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