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