn't updated yet, so
2530 new processes keep on trying.] We probably also don't want to try more of this
2531 message's addresses either.
2532
2533 If we have started a TLS session, we have to end it before passing the
2534 connection to a new process. However, not all servers can handle this (Exim
2535 can), so we do not pass such a connection on if the host matches
2536 hosts_nopass_tls. */
2537
2538 DEBUG(D_transport)
2539 debug_printf("ok=%d send_quit=%d send_rset=%d continue_more=%d "
2540 "yield=%d first_address is %sNULL\n", ok, send_quit, send_rset,
2541 continue_more, yield, (first_addr == NULL)? "":"not ");
2542
2543 if (completed_address && ok && send_quit)
2544 {
2545 BOOL more;
2546 if ( first_addr != NULL
2547 || continue_more
2548 || ( ( tls_out.active < 0
2549 || verify_check_given_host(&ob->hosts_nopass_tls, host) != OK
2550 )
2551 &&
2552 transport_check_waiting(tblock->name, host->name,
2553 tblock->connection_max_messages, new_message_id, &more)
2554 ) )
2555 {
2556 uschar *msg;
2557 BOOL pass_message;
2558
2559 if (send_rset)
2560 {
2561 if (! (ok = smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0))
2562 {
2563 msg = US string_sprintf("send() to %s [%s] failed: %s", host->name,
2564 host->address, strerror(save_errno));
2565 send_quit = FALSE;
2566 }
2567 else if (! (ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2568 ob->command_timeout)))
2569 {
2570 int code;
2571 send_quit = check_response(host, &errno, 0, buffer, &code, &msg,
2572 &pass_message);
2573 if (!send_quit)
2574 {
2575 DEBUG(D_transport) debug_printf("H=%s [%s] %s\n",
2576 host->name, host->address, msg);
2577 }
2578 }
2579 }
2580
2581 /* Either RSET was not needed, or it succeeded */
2582
2583 if (ok)
2584 {
2585 if (first_addr != NULL) /* More addresses still to be sent */
2586 { /* in this run of the transport */
2587 continue_sequence++; /* Causes * in logging */
2588 goto SEND_MESSAGE;
2589 }
2590 if (continue_more) return yield; /* More addresses for another run */
2591
2592 /* Pass the socket to a new Exim process. Before doing so, we must shut
2593 down TLS. Not all MTAs allow for the continuation of the SMTP session
2594 when TLS is shut down. We test for this by sending a new EHLO. If we
2595 don't get a good response, we don't attempt to pass the socket on. */
2596
2597 #ifdef SUPPORT_TLS
2598 if (tls_out.active >= 0)
2599 {
2600 tls_close(FALSE, TRUE);
2601 if (smtps)
2602 ok = FALSE;
2603 else
2604 ok = smtp_write_command(&outblock,FALSE,"EHLO %s\r\n",helo_data) >= 0 &&
2605 smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2606 ob->command_timeout);
2607 }
2608 #endif
2609
2610 /* If the socket is successfully passed, we musn't send QUIT (or
2611 indeed anything!) from here. */
2612
2613 if (ok && transport_pass_socket(tblock->name, host->name, host->address,
2614 new_message_id, inblock.sock))
2615 {
2616 send_quit = FALSE;
2617 }
2618 }
2619
2620 /* If RSET failed and there are addresses left, they get deferred. */
2621
2622 else set_errno(first_addr, errno, msg, DEFER, FALSE, host);
2623 }
2624 }
2625
2626 /* End off tidily with QUIT unless the connection has died or the socket has
2627 been passed to another process. There has been discussion on the net about what
2628 to do after sending QUIT. The wording of the RFC suggests that it is necessary
2629 to wait for a response, but on the other hand, there isn't anything one can do
2630 with an error response, other than log it. Exim used to do that. However,
2631 further discussion suggested that it is positively advantageous not to wait for
2632 the response, but to close the session immediately. This is supposed to move
2633 the TCP/IP TIME_WAIT state from the server to the client, thereby removing some
2634 load from the server. (Hosts that are both servers and clients may not see much
2635 difference, of course.) Further discussion indicated that this was safe to do
2636 on Unix systems which have decent implementations of TCP/IP that leave the
2637 connection around for a while (TIME_WAIT) after the application has gone away.
2638 This enables the response sent by the server to be properly ACKed rather than
2639 timed out, as can happen on broken TCP/IP implementations on other OS.
2640
2641 This change is being made on 31-Jul-98. After over a year of trouble-free
2642 operation, the old commented-out code was removed on 17-Sep-99. */
2643
2644 SEND_QUIT:
2645 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
2646
2647 END_OFF:
2648
2649 #ifdef SUPPORT_TLS
2650 tls_close(FALSE, TRUE);
2651 #endif
2652
2653 /* Close the socket, and return the appropriate value, first setting
2654 works because the NULL setting is passed back to the calling process, and
2655 remote_max_parallel is forced to 1 when delivering over an existing connection,
2656
2657 If all went well and continue_more is set, we shouldn't actually get here if
2658 there are further addresses, as the return above will be taken. However,
2659 writing RSET might have failed, or there may be other addresses whose hosts are
2660 specified in the transports, and therefore not visible at top level, in which
2661 case continue_more won't get set. */
2662
2663 (void)close(inblock.sock);
2664
2665 #ifdef EXPERIMENTAL_EVENT
2666 (void) event_raise(tblock->event_action, US"tcp:close", NULL);
2667 #endif
2668
2669 continue_transport = NULL;
2670 continue_hostname = NULL;
2671 return yield;
2672 }
2673
2674
2675
2676
2677 /*************************************************
2678 * Closedown entry point *
2679 *************************************************/
2680
2681 /* This function is called when exim is passed an open smtp channel
2682 from another incarnation, but the message which it has been asked
2683 to deliver no longer exists. The channel is on stdin.
2684
2685 We might do fancy things like looking for another message to send down
2686 the channel, but if the one we sought has gone, it has probably been
2687 delivered by some other process that itself will seek further messages,
2688 so just close down our connection.
2689
2690 Argument: pointer to the transport instance block
2691 Returns: nothing
2692 */
2693
2694 void
2695 smtp_transport_closedown(transport_instance *tblock)
2696 {
2697 smtp_transport_options_block *ob =
2698 (smtp_transport_options_block *)(tblock->options_block);
2699 smtp_inblock inblock;
2700 smtp_outblock outblock;
2701 uschar buffer[256];
2702 uschar inbuffer[4096];
2703 uschar outbuffer[16];
2704
2705 inblock.sock = fileno(stdin);
2706 inblock.buffer = inbuffer;
2707 inblock.buffersize = sizeof(inbuffer);
2708 inblock.ptr = inbuffer;
2709 inblock.ptrend = inbuffer;
2710
2711 outblock.sock = inblock.sock;
2712 outblock.buffersize = sizeof(outbuffer);
2713 outblock.buffer = outbuffer;
2714 outblock.ptr = outbuffer;
2715 outblock.cmd_count = 0;
2716 outblock.authenticating = FALSE;
2717
2718 (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
2719 (void)smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2720 ob->command_timeout);
2721 (void)close(inblock.sock);
2722 }
2723
2724
2725
2726 /*************************************************
2727 * Prepare addresses for delivery *
2728 *************************************************/
2729
2730 /* This function is called to flush out error settings from previous delivery
2731 attempts to other hosts. It also records whether we got here via an MX record
2732 or not in the more_errno field of the address. We are interested only in
2733 addresses that are still marked DEFER - others may have got delivered to a
2734 previously considered IP address. Set their status to PENDING_DEFER to indicate
2735 which ones are relevant this time.
2736
2737 Arguments:
2738 addrlist the list of addresses
2739 host the host we are delivering to
2740
2741 Returns: the first address for this delivery
2742 */
2743
2744 static address_item *
2745 prepare_addresses(address_item *addrlist, host_item *host)
2746 {
2747 address_item *first_addr = NULL;
2748 address_item *addr;
2749 for (addr = addrlist; addr != NULL; addr = addr->next)
2750 {
2751 if (addr->transport_return != DEFER) continue;
2752 if (first_addr == NULL) first_addr = addr;
2753 addr->transport_return = PENDING_DEFER;
2754 addr->basic_errno = 0;
2755 addr->more_errno = (host->mx >= 0)? 'M' : 'A';
2756 addr->message = NULL;
2757 #ifdef SUPPORT_TLS
2758 addr->cipher = NULL;
2759 addr->ourcert = NULL;
2760 addr->peercert = NULL;
2761 addr->peerdn = NULL;
2762 addr->ocsp = OCSP_NOT_REQ;
2763 #endif
2764 }
2765 return first_addr;
2766 }
2767
2768
2769
2770 /*************************************************
2771 * Main entry point *
2772 *************************************************/
2773
2774 /* See local README for interface details. As this is a remote transport, it is
2775 given a chain of addresses to be delivered in one connection, if possible. It
2776 always returns TRUE, indicating that each address has its own independent
2777 status set, except if there is a setting up problem, in which case it returns
2778 FALSE. */
2779
2780 BOOL
2781 smtp_transport_entry(
2782 transport_instance *tblock, /* data for this instantiation */
2783 address_item *addrlist) /* addresses we are working on */
2784 {
2785 int cutoff_retry;
2786 int port;
2787 int hosts_defer = 0;
2788 int hosts_fail = 0;
2789 int hosts_looked_up = 0;
2790 int hosts_retry = 0;
2791 int hosts_serial = 0;
2792 int hosts_total = 0;
2793 int total_hosts_tried = 0;
2794 address_item *addr;
2795 BOOL expired = TRUE;
2796 BOOL continuing = continue_hostname != NULL;
2797 uschar *expanded_hosts = NULL;
2798 uschar *pistring;
2799 uschar *tid = string_sprintf("%s transport", tblock->name);
2800 smtp_transport_options_block *ob =
2801 (smtp_transport_options_block *)(tblock->options_block);
2802 host_item *hostlist = addrlist->host_list;
2803 host_item *host = NULL;
2804
2805 DEBUG(D_transport)
2806 {
2807 debug_printf("%s transport entered\n", tblock->name);
2808 for (addr = addrlist; addr != NULL; addr = addr->next)
2809 debug_printf(" %s\n", addr->address);
2810 if (continuing) debug_printf("already connected to %s [%s]\n",
2811 continue_hostname, continue_host_address);
2812 }
2813
2814 /* Set the flag requesting that these hosts be added to the waiting
2815 database if the delivery fails temporarily or if we are running with
2816 queue_smtp or a 2-stage queue run. This gets unset for certain
2817 kinds of error, typically those that are specific to the message. */
2818
2819 update_waiting = TRUE;
2820
2821 /* If a host list is not defined for the addresses - they must all have the
2822 same one in order to be passed to a single transport - or if the transport has
2823 a host list with hosts_override set, use the host list supplied with the
2824 transport. It is an error for this not to exist. */
2825
2826 if (hostlist == NULL || (ob->hosts_override && ob->hosts != NULL))
2827 {
2828 if (ob->hosts == NULL)
2829 {
2830 addrlist->message = string_sprintf("%s transport called with no hosts set",
2831 tblock->name);
2832 addrlist->transport_return = PANIC;
2833 return FALSE; /* Only top address has status */
2834 }
2835
2836 DEBUG(D_transport) debug_printf("using the transport's hosts: %s\n",
2837 ob->hosts);
2838
2839 /* If the transport's host list contains no '$' characters, and we are not
2840 randomizing, it is fixed and therefore a chain of hosts can be built once
2841 and for all, and remembered for subsequent use by other calls to this
2842 transport. If, on the other hand, the host list does contain '$', or we are
2843 randomizing its order, we have to rebuild it each time. In the fixed case,
2844 as the hosts string will never be used again, it doesn't matter that we
2845 replace all the : characters with zeros. */
2846
2847 if (ob->hostlist == NULL)
2848 {
2849 uschar *s = ob->hosts;
2850
2851 if (Ustrchr(s, '$') != NULL)
2852 {
2853 expanded_hosts = expand_string(s);
2854 if (expanded_hosts == NULL)
2855 {
2856 addrlist->message = string_sprintf("failed to expand list of hosts "
2857 "\"%s\" in %s transport: %s", s, tblock->name, expand_string_message);
2858 addrlist->transport_return = search_find_defer? DEFER : PANIC;
2859 return FALSE; /* Only top address has status */
2860 }
2861 DEBUG(D_transport) debug_printf("expanded list of hosts \"%s\" to "
2862 "\"%s\"\n", s, expanded_hosts);
2863 s = expanded_hosts;
2864 }
2865 else
2866 if (ob->hosts_randomize) s = expanded_hosts = string_copy(s);
2867
2868 host_build_hostlist(&hostlist, s, ob->hosts_randomize);
2869
2870 /* Check that the expansion yielded something useful. */
2871 if (hostlist == NULL)
2872 {
2873 addrlist->message =
2874 string_sprintf("%s transport has empty hosts setting", tblock->name);
2875 addrlist->transport_return = PANIC;
2876 return FALSE; /* Only top address has status */
2877 }
2878
2879 /* If there was no expansion of hosts, save the host list for
2880 next time. */
2881
2882 if (expanded_hosts == NULL) ob->hostlist = hostlist;
2883 }
2884
2885 /* This is not the first time this transport has been run in this delivery;
2886 the host list was built previously. */
2887
2888 else hostlist = ob->hostlist;
2889 }
2890
2891 /* The host list was supplied with the address. If hosts_randomize is set, we
2892 must sort it into a random order if it did not come from MX records and has not
2893 already been randomized (but don't bother if continuing down an existing
2894 connection). */
2895
2896 else if (ob->hosts_randomize && hostlist->mx == MX_NONE && !continuing)
2897 {
2898 host_item *newlist = NULL;
2899 while (hostlist != NULL)
2900 {
2901 host_item *h = hostlist;
2902 hostlist = hostlist->next;
2903
2904 h->sort_key = random_number(100);
2905
2906 if (newlist == NULL)
2907 {
2908 h->next = NULL;
2909 newlist = h;
2910 }
2911 else if (h->sort_key < newlist->sort_key)
2912 {
2913 h->next = newlist;
2914 newlist = h;
2915 }
2916 else
2917 {
2918 host_item *hh = newlist;
2919 while (hh->next != NULL)
2920 {
2921 if (h->sort_key < hh->next->sort_key) break;
2922 hh = hh->next;
2923 }
2924 h->next = hh->next;
2925 hh->next = h;
2926 }
2927 }
2928
2929 hostlist = addrlist->host_list = newlist;
2930 }
2931
2932
2933 /* Sort out the default port. */
2934
2935 if (!smtp_get_port(ob->port, addrlist, &port, tid)) return FALSE;
2936
2937
2938 /* For each host-plus-IP-address on the list:
2939
2940 . If this is a continued delivery and the host isn't the one with the
2941 current connection, skip.
2942
2943 . If the status is unusable (i.e. previously failed or retry checked), skip.
2944
2945 . If no IP address set, get the address, either by turning the name into
2946 an address, calling gethostbyname if gethostbyname is on, or by calling
2947 the DNS. The DNS may yield multiple addresses, in which case insert the
2948 extra ones into the list.
2949
2950 . Get the retry data if not previously obtained for this address and set the
2951 field which remembers the state of this address. Skip if the retry time is
2952 not reached. If not, remember whether retry data was found. The retry string
2953 contains both the name and the IP address.
2954
2955 . Scan the list of addresses and mark those whose status is DEFER as
2956 PENDING_DEFER. These are the only ones that will be processed in this cycle
2957 of the hosts loop.
2958
2959 . Make a delivery attempt - addresses marked PENDING_DEFER will be tried.
2960 Some addresses may be successfully delivered, others may fail, and yet
2961 others may get temporary errors and so get marked DEFER.
2962
2963 . The return from the delivery attempt is OK if a connection was made and a
2964 valid SMTP dialogue was completed. Otherwise it is DEFER.
2965
2966 . If OK, add a "remove" retry item for this host/IPaddress, if any.
2967
2968 . If fail to connect, or other defer state, add a retry item.
2969
2970 . If there are any addresses whose status is still DEFER, carry on to the
2971 next host/IPaddress, unless we have tried the number of hosts given
2972 by hosts_max_try or hosts_max_try_hardlimit; otherwise return. Note that
2973 there is some fancy logic for hosts_max_try that means its limit can be
2974 overstepped in some circumstances.
2975
2976 If we get to the end of the list, all hosts have deferred at least one address,
2977 or not reached their retry times. If delay_after_cutoff is unset, it requests a
2978 delivery attempt to those hosts whose last try was before the arrival time of
2979 the current message. To cope with this, we have to go round the loop a second
2980 time. After that, set the status and error data for any addresses that haven't
2981 had it set already. */
2982
2983 for (cutoff_retry = 0; expired &&
2984 cutoff_retry < ((ob->delay_after_cutoff)? 1 : 2);
2985 cutoff_retry++)
2986 {
2987 host_item *nexthost = NULL;
2988 int unexpired_hosts_tried = 0;
2989
2990 for (host = hostlist;
2991 host != NULL &&
2992 unexpired_hosts_tried < ob->hosts_max_try &&
2993 total_hosts_tried < ob->hosts_max_try_hardlimit;
2994 host = nexthost)
2995 {
2996 int rc;
2997 int host_af;
2998 uschar *rs;
2999 BOOL serialized = FALSE;
3000 BOOL host_is_expired = FALSE;
3001 BOOL message_defer = FALSE;
3002 BOOL ifchanges = FALSE;
3003 BOOL some_deferred = FALSE;
3004 address_item *first_addr = NULL;
3005 uschar *interface = NULL;
3006 uschar *retry_host_key = NULL;
3007 uschar *retry_message_key = NULL;
3008 uschar *serialize_key = NULL;
3009
3010 /* Default next host is next host. :-) But this can vary if the
3011 hosts_max_try limit is hit (see below). It may also be reset if a host
3012 address is looked up here (in case the host was multihomed). */
3013
3014 nexthost = host->next;
3015
3016 /* If the address hasn't yet been obtained from the host name, look it up
3017 now, unless the host is already marked as unusable. If it is marked as
3018 unusable, it means that the router was unable to find its IP address (in
3019 the DNS or wherever) OR we are in the 2nd time round the cutoff loop, and
3020 the lookup failed last time. We don't get this far if *all* MX records
3021 point to non-existent hosts; that is treated as a hard error.
3022
3023 We can just skip this host entirely. When the hosts came from the router,
3024 the address will timeout based on the other host(s); when the address is
3025 looked up below, there is an explicit retry record added.
3026
3027 Note that we mustn't skip unusable hosts if the address is not unset; they
3028 may be needed as expired hosts on the 2nd time round the cutoff loop. */
3029
3030 if (host->address == NULL)
3031 {
3032 int new_port, flags;
3033 host_item *hh;
3034 uschar *canonical_name;
3035
3036 if (host->status >= hstatus_unusable)
3037 {
3038 DEBUG(D_transport) debug_printf("%s has no address and is unusable - skipping\n",
3039 host->name);
3040 continue;
3041 }
3042
3043 DEBUG(D_transport) debug_printf("getting address for %s\n", host->name);
3044
3045 /* The host name is permitted to have an attached port. Find it, and
3046 strip it from the name. Just remember it for now. */
3047
3048 new_port = host_item_get_port(host);
3049
3050 /* Count hosts looked up */
3051
3052 hosts_looked_up++;
3053
3054 /* Find by name if so configured, or if it's an IP address. We don't
3055 just copy the IP address, because we need the test-for-local to happen. */
3056
3057 flags = HOST_FIND_BY_A;
3058 if (ob->dns_qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
3059 if (ob->dns_search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
3060
3061 if (ob->gethostbyname || string_is_ip_address(host->name, NULL) != 0)
3062 rc = host_find_byname(host, NULL, flags, &canonical_name, TRUE);
3063 else
3064 rc = host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
3065 ob->dnssec_request_domains, ob->dnssec_require_domains,
3066 &canonical_name, NULL);
3067
3068 /* Update the host (and any additional blocks, resulting from
3069 multihoming) with a host-specific port, if any. */
3070
3071 for (hh = host; hh != nexthost; hh = hh->next) hh->port = new_port;
3072
3073 /* Failure to find the host at this time (usually DNS temporary failure)
3074 is really a kind of routing failure rather than a transport failure.
3075 Therefore we add a retry item of the routing kind, not to stop us trying
3076 to look this name up here again, but to ensure the address gets timed
3077 out if the failures go on long enough. A complete failure at this point
3078 commonly points to a configuration error, but the best action is still
3079 to carry on for the next host. */
3080
3081 if (rc == HOST_FIND_AGAIN || rc == HOST_FIND_FAILED)
3082 {
3083 retry_add_item(addrlist, string_sprintf("R:%s", host->name), 0);
3084 expired = FALSE;
3085 if (rc == HOST_FIND_AGAIN) hosts_defer++; else hosts_fail++;
3086 DEBUG(D_transport) debug_printf("rc = %s for %s\n", (rc == HOST_FIND_AGAIN)?
3087 "HOST_FIND_AGAIN" : "HOST_FIND_FAILED", host->name);
3088 host->status = hstatus_unusable;
3089
3090 for (addr = addrlist; addr != NULL; addr = addr->next)
3091 {
3092 if (addr->transport_return != DEFER) continue;
3093 addr->basic_errno = ERRNO_UNKNOWNHOST;
3094 addr->message =
3095 string_sprintf("failed to lookup IP address for %s", host->name);
3096 }
3097 continue;
3098 }
3099
3100 /* If the host is actually the local host, we may have a problem, or
3101 there may be some cunning configuration going on. In the problem case,
3102 log things and give up. The default transport status is already DEFER. */
3103
3104 if (rc == HOST_FOUND_LOCAL && !ob->allow_localhost)
3105 {
3106 for (addr = addrlist; addr != NULL; addr = addr->next)
3107 {
3108 addr->basic_errno = 0;
3109 addr->message = string_sprintf("%s transport found host %s to be "
3110 "local", tblock->name, host->name);
3111 }
3112 goto END_TRANSPORT;
3113 }
3114 } /* End of block for IP address lookup */
3115
3116 /* If this is a continued delivery, we are interested only in the host
3117 which matches the name of the existing open channel. The check is put
3118 here after the local host lookup, in case the name gets expanded as a
3119 result of the lookup. Set expired FALSE, to save the outer loop executing
3120 twice. */
3121
3122 if (continuing && (Ustrcmp(continue_hostname, host->name) != 0 ||
3123 Ustrcmp(continue_host_address, host->address) != 0))
3124 {
3125 expired = FALSE;
3126 continue; /* With next host */
3127 }
3128
3129 /* Reset the default next host in case a multihomed host whose addresses
3130 are not looked up till just above added to the host list. */
3131
3132 nexthost = host->next;
3133
3134 /* If queue_smtp is set (-odqs or the first part of a 2-stage run), or the
3135 domain is in queue_smtp_domains, we don't actually want to attempt any
3136 deliveries. When doing a queue run, queue_smtp_domains is always unset. If
3137 there is a lookup defer in queue_smtp_domains, proceed as if the domain
3138 were not in it. We don't want to hold up all SMTP deliveries! Except when
3139 doing a two-stage queue run, don't do this if forcing. */
3140
3141 if ((!deliver_force || queue_2stage) && (queue_smtp ||
3142 match_isinlist(addrlist->domain, &queue_smtp_domains, 0,
3143 &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL) == OK))
3144 {
3145 expired = FALSE;
3146 for (addr = addrlist; addr != NULL; addr = addr->next)
3147 {
3148 if (addr->transport_return != DEFER) continue;
3149 addr->message = US"domain matches queue_smtp_domains, or -odqs set";
3150 }
3151 continue; /* With next host */
3152 }
3153
3154 /* Count hosts being considered - purely for an intelligent comment
3155 if none are usable. */
3156
3157 hosts_total++;
3158
3159 /* Set $host and $host address now in case they are needed for the
3160 interface expansion or the serialize_hosts check; they remain set if an
3161 actual delivery happens. */
3162
3163 deliver_host = host->name;
3164 deliver_host_address = host->address;
3165 lookup_dnssec_authenticated = host->dnssec == DS_YES ? US"yes"
3166 : host->dnssec == DS_NO ? US"no"
3167 : US"";
3168
3169 /* Set up a string for adding to the retry key if the port number is not
3170 the standard SMTP port. A host may have its own port setting that overrides
3171 the default. */
3172
3173 pistring = string_sprintf(":%d", (host->port == PORT_NONE)?
3174 port : host->port);
3175 if (Ustrcmp(pistring, ":25") == 0) pistring = US"";
3176
3177 /* Select IPv4 or IPv6, and choose an outgoing interface. If the interface
3178 string changes upon expansion, we must add it to the key that is used for
3179 retries, because connections to the same host from a different interface
3180 should be treated separately. */
3181
3182 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET : AF_INET6;
3183 if (!smtp_get_interface(ob->interface, host_af, addrlist, &ifchanges,
3184 &interface, tid))
3185 return FALSE;
3186 if (ifchanges) pistring = string_sprintf("%s/%s", pistring, interface);
3187
3188 /* The first time round the outer loop, check the status of the host by
3189 inspecting the retry data. The second time round, we are interested only
3190 in expired hosts that haven't been tried since this message arrived. */
3191
3192 if (cutoff_retry == 0)
3193 {
3194 BOOL incl_ip;
3195 /* Ensure the status of the address is set by checking retry data if
3196 necessary. There may be host-specific retry data (applicable to all
3197 messages) and also data for retries of a specific message at this host.
3198 If either of these retry records are actually read, the keys used are
3199 returned to save recomputing them later. */
3200
3201 if (exp_bool(addrlist, US"transport", tblock->name, D_transport,
3202 US"retry_include_ip_address", ob->retry_include_ip_address,
3203 ob->expand_retry_include_ip_address, &incl_ip) != OK)
3204 continue; /* with next host */
3205
3206 host_is_expired = retry_check_address(addrlist->domain, host, pistring,
3207 incl_ip, &retry_host_key, &retry_message_key);
3208
3209 DEBUG(D_transport) debug_printf("%s [%s]%s status = %s\n", host->name,
3210 (host->address == NULL)? US"" : host->address, pistring,
3211 (host->status == hstatus_usable)? "usable" :
3212 (host->status == hstatus_unusable)? "unusable" :
3213 (host->status == hstatus_unusable_expired)? "unusable (expired)" : "?");
3214
3215 /* Skip this address if not usable at this time, noting if it wasn't
3216 actually expired, both locally and in the address. */
3217
3218 switch (host->status)
3219 {
3220 case hstatus_unusable:
3221 expired = FALSE;
3222 setflag(addrlist, af_retry_skipped);
3223 /* Fall through */
3224
3225 case hstatus_unusable_expired:
3226 switch (host->why)
3227 {
3228 case hwhy_retry: hosts_retry++; break;
3229 case hwhy_failed: hosts_fail++; break;
3230 case hwhy_deferred: hosts_defer++; break;
3231 }
3232
3233 /* If there was a retry message key, implying that previously there
3234 was a message-specific defer, we don't want to update the list of
3235 messages waiting for these hosts. */
3236
3237 if (retry_message_key != NULL) update_waiting = FALSE;
3238 continue; /* With the next host or IP address */
3239 }
3240 }
3241
3242 /* Second time round the loop: if the address is set but expired, and
3243 the message is newer than the last try, let it through. */
3244
3245 else
3246 {
3247 if (host->address == NULL ||
3248 host->status != hstatus_unusable_expired ||
3249 host->last_try > received_time)
3250 continue;
3251 DEBUG(D_transport)
3252 debug_printf("trying expired host %s [%s]%s\n",
3253 host->name, host->address, pistring);
3254 host_is_expired = TRUE;
3255 }
3256
3257 /* Setting "expired=FALSE" doesn't actually mean not all hosts are expired;
3258 it remains TRUE only if all hosts are expired and none are actually tried.
3259 */
3260
3261 expired = FALSE;
3262
3263 /* If this host is listed as one to which access must be serialized,
3264 see if another Exim process has a connection to it, and if so, skip
3265 this host. If not, update the database to record our connection to it
3266 and remember this for later deletion. Do not do any of this if we are
3267 sending the message down a pre-existing connection. */
3268
3269 if (!continuing &&
3270 verify_check_given_host(&ob->serialize_hosts, host) == OK)
3271 {
3272 serialize_key = string_sprintf("host-serialize-%s", host->name);
3273 if (!enq_start(serialize_key))
3274 {
3275 DEBUG(D_transport)
3276 debug_printf("skipping host %s because another Exim process "
3277 "is connected to it\n", host->name);
3278 hosts_serial++;
3279 continue;
3280 }
3281 serialized = TRUE;
3282 }
3283
3284 /* OK, we have an IP address that is not waiting for its retry time to
3285 arrive (it might be expired) OR (second time round the loop) we have an
3286 expired host that hasn't been tried since the message arrived. Have a go
3287 at delivering the message to it. First prepare the addresses by flushing
3288 out the result of previous attempts, and finding the first address that
3289 is still to be delivered. */
3290
3291 first_addr = prepare_addresses(addrlist, host);
3292
3293 DEBUG(D_transport) debug_printf("delivering %s to %s [%s] (%s%s)\n",
3294 message_id, host->name, host->address, addrlist->address,
3295 (addrlist->next == NULL)? "" : ", ...");
3296
3297 set_process_info("delivering %s to %s [%s] (%s%s)",
3298 message_id, host->name, host->address, addrlist->address,
3299 (addrlist->next == NULL)? "" : ", ...");
3300
3301 /* This is not for real; don't do the delivery. If there are
3302 any remaining hosts, list them. */
3303
3304 if (dont_deliver)
3305 {
3306 host_item *host2;
3307 set_errno(addrlist, 0, NULL, OK, FALSE, NULL);
3308 for (addr = addrlist; addr != NULL; addr = addr->next)
3309 {
3310 addr->host_used = host;
3311 addr->special_action = '*';
3312 addr->message = US"delivery bypassed by -N option";
3313 }
3314 DEBUG(D_transport)
3315 {
3316 debug_printf("*** delivery by %s transport bypassed by -N option\n"
3317 "*** host and remaining hosts:\n", tblock->name);
3318 for (host2 = host; host2 != NULL; host2 = host2->next)
3319 debug_printf(" %s [%s]\n", host2->name,
3320 (host2->address == NULL)? US"unset" : host2->address);
3321 }
3322 rc = OK;
3323 }
3324
3325 /* This is for real. If the host is expired, we don't count it for
3326 hosts_max_retry. This ensures that all hosts must expire before an address
3327 is timed out, unless hosts_max_try_hardlimit (which protects against
3328 lunatic DNS configurations) is reached.
3329
3330 If the host is not expired and we are about to hit the hosts_max_retry
3331 limit, check to see if there is a subsequent hosts with a different MX
3332 value. If so, make that the next host, and don't count this one. This is a
3333 heuristic to make sure that different MXs do get tried. With a normal kind
3334 of retry rule, they would get tried anyway when the earlier hosts were
3335 delayed, but if the domain has a "retry every time" type of rule - as is
3336 often used for the the very large ISPs, that won't happen. */
3337
3338 else
3339 {
3340 if (!host_is_expired && ++unexpired_hosts_tried >= ob->hosts_max_try)
3341 {
3342 host_item *h;
3343 DEBUG(D_transport)
3344 debug_printf("hosts_max_try limit reached with this host\n");
3345 for (h = host; h != NULL; h = h->next)
3346 if (h->mx != host->mx) break;
3347 if (h != NULL)
3348 {
3349 nexthost = h;
3350 unexpired_hosts_tried--;
3351 DEBUG(D_transport) debug_printf("however, a higher MX host exists "
3352 "and will be tried\n");
3353 }
3354 }
3355
3356 /* Attempt the delivery. */
3357
3358 total_hosts_tried++;
3359 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
3360 expanded_hosts != NULL, &message_defer, FALSE);
3361
3362 /* Yield is one of:
3363 OK => connection made, each address contains its result;
3364 message_defer is set for message-specific defers (when all
3365 recipients are marked defer)
3366 DEFER => there was a non-message-specific delivery problem;
3367 ERROR => there was a problem setting up the arguments for a filter,
3368 or there was a problem with expanding added headers
3369 */
3370
3371 /* If the result is not OK, there was a non-message-specific problem.
3372 If the result is DEFER, we need to write to the logs saying what happened
3373 for this particular host, except in the case of authentication and TLS
3374 failures, where the log has already been written. If all hosts defer a
3375 general message is written at the end. */
3376
3377 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL &&
3378 first_addr->basic_errno != ERRNO_TLSFAILURE)
3379 write_logs(first_addr, host);
3380
3381 #ifdef EXPERIMENTAL_EVENT
3382 if (rc == DEFER)
3383 deferred_event_raise(first_addr, host);
3384 #endif
3385
3386 /* If STARTTLS was accepted, but there was a failure in setting up the
3387 TLS session (usually a certificate screwup), and the host is not in
3388 hosts_require_tls, and tls_tempfail_tryclear is true, try again, with
3389 TLS forcibly turned off. We have to start from scratch with a new SMTP
3390 connection. That's why the retry is done from here, not from within
3391 smtp_deliver(). [Rejections of STARTTLS itself don't screw up the
3392 session, so the in-clear transmission after those errors, if permitted,
3393 happens inside smtp_deliver().] */
3394
3395 #ifdef SUPPORT_TLS
3396 if ( rc == DEFER
3397 && first_addr->basic_errno == ERRNO_TLSFAILURE
3398 && ob->tls_tempfail_tryclear
3399 && verify_check_given_host(&ob->hosts_require_tls, host) != OK
3400 )
3401 {
3402 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
3403 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
3404 first_addr = prepare_addresses(addrlist, host);
3405 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
3406 expanded_hosts != NULL, &message_defer, TRUE);
3407 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL)
3408 write_logs(first_addr, host);
3409 # ifdef EXPERIMENTAL_EVENT
3410 if (rc == DEFER)
3411 deferred_event_raise(first_addr, host);
3412 # endif
3413 }
3414 #endif /*SUPPORT_TLS*/
3415 }
3416
3417 /* Delivery attempt finished */
3418
3419 rs = (rc == OK)? US"OK" : (rc == DEFER)? US"DEFER" : (rc == ERROR)?
3420 US"ERROR" : US"?";
3421
3422 set_process_info("delivering %s: just tried %s [%s] for %s%s: result %s",
3423 message_id, host->name, host->address, addrlist->address,
3424 (addrlist->next == NULL)? "" : " (& others)", rs);
3425
3426 /* Release serialization if set up */
3427
3428 if (serialized) enq_end(serialize_key);
3429
3430 /* If the result is DEFER, or if a host retry record is known to exist, we
3431 need to add an item to the retry chain for updating the retry database
3432 at the end of delivery. We only need to add the item to the top address,
3433 of course. Also, if DEFER, we mark the IP address unusable so as to skip it
3434 for any other delivery attempts using the same address. (It is copied into
3435 the unusable tree at the outer level, so even if different address blocks
3436 contain the same address, it still won't get tried again.) */
3437
3438 if (rc == DEFER || retry_host_key != NULL)
3439 {
3440 int delete_flag = (rc != DEFER)? rf_delete : 0;
3441 if (retry_host_key == NULL)
3442 {
3443 BOOL incl_ip;
3444 if (exp_bool(addrlist, US"transport", tblock->name, D_transport,
3445 US"retry_include_ip_address", ob->retry_include_ip_address,
3446 ob->expand_retry_include_ip_address, &incl_ip) != OK)
3447 incl_ip = TRUE; /* error; use most-specific retry record */
3448
3449 retry_host_key = incl_ip ?
3450 string_sprintf("T:%S:%s%s", host->name, host->address, pistring) :
3451 string_sprintf("T:%S%s", host->name, pistring);
3452 }
3453
3454 /* If a delivery of another message over an existing SMTP connection
3455 yields DEFER, we do NOT set up retry data for the host. This covers the
3456 case when there are delays in routing the addresses in the second message
3457 that are so long that the server times out. This is alleviated by not
3458 routing addresses that previously had routing defers when handling an
3459 existing connection, but even so, this case may occur (e.g. if a
3460 previously happily routed address starts giving routing defers). If the
3461 host is genuinely down, another non-continued message delivery will
3462 notice it soon enough. */
3463
3464 if (delete_flag != 0 || !continuing)
3465 retry_add_item(first_addr, retry_host_key, rf_host | delete_flag);
3466
3467 /* We may have tried an expired host, if its retry time has come; ensure
3468 the status reflects the expiry for the benefit of any other addresses. */
3469
3470 if (rc == DEFER)
3471 {
3472 host->status = (host_is_expired)?
3473 hstatus_unusable_expired : hstatus_unusable;
3474 host->why = hwhy_deferred;
3475 }
3476 }
3477
3478 /* If message_defer is set (host was OK, but every recipient got deferred
3479 because of some message-specific problem), or if that had happened
3480 previously so that a message retry key exists, add an appropriate item
3481 to the retry chain. Note that if there was a message defer but now there is
3482 a host defer, the message defer record gets deleted. That seems perfectly
3483 reasonable. Also, stop the message from being remembered as waiting
3484 for specific hosts. */
3485
3486 if (message_defer || retry_message_key != NULL)
3487 {
3488 int delete_flag = message_defer? 0 : rf_delete;
3489 if (retry_message_key == NULL)
3490 {
3491 BOOL incl_ip;
3492 if (exp_bool(addrlist, US"transport", tblock->name, D_transport,
3493 US"retry_include_ip_address", ob->retry_include_ip_address,
3494 ob->expand_retry_include_ip_address, &incl_ip) != OK)
3495 incl_ip = TRUE; /* error; use most-specific retry record */
3496
3497 retry_message_key = incl_ip ?
3498 string_sprintf("T:%S:%s%s:%s", host->name, host->address, pistring,
3499 message_id) :
3500 string_sprintf("T:%S%s:%s", host->name, pistring, message_id);
3501 }
3502 retry_add_item(addrlist, retry_message_key,
3503 rf_message | rf_host | delete_flag);
3504 update_waiting = FALSE;
3505 }
3506
3507 /* Any return other than DEFER (that is, OK or ERROR) means that the
3508 addresses have got their final statuses filled in for this host. In the OK
3509 case, see if any of them are deferred. */
3510
3511 if (rc == OK)
3512 {
3513 for (addr = addrlist; addr != NULL; addr = addr->next)
3514 {
3515 if (addr->transport_return == DEFER)
3516 {
3517 some_deferred = TRUE;
3518 break;
3519 }
3520 }
3521 }
3522
3523 /* If no addresses deferred or the result was ERROR, return. We do this for
3524 ERROR because a failing filter set-up or add_headers expansion is likely to
3525 fail for any host we try. */
3526
3527 if (rc == ERROR || (rc == OK && !some_deferred))
3528 {
3529 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
3530 return TRUE; /* Each address has its status */
3531 }
3532
3533 /* If the result was DEFER or some individual addresses deferred, let
3534 the loop run to try other hosts with the deferred addresses, except for the
3535 case when we were trying to deliver down an existing channel and failed.
3536 Don't try any other hosts in this case. */
3537
3538 if (continuing) break;
3539
3540 /* If the whole delivery, or some individual addresses, were deferred and
3541 there are more hosts that could be tried, do not count this host towards
3542 the hosts_max_try limit if the age of the message is greater than the
3543 maximum retry time for this host. This means we may try try all hosts,
3544 ignoring the limit, when messages have been around for some time. This is
3545 important because if we don't try all hosts, the address will never time
3546 out. NOTE: this does not apply to hosts_max_try_hardlimit. */
3547
3548 if ((rc == DEFER || some_deferred) && nexthost != NULL)
3549 {
3550 BOOL timedout;
3551 retry_config *retry = retry_find_config(host->name, NULL, 0, 0);
3552
3553 if (retry != NULL && retry->rules != NULL)
3554 {
3555 retry_rule *last_rule;
3556 for (last_rule = retry->rules;
3557 last_rule->next != NULL;
3558 last_rule = last_rule->next);
3559 timedout = time(NULL) - received_time > last_rule->timeout;
3560 }
3561 else timedout = TRUE; /* No rule => timed out */
3562
3563 if (timedout)
3564 {
3565 unexpired_hosts_tried--;
3566 DEBUG(D_transport) debug_printf("temporary delivery error(s) override "
3567 "hosts_max_try (message older than host's retry time)\n");
3568 }
3569 }
3570 } /* End of loop for trying multiple hosts. */
3571
3572 /* This is the end of the loop that repeats iff expired is TRUE and
3573 ob->delay_after_cutoff is FALSE. The second time round we will
3574 try those hosts that haven't been tried since the message arrived. */
3575
3576 DEBUG(D_transport)
3577 {
3578 debug_printf("all IP addresses skipped or deferred at least one address\n");
3579 if (expired && !ob->delay_after_cutoff && cutoff_retry == 0)
3580 debug_printf("retrying IP addresses not tried since message arrived\n");
3581 }
3582 }
3583
3584
3585 /* Get here if all IP addresses are skipped or defer at least one address. In
3586 MUA wrapper mode, this will happen only for connection or other non-message-
3587 specific failures. Force the delivery status for all addresses to FAIL. */
3588
3589 if (mua_wrapper)
3590 {
3591 for (addr = addrlist; addr != NULL; addr = addr->next)
3592 addr->transport_return = FAIL;
3593 goto END_TRANSPORT;
3594 }
3595
3596 /* In the normal, non-wrapper case, add a standard message to each deferred
3597 address if there hasn't been an error, that is, if it hasn't actually been
3598 tried this time. The variable "expired" will be FALSE if any deliveries were
3599 actually tried, or if there was at least one host that was not expired. That
3600 is, it is TRUE only if no deliveries were tried and all hosts were expired. If
3601 a delivery has been tried, an error code will be set, and the failing of the
3602 message is handled by the retry code later.
3603
3604 If queue_smtp is set, or this transport was called to send a subsequent message
3605 down an existing TCP/IP connection, and something caused the host not to be
3606 found, we end up here, but can detect these cases and handle them specially. */
3607
3608 for (addr = addrlist; addr != NULL; addr = addr->next)
3609 {
3610 /* If host is not NULL, it means that we stopped processing the host list
3611 because of hosts_max_try or hosts_max_try_hardlimit. In the former case, this
3612 means we need to behave as if some hosts were skipped because their retry
3613 time had not come. Specifically, this prevents the address from timing out.
3614 However, if we have hit hosts_max_try_hardlimit, we want to behave as if all
3615 hosts were tried. */
3616
3617 if (host != NULL)
3618 {
3619 if (total_hosts_tried >= ob->hosts_max_try_hardlimit)
3620 {
3621 DEBUG(D_transport)
3622 debug_printf("hosts_max_try_hardlimit reached: behave as if all "
3623 "hosts were tried\n");
3624 }
3625 else
3626 {
3627 DEBUG(D_transport)
3628 debug_printf("hosts_max_try limit caused some hosts to be skipped\n");
3629 setflag(addr, af_retry_skipped);
3630 }
3631 }
3632
3633 if (queue_smtp) /* no deliveries attempted */
3634 {
3635 addr->transport_return = DEFER;
3636 addr->basic_errno = 0;
3637 addr->message = US"SMTP delivery explicitly queued";
3638 }
3639
3640 else if (addr->transport_return == DEFER &&
3641 (addr->basic_errno == ERRNO_UNKNOWNERROR || addr->basic_errno == 0) &&
3642 addr->message == NULL)
3643 {
3644 addr->basic_errno = ERRNO_HRETRY;
3645 if (continue_hostname != NULL)
3646 {
3647 addr->message = US"no host found for existing SMTP connection";
3648 }
3649 else if (expired)
3650 {
3651 setflag(addr, af_pass_message); /* This is not a security risk */
3652 addr->message = (ob->delay_after_cutoff)?
3653 US"retry time not reached for any host after a long failure period" :
3654 US"all hosts have been failing for a long time and were last tried "
3655 "after this message arrived";
3656
3657 /* If we are already using fallback hosts, or there are no fallback hosts
3658 defined, convert the result to FAIL to cause a bounce. */
3659
3660 if (addr->host_list == addr->fallback_hosts ||
3661 addr->fallback_hosts == NULL)
3662 addr->transport_return = FAIL;
3663 }
3664 else
3665 {
3666 if (hosts_retry == hosts_total)
3667 addr->message = US"retry time not reached for any host";
3668 else if (hosts_fail == hosts_total)
3669 addr->message = US"all host address lookups failed permanently";
3670 else if (hosts_defer == hosts_total)
3671 addr->message = US"all host address lookups failed temporarily";
3672 else if (hosts_serial == hosts_total)
3673 addr->message = US"connection limit reached for all hosts";
3674 else if (hosts_fail+hosts_defer == hosts_total)
3675 addr->message = US"all host address lookups failed";
3676 else addr->message = US"some host address lookups failed and retry time "
3677 "not reached for other hosts or connection limit reached";
3678 }
3679 }
3680 }
3681
3682 /* Update the database which keeps information about which messages are waiting
3683 for which hosts to become available. For some message-specific errors, the
3684 update_waiting flag is turned off because we don't want follow-on deliveries in
3685 those cases. If this transport instance is explicitly limited to one message
3686 per connection then follow-on deliveries are not possible and there's no need
3687 to create/update the per-transport wait-<transport_name> database. */
3688
3689 if (update_waiting && tblock->connection_max_messages != 1)
3690 transport_update_waiting(hostlist, tblock->name);
3691
3692 END_TRANSPORT:
3693
3694 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
3695
3696 return TRUE; /* Each address has its status */
3697 }
3698
3699 /* vi: aw ai sw=2
3700 */
3701 /* End of transport/smtp.c */
Unnamed repository; edit this file 'description' to name the repository.