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