af2d40fa060f9108cf25f42b1034876acd88ee63
[exim.git] / src / src / transports / smtp.c
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) University of Cambridge 1995 - 2016 */
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 #define DELIVER_BUFFER_SIZE 4096
16
17
18 /* Options specific to the smtp transport. This transport also supports LMTP
19 over TCP/IP. The options must be in alphabetic order (note that "_" comes
20 before the lower case letters). Some live in the transport_instance block so as
21 to be publicly visible; these are flagged with opt_public. */
22
23 optionlist smtp_transport_options[] = {
24 { "*expand_multi_domain", opt_stringptr | opt_hidden | opt_public,
25 (void *)offsetof(transport_instance, expand_multi_domain) },
26 { "*expand_retry_include_ip_address", opt_stringptr | opt_hidden,
27 (void *)(offsetof(smtp_transport_options_block, expand_retry_include_ip_address)) },
28
29 { "address_retry_include_sender", opt_bool,
30 (void *)offsetof(smtp_transport_options_block, address_retry_include_sender) },
31 { "allow_localhost", opt_bool,
32 (void *)offsetof(smtp_transport_options_block, allow_localhost) },
33 { "authenticated_sender", opt_stringptr,
34 (void *)offsetof(smtp_transport_options_block, authenticated_sender) },
35 { "authenticated_sender_force", opt_bool,
36 (void *)offsetof(smtp_transport_options_block, authenticated_sender_force) },
37 { "command_timeout", opt_time,
38 (void *)offsetof(smtp_transport_options_block, command_timeout) },
39 { "connect_timeout", opt_time,
40 (void *)offsetof(smtp_transport_options_block, connect_timeout) },
41 { "connection_max_messages", opt_int | opt_public,
42 (void *)offsetof(transport_instance, connection_max_messages) },
43 { "data_timeout", opt_time,
44 (void *)offsetof(smtp_transport_options_block, data_timeout) },
45 { "delay_after_cutoff", opt_bool,
46 (void *)offsetof(smtp_transport_options_block, delay_after_cutoff) },
47 #ifndef DISABLE_DKIM
48 { "dkim_canon", opt_stringptr,
49 (void *)offsetof(smtp_transport_options_block, dkim.dkim_canon) },
50 { "dkim_domain", opt_stringptr,
51 (void *)offsetof(smtp_transport_options_block, dkim.dkim_domain) },
52 { "dkim_private_key", opt_stringptr,
53 (void *)offsetof(smtp_transport_options_block, dkim.dkim_private_key) },
54 { "dkim_selector", opt_stringptr,
55 (void *)offsetof(smtp_transport_options_block, dkim.dkim_selector) },
56 { "dkim_sign_headers", opt_stringptr,
57 (void *)offsetof(smtp_transport_options_block, dkim.dkim_sign_headers) },
58 { "dkim_strict", opt_stringptr,
59 (void *)offsetof(smtp_transport_options_block, dkim.dkim_strict) },
60 #endif
61 { "dns_qualify_single", opt_bool,
62 (void *)offsetof(smtp_transport_options_block, dns_qualify_single) },
63 { "dns_search_parents", opt_bool,
64 (void *)offsetof(smtp_transport_options_block, dns_search_parents) },
65 { "dnssec_request_domains", opt_stringptr,
66 (void *)offsetof(smtp_transport_options_block, dnssec.request) },
67 { "dnssec_require_domains", opt_stringptr,
68 (void *)offsetof(smtp_transport_options_block, dnssec.require) },
69 { "dscp", opt_stringptr,
70 (void *)offsetof(smtp_transport_options_block, dscp) },
71 { "fallback_hosts", opt_stringptr,
72 (void *)offsetof(smtp_transport_options_block, fallback_hosts) },
73 { "final_timeout", opt_time,
74 (void *)offsetof(smtp_transport_options_block, final_timeout) },
75 { "gethostbyname", opt_bool,
76 (void *)offsetof(smtp_transport_options_block, gethostbyname) },
77 { "helo_data", opt_stringptr,
78 (void *)offsetof(smtp_transport_options_block, helo_data) },
79 { "hosts", opt_stringptr,
80 (void *)offsetof(smtp_transport_options_block, hosts) },
81 { "hosts_avoid_esmtp", opt_stringptr,
82 (void *)offsetof(smtp_transport_options_block, hosts_avoid_esmtp) },
83 { "hosts_avoid_pipelining", opt_stringptr,
84 (void *)offsetof(smtp_transport_options_block, hosts_avoid_pipelining) },
85 #ifdef SUPPORT_TLS
86 { "hosts_avoid_tls", opt_stringptr,
87 (void *)offsetof(smtp_transport_options_block, hosts_avoid_tls) },
88 #endif
89 { "hosts_max_try", opt_int,
90 (void *)offsetof(smtp_transport_options_block, hosts_max_try) },
91 { "hosts_max_try_hardlimit", opt_int,
92 (void *)offsetof(smtp_transport_options_block, hosts_max_try_hardlimit) },
93 #ifdef SUPPORT_TLS
94 { "hosts_nopass_tls", opt_stringptr,
95 (void *)offsetof(smtp_transport_options_block, hosts_nopass_tls) },
96 #endif
97 { "hosts_override", opt_bool,
98 (void *)offsetof(smtp_transport_options_block, hosts_override) },
99 { "hosts_randomize", opt_bool,
100 (void *)offsetof(smtp_transport_options_block, hosts_randomize) },
101 #if defined(SUPPORT_TLS) && !defined(DISABLE_OCSP)
102 { "hosts_request_ocsp", opt_stringptr,
103 (void *)offsetof(smtp_transport_options_block, hosts_request_ocsp) },
104 #endif
105 { "hosts_require_auth", opt_stringptr,
106 (void *)offsetof(smtp_transport_options_block, hosts_require_auth) },
107 #ifdef SUPPORT_TLS
108 # ifdef EXPERIMENTAL_DANE
109 { "hosts_require_dane", opt_stringptr,
110 (void *)offsetof(smtp_transport_options_block, hosts_require_dane) },
111 # endif
112 # ifndef DISABLE_OCSP
113 { "hosts_require_ocsp", opt_stringptr,
114 (void *)offsetof(smtp_transport_options_block, hosts_require_ocsp) },
115 # endif
116 { "hosts_require_tls", opt_stringptr,
117 (void *)offsetof(smtp_transport_options_block, hosts_require_tls) },
118 #endif
119 { "hosts_try_auth", opt_stringptr,
120 (void *)offsetof(smtp_transport_options_block, hosts_try_auth) },
121 { "hosts_try_chunking", opt_stringptr,
122 (void *)offsetof(smtp_transport_options_block, hosts_try_chunking) },
123 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
124 { "hosts_try_dane", opt_stringptr,
125 (void *)offsetof(smtp_transport_options_block, hosts_try_dane) },
126 #endif
127 #ifndef DISABLE_PRDR
128 { "hosts_try_prdr", opt_stringptr,
129 (void *)offsetof(smtp_transport_options_block, hosts_try_prdr) },
130 #endif
131 #ifdef SUPPORT_TLS
132 { "hosts_verify_avoid_tls", opt_stringptr,
133 (void *)offsetof(smtp_transport_options_block, hosts_verify_avoid_tls) },
134 #endif
135 { "interface", opt_stringptr,
136 (void *)offsetof(smtp_transport_options_block, interface) },
137 { "keepalive", opt_bool,
138 (void *)offsetof(smtp_transport_options_block, keepalive) },
139 { "lmtp_ignore_quota", opt_bool,
140 (void *)offsetof(smtp_transport_options_block, lmtp_ignore_quota) },
141 { "max_rcpt", opt_int | opt_public,
142 (void *)offsetof(transport_instance, max_addresses) },
143 { "multi_domain", opt_expand_bool | opt_public,
144 (void *)offsetof(transport_instance, multi_domain) },
145 { "port", opt_stringptr,
146 (void *)offsetof(smtp_transport_options_block, port) },
147 { "protocol", opt_stringptr,
148 (void *)offsetof(smtp_transport_options_block, protocol) },
149 { "retry_include_ip_address", opt_expand_bool,
150 (void *)offsetof(smtp_transport_options_block, retry_include_ip_address) },
151 { "serialize_hosts", opt_stringptr,
152 (void *)offsetof(smtp_transport_options_block, serialize_hosts) },
153 { "size_addition", opt_int,
154 (void *)offsetof(smtp_transport_options_block, size_addition) }
155 #ifdef SUPPORT_SOCKS
156 ,{ "socks_proxy", opt_stringptr,
157 (void *)offsetof(smtp_transport_options_block, socks_proxy) }
158 #endif
159 #ifdef SUPPORT_TLS
160 ,{ "tls_certificate", opt_stringptr,
161 (void *)offsetof(smtp_transport_options_block, tls_certificate) },
162 { "tls_crl", opt_stringptr,
163 (void *)offsetof(smtp_transport_options_block, tls_crl) },
164 { "tls_dh_min_bits", opt_int,
165 (void *)offsetof(smtp_transport_options_block, tls_dh_min_bits) },
166 { "tls_privatekey", opt_stringptr,
167 (void *)offsetof(smtp_transport_options_block, tls_privatekey) },
168 { "tls_require_ciphers", opt_stringptr,
169 (void *)offsetof(smtp_transport_options_block, tls_require_ciphers) },
170 { "tls_sni", opt_stringptr,
171 (void *)offsetof(smtp_transport_options_block, tls_sni) },
172 { "tls_tempfail_tryclear", opt_bool,
173 (void *)offsetof(smtp_transport_options_block, tls_tempfail_tryclear) },
174 { "tls_try_verify_hosts", opt_stringptr,
175 (void *)offsetof(smtp_transport_options_block, tls_try_verify_hosts) },
176 { "tls_verify_cert_hostnames", opt_stringptr,
177 (void *)offsetof(smtp_transport_options_block,tls_verify_cert_hostnames)},
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 US"*", /* hosts_try_chunking */
208 #ifdef EXPERIMENTAL_DANE
209 NULL, /* hosts_try_dane */
210 NULL, /* hosts_require_dane */
211 #endif
212 #ifndef DISABLE_PRDR
213 US"*", /* hosts_try_prdr */
214 #endif
215 #ifndef DISABLE_OCSP
216 US"*", /* hosts_request_ocsp (except under DANE; tls_client_start()) */
217 NULL, /* hosts_require_ocsp */
218 #endif
219 NULL, /* hosts_require_tls */
220 NULL, /* hosts_avoid_tls */
221 NULL, /* hosts_verify_avoid_tls */
222 NULL, /* hosts_avoid_pipelining */
223 NULL, /* hosts_avoid_esmtp */
224 NULL, /* hosts_nopass_tls */
225 5*60, /* command_timeout */
226 5*60, /* connect_timeout; shorter system default overrides */
227 5*60, /* data timeout */
228 10*60, /* final timeout */
229 1024, /* size_addition */
230 5, /* hosts_max_try */
231 50, /* hosts_max_try_hardlimit */
232 TRUE, /* address_retry_include_sender */
233 FALSE, /* allow_localhost */
234 FALSE, /* authenticated_sender_force */
235 FALSE, /* gethostbyname */
236 TRUE, /* dns_qualify_single */
237 FALSE, /* dns_search_parents */
238 { NULL, NULL }, /* dnssec_domains {request,require} */
239 TRUE, /* delay_after_cutoff */
240 FALSE, /* hosts_override */
241 FALSE, /* hosts_randomize */
242 TRUE, /* keepalive */
243 FALSE, /* lmtp_ignore_quota */
244 NULL, /* expand_retry_include_ip_address */
245 TRUE /* retry_include_ip_address */
246 #ifdef SUPPORT_SOCKS
247 ,NULL /* socks_proxy */
248 #endif
249 #ifdef SUPPORT_TLS
250 ,NULL, /* tls_certificate */
251 NULL, /* tls_crl */
252 NULL, /* tls_privatekey */
253 NULL, /* tls_require_ciphers */
254 NULL, /* tls_sni */
255 US"system", /* tls_verify_certificates */
256 EXIM_CLIENT_DH_DEFAULT_MIN_BITS,
257 /* tls_dh_min_bits */
258 TRUE, /* tls_tempfail_tryclear */
259 NULL, /* tls_verify_hosts */
260 US"*", /* tls_try_verify_hosts */
261 US"*" /* tls_verify_cert_hostnames */
262 #endif
263 #ifndef DISABLE_DKIM
264 , {NULL, /* dkim_canon */
265 NULL, /* dkim_domain */
266 NULL, /* dkim_private_key */
267 NULL, /* dkim_selector */
268 NULL, /* dkim_sign_headers */
269 NULL, /* dkim_strict */
270 FALSE} /* dot_stuffed */
271 #endif
272 };
273
274 /* some DSN flags for use later */
275
276 static int rf_list[] = {rf_notify_never, rf_notify_success,
277 rf_notify_failure, rf_notify_delay };
278
279 static uschar *rf_names[] = { US"NEVER", US"SUCCESS", US"FAILURE", US"DELAY" };
280
281
282
283 /* Local statics */
284
285 static uschar *smtp_command; /* Points to last cmd for error messages */
286 static uschar *mail_command; /* Points to MAIL cmd for error messages */
287 static BOOL update_waiting; /* TRUE to update the "wait" database */
288 static BOOL pipelining_active; /* current transaction is in pipe mode */
289
290
291 /*************************************************
292 * Setup entry point *
293 *************************************************/
294
295 /* This function is called when the transport is about to be used,
296 but before running it in a sub-process. It is used for two things:
297
298 (1) To set the fallback host list in addresses, when delivering.
299 (2) To pass back the interface, port, protocol, and other options, for use
300 during callout verification.
301
302 Arguments:
303 tblock pointer to the transport instance block
304 addrlist list of addresses about to be transported
305 tf if not NULL, pointer to block in which to return options
306 uid the uid that will be set (not used)
307 gid the gid that will be set (not used)
308 errmsg place for error message (not used)
309
310 Returns: OK always (FAIL, DEFER not used)
311 */
312
313 static int
314 smtp_transport_setup(transport_instance *tblock, address_item *addrlist,
315 transport_feedback *tf, uid_t uid, gid_t gid, uschar **errmsg)
316 {
317 smtp_transport_options_block *ob =
318 (smtp_transport_options_block *)(tblock->options_block);
319
320 errmsg = errmsg; /* Keep picky compilers happy */
321 uid = uid;
322 gid = gid;
323
324 /* Pass back options if required. This interface is getting very messy. */
325
326 if (tf != NULL)
327 {
328 tf->interface = ob->interface;
329 tf->port = ob->port;
330 tf->protocol = ob->protocol;
331 tf->hosts = ob->hosts;
332 tf->hosts_override = ob->hosts_override;
333 tf->hosts_randomize = ob->hosts_randomize;
334 tf->gethostbyname = ob->gethostbyname;
335 tf->qualify_single = ob->dns_qualify_single;
336 tf->search_parents = ob->dns_search_parents;
337 tf->helo_data = ob->helo_data;
338 }
339
340 /* Set the fallback host list for all the addresses that don't have fallback
341 host lists, provided that the local host wasn't present in the original host
342 list. */
343
344 if (!testflag(addrlist, af_local_host_removed))
345 {
346 for (; addrlist != NULL; addrlist = addrlist->next)
347 if (addrlist->fallback_hosts == NULL)
348 addrlist->fallback_hosts = ob->fallback_hostlist;
349 }
350
351 return OK;
352 }
353
354
355
356 /*************************************************
357 * Initialization entry point *
358 *************************************************/
359
360 /* Called for each instance, after its options have been read, to
361 enable consistency checks to be done, or anything else that needs
362 to be set up.
363
364 Argument: pointer to the transport instance block
365 Returns: nothing
366 */
367
368 void
369 smtp_transport_init(transport_instance *tblock)
370 {
371 smtp_transport_options_block *ob =
372 (smtp_transport_options_block *)(tblock->options_block);
373
374 /* Retry_use_local_part defaults FALSE if unset */
375
376 if (tblock->retry_use_local_part == TRUE_UNSET)
377 tblock->retry_use_local_part = FALSE;
378
379 /* Set the default port according to the protocol */
380
381 if (ob->port == NULL)
382 ob->port = (strcmpic(ob->protocol, US"lmtp") == 0)? US"lmtp" :
383 (strcmpic(ob->protocol, US"smtps") == 0)? US"smtps" : US"smtp";
384
385 /* Set up the setup entry point, to be called before subprocesses for this
386 transport. */
387
388 tblock->setup = smtp_transport_setup;
389
390 /* Complain if any of the timeouts are zero. */
391
392 if (ob->command_timeout <= 0 || ob->data_timeout <= 0 ||
393 ob->final_timeout <= 0)
394 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
395 "command, data, or final timeout value is zero for %s transport",
396 tblock->name);
397
398 /* If hosts_override is set and there are local hosts, set the global
399 flag that stops verify from showing router hosts. */
400
401 if (ob->hosts_override && ob->hosts != NULL) tblock->overrides_hosts = TRUE;
402
403 /* If there are any fallback hosts listed, build a chain of host items
404 for them, but do not do any lookups at this time. */
405
406 host_build_hostlist(&(ob->fallback_hostlist), ob->fallback_hosts, FALSE);
407 }
408
409
410
411
412
413 /*************************************************
414 * Set delivery info into all active addresses *
415 *************************************************/
416
417 /* Only addresses whose status is >= PENDING are relevant. A lesser
418 status means that an address is not currently being processed.
419
420 Arguments:
421 addrlist points to a chain of addresses
422 errno_value to put in each address's errno field
423 msg to put in each address's message field
424 rc to put in each address's transport_return field
425 pass_message if TRUE, set the "pass message" flag in the address
426 host if set, mark addrs as having used this host
427 smtp_greeting from peer
428 helo_response from peer
429
430 If errno_value has the special value ERRNO_CONNECTTIMEOUT, ETIMEDOUT is put in
431 the errno field, and RTEF_CTOUT is ORed into the more_errno field, to indicate
432 this particular type of timeout.
433
434 Returns: nothing
435 */
436
437 static void
438 set_errno(address_item *addrlist, int errno_value, uschar *msg, int rc,
439 BOOL pass_message, host_item * host
440 #ifdef EXPERIMENTAL_DSN_INFO
441 , const uschar * smtp_greeting, const uschar * helo_response
442 #endif
443 )
444 {
445 address_item *addr;
446 int orvalue = 0;
447 if (errno_value == ERRNO_CONNECTTIMEOUT)
448 {
449 errno_value = ETIMEDOUT;
450 orvalue = RTEF_CTOUT;
451 }
452 for (addr = addrlist; addr; addr = addr->next)
453 if (addr->transport_return >= PENDING)
454 {
455 addr->basic_errno = errno_value;
456 addr->more_errno |= orvalue;
457 if (msg != NULL)
458 {
459 addr->message = msg;
460 if (pass_message) setflag(addr, af_pass_message);
461 }
462 addr->transport_return = rc;
463 if (host)
464 {
465 addr->host_used = host;
466 #ifdef EXPERIMENTAL_DSN_INFO
467 if (smtp_greeting)
468 {uschar * s = Ustrchr(smtp_greeting, '\n'); if (s) *s = '\0';}
469 addr->smtp_greeting = smtp_greeting;
470
471 if (helo_response)
472 {uschar * s = Ustrchr(helo_response, '\n'); if (s) *s = '\0';}
473 addr->helo_response = helo_response;
474 #endif
475 }
476 }
477 }
478
479 static void
480 set_errno_nohost(address_item *addrlist, int errno_value, uschar *msg, int rc,
481 BOOL pass_message)
482 {
483 set_errno(addrlist, errno_value, msg, rc, pass_message, NULL
484 #ifdef EXPERIMENTAL_DSN_INFO
485 , NULL, NULL
486 #endif
487 );
488 }
489
490
491 /*************************************************
492 * Check an SMTP response *
493 *************************************************/
494
495 /* This function is given an errno code and the SMTP response buffer
496 to analyse, together with the host identification for generating messages. It
497 sets an appropriate message and puts the first digit of the response code into
498 the yield variable. If no response was actually read, a suitable digit is
499 chosen.
500
501 Arguments:
502 host the current host, to get its name for messages
503 errno_value pointer to the errno value
504 more_errno from the top address for use with ERRNO_FILTER_FAIL
505 buffer the SMTP response buffer
506 yield where to put a one-digit SMTP response code
507 message where to put an errror message
508 pass_message set TRUE if message is an SMTP response
509
510 Returns: TRUE if an SMTP "QUIT" command should be sent, else FALSE
511 */
512
513 static BOOL
514 check_response(host_item *host, int *errno_value, int more_errno,
515 uschar *buffer, int *yield, uschar **message, BOOL *pass_message)
516 {
517 uschar * pl = pipelining_active ? US"pipelined " : US"";
518
519 *yield = '4'; /* Default setting is to give a temporary error */
520
521 /* Handle response timeout */
522
523 if (*errno_value == ETIMEDOUT)
524 {
525 *message = US string_sprintf("SMTP timeout after %s%s",
526 pl, smtp_command);
527 if (transport_count > 0)
528 *message = US string_sprintf("%s (%d bytes written)", *message,
529 transport_count);
530 return FALSE;
531 }
532
533 /* Handle malformed SMTP response */
534
535 if (*errno_value == ERRNO_SMTPFORMAT)
536 {
537 const uschar *malfresp = string_printing(buffer);
538 while (isspace(*malfresp)) malfresp++;
539 *message = *malfresp == 0
540 ? string_sprintf("Malformed SMTP reply (an empty line) "
541 "in response to %s%s", pl, smtp_command)
542 : string_sprintf("Malformed SMTP reply in response to %s%s: %s",
543 pl, smtp_command, malfresp);
544 return FALSE;
545 }
546
547 /* Handle a failed filter process error; can't send QUIT as we mustn't
548 end the DATA. */
549
550 if (*errno_value == ERRNO_FILTER_FAIL)
551 {
552 *message = US string_sprintf("transport filter process failed (%d)%s",
553 more_errno,
554 (more_errno == EX_EXECFAILED)? ": unable to execute command" : "");
555 return FALSE;
556 }
557
558 /* Handle a failed add_headers expansion; can't send QUIT as we mustn't
559 end the DATA. */
560
561 if (*errno_value == ERRNO_CHHEADER_FAIL)
562 {
563 *message =
564 US string_sprintf("failed to expand headers_add or headers_remove: %s",
565 expand_string_message);
566 return FALSE;
567 }
568
569 /* Handle failure to write a complete data block */
570
571 if (*errno_value == ERRNO_WRITEINCOMPLETE)
572 {
573 *message = US string_sprintf("failed to write a data block");
574 return FALSE;
575 }
576
577 #ifdef SUPPORT_I18N
578 /* Handle lack of advertised SMTPUTF8, for international message */
579 if (*errno_value == ERRNO_UTF8_FWD)
580 {
581 *message = US string_sprintf("utf8 support required but not offered for forwarding");
582 DEBUG(D_deliver|D_transport) debug_printf("%s\n", *message);
583 return TRUE;
584 }
585 #endif
586
587 /* Handle error responses from the remote mailer. */
588
589 if (buffer[0] != 0)
590 {
591 const uschar *s = string_printing(buffer);
592 *message = US string_sprintf("SMTP error from remote mail server after %s%s: "
593 "%s", pl, smtp_command, s);
594 *pass_message = TRUE;
595 *yield = buffer[0];
596 return TRUE;
597 }
598
599 /* No data was read. If there is no errno, this must be the EOF (i.e.
600 connection closed) case, which causes deferral. An explicit connection reset
601 error has the same effect. Otherwise, put the host's identity in the message,
602 leaving the errno value to be interpreted as well. In all cases, we have to
603 assume the connection is now dead. */
604
605 if (*errno_value == 0 || *errno_value == ECONNRESET)
606 {
607 *errno_value = ERRNO_SMTPCLOSED;
608 *message = US string_sprintf("Remote host closed connection "
609 "in response to %s%s", pl, smtp_command);
610 }
611 else *message = US string_sprintf("%s [%s]", host->name, host->address);
612
613 return FALSE;
614 }
615
616
617
618 /*************************************************
619 * Write error message to logs *
620 *************************************************/
621
622 /* This writes to the main log and to the message log.
623
624 Arguments:
625 addr the address item containing error information
626 host the current host
627
628 Returns: nothing
629 */
630
631 static void
632 write_logs(address_item *addr, host_item *host)
633 {
634 uschar * message = LOGGING(outgoing_port)
635 ? string_sprintf("H=%s [%s]:%d", host->name, host->address,
636 host->port == PORT_NONE ? 25 : host->port)
637 : string_sprintf("H=%s [%s]", host->name, host->address);
638
639 if (addr->message)
640 {
641 message = string_sprintf("%s: %s", message, addr->message);
642 if (addr->basic_errno > 0)
643 message = string_sprintf("%s: %s", message, strerror(addr->basic_errno));
644 log_write(0, LOG_MAIN, "%s", message);
645 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
646 }
647 else
648 {
649 const uschar * s = exim_errstr(addr->basic_errno);
650 log_write(0, LOG_MAIN, "%s %s", message, s);
651 deliver_msglog("%s %s %s\n", tod_stamp(tod_log), message, s);
652 }
653 }
654
655 static void
656 msglog_line(host_item * host, uschar * message)
657 {
658 deliver_msglog("%s H=%s [%s] %s\n", tod_stamp(tod_log),
659 host->name, host->address, message);
660 }
661
662
663
664 #ifndef DISABLE_EVENT
665 /*************************************************
666 * Post-defer action *
667 *************************************************/
668
669 /* This expands an arbitrary per-transport string.
670 It might, for example, be used to write to the database log.
671
672 Arguments:
673 addr the address item containing error information
674 host the current host
675
676 Returns: nothing
677 */
678
679 static void
680 deferred_event_raise(address_item *addr, host_item *host)
681 {
682 uschar * action = addr->transport->event_action;
683 const uschar * save_domain;
684 uschar * save_local;
685
686 if (!action)
687 return;
688
689 save_domain = deliver_domain;
690 save_local = deliver_localpart;
691
692 /*XXX would ip & port already be set up? */
693 deliver_host_address = string_copy(host->address);
694 deliver_host_port = host->port == PORT_NONE ? 25 : host->port;
695 event_defer_errno = addr->basic_errno;
696
697 router_name = addr->router->name;
698 transport_name = addr->transport->name;
699 deliver_domain = addr->domain;
700 deliver_localpart = addr->local_part;
701
702 (void) event_raise(action, US"msg:host:defer",
703 addr->message
704 ? addr->basic_errno > 0
705 ? string_sprintf("%s: %s", addr->message, strerror(addr->basic_errno))
706 : string_copy(addr->message)
707 : addr->basic_errno > 0
708 ? string_copy(US strerror(addr->basic_errno))
709 : NULL);
710
711 deliver_localpart = save_local;
712 deliver_domain = save_domain;
713 router_name = transport_name = NULL;
714 }
715 #endif
716
717 /*************************************************
718 * Synchronize SMTP responses *
719 *************************************************/
720
721 /* This function is called from smtp_deliver() to receive SMTP responses from
722 the server, and match them up with the commands to which they relate. When
723 PIPELINING is not in use, this function is called after every command, and is
724 therefore somewhat over-engineered, but it is simpler to use a single scheme
725 that works both with and without PIPELINING instead of having two separate sets
726 of code.
727
728 The set of commands that are buffered up with pipelining may start with MAIL
729 and may end with DATA; in between are RCPT commands that correspond to the
730 addresses whose status is PENDING_DEFER. All other commands (STARTTLS, AUTH,
731 etc.) are never buffered.
732
733 Errors after MAIL or DATA abort the whole process leaving the response in the
734 buffer. After MAIL, pending responses are flushed, and the original command is
735 re-instated in big_buffer for error messages. For RCPT commands, the remote is
736 permitted to reject some recipient addresses while accepting others. However
737 certain errors clearly abort the whole process. Set the value in
738 transport_return to PENDING_OK if the address is accepted. If there is a
739 subsequent general error, it will get reset accordingly. If not, it will get
740 converted to OK at the end.
741
742 Arguments:
743 addrlist the complete address list
744 include_affixes TRUE if affixes include in RCPT
745 sync_addr ptr to the ptr of the one to start scanning at (updated)
746 host the host we are connected to
747 count the number of responses to read
748 address_retry_
749 include_sender true if 4xx retry is to include the sender it its key
750 pending_MAIL true if the first response is for MAIL
751 pending_DATA 0 if last command sent was not DATA
752 +1 if previously had a good recipient
753 -1 if not previously had a good recipient
754 inblock incoming SMTP block
755 timeout timeout value
756 buffer buffer for reading response
757 buffsize size of buffer
758
759 Returns: 3 if at least one address had 2xx and one had 5xx
760 2 if at least one address had 5xx but none had 2xx
761 1 if at least one host had a 2xx response, but none had 5xx
762 0 no address had 2xx or 5xx but no errors (all 4xx, or just DATA)
763 -1 timeout while reading RCPT response
764 -2 I/O or other non-response error for RCPT
765 -3 DATA or MAIL failed - errno and buffer set
766 */
767
768 static int
769 sync_responses(address_item *addrlist, BOOL include_affixes,
770 address_item **sync_addr, host_item *host, int count,
771 BOOL address_retry_include_sender, BOOL pending_MAIL,
772 int pending_DATA, smtp_inblock *inblock, int timeout, uschar *buffer,
773 int buffsize)
774 {
775 address_item *addr = *sync_addr;
776 int yield = 0;
777
778 /* Handle the response for a MAIL command. On error, reinstate the original
779 command in big_buffer for error message use, and flush any further pending
780 responses before returning, except after I/O errors and timeouts. */
781
782 if (pending_MAIL)
783 {
784 count--;
785 if (!smtp_read_response(inblock, buffer, buffsize, '2', timeout))
786 {
787 DEBUG(D_transport) debug_printf("bad response for MAIL\n");
788 Ustrcpy(big_buffer, mail_command); /* Fits, because it came from there! */
789 if (errno == 0 && buffer[0] != 0)
790 {
791 uschar flushbuffer[4096];
792 int save_errno = 0;
793 if (buffer[0] == '4')
794 {
795 save_errno = ERRNO_MAIL4XX;
796 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
797 }
798 while (count-- > 0)
799 {
800 if (!smtp_read_response(inblock, flushbuffer, sizeof(flushbuffer),
801 '2', timeout)
802 && (errno != 0 || flushbuffer[0] == 0))
803 break;
804 }
805 errno = save_errno;
806 }
807
808 if (pending_DATA) count--; /* Number of RCPT responses to come */
809 while (count-- > 0) /* Mark any pending addrs with the host used */
810 {
811 while (addr->transport_return != PENDING_DEFER) addr = addr->next;
812 addr->host_used = host;
813 addr = addr->next;
814 }
815 return -3;
816 }
817 }
818
819 if (pending_DATA) count--; /* Number of RCPT responses to come */
820
821 /* Read and handle the required number of RCPT responses, matching each one up
822 with an address by scanning for the next address whose status is PENDING_DEFER.
823 */
824
825 while (count-- > 0)
826 {
827 while (addr->transport_return != PENDING_DEFER) addr = addr->next;
828
829 /* The address was accepted */
830 addr->host_used = host;
831
832 if (smtp_read_response(inblock, buffer, buffsize, '2', timeout))
833 {
834 yield |= 1;
835 addr->transport_return = PENDING_OK;
836
837 /* If af_dr_retry_exists is set, there was a routing delay on this address;
838 ensure that any address-specific retry record is expunged. We do this both
839 for the basic key and for the version that also includes the sender. */
840
841 if (testflag(addr, af_dr_retry_exists))
842 {
843 uschar *altkey = string_sprintf("%s:<%s>", addr->address_retry_key,
844 sender_address);
845 retry_add_item(addr, altkey, rf_delete);
846 retry_add_item(addr, addr->address_retry_key, rf_delete);
847 }
848 }
849
850 /* Timeout while reading the response */
851
852 else if (errno == ETIMEDOUT)
853 {
854 uschar *message = string_sprintf("SMTP timeout after RCPT TO:<%s>",
855 transport_rcpt_address(addr, include_affixes));
856 set_errno_nohost(addrlist, ETIMEDOUT, message, DEFER, FALSE);
857 retry_add_item(addr, addr->address_retry_key, 0);
858 update_waiting = FALSE;
859 return -1;
860 }
861
862 /* Handle other errors in obtaining an SMTP response by returning -1. This
863 will cause all the addresses to be deferred. Restore the SMTP command in
864 big_buffer for which we are checking the response, so the error message
865 makes sense. */
866
867 else if (errno != 0 || buffer[0] == 0)
868 {
869 string_format(big_buffer, big_buffer_size, "RCPT TO:<%s>",
870 transport_rcpt_address(addr, include_affixes));
871 return -2;
872 }
873
874 /* Handle SMTP permanent and temporary response codes. */
875
876 else
877 {
878 addr->message =
879 string_sprintf("SMTP error from remote mail server after RCPT TO:<%s>: "
880 "%s", transport_rcpt_address(addr, include_affixes),
881 string_printing(buffer));
882 setflag(addr, af_pass_message);
883 msglog_line(host, addr->message);
884
885 /* The response was 5xx */
886
887 if (buffer[0] == '5')
888 {
889 addr->transport_return = FAIL;
890 yield |= 2;
891 }
892
893 /* The response was 4xx */
894
895 else
896 {
897 addr->transport_return = DEFER;
898 addr->basic_errno = ERRNO_RCPT4XX;
899 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
900
901 #ifndef DISABLE_EVENT
902 event_defer_errno = addr->more_errno;
903 msg_event_raise(US"msg:rcpt:host:defer", addr);
904 #endif
905
906 /* Log temporary errors if there are more hosts to be tried.
907 If not, log this last one in the == line. */
908
909 if (host->next)
910 log_write(0, LOG_MAIN, "H=%s [%s]: %s", host->name, host->address, addr->message);
911
912 #ifndef DISABLE_EVENT
913 else
914 msg_event_raise(US"msg:rcpt:defer", addr);
915 #endif
916
917 /* Do not put this message on the list of those waiting for specific
918 hosts, as otherwise it is likely to be tried too often. */
919
920 update_waiting = FALSE;
921
922 /* Add a retry item for the address so that it doesn't get tried again
923 too soon. If address_retry_include_sender is true, add the sender address
924 to the retry key. */
925
926 if (address_retry_include_sender)
927 {
928 uschar *altkey = string_sprintf("%s:<%s>", addr->address_retry_key,
929 sender_address);
930 retry_add_item(addr, altkey, 0);
931 }
932 else retry_add_item(addr, addr->address_retry_key, 0);
933 }
934 }
935 } /* Loop for next RCPT response */
936
937 /* Update where to start at for the next block of responses, unless we
938 have already handled all the addresses. */
939
940 if (addr != NULL) *sync_addr = addr->next;
941
942 /* Handle a response to DATA. If we have not had any good recipients, either
943 previously or in this block, the response is ignored. */
944
945 if (pending_DATA != 0 &&
946 !smtp_read_response(inblock, buffer, buffsize, '3', timeout))
947 {
948 int code;
949 uschar *msg;
950 BOOL pass_message;
951 if (pending_DATA > 0 || (yield & 1) != 0)
952 {
953 if (errno == 0 && buffer[0] == '4')
954 {
955 errno = ERRNO_DATA4XX;
956 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
957 }
958 return -3;
959 }
960 (void)check_response(host, &errno, 0, buffer, &code, &msg, &pass_message);
961 DEBUG(D_transport) debug_printf("%s\nerror for DATA ignored: pipelining "
962 "is in use and there were no good recipients\n", msg);
963 }
964
965 /* All responses read and handled; MAIL (if present) received 2xx and DATA (if
966 present) received 3xx. If any RCPTs were handled and yielded anything other
967 than 4xx, yield will be set non-zero. */
968
969 return yield;
970 }
971
972
973
974 /* Do the client side of smtp-level authentication */
975 /*
976 Arguments:
977 buffer EHLO response from server (gets overwritten)
978 addrlist chain of potential addresses to deliver
979 host host to deliver to
980 ob transport options
981 ibp, obp comms channel control blocks
982
983 Returns:
984 OK Success, or failed (but not required): global "smtp_authenticated" set
985 DEFER Failed authentication (and was required)
986 ERROR Internal problem
987
988 FAIL_SEND Failed communications - transmit
989 FAIL - response
990 */
991
992 int
993 smtp_auth(uschar *buffer, unsigned bufsize, address_item *addrlist, host_item *host,
994 smtp_transport_options_block *ob, BOOL is_esmtp,
995 smtp_inblock *ibp, smtp_outblock *obp)
996 {
997 int require_auth;
998 uschar *fail_reason = US"server did not advertise AUTH support";
999
1000 smtp_authenticated = FALSE;
1001 client_authenticator = client_authenticated_id = client_authenticated_sender = NULL;
1002 require_auth = verify_check_given_host(&ob->hosts_require_auth, host);
1003
1004 if (is_esmtp && !regex_AUTH) regex_AUTH =
1005 regex_must_compile(US"\\n250[\\s\\-]AUTH\\s+([\\-\\w\\s]+)(?:\\n|$)",
1006 FALSE, TRUE);
1007
1008 if (is_esmtp && regex_match_and_setup(regex_AUTH, buffer, 0, -1))
1009 {
1010 uschar *names = string_copyn(expand_nstring[1], expand_nlength[1]);
1011 expand_nmax = -1; /* reset */
1012
1013 /* Must not do this check until after we have saved the result of the
1014 regex match above. */
1015
1016 if (require_auth == OK ||
1017 verify_check_given_host(&ob->hosts_try_auth, host) == OK)
1018 {
1019 auth_instance *au;
1020 fail_reason = US"no common mechanisms were found";
1021
1022 DEBUG(D_transport) debug_printf("scanning authentication mechanisms\n");
1023
1024 /* Scan the configured authenticators looking for one which is configured
1025 for use as a client, which is not suppressed by client_condition, and
1026 whose name matches an authentication mechanism supported by the server.
1027 If one is found, attempt to authenticate by calling its client function.
1028 */
1029
1030 for (au = auths; !smtp_authenticated && au != NULL; au = au->next)
1031 {
1032 uschar *p = names;
1033 if (!au->client ||
1034 (au->client_condition != NULL &&
1035 !expand_check_condition(au->client_condition, au->name,
1036 US"client authenticator")))
1037 {
1038 DEBUG(D_transport) debug_printf("skipping %s authenticator: %s\n",
1039 au->name,
1040 (au->client)? "client_condition is false" :
1041 "not configured as a client");
1042 continue;
1043 }
1044
1045 /* Loop to scan supported server mechanisms */
1046
1047 while (*p != 0)
1048 {
1049 int rc;
1050 int len = Ustrlen(au->public_name);
1051 while (isspace(*p)) p++;
1052
1053 if (strncmpic(au->public_name, p, len) != 0 ||
1054 (p[len] != 0 && !isspace(p[len])))
1055 {
1056 while (*p != 0 && !isspace(*p)) p++;
1057 continue;
1058 }
1059
1060 /* Found data for a listed mechanism. Call its client entry. Set
1061 a flag in the outblock so that data is overwritten after sending so
1062 that reflections don't show it. */
1063
1064 fail_reason = US"authentication attempt(s) failed";
1065 obp->authenticating = TRUE;
1066 rc = (au->info->clientcode)(au, ibp, obp,
1067 ob->command_timeout, buffer, bufsize);
1068 obp->authenticating = FALSE;
1069 DEBUG(D_transport) debug_printf("%s authenticator yielded %d\n",
1070 au->name, rc);
1071
1072 /* A temporary authentication failure must hold up delivery to
1073 this host. After a permanent authentication failure, we carry on
1074 to try other authentication methods. If all fail hard, try to
1075 deliver the message unauthenticated unless require_auth was set. */
1076
1077 switch(rc)
1078 {
1079 case OK:
1080 smtp_authenticated = TRUE; /* stops the outer loop */
1081 client_authenticator = au->name;
1082 if (au->set_client_id != NULL)
1083 client_authenticated_id = expand_string(au->set_client_id);
1084 break;
1085
1086 /* Failure after writing a command */
1087
1088 case FAIL_SEND:
1089 return FAIL_SEND;
1090
1091 /* Failure after reading a response */
1092
1093 case FAIL:
1094 if (errno != 0 || buffer[0] != '5') return FAIL;
1095 log_write(0, LOG_MAIN, "%s authenticator failed H=%s [%s] %s",
1096 au->name, host->name, host->address, buffer);
1097 break;
1098
1099 /* Failure by some other means. In effect, the authenticator
1100 decided it wasn't prepared to handle this case. Typically this
1101 is the result of "fail" in an expansion string. Do we need to
1102 log anything here? Feb 2006: a message is now put in the buffer
1103 if logging is required. */
1104
1105 case CANCELLED:
1106 if (*buffer != 0)
1107 log_write(0, LOG_MAIN, "%s authenticator cancelled "
1108 "authentication H=%s [%s] %s", au->name, host->name,
1109 host->address, buffer);
1110 break;
1111
1112 /* Internal problem, message in buffer. */
1113
1114 case ERROR:
1115 set_errno_nohost(addrlist, ERRNO_AUTHPROB, string_copy(buffer),
1116 DEFER, FALSE);
1117 return ERROR;
1118 }
1119
1120 break; /* If not authenticated, try next authenticator */
1121 } /* Loop for scanning supported server mechanisms */
1122 } /* Loop for further authenticators */
1123 }
1124 }
1125
1126 /* If we haven't authenticated, but are required to, give up. */
1127
1128 if (require_auth == OK && !smtp_authenticated)
1129 {
1130 set_errno_nohost(addrlist, ERRNO_AUTHFAIL,
1131 string_sprintf("authentication required but %s", fail_reason), DEFER,
1132 FALSE);
1133 return DEFER;
1134 }
1135
1136 return OK;
1137 }
1138
1139
1140 /* Construct AUTH appendix string for MAIL TO */
1141 /*
1142 Arguments
1143 buffer to build string
1144 addrlist chain of potential addresses to deliver
1145 ob transport options
1146
1147 Globals smtp_authenticated
1148 client_authenticated_sender
1149 Return True on error, otherwise buffer has (possibly empty) terminated string
1150 */
1151
1152 BOOL
1153 smtp_mail_auth_str(uschar *buffer, unsigned bufsize, address_item *addrlist,
1154 smtp_transport_options_block *ob)
1155 {
1156 uschar *local_authenticated_sender = authenticated_sender;
1157
1158 #ifdef notdef
1159 debug_printf("smtp_mail_auth_str: as<%s> os<%s> SA<%s>\n", authenticated_sender, ob->authenticated_sender, smtp_authenticated?"Y":"N");
1160 #endif
1161
1162 if (ob->authenticated_sender != NULL)
1163 {
1164 uschar *new = expand_string(ob->authenticated_sender);
1165 if (new == NULL)
1166 {
1167 if (!expand_string_forcedfail)
1168 {
1169 uschar *message = string_sprintf("failed to expand "
1170 "authenticated_sender: %s", expand_string_message);
1171 set_errno_nohost(addrlist, ERRNO_EXPANDFAIL, message, DEFER, FALSE);
1172 return TRUE;
1173 }
1174 }
1175 else if (new[0] != 0) local_authenticated_sender = new;
1176 }
1177
1178 /* Add the authenticated sender address if present */
1179
1180 if ((smtp_authenticated || ob->authenticated_sender_force) &&
1181 local_authenticated_sender != NULL)
1182 {
1183 string_format(buffer, bufsize, " AUTH=%s",
1184 auth_xtextencode(local_authenticated_sender,
1185 Ustrlen(local_authenticated_sender)));
1186 client_authenticated_sender = string_copy(local_authenticated_sender);
1187 }
1188 else
1189 *buffer= 0;
1190
1191 return FALSE;
1192 }
1193
1194
1195
1196 #ifdef EXPERIMENTAL_DANE
1197 /* Lookup TLSA record for host/port.
1198 Return: OK success with dnssec; DANE mode
1199 DEFER Do not use this host now, may retry later
1200 FAIL_FORCED No TLSA record; DANE not usable
1201 FAIL Do not use this connection
1202 */
1203
1204 int
1205 tlsa_lookup(const host_item * host, dns_answer * dnsa, BOOL dane_required)
1206 {
1207 /* move this out to host.c given the similarity to dns_lookup() ? */
1208 uschar buffer[300];
1209 const uschar * fullname = buffer;
1210
1211 /* TLSA lookup string */
1212 (void)sprintf(CS buffer, "_%d._tcp.%.256s", host->port, host->name);
1213
1214 switch (dns_lookup(dnsa, buffer, T_TLSA, &fullname))
1215 {
1216 case DNS_SUCCEED:
1217 if (!dns_is_secure(dnsa))
1218 {
1219 log_write(0, LOG_MAIN, "DANE error: TLSA lookup not DNSSEC");
1220 return DEFER;
1221 }
1222 return OK;
1223
1224 case DNS_AGAIN:
1225 return DEFER; /* just defer this TLS'd conn */
1226
1227 case DNS_NODATA: /* no TLSA RR for this lookup */
1228 case DNS_NOMATCH: /* no records at all for this lookup */
1229 return dane_required ? FAIL : FAIL_FORCED;
1230
1231 default:
1232 case DNS_FAIL:
1233 return dane_required ? FAIL : DEFER;
1234 }
1235 }
1236 #endif
1237
1238
1239
1240 typedef struct smtp_compare_s
1241 {
1242 uschar *current_sender_address;
1243 struct transport_instance *tblock;
1244 } smtp_compare_t;
1245
1246 /*
1247 Create a unique string that identifies this message, it is based on
1248 sender_address, helo_data and tls_certificate if enabled. */
1249
1250 static uschar *
1251 smtp_local_identity(uschar * sender, struct transport_instance * tblock)
1252 {
1253 address_item * addr1;
1254 uschar * if1 = US"";
1255 uschar * helo1 = US"";
1256 #ifdef SUPPORT_TLS
1257 uschar * tlsc1 = US"";
1258 #endif
1259 uschar * save_sender_address = sender_address;
1260 uschar * local_identity = NULL;
1261 smtp_transport_options_block * ob =
1262 (smtp_transport_options_block *)tblock->options_block;
1263
1264 sender_address = sender;
1265
1266 addr1 = deliver_make_addr (sender, TRUE);
1267 deliver_set_expansions(addr1);
1268
1269 if (ob->interface)
1270 if1 = expand_string(ob->interface);
1271
1272 if (ob->helo_data)
1273 helo1 = expand_string(ob->helo_data);
1274
1275 #ifdef SUPPORT_TLS
1276 if (ob->tls_certificate)
1277 tlsc1 = expand_string(ob->tls_certificate);
1278 local_identity = string_sprintf ("%s^%s^%s", if1, helo1, tlsc1);
1279 #else
1280 local_identity = string_sprintf ("%s^%s", if1, helo1);
1281 #endif
1282
1283 deliver_set_expansions(NULL);
1284 sender_address = save_sender_address;
1285
1286 return local_identity;
1287 }
1288
1289
1290
1291 /* This routine is a callback that is called from transport_check_waiting.
1292 This function will evaluate the incoming message versus the previous
1293 message. If the incoming message is using a different local identity then
1294 we will veto this new message. */
1295
1296 static BOOL
1297 smtp_are_same_identities(uschar * message_id, smtp_compare_t * s_compare)
1298 {
1299 uschar * message_local_identity,
1300 * current_local_identity,
1301 * new_sender_address;
1302
1303 current_local_identity =
1304 smtp_local_identity(s_compare->current_sender_address, s_compare->tblock);
1305
1306 if (!(new_sender_address = deliver_get_sender_address(message_id)))
1307 return 0;
1308
1309 message_local_identity =
1310 smtp_local_identity(new_sender_address, s_compare->tblock);
1311
1312 return Ustrcmp(current_local_identity, message_local_identity) == 0;
1313 }
1314
1315
1316
1317 uschar
1318 ehlo_response(uschar * buf, size_t bsize, uschar checks)
1319 {
1320 #ifdef SUPPORT_TLS
1321 if ( checks & PEER_OFFERED_TLS
1322 && pcre_exec(regex_STARTTLS, NULL, CS buf, bsize, 0, PCRE_EOPT, NULL, 0) < 0)
1323 checks &= ~PEER_OFFERED_TLS;
1324 #endif
1325
1326 if ( checks & PEER_OFFERED_IGNQ
1327 && pcre_exec(regex_IGNOREQUOTA, NULL, CS buf, bsize, 0,
1328 PCRE_EOPT, NULL, 0) < 0)
1329 checks &= ~PEER_OFFERED_IGNQ;
1330
1331 if ( checks & PEER_OFFERED_CHUNKING
1332 && pcre_exec(regex_CHUNKING, NULL, CS buf, bsize, 0, PCRE_EOPT, NULL, 0) < 0)
1333 checks &= ~PEER_OFFERED_CHUNKING;
1334
1335 #ifndef DISABLE_PRDR
1336 if ( checks & PEER_OFFERED_PRDR
1337 && pcre_exec(regex_PRDR, NULL, CS buf, bsize, 0, PCRE_EOPT, NULL, 0) < 0)
1338 checks &= ~PEER_OFFERED_PRDR;
1339 #endif
1340
1341 #ifdef SUPPORT_I18N
1342 if ( checks & PEER_OFFERED_UTF8
1343 && pcre_exec(regex_UTF8, NULL, CS buf, bsize, 0, PCRE_EOPT, NULL, 0) < 0)
1344 checks &= ~PEER_OFFERED_UTF8;
1345 #endif
1346
1347 if ( checks & PEER_OFFERED_DSN
1348 && pcre_exec(regex_DSN, NULL, CS buf, bsize, 0, PCRE_EOPT, NULL, 0) < 0)
1349 checks &= ~PEER_OFFERED_DSN;
1350
1351 if ( checks & PEER_OFFERED_PIPE
1352 && pcre_exec(regex_PIPELINING, NULL, CS buf, bsize, 0,
1353 PCRE_EOPT, NULL, 0) < 0)
1354 checks &= ~PEER_OFFERED_PIPE;
1355
1356 if ( checks & PEER_OFFERED_SIZE
1357 && pcre_exec(regex_SIZE, NULL, CS buf, bsize, 0, PCRE_EOPT, NULL, 0) < 0)
1358 checks &= ~PEER_OFFERED_SIZE;
1359
1360 return checks;
1361 }
1362
1363
1364
1365 /* Callback for emitting a BDAT data chunk header.
1366
1367 If given a nonzero size, first flush any buffered SMTP commands
1368 then emit the command.
1369
1370 Reap previous SMTP command responses if requested.
1371 Reap one SMTP command response if requested.
1372
1373 Returns: OK or ERROR
1374 */
1375
1376 static int
1377 smtp_chunk_cmd_callback(int fd, transport_ctx * tctx,
1378 unsigned chunk_size, unsigned flags)
1379 {
1380 smtp_transport_options_block * ob =
1381 (smtp_transport_options_block *)(tctx->tblock->options_block);
1382 int cmd_count = 0;
1383 int prev_cmd_count;
1384 uschar * buffer = tctx->buffer;
1385
1386
1387 /* Write SMTP chunk header command */
1388
1389 if (chunk_size > 0)
1390 if((cmd_count = smtp_write_command(tctx->outblock, FALSE, "BDAT %u%s\r\n",
1391 chunk_size,
1392 flags & tc_chunk_last ? " LAST" : "")
1393 ) < 0) return ERROR;
1394
1395 prev_cmd_count = cmd_count += tctx->cmd_count;
1396
1397 /* Reap responses for any previous, but not one we just emitted */
1398
1399 if (chunk_size > 0)
1400 prev_cmd_count--;
1401 if (tctx->pending_BDAT)
1402 prev_cmd_count--;
1403
1404 if (flags & tc_reap_prev && prev_cmd_count > 0)
1405 {
1406 DEBUG(D_transport) debug_printf("look for %d responses"
1407 " for previous pipelined cmds\n", prev_cmd_count);
1408
1409 switch(sync_responses(tctx->first_addr, tctx->tblock->rcpt_include_affixes,
1410 tctx->sync_addr, tctx->host, prev_cmd_count,
1411 ob->address_retry_include_sender,
1412 tctx->pending_MAIL, 0,
1413 tctx->inblock,
1414 ob->command_timeout,
1415 buffer, DELIVER_BUFFER_SIZE))
1416 {
1417 case 1: /* 2xx (only) => OK */
1418 case 3: tctx->good_RCPT = TRUE; /* 2xx & 5xx => OK & progress made */
1419 case 2: *tctx->completed_address = TRUE; /* 5xx (only) => progress made */
1420 case 0: break; /* No 2xx or 5xx, but no probs */
1421
1422 case -1: /* Timeout on RCPT */
1423 default: return ERROR; /* I/O error, or any MAIL/DATA error */
1424 }
1425 cmd_count = 1;
1426 if (!tctx->pending_BDAT)
1427 pipelining_active = FALSE;
1428 }
1429
1430 /* Reap response for an outstanding BDAT */
1431
1432 if (tctx->pending_BDAT)
1433 {
1434 DEBUG(D_transport) debug_printf("look for one response for BDAT\n");
1435
1436 if (!smtp_read_response(tctx->inblock, buffer, DELIVER_BUFFER_SIZE, '2',
1437 ob->command_timeout))
1438 {
1439 if (errno == 0 && buffer[0] == '4')
1440 {
1441 errno = ERRNO_DATA4XX; /*XXX does this actually get used? */
1442 tctx->first_addr->more_errno |=
1443 ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1444 }
1445 return ERROR;
1446 }
1447 cmd_count--;
1448 tctx->pending_BDAT = FALSE;
1449 pipelining_active = FALSE;
1450 }
1451 else if (chunk_size > 0)
1452 tctx->pending_BDAT = TRUE;
1453
1454
1455 tctx->cmd_count = cmd_count;
1456 return OK;
1457 }
1458
1459
1460
1461 /*************************************************
1462 * Deliver address list to given host *
1463 *************************************************/
1464
1465 /* If continue_hostname is not null, we get here only when continuing to
1466 deliver down an existing channel. The channel was passed as the standard
1467 input. TLS is never active on a passed channel; the previous process always
1468 closes it down before passing the connection on.
1469
1470 Otherwise, we have to make a connection to the remote host, and do the
1471 initial protocol exchange.
1472
1473 When running as an MUA wrapper, if the sender or any recipient is rejected,
1474 temporarily or permanently, we force failure for all recipients.
1475
1476 Arguments:
1477 addrlist chain of potential addresses to deliver; only those whose
1478 transport_return field is set to PENDING_DEFER are currently
1479 being processed; others should be skipped - they have either
1480 been delivered to an earlier host or IP address, or been
1481 failed by one of them.
1482 host host to deliver to
1483 host_af AF_INET or AF_INET6
1484 port default TCP/IP port to use, in host byte order
1485 interface interface to bind to, or NULL
1486 tblock transport instance block
1487 message_defer set TRUE if yield is OK, but all addresses were deferred
1488 because of a non-recipient, non-host failure, that is, a
1489 4xx response to MAIL FROM, DATA, or ".". This is a defer
1490 that is specific to the message.
1491 suppress_tls if TRUE, don't attempt a TLS connection - this is set for
1492 a second attempt after TLS initialization fails
1493
1494 Returns: OK - the connection was made and the delivery attempted;
1495 the result for each address is in its data block.
1496 DEFER - the connection could not be made, or something failed
1497 while setting up the SMTP session, or there was a
1498 non-message-specific error, such as a timeout.
1499 ERROR - a filter command is specified for this transport,
1500 and there was a problem setting it up; OR helo_data
1501 or add_headers or authenticated_sender is specified
1502 for this transport, and the string failed to expand
1503 */
1504
1505 static int
1506 smtp_deliver(address_item *addrlist, host_item *host, int host_af, int port,
1507 uschar *interface, transport_instance *tblock,
1508 BOOL *message_defer, BOOL suppress_tls)
1509 {
1510 address_item *addr;
1511 address_item *sync_addr;
1512 address_item *first_addr = addrlist;
1513 int yield = OK;
1514 int address_count;
1515 int save_errno;
1516 int rc;
1517 time_t start_delivery_time = time(NULL);
1518 smtp_transport_options_block *ob =
1519 (smtp_transport_options_block *)(tblock->options_block);
1520 struct lflags {
1521 BOOL lmtp:1;
1522 BOOL smtps:1;
1523 BOOL ok:1;
1524 BOOL send_rset:1;
1525 BOOL send_quit:1;
1526 BOOL setting_up:1;
1527 BOOL esmtp:1;
1528 BOOL esmtp_sent:1;
1529 BOOL pending_MAIL:1;
1530 #ifndef DISABLE_PRDR
1531 BOOL prdr_active:1;
1532 #endif
1533 #ifdef SUPPORT_I18N
1534 BOOL utf8_needed:1;
1535 #endif
1536 BOOL dsn_all_lasthop:1;
1537 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
1538 BOOL dane:1;
1539 BOOL dane_required:1;
1540 #endif
1541 } lflags;
1542
1543 BOOL pass_message = FALSE;
1544 BOOL completed_address = FALSE;
1545 uschar peer_offered = 0;
1546 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
1547 dns_answer tlsa_dnsa;
1548 #endif
1549 smtp_inblock inblock;
1550 smtp_outblock outblock;
1551 int max_rcpt = tblock->max_addresses;
1552 uschar *igquotstr = US"";
1553
1554 #ifdef EXPERIMENTAL_DSN_INFO
1555 uschar *smtp_greeting = NULL;
1556 uschar *helo_response = NULL;
1557 #endif
1558 uschar *helo_data = NULL;
1559
1560 uschar *message = NULL;
1561 uschar new_message_id[MESSAGE_ID_LENGTH + 1];
1562 uschar *p;
1563 uschar buffer[DELIVER_BUFFER_SIZE];
1564 uschar inbuffer[4096];
1565 uschar outbuffer[4096];
1566
1567 suppress_tls = suppress_tls; /* stop compiler warning when no TLS support */
1568
1569 lflags.lmtp = strcmpic(ob->protocol, US"lmtp") == 0;
1570 lflags.smtps = strcmpic(ob->protocol, US"smtps") == 0;
1571 lflags.ok = FALSE;
1572 lflags.send_rset = TRUE;
1573 lflags.send_quit = TRUE;
1574 lflags.setting_up = TRUE;
1575 lflags.esmtp = TRUE;
1576 lflags.esmtp_sent = FALSE;
1577 #ifdef SUPPORT_I18N
1578 lflags.utf8_needed = FALSE;
1579 #endif
1580 lflags.dsn_all_lasthop = TRUE;
1581 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
1582 lflags.dane = FALSE;
1583 lflags.dane_required = verify_check_given_host(&ob->hosts_require_dane, host) == OK;
1584 #endif
1585
1586 *message_defer = FALSE;
1587 smtp_command = US"initial connection";
1588 if (max_rcpt == 0) max_rcpt = 999999;
1589
1590 /* Set up the buffer for reading SMTP response packets. */
1591
1592 inblock.buffer = inbuffer;
1593 inblock.buffersize = sizeof(inbuffer);
1594 inblock.ptr = inbuffer;
1595 inblock.ptrend = inbuffer;
1596
1597 /* Set up the buffer for holding SMTP commands while pipelining */
1598
1599 outblock.buffer = outbuffer;
1600 outblock.buffersize = sizeof(outbuffer);
1601 outblock.ptr = outbuffer;
1602 outblock.cmd_count = 0;
1603 outblock.authenticating = FALSE;
1604
1605 /* Reset the parameters of a TLS session. */
1606
1607 tls_out.bits = 0;
1608 tls_out.cipher = NULL; /* the one we may use for this transport */
1609 tls_out.ourcert = NULL;
1610 tls_out.peercert = NULL;
1611 tls_out.peerdn = NULL;
1612 #if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
1613 tls_out.sni = NULL;
1614 #endif
1615 tls_out.ocsp = OCSP_NOT_REQ;
1616
1617 /* Flip the legacy TLS-related variables over to the outbound set in case
1618 they're used in the context of the transport. Don't bother resetting
1619 afterward as we're in a subprocess. */
1620
1621 tls_modify_variables(&tls_out);
1622
1623 #ifndef SUPPORT_TLS
1624 if (lflags.smtps)
1625 {
1626 set_errno_nohost(addrlist, ERRNO_TLSFAILURE, US"TLS support not available",
1627 DEFER, FALSE);
1628 return ERROR;
1629 }
1630 #endif
1631
1632 /* Make a connection to the host if this isn't a continued delivery, and handle
1633 the initial interaction and HELO/EHLO/LHLO. Connect timeout errors are handled
1634 specially so they can be identified for retries. */
1635
1636 if (continue_hostname == NULL)
1637 {
1638 /* This puts port into host->port */
1639 inblock.sock = outblock.sock =
1640 smtp_connect(host, host_af, port, interface, ob->connect_timeout, tblock);
1641
1642 if (inblock.sock < 0)
1643 {
1644 set_errno_nohost(addrlist, errno == ETIMEDOUT ? ERRNO_CONNECTTIMEOUT : errno,
1645 NULL, DEFER, FALSE);
1646 return DEFER;
1647 }
1648
1649 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
1650 {
1651 tls_out.dane_verified = FALSE;
1652 tls_out.tlsa_usage = 0;
1653
1654 if (host->dnssec == DS_YES)
1655 {
1656 if( lflags.dane_required
1657 || verify_check_given_host(&ob->hosts_try_dane, host) == OK
1658 )
1659 switch (rc = tlsa_lookup(host, &tlsa_dnsa, lflags.dane_required))
1660 {
1661 case OK: lflags.dane = TRUE; break;
1662 case FAIL_FORCED: break;
1663 default: set_errno_nohost(addrlist, ERRNO_DNSDEFER,
1664 string_sprintf("DANE error: tlsa lookup %s",
1665 rc == DEFER ? "DEFER" : "FAIL"),
1666 rc, FALSE);
1667 return rc;
1668 }
1669 }
1670 else if (lflags.dane_required)
1671 {
1672 set_errno_nohost(addrlist, ERRNO_DNSDEFER,
1673 string_sprintf("DANE error: %s lookup not DNSSEC", host->name),
1674 FAIL, FALSE);
1675 return FAIL;
1676 }
1677
1678 if (lflags.dane)
1679 ob->tls_tempfail_tryclear = FALSE;
1680 }
1681 #endif /*DANE*/
1682
1683 /* Expand the greeting message while waiting for the initial response. (Makes
1684 sense if helo_data contains ${lookup dnsdb ...} stuff). The expansion is
1685 delayed till here so that $sending_interface and $sending_port are set. */
1686
1687 helo_data = expand_string(ob->helo_data);
1688 #ifdef SUPPORT_I18N
1689 if (helo_data)
1690 {
1691 uschar * errstr = NULL;
1692 if ((helo_data = string_domain_utf8_to_alabel(helo_data, &errstr)), errstr)
1693 {
1694 errstr = string_sprintf("failed to expand helo_data: %s", errstr);
1695 set_errno_nohost(addrlist, ERRNO_EXPANDFAIL, errstr, DEFER, FALSE);
1696 yield = DEFER;
1697 goto SEND_QUIT;
1698 }
1699 }
1700 #endif
1701
1702 /* The first thing is to wait for an initial OK response. The dreaded "goto"
1703 is nevertheless a reasonably clean way of programming this kind of logic,
1704 where you want to escape on any error. */
1705
1706 if (!lflags.smtps)
1707 {
1708 BOOL good_response = smtp_read_response(&inblock, buffer, sizeof(buffer),
1709 '2', ob->command_timeout);
1710 #ifdef EXPERIMENTAL_DSN_INFO
1711 smtp_greeting = string_copy(buffer);
1712 #endif
1713 if (!good_response) goto RESPONSE_FAILED;
1714
1715 #ifndef DISABLE_EVENT
1716 {
1717 uschar * s;
1718 lookup_dnssec_authenticated = host->dnssec==DS_YES ? US"yes"
1719 : host->dnssec==DS_NO ? US"no" : NULL;
1720 s = event_raise(tblock->event_action, US"smtp:connect", buffer);
1721 if (s)
1722 {
1723 set_errno_nohost(addrlist, ERRNO_EXPANDFAIL,
1724 string_sprintf("deferred by smtp:connect event expansion: %s", s),
1725 DEFER, FALSE);
1726 yield = DEFER;
1727 goto SEND_QUIT;
1728 }
1729 }
1730 #endif
1731
1732 /* Now check if the helo_data expansion went well, and sign off cleanly if
1733 it didn't. */
1734
1735 if (helo_data == NULL)
1736 {
1737 uschar *message = string_sprintf("failed to expand helo_data: %s",
1738 expand_string_message);
1739 set_errno_nohost(addrlist, ERRNO_EXPANDFAIL, message, DEFER, FALSE);
1740 yield = DEFER;
1741 goto SEND_QUIT;
1742 }
1743 }
1744
1745 /** Debugging without sending a message
1746 addrlist->transport_return = DEFER;
1747 goto SEND_QUIT;
1748 **/
1749
1750 /* Errors that occur after this point follow an SMTP command, which is
1751 left in big_buffer by smtp_write_command() for use in error messages. */
1752
1753 smtp_command = big_buffer;
1754
1755 /* Tell the remote who we are...
1756
1757 February 1998: A convention has evolved that ESMTP-speaking MTAs include the
1758 string "ESMTP" in their greeting lines, so make Exim send EHLO if the
1759 greeting is of this form. The assumption was that the far end supports it
1760 properly... but experience shows that there are some that give 5xx responses,
1761 even though the banner includes "ESMTP" (there's a bloody-minded one that
1762 says "ESMTP not spoken here"). Cope with that case.
1763
1764 September 2000: Time has passed, and it seems reasonable now to always send
1765 EHLO at the start. It is also convenient to make the change while installing
1766 the TLS stuff.
1767
1768 July 2003: Joachim Wieland met a broken server that advertises "PIPELINING"
1769 but times out after sending MAIL FROM, RCPT TO and DATA all together. There
1770 would be no way to send out the mails, so there is now a host list
1771 "hosts_avoid_esmtp" that disables ESMTP for special hosts and solves the
1772 PIPELINING problem as well. Maybe it can also be useful to cure other
1773 problems with broken servers.
1774
1775 Exim originally sent "Helo" at this point and ran for nearly a year that way.
1776 Then somebody tried it with a Microsoft mailer... It seems that all other
1777 mailers use upper case for some reason (the RFC is quite clear about case
1778 independence) so, for peace of mind, I gave in. */
1779
1780 lflags.esmtp = verify_check_given_host(&ob->hosts_avoid_esmtp, host) != OK;
1781
1782 /* Alas; be careful, since this goto is not an error-out, so conceivably
1783 we might set data between here and the target which we assume to exist
1784 and be usable. I can see this coming back to bite us. */
1785 #ifdef SUPPORT_TLS
1786 if (lflags.smtps)
1787 {
1788 smtp_peer_options |= PEER_OFFERED_TLS;
1789 suppress_tls = FALSE;
1790 ob->tls_tempfail_tryclear = FALSE;
1791 smtp_command = US"SSL-on-connect";
1792 goto TLS_NEGOTIATE;
1793 }
1794 #endif
1795
1796 if (lflags.esmtp)
1797 {
1798 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n",
1799 lflags.lmtp ? "LHLO" : "EHLO", helo_data) < 0)
1800 goto SEND_FAILED;
1801 lflags.esmtp_sent = TRUE;
1802 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1803 ob->command_timeout))
1804 {
1805 if (errno != 0 || buffer[0] == 0 || lflags.lmtp)
1806 {
1807 #ifdef EXPERIMENTAL_DSN_INFO
1808 helo_response = string_copy(buffer);
1809 #endif
1810 goto RESPONSE_FAILED;
1811 }
1812 lflags.esmtp = FALSE;
1813 }
1814 #ifdef EXPERIMENTAL_DSN_INFO
1815 helo_response = string_copy(buffer);
1816 #endif
1817 }
1818 else
1819 DEBUG(D_transport)
1820 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
1821
1822 if (!lflags.esmtp)
1823 {
1824 BOOL good_response;
1825 int n = sizeof(buffer);
1826 uschar * rsp = buffer;
1827
1828 if (lflags.esmtp_sent && (n = Ustrlen(buffer)) < sizeof(buffer)/2)
1829 { rsp = buffer + n + 1; n = sizeof(buffer) - n; }
1830
1831 if (smtp_write_command(&outblock, FALSE, "HELO %s\r\n", helo_data) < 0)
1832 goto SEND_FAILED;
1833 good_response = smtp_read_response(&inblock, rsp, n,
1834 '2', ob->command_timeout);
1835 #ifdef EXPERIMENTAL_DSN_INFO
1836 helo_response = string_copy(rsp);
1837 #endif
1838 if (!good_response)
1839 {
1840 /* Handle special logging for a closed connection after HELO
1841 when had previously sent EHLO */
1842
1843 if (rsp != buffer && rsp[0] == 0 && (errno == 0 || errno == ECONNRESET))
1844 {
1845 message = NULL;
1846 lflags.send_quit = FALSE;
1847 save_errno = ERRNO_SMTPCLOSED;
1848 message = string_sprintf("Remote host closed connection "
1849 "in response to %s (EHLO response was: %s)",
1850 smtp_command, buffer);
1851 goto FAILED;
1852 }
1853 Ustrncpy(buffer, rsp, sizeof(buffer)/2);
1854 goto RESPONSE_FAILED;
1855 }
1856 }
1857
1858 peer_offered = smtp_peer_options = 0;
1859
1860 if (lflags.esmtp || lflags.lmtp)
1861 {
1862 peer_offered = ehlo_response(buffer, Ustrlen(buffer),
1863 PEER_OFFERED_TLS /* others checked later */
1864 );
1865
1866 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
1867
1868 #ifdef SUPPORT_TLS
1869 smtp_peer_options |= peer_offered & PEER_OFFERED_TLS;
1870 #endif
1871 }
1872 }
1873
1874 /* For continuing deliveries down the same channel, the socket is the standard
1875 input, and we don't need to redo EHLO here (but may need to do so for TLS - see
1876 below). Set up the pointer to where subsequent commands will be left, for
1877 error messages. Note that smtp_peer_options will have been
1878 set from the command line if they were set in the process that passed the
1879 connection on. */
1880
1881 /*XXX continue case needs to propagate DSN_INFO, prob. in deliver.c
1882 as the contine goes via transport_pass_socket() and doublefork and exec.
1883 It does not wait. Unclear how we keep separate host's responses
1884 separate - we could match up by host ip+port as a bodge. */
1885
1886 else
1887 {
1888 inblock.sock = outblock.sock = fileno(stdin);
1889 smtp_command = big_buffer;
1890 host->port = port; /* Record the port that was used */
1891 }
1892
1893 /* If TLS is available on this connection, whether continued or not, attempt to
1894 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
1895 send another EHLO - the server may give a different answer in secure mode. We
1896 use a separate buffer for reading the response to STARTTLS so that if it is
1897 negative, the original EHLO data is available for subsequent analysis, should
1898 the client not be required to use TLS. If the response is bad, copy the buffer
1899 for error analysis. */
1900
1901 #ifdef SUPPORT_TLS
1902 if ( smtp_peer_options & PEER_OFFERED_TLS
1903 && !suppress_tls
1904 && verify_check_given_host(&ob->hosts_avoid_tls, host) != OK)
1905 {
1906 uschar buffer2[4096];
1907 if (smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") < 0)
1908 goto SEND_FAILED;
1909
1910 /* If there is an I/O error, transmission of this message is deferred. If
1911 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
1912 false, we also defer. However, if there is a temporary rejection of STARTTLS
1913 and tls_tempfail_tryclear is true, or if there is an outright rejection of
1914 STARTTLS, we carry on. This means we will try to send the message in clear,
1915 unless the host is in hosts_require_tls (tested below). */
1916
1917 if (!smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
1918 ob->command_timeout))
1919 {
1920 if ( errno != 0
1921 || buffer2[0] == 0
1922 || (buffer2[0] == '4' && !ob->tls_tempfail_tryclear)
1923 )
1924 {
1925 Ustrncpy(buffer, buffer2, sizeof(buffer));
1926 goto RESPONSE_FAILED;
1927 }
1928 }
1929
1930 /* STARTTLS accepted: try to negotiate a TLS session. */
1931
1932 else
1933 TLS_NEGOTIATE:
1934 {
1935 int rc = tls_client_start(inblock.sock, host, addrlist, tblock
1936 # ifdef EXPERIMENTAL_DANE
1937 , lflags.dane ? &tlsa_dnsa : NULL
1938 # endif
1939 );
1940
1941 /* TLS negotiation failed; give an error. From outside, this function may
1942 be called again to try in clear on a new connection, if the options permit
1943 it for this host. */
1944
1945 if (rc != OK)
1946 {
1947 # ifdef EXPERIMENTAL_DANE
1948 if (lflags.dane) log_write(0, LOG_MAIN,
1949 "DANE attempt failed; no TLS connection to %s [%s]",
1950 host->name, host->address);
1951 # endif
1952
1953 save_errno = ERRNO_TLSFAILURE;
1954 message = US"failure while setting up TLS session";
1955 lflags.send_quit = FALSE;
1956 goto TLS_FAILED;
1957 }
1958
1959 /* TLS session is set up */
1960
1961 smtp_peer_options_wrap = smtp_peer_options;
1962 for (addr = addrlist; addr; addr = addr->next)
1963 if (addr->transport_return == PENDING_DEFER)
1964 {
1965 addr->cipher = tls_out.cipher;
1966 addr->ourcert = tls_out.ourcert;
1967 addr->peercert = tls_out.peercert;
1968 addr->peerdn = tls_out.peerdn;
1969 addr->ocsp = tls_out.ocsp;
1970 }
1971 }
1972 }
1973
1974 /* if smtps, we'll have smtp_command set to something else; always safe to
1975 reset it here. */
1976 smtp_command = big_buffer;
1977
1978 /* If we started TLS, redo the EHLO/LHLO exchange over the secure channel. If
1979 helo_data is null, we are dealing with a connection that was passed from
1980 another process, and so we won't have expanded helo_data above. We have to
1981 expand it here. $sending_ip_address and $sending_port are set up right at the
1982 start of the Exim process (in exim.c). */
1983
1984 if (tls_out.active >= 0)
1985 {
1986 char *greeting_cmd;
1987 BOOL good_response;
1988
1989 if (helo_data == NULL)
1990 {
1991 helo_data = expand_string(ob->helo_data);
1992 if (helo_data == NULL)
1993 {
1994 uschar *message = string_sprintf("failed to expand helo_data: %s",
1995 expand_string_message);
1996 set_errno_nohost(addrlist, ERRNO_EXPANDFAIL, message, DEFER, FALSE);
1997 yield = DEFER;
1998 goto SEND_QUIT;
1999 }
2000 }
2001
2002 /* For SMTPS we need to wait for the initial OK response. */
2003 if (lflags.smtps)
2004 {
2005 good_response = smtp_read_response(&inblock, buffer, sizeof(buffer),
2006 '2', ob->command_timeout);
2007 #ifdef EXPERIMENTAL_DSN_INFO
2008 smtp_greeting = string_copy(buffer);
2009 #endif
2010 if (!good_response) goto RESPONSE_FAILED;
2011 }
2012
2013 if (lflags.esmtp)
2014 greeting_cmd = "EHLO";
2015 else
2016 {
2017 greeting_cmd = "HELO";
2018 DEBUG(D_transport)
2019 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
2020 }
2021
2022 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n",
2023 lflags.lmtp ? "LHLO" : greeting_cmd, helo_data) < 0)
2024 goto SEND_FAILED;
2025 good_response = smtp_read_response(&inblock, buffer, sizeof(buffer),
2026 '2', ob->command_timeout);
2027 #ifdef EXPERIMENTAL_DSN_INFO
2028 helo_response = string_copy(buffer);
2029 #endif
2030 if (!good_response) goto RESPONSE_FAILED;
2031 smtp_peer_options = 0;
2032 }
2033
2034 /* If the host is required to use a secure channel, ensure that we
2035 have one. */
2036
2037 else if ( lflags.smtps
2038 # ifdef EXPERIMENTAL_DANE
2039 || lflags.dane
2040 # endif
2041 || verify_check_given_host(&ob->hosts_require_tls, host) == OK
2042 )
2043 {
2044 save_errno = ERRNO_TLSREQUIRED;
2045 message = string_sprintf("a TLS session is required, but %s",
2046 smtp_peer_options & PEER_OFFERED_TLS
2047 ? "an attempt to start TLS failed" : "the server did not offer TLS support");
2048 goto TLS_FAILED;
2049 }
2050 #endif /*SUPPORT_TLS*/
2051
2052 /* If TLS is active, we have just started it up and re-done the EHLO command,
2053 so its response needs to be analyzed. If TLS is not active and this is a
2054 continued session down a previously-used socket, we haven't just done EHLO, so
2055 we skip this. */
2056
2057 if (continue_hostname == NULL
2058 #ifdef SUPPORT_TLS
2059 || tls_out.active >= 0
2060 #endif
2061 )
2062 {
2063 if (lflags.esmtp || lflags.lmtp)
2064 {
2065 peer_offered = ehlo_response(buffer, Ustrlen(buffer),
2066 0 /* no TLS */
2067 | (lflags.lmtp && ob->lmtp_ignore_quota ? PEER_OFFERED_IGNQ : 0)
2068 | PEER_OFFERED_CHUNKING
2069 | PEER_OFFERED_PRDR
2070 #ifdef SUPPORT_I18N
2071 | (addrlist->prop.utf8_msg ? PEER_OFFERED_UTF8 : 0)
2072 /*XXX if we hand peercaps on to continued-conn processes,
2073 must not depend on this addr */
2074 #endif
2075 | PEER_OFFERED_DSN
2076 | PEER_OFFERED_PIPE
2077 | (ob->size_addition >= 0 ? PEER_OFFERED_SIZE : 0)
2078 );
2079
2080 /* Set for IGNOREQUOTA if the response to LHLO specifies support and the
2081 lmtp_ignore_quota option was set. */
2082
2083 igquotstr = peer_offered & PEER_OFFERED_IGNQ ? US" IGNOREQUOTA" : US"";
2084
2085 /* If the response to EHLO specified support for the SIZE parameter, note
2086 this, provided size_addition is non-negative. */
2087
2088 smtp_peer_options |= peer_offered & PEER_OFFERED_SIZE;
2089
2090 /* Note whether the server supports PIPELINING. If hosts_avoid_esmtp matched
2091 the current host, esmtp will be false, so PIPELINING can never be used. If
2092 the current host matches hosts_avoid_pipelining, don't do it. */
2093
2094 if ( peer_offered & PEER_OFFERED_PIPE
2095 && verify_check_given_host(&ob->hosts_avoid_pipelining, host) != OK)
2096 smtp_peer_options |= PEER_OFFERED_PIPE;
2097
2098 DEBUG(D_transport) debug_printf("%susing PIPELINING\n",
2099 smtp_peer_options & PEER_OFFERED_PIPE ? "" : "not ");
2100
2101 if ( peer_offered & PEER_OFFERED_CHUNKING
2102 && verify_check_given_host(&ob->hosts_try_chunking, host) != OK)
2103 peer_offered &= ~PEER_OFFERED_CHUNKING;
2104
2105 if (peer_offered & PEER_OFFERED_CHUNKING)
2106 {DEBUG(D_transport) debug_printf("CHUNKING usable\n");}
2107
2108 #ifndef DISABLE_PRDR
2109 if ( peer_offered & PEER_OFFERED_PRDR
2110 && verify_check_given_host(&ob->hosts_try_prdr, host) != OK)
2111 peer_offered &= ~PEER_OFFERED_PRDR;
2112
2113 if (peer_offered & PEER_OFFERED_PRDR)
2114 {DEBUG(D_transport) debug_printf("PRDR usable\n");}
2115 #endif
2116
2117 /* Note if the server supports DSN */
2118 smtp_peer_options |= peer_offered & PEER_OFFERED_DSN;
2119 DEBUG(D_transport) debug_printf("%susing DSN\n",
2120 peer_offered & PEER_OFFERED_DSN ? "" : "not ");
2121
2122 /* Note if the response to EHLO specifies support for the AUTH extension.
2123 If it has, check that this host is one we want to authenticate to, and do
2124 the business. The host name and address must be available when the
2125 authenticator's client driver is running. */
2126
2127 switch (yield = smtp_auth(buffer, sizeof(buffer), addrlist, host,
2128 ob, lflags.esmtp, &inblock, &outblock))
2129 {
2130 default: goto SEND_QUIT;
2131 case OK: break;
2132 case FAIL_SEND: goto SEND_FAILED;
2133 case FAIL: goto RESPONSE_FAILED;
2134 }
2135 }
2136 }
2137 pipelining_active = !!(smtp_peer_options & PEER_OFFERED_PIPE);
2138
2139 /* The setting up of the SMTP call is now complete. Any subsequent errors are
2140 message-specific. */
2141
2142 lflags.setting_up = FALSE;
2143
2144 #ifdef SUPPORT_I18N
2145 if (addrlist->prop.utf8_msg)
2146 {
2147 lflags.utf8_needed = !addrlist->prop.utf8_downcvt
2148 && !addrlist->prop.utf8_downcvt_maybe;
2149 DEBUG(D_transport) if (!lflags.utf8_needed)
2150 debug_printf("utf8: %s downconvert\n",
2151 addrlist->prop.utf8_downcvt ? "mandatory" : "optional");
2152 }
2153
2154 /* If this is an international message we need the host to speak SMTPUTF8 */
2155 if (lflags.utf8_needed && !(peer_offered & PEER_OFFERED_UTF8))
2156 {
2157 errno = ERRNO_UTF8_FWD;
2158 goto RESPONSE_FAILED;
2159 }
2160 #endif
2161
2162 /* If there is a filter command specified for this transport, we can now
2163 set it up. This cannot be done until the identify of the host is known. */
2164
2165 if (tblock->filter_command != NULL)
2166 {
2167 BOOL rc;
2168 uschar buffer[64];
2169 sprintf(CS buffer, "%.50s transport", tblock->name);
2170 rc = transport_set_up_command(&transport_filter_argv, tblock->filter_command,
2171 TRUE, DEFER, addrlist, buffer, NULL);
2172 transport_filter_timeout = tblock->filter_timeout;
2173
2174 /* On failure, copy the error to all addresses, abandon the SMTP call, and
2175 yield ERROR. */
2176
2177 if (!rc)
2178 {
2179 set_errno_nohost(addrlist->next, addrlist->basic_errno, addrlist->message, DEFER,
2180 FALSE);
2181 yield = ERROR;
2182 goto SEND_QUIT;
2183 }
2184
2185 if ( transport_filter_argv
2186 && *transport_filter_argv
2187 && **transport_filter_argv
2188 && peer_offered & PEER_OFFERED_CHUNKING
2189 )
2190 {
2191 peer_offered &= ~PEER_OFFERED_CHUNKING;
2192 DEBUG(D_transport) debug_printf("CHUNKING not usable due to transport filter\n");
2193 }
2194 }
2195
2196
2197 /* For messages that have more than the maximum number of envelope recipients,
2198 we want to send several transactions down the same SMTP connection. (See
2199 comments in deliver.c as to how this reconciles, heuristically, with
2200 remote_max_parallel.) This optimization was added to Exim after the following
2201 code was already working. The simplest way to put it in without disturbing the
2202 code was to use a goto to jump back to this point when there is another
2203 transaction to handle. */
2204
2205 SEND_MESSAGE:
2206 sync_addr = first_addr;
2207 address_count = 0;
2208 lflags.ok = FALSE;
2209 lflags.send_rset = TRUE;
2210 completed_address = FALSE;
2211
2212
2213 /* Initiate a message transfer. If we know the receiving MTA supports the SIZE
2214 qualification, send it, adding something to the message size to allow for
2215 imprecision and things that get added en route. Exim keeps the number of lines
2216 in a message, so we can give an accurate value for the original message, but we
2217 need some additional to handle added headers. (Double "." characters don't get
2218 included in the count.) */
2219
2220 p = buffer;
2221 *p = 0;
2222
2223 if (peer_offered & PEER_OFFERED_SIZE)
2224 {
2225 sprintf(CS p, " SIZE=%d", message_size+message_linecount+ob->size_addition);
2226 while (*p) p++;
2227 }
2228
2229 #ifndef DISABLE_PRDR
2230 lflags.prdr_active = FALSE;
2231 if (peer_offered & PEER_OFFERED_PRDR)
2232 for (addr = first_addr; addr; addr = addr->next)
2233 if (addr->transport_return == PENDING_DEFER)
2234 {
2235 for (addr = addr->next; addr; addr = addr->next)
2236 if (addr->transport_return == PENDING_DEFER)
2237 { /* at least two recipients to send */
2238 lflags.prdr_active = TRUE;
2239 sprintf(CS p, " PRDR"); p += 5;
2240 break;
2241 }
2242 break;
2243 }
2244 #endif
2245
2246 #ifdef SUPPORT_I18N
2247 if ( addrlist->prop.utf8_msg
2248 && !addrlist->prop.utf8_downcvt
2249 && peer_offered & PEER_OFFERED_UTF8
2250 )
2251 sprintf(CS p, " SMTPUTF8"), p += 9;
2252 #endif
2253
2254 /* check if all addresses have lasthop flag */
2255 /* do not send RET and ENVID if true */
2256 for (lflags.dsn_all_lasthop = TRUE, addr = first_addr;
2257 address_count < max_rcpt && addr != NULL;
2258 addr = addr->next)
2259 if ((addr->dsn_flags & rf_dsnlasthop) != 1)
2260 {
2261 lflags.dsn_all_lasthop = FALSE;
2262 break;
2263 }
2264
2265 /* Add any DSN flags to the mail command */
2266
2267 if (peer_offered & PEER_OFFERED_DSN && !lflags.dsn_all_lasthop)
2268 {
2269 if (dsn_ret == dsn_ret_hdrs)
2270 { Ustrcpy(p, " RET=HDRS"); p += 9; }
2271 else if (dsn_ret == dsn_ret_full)
2272 { Ustrcpy(p, " RET=FULL"); p += 9; }
2273
2274 if (dsn_envid)
2275 {
2276 string_format(p, sizeof(buffer) - (p-buffer), " ENVID=%s", dsn_envid);
2277 while (*p) p++;
2278 }
2279 }
2280
2281 /* If an authenticated_sender override has been specified for this transport
2282 instance, expand it. If the expansion is forced to fail, and there was already
2283 an authenticated_sender for this message, the original value will be used.
2284 Other expansion failures are serious. An empty result is ignored, but there is
2285 otherwise no check - this feature is expected to be used with LMTP and other
2286 cases where non-standard addresses (e.g. without domains) might be required. */
2287
2288 if (smtp_mail_auth_str(p, sizeof(buffer) - (p-buffer), addrlist, ob))
2289 {
2290 yield = ERROR;
2291 goto SEND_QUIT;
2292 }
2293
2294 /* From here until we send the DATA command, we can make use of PIPELINING
2295 if the server host supports it. The code has to be able to check the responses
2296 at any point, for when the buffer fills up, so we write it totally generally.
2297 When PIPELINING is off, each command written reports that it has flushed the
2298 buffer. */
2299
2300 lflags.pending_MAIL = TRUE; /* The block starts with MAIL */
2301
2302 {
2303 uschar * s = return_path;
2304 #ifdef SUPPORT_I18N
2305 uschar * errstr = NULL;
2306
2307 /* If we must downconvert, do the from-address here. Remember we had to
2308 for the to-addresses (done below), and also (ugly) for re-doing when building
2309 the delivery log line. */
2310
2311 if ( addrlist->prop.utf8_msg
2312 && (addrlist->prop.utf8_downcvt || !(peer_offered & PEER_OFFERED_UTF8))
2313 )
2314 {
2315 if (s = string_address_utf8_to_alabel(return_path, &errstr), errstr)
2316 {
2317 set_errno_nohost(addrlist, ERRNO_EXPANDFAIL, errstr, DEFER, FALSE);
2318 yield = ERROR;
2319 goto SEND_QUIT;
2320 }
2321 setflag(addrlist, af_utf8_downcvt);
2322 }
2323 #endif
2324
2325 rc = smtp_write_command(&outblock, pipelining_active,
2326 "MAIL FROM:<%s>%s\r\n", s, buffer);
2327 }
2328
2329 mail_command = string_copy(big_buffer); /* Save for later error message */
2330
2331 switch(rc)
2332 {
2333 case -1: /* Transmission error */
2334 goto SEND_FAILED;
2335
2336 case +1: /* Block was sent */
2337 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2338 ob->command_timeout))
2339 {
2340 if (errno == 0 && buffer[0] == '4')
2341 {
2342 errno = ERRNO_MAIL4XX;
2343 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
2344 }
2345 goto RESPONSE_FAILED;
2346 }
2347 lflags.pending_MAIL = FALSE;
2348 break;
2349 }
2350
2351 /* Pass over all the relevant recipient addresses for this host, which are the
2352 ones that have status PENDING_DEFER. If we are using PIPELINING, we can send
2353 several before we have to read the responses for those seen so far. This
2354 checking is done by a subroutine because it also needs to be done at the end.
2355 Send only up to max_rcpt addresses at a time, leaving first_addr pointing to
2356 the next one if not all are sent.
2357
2358 In the MUA wrapper situation, we want to flush the PIPELINING buffer for the
2359 last address because we want to abort if any recipients have any kind of
2360 problem, temporary or permanent. We know that all recipient addresses will have
2361 the PENDING_DEFER status, because only one attempt is ever made, and we know
2362 that max_rcpt will be large, so all addresses will be done at once. */
2363
2364 for (addr = first_addr;
2365 addr && address_count < max_rcpt;
2366 addr = addr->next)
2367 if (addr->transport_return == PENDING_DEFER)
2368 {
2369 int count;
2370 BOOL no_flush;
2371 uschar * rcpt_addr;
2372
2373 addr->dsn_aware = peer_offered & PEER_OFFERED_DSN
2374 ? dsn_support_yes : dsn_support_no;
2375
2376 address_count++;
2377 no_flush = pipelining_active && (!mua_wrapper || addr->next);
2378
2379 /* Add any DSN flags to the rcpt command and add to the sent string */
2380
2381 p = buffer;
2382 *p = 0;
2383
2384 if (peer_offered & PEER_OFFERED_DSN && !(addr->dsn_flags & rf_dsnlasthop))
2385 {
2386 if (addr->dsn_flags & rf_dsnflags)
2387 {
2388 int i;
2389 BOOL first = TRUE;
2390 Ustrcpy(p, " NOTIFY=");
2391 while (*p) p++;
2392 for (i = 0; i < 4; i++)
2393 if ((addr->dsn_flags & rf_list[i]) != 0)
2394 {
2395 if (!first) *p++ = ',';
2396 first = FALSE;
2397 Ustrcpy(p, rf_names[i]);
2398 while (*p) p++;
2399 }
2400 }
2401
2402 if (addr->dsn_orcpt)
2403 {
2404 string_format(p, sizeof(buffer) - (p-buffer), " ORCPT=%s",
2405 addr->dsn_orcpt);
2406 while (*p) p++;
2407 }
2408 }
2409
2410 /* Now send the RCPT command, and process outstanding responses when
2411 necessary. After a timeout on RCPT, we just end the function, leaving the
2412 yield as OK, because this error can often mean that there is a problem with
2413 just one address, so we don't want to delay the host. */
2414
2415 rcpt_addr = transport_rcpt_address(addr, tblock->rcpt_include_affixes);
2416
2417 #ifdef SUPPORT_I18N
2418 {
2419 uschar * dummy_errstr;
2420 if ( testflag(addrlist, af_utf8_downcvt)
2421 && (rcpt_addr = string_address_utf8_to_alabel(rcpt_addr, &dummy_errstr),
2422 dummy_errstr
2423 ) )
2424 {
2425 errno = ERRNO_EXPANDFAIL;
2426 goto SEND_FAILED;
2427 }
2428 }
2429 #endif
2430
2431 count = smtp_write_command(&outblock, no_flush, "RCPT TO:<%s>%s%s\r\n",
2432 rcpt_addr, igquotstr, buffer);
2433
2434 if (count < 0) goto SEND_FAILED;
2435 if (count > 0)
2436 {
2437 switch(sync_responses(first_addr, tblock->rcpt_include_affixes,
2438 &sync_addr, host, count, ob->address_retry_include_sender,
2439 lflags.pending_MAIL, 0, &inblock, ob->command_timeout, buffer,
2440 sizeof(buffer)))
2441 {
2442 case 3: lflags.ok = TRUE; /* 2xx & 5xx => OK & progress made */
2443 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
2444 break;
2445
2446 case 1: lflags.ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
2447 if (!lflags.lmtp) completed_address = TRUE; /* can't tell about progress yet */
2448 case 0: /* No 2xx or 5xx, but no probs */
2449 break;
2450
2451 case -1: goto END_OFF; /* Timeout on RCPT */
2452 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL error */
2453 }
2454 lflags.pending_MAIL = FALSE; /* Dealt with MAIL */
2455 }
2456 } /* Loop for next address */
2457
2458 /* If we are an MUA wrapper, abort if any RCPTs were rejected, either
2459 permanently or temporarily. We should have flushed and synced after the last
2460 RCPT. */
2461
2462 if (mua_wrapper)
2463 {
2464 address_item *badaddr;
2465 for (badaddr = first_addr; badaddr; badaddr = badaddr->next)
2466 if (badaddr->transport_return != PENDING_OK)
2467 {
2468 /*XXX could we find a better errno than 0 here? */
2469 set_errno_nohost(addrlist, 0, badaddr->message, FAIL,
2470 testflag(badaddr, af_pass_message));
2471 lflags.ok = FALSE;
2472 break;
2473 }
2474 }
2475
2476 /* If ok is TRUE, we know we have got at least one good recipient, and must now
2477 send DATA, but if it is FALSE (in the normal, non-wrapper case), we may still
2478 have a good recipient buffered up if we are pipelining. We don't want to waste
2479 time sending DATA needlessly, so we only send it if either ok is TRUE or if we
2480 are pipelining. The responses are all handled by sync_responses().
2481 If using CHUNKING, do not send a BDAT until we know how big a chunk we want
2482 to send is. */
2483
2484 if ( !(peer_offered & PEER_OFFERED_CHUNKING)
2485 && (lflags.ok || (pipelining_active && !mua_wrapper)))
2486 {
2487 int count = smtp_write_command(&outblock, FALSE, "DATA\r\n");
2488
2489 if (count < 0) goto SEND_FAILED;
2490 switch(sync_responses(first_addr, tblock->rcpt_include_affixes, &sync_addr,
2491 host, count, ob->address_retry_include_sender, lflags.pending_MAIL,
2492 lflags.ok ? +1 : -1, &inblock, ob->command_timeout, buffer, sizeof(buffer)))
2493 {
2494 case 3: lflags.ok = TRUE; /* 2xx & 5xx => OK & progress made */
2495 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
2496 break;
2497
2498 case 1: lflags.ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
2499 if (!lflags.lmtp) completed_address = TRUE; /* can't tell about progress yet */
2500 case 0: break; /* No 2xx or 5xx, but no probs */
2501
2502 case -1: goto END_OFF; /* Timeout on RCPT */
2503 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */
2504 }
2505 pipelining_active = FALSE;
2506 }
2507
2508 /* If there were no good recipients (but otherwise there have been no
2509 problems), just set ok TRUE, since we have handled address-specific errors
2510 already. Otherwise, it's OK to send the message. Use the check/escape mechanism
2511 for handling the SMTP dot-handling protocol, flagging to apply to headers as
2512 well as body. Set the appropriate timeout value to be used for each chunk.
2513 (Haven't been able to make it work using select() for writing yet.) */
2514
2515 if (!(peer_offered & PEER_OFFERED_CHUNKING) && !lflags.ok)
2516 {
2517 /* Save the first address of the next batch. */
2518 first_addr = addr;
2519
2520 lflags.ok = TRUE;
2521 }
2522 else
2523 {
2524 transport_ctx tctx = {
2525 tblock,
2526 addrlist,
2527 US".", US"..", /* Escaping strings */
2528 topt_use_crlf | topt_escape_headers
2529 | (tblock->body_only ? topt_no_headers : 0)
2530 | (tblock->headers_only ? topt_no_body : 0)
2531 | (tblock->return_path_add ? topt_add_return_path : 0)
2532 | (tblock->delivery_date_add ? topt_add_delivery_date : 0)
2533 | (tblock->envelope_to_add ? topt_add_envelope_to : 0)
2534 };
2535
2536 /* If using CHUNKING we need a callback from the generic transport
2537 support to us, for the sending of BDAT smtp commands and the reaping
2538 of responses. The callback needs a whole bunch of state so set up
2539 a transport-context structure to be passed around. */
2540
2541 if (peer_offered & PEER_OFFERED_CHUNKING)
2542 {
2543 tctx.check_string = tctx.escape_string = NULL;
2544 tctx.options |= topt_use_bdat;
2545 tctx.chunk_cb = smtp_chunk_cmd_callback;
2546 tctx.inblock = &inblock;
2547 tctx.outblock = &outblock;
2548 tctx.host = host;
2549 tctx.first_addr = first_addr;
2550 tctx.sync_addr = &sync_addr;
2551 tctx.pending_MAIL = lflags.pending_MAIL;
2552 tctx.pending_BDAT = FALSE;
2553 tctx.good_RCPT = lflags.ok;
2554 tctx.completed_address = &completed_address;
2555 tctx.cmd_count = 0;
2556 tctx.buffer = buffer;
2557 }
2558 else
2559 tctx.options |= topt_end_dot;
2560
2561 /* Save the first address of the next batch. */
2562 first_addr = addr;
2563
2564 /* Responses from CHUNKING commands go in buffer. Otherwise,
2565 there has not been a response. */
2566
2567 buffer[0] = 0;
2568
2569 sigalrm_seen = FALSE;
2570 transport_write_timeout = ob->data_timeout;
2571 smtp_command = US"sending data block"; /* For error messages */
2572 DEBUG(D_transport|D_v)
2573 if (peer_offered & PEER_OFFERED_CHUNKING)
2574 debug_printf(" will write message using CHUNKING\n");
2575 else
2576 debug_printf(" SMTP>> writing message and terminating \".\"\n");
2577 transport_count = 0;
2578
2579 #ifndef DISABLE_DKIM
2580 lflags.ok = dkim_transport_write_message(inblock.sock, &tctx, &ob->dkim);
2581 #else
2582 lflags.ok = transport_write_message(inblock.sock, &tctx, 0);
2583 #endif
2584
2585 /* transport_write_message() uses write() because it is called from other
2586 places to write to non-sockets. This means that under some OS (e.g. Solaris)
2587 it can exit with "Broken pipe" as its error. This really means that the
2588 socket got closed at the far end. */
2589
2590 transport_write_timeout = 0; /* for subsequent transports */
2591
2592 /* Failure can either be some kind of I/O disaster (including timeout),
2593 or the failure of a transport filter or the expansion of added headers.
2594 Or, when CHUNKING, it can be a protocol-detected failure. */
2595
2596 if (!lflags.ok)
2597 goto RESPONSE_FAILED;
2598
2599 /* We used to send the terminating "." explicitly here, but because of
2600 buffering effects at both ends of TCP/IP connections, you don't gain
2601 anything by keeping it separate, so it might as well go in the final
2602 data buffer for efficiency. This is now done by setting the topt_end_dot
2603 flag above. */
2604
2605 smtp_command = US"end of data";
2606
2607 if (peer_offered & PEER_OFFERED_CHUNKING && tctx.cmd_count > 1)
2608 {
2609 /* Reap any outstanding MAIL & RCPT commands, but not a DATA-go-ahead */
2610 switch(sync_responses(first_addr, tblock->rcpt_include_affixes, &sync_addr,
2611 host, tctx.cmd_count-1, ob->address_retry_include_sender,
2612 lflags.pending_MAIL, 0,
2613 &inblock, ob->command_timeout, buffer, sizeof(buffer)))
2614 {
2615 case 3: lflags.ok = TRUE; /* 2xx & 5xx => OK & progress made */
2616 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
2617 break;
2618
2619 case 1: lflags.ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
2620 if (!lflags.lmtp) completed_address = TRUE; /* can't tell about progress yet */
2621 case 0: break; /* No 2xx or 5xx, but no probs */
2622
2623 case -1: goto END_OFF; /* Timeout on RCPT */
2624 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */
2625 }
2626 }
2627
2628 #ifndef DISABLE_PRDR
2629 /* For PRDR we optionally get a partial-responses warning
2630 * followed by the individual responses, before going on with
2631 * the overall response. If we don't get the warning then deal
2632 * with per non-PRDR. */
2633 if(lflags.prdr_active)
2634 {
2635 lflags.ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '3',
2636 ob->final_timeout);
2637 if (!lflags.ok && errno == 0) switch(buffer[0])
2638 {
2639 case '2': lflags.prdr_active = FALSE;
2640 lflags.ok = TRUE;
2641 break;
2642 case '4': errno = ERRNO_DATA4XX;
2643 addrlist->more_errno |=
2644 ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
2645 break;
2646 }
2647 }
2648 else
2649 #endif
2650
2651 /* For non-PRDR SMTP, we now read a single response that applies to the
2652 whole message. If it is OK, then all the addresses have been delivered. */
2653
2654 if (!lflags.lmtp)
2655 {
2656 lflags.ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2657 ob->final_timeout);
2658 if (!lflags.ok && errno == 0 && buffer[0] == '4')
2659 {
2660 errno = ERRNO_DATA4XX;
2661 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
2662 }
2663 }
2664
2665 /* For LMTP, we get back a response for every RCPT command that we sent;
2666 some may be accepted and some rejected. For those that get a response, their
2667 status is fixed; any that are accepted have been handed over, even if later
2668 responses crash - at least, that's how I read RFC 2033.
2669
2670 If all went well, mark the recipient addresses as completed, record which
2671 host/IPaddress they were delivered to, and cut out RSET when sending another
2672 message down the same channel. Write the completed addresses to the journal
2673 now so that they are recorded in case there is a crash of hardware or
2674 software before the spool gets updated. Also record the final SMTP
2675 confirmation if needed (for SMTP only). */
2676
2677 if (lflags.ok)
2678 {
2679 int flag = '=';
2680 int delivery_time = (int)(time(NULL) - start_delivery_time);
2681 int len;
2682 uschar *conf = NULL;
2683
2684 lflags.send_rset = FALSE;
2685 pipelining_active = FALSE;
2686
2687 /* Set up confirmation if needed - applies only to SMTP */
2688
2689 if (
2690 #ifdef DISABLE_EVENT
2691 LOGGING(smtp_confirmation) &&
2692 #endif
2693 !lflags.lmtp
2694 )
2695 {
2696 const uschar *s = string_printing(buffer);
2697 /* deconst cast ok here as string_printing was checked to have alloc'n'copied */
2698 conf = (s == buffer)? (uschar *)string_copy(s) : US s;
2699 }
2700
2701 /* Process all transported addresses - for LMTP or PRDR, read a status for
2702 each one. */
2703
2704 for (addr = addrlist; addr != first_addr; addr = addr->next)
2705 {
2706 if (addr->transport_return != PENDING_OK) continue;
2707
2708 /* LMTP - if the response fails badly (e.g. timeout), use it for all the
2709 remaining addresses. Otherwise, it's a return code for just the one
2710 address. For temporary errors, add a retry item for the address so that
2711 it doesn't get tried again too soon. */
2712
2713 #ifndef DISABLE_PRDR
2714 if (lflags.lmtp || lflags.prdr_active)
2715 #else
2716 if (lflags.lmtp)
2717 #endif
2718 {
2719 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2720 ob->final_timeout))
2721 {
2722 if (errno != 0 || buffer[0] == 0) goto RESPONSE_FAILED;
2723 addr->message = string_sprintf(
2724 #ifndef DISABLE_PRDR
2725 "%s error after %s: %s", lflags.prdr_active ? "PRDR":"LMTP",
2726 #else
2727 "LMTP error after %s: %s",
2728 #endif
2729 big_buffer, string_printing(buffer));
2730 setflag(addr, af_pass_message); /* Allow message to go to user */
2731 if (buffer[0] == '5')
2732 addr->transport_return = FAIL;
2733 else
2734 {
2735 errno = ERRNO_DATA4XX;
2736 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
2737 addr->transport_return = DEFER;
2738 #ifndef DISABLE_PRDR
2739 if (!lflags.prdr_active)
2740 #endif
2741 retry_add_item(addr, addr->address_retry_key, 0);
2742 }
2743 continue;
2744 }
2745 completed_address = TRUE; /* NOW we can set this flag */
2746 if (LOGGING(smtp_confirmation))
2747 {
2748 const uschar *s = string_printing(buffer);
2749 /* deconst cast ok here as string_printing was checked to have alloc'n'copied */
2750 conf = (s == buffer)? (uschar *)string_copy(s) : US s;
2751 }
2752 }
2753
2754 /* SMTP, or success return from LMTP for this address. Pass back the
2755 actual host that was used. */
2756
2757 addr->transport_return = OK;
2758 addr->more_errno = delivery_time;
2759 addr->host_used = host;
2760 addr->special_action = flag;
2761 addr->message = conf;
2762 #ifndef DISABLE_PRDR
2763 if (lflags.prdr_active) addr->flags |= af_prdr_used;
2764 #endif
2765 if (peer_offered & PEER_OFFERED_CHUNKING) addr->flags |= af_chunking_used;
2766 flag = '-';
2767
2768 #ifndef DISABLE_PRDR
2769 if (!lflags.prdr_active)
2770 #endif
2771 {
2772 /* Update the journal. For homonymic addresses, use the base address plus
2773 the transport name. See lots of comments in deliver.c about the reasons
2774 for the complications when homonyms are involved. Just carry on after
2775 write error, as it may prove possible to update the spool file later. */
2776
2777 if (testflag(addr, af_homonym))
2778 sprintf(CS buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
2779 else
2780 sprintf(CS buffer, "%.500s\n", addr->unique);
2781
2782 DEBUG(D_deliver) debug_printf("journalling %s\n", buffer);
2783 len = Ustrlen(CS buffer);
2784 if (write(journal_fd, buffer, len) != len)
2785 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
2786 "%s: %s", buffer, strerror(errno));
2787 }
2788 }
2789
2790 #ifndef DISABLE_PRDR
2791 if (lflags.prdr_active)
2792 {
2793 /* PRDR - get the final, overall response. For any non-success
2794 upgrade all the address statuses. */
2795 lflags.ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2796 ob->final_timeout);
2797 if (!lflags.ok)
2798 {
2799 if(errno == 0 && buffer[0] == '4')
2800 {
2801 errno = ERRNO_DATA4XX;
2802 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
2803 }
2804 for (addr = addrlist; addr != first_addr; addr = addr->next)
2805 if (buffer[0] == '5' || addr->transport_return == OK)
2806 addr->transport_return = PENDING_OK; /* allow set_errno action */
2807 goto RESPONSE_FAILED;
2808 }
2809
2810 /* Update the journal, or setup retry. */
2811 for (addr = addrlist; addr != first_addr; addr = addr->next)
2812 if (addr->transport_return == OK)
2813 {
2814 if (testflag(addr, af_homonym))
2815 sprintf(CS buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
2816 else
2817 sprintf(CS buffer, "%.500s\n", addr->unique);
2818
2819 DEBUG(D_deliver) debug_printf("journalling(PRDR) %s\n", buffer);
2820 len = Ustrlen(CS buffer);
2821 if (write(journal_fd, buffer, len) != len)
2822 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
2823 "%s: %s", buffer, strerror(errno));
2824 }
2825 else if (addr->transport_return == DEFER)
2826 retry_add_item(addr, addr->address_retry_key, -2);
2827 }
2828 #endif
2829
2830 /* Ensure the journal file is pushed out to disk. */
2831
2832 if (EXIMfsync(journal_fd) < 0)
2833 log_write(0, LOG_MAIN|LOG_PANIC, "failed to fsync journal: %s",
2834 strerror(errno));
2835 }
2836 }
2837
2838
2839 /* Handle general (not specific to one address) failures here. The value of ok
2840 is used to skip over this code on the falling through case. A timeout causes a
2841 deferral. Other errors may defer or fail according to the response code, and
2842 may set up a special errno value, e.g. after connection chopped, which is
2843 assumed if errno == 0 and there is no text in the buffer. If control reaches
2844 here during the setting up phase (i.e. before MAIL FROM) then always defer, as
2845 the problem is not related to this specific message. */
2846
2847 if (!lflags.ok)
2848 {
2849 int code, set_rc;
2850 uschar * set_message;
2851
2852 RESPONSE_FAILED:
2853 {
2854 save_errno = errno;
2855 message = NULL;
2856 lflags.send_quit = check_response(host, &save_errno, addrlist->more_errno,
2857 buffer, &code, &message, &pass_message);
2858 goto FAILED;
2859 }
2860
2861 SEND_FAILED:
2862 {
2863 save_errno = errno;
2864 code = '4';
2865 message = US string_sprintf("send() to %s [%s] failed: %s",
2866 host->name, host->address, strerror(save_errno));
2867 lflags.send_quit = FALSE;
2868 goto FAILED;
2869 }
2870
2871 /* This label is jumped to directly when a TLS negotiation has failed,
2872 or was not done for a host for which it is required. Values will be set
2873 in message and save_errno, and setting_up will always be true. Treat as
2874 a temporary error. */
2875
2876 #ifdef SUPPORT_TLS
2877 TLS_FAILED:
2878 code = '4';
2879 #endif
2880
2881 /* If the failure happened while setting up the call, see if the failure was
2882 a 5xx response (this will either be on connection, or following HELO - a 5xx
2883 after EHLO causes it to try HELO). If so, fail all addresses, as this host is
2884 never going to accept them. For other errors during setting up (timeouts or
2885 whatever), defer all addresses, and yield DEFER, so that the host is not
2886 tried again for a while. */
2887
2888 FAILED:
2889 lflags.ok = FALSE; /* For when reached by GOTO */
2890 set_message = message;
2891
2892 if (lflags.setting_up)
2893 if (code == '5')
2894 set_rc = FAIL;
2895 else
2896 yield = set_rc = DEFER;
2897
2898 /* We want to handle timeouts after MAIL or "." and loss of connection after
2899 "." specially. They can indicate a problem with the sender address or with
2900 the contents of the message rather than a real error on the connection. These
2901 cases are treated in the same way as a 4xx response. This next bit of code
2902 does the classification. */
2903
2904 else
2905 {
2906 BOOL message_error;
2907
2908 switch(save_errno)
2909 {
2910 #ifdef SUPPORT_I18N
2911 case ERRNO_UTF8_FWD:
2912 code = '5';
2913 /*FALLTHROUGH*/
2914 #endif
2915 case 0:
2916 case ERRNO_MAIL4XX:
2917 case ERRNO_DATA4XX:
2918 message_error = TRUE;
2919 break;
2920
2921 case ETIMEDOUT:
2922 message_error = Ustrncmp(smtp_command,"MAIL",4) == 0 ||
2923 Ustrncmp(smtp_command,"end ",4) == 0;
2924 break;
2925
2926 case ERRNO_SMTPCLOSED:
2927 message_error = Ustrncmp(smtp_command,"end ",4) == 0;
2928 break;
2929
2930 default:
2931 message_error = FALSE;
2932 break;
2933 }
2934
2935 /* Handle the cases that are treated as message errors. These are:
2936
2937 (a) negative response or timeout after MAIL
2938 (b) negative response after DATA
2939 (c) negative response or timeout or dropped connection after "."
2940 (d) utf8 support required and not offered
2941
2942 It won't be a negative response or timeout after RCPT, as that is dealt
2943 with separately above. The action in all cases is to set an appropriate
2944 error code for all the addresses, but to leave yield set to OK because the
2945 host itself has not failed. Of course, it might in practice have failed
2946 when we've had a timeout, but if so, we'll discover that at the next
2947 delivery attempt. For a temporary error, set the message_defer flag, and
2948 write to the logs for information if this is not the last host. The error
2949 for the last host will be logged as part of the address's log line. */
2950
2951 if (message_error)
2952 {
2953 if (mua_wrapper) code = '5'; /* Force hard failure in wrapper mode */
2954
2955 /* If there's an errno, the message contains just the identity of
2956 the host. */
2957
2958 if (code == '5')
2959 set_rc = FAIL;
2960 else /* Anything other than 5 is treated as temporary */
2961 {
2962 set_rc = DEFER;
2963 if (save_errno > 0)
2964 message = US string_sprintf("%s: %s", message, strerror(save_errno));
2965 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", message);
2966 msglog_line(host, message);
2967 *message_defer = TRUE;
2968 }
2969 }
2970
2971 /* Otherwise, we have an I/O error or a timeout other than after MAIL or
2972 ".", or some other transportation error. We defer all addresses and yield
2973 DEFER, except for the case of failed add_headers expansion, or a transport
2974 filter failure, when the yield should be ERROR, to stop it trying other
2975 hosts. */
2976
2977 else
2978 {
2979 set_rc = DEFER;
2980 yield = (save_errno == ERRNO_CHHEADER_FAIL ||
2981 save_errno == ERRNO_FILTER_FAIL)? ERROR : DEFER;
2982 }
2983 }
2984
2985 set_errno(addrlist, save_errno, set_message, set_rc, pass_message, host
2986 #ifdef EXPERIMENTAL_DSN_INFO
2987 , smtp_greeting, helo_response
2988 #endif
2989 );
2990 }
2991
2992
2993 /* If all has gone well, send_quit will be set TRUE, implying we can end the
2994 SMTP session tidily. However, if there were too many addresses to send in one
2995 message (indicated by first_addr being non-NULL) we want to carry on with the
2996 rest of them. Also, it is desirable to send more than one message down the SMTP
2997 connection if there are several waiting, provided we haven't already sent so
2998 many as to hit the configured limit. The function transport_check_waiting looks
2999 for a waiting message and returns its id. Then transport_pass_socket tries to
3000 set up a continued delivery by passing the socket on to another process. The
3001 variable send_rset is FALSE if a message has just been successfully transfered.
3002
3003 If we are already sending down a continued channel, there may be further
3004 addresses not yet delivered that are aimed at the same host, but which have not
3005 been passed in this run of the transport. In this case, continue_more will be
3006 true, and all we should do is send RSET if necessary, and return, leaving the
3007 channel open.
3008
3009 However, if no address was disposed of, i.e. all addresses got 4xx errors, we
3010 do not want to continue with other messages down the same channel, because that
3011 can lead to looping between two or more messages, all with the same,
3012 temporarily failing address(es). [The retry information isn't updated yet, so
3013 new processes keep on trying.] We probably also don't want to try more of this
3014 message's addresses either.
3015
3016 If we have started a TLS session, we have to end it before passing the
3017 connection to a new process. However, not all servers can handle this (Exim
3018 can), so we do not pass such a connection on if the host matches
3019 hosts_nopass_tls. */
3020
3021 DEBUG(D_transport)
3022 debug_printf("ok=%d send_quit=%d send_rset=%d continue_more=%d "
3023 "yield=%d first_address is %sNULL\n", lflags.ok, lflags.send_quit,
3024 lflags.send_rset, continue_more, yield, first_addr ? "not " : "");
3025
3026 if (completed_address && lflags.ok && lflags.send_quit)
3027 {
3028 BOOL more;
3029 smtp_compare_t t_compare;
3030
3031 t_compare.tblock = tblock;
3032 t_compare.current_sender_address = sender_address;
3033
3034 if ( first_addr != NULL
3035 || continue_more
3036 || ( ( tls_out.active < 0
3037 || verify_check_given_host(&ob->hosts_nopass_tls, host) != OK
3038 )
3039 &&
3040 transport_check_waiting(tblock->name, host->name,
3041 tblock->connection_max_messages, new_message_id, &more,
3042 (oicf)smtp_are_same_identities, (void*)&t_compare)
3043 ) )
3044 {
3045 uschar *msg;
3046 BOOL pass_message;
3047
3048 if (lflags.send_rset)
3049 {
3050 if (! (lflags.ok = smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0))
3051 {
3052 msg = US string_sprintf("send() to %s [%s] failed: %s", host->name,
3053 host->address, strerror(save_errno));
3054 lflags.send_quit = FALSE;
3055 }
3056 else if (! (lflags.ok = smtp_read_response(&inblock, buffer,
3057 sizeof(buffer), '2', ob->command_timeout)))
3058 {
3059 int code;
3060 lflags.send_quit = check_response(host, &errno, 0, buffer, &code, &msg,
3061 &pass_message);
3062 if (!lflags.send_quit)
3063 {
3064 DEBUG(D_transport) debug_printf("H=%s [%s] %s\n",
3065 host->name, host->address, msg);
3066 }
3067 }
3068 }
3069
3070 /* Either RSET was not needed, or it succeeded */
3071
3072 if (lflags.ok)
3073 {
3074 if (first_addr != NULL) /* More addresses still to be sent */
3075 { /* in this run of the transport */
3076 continue_sequence++; /* Causes * in logging */
3077 goto SEND_MESSAGE;
3078 }
3079 if (continue_more) return yield; /* More addresses for another run */
3080
3081 /* Pass the socket to a new Exim process. Before doing so, we must shut
3082 down TLS. Not all MTAs allow for the continuation of the SMTP session
3083 when TLS is shut down. We test for this by sending a new EHLO. If we
3084 don't get a good response, we don't attempt to pass the socket on. */
3085
3086 #ifdef SUPPORT_TLS
3087 if (tls_out.active >= 0)
3088 {
3089 tls_close(FALSE, TRUE);
3090 smtp_peer_options = smtp_peer_options_wrap;
3091 if (lflags.smtps)
3092 lflags.ok = FALSE;
3093 else
3094 lflags.ok = smtp_write_command(&outblock,FALSE,"EHLO %s\r\n",helo_data) >= 0 &&
3095 smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
3096 ob->command_timeout);
3097 }
3098 #endif
3099
3100 /* If the socket is successfully passed, we musn't send QUIT (or
3101 indeed anything!) from here. */
3102
3103 /*XXX DSN_INFO: assume likely to do new HELO; but for greet we'll want to
3104 propagate it from the initial
3105 */
3106 if (lflags.ok && transport_pass_socket(tblock->name, host->name,
3107 host->address, new_message_id, inblock.sock))
3108 lflags.send_quit = FALSE;
3109 }
3110
3111 /* If RSET failed and there are addresses left, they get deferred. */
3112
3113 else set_errno(first_addr, errno, msg, DEFER, FALSE, host
3114 #ifdef EXPERIMENTAL_DSN_INFO
3115 , smtp_greeting, helo_response
3116 #endif
3117 );
3118 }
3119 }
3120
3121 /* End off tidily with QUIT unless the connection has died or the socket has
3122 been passed to another process. There has been discussion on the net about what
3123 to do after sending QUIT. The wording of the RFC suggests that it is necessary
3124 to wait for a response, but on the other hand, there isn't anything one can do
3125 with an error response, other than log it. Exim used to do that. However,
3126 further discussion suggested that it is positively advantageous not to wait for
3127 the response, but to close the session immediately. This is supposed to move
3128 the TCP/IP TIME_WAIT state from the server to the client, thereby removing some
3129 load from the server. (Hosts that are both servers and clients may not see much
3130 difference, of course.) Further discussion indicated that this was safe to do
3131 on Unix systems which have decent implementations of TCP/IP that leave the
3132 connection around for a while (TIME_WAIT) after the application has gone away.
3133 This enables the response sent by the server to be properly ACKed rather than
3134 timed out, as can happen on broken TCP/IP implementations on other OS.
3135
3136 This change is being made on 31-Jul-98. After over a year of trouble-free
3137 operation, the old commented-out code was removed on 17-Sep-99. */
3138
3139 SEND_QUIT:
3140 if (lflags.send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
3141
3142 END_OFF:
3143
3144 #ifdef SUPPORT_TLS
3145 tls_close(FALSE, TRUE);
3146 #endif
3147
3148 /* Close the socket, and return the appropriate value, first setting
3149 works because the NULL setting is passed back to the calling process, and
3150 remote_max_parallel is forced to 1 when delivering over an existing connection,
3151
3152 If all went well and continue_more is set, we shouldn't actually get here if
3153 there are further addresses, as the return above will be taken. However,
3154 writing RSET might have failed, or there may be other addresses whose hosts are
3155 specified in the transports, and therefore not visible at top level, in which
3156 case continue_more won't get set. */
3157
3158 HDEBUG(D_transport|D_acl|D_v) debug_printf(" SMTP(close)>>\n");
3159 if (lflags.send_quit)
3160 {
3161 shutdown(outblock.sock, SHUT_WR);
3162 for (rc = 16; read(inblock.sock, inbuffer, sizeof(inbuffer)) > 0 && rc > 0;)
3163 rc--; /* drain socket */
3164 }
3165 (void)close(inblock.sock);
3166
3167 #ifndef DISABLE_EVENT
3168 (void) event_raise(tblock->event_action, US"tcp:close", NULL);
3169 #endif
3170
3171 continue_transport = NULL;
3172 continue_hostname = NULL;
3173 return yield;
3174 }
3175
3176
3177
3178
3179 /*************************************************
3180 * Closedown entry point *
3181 *************************************************/
3182
3183 /* This function is called when exim is passed an open smtp channel
3184 from another incarnation, but the message which it has been asked
3185 to deliver no longer exists. The channel is on stdin.
3186
3187 We might do fancy things like looking for another message to send down
3188 the channel, but if the one we sought has gone, it has probably been
3189 delivered by some other process that itself will seek further messages,
3190 so just close down our connection.
3191
3192 Argument: pointer to the transport instance block
3193 Returns: nothing
3194 */
3195
3196 void
3197 smtp_transport_closedown(transport_instance *tblock)
3198 {
3199 smtp_transport_options_block *ob =
3200 (smtp_transport_options_block *)(tblock->options_block);
3201 smtp_inblock inblock;
3202 smtp_outblock outblock;
3203 uschar buffer[256];
3204 uschar inbuffer[4096];
3205 uschar outbuffer[16];
3206
3207 inblock.sock = fileno(stdin);
3208 inblock.buffer = inbuffer;
3209 inblock.buffersize = sizeof(inbuffer);
3210 inblock.ptr = inbuffer;
3211 inblock.ptrend = inbuffer;
3212
3213 outblock.sock = inblock.sock;
3214 outblock.buffersize = sizeof(outbuffer);
3215 outblock.buffer = outbuffer;
3216 outblock.ptr = outbuffer;
3217 outblock.cmd_count = 0;
3218 outblock.authenticating = FALSE;
3219
3220 (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
3221 (void)smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
3222 ob->command_timeout);
3223 (void)close(inblock.sock);
3224 }
3225
3226
3227
3228 /*************************************************
3229 * Prepare addresses for delivery *
3230 *************************************************/
3231
3232 /* This function is called to flush out error settings from previous delivery
3233 attempts to other hosts. It also records whether we got here via an MX record
3234 or not in the more_errno field of the address. We are interested only in
3235 addresses that are still marked DEFER - others may have got delivered to a
3236 previously considered IP address. Set their status to PENDING_DEFER to indicate
3237 which ones are relevant this time.
3238
3239 Arguments:
3240 addrlist the list of addresses
3241 host the host we are delivering to
3242
3243 Returns: the first address for this delivery
3244 */
3245
3246 static address_item *
3247 prepare_addresses(address_item *addrlist, host_item *host)
3248 {
3249 address_item *first_addr = NULL;
3250 address_item *addr;
3251 for (addr = addrlist; addr; addr = addr->next)
3252 if (addr->transport_return == DEFER)
3253 {
3254 if (!first_addr) first_addr = addr;
3255 addr->transport_return = PENDING_DEFER;
3256 addr->basic_errno = 0;
3257 addr->more_errno = (host->mx >= 0)? 'M' : 'A';
3258 addr->message = NULL;
3259 #ifdef SUPPORT_TLS
3260 addr->cipher = NULL;
3261 addr->ourcert = NULL;
3262 addr->peercert = NULL;
3263 addr->peerdn = NULL;
3264 addr->ocsp = OCSP_NOT_REQ;
3265 #endif
3266 #ifdef EXPERIMENTAL_DSN_INFO
3267 addr->smtp_greeting = NULL;
3268 addr->helo_response = NULL;
3269 #endif
3270 }
3271 return first_addr;
3272 }
3273
3274
3275
3276 /*************************************************
3277 * Main entry point *
3278 *************************************************/
3279
3280 /* See local README for interface details. As this is a remote transport, it is
3281 given a chain of addresses to be delivered in one connection, if possible. It
3282 always returns TRUE, indicating that each address has its own independent
3283 status set, except if there is a setting up problem, in which case it returns
3284 FALSE. */
3285
3286 BOOL
3287 smtp_transport_entry(
3288 transport_instance *tblock, /* data for this instantiation */
3289 address_item *addrlist) /* addresses we are working on */
3290 {
3291 int cutoff_retry;
3292 int port;
3293 int hosts_defer = 0;
3294 int hosts_fail = 0;
3295 int hosts_looked_up = 0;
3296 int hosts_retry = 0;
3297 int hosts_serial = 0;
3298 int hosts_total = 0;
3299 int total_hosts_tried = 0;
3300 address_item *addr;
3301 BOOL expired = TRUE;
3302 uschar *expanded_hosts = NULL;
3303 uschar *pistring;
3304 uschar *tid = string_sprintf("%s transport", tblock->name);
3305 smtp_transport_options_block *ob =
3306 (smtp_transport_options_block *)(tblock->options_block);
3307 host_item *hostlist = addrlist->host_list;
3308 host_item *host = NULL;
3309
3310 DEBUG(D_transport)
3311 {
3312 debug_printf("%s transport entered\n", tblock->name);
3313 for (addr = addrlist; addr; addr = addr->next)
3314 debug_printf(" %s\n", addr->address);
3315 if (hostlist)
3316 {
3317 debug_printf("hostlist:\n");
3318 for (host = hostlist; host; host = host->next)
3319 debug_printf(" %s:%d\n", host->name, host->port);
3320 }
3321 if (continue_hostname) debug_printf("already connected to %s [%s]\n",
3322 continue_hostname, continue_host_address);
3323 }
3324
3325 /* Set the flag requesting that these hosts be added to the waiting
3326 database if the delivery fails temporarily or if we are running with
3327 queue_smtp or a 2-stage queue run. This gets unset for certain
3328 kinds of error, typically those that are specific to the message. */
3329
3330 update_waiting = TRUE;
3331
3332 /* If a host list is not defined for the addresses - they must all have the
3333 same one in order to be passed to a single transport - or if the transport has
3334 a host list with hosts_override set, use the host list supplied with the
3335 transport. It is an error for this not to exist. */
3336
3337 if (!hostlist || (ob->hosts_override && ob->hosts))
3338 {
3339 if (!ob->hosts)
3340 {
3341 addrlist->message = string_sprintf("%s transport called with no hosts set",
3342 tblock->name);
3343 addrlist->transport_return = PANIC;
3344 return FALSE; /* Only top address has status */
3345 }
3346
3347 DEBUG(D_transport) debug_printf("using the transport's hosts: %s\n",
3348 ob->hosts);
3349
3350 /* If the transport's host list contains no '$' characters, and we are not
3351 randomizing, it is fixed and therefore a chain of hosts can be built once
3352 and for all, and remembered for subsequent use by other calls to this
3353 transport. If, on the other hand, the host list does contain '$', or we are
3354 randomizing its order, we have to rebuild it each time. In the fixed case,
3355 as the hosts string will never be used again, it doesn't matter that we
3356 replace all the : characters with zeros. */
3357
3358 if (!ob->hostlist)
3359 {
3360 uschar *s = ob->hosts;
3361
3362 if (Ustrchr(s, '$') != NULL)
3363 {
3364 if (!(expanded_hosts = expand_string(s)))
3365 {
3366 addrlist->message = string_sprintf("failed to expand list of hosts "
3367 "\"%s\" in %s transport: %s", s, tblock->name, expand_string_message);
3368 addrlist->transport_return = search_find_defer ? DEFER : PANIC;
3369 return FALSE; /* Only top address has status */
3370 }
3371 DEBUG(D_transport) debug_printf("expanded list of hosts \"%s\" to "
3372 "\"%s\"\n", s, expanded_hosts);
3373 s = expanded_hosts;
3374 }
3375 else
3376 if (ob->hosts_randomize) s = expanded_hosts = string_copy(s);
3377
3378 host_build_hostlist(&hostlist, s, ob->hosts_randomize);
3379
3380 /* Check that the expansion yielded something useful. */
3381 if (!hostlist)
3382 {
3383 addrlist->message =
3384 string_sprintf("%s transport has empty hosts setting", tblock->name);
3385 addrlist->transport_return = PANIC;
3386 return FALSE; /* Only top address has status */
3387 }
3388
3389 /* If there was no expansion of hosts, save the host list for
3390 next time. */
3391
3392 if (!expanded_hosts) ob->hostlist = hostlist;
3393 }
3394
3395 /* This is not the first time this transport has been run in this delivery;
3396 the host list was built previously. */
3397
3398 else
3399 hostlist = ob->hostlist;
3400 }
3401
3402 /* The host list was supplied with the address. If hosts_randomize is set, we
3403 must sort it into a random order if it did not come from MX records and has not
3404 already been randomized (but don't bother if continuing down an existing
3405 connection). */
3406
3407 else if (ob->hosts_randomize && hostlist->mx == MX_NONE && !continue_hostname)
3408 {
3409 host_item *newlist = NULL;
3410 while (hostlist)
3411 {
3412 host_item *h = hostlist;
3413 hostlist = hostlist->next;
3414
3415 h->sort_key = random_number(100);
3416
3417 if (!newlist)
3418 {
3419 h->next = NULL;
3420 newlist = h;
3421 }
3422 else if (h->sort_key < newlist->sort_key)
3423 {
3424 h->next = newlist;
3425 newlist = h;
3426 }
3427 else
3428 {
3429 host_item *hh = newlist;
3430 while (hh->next)
3431 {
3432 if (h->sort_key < hh->next->sort_key) break;
3433 hh = hh->next;
3434 }
3435 h->next = hh->next;
3436 hh->next = h;
3437 }
3438 }
3439
3440 hostlist = addrlist->host_list = newlist;
3441 }
3442
3443 /* Sort out the default port. */
3444
3445 if (!smtp_get_port(ob->port, addrlist, &port, tid)) return FALSE;
3446
3447 /* For each host-plus-IP-address on the list:
3448
3449 . If this is a continued delivery and the host isn't the one with the
3450 current connection, skip.
3451
3452 . If the status is unusable (i.e. previously failed or retry checked), skip.
3453
3454 . If no IP address set, get the address, either by turning the name into
3455 an address, calling gethostbyname if gethostbyname is on, or by calling
3456 the DNS. The DNS may yield multiple addresses, in which case insert the
3457 extra ones into the list.
3458
3459 . Get the retry data if not previously obtained for this address and set the
3460 field which remembers the state of this address. Skip if the retry time is
3461 not reached. If not, remember whether retry data was found. The retry string
3462 contains both the name and the IP address.
3463
3464 . Scan the list of addresses and mark those whose status is DEFER as
3465 PENDING_DEFER. These are the only ones that will be processed in this cycle
3466 of the hosts loop.
3467
3468 . Make a delivery attempt - addresses marked PENDING_DEFER will be tried.
3469 Some addresses may be successfully delivered, others may fail, and yet
3470 others may get temporary errors and so get marked DEFER.
3471
3472 . The return from the delivery attempt is OK if a connection was made and a
3473 valid SMTP dialogue was completed. Otherwise it is DEFER.
3474
3475 . If OK, add a "remove" retry item for this host/IPaddress, if any.
3476
3477 . If fail to connect, or other defer state, add a retry item.
3478
3479 . If there are any addresses whose status is still DEFER, carry on to the
3480 next host/IPaddress, unless we have tried the number of hosts given
3481 by hosts_max_try or hosts_max_try_hardlimit; otherwise return. Note that
3482 there is some fancy logic for hosts_max_try that means its limit can be
3483 overstepped in some circumstances.
3484
3485 If we get to the end of the list, all hosts have deferred at least one address,
3486 or not reached their retry times. If delay_after_cutoff is unset, it requests a
3487 delivery attempt to those hosts whose last try was before the arrival time of
3488 the current message. To cope with this, we have to go round the loop a second
3489 time. After that, set the status and error data for any addresses that haven't
3490 had it set already. */
3491
3492 for (cutoff_retry = 0;
3493 expired && cutoff_retry < (ob->delay_after_cutoff ? 1 : 2);
3494 cutoff_retry++)
3495 {
3496 host_item *nexthost = NULL;
3497 int unexpired_hosts_tried = 0;
3498
3499 for (host = hostlist;
3500 host
3501 && unexpired_hosts_tried < ob->hosts_max_try
3502 && total_hosts_tried < ob->hosts_max_try_hardlimit;
3503 host = nexthost)
3504 {
3505 int rc;
3506 int host_af;
3507 uschar *rs;
3508 BOOL host_is_expired = FALSE;
3509 BOOL message_defer = FALSE;
3510 BOOL some_deferred = FALSE;
3511 address_item *first_addr = NULL;
3512 uschar *interface = NULL;
3513 uschar *retry_host_key = NULL;
3514 uschar *retry_message_key = NULL;
3515 uschar *serialize_key = NULL;
3516
3517 /* Default next host is next host. :-) But this can vary if the
3518 hosts_max_try limit is hit (see below). It may also be reset if a host
3519 address is looked up here (in case the host was multihomed). */
3520
3521 nexthost = host->next;
3522
3523 /* If the address hasn't yet been obtained from the host name, look it up
3524 now, unless the host is already marked as unusable. If it is marked as
3525 unusable, it means that the router was unable to find its IP address (in
3526 the DNS or wherever) OR we are in the 2nd time round the cutoff loop, and
3527 the lookup failed last time. We don't get this far if *all* MX records
3528 point to non-existent hosts; that is treated as a hard error.
3529
3530 We can just skip this host entirely. When the hosts came from the router,
3531 the address will timeout based on the other host(s); when the address is
3532 looked up below, there is an explicit retry record added.
3533
3534 Note that we mustn't skip unusable hosts if the address is not unset; they
3535 may be needed as expired hosts on the 2nd time round the cutoff loop. */
3536
3537 if (!host->address)
3538 {
3539 int new_port, flags;
3540 host_item *hh;
3541
3542 if (host->status >= hstatus_unusable)
3543 {
3544 DEBUG(D_transport) debug_printf("%s has no address and is unusable - skipping\n",
3545 host->name);
3546 continue;
3547 }
3548
3549 DEBUG(D_transport) debug_printf("getting address for %s\n", host->name);
3550
3551 /* The host name is permitted to have an attached port. Find it, and
3552 strip it from the name. Just remember it for now. */
3553
3554 new_port = host_item_get_port(host);
3555
3556 /* Count hosts looked up */
3557
3558 hosts_looked_up++;
3559
3560 /* Find by name if so configured, or if it's an IP address. We don't
3561 just copy the IP address, because we need the test-for-local to happen. */
3562
3563 flags = HOST_FIND_BY_A;
3564 if (ob->dns_qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
3565 if (ob->dns_search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
3566
3567 if (ob->gethostbyname || string_is_ip_address(host->name, NULL) != 0)
3568 rc = host_find_byname(host, NULL, flags, NULL, TRUE);
3569 else
3570 rc = host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
3571 &ob->dnssec, /* domains for request/require */
3572 NULL, NULL);
3573
3574 /* Update the host (and any additional blocks, resulting from
3575 multihoming) with a host-specific port, if any. */
3576
3577 for (hh = host; hh != nexthost; hh = hh->next) hh->port = new_port;
3578
3579 /* Failure to find the host at this time (usually DNS temporary failure)
3580 is really a kind of routing failure rather than a transport failure.
3581 Therefore we add a retry item of the routing kind, not to stop us trying
3582 to look this name up here again, but to ensure the address gets timed
3583 out if the failures go on long enough. A complete failure at this point
3584 commonly points to a configuration error, but the best action is still
3585 to carry on for the next host. */
3586
3587 if (rc == HOST_FIND_AGAIN || rc == HOST_FIND_FAILED)
3588 {
3589 retry_add_item(addrlist, string_sprintf("R:%s", host->name), 0);
3590 expired = FALSE;
3591 if (rc == HOST_FIND_AGAIN) hosts_defer++; else hosts_fail++;
3592 DEBUG(D_transport) debug_printf("rc = %s for %s\n", (rc == HOST_FIND_AGAIN)?
3593 "HOST_FIND_AGAIN" : "HOST_FIND_FAILED", host->name);
3594 host->status = hstatus_unusable;
3595
3596 for (addr = addrlist; addr; addr = addr->next)
3597 {
3598 if (addr->transport_return != DEFER) continue;
3599 addr->basic_errno = ERRNO_UNKNOWNHOST;
3600 addr->message =
3601 string_sprintf("failed to lookup IP address for %s", host->name);
3602 }
3603 continue;
3604 }
3605
3606 /* If the host is actually the local host, we may have a problem, or
3607 there may be some cunning configuration going on. In the problem case,
3608 log things and give up. The default transport status is already DEFER. */
3609
3610 if (rc == HOST_FOUND_LOCAL && !ob->allow_localhost)
3611 {
3612 for (addr = addrlist; addr; addr = addr->next)
3613 {
3614 addr->basic_errno = 0;
3615 addr->message = string_sprintf("%s transport found host %s to be "
3616 "local", tblock->name, host->name);
3617 }
3618 goto END_TRANSPORT;
3619 }
3620 } /* End of block for IP address lookup */
3621
3622 /* If this is a continued delivery, we are interested only in the host
3623 which matches the name of the existing open channel. The check is put
3624 here after the local host lookup, in case the name gets expanded as a
3625 result of the lookup. Set expired FALSE, to save the outer loop executing
3626 twice. */
3627
3628 if ( continue_hostname
3629 && ( Ustrcmp(continue_hostname, host->name) != 0
3630 || Ustrcmp(continue_host_address, host->address) != 0
3631 ) )
3632 {
3633 expired = FALSE;
3634 continue; /* With next host */
3635 }
3636
3637 /* Reset the default next host in case a multihomed host whose addresses
3638 are not looked up till just above added to the host list. */
3639
3640 nexthost = host->next;
3641
3642 /* If queue_smtp is set (-odqs or the first part of a 2-stage run), or the
3643 domain is in queue_smtp_domains, we don't actually want to attempt any
3644 deliveries. When doing a queue run, queue_smtp_domains is always unset. If
3645 there is a lookup defer in queue_smtp_domains, proceed as if the domain
3646 were not in it. We don't want to hold up all SMTP deliveries! Except when
3647 doing a two-stage queue run, don't do this if forcing. */
3648
3649 if ((!deliver_force || queue_2stage) && (queue_smtp ||
3650 match_isinlist(addrlist->domain,
3651 (const uschar **)&queue_smtp_domains, 0,
3652 &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL) == OK))
3653 {
3654 expired = FALSE;
3655 for (addr = addrlist; addr; addr = addr->next)
3656 if (addr->transport_return == DEFER)
3657 addr->message = US"domain matches queue_smtp_domains, or -odqs set";
3658 continue; /* With next host */
3659 }
3660
3661 /* Count hosts being considered - purely for an intelligent comment
3662 if none are usable. */
3663
3664 hosts_total++;
3665
3666 /* Set $host and $host address now in case they are needed for the
3667 interface expansion or the serialize_hosts check; they remain set if an
3668 actual delivery happens. */
3669
3670 deliver_host = host->name;
3671 deliver_host_address = host->address;
3672 lookup_dnssec_authenticated = host->dnssec == DS_YES ? US"yes"
3673 : host->dnssec == DS_NO ? US"no"
3674 : US"";
3675
3676 /* Set up a string for adding to the retry key if the port number is not
3677 the standard SMTP port. A host may have its own port setting that overrides
3678 the default. */
3679
3680 pistring = string_sprintf(":%d", host->port == PORT_NONE
3681 ? port : host->port);
3682 if (Ustrcmp(pistring, ":25") == 0) pistring = US"";
3683
3684 /* Select IPv4 or IPv6, and choose an outgoing interface. If the interface
3685 string is set, even if constant (as different transports can have different
3686 constant settings), we must add it to the key that is used for retries,
3687 because connections to the same host from a different interface should be
3688 treated separately. */
3689
3690 host_af = Ustrchr(host->address, ':') == NULL ? AF_INET : AF_INET6;
3691 if ((rs = ob->interface) && *rs)
3692 {
3693 if (!smtp_get_interface(rs, host_af, addrlist, &interface, tid))
3694 return FALSE;
3695 pistring = string_sprintf("%s/%s", pistring, interface);
3696 }
3697
3698 /* The first time round the outer loop, check the status of the host by
3699 inspecting the retry data. The second time round, we are interested only
3700 in expired hosts that haven't been tried since this message arrived. */
3701
3702 if (cutoff_retry == 0)
3703 {
3704 BOOL incl_ip;
3705 /* Ensure the status of the address is set by checking retry data if
3706 necessary. There may be host-specific retry data (applicable to all
3707 messages) and also data for retries of a specific message at this host.
3708 If either of these retry records are actually read, the keys used are
3709 returned to save recomputing them later. */
3710
3711 if (exp_bool(addrlist, US"transport", tblock->name, D_transport,
3712 US"retry_include_ip_address", ob->retry_include_ip_address,
3713 ob->expand_retry_include_ip_address, &incl_ip) != OK)
3714 continue; /* with next host */
3715
3716 host_is_expired = retry_check_address(addrlist->domain, host, pistring,
3717 incl_ip, &retry_host_key, &retry_message_key);
3718
3719 DEBUG(D_transport) debug_printf("%s [%s]%s status = %s\n", host->name,
3720 (host->address == NULL)? US"" : host->address, pistring,
3721 (host->status == hstatus_usable)? "usable" :
3722 (host->status == hstatus_unusable)? "unusable" :
3723 (host->status == hstatus_unusable_expired)? "unusable (expired)" : "?");
3724
3725 /* Skip this address if not usable at this time, noting if it wasn't
3726 actually expired, both locally and in the address. */
3727
3728 switch (host->status)
3729 {
3730 case hstatus_unusable:
3731 expired = FALSE;
3732 setflag(addrlist, af_retry_skipped);
3733 /* Fall through */
3734
3735 case hstatus_unusable_expired:
3736 switch (host->why)
3737 {
3738 case hwhy_retry: hosts_retry++; break;
3739 case hwhy_failed: hosts_fail++; break;
3740 case hwhy_deferred: hosts_defer++; break;
3741 }
3742
3743 /* If there was a retry message key, implying that previously there
3744 was a message-specific defer, we don't want to update the list of
3745 messages waiting for these hosts. */
3746
3747 if (retry_message_key) update_waiting = FALSE;
3748 continue; /* With the next host or IP address */
3749 }
3750 }
3751
3752 /* Second time round the loop: if the address is set but expired, and
3753 the message is newer than the last try, let it through. */
3754
3755 else
3756 {
3757 if ( !host->address
3758 || host->status != hstatus_unusable_expired
3759 || host->last_try > received_time)
3760 continue;
3761 DEBUG(D_transport) debug_printf("trying expired host %s [%s]%s\n",
3762 host->name, host->address, pistring);
3763 host_is_expired = TRUE;
3764 }
3765
3766 /* Setting "expired=FALSE" doesn't actually mean not all hosts are expired;
3767 it remains TRUE only if all hosts are expired and none are actually tried.
3768 */
3769
3770 expired = FALSE;
3771
3772 /* If this host is listed as one to which access must be serialized,
3773 see if another Exim process has a connection to it, and if so, skip
3774 this host. If not, update the database to record our connection to it
3775 and remember this for later deletion. Do not do any of this if we are
3776 sending the message down a pre-existing connection. */
3777
3778 if ( !continue_hostname
3779 && verify_check_given_host(&ob->serialize_hosts, host) == OK)
3780 {
3781 serialize_key = string_sprintf("host-serialize-%s", host->name);
3782 if (!enq_start(serialize_key, 1))
3783 {
3784 DEBUG(D_transport)
3785 debug_printf("skipping host %s because another Exim process "
3786 "is connected to it\n", host->name);
3787 hosts_serial++;
3788 continue;
3789 }
3790 }
3791
3792 /* OK, we have an IP address that is not waiting for its retry time to
3793 arrive (it might be expired) OR (second time round the loop) we have an
3794 expired host that hasn't been tried since the message arrived. Have a go
3795 at delivering the message to it. First prepare the addresses by flushing
3796 out the result of previous attempts, and finding the first address that
3797 is still to be delivered. */
3798
3799 first_addr = prepare_addresses(addrlist, host);
3800
3801 DEBUG(D_transport) debug_printf("delivering %s to %s [%s] (%s%s)\n",
3802 message_id, host->name, host->address, addrlist->address,
3803 addrlist->next ? ", ..." : "");
3804
3805 set_process_info("delivering %s to %s [%s] (%s%s)",
3806 message_id, host->name, host->address, addrlist->address,
3807 addrlist->next ? ", ..." : "");
3808
3809 /* This is not for real; don't do the delivery. If there are
3810 any remaining hosts, list them. */
3811
3812 if (dont_deliver)
3813 {
3814 host_item *host2;
3815 set_errno_nohost(addrlist, 0, NULL, OK, FALSE);
3816 for (addr = addrlist; addr; addr = addr->next)
3817 {
3818 addr->host_used = host;
3819 addr->special_action = '*';
3820 addr->message = US"delivery bypassed by -N option";
3821 }
3822 DEBUG(D_transport)
3823 {
3824 debug_printf("*** delivery by %s transport bypassed by -N option\n"
3825 "*** host and remaining hosts:\n", tblock->name);
3826 for (host2 = host; host2; host2 = host2->next)
3827 debug_printf(" %s [%s]\n", host2->name,
3828 host2->address ? host2->address : US"unset");
3829 }
3830 rc = OK;
3831 }
3832
3833 /* This is for real. If the host is expired, we don't count it for
3834 hosts_max_retry. This ensures that all hosts must expire before an address
3835 is timed out, unless hosts_max_try_hardlimit (which protects against
3836 lunatic DNS configurations) is reached.
3837
3838 If the host is not expired and we are about to hit the hosts_max_retry
3839 limit, check to see if there is a subsequent hosts with a different MX
3840 value. If so, make that the next host, and don't count this one. This is a
3841 heuristic to make sure that different MXs do get tried. With a normal kind
3842 of retry rule, they would get tried anyway when the earlier hosts were
3843 delayed, but if the domain has a "retry every time" type of rule - as is
3844 often used for the the very large ISPs, that won't happen. */
3845
3846 else
3847 {
3848 host_item * thost;
3849 /* Make a copy of the host if it is local to this invocation
3850 of the transport. */
3851
3852 if (expanded_hosts)
3853 {
3854 thost = store_get(sizeof(host_item));
3855 *thost = *host;
3856 thost->name = string_copy(host->name);
3857 thost->address = string_copy(host->address);
3858 }
3859 else
3860 thost = host;
3861
3862 if (!host_is_expired && ++unexpired_hosts_tried >= ob->hosts_max_try)
3863 {
3864 host_item *h;
3865 DEBUG(D_transport)
3866 debug_printf("hosts_max_try limit reached with this host\n");
3867 for (h = host; h; h = h->next) if (h->mx !=</