Add new errors mail_4xx, data_4xx, lost_connection, tls_required.
[exim.git] / src / src / transports / smtp.c
1 /* $Cambridge: exim/src/src/transports/smtp.c,v 1.25 2006/03/09 15:10:16 ph10 Exp $ */
2
3 /*************************************************
4 * Exim - an Internet mail transport agent *
5 *************************************************/
6
7 /* Copyright (c) University of Cambridge 1995 - 2006 */
8 /* See the file NOTICE for conditions of use and distribution. */
9
10 #include "../exim.h"
11 #include "smtp.h"
12
13 #define PENDING 256
14 #define PENDING_DEFER (PENDING + DEFER)
15 #define PENDING_OK (PENDING + OK)
16
17
18 /* Options specific to the smtp transport. This transport also supports LMTP
19 over TCP/IP. The options must be in alphabetic order (note that "_" comes
20 before the lower case letters). Some live in the transport_instance block so as
21 to be publicly visible; these are flagged with opt_public. */
22
23 optionlist smtp_transport_options[] = {
24 { "allow_localhost", opt_bool,
25 (void *)offsetof(smtp_transport_options_block, allow_localhost) },
26 { "authenticated_sender", opt_stringptr,
27 (void *)offsetof(smtp_transport_options_block, authenticated_sender) },
28 { "authenticated_sender_force", opt_bool,
29 (void *)offsetof(smtp_transport_options_block, authenticated_sender_force) },
30 { "command_timeout", opt_time,
31 (void *)offsetof(smtp_transport_options_block, command_timeout) },
32 { "connect_timeout", opt_time,
33 (void *)offsetof(smtp_transport_options_block, connect_timeout) },
34 { "connection_max_messages", opt_int | opt_public,
35 (void *)offsetof(transport_instance, connection_max_messages) },
36 { "data_timeout", opt_time,
37 (void *)offsetof(smtp_transport_options_block, data_timeout) },
38 { "delay_after_cutoff", opt_bool,
39 (void *)offsetof(smtp_transport_options_block, delay_after_cutoff) },
40 #ifdef EXPERIMENTAL_DOMAINKEYS
41 { "dk_canon", opt_stringptr,
42 (void *)offsetof(smtp_transport_options_block, dk_canon) },
43 { "dk_domain", opt_stringptr,
44 (void *)offsetof(smtp_transport_options_block, dk_domain) },
45 { "dk_headers", opt_stringptr,
46 (void *)offsetof(smtp_transport_options_block, dk_headers) },
47 { "dk_private_key", opt_stringptr,
48 (void *)offsetof(smtp_transport_options_block, dk_private_key) },
49 { "dk_selector", opt_stringptr,
50 (void *)offsetof(smtp_transport_options_block, dk_selector) },
51 { "dk_strict", opt_stringptr,
52 (void *)offsetof(smtp_transport_options_block, dk_strict) },
53 #endif
54 { "dns_qualify_single", opt_bool,
55 (void *)offsetof(smtp_transport_options_block, dns_qualify_single) },
56 { "dns_search_parents", opt_bool,
57 (void *)offsetof(smtp_transport_options_block, dns_search_parents) },
58 { "fallback_hosts", opt_stringptr,
59 (void *)offsetof(smtp_transport_options_block, fallback_hosts) },
60 { "final_timeout", opt_time,
61 (void *)offsetof(smtp_transport_options_block, final_timeout) },
62 { "gethostbyname", opt_bool,
63 (void *)offsetof(smtp_transport_options_block, gethostbyname) },
64 { "helo_data", opt_stringptr,
65 (void *)offsetof(smtp_transport_options_block, helo_data) },
66 { "hosts", opt_stringptr,
67 (void *)offsetof(smtp_transport_options_block, hosts) },
68 { "hosts_avoid_esmtp", opt_stringptr,
69 (void *)offsetof(smtp_transport_options_block, hosts_avoid_esmtp) },
70 #ifdef SUPPORT_TLS
71 { "hosts_avoid_tls", opt_stringptr,
72 (void *)offsetof(smtp_transport_options_block, hosts_avoid_tls) },
73 #endif
74 { "hosts_max_try", opt_int,
75 (void *)offsetof(smtp_transport_options_block, hosts_max_try) },
76 { "hosts_max_try_hardlimit", opt_int,
77 (void *)offsetof(smtp_transport_options_block, hosts_max_try_hardlimit) },
78 #ifdef SUPPORT_TLS
79 { "hosts_nopass_tls", opt_stringptr,
80 (void *)offsetof(smtp_transport_options_block, hosts_nopass_tls) },
81 #endif
82 { "hosts_override", opt_bool,
83 (void *)offsetof(smtp_transport_options_block, hosts_override) },
84 { "hosts_randomize", opt_bool,
85 (void *)offsetof(smtp_transport_options_block, hosts_randomize) },
86 { "hosts_require_auth", opt_stringptr,
87 (void *)offsetof(smtp_transport_options_block, hosts_require_auth) },
88 #ifdef SUPPORT_TLS
89 { "hosts_require_tls", opt_stringptr,
90 (void *)offsetof(smtp_transport_options_block, hosts_require_tls) },
91 #endif
92 { "hosts_try_auth", opt_stringptr,
93 (void *)offsetof(smtp_transport_options_block, hosts_try_auth) },
94 { "interface", opt_stringptr,
95 (void *)offsetof(smtp_transport_options_block, interface) },
96 { "keepalive", opt_bool,
97 (void *)offsetof(smtp_transport_options_block, keepalive) },
98 { "lmtp_ignore_quota", opt_bool,
99 (void *)offsetof(smtp_transport_options_block, lmtp_ignore_quota) },
100 { "max_rcpt", opt_int | opt_public,
101 (void *)offsetof(transport_instance, max_addresses) },
102 { "multi_domain", opt_bool | opt_public,
103 (void *)offsetof(transport_instance, multi_domain) },
104 { "port", opt_stringptr,
105 (void *)offsetof(smtp_transport_options_block, port) },
106 { "protocol", opt_stringptr,
107 (void *)offsetof(smtp_transport_options_block, protocol) },
108 { "retry_include_ip_address", opt_bool,
109 (void *)offsetof(smtp_transport_options_block, retry_include_ip_address) },
110 { "serialize_hosts", opt_stringptr,
111 (void *)offsetof(smtp_transport_options_block, serialize_hosts) },
112 { "size_addition", opt_int,
113 (void *)offsetof(smtp_transport_options_block, size_addition) }
114 #ifdef SUPPORT_TLS
115 ,{ "tls_certificate", opt_stringptr,
116 (void *)offsetof(smtp_transport_options_block, tls_certificate) },
117 { "tls_crl", opt_stringptr,
118 (void *)offsetof(smtp_transport_options_block, tls_crl) },
119 { "tls_privatekey", opt_stringptr,
120 (void *)offsetof(smtp_transport_options_block, tls_privatekey) },
121 { "tls_require_ciphers", opt_stringptr,
122 (void *)offsetof(smtp_transport_options_block, tls_require_ciphers) },
123 { "tls_tempfail_tryclear", opt_bool,
124 (void *)offsetof(smtp_transport_options_block, tls_tempfail_tryclear) },
125 { "tls_verify_certificates", opt_stringptr,
126 (void *)offsetof(smtp_transport_options_block, tls_verify_certificates) }
127 #endif
128 };
129
130 /* Size of the options list. An extern variable has to be used so that its
131 address can appear in the tables drtables.c. */
132
133 int smtp_transport_options_count =
134 sizeof(smtp_transport_options)/sizeof(optionlist);
135
136 /* Default private options block for the smtp transport. */
137
138 smtp_transport_options_block smtp_transport_option_defaults = {
139 NULL, /* hosts */
140 NULL, /* fallback_hosts */
141 NULL, /* hostlist */
142 NULL, /* fallback_hostlist */
143 NULL, /* authenticated_sender */
144 US"$primary_hostname", /* helo_data */
145 NULL, /* interface */
146 NULL, /* port */
147 US"smtp", /* protocol */
148 NULL, /* serialize_hosts */
149 NULL, /* hosts_try_auth */
150 NULL, /* hosts_require_auth */
151 NULL, /* hosts_require_tls */
152 NULL, /* hosts_avoid_tls */
153 NULL, /* hosts_avoid_esmtp */
154 NULL, /* hosts_nopass_tls */
155 5*60, /* command_timeout */
156 5*60, /* connect_timeout; shorter system default overrides */
157 5*60, /* data timeout */
158 10*60, /* final timeout */
159 1024, /* size_addition */
160 5, /* hosts_max_try */
161 50, /* hosts_max_try_hardlimit */
162 FALSE, /* allow_localhost */
163 FALSE, /* authenticated_sender_force */
164 FALSE, /* gethostbyname */
165 TRUE, /* dns_qualify_single */
166 FALSE, /* dns_search_parents */
167 TRUE, /* delay_after_cutoff */
168 FALSE, /* hosts_override */
169 FALSE, /* hosts_randomize */
170 TRUE, /* keepalive */
171 FALSE, /* lmtp_ignore_quota */
172 TRUE /* retry_include_ip_address */
173 #ifdef SUPPORT_TLS
174 ,NULL, /* tls_certificate */
175 NULL, /* tls_crl */
176 NULL, /* tls_privatekey */
177 NULL, /* tls_require_ciphers */
178 NULL, /* tls_verify_certificates */
179 TRUE /* tls_tempfail_tryclear */
180 #endif
181 #ifdef EXPERIMENTAL_DOMAINKEYS
182 ,NULL, /* dk_canon */
183 NULL, /* dk_domain */
184 NULL, /* dk_headers */
185 NULL, /* dk_private_key */
186 NULL, /* dk_selector */
187 NULL /* dk_strict */
188 #endif
189 };
190
191
192 /* Local statics */
193
194 static uschar *smtp_command; /* Points to last cmd for error messages */
195 static uschar *mail_command; /* Points to MAIL cmd for error messages */
196
197
198 /*************************************************
199 * Setup entry point *
200 *************************************************/
201
202 /* This function is called when the transport is about to be used,
203 but before running it in a sub-process. It is used for two things:
204
205 (1) To set the fallback host list in addresses, when delivering.
206 (2) To pass back the interface, port, and protocol options, for use during
207 callout verification.
208
209 Arguments:
210 tblock pointer to the transport instance block
211 addrlist list of addresses about to be transported
212 tf if not NULL, pointer to block in which to return options
213 uid the uid that will be set (not used)
214 gid the gid that will be set (not used)
215 errmsg place for error message (not used)
216
217 Returns: OK always (FAIL, DEFER not used)
218 */
219
220 static int
221 smtp_transport_setup(transport_instance *tblock, address_item *addrlist,
222 transport_feedback *tf, uid_t uid, gid_t gid, uschar **errmsg)
223 {
224 smtp_transport_options_block *ob =
225 (smtp_transport_options_block *)(tblock->options_block);
226
227 errmsg = errmsg; /* Keep picky compilers happy */
228 uid = uid;
229 gid = gid;
230
231 /* Pass back options if required. This interface is getting very messy. */
232
233 if (tf != NULL)
234 {
235 tf->interface = ob->interface;
236 tf->port = ob->port;
237 tf->protocol = ob->protocol;
238 tf->hosts = ob->hosts;
239 tf->hosts_override = ob->hosts_override;
240 tf->hosts_randomize = ob->hosts_randomize;
241 tf->gethostbyname = ob->gethostbyname;
242 tf->qualify_single = ob->dns_qualify_single;
243 tf->search_parents = ob->dns_search_parents;
244 }
245
246 /* Set the fallback host list for all the addresses that don't have fallback
247 host lists, provided that the local host wasn't present in the original host
248 list. */
249
250 if (!testflag(addrlist, af_local_host_removed))
251 {
252 for (; addrlist != NULL; addrlist = addrlist->next)
253 if (addrlist->fallback_hosts == NULL)
254 addrlist->fallback_hosts = ob->fallback_hostlist;
255 }
256
257 return OK;
258 }
259
260
261
262 /*************************************************
263 * Initialization entry point *
264 *************************************************/
265
266 /* Called for each instance, after its options have been read, to
267 enable consistency checks to be done, or anything else that needs
268 to be set up.
269
270 Argument: pointer to the transport instance block
271 Returns: nothing
272 */
273
274 void
275 smtp_transport_init(transport_instance *tblock)
276 {
277 smtp_transport_options_block *ob =
278 (smtp_transport_options_block *)(tblock->options_block);
279
280 /* Retry_use_local_part defaults FALSE if unset */
281
282 if (tblock->retry_use_local_part == TRUE_UNSET)
283 tblock->retry_use_local_part = FALSE;
284
285 /* Set the default port according to the protocol */
286
287 if (ob->port == NULL)
288 ob->port = (strcmpic(ob->protocol, US"lmtp") == 0)? US"lmtp" : US"smtp";
289
290 /* Set up the setup entry point, to be called before subprocesses for this
291 transport. */
292
293 tblock->setup = smtp_transport_setup;
294
295 /* Complain if any of the timeouts are zero. */
296
297 if (ob->command_timeout <= 0 || ob->data_timeout <= 0 ||
298 ob->final_timeout <= 0)
299 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
300 "command, data, or final timeout value is zero for %s transport",
301 tblock->name);
302
303 /* If hosts_override is set and there are local hosts, set the global
304 flag that stops verify from showing router hosts. */
305
306 if (ob->hosts_override && ob->hosts != NULL) tblock->overrides_hosts = TRUE;
307
308 /* If there are any fallback hosts listed, build a chain of host items
309 for them, but do not do any lookups at this time. */
310
311 host_build_hostlist(&(ob->fallback_hostlist), ob->fallback_hosts, FALSE);
312 }
313
314
315
316
317
318 /*************************************************
319 * Set delivery info into all active addresses *
320 *************************************************/
321
322 /* Only addresses whose status is >= PENDING are relevant. A lesser
323 status means that an address is not currently being processed.
324
325 Arguments:
326 addrlist points to a chain of addresses
327 errno_value to put in each address's errno field
328 msg to put in each address's message field
329 rc to put in each address's transport_return field
330 pass_message if TRUE, set the "pass message" flag in the address
331
332 If errno_value has the special value ERRNO_CONNECTTIMEOUT, ETIMEDOUT is put in
333 the errno field, and RTEF_CTOUT is ORed into the more_errno field, to indicate
334 this particular type of timeout.
335
336 Returns: nothing
337 */
338
339 static void
340 set_errno(address_item *addrlist, int errno_value, uschar *msg, int rc,
341 BOOL pass_message)
342 {
343 address_item *addr;
344 int orvalue = 0;
345 if (errno_value == ERRNO_CONNECTTIMEOUT)
346 {
347 errno_value = ETIMEDOUT;
348 orvalue = RTEF_CTOUT;
349 }
350 for (addr = addrlist; addr != NULL; addr = addr->next)
351 {
352 if (addr->transport_return < PENDING) continue;
353 addr->basic_errno = errno_value;
354 addr->more_errno |= orvalue;
355 if (msg != NULL)
356 {
357 addr->message = msg;
358 if (pass_message) setflag(addr, af_pass_message);
359 }
360 addr->transport_return = rc;
361 }
362 }
363
364
365
366 /*************************************************
367 * Check an SMTP response *
368 *************************************************/
369
370 /* This function is given an errno code and the SMTP response buffer
371 to analyse, together with the host identification for generating messages. It
372 sets an appropriate message and puts the first digit of the response code into
373 the yield variable. If no response was actually read, a suitable digit is
374 chosen.
375
376 Arguments:
377 host the current host, to get its name for messages
378 errno_value pointer to the errno value
379 more_errno from the top address for use with ERRNO_FILTER_FAIL
380 buffer the SMTP response buffer
381 yield where to put a one-digit SMTP response code
382 message where to put an errror message
383 pass_message set TRUE if message is an SMTP response
384
385 Returns: TRUE if an SMTP "QUIT" command should be sent, else FALSE
386 */
387
388 static BOOL check_response(host_item *host, int *errno_value, int more_errno,
389 uschar *buffer, int *yield, uschar **message, BOOL *pass_message)
390 {
391 uschar *pl = US"";
392
393 if (smtp_use_pipelining &&
394 (Ustrcmp(smtp_command, "MAIL") == 0 ||
395 Ustrcmp(smtp_command, "RCPT") == 0 ||
396 Ustrcmp(smtp_command, "DATA") == 0))
397 pl = US"pipelined ";
398
399 *yield = '4'; /* Default setting is to give a temporary error */
400
401 /* Handle response timeout */
402
403 if (*errno_value == ETIMEDOUT)
404 {
405 *message = US string_sprintf("SMTP timeout while connected to %s [%s] "
406 "after %s%s", host->name, host->address, pl, smtp_command);
407 if (transport_count > 0)
408 *message = US string_sprintf("%s (%d bytes written)", *message,
409 transport_count);
410 return FALSE;
411 }
412
413 /* Handle malformed SMTP response */
414
415 if (*errno_value == ERRNO_SMTPFORMAT)
416 {
417 uschar *malfresp = string_printing(buffer);
418 while (isspace(*malfresp)) malfresp++;
419 if (*malfresp == 0)
420 *message = string_sprintf("Malformed SMTP reply (an empty line) from "
421 "%s [%s] in response to %s%s", host->name, host->address, pl,
422 smtp_command);
423 else
424 *message = string_sprintf("Malformed SMTP reply from %s [%s] in response "
425 "to %s%s: %s", host->name, host->address, pl, smtp_command, malfresp);
426 return FALSE;
427 }
428
429 /* Handle a failed filter process error; can't send QUIT as we mustn't
430 end the DATA. */
431
432 if (*errno_value == ERRNO_FILTER_FAIL)
433 {
434 *message = US string_sprintf("transport filter process failed (%d)%s",
435 more_errno,
436 (more_errno == EX_EXECFAILED)? ": unable to execute command" : "");
437 return FALSE;
438 }
439
440 /* Handle a failed add_headers expansion; can't send QUIT as we mustn't
441 end the DATA. */
442
443 if (*errno_value == ERRNO_CHHEADER_FAIL)
444 {
445 *message =
446 US string_sprintf("failed to expand headers_add or headers_remove: %s",
447 expand_string_message);
448 return FALSE;
449 }
450
451 /* Handle failure to write a complete data block */
452
453 if (*errno_value == ERRNO_WRITEINCOMPLETE)
454 {
455 *message = US string_sprintf("failed to write a data block");
456 return FALSE;
457 }
458
459 /* Handle error responses from the remote mailer. */
460
461 if (buffer[0] != 0)
462 {
463 uschar *s = string_printing(buffer);
464 *message = US string_sprintf("SMTP error from remote mail server after %s%s: "
465 "host %s [%s]: %s", pl, smtp_command, host->name, host->address, s);
466 *pass_message = TRUE;
467 *yield = buffer[0];
468 return TRUE;
469 }
470
471 /* No data was read. If there is no errno, this must be the EOF (i.e.
472 connection closed) case, which causes deferral. An explicit connection reset
473 error has the same effect. Otherwise, put the host's identity in the message,
474 leaving the errno value to be interpreted as well. In all cases, we have to
475 assume the connection is now dead. */
476
477 if (*errno_value == 0 || *errno_value == ECONNRESET)
478 {
479 *errno_value = ERRNO_SMTPCLOSED;
480 *message = US string_sprintf("Remote host %s [%s] closed connection "
481 "in response to %s%s", host->name, host->address, pl, smtp_command);
482 }
483 else *message = US string_sprintf("%s [%s]", host->name, host->address);
484
485 return FALSE;
486 }
487
488
489
490 /*************************************************
491 * Write error message to logs *
492 *************************************************/
493
494 /* This writes to the main log and to the message log.
495
496 Arguments:
497 addr the address item containing error information
498 host the current host
499
500 Returns: nothing
501 */
502
503 static void
504 write_logs(address_item *addr, host_item *host)
505 {
506 if (addr->message != NULL)
507 {
508 uschar *message = addr->message;
509 if (addr->basic_errno > 0)
510 message = string_sprintf("%s: %s", message, strerror(addr->basic_errno));
511 log_write(0, LOG_MAIN, "%s", message);
512 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
513 }
514 else
515 {
516 uschar *msg =
517 ((log_extra_selector & LX_outgoing_port) != 0)?
518 string_sprintf("%s [%s]:%d", host->name, host->address,
519 (host->port == PORT_NONE)? 25 : host->port)
520 :
521 string_sprintf("%s [%s]", host->name, host->address);
522 log_write(0, LOG_MAIN, "%s %s", msg, strerror(addr->basic_errno));
523 deliver_msglog("%s %s %s\n", tod_stamp(tod_log), msg,
524 strerror(addr->basic_errno));
525 }
526 }
527
528
529
530 /*************************************************
531 * Synchronize SMTP responses *
532 *************************************************/
533
534 /* This function is called from smtp_deliver() to receive SMTP responses from
535 the server, and match them up with the commands to which they relate. When
536 PIPELINING is not in use, this function is called after every command, and is
537 therefore somewhat over-engineered, but it is simpler to use a single scheme
538 that works both with and without PIPELINING instead of having two separate sets
539 of code.
540
541 The set of commands that are buffered up with pipelining may start with MAIL
542 and may end with DATA; in between are RCPT commands that correspond to the
543 addresses whose status is PENDING_DEFER. All other commands (STARTTLS, AUTH,
544 etc.) are never buffered.
545
546 Errors after MAIL or DATA abort the whole process leaving the response in the
547 buffer. After MAIL, pending responses are flushed, and the original command is
548 re-instated in big_buffer for error messages. For RCPT commands, the remote is
549 permitted to reject some recipient addresses while accepting others. However
550 certain errors clearly abort the whole process. Set the value in
551 transport_return to PENDING_OK if the address is accepted. If there is a
552 subsequent general error, it will get reset accordingly. If not, it will get
553 converted to OK at the end.
554
555 Arguments:
556 addrlist the complete address list
557 include_affixes TRUE if affixes include in RCPT
558 sync_addr ptr to the ptr of the one to start scanning at (updated)
559 host the host we are connected to
560 count the number of responses to read
561 pending_MAIL true if the first response is for MAIL
562 pending_DATA 0 if last command sent was not DATA
563 +1 if previously had a good recipient
564 -1 if not previously had a good recipient
565 inblock incoming SMTP block
566 timeout timeout value
567 buffer buffer for reading response
568 buffsize size of buffer
569
570 Returns: 3 if at least one address had 2xx and one had 5xx
571 2 if at least one address had 5xx but none had 2xx
572 1 if at least one host had a 2xx response, but none had 5xx
573 0 no address had 2xx or 5xx but no errors (all 4xx, or just DATA)
574 -1 timeout while reading RCPT response
575 -2 I/O or other non-response error for RCPT
576 -3 DATA or MAIL failed - errno and buffer set
577 */
578
579 static int
580 sync_responses(address_item *addrlist, BOOL include_affixes,
581 address_item **sync_addr, host_item *host, int count, BOOL pending_MAIL,
582 int pending_DATA, smtp_inblock *inblock, int timeout, uschar *buffer,
583 int buffsize)
584 {
585 address_item *addr = *sync_addr;
586 int yield = 0;
587
588 /* Handle the response for a MAIL command. On error, reinstate the original
589 command in big_buffer for error message use, and flush any further pending
590 responses before returning, except after I/O errors and timeouts. */
591
592 if (pending_MAIL)
593 {
594 count--;
595 if (!smtp_read_response(inblock, buffer, buffsize, '2', timeout))
596 {
597 Ustrcpy(big_buffer, mail_command); /* Fits, because it came from there! */
598 if (errno == 0 && buffer[0] != 0)
599 {
600 uschar flushbuffer[4096];
601 int save_errno = 0;
602 if (buffer[0] == '4')
603 {
604 save_errno = ERRNO_MAIL4XX;
605 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
606 }
607 while (count-- > 0)
608 {
609 if (!smtp_read_response(inblock, flushbuffer, sizeof(flushbuffer),
610 '2', timeout)
611 && (errno != 0 || flushbuffer[0] == 0))
612 break;
613 }
614 errno = save_errno;
615 }
616 return -3;
617 }
618 }
619
620 if (pending_DATA) count--; /* Number of RCPT responses to come */
621
622 /* Read and handle the required number of RCPT responses, matching each one up
623 with an address by scanning for the next address whose status is PENDING_DEFER.
624 */
625
626 while (count-- > 0)
627 {
628 while (addr->transport_return != PENDING_DEFER) addr = addr->next;
629
630 /* The address was accepted */
631
632 if (smtp_read_response(inblock, buffer, buffsize, '2', timeout))
633 {
634 yield |= 1;
635 addr->transport_return = PENDING_OK;
636
637 /* If af_dr_retry_exists is set, there was a routing delay on this address;
638 ensure that any address-specific retry record is expunged. */
639
640 if (testflag(addr, af_dr_retry_exists))
641 retry_add_item(addr, addr->address_retry_key, rf_delete);
642 }
643
644 /* Timeout while reading the response */
645
646 else if (errno == ETIMEDOUT)
647 {
648 int save_errno = errno;
649 uschar *message = string_sprintf("SMTP timeout while connected to %s [%s] "
650 "after RCPT TO:<%s>", host->name, host->address,
651 transport_rcpt_address(addr, include_affixes));
652 set_errno(addrlist, save_errno, message, DEFER, FALSE);
653 retry_add_item(addr, addr->address_retry_key, 0);
654 host->update_waiting = FALSE;
655 return -1;
656 }
657
658 /* Handle other errors in obtaining an SMTP response by returning -1. This
659 will cause all the addresses to be deferred. Restore the SMTP command in
660 big_buffer for which we are checking the response, so the error message
661 makes sense. */
662
663 else if (errno != 0 || buffer[0] == 0)
664 {
665 string_format(big_buffer, big_buffer_size, "RCPT TO:<%s>",
666 transport_rcpt_address(addr, include_affixes));
667 return -2;
668 }
669
670 /* Handle SMTP permanent and temporary response codes. */
671
672 else
673 {
674 addr->message =
675 string_sprintf("SMTP error from remote mail server after RCPT TO:<%s>: "
676 "host %s [%s]: %s", transport_rcpt_address(addr, include_affixes),
677 host->name, host->address, string_printing(buffer));
678 setflag(addr, af_pass_message);
679 deliver_msglog("%s %s\n", tod_stamp(tod_log), addr->message);
680
681 /* The response was 5xx */
682
683 if (buffer[0] == '5')
684 {
685 addr->transport_return = FAIL;
686 yield |= 2;
687 }
688
689 /* The response was 4xx */
690
691 else
692 {
693 addr->transport_return = DEFER;
694 addr->basic_errno = ERRNO_RCPT4XX;
695 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
696
697 /* Log temporary errors if there are more hosts to be tried. */
698
699 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", addr->message);
700
701 /* Do not put this message on the list of those waiting for this host,
702 as otherwise it is likely to be tried too often. */
703
704 host->update_waiting = FALSE;
705
706 /* Add a retry item for the address so that it doesn't get tried
707 again too soon. */
708
709 retry_add_item(addr, addr->address_retry_key, 0);
710 }
711 }
712 } /* Loop for next RCPT response */
713
714 /* Update where to start at for the next block of responses, unless we
715 have already handled all the addresses. */
716
717 if (addr != NULL) *sync_addr = addr->next;
718
719 /* Handle a response to DATA. If we have not had any good recipients, either
720 previously or in this block, the response is ignored. */
721
722 if (pending_DATA != 0 &&
723 !smtp_read_response(inblock, buffer, buffsize, '3', timeout))
724 {
725 int code;
726 uschar *msg;
727 BOOL pass_message;
728 if (pending_DATA > 0 || (yield & 1) != 0)
729 {
730 if (errno == 0 && buffer[0] == '4')
731 {
732 errno = ERRNO_DATA4XX;
733 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
734 }
735 return -3;
736 }
737 (void)check_response(host, &errno, 0, buffer, &code, &msg, &pass_message);
738 DEBUG(D_transport) debug_printf("%s\nerror for DATA ignored: pipelining "
739 "is in use and there were no good recipients\n", msg);
740 }
741
742 /* All responses read and handled; MAIL (if present) received 2xx and DATA (if
743 present) received 3xx. If any RCPTs were handled and yielded anything other
744 than 4xx, yield will be set non-zero. */
745
746 return yield;
747 }
748
749
750
751 /*************************************************
752 * Deliver address list to given host *
753 *************************************************/
754
755 /* If continue_hostname is not null, we get here only when continuing to
756 deliver down an existing channel. The channel was passed as the standard
757 input.
758
759 Otherwise, we have to make a connection to the remote host, and do the
760 initial protocol exchange.
761
762 When running as an MUA wrapper, if the sender or any recipient is rejected,
763 temporarily or permanently, we force failure for all recipients.
764
765 Arguments:
766 addrlist chain of potential addresses to deliver; only those whose
767 transport_return field is set to PENDING_DEFER are currently
768 being processed; others should be skipped - they have either
769 been delivered to an earlier host or IP address, or been
770 failed by one of them.
771 host host to deliver to
772 host_af AF_INET or AF_INET6
773 port default TCP/IP port to use, in host byte order
774 interface interface to bind to, or NULL
775 tblock transport instance block
776 copy_host TRUE if host set in addr->host_used must be copied, because
777 it is specific to this call of the transport
778 message_defer set TRUE if yield is OK, but all addresses were deferred
779 because of a non-recipient, non-host failure, that is, a
780 4xx response to MAIL FROM, DATA, or ".". This is a defer
781 that is specific to the message.
782 suppress_tls if TRUE, don't attempt a TLS connection - this is set for
783 a second attempt after TLS initialization fails
784
785 Returns: OK - the connection was made and the delivery attempted;
786 the result for each address is in its data block.
787 DEFER - the connection could not be made, or something failed
788 while setting up the SMTP session, or there was a
789 non-message-specific error, such as a timeout.
790 ERROR - a filter command is specified for this transport,
791 and there was a problem setting it up; OR helo_data
792 or add_headers or authenticated_sender is specified
793 for this transport, and the string failed to expand
794 */
795
796 static int
797 smtp_deliver(address_item *addrlist, host_item *host, int host_af, int port,
798 uschar *interface, transport_instance *tblock, BOOL copy_host,
799 BOOL *message_defer, BOOL suppress_tls)
800 {
801 address_item *addr;
802 address_item *sync_addr;
803 address_item *first_addr = addrlist;
804 int yield = OK;
805 int address_count;
806 int save_errno;
807 int rc;
808 time_t start_delivery_time = time(NULL);
809 smtp_transport_options_block *ob =
810 (smtp_transport_options_block *)(tblock->options_block);
811 BOOL lmtp = strcmpic(ob->protocol, US"lmtp") == 0;
812 BOOL ok = FALSE;
813 BOOL send_rset = TRUE;
814 BOOL send_quit = TRUE;
815 BOOL setting_up = TRUE;
816 BOOL completed_address = FALSE;
817 BOOL esmtp = TRUE;
818 BOOL pending_MAIL;
819 BOOL pass_message = FALSE;
820 smtp_inblock inblock;
821 smtp_outblock outblock;
822 int max_rcpt = tblock->max_addresses;
823 uschar *igquotstr = US"";
824 uschar *local_authenticated_sender = authenticated_sender;
825 uschar *helo_data;
826 uschar *message = NULL;
827 uschar new_message_id[MESSAGE_ID_LENGTH + 1];
828 uschar *p;
829 uschar buffer[4096];
830 uschar inbuffer[4096];
831 uschar outbuffer[1024];
832
833 suppress_tls = suppress_tls; /* stop compiler warning when no TLS support */
834
835 *message_defer = FALSE;
836 smtp_command = US"initial connection";
837 if (max_rcpt == 0) max_rcpt = 999999;
838
839 /* Set up the buffer for reading SMTP response packets. */
840
841 inblock.buffer = inbuffer;
842 inblock.buffersize = sizeof(inbuffer);
843 inblock.ptr = inbuffer;
844 inblock.ptrend = inbuffer;
845
846 /* Set up the buffer for holding SMTP commands while pipelining */
847
848 outblock.buffer = outbuffer;
849 outblock.buffersize = sizeof(outbuffer);
850 outblock.ptr = outbuffer;
851 outblock.cmd_count = 0;
852 outblock.authenticating = FALSE;
853
854 /* Expand the greeting message */
855
856 helo_data = expand_string(ob->helo_data);
857 if (helo_data == NULL)
858 {
859 uschar *message = string_sprintf("failed to expand helo_data: %s",
860 expand_string_message);
861 set_errno(addrlist, 0, message, DEFER, FALSE);
862 return ERROR;
863 }
864
865 /* If an authenticated_sender override has been specified for this transport
866 instance, expand it. If the expansion is forced to fail, and there was already
867 an authenticated_sender for this message, the original value will be used.
868 Other expansion failures are serious. An empty result is ignored, but there is
869 otherwise no check - this feature is expected to be used with LMTP and other
870 cases where non-standard addresses (e.g. without domains) might be required. */
871
872 if (ob->authenticated_sender != NULL)
873 {
874 uschar *new = expand_string(ob->authenticated_sender);
875 if (new == NULL)
876 {
877 if (!expand_string_forcedfail)
878 {
879 uschar *message = string_sprintf("failed to expand "
880 "authenticated_sender: %s", expand_string_message);
881 set_errno(addrlist, 0, message, DEFER, FALSE);
882 return ERROR;
883 }
884 }
885 else if (new[0] != 0) local_authenticated_sender = new;
886 }
887
888 /* Make a connection to the host if this isn't a continued delivery, and handle
889 the initial interaction and HELO/EHLO/LHLO. Connect timeout errors are handled
890 specially so they can be identified for retries. */
891
892 if (continue_hostname == NULL)
893 {
894 inblock.sock = outblock.sock =
895 smtp_connect(host, host_af, port, interface, ob->connect_timeout,
896 ob->keepalive);
897 if (inblock.sock < 0)
898 {
899 set_errno(addrlist, (errno == ETIMEDOUT)? ERRNO_CONNECTTIMEOUT : errno,
900 NULL, DEFER, FALSE);
901 return DEFER;
902 }
903
904 /* The first thing is to wait for an initial OK response. The dreaded "goto"
905 is nevertheless a reasonably clean way of programming this kind of logic,
906 where you want to escape on any error. */
907
908 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
909 ob->command_timeout)) goto RESPONSE_FAILED;
910
911 /** Debugging without sending a message
912 addrlist->transport_return = DEFER;
913 goto SEND_QUIT;
914 **/
915
916 /* Errors that occur after this point follow an SMTP command, which is
917 left in big_buffer by smtp_write_command() for use in error messages. */
918
919 smtp_command = big_buffer;
920
921 /* Tell the remote who we are...
922
923 February 1998: A convention has evolved that ESMTP-speaking MTAs include the
924 string "ESMTP" in their greeting lines, so make Exim send EHLO if the
925 greeting is of this form. The assumption was that the far end supports it
926 properly... but experience shows that there are some that give 5xx responses,
927 even though the banner includes "ESMTP" (there's a bloody-minded one that
928 says "ESMTP not spoken here"). Cope with that case.
929
930 September 2000: Time has passed, and it seems reasonable now to always send
931 EHLO at the start. It is also convenient to make the change while installing
932 the TLS stuff.
933
934 July 2003: Joachim Wieland met a broken server that advertises "PIPELINING"
935 but times out after sending MAIL FROM, RCPT TO and DATA all together. There
936 would be no way to send out the mails, so there is now a host list
937 "hosts_avoid_esmtp" that disables ESMTP for special hosts and solves the
938 PIPELINING problem as well. Maybe it can also be useful to cure other
939 problems with broken servers.
940
941 Exim originally sent "Helo" at this point and ran for nearly a year that way.
942 Then somebody tried it with a Microsoft mailer... It seems that all other
943 mailers use upper case for some reason (the RFC is quite clear about case
944 independence) so, for peace of mind, I gave in. */
945
946 esmtp = verify_check_this_host(&(ob->hosts_avoid_esmtp), NULL,
947 host->name, host->address, NULL) != OK;
948
949 if (esmtp)
950 {
951 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n",
952 lmtp? "LHLO" : "EHLO", helo_data) < 0)
953 goto SEND_FAILED;
954 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
955 ob->command_timeout))
956 {
957 if (errno != 0 || buffer[0] == 0 || lmtp) goto RESPONSE_FAILED;
958 esmtp = FALSE;
959 }
960 }
961 else
962 {
963 DEBUG(D_transport)
964 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
965 }
966
967 if (!esmtp)
968 {
969 if (smtp_write_command(&outblock, FALSE, "HELO %s\r\n", helo_data) < 0)
970 goto SEND_FAILED;
971 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
972 ob->command_timeout)) goto RESPONSE_FAILED;
973 }
974
975 /* Set IGNOREQUOTA if the response to LHLO specifies support and the
976 lmtp_ignore_quota option was set. */
977
978 igquotstr = (lmtp && ob->lmtp_ignore_quota &&
979 pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer, Ustrlen(CS buffer), 0,
980 PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
981
982 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
983
984 #ifdef SUPPORT_TLS
985 tls_offered = esmtp &&
986 pcre_exec(regex_STARTTLS, NULL, CS buffer, Ustrlen(buffer), 0,
987 PCRE_EOPT, NULL, 0) >= 0;
988 #endif
989 }
990
991 /* For continuing deliveries down the same channel, the socket is the standard
992 input, and we don't need to redo EHLO here (but may need to do so for TLS - see
993 below). Set up the pointer to where subsequent commands will be left, for
994 error messages. Note that smtp_use_size and smtp_use_pipelining will have been
995 set from the command line if they were set in the process that passed the
996 connection on. */
997
998 else
999 {
1000 inblock.sock = outblock.sock = fileno(stdin);
1001 smtp_command = big_buffer;
1002 }
1003
1004 /* If TLS is available on this connection, whether continued or not, attempt to
1005 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
1006 send another EHLO - the server may give a different answer in secure mode. We
1007 use a separate buffer for reading the response to STARTTLS so that if it is
1008 negative, the original EHLO data is available for subsequent analysis, should
1009 the client not be required to use TLS. If the response is bad, copy the buffer
1010 for error analysis. */
1011
1012 #ifdef SUPPORT_TLS
1013 if (tls_offered && !suppress_tls &&
1014 verify_check_this_host(&(ob->hosts_avoid_tls), NULL, host->name,
1015 host->address, NULL) != OK)
1016 {
1017 uschar buffer2[4096];
1018 if (smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") < 0)
1019 goto SEND_FAILED;
1020
1021 /* If there is an I/O error, transmission of this message is deferred. If
1022 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
1023 false, we also defer. However, if there is a temporary rejection of STARTTLS
1024 and tls_tempfail_tryclear is true, or if there is an outright rejection of
1025 STARTTLS, we carry on. This means we will try to send the message in clear,
1026 unless the host is in hosts_require_tls (tested below). */
1027
1028 if (!smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
1029 ob->command_timeout))
1030 {
1031 Ustrncpy(buffer, buffer2, sizeof(buffer));
1032 if (errno != 0 || buffer2[0] == 0 ||
1033 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
1034 goto RESPONSE_FAILED;
1035 }
1036
1037 /* STARTTLS accepted: try to negotiate a TLS session. */
1038
1039 else
1040 {
1041 int rc = tls_client_start(inblock.sock, host, addrlist,
1042 NULL, /* No DH param */
1043 ob->tls_certificate,
1044 ob->tls_privatekey,
1045 ob->tls_verify_certificates,
1046 ob->tls_crl,
1047 ob->tls_require_ciphers,
1048 ob->command_timeout);
1049
1050 /* TLS negotiation failed; give an error. From outside, this function may
1051 be called again to try in clear on a new connection, if the options permit
1052 it for this host. */
1053
1054 if (rc != OK)
1055 {
1056 save_errno = ERRNO_TLSFAILURE;
1057 message = US"failure while setting up TLS session";
1058 send_quit = FALSE;
1059 goto TLS_FAILED;
1060 }
1061
1062 /* TLS session is set up */
1063
1064 for (addr = addrlist; addr != NULL; addr = addr->next)
1065 {
1066 if (addr->transport_return == PENDING_DEFER)
1067 {
1068 addr->cipher = tls_cipher;
1069 addr->peerdn = tls_peerdn;
1070 }
1071 }
1072 }
1073 }
1074
1075 /* If we started TLS, redo the EHLO/LHLO exchange over the secure channel. */
1076
1077 if (tls_active >= 0)
1078 {
1079 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n", lmtp? "LHLO" : "EHLO",
1080 helo_data) < 0)
1081 goto SEND_FAILED;
1082 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1083 ob->command_timeout))
1084 goto RESPONSE_FAILED;
1085 }
1086
1087 /* If the host is required to use a secure channel, ensure that we
1088 have one. */
1089
1090 else if (verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
1091 host->address, NULL) == OK)
1092 {
1093 save_errno = ERRNO_TLSREQUIRED;
1094 message = string_sprintf("a TLS session is required for %s [%s], but %s",
1095 host->name, host->address,
1096 tls_offered? "an attempt to start TLS failed" :
1097 "the server did not offer TLS support");
1098 goto TLS_FAILED;
1099 }
1100 #endif
1101
1102 /* If TLS is active, we have just started it up and re-done the EHLO command,
1103 so its response needs to be analyzed. If TLS is not active and this is a
1104 continued session down a previously-used socket, we haven't just done EHLO, so
1105 we skip this. */
1106
1107 if (continue_hostname == NULL
1108 #ifdef SUPPORT_TLS
1109 || tls_active >= 0
1110 #endif
1111 )
1112 {
1113 int require_auth;
1114 uschar *fail_reason = US"server did not advertise AUTH support";
1115
1116 /* Set for IGNOREQUOTA if the response to LHLO specifies support and the
1117 lmtp_ignore_quota option was set. */
1118
1119 igquotstr = (lmtp && ob->lmtp_ignore_quota &&
1120 pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer, Ustrlen(CS buffer), 0,
1121 PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
1122
1123 /* If the response to EHLO specified support for the SIZE parameter, note
1124 this, provided size_addition is non-negative. */
1125
1126 smtp_use_size = esmtp && ob->size_addition >= 0 &&
1127 pcre_exec(regex_SIZE, NULL, CS buffer, Ustrlen(CS buffer), 0,
1128 PCRE_EOPT, NULL, 0) >= 0;
1129
1130 /* Note whether the server supports PIPELINING. If hosts_avoid_esmtp matched
1131 the current host, esmtp will be false, so PIPELINING can never be used. */
1132
1133 smtp_use_pipelining = esmtp &&
1134 pcre_exec(regex_PIPELINING, NULL, CS buffer, Ustrlen(CS buffer), 0,
1135 PCRE_EOPT, NULL, 0) >= 0;
1136
1137 DEBUG(D_transport) debug_printf("%susing PIPELINING\n",
1138 smtp_use_pipelining? "" : "not ");
1139
1140 /* Note if the response to EHLO specifies support for the AUTH extension.
1141 If it has, check that this host is one we want to authenticate to, and do
1142 the business. The host name and address must be available when the
1143 authenticator's client driver is running. */
1144
1145 smtp_authenticated = FALSE;
1146 require_auth = verify_check_this_host(&(ob->hosts_require_auth), NULL,
1147 host->name, host->address, NULL);
1148
1149 if (esmtp && regex_match_and_setup(regex_AUTH, buffer, 0, -1))
1150 {
1151 uschar *names = string_copyn(expand_nstring[1], expand_nlength[1]);
1152 expand_nmax = -1; /* reset */
1153
1154 /* Must not do this check until after we have saved the result of the
1155 regex match above. */
1156
1157 if (require_auth == OK ||
1158 verify_check_this_host(&(ob->hosts_try_auth), NULL, host->name,
1159 host->address, NULL) == OK)
1160 {
1161 auth_instance *au;
1162 fail_reason = US"no common mechanisms were found";
1163
1164 DEBUG(D_transport) debug_printf("scanning authentication mechanisms\n");
1165
1166 /* Scan the configured authenticators looking for one which is configured
1167 for use as a client and whose name matches an authentication mechanism
1168 supported by the server. If one is found, attempt to authenticate by
1169 calling its client function. */
1170
1171 for (au = auths; !smtp_authenticated && au != NULL; au = au->next)
1172 {
1173 uschar *p = names;
1174 if (!au->client) continue;
1175
1176 /* Loop to scan supported server mechanisms */
1177
1178 while (*p != 0)
1179 {
1180 int rc;
1181 int len = Ustrlen(au->public_name);
1182 while (isspace(*p)) p++;
1183
1184 if (strncmpic(au->public_name, p, len) != 0 ||
1185 (p[len] != 0 && !isspace(p[len])))
1186 {
1187 while (*p != 0 && !isspace(*p)) p++;
1188 continue;
1189 }
1190
1191 /* Found data for a listed mechanism. Call its client entry. Set
1192 a flag in the outblock so that data is overwritten after sending so
1193 that reflections don't show it. */
1194
1195 fail_reason = US"authentication attempt(s) failed";
1196 outblock.authenticating = TRUE;
1197 rc = (au->info->clientcode)(au, &inblock, &outblock,
1198 ob->command_timeout, buffer, sizeof(buffer));
1199 outblock.authenticating = FALSE;
1200 DEBUG(D_transport) debug_printf("%s authenticator yielded %d\n",
1201 au->name, rc);
1202
1203 /* A temporary authentication failure must hold up delivery to
1204 this host. After a permanent authentication failure, we carry on
1205 to try other authentication methods. If all fail hard, try to
1206 deliver the message unauthenticated unless require_auth was set. */
1207
1208 switch(rc)
1209 {
1210 case OK:
1211 smtp_authenticated = TRUE; /* stops the outer loop */
1212 break;
1213
1214 /* Failure after writing a command */
1215
1216 case FAIL_SEND:
1217 goto SEND_FAILED;
1218
1219 /* Failure after reading a response */
1220
1221 case FAIL:
1222 if (errno != 0 || buffer[0] != '5') goto RESPONSE_FAILED;
1223 log_write(0, LOG_MAIN, "%s authenticator failed H=%s [%s] %s",
1224 au->name, host->name, host->address, buffer);
1225 break;
1226
1227 /* Failure by some other means. In effect, the authenticator
1228 decided it wasn't prepared to handle this case. Typically this
1229 is the result of "fail" in an expansion string. Do we need to
1230 log anything here? Feb 2006: a message is now put in the buffer
1231 if logging is required. */
1232
1233 case CANCELLED:
1234 if (*buffer != 0)
1235 log_write(0, LOG_MAIN, "%s authenticator cancelled "
1236 "authentication H=%s [%s] %s", au->name, host->name,
1237 host->address, buffer);
1238 break;
1239
1240 /* Internal problem, message in buffer. */
1241
1242 case ERROR:
1243 yield = ERROR;
1244 set_errno(addrlist, 0, string_copy(buffer), DEFER, FALSE);
1245 goto SEND_QUIT;
1246 }
1247
1248 break; /* If not authenticated, try next authenticator */
1249 } /* Loop for scanning supported server mechanisms */
1250 } /* Loop for further authenticators */
1251 }
1252 }
1253
1254 /* If we haven't authenticated, but are required to, give up. */
1255
1256 if (require_auth == OK && !smtp_authenticated)
1257 {
1258 yield = DEFER;
1259 set_errno(addrlist, ERRNO_AUTHFAIL,
1260 string_sprintf("authentication required but %s", fail_reason), DEFER,
1261 FALSE);
1262 goto SEND_QUIT;
1263 }
1264 }
1265
1266 /* The setting up of the SMTP call is now complete. Any subsequent errors are
1267 message-specific. */
1268
1269 setting_up = FALSE;
1270
1271 /* If there is a filter command specified for this transport, we can now
1272 set it up. This cannot be done until the identify of the host is known. */
1273
1274 if (tblock->filter_command != NULL)
1275 {
1276 BOOL rc;
1277 uschar buffer[64];
1278 sprintf(CS buffer, "%.50s transport", tblock->name);
1279 rc = transport_set_up_command(&transport_filter_argv, tblock->filter_command,
1280 TRUE, DEFER, addrlist, buffer, NULL);
1281
1282 /* On failure, copy the error to all addresses, abandon the SMTP call, and
1283 yield ERROR. */
1284
1285 if (!rc)
1286 {
1287 set_errno(addrlist->next, addrlist->basic_errno, addrlist->message, DEFER,
1288 FALSE);
1289 yield = ERROR;
1290 goto SEND_QUIT;
1291 }
1292 }
1293
1294
1295 /* For messages that have more than the maximum number of envelope recipients,
1296 we want to send several transactions down the same SMTP connection. (See
1297 comments in deliver.c as to how this reconciles, heuristically, with
1298 remote_max_parallel.) This optimization was added to Exim after the following
1299 code was already working. The simplest way to put it in without disturbing the
1300 code was to use a goto to jump back to this point when there is another
1301 transaction to handle. */
1302
1303 SEND_MESSAGE:
1304 sync_addr = first_addr;
1305 address_count = 0;
1306 ok = FALSE;
1307 send_rset = TRUE;
1308 completed_address = FALSE;
1309
1310
1311 /* Initiate a message transfer. If we know the receiving MTA supports the SIZE
1312 qualification, send it, adding something to the message size to allow for
1313 imprecision and things that get added en route. Exim keeps the number of lines
1314 in a message, so we can give an accurate value for the original message, but we
1315 need some additional to handle added headers. (Double "." characters don't get
1316 included in the count.) */
1317
1318 p = buffer;
1319 *p = 0;
1320
1321 if (smtp_use_size)
1322 {
1323 sprintf(CS p, " SIZE=%d", message_size+message_linecount+ob->size_addition);
1324 while (*p) p++;
1325 }
1326
1327 /* Add the authenticated sender address if present */
1328
1329 if ((smtp_authenticated || ob->authenticated_sender_force) &&
1330 local_authenticated_sender != NULL)
1331 {
1332 string_format(p, sizeof(buffer) - (p-buffer), " AUTH=%s",
1333 auth_xtextencode(local_authenticated_sender,
1334 Ustrlen(local_authenticated_sender)));
1335 }
1336
1337 /* From here until we send the DATA command, we can make use of PIPELINING
1338 if the server host supports it. The code has to be able to check the responses
1339 at any point, for when the buffer fills up, so we write it totally generally.
1340 When PIPELINING is off, each command written reports that it has flushed the
1341 buffer. */
1342
1343 pending_MAIL = TRUE; /* The block starts with MAIL */
1344
1345 rc = smtp_write_command(&outblock, smtp_use_pipelining,
1346 "MAIL FROM:<%s>%s\r\n", return_path, buffer);
1347 mail_command = string_copy(big_buffer); /* Save for later error message */
1348
1349 switch(rc)
1350 {
1351 case -1: /* Transmission error */
1352 goto SEND_FAILED;
1353
1354 case +1: /* Block was sent */
1355 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1356 ob->command_timeout))
1357 {
1358 if (errno == 0 && buffer[0] == '4')
1359 {
1360 errno = ERRNO_MAIL4XX;
1361 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1362 }
1363 goto RESPONSE_FAILED;
1364 }
1365 pending_MAIL = FALSE;
1366 break;
1367 }
1368
1369 /* Pass over all the relevant recipient addresses for this host, which are the
1370 ones that have status PENDING_DEFER. If we are using PIPELINING, we can send
1371 several before we have to read the responses for those seen so far. This
1372 checking is done by a subroutine because it also needs to be done at the end.
1373 Send only up to max_rcpt addresses at a time, leaving first_addr pointing to
1374 the next one if not all are sent.
1375
1376 In the MUA wrapper situation, we want to flush the PIPELINING buffer for the
1377 last address because we want to abort if any recipients have any kind of
1378 problem, temporary or permanent. We know that all recipient addresses will have
1379 the PENDING_DEFER status, because only one attempt is ever made, and we know
1380 that max_rcpt will be large, so all addresses will be done at once. */
1381
1382 for (addr = first_addr;
1383 address_count < max_rcpt && addr != NULL;
1384 addr = addr->next)
1385 {
1386 int count;
1387 BOOL no_flush;
1388
1389 if (addr->transport_return != PENDING_DEFER) continue;
1390
1391 address_count++;
1392 no_flush = smtp_use_pipelining && (!mua_wrapper || addr->next != NULL);
1393
1394 /* Now send the RCPT command, and process outstanding responses when
1395 necessary. After a timeout on RCPT, we just end the function, leaving the
1396 yield as OK, because this error can often mean that there is a problem with
1397 just one address, so we don't want to delay the host. */
1398
1399 count = smtp_write_command(&outblock, no_flush, "RCPT TO:<%s>%s\r\n",
1400 transport_rcpt_address(addr, tblock->rcpt_include_affixes), igquotstr);
1401 if (count < 0) goto SEND_FAILED;
1402 if (count > 0)
1403 {
1404 switch(sync_responses(first_addr, tblock->rcpt_include_affixes,
1405 &sync_addr, host, count, pending_MAIL, 0, &inblock,
1406 ob->command_timeout, buffer, sizeof(buffer)))
1407 {
1408 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1409 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1410 break;
1411
1412 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1413 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1414 case 0: /* No 2xx or 5xx, but no probs */
1415 break;
1416
1417 case -1: goto END_OFF; /* Timeout on RCPT */
1418 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL error */
1419 }
1420 pending_MAIL = FALSE; /* Dealt with MAIL */
1421 }
1422 } /* Loop for next address */
1423
1424 /* If we are an MUA wrapper, abort if any RCPTs were rejected, either
1425 permanently or temporarily. We should have flushed and synced after the last
1426 RCPT. */
1427
1428 if (mua_wrapper)
1429 {
1430 address_item *badaddr;
1431 for (badaddr = first_addr; badaddr != NULL; badaddr = badaddr->next)
1432 {
1433 if (badaddr->transport_return != PENDING_OK) break;
1434 }
1435 if (badaddr != NULL)
1436 {
1437 set_errno(addrlist, 0, badaddr->message, FAIL,
1438 testflag(badaddr, af_pass_message));
1439 ok = FALSE;
1440 }
1441 }
1442
1443 /* If ok is TRUE, we know we have got at least one good recipient, and must now
1444 send DATA, but if it is FALSE (in the normal, non-wrapper case), we may still
1445 have a good recipient buffered up if we are pipelining. We don't want to waste
1446 time sending DATA needlessly, so we only send it if either ok is TRUE or if we
1447 are pipelining. The responses are all handled by sync_responses(). */
1448
1449 if (ok || (smtp_use_pipelining && !mua_wrapper))
1450 {
1451 int count = smtp_write_command(&outblock, FALSE, "DATA\r\n");
1452 if (count < 0) goto SEND_FAILED;
1453 switch(sync_responses(first_addr, tblock->rcpt_include_affixes, &sync_addr,
1454 host, count, pending_MAIL, ok? +1 : -1, &inblock,
1455 ob->command_timeout, buffer, sizeof(buffer)))
1456 {
1457 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1458 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1459 break;
1460
1461 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1462 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1463 case 0: break; /* No 2xx or 5xx, but no probs */
1464
1465 case -1: goto END_OFF; /* Timeout on RCPT */
1466 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */
1467 }
1468 }
1469
1470 /* Save the first address of the next batch. */
1471
1472 first_addr = addr;
1473
1474 /* If there were no good recipients (but otherwise there have been no
1475 problems), just set ok TRUE, since we have handled address-specific errors
1476 already. Otherwise, it's OK to send the message. Use the check/escape mechanism
1477 for handling the SMTP dot-handling protocol, flagging to apply to headers as
1478 well as body. Set the appropriate timeout value to be used for each chunk.
1479 (Haven't been able to make it work using select() for writing yet.) */
1480
1481 if (!ok) ok = TRUE; else
1482 {
1483 sigalrm_seen = FALSE;
1484 transport_write_timeout = ob->data_timeout;
1485 smtp_command = US"sending data block"; /* For error messages */
1486 DEBUG(D_transport|D_v)
1487 debug_printf(" SMTP>> writing message and terminating \".\"\n");
1488 transport_count = 0;
1489 #ifdef EXPERIMENTAL_DOMAINKEYS
1490 if ( (ob->dk_private_key != NULL) && (ob->dk_selector != NULL) )
1491 ok = dk_transport_write_message(addrlist, inblock.sock,
1492 topt_use_crlf | topt_end_dot | topt_escape_headers |
1493 (tblock->body_only? topt_no_headers : 0) |
1494 (tblock->headers_only? topt_no_body : 0) |
1495 (tblock->return_path_add? topt_add_return_path : 0) |
1496 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1497 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1498 0, /* No size limit */
1499 tblock->add_headers, tblock->remove_headers,
1500 US".", US"..", /* Escaping strings */
1501 tblock->rewrite_rules, tblock->rewrite_existflags,
1502 ob->dk_private_key, ob->dk_domain, ob->dk_selector,
1503 ob->dk_canon, ob->dk_headers, ob->dk_strict);
1504 else
1505 #endif
1506 ok = transport_write_message(addrlist, inblock.sock,
1507 topt_use_crlf | topt_end_dot | topt_escape_headers |
1508 (tblock->body_only? topt_no_headers : 0) |
1509 (tblock->headers_only? topt_no_body : 0) |
1510 (tblock->return_path_add? topt_add_return_path : 0) |
1511 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1512 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1513 0, /* No size limit */
1514 tblock->add_headers, tblock->remove_headers,
1515 US".", US"..", /* Escaping strings */
1516 tblock->rewrite_rules, tblock->rewrite_existflags);
1517
1518 /* transport_write_message() uses write() because it is called from other
1519 places to write to non-sockets. This means that under some OS (e.g. Solaris)
1520 it can exit with "Broken pipe" as its error. This really means that the
1521 socket got closed at the far end. */
1522
1523 transport_write_timeout = 0; /* for subsequent transports */
1524
1525 /* Failure can either be some kind of I/O disaster (including timeout),
1526 or the failure of a transport filter or the expansion of added headers. */
1527
1528 if (!ok)
1529 {
1530 buffer[0] = 0; /* There hasn't been a response */
1531 goto RESPONSE_FAILED;
1532 }
1533
1534 /* We used to send the terminating "." explicitly here, but because of
1535 buffering effects at both ends of TCP/IP connections, you don't gain
1536 anything by keeping it separate, so it might as well go in the final
1537 data buffer for efficiency. This is now done by setting the topt_end_dot
1538 flag above. */
1539
1540 smtp_command = US"end of data";
1541
1542 /* For SMTP, we now read a single response that applies to the whole message.
1543 If it is OK, then all the addresses have been delivered. */
1544
1545 if (!lmtp)
1546 {
1547 ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1548 ob->final_timeout);
1549 if (!ok && errno == 0 && buffer[0] == '4')
1550 {
1551 errno = ERRNO_DATA4XX;
1552 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1553 }
1554 }
1555
1556 /* For LMTP, we get back a response for every RCPT command that we sent;
1557 some may be accepted and some rejected. For those that get a response, their
1558 status is fixed; any that are accepted have been handed over, even if later
1559 responses crash - at least, that's how I read RFC 2033.
1560
1561 If all went well, mark the recipient addresses as completed, record which
1562 host/IPaddress they were delivered to, and cut out RSET when sending another
1563 message down the same channel. Write the completed addresses to the journal
1564 now so that they are recorded in case there is a crash of hardware or
1565 software before the spool gets updated. Also record the final SMTP
1566 confirmation if needed (for SMTP only). */
1567
1568 if (ok)
1569 {
1570 int flag = '=';
1571 int delivery_time = (int)(time(NULL) - start_delivery_time);
1572 int len;
1573 host_item *thost;
1574 uschar *conf = NULL;
1575 send_rset = FALSE;
1576
1577 /* Make a copy of the host if it is local to this invocation
1578 of the transport. */
1579
1580 if (copy_host)
1581 {
1582 thost = store_get(sizeof(host_item));
1583 *thost = *host;
1584 thost->name = string_copy(host->name);
1585 thost->address = string_copy(host->address);
1586 }
1587 else thost = host;
1588
1589 /* Set up confirmation if needed - applies only to SMTP */
1590
1591 if ((log_extra_selector & LX_smtp_confirmation) != 0 && !lmtp)
1592 {
1593 uschar *s = string_printing(buffer);
1594 conf = (s == buffer)? (uschar *)string_copy(s) : s;
1595 }
1596
1597 /* Process all transported addresses - for LMTP, read a status for
1598 each one. */
1599
1600 for (addr = addrlist; addr != first_addr; addr = addr->next)
1601 {
1602 if (addr->transport_return != PENDING_OK) continue;
1603
1604 /* LMTP - if the response fails badly (e.g. timeout), use it for all the
1605 remaining addresses. Otherwise, it's a return code for just the one
1606 address. For temporary errors, add a retry item for the address so that
1607 it doesn't get tried again too soon. */
1608
1609 if (lmtp)
1610 {
1611 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1612 ob->final_timeout))
1613 {
1614 if (errno != 0 || buffer[0] == 0) goto RESPONSE_FAILED;
1615 addr->message = string_sprintf("LMTP error after %s: %s",
1616 big_buffer, string_printing(buffer));
1617 setflag(addr, af_pass_message); /* Allow message to go to user */
1618 if (buffer[0] == '5')
1619 addr->transport_return = FAIL;
1620 else
1621 {
1622 errno = ERRNO_DATA4XX;
1623 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1624 addr->transport_return = DEFER;
1625 retry_add_item(addr, addr->address_retry_key, 0);
1626 }
1627 continue;
1628 }
1629 completed_address = TRUE; /* NOW we can set this flag */
1630 }
1631
1632 /* SMTP, or success return from LMTP for this address. Pass back the
1633 actual host that was used. */
1634
1635 addr->transport_return = OK;
1636 addr->more_errno = delivery_time;
1637 addr->host_used = thost;
1638 addr->special_action = flag;
1639 addr->message = conf;
1640 flag = '-';
1641
1642 /* Update the journal. For homonymic addresses, use the base address plus
1643 the transport name. See lots of comments in deliver.c about the reasons
1644 for the complications when homonyms are involved. Just carry on after
1645 write error, as it may prove possible to update the spool file later. */
1646
1647 if (testflag(addr, af_homonym))
1648 sprintf(CS buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
1649 else
1650 sprintf(CS buffer, "%.500s\n", addr->unique);
1651
1652 DEBUG(D_deliver) debug_printf("journalling %s", buffer);
1653 len = Ustrlen(CS buffer);
1654 if (write(journal_fd, buffer, len) != len)
1655 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
1656 "%s: %s", buffer, strerror(errno));
1657 }
1658
1659 /* Ensure the journal file is pushed out to disk. */
1660
1661 if (fsync(journal_fd) < 0)
1662 log_write(0, LOG_MAIN|LOG_PANIC, "failed to fsync journal: %s",
1663 strerror(errno));
1664 }
1665 }
1666
1667
1668 /* Handle general (not specific to one address) failures here. The value of ok
1669 is used to skip over this code on the falling through case. A timeout causes a
1670 deferral. Other errors may defer or fail according to the response code, and
1671 may set up a special errno value, e.g. after connection chopped, which is
1672 assumed if errno == 0 and there is no text in the buffer. If control reaches
1673 here during the setting up phase (i.e. before MAIL FROM) then always defer, as
1674 the problem is not related to this specific message. */
1675
1676 if (!ok)
1677 {
1678 int code;
1679
1680 RESPONSE_FAILED:
1681 save_errno = errno;
1682 message = NULL;
1683 send_quit = check_response(host, &save_errno, addrlist->more_errno,
1684 buffer, &code, &message, &pass_message);
1685 goto FAILED;
1686
1687 SEND_FAILED:
1688 save_errno = errno;
1689 code = '4';
1690 message = US string_sprintf("send() to %s [%s] failed: %s",
1691 host->name, host->address, strerror(save_errno));
1692 send_quit = FALSE;
1693 goto FAILED;
1694
1695 /* This label is jumped to directly when a TLS negotiation has failed,
1696 or was not done for a host for which it is required. Values will be set
1697 in message and save_errno, and setting_up will always be true. Treat as
1698 a temporary error. */
1699
1700 #ifdef SUPPORT_TLS
1701 TLS_FAILED:
1702 code = '4';
1703 #endif
1704
1705 /* If the failure happened while setting up the call, see if the failure was
1706 a 5xx response (this will either be on connection, or following HELO - a 5xx
1707 after EHLO causes it to try HELO). If so, fail all addresses, as this host is
1708 never going to accept them. For other errors during setting up (timeouts or
1709 whatever), defer all addresses, and yield DEFER, so that the host is not
1710 tried again for a while. */
1711
1712 FAILED:
1713 ok = FALSE; /* For when reached by GOTO */
1714
1715 if (setting_up)
1716 {
1717 if (code == '5')
1718 {
1719 set_errno(addrlist, save_errno, message, FAIL, pass_message);
1720 }
1721 else
1722 {
1723 set_errno(addrlist, save_errno, message, DEFER, pass_message);
1724 yield = DEFER;
1725 }
1726 }
1727
1728 /* We want to handle timeouts after MAIL or "." and loss of connection after
1729 "." specially. They can indicate a problem with the sender address or with
1730 the contents of the message rather than a real error on the connection. These
1731 cases are treated in the same way as a 4xx response. This next bit of code
1732 does the classification. */
1733
1734 else
1735 {
1736 BOOL message_error;
1737
1738 switch(save_errno)
1739 {
1740 case 0:
1741 case ERRNO_MAIL4XX:
1742 case ERRNO_DATA4XX:
1743 message_error = TRUE;
1744 break;
1745
1746 case ETIMEDOUT:
1747 message_error = Ustrncmp(smtp_command,"MAIL",4) == 0 ||
1748 Ustrncmp(smtp_command,"end ",4) == 0;
1749 break;
1750
1751 case ERRNO_SMTPCLOSED:
1752 message_error = Ustrncmp(smtp_command,"end ",4) == 0;
1753 break;
1754
1755 default:
1756 message_error = FALSE;
1757 break;
1758 }
1759
1760 /* Handle the cases that are treated as message errors. These are:
1761
1762 (a) negative response or timeout after MAIL
1763 (b) negative response after DATA
1764 (c) negative response or timeout or dropped connection after "."
1765
1766 It won't be a negative response or timeout after RCPT, as that is dealt
1767 with separately above. The action in all cases is to set an appropriate
1768 error code for all the addresses, but to leave yield set to OK because the
1769 host itself has not failed. Of course, it might in practice have failed
1770 when we've had a timeout, but if so, we'll discover that at the next
1771 delivery attempt. For a temporary error, set the message_defer flag, and
1772 write to the logs for information if this is not the last host. The error
1773 for the last host will be logged as part of the address's log line. */
1774
1775 if (message_error)
1776 {
1777 if (mua_wrapper) code = '5'; /* Force hard failure in wrapper mode */
1778 set_errno(addrlist, save_errno, message, (code == '5')? FAIL : DEFER,
1779 pass_message);
1780
1781 /* If there's an errno, the message contains just the identity of
1782 the host. */
1783
1784 if (code != '5') /* Anything other than 5 is treated as temporary */
1785 {
1786 if (save_errno > 0)
1787 message = US string_sprintf("%s: %s", message, strerror(save_errno));
1788 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", message);
1789 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
1790 *message_defer = TRUE;
1791 }
1792 }
1793
1794 /* Otherwise, we have an I/O error or a timeout other than after MAIL or
1795 ".", or some other transportation error. We defer all addresses and yield
1796 DEFER, except for the case of failed add_headers expansion, or a transport
1797 filter failure, when the yield should be ERROR, to stop it trying other
1798 hosts. */
1799
1800 else
1801 {
1802 yield = (save_errno == ERRNO_CHHEADER_FAIL ||
1803 save_errno == ERRNO_FILTER_FAIL)? ERROR : DEFER;
1804 set_errno(addrlist, save_errno, message, DEFER, pass_message);
1805 }
1806 }
1807 }
1808
1809
1810 /* If all has gone well, send_quit will be set TRUE, implying we can end the
1811 SMTP session tidily. However, if there were too many addresses to send in one
1812 message (indicated by first_addr being non-NULL) we want to carry on with the
1813 rest of them. Also, it is desirable to send more than one message down the SMTP
1814 connection if there are several waiting, provided we haven't already sent so
1815 many as to hit the configured limit. The function transport_check_waiting looks
1816 for a waiting message and returns its id. Then transport_pass_socket tries to
1817 set up a continued delivery by passing the socket on to another process. The
1818 variable send_rset is FALSE if a message has just been successfully transfered.
1819
1820 If we are already sending down a continued channel, there may be further
1821 addresses not yet delivered that are aimed at the same host, but which have not
1822 been passed in this run of the transport. In this case, continue_more will be
1823 true, and all we should do is send RSET if necessary, and return, leaving the
1824 channel open.
1825
1826 However, if no address was disposed of, i.e. all addresses got 4xx errors, we
1827 do not want to continue with other messages down the same channel, because that
1828 can lead to looping between two or more messages, all with the same,
1829 temporarily failing address(es). [The retry information isn't updated yet, so
1830 new processes keep on trying.] We probably also don't want to try more of this
1831 message's addresses either.
1832
1833 If we have started a TLS session, we have to end it before passing the
1834 connection to a new process. However, not all servers can handle this (Exim
1835 can), so we do not pass such a connection on if the host matches
1836 hosts_nopass_tls. */
1837
1838 DEBUG(D_transport)
1839 debug_printf("ok=%d send_quit=%d send_rset=%d continue_more=%d "
1840 "yield=%d first_address is %sNULL\n", ok, send_quit, send_rset,
1841 continue_more, yield, (first_addr == NULL)? "":"not ");
1842
1843 if (completed_address && ok && send_quit)
1844 {
1845 BOOL more;
1846 if (first_addr != NULL || continue_more ||
1847 (
1848 (tls_active < 0 ||
1849 verify_check_this_host(&(ob->hosts_nopass_tls), NULL, host->name,
1850 host->address, NULL) != OK)
1851 &&
1852 transport_check_waiting(tblock->name, host->name,
1853 tblock->connection_max_messages, new_message_id, &more)
1854 ))
1855 {
1856 uschar *msg;
1857 BOOL pass_message;
1858
1859 if (send_rset)
1860 {
1861 if (! (ok = smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0))
1862 {
1863 msg = US string_sprintf("send() to %s [%s] failed: %s", host->name,
1864 host->address, strerror(save_errno));
1865 send_quit = FALSE;
1866 }
1867 else if (! (ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1868 ob->command_timeout)))
1869 {
1870 int code;
1871 send_quit = check_response(host, &errno, 0, buffer, &code, &msg,
1872 &pass_message);
1873 if (!send_quit)
1874 {
1875 DEBUG(D_transport) debug_printf("%s\n", msg);
1876 }
1877 }
1878 }
1879
1880 /* Either RSET was not needed, or it succeeded */
1881
1882 if (ok)
1883 {
1884 if (first_addr != NULL) /* More addresses still to be sent */
1885 { /* in this run of the transport */
1886 continue_sequence++; /* Causes * in logging */
1887 goto SEND_MESSAGE;
1888 }
1889 if (continue_more) return yield; /* More addresses for another run */
1890
1891 /* Pass the socket to a new Exim process. Before doing so, we must shut
1892 down TLS. Not all MTAs allow for the continuation of the SMTP session
1893 when TLS is shut down. We test for this by sending a new EHLO. If we
1894 don't get a good response, we don't attempt to pass the socket on. */
1895
1896 #ifdef SUPPORT_TLS
1897 if (tls_active >= 0)
1898 {
1899 tls_close(TRUE);
1900 ok = smtp_write_command(&outblock,FALSE,"EHLO %s\r\n",helo_data) >= 0 &&
1901 smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1902 ob->command_timeout);
1903 }
1904 #endif
1905
1906 /* If the socket is successfully passed, we musn't send QUIT (or
1907 indeed anything!) from here. */
1908
1909 if (ok && transport_pass_socket(tblock->name, host->name, host->address,
1910 new_message_id, inblock.sock))
1911 {
1912 send_quit = FALSE;
1913 }
1914 }
1915
1916 /* If RSET failed and there are addresses left, they get deferred. */
1917
1918 else set_errno(first_addr, errno, msg, DEFER, FALSE);
1919 }
1920 }
1921
1922 /* End off tidily with QUIT unless the connection has died or the socket has
1923 been passed to another process. There has been discussion on the net about what
1924 to do after sending QUIT. The wording of the RFC suggests that it is necessary
1925 to wait for a response, but on the other hand, there isn't anything one can do
1926 with an error response, other than log it. Exim used to do that. However,
1927 further discussion suggested that it is positively advantageous not to wait for
1928 the response, but to close the session immediately. This is supposed to move
1929 the TCP/IP TIME_WAIT state from the server to the client, thereby removing some
1930 load from the server. (Hosts that are both servers and clients may not see much
1931 difference, of course.) Further discussion indicated that this was safe to do
1932 on Unix systems which have decent implementations of TCP/IP that leave the
1933 connection around for a while (TIME_WAIT) after the application has gone away.
1934 This enables the response sent by the server to be properly ACKed rather than
1935 timed out, as can happen on broken TCP/IP implementations on other OS.
1936
1937 This change is being made on 31-Jul-98. After over a year of trouble-free
1938 operation, the old commented-out code was removed on 17-Sep-99. */
1939
1940 SEND_QUIT:
1941 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1942
1943 END_OFF:
1944
1945 #ifdef SUPPORT_TLS
1946 tls_close(TRUE);
1947 #endif
1948
1949 /* Close the socket, and return the appropriate value, first setting
1950 continue_transport and continue_hostname NULL to prevent any other addresses
1951 that may include the host from trying to re-use a continuation socket. This
1952 works because the NULL setting is passed back to the calling process, and
1953 remote_max_parallel is forced to 1 when delivering over an existing connection,
1954
1955 If all went well and continue_more is set, we shouldn't actually get here if
1956 there are further addresses, as the return above will be taken. However,
1957 writing RSET might have failed, or there may be other addresses whose hosts are
1958 specified in the transports, and therefore not visible at top level, in which
1959 case continue_more won't get set. */
1960
1961 (void)close(inblock.sock);
1962 continue_transport = NULL;
1963 continue_hostname = NULL;
1964 return yield;
1965 }
1966
1967
1968
1969
1970 /*************************************************
1971 * Closedown entry point *
1972 *************************************************/
1973
1974 /* This function is called when exim is passed an open smtp channel
1975 from another incarnation, but the message which it has been asked
1976 to deliver no longer exists. The channel is on stdin.
1977
1978 We might do fancy things like looking for another message to send down
1979 the channel, but if the one we sought has gone, it has probably been
1980 delivered by some other process that itself will seek further messages,
1981 so just close down our connection.
1982
1983 Argument: pointer to the transport instance block
1984 Returns: nothing
1985 */
1986
1987 void
1988 smtp_transport_closedown(transport_instance *tblock)
1989 {
1990 smtp_transport_options_block *ob =
1991 (smtp_transport_options_block *)(tblock->options_block);
1992 smtp_inblock inblock;
1993 smtp_outblock outblock;
1994 uschar buffer[256];
1995 uschar inbuffer[4096];
1996 uschar outbuffer[16];
1997
1998 inblock.sock = fileno(stdin);
1999 inblock.buffer = inbuffer;
2000 inblock.buffersize = sizeof(inbuffer);
2001 inblock.ptr = inbuffer;
2002 inblock.ptrend = inbuffer;
2003
2004 outblock.sock = inblock.sock;
2005 outblock.buffersize = sizeof(outbuffer);
2006 outblock.buffer = outbuffer;
2007 outblock.ptr = outbuffer;
2008 outblock.cmd_count = 0;
2009 outblock.authenticating = FALSE;
2010
2011 (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
2012 (void)smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2013 ob->command_timeout);
2014 (void)close(inblock.sock);
2015 }
2016
2017
2018
2019 /*************************************************
2020 * Prepare addresses for delivery *
2021 *************************************************/
2022
2023 /* This function is called to flush out error settings from previous delivery
2024 attempts to other hosts. It also records whether we got here via an MX record
2025 or not in the more_errno field of the address. We are interested only in
2026 addresses that are still marked DEFER - others may have got delivered to a
2027 previously considered IP address. Set their status to PENDING_DEFER to indicate
2028 which ones are relevant this time.
2029
2030 Arguments:
2031 addrlist the list of addresses
2032 host the host we are delivering to
2033
2034 Returns: the first address for this delivery
2035 */
2036
2037 static address_item *
2038 prepare_addresses(address_item *addrlist, host_item *host)
2039 {
2040 address_item *first_addr = NULL;
2041 address_item *addr;
2042 for (addr = addrlist; addr != NULL; addr = addr->next)
2043 {
2044 if (addr->transport_return != DEFER) continue;
2045 if (first_addr == NULL) first_addr = addr;
2046 addr->transport_return = PENDING_DEFER;
2047 addr->basic_errno = 0;
2048 addr->more_errno = (host->mx >= 0)? 'M' : 'A';
2049 addr->message = NULL;
2050 #ifdef SUPPORT_TLS
2051 addr->cipher = NULL;
2052 addr->peerdn = NULL;
2053 #endif
2054 }
2055 return first_addr;
2056 }
2057
2058
2059
2060 /*************************************************
2061 * Main entry point *
2062 *************************************************/
2063
2064 /* See local README for interface details. As this is a remote transport, it is
2065 given a chain of addresses to be delivered in one connection, if possible. It
2066 always returns TRUE, indicating that each address has its own independent
2067 status set, except if there is a setting up problem, in which case it returns
2068 FALSE. */
2069
2070 BOOL
2071 smtp_transport_entry(
2072 transport_instance *tblock, /* data for this instantiation */
2073 address_item *addrlist) /* addresses we are working on */
2074 {
2075 int cutoff_retry;
2076 int port;
2077 int hosts_defer = 0;
2078 int hosts_fail = 0;
2079 int hosts_looked_up = 0;
2080 int hosts_retry = 0;
2081 int hosts_serial = 0;
2082 int hosts_total = 0;
2083 int total_hosts_tried = 0;
2084 address_item *addr;
2085 BOOL expired = TRUE;
2086 BOOL continuing = continue_hostname != NULL;
2087 uschar *expanded_hosts = NULL;
2088 uschar *pistring;
2089 uschar *tid = string_sprintf("%s transport", tblock->name);
2090 smtp_transport_options_block *ob =
2091 (smtp_transport_options_block *)(tblock->options_block);
2092 host_item *hostlist = addrlist->host_list;
2093 host_item *host = NULL;
2094
2095 DEBUG(D_transport)
2096 {
2097 debug_printf("%s transport entered\n", tblock->name);
2098 for (addr = addrlist; addr != NULL; addr = addr->next)
2099 debug_printf(" %s\n", addr->address);
2100 if (continuing) debug_printf("already connected to %s [%s]\n",
2101 continue_hostname, continue_host_address);
2102 }
2103
2104 /* If a host list is not defined for the addresses - they must all have the
2105 same one in order to be passed to a single transport - or if the transport has
2106 a host list with hosts_override set, use the host list supplied with the
2107 transport. It is an error for this not to exist. */
2108
2109 if (hostlist == NULL || (ob->hosts_override && ob->hosts != NULL))
2110 {
2111 if (ob->hosts == NULL)
2112 {
2113 addrlist->message = string_sprintf("%s transport called with no hosts set",
2114 tblock->name);
2115 addrlist->transport_return = PANIC;
2116 return FALSE; /* Only top address has status */
2117 }
2118
2119 DEBUG(D_transport) debug_printf("using the transport's hosts: %s\n",
2120 ob->hosts);
2121
2122 /* If the transport's host list contains no '$' characters, and we are not
2123 randomizing, it is fixed and therefore a chain of hosts can be built once
2124 and for all, and remembered for subsequent use by other calls to this
2125 transport. If, on the other hand, the host list does contain '$', or we are
2126 randomizing its order, we have to rebuild it each time. In the fixed case,
2127 as the hosts string will never be used again, it doesn't matter that we
2128 replace all the : characters with zeros. */
2129
2130 if (ob->hostlist == NULL)
2131 {
2132 uschar *s = ob->hosts;
2133
2134 if (Ustrchr(s, '$') != NULL)
2135 {
2136 expanded_hosts = expand_string(s);
2137 if (expanded_hosts == NULL)
2138 {
2139 addrlist->message = string_sprintf("failed to expand list of hosts "
2140 "\"%s\" in %s transport: %s", s, tblock->name, expand_string_message);
2141 addrlist->transport_return = search_find_defer? DEFER : PANIC;
2142 return FALSE; /* Only top address has status */
2143 }
2144 DEBUG(D_transport) debug_printf("expanded list of hosts \"%s\" to "
2145 "\"%s\"\n", s, expanded_hosts);
2146 s = expanded_hosts;
2147 }
2148 else
2149 if (ob->hosts_randomize) s = expanded_hosts = string_copy(s);
2150
2151 host_build_hostlist(&hostlist, s, ob->hosts_randomize);
2152
2153 /* If there was no expansion of hosts, save the host list for
2154 next time. */
2155
2156 if (expanded_hosts == NULL) ob->hostlist = hostlist;
2157 }
2158
2159 /* This is not the first time this transport has been run in this delivery;
2160 the host list was built previously. */
2161
2162 else hostlist = ob->hostlist;
2163 }
2164
2165 /* The host list was supplied with the address. If hosts_randomize is set, we
2166 must sort it into a random order if it did not come from MX records and has not
2167 already been randomized (but don't bother if continuing down an existing
2168 connection). */
2169
2170 else if (ob->hosts_randomize && hostlist->mx == MX_NONE && !continuing)
2171 {
2172 host_item *newlist = NULL;
2173 while (hostlist != NULL)
2174 {
2175 host_item *h = hostlist;
2176 hostlist = hostlist->next;
2177
2178 h->sort_key = random_number(100);
2179
2180 if (newlist == NULL)
2181 {
2182 h->next = NULL;
2183 newlist = h;
2184 }
2185 else if (h->sort_key < newlist->sort_key)
2186 {
2187 h->next = newlist;
2188 newlist = h;
2189 }
2190 else
2191 {
2192 host_item *hh = newlist;
2193 while (hh->next != NULL)
2194 {
2195 if (h->sort_key < hh->next->sort_key) break;
2196 hh = hh->next;
2197 }
2198 h->next = hh->next;
2199 hh->next = h;
2200 }
2201 }
2202
2203 hostlist = addrlist->host_list = newlist;
2204 }
2205
2206
2207 /* Sort out the default port. */
2208
2209 if (!smtp_get_port(ob->port, addrlist, &port, tid)) return FALSE;
2210
2211
2212 /* For each host-plus-IP-address on the list:
2213
2214 . If this is a continued delivery and the host isn't the one with the
2215 current connection, skip.
2216
2217 . If the status is unusable (i.e. previously failed or retry checked), skip.
2218
2219 . If no IP address set, get the address, either by turning the name into
2220 an address, calling gethostbyname if gethostbyname is on, or by calling
2221 the DNS. The DNS may yield multiple addresses, in which case insert the
2222 extra ones into the list.
2223
2224 . Get the retry data if not previously obtained for this address and set the
2225 field which remembers the state of this address. Skip if the retry time is
2226 not reached. If not, remember whether retry data was found. The retry string
2227 contains both the name and the IP address.
2228
2229 . Scan the list of addresses and mark those whose status is DEFER as
2230 PENDING_DEFER. These are the only ones that will be processed in this cycle
2231 of the hosts loop.
2232
2233 . Make a delivery attempt - addresses marked PENDING_DEFER will be tried.
2234 Some addresses may be successfully delivered, others may fail, and yet
2235 others may get temporary errors and so get marked DEFER.
2236
2237 . The return from the delivery attempt is OK if a connection was made and a
2238 valid SMTP dialogue was completed. Otherwise it is DEFER.
2239
2240 . If OK, add a "remove" retry item for this host/IPaddress, if any.
2241
2242 . If fail to connect, or other defer state, add a retry item.
2243
2244 . If there are any addresses whose status is still DEFER, carry on to the
2245 next host/IPaddress, unless we have tried the number of hosts given
2246 by hosts_max_try or hosts_max_try_hardlimit; otherwise return. Note that
2247 there is some fancy logic for hosts_max_try that means its limit can be
2248 overstepped in some circumstances.
2249
2250 If we get to the end of the list, all hosts have deferred at least one address,
2251 or not reached their retry times. If delay_after_cutoff is unset, it requests a
2252 delivery attempt to those hosts whose last try was before the arrival time of
2253 the current message. To cope with this, we have to go round the loop a second
2254 time. After that, set the status and error data for any addresses that haven't
2255 had it set already. */
2256
2257 for (cutoff_retry = 0; expired &&
2258 cutoff_retry < ((ob->delay_after_cutoff)? 1 : 2);
2259 cutoff_retry++)
2260 {
2261 host_item *nexthost = NULL;
2262 int unexpired_hosts_tried = 0;
2263
2264 for (host = hostlist;
2265 host != NULL &&
2266 unexpired_hosts_tried < ob->hosts_max_try &&
2267 total_hosts_tried < ob->hosts_max_try_hardlimit;
2268 host = nexthost)
2269 {
2270 int rc;
2271 int host_af;
2272 uschar *rs;
2273 BOOL serialized = FALSE;
2274 BOOL host_is_expired = FALSE;
2275 BOOL message_defer = FALSE;
2276 BOOL ifchanges = FALSE;
2277 BOOL some_deferred = FALSE;
2278 address_item *first_addr = NULL;
2279 uschar *interface = NULL;
2280 uschar *retry_host_key = NULL;
2281 uschar *retry_message_key = NULL;
2282 uschar *serialize_key = NULL;
2283
2284 /* Default next host is next host. :-) But this can vary if the
2285 hosts_max_try limit is hit (see below). It may also be reset if a host
2286 address is looked up here (in case the host was multihomed). */
2287
2288 nexthost = host->next;
2289
2290 /* Set the flag requesting that this host be added to the waiting
2291 database if the delivery fails temporarily or if we are running with
2292 queue_smtp or a 2-stage queue run. This gets unset for certain
2293 kinds of error, typically those that are specific to the message. */
2294
2295 host->update_waiting = TRUE;
2296
2297 /* If the address hasn't yet been obtained from the host name, look it up
2298 now, unless the host is already marked as unusable. If it is marked as
2299 unusable, it means that the router was unable to find its IP address (in
2300 the DNS or wherever) OR we are in the 2nd time round the cutoff loop, and
2301 the lookup failed last time. We don't get this far if *all* MX records
2302 point to non-existent hosts; that is treated as a hard error.
2303
2304 We can just skip this host entirely. When the hosts came from the router,
2305 the address will timeout based on the other host(s); when the address is
2306 looked up below, there is an explicit retry record added.
2307
2308 Note that we mustn't skip unusable hosts if the address is not unset; they
2309 may be needed as expired hosts on the 2nd time round the cutoff loop. */
2310
2311 if (host->address == NULL)
2312 {
2313 int new_port;
2314 host_item *hh;
2315 uschar *canonical_name;
2316
2317 if (host->status >= hstatus_unusable)
2318 {
2319 DEBUG(D_transport) debug_printf("%s has no address and is unusable - skipping\n",
2320 host->name);
2321 continue;
2322 }
2323
2324 DEBUG(D_transport) debug_printf("getting address for %s\n", host->name);
2325
2326 /* The host name is permitted to have an attached port. Find it, and
2327 strip it from the name. Just remember it for now. */
2328
2329 new_port = host_item_get_port(host);
2330
2331 /* Count hosts looked up */
2332
2333 hosts_looked_up++;
2334
2335 /* Find by name if so configured, or if it's an IP address. We don't
2336 just copy the IP address, because we need the test-for-local to happen. */
2337
2338 if (ob->gethostbyname || string_is_ip_address(host->name, NULL) != 0)
2339 rc = host_find_byname(host, NULL, &canonical_name, TRUE);
2340 else
2341 {
2342 int flags = HOST_FIND_BY_A;
2343 if (ob->dns_qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
2344 if (ob->dns_search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
2345 rc = host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
2346 &canonical_name, NULL);
2347 }
2348
2349 /* Update the host (and any additional blocks, resulting from
2350 multihoming) with a host-specific port, if any. */
2351
2352 for (hh = host; hh != nexthost; hh = hh->next) hh->port = new_port;
2353
2354 /* Failure to find the host at this time (usually DNS temporary failure)
2355 is really a kind of routing failure rather than a transport failure.
2356 Therefore we add a retry item of the routing kind, not to stop us trying
2357 to look this name up here again, but to ensure the address gets timed
2358 out if the failures go on long enough. A complete failure at this point
2359 commonly points to a configuration error, but the best action is still
2360 to carry on for the next host. */
2361
2362 if (rc == HOST_FIND_AGAIN || rc == HOST_FIND_FAILED)
2363 {
2364 retry_add_item(addrlist, string_sprintf("R:%s", host->name), 0);
2365 expired = FALSE;
2366 if (rc == HOST_FIND_AGAIN) hosts_defer++; else hosts_fail++;
2367 DEBUG(D_transport) debug_printf("rc = %s for %s\n", (rc == HOST_FIND_AGAIN)?
2368 "HOST_FIND_AGAIN" : "HOST_FIND_FAILED", host->name);
2369 host->status = hstatus_unusable;
2370
2371 for (addr = addrlist; addr != NULL; addr = addr->next)
2372 {
2373 if (addr->transport_return != DEFER) continue;
2374 addr->basic_errno = ERRNO_UNKNOWNHOST;
2375 addr->message =
2376 string_sprintf("failed to lookup IP address for %s", host->name);
2377 }
2378 continue;
2379 }
2380
2381 /* If the host is actually the local host, we may have a problem, or
2382 there may be some cunning configuration going on. In the problem case,
2383 log things and give up. The default transport status is already DEFER. */
2384
2385 if (rc == HOST_FOUND_LOCAL && !ob->allow_localhost)
2386 {
2387 for (addr = addrlist; addr != NULL; addr = addr->next)
2388 {
2389 addr->basic_errno = 0;
2390 addr->message = string_sprintf("%s transport found host %s to be "
2391 "local", tblock->name, host->name);
2392 }
2393 goto END_TRANSPORT;
2394 }
2395 } /* End of block for IP address lookup */
2396
2397 /* If this is a continued delivery, we are interested only in the host
2398 which matches the name of the existing open channel. The check is put
2399 here after the local host lookup, in case the name gets expanded as a
2400 result of the lookup. Set expired FALSE, to save the outer loop executing
2401 twice. */
2402
2403 if (continuing && (Ustrcmp(continue_hostname, host->name) != 0 ||
2404 Ustrcmp(continue_host_address, host->address) != 0))
2405 {
2406 expired = FALSE;
2407 continue; /* With next host */
2408 }
2409
2410 /* Reset the default next host in case a multihomed host whose addresses
2411 are not looked up till just above added to the host list. */
2412
2413 nexthost = host->next;
2414
2415 /* If queue_smtp is set (-odqs or the first part of a 2-stage run), or the
2416 domain is in queue_smtp_domains, we don't actually want to attempt any
2417 deliveries. When doing a queue run, queue_smtp_domains is always unset. If
2418 there is a lookup defer in queue_smtp_domains, proceed as if the domain
2419 were not in it. We don't want to hold up all SMTP deliveries! Except when
2420 doing a two-stage queue run, don't do this if forcing. */
2421
2422 if ((!deliver_force || queue_2stage) && (queue_smtp ||
2423 match_isinlist(addrlist->domain, &queue_smtp_domains, 0,
2424 &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL) == OK))
2425 {
2426 expired = FALSE;
2427 for (addr = addrlist; addr != NULL; addr = addr->next)
2428 {
2429 if (addr->transport_return != DEFER) continue;
2430 addr->message = US"domain matches queue_smtp_domains, or -odqs set";
2431 }
2432 continue; /* With next host */
2433 }
2434
2435 /* Count hosts being considered - purely for an intelligent comment
2436 if none are usable. */
2437
2438 hosts_total++;
2439
2440 /* Set $host and $host address now in case they are needed for the
2441 interface expansion or the serialize_hosts check; they remain set if an
2442 actual delivery happens. */
2443
2444 deliver_host = host->name;
2445 deliver_host_address = host->address;
2446
2447 /* Set up a string for adding to the retry key if the port number is not
2448 the standard SMTP port. A host may have its own port setting that overrides
2449 the default. */
2450
2451 pistring = string_sprintf(":%d", (host->port == PORT_NONE)?
2452 port : host->port);
2453 if (Ustrcmp(pistring, ":25") == 0) pistring = US"";
2454
2455 /* Select IPv4 or IPv6, and choose an outgoing interface. If the interface
2456 string changes upon expansion, we must add it to the key that is used for
2457 retries, because connections to the same host from a different interface
2458 should be treated separately. */
2459
2460 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET : AF_INET6;
2461 if (!smtp_get_interface(ob->interface, host_af, addrlist, &ifchanges,
2462 &interface, tid))
2463 return FALSE;
2464 if (ifchanges) pistring = string_sprintf("%s/%s", pistring, interface);
2465
2466 /* The first time round the outer loop, check the status of the host by
2467 inspecting the retry data. The second time round, we are interested only
2468 in expired hosts that haven't been tried since this message arrived. */
2469
2470 if (cutoff_retry == 0)
2471 {
2472 /* Ensure the status of the address is set by checking retry data if
2473 necessary. There maybe host-specific retry data (applicable to all
2474 messages) and also data for retries of a specific message at this host.
2475 If either of these retry records are actually read, the keys used are
2476 returned to save recomputing them later. */
2477
2478 host_is_expired = retry_check_address(addrlist->domain, host, pistring,
2479 ob->retry_include_ip_address, &retry_host_key, &retry_message_key);
2480
2481 DEBUG(D_transport) debug_printf("%s [%s]%s status = %s\n", host->name,
2482 (host->address == NULL)? US"" : host->address, pistring,
2483 (host->status == hstatus_usable)? "usable" :
2484 (host->status == hstatus_unusable)? "unusable" :
2485 (host->status == hstatus_unusable_expired)? "unusable (expired)" : "?");
2486
2487 /* Skip this address if not usable at this time, noting if it wasn't
2488 actually expired, both locally and in the address. */
2489
2490 switch (host->status)
2491 {
2492 case hstatus_unusable:
2493 expired = FALSE;
2494 setflag(addrlist, af_retry_skipped);
2495 /* Fall through */
2496
2497 case hstatus_unusable_expired:
2498 switch (host->why)
2499 {
2500 case hwhy_retry: hosts_retry++; break;
2501 case hwhy_failed: hosts_fail++; break;
2502 case hwhy_deferred: hosts_defer++; break;
2503 }
2504
2505 /* If there was a retry message key, implying that previously there
2506 was a message-specific defer, we don't want to update the list of
2507 messages waiting for this host. */
2508
2509 if (retry_message_key != NULL) host->update_waiting = FALSE;
2510 continue; /* With the next host or IP address */
2511 }
2512 }
2513
2514 /* Second time round the loop: if the address is set but expired, and
2515 the message is newer than the last try, let it through. */
2516
2517 else
2518 {
2519 if (host->address == NULL ||
2520 host->status != hstatus_unusable_expired ||
2521 host->last_try > received_time)
2522 continue;
2523 DEBUG(D_transport)
2524 debug_printf("trying expired host %s [%s]%s\n",
2525 host->name, host->address, pistring);
2526 host_is_expired = TRUE;
2527 }
2528
2529 /* Setting "expired=FALSE" doesn't actually mean not all hosts are expired;
2530 it remains TRUE only if all hosts are expired and none are actually tried.
2531 */
2532
2533 expired = FALSE;
2534
2535 /* If this host is listed as one to which access must be serialized,
2536 see if another Exim process has a connection to it, and if so, skip
2537 this host. If not, update the database to record our connection to it
2538 and remember this for later deletion. Do not do any of this if we are
2539 sending the message down a pre-existing connection. */
2540
2541 if (!continuing &&
2542 verify_check_this_host(&(ob->serialize_hosts), NULL, host->name,
2543 host->address, NULL) == OK)
2544 {
2545 serialize_key = string_sprintf("host-serialize-%s", host->name);
2546 if (!enq_start(serialize_key))
2547 {
2548 DEBUG(D_transport)
2549 debug_printf("skipping host %s because another Exim process "
2550 "is connected to it\n", host->name);
2551 hosts_serial++;
2552 continue;
2553 }
2554 serialized = TRUE;
2555 }
2556
2557 /* OK, we have an IP address that is not waiting for its retry time to
2558 arrive (it might be expired) OR (second time round the loop) we have an
2559 expired host that hasn't been tried since the message arrived. Have a go
2560 at delivering the message to it. First prepare the addresses by flushing
2561 out the result of previous attempts, and finding the first address that
2562 is still to be delivered. */
2563
2564 first_addr = prepare_addresses(addrlist, host);
2565
2566 DEBUG(D_transport) debug_printf("delivering %s to %s [%s] (%s%s)\n",
2567 message_id, host->name, host->address, addrlist->address,
2568 (addrlist->next == NULL)? "" : ", ...");
2569
2570 set_process_info("delivering %s to %s [%s] (%s%s)",
2571 message_id, host->name, host->address, addrlist->address,
2572 (addrlist->next == NULL)? "" : ", ...");
2573
2574 /* This is not for real; don't do the delivery. If there are
2575 any remaining hosts, list them. */
2576
2577 if (dont_deliver)
2578 {
2579 host_item *host2;
2580 set_errno(addrlist, 0, NULL, OK, FALSE);
2581 for (addr = addrlist; addr != NULL; addr = addr->next)
2582 {
2583 addr->host_used = host;
2584 addr->special_action = '*';
2585 addr->message = US"delivery bypassed by -N option";
2586 }
2587 DEBUG(D_transport)
2588 {
2589 debug_printf("*** delivery by %s transport bypassed by -N option\n"
2590 "*** host and remaining hosts:\n", tblock->name);
2591 for (host2 = host; host2 != NULL; host2 = host2->next)
2592 debug_printf(" %s [%s]\n", host2->name,
2593 (host2->address == NULL)? US"unset" : host2->address);
2594 }
2595 rc = OK;
2596 }
2597
2598 /* This is for real. If the host is expired, we don't count it for
2599 hosts_max_retry. This ensures that all hosts must expire before an address
2600 is timed out, unless hosts_max_try_hardlimit (which protects against
2601 lunatic DNS configurations) is reached.
2602
2603 If the host is not expired and we are about to hit the hosts_max_retry
2604 limit, check to see if there is a subsequent hosts with a different MX
2605 value. If so, make that the next host, and don't count this one. This is a
2606 heuristic to make sure that different MXs do get tried. With a normal kind
2607 of retry rule, they would get tried anyway when the earlier hosts were
2608 delayed, but if the domain has a "retry every time" type of rule - as is
2609 often used for the the very large ISPs, that won't happen. */
2610
2611 else
2612 {
2613 if (!host_is_expired && ++unexpired_hosts_tried >= ob->hosts_max_try)
2614 {
2615 host_item *h;
2616 DEBUG(D_transport)
2617 debug_printf("hosts_max_try limit reached with this host\n");
2618 for (h = host; h != NULL; h = h->next)
2619 if (h->mx != host->mx) break;
2620 if (h != NULL)
2621 {
2622 nexthost = h;
2623 unexpired_hosts_tried--;
2624 DEBUG(D_transport) debug_printf("however, a higher MX host exists "
2625 "and will be tried\n");
2626 }
2627 }
2628
2629 /* Attempt the delivery. */
2630
2631 total_hosts_tried++;
2632 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2633 expanded_hosts != NULL, &message_defer, FALSE);
2634
2635 /* Yield is one of:
2636 OK => connection made, each address contains its result;
2637 message_defer is set for message-specific defers (when all
2638 recipients are marked defer)
2639 DEFER => there was a non-message-specific delivery problem;
2640 ERROR => there was a problem setting up the arguments for a filter,
2641 or there was a problem with expanding added headers
2642 */
2643
2644 /* If the result is not OK, there was a non-message-specific problem.
2645 If the result is DEFER, we need to write to the logs saying what happened
2646 for this particular host, except in the case of authentication and TLS
2647 failures, where the log has already been written. If all hosts defer a
2648 general message is written at the end. */
2649
2650 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL &&
2651 first_addr->basic_errno != ERRNO_TLSFAILURE)
2652 write_logs(first_addr, host);
2653
2654 /* If STARTTLS was accepted, but there was a failure in setting up the
2655 TLS session (usually a certificate screwup), and the host is not in
2656 hosts_require_tls, and tls_tempfail_tryclear is true, try again, with
2657 TLS forcibly turned off. We have to start from scratch with a new SMTP
2658 connection. That's why the retry is done from here, not from within
2659 smtp_deliver(). [Rejections of STARTTLS itself don't screw up the
2660 session, so the in-clear transmission after those errors, if permitted,
2661 happens inside smtp_deliver().] */
2662
2663 #ifdef SUPPORT_TLS
2664 if (rc == DEFER && first_addr->basic_errno == ERRNO_TLSFAILURE &&
2665 ob->tls_tempfail_tryclear &&
2666 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
2667 host->address, NULL) != OK)
2668 {
2669 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
2670 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
2671 first_addr = prepare_addresses(addrlist, host);
2672 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2673 expanded_hosts != NULL, &message_defer, TRUE);
2674 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL)
2675 write_logs(first_addr, host);
2676 }
2677 #endif
2678 }
2679
2680 /* Delivery attempt finished */
2681
2682 rs = (rc == OK)? US"OK" : (rc == DEFER)? US"DEFER" : (rc == ERROR)?
2683 US"ERROR" : US"?";
2684
2685 set_process_info("delivering %s: just tried %s [%s] for %s%s: result %s",
2686 message_id, host->name, host->address, addrlist->address,
2687 (addrlist->next == NULL)? "" : " (& others)", rs);
2688
2689 /* Release serialization if set up */
2690
2691 if (serialized) enq_end(serialize_key);
2692
2693 /* If the result is DEFER, or if a host retry record is known to exist, we
2694 need to add an item to the retry chain for updating the retry database
2695 at the end of delivery. We only need to add the item to the top address,
2696 of course. Also, if DEFER, we mark the IP address unusable so as to skip it
2697 for any other delivery attempts using the same address. (It is copied into
2698 the unusable tree at the outer level, so even if different address blocks
2699 contain the same address, it still won't get tried again.) */
2700
2701 if (rc == DEFER || retry_host_key != NULL)
2702 {
2703 int delete_flag = (rc != DEFER)? rf_delete : 0;
2704 if (retry_host_key == NULL)
2705 {
2706 retry_host_key = ob->retry_include_ip_address?
2707 string_sprintf("T:%S:%s%s", host->name, host->address, pistring) :
2708 string_sprintf("T:%S%s", host->name, pistring);
2709 }
2710
2711 /* If a delivery of another message over an existing SMTP connection
2712 yields DEFER, we do NOT set up retry data for the host. This covers the
2713 case when there are delays in routing the addresses in the second message
2714 that are so long that the server times out. This is alleviated by not
2715 routing addresses that previously had routing defers when handling an
2716 existing connection, but even so, this case may occur (e.g. if a
2717 previously happily routed address starts giving routing defers). If the
2718 host is genuinely down, another non-continued message delivery will
2719 notice it soon enough. */
2720
2721 if (delete_flag != 0 || !continuing)
2722 retry_add_item(first_addr, retry_host_key, rf_host | delete_flag);
2723
2724 /* We may have tried an expired host, if its retry time has come; ensure
2725 the status reflects the expiry for the benefit of any other addresses. */
2726
2727 if (rc == DEFER)
2728 {
2729 host->status = (host_is_expired)?
2730 hstatus_unusable_expired : hstatus_unusable;
2731 host->why = hwhy_deferred;
2732 }
2733 }
2734
2735 /* If message_defer is set (host was OK, but every recipient got deferred
2736 because of some message-specific problem), or if that had happened
2737 previously so that a message retry key exists, add an appropriate item
2738 to the retry chain. Note that if there was a message defer but now there is
2739 a host defer, the message defer record gets deleted. That seems perfectly
2740 reasonable. Also, stop the message from being remembered as waiting
2741 for this host. */
2742
2743 if (message_defer || retry_message_key != NULL)
2744 {
2745 int delete_flag = message_defer? 0 : rf_delete;
2746 if (retry_message_key == NULL)
2747 {
2748 retry_message_key = ob->retry_include_ip_address?
2749 string_sprintf("T:%S:%s%s:%s", host->name, host->address, pistring,
2750 message_id) :
2751 string_sprintf("T:%S%s:%s", host->name, pistring, message_id);
2752 }
2753 retry_add_item(addrlist, retry_message_key,
2754 rf_message | rf_host | delete_flag);
2755 host->update_waiting = FALSE;
2756 }
2757
2758 /* Any return other than DEFER (that is, OK or ERROR) means that the
2759 addresses have got their final statuses filled in for this host. In the OK
2760 case, see if any of them are deferred. */
2761
2762 if (rc == OK)
2763 {
2764 for (addr = addrlist; addr != NULL; addr = addr->next)
2765 {
2766 if (addr->transport_return == DEFER)
2767 {
2768 some_deferred = TRUE;
2769 break;
2770 }
2771 }
2772 }
2773
2774 /* If no addresses deferred or the result was ERROR, return. We do this for
2775 ERROR because a failing filter set-up or add_headers expansion is likely to
2776 fail for any host we try. */
2777
2778 if (rc == ERROR || (rc == OK && !some_deferred))
2779 {
2780 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2781 return TRUE; /* Each address has its status */
2782 }
2783
2784 /* If the result was DEFER or some individual addresses deferred, let
2785 the loop run to try other hosts with the deferred addresses, except for the
2786 case when we were trying to deliver down an existing channel and failed.
2787 Don't try any other hosts in this case. */
2788
2789 if (continuing) break;
2790
2791 /* If the whole delivery, or some individual addresses, were deferred and
2792 there are more hosts that could be tried, do not count this host towards
2793 the hosts_max_try limit if the age of the message is greater than the
2794 maximum retry time for this host. This means we may try try all hosts,
2795 ignoring the limit, when messages have been around for some time. This is
2796 important because if we don't try all hosts, the address will never time
2797 out. NOTE: this does not apply to hosts_max_try_hardlimit. */
2798
2799 if ((rc == DEFER || some_deferred) && nexthost != NULL)
2800 {
2801 BOOL timedout;
2802 retry_config *retry = retry_find_config(host->name, NULL, 0, 0);
2803
2804 if (retry != NULL && retry->rules != NULL)
2805 {
2806 retry_rule *last_rule;
2807 for (last_rule = retry->rules;
2808 last_rule->next != NULL;
2809 last_rule = last_rule->next);
2810 timedout = time(NULL) - received_time > last_rule->timeout;
2811 }
2812 else timedout = TRUE; /* No rule => timed out */
2813
2814 if (timedout)
2815 {
2816 unexpired_hosts_tried--;
2817 DEBUG(D_transport) debug_printf("temporary delivery error(s) override "
2818 "hosts_max_try (message older than host's retry time)\n");
2819 }
2820 }
2821 } /* End of loop for trying multiple hosts. */
2822
2823 /* This is the end of the loop that repeats iff expired is TRUE and
2824 ob->delay_after_cutoff is FALSE. The second time round we will
2825 try those hosts that haven't been tried since the message arrived. */
2826
2827 DEBUG(D_transport)
2828 {
2829 debug_printf("all IP addresses skipped or deferred at least one address\n");
2830 if (expired && !ob->delay_after_cutoff && cutoff_retry == 0)
2831 debug_printf("retrying IP addresses not tried since message arrived\n");
2832 }
2833 }
2834
2835
2836 /* Get here if all IP addresses are skipped or defer at least one address. In
2837 MUA wrapper mode, this will happen only for connection or other non-message-
2838 specific failures. Force the delivery status for all addresses to FAIL. */
2839
2840 if (mua_wrapper)
2841 {
2842 for (addr = addrlist; addr != NULL; addr = addr->next)
2843 addr->transport_return = FAIL;
2844 goto END_TRANSPORT;
2845 }
2846
2847 /* In the normal, non-wrapper case, add a standard message to each deferred
2848 address if there hasn't been an error, that is, if it hasn't actually been
2849 tried this time. The variable "expired" will be FALSE if any deliveries were
2850 actually tried, or if there was at least one host that was not expired. That
2851 is, it is TRUE only if no deliveries were tried and all hosts were expired. If
2852 a delivery has been tried, an error code will be set, and the failing of the
2853 message is handled by the retry code later.
2854
2855 If queue_smtp is set, or this transport was called to send a subsequent message
2856 down an existing TCP/IP connection, and something caused the host not to be
2857 found, we end up here, but can detect these cases and handle them specially. */
2858
2859 for (addr = addrlist; addr != NULL; addr = addr->next)
2860 {
2861 /* If host is not NULL, it means that we stopped processing the host list
2862 because of hosts_max_try or hosts_max_try_hardlimit. In the former case, this
2863 means we need to behave as if some hosts were skipped because their retry
2864 time had not come. Specifically, this prevents the address from timing out.
2865 However, if we have hit hosts_max_try_hardlimit, we want to behave as if all
2866 hosts were tried. */
2867
2868 if (host != NULL)
2869 {
2870 if (total_hosts_tried >= ob->hosts_max_try_hardlimit)
2871 {
2872 DEBUG(D_transport)
2873 debug_printf("hosts_max_try_hardlimit reached: behave as if all "
2874 "hosts were tried\n");
2875 }
2876 else
2877 {
2878 DEBUG(D_transport)
2879 debug_printf("hosts_max_try limit caused some hosts to be skipped\n");
2880 setflag(addr, af_retry_skipped);
2881 }
2882 }
2883
2884 if (queue_smtp) /* no deliveries attempted */
2885 {
2886 addr->transport_return = DEFER;
2887 addr->basic_errno = 0;
2888 addr->message = US"SMTP delivery explicitly queued";
2889 }
2890
2891 else if (addr->transport_return == DEFER &&
2892 (addr->basic_errno == ERRNO_UNKNOWNERROR || addr->basic_errno == 0) &&
2893 addr->message == NULL)
2894 {
2895 addr->basic_errno = ERRNO_HRETRY;
2896 if (continue_hostname != NULL)
2897 {
2898 addr->message = US"no host found for existing SMTP connection";
2899 }
2900 else if (expired)
2901 {
2902 setflag(addr, af_pass_message); /* This is not a security risk */
2903 addr->message = (ob->delay_after_cutoff)?
2904 US"retry time not reached for any host after a long failure period" :
2905 US"all hosts have been failing for a long time and were last tried "
2906 "after this message arrived";
2907
2908 /* If we are already using fallback hosts, or there are no fallback hosts
2909 defined, convert the result to FAIL to cause a bounce. */
2910
2911 if (addr->host_list == addr->fallback_hosts ||
2912 addr->fallback_hosts == NULL)
2913 addr->transport_return = FAIL;
2914 }
2915 else
2916 {
2917 if (hosts_retry == hosts_total)
2918 addr->message = US"retry time not reached for any host";
2919 else if (hosts_fail == hosts_total)
2920 addr->message = US"all host address lookups failed permanently";
2921 else if (hosts_defer == hosts_total)
2922 addr->message = US"all host address lookups failed temporarily";
2923 else if (hosts_serial == hosts_total)
2924 addr->message = US"connection limit reached for all hosts";
2925 else if (hosts_fail+hosts_defer == hosts_total)
2926 addr->message = US"all host address lookups failed";
2927 else addr->message = US"some host address lookups failed and retry time "
2928 "not reached for other hosts or connection limit reached";
2929 }
2930 }
2931 }
2932
2933 /* Update the database which keeps information about which messages are waiting
2934 for which hosts to become available. Each host in the list has a flag which is
2935 set if the data is to be updated. For some message-specific errors, the flag is
2936 turned off because we don't want follow-on deliveries in those cases. */
2937
2938 transport_update_waiting(hostlist, tblock->name);
2939
2940 END_TRANSPORT:
2941
2942 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2943
2944 return TRUE; /* Each address has its status */
2945 }
2946
2947 /* End of transport/smtp.c */