d424c182cdf85208ed3008d223ee50997a8b120c
[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
190 #ifdef MACRO_PREDEF
191
192 /* Dummy values */
193 smtp_transport_options_block smtp_transport_option_defaults = {0};
194 void smtp_transport_init(transport_instance *tblock) {}
195 BOOL smtp_transport_entry(transport_instance *tblock, address_item *addr) {return FALSE;}
196 void smtp_transport_closedown(transport_instance *tblock) {}
197
198 #else /*!MACRO_PREDEF*/
199
200
201 /* Default private options block for the smtp transport. */
202
203 smtp_transport_options_block smtp_transport_option_defaults = {
204 NULL, /* hosts */
205 NULL, /* fallback_hosts */
206 NULL, /* hostlist */
207 NULL, /* fallback_hostlist */
208 NULL, /* authenticated_sender */
209 US"$primary_hostname", /* helo_data */
210 NULL, /* interface */
211 NULL, /* port */
212 US"smtp", /* protocol */
213 NULL, /* DSCP */
214 NULL, /* serialize_hosts */
215 NULL, /* hosts_try_auth */
216 NULL, /* hosts_require_auth */
217 US"*", /* hosts_try_chunking */
218 #ifdef EXPERIMENTAL_DANE
219 NULL, /* hosts_try_dane */
220 NULL, /* hosts_require_dane */
221 #endif
222 NULL, /* hosts_try_fastopen */
223 #ifndef DISABLE_PRDR
224 US"*", /* hosts_try_prdr */
225 #endif
226 #ifndef DISABLE_OCSP
227 US"*", /* hosts_request_ocsp (except under DANE; tls_client_start()) */
228 NULL, /* hosts_require_ocsp */
229 #endif
230 NULL, /* hosts_require_tls */
231 NULL, /* hosts_avoid_tls */
232 NULL, /* hosts_verify_avoid_tls */
233 NULL, /* hosts_avoid_pipelining */
234 NULL, /* hosts_avoid_esmtp */
235 #ifdef SUPPORT_TLS
236 NULL, /* hosts_nopass_tls */
237 US"*", /* hosts_noproxy_tls */
238 #endif
239 5*60, /* command_timeout */
240 5*60, /* connect_timeout; shorter system default overrides */
241 5*60, /* data timeout */
242 10*60, /* final timeout */
243 1024, /* size_addition */
244 5, /* hosts_max_try */
245 50, /* hosts_max_try_hardlimit */
246 TRUE, /* address_retry_include_sender */
247 FALSE, /* allow_localhost */
248 FALSE, /* authenticated_sender_force */
249 FALSE, /* gethostbyname */
250 TRUE, /* dns_qualify_single */
251 FALSE, /* dns_search_parents */
252 { NULL, NULL }, /* dnssec_domains {request,require} */
253 TRUE, /* delay_after_cutoff */
254 FALSE, /* hosts_override */
255 FALSE, /* hosts_randomize */
256 TRUE, /* keepalive */
257 FALSE, /* lmtp_ignore_quota */
258 NULL, /* expand_retry_include_ip_address */
259 TRUE /* retry_include_ip_address */
260 #ifdef SUPPORT_SOCKS
261 ,NULL /* socks_proxy */
262 #endif
263 #ifdef SUPPORT_TLS
264 ,NULL, /* tls_certificate */
265 NULL, /* tls_crl */
266 NULL, /* tls_privatekey */
267 NULL, /* tls_require_ciphers */
268 NULL, /* tls_sni */
269 US"system", /* tls_verify_certificates */
270 EXIM_CLIENT_DH_DEFAULT_MIN_BITS,
271 /* tls_dh_min_bits */
272 TRUE, /* tls_tempfail_tryclear */
273 NULL, /* tls_verify_hosts */
274 US"*", /* tls_try_verify_hosts */
275 US"*" /* tls_verify_cert_hostnames */
276 #endif
277 #ifndef DISABLE_DKIM
278 , {NULL, /* dkim_canon */
279 NULL, /* dkim_domain */
280 NULL, /* dkim_private_key */
281 NULL, /* dkim_selector */
282 NULL, /* dkim_sign_headers */
283 NULL, /* dkim_strict */
284 FALSE} /* dot_stuffed */
285 #endif
286 };
287
288 /* some DSN flags for use later */
289
290 static int rf_list[] = {rf_notify_never, rf_notify_success,
291 rf_notify_failure, rf_notify_delay };
292
293 static uschar *rf_names[] = { US"NEVER", US"SUCCESS", US"FAILURE", US"DELAY" };
294
295
296
297 /* Local statics */
298
299 static uschar *smtp_command; /* Points to last cmd for error messages */
300 static uschar *mail_command; /* Points to MAIL cmd for error messages */
301 static uschar *data_command = US""; /* Points to DATA cmd for error messages */
302 static BOOL update_waiting; /* TRUE to update the "wait" database */
303
304 /*XXX move to smtp_context */
305 static BOOL pipelining_active; /* current transaction is in pipe mode */
306
307
308 /*************************************************
309 * Setup entry point *
310 *************************************************/
311
312 /* This function is called when the transport is about to be used,
313 but before running it in a sub-process. It is used for two things:
314
315 (1) To set the fallback host list in addresses, when delivering.
316 (2) To pass back the interface, port, protocol, and other options, for use
317 during callout verification.
318
319 Arguments:
320 tblock pointer to the transport instance block
321 addrlist list of addresses about to be transported
322 tf if not NULL, pointer to block in which to return options
323 uid the uid that will be set (not used)
324 gid the gid that will be set (not used)
325 errmsg place for error message (not used)
326
327 Returns: OK always (FAIL, DEFER not used)
328 */
329
330 static int
331 smtp_transport_setup(transport_instance *tblock, address_item *addrlist,
332 transport_feedback *tf, uid_t uid, gid_t gid, uschar **errmsg)
333 {
334 smtp_transport_options_block *ob =
335 (smtp_transport_options_block *)(tblock->options_block);
336
337 errmsg = errmsg; /* Keep picky compilers happy */
338 uid = uid;
339 gid = gid;
340
341 /* Pass back options if required. This interface is getting very messy. */
342
343 if (tf)
344 {
345 tf->interface = ob->interface;
346 tf->port = ob->port;
347 tf->protocol = ob->protocol;
348 tf->hosts = ob->hosts;
349 tf->hosts_override = ob->hosts_override;
350 tf->hosts_randomize = ob->hosts_randomize;
351 tf->gethostbyname = ob->gethostbyname;
352 tf->qualify_single = ob->dns_qualify_single;
353 tf->search_parents = ob->dns_search_parents;
354 tf->helo_data = ob->helo_data;
355 }
356
357 /* Set the fallback host list for all the addresses that don't have fallback
358 host lists, provided that the local host wasn't present in the original host
359 list. */
360
361 if (!testflag(addrlist, af_local_host_removed))
362 for (; addrlist; addrlist = addrlist->next)
363 if (!addrlist->fallback_hosts) addrlist->fallback_hosts = ob->fallback_hostlist;
364
365 return OK;
366 }
367
368
369
370 /*************************************************
371 * Initialization entry point *
372 *************************************************/
373
374 /* Called for each instance, after its options have been read, to
375 enable consistency checks to be done, or anything else that needs
376 to be set up.
377
378 Argument: pointer to the transport instance block
379 Returns: nothing
380 */
381
382 void
383 smtp_transport_init(transport_instance *tblock)
384 {
385 smtp_transport_options_block *ob =
386 (smtp_transport_options_block *)(tblock->options_block);
387
388 /* Retry_use_local_part defaults FALSE if unset */
389
390 if (tblock->retry_use_local_part == TRUE_UNSET)
391 tblock->retry_use_local_part = FALSE;
392
393 /* Set the default port according to the protocol */
394
395 if (ob->port == NULL)
396 ob->port = (strcmpic(ob->protocol, US"lmtp") == 0)? US"lmtp" :
397 (strcmpic(ob->protocol, US"smtps") == 0)? US"smtps" : US"smtp";
398
399 /* Set up the setup entry point, to be called before subprocesses for this
400 transport. */
401
402 tblock->setup = smtp_transport_setup;
403
404 /* Complain if any of the timeouts are zero. */
405
406 if (ob->command_timeout <= 0 || ob->data_timeout <= 0 ||
407 ob->final_timeout <= 0)
408 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
409 "command, data, or final timeout value is zero for %s transport",
410 tblock->name);
411
412 /* If hosts_override is set and there are local hosts, set the global
413 flag that stops verify from showing router hosts. */
414
415 if (ob->hosts_override && ob->hosts != NULL) tblock->overrides_hosts = TRUE;
416
417 /* If there are any fallback hosts listed, build a chain of host items
418 for them, but do not do any lookups at this time. */
419
420 host_build_hostlist(&(ob->fallback_hostlist), ob->fallback_hosts, FALSE);
421 }
422
423
424
425
426
427 /*************************************************
428 * Set delivery info into all active addresses *
429 *************************************************/
430
431 /* Only addresses whose status is >= PENDING are relevant. A lesser
432 status means that an address is not currently being processed.
433
434 Arguments:
435 addrlist points to a chain of addresses
436 errno_value to put in each address's errno field
437 msg to put in each address's message field
438 rc to put in each address's transport_return field
439 pass_message if TRUE, set the "pass message" flag in the address
440 host if set, mark addrs as having used this host
441 smtp_greeting from peer
442 helo_response from peer
443
444 If errno_value has the special value ERRNO_CONNECTTIMEOUT, ETIMEDOUT is put in
445 the errno field, and RTEF_CTOUT is ORed into the more_errno field, to indicate
446 this particular type of timeout.
447
448 Returns: nothing
449 */
450
451 static void
452 set_errno(address_item *addrlist, int errno_value, uschar *msg, int rc,
453 BOOL pass_message, host_item * host
454 #ifdef EXPERIMENTAL_DSN_INFO
455 , const uschar * smtp_greeting, const uschar * helo_response
456 #endif
457 )
458 {
459 address_item *addr;
460 int orvalue = 0;
461 if (errno_value == ERRNO_CONNECTTIMEOUT)
462 {
463 errno_value = ETIMEDOUT;
464 orvalue = RTEF_CTOUT;
465 }
466 for (addr = addrlist; addr; addr = addr->next)
467 if (addr->transport_return >= PENDING)
468 {
469 addr->basic_errno = errno_value;
470 addr->more_errno |= orvalue;
471 if (msg)
472 {
473 addr->message = msg;
474 if (pass_message) setflag(addr, af_pass_message);
475 }
476 addr->transport_return = rc;
477 if (host)
478 {
479 addr->host_used = host;
480 #ifdef EXPERIMENTAL_DSN_INFO
481 if (smtp_greeting)
482 {uschar * s = Ustrchr(smtp_greeting, '\n'); if (s) *s = '\0';}
483 addr->smtp_greeting = smtp_greeting;
484
485 if (helo_response)
486 {uschar * s = Ustrchr(helo_response, '\n'); if (s) *s = '\0';}
487 addr->helo_response = helo_response;
488 #endif
489 }
490 }
491 }
492
493 static void
494 set_errno_nohost(address_item *addrlist, int errno_value, uschar *msg, int rc,
495 BOOL pass_message)
496 {
497 set_errno(addrlist, errno_value, msg, rc, pass_message, NULL
498 #ifdef EXPERIMENTAL_DSN_INFO
499 , NULL, NULL
500 #endif
501 );
502 }
503
504
505 /*************************************************
506 * Check an SMTP response *
507 *************************************************/
508
509 /* This function is given an errno code and the SMTP response buffer
510 to analyse, together with the host identification for generating messages. It
511 sets an appropriate message and puts the first digit of the response code into
512 the yield variable. If no response was actually read, a suitable digit is
513 chosen.
514
515 Arguments:
516 host the current host, to get its name for messages
517 errno_value pointer to the errno value
518 more_errno from the top address for use with ERRNO_FILTER_FAIL
519 buffer the SMTP response buffer
520 yield where to put a one-digit SMTP response code
521 message where to put an error message
522 pass_message set TRUE if message is an SMTP response
523
524 Returns: TRUE if an SMTP "QUIT" command should be sent, else FALSE
525 */
526
527 static BOOL
528 check_response(host_item *host, int *errno_value, int more_errno,
529 uschar *buffer, int *yield, uschar **message, BOOL *pass_message)
530 {
531 uschar * pl = pipelining_active ? US"pipelined " : US"";
532 const uschar * s;
533
534 *yield = '4'; /* Default setting is to give a temporary error */
535
536 switch(*errno_value)
537 {
538 case ETIMEDOUT: /* Handle response timeout */
539 *message = US string_sprintf("SMTP timeout after %s%s",
540 pl, smtp_command);
541 if (transport_count > 0)
542 *message = US string_sprintf("%s (%d bytes written)", *message,
543 transport_count);
544 return FALSE;
545
546 case ERRNO_SMTPFORMAT: /* Handle malformed SMTP response */
547 s = string_printing(buffer);
548 while (isspace(*s)) s++;
549 *message = *s == 0
550 ? string_sprintf("Malformed SMTP reply (an empty line) "
551 "in response to %s%s", pl, smtp_command)
552 : string_sprintf("Malformed SMTP reply in response to %s%s: %s",
553 pl, smtp_command, s);
554 return FALSE;
555
556 case ERRNO_FILTER_FAIL: /* Handle a failed filter process error;
557 can't send QUIT as we mustn't end the DATA. */
558 *message = string_sprintf("transport filter process failed (%d)%s",
559 more_errno,
560 more_errno == EX_EXECFAILED ? ": unable to execute command" : "");
561 return FALSE;
562
563 case ERRNO_CHHEADER_FAIL: /* Handle a failed add_headers expansion;
564 can't send QUIT as we mustn't end the DATA. */
565 *message =
566 string_sprintf("failed to expand headers_add or headers_remove: %s",
567 expand_string_message);
568 return FALSE;
569
570 case ERRNO_WRITEINCOMPLETE: /* failure to write a complete data block */
571 *message = string_sprintf("failed to write a data block");
572 return FALSE;
573
574 #ifdef SUPPORT_I18N
575 case ERRNO_UTF8_FWD: /* no advertised SMTPUTF8, for international message */
576 *message = US"utf8 support required but not offered for forwarding";
577 DEBUG(D_deliver|D_transport) debug_printf("%s\n", *message);
578 return TRUE;
579 #endif
580 }
581
582 /* Handle error responses from the remote mailer. */
583
584 if (buffer[0] != 0)
585 {
586 *message = string_sprintf("SMTP error from remote mail server after %s%s: "
587 "%s", pl, smtp_command, s = string_printing(buffer));
588 *pass_message = TRUE;
589 *yield = buffer[0];
590 return TRUE;
591 }
592
593 /* No data was read. If there is no errno, this must be the EOF (i.e.
594 connection closed) case, which causes deferral. An explicit connection reset
595 error has the same effect. Otherwise, put the host's identity in the message,
596 leaving the errno value to be interpreted as well. In all cases, we have to
597 assume the connection is now dead. */
598
599 if (*errno_value == 0 || *errno_value == ECONNRESET)
600 {
601 *errno_value = ERRNO_SMTPCLOSED;
602 *message = US string_sprintf("Remote host closed connection "
603 "in response to %s%s", pl, smtp_command);
604 }
605 else
606 *message = US string_sprintf("%s [%s]", host->name, host->address);
607
608 return FALSE;
609 }
610
611
612
613 /*************************************************
614 * Write error message to logs *
615 *************************************************/
616
617 /* This writes to the main log and to the message log.
618
619 Arguments:
620 addr the address item containing error information
621 host the current host
622
623 Returns: nothing
624 */
625
626 static void
627 write_logs(address_item *addr, host_item *host)
628 {
629 uschar * message = LOGGING(outgoing_port)
630 ? string_sprintf("H=%s [%s]:%d", host->name, host->address,
631 host->port == PORT_NONE ? 25 : host->port)
632 : string_sprintf("H=%s [%s]", host->name, host->address);
633
634 if (addr->message)
635 {
636 message = string_sprintf("%s: %s", message, addr->message);
637 if (addr->basic_errno > 0)
638 message = string_sprintf("%s: %s", message, strerror(addr->basic_errno));
639 log_write(0, LOG_MAIN, "%s", message);
640 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
641 }
642 else
643 {
644 const uschar * s = exim_errstr(addr->basic_errno);
645 log_write(0, LOG_MAIN, "%s %s", message, s);
646 deliver_msglog("%s %s %s\n", tod_stamp(tod_log), message, s);
647 }
648 }
649
650 static void
651 msglog_line(host_item * host, uschar * message)
652 {
653 deliver_msglog("%s H=%s [%s] %s\n", tod_stamp(tod_log),
654 host->name, host->address, message);
655 }
656
657
658
659 #ifndef DISABLE_EVENT
660 /*************************************************
661 * Post-defer action *
662 *************************************************/
663
664 /* This expands an arbitrary per-transport string.
665 It might, for example, be used to write to the database log.
666
667 Arguments:
668 addr the address item containing error information
669 host the current host
670
671 Returns: nothing
672 */
673
674 static void
675 deferred_event_raise(address_item *addr, host_item *host)
676 {
677 uschar * action = addr->transport->event_action;
678 const uschar * save_domain;
679 uschar * save_local;
680
681 if (!action)
682 return;
683
684 save_domain = deliver_domain;
685 save_local = deliver_localpart;
686
687 /*XXX would ip & port already be set up? */
688 deliver_host_address = string_copy(host->address);
689 deliver_host_port = host->port == PORT_NONE ? 25 : host->port;
690 event_defer_errno = addr->basic_errno;
691
692 router_name = addr->router->name;
693 transport_name = addr->transport->name;
694 deliver_domain = addr->domain;
695 deliver_localpart = addr->local_part;
696
697 (void) event_raise(action, US"msg:host:defer",
698 addr->message
699 ? addr->basic_errno > 0
700 ? string_sprintf("%s: %s", addr->message, strerror(addr->basic_errno))
701 : string_copy(addr->message)
702 : addr->basic_errno > 0
703 ? string_copy(US strerror(addr->basic_errno))
704 : NULL);
705
706 deliver_localpart = save_local;
707 deliver_domain = save_domain;
708 router_name = transport_name = NULL;
709 }
710 #endif
711
712 /*************************************************
713 * Synchronize SMTP responses *
714 *************************************************/
715
716 /* This function is called from smtp_deliver() to receive SMTP responses from
717 the server, and match them up with the commands to which they relate. When
718 PIPELINING is not in use, this function is called after every command, and is
719 therefore somewhat over-engineered, but it is simpler to use a single scheme
720 that works both with and without PIPELINING instead of having two separate sets
721 of code.
722
723 The set of commands that are buffered up with pipelining may start with MAIL
724 and may end with DATA; in between are RCPT commands that correspond to the
725 addresses whose status is PENDING_DEFER. All other commands (STARTTLS, AUTH,
726 etc.) are never buffered.
727
728 Errors after MAIL or DATA abort the whole process leaving the response in the
729 buffer. After MAIL, pending responses are flushed, and the original command is
730 re-instated in big_buffer for error messages. For RCPT commands, the remote is
731 permitted to reject some recipient addresses while accepting others. However
732 certain errors clearly abort the whole process. Set the value in
733 transport_return to PENDING_OK if the address is accepted. If there is a
734 subsequent general error, it will get reset accordingly. If not, it will get
735 converted to OK at the end.
736
737 Arguments:
738 sx smtp connection context
739 count the number of responses to read
740 pending_DATA 0 if last command sent was not DATA
741 +1 if previously had a good recipient
742 -1 if not previously had a good recipient
743
744 Returns: 3 if at least one address had 2xx and one had 5xx
745 2 if at least one address had 5xx but none had 2xx
746 1 if at least one host had a 2xx response, but none had 5xx
747 0 no address had 2xx or 5xx but no errors (all 4xx, or just DATA)
748 -1 timeout while reading RCPT response
749 -2 I/O or other non-response error for RCPT
750 -3 DATA or MAIL failed - errno and buffer set
751 */
752
753 static int
754 sync_responses(smtp_context * sx, int count, int pending_DATA)
755 {
756 address_item *addr = sx->sync_addr;
757 smtp_transport_options_block *ob =
758 (smtp_transport_options_block *)sx->tblock->options_block;
759 int yield = 0;
760
761 /* Handle the response for a MAIL command. On error, reinstate the original
762 command in big_buffer for error message use, and flush any further pending
763 responses before returning, except after I/O errors and timeouts. */
764
765 if (sx->pending_MAIL)
766 {
767 count--;
768 if (!smtp_read_response(&sx->inblock, sx->buffer, sizeof(sx->buffer),
769 '2', ob->command_timeout))
770 {
771 DEBUG(D_transport) debug_printf("bad response for MAIL\n");
772 Ustrcpy(big_buffer, mail_command); /* Fits, because it came from there! */
773 if (errno == 0 && sx->buffer[0] != 0)
774 {
775 uschar flushbuffer[4096];
776 int save_errno = 0;
777 if (sx->buffer[0] == '4')
778 {
779 save_errno = ERRNO_MAIL4XX;
780 addr->more_errno |= ((sx->buffer[1] - '0')*10 + sx->buffer[2] - '0') << 8;
781 }
782 while (count-- > 0)
783 {
784 if (!smtp_read_response(&sx->inblock, flushbuffer, sizeof(flushbuffer),
785 '2', ob->command_timeout)
786 && (errno != 0 || flushbuffer[0] == 0))
787 break;
788 }
789 errno = save_errno;
790 }
791
792 if (pending_DATA) count--; /* Number of RCPT responses to come */
793 while (count-- > 0) /* Mark any pending addrs with the host used */
794 {
795 while (addr->transport_return != PENDING_DEFER) addr = addr->next;
796 addr->host_used = sx->host;
797 addr = addr->next;
798 }
799 return -3;
800 }
801 }
802
803 if (pending_DATA) count--; /* Number of RCPT responses to come */
804
805 /* Read and handle the required number of RCPT responses, matching each one up
806 with an address by scanning for the next address whose status is PENDING_DEFER.
807 */
808
809 while (count-- > 0)
810 {
811 while (addr->transport_return != PENDING_DEFER)
812 if (!(addr = addr->next))
813 return -2;
814
815 /* The address was accepted */
816 addr->host_used = sx->host;
817
818 if (smtp_read_response(&sx->inblock, sx->buffer, sizeof(sx->buffer),
819 '2', ob->command_timeout))
820 {
821 yield |= 1;
822 addr->transport_return = PENDING_OK;
823
824 /* If af_dr_retry_exists is set, there was a routing delay on this address;
825 ensure that any address-specific retry record is expunged. We do this both
826 for the basic key and for the version that also includes the sender. */
827
828 if (testflag(addr, af_dr_retry_exists))
829 {
830 uschar *altkey = string_sprintf("%s:<%s>", addr->address_retry_key,
831 sender_address);
832 retry_add_item(addr, altkey, rf_delete);
833 retry_add_item(addr, addr->address_retry_key, rf_delete);
834 }
835 }
836
837 /* Timeout while reading the response */
838
839 else if (errno == ETIMEDOUT)
840 {
841 uschar *message = string_sprintf("SMTP timeout after RCPT TO:<%s>",
842 transport_rcpt_address(addr, sx->tblock->rcpt_include_affixes));
843 set_errno_nohost(sx->first_addr, ETIMEDOUT, message, DEFER, FALSE);
844 retry_add_item(addr, addr->address_retry_key, 0);
845 update_waiting = FALSE;
846 return -1;
847 }
848
849 /* Handle other errors in obtaining an SMTP response by returning -1. This
850 will cause all the addresses to be deferred. Restore the SMTP command in
851 big_buffer for which we are checking the response, so the error message
852 makes sense. */
853
854 else if (errno != 0 || sx->buffer[0] == 0)
855 {
856 string_format(big_buffer, big_buffer_size, "RCPT TO:<%s>",
857 transport_rcpt_address(addr, sx->tblock->rcpt_include_affixes));
858 return -2;
859 }
860
861 /* Handle SMTP permanent and temporary response codes. */
862
863 else
864 {
865 addr->message =
866 string_sprintf("SMTP error from remote mail server after RCPT TO:<%s>: "
867 "%s", transport_rcpt_address(addr, sx->tblock->rcpt_include_affixes),
868 string_printing(sx->buffer));
869 setflag(addr, af_pass_message);
870 if (!sx->verify)
871 msglog_line(sx->host, addr->message);
872
873 /* The response was 5xx */
874
875 if (sx->buffer[0] == '5')
876 {
877 addr->transport_return = FAIL;
878 yield |= 2;
879 }
880
881 /* The response was 4xx */
882
883 else
884 {
885 addr->transport_return = DEFER;
886 addr->basic_errno = ERRNO_RCPT4XX;
887 addr->more_errno |= ((sx->buffer[1] - '0')*10 + sx->buffer[2] - '0') << 8;
888
889 if (!sx->verify)
890 {
891 #ifndef DISABLE_EVENT
892 event_defer_errno = addr->more_errno;
893 msg_event_raise(US"msg:rcpt:host:defer", addr);
894 #endif
895
896 /* Log temporary errors if there are more hosts to be tried.
897 If not, log this last one in the == line. */
898
899 if (sx->host->next)
900 log_write(0, LOG_MAIN, "H=%s [%s]: %s",
901 sx->host->name, sx->host->address, addr->message);
902
903 #ifndef DISABLE_EVENT
904 else
905 msg_event_raise(US"msg:rcpt:defer", addr);
906 #endif
907
908 /* Do not put this message on the list of those waiting for specific
909 hosts, as otherwise it is likely to be tried too often. */
910
911 update_waiting = FALSE;
912
913 /* Add a retry item for the address so that it doesn't get tried again
914 too soon. If address_retry_include_sender is true, add the sender address
915 to the retry key. */
916
917 retry_add_item(addr,
918 ob->address_retry_include_sender
919 ? string_sprintf("%s:<%s>", addr->address_retry_key, sender_address)
920 : addr->address_retry_key,
921 0);
922 }
923 }
924 }
925 } /* Loop for next RCPT response */
926
927 /* Update where to start at for the next block of responses, unless we
928 have already handled all the addresses. */
929
930 if (addr) sx->sync_addr = addr->next;
931
932 /* Handle a response to DATA. If we have not had any good recipients, either
933 previously or in this block, the response is ignored. */
934
935 if (pending_DATA != 0 &&
936 !smtp_read_response(&sx->inblock, sx->buffer, sizeof(sx->buffer),
937 '3', ob->command_timeout))
938 {
939 int code;
940 uschar *msg;
941 BOOL pass_message;
942 if (pending_DATA > 0 || (yield & 1) != 0)
943 {
944 if (errno == 0 && sx->buffer[0] == '4')
945 {
946 errno = ERRNO_DATA4XX;
947 sx->first_addr->more_errno |= ((sx->buffer[1] - '0')*10 + sx->buffer[2] - '0') << 8;
948 }
949 return -3;
950 }
951 (void)check_response(sx->host, &errno, 0, sx->buffer, &code, &msg, &pass_message);
952 DEBUG(D_transport) debug_printf("%s\nerror for DATA ignored: pipelining "
953 "is in use and there were no good recipients\n", msg);
954 }
955
956 /* All responses read and handled; MAIL (if present) received 2xx and DATA (if
957 present) received 3xx. If any RCPTs were handled and yielded anything other
958 than 4xx, yield will be set non-zero. */
959
960 return yield;
961 }
962
963
964
965 /* Do the client side of smtp-level authentication */
966 /*
967 Arguments:
968 buffer EHLO response from server (gets overwritten)
969 addrlist chain of potential addresses to deliver
970 host host to deliver to
971 ob transport options
972 ibp, obp comms channel control blocks
973
974 Returns:
975 OK Success, or failed (but not required): global "smtp_authenticated" set
976 DEFER Failed authentication (and was required)
977 ERROR Internal problem
978
979 FAIL_SEND Failed communications - transmit
980 FAIL - response
981 */
982
983 int
984 smtp_auth(uschar *buffer, unsigned bufsize, address_item *addrlist, host_item *host,
985 smtp_transport_options_block *ob, BOOL is_esmtp,
986 smtp_inblock *ibp, smtp_outblock *obp)
987 {
988 int require_auth;
989 uschar *fail_reason = US"server did not advertise AUTH support";
990
991 smtp_authenticated = FALSE;
992 client_authenticator = client_authenticated_id = client_authenticated_sender = NULL;
993 require_auth = verify_check_given_host(&ob->hosts_require_auth, host);
994
995 if (is_esmtp && !regex_AUTH) regex_AUTH =
996 regex_must_compile(US"\\n250[\\s\\-]AUTH\\s+([\\-\\w\\s]+)(?:\\n|$)",
997 FALSE, TRUE);
998
999 if (is_esmtp && regex_match_and_setup(regex_AUTH, buffer, 0, -1))
1000 {
1001 uschar *names = string_copyn(expand_nstring[1], expand_nlength[1]);
1002 expand_nmax = -1; /* reset */
1003
1004 /* Must not do this check until after we have saved the result of the
1005 regex match above. */
1006
1007 if (require_auth == OK ||
1008 verify_check_given_host(&ob->hosts_try_auth, host) == OK)
1009 {
1010 auth_instance *au;
1011 fail_reason = US"no common mechanisms were found";
1012
1013 DEBUG(D_transport) debug_printf("scanning authentication mechanisms\n");
1014
1015 /* Scan the configured authenticators looking for one which is configured
1016 for use as a client, which is not suppressed by client_condition, and
1017 whose name matches an authentication mechanism supported by the server.
1018 If one is found, attempt to authenticate by calling its client function.
1019 */
1020
1021 for (au = auths; !smtp_authenticated && au != NULL; au = au->next)
1022 {
1023 uschar *p = names;
1024 if (!au->client ||
1025 (au->client_condition != NULL &&
1026 !expand_check_condition(au->client_condition, au->name,
1027 US"client authenticator")))
1028 {
1029 DEBUG(D_transport) debug_printf("skipping %s authenticator: %s\n",
1030 au->name,
1031 (au->client)? "client_condition is false" :
1032 "not configured as a client");
1033 continue;
1034 }
1035
1036 /* Loop to scan supported server mechanisms */
1037
1038 while (*p != 0)
1039 {
1040 int rc;
1041 int len = Ustrlen(au->public_name);
1042 while (isspace(*p)) p++;
1043
1044 if (strncmpic(au->public_name, p, len) != 0 ||
1045 (p[len] != 0 && !isspace(p[len])))
1046 {
1047 while (*p != 0 && !isspace(*p)) p++;
1048 continue;
1049 }
1050
1051 /* Found data for a listed mechanism. Call its client entry. Set
1052 a flag in the outblock so that data is overwritten after sending so
1053 that reflections don't show it. */
1054
1055 fail_reason = US"authentication attempt(s) failed";
1056 obp->authenticating = TRUE;
1057 rc = (au->info->clientcode)(au, ibp, obp,
1058 ob->command_timeout, buffer, bufsize);
1059 obp->authenticating = FALSE;
1060 DEBUG(D_transport) debug_printf("%s authenticator yielded %d\n",
1061 au->name, rc);
1062
1063 /* A temporary authentication failure must hold up delivery to
1064 this host. After a permanent authentication failure, we carry on
1065 to try other authentication methods. If all fail hard, try to
1066 deliver the message unauthenticated unless require_auth was set. */
1067
1068 switch(rc)
1069 {
1070 case OK:
1071 smtp_authenticated = TRUE; /* stops the outer loop */
1072 client_authenticator = au->name;
1073 if (au->set_client_id != NULL)
1074 client_authenticated_id = expand_string(au->set_client_id);
1075 break;
1076
1077 /* Failure after writing a command */
1078
1079 case FAIL_SEND:
1080 return FAIL_SEND;
1081
1082 /* Failure after reading a response */
1083
1084 case FAIL:
1085 if (errno != 0 || buffer[0] != '5') return FAIL;
1086 log_write(0, LOG_MAIN, "%s authenticator failed H=%s [%s] %s",
1087 au->name, host->name, host->address, buffer);
1088 break;
1089
1090 /* Failure by some other means. In effect, the authenticator
1091 decided it wasn't prepared to handle this case. Typically this
1092 is the result of "fail" in an expansion string. Do we need to
1093 log anything here? Feb 2006: a message is now put in the buffer
1094 if logging is required. */
1095
1096 case CANCELLED:
1097 if (*buffer != 0)
1098 log_write(0, LOG_MAIN, "%s authenticator cancelled "
1099 "authentication H=%s [%s] %s", au->name, host->name,
1100 host->address, buffer);
1101 break;
1102
1103 /* Internal problem, message in buffer. */
1104
1105 case ERROR:
1106 set_errno_nohost(addrlist, ERRNO_AUTHPROB, string_copy(buffer),
1107 DEFER, FALSE);
1108 return ERROR;
1109 }
1110
1111 break; /* If not authenticated, try next authenticator */
1112 } /* Loop for scanning supported server mechanisms */
1113 } /* Loop for further authenticators */
1114 }
1115 }
1116
1117 /* If we haven't authenticated, but are required to, give up. */
1118
1119 if (require_auth == OK && !smtp_authenticated)
1120 {
1121 set_errno_nohost(addrlist, ERRNO_AUTHFAIL,
1122 string_sprintf("authentication required but %s", fail_reason), DEFER,
1123 FALSE);
1124 return DEFER;
1125 }
1126
1127 return OK;
1128 }
1129
1130
1131 /* Construct AUTH appendix string for MAIL TO */
1132 /*
1133 Arguments
1134 buffer to build string
1135 addrlist chain of potential addresses to deliver
1136 ob transport options
1137
1138 Globals smtp_authenticated
1139 client_authenticated_sender
1140 Return True on error, otherwise buffer has (possibly empty) terminated string
1141 */
1142
1143 BOOL
1144 smtp_mail_auth_str(uschar *buffer, unsigned bufsize, address_item *addrlist,
1145 smtp_transport_options_block *ob)
1146 {
1147 uschar *local_authenticated_sender = authenticated_sender;
1148
1149 #ifdef notdef
1150 debug_printf("smtp_mail_auth_str: as<%s> os<%s> SA<%s>\n", authenticated_sender, ob->authenticated_sender, smtp_authenticated?"Y":"N");
1151 #endif
1152
1153 if (ob->authenticated_sender != NULL)
1154 {
1155 uschar *new = expand_string(ob->authenticated_sender);
1156 if (new == NULL)
1157 {
1158 if (!expand_string_forcedfail)
1159 {
1160 uschar *message = string_sprintf("failed to expand "
1161 "authenticated_sender: %s", expand_string_message);
1162 set_errno_nohost(addrlist, ERRNO_EXPANDFAIL, message, DEFER, FALSE);
1163 return TRUE;
1164 }
1165 }
1166 else if (new[0] != 0) local_authenticated_sender = new;
1167 }
1168
1169 /* Add the authenticated sender address if present */
1170
1171 if ((smtp_authenticated || ob->authenticated_sender_force) &&
1172 local_authenticated_sender != NULL)
1173 {
1174 string_format(buffer, bufsize, " AUTH=%s",
1175 auth_xtextencode(local_authenticated_sender,
1176 Ustrlen(local_authenticated_sender)));
1177 client_authenticated_sender = string_copy(local_authenticated_sender);
1178 }
1179 else
1180 *buffer= 0;
1181
1182 return FALSE;
1183 }
1184
1185
1186
1187 #ifdef EXPERIMENTAL_DANE
1188 /* Lookup TLSA record for host/port.
1189 Return: OK success with dnssec; DANE mode
1190 DEFER Do not use this host now, may retry later
1191 FAIL_FORCED No TLSA record; DANE not usable
1192 FAIL Do not use this connection
1193 */
1194
1195 int
1196 tlsa_lookup(const host_item * host, dns_answer * dnsa, BOOL dane_required)
1197 {
1198 /* move this out to host.c given the similarity to dns_lookup() ? */
1199 uschar buffer[300];
1200 const uschar * fullname = buffer;
1201 int rc;
1202 BOOL sec;
1203
1204 /* TLSA lookup string */
1205 (void)sprintf(CS buffer, "_%d._tcp.%.256s", host->port, host->name);
1206
1207 rc = dns_lookup(dnsa, buffer, T_TLSA, &fullname);
1208 sec = dns_is_secure(dnsa);
1209 DEBUG(D_transport)
1210 debug_printf("TLSA lookup ret %d %sDNSSEC\n", rc, sec ? "" : "not ");
1211
1212 switch (rc)
1213 {
1214 case DNS_SUCCEED:
1215 if (sec) return OK;
1216
1217 log_write(0, LOG_MAIN, "DANE error: TLSA lookup not DNSSEC");
1218 /*FALLTHROUGH*/
1219 case DNS_AGAIN:
1220 return DEFER; /* just defer this TLS'd conn */
1221
1222 case DNS_NODATA: /* no TLSA RR for this lookup */
1223 case DNS_NOMATCH: /* no records at all for this lookup */
1224 return dane_required ? FAIL : FAIL_FORCED;
1225
1226 default:
1227 case DNS_FAIL:
1228 return dane_required ? FAIL : DEFER;
1229 }
1230 }
1231 #endif
1232
1233
1234
1235 typedef struct smtp_compare_s
1236 {
1237 uschar *current_sender_address;
1238 struct transport_instance *tblock;
1239 } smtp_compare_t;
1240
1241
1242 /* Create a unique string that identifies this message, it is based on
1243 sender_address, helo_data and tls_certificate if enabled.
1244 */
1245
1246 static uschar *
1247 smtp_local_identity(uschar * sender, struct transport_instance * tblock)
1248 {
1249 address_item * addr1;
1250 uschar * if1 = US"";
1251 uschar * helo1 = US"";
1252 #ifdef SUPPORT_TLS
1253 uschar * tlsc1 = US"";
1254 #endif
1255 uschar * save_sender_address = sender_address;
1256 uschar * local_identity = NULL;
1257 smtp_transport_options_block * ob =
1258 (smtp_transport_options_block *)tblock->options_block;
1259
1260 sender_address = sender;
1261
1262 addr1 = deliver_make_addr (sender, TRUE);
1263 deliver_set_expansions(addr1);
1264
1265 if (ob->interface)
1266 if1 = expand_string(ob->interface);
1267
1268 if (ob->helo_data)
1269 helo1 = expand_string(ob->helo_data);
1270
1271 #ifdef SUPPORT_TLS
1272 if (ob->tls_certificate)
1273 tlsc1 = expand_string(ob->tls_certificate);
1274 local_identity = string_sprintf ("%s^%s^%s", if1, helo1, tlsc1);
1275 #else
1276 local_identity = string_sprintf ("%s^%s", if1, helo1);
1277 #endif
1278
1279 deliver_set_expansions(NULL);
1280 sender_address = save_sender_address;
1281
1282 return local_identity;
1283 }
1284
1285
1286
1287 /* This routine is a callback that is called from transport_check_waiting.
1288 This function will evaluate the incoming message versus the previous
1289 message. If the incoming message is using a different local identity then
1290 we will veto this new message. */
1291
1292 static BOOL
1293 smtp_are_same_identities(uschar * message_id, smtp_compare_t * s_compare)
1294 {
1295 uschar * message_local_identity,
1296 * current_local_identity,
1297 * new_sender_address;
1298
1299 current_local_identity =
1300 smtp_local_identity(s_compare->current_sender_address, s_compare->tblock);
1301
1302 if (!(new_sender_address = deliver_get_sender_address(message_id)))
1303 return 0;
1304
1305 message_local_identity =
1306 smtp_local_identity(new_sender_address, s_compare->tblock);
1307
1308 return Ustrcmp(current_local_identity, message_local_identity) == 0;
1309 }
1310
1311
1312
1313 static uschar
1314 ehlo_response(uschar * buf, uschar checks)
1315 {
1316 size_t bsize = Ustrlen(buf);
1317
1318 #ifdef SUPPORT_TLS
1319 if ( checks & OPTION_TLS
1320 && pcre_exec(regex_STARTTLS, NULL, CS buf, bsize, 0, PCRE_EOPT, NULL, 0) < 0)
1321 checks &= ~OPTION_TLS;
1322 #endif
1323
1324 if ( checks & OPTION_IGNQ
1325 && pcre_exec(regex_IGNOREQUOTA, NULL, CS buf, bsize, 0,
1326 PCRE_EOPT, NULL, 0) < 0)
1327 checks &= ~OPTION_IGNQ;
1328
1329 if ( checks & OPTION_CHUNKING
1330 && pcre_exec(regex_CHUNKING, NULL, CS buf, bsize, 0, PCRE_EOPT, NULL, 0) < 0)
1331 checks &= ~OPTION_CHUNKING;
1332
1333 #ifndef DISABLE_PRDR
1334 if ( checks & OPTION_PRDR
1335 && pcre_exec(regex_PRDR, NULL, CS buf, bsize, 0, PCRE_EOPT, NULL, 0) < 0)
1336 checks &= ~OPTION_PRDR;
1337 #endif
1338
1339 #ifdef SUPPORT_I18N
1340 if ( checks & OPTION_UTF8
1341 && pcre_exec(regex_UTF8, NULL, CS buf, bsize, 0, PCRE_EOPT, NULL, 0) < 0)
1342 checks &= ~OPTION_UTF8;
1343 #endif
1344
1345 if ( checks & OPTION_DSN
1346 && pcre_exec(regex_DSN, NULL, CS buf, bsize, 0, PCRE_EOPT, NULL, 0) < 0)
1347 checks &= ~OPTION_DSN;
1348
1349 if ( checks & OPTION_PIPE
1350 && pcre_exec(regex_PIPELINING, NULL, CS buf, bsize, 0,
1351 PCRE_EOPT, NULL, 0) < 0)
1352 checks &= ~OPTION_PIPE;
1353
1354 if ( checks & OPTION_SIZE
1355 && pcre_exec(regex_SIZE, NULL, CS buf, bsize, 0, PCRE_EOPT, NULL, 0) < 0)
1356 checks &= ~OPTION_SIZE;
1357
1358 return checks;
1359 }
1360
1361
1362
1363 /* Callback for emitting a BDAT data chunk header.
1364
1365 If given a nonzero size, first flush any buffered SMTP commands
1366 then emit the command.
1367
1368 Reap previous SMTP command responses if requested, and always reap
1369 the response from a previous BDAT command.
1370
1371 Args:
1372 tctx transport context
1373 chunk_size value for SMTP BDAT command
1374 flags
1375 tc_chunk_last add LAST option to SMTP BDAT command
1376 tc_reap_prev reap response to previous SMTP commands
1377
1378 Returns: OK or ERROR
1379 */
1380
1381 static int
1382 smtp_chunk_cmd_callback(transport_ctx * tctx, unsigned chunk_size,
1383 unsigned flags)
1384 {
1385 smtp_transport_options_block * ob =
1386 (smtp_transport_options_block *)(tctx->tblock->options_block);
1387 smtp_context * sx = tctx->smtp_context;
1388 int cmd_count = 0;
1389 int prev_cmd_count;
1390
1391 /* Write SMTP chunk header command. If not reaping responses, note that
1392 there may be more writes (like, the chunk data) done soon. */
1393
1394 if (chunk_size > 0)
1395 {
1396 if((cmd_count = smtp_write_command(&sx->outblock,
1397 flags & tc_reap_prev ? SCMD_FLUSH : SCMD_MORE,
1398 "BDAT %u%s\r\n", chunk_size, flags & tc_chunk_last ? " LAST" : "")
1399 ) < 0) return ERROR;
1400 if (flags & tc_chunk_last)
1401 data_command = string_copy(big_buffer); /* Save for later error message */
1402 }
1403
1404 prev_cmd_count = cmd_count += sx->cmd_count;
1405
1406 /* Reap responses for any previous, but not one we just emitted */
1407
1408 if (chunk_size > 0)
1409 prev_cmd_count--;
1410 if (sx->pending_BDAT)
1411 prev_cmd_count--;
1412
1413 if (flags & tc_reap_prev && prev_cmd_count > 0)
1414 {
1415 DEBUG(D_transport) debug_printf("look for %d responses"
1416 " for previous pipelined cmds\n", prev_cmd_count);
1417
1418 switch(sync_responses(sx, prev_cmd_count, 0))
1419 {
1420 case 1: /* 2xx (only) => OK */
1421 case 3: sx->good_RCPT = TRUE; /* 2xx & 5xx => OK & progress made */
1422 case 2: sx->completed_addr = TRUE; /* 5xx (only) => progress made */
1423 case 0: break; /* No 2xx or 5xx, but no probs */
1424
1425 case -1: /* Timeout on RCPT */
1426 default: return ERROR; /* I/O error, or any MAIL/DATA error */
1427 }
1428 cmd_count = 1;
1429 if (!sx->pending_BDAT)
1430 pipelining_active = FALSE;
1431 }
1432
1433 /* Reap response for an outstanding BDAT */
1434
1435 if (sx->pending_BDAT)
1436 {
1437 DEBUG(D_transport) debug_printf("look for one response for BDAT\n");
1438
1439 if (!smtp_read_response(&sx->inblock, sx->buffer, sizeof(sx->buffer), '2',
1440 ob->command_timeout))
1441 {
1442 if (errno == 0 && sx->buffer[0] == '4')
1443 {
1444 errno = ERRNO_DATA4XX; /*XXX does this actually get used? */
1445 sx->addrlist->more_errno |=
1446 ((sx->buffer[1] - '0')*10 + sx->buffer[2] - '0') << 8;
1447 }
1448 return ERROR;
1449 }
1450 cmd_count--;
1451 sx->pending_BDAT = FALSE;
1452 pipelining_active = FALSE;
1453 }
1454 else if (chunk_size > 0)
1455 sx->pending_BDAT = TRUE;
1456
1457
1458 sx->cmd_count = cmd_count;
1459 return OK;
1460 }
1461
1462
1463
1464 /*************************************************
1465 * Make connection for given message *
1466 *************************************************/
1467
1468 /*
1469 Arguments:
1470 ctx connection context
1471 suppress_tls if TRUE, don't attempt a TLS connection - this is set for
1472 a second attempt after TLS initialization fails
1473
1474 Returns: OK - the connection was made and the delivery attempted;
1475 fd is set in the conn context, tls_out set up.
1476 DEFER - the connection could not be made, or something failed
1477 while setting up the SMTP session, or there was a
1478 non-message-specific error, such as a timeout.
1479 ERROR - helo_data or add_headers or authenticated_sender is
1480 specified for this transport, and the string failed
1481 to expand
1482 */
1483 int
1484 smtp_setup_conn(smtp_context * sx, BOOL suppress_tls)
1485 {
1486 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
1487 dns_answer tlsa_dnsa;
1488 #endif
1489 BOOL pass_message = FALSE;
1490 uschar * message = NULL;
1491 int yield = OK;
1492 int rc;
1493
1494 sx->ob = (smtp_transport_options_block *) sx->tblock->options_block;
1495
1496 sx->lmtp = strcmpic(sx->ob->protocol, US"lmtp") == 0;
1497 sx->smtps = strcmpic(sx->ob->protocol, US"smtps") == 0;
1498 sx->ok = FALSE;
1499 sx->send_rset = TRUE;
1500 sx->send_quit = TRUE;
1501 sx->setting_up = TRUE;
1502 sx->esmtp = TRUE;
1503 sx->esmtp_sent = FALSE;
1504 #ifdef SUPPORT_I18N
1505 sx->utf8_needed = FALSE;
1506 #endif
1507 sx->dsn_all_lasthop = TRUE;
1508 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
1509 sx->dane = FALSE;
1510 sx->dane_required = verify_check_given_host(&sx->ob->hosts_require_dane, sx->host) == OK;
1511 #endif
1512
1513 if ((sx->max_rcpt = sx->tblock->max_addresses) == 0) sx->max_rcpt = 999999;
1514 sx->peer_offered = 0;
1515 sx->avoid_option = 0;
1516 sx->igquotstr = US"";
1517 if (!sx->helo_data) sx->helo_data = sx->ob->helo_data;
1518 #ifdef EXPERIMENTAL_DSN_INFO
1519 sx->smtp_greeting = NULL;
1520 sx->helo_response = NULL;
1521 #endif
1522
1523 smtp_command = US"initial connection";
1524 sx->buffer[0] = '\0';
1525
1526 /* Set up the buffer for reading SMTP response packets. */
1527
1528 sx->inblock.buffer = sx->inbuffer;
1529 sx->inblock.buffersize = sizeof(sx->inbuffer);
1530 sx->inblock.ptr = sx->inbuffer;
1531 sx->inblock.ptrend = sx->inbuffer;
1532
1533 /* Set up the buffer for holding SMTP commands while pipelining */
1534
1535 sx->outblock.buffer = sx->outbuffer;
1536 sx->outblock.buffersize = sizeof(sx->outbuffer);
1537 sx->outblock.ptr = sx->outbuffer;
1538 sx->outblock.cmd_count = 0;
1539 sx->outblock.authenticating = FALSE;
1540
1541 /* Reset the parameters of a TLS session. */
1542
1543 tls_out.bits = 0;
1544 tls_out.cipher = NULL; /* the one we may use for this transport */
1545 tls_out.ourcert = NULL;
1546 tls_out.peercert = NULL;
1547 tls_out.peerdn = NULL;
1548 #if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
1549 tls_out.sni = NULL;
1550 #endif
1551 tls_out.ocsp = OCSP_NOT_REQ;
1552
1553 /* Flip the legacy TLS-related variables over to the outbound set in case
1554 they're used in the context of the transport. Don't bother resetting
1555 afterward (when being used by a transport) as we're in a subprocess.
1556 For verify, unflipped once the callout is dealt with */
1557
1558 tls_modify_variables(&tls_out);
1559
1560 #ifndef SUPPORT_TLS
1561 if (sx->smtps)
1562 {
1563 set_errno_nohost(sx->addrlist, ERRNO_TLSFAILURE, US"TLS support not available",
1564 DEFER, FALSE);
1565 return ERROR;
1566 }
1567 #endif
1568
1569 /* Make a connection to the host if this isn't a continued delivery, and handle
1570 the initial interaction and HELO/EHLO/LHLO. Connect timeout errors are handled
1571 specially so they can be identified for retries. */
1572
1573 if (!continue_hostname)
1574 {
1575 if (sx->verify)
1576 HDEBUG(D_verify) debug_printf("interface=%s port=%d\n", sx->interface, sx->port);
1577
1578 /* Get the actual port the connection will use, into sx->host */
1579
1580 smtp_port_for_connect(sx->host, sx->port);
1581
1582 #if defined(SUPPORT_TLS) && defined(EXPERIMENTAL_DANE)
1583 /* Do TLSA lookup for DANE */
1584 {
1585 tls_out.dane_verified = FALSE;
1586 tls_out.tlsa_usage = 0;
1587
1588 if (sx->host->dnssec == DS_YES)
1589 {
1590 if( sx->dane_required
1591 || verify_check_given_host(&sx->ob->hosts_try_dane, sx->host) == OK
1592 )
1593 switch (rc = tlsa_lookup(sx->host, &tlsa_dnsa, sx->dane_required))
1594 {
1595 case OK: sx->dane = TRUE;
1596 sx->ob->tls_tempfail_tryclear = FALSE;
1597 break;
1598 case FAIL_FORCED: break;
1599 default: set_errno_nohost(sx->addrlist, ERRNO_DNSDEFER,
1600 string_sprintf("DANE error: tlsa lookup %s",
1601 rc == DEFER ? "DEFER" : "FAIL"),
1602 rc, FALSE);
1603 return rc;
1604 }
1605 }
1606 else if (sx->dane_required)
1607 {
1608 set_errno_nohost(sx->addrlist, ERRNO_DNSDEFER,
1609 string_sprintf("DANE error: %s lookup not DNSSEC", sx->host->name),
1610 FAIL, FALSE);
1611 return FAIL;
1612 }
1613 }
1614 #endif /*DANE*/
1615
1616 /* Make the TCP connection */
1617
1618 sx->inblock.sock = sx->outblock.sock =
1619 smtp_connect(sx->host, sx->host_af, sx->interface,
1620 sx->ob->connect_timeout, sx->tblock);
1621
1622 if (sx->inblock.sock < 0)
1623 {
1624 uschar * msg = NULL;
1625 if (sx->verify)
1626 {
1627 msg = US strerror(errno);
1628 HDEBUG(D_verify) debug_printf("connect: %s\n", msg);
1629 }
1630 set_errno_nohost(sx->addrlist,
1631 errno == ETIMEDOUT ? ERRNO_CONNECTTIMEOUT : errno,
1632 sx->verify ? string_sprintf("could not connect: %s", msg)
1633 : NULL,
1634 DEFER, FALSE);
1635 sx->send_quit = FALSE;
1636 return DEFER;
1637 }
1638
1639 /* Expand the greeting message while waiting for the initial response. (Makes
1640 sense if helo_data contains ${lookup dnsdb ...} stuff). The expansion is
1641 delayed till here so that $sending_interface and $sending_port are set. */
1642
1643 if (sx->helo_data)
1644 if (!(sx->helo_data = expand_string(sx->helo_data)))
1645 if (sx->verify)
1646 log_write(0, LOG_MAIN|LOG_PANIC,
1647 "<%s>: failed to expand transport's helo_data value for callout: %s",
1648 sx->addrlist->address, expand_string_message);
1649
1650 #ifdef SUPPORT_I18N
1651 if (sx->helo_data)
1652 {
1653 expand_string_message = NULL;
1654 if ((sx->helo_data = string_domain_utf8_to_alabel(sx->helo_data,
1655 &expand_string_message)),
1656 expand_string_message)
1657 if (sx->verify)
1658 log_write(0, LOG_MAIN|LOG_PANIC,
1659 "<%s>: failed to expand transport's helo_data value for callout: %s",
1660 sx->addrlist->address, expand_string_message);
1661 else
1662 sx->helo_data = NULL;
1663 }
1664 #endif
1665
1666 /* The first thing is to wait for an initial OK response. The dreaded "goto"
1667 is nevertheless a reasonably clean way of programming this kind of logic,
1668 where you want to escape on any error. */
1669
1670 if (!sx->smtps)
1671 {
1672 BOOL good_response;
1673
1674 #ifdef TCP_QUICKACK
1675 (void) setsockopt(sx->inblock.sock, IPPROTO_TCP, TCP_QUICKACK, US &off, sizeof(off));
1676 #endif
1677 good_response = smtp_read_response(&sx->inblock, sx->buffer, sizeof(sx->buffer),
1678 '2', sx->ob->command_timeout);
1679 #ifdef EXPERIMENTAL_DSN_INFO
1680 sx->smtp_greeting = string_copy(sx->buffer);
1681 #endif
1682 if (!good_response) goto RESPONSE_FAILED;
1683
1684 #ifndef DISABLE_EVENT
1685 {
1686 uschar * s;
1687 lookup_dnssec_authenticated = sx->host->dnssec==DS_YES ? US"yes"
1688 : sx->host->dnssec==DS_NO ? US"no" : NULL;
1689 s = event_raise(sx->tblock->event_action, US"smtp:connect", sx->buffer);
1690 if (s)
1691 {
1692 set_errno_nohost(sx->addrlist, ERRNO_EXPANDFAIL,
1693 string_sprintf("deferred by smtp:connect event expansion: %s", s),
1694 DEFER, FALSE);
1695 yield = DEFER;
1696 goto SEND_QUIT;
1697 }
1698 }
1699 #endif
1700
1701 /* Now check if the helo_data expansion went well, and sign off cleanly if
1702 it didn't. */
1703
1704 if (!sx->helo_data)
1705 {
1706 message = string_sprintf("failed to expand helo_data: %s",
1707 expand_string_message);
1708 set_errno_nohost(sx->addrlist, ERRNO_EXPANDFAIL, message, DEFER, FALSE);
1709 yield = DEFER;
1710 goto SEND_QUIT;
1711 }
1712 }
1713
1714 /** Debugging without sending a message
1715 sx->addrlist->transport_return = DEFER;
1716 goto SEND_QUIT;
1717 **/
1718
1719 /* Errors that occur after this point follow an SMTP command, which is
1720 left in big_buffer by smtp_write_command() for use in error messages. */
1721
1722 smtp_command = big_buffer;
1723
1724 /* Tell the remote who we are...
1725
1726 February 1998: A convention has evolved that ESMTP-speaking MTAs include the
1727 string "ESMTP" in their greeting lines, so make Exim send EHLO if the
1728 greeting is of this form. The assumption was that the far end supports it
1729 properly... but experience shows that there are some that give 5xx responses,
1730 even though the banner includes "ESMTP" (there's a bloody-minded one that
1731 says "ESMTP not spoken here"). Cope with that case.
1732
1733 September 2000: Time has passed, and it seems reasonable now to always send
1734 EHLO at the start. It is also convenient to make the change while installing
1735 the TLS stuff.
1736
1737 July 2003: Joachim Wieland met a broken server that advertises "PIPELINING"
1738 but times out after sending MAIL FROM, RCPT TO and DATA all together. There
1739 would be no way to send out the mails, so there is now a host list
1740 "hosts_avoid_esmtp" that disables ESMTP for special hosts and solves the
1741 PIPELINING problem as well. Maybe it can also be useful to cure other
1742 problems with broken servers.
1743
1744 Exim originally sent "Helo" at this point and ran for nearly a year that way.
1745 Then somebody tried it with a Microsoft mailer... It seems that all other
1746 mailers use upper case for some reason (the RFC is quite clear about case
1747 independence) so, for peace of mind, I gave in. */
1748
1749 sx->esmtp = verify_check_given_host(&sx->ob->hosts_avoid_esmtp, sx->host) != OK;
1750
1751 /* Alas; be careful, since this goto is not an error-out, so conceivably
1752 we might set data between here and the target which we assume to exist
1753 and be usable. I can see this coming back to bite us. */
1754 #ifdef SUPPORT_TLS
1755 if (sx->smtps)
1756 {
1757 smtp_peer_options |= OPTION_TLS;
1758 suppress_tls = FALSE;
1759 sx->ob->tls_tempfail_tryclear = FALSE;
1760 smtp_command = US"SSL-on-connect";
1761 goto TLS_NEGOTIATE;
1762 }
1763 #endif
1764
1765 if (sx->esmtp)
1766 {
1767 if (smtp_write_command(&sx->outblock, SCMD_FLUSH, "%s %s\r\n",
1768 sx->lmtp ? "LHLO" : "EHLO", sx->helo_data) < 0)
1769 goto SEND_FAILED;
1770 sx->esmtp_sent = TRUE;
1771 if (!smtp_read_response(&sx->inblock, sx->buffer, sizeof(sx->buffer), '2',
1772 sx->ob->command_timeout))
1773 {
1774 if (errno != 0 || sx->buffer[0] == 0 || sx->lmtp)
1775 {
1776 #ifdef EXPERIMENTAL_DSN_INFO
1777 sx->helo_response = string_copy(sx->buffer);
1778 #endif
1779 goto RESPONSE_FAILED;
1780 }
1781 sx->esmtp = FALSE;
1782 }
1783 #ifdef EXPERIMENTAL_DSN_INFO
1784 sx->helo_response = string_copy(sx->buffer);
1785 #endif
1786 }
1787 else
1788 DEBUG(D_transport)
1789 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
1790
1791 if (!sx->esmtp)
1792 {
1793 BOOL good_response;
1794 int n = sizeof(sx->buffer);
1795 uschar * rsp = sx->buffer;
1796
1797 if (sx->esmtp_sent && (n = Ustrlen(sx->buffer)) < sizeof(sx->buffer)/2)
1798 { rsp = sx->buffer + n + 1; n = sizeof(sx->buffer) - n; }
1799
1800 if (smtp_write_command(&sx->outblock, SCMD_FLUSH, "HELO %s\r\n", sx->helo_data) < 0)
1801 goto SEND_FAILED;
1802 good_response = smtp_read_response(&sx->inblock, rsp, n,
1803 '2', sx->ob->command_timeout);
1804 #ifdef EXPERIMENTAL_DSN_INFO
1805 sx->helo_response = string_copy(rsp);
1806 #endif
1807 if (!good_response)
1808 {
1809 /* Handle special logging for a closed connection after HELO
1810 when had previously sent EHLO */
1811
1812 if (rsp != sx->buffer && rsp[0] == 0 && (errno == 0 || errno == ECONNRESET))
1813 {
1814 errno = ERRNO_SMTPCLOSED;
1815 goto EHLOHELO_FAILED;
1816 }
1817 Ustrncpy(sx->buffer, rsp, sizeof(sx->buffer)/2);
1818 goto RESPONSE_FAILED;
1819 }
1820 }
1821
1822 sx->avoid_option = sx->peer_offered = smtp_peer_options = 0;
1823
1824 if (sx->esmtp || sx->lmtp)
1825 {
1826 sx->peer_offered = ehlo_response(sx->buffer,
1827 OPTION_TLS /* others checked later */
1828 );
1829
1830 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
1831
1832 #ifdef SUPPORT_TLS
1833 smtp_peer_options |= sx->peer_offered & OPTION_TLS;
1834 #endif
1835 }
1836 }
1837
1838 /* For continuing deliveries down the same channel, having re-exec'd the socket
1839 is the standard input; for a socket held open from verify it is recorded
1840 in the cutthrough context block. Either way we don't need to redo EHLO here
1841 (but may need to do so for TLS - see below).
1842 Set up the pointer to where subsequent commands will be left, for
1843 error messages. Note that smtp_peer_options will have been
1844 set from the command line if they were set in the process that passed the
1845 connection on. */
1846
1847 /*XXX continue case needs to propagate DSN_INFO, prob. in deliver.c
1848 as the continue goes via transport_pass_socket() and doublefork and exec.
1849 It does not wait. Unclear how we keep separate host's responses
1850 separate - we could match up by host ip+port as a bodge. */
1851
1852 else
1853 {
1854 if (cutthrough.fd >= 0 && cutthrough.callout_hold_only)
1855 {
1856 sx->inblock.sock = sx->outblock.sock = cutthrough.fd;
1857 sx->host->port = sx->port = cutthrough.host.port;
1858 }
1859 else
1860 {
1861 sx->inblock.sock = sx->outblock.sock = 0; /* stdin */
1862 smtp_port_for_connect(sx->host, sx->port); /* Record the port that was used */
1863 }
1864 smtp_command = big_buffer;
1865 sx->helo_data = NULL; /* ensure we re-expand ob->helo_data */
1866
1867 /* For a continued connection with TLS being proxied for us, or a
1868 held-open verify connection with TLS, nothing more to do. */
1869
1870 if ( continue_proxy_cipher
1871 || (cutthrough.fd >= 0 && cutthrough.callout_hold_only && cutthrough.is_tls)
1872 )
1873 {
1874 sx->peer_offered = smtp_peer_options;
1875 pipelining_active = !!(smtp_peer_options & OPTION_PIPE);
1876 HDEBUG(D_transport) debug_printf("continued connection, %s TLS\n",
1877 continue_proxy_cipher ? "proxied" : "verify conn with");
1878 return OK;
1879 }
1880 HDEBUG(D_transport) debug_printf("continued connection, no TLS\n");
1881 }
1882
1883 /* If TLS is available on this connection, whether continued or not, attempt to
1884 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
1885 send another EHLO - the server may give a different answer in secure mode. We
1886 use a separate buffer for reading the response to STARTTLS so that if it is
1887 negative, the original EHLO data is available for subsequent analysis, should
1888 the client not be required to use TLS. If the response is bad, copy the buffer
1889 for error analysis. */
1890
1891 #ifdef SUPPORT_TLS
1892 if ( smtp_peer_options & OPTION_TLS
1893 && !suppress_tls
1894 && verify_check_given_host(&sx->ob->hosts_avoid_tls, sx->host) != OK
1895 && ( !sx->verify
1896 || verify_check_given_host(&sx->ob->hosts_verify_avoid_tls, sx->host) != OK
1897 ) )
1898 {
1899 uschar buffer2[4096];
1900 if (smtp_write_command(&sx->outblock, SCMD_FLUSH, "STARTTLS\r\n") < 0)
1901 goto SEND_FAILED;
1902
1903 /* If there is an I/O error, transmission of this message is deferred. If
1904 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
1905 false, we also defer. However, if there is a temporary rejection of STARTTLS
1906 and tls_tempfail_tryclear is true, or if there is an outright rejection of
1907 STARTTLS, we carry on. This means we will try to send the message in clear,
1908 unless the host is in hosts_require_tls (tested below). */
1909
1910 if (!smtp_read_response(&sx->inblock, buffer2, sizeof(buffer2), '2',
1911 sx->ob->command_timeout))
1912 {
1913 if ( errno != 0
1914 || buffer2[0] == 0
1915 || (buffer2[0] == '4' && !sx->ob->tls_tempfail_tryclear)
1916 )
1917 {
1918 Ustrncpy(sx->buffer, buffer2, sizeof(sx->buffer));
1919 sx->buffer[sizeof(sx->buffer)-1] = '\0';
1920 goto RESPONSE_FAILED;
1921 }
1922 }
1923
1924 /* STARTTLS accepted: try to negotiate a TLS session. */
1925
1926 else
1927 TLS_NEGOTIATE:
1928 {
1929 address_item * addr;
1930 uschar * errstr;
1931 int rc = tls_client_start(sx->inblock.sock, sx->host, sx->addrlist, sx->tblock,
1932 # ifdef EXPERIMENTAL_DANE
1933 sx->dane ? &tlsa_dnsa : NULL,
1934 # endif
1935 &errstr);
1936
1937 /* TLS negotiation failed; give an error. From outside, this function may
1938 be called again to try in clear on a new connection, if the options permit
1939 it for this host. */
1940
1941 if (rc != OK)
1942 {
1943 # ifdef EXPERIMENTAL_DANE
1944 if (sx->dane) log_write(0, LOG_MAIN,
1945 "DANE attempt failed; TLS connection to %s [%s]: %s",
1946 sx->host->name, sx->host->address, errstr);
1947 # endif
1948
1949 errno = ERRNO_TLSFAILURE;
1950 message = string_sprintf("TLS session: %s", errstr);
1951 sx->send_quit = FALSE;
1952 goto TLS_FAILED;
1953 }
1954
1955 /* TLS session is set up */
1956
1957 smtp_peer_options_wrap = smtp_peer_options;
1958 for (addr = sx->addrlist; addr; addr = addr->next)
1959 if (addr->transport_return == PENDING_DEFER)
1960 {
1961 addr->cipher = tls_out.cipher;
1962 addr->ourcert = tls_out.ourcert;
1963 addr->peercert = tls_out.peercert;
1964 addr->peerdn = tls_out.peerdn;
1965 addr->ocsp = tls_out.ocsp;
1966 }
1967 }
1968 }
1969
1970 /* if smtps, we'll have smtp_command set to something else; always safe to
1971 reset it here. */
1972 smtp_command = big_buffer;
1973
1974 /* If we started TLS, redo the EHLO/LHLO exchange over the secure channel. If
1975 helo_data is null, we are dealing with a connection that was passed from
1976 another process, and so we won't have expanded helo_data above. We have to
1977 expand it here. $sending_ip_address and $sending_port are set up right at the
1978 start of the Exim process (in exim.c). */
1979
1980 if (tls_out.active >= 0)
1981 {
1982 char *greeting_cmd;
1983 BOOL good_response;
1984
1985 if (!sx->helo_data && !(sx->helo_data = expand_string(sx->ob->helo_data)))
1986 {
1987 uschar *message = string_sprintf("failed to expand helo_data: %s",
1988 expand_string_message);
1989 set_errno_nohost(sx->addrlist, ERRNO_EXPANDFAIL, message, DEFER, FALSE);
1990 yield = DEFER;
1991 goto SEND_QUIT;
1992 }
1993
1994 /* For SMTPS we need to wait for the initial OK response. */
1995 if (sx->smtps)
1996 {
1997 good_response = smtp_read_response(&sx->inblock, sx->buffer, sizeof(sx->buffer),
1998 '2', sx->ob->command_timeout);
1999 #ifdef EXPERIMENTAL_DSN_INFO
2000 sx->smtp_greeting = string_copy(sx->buffer);
2001 #endif
2002 if (!good_response) goto RESPONSE_FAILED;
2003 }
2004
2005 if (sx->esmtp)
2006 greeting_cmd = "EHLO";
2007 else
2008 {
2009 greeting_cmd = "HELO";
2010 DEBUG(D_transport)
2011 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
2012 }
2013
2014 if (smtp_write_command(&sx->outblock, SCMD_FLUSH, "%s %s\r\n",
2015 sx->lmtp ? "LHLO" : greeting_cmd, sx->helo_data) < 0)
2016 goto SEND_FAILED;
2017 good_response = smtp_read_response(&sx->inblock, sx->buffer, sizeof(sx->buffer),
2018 '2', sx->ob->command_timeout);
2019 #ifdef EXPERIMENTAL_DSN_INFO
2020 sx->helo_response = string_copy(sx->buffer);
2021 #endif
2022 if (!good_response) goto RESPONSE_FAILED;
2023 smtp_peer_options = 0;
2024 }
2025
2026 /* If the host is required to use a secure channel, ensure that we
2027 have one. */
2028
2029 else if ( sx->smtps
2030 # ifdef EXPERIMENTAL_DANE
2031 || sx->dane
2032 # endif
2033 || verify_check_given_host(&sx->ob->hosts_require_tls, sx->host) == OK
2034 )
2035 {
2036 errno = ERRNO_TLSREQUIRED;
2037 message = string_sprintf("a TLS session is required, but %s",
2038 smtp_peer_options & OPTION_TLS
2039 ? "an attempt to start TLS failed" : "the server did not offer TLS support");
2040 goto TLS_FAILED;
2041 }
2042 #endif /*SUPPORT_TLS*/
2043
2044 /* If TLS is active, we have just started it up and re-done the EHLO command,
2045 so its response needs to be analyzed. If TLS is not active and this is a
2046 continued session down a previously-used socket, we haven't just done EHLO, so
2047 we skip this. */
2048
2049 if (continue_hostname == NULL
2050 #ifdef SUPPORT_TLS
2051 || tls_out.active >= 0
2052 #endif
2053 )
2054 {
2055 if (sx->esmtp || sx->lmtp)
2056 {
2057 sx->peer_offered = ehlo_response(sx->buffer,
2058 0 /* no TLS */
2059 | (sx->lmtp && sx->ob->lmtp_ignore_quota ? OPTION_IGNQ : 0)
2060 | OPTION_CHUNKING
2061 | OPTION_PRDR
2062 #ifdef SUPPORT_I18N
2063 | (sx->addrlist->prop.utf8_msg ? OPTION_UTF8 : 0)
2064 /*XXX if we hand peercaps on to continued-conn processes,
2065 must not depend on this addr */
2066 #endif
2067 | OPTION_DSN
2068 | OPTION_PIPE
2069 | (sx->ob->size_addition >= 0 ? OPTION_SIZE : 0)
2070 );
2071
2072 /* Set for IGNOREQUOTA if the response to LHLO specifies support and the
2073 lmtp_ignore_quota option was set. */
2074
2075 sx->igquotstr = sx->peer_offered & OPTION_IGNQ ? US" IGNOREQUOTA" : US"";
2076
2077 /* If the response to EHLO specified support for the SIZE parameter, note
2078 this, provided size_addition is non-negative. */
2079
2080 smtp_peer_options |= sx->peer_offered & OPTION_SIZE;
2081
2082 /* Note whether the server supports PIPELINING. If hosts_avoid_esmtp matched
2083 the current host, esmtp will be false, so PIPELINING can never be used. If
2084 the current host matches hosts_avoid_pipelining, don't do it. */
2085
2086 if ( sx->peer_offered & OPTION_PIPE
2087 && verify_check_given_host(&sx->ob->hosts_avoid_pipelining, sx->host) != OK)
2088 smtp_peer_options |= OPTION_PIPE;
2089
2090 DEBUG(D_transport) debug_printf("%susing PIPELINING\n",
2091 smtp_peer_options & OPTION_PIPE ? "" : "not ");
2092
2093 if ( sx->peer_offered & OPTION_CHUNKING
2094 && verify_check_given_host(&sx->ob->hosts_try_chunking, sx->host) != OK)
2095 sx->peer_offered &= ~OPTION_CHUNKING;
2096
2097 if (sx->peer_offered & OPTION_CHUNKING)
2098 {DEBUG(D_transport) debug_printf("CHUNKING usable\n");}
2099
2100 #ifndef DISABLE_PRDR
2101 if ( sx->peer_offered & OPTION_PRDR
2102 && verify_check_given_host(&sx->ob->hosts_try_prdr, sx->host) != OK)
2103 sx->peer_offered &= ~OPTION_PRDR;
2104
2105 if (sx->peer_offered & OPTION_PRDR)
2106 {DEBUG(D_transport) debug_printf("PRDR usable\n");}
2107 #endif
2108
2109 /* Note if the server supports DSN */
2110 smtp_peer_options |= sx->peer_offered & OPTION_DSN;
2111 DEBUG(D_transport) debug_printf("%susing DSN\n",
2112 sx->peer_offered & OPTION_DSN ? "" : "not ");
2113
2114 /* Note if the response to EHLO specifies support for the AUTH extension.
2115 If it has, check that this host is one we want to authenticate to, and do
2116 the business. The host name and address must be available when the
2117 authenticator's client driver is running. */
2118
2119 switch (yield = smtp_auth(sx->buffer, sizeof(sx->buffer), sx->addrlist, sx->host,
2120 sx->ob, sx->esmtp, &sx->inblock, &sx->outblock))
2121 {
2122 default: goto SEND_QUIT;
2123 case OK: break;
2124 case FAIL_SEND: goto SEND_FAILED;
2125 case FAIL: goto RESPONSE_FAILED;
2126 }
2127 }
2128 }
2129 pipelining_active = !!(smtp_peer_options & OPTION_PIPE);
2130
2131 /* The setting up of the SMTP call is now complete. Any subsequent errors are
2132 message-specific. */
2133
2134 sx->setting_up = FALSE;
2135
2136 #ifdef SUPPORT_I18N
2137 if (sx->addrlist->prop.utf8_msg)
2138 {
2139 sx->utf8_needed = !sx->addrlist->prop.utf8_downcvt
2140 && !sx->addrlist->prop.utf8_downcvt_maybe;
2141 DEBUG(D_transport) if (!sx->utf8_needed)
2142 debug_printf("utf8: %s downconvert\n",
2143 sx->addrlist->prop.utf8_downcvt ? "mandatory" : "optional");
2144 }
2145
2146 /* If this is an international message we need the host to speak SMTPUTF8 */
2147 if (sx->utf8_needed && !(sx->peer_offered & OPTION_UTF8))
2148 {
2149 errno = ERRNO_UTF8_FWD;
2150 goto RESPONSE_FAILED;
2151 }
2152 #endif
2153
2154 return OK;
2155
2156
2157 {
2158 int code;
2159
2160 RESPONSE_FAILED:
2161 message = NULL;
2162 sx->send_quit = check_response(sx->host, &errno, sx->addrlist->more_errno,
2163 sx->buffer, &code, &message, &pass_message);
2164 goto FAILED;
2165
2166 SEND_FAILED:
2167 code = '4';
2168 message = US string_sprintf("send() to %s [%s] failed: %s",
2169 sx->host->name, sx->host->address, strerror(errno));
2170 sx->send_quit = FALSE;
2171 goto FAILED;
2172
2173 /* This label is jumped to directly when a TLS negotiation has failed,
2174 or was not done for a host for which it is required. Values will be set
2175 in message and errno, and setting_up will always be true. Treat as
2176 a temporary error. */
2177
2178 EHLOHELO_FAILED:
2179 code = '4';
2180 message = string_sprintf("Remote host closed connection in response to %s"
2181 " (EHLO response was: %s)", smtp_command, sx->buffer);
2182 sx->send_quit = FALSE;
2183 goto FAILED;
2184
2185 #ifdef SUPPORT_TLS
2186 TLS_FAILED:
2187 code = '4';
2188 goto FAILED;
2189 #endif
2190
2191 /* The failure happened while setting up the call; see if the failure was
2192 a 5xx response (this will either be on connection, or following HELO - a 5xx
2193 after EHLO causes it to try HELO). If so, and there are no more hosts to try,
2194 fail all addresses, as this host is never going to accept them. For other
2195 errors during setting up (timeouts or whatever), defer all addresses, and
2196 yield DEFER, so that the host is not tried again for a while.
2197
2198 XXX This peeking for another host feels like a layering violation. We want
2199 to note the host as unusable, but down here we shouldn't know if this was
2200 the last host to try for the addr(list). Perhaps the upper layer should be
2201 the one to do set_errno() ? The problem is that currently the addr is where
2202 errno etc. are stashed, but until we run out of hosts to try the errors are
2203 host-specific. Maybe we should enhance the host_item definition? */
2204
2205 FAILED:
2206 sx->ok = FALSE; /* For when reached by GOTO */
2207 set_errno(sx->addrlist, errno, message,
2208 sx->host->next
2209 ? DEFER
2210 : code == '5'
2211 #ifdef SUPPORT_I18N
2212 || errno == ERRNO_UTF8_FWD
2213 #endif
2214 ? FAIL : DEFER,
2215 pass_message, sx->host
2216 #ifdef EXPERIMENTAL_DSN_INFO
2217 , sx->smtp_greeting, sx->helo_response
2218 #endif
2219 );
2220 yield = DEFER;
2221 }
2222
2223
2224 SEND_QUIT:
2225
2226 if (sx->send_quit)
2227 (void)smtp_write_command(&sx->outblock, SCMD_FLUSH, "QUIT\r\n");
2228
2229 #ifdef SUPPORT_TLS
2230 tls_close(FALSE, TRUE);
2231 #endif
2232
2233 /* Close the socket, and return the appropriate value, first setting
2234 works because the NULL setting is passed back to the calling process, and
2235 remote_max_parallel is forced to 1 when delivering over an existing connection,
2236 */
2237
2238 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
2239 if (sx->send_quit)
2240 {
2241 shutdown(sx->outblock.sock, SHUT_WR);
2242 if (fcntl(sx->inblock.sock, F_SETFL, O_NONBLOCK) == 0)
2243 for (rc = 16; read(sx->inblock.sock, sx->inbuffer, sizeof(sx->inbuffer)) > 0 && rc > 0;)
2244 rc--; /* drain socket */
2245 sx->send_quit = FALSE;
2246 }
2247 (void)close(sx->inblock.sock);
2248 sx->inblock.sock = sx->outblock.sock = -1;
2249
2250 #ifndef DISABLE_EVENT
2251 (void) event_raise(sx->tblock->event_action, US"tcp:close", NULL);
2252 #endif
2253
2254 continue_transport = NULL;
2255 continue_hostname = NULL;
2256 return yield;
2257 }
2258
2259
2260
2261
2262 /* Create the string of options that will be appended to the MAIL FROM:
2263 in the connection context buffer */
2264
2265 static int
2266 build_mailcmd_options(smtp_context * sx, address_item * addrlist)
2267 {
2268 uschar * p = sx->buffer;
2269 address_item * addr;
2270 int address_count;
2271
2272 *p = 0;
2273
2274 /* If we know the receiving MTA supports the SIZE qualification, and we know it,
2275 send it, adding something to the message size to allow for imprecision
2276 and things that get added en route. Exim keeps the number of lines
2277 in a message, so we can give an accurate value for the original message, but we
2278 need some additional to handle added headers. (Double "." characters don't get
2279 included in the count.) */
2280
2281 if ( message_size > 0
2282 && sx->peer_offered & OPTION_SIZE && !(sx->avoid_option & OPTION_SIZE))
2283 {
2284 /*XXX problem here under spool_files_wireformat?
2285 Or just forget about lines? Or inflate by a fixed proportion? */
2286
2287 sprintf(CS p, " SIZE=%d", message_size+message_linecount+sx->ob->size_addition);
2288 while (*p) p++;
2289 }
2290
2291 #ifndef DISABLE_PRDR
2292 /* If it supports Per-Recipient Data Reponses, and we have omre than one recipient,
2293 request that */
2294
2295 sx->prdr_active = FALSE;
2296 if (sx->peer_offered & OPTION_PRDR)
2297 for (addr = addrlist; addr; addr = addr->next)
2298 if (addr->transport_return == PENDING_DEFER)
2299 {
2300 for (addr = addr->next; addr; addr = addr->next)
2301 if (addr->transport_return == PENDING_DEFER)
2302 { /* at least two recipients to send */
2303 sx->prdr_active = TRUE;
2304 sprintf(CS p, " PRDR"); p += 5;
2305 break;
2306 }
2307 break;
2308 }
2309 #endif
2310
2311 #ifdef SUPPORT_I18N
2312 /* If it supports internationalised messages, and this meesage need that,
2313 request it */
2314
2315 if ( sx->peer_offered & OPTION_UTF8
2316 && addrlist->prop.utf8_msg
2317 && !addrlist->prop.utf8_downcvt
2318 )
2319 Ustrcpy(p, " SMTPUTF8"), p += 9;
2320 #endif
2321
2322 /* check if all addresses have DSN-lasthop flag; do not send RET and ENVID if so */
2323 for (sx->dsn_all_lasthop = TRUE, addr = addrlist, address_count = 0;
2324 addr && address_count < sx->max_rcpt;
2325 addr = addr->next) if (addr->transport_return == PENDING_DEFER)
2326 {
2327 address_count++;
2328 if (!(addr->dsn_flags & rf_dsnlasthop))
2329 {
2330 sx->dsn_all_lasthop = FALSE;
2331 break;
2332 }
2333 }
2334
2335 /* Add any DSN flags to the mail command */
2336
2337 if (sx->peer_offered & OPTION_DSN && !sx->dsn_all_lasthop)
2338 {
2339 if (dsn_ret == dsn_ret_hdrs)
2340 { Ustrcpy(p, " RET=HDRS"); p += 9; }
2341 else if (dsn_ret == dsn_ret_full)
2342 { Ustrcpy(p, " RET=FULL"); p += 9; }
2343
2344 if (dsn_envid)
2345 {
2346 string_format(p, sizeof(sx->buffer) - (p-sx->buffer), " ENVID=%s", dsn_envid);
2347 while (*p) p++;
2348 }
2349 }
2350
2351 /* If an authenticated_sender override has been specified for this transport
2352 instance, expand it. If the expansion is forced to fail, and there was already
2353 an authenticated_sender for this message, the original value will be used.
2354 Other expansion failures are serious. An empty result is ignored, but there is
2355 otherwise no check - this feature is expected to be used with LMTP and other
2356 cases where non-standard addresses (e.g. without domains) might be required. */
2357
2358 if (smtp_mail_auth_str(p, sizeof(sx->buffer) - (p-sx->buffer), addrlist, sx->ob))
2359 return ERROR;
2360
2361 return OK;
2362 }
2363
2364
2365 static void
2366 build_rcptcmd_options(smtp_context * sx, const address_item * addr)
2367 {
2368 uschar * p = sx->buffer;
2369 *p = 0;
2370
2371 /* Add any DSN flags to the rcpt command */
2372
2373 if (sx->peer_offered & OPTION_DSN && !(addr->dsn_flags & rf_dsnlasthop))
2374 {
2375 if (addr->dsn_flags & rf_dsnflags)
2376 {
2377 int i;
2378 BOOL first = TRUE;
2379
2380 Ustrcpy(p, " NOTIFY=");
2381 while (*p) p++;
2382 for (i = 0; i < nelem(rf_list); i++) if (addr->dsn_flags & rf_list[i])
2383 {
2384 if (!first) *p++ = ',';
2385 first = FALSE;
2386 Ustrcpy(p, rf_names[i]);
2387 while (*p) p++;
2388 }
2389 }
2390
2391 if (addr->dsn_orcpt)
2392 {
2393 string_format(p, sizeof(sx->buffer) - (p-sx->buffer), " ORCPT=%s",
2394 addr->dsn_orcpt);
2395 while (*p) p++;
2396 }
2397 }
2398 }
2399
2400
2401
2402 /*
2403 Return:
2404 0 good, rcpt results in addr->transport_return (PENDING_OK, DEFER, FAIL)
2405 -1 MAIL response error
2406 -2 any non-MAIL read i/o error
2407 -3 non-MAIL response timeout
2408 -4 internal error; channel still usable
2409 -5 transmit failed
2410 */
2411
2412 int
2413 smtp_write_mail_and_rcpt_cmds(smtp_context * sx, int * yield)
2414 {
2415 address_item * addr;
2416 int address_count;
2417 int rc;
2418
2419 if (build_mailcmd_options(sx, sx->first_addr) != OK)
2420 {
2421 *yield = ERROR;
2422 return -4;
2423 }
2424
2425 /* From here until we send the DATA command, we can make use of PIPELINING
2426 if the server host supports it. The code has to be able to check the responses
2427 at any point, for when the buffer fills up, so we write it totally generally.
2428 When PIPELINING is off, each command written reports that it has flushed the
2429 buffer. */
2430
2431 sx->pending_MAIL = TRUE; /* The block starts with MAIL */
2432
2433 {
2434 uschar * s = sx->from_addr;
2435 #ifdef SUPPORT_I18N
2436 uschar * errstr = NULL;
2437
2438 /* If we must downconvert, do the from-address here. Remember we had to
2439 for the to-addresses (done below), and also (ugly) for re-doing when building
2440 the delivery log line. */
2441
2442 if ( sx->addrlist->prop.utf8_msg
2443 && (sx->addrlist->prop.utf8_downcvt || !(sx->peer_offered & OPTION_UTF8))
2444 )
2445 {
2446 if (s = string_address_utf8_to_alabel(s, &errstr), errstr)
2447 {
2448 set_errno_nohost(sx->addrlist, ERRNO_EXPANDFAIL, errstr, DEFER, FALSE);
2449 *yield = ERROR;
2450 return -4;
2451 }
2452 setflag(sx->addrlist, af_utf8_downcvt);
2453 }
2454 #endif
2455
2456 rc = smtp_write_command(&sx->outblock, pipelining_active ? SCMD_BUFFER : SCMD_FLUSH,
2457 "MAIL FROM:<%s>%s\r\n", s, sx->buffer);
2458 }
2459
2460 mail_command = string_copy(big_buffer); /* Save for later error message */
2461
2462 switch(rc)
2463 {
2464 case -1: /* Transmission error */
2465 return -5;
2466
2467 case +1: /* Cmd was sent */
2468 if (!smtp_read_response(&sx->inblock, sx->buffer, sizeof(sx->buffer), '2',
2469 sx->ob->command_timeout))
2470 {
2471 if (errno == 0 && sx->buffer[0] == '4')
2472 {
2473 errno = ERRNO_MAIL4XX;
2474 sx->addrlist->more_errno |= ((sx->buffer[1] - '0')*10 + sx->buffer[2] - '0') << 8;
2475 }
2476 return -1;
2477 }
2478 sx->pending_MAIL = FALSE;
2479 break;
2480
2481 /* otherwise zero: command queued for pipeline */
2482 }
2483
2484 /* Pass over all the relevant recipient addresses for this host, which are the
2485 ones that have status PENDING_DEFER. If we are using PIPELINING, we can send
2486 several before we have to read the responses for those seen so far. This
2487 checking is done by a subroutine because it also needs to be done at the end.
2488 Send only up to max_rcpt addresses at a time, leaving next_addr pointing to
2489 the next one if not all are sent.
2490
2491 In the MUA wrapper situation, we want to flush the PIPELINING buffer for the
2492 last address because we want to abort if any recipients have any kind of
2493 problem, temporary or permanent. We know that all recipient addresses will have
2494 the PENDING_DEFER status, because only one attempt is ever made, and we know
2495 that max_rcpt will be large, so all addresses will be done at once.
2496
2497 For verify we flush the pipeline after any (the only) rcpt address. */
2498
2499 for (addr = sx->first_addr, address_count = 0;
2500 addr && address_count < sx->max_rcpt;
2501 addr = addr->next) if (addr->transport_return == PENDING_DEFER)
2502 {
2503 int count;
2504 BOOL no_flush;
2505 uschar * rcpt_addr;
2506
2507 addr->dsn_aware = sx->peer_offered & OPTION_DSN
2508 ? dsn_support_yes : dsn_support_no;
2509
2510 address_count++;
2511 no_flush = pipelining_active && !sx->verify
2512 && (!mua_wrapper || addr->next && address_count < sx->max_rcpt);
2513
2514 build_rcptcmd_options(sx, addr);
2515
2516 /* Now send the RCPT command, and process outstanding responses when
2517 necessary. After a timeout on RCPT, we just end the function, leaving the
2518 yield as OK, because this error can often mean that there is a problem with
2519 just one address, so we don't want to delay the host. */
2520
2521 rcpt_addr = transport_rcpt_address(addr, sx->tblock->rcpt_include_affixes);
2522
2523 #ifdef SUPPORT_I18N
2524 if ( testflag(sx->addrlist, af_utf8_downcvt)
2525 && !(rcpt_addr = string_address_utf8_to_alabel(rcpt_addr, NULL))
2526 )
2527 {
2528 /*XXX could we use a per-address errstr here? Not fail the whole send? */
2529 errno = ERRNO_EXPANDFAIL;
2530 return -5; /*XXX too harsh? */
2531 }
2532 #endif
2533
2534 count = smtp_write_command(&sx->outblock, no_flush ? SCMD_BUFFER : SCMD_FLUSH,
2535 "RCPT TO:<%s>%s%s\r\n", rcpt_addr, sx->igquotstr, sx->buffer);
2536
2537 if (count < 0) return -5;
2538 if (count > 0)
2539 {
2540 switch(sync_responses(sx, count, 0))
2541 {
2542 case 3: sx->ok = TRUE; /* 2xx & 5xx => OK & progress made */
2543 case 2: sx->completed_addr = TRUE; /* 5xx (only) => progress made */
2544 break;
2545
2546 case 1: sx->ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
2547 if (!sx->lmtp) /* can't tell about progress yet */
2548 sx->completed_addr = TRUE;
2549 case 0: /* No 2xx or 5xx, but no probs */
2550 break;
2551
2552 case -1: return -3; /* Timeout on RCPT */
2553 case -2: return -2; /* non-MAIL read i/o error */
2554 default: return -1; /* any MAIL error */
2555 }
2556 sx->pending_MAIL = FALSE; /* Dealt with MAIL */
2557 }
2558 } /* Loop for next address */
2559
2560 sx->next_addr = addr;
2561 return 0;
2562 }
2563
2564
2565 #ifdef SUPPORT_TLS
2566 /*****************************************************
2567 * Proxy TLS connection for another transport process *
2568 ******************************************************/
2569 /*
2570 Use the given buffer as a staging area, and select on both the given fd
2571 and the TLS'd client-fd for data to read (per the coding in ip_recv() and
2572 fd_ready() this is legitimate). Do blocking full-size writes, and reads
2573 under a timeout.
2574
2575 Arguments:
2576 buf space to use for buffering
2577 bufsiz size of buffer
2578 proxy_fd comms to proxied process
2579 timeout per-read timeout, seconds
2580 */
2581
2582 void
2583 smtp_proxy_tls(uschar * buf, size_t bsize, int proxy_fd, int timeout)
2584 {
2585 fd_set rfds, efds;
2586 int max_fd = MAX(proxy_fd, tls_out.active) + 1;
2587 int rc, i, fd_bits, nbytes;
2588
2589 set_process_info("proxying TLS connection for continued transport");
2590 FD_ZERO(&rfds);
2591 FD_SET(tls_out.active, &rfds);
2592 FD_SET(proxy_fd, &rfds);
2593
2594 for (fd_bits = 3; fd_bits; )
2595 {
2596 time_t time_left = timeout;
2597 time_t time_start = time(NULL);
2598
2599 /* wait for data */
2600 efds = rfds;
2601 do
2602 {
2603 struct timeval tv = { time_left, 0 };
2604
2605 rc = select(max_fd,
2606 (SELECT_ARG2_TYPE *)&rfds, NULL, (SELECT_ARG2_TYPE *)&efds, &tv);
2607
2608 if (rc < 0 && errno == EINTR)
2609 if ((time_left -= time(NULL) - time_start) > 0) continue;
2610
2611 if (rc <= 0)
2612 {
2613 DEBUG(D_transport) if (rc == 0) debug_printf("%s: timed out\n", __FUNCTION__);
2614 return;
2615 }
2616
2617 if (FD_ISSET(tls_out.active, &efds) || FD_ISSET(proxy_fd, &efds))
2618 {
2619 DEBUG(D_transport) debug_printf("select: exceptional cond on %s fd\n",
2620 FD_ISSET(proxy_fd, &efds) ? "proxy" : "tls");
2621 return;
2622 }
2623 }
2624 while (rc < 0 || !(FD_ISSET(tls_out.active, &rfds) || FD_ISSET(proxy_fd, &rfds)));
2625
2626 /* handle inbound data */
2627 if (FD_ISSET(tls_out.active, &rfds))
2628 if ((rc = tls_read(FALSE, buf, bsize)) <= 0)
2629 {
2630 fd_bits &= ~1;
2631 FD_CLR(tls_out.active, &rfds);
2632 shutdown(proxy_fd, SHUT_WR);
2633 timeout = 5;
2634 }
2635 else
2636 {
2637 for (nbytes = 0; rc - nbytes > 0; nbytes += i)
2638 if ((i = write(proxy_fd, buf + nbytes, rc - nbytes)) < 0) return;
2639 }
2640 else if (fd_bits & 1)
2641 FD_SET(tls_out.active, &rfds);
2642
2643 /* handle outbound data */
2644 if (FD_ISSET(proxy_fd, &rfds))
2645 if ((rc = read(proxy_fd, buf, bsize)) <= 0)
2646 {
2647 fd_bits = 0;
2648 tls_close(FALSE, TRUE);
2649 }
2650 else
2651 {
2652 for (nbytes = 0; rc - nbytes > 0; nbytes += i)
2653 if ((i = tls_write(FALSE, buf + nbytes, rc - nbytes, FALSE)) < 0)
2654 return;
2655 }
2656 else if (fd_bits & 2)
2657 FD_SET(proxy_fd, &rfds);
2658 }
2659 }
2660 #endif
2661
2662
2663 /*************************************************
2664 * Deliver address list to given host *
2665 *************************************************/
2666
2667 /* If continue_hostname is not null, we get here only when continuing to
2668 deliver down an existing channel. The channel was passed as the standard
2669 input. TLS is never active on a passed channel; the previous process always
2670 closes it down before passing the connection on.
2671
2672 Otherwise, we have to make a connection to the remote host, and do the
2673 initial protocol exchange.
2674
2675 When running as an MUA wrapper, if the sender or any recipient is rejected,
2676 temporarily or permanently, we force failure for all recipients.
2677
2678 Arguments:
2679 addrlist chain of potential addresses to deliver; only those whose
2680 transport_return field is set to PENDING_DEFER are currently
2681 being processed; others should be skipped - they have either
2682 been delivered to an earlier host or IP address, or been
2683 failed by one of them.
2684 host host to deliver to
2685 host_af AF_INET or AF_INET6
2686 defport default TCP/IP port to use if host does not specify, in host
2687 byte order
2688 interface interface to bind to, or NULL
2689 tblock transport instance block
2690 message_defer set TRUE if yield is OK, but all addresses were deferred
2691 because of a non-recipient, non-host failure, that is, a
2692 4xx response to MAIL FROM, DATA, or ".". This is a defer
2693 that is specific to the message.
2694 suppress_tls if TRUE, don't attempt a TLS connection - this is set for
2695 a second attempt after TLS initialization fails
2696
2697 Returns: OK - the connection was made and the delivery attempted;
2698 the result for each address is in its data block.
2699 DEFER - the connection could not be made, or something failed
2700 while setting up the SMTP session, or there was a
2701 non-message-specific error, such as a timeout.
2702 ERROR - a filter command is specified for this transport,
2703 and there was a problem setting it up; OR helo_data
2704 or add_headers or authenticated_sender is specified
2705 for this transport, and the string failed to expand
2706 */
2707
2708 static int
2709 smtp_deliver(address_item *addrlist, host_item *host, int host_af, int defport,
2710 uschar *interface, transport_instance *tblock,
2711 BOOL *message_defer, BOOL suppress_tls)
2712 {
2713 address_item *addr;
2714 int yield = OK;
2715 int save_errno;
2716 int rc;
2717 struct timeval start_delivery_time;
2718
2719 BOOL pass_message = FALSE;
2720 uschar *message = NULL;
2721 uschar new_message_id[MESSAGE_ID_LENGTH + 1];
2722 uschar *p;
2723
2724 smtp_context sx;
2725
2726 gettimeofday(&start_delivery_time, NULL);
2727 suppress_tls = suppress_tls; /* stop compiler warning when no TLS support */
2728 *message_defer = FALSE;
2729
2730 sx.addrlist = addrlist;
2731 sx.host = host;
2732 sx.host_af = host_af,
2733 sx.port = defport;
2734 sx.interface = interface;
2735 sx.helo_data = NULL;
2736 sx.tblock = tblock;
2737 sx.verify = FALSE;
2738
2739 /* Get the channel set up ready for a message (MAIL FROM being the next
2740 SMTP command to send */
2741
2742 if ((rc = smtp_setup_conn(&sx, suppress_tls)) != OK)
2743 return rc;
2744
2745 /* If there is a filter command specified for this transport, we can now
2746 set it up. This cannot be done until the identify of the host is known. */
2747
2748 if (tblock->filter_command)
2749 {
2750 transport_filter_timeout = tblock->filter_timeout;
2751
2752 /* On failure, copy the error to all addresses, abandon the SMTP call, and
2753 yield ERROR. */
2754
2755 if (!transport_set_up_command(&transport_filter_argv,
2756 tblock->filter_command, TRUE, DEFER, addrlist,
2757 string_sprintf("%.50s transport", tblock->name), NULL))
2758 {
2759 set_errno_nohost(addrlist->next, addrlist->basic_errno, addrlist->message, DEFER,
2760 FALSE);
2761 yield = ERROR;
2762 goto SEND_QUIT;
2763 }
2764
2765 if ( transport_filter_argv
2766 && *transport_filter_argv
2767 && **transport_filter_argv
2768 && sx.peer_offered & OPTION_CHUNKING
2769 )
2770 {
2771 sx.peer_offered &= ~OPTION_CHUNKING;
2772 DEBUG(D_transport) debug_printf("CHUNKING not usable due to transport filter\n");
2773 }
2774 }
2775
2776 sx.first_addr = addrlist;
2777
2778 /* For messages that have more than the maximum number of envelope recipients,
2779 we want to send several transactions down the same SMTP connection. (See
2780 comments in deliver.c as to how this reconciles, heuristically, with
2781 remote_max_parallel.) This optimization was added to Exim after the following
2782 code was already working. The simplest way to put it in without disturbing the
2783 code was to use a goto to jump back to this point when there is another
2784 transaction to handle. */
2785
2786 SEND_MESSAGE:
2787 sx.from_addr = return_path;
2788 sx.sync_addr = sx.first_addr;
2789 sx.ok = FALSE;
2790 sx.send_rset = TRUE;
2791 sx.completed_addr = FALSE;
2792
2793
2794 /* If we are a continued-connection-after-verify the MAIL and RCPT
2795 commands were already sent; do not re-send but do mark the addrs as
2796 having been accepted up to RCPT stage. A traditional cont-conn
2797 always has a sequence number greater than one. */
2798
2799 if (continue_hostname && continue_sequence == 1)
2800 {
2801 address_item * addr;
2802
2803 sx.peer_offered = smtp_peer_options;
2804 sx.pending_MAIL = FALSE;
2805 sx.ok = TRUE;
2806 sx.next_addr = NULL;
2807
2808 for (addr = addrlist; addr; addr = addr->next)
2809 addr->transport_return = PENDING_OK;
2810 }
2811 else
2812 {
2813 /* Initiate a message transfer. */
2814
2815 switch(smtp_write_mail_and_rcpt_cmds(&sx, &yield))
2816 {
2817 case 0: break;
2818 case -1: case -2: goto RESPONSE_FAILED;
2819 case -3: goto END_OFF;
2820 case -4: goto SEND_QUIT;
2821 default: goto SEND_FAILED;
2822 }
2823
2824 /* If we are an MUA wrapper, abort if any RCPTs were rejected, either
2825 permanently or temporarily. We should have flushed and synced after the last
2826 RCPT. */
2827
2828 if (mua_wrapper)
2829 {
2830 address_item * a;
2831 unsigned cnt;
2832
2833 for (a = sx.first_addr, cnt = 0; a && cnt < sx.max_rcpt; a = a->next, cnt++)
2834 if (a->transport_return != PENDING_OK)
2835 {
2836 /*XXX could we find a better errno than 0 here? */
2837 set_errno_nohost(addrlist, 0, a->message, FAIL,
2838 testflag(a, af_pass_message));
2839 sx.ok = FALSE;
2840 break;
2841 }
2842 }
2843 }
2844
2845 /* If ok is TRUE, we know we have got at least one good recipient, and must now
2846 send DATA, but if it is FALSE (in the normal, non-wrapper case), we may still
2847 have a good recipient buffered up if we are pipelining. We don't want to waste
2848 time sending DATA needlessly, so we only send it if either ok is TRUE or if we
2849 are pipelining. The responses are all handled by sync_responses().
2850 If using CHUNKING, do not send a BDAT until we know how big a chunk we want
2851 to send is. */
2852
2853 if ( !(sx.peer_offered & OPTION_CHUNKING)
2854 && (sx.ok || (pipelining_active && !mua_wrapper)))
2855 {
2856 int count = smtp_write_command(&sx.outblock, SCMD_FLUSH, "DATA\r\n");
2857
2858 if (count < 0) goto SEND_FAILED;
2859 switch(sync_responses(&sx, count, sx.ok ? +1 : -1))
2860 {
2861 case 3: sx.ok = TRUE; /* 2xx & 5xx => OK & progress made */
2862 case 2: sx.completed_addr = TRUE; /* 5xx (only) => progress made */
2863 break;
2864
2865 case 1: sx.ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
2866 if (!sx.lmtp) sx.completed_addr = TRUE; /* can't tell about progress yet */
2867 case 0: break; /* No 2xx or 5xx, but no probs */
2868
2869 case -1: goto END_OFF; /* Timeout on RCPT */
2870 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */
2871 }
2872 pipelining_active = FALSE;
2873 data_command = string_copy(big_buffer); /* Save for later error message */
2874 }
2875
2876 /* If there were no good recipients (but otherwise there have been no
2877 problems), just set ok TRUE, since we have handled address-specific errors
2878 already. Otherwise, it's OK to send the message. Use the check/escape mechanism
2879 for handling the SMTP dot-handling protocol, flagging to apply to headers as
2880 well as body. Set the appropriate timeout value to be used for each chunk.
2881 (Haven't been able to make it work using select() for writing yet.) */
2882
2883 if (!(sx.peer_offered & OPTION_CHUNKING) && !sx.ok)
2884 {
2885 /* Save the first address of the next batch. */
2886 sx.first_addr = sx.next_addr;
2887
2888 sx.ok = TRUE;
2889 }
2890 else
2891 {
2892 transport_ctx tctx = {
2893 sx.inblock.sock,
2894 tblock,
2895 addrlist,
2896 US".", US"..", /* Escaping strings */
2897 topt_use_crlf | topt_escape_headers
2898 | (tblock->body_only ? topt_no_headers : 0)
2899 | (tblock->headers_only ? topt_no_body : 0)
2900 | (tblock->return_path_add ? topt_add_return_path : 0)
2901 | (tblock->delivery_date_add ? topt_add_delivery_date : 0)
2902 | (tblock->envelope_to_add ? topt_add_envelope_to : 0)
2903 };
2904
2905 /* If using CHUNKING we need a callback from the generic transport
2906 support to us, for the sending of BDAT smtp commands and the reaping
2907 of responses. The callback needs a whole bunch of state so set up
2908 a transport-context structure to be passed around. */
2909
2910 if (sx.peer_offered & OPTION_CHUNKING)
2911 {
2912 tctx.check_string = tctx.escape_string = NULL;
2913 tctx.options |= topt_use_bdat;
2914 tctx.chunk_cb = smtp_chunk_cmd_callback;
2915 sx.pending_BDAT = FALSE;
2916 sx.good_RCPT = sx.ok;
2917 sx.cmd_count = 0;
2918 tctx.smtp_context = &sx;
2919 }
2920 else
2921 tctx.options |= topt_end_dot;
2922
2923 /* Save the first address of the next batch. */
2924 sx.first_addr = sx.next_addr;
2925
2926 /* Responses from CHUNKING commands go in buffer. Otherwise,
2927 there has not been a response. */
2928
2929 sx.buffer[0] = 0;
2930
2931 sigalrm_seen = FALSE;
2932 transport_write_timeout = sx.ob->data_timeout;
2933 smtp_command = US"sending data block"; /* For error messages */
2934 DEBUG(D_transport|D_v)
2935 if (sx.peer_offered & OPTION_CHUNKING)
2936 debug_printf(" will write message using CHUNKING\n");
2937 else
2938 debug_printf(" SMTP>> writing message and terminating \".\"\n");
2939 transport_count = 0;
2940
2941 #ifndef DISABLE_DKIM
2942 sx.ok = dkim_transport_write_message(&tctx, &sx.ob->dkim, CUSS &message);
2943 #else
2944 sx.ok = transport_write_message(&tctx, 0);
2945 #endif
2946
2947 /* transport_write_message() uses write() because it is called from other
2948 places to write to non-sockets. This means that under some OS (e.g. Solaris)
2949 it can exit with "Broken pipe" as its error. This really means that the
2950 socket got closed at the far end. */
2951
2952 transport_write_timeout = 0; /* for subsequent transports */
2953
2954 /* Failure can either be some kind of I/O disaster (including timeout),
2955 or the failure of a transport filter or the expansion of added headers.
2956 Or, when CHUNKING, it can be a protocol-detected failure. */
2957
2958 if (!sx.ok)
2959 if (message) goto SEND_FAILED;
2960 else goto RESPONSE_FAILED;
2961
2962 /* We used to send the terminating "." explicitly here, but because of
2963 buffering effects at both ends of TCP/IP connections, you don't gain
2964 anything by keeping it separate, so it might as well go in the final
2965 data buffer for efficiency. This is now done by setting the topt_end_dot
2966 flag above. */
2967
2968 smtp_command = US"end of data";
2969
2970 if (sx.peer_offered & OPTION_CHUNKING && sx.cmd_count > 1)
2971 {
2972 /* Reap any outstanding MAIL & RCPT commands, but not a DATA-go-ahead */
2973 switch(sync_responses(&sx, sx.cmd_count-1, 0))
2974 {
2975 case 3: sx.ok = TRUE; /* 2xx & 5xx => OK & progress made */
2976 case 2: sx.completed_addr = TRUE; /* 5xx (only) => progress made */
2977 break;
2978
2979 case 1: sx.ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
2980 if (!sx.lmtp) sx.completed_addr = TRUE; /* can't tell about progress yet */
2981 case 0: break; /* No 2xx or 5xx, but no probs */
2982
2983 case -1: goto END_OFF; /* Timeout on RCPT */
2984 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */
2985 }
2986 }
2987
2988 #ifndef DISABLE_PRDR
2989 /* For PRDR we optionally get a partial-responses warning
2990 * followed by the individual responses, before going on with
2991 * the overall response. If we don't get the warning then deal
2992 * with per non-PRDR. */
2993 if(sx.prdr_active)
2994 {
2995 sx.ok = smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer), '3',
2996 sx.ob->final_timeout);
2997 if (!sx.ok && errno == 0) switch(sx.buffer[0])
2998 {
2999 case '2': sx.prdr_active = FALSE;
3000 sx.ok = TRUE;
3001 break;
3002 case '4': errno = ERRNO_DATA4XX;
3003 addrlist->more_errno |=
3004 ((sx.buffer[1] - '0')*10 + sx.buffer[2] - '0') << 8;
3005 break;
3006 }
3007 }
3008 else
3009 #endif
3010
3011 /* For non-PRDR SMTP, we now read a single response that applies to the
3012 whole message. If it is OK, then all the addresses have been delivered. */
3013
3014 if (!sx.lmtp)
3015 {
3016 sx.ok = smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer), '2',
3017 sx.ob->final_timeout);
3018 if (!sx.ok && errno == 0 && sx.buffer[0] == '4')
3019 {
3020 errno = ERRNO_DATA4XX;
3021 addrlist->more_errno |= ((sx.buffer[1] - '0')*10 + sx.buffer[2] - '0') << 8;
3022 }
3023 }
3024
3025 /* For LMTP, we get back a response for every RCPT command that we sent;
3026 some may be accepted and some rejected. For those that get a response, their
3027 status is fixed; any that are accepted have been handed over, even if later
3028 responses crash - at least, that's how I read RFC 2033.
3029
3030 If all went well, mark the recipient addresses as completed, record which
3031 host/IPaddress they were delivered to, and cut out RSET when sending another
3032 message down the same channel. Write the completed addresses to the journal
3033 now so that they are recorded in case there is a crash of hardware or
3034 software before the spool gets updated. Also record the final SMTP
3035 confirmation if needed (for SMTP only). */
3036
3037 if (sx.ok)
3038 {
3039 int flag = '=';
3040 struct timeval delivery_time;
3041 int len;
3042 uschar * conf = NULL;
3043
3044 timesince(&delivery_time, &start_delivery_time);
3045 sx.send_rset = FALSE;
3046 pipelining_active = FALSE;
3047
3048 /* Set up confirmation if needed - applies only to SMTP */
3049
3050 if (
3051 #ifdef DISABLE_EVENT
3052 LOGGING(smtp_confirmation) &&
3053 #endif
3054 !sx.lmtp
3055 )
3056 {
3057 const uschar *s = string_printing(sx.buffer);
3058 /* deconst cast ok here as string_printing was checked to have alloc'n'copied */
3059 conf = (s == sx.buffer)? (uschar *)string_copy(s) : US s;
3060 }
3061
3062 /* Process all transported addresses - for LMTP or PRDR, read a status for
3063 each one. */
3064
3065 for (addr = addrlist; addr != sx.first_addr; addr = addr->next)
3066 {
3067 if (addr->transport_return != PENDING_OK) continue;
3068
3069 /* LMTP - if the response fails badly (e.g. timeout), use it for all the
3070 remaining addresses. Otherwise, it's a return code for just the one
3071 address. For temporary errors, add a retry item for the address so that
3072 it doesn't get tried again too soon. */
3073
3074 #ifndef DISABLE_PRDR
3075 if (sx.lmtp || sx.prdr_active)
3076 #else
3077 if (sx.lmtp)
3078 #endif
3079 {
3080 if (!smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer), '2',
3081 sx.ob->final_timeout))
3082 {
3083 if (errno != 0 || sx.buffer[0] == 0) goto RESPONSE_FAILED;
3084 addr->message = string_sprintf(
3085 #ifndef DISABLE_PRDR
3086 "%s error after %s: %s", sx.prdr_active ? "PRDR":"LMTP",
3087 #else
3088 "LMTP error after %s: %s",
3089 #endif
3090 data_command, string_printing(sx.buffer));
3091 setflag(addr, af_pass_message); /* Allow message to go to user */
3092 if (sx.buffer[0] == '5')
3093 addr->transport_return = FAIL;
3094 else
3095 {
3096 errno = ERRNO_DATA4XX;
3097 addr->more_errno |= ((sx.buffer[1] - '0')*10 + sx.buffer[2] - '0') << 8;
3098 addr->transport_return = DEFER;
3099 #ifndef DISABLE_PRDR
3100 if (!sx.prdr_active)
3101 #endif
3102 retry_add_item(addr, addr->address_retry_key, 0);
3103 }
3104 continue;
3105 }
3106 sx.completed_addr = TRUE; /* NOW we can set this flag */
3107 if (LOGGING(smtp_confirmation))
3108 {
3109 const uschar *s = string_printing(sx.buffer);
3110 /* deconst cast ok here as string_printing was checked to have alloc'n'copied */
3111 conf = (s == sx.buffer) ? US string_copy(s) : US s;
3112 }
3113 }
3114
3115 /* SMTP, or success return from LMTP for this address. Pass back the
3116 actual host that was used. */
3117
3118 addr->transport_return = OK;
3119 addr->more_errno = delivery_time.tv_sec;
3120 addr->delivery_usec = delivery_time.tv_usec;
3121 addr->host_used = host;
3122 addr->special_action = flag;
3123 addr->message = conf;
3124 #ifndef DISABLE_PRDR
3125 if (sx.prdr_active) addr->flags |= af_prdr_used;
3126 #endif
3127 if (sx.peer_offered & OPTION_CHUNKING) addr->flags |= af_chunking_used;
3128 flag = '-';
3129
3130 #ifndef DISABLE_PRDR
3131 if (!sx.prdr_active)
3132 #endif
3133 {
3134 /* Update the journal. For homonymic addresses, use the base address plus
3135 the transport name. See lots of comments in deliver.c about the reasons
3136 for the complications when homonyms are involved. Just carry on after
3137 write error, as it may prove possible to update the spool file later. */
3138
3139 if (testflag(addr, af_homonym))
3140 sprintf(CS sx.buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
3141 else
3142 sprintf(CS sx.buffer, "%.500s\n", addr->unique);
3143
3144 DEBUG(D_deliver) debug_printf("S:journalling %s\n", sx.buffer);
3145 len = Ustrlen(CS sx.buffer);
3146 if (write(journal_fd, sx.buffer, len) != len)
3147 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
3148 "%s: %s", sx.buffer, strerror(errno));
3149 }
3150 }
3151
3152 #ifndef DISABLE_PRDR
3153 if (sx.prdr_active)
3154 {
3155 /* PRDR - get the final, overall response. For any non-success
3156 upgrade all the address statuses. */
3157 sx.ok = smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer), '2',
3158 sx.ob->final_timeout);
3159 if (!sx.ok)
3160 {
3161 if(errno == 0 && sx.buffer[0] == '4')
3162 {
3163 errno = ERRNO_DATA4XX;
3164 addrlist->more_errno |= ((sx.buffer[1] - '0')*10 + sx.buffer[2] - '0') << 8;
3165 }
3166 for (addr = addrlist; addr != sx.first_addr; addr = addr->next)
3167 if (sx.buffer[0] == '5' || addr->transport_return == OK)
3168 addr->transport_return = PENDING_OK; /* allow set_errno action */
3169 goto RESPONSE_FAILED;
3170 }
3171
3172 /* Update the journal, or setup retry. */
3173 for (addr = addrlist; addr != sx.first_addr; addr = addr->next)
3174 if (addr->transport_return == OK)
3175 {
3176 if (testflag(addr, af_homonym))
3177 sprintf(CS sx.buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
3178 else
3179 sprintf(CS sx.buffer, "%.500s\n", addr->unique);
3180
3181 DEBUG(D_deliver) debug_printf("journalling(PRDR) %s\n", sx.buffer);
3182 len = Ustrlen(CS sx.buffer);
3183 if (write(journal_fd, sx.buffer, len) != len)
3184 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
3185 "%s: %s", sx.buffer, strerror(errno));
3186 }
3187 else if (addr->transport_return == DEFER)
3188 retry_add_item(addr, addr->address_retry_key, -2);
3189 }
3190 #endif
3191
3192 /* Ensure the journal file is pushed out to disk. */
3193
3194 if (EXIMfsync(journal_fd) < 0)
3195 log_write(0, LOG_MAIN|LOG_PANIC, "failed to fsync journal: %s",
3196 strerror(errno));
3197 }
3198 }
3199
3200
3201 /* Handle general (not specific to one address) failures here. The value of ok
3202 is used to skip over this code on the falling through case. A timeout causes a
3203 deferral. Other errors may defer or fail according to the response code, and
3204 may set up a special errno value, e.g. after connection chopped, which is
3205 assumed if errno == 0 and there is no text in the buffer. If control reaches
3206 here during the setting up phase (i.e. before MAIL FROM) then always defer, as
3207 the problem is not related to this specific message. */
3208
3209 if (!sx.ok)
3210 {
3211 int code, set_rc;
3212 uschar * set_message;
3213
3214 RESPONSE_FAILED:
3215 {
3216 save_errno = errno;
3217 message = NULL;
3218 sx.send_quit = check_response(host, &save_errno, addrlist->more_errno,
3219 sx.buffer, &code, &message, &pass_message);
3220 goto FAILED;
3221 }
3222
3223 SEND_FAILED:
3224 {
3225 save_errno = errno;
3226 code = '4';
3227 message = string_sprintf("send() to %s [%s] failed: %s",
3228 host->name, host->address, message ? message : US strerror(save_errno));
3229 sx.send_quit = FALSE;
3230 goto FAILED;
3231 }
3232
3233 FAILED:
3234 {
3235 BOOL message_error;
3236
3237 sx.ok = FALSE; /* For when reached by GOTO */
3238 set_message = message;
3239
3240 /* We want to handle timeouts after MAIL or "." and loss of connection after
3241 "." specially. They can indicate a problem with the sender address or with
3242 the contents of the message rather than a real error on the connection. These
3243 cases are treated in the same way as a 4xx response. This next bit of code
3244 does the classification. */
3245
3246 switch(save_errno)
3247 {
3248 case 0:
3249 case ERRNO_MAIL4XX:
3250 case ERRNO_DATA4XX:
3251 message_error = TRUE;
3252 break;
3253
3254 case ETIMEDOUT:
3255 message_error = Ustrncmp(smtp_command,"MAIL",4) == 0 ||
3256 Ustrncmp(smtp_command,"end ",4) == 0;
3257 break;
3258
3259 case ERRNO_SMTPCLOSED:
3260 message_error = Ustrncmp(smtp_command,"end ",4) == 0;
3261 break;
3262
3263 default:
3264 message_error = FALSE;
3265 break;
3266 }
3267
3268 /* Handle the cases that are treated as message errors. These are:
3269
3270 (a) negative response or timeout after MAIL
3271 (b) negative response after DATA
3272 (c) negative response or timeout or dropped connection after "."
3273 (d) utf8 support required and not offered
3274
3275 It won't be a negative response or timeout after RCPT, as that is dealt
3276 with separately above. The action in all cases is to set an appropriate
3277 error code for all the addresses, but to leave yield set to OK because the
3278 host itself has not failed. Of course, it might in practice have failed
3279 when we've had a timeout, but if so, we'll discover that at the next
3280 delivery attempt. For a temporary error, set the message_defer flag, and
3281 write to the logs for information if this is not the last host. The error
3282 for the last host will be logged as part of the address's log line. */
3283
3284 if (message_error)
3285 {
3286 if (mua_wrapper) code = '5'; /* Force hard failure in wrapper mode */
3287
3288 /* If there's an errno, the message contains just the identity of
3289 the host. */
3290
3291 if (code == '5')
3292 set_rc = FAIL;
3293 else /* Anything other than 5 is treated as temporary */
3294 {
3295 set_rc = DEFER;
3296 if (save_errno > 0)
3297 message = US string_sprintf("%s: %s", message, strerror(save_errno));
3298 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", message);
3299 msglog_line(host, message);
3300 *message_defer = TRUE;
3301 }
3302 }
3303
3304 /* Otherwise, we have an I/O error or a timeout other than after MAIL or
3305 ".", or some other transportation error. We defer all addresses and yield
3306 DEFER, except for the case of failed add_headers expansion, or a transport
3307 filter failure, when the yield should be ERROR, to stop it trying other
3308 hosts. */
3309
3310 else
3311 {
3312 set_rc = DEFER;
3313 yield = (save_errno == ERRNO_CHHEADER_FAIL ||
3314 save_errno == ERRNO_FILTER_FAIL)? ERROR : DEFER;
3315 }
3316 }
3317
3318 set_errno(addrlist, save_errno, set_message, set_rc, pass_message, host
3319 #ifdef EXPERIMENTAL_DSN_INFO
3320 , sx.smtp_greeting, sx.helo_response
3321 #endif
3322 );
3323 }
3324
3325
3326 /* If all has gone well, send_quit will be set TRUE, implying we can end the
3327 SMTP session tidily. However, if there were too many addresses to send in one
3328 message (indicated by first_addr being non-NULL) we want to carry on with the
3329 rest of them. Also, it is desirable to send more than one message down the SMTP
3330 connection if there are several waiting, provided we haven't already sent so
3331 many as to hit the configured limit. The function transport_check_waiting looks
3332 for a waiting message and returns its id. Then transport_pass_socket tries to
3333 set up a continued delivery by passing the socket on to another process. The
3334 variable send_rset is FALSE if a message has just been successfully transfered.
3335
3336 If we are already sending down a continued channel, there may be further
3337 addresses not yet delivered that are aimed at the same host, but which have not
3338 been passed in this run of the transport. In this case, continue_more will be
3339 true, and all we should do is send RSET if necessary, and return, leaving the
3340 channel open.
3341
3342 However, if no address was disposed of, i.e. all addresses got 4xx errors, we
3343 do not want to continue with other messages down the same channel, because that
3344 can lead to looping between two or more messages, all with the same,
3345 temporarily failing address(es). [The retry information isn't updated yet, so
3346 new processes keep on trying.] We probably also don't want to try more of this
3347 message's addresses either.
3348
3349 If we have started a TLS session, we have to end it before passing the
3350 connection to a new process. However, not all servers can handle this (Exim
3351 can), so we do not pass such a connection on if the host matches
3352 hosts_nopass_tls. */
3353
3354 DEBUG(D_transport)
3355 debug_printf("ok=%d send_quit=%d send_rset=%d continue_more=%d "
3356 "yield=%d first_address is %sNULL\n", sx.ok, sx.send_quit,
3357 sx.send_rset, continue_more, yield, sx.first_addr ? "not " : "");
3358
3359 if (sx.completed_addr && sx.ok && sx.send_quit)
3360 {
3361 BOOL more;
3362 smtp_compare_t t_compare;
3363
3364 t_compare.tblock = tblock;
3365 t_compare.current_sender_address = sender_address;
3366
3367 if ( sx.first_addr != NULL
3368 || continue_more
3369 || (
3370 #ifdef SUPPORT_TLS
3371 ( tls_out.active < 0 && !continue_proxy_cipher
3372 || verify_check_given_host(&sx.ob->hosts_nopass_tls, host) != OK
3373 )
3374 &&
3375 #endif
3376 transport_check_waiting(tblock->name, host->name,
3377 tblock->connection_max_messages, new_message_id, &more,
3378 (oicf)smtp_are_same_identities, (void*)&t_compare)
3379 ) )
3380 {
3381 uschar *msg;
3382 BOOL pass_message;
3383
3384 if (sx.send_rset)
3385 if (! (sx.ok = smtp_write_command(&sx.outblock, SCMD_FLUSH, "RSET\r\n") >= 0))
3386 {
3387 msg = US string_sprintf("send() to %s [%s] failed: %s", host->name,
3388 host->address, strerror(errno));
3389 sx.send_quit = FALSE;
3390 }
3391 else if (! (sx.ok = smtp_read_response(&sx.inblock, sx.buffer,
3392 sizeof(sx.buffer), '2', sx.ob->command_timeout)))
3393 {
3394 int code;
3395 sx.send_quit = check_response(host, &errno, 0, sx.buffer, &code, &msg,
3396 &pass_message);
3397 if (!sx.send_quit)
3398 {
3399 DEBUG(D_transport) debug_printf("H=%s [%s] %s\n",
3400 host->name, host->address, msg);
3401 }
3402 }
3403
3404 /* Either RSET was not needed, or it succeeded */
3405
3406 if (sx.ok)
3407 {
3408 int pfd[2];
3409 int socket_fd = sx.inblock.sock;
3410
3411
3412 if (sx.first_addr != NULL) /* More addresses still to be sent */
3413 { /* in this run of the transport */
3414 continue_sequence++; /* Causes * in logging */
3415 goto SEND_MESSAGE;
3416 }
3417
3418 /* Unless caller said it already has more messages listed for this host,
3419 pass the connection on to a new Exim process (below, the call to
3420 transport_pass_socket). If the caller has more ready, just return with
3421 the connection still open. */
3422
3423 #ifdef SUPPORT_TLS
3424 if (tls_out.active >= 0)
3425 if ( continue_more
3426 || verify_check_given_host(&sx.ob->hosts_noproxy_tls, host) == OK)
3427 {
3428 /* Before passing the socket on, or returning to caller with it still
3429 open, we must shut down TLS. Not all MTAs allow for the continuation
3430 of the SMTP session when TLS is shut down. We test for this by sending
3431 a new EHLO. If we don't get a good response, we don't attempt to pass
3432 the socket on. */
3433
3434 tls_close(FALSE, TRUE);
3435 smtp_peer_options = smtp_peer_options_wrap;
3436 sx.ok = !sx.smtps
3437 && smtp_write_command(&sx.outblock, SCMD_FLUSH,
3438 "EHLO %s\r\n", sx.helo_data) >= 0
3439 && smtp_read_response(&sx.inblock, sx.buffer, sizeof(sx.buffer),
3440 '2', sx.ob->command_timeout);
3441
3442 if (sx.ok && continue_more)
3443 return yield; /* More addresses for another run */
3444 }
3445 else
3446 {
3447 /* Set up a pipe for proxying TLS for the new transport process */
3448
3449 smtp_peer_options |= OPTION_TLS;
3450 if (sx.ok = (socketpair(AF_UNIX, SOCK_STREAM, 0, pfd) == 0))
3451 socket_fd = pfd[1];
3452 else
3453 set_errno(sx.first_addr, errno, US"internal allocation problem",
3454 DEFER, FALSE, host
3455 # ifdef EXPERIMENTAL_DSN_INFO
3456 , sx.smtp_greeting, sx.helo_response
3457 # endif
3458 );
3459 }
3460 else
3461 #endif
3462 if (continue_more)
3463 return yield; /* More addresses for another run */
3464
3465 /* If the socket is successfully passed, we mustn't send QUIT (or
3466 indeed anything!) from here. */
3467
3468 /*XXX DSN_INFO: assume likely to do new HELO; but for greet we'll want to
3469 propagate it from the initial
3470 */
3471 if (sx.ok && transport_pass_socket(tblock->name, host->name,
3472 host->address, new_message_id, socket_fd))
3473 {
3474 sx.send_quit = FALSE;
3475
3476 /* If TLS is still active, we need to proxy it for the transport we
3477 just passed the baton to. Fork a child to to do it, and return to
3478 get logging done asap. Which way to place the work makes assumptions
3479 about post-fork prioritisation which may not hold on all platforms. */
3480 #ifdef SUPPORT_TLS
3481 if (tls_out.active >= 0)
3482 {
3483 int pid = fork();
3484 if (pid > 0) /* parent */
3485 {
3486 DEBUG(D_transport) debug_printf("proxy-proc inter-pid %d\n", pid);
3487 close(pfd[0]);
3488 waitpid(pid, NULL, 0);
3489 tls_close(FALSE, FALSE);
3490 (void)close(sx.inblock.sock);
3491 continue_transport = NULL;
3492 continue_hostname = NULL;
3493 return yield;
3494 }
3495 else if (pid == 0) /* child; fork again to disconnect totally */
3496 {
3497 close(pfd[1]);
3498 if ((pid = fork()))
3499 {
3500 DEBUG(D_transport) debug_printf("proxy-prox final-pid %d\n", pid);
3501 _exit(pid ? EXIT_FAILURE : EXIT_SUCCESS);
3502 }
3503 smtp_proxy_tls(sx.buffer, sizeof(sx.buffer), pfd[0], sx.ob->command_timeout);
3504 exim_exit(0);
3505 }
3506 }
3507 #endif
3508 }
3509 }
3510
3511 /* If RSET failed and there are addresses left, they get deferred. */
3512 else
3513 set_errno(sx.first_addr, errno, msg, DEFER, FALSE, host
3514 #ifdef EXPERIMENTAL_DSN_INFO
3515 , sx.smtp_greeting, sx.helo_response
3516 #endif
3517 );
3518 }
3519 }
3520
3521 /* End off tidily with QUIT unless the connection has died or the socket has
3522 been passed to another process. There has been discussion on the net about what
3523 to do after sending QUIT. The wording of the RFC suggests that it is necessary
3524 to wait for a response, but on the other hand, there isn't anything one can do
3525 with an error response, other than log it. Exim used to do that. However,
3526 further discussion suggested that it is positively advantageous not to wait for
3527 the response, but to close the session immediately. This is supposed to move
3528 the TCP/IP TIME_WAIT state from the server to the client, thereby removing some
3529 load from the server. (Hosts that are both servers and clients may not see much
3530 difference, of course.) Further discussion indicated that this was safe to do
3531 on Unix systems which have decent implementations of TCP/IP that leave the
3532 connection around for a while (TIME_WAIT) after the application has gone away.
3533 This enables the response sent by the server to be properly ACKed rather than
3534 timed out, as can happen on broken TCP/IP implementations on other OS.
3535
3536 This change is being made on 31-Jul-98. After over a year of trouble-free
3537 operation, the old commented-out code was removed on 17-Sep-99. */
3538
3539 SEND_QUIT:
3540 if (sx.send_quit) (void)smtp_write_command(&sx.outblock, SCMD_FLUSH, "QUIT\r\n");
3541
3542 END_OFF:
3543
3544 #ifdef SUPPORT_TLS
3545 tls_close(FALSE, TRUE);
3546 #endif
3547
3548 /* Close the socket, and return the appropriate value, first setting
3549 works because the NULL setting is passed back to the calling process, and
3550 remote_max_parallel is forced to 1 when delivering over an existing connection,
3551
3552 If all went well and continue_more is set, we shouldn't actually get here if
3553 there are further addresses, as the return above will be taken. However,
3554 writing RSET might have failed, or there may be other addresses whose hosts are
3555 specified in the transports, and therefore not visible at top level, in which
3556 case continue_more won't get set. */
3557
3558 HDEBUG(D_transport|D_acl|D_v) debug_printf_indent(" SMTP(close)>>\n");
3559 if (sx.send_quit)
3560 {
3561 shutdown(sx.outblock.sock, SHUT_WR);
3562 if (fcntl(sx.inblock.sock, F_SETFL, O_NONBLOCK) == 0)
3563 for (rc = 16; read(sx.inblock.sock, sx.inbuffer, sizeof(sx.inbuffer)) > 0 && rc > 0;)
3564 rc--; /* drain socket */
3565 }
3566 (void)close(sx.inblock.sock);
3567
3568 #ifndef DISABLE_EVENT
3569 (void) event_raise(tblock->event_action, US"tcp:close", NULL);
3570 #endif
3571
3572 continue_transport = NULL;
3573 continue_hostname = NULL;
3574 return yield;
3575 }
3576
3577
3578
3579
3580 /*************************************************
3581 * Closedown entry point *
3582 *************************************************/
3583
3584 /* This function is called when exim is passed an open smtp channel
3585 from another incarnation, but the message which it has been asked
3586 to deliver no longer exists. The channel is on stdin.
3587
3588 We might do fancy things like looking for another message to send down
3589 the channel, but if the one we sought has gone, it has probably been
3590 delivered by some other process that itself will seek further messages,
3591 so just close down our connection.
3592
3593 Argument: pointer to the transport instance block
3594 Returns: nothing
3595 */
3596
3597 void
3598 smtp_transport_closedown(transport_instance *tblock)
3599 {
3600 smtp_transport_options_block *ob =
3601 (smtp_transport_options_block *)tblock->options_block;
3602 smtp_inblock inblock;
3603 smtp_outblock outblock;
3604 uschar buffer[256];
3605 uschar inbuffer[4096];
3606 uschar outbuffer[16];
3607
3608 inblock.sock = fileno(stdin);
3609 inblock.buffer = inbuffer;
3610 inblock.buffersize = sizeof(inbuffer);
3611 inblock.ptr = inbuffer;
3612 inblock.ptrend = inbuffer;
3613
3614 outblock.sock = inblock.sock;
3615 outblock.buffersize = sizeof(outbuffer);
3616 outblock.buffer = outbuffer;
3617 outblock.ptr = outbuffer;
3618 outblock.cmd_count = 0;
3619 outblock.authenticating = FALSE;
3620
3621 (void)smtp_write_command(&outblock, SCMD_FLUSH, "QUIT\r\n");
3622 (void)smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
3623 ob->command_timeout);
3624 (void)close(inblock.sock);
3625 }
3626
3627
3628
3629 /*************************************************
3630 * Prepare addresses for delivery *
3631 *************************************************/
3632
3633 /* This function is called to flush out error settings from previous delivery
3634 attempts to other hosts. It also records whether we got here via an MX record
3635 or not in the more_errno field of the address. We are interested only in
3636 addresses that are still marked DEFER - others may have got delivered to a
3637 previously considered IP address. Set their status to PENDING_DEFER to indicate
3638 which ones are relevant this time.
3639
3640 Arguments:
3641 addrlist the list of addresses
3642 host the host we are delivering to
3643
3644 Returns: the first address for this delivery
3645 */
3646
3647 static address_item *
3648 prepare_addresses(address_item *addrlist, host_item *host)
3649 {
3650 address_item *first_addr = NULL;
3651 address_item *addr;
3652 for (addr = addrlist; addr; addr = addr->next)
3653 if (addr->transport_return == DEFER)
3654 {
3655 if (!first_addr) first_addr = addr;
3656 addr->transport_return = PENDING_DEFER;
3657 addr->basic_errno = 0;
3658 addr->more_errno = (host->mx >= 0)? 'M' : 'A';
3659 addr->message = NULL;
3660 #ifdef SUPPORT_TLS
3661 addr->cipher = NULL;
3662 addr->ourcert = NULL;
3663 addr->peercert = NULL;
3664 addr->peerdn = NULL;
3665 addr->ocsp = OCSP_NOT_REQ;
3666 #endif
3667 #ifdef EXPERIMENTAL_DSN_INFO
3668 addr->smtp_greeting = NULL;
3669 addr->helo_response = NULL;
3670 #endif
3671 }
3672 return first_addr;
3673 }
3674
3675
3676
3677 /*************************************************
3678 * Main entry point *
3679 *************************************************/
3680
3681 /* See local README for interface details. As this is a remote transport, it is
3682 given a chain of addresses to be delivered in one connection, if possible. It
3683 always returns TRUE, indicating that each address has its own independent
3684 status set, except if there is a setting up problem, in which case it returns
3685 FALSE. */
3686
3687 BOOL
3688 smtp_transport_entry(
3689 transport_instance *tblock, /* data for this instantiation */
3690 address_item *addrlist) /* addresses we are working on */
3691 {
3692 int cutoff_retry;
3693 int defport;
3694 int hosts_defer = 0;
3695 int hosts_fail = 0;
3696 int hosts_looked_up = 0;
3697 int hosts_retry = 0;
3698 int hosts_serial = 0;
3699 int hosts_total = 0;
3700 int total_hosts_tried = 0;
3701 address_item *addr;
3702 BOOL expired = TRUE;
3703 uschar *expanded_hosts = NULL;
3704 uschar *pistring;
3705 uschar *tid = string_sprintf("%s transport", tblock->name);
3706 smtp_transport_options_block *ob =
3707 (smtp_transport_options_block *)(tblock->options_block);
3708 host_item *hostlist = addrlist->host_list;
3709 host_item *host = NULL;
3710
3711 DEBUG(D_transport)
3712 {
3713 debug_printf("%s transport entered\n", tblock->name);
3714 for (addr = addrlist; addr; addr = addr->next)
3715 debug_printf(" %s\n", addr->address);
3716 if (hostlist)
3717 {
3718 debug_printf("hostlist:\n");
3719 for (host = hostlist; host; host = host->next)
3720 debug_printf(" %s:%d\n", host->name, host->port);
3721 }
3722 if (continue_hostname)
3723 debug_printf("already connected to %s [%s] (on fd %d)\n",
3724 continue_hostname, continue_host_address,
3725 cutthrough.fd >= 0 ? cutthrough.fd : 0);
3726 }
3727
3728 /* Set the flag requesting that these hosts be added to the waiting
3729 database if the delivery fails temporarily or if we are running with
3730 queue_smtp or a 2-stage queue run. This gets unset for certain
3731 kinds of error, typically those that are specific to the message. */
3732
3733 update_waiting = TRUE;
3734
3735 /* If a host list is not defined for the addresses - they must all have the
3736 same one in order to be passed to a single transport - or if the transport has
3737 a host list with hosts_override set, use the host list supplied with the
3738 transport. It is an error for this not to exist. */
3739
3740 if (!hostlist || (ob->hosts_override && ob->hosts))
3741 {
3742 if (!ob->hosts)
3743 {
3744 addrlist->message = string_sprintf("%s transport called with no hosts set",
3745 tblock->name);
3746 addrlist->transport_return = PANIC;
3747 return FALSE; /* Only top address has status */
3748 }
3749
3750 DEBUG(D_transport) debug_printf("using the transport's hosts: %s\n",
3751 ob->hosts);
3752
3753 /* If the transport's host list contains no '$' characters, and we are not
3754 randomizing, it is fixed and therefore a chain of hosts can be built once
3755 and for all, and remembered for subsequent use by other calls to this
3756 transport. If, on the other hand, the host list does contain '$', or we are
3757 randomizing its order, we have to rebuild it each time. In the fixed case,
3758 as the hosts string will never be used again, it doesn't matter that we
3759 replace all the : characters with zeros. */
3760
3761 if (!ob->hostlist)
3762 {
3763 uschar *s = ob->hosts;
3764
3765 if (Ustrchr(s, '$') != NULL)
3766 {
3767 if (!(expanded_hosts = expand_string(s)))
3768 {
3769 addrlist->message = string_sprintf("failed to expand list of hosts "
3770 "\"%s\" in %s transport: %s", s, tblock->name, expand_string_message);
3771 addrlist->transport_return = search_find_defer ? DEFER : PANIC;
3772 return FALSE; /* Only top address has status */
3773 }
3774 DEBUG(D_transport) debug_printf("expanded list of hosts \"%s\" to "
3775 "\"%s\"\n", s, expanded_hosts);
3776 s = expanded_hosts;
3777 }
3778 else
3779 if (ob->hosts_randomize) s = expanded_hosts = string_copy(s);
3780
3781 host_build_hostlist(&hostlist, s, ob->hosts_randomize);
3782
3783 /* Check that the expansion yielded something useful. */
3784 if (!hostlist)
3785 {
3786 addrlist->message =
3787 string_sprintf("%s transport has empty hosts setting", tblock->name);
3788 addrlist->transport_return = PANIC;
3789 return FALSE; /* Only top address has status */
3790 }
3791
3792 /* If there was no expansion of hosts, save the host list for
3793 next time. */
3794
3795 if (!expanded_hosts) ob->hostlist = hostlist;
3796 }
3797
3798 /* This is not the first time this transport has been run in this delivery;
3799 the host list was built previously. */
3800
3801 else
3802 hostlist = ob->hostlist;
3803 }
3804
3805 /* The host list was supplied with the address. If hosts_randomize is set, we
3806 must sort it into a random order if it did not come from MX records and has not
3807 already been randomized (but don't bother if continuing down an existing
3808 connection). */
3809
3810 else if (ob->hosts_randomize && hostlist->mx == MX_NONE && !continue_hostname)
3811 {
3812 host_item *newlist = NULL