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