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