d6a52034bb4fe71c9bbf810974a42c476944c729
[exim.git] / src / src / transports / smtp.c
1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
4
5 /* Copyright (c) University of Cambridge 1995 - 2017 */
6 /* See the file NOTICE for conditions of use and distribution. */
7
8 #include "../exim.h"
9 #include "smtp.h"
10
11
12 /* Options specific to the smtp transport. This transport also supports LMTP
13 over TCP/IP. The options must be in alphabetic order (note that "_" comes
14 before the lower case letters). Some live in the transport_instance block so as
15 to be publicly visible; these are flagged with opt_public. */
16
17 optionlist smtp_transport_options[] = {
18 { "*expand_multi_domain", opt_stringptr | opt_hidden | opt_public,
19 (void *)offsetof(transport_instance, expand_multi_domain) },
20 { "*expand_retry_include_ip_address", opt_stringptr | opt_hidden,
21 (void *)(offsetof(smtp_transport_options_block, expand_retry_include_ip_address)) },
22
23 { "address_retry_include_sender", opt_bool,
24 (void *)offsetof(smtp_transport_options_block, address_retry_include_sender) },
25 { "allow_localhost", opt_bool,
26 (void *)offsetof(smtp_transport_options_block, allow_localhost) },
27 { "authenticated_sender", opt_stringptr,
28 (void *)offsetof(smtp_transport_options_block, authenticated_sender) },
29 { "authenticated_sender_force", opt_bool,
30 (void *)offsetof(smtp_transport_options_block, authenticated_sender_force) },
31 { "command_timeout", opt_time,
32 (void *)offsetof(smtp_transport_options_block, command_timeout) },
33 { "connect_timeout", opt_time,
34 (void *)offsetof(smtp_transport_options_block, connect_timeout) },
35 { "connection_max_messages", opt_int | opt_public,
36 (void *)offsetof(transport_instance, connection_max_messages) },
37 { "data_timeout", opt_time,
38 (void *)offsetof(smtp_transport_options_block, data_timeout) },
39 { "delay_after_cutoff", opt_bool,
40 (void *)offsetof(smtp_transport_options_block, delay_after_cutoff) },
41 #ifndef DISABLE_DKIM
42 { "dkim_canon", opt_stringptr,
43 (void *)offsetof(smtp_transport_options_block, dkim.dkim_canon) },
44 { "dkim_domain", opt_stringptr,
45 (void *)offsetof(smtp_transport_options_block, dkim.dkim_domain) },
46 { "dkim_private_key", opt_stringptr,
47 (void *)offsetof(smtp_transport_options_block, dkim.dkim_private_key) },
48 { "dkim_selector", opt_stringptr,
49 (void *)offsetof(smtp_transport_options_block, dkim.dkim_selector) },
50 { "dkim_sign_headers", opt_stringptr,
51 (void *)offsetof(smtp_transport_options_block, dkim.dkim_sign_headers) },
52 { "dkim_strict", opt_stringptr,
53 (void *)offsetof(smtp_transport_options_block, dkim.dkim_strict) },
54 #endif
55 { "dns_qualify_single", opt_bool,
56 (void *)offsetof(smtp_transport_options_block, dns_qualify_single) },
57 { "dns_search_parents", opt_bool,
58 (void *)offsetof(smtp_transport_options_block, dns_search_parents) },
59 { "dnssec_request_domains", opt_stringptr,
60 (void *)offsetof(smtp_transport_options_block, dnssec.request) },
61 { "dnssec_require_domains", opt_stringptr,
62 (void *)offsetof(smtp_transport_options_block, dnssec.require) },
63 { "dscp", opt_stringptr,
64 (void *)offsetof(smtp_transport_options_block, dscp) },
65 { "fallback_hosts", opt_stringptr,
66 (void *)offsetof(smtp_transport_options_block, fallback_hosts) },
67 { "final_timeout", opt_time,
68 (void *)offsetof(smtp_transport_options_block, final_timeout) },
69 { "gethostbyname", opt_bool,
70 (void *)offsetof(smtp_transport_options_block, gethostbyname) },
71 { "helo_data", opt_stringptr,
72 (void *)offsetof(smtp_transport_options_block, helo_data) },
73 { "hosts", opt_stringptr,
74 (void *)offsetof(smtp_transport_options_block, hosts) },
75 { "hosts_avoid_esmtp", opt_stringptr,
76 (void *)offsetof(smtp_transport_options_block, hosts_avoid_esmtp) },
77 { "hosts_avoid_pipelining", opt_stringptr,
78 (void *)offsetof(smtp_transport_options_block, hosts_avoid_pipelining) },
79 #ifdef SUPPORT_TLS
80 { "hosts_avoid_tls", opt_stringptr,
81 (void *)offsetof(smtp_transport_options_block, hosts_avoid_tls) },
82 #endif
83 { "hosts_max_try", opt_int,
84 (void *)offsetof(smtp_transport_options_block, hosts_max_try) },
85 { "hosts_max_try_hardlimit", opt_int,
86 (void *)offsetof(smtp_transport_options_block, hosts_max_try_hardlimit) },
87 #ifdef SUPPORT_TLS
88 { "hosts_nopass_tls", opt_stringptr,
89 (void *)offsetof(smtp_transport_options_block, hosts_nopass_tls) },
90 { "hosts_noproxy_tls", opt_stringptr,
91 (void *)offsetof(smtp_transport_options_block, hosts_noproxy_tls) },
92 #endif
93 { "hosts_override", opt_bool,
94 (void *)offsetof(smtp_transport_options_block, hosts_override) },
95 { "hosts_randomize", opt_bool,
96 (void *)offsetof(smtp_transport_options_block, hosts_randomize) },
97 #if defined(SUPPORT_TLS) && !defined(DISABLE_OCSP)
98 { "hosts_request_ocsp", opt_stringptr,
99 (void *)offsetof(smtp_transport_options_block, hosts_request_ocsp) },
100 #endif
101 { "hosts_require_auth", opt_stringptr,
102 (void *)offsetof(smtp_transport_options_block, hosts_require_auth) },
103 #ifdef SUPPORT_TLS
104 # ifdef EXPERIMENTAL_DANE
105 { "hosts_require_dane", opt_stringptr,
106 (void *)offsetof(smtp_transport_options_block, hosts_require_dane) },
107 # endif
108 # ifndef DISABLE_OCSP
109 { "hosts_require_ocsp", opt_stringptr,
110 (void *)offsetof(smtp_transport_options_block, hosts_require_ocsp) },
111 # endif
112 { "hosts_require_tls", opt_stringptr,
113 (void *)offsetof(smtp_transport_options_block, hosts_require_tls) },
114 #endif
115 { "hosts_try_auth", opt_stringptr,
116 (void *)offsetof(smtp_transport_options_block, hosts_try_auth) },
117 { "hosts_try_chunking", opt_stringptr,
118 (void *)offsetof(smtp_transport_options_block, hosts_try_chunking) },
119 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
120 { "hosts_try_dane", opt_stringptr,
121 (void *)offsetof(smtp_transport_options_block, hosts_try_dane) },
122 #endif
123 { "hosts_try_fastopen", opt_stringptr,
124 (void *)offsetof(smtp_transport_options_block, hosts_try_fastopen) },
125 #ifndef DISABLE_PRDR
126 { "hosts_try_prdr", opt_stringptr,
127 (void *)offsetof(smtp_transport_options_block, hosts_try_prdr) },
128 #endif
129 #ifdef SUPPORT_TLS
130 { "hosts_verify_avoid_tls", opt_stringptr,
131 (void *)offsetof(smtp_transport_options_block, hosts_verify_avoid_tls) },
132 #endif
133 { "interface", opt_stringptr,
134 (void *)offsetof(smtp_transport_options_block, interface) },
135 { "keepalive", opt_bool,
136 (void *)offsetof(smtp_transport_options_block, keepalive) },
137 { "lmtp_ignore_quota", opt_bool,
138 (void *)offsetof(smtp_transport_options_block, lmtp_ignore_quota) },
139 { "max_rcpt", opt_int | opt_public,
140 (void *)offsetof(transport_instance, max_addresses) },
141 { "multi_domain", opt_expand_bool | opt_public,
142 (void *)offsetof(transport_instance, multi_domain) },
143 { "port", opt_stringptr,
144 (void *)offsetof(smtp_transport_options_block, port) },
145 { "protocol", opt_stringptr,
146 (void *)offsetof(smtp_transport_options_block, protocol) },
147 { "retry_include_ip_address", opt_expand_bool,
148 (void *)offsetof(smtp_transport_options_block, retry_include_ip_address) },
149 { "serialize_hosts", opt_stringptr,
150 (void *)offsetof(smtp_transport_options_block, serialize_hosts) },
151 { "size_addition", opt_int,
152 (void *)offsetof(smtp_transport_options_block, size_addition) }
153 #ifdef SUPPORT_SOCKS
154 ,{ "socks_proxy", opt_stringptr,
155 (void *)offsetof(smtp_transport_options_block, socks_proxy) }
156 #endif
157 #ifdef SUPPORT_TLS
158 ,{ "tls_certificate", opt_stringptr,
159 (void *)offsetof(smtp_transport_options_block, tls_certificate) },
160 { "tls_crl", opt_stringptr,
161 (void *)offsetof(smtp_transport_options_block, tls_crl) },
162 { "tls_dh_min_bits", opt_int,
163 (void *)offsetof(smtp_transport_options_block, tls_dh_min_bits) },
164 { "tls_privatekey", opt_stringptr,
165 (void *)offsetof(smtp_transport_options_block, tls_privatekey) },
166 { "tls_require_ciphers", opt_stringptr,
167 (void *)offsetof(smtp_transport_options_block, tls_require_ciphers) },
168 { "tls_sni", opt_stringptr,
169 (void *)offsetof(smtp_transport_options_block, tls_sni) },
170 { "tls_tempfail_tryclear", opt_bool,
171 (void *)offsetof(smtp_transport_options_block, tls_tempfail_tryclear) },
172 { "tls_try_verify_hosts", opt_stringptr,
173 (void *)offsetof(smtp_transport_options_block, tls_try_verify_hosts) },
174 { "tls_verify_cert_hostnames", opt_stringptr,
175 (void *)offsetof(smtp_transport_options_block,tls_verify_cert_hostnames)},
176 { "tls_verify_certificates", opt_stringptr,
177 (void *)offsetof(smtp_transport_options_block, tls_verify_certificates) },
178 { "tls_verify_hosts", opt_stringptr,
179 (void *)offsetof(smtp_transport_options_block, tls_verify_hosts) }
180 #endif
181 };
182
183 /* Size of the options list. An extern variable has to be used so that its
184 address can appear in the tables drtables.c. */
185
186 int smtp_transport_options_count =
187 sizeof(smtp_transport_options)/sizeof(optionlist);
188
189 /* Default private options block for the smtp transport. */
190
191 smtp_transport_options_block smtp_transport_option_defaults = {
192 NULL, /* hosts */
193 NULL, /* fallback_hosts */
194 NULL, /* hostlist */
195 NULL, /* fallback_hostlist */
196 NULL, /* authenticated_sender */
197 US"$primary_hostname", /* helo_data */
198 NULL, /* interface */
199 NULL, /* port */
200 US"smtp", /* protocol */
201 NULL, /* DSCP */
202 NULL, /* serialize_hosts */
203 NULL, /* hosts_try_auth */
204 NULL, /* hosts_require_auth */
205 US"*", /* hosts_try_chunking */
206 #ifdef EXPERIMENTAL_DANE
207 NULL, /* hosts_try_dane */
208 NULL, /* hosts_require_dane */
209 #endif
210 NULL, /* hosts_try_fastopen */
211 #ifndef DISABLE_PRDR
212 US"*", /* hosts_try_prdr */
213 #endif
214 #ifndef DISABLE_OCSP
215 US"*", /* hosts_request_ocsp (except under DANE; tls_client_start()) */
216 NULL, /* hosts_require_ocsp */
217 #endif
218 NULL, /* hosts_require_tls */
219 NULL, /* hosts_avoid_tls */
220 NULL, /* hosts_verify_avoid_tls */
221 NULL, /* hosts_avoid_pipelining */
222 NULL, /* hosts_avoid_esmtp */
223 #ifdef SUPPORT_TLS
224 NULL, /* hosts_nopass_tls */
225 US"*", /* hosts_noproxy_tls */
226 #endif
227 5*60, /* command_timeout */
228 5*60, /* connect_timeout; shorter system default overrides */
229 5*60, /* data timeout */
230 10*60, /* final timeout */
231 1024, /* size_addition */
232 5, /* hosts_max_try */
233 50, /* hosts_max_try_hardlimit */
234 TRUE, /* address_retry_include_sender */
235 FALSE, /* allow_localhost */
236 FALSE, /* authenticated_sender_force */
237 FALSE, /* gethostbyname */
238 TRUE, /* dns_qualify_single */
239 FALSE, /* dns_search_parents */
240 { NULL, NULL }, /* dnssec_domains {request,require} */
241 TRUE, /* delay_after_cutoff */
242 FALSE, /* hosts_override */
243 FALSE, /* hosts_randomize */
244 TRUE, /* keepalive */
245 FALSE, /* lmtp_ignore_quota */
246 NULL, /* expand_retry_include_ip_address */
247 TRUE /* retry_include_ip_address */
248 #ifdef SUPPORT_SOCKS
249 ,NULL /* socks_proxy */
250 #endif
251 #ifdef SUPPORT_TLS
252 ,NULL, /* tls_certificate */
253 NULL, /* tls_crl */
254 NULL, /* tls_privatekey */
255 NULL, /* tls_require_ciphers */
256 NULL, /* tls_sni */
257 US"system", /* tls_verify_certificates */
258 EXIM_CLIENT_DH_DEFAULT_MIN_BITS,
259 /* tls_dh_min_bits */
260 TRUE, /* tls_tempfail_tryclear */
261 NULL, /* tls_verify_hosts */
262 US"*", /* tls_try_verify_hosts */
263 US"*" /* tls_verify_cert_hostnames */
264 #endif
265 #ifndef DISABLE_DKIM
266 , {NULL, /* dkim_canon */
267 NULL, /* dkim_domain */
268 NULL, /* dkim_private_key */
269 NULL, /* dkim_selector */
270 NULL, /* dkim_sign_headers */
271 NULL, /* dkim_strict */
272 FALSE} /* dot_stuffed */
273 #endif
274 };
275
276 /* some DSN flags for use later */
277
278 static int rf_list[] = {rf_notify_never, rf_notify_success,
279 rf_notify_failure, rf_notify_delay };
280
281 static uschar *rf_names[] = { US"NEVER", US"SUCCESS", US"FAILURE", US"DELAY" };
282
283
284
285 /* Local statics */
286
287 static uschar *smtp_command; /* Points to last cmd for error messages */
288 static uschar *mail_command; /* Points to MAIL cmd for error messages */
289 static uschar *data_command = US""; /* Points to DATA cmd for error messages */
290 static BOOL update_waiting; /* TRUE to update the "wait" database */
291
292 /*XXX move to smtp_context */
293 static BOOL pipelining_active; /* current transaction is in pipe mode */
294
295
296 /*************************************************
297 * Setup entry point *
298 *************************************************/
299
300 /* This function is called when the transport is about to be used,
301 but before running it in a sub-process. It is used for two things:
302
303 (1) To set the fallback host list in addresses, when delivering.
304 (2) To pass back the interface, port, protocol, and other options, for use
305 during callout verification.
306
307 Arguments:
308 tblock pointer to the transport instance block
309 addrlist list of addresses about to be transported
310 tf if not NULL, pointer to block in which to return options
311 uid the uid that will be set (not used)
312 gid the gid that will be set (not used)
313 errmsg place for error message (not used)
314
315 Returns: OK always (FAIL, DEFER not used)
316 */
317
318 static int
319 smtp_transport_setup(transport_instance *tblock, address_item *addrlist,
320 transport_feedback *tf, uid_t uid, gid_t gid, uschar **errmsg)
321 {
322 smtp_transport_options_block *ob =
323 (smtp_transport_options_block *)(tblock->options_block);
324
325 errmsg = errmsg; /* Keep picky compilers happy */
326 uid = uid;
327 gid = gid;
328
329 /* Pass back options if required. This interface is getting very messy. */
330
331 if (tf)
332 {
333 tf->interface = ob->interface;
334 tf->port = ob->port;
335 tf->protocol = ob->protocol;
336 tf->hosts = ob->hosts;
337 tf->hosts_override = ob->hosts_override;
338 tf->hosts_randomize = ob->hosts_randomize;
339 tf->gethostbyname = ob->gethostbyname;
340 tf->qualify_single = ob->dns_qualify_single;
341 tf->search_parents = ob->dns_search_parents;
342 tf->helo_data = ob->helo_data;
343 }
344
345 /* Set the fallback host list for all the addresses that don't have fallback
346 host lists, provided that the local host wasn't present in the original host
347 list. */
348
349 if (!testflag(addrlist, af_local_host_removed))
350 for (; addrlist; addrlist = addrlist->next)
351 if (!addrlist->fallback_hosts) addrlist->fallback_hosts = ob->fallback_hostlist;
352
353 return OK;
354 }
355
356
357
358 /*************************************************
359 * Initialization entry point *
360 *************************************************/
361
362 /* Called for each instance, after its options have been read, to
363 enable consistency checks to be done, or anything else that needs
364 to be set up.
365
366 Argument: pointer to the transport instance block
367 Returns: nothing
368 */
369
370 void
371 smtp_transport_init(transport_instance *tblock)
372 {
373 smtp_transport_options_block *ob =
374 (smtp_transport_options_block *)(tblock->options_block);
375
376 /* Retry_use_local_part defaults FALSE if unset */
377
378 if (tblock->retry_use_local_part == TRUE_UNSET)
379 tblock->retry_use_local_part = FALSE;
380
381 /* Set the default port according to the protocol */
382
383 if (ob->port == NULL)
384 ob->port = (strcmpic(ob->protocol, US"lmtp") == 0)? US"lmtp" :
385 (strcmpic(ob->protocol, US"smtps") == 0)? US"smtps" : US"smtp";
386
387 /* Set up the setup entry point, to be called before subprocesses for this
388 transport. */
389
390 tblock->setup = smtp_transport_setup;
391
392 /* Complain if any of the timeouts are zero. */
393
394 if (ob->command_timeout <= 0 || ob->data_timeout <= 0 ||
395 ob->final_timeout <= 0)
396 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
397 "command, data, or final timeout value is zero for %s transport",
398 tblock->name);
399
400 /* If hosts_override is set and there are local hosts, set the global
401 flag that stops verify from showing router hosts. */
402
403 if (ob->hosts_override && ob->hosts != NULL) tblock->overrides_hosts = TRUE;
404
405 /* If there are any fallback hosts listed, build a chain of host items
406 for them, but do not do any lookups at this time. */
407
408 host_build_hostlist(&(ob->fallback_hostlist), ob->fallback_hosts, FALSE);
409 }
410
411
412
413
414
415 /*************************************************
416 * Set delivery info into all active addresses *
417 *************************************************/
418
419 /* Only addresses whose status is >= PENDING are relevant. A lesser
420 status means that an address is not currently being processed.
421
422 Arguments:
423 addrlist points to a chain of addresses
424 errno_value to put in each address's errno field
425 msg to put in each address's message field
426 rc to put in each address's transport_return field
427 pass_message if TRUE, set the "pass message" flag in the address
428 host if set, mark addrs as having used this host
429 smtp_greeting from peer
430 helo_response from peer
431
432 If errno_value has the special value ERRNO_CONNECTTIMEOUT, ETIMEDOUT is put in
433 the errno field, and RTEF_CTOUT is ORed into the more_errno field, to indicate
434 this particular type of timeout.
435
436 Returns: nothing
437 */
438
439 static void
440 set_errno(address_item *addrlist, int errno_value, uschar *msg, int rc,
441 BOOL pass_message, host_item * host
442 #ifdef EXPERIMENTAL_DSN_INFO
443 , const uschar * smtp_greeting, const uschar * helo_response
444 #endif
445 )
446 {
447 address_item *addr;
448 int orvalue = 0;
449 if (errno_value == ERRNO_CONNECTTIMEOUT)
450 {
451 errno_value = ETIMEDOUT;
452 orvalue = RTEF_CTOUT;
453 }
454 for (addr = addrlist; addr; addr = addr->next)
455 if (addr->transport_return >= PENDING)
456 {
457 addr->basic_errno = errno_value;
458 addr->more_errno |= orvalue;
459 if (msg)
460 {
461 addr->message = msg;
462 if (pass_message) setflag(addr, af_pass_message);
463 }
464 addr->transport_return = rc;
465 if (host)
466 {
467 addr->host_used = host;
468 #ifdef EXPERIMENTAL_DSN_INFO
469 if (smtp_greeting)
470 {uschar * s = Ustrchr(smtp_greeting, '\n'); if (s) *s = '\0';}
471 addr->smtp_greeting = smtp_greeting;
472
473 if (helo_response)
474 {uschar * s = Ustrchr(helo_response, '\n'); if (s) *s = '\0';}
475 addr->helo_response = helo_response;
476 #endif
477 }
478 }
479 }
480
481 static void
482 set_errno_nohost(address_item *addrlist, int errno_value, uschar *msg, int rc,
483 BOOL pass_message)
484 {
485 set_errno(addrlist, errno_value, msg, rc, pass_message, NULL
486 #ifdef EXPERIMENTAL_DSN_INFO
487 , NULL, NULL
488 #endif
489 );
490 }
491
492
493 /*************************************************
494 * Check an SMTP response *
495 *************************************************/
496
497 /* This function is given an errno code and the SMTP response buffer
498 to analyse, together with the host identification for generating messages. It
499 sets an appropriate message and puts the first digit of the response code into
500 the yield variable. If no response was actually read, a suitable digit is
501 chosen.
502
503 Arguments:
504 host the current host, to get its name for messages
505 errno_value pointer to the errno value
506 more_errno from the top address for use with ERRNO_FILTER_FAIL
507 buffer the SMTP response buffer
508 yield where to put a one-digit SMTP response code
509 message where to put an error message
510 pass_message set TRUE if message is an SMTP response
511
512 Returns: TRUE if an SMTP "QUIT" command should be sent, else FALSE
513 */
514
515 static BOOL
516 check_response(host_item *host, int *errno_value, int more_errno,
517 uschar *buffer, int *yield, uschar **message, BOOL *pass_message)
518 {
519 uschar * pl = pipelining_active ? US"pipelined " : US"";
520 const uschar * s;
521
522 *yield = '4'; /* Default setting is to give a temporary error */
523
524 switch(*errno_value)
525 {
526 case ETIMEDOUT: /* Handle response timeout */
527 *message = US string_sprintf("SMTP timeout after %s%s",
528 pl, smtp_command);
529 if (transport_count > 0)
530 *message = US string_sprintf("%s (%d bytes written)", *message,
531 transport_count);
532 return FALSE;
533
534 case ERRNO_SMTPFORMAT: /* Handle malformed SMTP response */
535 s = string_printing(buffer);
536 while (isspace(*s)) s++;
537 *message = *s == 0
538 ? string_sprintf("Malformed SMTP reply (an empty line) "
539 "in response to %s%s", pl, smtp_command)
540 : string_sprintf("Malformed SMTP reply in response to %s%s: %s",
541 pl, smtp_command, s);
542 return FALSE;
543
544 case ERRNO_FILTER_FAIL: /* Handle a failed filter process error;
545 can't send QUIT as we mustn't end the DATA. */
546 *message = string_sprintf("transport filter process failed (%d)%s",
547 more_errno,
548 more_errno == EX_EXECFAILED ? ": unable to execute command" : "");
549 return FALSE;
550
551 case ERRNO_CHHEADER_FAIL: /* Handle a failed add_headers expansion;
552 can't send QUIT as we mustn't end the DATA. */
553 *message =
554 string_sprintf("failed to expand headers_add or headers_remove: %s",
555 expand_string_message);
556 return FALSE;
557
558 case ERRNO_WRITEINCOMPLETE: /* failure to write a complete data block */
559 *message = string_sprintf("failed to write a data block");
560 return FALSE;
561
562 #ifdef SUPPORT_I18N
563 case ERRNO_UTF8_FWD: /* no advertised SMTPUTF8, for international message */
564 *message = US"utf8 support required but not offered for forwarding";
565 DEBUG(D_deliver|D_transport) debug_printf("%s\n", *message);
566 return TRUE;
567 #endif
568 }
569
570 /* Handle error responses from the remote mailer. */
571
572 if (buffer[0] != 0)
573 {
574 *message = string_sprintf("SMTP error from remote mail server after %s%s: "
575 "%s", pl, smtp_command, s = string_printing(buffer));
576 *pass_message = TRUE;
577 *yield = buffer[0];
578 return TRUE;
579 }
580
581 /* No data was read. If there is no errno, this must be the EOF (i.e.
582 connection closed) case, which causes deferral. An explicit connection reset
583 error has the same effect. Otherwise, put the host's identity in the message,
584 leaving the errno value to be interpreted as well. In all cases, we have to
585 assume the connection is now dead. */
586
587 if (*errno_value == 0 || *errno_value == ECONNRESET)
588 {
589 *errno_value = ERRNO_SMTPCLOSED;
590 *message = US string_sprintf("Remote host closed connection "
591 "in response to %s%s", pl, smtp_command);
592 }
593 else
594 *message = US string_sprintf("%s [%s]", host->name, host->address);
595
596 return FALSE;
597 }
598
599
600
601 /*************************************************
602 * Write error message to logs *
603 *************************************************/
604
605 /* This writes to the main log and to the message log.
606
607 Arguments:
608 addr the address item containing error information
609 host the current host
610
611 Returns: nothing
612 */
613
614 static void
615 write_logs(address_item *addr, host_item *host)
616 {
617 uschar * message = LOGGING(outgoing_port)
618 ? string_sprintf("H=%s [%s]:%d", host->name, host->address,
619 host->port == PORT_NONE ? 25 : host->port)
620 : string_sprintf("H=%s [%s]", host->name, host->address);
621
622 if (addr->message)
623 {
624 message = string_sprintf("%s: %s", message, addr->message);
625 if (addr->basic_errno > 0)
626 message = string_sprintf("%s: %s", message, strerror(addr->basic_errno));
627 log_write(0, LOG_MAIN, "%s", message);
628 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
629 }
630 else
631 {
632 const uschar * s = exim_errstr(addr->basic_errno);
633 log_write(0, LOG_MAIN, "%s %s", message, s);
634 deliver_msglog("%s %s %s\n", tod_stamp(tod_log), message, s);
635 }
636 }
637
638 static void
639 msglog_line(host_item * host, uschar * message)
640 {
641 deliver_msglog("%s H=%s [%s] %s\n", tod_stamp(tod_log),
642 host->name, host->address, message);
643 }
644
645
646
647 #ifndef DISABLE_EVENT
648 /*************************************************
649 * Post-defer action *
650 *************************************************/
651
652 /* This expands an arbitrary per-transport string.
653 It might, for example, be used to write to the database log.
654
655 Arguments:
656 addr the address item containing error information
657 host the current host
658
659 Returns: nothing
660 */
661
662 static void
663 deferred_event_raise(address_item *addr, host_item *host)
664 {
665 uschar * action = addr->transport->event_action;
666 const uschar * save_domain;
667 uschar * save_local;
668
669 if (!action)
670 return;
671
672 save_domain = deliver_domain;
673 save_local = deliver_localpart;
674
675 /*XXX would ip & port already be set up? */
676 deliver_host_address = string_copy(host->address);
677 deliver_host_port = host->port == PORT_NONE ? 25 : host->port;
678 event_defer_errno = addr->basic_errno;
679
680 router_name = addr->router->name;
681 transport_name = addr->transport->name;
682 deliver_domain = addr->domain;
683 deliver_localpart = addr->local_part;
684
685 (void) event_raise(action, US"msg:host:defer",
686 addr->message
687 ? addr->basic_errno > 0
688 ? string_sprintf("%s: %s", addr->message, strerror(addr->basic_errno))
689 : string_copy(addr->message)
690 : addr->basic_errno > 0
691 ? string_copy(US strerror(addr->basic_errno))
692 : NULL);
693
694 deliver_localpart = save_local;
695 deliver_domain = save_domain;
696 router_name = transport_name = NULL;
697 }
698 #endif
699
700 /*************************************************
701 * Synchronize SMTP responses *
702 *************************************************/
703
704 /* This function is called from smtp_deliver() to receive SMTP responses from
705 the server, and match them up with the commands to which they relate. When
706 PIPELINING is not in use, this function is called after every command, and is
707 therefore somewhat over-engineered, but it is simpler to use a single scheme
708 that works both with and without PIPELINING instead of having two separate sets
709 of code.
710
711 The set of commands that are buffered up with pipelining may start with MAIL
712 and may end with DATA; in between are RCPT commands that correspond to the
713 addresses whose status is PENDING_DEFER. All other commands (STARTTLS, AUTH,
714 etc.) are never buffered.
715
716 Errors after MAIL or DATA abort the whole process leaving the response in the
717 buffer. After MAIL, pending responses are flushed, and the original command is
718 re-instated in big_buffer for error messages. For RCPT commands, the remote is
719 permitted to reject some recipient addresses while accepting others. However
720 certain errors clearly abort the whole process. Set the value in
721 transport_return to PENDING_OK if the address is accepted. If there is a
722 subsequent general error, it will get reset accordingly. If not, it will get
723 converted to OK at the end.
724
725 Arguments:
726 sx smtp connection context
727 count the number of responses to read
728 pending_DATA 0 if last command sent was not DATA
729 +1 if previously had a good recipient
730 -1 if not previously had a good recipient
731
732 Returns: 3 if at least one address had 2xx and one had 5xx
733 2 if at least one address had 5xx but none had 2xx
734 1 if at least one host had a 2xx response, but none had 5xx
735 0 no address had 2xx or 5xx but no errors (all 4xx, or just DATA)
736 -1 timeout while reading RCPT response
737 -2 I/O or other non-response error for RCPT
738 -3 DATA or MAIL failed - errno and buffer set
739 */
740
741 static int
742 sync_responses(smtp_context * sx, int count, int pending_DATA)
743 {
744 address_item *addr = sx->sync_addr;
745 smtp_transport_options_block *ob =
746 (smtp_transport_options_block *)sx->tblock->options_block;
747 int yield = 0;
748
749 /* Handle the response for a MAIL command. On error, reinstate the original
750 command in big_buffer for error message use, and flush any further pending
751 responses before returning, except after I/O errors and timeouts. */
752
753 if (sx->pending_MAIL)
754 {
755 count--;
756 if (!smtp_read_response(&sx->inblock, sx->buffer, sizeof(sx->buffer),
757 '2', ob->command_timeout))
758 {
759 DEBUG(D_transport) debug_printf("bad response for MAIL\n");
760 Ustrcpy(big_buffer, mail_command); /* Fits, because it came from there! */
761 if (errno == 0 && sx->buffer[0] != 0)
762 {
763 uschar flushbuffer[4096];
764 int save_errno = 0;
765 if (sx->buffer[0] == '4')
766 {
767 save_errno = ERRNO_MAIL4XX;
768 addr->more_errno |= ((sx->buffer[1] - '0')*10 + sx->buffer[2] - '0') << 8;
769 }
770 while (count-- > 0)
771 {
772 if (!smtp_read_response(&sx->inblock, flushbuffer, sizeof(flushbuffer),
773 '2', ob->command_timeout)
774 && (errno != 0 || flushbuffer[0] == 0))
775 break;
776 }
777 errno = save_errno;
778 }
779
780 if (pending_DATA) count--; /* Number of RCPT responses to come */
781 while (count-- > 0) /* Mark any pending addrs with the host used */
782 {
783 while (addr->transport_return != PENDING_DEFER) addr = addr->next;
784 addr->host_used = sx->host;
785 addr = addr->next;
786 }
787 return -3;
788 }
789 }
790
791 if (pending_DATA) count--; /* Number of RCPT responses to come */
792
793 /* Read and handle the required number of RCPT responses, matching each one up
794 with an address by scanning for the next address whose status is PENDING_DEFER.
795 */
796
797 while (count-- > 0)
798 {
799 while (addr->transport_return != PENDING_DEFER)
800 if (!(addr = addr->next))
801 return -2;
802
803 /* The address was accepted */
804 addr->host_used = sx->host;
805
806 if (smtp_read_response(&sx->inblock, sx->buffer, sizeof(sx->buffer),
807 '2', ob->command_timeout))
808 {
809 yield |= 1;
810 addr->transport_return = PENDING_OK;
811
812 /* If af_dr_retry_exists is set, there was a routing delay on this address;
813 ensure that any address-specific retry record is expunged. We do this both
814 for the basic key and for the version that also includes the sender. */
815
816 if (testflag(addr, af_dr_retry_exists))
817 {
818 uschar *altkey = string_sprintf("%s:<%s>", addr->address_retry_key,
819 sender_address);
820 retry_add_item(addr, altkey, rf_delete);
821 retry_add_item(addr, addr->address_retry_key, rf_delete);
822 }
823 }
824
825 /* Timeout while reading the response */
826
827 else if (errno == ETIMEDOUT)
828 {
829 uschar *message = string_sprintf("SMTP timeout after RCPT TO:<%s>",
830 transport_rcpt_address(addr, sx->tblock->rcpt_include_affixes));
831 set_errno_nohost(sx->first_addr, ETIMEDOUT, message, DEFER, FALSE);
832 retry_add_item(addr, addr->address_retry_key, 0);
833 update_waiting = FALSE;
834 return -1;
835 }
836
837 /* Handle other errors in obtaining an SMTP response by returning -1. This
838 will cause all the addresses to be deferred. Restore the SMTP command in
839 big_buffer for which we are checking the response, so the error message
840 makes sense. */
841
842 else if (errno != 0 || sx->buffer[0] == 0)
843 {
844 string_format(big_buffer, big_buffer_size, "RCPT TO:<%s>",
845 transport_rcpt_address(addr, sx->tblock->rcpt_include_affixes));
846 return -2;
847 }
848
849 /* Handle SMTP permanent and temporary response codes. */
850
851 else
852 {
853 addr->message =
854 string_sprintf("SMTP error from remote mail server after RCPT TO:<%s>: "
855 "%s", transport_rcpt_address(addr, sx->tblock->rcpt_include_affixes),
856 string_printing(sx->buffer));
857 setflag(addr, af_pass_message);
858 if (!sx->verify)
859 msglog_line(sx->host, addr->message);
860
861 /* The response was 5xx */
862
863 if (sx->buffer[0] == '5')
864 {
865 addr->transport_return = FAIL;
866 yield |= 2;
867 }
868
869 /* The response was 4xx */
870
871 else
872 {
873 addr->transport_return = DEFER;
874 addr->basic_errno = ERRNO_RCPT4XX;
875 addr->more_errno |= ((sx->buffer[1] - '0')*10 + sx->buffer[2] - '0') << 8;
876
877 if (!sx->verify)
878 {
879 #ifndef DISABLE_EVENT
880 event_defer_errno = addr->more_errno;
881 msg_event_raise(US"msg:rcpt:host:defer", addr);
882 #endif
883
884 /* Log temporary errors if there are more hosts to be tried.
885 If not, log this last one in the == line. */
886
887 if (sx->host->next)
888 log_write(0, LOG_MAIN, "H=%s [%s]: %s",
889 sx->host->name, sx->host->address, addr->message);
890
891 #ifndef DISABLE_EVENT
892 else
893 msg_event_raise(US"msg:rcpt:defer", addr);
894 #endif
895
896 /* Do not put this message on the list of those waiting for specific
897 hosts, as otherwise it is likely to be tried too often. */
898
899 update_waiting = FALSE;
900
901 /* Add a retry item for the address so that it doesn't get tried again
902 too soon. If address_retry_include_sender is true, add the sender address
903 to the retry key. */
904
905 retry_add_item(addr,
906 ob->address_retry_include_sender
907 ? string_sprintf("%s:<%s>", addr->address_retry_key, sender_address)
908 : addr->address_retry_key,
909 0);
910 }
911 }
912 }
913 } /* Loop for next RCPT response */
914
915 /* Update where to start at for the next block of responses, unless we
916 have already handled all the addresses. */
917
918 if (addr) sx->sync_addr = addr->next;
919
920 /* Handle a response to DATA. If we have not had any good recipients, either
921 previously or in this block, the response is ignored. */
922
923 if (pending_DATA != 0 &&
924 !smtp_read_response(&sx->inblock, sx->buffer, sizeof(sx->buffer),
925 '3', ob->command_timeout))
926 {
927 int code;
928 uschar *msg;
929 BOOL pass_message;
930 if (pending_DATA > 0 || (yield & 1) != 0)
931 {
932 if (errno == 0 && sx->buffer[0] == '4')
933 {
934 errno = ERRNO_DATA4XX;
935 sx->first_addr->more_errno |= ((sx->buffer[1] - '0')*10 + sx->buffer[2] - '0') << 8;
936 }
937 return -3;
938 }
939 (void)check_response(sx->host, &errno, 0, sx->buffer, &code, &msg, &pass_message);
940 DEBUG(D_transport) debug_printf("%s\nerror for DATA ignored: pipelining "
941 "is in use and there were no good recipients\n", msg);
942 }
943
944 /* All responses read and handled; MAIL (if present) received 2xx and DATA (if
945 present) received 3xx. If any RCPTs were handled and yielded anything other
946 than 4xx, yield will be set non-zero. */
947
948 return yield;
949 }
950
951
952
953 /* Do the client side of smtp-level authentication */
954 /*
955 Arguments:
956 buffer EHLO response from server (gets overwritten)
957 addrlist chain of potential addresses to deliver
958 host host to deliver to
959 ob transport options
960 ibp, obp comms channel control blocks
961
962 Returns:
963 OK Success, or failed (but not required): global "smtp_authenticated" set
964 DEFER Failed authentication (and was required)
965 ERROR Internal problem
966
967 FAIL_SEND Failed communications - transmit
968 FAIL - response
969 */
970
971 int
972 smtp_auth(uschar *buffer, unsigned bufsize, address_item *addrlist, host_item *host,
973 smtp_transport_options_block *ob, BOOL is_esmtp,
974 smtp_inblock *ibp, smtp_outblock *obp)
975 {
976 int require_auth;
977 uschar *fail_reason = US"server did not advertise AUTH support";
978
979 smtp_authenticated = FALSE;
980 client_authenticator = client_authenticated_id = client_authenticated_sender = NULL;
981 require_auth = verify_check_given_host(&ob->hosts_require_auth, host);
982
983 if (is_esmtp && !regex_AUTH) regex_AUTH =
984 regex_must_compile(US"\\n250[\\s\\-]AUTH\\s+([\\-\\w\\s]+)(?:\\n|$)",
985 FALSE, TRUE);
986
987 if (is_esmtp && regex_match_and_setup(regex_AUTH, buffer, 0, -1))
988 {
989 uschar *names = string_copyn(expand_nstring[1], expand_nlength[1]);
990 expand_nmax = -1; /* reset */
991
992 /* Must not do this check until after we have saved the result of the
993 regex match above. */
994
995 if (require_auth == OK ||
996 verify_check_given_host(&ob->hosts_try_auth, host) == OK)
997 {
998 auth_instance *au;
999 fail_reason = US"no common mechanisms were found";
1000
1001 DEBUG(D_transport) debug_printf("scanning authentication mechanisms\n");
1002
1003 /* Scan the configured authenticators looking for one which is configured
1004 for use as a client, which is not suppressed by client_condition, and
1005 whose name matches an authentication mechanism supported by the server.
1006 If one is found, attempt to authenticate by calling its client function.
1007 */
1008
1009 for (au = auths; !smtp_authenticated && au != NULL; au = au->next)
1010 {
1011 uschar *p = names;
1012 if (!au->client ||
1013 (au->client_condition != NULL &&
1014 !expand_check_condition(au->client_condition, au->name,
1015 US"client authenticator")))
1016 {
1017 DEBUG(D_transport) debug_printf("skipping %s authenticator: %s\n",
1018 au->name,
1019 (au->client)? "client_condition is false" :
1020 "not configured as a client");
1021 continue;
1022 }
1023
1024 /* Loop to scan supported server mechanisms */
1025
1026 while (*p != 0)
1027 {
1028 int rc;
1029 int len = Ustrlen(au->public_name);
1030 while (isspace(*p)) p++;
1031
1032 if (strncmpic(au->public_name, p, len) != 0 ||
1033 (p[len] != 0 && !isspace(p[len])))
1034 {
1035 while (*p != 0 && !isspace(*p)) p++;
1036 continue;
1037 }
1038
1039 /* Found data for a listed mechanism. Call its client entry. Set
1040 a flag in the outblock so that data is overwritten after sending so
1041 that reflections don't show it. */
1042
1043 fail_reason = US"authentication attempt(s) failed";
1044 obp->authenticating = TRUE;
1045 rc = (au->info->clientcode)(au, ibp, obp,
1046 ob->command_timeout, buffer, bufsize);
1047 obp->authenticating = FALSE;
1048 DEBUG(D_transport) debug_printf("%s authenticator yielded %d\n",
1049 au->name, rc);
1050
1051 /* A temporary authentication failure must hold up delivery to
1052 this host. After a permanent authentication failure, we carry on
1053 to try other authentication methods. If all fail hard, try to
1054 deliver the message unauthenticated unless require_auth was set. */
1055
1056 switch(rc)
1057 {
1058 case OK:
1059 smtp_authenticated = TRUE; /* stops the outer loop */
1060 client_authenticator = au->name;
1061 if (au->set_client_id != NULL)
1062 client_authenticated_id = expand_string(au->set_client_id);
1063 break;
1064
1065 /* Failure after writing a command */
1066
1067 case FAIL_SEND:
1068 return FAIL_SEND;
1069
1070 /* Failure after reading a response */
1071
1072 case FAIL:
1073 if (errno != 0 || buffer[0] != '5') return FAIL;
1074 log_write(0, LOG_MAIN, "%s authenticator failed H=%s [%s] %s",
1075 au->name, host->name, host->address, buffer);
1076 break;
1077
1078 /* Failure by some other means. In effect, the authenticator
1079 decided it wasn't prepared to handle this case. Typically this
1080 is the result of "fail" in an expansion string. Do we need to
1081 log anything here? Feb 2006: a message is now put in the buffer
1082 if logging is required. */
1083
1084 case CANCELLED:
1085 if (*buffer != 0)
1086 log_write(0, LOG_MAIN, "%s authenticator cancelled "
1087 "authentication H=%s [%s] %s", au->name, host->name,
1088 host->address, buffer);
1089 break;
1090
1091 /* Internal problem, message in buffer. */
1092
1093 case ERROR:
1094 set_errno_nohost(addrlist, ERRNO_AUTHPROB, string_copy(buffer),
1095 DEFER, FALSE);
1096 return ERROR;
1097 }
1098
1099 break; /* If not authenticated, try next authenticator */
1100 } /* Loop for scanning supported server mechanisms */
1101 } /* Loop for further authenticators */
1102 }
1103 }
1104
1105 /* If we haven't authenticated, but are required to, give up. */
1106
1107 if (require_auth == OK && !smtp_authenticated)
1108 {
1109 set_errno_nohost(addrlist, ERRNO_AUTHFAIL,
1110 string_sprintf("authentication required but %s", fail_reason), DEFER,
1111 FALSE);
1112 return DEFER;
1113 }
1114
1115 return OK;
1116 }
1117
1118
1119 /* Construct AUTH appendix string for MAIL TO */
1120 /*
1121 Arguments
1122 buffer to build string
1123 addrlist chain of potential addresses to deliver
1124 ob transport options
1125
1126 Globals smtp_authenticated
1127 client_authenticated_sender
1128 Return True on error, otherwise buffer has (possibly empty) terminated string
1129 */
1130
1131 BOOL
1132 smtp_mail_auth_str(uschar *buffer, unsigned bufsize, address_item *addrlist,
1133 smtp_transport_options_block *ob)
1134 {
1135 uschar *local_authenticated_sender = authenticated_sender;
1136
1137 #ifdef notdef
1138 debug_printf("smtp_mail_auth_str: as<%s> os<%s> SA<%s>\n", authenticated_sender, ob->authenticated_sender, smtp_authenticated?"Y":"N");
1139 #endif
1140
1141 if (ob->authenticated_sender != NULL)
1142 {
1143 uschar *new = expand_string(ob->authenticated_sender);
1144 if (new == NULL)
1145 {
1146 if (!expand_string_forcedfail)
1147 {
1148 uschar *message = string_sprintf("failed to expand "
1149 "authenticated_sender: %s", expand_string_message);
1150 set_errno_nohost(addrlist, ERRNO_EXPANDFAIL, message, DEFER, FALSE);
1151 return TRUE;
1152 }
1153 }
1154 else if (new[0] != 0) local_authenticated_sender = new;
1155 }
1156
1157 /* Add the authenticated sender address if present */
1158
1159 if ((smtp_authenticated || ob->authenticated_sender_force) &&
1160 local_authenticated_sender != NULL)
1161 {
1162 string_format(buffer, bufsize, " AUTH=%s",
1163 auth_xtextencode(local_authenticated_sender,
1164 Ustrlen(local_authenticated_sender)));
1165 client_authenticated_sender = string_copy(local_authenticated_sender);
1166 }
1167 else
1168 *buffer= 0;
1169
1170 return FALSE;
1171 }
1172
1173
1174
1175 #ifdef EXPERIMENTAL_DANE
1176 /* Lookup TLSA record for host/port.
1177 Return: OK success with dnssec; DANE mode
1178 DEFER Do not use this host now, may retry later
1179 FAIL_FORCED No TLSA record; DANE not usable
1180 FAIL Do not use this connection
1181 */
1182
1183 int
1184 tlsa_lookup(const host_item * host, dns_answer * dnsa, BOOL dane_required)
1185 {
1186 /* move this out to host.c given the similarity to dns_lookup() ? */
1187 uschar buffer[300];
1188 const uschar * fullname = buffer;
1189 int rc;
1190 BOOL sec;
1191
1192 /* TLSA lookup string */
1193 (void)sprintf(CS buffer, "_%d._tcp.%.256s", host->port, host->name);
1194
1195 rc = dns_lookup(dnsa, buffer, T_TLSA, &fullname);
1196 sec = dns_is_secure(dnsa);
1197 DEBUG(D_transport)
1198 debug_printf("TLSA lookup ret %d %sDNSSEC\n", rc, sec ? "" : "not ");
1199
1200 switch (rc)
1201 {
1202 case DNS_SUCCEED:
1203 if (sec) return OK;
1204
1205 log_write(0, LOG_MAIN, "DANE error: TLSA lookup not DNSSEC");
1206 /*FALLTHROUGH*/
1207 case DNS_AGAIN:
1208 return DEFER; /* just defer this TLS'd conn */
1209
1210 case DNS_NODATA: /* no TLSA RR for this lookup */
1211 case DNS_NOMATCH: /* no records at all for this lookup */
1212 return dane_required ? FAIL : FAIL_FORCED;
1213
1214 default:
1215 case DNS_FAIL:
1216 return dane_required ? FAIL : DEFER;
1217 }
1218 }
1219 #endif
1220
1221
1222
1223 typedef struct smtp_compare_s
1224 {
1225 uschar *current_sender_address;
1226 struct transport_instance *tblock;
1227 } smtp_compare_t;
1228
1229
1230 /* Create a unique string that identifies this message, it is based on
1231 sender_address, helo_data and tls_certificate if enabled.
1232 */
1233
1234 static uschar *
1235 smtp_local_identity(uschar * sender, struct transport_instance * tblock)
1236 {
1237 address_item * addr1;
1238 uschar * if1 = US"";
1239 uschar * helo1 = US"";
1240 #ifdef SUPPORT_TLS
1241 uschar * tlsc1 = US"";
1242 #endif
1243 uschar * save_sender_address = sender_address;
1244 uschar * local_identity = NULL;
1245 smtp_transport_options_block * ob =
1246 (smtp_transport_options_block *)tblock->options_block;
1247
1248 sender_address = sender;
1249
1250 addr1 = deliver_make_addr (sender, TRUE);
1251 deliver_set_expansions(addr1);
1252
1253 if (ob->interface)
1254 if1 = expand_string(ob->interface);
1255
1256 if (ob->helo_data)
1257 helo1 = expand_string(ob->helo_data);
1258
1259 #ifdef SUPPORT_TLS
1260 if (ob->tls_certificate)
1261 tlsc1 = expand_string(ob->tls_certificate);
1262 local_identity = string_sprintf ("%s^%s^%s", if1, helo1, tlsc1);
1263 #else
1264 local_identity = string_sprintf ("%s^%s", if1, helo1);
1265 #endif
1266
1267 deliver_set_expansions(NULL);
1268 sender_address = save_sender_address;
1269
1270 return local_identity;
1271 }
1272
1273
1274
1275 /* This routine is a callback that is called from transport_check_waiting.
1276 This function will evaluate the incoming message versus the previous
1277 message. If the incoming message is using a different local identity then
1278 we will veto this new message. */
1279
1280 static BOOL
1281 smtp_are_same_identities(uschar * message_id, smtp_compare_t * s_compare)
1282 {
1283 uschar * message_local_identity,
1284 * current_local_identity,
1285 * new_sender_address;
1286
1287 current_local_identity =
1288 smtp_local_identity(s_compare->current_sender_address, s_compare->tblock);
1289
1290 if (!(new_sender_address = deliver_get_sender_address(message_id)))
1291 return 0;
1292
1293 message_local_identity =
1294 smtp_local_identity(new_sender_address, s_compare->tblock);
1295
1296 return Ustrcmp(current_local_identity, message_local_identity) == 0;
1297 }
1298
1299
1300
1301 static uschar
1302 ehlo_response(uschar * buf, uschar checks)
1303 {
1304 size_t bsize = Ustrlen(buf);
1305
1306 #ifdef SUPPORT_TLS
1307 if ( checks & PEER_OFFERED_TLS
1308 && pcre_exec(regex_STARTTLS, NULL, CS buf, bsize, 0, PCRE_EOPT, NULL, 0) < 0)
1309 checks &= ~PEER_OFFERED_TLS;
1310 #endif
1311
1312 if ( checks & PEER_OFFERED_IGNQ
1313 && pcre_exec(regex_IGNOREQUOTA, NULL, CS buf, bsize, 0,
1314 PCRE_EOPT, NULL, 0) < 0)
1315 checks &= ~PEER_OFFERED_IGNQ;
1316
1317 if ( checks & PEER_OFFERED_CHUNKING
1318 && pcre_exec(regex_CHUNKING, NULL, CS buf, bsize, 0, PCRE_EOPT, NULL, 0) < 0)
1319 checks &= ~PEER_OFFERED_CHUNKING;
1320
1321 #ifndef DISABLE_PRDR
1322 if ( checks & PEER_OFFERED_PRDR
1323 && pcre_exec(regex_PRDR, NULL, CS buf, bsize, 0, PCRE_EOPT, NULL, 0) < 0)
1324 checks &= ~PEER_OFFERED_PRDR;
1325 #endif
1326
1327 #ifdef SUPPORT_I18N
1328 if ( checks & PEER_OFFERED_UTF8
1329 && pcre_exec(regex_UTF8, NULL, CS buf, bsize, 0, PCRE_EOPT, NULL, 0) < 0)
1330 checks &= ~PEER_OFFERED_UTF8;
1331 #endif
1332
1333 if ( checks & PEER_OFFERED_DSN
1334 && pcre_exec(regex_DSN, NULL, CS buf, bsize, 0, PCRE_EOPT, NULL, 0) < 0)
1335 checks &= ~PEER_OFFERED_DSN;
1336
1337 if ( checks & PEER_OFFERED_PIPE
1338 && pcre_exec(regex_PIPELINING, NULL, CS buf, bsize, 0,
1339 PCRE_EOPT, NULL, 0) < 0)
1340 checks &= ~PEER_OFFERED_PIPE;
1341
1342 if ( checks & PEER_OFFERED_SIZE
1343 && pcre_exec(regex_SIZE, NULL, CS buf, bsize, 0, PCRE_EOPT, NULL, 0) < 0)
1344 checks &= ~PEER_OFFERED_SIZE;
1345
1346 return checks;
1347 }
1348
1349
1350
1351 /* Callback for emitting a BDAT data chunk header.
1352
1353 If given a nonzero size, first flush any buffered SMTP commands
1354 then emit the command.
1355
1356 Reap previous SMTP command responses if requested, and always reap
1357 the response from a previous BDAT command.
1358
1359 Args:
1360 tctx transport context
1361 chunk_size value for SMTP BDAT command
1362 flags
1363 tc_chunk_last add LAST option to SMTP BDAT command
1364 tc_reap_prev reap response to previous SMTP commands
1365
1366 Returns: OK or ERROR
1367 */
1368
1369 static int
1370 smtp_chunk_cmd_callback(transport_ctx * tctx, unsigned chunk_size,
1371 unsigned flags)
1372 {
1373 smtp_transport_options_block * ob =
1374 (smtp_transport_options_block *)(tctx->tblock->options_block);
1375 smtp_context * sx = tctx->smtp_context;
1376 int cmd_count = 0;
1377 int prev_cmd_count;
1378
1379 /* Write SMTP chunk header command. If not reaping responses, note that
1380 there may be more writes (like, the chunk data) done soon. */
1381
1382 if (chunk_size > 0)
1383 {
1384 if((cmd_count = smtp_write_command(&sx->outblock,
1385 flags & tc_reap_prev ? SCMD_FLUSH : SCMD_MORE,
1386 "BDAT %u%s\r\n", chunk_size, flags & tc_chunk_last ? " LAST" : "")
1387 ) < 0) return ERROR;
1388 if (flags & tc_chunk_last)
1389 data_command = string_copy(big_buffer); /* Save for later error message */
1390 }
1391
1392 prev_cmd_count = cmd_count += sx->cmd_count;
1393
1394 /* Reap responses for any previous, but not one we just emitted */
1395
1396 if (chunk_size > 0)
1397 prev_cmd_count--;
1398 if (sx->pending_BDAT)
1399 prev_cmd_count--;
1400
1401 if (flags & tc_reap_prev && prev_cmd_count > 0)
1402 {
1403 DEBUG(D_transport) debug_printf("look for %d responses"
1404 " for previous pipelined cmds\n", prev_cmd_count);
1405
1406 switch(sync_responses(sx, prev_cmd_count, 0))
1407 {
1408 case 1: /* 2xx (only) => OK */
1409 case 3: sx->good_RCPT = TRUE; /* 2xx & 5xx => OK & progress made */
1410 case 2: sx->completed_addr = TRUE; /* 5xx (only) => progress made */
1411 case 0: break; /* No 2xx or 5xx, but no probs */
1412
1413 case -1: /* Timeout on RCPT */
1414 default: return ERROR; /* I/O error, or any MAIL/DATA error */
1415 }
1416 cmd_count = 1;
1417 if (!sx->pending_BDAT)
1418 pipelining_active = FALSE;
1419 }
1420
1421 /* Reap response for an outstanding BDAT */
1422
1423 if (sx->pending_BDAT)
1424 {
1425 DEBUG(D_transport) debug_printf("look for one response for BDAT\n");
1426
1427 if (!smtp_read_response(&sx->inblock, sx->buffer, sizeof(sx->buffer), '2',
1428 ob->command_timeout))
1429 {
1430 if (errno == 0 && sx->buffer[0] == '4')
1431 {
1432 errno = ERRNO_DATA4XX; /*XXX does this actually get used? */
1433 sx->addrlist->more_errno |=
1434 ((sx->buffer[1] - '0')*10 + sx->buffer[2] - '0') << 8;
1435 }
1436 return ERROR;
1437 }
1438 cmd_count--;
1439 sx->pending_BDAT = FALSE;
1440 pipelining_active = FALSE;
1441 }
1442 else if (chunk_size > 0)
1443 sx->pending_BDAT = TRUE;
1444
1445
1446 sx->cmd_count = cmd_count;
1447 return OK;
1448 }
1449
1450
1451
1452 /*************************************************
1453 * Make connection for given message *
1454 *************************************************/
1455
1456 /*
1457 Arguments:
1458 ctx connection context
1459 suppress_tls if TRUE, don't attempt a TLS connection - this is set for
1460 a second attempt after TLS initialization fails
1461
1462 Returns: OK - the connection was made and the delivery attempted;
1463 fd is set in the conn context, tls_out set up.
1464 DEFER - the connection could not be made, or something failed
1465 while setting up the SMTP session, or there was a
1466 non-message-specific error, such as a timeout.
1467 ERROR - helo_data or add_headers or authenticated_sender is
1468 specified for this transport, and the string failed
1469 to expand
1470 */
1471 int
1472 smtp_setup_conn(smtp_context * sx, BOOL suppress_tls)
1473 {
1474 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
1475 dns_answer tlsa_dnsa;
1476 #endif
1477 BOOL pass_message = FALSE;
1478 uschar * message = NULL;
1479 int yield = OK;
1480 int rc;
1481
1482 sx->ob = (smtp_transport_options_block *) sx->tblock->options_block;
1483
1484 sx->lmtp = strcmpic(sx->ob->protocol, US"lmtp") == 0;
1485 sx->smtps = strcmpic(sx->ob->protocol, US"smtps") == 0;
1486 sx->ok = FALSE;
1487 sx->send_rset = TRUE;
1488 sx->send_quit = TRUE;
1489 sx->setting_up = TRUE;
1490 sx->esmtp = TRUE;
1491 sx->esmtp_sent = FALSE;
1492 #ifdef SUPPORT_I18N
1493 sx->utf8_needed = FALSE;
1494 #endif
1495 sx->dsn_all_lasthop = TRUE;
1496 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
1497 sx->dane = FALSE;
1498 sx->dane_required = verify_check_given_host(&sx->ob->hosts_require_dane, sx->host) == OK;
1499 #endif
1500
1501 if ((sx->max_rcpt = sx->tblock->max_addresses) == 0) sx->max_rcpt = 999999;
1502 sx->peer_offered = 0;
1503 sx->igquotstr = US"";
1504 if (!sx->helo_data) sx->helo_data = sx->ob->helo_data;
1505 #ifdef EXPERIMENTAL_DSN_INFO
1506 sx->smtp_greeting = NULL;
1507 sx->helo_response = NULL;
1508 #endif
1509
1510 smtp_command = US"initial connection";
1511 sx->buffer[0] = '\0';
1512
1513 /* Set up the buffer for reading SMTP response packets. */
1514
1515 sx->inblock.buffer = sx->inbuffer;
1516 sx->inblock.buffersize = sizeof(sx->inbuffer);
1517 sx->inblock.ptr = sx->inbuffer;
1518 sx->inblock.ptrend = sx->inbuffer;
1519
1520 /* Set up the buffer for holding SMTP commands while pipelining */
1521
1522 sx->outblock.buffer = sx->outbuffer;
1523 sx->outblock.buffersize = sizeof(sx->outbuffer);
1524 sx->outblock.ptr = sx->outbuffer;
1525 sx->outblock.cmd_count = 0;
1526 sx->outblock.authenticating = FALSE;
1527
1528 /* Reset the parameters of a TLS session. */
1529
1530 tls_out.bits = 0;
1531 tls_out.cipher = NULL; /* the one we may use for this transport */
1532 tls_out.ourcert = NULL;
1533 tls_out.peercert = NULL;
1534 tls_out.peerdn = NULL;
1535 #if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
1536 tls_out.sni = NULL;
1537 #endif
1538 tls_out.ocsp = OCSP_NOT_REQ;
1539
1540 /* Flip the legacy TLS-related variables over to the outbound set in case
1541 they're used in the context of the transport. Don't bother resetting
1542 afterward (when being used by a transport) as we're in a subprocess.
1543 For verify, unflipped once the callout is dealt with */
1544
1545 tls_modify_variables(&tls_out);
1546
1547 #ifndef SUPPORT_TLS
1548 if (sx->smtps)
1549 {
1550 set_errno_nohost(sx->addrlist, ERRNO_TLSFAILURE, US"TLS support not available",
1551 DEFER, FALSE);
1552 return ERROR;
1553 }
1554 #endif
1555
1556 /* Make a connection to the host if this isn't a continued delivery, and handle
1557 the initial interaction and HELO/EHLO/LHLO. Connect timeout errors are handled
1558 specially so they can be identified for retries. */
1559
1560 if (!continue_hostname)
1561 {
1562 if (sx->verify)
1563 HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", sx->interface, sx->port);
1564
1565 /* Get the actual port the connection will use, into sx->host */
1566
1567 smtp_port_for_connect(sx->host, sx->port);
1568
1569 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
1570 /* Do TLSA lookup for DANE */
1571 {
1572 tls_out.dane_verified = FALSE;
1573 tls_out.tlsa_usage = 0;
1574
1575 if (sx->host->dnssec == DS_YES)
1576 {
1577 if( sx->dane_required
1578 || verify_check_given_host(&sx->ob->hosts_try_dane, sx->host) == OK
1579 )
1580 switch (rc = tlsa_lookup(sx->host, &tlsa_dnsa, sx->dane_required))
1581 {
1582 case OK: sx->dane = TRUE;
1583 sx->ob->tls_tempfail_tryclear = FALSE;
1584 break;
1585 case FAIL_FORCED: break;
1586 default: set_errno_nohost(sx->addrlist, ERRNO_DNSDEFER,
1587 string_sprintf("DANE error: tlsa lookup %s",
1588 rc == DEFER ? "DEFER" : "FAIL"),
1589 rc, FALSE);
1590 return rc;
1591 }
1592 }
1593 else if (sx->dane_required)
1594 {
1595 set_errno_nohost(sx->addrlist, ERRNO_DNSDEFER,
1596 string_sprintf("DANE error: %s lookup not DNSSEC", sx->host->name),
1597 FAIL, FALSE);
1598 return FAIL;
1599 }
1600 }
1601 #endif /*DANE*/
1602
1603 /* Make the TCP connection */
1604
1605 sx->inblock.sock = sx->outblock.sock =
1606 smtp_connect(sx->host, sx->host_af, sx->interface,
1607 sx->ob->connect_timeout, sx->tblock);
1608
1609 if (sx->inblock.sock < 0)
1610 {
1611 uschar * msg = NULL;
1612 if (sx->verify)
1613 {
1614 msg = US strerror(errno);
1615 HDEBUG(D_verify) debug_printf("connect: %s\n", msg);
1616 }
1617 set_errno_nohost(sx->addrlist,
1618 errno == ETIMEDOUT ? ERRNO_CONNECTTIMEOUT : errno,
1619 sx->verify ? string_sprintf("could not connect: %s", msg)
1620 : NULL,
1621 DEFER, FALSE);
1622 sx->send_quit = FALSE;
1623 return DEFER;
1624 }
1625
1626 /* Expand the greeting message while waiting for the initial response. (Makes
1627 sense if helo_data contains ${lookup dnsdb ...} stuff). The expansion is
1628 delayed till here so that $sending_interface and $sending_port are set. */
1629
1630 if (sx->helo_data)
1631 if (!(sx->helo_data = expand_string(sx->helo_data)))
1632 if (sx->verify)
1633 log_write(0, LOG_MAIN|LOG_PANIC,
1634 "<%s>: failed to expand transport's helo_data value for callout: %s",
1635 sx->addrlist->address, expand_string_message);
1636
1637 #ifdef SUPPORT_I18N
1638 if (sx->helo_data)
1639 {
1640 expand_string_message = NULL;
1641 if ((sx->helo_data = string_domain_utf8_to_alabel(sx->helo_data,
1642 &expand_string_message)),
1643 expand_string_message)
1644 if (sx->verify)
1645 log_write(0, LOG_MAIN|LOG_PANIC,
1646 "<%s>: failed to expand transport's helo_data value for callout: %s",
1647 sx->addrlist->address, expand_string_message);
1648 else
1649 sx->helo_data = NULL;
1650 }
1651 #endif
1652
1653 /* The first thing is to wait for an initial OK response. The dreaded "goto"
1654 is nevertheless a reasonably clean way of programming this kind of logic,
1655 where you want to escape on any error. */
1656
1657 if (!sx->smtps)
1658 {
1659 BOOL good_response;
1660
1661 #ifdef TCP_QUICKACK
1662 (void) setsockopt(sx->inblock.sock, IPPROTO_TCP, TCP_QUICKACK, US &off, sizeof(off));
1663 #endif
1664 good_response = smtp_read_response(&sx->inblock, sx->buffer, sizeof(sx->buffer),
1665 '2', sx->ob->command_timeout);
1666 #ifdef EXPERIMENTAL_DSN_INFO
1667 sx->smtp_greeting = string_copy(sx->buffer);
1668 #endif
1669 if (!good_response) goto RESPONSE_FAILED;
1670
1671 #ifndef DISABLE_EVENT
1672 {
1673 uschar * s;
1674 lookup_dnssec_authenticated = sx->host->dnssec==DS_YES ? US"yes"
1675 : sx->host->dnssec==DS_NO ? US"no" : NULL;
1676 s = event_raise(sx->tblock->event_action, US"smtp:connect", sx->buffer);
1677 if (s)
1678 {
1679 set_errno_nohost(sx->addrlist, ERRNO_EXPANDFAIL,
1680 string_sprintf("deferred by smtp:connect event expansion: %s", s),
1681 DEFER, FALSE);
1682 yield = DEFER;
1683 goto SEND_QUIT;
1684 }
1685 }
1686 #endif
1687
1688 /* Now check if the helo_data expansion went well, and sign off cleanly if
1689 it didn't. */
1690
1691 if (!sx->helo_data)
1692 {
1693 message = string_sprintf("failed to expand helo_data: %s",
1694 expand_string_message);
1695 set_errno_nohost(sx->addrlist, ERRNO_EXPANDFAIL, message, DEFER, FALSE);
1696 yield = DEFER;
1697 goto SEND_QUIT;
1698 }
1699 }
1700
1701 /** Debugging without sending a message
1702 sx->addrlist->transport_return = DEFER;
1703 goto SEND_QUIT;
1704 **/
1705
1706 /* Errors that occur after this point follow an SMTP command, which is
1707 left in big_buffer by smtp_write_command() for use in error messages. */
1708
1709 smtp_command = big_buffer;
1710
1711 /* Tell the remote who we are...
1712
1713 February 1998: A convention has evolved that ESMTP-speaking MTAs include the
1714 string "ESMTP" in their greeting lines, so make Exim send EHLO if the
1715 greeting is of this form. The assumption was that the far end supports it
1716 properly... but experience shows that there are some that give 5xx responses,
1717 even though the banner includes "ESMTP" (there's a bloody-minded one that
1718 says "ESMTP not spoken here"). Cope with that case.
1719
1720 September 2000: Time has passed, and it seems reasonable now to always send
1721 EHLO at the start. It is also convenient to make the change while installing
1722 the TLS stuff.
1723
1724 July 2003: Joachim Wieland met a broken server that advertises "PIPELINING"
1725 but times out after sending MAIL FROM, RCPT TO and DATA all together. There
1726 would be no way to send out the mails, so there is now a host list
1727 "hosts_avoid_esmtp" that disables ESMTP for special hosts and solves the
1728 PIPELINING problem as well. Maybe it can also be useful to cure other
1729 problems with broken servers.
1730
1731 Exim originally sent "Helo" at this point and ran for nearly a year that way.
1732 Then somebody tried it with a Microsoft mailer... It seems that all other
1733 mailers use upper case for some reason (the RFC is quite clear about case
1734 independence) so, for peace of mind, I gave in. */
1735
1736 sx->esmtp = verify_check_given_host(&sx->ob->hosts_avoid_esmtp, sx->host) != OK;
1737
1738 /* Alas; be careful, since this goto is not an error-out, so conceivably
1739 we might set data between here and the target which we assume to exist
1740 and be usable. I can see this coming back to bite us. */
1741 #ifdef SUPPORT_TLS
1742 if (sx->smtps)
1743 {
1744 smtp_peer_options |= PEER_OFFERED_TLS;
1745 suppress_tls = FALSE;
1746 sx->ob->tls_tempfail_tryclear = FALSE;
1747 smtp_command = US"SSL-on-connect";
1748 goto TLS_NEGOTIATE;
1749 }
1750 #endif
1751
1752 if (sx->esmtp)
1753 {
1754 if (smtp_write_command(&sx->outblock, SCMD_FLUSH, "%s %s\r\n",
1755 sx->lmtp ? "LHLO" : "EHLO", sx->helo_data) < 0)
1756 goto SEND_FAILED;
1757 sx->esmtp_sent = TRUE;
1758 if (!smtp_read_response(&sx->inblock, sx->buffer, sizeof(sx->buffer), '2',
1759 sx->ob->command_timeout))
1760 {
1761 if (errno != 0 || sx->buffer[0] == 0 || sx->lmtp)
1762 {
1763 #ifdef EXPERIMENTAL_DSN_INFO
1764 sx->helo_response = string_copy(sx->buffer);
1765 #endif
1766 goto RESPONSE_FAILED;
1767 }
1768 sx->esmtp = FALSE;
1769 }
1770 #ifdef EXPERIMENTAL_DSN_INFO
1771 sx->helo_response = string_copy(sx->buffer);
1772 #endif
1773 }
1774 else
1775 DEBUG(D_transport)
1776 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
1777
1778 if (!sx->esmtp)
1779 {
1780 BOOL good_response;
1781 int n = sizeof(sx->buffer);
1782 uschar * rsp = sx->buffer;
1783
1784 if (sx->esmtp_sent && (n = Ustrlen(sx->buffer)) < sizeof(sx->buffer)/2)
1785 { rsp = sx->buffer + n + 1; n = sizeof(sx->buffer) - n; }
1786
1787 if (smtp_write_command(&sx->outblock, SCMD_FLUSH, "HELO %s\r\n", sx->helo_data) < 0)
1788 goto SEND_FAILED;
1789 good_response = smtp_read_response(&sx->inblock, rsp, n,
1790 '2', sx->ob->command_timeout);
1791 #ifdef EXPERIMENTAL_DSN_INFO
1792 sx->helo_response = string_copy(rsp);
1793 #endif
1794 if (!good_response)
1795 {
1796 /* Handle special logging for a closed connection after HELO
1797 when had previously sent EHLO */
1798
1799 if (rsp != sx->buffer && rsp[0] == 0 && (errno == 0 || errno == ECONNRESET))
1800 {
1801 errno = ERRNO_SMTPCLOSED;
1802 goto EHLOHELO_FAILED;
1803 }
1804 Ustrncpy(sx->buffer, rsp, sizeof(sx->buffer)/2);
1805 goto RESPONSE_FAILED;
1806 }
1807 }
1808
1809 sx->peer_offered = smtp_peer_options = 0;
1810
1811 if (sx->esmtp || sx->lmtp)
1812 {
1813 sx->peer_offered = ehlo_response(sx->buffer,
1814 PEER_OFFERED_TLS /* others checked later */
1815 );
1816
1817 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
1818
1819 #ifdef SUPPORT_TLS
1820 smtp_peer_options |= sx->peer_offered & PEER_OFFERED_TLS;
1821 #endif
1822 }
1823 }
1824
1825 /* For continuing deliveries down the same channel, having re-exec'd the socket
1826 is the standard input; for a socket held open from verify it is recorded
1827 in the cutthrough context block. Either way we don't need to redo EHLO here
1828 (but may need to do so for TLS - see below).
1829 Set up the pointer to where subsequent commands will be left, for
1830 error messages. Note that smtp_peer_options will have been
1831 set from the command line if they were set in the process that passed the
1832 connection on. */
1833
1834 /*XXX continue case needs to propagate DSN_INFO, prob. in deliver.c
1835 as the continue goes via transport_pass_socket() and doublefork and exec.
1836 It does not wait. Unclear how we keep separate host's responses
1837 separate - we could match up by host ip+port as a bodge. */
1838
1839 else
1840 {
1841 if (cutthrough.fd >= 0 && cutthrough.callout_hold_only)
1842 {
1843 sx->inblock.sock = sx->outblock.sock = cutthrough.fd;
1844 sx->host->port = sx->port = cutthrough.host.port;
1845 }
1846 else
1847 {
1848 sx->inblock.sock = sx->outblock.sock = 0; /* stdin */
1849 smtp_port_for_connect(sx->host, sx->port); /* Record the port that was used */
1850 }
1851 smtp_command = big_buffer;
1852 sx->helo_data = NULL; /* ensure we re-expand ob->helo_data */
1853
1854 /* For a continued connection with TLS being proxied for us, or a
1855 held-open verify connection with TLS, nothing more to do. */
1856
1857 if ( continue_proxy_cipher
1858 || (cutthrough.fd >= 0 && cutthrough.callout_hold_only && cutthrough.is_tls)
1859 )
1860 {
1861 sx->peer_offered = smtp_peer_options;
1862 pipelining_active = !!(smtp_peer_options & PEER_OFFERED_PIPE);
1863 HDEBUG(D_transport) debug_printf("continued connection, %s TLS\n",
1864 continue_proxy_cipher ? "proxied" : "verify conn with");
1865 return OK;
1866 }
1867 HDEBUG(D_transport) debug_printf("continued connection, no TLS\n");
1868 }
1869
1870 /* If TLS is available on this connection, whether continued or not, attempt to
1871 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
1872 send another EHLO - the server may give a different answer in secure mode. We
1873 use a separate buffer for reading the response to STARTTLS so that if it is
1874 negative, the original EHLO data is available for subsequent analysis, should
1875 the client not be required to use TLS. If the response is bad, copy the buffer
1876 for error analysis. */
1877
1878 #ifdef SUPPORT_TLS
1879 if ( smtp_peer_options & PEER_OFFERED_TLS
1880 && !suppress_tls
1881 && verify_check_given_host(&sx->ob->hosts_avoid_tls, sx->host) != OK
1882 && ( !sx->verify
1883 || verify_check_given_host(&sx->ob->hosts_verify_avoid_tls, sx->host) != OK
1884 ) )
1885 {
1886 uschar buffer2[4096];
1887 if (smtp_write_command(&sx->outblock, SCMD_FLUSH, "STARTTLS\r\n") < 0)
1888 goto SEND_FAILED;
1889
1890 /* If there is an I/O error, transmission of this message is deferred. If
1891 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
1892 false, we also defer. However, if there is a temporary rejection of STARTTLS
1893 and tls_tempfail_tryclear is true, or if there is an outright rejection of
1894 STARTTLS, we carry on. This means we will try to send the message in clear,
1895 unless the host is in hosts_require_tls (tested below). */
1896
1897 if (!smtp_read_response(&sx->inblock, buffer2, sizeof(buffer2), '2',
1898 sx->ob->command_timeout))
1899 {
1900 if ( errno != 0
1901 || buffer2[0] == 0
1902 || (buffer2[0] == '4' && !sx->ob->tls_tempfail_tryclear)
1903 )
1904 {
1905 Ustrncpy(sx->buffer, buffer2, sizeof(sx->buffer));
1906 sx->buffer[sizeof(sx->buffer)-1] = '\0';
1907 goto RESPONSE_FAILED;
1908 }
1909 }
1910
1911 /* STARTTLS accepted: try to negotiate a TLS session. */
1912
1913 else
1914 TLS_NEGOTIATE:
1915 {
1916 address_item * addr;
1917 uschar * errstr;
1918 int rc = tls_client_start(sx->inblock.sock, sx->host, sx->addrlist, sx->tblock,
1919 # ifdef EXPERIMENTAL_DANE
1920 sx->dane ? &tlsa_dnsa : NULL,
1921 # endif
1922 &errstr);
1923
1924 /* TLS negotiation failed; give an error. From outside, this function may
1925 be called again to try in clear on a new connection, if the options permit
1926 it for this host. */
1927
1928 if (rc != OK)
1929 {
1930 # ifdef EXPERIMENTAL_DANE
1931 if (sx->dane) log_write(0, LOG_MAIN,
1932 "DANE attempt failed; TLS connection to %s [%s]: %s",
1933 sx->host->name, sx->host->address, errstr);
1934 # endif
1935
1936 errno = ERRNO_TLSFAILURE;
1937 message = string_sprintf("TLS session: %s", errstr);
1938 sx->send_quit = FALSE;
1939 goto TLS_FAILED;
1940 }
1941
1942 /* TLS session is set up */
1943
1944 smtp_peer_options_wrap = smtp_peer_options;
1945 for (addr = sx->addrlist; addr; addr = addr->next)
1946 if (addr->transport_return == PENDING_DEFER)
1947 {
1948 addr->cipher = tls_out.cipher;
1949 addr->ourcert = tls_out.ourcert;
1950 addr->peercert = tls_out.peercert;
1951 addr->peerdn = tls_out.peerdn;
1952 addr->ocsp = tls_out.ocsp;
1953 }
1954 }
1955 }
1956
1957 /* if smtps, we'll have smtp_command set to something else; always safe to
1958 reset it here. */
1959 smtp_command = big_buffer;
1960
1961 /* If we started TLS, redo the EHLO/LHLO exchange over the secure channel. If
1962 helo_data is null, we are dealing with a connection that was passed from
1963 another process, and so we won't have expanded helo_data above. We have to
1964 expand it here. $sending_ip_address and $sending_port are set up right at the
1965 start of the Exim process (in exim.c). */
1966
1967 if (tls_out.active >= 0)
1968 {
1969 char *greeting_cmd;
1970 BOOL good_response;
1971
1972 if (!sx->helo_data && !(sx->helo_data = expand_string(sx->ob->helo_data)))
1973 {
1974 uschar *message = string_sprintf("failed to expand helo_data: %s",
1975 expand_string_message);
1976 set_errno_nohost(sx->addrlist, ERRNO_EXPANDFAIL, message, DEFER, FALSE);
1977 yield = DEFER;
1978 goto SEND_QUIT;
1979 }
1980
1981 /* For SMTPS we need to wait for the initial OK response. */
1982 if (sx->smtps)
1983 {
1984 good_response = smtp_read_response(&sx->inblock, sx->buffer, sizeof(sx->buffer),
1985 '2', sx->ob->command_timeout);
1986 #ifdef EXPERIMENTAL_DSN_INFO
1987 sx->smtp_greeting = string_copy(sx->buffer);
1988 #endif
1989 if (!good_response) goto RESPONSE_FAILED;
1990 }
1991
1992 if (sx->esmtp)
1993 greeting_cmd = "EHLO";
1994 else
1995 {
1996 greeting_cmd = "HELO";
1997 DEBUG(D_transport)
1998 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
1999 }
2000
2001 if (smtp_write_command(&sx->outblock, SCMD_FLUSH, "%s %s\r\n",
2002 sx->lmtp ? "LHLO" : greeting_cmd, sx->helo_data) < 0)
2003 goto SEND_FAILED;
2004 good_response = smtp_read_response(&sx->inblock, sx->buffer, sizeof(sx->buffer),
2005 '2', sx->ob->command_timeout);
2006 #ifdef EXPERIMENTAL_DSN_INFO
2007 sx->helo_response = string_copy(sx->buffer);
2008 #endif
2009 if (!good_response) goto RESPONSE_FAILED;
2010 smtp_peer_options = 0;
2011 }
2012
2013 /* If the host is required to use a secure channel, ensure that we
2014 have one. */
2015
2016 else if ( sx->smtps
2017 # ifdef EXPERIMENTAL_DANE
2018 || sx->dane
2019 # endif
2020 || verify_check_given_host(&sx->ob->hosts_require_tls, sx->host) == OK
2021 )
2022 {
2023 errno = ERRNO_TLSREQUIRED;
2024 message = string_sprintf("a TLS session is required, but %s",
2025 smtp_peer_options & PEER_OFFERED_TLS
2026 ? "an attempt to start TLS failed" : "the server did not offer TLS support");
2027 goto TLS_FAILED;
2028 }
2029 #endif /*SUPPORT_TLS*/
2030
2031 /* If TLS is active, we have just started it up and re-done the EHLO command,
2032 so its response needs to be analyzed. If TLS is not active and this is a
2033 continued session down a previously-used socket, we haven't just done EHLO, so
2034 we skip this. */
2035
2036 if (continue_hostname == NULL
2037 #ifdef SUPPORT_TLS
2038 || tls_out.active >= 0
2039 #endif
2040 )
2041 {
2042 if (sx->esmtp || sx->lmtp)
2043 {
2044 sx->peer_offered = ehlo_response(sx->buffer,
2045 0 /* no TLS */
2046 | (sx->lmtp && sx->ob->lmtp_ignore_quota ? PEER_OFFERED_IGNQ : 0)
2047 | PEER_OFFERED_CHUNKING
2048 | PEER_OFFERED_PRDR
2049 #ifdef SUPPORT_I18N
2050 | (sx->addrlist->prop.utf8_msg ? PEER_OFFERED_UTF8 : 0)
2051 /*XXX if we hand peercaps on to continued-conn processes,
2052 must not depend on this addr */
2053 #endif
2054 | PEER_OFFERED_DSN
2055 | PEER_OFFERED_PIPE
2056 | (sx->ob->size_addition >= 0 ? PEER_OFFERED_SIZE : 0)
2057 );
2058
2059 /* Set for IGNOREQUOTA if the response to LHLO specifies support and the
2060 lmtp_ignore_quota option was set. */
2061
2062 sx->igquotstr = sx->peer_offered & PEER_OFFERED_IGNQ ? US" IGNOREQUOTA" : US"";
2063
2064 /* If the response to EHLO specified support for the SIZE parameter, note
2065 this, provided size_addition is non-negative. */
2066
2067 smtp_peer_options |= sx->peer_offered & PEER_OFFERED_SIZE;
2068
2069 /* Note whether the server supports PIPELINING. If hosts_avoid_esmtp matched
2070 the current host, esmtp will be false, so PIPELINING can never be used. If
2071 the current host matches hosts_avoid_pipelining, don't do it. */
2072
2073 if ( sx->peer_offered & PEER_OFFERED_PIPE
2074 && verify_check_given_host(&sx->ob->hosts_avoid_pipelining, sx->host) != OK)
2075 smtp_peer_options |= PEER_OFFERED_PIPE;
2076
2077 DEBUG(D_transport) debug_printf("%susing PIPELINING\n",
2078 smtp_peer_options & PEER_OFFERED_PIPE ? "" : "not ");
2079
2080 if ( sx->peer_offered & PEER_OFFERED_CHUNKING
2081 && verify_check_given_host(&sx->ob->hosts_try_chunking, sx->host) != OK)
2082 sx->peer_offered &= ~PEER_OFFERED_CHUNKING;
2083
2084 if (sx->peer_offered & PEER_OFFERED_CHUNKING)
2085 {DEBUG(D_transport) debug_printf("CHUNKING usable\n");}
2086
2087 #ifndef DISABLE_PRDR
2088 if ( sx->peer_offered & PEER_OFFERED_PRDR
2089 && verify_check_given_host(&sx->ob->hosts_try_prdr, sx->host) != OK)
2090 sx->peer_offered &= ~PEER_OFFERED_PRDR;
2091
2092 if (sx->peer_offered & PEER_OFFERED_PRDR)
2093 {DEBUG(D_transport) debug_printf("PRDR usable\n");}
2094 #endif
2095
2096 /* Note if the server supports DSN */
2097 smtp_peer_options |= sx->peer_offered & PEER_OFFERED_DSN;
2098 DEBUG(D_transport) debug_printf("%susing DSN\n",
2099 sx->peer_offered & PEER_OFFERED_DSN ? "" : "not ");
2100
2101 /* Note if the response to EHLO specifies support for the AUTH extension.
2102 If it has, check that this host is one we want to authenticate to, and do
2103 the business. The host name and address must be available when the
2104 authenticator's client driver is running. */
2105
2106 switch (yield = smtp_auth(sx->buffer, sizeof(sx->buffer), sx->addrlist, sx->host,
2107 sx->ob, sx->esmtp, &sx->inblock, &sx->outblock))
2108 {
2109 default: goto SEND_QUIT;
2110 case OK: break;
2111 case FAIL_SEND: goto SEND_FAILED;
2112 case FAIL: goto RESPONSE_FAILED;
2113 }
2114 }
2115 }
2116 pipelining_active = !!(smtp_peer_options & PEER_OFFERED_PIPE);
2117
2118 /* The setting up of the SMTP call is now complete. Any subsequent errors are
2119 message-specific. */
2120
2121 sx->setting_up = FALSE;
2122
2123 #ifdef SUPPORT_I18N
2124 if (sx->addrlist->prop.utf8_msg)
2125 {
2126 sx->utf8_needed = !sx->addrlist->prop.utf8_downcvt
2127 && !sx->addrlist->prop.utf8_downcvt_maybe;
2128 DEBUG(D_transport) if (!sx->utf8_needed)
2129 debug_printf("utf8: %s downconvert\n",
2130 sx->addrlist->prop.utf8_downcvt ? "mandatory" : "optional");
2131 }
2132
2133 /* If this is an international message we need the host to speak SMTPUTF8 */
2134 if (sx->utf8_needed && !(sx->peer_offered & PEER_OFFERED_UTF8))
2135 {
2136 errno = ERRNO_UTF8_FWD;
2137 goto RESPONSE_FAILED;
2138 }
2139 #endif
2140
2141 return OK;
2142
2143
2144 {
2145 int code;
2146
2147 RESPONSE_FAILED:
2148 message = NULL;
2149 sx->send_quit = check_response(sx->host, &errno, sx->addrlist->more_errno,
2150 sx->buffer, &code, &message, &pass_message);
2151 goto FAILED;
2152
2153 SEND_FAILED:
2154 code = '4';
2155 message = US string_sprintf("send() to %s [%s] failed: %s",
2156 sx->host->name, sx->host->address, strerror(errno));
2157 sx->send_quit = FALSE;
2158 goto FAILED;
2159
2160 /* This label is jumped to directly when a TLS negotiation has failed,
2161 or was not done for a host for which it is required. Values will be set
2162 in message and errno, and setting_up will always be true. Treat as
2163 a temporary error. */
2164
2165 EHLOHELO_FAILED:
2166 code = '4';
2167 message = string_sprintf("Remote host closed connection in response to %s"
2168 " (EHLO response was: %s)", smtp_command, sx->buffer);
2169 sx->send_quit = FALSE;
2170 goto FAILED;
2171
2172 #ifdef SUPPORT_TLS
2173 TLS_FAILED:
2174 code = '4';
2175 goto FAILED;
2176 #endif
2177
2178 /* The failure happened while setting up the call; see if the failure was
2179 a 5xx response (this will either be on connection, or following HELO - a 5xx
2180 after EHLO causes it to try HELO). If so, and there are no more hosts to try,
2181 fail all addresses, as this host is never going to accept them. For other
2182 errors during setting up (timeouts or whatever), defer all addresses, and
2183 yield DEFER, so that the host is not tried again for a while.
2184
2185 XXX This peeking for another host feels like a layering violation. We want
2186 to note the host as unusable, but down here we shouldn't know if this was
2187 the last host to try for the addr(list). Perhaps the upper layer should be
2188 the one to do set_errno() ? The problem is that currently the addr is where
2189 errno etc. are stashed, but until we run out of hosts to try the errors are
2190 host-specific. Maybe we should enhance the host_item definition? */
2191
2192 FAILED:
2193 sx->ok = FALSE; /* For when reached by GOTO */
2194 set_errno(sx->addrlist, errno, message,
2195 sx->host->next
2196 ? DEFER
2197 : code == '5'
2198 #ifdef SUPPORT_I18N
2199 || errno == ERRNO_UTF8_FWD
2200 #endif
2201 ? FAIL : DEFER,
2202 pass_message, sx->host
2203 #ifdef EXPERIMENTAL_DSN_INFO
2204 , sx->smtp_greeting, sx->helo_response
2205 #endif
2206 );
2207 yield = DEFER;
2208 }
2209
2210
2211 SEND_QUIT:
2212
2213 if (sx->send_quit)
2214 (void)smtp_write_command(&sx->outblock, SCMD_FLUSH, "QUIT\r\n");
2215
2216 #ifdef SUPPORT_TLS
2217 tls_close(FALSE, TRUE);
2218 #endif
2219
2220 /* Close the socket, and return the appropriate value, first setting
2221 works because the NULL setting is passed back to the calling process, and
2222 remote_max_parallel is forced to 1 when delivering over an existing connection,
2223 */
2224
2225 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
2226 if (sx->send_quit)
2227 {
2228 shutdown(sx->outblock.sock, SHUT_WR);
2229 if (fcntl(sx->inblock.sock, F_SETFL, O_NONBLOCK) == 0)
2230 for (rc = 16; read(sx->inblock.sock, sx->inbuffer, sizeof(sx->inbuffer)) > 0 && rc > 0;)
2231 rc--; /* drain socket */
2232 sx->send_quit = FALSE;
2233 }
2234 (void)close(sx->inblock.sock);
2235 sx->inblock.sock = sx->outblock.sock = -1;
2236
2237 #ifndef DISABLE_EVENT
2238 (void) event_raise(sx->tblock->event_action, US"tcp:close", NULL);
2239 #endif
2240
2241 continue_transport = NULL;
2242 continue_hostname = NULL;
2243 return yield;
2244 }
2245
2246
2247
2248
2249 /* Create the string of options that will be appended to the MAIL FROM:
2250 in the connection context buffer */
2251
2252 static int
2253 build_mailcmd_options(smtp_context * sx, address_item * addrlist)
2254 {
2255 uschar * p = sx->buffer;
2256 address_item * addr;
2257 int address_count;
2258
2259 *p = 0;
2260
2261 /* If we know the receiving MTA supports the SIZE qualification,
2262 send it, adding something to the message size to allow for imprecision
2263 and things that get added en route. Exim keeps the number of lines
2264 in a message, so we can give an accurate value for the original message, but we
2265 need some additional to handle added headers. (Double "." characters don't get
2266 included in the count.) */
2267
2268 if (sx->peer_offered & PEER_OFFERED_SIZE)
2269 {
2270 /*XXX problem here under spool_files_wireformat?
2271 Or just forget about lines? Or inflate by a fixed proportion? */
2272
2273 sprintf(CS p, " SIZE=%d", message_size+message_linecount+sx->ob->size_addition);
2274 while (*p) p++;
2275 }
2276
2277 #ifndef DISABLE_PRDR
2278 /* If it supports Per-Recipient Data Reponses, and we have omre than one recipient,
2279 request that */
2280
2281 sx->prdr_active = FALSE;
2282 if (sx->peer_offered & PEER_OFFERED_PRDR)
2283 for (addr = addrlist; addr; addr = addr->next)
2284 if (addr->transport_return == PENDING_DEFER)
2285 {
2286 for (addr = addr->next; addr; addr = addr->next)
2287 if (addr->transport_return == PENDING_DEFER)
2288 { /* at least two recipients to send */
2289 sx->prdr_active = TRUE;
2290 sprintf(CS p, " PRDR"); p += 5;
2291 break;
2292 }
2293 break;
2294 }
2295 #endif
2296
2297 #ifdef SUPPORT_I18N
2298 /* If it supports internationalised messages, and this meesage need that,
2299 request it */
2300
2301 if ( sx->peer_offered & PEER_OFFERED_UTF8
2302 && addrlist->prop.utf8_msg
2303 && !addrlist->prop.utf8_downcvt
2304 )
2305 Ustrcpy(p, " SMTPUTF8"), p += 9;
2306 #endif
2307
2308 /* check if all addresses have DSN-lasthop flag; do not send RET and ENVID if so */
2309 for (sx->dsn_all_lasthop = TRUE, addr = addrlist, address_count = 0;
2310 addr && address_count < sx->max_rcpt;
2311 addr = addr->next) if (addr->transport_return == PENDING_DEFER)
2312 {
2313 address_count++;
2314 if (!(addr->dsn_flags & rf_dsnlasthop))
2315 {
2316 sx->dsn_all_lasthop = FALSE;
2317 break;
2318 }
2319 }
2320
2321 /* Add any DSN flags to the mail command */
2322
2323 if (sx->peer_offered & PEER_OFFERED_DSN && !sx->dsn_all_lasthop)
2324 {
2325 if (dsn_ret == dsn_ret_hdrs)
2326 { Ustrcpy(p, " RET=HDRS"); p += 9; }
2327 else if (dsn_ret == dsn_ret_full)
2328 { Ustrcpy(p, " RET=FULL"); p += 9; }
2329
2330 if (dsn_envid)
2331 {
2332 string_format(p, sizeof(sx->buffer) - (p-sx->buffer), " ENVID=%s", dsn_envid);
2333 while (*p) p++;
2334 }
2335 }
2336
2337 /* If an authenticated_sender override has been specified for this transport
2338 instance, expand it. If the expansion is forced to fail, and there was already
2339 an authenticated_sender for this message, the original value will be used.
2340 Other expansion failures are serious. An empty result is ignored, but there is
2341 otherwise no check - this feature is expected to be used with LMTP and other
2342 cases where non-standard addresses (e.g. without domains) might be required. */
2343
2344 if (smtp_mail_auth_str(p, sizeof(sx->buffer) - (p-sx->buffer), addrlist, sx->ob))
2345 return ERROR;
2346
2347 return OK;
2348 }
2349
2350
2351 static void
2352 build_rcptcmd_options(smtp_context * sx, const address_item * addr)
2353 {
2354 uschar * p = sx->buffer;
2355 *p = 0;
2356
2357 /* Add any DSN flags to the rcpt command */
2358
2359 if (sx->peer_offered & PEER_OFFERED_DSN && !(addr->dsn_flags & rf_dsnlasthop))
2360 {
2361 if (addr->dsn_flags & rf_dsnflags)
2362 {
2363 int i;
2364 BOOL first = TRUE;
2365
2366 Ustrcpy(p, " NOTIFY=");
2367 while (*p) p++;
2368 for (i = 0; i < nelem(rf_list); i++) if (addr->dsn_flags & rf_list[i])
2369 {
2370 if (!first) *p++ = ',';
2371 first = FALSE;
2372 Ustrcpy(p, rf_names[i]);
2373 while (*p) p++;
2374 }
2375 }
2376
2377 if (addr->dsn_orcpt)
2378 {
2379 string_format(p, sizeof(sx->buffer) - (p-sx->buffer), " ORCPT=%s",
2380 addr->dsn_orcpt);
2381 while (*p) p++;
2382 }
2383 }
2384 }
2385
2386
2387
2388 /*
2389 Return:
2390 0 good, rcpt results in addr->transport_return (PENDING_OK, DEFER, FAIL)
2391 -1 MAIL response error
2392 -2 any non-MAIL read i/o error
2393 -3 non-MAIL response timeout
2394 -4 internal error; channel still usable
2395 -5 transmit failed
2396 */
2397
2398 int
2399 smtp_write_mail_and_rcpt_cmds(smtp_context * sx, int * yield)
2400 {
2401 address_item * addr;
2402 int address_count;
2403 int rc;
2404
2405 if (build_mailcmd_options(sx, sx->first_addr) != OK)
2406 {
2407 *yield = ERROR;
2408 return -4;
2409 }
2410
2411 /* From here until we send the DATA command, we can make use of PIPELINING
2412 if the server host supports it. The code has to be able to check the responses
2413 at any point, for when the buffer fills up, so we write it totally generally.
2414 When PIPELINING is off, each command written reports that it has flushed the
2415 buffer. */
2416
2417 sx->pending_MAIL = TRUE; /* The block starts with MAIL */
2418
2419 {
2420 uschar * s = sx->from_addr;
2421 #ifdef SUPPORT_I18N
2422 uschar * errstr = NULL;
2423
2424 /* If we must downconvert, do the from-address here. Remember we had to
2425 for the to-addresses (done below), and also (ugly) for re-doing when building
2426 the delivery log line. */
2427
2428 if ( sx->addrlist->prop.utf8_msg
2429 && (sx->addrlist->prop.utf8_downcvt || !(sx->peer_offered & PEER_OFFERED_UTF8))
2430 )
2431 {
2432 if (s = string_address_utf8_to_alabel(s, &errstr), errstr)
2433 {
2434 set_errno_nohost(sx->addrlist, ERRNO_EXPANDFAIL, errstr, DEFER, FALSE);
2435 *yield = ERROR;
2436 return -4;
2437 }
2438 setflag(sx->addrlist, af_utf8_downcvt);
2439 }
2440 #endif
2441
2442 rc = smtp_write_command(&sx->outblock, pipelining_active ? SCMD_BUFFER : SCMD_FLUSH,
2443 "MAIL FROM:<%s>%s\r\n", s, sx->buffer);
2444 }
2445
2446 mail_command = string_copy(big_buffer); /* Save for later error message */
2447
2448 switch(rc)
2449 {
2450 case -1: /* Transmission error */
2451 return -5;
2452
2453 case +1: /* Cmd was sent */
2454 if (!smtp_read_response(&sx->inblock, sx->buffer, sizeof(sx->buffer), '2',
2455 sx->ob->command_timeout))
2456 {
2457 if (errno == 0 && sx->buffer[0] == '4')
2458 {
2459 errno = ERRNO_MAIL4XX;
2460 sx->addrlist->more_errno |= ((sx->buffer[1] - '0')*10 + sx->buffer[2] - '0') << 8;
2461 }
2462 return -1;
2463 }
2464 sx->pending_MAIL = FALSE;
2465 break;
2466
2467 /* otherwise zero: command queued for pipeline */
2468 }
2469
2470 /* Pass over all the relevant recipient addresses for this host, which are the
2471 ones that have status PENDING_DEFER. If we are using PIPELINING, we can send
2472 several before we have to read the responses for those seen so far. This
2473 checking is done by a subroutine because it also needs to be done at the end.
2474 Send only up to max_rcpt addresses at a time, leaving next_addr pointing to
2475 the next one if not all are sent.
2476
2477 In the MUA wrapper situation, we want to flush the PIPELINING buffer for the
2478 last address because we want to abort if any recipients have any kind of
2479 problem, temporary or permanent. We know that all recipient addresses will have
2480 the PENDING_DEFER status, because only one attempt is ever made, and we know
2481 that max_rcpt will be large, so all addresses will be done at once.
2482
2483 For verify we flush the pipeline after any (the only) rcpt address. */
2484
2485 for (addr = sx->first_addr, address_count = 0;
2486 addr && address_count < sx->max_rcpt;
2487 addr = addr->next) if (addr->transport_return == PENDING_DEFER)
2488 {
2489 int count;
2490 BOOL no_flush;
2491 uschar * rcpt_addr;
2492
2493 addr->dsn_aware = sx->peer_offered & PEER_OFFERED_DSN
2494 ? dsn_support_yes : dsn_support_no;
2495
2496 address_count++;
2497 no_flush = pipelining_active && !sx->verify
2498 && (!mua_wrapper || addr->next && address_count < sx->max_rcpt);
2499
2500 build_rcptcmd_options(sx, addr);
2501
2502 /* Now send the RCPT command, and process outstanding responses when
2503 necessary. After a timeout on RCPT, we just end the function, leaving the
2504 yield as OK, because this error can often mean that there is a problem with
2505 just one address, so we don't want to delay the host. */
2506
2507 rcpt_addr = transport_rcpt_address(addr, sx->tblock->rcpt_include_affixes);
2508
2509 #ifdef SUPPORT_I18N
2510 if ( testflag(sx->addrlist, af_utf8_downcvt)
2511 && !(rcpt_addr = string_address_utf8_to_alabel(rcpt_addr, NULL))
2512 )
2513 {
2514 /*XXX could we use a per-address errstr here? Not fail the whole send? */
2515 errno = ERRNO_EXPANDFAIL;
2516 return -5; /*XXX too harsh? */
2517 }
2518 #endif
2519
2520 count = smtp_write_command(&sx->outblock, no_flush ? SCMD_BUFFER : SCMD_FLUSH,
2521 "RCPT TO:<%s>%s%s\r\n", rcpt_addr, sx->igquotstr, sx->buffer);
2522
2523 if (count < 0) return -5;
2524 if (count > 0)
2525 {
2526 switch(sync_responses(sx, count, 0))
2527 {
2528 case 3: sx->ok = TRUE; /* 2xx & 5xx => OK & progress made */
2529 case 2: sx->completed_addr = TRUE; /* 5xx (only) => progress made */
2530 break;
2531
2532 case 1: sx->ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
2533 if (!sx->lmtp) /* can't tell about progress yet */
2534 sx->completed_addr = TRUE;
2535 case 0: /* No 2xx or 5xx, but no probs */
2536 break;
2537
2538 case -1: return -3; /* Timeout on RCPT */
2539 case -2: return -2; /* non-MAIL read i/o error */
2540 default: return -1; /* any MAIL error */
2541 }
2542 sx->pending_MAIL = FALSE; /* Dealt with MAIL */
2543 }
2544 } /* Loop for next address */
2545
2546 sx->next_addr = addr;
2547 return 0;
2548 }
2549
2550
2551 #ifdef SUPPORT_TLS
2552 /*****************************************************
2553 * Proxy TLS connection for another transport process *
2554 ******************************************************/
2555 /*
2556 Use the given buffer as a staging area, and select on both the given fd
2557 and the TLS'd client-fd for data to read (per the coding in ip_recv() and
2558 fd_ready() this is legitimate). Do blocking full-size writes, and reads
2559 under a timeout.
2560
2561 Arguments:
2562 buf space to use for buffering
2563 bufsiz size of buffer
2564 proxy_fd comms to proxied process
2565 timeout per-read timeout, seconds
2566 */
2567
2568 void
2569 smtp_proxy_tls(uschar * buf, size_t bsize, int proxy_fd, int timeout)
2570 {
2571 fd_set fds;
2572 int max_fd = MAX(proxy_fd, tls_out.active) + 1;
2573 int rc, i, fd_bits, nbytes;
2574
2575 set_process_info("proxying TLS connection for continued transport");
2576 FD_ZERO(&fds);
2577 FD_SET(tls_out.active, &fds);
2578 FD_SET(proxy_fd, &fds);
2579
2580 for (fd_bits = 3; fd_bits; )
2581 {
2582 time_t time_left = timeout;
2583 time_t time_start = time(NULL);
2584
2585 /* wait for data */
2586 do
2587 {
2588 struct timeval tv = { time_left, 0 };
2589
2590 rc = select(max_fd, (SELECT_ARG2_TYPE *)&fds, NULL, NULL, &tv);
2591
2592 if (rc < 0 && errno == EINTR)
2593 if ((time_left -= time(NULL) - time_start) > 0) continue;
2594
2595 if (rc <= 0)
2596 {
2597 DEBUG(D_transport) if (rc == 0) debug_printf("%s: timed out\n", __FUNCTION__);
2598 return;
2599 }
2600 }
2601 while (rc < 0 || !(FD_ISSET(tls_out.active, &fds) || FD_ISSET(proxy_fd, &fds)));
2602
2603 /* handle inbound data */
2604 if (FD_ISSET(tls_out.active, &fds))
2605 if ((rc = tls_read(FALSE, buf, bsize)) <= 0)
2606 {
2607 fd_bits &= ~1;
2608 FD_CLR(tls_out.active, &fds);
2609 shutdown(proxy_fd, SHUT_WR);
2610 }
2611 else
2612 {
2613 for (nbytes = 0; rc - nbytes > 0; nbytes += i)
2614 if ((i = write(proxy_fd, buf + nbytes, rc - nbytes)) < 0) return;
2615 }
2616 else if (fd_bits & 1)
2617 FD_SET(tls_out.active, &fds);
2618
2619 /* handle outbound data */
2620 if (FD_ISSET(proxy_fd, &fds))
2621 if ((rc = read(proxy_fd, buf, bsize)) <= 0)
2622 {
2623 fd_bits &= ~2;
2624 FD_CLR(proxy_fd, &fds);
2625 shutdown(tls_out.active, SHUT_WR);
2626 }
2627 else
2628 {
2629 for (nbytes = 0; rc - nbytes > 0; nbytes += i)
2630 if ((i = tls_write(FALSE, buf + nbytes, rc - nbytes, FALSE)) < 0)
2631 return;
2632 }
2633 else if (fd_bits & 2)
2634 FD_SET(proxy_fd, &fds);
2635 }
2636 }
2637 #endif
2638
2639
2640 /*************************************************
2641 * Deliver address list to given host *
2642 *************************************************/
2643
2644 /* If continue_hostname is not null, we get here only when continuing to
2645 deliver down an existing channel. The channel was passed as the standard
2646 input. TLS is never active on a passed channel; the previous process always
2647 closes it down before passing the connection on.
2648
2649 Otherwise, we have to make a connection to the remote host, and do the
2650 initial protocol exchange.
2651
2652 When running as an MUA wrapper, if the sender or any recipient is rejected,
2653 temporarily or permanently, we force failure for all recipients.
2654
2655 Arguments:
2656 addrlist chain of potential addresses to deliver; only those whose
2657 transport_return field is set to PENDING_DEFER are currently
2658 being processed; others should be skipped - they have either
2659 been delivered to an earlier host or IP address, or been
2660 failed by one of them.
2661 host host to deliver to
2662 host_af AF_INET or AF_INET6
2663 defport default TCP/IP port to use if host does not specify, in host
2664 byte order
2665 interface interface to bind to, or NULL
2666 tblock transport instance block
2667 message_defer set TRUE if yield is OK, but all addresses were deferred
2668 because of a non-recipient, non-host failure, that is, a
2669 4xx response to MAIL FROM, DATA, or ".". This is a defer
2670 that is specific to the message.
2671 suppress_tls if TRUE, don't attempt a TLS connection - this is set for
2672 a second attempt after TLS initialization fails
2673
2674 Returns: OK - the connection was made and the delivery attempted;
2675 the result for each address is in its data block.
2676 DEFER - the connection could not be made, or something failed
2677 while setting up the SMTP session, or there was a
2678 non-message-specific error, such as a timeout.
2679 ERROR - a filter command is specified for this transport,
2680 and there was a problem setting it up; OR helo_data
2681 or add_headers or authenticated_sender is specified
2682 for this transport, and the string failed to expand
2683 */
2684
2685 static int
2686 smtp_deliver(address_item *addrlist, host_item *host, int host_af, int defport,
2687 uschar *interface, transport_instance *tblock,
2688 BOOL *message_defer, BOOL suppress_tls)
2689 {
2690 address_item *addr;
2691 int yield = OK;
2692 int save_errno;
2693 int rc;
2694 time_t start_delivery_time = time(NULL);
2695
2696 BOOL pass_message = FALSE;
2697 uschar *message = NULL;
2698 uschar new_message_id[MESSAGE_ID_LENGTH + 1];
2699 uschar *p;
2700
2701 smtp_context sx;
2702
2703 suppress_tls = suppress_tls; /* stop compiler warning when no TLS support */
2704 *message_defer = FALSE;
2705
2706 sx.addrlist = addrlist;
2707 sx.host = host;
2708 sx.host_af = host_af,
2709 sx.port = defport;
2710 sx.interface = interface;
2711 sx.helo_data = NULL;
2712 sx.tblock = tblock;
2713 sx.verify = FALSE;
2714
2715 /* Get the channel set up ready for a message (MAIL FROM being the next
2716 SMTP command to send */
2717
2718 if ((rc = smtp_setup_conn(&sx, suppress_tls)) != OK)
2719 return rc;
2720
2721 /* If there is a filter command specified for this transport, we can now
2722 set it up. This cannot be done until the identify of the host is known. */
2723
2724 if (tblock->filter_command)
2725 {
2726 transport_filter_timeout = tblock->filter_timeout;
2727
2728 /* On failure, copy the error to all addresses, abandon the SMTP call, and
2729 yield ERROR. */
2730
2731 if (!transport_set_up_command(&transport_filter_argv,
2732 tblock->filter_command, TRUE, DEFER, addrlist,
2733 string_sprintf("%.50s transport", tblock->name), NULL))
2734 {
2735 set_errno_nohost(addrlist->next, addrlist->basic_errno, addrlist->message, DEFER,
2736 FALSE);
2737 yield = ERROR;
2738 goto SEND_QUIT;
2739 }
2740
2741 if ( transport_filter_argv
2742 && *transport_filter_argv
2743 && **transport_filter_argv
2744 && sx.peer_offered & PEER_OFFERED_CHUNKING
2745 )
2746 {
2747 sx.peer_offered &= ~PEER_OFFERED_CHUNKING;
2748 DEBUG(D_transport) debug_printf("CHUNKING not usable due to transport filter\n");
2749 }
2750 }
2751
2752 sx.first_addr = addrlist;
2753
2754 /* For messages that have more than the maximum number of envelope recipients,
2755 we want to send several transactions down the same SMTP connection. (See
2756 comments in deliver.c as to how this reconciles, heuristically, with
2757 remote_max_parallel.) This optimization was added to Exim after the following
2758 code was already working. The simplest way to put it in without disturbing the
2759 code was to use a goto to jump back to this point when there is another
2760 transaction to handle. */
2761
2762 SEND_MESSAGE:
2763 sx.from_addr = return_path;
2764 sx.sync_addr = sx.first_addr;
2765 sx.ok = FALSE;
2766 sx.send_rset = TRUE;
2767 sx.completed_addr = FALSE;
2768
2769
2770 /* If we are a continued-connection-after-verify the MAIL and RCPT
2771 commands were already sent; do not re-send but do mark the addrs as
2772 having been accepted up to RCPT stage. A traditional cont-conn
2773 always has a sequence number greater than one. */
2774
2775 if (continue_hostname && continue_sequence == 1)
2776 {
2777 address_item * addr;
2778
2779 sx.peer_offered = smtp_peer_options;
2780 sx.pending_MAIL = FALSE;
2781 sx.ok = TRUE;
2782 sx.next_addr = NULL;
2783
2784 for (addr = addrlist; addr; addr = addr->next)
2785 addr->transport_return = PENDING_OK;
2786 }
2787 else
2788 {
2789 /* Initiate a message transfer. */
2790
2791 switch(smtp_write_mail_and_rcpt_cmds(&sx, &yield))
2792 {
2793 case 0: break;
2794 case -1: case -2: goto RESPONSE_FAILED;
2795 case -3: goto END_OFF;
2796 case -4: goto SEND_QUIT;
2797 default: goto SEND_FAILED;
2798 }
2799
2800 /* If we are an MUA wrapper, abort if any RCPTs were rejected, either
2801 permanently or temporarily. We should have flushed and synced after the last
2802 RCPT. */
2803
2804 if (mua_wrapper)
2805 {
2806 address_item * a;
2807 unsigned cnt;
2808
2809 for (a = sx.first_addr, cnt = 0; a && cnt < sx.max_rcpt; a = a->next, cnt++)
2810 if (a->transport_return != PENDING_OK)
2811 {
2812 /*XXX could we find a better errno than 0 here? */
2813 set_errno_nohost(addrlist, 0, a->message, FAIL,
2814 testflag(a, af_pass_message));
2815 sx.ok = FALSE;
2816 break;
2817 }
2818 }
2819 }
2820
2821 /* If ok is TRUE, we know we have got at least one good recipient, and must now
2822 send DATA, but if it is FALSE (in the normal, non-wrapper case), we may still
2823 have a good recipient buffered up if we are pipelining. We don't want to waste
2824 time sending DATA needlessly, so we only send it if either ok is TRUE or if we
2825 are pipelining. The responses are all handled by sync_responses().
2826 If using CHUNKING, do not send a BDAT until we know how big a chunk we want
2827 to send is. */
2828
2829 if ( !(sx.peer_offered & PEER_OFFERED_CHUNKING)
2830 && (sx.ok || (pipelining_active && !mua_wrapper)))
2831 {
2832 int count = smtp_write_command(&sx.outblock, SCMD_FLUSH, "DATA\r\n");
2833
2834 if (count < 0) goto SEND_FAILED;
2835 switch(sync_responses(&sx, count, sx.ok ? +1 : -1))
2836 {
2837 case 3: sx.ok = TRUE; /* 2xx & 5xx => OK & progress made */
2838 case 2: sx.completed_addr = TRUE; /* 5xx (only) => progress made */
2839 break;
2840
2841 case 1: sx.ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
2842 if (!sx.lmtp) sx.completed_addr = TRUE; /* can't tell about progress yet */
2843 case 0: break; /* No 2xx or 5xx, but no probs */
2844
2845 case -1: goto END_OFF; /* Timeout on RCPT */
2846 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */
2847 }
2848 pipelining_active = FALSE;
2849 data_command = string_copy(big_buffer); /* Save for later error message */
2850 }
2851
2852 /* If there were no good recipients (but otherwise there have been no
2853 problems), just set ok TRUE, since we have handled address-specific errors
2854 already. Otherwise, it's OK to send the message. Use the check/escape mechanism
2855 for handling the SMTP dot-handling protocol, flagging to apply to headers as
2856 well as body. Set the appropriate timeout value to be used for each chunk.
2857 (Haven't been able to make it work using select() for writing yet.) */
2858
2859 if (!(sx.peer_offered & PEER_OFFERED_CHUNKING) && !sx.ok)
2860 {
2861 /* Save the first address of the next batch. */
2862 sx.first_addr = sx.next_addr;
2863
2864 sx.ok = TRUE;
2865 }
2866 else
2867 {
2868 transport_ctx tctx = {
2869 sx.inblock.sock,
2870 tblock,
2871 addrlist,
2872 US".", US"..", /* Escaping strings */
2873 topt_use_crlf | topt_escape_headers
2874 | (tblock->body_only ? topt_no_headers : 0)
2875 | (tblock->headers_only ? topt_no_body : 0)
2876 | (tblock->return_path_add ? topt_add_return_path : 0)
2877 | (tblock->delivery_date_add ? topt_add_delivery_date : 0)
2878 | (tblock->envelope_to_add ? topt_add_envelope_to : 0)
2879 };
2880
2881 /* If using CHUNKING we need a callback from the generic transport
2882 support to us, for the sending of BDAT smtp commands and the reaping
2883 of responses. The callback needs a whole bunch of state so set up
2884 a transport-context structure to be passed around. */
2885
2886 if (sx.peer_offered & PEER_OFFERED_CHUNKING)
2887 {
2888 tctx.check_string = tctx.escape_string = NULL;
2889 tctx.options |= topt_use_bdat;
2890 tctx.chunk_cb = smtp_chunk_cmd_callback;
2891 sx.pending_BDAT = FALSE;
2892 sx.good_RCPT = sx.ok;
2893 sx.cmd_count = 0;
2894 tctx.smtp_context = &sx;
2895 }
2896 else
2897 tctx.options |= topt_end_dot;
2898
2899 /* Save the first address of the next batch. */
2900 sx.first_addr = sx.next_addr;
2901
2902 /* Responses from CHUNKING commands go in buffer. Otherwise,
2903 there has not been a response. */
2904
2905 sx.buffer[0] = 0;
2906
2907 sigalrm_seen = FALSE;
2908 transport_write_timeout = sx.ob->data_timeout;
2909 smtp_command = US"sending data block"; /* For error messages */
2910 DEBUG(D_transport|D_v)
2911 if (sx.peer_offered & PEER_OFFERED_CHUNKING)
2912 debug_printf(" will write message using CHUNKING\n");
2913 else
2914 debug_printf(" SMTP>> writing message and terminating \".\"\n");
2915 transport_count = 0;
2916
2917 #ifndef DISABLE_DKIM
2918 sx.ok = dkim_transport_write_message(&tctx, &sx.ob->dkim, CUSS &message);
2919 #else
2920 sx.ok = transport_write_message(&tctx, 0);
2921 #endif
2922
2923 /* transport_write_message() uses write() because it is called from other
2924 places to write to non-sockets. This means that under some OS (e.g. Solaris)
2925 it can exit with "Broken pipe" as its error. This really means that the
2926 socket got closed at the far end. */
2927
2928 transport_write_timeout = 0; /* for subsequent transports */
2929
2930 /* Failure can either be some kind of I/O disaster (including timeout),
2931 or the failure of a transport filter or the expansion of added headers.
2932 Or, when CHUNKING, it can be a protocol-detected failure. */
2933
2934 if (!sx.ok)
2935 if (message) goto SEND_FAILED;
2936 else goto RESPONSE_FAILED;
2937
2938 /* We used to send the terminating "." explicitly here, but because of
2939 buffering effects at both ends of TCP/IP connections, you don't gain
2940 anything by keeping it separate, so it might as well go in the final
2941 data buffer for efficiency. This is now done by setting the topt_end_dot
2942 flag above. */
2943
2944 smtp_command = US"end of data";
2945
2946 if (sx.peer_offered & PEER_OFFERED_CHUNKING && sx.cmd_count > 1)
2947 {
2948 /* Reap any outstanding MAIL & RCPT commands, but not a DATA-go-ahead */
2949 switch(sync_responses(&sx, sx.cmd_count-1, 0))
2950 {
2951 case 3: sx.ok = TRUE; /* 2xx & 5xx => OK & progress made */
2952 case 2: sx.completed_addr = TRUE; /* 5xx (only) => progress made */
2953 break;
2954
2955 case 1: sx.ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
2956 if (!sx.lmtp) sx.completed_addr = TRUE; /* can't tell about progress yet */
2957 case 0: break; /* No 2xx or 5xx, but no probs */
2958
2959 case -1: goto END_OFF; /* Timeout on RCPT */
2960 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */
2961 }
2962 }
2963
2964 #ifndef DISABLE_PRDR
2965 /* For PRDR we optionally get a partial-responses warning
2966 * followed by the individual responses, before going on with
2967 * the overall response. If we don't get the warning then deal
2968 * with per non-PRDR. */
2969 if(sx.prdr_active)
2970 {
2971 sx.ok = smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer), '3',
2972 sx.ob->final_timeout);
2973 if (!sx.ok && errno == 0) switch(sx.buffer[0])
2974 {
2975 case '2': sx.prdr_active = FALSE;
2976 sx.ok = TRUE;
2977 break;
2978 case '4': errno = ERRNO_DATA4XX;
2979 addrlist->more_errno |=
2980 ((sx.buffer[1] - '0')*10 + sx.buffer[2] - '0') << 8;
2981 break;
2982 }
2983 }
2984 else
2985 #endif
2986
2987 /* For non-PRDR SMTP, we now read a single response that applies to the
2988 whole message. If it is OK, then all the addresses have been delivered. */
2989
2990 if (!sx.lmtp)
2991 {
2992 sx.ok = smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer), '2',
2993 sx.ob->final_timeout);
2994 if (!sx.ok && errno == 0 && sx.buffer[0] == '4')
2995 {
2996 errno = ERRNO_DATA4XX;
2997 addrlist->more_errno |= ((sx.buffer[1] - '0')*10 + sx.buffer[2] - '0') << 8;
2998 }
2999 }
3000
3001 /* For LMTP, we get back a response for every RCPT command that we sent;
3002 some may be accepted and some rejected. For those that get a response, their
3003 status is fixed; any that are accepted have been handed over, even if later
3004 responses crash - at least, that's how I read RFC 2033.
3005
3006 If all went well, mark the recipient addresses as completed, record which
3007 host/IPaddress they were delivered to, and cut out RSET when sending another
3008 message down the same channel. Write the completed addresses to the journal
3009 now so that they are recorded in case there is a crash of hardware or
3010 software before the spool gets updated. Also record the final SMTP
3011 confirmation if needed (for SMTP only). */
3012
3013 if (sx.ok)
3014 {
3015 int flag = '=';
3016 int delivery_time = (int)(time(NULL) - start_delivery_time);
3017 int len;
3018 uschar *conf = NULL;
3019
3020 sx.send_rset = FALSE;
3021 pipelining_active = FALSE;
3022
3023 /* Set up confirmation if needed - applies only to SMTP */
3024
3025 if (
3026 #ifdef DISABLE_EVENT
3027 LOGGING(smtp_confirmation) &&
3028 #endif
3029 !sx.lmtp
3030 )
3031 {
3032 const uschar *s = string_printing(sx.buffer);
3033 /* deconst cast ok here as string_printing was checked to have alloc'n'copied */
3034 conf = (s == sx.buffer)? (uschar *)string_copy(s) : US s;
3035 }
3036
3037 /* Process all transported addresses - for LMTP or PRDR, read a status for
3038 each one. */
3039
3040 for (addr = addrlist; addr != sx.first_addr; addr = addr->next)
3041 {
3042 if (addr->transport_return != PENDING_OK) continue;
3043
3044 /* LMTP - if the response fails badly (e.g. timeout), use it for all the
3045 remaining addresses. Otherwise, it's a return code for just the one
3046 address. For temporary errors, add a retry item for the address so that
3047 it doesn't get tried again too soon. */
3048
3049 #ifndef DISABLE_PRDR
3050 if (sx.lmtp || sx.prdr_active)
3051 #else
3052 if (sx.lmtp)
3053 #endif
3054 {
3055 if (!smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer), '2',
3056 sx.ob->final_timeout))
3057 {
3058 if (errno != 0 || sx.buffer[0] == 0) goto RESPONSE_FAILED;
3059 addr->message = string_sprintf(
3060 #ifndef DISABLE_PRDR
3061 "%s error after %s: %s", sx.prdr_active ? "PRDR":"LMTP",
3062 #else
3063 "LMTP error after %s: %s",
3064 #endif
3065 data_command, string_printing(sx.buffer));
3066 setflag(addr, af_pass_message); /* Allow message to go to user */
3067 if (sx.buffer[0] == '5')
3068 addr->transport_return = FAIL;
3069 else
3070 {
3071 errno = ERRNO_DATA4XX;
3072 addr->more_errno |= ((sx.buffer[1] - '0')*10 + sx.buffer[2] - '0') << 8;
3073 addr->transport_return = DEFER;
3074 #ifndef DISABLE_PRDR
3075 if (!sx.prdr_active)
3076 #endif
3077 retry_add_item(addr, addr->address_retry_key, 0);
3078 }
3079 continue;
3080 }
3081 sx.completed_addr = TRUE; /* NOW we can set this flag */
3082 if (LOGGING(smtp_confirmation))
3083 {
3084 const uschar *s = string_printing(sx.buffer);
3085 /* deconst cast ok here as string_printing was checked to have alloc'n'copied */
3086 conf = (s == sx.buffer) ? US string_copy(s) : US s;
3087 }
3088 }
3089
3090 /* SMTP, or success return from LMTP for this address. Pass back the
3091 actual host that was used. */
3092
3093 addr->transport_return = OK;
3094 addr->more_errno = delivery_time;
3095 addr->host_used = host;
3096 addr->special_action = flag;
3097 addr->message = conf;
3098 #ifndef DISABLE_PRDR
3099 if (sx.prdr_active) addr->flags |= af_prdr_used;
3100 #endif
3101 if (sx.peer_offered & PEER_OFFERED_CHUNKING) addr->flags |= af_chunking_used;
3102 flag = '-';
3103
3104 #ifndef DISABLE_PRDR
3105 if (!sx.prdr_active)
3106 #endif
3107 {
3108 /* Update the journal. For homonymic addresses, use the base address plus
3109 the transport name. See lots of comments in deliver.c about the reasons
3110 for the complications when homonyms are involved. Just carry on after
3111 write error, as it may prove possible to update the spool file later. */
3112
3113 if (testflag(addr, af_homonym))
3114 sprintf(CS sx.buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
3115 else
3116 sprintf(CS sx.buffer, "%.500s\n", addr->unique);
3117
3118 DEBUG(D_deliver) debug_printf("S:journalling %s\n", sx.buffer);
3119 len = Ustrlen(CS sx.buffer);
3120 if (write(journal_fd, sx.buffer, len) != len)
3121 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
3122 "%s: %s", sx.buffer, strerror(errno));
3123 }
3124 }
3125
3126 #ifndef DISABLE_PRDR
3127 if (sx.prdr_active)
3128 {
3129 /* PRDR - get the final, overall response. For any non-success
3130 upgrade all the address statuses. */
3131 sx.ok = smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer), '2',
3132 sx.ob->final_timeout);
3133 if (!sx.ok)
3134 {
3135 if(errno == 0 && sx.buffer[0] == '4')
3136 {
3137 errno = ERRNO_DATA4XX;
3138 addrlist->more_errno |= ((sx.buffer[1] - '0')*10 + sx.buffer[2] - '0') << 8;
3139 }
3140 for (addr = addrlist; addr != sx.first_addr; addr = addr->next)
3141 if (sx.buffer[0] == '5' || addr->transport_return == OK)
3142 addr->transport_return = PENDING_OK; /* allow set_errno action */
3143 goto RESPONSE_FAILED;
3144 }
3145
3146 /* Update the journal, or setup retry. */
3147 for (addr = addrlist; addr != sx.first_addr; addr = addr->next)
3148 if (addr->transport_return == OK)
3149 {
3150 if (testflag(addr, af_homonym))
3151 sprintf(CS sx.buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
3152 else
3153 sprintf(CS sx.buffer, "%.500s\n", addr->unique);
3154
3155 DEBUG(D_deliver) debug_printf("journalling(PRDR) %s\n", sx.buffer);
3156 len = Ustrlen(CS sx.buffer);
3157 if (write(journal_fd, sx.buffer, len) != len)
3158 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
3159 "%s: %s", sx.buffer, strerror(errno));
3160 }
3161 else if (addr->transport_return == DEFER)
3162 retry_add_item(addr, addr->address_retry_key, -2);
3163 }
3164 #endif
3165
3166 /* Ensure the journal file is pushed out to disk. */
3167
3168 if (EXIMfsync(journal_fd) < 0)
3169 log_write(0, LOG_MAIN|LOG_PANIC, "failed to fsync journal: %s",
3170 strerror(errno));
3171 }
3172 }
3173
3174
3175 /* Handle general (not specific to one address) failures here. The value of ok
3176 is used to skip over this code on the falling through case. A timeout causes a
3177 deferral. Other errors may defer or fail according to the response code, and
3178 may set up a special errno value, e.g. after connection chopped, which is
3179 assumed if errno == 0 and there is no text in the buffer. If control reaches
3180 here during the setting up phase (i.e. before MAIL FROM) then always defer, as
3181 the problem is not related to this specific message. */
3182
3183 if (!sx.ok)
3184 {
3185 int code, set_rc;
3186 uschar * set_message;
3187
3188 RESPONSE_FAILED:
3189 {
3190 save_errno = errno;
3191 message = NULL;
3192 sx.send_quit = check_response(host, &save_errno, addrlist->more_errno,
3193 sx.buffer, &code, &message, &pass_message);
3194 goto FAILED;
3195 }
3196
3197 SEND_FAILED:
3198 {
3199 save_errno = errno;
3200 code = '4';
3201 message = string_sprintf("send() to %s [%s] failed: %s",
3202 host->name, host->address, message ? message : US strerror(save_errno));
3203 sx.send_quit = FALSE;
3204 goto FAILED;
3205 }
3206
3207 FAILED:
3208 {
3209 BOOL message_error;
3210
3211 sx.ok = FALSE; /* For when reached by GOTO */
3212 set_message = message;
3213
3214 /* We want to handle timeouts after MAIL or "." and loss of connection after
3215 "." specially. They can indicate a problem with the sender address or with
3216 the contents of the message rather than a real error on the connection. These
3217 cases are treated in the same way as a 4xx response. This next bit of code
3218 does the classification. */
3219
3220 switch(save_errno)
3221 {
3222 case 0:
3223 case ERRNO_MAIL4XX:
3224 case ERRNO_DATA4XX:
3225 message_error = TRUE;
3226 break;
3227
3228 case ETIMEDOUT:
3229 message_error = Ustrncmp(smtp_command,"MAIL",4) == 0 ||
3230 Ustrncmp(smtp_command,"end ",4) == 0;
3231 break;
3232
3233 case ERRNO_SMTPCLOSED:
3234 message_error = Ustrncmp(smtp_command,"end ",4) == 0;
3235 break;
3236
3237 default:
3238 message_error = FALSE;
3239 break;
3240 }
3241
3242 /* Handle the cases that are treated as message errors. These are:
3243
3244 (a) negative response or timeout after MAIL
3245 (b) negative response after DATA
3246 (c) negative response or timeout or dropped connection after "."
3247 (d) utf8 support required and not offered
3248
3249 It won't be a negative response or timeout after RCPT, as that is dealt
3250 with separately above. The action in all cases is to set an appropriate
3251 error code for all the addresses, but to leave yield set to OK because the
3252 host itself has not failed. Of course, it might in practice have failed
3253 when we've had a timeout, but if so, we'll discover that at the next
3254 delivery attempt. For a temporary error, set the message_defer flag, and
3255 write to the logs for information if this is not the last host. The error
3256 for the last host will be logged as part of the address's log line. */
3257
3258 if (message_error)
3259 {
3260 if (mua_wrapper) code = '5'; /* Force hard failure in wrapper mode */
3261
3262 /* If there's an errno, the message contains just the identity of
3263 the host. */
3264
3265 if (code == '5')
3266 set_rc = FAIL;
3267 else /* Anything other than 5 is treated as temporary */
3268 {
3269 set_rc = DEFER;
3270 if (save_errno > 0)
3271 message = US string_sprintf("%s: %s", message, strerror(save_errno));
3272 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", message);
3273 msglog_line(host, message);
3274 *message_defer = TRUE;
3275 }
3276 }
3277
3278 /* Otherwise, we have an I/O error or a timeout other than after MAIL or
3279 ".", or some other transportation error. We defer all addresses and yield
3280 DEFER, except for the case of failed add_headers expansion, or a transport
3281 filter failure, when the yield should be ERROR, to stop it trying other
3282 hosts. */
3283
3284 else
3285 {
3286 set_rc = DEFER;
3287 yield = (save_errno == ERRNO_CHHEADER_FAIL ||
3288 save_errno == ERRNO_FILTER_FAIL)? ERROR : DEFER;
3289 }
3290 }
3291
3292 set_errno(addrlist, save_errno, set_message, set_rc, pass_message, host
3293 #ifdef EXPERIMENTAL_DSN_INFO
3294 , sx.smtp_greeting, sx.helo_response
3295 #endif
3296 );
3297 }
3298
3299
3300 /* If all has gone well, send_quit will be set TRUE, implying we can end the
3301 SMTP session tidily. However, if there were too many addresses to send in one
3302 message (indicated by first_addr being non-NULL) we want to carry on with the
3303 rest of them. Also, it is desirable to send more than one message down the SMTP
3304 connection if there are several waiting, provided we haven't already sent so
3305 many as to hit the configured limit. The function transport_check_waiting looks
3306 for a waiting message and returns its id. Then transport_pass_socket tries to
3307 set up a continued delivery by passing the socket on to another process. The
3308 variable send_rset is FALSE if a message has just been successfully transfered.
3309
3310 If we are already sending down a continued channel, there may be further
3311 addresses not yet delivered that are aimed at the same host, but which have not
3312 been passed in this run of the transport. In this case, continue_more will be
3313 true, and all we should do is send RSET if necessary, and return, leaving the
3314 channel open.
3315
3316 However, if no address was disposed of, i.e. all addresses got 4xx errors, we
3317 do not want to continue with other messages down the same channel, because that
3318 can lead to looping between two or more messages, all with the same,
3319 temporarily failing address(es). [The retry information isn't updated yet, so
3320 new processes keep on trying.] We probably also don't want to try more of this
3321 message's addresses either.
3322
3323 If we have started a TLS session, we have to end it before passing the
3324 connection to a new process. However, not all servers can handle this (Exim
3325 can), so we do not pass such a connection on if the host matches
3326 hosts_nopass_tls. */
3327
3328 DEBUG(D_transport)
3329 debug_printf("ok=%d send_quit=%d send_rset=%d continue_more=%d "
3330 "yield=%d first_address is %sNULL\n", sx.ok, sx.send_quit,
3331 sx.send_rset, continue_more, yield, sx.first_addr ? "not " : "");
3332
3333 if (sx.completed_addr && sx.ok && sx.send_quit)
3334 {
3335 BOOL more;
3336 smtp_compare_t t_compare;
3337
3338 t_compare.tblock = tblock;
3339 t_compare.current_sender_address = sender_address;
3340
3341 if ( sx.first_addr != NULL
3342 || continue_more
3343 || (
3344 #ifdef SUPPORT_TLS
3345 ( tls_out.active < 0 && !continue_proxy_cipher
3346 || verify_check_given_host(&sx.ob->hosts_nopass_tls, host) != OK
3347 )
3348 &&
3349 #endif
3350 transport_check_waiting(tblock->name, host->name,
3351 tblock->connection_max_messages, new_message_id, &more,
3352 (oicf)smtp_are_same_identities, (void*)&t_compare)
3353 ) )
3354 {
3355 uschar *msg;
3356 BOOL pass_message;
3357
3358 if (sx.send_rset)
3359 if (! (sx.ok = smtp_write_command(&sx.outblock, SCMD_FLUSH, "RSET\r\n") >= 0))
3360 {
3361 msg = US string_sprintf("send() to %s [%s] failed: %s", host->name,
3362 host->address, strerror(errno));
3363 sx.send_quit = FALSE;
3364 }
3365 else if (! (sx.ok = smtp_read_response(&sx.inblock, sx.buffer,
3366 sizeof(sx.buffer), '2', sx.ob->command_timeout)))
3367 {
3368 int code;
3369 sx.send_quit = check_response(host, &errno, 0, sx.buffer, &code, &msg,
3370 &pass_message);
3371 if (!sx.send_quit)
3372 {
3373 DEBUG(D_transport) debug_printf("H=%s [%s] %s\n",
3374 host->name, host->address, msg);
3375 }
3376 }
3377
3378 /* Either RSET was not needed, or it succeeded */
3379
3380 if (sx.ok)
3381 {
3382 int pfd[2];
3383 int socket_fd = sx.inblock.sock;
3384
3385
3386 if (sx.first_addr != NULL) /* More addresses still to be sent */
3387 { /* in this run of the transport */
3388 continue_sequence++; /* Causes * in logging */
3389 goto SEND_MESSAGE;
3390 }
3391
3392 /* Unless caller said it already has more messages listed for this host,
3393 pass the connection on to a new Exim process (below, the call to
3394 transport_pass_socket). If the caller has more ready, just return with
3395 the connection still open. */
3396
3397 #ifdef SUPPORT_TLS
3398 if (tls_out.active >= 0)
3399 if ( continue_more
3400 || verify_check_given_host(&sx.ob->hosts_noproxy_tls, host) == OK)
3401 {
3402 /* Before passing the socket on, or returning to caller with it still
3403 open, we must shut down TLS. Not all MTAs allow for the continuation
3404 of the SMTP session when TLS is shut down. We test for this by sending
3405 a new EHLO. If we don't get a good response, we don't attempt to pass
3406 the socket on. */
3407
3408 tls_close(FALSE, TRUE);
3409 smtp_peer_options = smtp_peer_options_wrap;
3410 sx.ok = !sx.smtps
3411 && smtp_write_command(&sx.outblock, SCMD_FLUSH,
3412 "EHLO %s\r\n", sx.helo_data) >= 0
3413 && smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer),
3414 '2', sx.ob->command_timeout);
3415
3416 if (sx.ok && continue_more)
3417 return yield; /* More addresses for another run */
3418 }
3419 else
3420 {
3421 /* Set up a pipe for proxying TLS for the new transport process */
3422
3423 smtp_peer_options |= PEER_OFFERED_TLS;
3424 if (sx.ok = (socketpair(AF_UNIX, SOCK_STREAM, 0, pfd) == 0))
3425 socket_fd = pfd[1];
3426 else
3427 set_errno(sx.first_addr, errno, US"internal allocation problem",
3428 DEFER, FALSE, host
3429 # ifdef EXPERIMENTAL_DSN_INFO
3430 , sx.smtp_greeting, sx.helo_response
3431 # endif
3432 );
3433 }
3434 else
3435 #endif
3436 if (continue_more)
3437 return yield; /* More addresses for another run */
3438
3439 /* If the socket is successfully passed, we mustn't send QUIT (or
3440 indeed anything!) from here. */
3441
3442 /*XXX DSN_INFO: assume likely to do new HELO; but for greet we'll want to
3443 propagate it from the initial
3444 */
3445 if (sx.ok && transport_pass_socket(tblock->name, host->name,
3446 host->address, new_message_id, socket_fd))
3447 {
3448 sx.send_quit = FALSE;
3449
3450 /* If TLS is still active, we need to proxy it for the transport we
3451 just passed the baton to. Fork a child to to do it, and return to
3452 get logging done asap. Which way to place the work makes assumptions
3453 about post-fork prioritisation which may not hold on all platforms. */
3454 #ifdef SUPPORT_TLS
3455 if (tls_out.active >= 0)
3456 {
3457 int pid = fork();
3458 if (pid > 0) /* parent */
3459 {
3460 DEBUG(D_transport) debug_printf("proxy-proc inter-pid %d\n", pid);
3461 waitpid(pid, NULL, 0);
3462 tls_close(FALSE, FALSE);
3463 (void)close(sx.inblock.sock);
3464 continue_transport = NULL;
3465 continue_hostname = NULL;
3466 return yield;
3467 }
3468 else if (pid == 0) /* child; fork again to disconnect totally */
3469 {
3470 if ((pid = fork()))
3471 {
3472 DEBUG(D_transport) debug_printf("proxy-prox final-pid %d\n", pid);
3473 _exit(pid ? EXIT_FAILURE : EXIT_SUCCESS);
3474 }
3475 smtp_proxy_tls(sx.buffer, sizeof(sx.buffer), pfd[0], sx.ob->command_timeout);
3476 exim_exit(0);
3477 }
3478 }
3479 #endif
3480 }
3481 }
3482
3483 /* If RSET failed and there are addresses left, they get deferred. */
3484 else
3485 set_errno(sx.first_addr, errno, msg, DEFER, FALSE, host
3486 #ifdef EXPERIMENTAL_DSN_INFO
3487 , sx.smtp_greeting, sx.helo_response
3488 #endif
3489 );
3490 }
3491 }
3492
3493 /* End off tidily with QUIT unless the connection has died or the socket has
3494 been passed to another process. There has been discussion on the net about what
3495 to do after sending QUIT. The wording of the RFC suggests that it is necessary
3496 to wait for a response, but on the other hand, there isn't anything one can do
3497 with an error response, other than log it. Exim used to do that. However,
3498 further discussion suggested that it is positively advantageous not to wait for
3499 the response, but to close the session immediately. This is supposed to move
3500 the TCP/IP TIME_WAIT state from the server to the client, thereby removing some
3501 load from the server. (Hosts that are both servers and clients may not see much
3502 difference, of course.) Further discussion indicated that this was safe to do
3503 on Unix systems which have decent implementations of TCP/IP that leave the
3504 connection around for a while (TIME_WAIT) after the application has gone away.
3505 This enables the response sent by the server to be properly ACKed rather than
3506 timed out, as can happen on broken TCP/IP implementations on other OS.
3507
3508 This change is being made on 31-Jul-98. After over a year of trouble-free
3509 operation, the old commented-out code was removed on 17-Sep-99. */
3510
3511 SEND_QUIT:
3512 if (sx.send_quit) (void)smtp_write_command(&sx.outblock, SCMD_FLUSH, "QUIT\r\n");
3513
3514 END_OFF:
3515
3516 #ifdef SUPPORT_TLS
3517 tls_close(FALSE, TRUE);
3518 #endif
3519
3520 /* Close the socket, and return the appropriate value, first setting
3521 works because the NULL setting is passed back to the calling process, and
3522 remote_max_parallel is forced to 1 when delivering over an existing connection,
3523
3524 If all went well and continue_more is set, we shouldn't actually get here if
3525 there are further addresses, as the return above will be taken. However,
3526 writing RSET might have failed, or there may be other addresses whose hosts are
3527 specified in the transports, and therefore not visible at top level, in which
3528 case continue_more won't get set. */
3529
3530 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
3531 if (sx.send_quit)
3532 {
3533 shutdown(sx.outblock.sock, SHUT_WR);
3534 if (fcntl(sx.inblock.sock, F_SETFL, O_NONBLOCK) == 0)
3535 for (rc = 16; read(sx.inblock.sock, sx.inbuffer, sizeof(sx.inbuffer)) > 0 && rc > 0;)
3536 rc--; /* drain socket */
3537 }
3538 (void)close(sx.inblock.sock);
3539
3540 #ifndef DISABLE_EVENT
3541 (void) event_raise(tblock->event_action, US"tcp:close", NULL);
3542 #endif
3543
3544 continue_transport = NULL;
3545 continue_hostname = NULL;
3546 return yield;
3547 }
3548
3549
3550
3551
3552 /*************************************************
3553 * Closedown entry point *
3554 *************************************************/
3555
3556 /* This function is called when exim is passed an open smtp channel
3557 from another incarnation, but the message which it has been asked
3558 to deliver no longer exists. The channel is on stdin.
3559
3560 We might do fancy things like looking for another message to send down
3561 the channel, but if the one we sought has gone, it has probably been
3562 delivered by some other process that itself will seek further messages,
3563 so just close down our connection.
3564
3565 Argument: pointer to the transport instance block
3566 Returns: nothing
3567 */
3568
3569 void
3570 smtp_transport_closedown(transport_instance *tblock)
3571 {
3572 smtp_transport_options_block *ob =
3573 (smtp_transport_options_block *)tblock->options_block;
3574 smtp_inblock inblock;
3575 smtp_outblock outblock;
3576 uschar buffer[256];
3577 uschar inbuffer[4096];
3578 uschar outbuffer[16];
3579
3580 inblock.sock = fileno(stdin);
3581 inblock.buffer = inbuffer;
3582 inblock.buffersize = sizeof(inbuffer);
3583 inblock.ptr = inbuffer;
3584 inblock.ptrend = inbuffer;
3585
3586 outblock.sock = inblock.sock;
3587 outblock.buffersize = sizeof(outbuffer);
3588 outblock.buffer = outbuffer;
3589 outblock.ptr = outbuffer;
3590 outblock.cmd_count = 0;
3591 outblock.authenticating = FALSE;
3592
3593 (void)smtp_write_command(&outblock, SCMD_FLUSH, "QUIT\r\n");
3594 (void)smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
3595 ob->command_timeout);
3596 (void)close(inblock.sock);
3597 }
3598
3599
3600
3601 /*************************************************
3602 * Prepare addresses for delivery *
3603 *************************************************/
3604
3605 /* This function is called to flush out error settings from previous delivery
3606 attempts to other hosts. It also records whether we got here via an MX record
3607 or not in the more_errno field of the address. We are interested only in
3608 addresses that are still marked DEFER - others may have got delivered to a
3609 previously considered IP address. Set their status to PENDING_DEFER to indicate
3610 which ones are relevant this time.
3611
3612 Arguments:
3613 addrlist the list of addresses
3614 host the host we are delivering to
3615
3616 Returns: the first address for this delivery
3617 */
3618
3619 static address_item *
3620 prepare_addresses(address_item *addrlist, host_item *host)
3621 {
3622 address_item *first_addr = NULL;
3623 address_item *addr;
3624 for (addr = addrlist; addr; addr = addr->next)
3625 if (addr->transport_return == DEFER)
3626 {
3627 if (!first_addr) first_addr = addr;
3628 addr->transport_return = PENDING_DEFER;
3629 addr->basic_errno = 0;
3630 addr->more_errno = (host->mx >= 0)? 'M' : 'A';
3631 addr->message = NULL;
3632 #ifdef SUPPORT_TLS
3633 addr->cipher = NULL;
3634 addr->ourcert = NULL;
3635 addr->peercert = NULL;
3636 addr->peerdn = NULL;
3637 addr->ocsp = OCSP_NOT_REQ;
3638 #endif
3639 #ifdef EXPERIMENTAL_DSN_INFO
3640 addr->smtp_greeting = NULL;
3641 addr->helo_response = NULL;
3642 #endif
3643 }
3644 return first_addr;
3645 }
3646
3647
3648
3649 /*************************************************
3650 * Main entry point *
3651 *************************************************/
3652
3653 /* See local README for interface details. As this is a remote transport, it is
3654 given a chain of addresses to be delivered in one connection, if possible. It
3655 always returns TRUE, indicating that each address has its own independent
3656 status set, except if there is a setting up problem, in which case it returns
3657 FALSE. */
3658
3659 BOOL
3660 smtp_transport_entry(
3661 transport_instance *tblock, /* data for this instantiation */
3662 address_item *addrlist) /* addresses we are working on */
3663 {
3664 int cutoff_retry;
3665 int defport;
3666 int hosts_defer = 0;
3667 int hosts_fail = 0;
3668 int hosts_looked_up = 0;
3669 int hosts_retry = 0;
3670 int hosts_serial = 0;
3671 int hosts_total = 0;
3672 int total_hosts_tried = 0;
3673 address_item *addr;
3674 BOOL expired = TRUE;
3675 uschar *expanded_hosts = NULL;
3676 uschar *pistring;
3677 uschar *tid = string_sprintf("%s transport", tblock->name);
3678 smtp_transport_options_block *ob =
3679 (smtp_transport_options_block *)(tblock->options_block);
3680 host_item *hostlist = addrlist->host_list;
3681 host_item *host = NULL;
3682
3683 DEBUG(D_transport)
3684 {
3685 debug_printf("%s transport entered\n", tblock->name);
3686 for (addr = addrlist; addr; addr = addr->next)
3687 debug_printf(" %s\n", addr->address);
3688 if (hostlist)
3689 {
3690 debug_printf("hostlist:\n");
3691 for (host = hostlist; host; host = host->next)
3692 debug_printf(" %s:%d\n", host->name, host->port);
3693 }
3694 if (continue_hostname)
3695 debug_printf("already connected to %s [%s] (on fd %d)\n",
3696 continue_hostname, continue_host_address,
3697 cutthrough.fd >= 0 ? cutthrough.fd : 0);
3698 }
3699
3700 /* Set the flag requesting that these hosts be added to the waiting
3701 database if the delivery fails temporarily or if we are running with
3702 queue_smtp or a 2-stage queue run. This gets unset for certain
3703 kinds of error, typically those that are specific to the message. */
3704
3705 update_waiting = TRUE;
3706
3707 /* If a host list is not defined for the addresses - they must all have the
3708 same one in order to be passed to a single transport - or if the transport has
3709 a host list with hosts_override set, use the host list supplied with the
3710 transport. It is an error for this not to exist. */
3711
3712 if (!hostlist || (ob->hosts_override && ob->hosts))
3713 {
3714 if (!ob->hosts)
3715 {
3716 addrlist->message = string_sprintf("%s transport called with no hosts set",
3717 tblock->name);
3718 addrlist->transport_return = PANIC;
3719 return FALSE; /* Only top address has status */
3720 }
3721
3722 DEBUG(D_transport) debug_printf("using the transport's hosts: %s\n",
3723 ob->hosts);
3724
3725 /* If the transport's host list contains no '$' characters, and we are not
3726 randomizing, it is fixed and therefore a chain of hosts can be built once
3727 and for all, and remembered for subsequent use by other calls to this
3728 transport. If, on the other hand, the host list does contain '$', or we are
3729 randomizing its order, we have to rebuild it each time. In the fixed case,
3730 as the hosts string will never be used again, it doesn't matter that we
3731 replace all the : characters with zeros. */
3732
3733 if (!ob->hostlist)
3734 {
3735 uschar *s = ob->hosts;
3736
3737 if (Ustrchr(s, '$') != NULL)
3738 {
3739 if (!(expanded_hosts = expand_string(s)))
3740 {
3741 addrlist->message = string_sprintf("failed to expand list of hosts "
3742 "\"%s\" in %s transport: %s", s, tblock->name, expand_string_message);
3743 addrlist->transport_return = search_find_defer ? DEFER : PANIC;
3744 return FALSE; /* Only top address has status */
3745 }
3746 DEBUG(D_transport) debug_printf("expanded list of hosts \"%s\" to "
3747 "\"%s\"\n", s, expanded_hosts);
3748 s = expanded_hosts;
3749 }
3750 else
3751 if (ob->hosts_randomize) s = expanded_hosts = string_copy(s);
3752
3753 host_build_hostlist(&hostlist, s, ob->hosts_randomize);
3754
3755 /* Check that the expansion yielded something useful. */
3756 if (!hostlist)
3757 {
3758 addrlist->message =
3759 string_sprintf("%s transport has empty hosts setting", tblock->name);
3760 addrlist->transport_return = PANIC;
3761 return FALSE; /* Only top address has status */
3762 }
3763
3764 /* If there was no expansion of hosts, save the host list for
3765 next time. */
3766
3767 if (!expanded_hosts) ob->hostlist = hostlist;
3768 }
3769
3770 /* This is not the first time this transport has been run in this delivery;
3771 the host list was built previously. */
3772
3773 else
3774 hostlist = ob->hostlist;
3775 }
3776
3777 /* The host list was supplied with the address. If hosts_randomize is set, we
3778 must sort it into a random order if it did not come from MX records and has not
3779 already been randomized (but don't bother if continuing down an existing
3780 connection). */
3781
3782 else if (ob->hosts_randomize && hostlist->mx == MX_NONE && !continue_hostname)
3783 {
3784 host_item *newlist = NULL;
3785 while (hostlist)
3786 {
3787 host_item *h = hostlist;
3788 hostlist = hostlist->next;
3789
3790 h->sort_key = random_number(100);
3791
3792 if (!newlist)
3793 {
3794 h->next = NULL;
3795 newlist = h;
3796 }
3797 else if (h->sort_key < newlist->sort_key)
3798 {
3799 h->next = newlist;
3800 newlist = h;
3801 }
3802 else
3803 {
3804 host_item *hh = newlist;
3805 while (hh->next)
3806 {
3807 if (h->sort_key < hh->next->sort_key) break;
3808 hh = hh->next;
3809 }
3810 h->next = hh->next;
3811 hh->next = h;
3812 }
3813 }
3814