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List separator specifiers in router/transport headers_add/remove. Bug 1581
[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 if (addr->transport_return >= PENDING)
458 {
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 uschar *message = string_sprintf("SMTP timeout after RCPT TO:<%s>",
835 transport_rcpt_address(addr, include_affixes));
836 set_errno(addrlist, ETIMEDOUT, message, DEFER, FALSE, NULL);
837 retry_add_item(addr, addr->address_retry_key, 0);
838 update_waiting = FALSE;
839 return -1;
840 }
841
842 /* Handle other errors in obtaining an SMTP response by returning -1. This
843 will cause all the addresses to be deferred. Restore the SMTP command in
844 big_buffer for which we are checking the response, so the error message
845 makes sense. */
846
847 else if (errno != 0 || buffer[0] == 0)
848 {
849 string_format(big_buffer, big_buffer_size, "RCPT TO:<%s>",
850 transport_rcpt_address(addr, include_affixes));
851 return -2;
852 }
853
854 /* Handle SMTP permanent and temporary response codes. */
855
856 else
857 {
858 addr->message =
859 string_sprintf("SMTP error from remote mail server after RCPT TO:<%s>: "
860 "%s", transport_rcpt_address(addr, include_affixes),
861 string_printing(buffer));
862 setflag(addr, af_pass_message);
863 msglog_line(host, addr->message);
864
865 /* The response was 5xx */
866
867 if (buffer[0] == '5')
868 {
869 addr->transport_return = FAIL;
870 yield |= 2;
871 }
872
873 /* The response was 4xx */
874
875 else
876 {
877 addr->transport_return = DEFER;
878 addr->basic_errno = ERRNO_RCPT4XX;
879 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
880
881 /* Log temporary errors if there are more hosts to be tried.
882 If not, log this last one in the == line. */
883
884 if (host->next)
885 log_write(0, LOG_MAIN, "H=%s [%s]: %s", host->name, host->address, addr->message);
886
887 /* Do not put this message on the list of those waiting for specific
888 hosts, as otherwise it is likely to be tried too often. */
889
890 update_waiting = FALSE;
891
892 /* Add a retry item for the address so that it doesn't get tried again
893 too soon. If address_retry_include_sender is true, add the sender address
894 to the retry key. */
895
896 if (address_retry_include_sender)
897 {
898 uschar *altkey = string_sprintf("%s:<%s>", addr->address_retry_key,
899 sender_address);
900 retry_add_item(addr, altkey, 0);
901 }
902 else retry_add_item(addr, addr->address_retry_key, 0);
903 }
904 }
905 } /* Loop for next RCPT response */
906
907 /* Update where to start at for the next block of responses, unless we
908 have already handled all the addresses. */
909
910 if (addr != NULL) *sync_addr = addr->next;
911
912 /* Handle a response to DATA. If we have not had any good recipients, either
913 previously or in this block, the response is ignored. */
914
915 if (pending_DATA != 0 &&
916 !smtp_read_response(inblock, buffer, buffsize, '3', timeout))
917 {
918 int code;
919 uschar *msg;
920 BOOL pass_message;
921 if (pending_DATA > 0 || (yield & 1) != 0)
922 {
923 if (errno == 0 && buffer[0] == '4')
924 {
925 errno = ERRNO_DATA4XX;
926 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
927 }
928 return -3;
929 }
930 (void)check_response(host, &errno, 0, buffer, &code, &msg, &pass_message);
931 DEBUG(D_transport) debug_printf("%s\nerror for DATA ignored: pipelining "
932 "is in use and there were no good recipients\n", msg);
933 }
934
935 /* All responses read and handled; MAIL (if present) received 2xx and DATA (if
936 present) received 3xx. If any RCPTs were handled and yielded anything other
937 than 4xx, yield will be set non-zero. */
938
939 return yield;
940 }
941
942
943
944 /* Do the client side of smtp-level authentication */
945 /*
946 Arguments:
947 buffer EHLO response from server (gets overwritten)
948 addrlist chain of potential addresses to deliver
949 host host to deliver to
950 ob transport options
951 ibp, obp comms channel control blocks
952
953 Returns:
954 OK Success, or failed (but not required): global "smtp_authenticated" set
955 DEFER Failed authentication (and was required)
956 ERROR Internal problem
957
958 FAIL_SEND Failed communications - transmit
959 FAIL - response
960 */
961
962 int
963 smtp_auth(uschar *buffer, unsigned bufsize, address_item *addrlist, host_item *host,
964 smtp_transport_options_block *ob, BOOL is_esmtp,
965 smtp_inblock *ibp, smtp_outblock *obp)
966 {
967 int require_auth;
968 uschar *fail_reason = US"server did not advertise AUTH support";
969
970 smtp_authenticated = FALSE;
971 client_authenticator = client_authenticated_id = client_authenticated_sender = NULL;
972 require_auth = verify_check_given_host(&ob->hosts_require_auth, host);
973
974 if (is_esmtp && !regex_AUTH) regex_AUTH =
975 regex_must_compile(US"\\n250[\\s\\-]AUTH\\s+([\\-\\w\\s]+)(?:\\n|$)",
976 FALSE, TRUE);
977
978 if (is_esmtp && regex_match_and_setup(regex_AUTH, buffer, 0, -1))
979 {
980 uschar *names = string_copyn(expand_nstring[1], expand_nlength[1]);
981 expand_nmax = -1; /* reset */
982
983 /* Must not do this check until after we have saved the result of the
984 regex match above. */
985
986 if (require_auth == OK ||
987 verify_check_given_host(&ob->hosts_try_auth, host) == OK)
988 {
989 auth_instance *au;
990 fail_reason = US"no common mechanisms were found";
991
992 DEBUG(D_transport) debug_printf("scanning authentication mechanisms\n");
993
994 /* Scan the configured authenticators looking for one which is configured
995 for use as a client, which is not suppressed by client_condition, and
996 whose name matches an authentication mechanism supported by the server.
997 If one is found, attempt to authenticate by calling its client function.
998 */
999
1000 for (au = auths; !smtp_authenticated && au != NULL; au = au->next)
1001 {
1002 uschar *p = names;
1003 if (!au->client ||
1004 (au->client_condition != NULL &&
1005 !expand_check_condition(au->client_condition, au->name,
1006 US"client authenticator")))
1007 {
1008 DEBUG(D_transport) debug_printf("skipping %s authenticator: %s\n",
1009 au->name,
1010 (au->client)? "client_condition is false" :
1011 "not configured as a client");
1012 continue;
1013 }
1014
1015 /* Loop to scan supported server mechanisms */
1016
1017 while (*p != 0)
1018 {
1019 int rc;
1020 int len = Ustrlen(au->public_name);
1021 while (isspace(*p)) p++;
1022
1023 if (strncmpic(au->public_name, p, len) != 0 ||
1024 (p[len] != 0 && !isspace(p[len])))
1025 {
1026 while (*p != 0 && !isspace(*p)) p++;
1027 continue;
1028 }
1029
1030 /* Found data for a listed mechanism. Call its client entry. Set
1031 a flag in the outblock so that data is overwritten after sending so
1032 that reflections don't show it. */
1033
1034 fail_reason = US"authentication attempt(s) failed";
1035 obp->authenticating = TRUE;
1036 rc = (au->info->clientcode)(au, ibp, obp,
1037 ob->command_timeout, buffer, bufsize);
1038 obp->authenticating = FALSE;
1039 DEBUG(D_transport) debug_printf("%s authenticator yielded %d\n",
1040 au->name, rc);
1041
1042 /* A temporary authentication failure must hold up delivery to
1043 this host. After a permanent authentication failure, we carry on
1044 to try other authentication methods. If all fail hard, try to
1045 deliver the message unauthenticated unless require_auth was set. */
1046
1047 switch(rc)
1048 {
1049 case OK:
1050 smtp_authenticated = TRUE; /* stops the outer loop */
1051 client_authenticator = au->name;
1052 if (au->set_client_id != NULL)
1053 client_authenticated_id = expand_string(au->set_client_id);
1054 break;
1055
1056 /* Failure after writing a command */
1057
1058 case FAIL_SEND:
1059 return FAIL_SEND;
1060
1061 /* Failure after reading a response */
1062
1063 case FAIL:
1064 if (errno != 0 || buffer[0] != '5') return FAIL;
1065 log_write(0, LOG_MAIN, "%s authenticator failed H=%s [%s] %s",
1066 au->name, host->name, host->address, buffer);
1067 break;
1068
1069 /* Failure by some other means. In effect, the authenticator
1070 decided it wasn't prepared to handle this case. Typically this
1071 is the result of "fail" in an expansion string. Do we need to
1072 log anything here? Feb 2006: a message is now put in the buffer
1073 if logging is required. */
1074
1075 case CANCELLED:
1076 if (*buffer != 0)
1077 log_write(0, LOG_MAIN, "%s authenticator cancelled "
1078 "authentication H=%s [%s] %s", au->name, host->name,
1079 host->address, buffer);
1080 break;
1081
1082 /* Internal problem, message in buffer. */
1083
1084 case ERROR:
1085 set_errno(addrlist, ERRNO_AUTHPROB, string_copy(buffer),
1086 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, ERRNO_EXPANDFAIL, 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(const 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 message_defer set TRUE if yield is OK, but all addresses were deferred
1233 because of a non-recipient, non-host failure, that is, a
1234 4xx response to MAIL FROM, DATA, or ".". This is a defer
1235 that is specific to the message.
1236 suppress_tls if TRUE, don't attempt a TLS connection - this is set for
1237 a second attempt after TLS initialization fails
1238
1239 Returns: OK - the connection was made and the delivery attempted;
1240 the result for each address is in its data block.
1241 DEFER - the connection could not be made, or something failed
1242 while setting up the SMTP session, or there was a
1243 non-message-specific error, such as a timeout.
1244 ERROR - a filter command is specified for this transport,
1245 and there was a problem setting it up; OR helo_data
1246 or add_headers or authenticated_sender is specified
1247 for this transport, and the string failed to expand
1248 */
1249
1250 static int
1251 smtp_deliver(address_item *addrlist, host_item *host, int host_af, int port,
1252 uschar *interface, transport_instance *tblock,
1253 BOOL *message_defer, BOOL suppress_tls)
1254 {
1255 address_item *addr;
1256 address_item *sync_addr;
1257 address_item *first_addr = addrlist;
1258 int yield = OK;
1259 int address_count;
1260 int save_errno;
1261 int rc;
1262 time_t start_delivery_time = time(NULL);
1263 smtp_transport_options_block *ob =
1264 (smtp_transport_options_block *)(tblock->options_block);
1265 BOOL lmtp = strcmpic(ob->protocol, US"lmtp") == 0;
1266 BOOL smtps = strcmpic(ob->protocol, US"smtps") == 0;
1267 BOOL ok = FALSE;
1268 BOOL send_rset = TRUE;
1269 BOOL send_quit = TRUE;
1270 BOOL setting_up = TRUE;
1271 BOOL completed_address = FALSE;
1272 BOOL esmtp = TRUE;
1273 BOOL pending_MAIL;
1274 BOOL pass_message = FALSE;
1275 #ifndef DISABLE_PRDR
1276 BOOL prdr_offered = FALSE;
1277 BOOL prdr_active;
1278 #endif
1279 BOOL dsn_all_lasthop = TRUE;
1280 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
1281 BOOL dane = FALSE;
1282 BOOL dane_required;
1283 dns_answer tlsa_dnsa;
1284 #endif
1285 smtp_inblock inblock;
1286 smtp_outblock outblock;
1287 int max_rcpt = tblock->max_addresses;
1288 uschar *igquotstr = US"";
1289 uschar *helo_data = NULL;
1290 uschar *message = NULL;
1291 uschar new_message_id[MESSAGE_ID_LENGTH + 1];
1292 uschar *p;
1293 uschar buffer[4096];
1294 uschar inbuffer[4096];
1295 uschar outbuffer[4096];
1296
1297 suppress_tls = suppress_tls; /* stop compiler warning when no TLS support */
1298
1299 *message_defer = FALSE;
1300 smtp_command = US"initial connection";
1301 if (max_rcpt == 0) max_rcpt = 999999;
1302
1303 /* Set up the buffer for reading SMTP response packets. */
1304
1305 inblock.buffer = inbuffer;
1306 inblock.buffersize = sizeof(inbuffer);
1307 inblock.ptr = inbuffer;
1308 inblock.ptrend = inbuffer;
1309
1310 /* Set up the buffer for holding SMTP commands while pipelining */
1311
1312 outblock.buffer = outbuffer;
1313 outblock.buffersize = sizeof(outbuffer);
1314 outblock.ptr = outbuffer;
1315 outblock.cmd_count = 0;
1316 outblock.authenticating = FALSE;
1317
1318 /* Reset the parameters of a TLS session. */
1319
1320 tls_out.bits = 0;
1321 tls_out.cipher = NULL; /* the one we may use for this transport */
1322 tls_out.ourcert = NULL;
1323 tls_out.peercert = NULL;
1324 tls_out.peerdn = NULL;
1325 #if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
1326 tls_out.sni = NULL;
1327 #endif
1328 tls_out.ocsp = OCSP_NOT_REQ;
1329
1330 /* Flip the legacy TLS-related variables over to the outbound set in case
1331 they're used in the context of the transport. Don't bother resetting
1332 afterward as we're in a subprocess. */
1333
1334 tls_modify_variables(&tls_out);
1335
1336 #ifndef SUPPORT_TLS
1337 if (smtps)
1338 {
1339 set_errno(addrlist, ERRNO_TLSFAILURE, US"TLS support not available",
1340 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 tls_out.dane_verified = FALSE;
1370 tls_out.tlsa_usage = 0;
1371
1372 dane_required = verify_check_given_host(&ob->hosts_require_dane, host) == OK;
1373
1374 if (host->dnssec == DS_YES)
1375 {
1376 if( dane_required
1377 || verify_check_given_host(&ob->hosts_try_dane, host) == OK
1378 )
1379 if ((rc = tlsa_lookup(host, &tlsa_dnsa, dane_required, &dane)) != OK)
1380 return rc;
1381 }
1382 else if (dane_required)
1383 {
1384 log_write(0, LOG_MAIN, "DANE error: %s lookup not DNSSEC", host->name);
1385 return FAIL;
1386 }
1387
1388 if (dane)
1389 ob->tls_tempfail_tryclear = FALSE;
1390 }
1391 #endif /*DANE*/
1392
1393 /* Expand the greeting message while waiting for the initial response. (Makes
1394 sense if helo_data contains ${lookup dnsdb ...} stuff). The expansion is
1395 delayed till here so that $sending_interface and $sending_port are set. */
1396
1397 helo_data = expand_string(ob->helo_data);
1398
1399 /* The first thing is to wait for an initial OK response. The dreaded "goto"
1400 is nevertheless a reasonably clean way of programming this kind of logic,
1401 where you want to escape on any error. */
1402
1403 if (!smtps)
1404 {
1405 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1406 ob->command_timeout)) goto RESPONSE_FAILED;
1407
1408 #ifdef EXPERIMENTAL_EVENT
1409 {
1410 uschar * s;
1411 lookup_dnssec_authenticated = host->dnssec==DS_YES ? US"yes"
1412 : host->dnssec==DS_NO ? US"no" : NULL;
1413 s = event_raise(tblock->event_action, US"smtp:connect", buffer);
1414 if (s)
1415 {
1416 set_errno(addrlist, ERRNO_EXPANDFAIL,
1417 string_sprintf("deferred by smtp:connect event expansion: %s", s),
1418 DEFER, FALSE, NULL);
1419 yield = DEFER;
1420 goto SEND_QUIT;
1421 }
1422 }
1423 #endif
1424
1425 /* Now check if the helo_data expansion went well, and sign off cleanly if
1426 it didn't. */
1427
1428 if (helo_data == NULL)
1429 {
1430 uschar *message = string_sprintf("failed to expand helo_data: %s",
1431 expand_string_message);
1432 set_errno(addrlist, ERRNO_EXPANDFAIL, message, DEFER, FALSE, NULL);
1433 yield = DEFER;
1434 goto SEND_QUIT;
1435 }
1436 }
1437
1438 /** Debugging without sending a message
1439 addrlist->transport_return = DEFER;
1440 goto SEND_QUIT;
1441 **/
1442
1443 /* Errors that occur after this point follow an SMTP command, which is
1444 left in big_buffer by smtp_write_command() for use in error messages. */
1445
1446 smtp_command = big_buffer;
1447
1448 /* Tell the remote who we are...
1449
1450 February 1998: A convention has evolved that ESMTP-speaking MTAs include the
1451 string "ESMTP" in their greeting lines, so make Exim send EHLO if the
1452 greeting is of this form. The assumption was that the far end supports it
1453 properly... but experience shows that there are some that give 5xx responses,
1454 even though the banner includes "ESMTP" (there's a bloody-minded one that
1455 says "ESMTP not spoken here"). Cope with that case.
1456
1457 September 2000: Time has passed, and it seems reasonable now to always send
1458 EHLO at the start. It is also convenient to make the change while installing
1459 the TLS stuff.
1460
1461 July 2003: Joachim Wieland met a broken server that advertises "PIPELINING"
1462 but times out after sending MAIL FROM, RCPT TO and DATA all together. There
1463 would be no way to send out the mails, so there is now a host list
1464 "hosts_avoid_esmtp" that disables ESMTP for special hosts and solves the
1465 PIPELINING problem as well. Maybe it can also be useful to cure other
1466 problems with broken servers.
1467
1468 Exim originally sent "Helo" at this point and ran for nearly a year that way.
1469 Then somebody tried it with a Microsoft mailer... It seems that all other
1470 mailers use upper case for some reason (the RFC is quite clear about case
1471 independence) so, for peace of mind, I gave in. */
1472
1473 esmtp = verify_check_given_host(&ob->hosts_avoid_esmtp, host) != OK;
1474
1475 /* Alas; be careful, since this goto is not an error-out, so conceivably
1476 we might set data between here and the target which we assume to exist
1477 and be usable. I can see this coming back to bite us. */
1478 #ifdef SUPPORT_TLS
1479 if (smtps)
1480 {
1481 tls_offered = TRUE;
1482 suppress_tls = FALSE;
1483 ob->tls_tempfail_tryclear = FALSE;
1484 smtp_command = US"SSL-on-connect";
1485 goto TLS_NEGOTIATE;
1486 }
1487 #endif
1488
1489 if (esmtp)
1490 {
1491 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n",
1492 lmtp? "LHLO" : "EHLO", helo_data) < 0)
1493 goto SEND_FAILED;
1494 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1495 ob->command_timeout))
1496 {
1497 if (errno != 0 || buffer[0] == 0 || lmtp) goto RESPONSE_FAILED;
1498 esmtp = FALSE;
1499 }
1500 }
1501 else
1502 {
1503 DEBUG(D_transport)
1504 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
1505 }
1506
1507 if (!esmtp)
1508 {
1509 if (smtp_write_command(&outblock, FALSE, "HELO %s\r\n", helo_data) < 0)
1510 goto SEND_FAILED;
1511 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1512 ob->command_timeout)) goto RESPONSE_FAILED;
1513 }
1514
1515 /* Set IGNOREQUOTA if the response to LHLO specifies support and the
1516 lmtp_ignore_quota option was set. */
1517
1518 igquotstr = (lmtp && ob->lmtp_ignore_quota &&
1519 pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer, Ustrlen(CS buffer), 0,
1520 PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
1521
1522 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
1523
1524 #ifdef SUPPORT_TLS
1525 tls_offered = esmtp &&
1526 pcre_exec(regex_STARTTLS, NULL, CS buffer, Ustrlen(buffer), 0,
1527 PCRE_EOPT, NULL, 0) >= 0;
1528 #endif
1529
1530 #ifndef DISABLE_PRDR
1531 prdr_offered = esmtp
1532 && pcre_exec(regex_PRDR, NULL, CS buffer, Ustrlen(buffer), 0,
1533 PCRE_EOPT, NULL, 0) >= 0
1534 && verify_check_given_host(&ob->hosts_try_prdr, host) == OK;
1535
1536 if (prdr_offered)
1537 {DEBUG(D_transport) debug_printf("PRDR usable\n");}
1538 #endif
1539 }
1540
1541 /* For continuing deliveries down the same channel, the socket is the standard
1542 input, and we don't need to redo EHLO here (but may need to do so for TLS - see
1543 below). Set up the pointer to where subsequent commands will be left, for
1544 error messages. Note that smtp_use_size and smtp_use_pipelining will have been
1545 set from the command line if they were set in the process that passed the
1546 connection on. */
1547
1548 else
1549 {
1550 inblock.sock = outblock.sock = fileno(stdin);
1551 smtp_command = big_buffer;
1552 host->port = port; /* Record the port that was used */
1553 }
1554
1555 /* If TLS is available on this connection, whether continued or not, attempt to
1556 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
1557 send another EHLO - the server may give a different answer in secure mode. We
1558 use a separate buffer for reading the response to STARTTLS so that if it is
1559 negative, the original EHLO data is available for subsequent analysis, should
1560 the client not be required to use TLS. If the response is bad, copy the buffer
1561 for error analysis. */
1562
1563 #ifdef SUPPORT_TLS
1564 if ( tls_offered
1565 && !suppress_tls
1566 && verify_check_given_host(&ob->hosts_avoid_tls, host) != OK)
1567 {
1568 uschar buffer2[4096];
1569 if (smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") < 0)
1570 goto SEND_FAILED;
1571
1572 /* If there is an I/O error, transmission of this message is deferred. If
1573 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
1574 false, we also defer. However, if there is a temporary rejection of STARTTLS
1575 and tls_tempfail_tryclear is true, or if there is an outright rejection of
1576 STARTTLS, we carry on. This means we will try to send the message in clear,
1577 unless the host is in hosts_require_tls (tested below). */
1578
1579 if (!smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
1580 ob->command_timeout))
1581 {
1582 if (errno != 0 || buffer2[0] == 0 ||
1583 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
1584 {
1585 Ustrncpy(buffer, buffer2, sizeof(buffer));
1586 goto RESPONSE_FAILED;
1587 }
1588 }
1589
1590 /* STARTTLS accepted: try to negotiate a TLS session. */
1591
1592 else
1593 TLS_NEGOTIATE:
1594 {
1595 int rc = tls_client_start(inblock.sock, host, addrlist, tblock
1596 # ifdef EXPERIMENTAL_DANE
1597 , dane ? &tlsa_dnsa : NULL
1598 # endif
1599 );
1600
1601 /* TLS negotiation failed; give an error. From outside, this function may
1602 be called again to try in clear on a new connection, if the options permit
1603 it for this host. */
1604
1605 if (rc != OK)
1606 {
1607 # ifdef EXPERIMENTAL_DANE
1608 if (rc == DEFER && dane && !dane_required)
1609 {
1610 log_write(0, LOG_MAIN, "DANE attempt failed;"
1611 " trying CA-root TLS to %s [%s] (not in hosts_require_dane)",
1612 host->name, host->address);
1613 dane = FALSE;
1614 goto TLS_NEGOTIATE;
1615 }
1616 # endif
1617
1618 save_errno = ERRNO_TLSFAILURE;
1619 message = US"failure while setting up TLS session";
1620 send_quit = FALSE;
1621 goto TLS_FAILED;
1622 }
1623
1624 /* TLS session is set up */
1625
1626 for (addr = addrlist; addr != NULL; addr = addr->next)
1627 if (addr->transport_return == PENDING_DEFER)
1628 {
1629 addr->cipher = tls_out.cipher;
1630 addr->ourcert = tls_out.ourcert;
1631 addr->peercert = tls_out.peercert;
1632 addr->peerdn = tls_out.peerdn;
1633 addr->ocsp = tls_out.ocsp;
1634 }
1635 }
1636 }
1637
1638 /* if smtps, we'll have smtp_command set to something else; always safe to
1639 reset it here. */
1640 smtp_command = big_buffer;
1641
1642 /* If we started TLS, redo the EHLO/LHLO exchange over the secure channel. If
1643 helo_data is null, we are dealing with a connection that was passed from
1644 another process, and so we won't have expanded helo_data above. We have to
1645 expand it here. $sending_ip_address and $sending_port are set up right at the
1646 start of the Exim process (in exim.c). */
1647
1648 if (tls_out.active >= 0)
1649 {
1650 char *greeting_cmd;
1651 if (helo_data == NULL)
1652 {
1653 helo_data = expand_string(ob->helo_data);
1654 if (helo_data == NULL)
1655 {
1656 uschar *message = string_sprintf("failed to expand helo_data: %s",
1657 expand_string_message);
1658 set_errno(addrlist, ERRNO_EXPANDFAIL, message, DEFER, FALSE, NULL);
1659 yield = DEFER;
1660 goto SEND_QUIT;
1661 }
1662 }
1663
1664 /* For SMTPS we need to wait for the initial OK response. */
1665 if (smtps)
1666 {
1667 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1668 ob->command_timeout)) goto RESPONSE_FAILED;
1669 }
1670
1671 if (esmtp)
1672 greeting_cmd = "EHLO";
1673 else
1674 {
1675 greeting_cmd = "HELO";
1676 DEBUG(D_transport)
1677 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
1678 }
1679
1680 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n",
1681 lmtp? "LHLO" : greeting_cmd, helo_data) < 0)
1682 goto SEND_FAILED;
1683 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1684 ob->command_timeout))
1685 goto RESPONSE_FAILED;
1686 }
1687
1688 /* If the host is required to use a secure channel, ensure that we
1689 have one. */
1690
1691 else if (
1692 # ifdef EXPERIMENTAL_DANE
1693 dane ||
1694 # endif
1695 verify_check_given_host(&ob->hosts_require_tls, host) == OK
1696 )
1697 {
1698 save_errno = ERRNO_TLSREQUIRED;
1699 message = string_sprintf("a TLS session is required, but %s",
1700 tls_offered? "an attempt to start TLS failed" :
1701 "the server did not offer TLS support");
1702 goto TLS_FAILED;
1703 }
1704 #endif /*SUPPORT_TLS*/
1705
1706 /* If TLS is active, we have just started it up and re-done the EHLO command,
1707 so its response needs to be analyzed. If TLS is not active and this is a
1708 continued session down a previously-used socket, we haven't just done EHLO, so
1709 we skip this. */
1710
1711 if (continue_hostname == NULL
1712 #ifdef SUPPORT_TLS
1713 || tls_out.active >= 0
1714 #endif
1715 )
1716 {
1717 /* Set for IGNOREQUOTA if the response to LHLO specifies support and the
1718 lmtp_ignore_quota option was set. */
1719
1720 igquotstr = (lmtp && ob->lmtp_ignore_quota &&
1721 pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer, Ustrlen(CS buffer), 0,
1722 PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
1723
1724 /* If the response to EHLO specified support for the SIZE parameter, note
1725 this, provided size_addition is non-negative. */
1726
1727 smtp_use_size = esmtp && ob->size_addition >= 0 &&
1728 pcre_exec(regex_SIZE, NULL, CS buffer, Ustrlen(CS buffer), 0,
1729 PCRE_EOPT, NULL, 0) >= 0;
1730
1731 /* Note whether the server supports PIPELINING. If hosts_avoid_esmtp matched
1732 the current host, esmtp will be false, so PIPELINING can never be used. If
1733 the current host matches hosts_avoid_pipelining, don't do it. */
1734
1735 smtp_use_pipelining = esmtp
1736 && verify_check_given_host(&ob->hosts_avoid_pipelining, host) != OK
1737 && pcre_exec(regex_PIPELINING, NULL, CS buffer, Ustrlen(CS buffer), 0,
1738 PCRE_EOPT, NULL, 0) >= 0;
1739
1740 DEBUG(D_transport) debug_printf("%susing PIPELINING\n",
1741 smtp_use_pipelining? "" : "not ");
1742
1743 #ifndef DISABLE_PRDR
1744 prdr_offered = esmtp
1745 && pcre_exec(regex_PRDR, NULL, CS buffer, Ustrlen(CS buffer), 0,
1746 PCRE_EOPT, NULL, 0) >= 0
1747 && verify_check_given_host(&ob->hosts_try_prdr, host) == OK;
1748
1749 if (prdr_offered)
1750 {DEBUG(D_transport) debug_printf("PRDR usable\n");}
1751 #endif
1752
1753 /* Note if the server supports DSN */
1754 smtp_use_dsn = esmtp && pcre_exec(regex_DSN, NULL, CS buffer, (int)Ustrlen(CS buffer), 0,
1755 PCRE_EOPT, NULL, 0) >= 0;
1756 DEBUG(D_transport) debug_printf("use_dsn=%d\n", smtp_use_dsn);
1757
1758 /* Note if the response to EHLO specifies support for the AUTH extension.
1759 If it has, check that this host is one we want to authenticate to, and do
1760 the business. The host name and address must be available when the
1761 authenticator's client driver is running. */
1762
1763 switch (yield = smtp_auth(buffer, sizeof(buffer), addrlist, host,
1764 ob, esmtp, &inblock, &outblock))
1765 {
1766 default: goto SEND_QUIT;
1767 case OK: break;
1768 case FAIL_SEND: goto SEND_FAILED;
1769 case FAIL: goto RESPONSE_FAILED;
1770 }
1771 }
1772
1773 /* The setting up of the SMTP call is now complete. Any subsequent errors are
1774 message-specific. */
1775
1776 setting_up = FALSE;
1777
1778 /* If there is a filter command specified for this transport, we can now
1779 set it up. This cannot be done until the identify of the host is known. */
1780
1781 if (tblock->filter_command != NULL)
1782 {
1783 BOOL rc;
1784 uschar buffer[64];
1785 sprintf(CS buffer, "%.50s transport", tblock->name);
1786 rc = transport_set_up_command(&transport_filter_argv, tblock->filter_command,
1787 TRUE, DEFER, addrlist, buffer, NULL);
1788 transport_filter_timeout = tblock->filter_timeout;
1789
1790 /* On failure, copy the error to all addresses, abandon the SMTP call, and
1791 yield ERROR. */
1792
1793 if (!rc)
1794 {
1795 set_errno(addrlist->next, addrlist->basic_errno, addrlist->message, DEFER,
1796 FALSE, NULL);
1797 yield = ERROR;
1798 goto SEND_QUIT;
1799 }
1800 }
1801
1802
1803 /* For messages that have more than the maximum number of envelope recipients,
1804 we want to send several transactions down the same SMTP connection. (See
1805 comments in deliver.c as to how this reconciles, heuristically, with
1806 remote_max_parallel.) This optimization was added to Exim after the following
1807 code was already working. The simplest way to put it in without disturbing the
1808 code was to use a goto to jump back to this point when there is another
1809 transaction to handle. */
1810
1811 SEND_MESSAGE:
1812 sync_addr = first_addr;
1813 address_count = 0;
1814 ok = FALSE;
1815 send_rset = TRUE;
1816 completed_address = FALSE;
1817
1818
1819 /* Initiate a message transfer. If we know the receiving MTA supports the SIZE
1820 qualification, send it, adding something to the message size to allow for
1821 imprecision and things that get added en route. Exim keeps the number of lines
1822 in a message, so we can give an accurate value for the original message, but we
1823 need some additional to handle added headers. (Double "." characters don't get
1824 included in the count.) */
1825
1826 p = buffer;
1827 *p = 0;
1828
1829 if (smtp_use_size)
1830 {
1831 sprintf(CS p, " SIZE=%d", message_size+message_linecount+ob->size_addition);
1832 while (*p) p++;
1833 }
1834
1835 #ifndef DISABLE_PRDR
1836 prdr_active = FALSE;
1837 if (prdr_offered)
1838 {
1839 for (addr = first_addr; addr; addr = addr->next)
1840 if (addr->transport_return == PENDING_DEFER)
1841 {
1842 for (addr = addr->next; addr; addr = addr->next)
1843 if (addr->transport_return == PENDING_DEFER)
1844 { /* at least two recipients to send */
1845 prdr_active = TRUE;
1846 sprintf(CS p, " PRDR"); p += 5;
1847 break;
1848 }
1849 break;
1850 }
1851 }
1852 #endif
1853
1854 /* check if all addresses have lasthop flag */
1855 /* do not send RET and ENVID if true */
1856 dsn_all_lasthop = TRUE;
1857 for (addr = first_addr;
1858 address_count < max_rcpt && addr != NULL;
1859 addr = addr->next)
1860 if ((addr->dsn_flags & rf_dsnlasthop) != 1)
1861 dsn_all_lasthop = FALSE;
1862
1863 /* Add any DSN flags to the mail command */
1864
1865 if ((smtp_use_dsn) && (dsn_all_lasthop == FALSE))
1866 {
1867 if (dsn_ret == dsn_ret_hdrs)
1868 {
1869 Ustrcpy(p, " RET=HDRS");
1870 while (*p) p++;
1871 }
1872 else if (dsn_ret == dsn_ret_full)
1873 {
1874 Ustrcpy(p, " RET=FULL");
1875 while (*p) p++;
1876 }
1877 if (dsn_envid != NULL)
1878 {
1879 string_format(p, sizeof(buffer) - (p-buffer), " ENVID=%s", dsn_envid);
1880 while (*p) p++;
1881 }
1882 }
1883
1884 /* If an authenticated_sender override has been specified for this transport
1885 instance, expand it. If the expansion is forced to fail, and there was already
1886 an authenticated_sender for this message, the original value will be used.
1887 Other expansion failures are serious. An empty result is ignored, but there is
1888 otherwise no check - this feature is expected to be used with LMTP and other
1889 cases where non-standard addresses (e.g. without domains) might be required. */
1890
1891 if (smtp_mail_auth_str(p, sizeof(buffer) - (p-buffer), addrlist, ob))
1892 {
1893 yield = ERROR;
1894 goto SEND_QUIT;
1895 }
1896
1897 /* From here until we send the DATA command, we can make use of PIPELINING
1898 if the server host supports it. The code has to be able to check the responses
1899 at any point, for when the buffer fills up, so we write it totally generally.
1900 When PIPELINING is off, each command written reports that it has flushed the
1901 buffer. */
1902
1903 pending_MAIL = TRUE; /* The block starts with MAIL */
1904
1905 rc = smtp_write_command(&outblock, smtp_use_pipelining,
1906 "MAIL FROM:<%s>%s\r\n", return_path, buffer);
1907 mail_command = string_copy(big_buffer); /* Save for later error message */
1908
1909 switch(rc)
1910 {
1911 case -1: /* Transmission error */
1912 goto SEND_FAILED;
1913
1914 case +1: /* Block was sent */
1915 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1916 ob->command_timeout))
1917 {
1918 if (errno == 0 && buffer[0] == '4')
1919 {
1920 errno = ERRNO_MAIL4XX;
1921 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1922 }
1923 goto RESPONSE_FAILED;
1924 }
1925 pending_MAIL = FALSE;
1926 break;
1927 }
1928
1929 /* Pass over all the relevant recipient addresses for this host, which are the
1930 ones that have status PENDING_DEFER. If we are using PIPELINING, we can send
1931 several before we have to read the responses for those seen so far. This
1932 checking is done by a subroutine because it also needs to be done at the end.
1933 Send only up to max_rcpt addresses at a time, leaving first_addr pointing to
1934 the next one if not all are sent.
1935
1936 In the MUA wrapper situation, we want to flush the PIPELINING buffer for the
1937 last address because we want to abort if any recipients have any kind of
1938 problem, temporary or permanent. We know that all recipient addresses will have
1939 the PENDING_DEFER status, because only one attempt is ever made, and we know
1940 that max_rcpt will be large, so all addresses will be done at once. */
1941
1942 for (addr = first_addr;
1943 address_count < max_rcpt && addr != NULL;
1944 addr = addr->next)
1945 {
1946 int count;
1947 BOOL no_flush;
1948
1949 addr->dsn_aware = smtp_use_dsn ? dsn_support_yes : dsn_support_no;
1950
1951 if (addr->transport_return != PENDING_DEFER) continue;
1952
1953 address_count++;
1954 no_flush = smtp_use_pipelining && (!mua_wrapper || addr->next != NULL);
1955
1956 /* Add any DSN flags to the rcpt command and add to the sent string */
1957
1958 p = buffer;
1959 *p = 0;
1960
1961 if (smtp_use_dsn && (addr->dsn_flags & rf_dsnlasthop) != 1)
1962 {
1963 if ((addr->dsn_flags & rf_dsnflags) != 0)
1964 {
1965 int i;
1966 BOOL first = TRUE;
1967 Ustrcpy(p, " NOTIFY=");
1968 while (*p) p++;
1969 for (i = 0; i < 4; i++)
1970 if ((addr->dsn_flags & rf_list[i]) != 0)
1971 {
1972 if (!first) *p++ = ',';
1973 first = FALSE;
1974 Ustrcpy(p, rf_names[i]);
1975 while (*p) p++;
1976 }
1977 }
1978
1979 if (addr->dsn_orcpt != NULL)
1980 {
1981 string_format(p, sizeof(buffer) - (p-buffer), " ORCPT=%s",
1982 addr->dsn_orcpt);
1983 while (*p) p++;
1984 }
1985 }
1986
1987 /* Now send the RCPT command, and process outstanding responses when
1988 necessary. After a timeout on RCPT, we just end the function, leaving the
1989 yield as OK, because this error can often mean that there is a problem with
1990 just one address, so we don't want to delay the host. */
1991
1992 count = smtp_write_command(&outblock, no_flush, "RCPT TO:<%s>%s%s\r\n",
1993 transport_rcpt_address(addr, tblock->rcpt_include_affixes), igquotstr, buffer);
1994
1995 if (count < 0) goto SEND_FAILED;
1996 if (count > 0)
1997 {
1998 switch(sync_responses(first_addr, tblock->rcpt_include_affixes,
1999 &sync_addr, host, count, ob->address_retry_include_sender,
2000 pending_MAIL, 0, &inblock, ob->command_timeout, buffer,
2001 sizeof(buffer)))
2002 {
2003 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
2004 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
2005 break;
2006
2007 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
2008 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
2009 case 0: /* No 2xx or 5xx, but no probs */
2010 break;
2011
2012 case -1: goto END_OFF; /* Timeout on RCPT */
2013 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL error */
2014 }
2015 pending_MAIL = FALSE; /* Dealt with MAIL */
2016 }
2017 } /* Loop for next address */
2018
2019 /* If we are an MUA wrapper, abort if any RCPTs were rejected, either
2020 permanently or temporarily. We should have flushed and synced after the last
2021 RCPT. */
2022
2023 if (mua_wrapper)
2024 {
2025 address_item *badaddr;
2026 for (badaddr = first_addr; badaddr; badaddr = badaddr->next)
2027 if (badaddr->transport_return != PENDING_OK)
2028 {
2029 /*XXX could we find a better errno than 0 here? */
2030 set_errno(addrlist, 0, badaddr->message, FAIL,
2031 testflag(badaddr, af_pass_message), NULL);
2032 ok = FALSE;
2033 break;
2034 }
2035 }
2036
2037 /* If ok is TRUE, we know we have got at least one good recipient, and must now
2038 send DATA, but if it is FALSE (in the normal, non-wrapper case), we may still
2039 have a good recipient buffered up if we are pipelining. We don't want to waste
2040 time sending DATA needlessly, so we only send it if either ok is TRUE or if we
2041 are pipelining. The responses are all handled by sync_responses(). */
2042
2043 if (ok || (smtp_use_pipelining && !mua_wrapper))
2044 {
2045 int count = smtp_write_command(&outblock, FALSE, "DATA\r\n");
2046 if (count < 0) goto SEND_FAILED;
2047 switch(sync_responses(first_addr, tblock->rcpt_include_affixes, &sync_addr,
2048 host, count, ob->address_retry_include_sender, pending_MAIL,
2049 ok? +1 : -1, &inblock, ob->command_timeout, buffer, sizeof(buffer)))
2050 {
2051 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
2052 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
2053 break;
2054
2055 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
2056 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
2057 case 0: break; /* No 2xx or 5xx, but no probs */
2058
2059 case -1: goto END_OFF; /* Timeout on RCPT */
2060 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */
2061 }
2062 }
2063
2064 /* Save the first address of the next batch. */
2065
2066 first_addr = addr;
2067
2068 /* If there were no good recipients (but otherwise there have been no
2069 problems), just set ok TRUE, since we have handled address-specific errors
2070 already. Otherwise, it's OK to send the message. Use the check/escape mechanism
2071 for handling the SMTP dot-handling protocol, flagging to apply to headers as
2072 well as body. Set the appropriate timeout value to be used for each chunk.
2073 (Haven't been able to make it work using select() for writing yet.) */
2074
2075 if (!ok) ok = TRUE; else
2076 {
2077 sigalrm_seen = FALSE;
2078 transport_write_timeout = ob->data_timeout;
2079 smtp_command = US"sending data block"; /* For error messages */
2080 DEBUG(D_transport|D_v)
2081 debug_printf(" SMTP>> writing message and terminating \".\"\n");
2082 transport_count = 0;
2083
2084 #ifndef DISABLE_DKIM
2085 ok = dkim_transport_write_message(addrlist, inblock.sock,
2086 topt_use_crlf | topt_end_dot | topt_escape_headers |
2087 (tblock->body_only? topt_no_headers : 0) |
2088 (tblock->headers_only? topt_no_body : 0) |
2089 (tblock->return_path_add? topt_add_return_path : 0) |
2090 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
2091 (tblock->envelope_to_add? topt_add_envelope_to : 0),
2092 0, /* No size limit */
2093 tblock->add_headers, tblock->remove_headers,
2094 US".", US"..", /* Escaping strings */
2095 tblock->rewrite_rules, tblock->rewrite_existflags,
2096 ob->dkim_private_key, ob->dkim_domain, ob->dkim_selector,
2097 ob->dkim_canon, ob->dkim_strict, ob->dkim_sign_headers
2098 );
2099 #else
2100 ok = transport_write_message(addrlist, inblock.sock,
2101 topt_use_crlf | topt_end_dot | topt_escape_headers |
2102 (tblock->body_only? topt_no_headers : 0) |
2103 (tblock->headers_only? topt_no_body : 0) |
2104 (tblock->return_path_add? topt_add_return_path : 0) |
2105 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
2106 (tblock->envelope_to_add? topt_add_envelope_to : 0),
2107 0, /* No size limit */
2108 tblock->add_headers, tblock->remove_headers,
2109 US".", US"..", /* Escaping strings */
2110 tblock->rewrite_rules, tblock->rewrite_existflags);
2111 #endif
2112
2113 /* transport_write_message() uses write() because it is called from other
2114 places to write to non-sockets. This means that under some OS (e.g. Solaris)
2115 it can exit with "Broken pipe" as its error. This really means that the
2116 socket got closed at the far end. */
2117
2118 transport_write_timeout = 0; /* for subsequent transports */
2119
2120 /* Failure can either be some kind of I/O disaster (including timeout),
2121 or the failure of a transport filter or the expansion of added headers. */
2122
2123 if (!ok)
2124 {
2125 buffer[0] = 0; /* There hasn't been a response */
2126 goto RESPONSE_FAILED;
2127 }
2128
2129 /* We used to send the terminating "." explicitly here, but because of
2130 buffering effects at both ends of TCP/IP connections, you don't gain
2131 anything by keeping it separate, so it might as well go in the final
2132 data buffer for efficiency. This is now done by setting the topt_end_dot
2133 flag above. */
2134
2135 smtp_command = US"end of data";
2136
2137 #ifndef DISABLE_PRDR
2138 /* For PRDR we optionally get a partial-responses warning
2139 * followed by the individual responses, before going on with
2140 * the overall response. If we don't get the warning then deal
2141 * with per non-PRDR. */
2142 if(prdr_active)
2143 {
2144 ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '3',
2145 ob->final_timeout);
2146 if (!ok && errno == 0)
2147 switch(buffer[0])
2148 {
2149 case '2': prdr_active = FALSE;
2150 ok = TRUE;
2151 break;
2152 case '4': errno = ERRNO_DATA4XX;
2153 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
2154 break;
2155 }
2156 }
2157 else
2158 #endif
2159
2160 /* For non-PRDR SMTP, we now read a single response that applies to the
2161 whole message. If it is OK, then all the addresses have been delivered. */
2162
2163 if (!lmtp)
2164 {
2165 ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2166 ob->final_timeout);
2167 if (!ok && errno == 0 && buffer[0] == '4')
2168 {
2169 errno = ERRNO_DATA4XX;
2170 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
2171 }
2172 }
2173
2174 /* For LMTP, we get back a response for every RCPT command that we sent;
2175 some may be accepted and some rejected. For those that get a response, their
2176 status is fixed; any that are accepted have been handed over, even if later
2177 responses crash - at least, that's how I read RFC 2033.
2178
2179 If all went well, mark the recipient addresses as completed, record which
2180 host/IPaddress they were delivered to, and cut out RSET when sending another
2181 message down the same channel. Write the completed addresses to the journal
2182 now so that they are recorded in case there is a crash of hardware or
2183 software before the spool gets updated. Also record the final SMTP
2184 confirmation if needed (for SMTP only). */
2185
2186 if (ok)
2187 {
2188 int flag = '=';
2189 int delivery_time = (int)(time(NULL) - start_delivery_time);
2190 int len;
2191 uschar *conf = NULL;
2192 send_rset = FALSE;
2193
2194 /* Set up confirmation if needed - applies only to SMTP */
2195
2196 if (
2197 #ifndef EXPERIMENTAL_EVENT
2198 (log_extra_selector & LX_smtp_confirmation) != 0 &&
2199 #endif
2200 !lmtp
2201 )
2202 {
2203 uschar *s = string_printing(buffer);
2204 conf = (s == buffer)? (uschar *)string_copy(s) : s;
2205 }
2206
2207 /* Process all transported addresses - for LMTP or PRDR, read a status for
2208 each one. */
2209
2210 for (addr = addrlist; addr != first_addr; addr = addr->next)
2211 {
2212 if (addr->transport_return != PENDING_OK) continue;
2213
2214 /* LMTP - if the response fails badly (e.g. timeout), use it for all the
2215 remaining addresses. Otherwise, it's a return code for just the one
2216 address. For temporary errors, add a retry item for the address so that
2217 it doesn't get tried again too soon. */
2218
2219 #ifndef DISABLE_PRDR
2220 if (lmtp || prdr_active)
2221 #else
2222 if (lmtp)
2223 #endif
2224 {
2225 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2226 ob->final_timeout))
2227 {
2228 if (errno != 0 || buffer[0] == 0) goto RESPONSE_FAILED;
2229 addr->message = string_sprintf(
2230 #ifndef DISABLE_PRDR
2231 "%s error after %s: %s", prdr_active ? "PRDR":"LMTP",
2232 #else
2233 "LMTP error after %s: %s",
2234 #endif
2235 big_buffer, string_printing(buffer));
2236 setflag(addr, af_pass_message); /* Allow message to go to user */
2237 if (buffer[0] == '5')
2238 addr->transport_return = FAIL;
2239 else
2240 {
2241 errno = ERRNO_DATA4XX;
2242 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
2243 addr->transport_return = DEFER;
2244 #ifndef DISABLE_PRDR
2245 if (!prdr_active)
2246 #endif
2247 retry_add_item(addr, addr->address_retry_key, 0);
2248 }
2249 continue;
2250 }
2251 completed_address = TRUE; /* NOW we can set this flag */
2252 if ((log_extra_selector & LX_smtp_confirmation) != 0)
2253 {
2254 uschar *s = string_printing(buffer);
2255 conf = (s == buffer)? (uschar *)string_copy(s) : s;
2256 }
2257 }
2258
2259 /* SMTP, or success return from LMTP for this address. Pass back the
2260 actual host that was used. */
2261
2262 addr->transport_return = OK;
2263 addr->more_errno = delivery_time;
2264 addr->host_used = host;
2265 addr->special_action = flag;
2266 addr->message = conf;
2267 #ifndef DISABLE_PRDR
2268 if (prdr_active) addr->flags |= af_prdr_used;
2269 #endif
2270 flag = '-';
2271
2272 #ifndef DISABLE_PRDR
2273 if (!prdr_active)
2274 #endif
2275 {
2276 /* Update the journal. For homonymic addresses, use the base address plus
2277 the transport name. See lots of comments in deliver.c about the reasons
2278 for the complications when homonyms are involved. Just carry on after
2279 write error, as it may prove possible to update the spool file later. */
2280
2281 if (testflag(addr, af_homonym))
2282 sprintf(CS buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
2283 else
2284 sprintf(CS buffer, "%.500s\n", addr->unique);
2285
2286 DEBUG(D_deliver) debug_printf("journalling %s", buffer);
2287 len = Ustrlen(CS buffer);
2288 if (write(journal_fd, buffer, len) != len)
2289 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
2290 "%s: %s", buffer, strerror(errno));
2291 }
2292 }
2293
2294 #ifndef DISABLE_PRDR
2295 if (prdr_active)
2296 {
2297 /* PRDR - get the final, overall response. For any non-success
2298 upgrade all the address statuses. */
2299 ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2300 ob->final_timeout);
2301 if (!ok)
2302 {
2303 if(errno == 0 && buffer[0] == '4')
2304 {
2305 errno = ERRNO_DATA4XX;
2306 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
2307 }
2308 for (addr = addrlist; addr != first_addr; addr = addr->next)
2309 if (buffer[0] == '5' || addr->transport_return == OK)
2310 addr->transport_return = PENDING_OK; /* allow set_errno action */
2311 goto RESPONSE_FAILED;
2312 }
2313
2314 /* Update the journal, or setup retry. */
2315 for (addr = addrlist; addr != first_addr; addr = addr->next)
2316 if (addr->transport_return == OK)
2317 {
2318 if (testflag(addr, af_homonym))
2319 sprintf(CS buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
2320 else
2321 sprintf(CS buffer, "%.500s\n", addr->unique);
2322
2323 DEBUG(D_deliver) debug_printf("journalling(PRDR) %s", buffer);
2324 len = Ustrlen(CS buffer);
2325 if (write(journal_fd, buffer, len) != len)
2326 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
2327 "%s: %s", buffer, strerror(errno));
2328 }
2329 else if (addr->transport_return == DEFER)
2330 retry_add_item(addr, addr->address_retry_key, -2);
2331 }
2332 #endif
2333
2334 /* Ensure the journal file is pushed out to disk. */
2335
2336 if (EXIMfsync(journal_fd) < 0)
2337 log_write(0, LOG_MAIN|LOG_PANIC, "failed to fsync journal: %s",
2338 strerror(errno));
2339 }
2340 }
2341
2342
2343 /* Handle general (not specific to one address) failures here. The value of ok
2344 is used to skip over this code on the falling through case. A timeout causes a
2345 deferral. Other errors may defer or fail according to the response code, and
2346 may set up a special errno value, e.g. after connection chopped, which is
2347 assumed if errno == 0 and there is no text in the buffer. If control reaches
2348 here during the setting up phase (i.e. before MAIL FROM) then always defer, as
2349 the problem is not related to this specific message. */
2350
2351 if (!ok)
2352 {
2353 int code;
2354
2355 RESPONSE_FAILED:
2356 save_errno = errno;
2357 message = NULL;
2358 send_quit = check_response(host, &save_errno, addrlist->more_errno,
2359 buffer, &code, &message, &pass_message);
2360 goto FAILED;
2361
2362 SEND_FAILED:
2363 save_errno = errno;
2364 code = '4';
2365 message = US string_sprintf("send() to %s [%s] failed: %s",
2366 host->name, host->address, strerror(save_errno));
2367 send_quit = FALSE;
2368 goto FAILED;
2369
2370 /* This label is jumped to directly when a TLS negotiation has failed,
2371 or was not done for a host for which it is required. Values will be set
2372 in message and save_errno, and setting_up will always be true. Treat as
2373 a temporary error. */
2374
2375 #ifdef SUPPORT_TLS
2376 TLS_FAILED:
2377 code = '4';
2378 #endif
2379
2380 /* If the failure happened while setting up the call, see if the failure was
2381 a 5xx response (this will either be on connection, or following HELO - a 5xx
2382 after EHLO causes it to try HELO). If so, fail all addresses, as this host is
2383 never going to accept them. For other errors during setting up (timeouts or
2384 whatever), defer all addresses, and yield DEFER, so that the host is not
2385 tried again for a while. */
2386
2387 FAILED:
2388 ok = FALSE; /* For when reached by GOTO */
2389
2390 if (setting_up)
2391 {
2392 if (code == '5')
2393 set_errno(addrlist, save_errno, message, FAIL, pass_message, host);
2394 else
2395 {
2396 set_errno(addrlist, save_errno, message, DEFER, pass_message, host);
2397 yield = DEFER;
2398 }
2399 }
2400
2401 /* We want to handle timeouts after MAIL or "." and loss of connection after
2402 "." specially. They can indicate a problem with the sender address or with
2403 the contents of the message rather than a real error on the connection. These
2404 cases are treated in the same way as a 4xx response. This next bit of code
2405 does the classification. */
2406
2407 else
2408 {
2409 BOOL message_error;
2410
2411 switch(save_errno)
2412 {
2413 case 0:
2414 case ERRNO_MAIL4XX:
2415 case ERRNO_DATA4XX:
2416 message_error = TRUE;
2417 break;
2418
2419 case ETIMEDOUT:
2420 message_error = Ustrncmp(smtp_command,"MAIL",4) == 0 ||
2421 Ustrncmp(smtp_command,"end ",4) == 0;
2422 break;
2423
2424 case ERRNO_SMTPCLOSED:
2425 message_error = Ustrncmp(smtp_command,"end ",4) == 0;
2426 break;
2427
2428 default:
2429 message_error = FALSE;
2430 break;
2431 }
2432
2433 /* Handle the cases that are treated as message errors. These are:
2434
2435 (a) negative response or timeout after MAIL
2436 (b) negative response after DATA
2437 (c) negative response or timeout or dropped connection after "."
2438
2439 It won't be a negative response or timeout after RCPT, as that is dealt
2440 with separately above. The action in all cases is to set an appropriate
2441 error code for all the addresses, but to leave yield set to OK because the
2442 host itself has not failed. Of course, it might in practice have failed
2443 when we've had a timeout, but if so, we'll discover that at the next
2444 delivery attempt. For a temporary error, set the message_defer flag, and
2445 write to the logs for information if this is not the last host. The error
2446 for the last host will be logged as part of the address's log line. */
2447
2448 if (message_error)
2449 {
2450 if (mua_wrapper) code = '5'; /* Force hard failure in wrapper mode */
2451 set_errno(addrlist, save_errno, message, (code == '5')? FAIL : DEFER,
2452 pass_message, host);
2453
2454 /* If there's an errno, the message contains just the identity of
2455 the host. */
2456
2457 if (code != '5') /* Anything other than 5 is treated as temporary */
2458 {
2459 if (save_errno > 0)
2460 message = US string_sprintf("%s: %s", message, strerror(save_errno));
2461 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", message);
2462 msglog_line(host, message);
2463 *message_defer = TRUE;
2464 }
2465 }
2466
2467 /* Otherwise, we have an I/O error or a timeout other than after MAIL or
2468 ".", or some other transportation error. We defer all addresses and yield
2469 DEFER, except for the case of failed add_headers expansion, or a transport
2470 filter failure, when the yield should be ERROR, to stop it trying other
2471 hosts. */
2472
2473 else
2474 {
2475 yield = (save_errno == ERRNO_CHHEADER_FAIL ||
2476 save_errno == ERRNO_FILTER_FAIL)? ERROR : DEFER;
2477 set_errno(addrlist, save_errno, message, DEFER, pass_message, host);
2478 }
2479 }
2480 }
2481
2482
2483 /* If all has gone well, send_quit will be set TRUE, implying we can end the
2484 SMTP session tidily. However, if there were too many addresses to send in one
2485 message (indicated by first_addr being non-NULL) we want to carry on with the
2486 rest of them. Also, it is desirable to send more than one message down the SMTP
2487 connection if there are several waiting, provided we haven't already sent so
2488 many as to hit the configured limit. The function transport_check_waiting looks
2489 for a waiting message and returns its id. Then transport_pass_socket tries to
2490 set up a continued delivery by passing the socket on to another process. The
2491 variable send_rset is FALSE if a message has just been successfully transfered.
2492
2493 If we are already sending down a continued channel, there may be further
2494 addresses not yet delivered that are aimed at the same host, but which have not
2495 been passed in this run of the transport. In this case, continue_more will be
2496 true, and all we should do is send RSET if necessary, and return, leaving the
2497 channel open.
2498
2499 However, if no address was disposed of, i.e. all addresses got 4xx errors, we
2500 do not want to continue with other messages down the same channel, because that
2501 can lead to looping between two or more messages, all with the same,
2502 temporarily failing address(es). [The retry information isn't updated yet, so
2503 new processes keep on trying.] We probably also don't want to try more of this
2504 message's addresses either.
2505
2506 If we have started a TLS session, we have to end it before passing the
2507 connection to a new process. However, not all servers can handle this (Exim
2508 can), so we do not pass such a connection on if the host matches
2509 hosts_nopass_tls. */
2510
2511 DEBUG(D_transport)
2512 debug_printf("ok=%d send_quit=%d send_rset=%d continue_more=%d "
2513 "yield=%d first_address is %sNULL\n", ok, send_quit, send_rset,
2514 continue_more, yield, (first_addr == NULL)? "":"not ");
2515
2516 if (completed_address && ok && send_quit)
2517 {
2518 BOOL more;
2519 if ( first_addr != NULL
2520 || continue_more
2521 || ( ( tls_out.active < 0
2522 || verify_check_given_host(&ob->hosts_nopass_tls, host) != OK
2523 )
2524 &&
2525 transport_check_waiting(tblock->name, host->name,
2526 tblock->connection_max_messages, new_message_id, &more)
2527 ) )
2528 {
2529 uschar *msg;
2530 BOOL pass_message;
2531
2532 if (send_rset)
2533 {
2534 if (! (ok = smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0))
2535 {
2536 msg = US string_sprintf("send() to %s [%s] failed: %s", host->name,
2537 host->address, strerror(save_errno));
2538 send_quit = FALSE;
2539 }
2540 else if (! (ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2541 ob->command_timeout)))
2542 {
2543 int code;
2544 send_quit = check_response(host, &errno, 0, buffer, &code, &msg,
2545 &pass_message);
2546 if (!send_quit)
2547 {
2548 DEBUG(D_transport) debug_printf("H=%s [%s] %s\n",
2549 host->name, host->address, msg);
2550 }
2551 }
2552 }
2553
2554 /* Either RSET was not needed, or it succeeded */
2555
2556 if (ok)
2557 {
2558 if (first_addr != NULL) /* More addresses still to be sent */
2559 { /* in this run of the transport */
2560 continue_sequence++; /* Causes * in logging */
2561 goto SEND_MESSAGE;
2562 }
2563 if (continue_more) return yield; /* More addresses for another run */
2564
2565 /* Pass the socket to a new Exim process. Before doing so, we must shut
2566 down TLS. Not all MTAs allow for the continuation of the SMTP session
2567 when TLS is shut down. We test for this by sending a new EHLO. If we
2568 don't get a good response, we don't attempt to pass the socket on. */
2569
2570 #ifdef SUPPORT_TLS
2571 if (tls_out.active >= 0)
2572 {
2573 tls_close(FALSE, TRUE);
2574 if (smtps)
2575 ok = FALSE;
2576 else
2577 ok = smtp_write_command(&outblock,FALSE,"EHLO %s\r\n",helo_data) >= 0 &&
2578 smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2579 ob->command_timeout);
2580 }
2581 #endif
2582
2583 /* If the socket is successfully passed, we musn't send QUIT (or
2584 indeed anything!) from here. */
2585
2586 if (ok && transport_pass_socket(tblock->name, host->name, host->address,
2587 new_message_id, inblock.sock))
2588 {
2589 send_quit = FALSE;
2590 }
2591 }
2592
2593 /* If RSET failed and there are addresses left, they get deferred. */
2594
2595 else set_errno(first_addr, errno, msg, DEFER, FALSE, host);
2596 }
2597 }
2598
2599 /* End off tidily with QUIT unless the connection has died or the socket has
2600 been passed to another process. There has been discussion on the net about what
2601 to do after sending QUIT. The wording of the RFC suggests that it is necessary
2602 to wait for a response, but on the other hand, there isn't anything one can do
2603 with an error response, other than log it. Exim used to do that. However,
2604 further discussion suggested that it is positively advantageous not to wait for
2605 the response, but to close the session immediately. This is supposed to move
2606 the TCP/IP TIME_WAIT state from the server to the client, thereby removing some
2607 load from the server. (Hosts that are both servers and clients may not see much
2608 difference, of course.) Further discussion indicated that this was safe to do
2609 on Unix systems which have decent implementations of TCP/IP that leave the
2610 connection around for a while (TIME_WAIT) after the application has gone away.
2611 This enables the response sent by the server to be properly ACKed rather than
2612 timed out, as can happen on broken TCP/IP implementations on other OS.
2613
2614 This change is being made on 31-Jul-98. After over a year of trouble-free
2615 operation, the old commented-out code was removed on 17-Sep-99. */
2616
2617 SEND_QUIT:
2618 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
2619
2620 END_OFF:
2621
2622 #ifdef SUPPORT_TLS
2623 tls_close(FALSE, TRUE);
2624 #endif
2625
2626 /* Close the socket, and return the appropriate value, first setting
2627 works because the NULL setting is passed back to the calling process, and
2628 remote_max_parallel is forced to 1 when delivering over an existing connection,
2629
2630 If all went well and continue_more is set, we shouldn't actually get here if
2631 there are further addresses, as the return above will be taken. However,
2632 writing RSET might have failed, or there may be other addresses whose hosts are
2633 specified in the transports, and therefore not visible at top level, in which
2634 case continue_more won't get set. */
2635
2636 (void)close(inblock.sock);
2637
2638 #ifdef EXPERIMENTAL_EVENT
2639 (void) event_raise(tblock->event_action, US"tcp:close", NULL);
2640 #endif
2641
2642 continue_transport = NULL;
2643 continue_hostname = NULL;
2644 return yield;
2645 }
2646
2647
2648
2649
2650 /*************************************************
2651 * Closedown entry point *
2652 *************************************************/
2653
2654 /* This function is called when exim is passed an open smtp channel
2655 from another incarnation, but the message which it has been asked
2656 to deliver no longer exists. The channel is on stdin.
2657
2658 We might do fancy things like looking for another message to send down
2659 the channel, but if the one we sought has gone, it has probably been
2660 delivered by some other process that itself will seek further messages,
2661 so just close down our connection.
2662
2663 Argument: pointer to the transport instance block
2664 Returns: nothing
2665 */
2666
2667 void
2668 smtp_transport_closedown(transport_instance *tblock)
2669 {
2670 smtp_transport_options_block *ob =
2671 (smtp_transport_options_block *)(tblock->options_block);
2672 smtp_inblock inblock;
2673 smtp_outblock outblock;
2674 uschar buffer[256];
2675 uschar inbuffer[4096];
2676 uschar outbuffer[16];
2677
2678 inblock.sock = fileno(stdin);
2679 inblock.buffer = inbuffer;
2680 inblock.buffersize = sizeof(inbuffer);
2681 inblock.ptr = inbuffer;
2682 inblock.ptrend = inbuffer;
2683
2684 outblock.sock = inblock.sock;
2685 outblock.buffersize = sizeof(outbuffer);
2686 outblock.buffer = outbuffer;
2687 outblock.ptr = outbuffer;
2688 outblock.cmd_count = 0;
2689 outblock.authenticating = FALSE;
2690
2691 (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
2692 (void)smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2693 ob->command_timeout);
2694 (void)close(inblock.sock);
2695 }
2696
2697
2698
2699 /*************************************************
2700 * Prepare addresses for delivery *
2701 *************************************************/
2702
2703 /* This function is called to flush out error settings from previous delivery
2704 attempts to other hosts. It also records whether we got here via an MX record
2705 or not in the more_errno field of the address. We are interested only in
2706 addresses that are still marked DEFER - others may have got delivered to a
2707 previously considered IP address. Set their status to PENDING_DEFER to indicate
2708 which ones are relevant this time.
2709
2710 Arguments:
2711 addrlist the list of addresses
2712 host the host we are delivering to
2713
2714 Returns: the first address for this delivery
2715 */
2716
2717 static address_item *
2718 prepare_addresses(address_item *addrlist, host_item *host)
2719 {
2720 address_item *first_addr = NULL;
2721 address_item *addr;
2722 for (addr = addrlist; addr != NULL; addr = addr->next)
2723 if (addr->transport_return == DEFER)
2724 {
2725 if (first_addr == NULL) first_addr = addr;
2726 addr->transport_return = PENDING_DEFER;
2727 addr->basic_errno = 0;
2728 addr->more_errno = (host->mx >= 0)? 'M' : 'A';
2729 addr->message = NULL;
2730 #ifdef SUPPORT_TLS
2731 addr->cipher = NULL;
2732 addr->ourcert = NULL;
2733 addr->peercert = NULL;
2734 addr->peerdn = NULL;
2735 addr->ocsp = OCSP_NOT_REQ;
2736 #endif
2737 }
2738 return first_addr;
2739 }
2740
2741
2742
2743 /*************************************************
2744 * Main entry point *
2745 *************************************************/
2746
2747 /* See local README for interface details. As this is a remote transport, it is
2748 given a chain of addresses to be delivered in one connection, if possible. It
2749 always returns TRUE, indicating that each address has its own independent
2750 status set, except if there is a setting up problem, in which case it returns
2751 FALSE. */
2752
2753 BOOL
2754 smtp_transport_entry(
2755 transport_instance *tblock, /* data for this instantiation */
2756 address_item *addrlist) /* addresses we are working on */
2757 {
2758 int cutoff_retry;
2759 int port;
2760 int hosts_defer = 0;
2761 int hosts_fail = 0;
2762 int hosts_looked_up = 0;
2763 int hosts_retry = 0;
2764 int hosts_serial = 0;
2765 int hosts_total = 0;
2766 int total_hosts_tried = 0;
2767 address_item *addr;
2768 BOOL expired = TRUE;
2769 BOOL continuing = continue_hostname != NULL;
2770 uschar *expanded_hosts = NULL;
2771 uschar *pistring;
2772 uschar *tid = string_sprintf("%s transport", tblock->name);
2773 smtp_transport_options_block *ob =
2774 (smtp_transport_options_block *)(tblock->options_block);
2775 host_item *hostlist = addrlist->host_list;
2776 host_item *host = NULL;
2777
2778 DEBUG(D_transport)
2779 {
2780 debug_printf("%s transport entered\n", tblock->name);
2781 for (addr = addrlist; addr != NULL; addr = addr->next)
2782 debug_printf(" %s\n", addr->address);
2783 if (continuing) debug_printf("already connected to %s [%s]\n",
2784 continue_hostname, continue_host_address);
2785 }
2786
2787 /* Set the flag requesting that these hosts be added to the waiting
2788 database if the delivery fails temporarily or if we are running with
2789 queue_smtp or a 2-stage queue run. This gets unset for certain
2790 kinds of error, typically those that are specific to the message. */
2791
2792 update_waiting = TRUE;
2793
2794 /* If a host list is not defined for the addresses - they must all have the
2795 same one in order to be passed to a single transport - or if the transport has
2796 a host list with hosts_override set, use the host list supplied with the
2797 transport. It is an error for this not to exist. */
2798
2799 if (hostlist == NULL || (ob->hosts_override && ob->hosts != NULL))
2800 {
2801 if (ob->hosts == NULL)
2802 {
2803 addrlist->message = string_sprintf("%s transport called with no hosts set",
2804 tblock->name);
2805 addrlist->transport_return = PANIC;
2806 return FALSE; /* Only top address has status */
2807 }
2808
2809 DEBUG(D_transport) debug_printf("using the transport's hosts: %s\n",
2810 ob->hosts);
2811
2812 /* If the transport's host list contains no '$' characters, and we are not
2813 randomizing, it is fixed and therefore a chain of hosts can be built once
2814 and for all, and remembered for subsequent use by other calls to this
2815 transport. If, on the other hand, the host list does contain '$', or we are
2816 randomizing its order, we have to rebuild it each time. In the fixed case,
2817 as the hosts string will never be used again, it doesn't matter that we
2818 replace all the : characters with zeros. */
2819
2820 if (ob->hostlist == NULL)
2821 {
2822 uschar *s = ob->hosts;
2823
2824 if (Ustrchr(s, '$') != NULL)
2825 {
2826 if (!(expanded_hosts = expand_string(s)))
2827 {
2828 addrlist->message = string_sprintf("failed to expand list of hosts "
2829 "\"%s\" in %s transport: %s", s, tblock->name, expand_string_message);
2830 addrlist->transport_return = search_find_defer? DEFER : PANIC;
2831 return FALSE; /* Only top address has status */
2832 }
2833 DEBUG(D_transport) debug_printf("expanded list of hosts \"%s\" to "
2834 "\"%s\"\n", s, expanded_hosts);
2835 s = expanded_hosts;
2836 }
2837 else
2838 if (ob->hosts_randomize) s = expanded_hosts = string_copy(s);
2839
2840 host_build_hostlist(&hostlist, s, ob->hosts_randomize);
2841
2842 /* Check that the expansion yielded something useful. */
2843 if (hostlist == NULL)
2844 {
2845 addrlist->message =
2846 string_sprintf("%s transport has empty hosts setting", tblock->name);
2847 addrlist->transport_return = PANIC;
2848 return FALSE; /* Only top address has status */
2849 }
2850
2851 /* If there was no expansion of hosts, save the host list for
2852 next time. */
2853
2854 if (!expanded_hosts) ob->hostlist = hostlist;
2855 }
2856
2857 /* This is not the first time this transport has been run in this delivery;
2858 the host list was built previously. */
2859
2860 else hostlist = ob->hostlist;
2861 }
2862
2863 /* The host list was supplied with the address. If hosts_randomize is set, we
2864 must sort it into a random order if it did not come from MX records and has not
2865 already been randomized (but don't bother if continuing down an existing
2866 connection). */
2867
2868 else if (ob->hosts_randomize && hostlist->mx == MX_NONE && !continuing)
2869 {
2870 host_item *newlist = NULL;
2871 while (hostlist != NULL)
2872 {
2873 host_item *h = hostlist;
2874 hostlist = hostlist->next;
2875
2876 h->sort_key = random_number(100);
2877
2878 if (newlist == NULL)
2879 {
2880 h->next = NULL;
2881 newlist = h;
2882 }
2883 else if (h->sort_key < newlist->sort_key)
2884 {
2885 h->next = newlist;
2886 newlist = h;
2887 }
2888 else
2889 {
2890 host_item *hh = newlist;
2891 while (hh->next != NULL)
2892 {
2893 if (h->sort_key < hh->next->sort_key) break;
2894 hh = hh->next;
2895 }
2896 h->next = hh->next;
2897 hh->next = h;
2898 }
2899 }
2900
2901 hostlist = addrlist->host_list = newlist;
2902 }
2903
2904
2905 /* Sort out the default port. */
2906
2907 if (!smtp_get_port(ob->port, addrlist, &port, tid)) return FALSE;
2908
2909
2910 /* For each host-plus-IP-address on the list:
2911
2912 . If this is a continued delivery and the host isn't the one with the
2913 current connection, skip.
2914
2915 . If the status is unusable (i.e. previously failed or retry checked), skip.
2916
2917 . If no IP address set, get the address, either by turning the name into
2918 an address, calling gethostbyname if gethostbyname is on, or by calling
2919 the DNS. The DNS may yield multiple addresses, in which case insert the
2920 extra ones into the list.
2921
2922 . Get the retry data if not previously obtained for this address and set the
2923 field which remembers the state of this address. Skip if the retry time is
2924 not reached. If not, remember whether retry data was found. The retry string
2925 contains both the name and the IP address.
2926
2927 . Scan the list of addresses and mark those whose status is DEFER as
2928 PENDING_DEFER. These are the only ones that will be processed in this cycle
2929 of the hosts loop.
2930
2931 . Make a delivery attempt - addresses marked PENDING_DEFER will be tried.
2932 Some addresses may be successfully delivered, others may fail, and yet
2933 others may get temporary errors and so get marked DEFER.
2934
2935 . The return from the delivery attempt is OK if a connection was made and a
2936 valid SMTP dialogue was completed. Otherwise it is DEFER.
2937
2938 . If OK, add a "remove" retry item for this host/IPaddress, if any.
2939
2940 . If fail to connect, or other defer state, add a retry item.
2941
2942 . If there are any addresses whose status is still DEFER, carry on to the
2943 next host/IPaddress, unless we have tried the number of hosts given
2944 by hosts_max_try or hosts_max_try_hardlimit; otherwise return. Note that
2945 there is some fancy logic for hosts_max_try that means its limit can be
2946 overstepped in some circumstances.
2947
2948 If we get to the end of the list, all hosts have deferred at least one address,
2949 or not reached their retry times. If delay_after_cutoff is unset, it requests a
2950 delivery attempt to those hosts whose last try was before the arrival time of
2951 the current message. To cope with this, we have to go round the loop a second
2952 time. After that, set the status and error data for any addresses that haven't
2953 had it set already. */
2954
2955 for (cutoff_retry = 0; expired &&
2956 cutoff_retry < ((ob->delay_after_cutoff)? 1 : 2);
2957 cutoff_retry++)
2958 {
2959 host_item *nexthost = NULL;
2960 int unexpired_hosts_tried = 0;
2961
2962 for (host = hostlist;
2963 host != NULL &&
2964 unexpired_hosts_tried < ob->hosts_max_try &&
2965 total_hosts_tried < ob->hosts_max_try_hardlimit;
2966 host = nexthost)
2967 {
2968 int rc;
2969 int host_af;
2970 uschar *rs;
2971 BOOL serialized = FALSE;
2972 BOOL host_is_expired = FALSE;
2973 BOOL message_defer = FALSE;
2974 BOOL ifchanges = FALSE;
2975 BOOL some_deferred = FALSE;
2976 address_item *first_addr = NULL;
2977 uschar *interface = NULL;
2978 uschar *retry_host_key = NULL;
2979 uschar *retry_message_key = NULL;
2980 uschar *serialize_key = NULL;
2981
2982 /* Default next host is next host. :-) But this can vary if the
2983 hosts_max_try limit is hit (see below). It may also be reset if a host
2984 address is looked up here (in case the host was multihomed). */
2985
2986 nexthost = host->next;
2987
2988 /* If the address hasn't yet been obtained from the host name, look it up
2989 now, unless the host is already marked as unusable. If it is marked as
2990 unusable, it means that the router was unable to find its IP address (in
2991 the DNS or wherever) OR we are in the 2nd time round the cutoff loop, and
2992 the lookup failed last time. We don't get this far if *all* MX records
2993 point to non-existent hosts; that is treated as a hard error.
2994
2995 We can just skip this host entirely. When the hosts came from the router,
2996 the address will timeout based on the other host(s); when the address is
2997 looked up below, there is an explicit retry record added.
2998
2999 Note that we mustn't skip unusable hosts if the address is not unset; they
3000 may be needed as expired hosts on the 2nd time round the cutoff loop. */
3001
3002 if (host->address == NULL)
3003 {
3004 int new_port, flags;
3005 host_item *hh;
3006 uschar *canonical_name;
3007
3008 if (host->status >= hstatus_unusable)
3009 {
3010 DEBUG(D_transport) debug_printf("%s has no address and is unusable - skipping\n",
3011 host->name);
3012 continue;
3013 }
3014
3015 DEBUG(D_transport) debug_printf("getting address for %s\n", host->name);
3016
3017 /* The host name is permitted to have an attached port. Find it, and
3018 strip it from the name. Just remember it for now. */
3019
3020 new_port = host_item_get_port(host);
3021
3022 /* Count hosts looked up */
3023
3024 hosts_looked_up++;
3025
3026 /* Find by name if so configured, or if it's an IP address. We don't
3027 just copy the IP address, because we need the test-for-local to happen. */
3028
3029 flags = HOST_FIND_BY_A;
3030 if (ob->dns_qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
3031 if (ob->dns_search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
3032
3033 if (ob->gethostbyname || string_is_ip_address(host->name, NULL) != 0)
3034 rc = host_find_byname(host, NULL, flags, &canonical_name, TRUE);
3035 else
3036 rc = host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
3037 ob->dnssec_request_domains, ob->dnssec_require_domains,
3038 &canonical_name, NULL);
3039
3040 /* Update the host (and any additional blocks, resulting from
3041 multihoming) with a host-specific port, if any. */
3042
3043 for (hh = host; hh != nexthost; hh = hh->next) hh->port = new_port;
3044
3045 /* Failure to find the host at this time (usually DNS temporary failure)
3046 is really a kind of routing failure rather than a transport failure.
3047 Therefore we add a retry item of the routing kind, not to stop us trying
3048 to look this name up here again, but to ensure the address gets timed
3049 out if the failures go on long enough. A complete failure at this point
3050 commonly points to a configuration error, but the best action is still
3051 to carry on for the next host. */
3052
3053 if (rc == HOST_FIND_AGAIN || rc == HOST_FIND_FAILED)
3054 {
3055 retry_add_item(addrlist, string_sprintf("R:%s", host->name), 0);
3056 expired = FALSE;
3057 if (rc == HOST_FIND_AGAIN) hosts_defer++; else hosts_fail++;
3058 DEBUG(D_transport) debug_printf("rc = %s for %s\n", (rc == HOST_FIND_AGAIN)?
3059 "HOST_FIND_AGAIN" : "HOST_FIND_FAILED", host->name);
3060 host->status = hstatus_unusable;
3061
3062 for (addr = addrlist; addr != NULL; addr = addr->next)
3063 {
3064 if (addr->transport_return != DEFER) continue;
3065 addr->basic_errno = ERRNO_UNKNOWNHOST;
3066 addr->message =
3067 string_sprintf("failed to lookup IP address for %s", host->name);
3068 }
3069 continue;
3070 }
3071
3072 /* If the host is actually the local host, we may have a problem, or
3073 there may be some cunning configuration going on. In the problem case,
3074 log things and give up. The default transport status is already DEFER. */
3075
3076 if (rc == HOST_FOUND_LOCAL && !ob->allow_localhost)
3077 {
3078 for (addr = addrlist; addr != NULL; addr = addr->next)
3079 {
3080 addr->basic_errno = 0;
3081 addr->message = string_sprintf("%s transport found host %s to be "
3082 "local", tblock->name, host->name);
3083 }
3084 goto END_TRANSPORT;
3085 }
3086 } /* End of block for IP address lookup */
3087
3088 /* If this is a continued delivery, we are interested only in the host
3089 which matches the name of the existing open channel. The check is put
3090 here after the local host lookup, in case the name gets expanded as a
3091 result of the lookup. Set expired FALSE, to save the outer loop executing
3092 twice. */
3093
3094 if (continuing && (Ustrcmp(continue_hostname, host->name) != 0 ||
3095 Ustrcmp(continue_host_address, host->address) != 0))
3096 {
3097 expired = FALSE;
3098 continue; /* With next host */
3099 }
3100
3101 /* Reset the default next host in case a multihomed host whose addresses
3102 are not looked up till just above added to the host list. */
3103
3104 nexthost = host->next;
3105
3106 /* If queue_smtp is set (-odqs or the first part of a 2-stage run), or the
3107 domain is in queue_smtp_domains, we don't actually want to attempt any
3108 deliveries. When doing a queue run, queue_smtp_domains is always unset. If
3109 there is a lookup defer in queue_smtp_domains, proceed as if the domain
3110 were not in it. We don't want to hold up all SMTP deliveries! Except when
3111 doing a two-stage queue run, don't do this if forcing. */
3112
3113 if ((!deliver_force || queue_2stage) && (queue_smtp ||
3114 match_isinlist(addrlist->domain, &queue_smtp_domains, 0,
3115 &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL) == OK))
3116 {
3117 expired = FALSE;
3118 for (addr = addrlist; addr != NULL; addr = addr->next)
3119 {
3120 if (addr->transport_return != DEFER) continue;
3121 addr->message = US"domain matches queue_smtp_domains, or -odqs set";
3122 }
3123 continue; /* With next host */
3124 }
3125
3126 /* Count hosts being considered - purely for an intelligent comment
3127 if none are usable. */
3128
3129 hosts_total++;
3130
3131 /* Set $host and $host address now in case they are needed for the
3132 interface expansion or the serialize_hosts check; they remain set if an
3133 actual delivery happens. */
3134
3135 deliver_host = host->name;
3136 deliver_host_address = host->address;
3137 lookup_dnssec_authenticated = host->dnssec == DS_YES ? US"yes"
3138 : host->dnssec == DS_NO ? US"no"
3139 : US"";
3140
3141 /* Set up a string for adding to the retry key if the port number is not
3142 the standard SMTP port. A host may have its own port setting that overrides
3143 the default. */
3144
3145 pistring = string_sprintf(":%d", (host->port == PORT_NONE)?
3146 port : host->port);
3147 if (Ustrcmp(pistring, ":25") == 0) pistring = US"";
3148
3149 /* Select IPv4 or IPv6, and choose an outgoing interface. If the interface
3150 string changes upon expansion, we must add it to the key that is used for
3151 retries, because connections to the same host from a different interface
3152 should be treated separately. */
3153
3154 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET : AF_INET6;
3155 if (!smtp_get_interface(ob->interface, host_af, addrlist, &ifchanges,
3156 &interface, tid))
3157 return FALSE;
3158 if (ifchanges) pistring = string_sprintf("%s/%s", pistring, interface);
3159
3160 /* The first time round the outer loop, check the status of the host by
3161 inspecting the retry data. The second time round, we are interested only
3162 in expired hosts that haven't been tried since this message arrived. */
3163
3164 if (cutoff_retry == 0)
3165 {
3166 BOOL incl_ip;
3167 /* Ensure the status of the address is set by checking retry data if
3168 necessary. There may be host-specific retry data (applicable to all
3169 messages) and also data for retries of a specific message at this host.
3170 If either of these retry records are actually read, the keys used are
3171 returned to save recomputing them later. */
3172
3173 if (exp_bool(addrlist, US"transport", tblock->name, D_transport,
3174 US"retry_include_ip_address", ob->retry_include_ip_address,
3175 ob->expand_retry_include_ip_address, &incl_ip) != OK)
3176 continue; /* with next host */
3177
3178 host_is_expired = retry_check_address(addrlist->domain, host, pistring,
3179 incl_ip, &retry_host_key, &retry_message_key);
3180
3181 DEBUG(D_transport) debug_printf("%s [%s]%s status = %s\n", host->name,
3182 (host->address == NULL)? US"" : host->address, pistring,
3183 (host->status == hstatus_usable)? "usable" :
3184 (host->status == hstatus_unusable)? "unusable" :
3185 (host->status == hstatus_unusable_expired)? "unusable (expired)" : "?");
3186
3187 /* Skip this address if not usable at this time, noting if it wasn't
3188 actually expired, both locally and in the address. */
3189
3190 switch (host->status)
3191 {
3192 case hstatus_unusable:
3193 expired = FALSE;
3194 setflag(addrlist, af_retry_skipped);
3195 /* Fall through */
3196
3197 case hstatus_unusable_expired:
3198 switch (host->why)
3199 {
3200 case hwhy_retry: hosts_retry++; break;
3201 case hwhy_failed: hosts_fail++; break;
3202 case hwhy_deferred: hosts_defer++; break;
3203 }
3204
3205 /* If there was a retry message key, implying that previously there
3206 was a message-specific defer, we don't want to update the list of
3207 messages waiting for these hosts. */
3208
3209 if (retry_message_key != NULL) update_waiting = FALSE;
3210 continue; /* With the next host or IP address */
3211 }
3212 }
3213
3214 /* Second time round the loop: if the address is set but expired, and
3215 the message is newer than the last try, let it through. */
3216
3217 else
3218 {
3219 if (host->address == NULL ||
3220 host->status != hstatus_unusable_expired ||
3221 host->last_try > received_time)
3222 continue;
3223 DEBUG(D_transport)
3224 debug_printf("trying expired host %s [%s]%s\n",
3225 host->name, host->address, pistring);
3226 host_is_expired = TRUE;
3227 }
3228
3229 /* Setting "expired=FALSE" doesn't actually mean not all hosts are expired;
3230 it remains TRUE only if all hosts are expired and none are actually tried.
3231 */
3232
3233 expired = FALSE;
3234
3235 /* If this host is listed as one to which access must be serialized,
3236 see if another Exim process has a connection to it, and if so, skip
3237 this host. If not, update the database to record our connection to it
3238 and remember this for later deletion. Do not do any of this if we are
3239 sending the message down a pre-existing connection. */
3240
3241 if (!continuing &&
3242 verify_check_given_host(&ob->serialize_hosts, host) == OK)
3243 {
3244 serialize_key = string_sprintf("host-serialize-%s", host->name);
3245 if (!enq_start(serialize_key))
3246 {
3247 DEBUG(D_transport)
3248 debug_printf("skipping host %s because another Exim process "
3249 "is connected to it\n", host->name);
3250 hosts_serial++;
3251 continue;
3252 }
3253 serialized = TRUE;
3254 }
3255
3256 /* OK, we have an IP address that is not waiting for its retry time to
3257 arrive (it might be expired) OR (second time round the loop) we have an
3258 expired host that hasn't been tried since the message arrived. Have a go
3259 at delivering the message to it. First prepare the addresses by flushing
3260 out the result of previous attempts, and finding the first address that
3261 is still to be delivered. */
3262
3263 first_addr = prepare_addresses(addrlist, host);
3264
3265 DEBUG(D_transport) debug_printf("delivering %s to %s [%s] (%s%s)\n",
3266 message_id, host->name, host->address, addrlist->address,
3267 (addrlist->next == NULL)? "" : ", ...");
3268
3269 set_process_info("delivering %s to %s [%s] (%s%s)",
3270 message_id, host->name, host->address, addrlist->address,
3271 (addrlist->next == NULL)? "" : ", ...");
3272
3273 /* This is not for real; don't do the delivery. If there are
3274 any remaining hosts, list them. */
3275
3276 if (dont_deliver)
3277 {
3278 host_item *host2;
3279 set_errno(addrlist, 0, NULL, OK, FALSE, NULL);
3280 for (addr = addrlist; addr != NULL; addr = addr->next)
3281 {
3282 addr->host_used = host;
3283 addr->special_action = '*';
3284 addr->message = US"delivery bypassed by -N option";
3285 }
3286 DEBUG(D_transport)
3287 {
3288 debug_printf("*** delivery by %s transport bypassed by -N option\n"
3289 "*** host and remaining hosts:\n", tblock->name);
3290 for (host2 = host; host2 != NULL; host2 = host2->next)
3291 debug_printf(" %s [%s]\n", host2->name,
3292 (host2->address == NULL)? US"unset" : host2->address);
3293 }
3294 rc = OK;
3295 }
3296
3297 /* This is for real. If the host is expired, we don't count it for
3298 hosts_max_retry. This ensures that all hosts must expire before an address
3299 is timed out, unless hosts_max_try_hardlimit (which protects against
3300 lunatic DNS configurations) is reached.
3301
3302 If the host is not expired and we are about to hit the hosts_max_retry
3303 limit, check to see if there is a subsequent hosts with a different MX
3304 value. If so, make that the next host, and don't count this one. This is a
3305 heuristic to make sure that different MXs do get tried. With a normal kind
3306 of retry rule, they would get tried anyway when the earlier hosts were
3307 delayed, but if the domain has a "retry every time" type of rule - as is
3308 often used for the the very large ISPs, that won't happen. */
3309
3310 else
3311 {
3312 host_item * thost;
3313 /* Make a copy of the host if it is local to this invocation
3314 of the transport. */
3315
3316 if (expanded_hosts)
3317 {
3318 thost = store_get(sizeof(host_item));
3319 *thost = *host;
3320 thost->name = string_copy(host->name);
3321 thost->address = string_copy(host->address);
3322 }
3323 else
3324 thost = host;
3325
3326 if (!host_is_expired && ++unexpired_hosts_tried >= ob->hosts_max_try)
3327 {
3328 host_item *h;
3329 DEBUG(D_transport)
3330 debug_printf("hosts_max_try limit reached with this host\n");
3331 for (h = host; h != NULL; h = h->next)
3332 if (h->mx != host->mx) break;
3333 if (h != NULL)
3334 {
3335 nexthost = h;
3336 unexpired_hosts_tried--;
3337 DEBUG(D_transport) debug_printf("however, a higher MX host exists "
3338 "and will be tried\n");
3339 }
3340 }
3341
3342 /* Attempt the delivery. */
3343
3344 total_hosts_tried++;
3345 rc = smtp_deliver(addrlist, thost, host_af, port, interface, tblock,
3346 &message_defer, FALSE);
3347
3348 /* Yield is one of:
3349 OK => connection made, each address contains its result;
3350 message_defer is set for message-specific defers (when all
3351 recipients are marked defer)
3352 DEFER => there was a non-message-specific delivery problem;
3353 ERROR => there was a problem setting up the arguments for a filter,
3354 or there was a problem with expanding added headers
3355 */
3356
3357 /* If the result is not OK, there was a non-message-specific problem.
3358 If the result is DEFER, we need to write to the logs saying what happened
3359 for this particular host, except in the case of authentication and TLS
3360 failures, where the log has already been written. If all hosts defer a
3361 general message is written at the end. */
3362
3363 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL &&
3364 first_addr->basic_errno != ERRNO_TLSFAILURE)
3365 write_logs(first_addr, host);
3366
3367 #ifdef EXPERIMENTAL_EVENT
3368 if (rc == DEFER)
3369 deferred_event_raise(first_addr, host);
3370 #endif
3371
3372 /* If STARTTLS was accepted, but there was a failure in setting up the
3373 TLS session (usually a certificate screwup), and the host is not in
3374 hosts_require_tls, and tls_tempfail_tryclear is true, try again, with
3375 TLS forcibly turned off. We have to start from scratch with a new SMTP
3376 connection. That's why the retry is done from here, not from within
3377 smtp_deliver(). [Rejections of STARTTLS itself don't screw up the
3378 session, so the in-clear transmission after those errors, if permitted,
3379 happens inside smtp_deliver().] */
3380
3381 #ifdef SUPPORT_TLS
3382 if ( rc == DEFER
3383 && first_addr->basic_errno == ERRNO_TLSFAILURE
3384 && ob->tls_tempfail_tryclear
3385 && verify_check_given_host(&ob->hosts_require_tls, host) != OK
3386 )
3387 {
3388 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
3389 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
3390 first_addr = prepare_addresses(addrlist, host);
3391 rc = smtp_deliver(addrlist, thost, host_af, port, interface, tblock,
3392 &message_defer, TRUE);
3393 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL)
3394 write_logs(first_addr, host);
3395 # ifdef EXPERIMENTAL_EVENT
3396 if (rc == DEFER)
3397 deferred_event_raise(first_addr, host);
3398 # endif
3399 }
3400 #endif /*SUPPORT_TLS*/
3401 }
3402
3403 /* Delivery attempt finished */
3404
3405 rs = (rc == OK)? US"OK" : (rc == DEFER)? US"DEFER" : (rc == ERROR)?
3406 US"ERROR" : US"?";
3407
3408 set_process_info("delivering %s: just tried %s [%s] for %s%s: result %s",
3409 message_id, host->name, host->address, addrlist->address,
3410 (addrlist->next == NULL)? "" : " (& others)", rs);
3411
3412 /* Release serialization if set up */
3413
3414 if (serialized) enq_end(serialize_key);
3415
3416 /* If the result is DEFER, or if a host retry record is known to exist, we
3417 need to add an item to the retry chain for updating the retry database
3418 at the end of delivery. We only need to add the item to the top address,
3419 of course. Also, if DEFER, we mark the IP address unusable so as to skip it
3420 for any other delivery attempts using the same address. (It is copied into
3421 the unusable tree at the outer level, so even if different address blocks
3422 contain the same address, it still won't get tried again.) */
3423
3424 if (rc == DEFER || retry_host_key != NULL)
3425 {
3426 int delete_flag = (rc != DEFER)? rf_delete : 0;
3427 if (retry_host_key == NULL)
3428 {
3429 BOOL incl_ip;
3430 if (exp_bool(addrlist, US"transport", tblock->name, D_transport,
3431 US"retry_include_ip_address", ob->retry_include_ip_address,
3432 ob->expand_retry_include_ip_address, &incl_ip) != OK)
3433 incl_ip = TRUE; /* error; use most-specific retry record */
3434
3435 retry_host_key = incl_ip ?
3436 string_sprintf("T:%S:%s%s", host->name, host->address, pistring) :
3437 string_sprintf("T:%S%s", host->name, pistring);
3438 }
3439
3440 /* If a delivery of another message over an existing SMTP connection
3441 yields DEFER, we do NOT set up retry data for the host. This covers the
3442 case when there are delays in routing the addresses in the second message
3443 that are so long that the server times out. This is alleviated by not
3444 routing addresses that previously had routing defers when handling an
3445 existing connection, but even so, this case may occur (e.g. if a
3446 previously happily routed address starts giving routing defers). If the
3447 host is genuinely down, another non-continued message delivery will
3448 notice it soon enough. */
3449
3450 if (delete_flag != 0 || !continuing)
3451 retry_add_item(first_addr, retry_host_key, rf_host | delete_flag);
3452
3453 /* We may have tried an expired host, if its retry time has come; ensure
3454 the status reflects the expiry for the benefit of any other addresses. */
3455
3456 if (rc == DEFER)
3457 {
3458 host->status = (host_is_expired)?
3459 hstatus_unusable_expired : hstatus_unusable;
3460 host->why = hwhy_deferred;
3461 }
3462 }
3463
3464 /* If message_defer is set (host was OK, but every recipient got deferred
3465 because of some message-specific problem), or if that had happened
3466 previously so that a message retry key exists, add an appropriate item
3467 to the retry chain. Note that if there was a message defer but now there is
3468 a host defer, the message defer record gets deleted. That seems perfectly
3469 reasonable. Also, stop the message from being remembered as waiting
3470 for specific hosts. */
3471
3472 if (message_defer || retry_message_key != NULL)
3473 {
3474 int delete_flag = message_defer? 0 : rf_delete;
3475 if (retry_message_key == NULL)
3476 {
3477 BOOL incl_ip;
3478 if (exp_bool(addrlist, US"transport", tblock->name, D_transport,
3479 US"retry_include_ip_address", ob->retry_include_ip_address,
3480 ob->expand_retry_include_ip_address, &incl_ip) != OK)
3481 incl_ip = TRUE; /* error; use most-specific retry record */
3482
3483 retry_message_key = incl_ip ?
3484 string_sprintf("T:%S:%s%s:%s", host->name, host->address, pistring,
3485 message_id) :
3486 string_sprintf("T:%S%s:%s", host->name, pistring, message_id);
3487 }
3488 retry_add_item(addrlist, retry_message_key,
3489 rf_message | rf_host | delete_flag);
3490 update_waiting = FALSE;
3491 }
3492
3493 /* Any return other than DEFER (that is, OK or ERROR) means that the
3494 addresses have got their final statuses filled in for this host. In the OK
3495 case, see if any of them are deferred. */
3496
3497 if (rc == OK)
3498 {
3499 for (addr = addrlist; addr != NULL; addr = addr->next)
3500 {
3501 if (addr->transport_return == DEFER)
3502 {
3503 some_deferred = TRUE;
3504 break;
3505 }
3506 }
3507 }
3508
3509 /* If no addresses deferred or the result was ERROR, return. We do this for
3510 ERROR because a failing filter set-up or add_headers expansion is likely to
3511 fail for any host we try. */
3512
3513 if (rc == ERROR || (rc == OK && !some_deferred))
3514 {
3515 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
3516 return TRUE; /* Each address has its status */
3517 }
3518
3519 /* If the result was DEFER or some individual addresses deferred, let
3520 the loop run to try other hosts with the deferred addresses, except for the
3521 case when we were trying to deliver down an existing channel and failed.
3522 Don't try any other hosts in this case. */
3523
3524 if (continuing) break;
3525
3526 /* If the whole delivery, or some individual addresses, were deferred and
3527 there are more hosts that could be tried, do not count this host towards
3528 the hosts_max_try limit if the age of the message is greater than the
3529 maximum retry time for this host. This means we may try try all hosts,
3530 ignoring the limit, when messages have been around for some time. This is
3531 important because if we don't try all hosts, the address will never time
3532 out. NOTE: this does not apply to hosts_max_try_hardlimit. */
3533
3534 if ((rc == DEFER || some_deferred) && nexthost != NULL)
3535 {
3536 BOOL timedout;
3537 retry_config *retry = retry_find_config(host->name, NULL, 0, 0);
3538
3539 if (retry != NULL && retry->rules != NULL)
3540 {
3541 retry_rule *last_rule;
3542 for (last_rule = retry->rules;
3543 last_rule->next != NULL;
3544 last_rule = last_rule->next);
3545 timedout = time(NULL) - received_time > last_rule->timeout;
3546 }
3547 else timedout = TRUE; /* No rule => timed out */
3548
3549 if (timedout)
3550 {
3551 unexpired_hosts_tried--;
3552 DEBUG(D_transport) debug_printf("temporary delivery error(s) override "
3553 "hosts_max_try (message older than host's retry time)\n");
3554 }
3555 }
3556 } /* End of loop for trying multiple hosts. */
3557
3558 /* This is the end of the loop that repeats iff expired is TRUE and
3559 ob->delay_after_cutoff is FALSE. The second time round we will
3560 try those hosts that haven't been tried since the message arrived. */
3561
3562 DEBUG(D_transport)
3563 {
3564 debug_printf("all IP addresses skipped or deferred at least one address\n");
3565 if (expired && !ob->delay_after_cutoff && cutoff_retry == 0)
3566 debug_printf("retrying IP addresses not tried since message arrived\n");
3567 }
3568 }
3569
3570
3571 /* Get here if all IP addresses are skipped or defer at least one address. In
3572 MUA wrapper mode, this will happen only for connection or other non-message-
3573 specific failures. Force the delivery status for all addresses to FAIL. */
3574
3575 if (mua_wrapper)
3576 {
3577 for (addr = addrlist; addr != NULL; addr = addr->next)
3578 addr->transport_return = FAIL;
3579 goto END_TRANSPORT;
3580 }
3581
3582 /* In the normal, non-wrapper case, add a standard message to each deferred
3583 address if there hasn't been an error, that is, if it hasn't actually been
3584 tried this time. The variable "expired" will be FALSE if any deliveries were
3585 actually tried, or if there was at least one host that was not expired. That
3586 is, it is TRUE only if no deliveries were tried and all hosts were expired. If
3587 a delivery has been tried, an error code will be set, and the failing of the
3588 message is handled by the retry code later.
3589
3590 If queue_smtp is set, or this transport was called to send a subsequent message
3591 down an existing TCP/IP connection, and something caused the host not to be
3592 found, we end up here, but can detect these cases and handle them specially. */
3593
3594 for (addr = addrlist; addr != NULL; addr = addr->next)
3595 {
3596 /* If host is not NULL, it means that we stopped processing the host list
3597 because of hosts_max_try or hosts_max_try_hardlimit. In the former case, this
3598 means we need to behave as if some hosts were skipped because their retry
3599 time had not come. Specifically, this prevents the address from timing out.
3600 However, if we have hit hosts_max_try_hardlimit, we want to behave as if all
3601 hosts were tried. */
3602
3603 if (host != NULL)
3604 {
3605 if (total_hosts_tried >= ob->hosts_max_try_hardlimit)
3606 {
3607 DEBUG(D_transport)
3608 debug_printf("hosts_max_try_hardlimit reached: behave as if all "
3609 "hosts were tried\n");
3610 }
3611 else
3612 {
3613 DEBUG(D_transport)
3614 debug_printf("hosts_max_try limit caused some hosts to be skipped\n");
3615 setflag(addr, af_retry_skipped);
3616 }
3617 }
3618
3619 if (queue_smtp) /* no deliveries attempted */
3620 {
3621 addr->transport_return = DEFER;
3622 addr->basic_errno = 0;
3623 addr->message = US"SMTP delivery explicitly queued";
3624 }
3625
3626 else if (addr->transport_return == DEFER &&
3627 (addr->basic_errno == ERRNO_UNKNOWNERROR || addr->basic_errno == 0) &&
3628 addr->message == NULL)
3629 {
3630 addr->basic_errno = ERRNO_HRETRY;
3631 if (continue_hostname != NULL)
3632 {
3633 addr->message = US"no host found for existing SMTP connection";
3634 }
3635 else if (expired)
3636 {
3637 setflag(addr, af_pass_message); /* This is not a security risk */
3638 addr->message = (ob->delay_after_cutoff)?
3639 US"retry time not reached for any host after a long failure period" :
3640 US"all hosts have been failing for a long time and were last tried "
3641 "after this message arrived";
3642
3643 /* If we are already using fallback hosts, or there are no fallback hosts
3644 defined, convert the result to FAIL to cause a bounce. */
3645
3646 if (addr->host_list == addr->fallback_hosts ||
3647 addr->fallback_hosts == NULL)
3648 addr->transport_return = FAIL;
3649 }
3650 else
3651 {
3652 if (hosts_retry == hosts_total)
3653 addr->message = US"retry time not reached for any host";
3654 else if (hosts_fail == hosts_total)
3655 addr->message = US"all host address lookups failed permanently";
3656 else if (hosts_defer == hosts_total)
3657 addr->message = US"all host address lookups failed temporarily";
3658 else if (hosts_serial == hosts_total)
3659 addr->message = US"connection limit reached for all hosts";
3660 else if (hosts_fail+hosts_defer == hosts_total)
3661 addr->message = US"all host address lookups failed";
3662 else addr->message = US"some host address lookups failed and retry time "
3663 "not reached for other hosts or connection limit reached";
3664 }
3665 }
3666 }
3667
3668 /* Update the database which keeps information about which messages are waiting
3669 for which hosts to become available. For some message-specific errors, the
3670 update_waiting flag is turned off because we don't want follow-on deliveries in
3671 those cases. If this transport instance is explicitly limited to one message
3672 per connection then follow-on deliveries are not possible and there's no need
3673 to create/update the per-transport wait-<transport_name> database. */
3674
3675 if (update_waiting && tblock->connection_max_messages != 1)
3676 transport_update_waiting(hostlist, tblock->name);
3677
3678 END_TRANSPORT:
3679
3680 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
3681
3682 return TRUE; /* Each address has its status */
3683 }
3684
3685 /* vi: aw ai sw=2
3686 */
3687 /* End of transport/smtp.c */
Unnamed repository; edit this file 'description' to name the repository.