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