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