Merge branch 'master' into dane
[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) */
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 /*************************************************
1152 * Deliver address list to given host *
1153 *************************************************/
1154
1155 /* If continue_hostname is not null, we get here only when continuing to
1156 deliver down an existing channel. The channel was passed as the standard
1157 input. TLS is never active on a passed channel; the previous process always
1158 closes it down before passing the connection on.
1159
1160 Otherwise, we have to make a connection to the remote host, and do the
1161 initial protocol exchange.
1162
1163 When running as an MUA wrapper, if the sender or any recipient is rejected,
1164 temporarily or permanently, we force failure for all recipients.
1165
1166 Arguments:
1167 addrlist chain of potential addresses to deliver; only those whose
1168 transport_return field is set to PENDING_DEFER are currently
1169 being processed; others should be skipped - they have either
1170 been delivered to an earlier host or IP address, or been
1171 failed by one of them.
1172 host host to deliver to
1173 host_af AF_INET or AF_INET6
1174 port default TCP/IP port to use, in host byte order
1175 interface interface to bind to, or NULL
1176 tblock transport instance block
1177 copy_host TRUE if host set in addr->host_used must be copied, because
1178 it is specific to this call of the transport
1179 message_defer set TRUE if yield is OK, but all addresses were deferred
1180 because of a non-recipient, non-host failure, that is, a
1181 4xx response to MAIL FROM, DATA, or ".". This is a defer
1182 that is specific to the message.
1183 suppress_tls if TRUE, don't attempt a TLS connection - this is set for
1184 a second attempt after TLS initialization fails
1185
1186 Returns: OK - the connection was made and the delivery attempted;
1187 the result for each address is in its data block.
1188 DEFER - the connection could not be made, or something failed
1189 while setting up the SMTP session, or there was a
1190 non-message-specific error, such as a timeout.
1191 ERROR - a filter command is specified for this transport,
1192 and there was a problem setting it up; OR helo_data
1193 or add_headers or authenticated_sender is specified
1194 for this transport, and the string failed to expand
1195 */
1196
1197 static int
1198 smtp_deliver(address_item *addrlist, host_item *host, int host_af, int port,
1199 uschar *interface, transport_instance *tblock, BOOL copy_host,
1200 BOOL *message_defer, BOOL suppress_tls)
1201 {
1202 address_item *addr;
1203 address_item *sync_addr;
1204 address_item *first_addr = addrlist;
1205 int yield = OK;
1206 int address_count;
1207 int save_errno;
1208 int rc;
1209 time_t start_delivery_time = time(NULL);
1210 smtp_transport_options_block *ob =
1211 (smtp_transport_options_block *)(tblock->options_block);
1212 BOOL lmtp = strcmpic(ob->protocol, US"lmtp") == 0;
1213 BOOL smtps = strcmpic(ob->protocol, US"smtps") == 0;
1214 BOOL ok = FALSE;
1215 BOOL send_rset = TRUE;
1216 BOOL send_quit = TRUE;
1217 BOOL setting_up = TRUE;
1218 BOOL completed_address = FALSE;
1219 BOOL esmtp = TRUE;
1220 BOOL pending_MAIL;
1221 BOOL pass_message = FALSE;
1222 #ifndef DISABLE_PRDR
1223 BOOL prdr_offered = FALSE;
1224 BOOL prdr_active;
1225 #endif
1226 #ifdef EXPERIMENTAL_DSN
1227 BOOL dsn_all_lasthop = TRUE;
1228 #endif
1229 smtp_inblock inblock;
1230 smtp_outblock outblock;
1231 int max_rcpt = tblock->max_addresses;
1232 uschar *igquotstr = US"";
1233 uschar *helo_data = NULL;
1234 uschar *message = NULL;
1235 uschar new_message_id[MESSAGE_ID_LENGTH + 1];
1236 uschar *p;
1237 uschar buffer[4096];
1238 uschar inbuffer[4096];
1239 uschar outbuffer[4096];
1240
1241 suppress_tls = suppress_tls; /* stop compiler warning when no TLS support */
1242
1243 *message_defer = FALSE;
1244 smtp_command = US"initial connection";
1245 if (max_rcpt == 0) max_rcpt = 999999;
1246
1247 /* Set up the buffer for reading SMTP response packets. */
1248
1249 inblock.buffer = inbuffer;
1250 inblock.buffersize = sizeof(inbuffer);
1251 inblock.ptr = inbuffer;
1252 inblock.ptrend = inbuffer;
1253
1254 /* Set up the buffer for holding SMTP commands while pipelining */
1255
1256 outblock.buffer = outbuffer;
1257 outblock.buffersize = sizeof(outbuffer);
1258 outblock.ptr = outbuffer;
1259 outblock.cmd_count = 0;
1260 outblock.authenticating = FALSE;
1261
1262 /* Reset the parameters of a TLS session. */
1263
1264 tls_out.bits = 0;
1265 tls_out.cipher = NULL; /* the one we may use for this transport */
1266 tls_out.ourcert = NULL;
1267 tls_out.peercert = NULL;
1268 tls_out.peerdn = NULL;
1269 #if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
1270 tls_out.sni = NULL;
1271 #endif
1272 tls_out.ocsp = OCSP_NOT_REQ;
1273
1274 /* Flip the legacy TLS-related variables over to the outbound set in case
1275 they're used in the context of the transport. Don't bother resetting
1276 afterward as we're in a subprocess. */
1277
1278 tls_modify_variables(&tls_out);
1279
1280 #ifndef SUPPORT_TLS
1281 if (smtps)
1282 {
1283 set_errno(addrlist, 0, US"TLS support not available", DEFER, FALSE);
1284 return ERROR;
1285 }
1286 #endif
1287
1288 /* Make a connection to the host if this isn't a continued delivery, and handle
1289 the initial interaction and HELO/EHLO/LHLO. Connect timeout errors are handled
1290 specially so they can be identified for retries. */
1291
1292 if (continue_hostname == NULL)
1293 {
1294 /* This puts port into host->port */
1295 inblock.sock = outblock.sock =
1296 smtp_connect(host, host_af, port, interface, ob->connect_timeout,
1297 ob->keepalive, ob->dscp
1298 #ifdef EXPERIMENTAL_TPDA
1299 , tblock->tpda_event_action
1300 #endif
1301 );
1302
1303 if (inblock.sock < 0)
1304 {
1305 set_errno(addrlist, (errno == ETIMEDOUT)? ERRNO_CONNECTTIMEOUT : errno,
1306 NULL, DEFER, FALSE);
1307 return DEFER;
1308 }
1309
1310 /* Expand the greeting message while waiting for the initial response. (Makes
1311 sense if helo_data contains ${lookup dnsdb ...} stuff). The expansion is
1312 delayed till here so that $sending_interface and $sending_port are set. */
1313
1314 helo_data = expand_string(ob->helo_data);
1315
1316 /* The first thing is to wait for an initial OK response. The dreaded "goto"
1317 is nevertheless a reasonably clean way of programming this kind of logic,
1318 where you want to escape on any error. */
1319
1320 if (!smtps)
1321 {
1322 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1323 ob->command_timeout)) goto RESPONSE_FAILED;
1324
1325 #ifdef EXPERIMENTAL_TPDA
1326 if (tpda_raise_event(tblock->tpda_event_action, US"smtp:connect", buffer)
1327 == DEFER)
1328 {
1329 uschar *message = US"deferred by smtp:connect event expansion";
1330 set_errno(addrlist, 0, message, DEFER, FALSE);
1331 yield = DEFER;
1332 goto SEND_QUIT;
1333 }
1334 #endif
1335
1336 /* Now check if the helo_data expansion went well, and sign off cleanly if
1337 it didn't. */
1338
1339 if (helo_data == NULL)
1340 {
1341 uschar *message = string_sprintf("failed to expand helo_data: %s",
1342 expand_string_message);
1343 set_errno(addrlist, 0, message, DEFER, FALSE);
1344 yield = DEFER;
1345 goto SEND_QUIT;
1346 }
1347 }
1348
1349 /** Debugging without sending a message
1350 addrlist->transport_return = DEFER;
1351 goto SEND_QUIT;
1352 **/
1353
1354 /* Errors that occur after this point follow an SMTP command, which is
1355 left in big_buffer by smtp_write_command() for use in error messages. */
1356
1357 smtp_command = big_buffer;
1358
1359 /* Tell the remote who we are...
1360
1361 February 1998: A convention has evolved that ESMTP-speaking MTAs include the
1362 string "ESMTP" in their greeting lines, so make Exim send EHLO if the
1363 greeting is of this form. The assumption was that the far end supports it
1364 properly... but experience shows that there are some that give 5xx responses,
1365 even though the banner includes "ESMTP" (there's a bloody-minded one that
1366 says "ESMTP not spoken here"). Cope with that case.
1367
1368 September 2000: Time has passed, and it seems reasonable now to always send
1369 EHLO at the start. It is also convenient to make the change while installing
1370 the TLS stuff.
1371
1372 July 2003: Joachim Wieland met a broken server that advertises "PIPELINING"
1373 but times out after sending MAIL FROM, RCPT TO and DATA all together. There
1374 would be no way to send out the mails, so there is now a host list
1375 "hosts_avoid_esmtp" that disables ESMTP for special hosts and solves the
1376 PIPELINING problem as well. Maybe it can also be useful to cure other
1377 problems with broken servers.
1378
1379 Exim originally sent "Helo" at this point and ran for nearly a year that way.
1380 Then somebody tried it with a Microsoft mailer... It seems that all other
1381 mailers use upper case for some reason (the RFC is quite clear about case
1382 independence) so, for peace of mind, I gave in. */
1383
1384 esmtp = verify_check_this_host(&(ob->hosts_avoid_esmtp), NULL,
1385 host->name, host->address, NULL) != OK;
1386
1387 /* Alas; be careful, since this goto is not an error-out, so conceivably
1388 we might set data between here and the target which we assume to exist
1389 and be usable. I can see this coming back to bite us. */
1390 #ifdef SUPPORT_TLS
1391 if (smtps)
1392 {
1393 tls_offered = TRUE;
1394 suppress_tls = FALSE;
1395 ob->tls_tempfail_tryclear = FALSE;
1396 smtp_command = US"SSL-on-connect";
1397 goto TLS_NEGOTIATE;
1398 }
1399 #endif
1400
1401 if (esmtp)
1402 {
1403 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n",
1404 lmtp? "LHLO" : "EHLO", helo_data) < 0)
1405 goto SEND_FAILED;
1406 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1407 ob->command_timeout))
1408 {
1409 if (errno != 0 || buffer[0] == 0 || lmtp) goto RESPONSE_FAILED;
1410 esmtp = FALSE;
1411 }
1412 }
1413 else
1414 {
1415 DEBUG(D_transport)
1416 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
1417 }
1418
1419 if (!esmtp)
1420 {
1421 if (smtp_write_command(&outblock, FALSE, "HELO %s\r\n", helo_data) < 0)
1422 goto SEND_FAILED;
1423 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1424 ob->command_timeout)) goto RESPONSE_FAILED;
1425 }
1426
1427 /* Set IGNOREQUOTA if the response to LHLO specifies support and the
1428 lmtp_ignore_quota option was set. */
1429
1430 igquotstr = (lmtp && ob->lmtp_ignore_quota &&
1431 pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer, Ustrlen(CS buffer), 0,
1432 PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
1433
1434 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
1435
1436 #ifdef SUPPORT_TLS
1437 tls_offered = esmtp &&
1438 pcre_exec(regex_STARTTLS, NULL, CS buffer, Ustrlen(buffer), 0,
1439 PCRE_EOPT, NULL, 0) >= 0;
1440 #endif
1441
1442 #ifndef DISABLE_PRDR
1443 prdr_offered = esmtp &&
1444 (pcre_exec(regex_PRDR, NULL, CS buffer, Ustrlen(buffer), 0,
1445 PCRE_EOPT, NULL, 0) >= 0) &&
1446 (verify_check_this_host(&(ob->hosts_try_prdr), NULL, host->name,
1447 host->address, NULL) == OK);
1448
1449 if (prdr_offered)
1450 {DEBUG(D_transport) debug_printf("PRDR usable\n");}
1451 #endif
1452 }
1453
1454 /* For continuing deliveries down the same channel, the socket is the standard
1455 input, and we don't need to redo EHLO here (but may need to do so for TLS - see
1456 below). Set up the pointer to where subsequent commands will be left, for
1457 error messages. Note that smtp_use_size and smtp_use_pipelining will have been
1458 set from the command line if they were set in the process that passed the
1459 connection on. */
1460
1461 else
1462 {
1463 inblock.sock = outblock.sock = fileno(stdin);
1464 smtp_command = big_buffer;
1465 host->port = port; /* Record the port that was used */
1466 }
1467
1468 /* If TLS is available on this connection, whether continued or not, attempt to
1469 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
1470 send another EHLO - the server may give a different answer in secure mode. We
1471 use a separate buffer for reading the response to STARTTLS so that if it is
1472 negative, the original EHLO data is available for subsequent analysis, should
1473 the client not be required to use TLS. If the response is bad, copy the buffer
1474 for error analysis. */
1475
1476 #ifdef SUPPORT_TLS
1477 if (tls_offered && !suppress_tls &&
1478 verify_check_this_host(&(ob->hosts_avoid_tls), NULL, host->name,
1479 host->address, NULL) != OK)
1480 {
1481 uschar buffer2[4096];
1482 if (smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") < 0)
1483 goto SEND_FAILED;
1484
1485 /* If there is an I/O error, transmission of this message is deferred. If
1486 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
1487 false, we also defer. However, if there is a temporary rejection of STARTTLS
1488 and tls_tempfail_tryclear is true, or if there is an outright rejection of
1489 STARTTLS, we carry on. This means we will try to send the message in clear,
1490 unless the host is in hosts_require_tls (tested below). */
1491
1492 if (!smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
1493 ob->command_timeout))
1494 {
1495 if (errno != 0 || buffer2[0] == 0 ||
1496 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
1497 {
1498 Ustrncpy(buffer, buffer2, sizeof(buffer));
1499 goto RESPONSE_FAILED;
1500 }
1501 }
1502
1503 /* STARTTLS accepted: try to negotiate a TLS session. */
1504
1505 else
1506 TLS_NEGOTIATE:
1507 {
1508 int rc = tls_client_start(inblock.sock, host, addrlist, tblock);
1509
1510 /* TLS negotiation failed; give an error. From outside, this function may
1511 be called again to try in clear on a new connection, if the options permit
1512 it for this host. */
1513
1514 if (rc != OK)
1515 {
1516 save_errno = ERRNO_TLSFAILURE;
1517 message = US"failure while setting up TLS session";
1518 send_quit = FALSE;
1519 goto TLS_FAILED;
1520 }
1521
1522 /* TLS session is set up */
1523
1524 for (addr = addrlist; addr != NULL; addr = addr->next)
1525 {
1526 if (addr->transport_return == PENDING_DEFER)
1527 {
1528 addr->cipher = tls_out.cipher;
1529 addr->ourcert = tls_out.ourcert;
1530 addr->peercert = tls_out.peercert;
1531 addr->peerdn = tls_out.peerdn;
1532 addr->ocsp = tls_out.ocsp;
1533 }
1534 }
1535 }
1536 }
1537
1538 /* if smtps, we'll have smtp_command set to something else; always safe to
1539 reset it here. */
1540 smtp_command = big_buffer;
1541
1542 /* If we started TLS, redo the EHLO/LHLO exchange over the secure channel. If
1543 helo_data is null, we are dealing with a connection that was passed from
1544 another process, and so we won't have expanded helo_data above. We have to
1545 expand it here. $sending_ip_address and $sending_port are set up right at the
1546 start of the Exim process (in exim.c). */
1547
1548 if (tls_out.active >= 0)
1549 {
1550 char *greeting_cmd;
1551 if (helo_data == NULL)
1552 {
1553 helo_data = expand_string(ob->helo_data);
1554 if (helo_data == NULL)
1555 {
1556 uschar *message = string_sprintf("failed to expand helo_data: %s",
1557 expand_string_message);
1558 set_errno(addrlist, 0, message, DEFER, FALSE);
1559 yield = DEFER;
1560 goto SEND_QUIT;
1561 }
1562 }
1563
1564 /* For SMTPS we need to wait for the initial OK response. */
1565 if (smtps)
1566 {
1567 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1568 ob->command_timeout)) goto RESPONSE_FAILED;
1569 }
1570
1571 if (esmtp)
1572 greeting_cmd = "EHLO";
1573 else
1574 {
1575 greeting_cmd = "HELO";
1576 DEBUG(D_transport)
1577 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
1578 }
1579
1580 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n",
1581 lmtp? "LHLO" : greeting_cmd, helo_data) < 0)
1582 goto SEND_FAILED;
1583 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1584 ob->command_timeout))
1585 goto RESPONSE_FAILED;
1586 }
1587
1588 /* If the host is required to use a secure channel, ensure that we
1589 have one. */
1590
1591 else if ( verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
1592 host->address, NULL) == OK
1593 #ifdef EXPERIMENTAL_DANE
1594 || verify_check_this_host(&(ob->hosts_require_dane), NULL, host->name,
1595 host->address, NULL) == OK
1596 #endif
1597 )
1598 {
1599 save_errno = ERRNO_TLSREQUIRED;
1600 message = string_sprintf("a TLS session is required for %s [%s], but %s",
1601 host->name, host->address,
1602 tls_offered? "an attempt to start TLS failed" :
1603 "the server did not offer TLS support");
1604 goto TLS_FAILED;
1605 }
1606 #endif
1607
1608 /* If TLS is active, we have just started it up and re-done the EHLO command,
1609 so its response needs to be analyzed. If TLS is not active and this is a
1610 continued session down a previously-used socket, we haven't just done EHLO, so
1611 we skip this. */
1612
1613 if (continue_hostname == NULL
1614 #ifdef SUPPORT_TLS
1615 || tls_out.active >= 0
1616 #endif
1617 )
1618 {
1619 /* Set for IGNOREQUOTA if the response to LHLO specifies support and the
1620 lmtp_ignore_quota option was set. */
1621
1622 igquotstr = (lmtp && ob->lmtp_ignore_quota &&
1623 pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer, Ustrlen(CS buffer), 0,
1624 PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
1625
1626 /* If the response to EHLO specified support for the SIZE parameter, note
1627 this, provided size_addition is non-negative. */
1628
1629 smtp_use_size = esmtp && ob->size_addition >= 0 &&
1630 pcre_exec(regex_SIZE, NULL, CS buffer, Ustrlen(CS buffer), 0,
1631 PCRE_EOPT, NULL, 0) >= 0;
1632
1633 /* Note whether the server supports PIPELINING. If hosts_avoid_esmtp matched
1634 the current host, esmtp will be false, so PIPELINING can never be used. If
1635 the current host matches hosts_avoid_pipelining, don't do it. */
1636
1637 smtp_use_pipelining = esmtp &&
1638 verify_check_this_host(&(ob->hosts_avoid_pipelining), NULL, host->name,
1639 host->address, NULL) != OK &&
1640 pcre_exec(regex_PIPELINING, NULL, CS buffer, Ustrlen(CS buffer), 0,
1641 PCRE_EOPT, NULL, 0) >= 0;
1642
1643 DEBUG(D_transport) debug_printf("%susing PIPELINING\n",
1644 smtp_use_pipelining? "" : "not ");
1645
1646 #ifndef DISABLE_PRDR
1647 prdr_offered = esmtp &&
1648 pcre_exec(regex_PRDR, NULL, CS buffer, Ustrlen(CS buffer), 0,
1649 PCRE_EOPT, NULL, 0) >= 0 &&
1650 verify_check_this_host(&(ob->hosts_try_prdr), NULL, host->name,
1651 host->address, NULL) == OK;
1652
1653 if (prdr_offered)
1654 {DEBUG(D_transport) debug_printf("PRDR usable\n");}
1655 #endif
1656
1657 #ifdef EXPERIMENTAL_DSN
1658 /* Note if the server supports DSN */
1659 smtp_use_dsn = esmtp && pcre_exec(regex_DSN, NULL, CS buffer, (int)Ustrlen(CS buffer), 0,
1660 PCRE_EOPT, NULL, 0) >= 0;
1661 DEBUG(D_transport) debug_printf("use_dsn=%d\n", smtp_use_dsn);
1662 #endif
1663
1664 /* Note if the response to EHLO specifies support for the AUTH extension.
1665 If it has, check that this host is one we want to authenticate to, and do
1666 the business. The host name and address must be available when the
1667 authenticator's client driver is running. */
1668
1669 switch (yield = smtp_auth(buffer, sizeof(buffer), addrlist, host,
1670 ob, esmtp, &inblock, &outblock))
1671 {
1672 default: goto SEND_QUIT;
1673 case OK: break;
1674 case FAIL_SEND: goto SEND_FAILED;
1675 case FAIL: goto RESPONSE_FAILED;
1676 }
1677 }
1678
1679 /* The setting up of the SMTP call is now complete. Any subsequent errors are
1680 message-specific. */
1681
1682 setting_up = FALSE;
1683
1684 /* If there is a filter command specified for this transport, we can now
1685 set it up. This cannot be done until the identify of the host is known. */
1686
1687 if (tblock->filter_command != NULL)
1688 {
1689 BOOL rc;
1690 uschar buffer[64];
1691 sprintf(CS buffer, "%.50s transport", tblock->name);
1692 rc = transport_set_up_command(&transport_filter_argv, tblock->filter_command,
1693 TRUE, DEFER, addrlist, buffer, NULL);
1694 transport_filter_timeout = tblock->filter_timeout;
1695
1696 /* On failure, copy the error to all addresses, abandon the SMTP call, and
1697 yield ERROR. */
1698
1699 if (!rc)
1700 {
1701 set_errno(addrlist->next, addrlist->basic_errno, addrlist->message, DEFER,
1702 FALSE);
1703 yield = ERROR;
1704 goto SEND_QUIT;
1705 }
1706 }
1707
1708
1709 /* For messages that have more than the maximum number of envelope recipients,
1710 we want to send several transactions down the same SMTP connection. (See
1711 comments in deliver.c as to how this reconciles, heuristically, with
1712 remote_max_parallel.) This optimization was added to Exim after the following
1713 code was already working. The simplest way to put it in without disturbing the
1714 code was to use a goto to jump back to this point when there is another
1715 transaction to handle. */
1716
1717 SEND_MESSAGE:
1718 sync_addr = first_addr;
1719 address_count = 0;
1720 ok = FALSE;
1721 send_rset = TRUE;
1722 completed_address = FALSE;
1723
1724
1725 /* Initiate a message transfer. If we know the receiving MTA supports the SIZE
1726 qualification, send it, adding something to the message size to allow for
1727 imprecision and things that get added en route. Exim keeps the number of lines
1728 in a message, so we can give an accurate value for the original message, but we
1729 need some additional to handle added headers. (Double "." characters don't get
1730 included in the count.) */
1731
1732 p = buffer;
1733 *p = 0;
1734
1735 if (smtp_use_size)
1736 {
1737 sprintf(CS p, " SIZE=%d", message_size+message_linecount+ob->size_addition);
1738 while (*p) p++;
1739 }
1740
1741 #ifndef DISABLE_PRDR
1742 prdr_active = FALSE;
1743 if (prdr_offered)
1744 {
1745 for (addr = first_addr; addr; addr = addr->next)
1746 if (addr->transport_return == PENDING_DEFER)
1747 {
1748 for (addr = addr->next; addr; addr = addr->next)
1749 if (addr->transport_return == PENDING_DEFER)
1750 { /* at least two recipients to send */
1751 prdr_active = TRUE;
1752 sprintf(CS p, " PRDR"); p += 5;
1753 break;
1754 }
1755 break;
1756 }
1757 }
1758 #endif
1759
1760 #ifdef EXPERIMENTAL_DSN
1761 /* check if all addresses have lasthop flag */
1762 /* do not send RET and ENVID if true */
1763 dsn_all_lasthop = TRUE;
1764 for (addr = first_addr;
1765 address_count < max_rcpt && addr != NULL;
1766 addr = addr->next)
1767 if ((addr->dsn_flags & rf_dsnlasthop) != 1)
1768 dsn_all_lasthop = FALSE;
1769
1770 /* Add any DSN flags to the mail command */
1771
1772 if ((smtp_use_dsn) && (dsn_all_lasthop == FALSE))
1773 {
1774 if (dsn_ret == dsn_ret_hdrs)
1775 {
1776 strcpy(p, " RET=HDRS");
1777 while (*p) p++;
1778 }
1779 else if (dsn_ret == dsn_ret_full)
1780 {
1781 strcpy(p, " RET=FULL");
1782 while (*p) p++;
1783 }
1784 if (dsn_envid != NULL)
1785 {
1786 string_format(p, sizeof(buffer) - (p-buffer), " ENVID=%s", dsn_envid);
1787 while (*p) p++;
1788 }
1789 }
1790 #endif
1791
1792 /* If an authenticated_sender override has been specified for this transport
1793 instance, expand it. If the expansion is forced to fail, and there was already
1794 an authenticated_sender for this message, the original value will be used.
1795 Other expansion failures are serious. An empty result is ignored, but there is
1796 otherwise no check - this feature is expected to be used with LMTP and other
1797 cases where non-standard addresses (e.g. without domains) might be required. */
1798
1799 if (smtp_mail_auth_str(p, sizeof(buffer) - (p-buffer), addrlist, ob))
1800 {
1801 yield = ERROR;
1802 goto SEND_QUIT;
1803 }
1804
1805 /* From here until we send the DATA command, we can make use of PIPELINING
1806 if the server host supports it. The code has to be able to check the responses
1807 at any point, for when the buffer fills up, so we write it totally generally.
1808 When PIPELINING is off, each command written reports that it has flushed the
1809 buffer. */
1810
1811 pending_MAIL = TRUE; /* The block starts with MAIL */
1812
1813 rc = smtp_write_command(&outblock, smtp_use_pipelining,
1814 "MAIL FROM:<%s>%s\r\n", return_path, buffer);
1815 mail_command = string_copy(big_buffer); /* Save for later error message */
1816
1817 switch(rc)
1818 {
1819 case -1: /* Transmission error */
1820 goto SEND_FAILED;
1821
1822 case +1: /* Block was sent */
1823 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1824 ob->command_timeout))
1825 {
1826 if (errno == 0 && buffer[0] == '4')
1827 {
1828 errno = ERRNO_MAIL4XX;
1829 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1830 }
1831 goto RESPONSE_FAILED;
1832 }
1833 pending_MAIL = FALSE;
1834 break;
1835 }
1836
1837 /* Pass over all the relevant recipient addresses for this host, which are the
1838 ones that have status PENDING_DEFER. If we are using PIPELINING, we can send
1839 several before we have to read the responses for those seen so far. This
1840 checking is done by a subroutine because it also needs to be done at the end.
1841 Send only up to max_rcpt addresses at a time, leaving first_addr pointing to
1842 the next one if not all are sent.
1843
1844 In the MUA wrapper situation, we want to flush the PIPELINING buffer for the
1845 last address because we want to abort if any recipients have any kind of
1846 problem, temporary or permanent. We know that all recipient addresses will have
1847 the PENDING_DEFER status, because only one attempt is ever made, and we know
1848 that max_rcpt will be large, so all addresses will be done at once. */
1849
1850 for (addr = first_addr;
1851 address_count < max_rcpt && addr != NULL;
1852 addr = addr->next)
1853 {
1854 int count;
1855 BOOL no_flush;
1856
1857 #ifdef EXPERIMENTAL_DSN
1858 addr->dsn_aware = smtp_use_dsn ? dsn_support_yes : dsn_support_no;
1859 #endif
1860
1861 if (addr->transport_return != PENDING_DEFER) continue;
1862
1863 address_count++;
1864 no_flush = smtp_use_pipelining && (!mua_wrapper || addr->next != NULL);
1865
1866 #ifdef EXPERIMENTAL_DSN
1867 /* Add any DSN flags to the rcpt command and add to the sent string */
1868
1869 p = buffer;
1870 *p = 0;
1871
1872 if (smtp_use_dsn && (addr->dsn_flags & rf_dsnlasthop) != 1)
1873 {
1874 if ((addr->dsn_flags & rf_dsnflags) != 0)
1875 {
1876 int i;
1877 BOOL first = TRUE;
1878 strcpy(p, " NOTIFY=");
1879 while (*p) p++;
1880 for (i = 0; i < 4; i++)
1881 if ((addr->dsn_flags & rf_list[i]) != 0)
1882 {
1883 if (!first) *p++ = ',';
1884 first = FALSE;
1885 strcpy(p, rf_names[i]);
1886 while (*p) p++;
1887 }
1888 }
1889
1890 if (addr->dsn_orcpt != NULL)
1891 {
1892 string_format(p, sizeof(buffer) - (p-buffer), " ORCPT=%s",
1893 addr->dsn_orcpt);
1894 while (*p) p++;
1895 }
1896 }
1897 #endif
1898
1899
1900 /* Now send the RCPT command, and process outstanding responses when
1901 necessary. After a timeout on RCPT, we just end the function, leaving the
1902 yield as OK, because this error can often mean that there is a problem with
1903 just one address, so we don't want to delay the host. */
1904
1905 #ifdef EXPERIMENTAL_DSN
1906 count = smtp_write_command(&outblock, no_flush, "RCPT TO:<%s>%s%s\r\n",
1907 transport_rcpt_address(addr, tblock->rcpt_include_affixes), igquotstr, buffer);
1908 #else
1909 count = smtp_write_command(&outblock, no_flush, "RCPT TO:<%s>%s\r\n",
1910 transport_rcpt_address(addr, tblock->rcpt_include_affixes), igquotstr);
1911 #endif
1912
1913 if (count < 0) goto SEND_FAILED;
1914 if (count > 0)
1915 {
1916 switch(sync_responses(first_addr, tblock->rcpt_include_affixes,
1917 &sync_addr, host, count, ob->address_retry_include_sender,
1918 pending_MAIL, 0, &inblock, ob->command_timeout, buffer,
1919 sizeof(buffer)))
1920 {
1921 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1922 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1923 break;
1924
1925 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1926 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1927 case 0: /* No 2xx or 5xx, but no probs */
1928 break;
1929
1930 case -1: goto END_OFF; /* Timeout on RCPT */
1931 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL error */
1932 }
1933 pending_MAIL = FALSE; /* Dealt with MAIL */
1934 }
1935 } /* Loop for next address */
1936
1937 /* If we are an MUA wrapper, abort if any RCPTs were rejected, either
1938 permanently or temporarily. We should have flushed and synced after the last
1939 RCPT. */
1940
1941 if (mua_wrapper)
1942 {
1943 address_item *badaddr;
1944 for (badaddr = first_addr; badaddr != NULL; badaddr = badaddr->next)
1945 {
1946 if (badaddr->transport_return != PENDING_OK) break;
1947 }
1948 if (badaddr != NULL)
1949 {
1950 set_errno(addrlist, 0, badaddr->message, FAIL,
1951 testflag(badaddr, af_pass_message));
1952 ok = FALSE;
1953 }
1954 }
1955
1956 /* If ok is TRUE, we know we have got at least one good recipient, and must now
1957 send DATA, but if it is FALSE (in the normal, non-wrapper case), we may still
1958 have a good recipient buffered up if we are pipelining. We don't want to waste
1959 time sending DATA needlessly, so we only send it if either ok is TRUE or if we
1960 are pipelining. The responses are all handled by sync_responses(). */
1961
1962 if (ok || (smtp_use_pipelining && !mua_wrapper))
1963 {
1964 int count = smtp_write_command(&outblock, FALSE, "DATA\r\n");
1965 if (count < 0) goto SEND_FAILED;
1966 switch(sync_responses(first_addr, tblock->rcpt_include_affixes, &sync_addr,
1967 host, count, ob->address_retry_include_sender, pending_MAIL,
1968 ok? +1 : -1, &inblock, ob->command_timeout, buffer, sizeof(buffer)))
1969 {
1970 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1971 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1972 break;
1973
1974 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1975 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1976 case 0: break; /* No 2xx or 5xx, but no probs */
1977
1978 case -1: goto END_OFF; /* Timeout on RCPT */
1979 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */
1980 }
1981 }
1982
1983 /* Save the first address of the next batch. */
1984
1985 first_addr = addr;
1986
1987 /* If there were no good recipients (but otherwise there have been no
1988 problems), just set ok TRUE, since we have handled address-specific errors
1989 already. Otherwise, it's OK to send the message. Use the check/escape mechanism
1990 for handling the SMTP dot-handling protocol, flagging to apply to headers as
1991 well as body. Set the appropriate timeout value to be used for each chunk.
1992 (Haven't been able to make it work using select() for writing yet.) */
1993
1994 if (!ok) ok = TRUE; else
1995 {
1996 sigalrm_seen = FALSE;
1997 transport_write_timeout = ob->data_timeout;
1998 smtp_command = US"sending data block"; /* For error messages */
1999 DEBUG(D_transport|D_v)
2000 debug_printf(" SMTP>> writing message and terminating \".\"\n");
2001 transport_count = 0;
2002
2003 #ifndef DISABLE_DKIM
2004 ok = dkim_transport_write_message(addrlist, inblock.sock,
2005 topt_use_crlf | topt_end_dot | topt_escape_headers |
2006 (tblock->body_only? topt_no_headers : 0) |
2007 (tblock->headers_only? topt_no_body : 0) |
2008 (tblock->return_path_add? topt_add_return_path : 0) |
2009 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
2010 (tblock->envelope_to_add? topt_add_envelope_to : 0),
2011 0, /* No size limit */
2012 tblock->add_headers, tblock->remove_headers,
2013 US".", US"..", /* Escaping strings */
2014 tblock->rewrite_rules, tblock->rewrite_existflags,
2015 ob->dkim_private_key, ob->dkim_domain, ob->dkim_selector,
2016 ob->dkim_canon, ob->dkim_strict, ob->dkim_sign_headers
2017 );
2018 #else
2019 ok = transport_write_message(addrlist, inblock.sock,
2020 topt_use_crlf | topt_end_dot | topt_escape_headers |
2021 (tblock->body_only? topt_no_headers : 0) |
2022 (tblock->headers_only? topt_no_body : 0) |
2023 (tblock->return_path_add? topt_add_return_path : 0) |
2024 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
2025 (tblock->envelope_to_add? topt_add_envelope_to : 0),
2026 0, /* No size limit */
2027 tblock->add_headers, tblock->remove_headers,
2028 US".", US"..", /* Escaping strings */
2029 tblock->rewrite_rules, tblock->rewrite_existflags);
2030 #endif
2031
2032 /* transport_write_message() uses write() because it is called from other
2033 places to write to non-sockets. This means that under some OS (e.g. Solaris)
2034 it can exit with "Broken pipe" as its error. This really means that the
2035 socket got closed at the far end. */
2036
2037 transport_write_timeout = 0; /* for subsequent transports */
2038
2039 /* Failure can either be some kind of I/O disaster (including timeout),
2040 or the failure of a transport filter or the expansion of added headers. */
2041
2042 if (!ok)
2043 {
2044 buffer[0] = 0; /* There hasn't been a response */
2045 goto RESPONSE_FAILED;
2046 }
2047
2048 /* We used to send the terminating "." explicitly here, but because of
2049 buffering effects at both ends of TCP/IP connections, you don't gain
2050 anything by keeping it separate, so it might as well go in the final
2051 data buffer for efficiency. This is now done by setting the topt_end_dot
2052 flag above. */
2053
2054 smtp_command = US"end of data";
2055
2056 #ifndef DISABLE_PRDR
2057 /* For PRDR we optionally get a partial-responses warning
2058 * followed by the individual responses, before going on with
2059 * the overall response. If we don't get the warning then deal
2060 * with per non-PRDR. */
2061 if(prdr_active)
2062 {
2063 ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '3',
2064 ob->final_timeout);
2065 if (!ok && errno == 0)
2066 switch(buffer[0])
2067 {
2068 case '2': prdr_active = FALSE;
2069 ok = TRUE;
2070 break;
2071 case '4': errno = ERRNO_DATA4XX;
2072 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
2073 break;
2074 }
2075 }
2076 else
2077 #endif
2078
2079 /* For non-PRDR SMTP, we now read a single response that applies to the
2080 whole message. If it is OK, then all the addresses have been delivered. */
2081
2082 if (!lmtp)
2083 {
2084 ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2085 ob->final_timeout);
2086 if (!ok && errno == 0 && buffer[0] == '4')
2087 {
2088 errno = ERRNO_DATA4XX;
2089 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
2090 }
2091 }
2092
2093 /* For LMTP, we get back a response for every RCPT command that we sent;
2094 some may be accepted and some rejected. For those that get a response, their
2095 status is fixed; any that are accepted have been handed over, even if later
2096 responses crash - at least, that's how I read RFC 2033.
2097
2098 If all went well, mark the recipient addresses as completed, record which
2099 host/IPaddress they were delivered to, and cut out RSET when sending another
2100 message down the same channel. Write the completed addresses to the journal
2101 now so that they are recorded in case there is a crash of hardware or
2102 software before the spool gets updated. Also record the final SMTP
2103 confirmation if needed (for SMTP only). */
2104
2105 if (ok)
2106 {
2107 int flag = '=';
2108 int delivery_time = (int)(time(NULL) - start_delivery_time);
2109 int len;
2110 host_item *thost;
2111 uschar *conf = NULL;
2112 send_rset = FALSE;
2113
2114 /* Make a copy of the host if it is local to this invocation
2115 of the transport. */
2116
2117 if (copy_host)
2118 {
2119 thost = store_get(sizeof(host_item));
2120 *thost = *host;
2121 thost->name = string_copy(host->name);
2122 thost->address = string_copy(host->address);
2123 }
2124 else thost = host;
2125
2126 /* Set up confirmation if needed - applies only to SMTP */
2127
2128 if (
2129 #ifndef EXPERIMENTAL_TPDA
2130 (log_extra_selector & LX_smtp_confirmation) != 0 &&
2131 #endif
2132 !lmtp
2133 )
2134 {
2135 uschar *s = string_printing(buffer);
2136 conf = (s == buffer)? (uschar *)string_copy(s) : s;
2137 }
2138
2139 /* Process all transported addresses - for LMTP or PRDR, read a status for
2140 each one. */
2141
2142 for (addr = addrlist; addr != first_addr; addr = addr->next)
2143 {
2144 if (addr->transport_return != PENDING_OK) continue;
2145
2146 /* LMTP - if the response fails badly (e.g. timeout), use it for all the
2147 remaining addresses. Otherwise, it's a return code for just the one
2148 address. For temporary errors, add a retry item for the address so that
2149 it doesn't get tried again too soon. */
2150
2151 #ifndef DISABLE_PRDR
2152 if (lmtp || prdr_active)
2153 #else
2154 if (lmtp)
2155 #endif
2156 {
2157 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2158 ob->final_timeout))
2159 {
2160 if (errno != 0 || buffer[0] == 0) goto RESPONSE_FAILED;
2161 addr->message = string_sprintf(
2162 #ifndef DISABLE_PRDR
2163 "%s error after %s: %s", prdr_active ? "PRDR":"LMTP",
2164 #else
2165 "LMTP error after %s: %s",
2166 #endif
2167 big_buffer, string_printing(buffer));
2168 setflag(addr, af_pass_message); /* Allow message to go to user */
2169 if (buffer[0] == '5')
2170 addr->transport_return = FAIL;
2171 else
2172 {
2173 errno = ERRNO_DATA4XX;
2174 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
2175 addr->transport_return = DEFER;
2176 #ifndef DISABLE_PRDR
2177 if (!prdr_active)
2178 #endif
2179 retry_add_item(addr, addr->address_retry_key, 0);
2180 }
2181 continue;
2182 }
2183 completed_address = TRUE; /* NOW we can set this flag */
2184 if ((log_extra_selector & LX_smtp_confirmation) != 0)
2185 {
2186 uschar *s = string_printing(buffer);
2187 conf = (s == buffer)? (uschar *)string_copy(s) : s;
2188 }
2189 }
2190
2191 /* SMTP, or success return from LMTP for this address. Pass back the
2192 actual host that was used. */
2193
2194 addr->transport_return = OK;
2195 addr->more_errno = delivery_time;
2196 addr->host_used = thost;
2197 addr->special_action = flag;
2198 addr->message = conf;
2199 #ifndef DISABLE_PRDR
2200 if (prdr_active) addr->flags |= af_prdr_used;
2201 #endif
2202 flag = '-';
2203
2204 #ifndef DISABLE_PRDR
2205 if (!prdr_active)
2206 #endif
2207 {
2208 /* Update the journal. For homonymic addresses, use the base address plus
2209 the transport name. See lots of comments in deliver.c about the reasons
2210 for the complications when homonyms are involved. Just carry on after
2211 write error, as it may prove possible to update the spool file later. */
2212
2213 if (testflag(addr, af_homonym))
2214 sprintf(CS buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
2215 else
2216 sprintf(CS buffer, "%.500s\n", addr->unique);
2217
2218 DEBUG(D_deliver) debug_printf("journalling %s", buffer);
2219 len = Ustrlen(CS buffer);
2220 if (write(journal_fd, buffer, len) != len)
2221 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
2222 "%s: %s", buffer, strerror(errno));
2223 }
2224 }
2225
2226 #ifndef DISABLE_PRDR
2227 if (prdr_active)
2228 {
2229 /* PRDR - get the final, overall response. For any non-success
2230 upgrade all the address statuses. */
2231 ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2232 ob->final_timeout);
2233 if (!ok)
2234 {
2235 if(errno == 0 && buffer[0] == '4')
2236 {
2237 errno = ERRNO_DATA4XX;
2238 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
2239 }
2240 for (addr = addrlist; addr != first_addr; addr = addr->next)
2241 if (buffer[0] == '5' || addr->transport_return == OK)
2242 addr->transport_return = PENDING_OK; /* allow set_errno action */
2243 goto RESPONSE_FAILED;
2244 }
2245
2246 /* Update the journal, or setup retry. */
2247 for (addr = addrlist; addr != first_addr; addr = addr->next)
2248 if (addr->transport_return == OK)
2249 {
2250 if (testflag(addr, af_homonym))
2251 sprintf(CS buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
2252 else
2253 sprintf(CS buffer, "%.500s\n", addr->unique);
2254
2255 DEBUG(D_deliver) debug_printf("journalling(PRDR) %s", buffer);
2256 len = Ustrlen(CS buffer);
2257 if (write(journal_fd, buffer, len) != len)
2258 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
2259 "%s: %s", buffer, strerror(errno));
2260 }
2261 else if (addr->transport_return == DEFER)
2262 retry_add_item(addr, addr->address_retry_key, -2);
2263 }
2264 #endif
2265
2266 /* Ensure the journal file is pushed out to disk. */
2267
2268 if (EXIMfsync(journal_fd) < 0)
2269 log_write(0, LOG_MAIN|LOG_PANIC, "failed to fsync journal: %s",
2270 strerror(errno));
2271 }
2272 }
2273
2274
2275 /* Handle general (not specific to one address) failures here. The value of ok
2276 is used to skip over this code on the falling through case. A timeout causes a
2277 deferral. Other errors may defer or fail according to the response code, and
2278 may set up a special errno value, e.g. after connection chopped, which is
2279 assumed if errno == 0 and there is no text in the buffer. If control reaches
2280 here during the setting up phase (i.e. before MAIL FROM) then always defer, as
2281 the problem is not related to this specific message. */
2282
2283 if (!ok)
2284 {
2285 int code;
2286
2287 RESPONSE_FAILED:
2288 save_errno = errno;
2289 message = NULL;
2290 send_quit = check_response(host, &save_errno, addrlist->more_errno,
2291 buffer, &code, &message, &pass_message);
2292 goto FAILED;
2293
2294 SEND_FAILED:
2295 save_errno = errno;
2296 code = '4';
2297 message = US string_sprintf("send() to %s [%s] failed: %s",
2298 host->name, host->address, strerror(save_errno));
2299 send_quit = FALSE;
2300 goto FAILED;
2301
2302 /* This label is jumped to directly when a TLS negotiation has failed,
2303 or was not done for a host for which it is required. Values will be set
2304 in message and save_errno, and setting_up will always be true. Treat as
2305 a temporary error. */
2306
2307 #ifdef SUPPORT_TLS
2308 TLS_FAILED:
2309 code = '4';
2310 #endif
2311
2312 /* If the failure happened while setting up the call, see if the failure was
2313 a 5xx response (this will either be on connection, or following HELO - a 5xx
2314 after EHLO causes it to try HELO). If so, fail all addresses, as this host is
2315 never going to accept them. For other errors during setting up (timeouts or
2316 whatever), defer all addresses, and yield DEFER, so that the host is not
2317 tried again for a while. */
2318
2319 FAILED:
2320 ok = FALSE; /* For when reached by GOTO */
2321
2322 if (setting_up)
2323 {
2324 if (code == '5')
2325 {
2326 set_errno(addrlist, save_errno, message, FAIL, pass_message);
2327 }
2328 else
2329 {
2330 set_errno(addrlist, save_errno, message, DEFER, pass_message);
2331 yield = DEFER;
2332 }
2333 }
2334
2335 /* We want to handle timeouts after MAIL or "." and loss of connection after
2336 "." specially. They can indicate a problem with the sender address or with
2337 the contents of the message rather than a real error on the connection. These
2338 cases are treated in the same way as a 4xx response. This next bit of code
2339 does the classification. */
2340
2341 else
2342 {
2343 BOOL message_error;
2344
2345 switch(save_errno)
2346 {
2347 case 0:
2348 case ERRNO_MAIL4XX:
2349 case ERRNO_DATA4XX:
2350 message_error = TRUE;
2351 break;
2352
2353 case ETIMEDOUT:
2354 message_error = Ustrncmp(smtp_command,"MAIL",4) == 0 ||
2355 Ustrncmp(smtp_command,"end ",4) == 0;
2356 break;
2357
2358 case ERRNO_SMTPCLOSED:
2359 message_error = Ustrncmp(smtp_command,"end ",4) == 0;
2360 break;
2361
2362 default:
2363 message_error = FALSE;
2364 break;
2365 }
2366
2367 /* Handle the cases that are treated as message errors. These are:
2368
2369 (a) negative response or timeout after MAIL
2370 (b) negative response after DATA
2371 (c) negative response or timeout or dropped connection after "."
2372
2373 It won't be a negative response or timeout after RCPT, as that is dealt
2374 with separately above. The action in all cases is to set an appropriate
2375 error code for all the addresses, but to leave yield set to OK because the
2376 host itself has not failed. Of course, it might in practice have failed
2377 when we've had a timeout, but if so, we'll discover that at the next
2378 delivery attempt. For a temporary error, set the message_defer flag, and
2379 write to the logs for information if this is not the last host. The error
2380 for the last host will be logged as part of the address's log line. */
2381
2382 if (message_error)
2383 {
2384 if (mua_wrapper) code = '5'; /* Force hard failure in wrapper mode */
2385 set_errno(addrlist, save_errno, message, (code == '5')? FAIL : DEFER,
2386 pass_message);
2387
2388 /* If there's an errno, the message contains just the identity of
2389 the host. */
2390
2391 if (code != '5') /* Anything other than 5 is treated as temporary */
2392 {
2393 if (save_errno > 0)
2394 message = US string_sprintf("%s: %s", message, strerror(save_errno));
2395 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", message);
2396 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
2397 *message_defer = TRUE;
2398 }
2399 }
2400
2401 /* Otherwise, we have an I/O error or a timeout other than after MAIL or
2402 ".", or some other transportation error. We defer all addresses and yield
2403 DEFER, except for the case of failed add_headers expansion, or a transport
2404 filter failure, when the yield should be ERROR, to stop it trying other
2405 hosts. */
2406
2407 else
2408 {
2409 yield = (save_errno == ERRNO_CHHEADER_FAIL ||
2410 save_errno == ERRNO_FILTER_FAIL)? ERROR : DEFER;
2411 set_errno(addrlist, save_errno, message, DEFER, pass_message);
2412 }
2413 }
2414 }
2415
2416
2417 /* If all has gone well, send_quit will be set TRUE, implying we can end the
2418 SMTP session tidily. However, if there were too many addresses to send in one
2419 message (indicated by first_addr being non-NULL) we want to carry on with the
2420 rest of them. Also, it is desirable to send more than one message down the SMTP
2421 connection if there are several waiting, provided we haven't already sent so
2422 many as to hit the configured limit. The function transport_check_waiting looks
2423 for a waiting message and returns its id. Then transport_pass_socket tries to
2424 set up a continued delivery by passing the socket on to another process. The
2425 variable send_rset is FALSE if a message has just been successfully transfered.
2426
2427 If we are already sending down a continued channel, there may be further
2428 addresses not yet delivered that are aimed at the same host, but which have not
2429 been passed in this run of the transport. In this case, continue_more will be
2430 true, and all we should do is send RSET if necessary, and return, leaving the
2431 channel open.
2432
2433 However, if no address was disposed of, i.e. all addresses got 4xx errors, we
2434 do not want to continue with other messages down the same channel, because that
2435 can lead to looping between two or more messages, all with the same,
2436 temporarily failing address(es). [The retry information isn't updated yet, so
2437 new processes keep on trying.] We probably also don't want to try more of this
2438 message's addresses either.
2439
2440 If we have started a TLS session, we have to end it before passing the
2441 connection to a new process. However, not all servers can handle this (Exim
2442 can), so we do not pass such a connection on if the host matches
2443 hosts_nopass_tls. */
2444
2445 DEBUG(D_transport)
2446 debug_printf("ok=%d send_quit=%d send_rset=%d continue_more=%d "
2447 "yield=%d first_address is %sNULL\n", ok, send_quit, send_rset,
2448 continue_more, yield, (first_addr == NULL)? "":"not ");
2449
2450 if (completed_address && ok && send_quit)
2451 {
2452 BOOL more;
2453 if (first_addr != NULL || continue_more ||
2454 (
2455 (tls_out.active < 0 ||
2456 verify_check_this_host(&(ob->hosts_nopass_tls), NULL, host->name,
2457 host->address, NULL) != OK)
2458 &&
2459 transport_check_waiting(tblock->name, host->name,
2460 tblock->connection_max_messages, new_message_id, &more)
2461 ))
2462 {
2463 uschar *msg;
2464 BOOL pass_message;
2465
2466 if (send_rset)
2467 {
2468 if (! (ok = smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0))
2469 {
2470 msg = US string_sprintf("send() to %s [%s] failed: %s", host->name,
2471 host->address, strerror(save_errno));
2472 send_quit = FALSE;
2473 }
2474 else if (! (ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2475 ob->command_timeout)))
2476 {
2477 int code;
2478 send_quit = check_response(host, &errno, 0, buffer, &code, &msg,
2479 &pass_message);
2480 if (!send_quit)
2481 {
2482 DEBUG(D_transport) debug_printf("%s\n", msg);
2483 }
2484 }
2485 }
2486
2487 /* Either RSET was not needed, or it succeeded */
2488
2489 if (ok)
2490 {
2491 if (first_addr != NULL) /* More addresses still to be sent */
2492 { /* in this run of the transport */
2493 continue_sequence++; /* Causes * in logging */
2494 goto SEND_MESSAGE;
2495 }
2496 if (continue_more) return yield; /* More addresses for another run */
2497
2498 /* Pass the socket to a new Exim process. Before doing so, we must shut
2499 down TLS. Not all MTAs allow for the continuation of the SMTP session
2500 when TLS is shut down. We test for this by sending a new EHLO. If we
2501 don't get a good response, we don't attempt to pass the socket on. */
2502
2503 #ifdef SUPPORT_TLS
2504 if (tls_out.active >= 0)
2505 {
2506 tls_close(FALSE, TRUE);
2507 if (smtps)
2508 ok = FALSE;
2509 else
2510 ok = smtp_write_command(&outblock,FALSE,"EHLO %s\r\n",helo_data) >= 0 &&
2511 smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2512 ob->command_timeout);
2513 }
2514 #endif
2515
2516 /* If the socket is successfully passed, we musn't send QUIT (or
2517 indeed anything!) from here. */
2518
2519 if (ok && transport_pass_socket(tblock->name, host->name, host->address,
2520 new_message_id, inblock.sock))
2521 {
2522 send_quit = FALSE;
2523 }
2524 }
2525
2526 /* If RSET failed and there are addresses left, they get deferred. */
2527
2528 else set_errno(first_addr, errno, msg, DEFER, FALSE);
2529 }
2530 }
2531
2532 /* End off tidily with QUIT unless the connection has died or the socket has
2533 been passed to another process. There has been discussion on the net about what
2534 to do after sending QUIT. The wording of the RFC suggests that it is necessary
2535 to wait for a response, but on the other hand, there isn't anything one can do
2536 with an error response, other than log it. Exim used to do that. However,
2537 further discussion suggested that it is positively advantageous not to wait for
2538 the response, but to close the session immediately. This is supposed to move
2539 the TCP/IP TIME_WAIT state from the server to the client, thereby removing some
2540 load from the server. (Hosts that are both servers and clients may not see much
2541 difference, of course.) Further discussion indicated that this was safe to do
2542 on Unix systems which have decent implementations of TCP/IP that leave the
2543 connection around for a while (TIME_WAIT) after the application has gone away.
2544 This enables the response sent by the server to be properly ACKed rather than
2545 timed out, as can happen on broken TCP/IP implementations on other OS.
2546
2547 This change is being made on 31-Jul-98. After over a year of trouble-free
2548 operation, the old commented-out code was removed on 17-Sep-99. */
2549
2550 SEND_QUIT:
2551 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
2552
2553 END_OFF:
2554
2555 #ifdef SUPPORT_TLS
2556 tls_close(FALSE, TRUE);
2557 #endif
2558
2559 /* Close the socket, and return the appropriate value, first setting
2560 works because the NULL setting is passed back to the calling process, and
2561 remote_max_parallel is forced to 1 when delivering over an existing connection,
2562
2563 If all went well and continue_more is set, we shouldn't actually get here if
2564 there are further addresses, as the return above will be taken. However,
2565 writing RSET might have failed, or there may be other addresses whose hosts are
2566 specified in the transports, and therefore not visible at top level, in which
2567 case continue_more won't get set. */
2568
2569 (void)close(inblock.sock);
2570
2571 #ifdef EXPERIMENTAL_TPDA
2572 (void) tpda_raise_event(tblock->tpda_event_action, US"tcp:close", NULL);
2573 #endif
2574
2575 continue_transport = NULL;
2576 continue_hostname = NULL;
2577 return yield;
2578 }
2579
2580
2581
2582
2583 /*************************************************
2584 * Closedown entry point *
2585 *************************************************/
2586
2587 /* This function is called when exim is passed an open smtp channel
2588 from another incarnation, but the message which it has been asked
2589 to deliver no longer exists. The channel is on stdin.
2590
2591 We might do fancy things like looking for another message to send down
2592 the channel, but if the one we sought has gone, it has probably been
2593 delivered by some other process that itself will seek further messages,
2594 so just close down our connection.
2595
2596 Argument: pointer to the transport instance block
2597 Returns: nothing
2598 */
2599
2600 void
2601 smtp_transport_closedown(transport_instance *tblock)
2602 {
2603 smtp_transport_options_block *ob =
2604 (smtp_transport_options_block *)(tblock->options_block);
2605 smtp_inblock inblock;
2606 smtp_outblock outblock;
2607 uschar buffer[256];
2608 uschar inbuffer[4096];
2609 uschar outbuffer[16];
2610
2611 inblock.sock = fileno(stdin);
2612 inblock.buffer = inbuffer;
2613 inblock.buffersize = sizeof(inbuffer);
2614 inblock.ptr = inbuffer;
2615 inblock.ptrend = inbuffer;
2616
2617 outblock.sock = inblock.sock;
2618 outblock.buffersize = sizeof(outbuffer);
2619 outblock.buffer = outbuffer;
2620 outblock.ptr = outbuffer;
2621 outblock.cmd_count = 0;
2622 outblock.authenticating = FALSE;
2623
2624 (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
2625 (void)smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2626 ob->command_timeout);
2627 (void)close(inblock.sock);
2628 }
2629
2630
2631
2632 /*************************************************
2633 * Prepare addresses for delivery *
2634 *************************************************/
2635
2636 /* This function is called to flush out error settings from previous delivery
2637 attempts to other hosts. It also records whether we got here via an MX record
2638 or not in the more_errno field of the address. We are interested only in
2639 addresses that are still marked DEFER - others may have got delivered to a
2640 previously considered IP address. Set their status to PENDING_DEFER to indicate
2641 which ones are relevant this time.
2642
2643 Arguments:
2644 addrlist the list of addresses
2645 host the host we are delivering to
2646
2647 Returns: the first address for this delivery
2648 */
2649
2650 static address_item *
2651 prepare_addresses(address_item *addrlist, host_item *host)
2652 {
2653 address_item *first_addr = NULL;
2654 address_item *addr;
2655 for (addr = addrlist; addr != NULL; addr = addr->next)
2656 {
2657 if (addr->transport_return != DEFER) continue;
2658 if (first_addr == NULL) first_addr = addr;
2659 addr->transport_return = PENDING_DEFER;
2660 addr->basic_errno = 0;
2661 addr->more_errno = (host->mx >= 0)? 'M' : 'A';
2662 addr->message = NULL;
2663 #ifdef SUPPORT_TLS
2664 addr->cipher = NULL;
2665 addr->ourcert = NULL;
2666 addr->peercert = NULL;
2667 addr->peerdn = NULL;
2668 addr->ocsp = OCSP_NOT_REQ;
2669 #endif
2670 }
2671 return first_addr;
2672 }
2673
2674
2675
2676 /*************************************************
2677 * Main entry point *
2678 *************************************************/
2679
2680 /* See local README for interface details. As this is a remote transport, it is
2681 given a chain of addresses to be delivered in one connection, if possible. It
2682 always returns TRUE, indicating that each address has its own independent
2683 status set, except if there is a setting up problem, in which case it returns
2684 FALSE. */
2685
2686 BOOL
2687 smtp_transport_entry(
2688 transport_instance *tblock, /* data for this instantiation */
2689 address_item *addrlist) /* addresses we are working on */
2690 {
2691 int cutoff_retry;
2692 int port;
2693 int hosts_defer = 0;
2694 int hosts_fail = 0;
2695 int hosts_looked_up = 0;
2696 int hosts_retry = 0;
2697 int hosts_serial = 0;
2698 int hosts_total = 0;
2699 int total_hosts_tried = 0;
2700 address_item *addr;
2701 BOOL expired = TRUE;
2702 BOOL continuing = continue_hostname != NULL;
2703 uschar *expanded_hosts = NULL;
2704 uschar *pistring;
2705 uschar *tid = string_sprintf("%s transport", tblock->name);
2706 smtp_transport_options_block *ob =
2707 (smtp_transport_options_block *)(tblock->options_block);
2708 host_item *hostlist = addrlist->host_list;
2709 host_item *host = NULL;
2710
2711 DEBUG(D_transport)
2712 {
2713 debug_printf("%s transport entered\n", tblock->name);
2714 for (addr = addrlist; addr != NULL; addr = addr->next)
2715 debug_printf(" %s\n", addr->address);
2716 if (continuing) debug_printf("already connected to %s [%s]\n",
2717 continue_hostname, continue_host_address);
2718 }
2719
2720 /* Set the flag requesting that these hosts be added to the waiting
2721 database if the delivery fails temporarily or if we are running with
2722 queue_smtp or a 2-stage queue run. This gets unset for certain
2723 kinds of error, typically those that are specific to the message. */
2724
2725 update_waiting = TRUE;
2726
2727 /* If a host list is not defined for the addresses - they must all have the
2728 same one in order to be passed to a single transport - or if the transport has
2729 a host list with hosts_override set, use the host list supplied with the
2730 transport. It is an error for this not to exist. */
2731
2732 if (hostlist == NULL || (ob->hosts_override && ob->hosts != NULL))
2733 {
2734 if (ob->hosts == NULL)
2735 {
2736 addrlist->message = string_sprintf("%s transport called with no hosts set",
2737 tblock->name);
2738 addrlist->transport_return = PANIC;
2739 return FALSE; /* Only top address has status */
2740 }
2741
2742 DEBUG(D_transport) debug_printf("using the transport's hosts: %s\n",
2743 ob->hosts);
2744
2745 /* If the transport's host list contains no '$' characters, and we are not
2746 randomizing, it is fixed and therefore a chain of hosts can be built once
2747 and for all, and remembered for subsequent use by other calls to this
2748 transport. If, on the other hand, the host list does contain '$', or we are
2749 randomizing its order, we have to rebuild it each time. In the fixed case,
2750 as the hosts string will never be used again, it doesn't matter that we
2751 replace all the : characters with zeros. */
2752
2753 if (ob->hostlist == NULL)
2754 {
2755 uschar *s = ob->hosts;
2756
2757 if (Ustrchr(s, '$') != NULL)
2758 {
2759 expanded_hosts = expand_string(s);
2760 if (expanded_hosts == NULL)
2761 {
2762 addrlist->message = string_sprintf("failed to expand list of hosts "
2763 "\"%s\" in %s transport: %s", s, tblock->name, expand_string_message);
2764 addrlist->transport_return = search_find_defer? DEFER : PANIC;
2765 return FALSE; /* Only top address has status */
2766 }
2767 DEBUG(D_transport) debug_printf("expanded list of hosts \"%s\" to "
2768 "\"%s\"\n", s, expanded_hosts);
2769 s = expanded_hosts;
2770 }
2771 else
2772 if (ob->hosts_randomize) s = expanded_hosts = string_copy(s);
2773
2774 host_build_hostlist(&hostlist, s, ob->hosts_randomize);
2775
2776 /* Check that the expansion yielded something useful. */
2777 if (hostlist == NULL)
2778 {
2779 addrlist->message =
2780 string_sprintf("%s transport has empty hosts setting", tblock->name);
2781 addrlist->transport_return = PANIC;
2782 return FALSE; /* Only top address has status */
2783 }
2784
2785 /* If there was no expansion of hosts, save the host list for
2786 next time. */
2787
2788 if (expanded_hosts == NULL) ob->hostlist = hostlist;
2789 }
2790
2791 /* This is not the first time this transport has been run in this delivery;
2792 the host list was built previously. */
2793
2794 else hostlist = ob->hostlist;
2795 }
2796
2797 /* The host list was supplied with the address. If hosts_randomize is set, we
2798 must sort it into a random order if it did not come from MX records and has not
2799 already been randomized (but don't bother if continuing down an existing
2800 connection). */
2801
2802 else if (ob->hosts_randomize && hostlist->mx == MX_NONE && !continuing)
2803 {
2804 host_item *newlist = NULL;
2805 while (hostlist != NULL)
2806 {
2807 host_item *h = hostlist;
2808 hostlist = hostlist->next;
2809
2810 h->sort_key = random_number(100);
2811
2812 if (newlist == NULL)
2813 {
2814 h->next = NULL;
2815 newlist = h;
2816 }
2817 else if (h->sort_key < newlist->sort_key)
2818 {
2819 h->next = newlist;
2820 newlist = h;
2821 }
2822 else
2823 {
2824 host_item *hh = newlist;
2825 while (hh->next != NULL)
2826 {
2827 if (h->sort_key < hh->next->sort_key) break;
2828 hh = hh->next;
2829 }
2830 h->next = hh->next;
2831 hh->next = h;
2832 }
2833 }
2834
2835 hostlist = addrlist->host_list = newlist;
2836 }
2837
2838
2839 /* Sort out the default port. */
2840
2841 if (!smtp_get_port(ob->port, addrlist, &port, tid)) return FALSE;
2842
2843
2844 /* For each host-plus-IP-address on the list:
2845
2846 . If this is a continued delivery and the host isn't the one with the
2847 current connection, skip.
2848
2849 . If the status is unusable (i.e. previously failed or retry checked), skip.
2850
2851 . If no IP address set, get the address, either by turning the name into
2852 an address, calling gethostbyname if gethostbyname is on, or by calling
2853 the DNS. The DNS may yield multiple addresses, in which case insert the
2854 extra ones into the list.
2855
2856 . Get the retry data if not previously obtained for this address and set the
2857 field which remembers the state of this address. Skip if the retry time is
2858 not reached. If not, remember whether retry data was found. The retry string
2859 contains both the name and the IP address.
2860
2861 . Scan the list of addresses and mark those whose status is DEFER as
2862 PENDING_DEFER. These are the only ones that will be processed in this cycle
2863 of the hosts loop.
2864
2865 . Make a delivery attempt - addresses marked PENDING_DEFER will be tried.
2866 Some addresses may be successfully delivered, others may fail, and yet
2867 others may get temporary errors and so get marked DEFER.
2868
2869 . The return from the delivery attempt is OK if a connection was made and a
2870 valid SMTP dialogue was completed. Otherwise it is DEFER.
2871
2872 . If OK, add a "remove" retry item for this host/IPaddress, if any.
2873
2874 . If fail to connect, or other defer state, add a retry item.
2875
2876 . If there are any addresses whose status is still DEFER, carry on to the
2877 next host/IPaddress, unless we have tried the number of hosts given
2878 by hosts_max_try or hosts_max_try_hardlimit; otherwise return. Note that
2879 there is some fancy logic for hosts_max_try that means its limit can be
2880 overstepped in some circumstances.
2881
2882 If we get to the end of the list, all hosts have deferred at least one address,
2883 or not reached their retry times. If delay_after_cutoff is unset, it requests a
2884 delivery attempt to those hosts whose last try was before the arrival time of
2885 the current message. To cope with this, we have to go round the loop a second
2886 time. After that, set the status and error data for any addresses that haven't
2887 had it set already. */
2888
2889 for (cutoff_retry = 0; expired &&
2890 cutoff_retry < ((ob->delay_after_cutoff)? 1 : 2);
2891 cutoff_retry++)
2892 {
2893 host_item *nexthost = NULL;
2894 int unexpired_hosts_tried = 0;
2895
2896 for (host = hostlist;
2897 host != NULL &&
2898 unexpired_hosts_tried < ob->hosts_max_try &&
2899 total_hosts_tried < ob->hosts_max_try_hardlimit;
2900 host = nexthost)
2901 {
2902 int rc;
2903 int host_af;
2904 uschar *rs;
2905 BOOL serialized = FALSE;
2906 BOOL host_is_expired = FALSE;
2907 BOOL message_defer = FALSE;
2908 BOOL ifchanges = FALSE;
2909 BOOL some_deferred = FALSE;
2910 address_item *first_addr = NULL;
2911 uschar *interface = NULL;
2912 uschar *retry_host_key = NULL;
2913 uschar *retry_message_key = NULL;
2914 uschar *serialize_key = NULL;
2915
2916 /* Default next host is next host. :-) But this can vary if the
2917 hosts_max_try limit is hit (see below). It may also be reset if a host
2918 address is looked up here (in case the host was multihomed). */
2919
2920 nexthost = host->next;
2921
2922 /* If the address hasn't yet been obtained from the host name, look it up
2923 now, unless the host is already marked as unusable. If it is marked as
2924 unusable, it means that the router was unable to find its IP address (in
2925 the DNS or wherever) OR we are in the 2nd time round the cutoff loop, and
2926 the lookup failed last time. We don't get this far if *all* MX records
2927 point to non-existent hosts; that is treated as a hard error.
2928
2929 We can just skip this host entirely. When the hosts came from the router,
2930 the address will timeout based on the other host(s); when the address is
2931 looked up below, there is an explicit retry record added.
2932
2933 Note that we mustn't skip unusable hosts if the address is not unset; they
2934 may be needed as expired hosts on the 2nd time round the cutoff loop. */
2935
2936 if (host->address == NULL)
2937 {
2938 int new_port, flags;
2939 host_item *hh;
2940 uschar *canonical_name;
2941
2942 if (host->status >= hstatus_unusable)
2943 {
2944 DEBUG(D_transport) debug_printf("%s has no address and is unusable - skipping\n",
2945 host->name);
2946 continue;
2947 }
2948
2949 DEBUG(D_transport) debug_printf("getting address for %s\n", host->name);
2950
2951 /* The host name is permitted to have an attached port. Find it, and
2952 strip it from the name. Just remember it for now. */
2953
2954 new_port = host_item_get_port(host);
2955
2956 /* Count hosts looked up */
2957
2958 hosts_looked_up++;
2959
2960 /* Find by name if so configured, or if it's an IP address. We don't
2961 just copy the IP address, because we need the test-for-local to happen. */
2962
2963 flags = HOST_FIND_BY_A;
2964 if (ob->dns_qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
2965 if (ob->dns_search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
2966
2967 if (ob->gethostbyname || string_is_ip_address(host->name, NULL) != 0)
2968 rc = host_find_byname(host, NULL, flags, &canonical_name, TRUE);
2969 else
2970 rc = host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
2971 ob->dnssec_request_domains, ob->dnssec_require_domains,
2972 &canonical_name, NULL);
2973
2974 /* Update the host (and any additional blocks, resulting from
2975 multihoming) with a host-specific port, if any. */
2976
2977 for (hh = host; hh != nexthost; hh = hh->next) hh->port = new_port;
2978
2979 /* Failure to find the host at this time (usually DNS temporary failure)
2980 is really a kind of routing failure rather than a transport failure.
2981 Therefore we add a retry item of the routing kind, not to stop us trying
2982 to look this name up here again, but to ensure the address gets timed
2983 out if the failures go on long enough. A complete failure at this point
2984 commonly points to a configuration error, but the best action is still
2985 to carry on for the next host. */
2986
2987 if (rc == HOST_FIND_AGAIN || rc == HOST_FIND_FAILED)
2988 {
2989 retry_add_item(addrlist, string_sprintf("R:%s", host->name), 0);
2990 expired = FALSE;
2991 if (rc == HOST_FIND_AGAIN) hosts_defer++; else hosts_fail++;
2992 DEBUG(D_transport) debug_printf("rc = %s for %s\n", (rc == HOST_FIND_AGAIN)?
2993 "HOST_FIND_AGAIN" : "HOST_FIND_FAILED", host->name);
2994 host->status = hstatus_unusable;
2995
2996 for (addr = addrlist; addr != NULL; addr = addr->next)
2997 {
2998 if (addr->transport_return != DEFER) continue;
2999 addr->basic_errno = ERRNO_UNKNOWNHOST;
3000 addr->message =
3001 string_sprintf("failed to lookup IP address for %s", host->name);
3002 }
3003 continue;
3004 }
3005
3006 /* If the host is actually the local host, we may have a problem, or
3007 there may be some cunning configuration going on. In the problem case,
3008 log things and give up. The default transport status is already DEFER. */
3009
3010 if (rc == HOST_FOUND_LOCAL && !ob->allow_localhost)
3011 {
3012 for (addr = addrlist; addr != NULL; addr = addr->next)
3013 {
3014 addr->basic_errno = 0;
3015 addr->message = string_sprintf("%s transport found host %s to be "
3016 "local", tblock->name, host->name);
3017 }
3018 goto END_TRANSPORT;
3019 }
3020 } /* End of block for IP address lookup */
3021
3022 /* If this is a continued delivery, we are interested only in the host
3023 which matches the name of the existing open channel. The check is put
3024 here after the local host lookup, in case the name gets expanded as a
3025 result of the lookup. Set expired FALSE, to save the outer loop executing
3026 twice. */
3027
3028 if (continuing && (Ustrcmp(continue_hostname, host->name) != 0 ||
3029 Ustrcmp(continue_host_address, host->address) != 0))
3030 {
3031 expired = FALSE;
3032 continue; /* With next host */
3033 }
3034
3035 /* Reset the default next host in case a multihomed host whose addresses
3036 are not looked up till just above added to the host list. */
3037
3038 nexthost = host->next;
3039
3040 /* If queue_smtp is set (-odqs or the first part of a 2-stage run), or the
3041 domain is in queue_smtp_domains, we don't actually want to attempt any
3042 deliveries. When doing a queue run, queue_smtp_domains is always unset. If
3043 there is a lookup defer in queue_smtp_domains, proceed as if the domain
3044 were not in it. We don't want to hold up all SMTP deliveries! Except when
3045 doing a two-stage queue run, don't do this if forcing. */
3046
3047 if ((!deliver_force || queue_2stage) && (queue_smtp ||
3048 match_isinlist(addrlist->domain, &queue_smtp_domains, 0,
3049 &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL) == OK))
3050 {
3051 expired = FALSE;
3052 for (addr = addrlist; addr != NULL; addr = addr->next)
3053 {
3054 if (addr->transport_return != DEFER) continue;
3055 addr->message = US"domain matches queue_smtp_domains, or -odqs set";
3056 }
3057 continue; /* With next host */
3058 }
3059
3060 /* Count hosts being considered - purely for an intelligent comment
3061 if none are usable. */
3062
3063 hosts_total++;
3064
3065 /* Set $host and $host address now in case they are needed for the
3066 interface expansion or the serialize_hosts check; they remain set if an
3067 actual delivery happens. */
3068
3069 deliver_host = host->name;
3070 deliver_host_address = host->address;
3071 lookup_dnssec_authenticated = host->dnssec == DS_YES ? US"yes"
3072 : host->dnssec == DS_NO ? US"no"
3073 : US"";
3074
3075 /* Set up a string for adding to the retry key if the port number is not
3076 the standard SMTP port. A host may have its own port setting that overrides
3077 the default. */
3078
3079 pistring = string_sprintf(":%d", (host->port == PORT_NONE)?
3080 port : host->port);
3081 if (Ustrcmp(pistring, ":25") == 0) pistring = US"";
3082
3083 /* Select IPv4 or IPv6, and choose an outgoing interface. If the interface
3084 string changes upon expansion, we must add it to the key that is used for
3085 retries, because connections to the same host from a different interface
3086 should be treated separately. */
3087
3088 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET : AF_INET6;
3089 if (!smtp_get_interface(ob->interface, host_af, addrlist, &ifchanges,
3090 &interface, tid))
3091 return FALSE;
3092 if (ifchanges) pistring = string_sprintf("%s/%s", pistring, interface);
3093
3094 /* The first time round the outer loop, check the status of the host by
3095 inspecting the retry data. The second time round, we are interested only
3096 in expired hosts that haven't been tried since this message arrived. */
3097
3098 if (cutoff_retry == 0)
3099 {
3100 /* Ensure the status of the address is set by checking retry data if
3101 necessary. There maybe host-specific retry data (applicable to all
3102 messages) and also data for retries of a specific message at this host.
3103 If either of these retry records are actually read, the keys used are
3104 returned to save recomputing them later. */
3105
3106 host_is_expired = retry_check_address(addrlist->domain, host, pistring,
3107 ob->retry_include_ip_address, &retry_host_key, &retry_message_key);
3108
3109 DEBUG(D_transport) debug_printf("%s [%s]%s status = %s\n", host->name,
3110 (host->address == NULL)? US"" : host->address, pistring,
3111 (host->status == hstatus_usable)? "usable" :
3112 (host->status == hstatus_unusable)? "unusable" :
3113 (host->status == hstatus_unusable_expired)? "unusable (expired)" : "?");
3114
3115 /* Skip this address if not usable at this time, noting if it wasn't
3116 actually expired, both locally and in the address. */
3117
3118 switch (host->status)
3119 {
3120 case hstatus_unusable:
3121 expired = FALSE;
3122 setflag(addrlist, af_retry_skipped);
3123 /* Fall through */
3124
3125 case hstatus_unusable_expired:
3126 switch (host->why)
3127 {
3128 case hwhy_retry: hosts_retry++; break;
3129 case hwhy_failed: hosts_fail++; break;
3130 case hwhy_deferred: hosts_defer++; break;
3131 }
3132
3133 /* If there was a retry message key, implying that previously there
3134 was a message-specific defer, we don't want to update the list of
3135 messages waiting for these hosts. */
3136
3137 if (retry_message_key != NULL) update_waiting = FALSE;
3138 continue; /* With the next host or IP address */
3139 }
3140 }
3141
3142 /* Second time round the loop: if the address is set but expired, and
3143 the message is newer than the last try, let it through. */
3144
3145 else
3146 {
3147 if (host->address == NULL ||
3148 host->status != hstatus_unusable_expired ||
3149 host->last_try > received_time)
3150 continue;
3151 DEBUG(D_transport)
3152 debug_printf("trying expired host %s [%s]%s\n",
3153 host->name, host->address, pistring);
3154 host_is_expired = TRUE;
3155 }
3156
3157 /* Setting "expired=FALSE" doesn't actually mean not all hosts are expired;
3158 it remains TRUE only if all hosts are expired and none are actually tried.
3159 */
3160
3161 expired = FALSE;
3162
3163 /* If this host is listed as one to which access must be serialized,
3164 see if another Exim process has a connection to it, and if so, skip
3165 this host. If not, update the database to record our connection to it
3166 and remember this for later deletion. Do not do any of this if we are
3167 sending the message down a pre-existing connection. */
3168
3169 if (!continuing &&
3170 verify_check_this_host(&(ob->serialize_hosts), NULL, host->name,
3171 host->address, NULL) == OK)
3172 {
3173 serialize_key = string_sprintf("host-serialize-%s", host->name);
3174 if (!enq_start(serialize_key))
3175 {
3176 DEBUG(D_transport)
3177 debug_printf("skipping host %s because another Exim process "
3178 "is connected to it\n", host->name);
3179 hosts_serial++;
3180 continue;
3181 }
3182 serialized = TRUE;
3183 }
3184
3185 /* OK, we have an IP address that is not waiting for its retry time to
3186 arrive (it might be expired) OR (second time round the loop) we have an
3187 expired host that hasn't been tried since the message arrived. Have a go
3188 at delivering the message to it. First prepare the addresses by flushing
3189 out the result of previous attempts, and finding the first address that
3190 is still to be delivered. */
3191
3192 first_addr = prepare_addresses(addrlist, host);
3193
3194 DEBUG(D_transport) debug_printf("delivering %s to %s [%s] (%s%s)\n",
3195 message_id, host->name, host->address, addrlist->address,
3196 (addrlist->next == NULL)? "" : ", ...");
3197
3198 set_process_info("delivering %s to %s [%s] (%s%s)",
3199 message_id, host->name, host->address, addrlist->address,
3200 (addrlist->next == NULL)? "" : ", ...");
3201
3202 /* This is not for real; don't do the delivery. If there are
3203 any remaining hosts, list them. */
3204
3205 if (dont_deliver)
3206 {
3207 host_item *host2;
3208 set_errno(addrlist, 0, NULL, OK, FALSE);
3209 for (addr = addrlist; addr != NULL; addr = addr->next)
3210 {
3211 addr->host_used = host;
3212 addr->special_action = '*';
3213 addr->message = US"delivery bypassed by -N option";
3214 }
3215 DEBUG(D_transport)
3216 {
3217 debug_printf("*** delivery by %s transport bypassed by -N option\n"
3218 "*** host and remaining hosts:\n", tblock->name);
3219 for (host2 = host; host2 != NULL; host2 = host2->next)
3220 debug_printf(" %s [%s]\n", host2->name,
3221 (host2->address == NULL)? US"unset" : host2->address);
3222 }
3223 rc = OK;
3224 }
3225
3226 /* This is for real. If the host is expired, we don't count it for
3227 hosts_max_retry. This ensures that all hosts must expire before an address
3228 is timed out, unless hosts_max_try_hardlimit (which protects against
3229 lunatic DNS configurations) is reached.
3230
3231 If the host is not expired and we are about to hit the hosts_max_retry
3232 limit, check to see if there is a subsequent hosts with a different MX
3233 value. If so, make that the next host, and don't count this one. This is a
3234 heuristic to make sure that different MXs do get tried. With a normal kind
3235 of retry rule, they would get tried anyway when the earlier hosts were
3236 delayed, but if the domain has a "retry every time" type of rule - as is
3237 often used for the the very large ISPs, that won't happen. */
3238
3239 else
3240 {
3241 if (!host_is_expired && ++unexpired_hosts_tried >= ob->hosts_max_try)
3242 {
3243 host_item *h;
3244 DEBUG(D_transport)
3245 debug_printf("hosts_max_try limit reached with this host\n");
3246 for (h = host; h != NULL; h = h->next)
3247 if (h->mx != host->mx) break;
3248 if (h != NULL)
3249 {
3250 nexthost = h;
3251 unexpired_hosts_tried--;
3252 DEBUG(D_transport) debug_printf("however, a higher MX host exists "
3253 "and will be tried\n");
3254 }
3255 }
3256
3257 /* Attempt the delivery. */
3258
3259 total_hosts_tried++;
3260 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
3261 expanded_hosts != NULL, &message_defer, FALSE);
3262
3263 /* Yield is one of:
3264 OK => connection made, each address contains its result;
3265 message_defer is set for message-specific defers (when all
3266 recipients are marked defer)
3267 DEFER => there was a non-message-specific delivery problem;
3268 ERROR => there was a problem setting up the arguments for a filter,
3269 or there was a problem with expanding added headers
3270 */
3271
3272 /* If the result is not OK, there was a non-message-specific problem.
3273 If the result is DEFER, we need to write to the logs saying what happened
3274 for this particular host, except in the case of authentication and TLS
3275 failures, where the log has already been written. If all hosts defer a
3276 general message is written at the end. */
3277
3278 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL &&
3279 first_addr->basic_errno != ERRNO_TLSFAILURE)
3280 write_logs(first_addr, host);
3281
3282 #ifdef EXPERIMENTAL_TPDA
3283 if (rc == DEFER)
3284 tpda_deferred(first_addr, host);
3285 #endif
3286
3287 /* If STARTTLS was accepted, but there was a failure in setting up the
3288 TLS session (usually a certificate screwup), and the host is not in
3289 hosts_require_tls, and tls_tempfail_tryclear is true, try again, with
3290 TLS forcibly turned off. We have to start from scratch with a new SMTP
3291 connection. That's why the retry is done from here, not from within
3292 smtp_deliver(). [Rejections of STARTTLS itself don't screw up the
3293 session, so the in-clear transmission after those errors, if permitted,
3294 happens inside smtp_deliver().] */
3295
3296 #ifdef SUPPORT_TLS
3297 if ( rc == DEFER
3298 && first_addr->basic_errno == ERRNO_TLSFAILURE
3299 && ob->tls_tempfail_tryclear
3300 && verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
3301 host->address, NULL) != OK
3302 # ifdef EXPERIMENTAL_DANE
3303 && verify_check_this_host(&(ob->hosts_require_dane), NULL, host->name,
3304 host->address, NULL) != OK
3305 # endif
3306 )
3307 {
3308 log_write(0, LOG_MAIN, "TLS se