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[exim.git] / src / src / transports / smtp.c
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1/* $Cambridge: exim/src/src/transports/smtp.c,v 1.1 2004/10/07 13:10:02 ph10 Exp $ */
2
3/*************************************************
4* Exim - an Internet mail transport agent *
5*************************************************/
6
7/* Copyright (c) University of Cambridge 1995 - 2004 */
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
19over TCP/IP. The options must be in alphabetic order (note that "_" comes
20before the lower case letters). Some live in the transport_instance block so as
21to be publicly visible; these are flagged with opt_public. */
22
23optionlist 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 { "command_timeout", opt_time,
29 (void *)offsetof(smtp_transport_options_block, command_timeout) },
30 { "connect_timeout", opt_time,
31 (void *)offsetof(smtp_transport_options_block, connect_timeout) },
32 { "connection_max_messages", opt_int | opt_public,
33 (void *)offsetof(transport_instance, connection_max_messages) },
34 { "data_timeout", opt_time,
35 (void *)offsetof(smtp_transport_options_block, data_timeout) },
36 { "delay_after_cutoff", opt_bool,
37 (void *)offsetof(smtp_transport_options_block, delay_after_cutoff) },
38 { "dns_qualify_single", opt_bool,
39 (void *)offsetof(smtp_transport_options_block, dns_qualify_single) },
40 { "dns_search_parents", opt_bool,
41 (void *)offsetof(smtp_transport_options_block, dns_search_parents) },
42 { "fallback_hosts", opt_stringptr,
43 (void *)offsetof(smtp_transport_options_block, fallback_hosts) },
44 { "final_timeout", opt_time,
45 (void *)offsetof(smtp_transport_options_block, final_timeout) },
46 { "gethostbyname", opt_bool,
47 (void *)offsetof(smtp_transport_options_block, gethostbyname) },
48 { "helo_data", opt_stringptr,
49 (void *)offsetof(smtp_transport_options_block, helo_data) },
50 { "hosts", opt_stringptr,
51 (void *)offsetof(smtp_transport_options_block, hosts) },
52 { "hosts_avoid_esmtp", opt_stringptr,
53 (void *)offsetof(smtp_transport_options_block, hosts_avoid_esmtp) },
54 #ifdef SUPPORT_TLS
55 { "hosts_avoid_tls", opt_stringptr,
56 (void *)offsetof(smtp_transport_options_block, hosts_avoid_tls) },
57 #endif
58 { "hosts_max_try", opt_int,
59 (void *)offsetof(smtp_transport_options_block, hosts_max_try) },
60 #ifdef SUPPORT_TLS
61 { "hosts_nopass_tls", opt_stringptr,
62 (void *)offsetof(smtp_transport_options_block, hosts_nopass_tls) },
63 #endif
64 { "hosts_override", opt_bool,
65 (void *)offsetof(smtp_transport_options_block, hosts_override) },
66 { "hosts_randomize", opt_bool,
67 (void *)offsetof(smtp_transport_options_block, hosts_randomize) },
68 { "hosts_require_auth", opt_stringptr,
69 (void *)offsetof(smtp_transport_options_block, hosts_require_auth) },
70 #ifdef SUPPORT_TLS
71 { "hosts_require_tls", opt_stringptr,
72 (void *)offsetof(smtp_transport_options_block, hosts_require_tls) },
73 #endif
74 { "hosts_try_auth", opt_stringptr,
75 (void *)offsetof(smtp_transport_options_block, hosts_try_auth) },
76 { "interface", opt_stringptr,
77 (void *)offsetof(smtp_transport_options_block, interface) },
78 { "keepalive", opt_bool,
79 (void *)offsetof(smtp_transport_options_block, keepalive) },
80 { "max_rcpt", opt_int | opt_public,
81 (void *)offsetof(transport_instance, max_addresses) },
82 { "multi_domain", opt_bool | opt_public,
83 (void *)offsetof(transport_instance, multi_domain) },
84 { "port", opt_stringptr,
85 (void *)offsetof(smtp_transport_options_block, port) },
86 { "protocol", opt_stringptr,
87 (void *)offsetof(smtp_transport_options_block, protocol) },
88 { "retry_include_ip_address", opt_bool,
89 (void *)offsetof(smtp_transport_options_block, retry_include_ip_address) },
90 { "serialize_hosts", opt_stringptr,
91 (void *)offsetof(smtp_transport_options_block, serialize_hosts) },
92 { "size_addition", opt_int,
93 (void *)offsetof(smtp_transport_options_block, size_addition) }
94 #ifdef SUPPORT_TLS
95 ,{ "tls_certificate", opt_stringptr,
96 (void *)offsetof(smtp_transport_options_block, tls_certificate) },
97 { "tls_crl", opt_stringptr,
98 (void *)offsetof(smtp_transport_options_block, tls_crl) },
99 { "tls_privatekey", opt_stringptr,
100 (void *)offsetof(smtp_transport_options_block, tls_privatekey) },
101 { "tls_require_ciphers", opt_stringptr,
102 (void *)offsetof(smtp_transport_options_block, tls_require_ciphers) },
103 { "tls_tempfail_tryclear", opt_bool,
104 (void *)offsetof(smtp_transport_options_block, tls_tempfail_tryclear) },
105 { "tls_verify_certificates", opt_stringptr,
106 (void *)offsetof(smtp_transport_options_block, tls_verify_certificates) }
107 #endif
108};
109
110/* Size of the options list. An extern variable has to be used so that its
111address can appear in the tables drtables.c. */
112
113int smtp_transport_options_count =
114 sizeof(smtp_transport_options)/sizeof(optionlist);
115
116/* Default private options block for the smtp transport. */
117
118smtp_transport_options_block smtp_transport_option_defaults = {
119 NULL, /* hosts */
120 NULL, /* fallback_hosts */
121 NULL, /* hostlist */
122 NULL, /* fallback_hostlist */
123 NULL, /* authenticated_sender */
124 US"$primary_hostname", /* helo_data */
125 NULL, /* interface */
126 NULL, /* port */
127 US"smtp", /* protocol */
128 NULL, /* serialize_hosts */
129 NULL, /* hosts_try_auth */
130 NULL, /* hosts_require_auth */
131 NULL, /* hosts_require_tls */
132 NULL, /* hosts_avoid_tls */
133 NULL, /* hosts_avoid_esmtp */
134 NULL, /* hosts_nopass_tls */
135 5*60, /* command_timeout */
136 5*60, /* connect_timeout; shorter system default overrides */
137 5*60, /* data timeout */
138 10*60, /* final timeout */
139 1024, /* size_addition */
140 5, /* hosts_max_try */
141 FALSE, /* allow_localhost */
142 FALSE, /* gethostbyname */
143 TRUE, /* dns_qualify_single */
144 FALSE, /* dns_search_parents */
145 TRUE, /* delay_after_cutoff */
146 FALSE, /* hosts_override */
147 FALSE, /* hosts_randomize */
148 TRUE, /* keepalive */
149 TRUE /* retry_include_ip_address */
150 #ifdef SUPPORT_TLS
151 ,NULL, /* tls_certificate */
152 NULL, /* tls_crl */
153 NULL, /* tls_privatekey */
154 NULL, /* tls_require_ciphers */
155 NULL, /* tls_verify_certificates */
156 TRUE /* tls_tempfail_tryclear */
157 #endif
158};
159
160
161/* Local statics */
162
163static uschar *smtp_command; /* Points to last cmd for error messages */
164static uschar *mail_command; /* Points to MAIL cmd for error messages */
165
166
167/*************************************************
168* Setup entry point *
169*************************************************/
170
171/* This function is called when the transport is about to be used,
172but before running it in a sub-process. It is used for two things:
173
174 (1) To set the fallback host list in addresses, when delivering.
175 (2) To pass back the interface, port, and protocol options, for use during
176 callout verification.
177
178Arguments:
179 tblock pointer to the transport instance block
180 addrlist list of addresses about to be transported
181 tf if not NULL, pointer to block in which to return options
182 errmsg place for error message (not used)
183
184Returns: OK always (FAIL, DEFER not used)
185*/
186
187static int
188smtp_transport_setup(transport_instance *tblock, address_item *addrlist,
189 transport_feedback *tf, uschar **errmsg)
190{
191smtp_transport_options_block *ob =
192 (smtp_transport_options_block *)(tblock->options_block);
193
194errmsg = errmsg; /* Keep picky compilers happy */
195
196/* Pass back options if required. This interface is getting very messy. */
197
198if (tf != NULL)
199 {
200 tf->interface = ob->interface;
201 tf->port = ob->port;
202 tf->protocol = ob->protocol;
203 tf->hosts = ob->hosts;
204 tf->hosts_override = ob->hosts_override;
205 tf->hosts_randomize = ob->hosts_randomize;
206 tf->gethostbyname = ob->gethostbyname;
207 tf->qualify_single = ob->dns_qualify_single;
208 tf->search_parents = ob->dns_search_parents;
209 }
210
211/* Set the fallback host list for all the addresses that don't have fallback
212host lists, provided that the local host wasn't present in the original host
213list. */
214
215if (!testflag(addrlist, af_local_host_removed))
216 {
217 for (; addrlist != NULL; addrlist = addrlist->next)
218 if (addrlist->fallback_hosts == NULL)
219 addrlist->fallback_hosts = ob->fallback_hostlist;
220 }
221
222return OK;
223}
224
225
226
227/*************************************************
228* Initialization entry point *
229*************************************************/
230
231/* Called for each instance, after its options have been read, to
232enable consistency checks to be done, or anything else that needs
233to be set up.
234
235Argument: pointer to the transport instance block
236Returns: nothing
237*/
238
239void
240smtp_transport_init(transport_instance *tblock)
241{
242smtp_transport_options_block *ob =
243 (smtp_transport_options_block *)(tblock->options_block);
244
245/* Retry_use_local_part defaults FALSE if unset */
246
247if (tblock->retry_use_local_part == TRUE_UNSET)
248 tblock->retry_use_local_part = FALSE;
249
250/* Set the default port according to the protocol */
251
252if (ob->port == NULL)
253 ob->port = (strcmpic(ob->protocol, US"lmtp") == 0)? US"lmtp" : US"smtp";
254
255/* Set up the setup entry point, to be called before subprocesses for this
256transport. */
257
258tblock->setup = smtp_transport_setup;
259
260/* Complain if any of the timeouts are zero. */
261
262if (ob->command_timeout <= 0 || ob->data_timeout <= 0 ||
263 ob->final_timeout <= 0)
264 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
265 "command, data, or final timeout value is zero for %s transport",
266 tblock->name);
267
268/* If hosts_override is set and there are local hosts, set the global
269flag that stops verify from showing router hosts. */
270
271if (ob->hosts_override && ob->hosts != NULL) tblock->overrides_hosts = TRUE;
272
273/* If there are any fallback hosts listed, build a chain of host items
274for them, but do not do any lookups at this time. */
275
276host_build_hostlist(&(ob->fallback_hostlist), ob->fallback_hosts, FALSE);
277}
278
279
280
281
282
283/*************************************************
284* Set delivery info into all active addresses *
285*************************************************/
286
287/* Only addresses whose status is >= PENDING are relevant. A lesser
288status means that an address is not currently being processed.
289
290Arguments:
291 addrlist points to a chain of addresses
292 errno_value to put in each address's errno field
293 msg to put in each address's message field
294 rc to put in each address's transport_return field
295
296If errno_value has the special value ERRNO_CONNECTTIMEOUT, ETIMEDOUT is put in
297the errno field, and RTEF_CTOUT is ORed into the more_errno field, to indicate
298this particular type of timeout.
299
300Returns: nothing
301*/
302
303static
304void set_errno(address_item *addrlist, int errno_value, uschar *msg, int rc)
305{
306address_item *addr;
307int orvalue = 0;
308if (errno_value == ERRNO_CONNECTTIMEOUT)
309 {
310 errno_value = ETIMEDOUT;
311 orvalue = RTEF_CTOUT;
312 }
313for (addr = addrlist; addr != NULL; addr = addr->next)
314 {
315 if (addr->transport_return < PENDING) continue;
316 addr->basic_errno = errno_value;
317 addr->more_errno |= orvalue;
318 if (msg != NULL) addr->message = msg;
319 addr->transport_return = rc;
320 }
321}
322
323
324
325/*************************************************
326* Check an SMTP response *
327*************************************************/
328
329/* This function is given an errno code and the SMTP response buffer
330to analyse, together with the host identification for generating messages. It
331sets an appropriate message and puts the first digit of the response code into
332the yield variable. If no response was actually read, a suitable digit is
333chosen.
334
335Arguments:
336 host the current host, to get its name for messages
337 errno_value pointer to the errno value
338 more_errno from the top address for use with ERRNO_FILTER_FAIL
339 buffer the SMTP response buffer
340 yield where to put a one-digit SMTP response code
341 message where to put an errror message
342
343Returns: TRUE if an SMTP "QUIT" command should be sent, else FALSE
344*/
345
346static BOOL check_response(host_item *host, int *errno_value, int more_errno,
347 uschar *buffer, int *yield, uschar **message)
348{
349uschar *pl = US"";
350
351if (smtp_use_pipelining &&
352 (Ustrcmp(smtp_command, "MAIL") == 0 ||
353 Ustrcmp(smtp_command, "RCPT") == 0 ||
354 Ustrcmp(smtp_command, "DATA") == 0))
355 pl = US"pipelined ";
356
357*yield = '4'; /* Default setting is to give a temporary error */
358
359/* Handle response timeout */
360
361if (*errno_value == ETIMEDOUT)
362 {
363 *message = US string_sprintf("SMTP timeout while connected to %s [%s] "
364 "after %s%s", host->name, host->address, pl, smtp_command);
365 if (transport_count > 0)
366 *message = US string_sprintf("%s (%d bytes written)", *message,
367 transport_count);
368 return FALSE;
369 }
370
371/* Handle malformed SMTP response */
372
373if (*errno_value == ERRNO_SMTPFORMAT)
374 {
375 uschar *malfresp = string_printing(buffer);
376 while (isspace(*malfresp)) malfresp++;
377 if (*malfresp == 0)
378 *message = string_sprintf("Malformed SMTP reply (an empty line) from "
379 "%s [%s] in response to %s%s", host->name, host->address, pl,
380 smtp_command);
381 else
382 *message = string_sprintf("Malformed SMTP reply from %s [%s] in response "
383 "to %s%s: %s", host->name, host->address, pl, smtp_command, malfresp);
384 return FALSE;
385 }
386
387/* Handle a failed filter process error; can't send QUIT as we mustn't
388end the DATA. */
389
390if (*errno_value == ERRNO_FILTER_FAIL)
391 {
392 *message = US string_sprintf("transport filter process failed (%d)",
393 more_errno);
394 return FALSE;
395 }
396
397/* Handle a failed add_headers expansion; can't send QUIT as we mustn't
398end the DATA. */
399
400if (*errno_value == ERRNO_CHHEADER_FAIL)
401 {
402 *message =
403 US string_sprintf("failed to expand headers_add or headers_remove: %s",
404 expand_string_message);
405 return FALSE;
406 }
407
408/* Handle failure to write a complete data block */
409
410if (*errno_value == ERRNO_WRITEINCOMPLETE)
411 {
412 *message = US string_sprintf("failed to write a data block");
413 return FALSE;
414 }
415
416/* Handle error responses from the remote mailer. */
417
418if (buffer[0] != 0)
419 {
420 uschar *s = string_printing(buffer);
421 *message = US string_sprintf("SMTP error from remote mailer after %s%s: "
422 "host %s [%s]: %s", pl, smtp_command, host->name, host->address, s);
423 *yield = buffer[0];
424 return TRUE;
425 }
426
427/* No data was read. If there is no errno, this must be the EOF (i.e.
428connection closed) case, which causes deferral. Otherwise, put the host's
429identity in the message, leaving the errno value to be interpreted as well. In
430all cases, we have to assume the connection is now dead. */
431
432if (*errno_value == 0)
433 {
434 *errno_value = ERRNO_SMTPCLOSED;
435 *message = US string_sprintf("Remote host %s [%s] closed connection "
436 "in response to %s%s", host->name, host->address, pl, smtp_command);
437 }
438else *message = US string_sprintf("%s [%s]", host->name, host->address);
439
440return FALSE;
441}
442
443
444
445/*************************************************
446* Write error message to logs *
447*************************************************/
448
449/* This writes to the main log and to the message log.
450
451Arguments:
452 addr the address item containing error information
453 host the current host
454
455Returns: nothing
456*/
457
458static void
459write_logs(address_item *addr, host_item *host)
460{
461if (addr->message != NULL)
462 {
463 uschar *message = addr->message;
464 if (addr->basic_errno > 0)
465 message = string_sprintf("%s: %s", message, strerror(addr->basic_errno));
466 log_write(0, LOG_MAIN, "%s", message);
467 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
468 }
469else
470 {
471 log_write(0, LOG_MAIN, "%s [%s]: %s",
472 host->name,
473 host->address,
474 strerror(addr->basic_errno));
475 deliver_msglog("%s %s [%s]: %s\n",
476 tod_stamp(tod_log),
477 host->name,
478 host->address,
479 strerror(addr->basic_errno));
480 }
481}
482
483
484
485/*************************************************
486* Synchronize SMTP responses *
487*************************************************/
488
489/* This function is called from smtp_deliver() to receive SMTP responses from
490the server, and match them up with the commands to which they relate. When
491PIPELINING is not in use, this function is called after every command, and is
492therefore somewhat over-engineered, but it is simpler to use a single scheme
493that works both with and without PIPELINING instead of having two separate sets
494of code.
495
496The set of commands that are buffered up with pipelining may start with MAIL
497and may end with DATA; in between are RCPT commands that correspond to the
498addresses whose status is PENDING_DEFER. All other commands (STARTTLS, AUTH,
499etc.) are never buffered.
500
501Errors after MAIL or DATA abort the whole process leaving the response in the
502buffer. After MAIL, pending responses are flushed, and the original command is
503re-instated in big_buffer for error messages. For RCPT commands, the remote is
504permitted to reject some recipient addresses while accepting others. However
505certain errors clearly abort the whole process. Set the value in
506transport_return to PENDING_OK if the address is accepted. If there is a
507subsequent general error, it will get reset accordingly. If not, it will get
508converted to OK at the end.
509
510Arguments:
511 addrlist the complete address list
512 include_affixes TRUE if affixes include in RCPT
513 sync_addr ptr to the ptr of the one to start scanning at (updated)
514 host the host we are connected to
515 count the number of responses to read
516 pending_MAIL true if the first response is for MAIL
517 pending_DATA 0 if last command sent was not DATA
518 +1 if previously had a good recipient
519 -1 if not previously had a good recipient
520 inblock incoming SMTP block
521 timeout timeout value
522 buffer buffer for reading response
523 buffsize size of buffer
524
525Returns: 3 if at least one address had 2xx and one had 5xx
526 2 if at least one address had 5xx but none had 2xx
527 1 if at least one host had a 2xx response, but none had 5xx
528 0 no address had 2xx or 5xx but no errors (all 4xx, or just DATA)
529 -1 timeout while reading RCPT response
530 -2 I/O or other non-response error for RCPT
531 -3 DATA or MAIL failed - errno and buffer set
532*/
533
534static int
535sync_responses(address_item *addrlist, BOOL include_affixes,
536 address_item **sync_addr, host_item *host, int count, BOOL pending_MAIL,
537 int pending_DATA, smtp_inblock *inblock, int timeout, uschar *buffer,
538 int buffsize)
539{
540address_item *addr = *sync_addr;
541int yield = 0;
542
543/* Handle the response for a MAIL command. On error, reinstate the original
544command in big_buffer for error message use, and flush any further pending
545responses before returning, except after I/O errors and timeouts. */
546
547if (pending_MAIL)
548 {
549 count--;
550 if (!smtp_read_response(inblock, buffer, buffsize, '2', timeout))
551 {
552 Ustrcpy(big_buffer, mail_command); /* Fits, because it came from there! */
553 if (errno == 0 && buffer[0] != 0)
554 {
555 uschar flushbuffer[4096];
556 while (count-- > 0)
557 {
558 if (!smtp_read_response(inblock, flushbuffer, sizeof(flushbuffer),
559 '2', timeout)
560 && (errno != 0 || flushbuffer[0] == 0))
561 break;
562 }
563 }
564 return -3;
565 }
566 }
567
568if (pending_DATA) count--; /* Number of RCPT responses to come */
569
570/* Read and handle the required number of RCPT responses, matching each one up
571with an address by scanning for the next address whose status is PENDING_DEFER.
572*/
573
574while (count-- > 0)
575 {
576 while (addr->transport_return != PENDING_DEFER) addr = addr->next;
577
578 /* The address was accepted */
579
580 if (smtp_read_response(inblock, buffer, buffsize, '2', timeout))
581 {
582 yield |= 1;
583 addr->transport_return = PENDING_OK;
584
585 /* If af_dr_retry_exists is set, there was a routing delay on this address;
586 ensure that any address-specific retry record is expunged. */
587
588 if (testflag(addr, af_dr_retry_exists))
589 retry_add_item(addr, addr->address_retry_key, rf_delete);
590 }
591
592 /* Timeout while reading the response */
593
594 else if (errno == ETIMEDOUT)
595 {
596 int save_errno = errno;
597 uschar *message = string_sprintf("SMTP timeout while connected to %s [%s] "
598 "after RCPT TO:<%s>", host->name, host->address,
599 transport_rcpt_address(addr, include_affixes));
600 set_errno(addrlist, save_errno, message, DEFER);
601 retry_add_item(addr, addr->address_retry_key, 0);
602 host->update_waiting = FALSE;
603 return -1;
604 }
605
606 /* Handle other errors in obtaining an SMTP response by returning -1. This
607 will cause all the addresses to be deferred. Restore the SMTP command in
608 big_buffer for which we are checking the response, so the error message
609 makes sense. */
610
611 else if (errno != 0 || buffer[0] == 0)
612 {
613 string_format(big_buffer, big_buffer_size, "RCPT TO:<%s>",
614 transport_rcpt_address(addr, include_affixes));
615 return -2;
616 }
617
618 /* Handle SMTP permanent and temporary response codes. */
619
620 else
621 {
622 addr->message =
623 string_sprintf("SMTP error from remote mailer after RCPT TO:<%s>: "
624 "host %s [%s]: %s", transport_rcpt_address(addr, include_affixes),
625 host->name, host->address, string_printing(buffer));
626 deliver_msglog("%s %s\n", tod_stamp(tod_log), addr->message);
627
628 /* The response was 5xx */
629
630 if (buffer[0] == '5')
631 {
632 addr->transport_return = FAIL;
633 yield |= 2;
634 }
635
636 /* The response was 4xx */
637
638 else
639 {
640 int bincode = (buffer[1] - '0')*10 + buffer[2] - '0';
641
642 addr->transport_return = DEFER;
643 addr->basic_errno = ERRNO_RCPT4XX;
644 addr->more_errno |= bincode << 8;
645
646 /* Log temporary errors if there are more hosts to be tried. */
647
648 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", addr->message);
649
650 /* Do not put this message on the list of those waiting for this host,
651 as otherwise it is likely to be tried too often. */
652
653 host->update_waiting = FALSE;
654
655 /* Add a retry item for the address so that it doesn't get tried
656 again too soon. */
657
658 retry_add_item(addr, addr->address_retry_key, 0);
659 }
660 }
661 } /* Loop for next RCPT response */
662
663/* Update where to start at for the next block of responses, unless we
664have already handled all the addresses. */
665
666if (addr != NULL) *sync_addr = addr->next;
667
668/* Handle a response to DATA. If we have not had any good recipients, either
669previously or in this block, the response is ignored. */
670
671if (pending_DATA != 0 &&
672 !smtp_read_response(inblock, buffer, buffsize, '3', timeout))
673 {
674 int code;
675 uschar *msg;
676 if (pending_DATA > 0 || (yield & 1) != 0) return -3;
677 (void)check_response(host, &errno, 0, buffer, &code, &msg);
678 DEBUG(D_transport) debug_printf("%s\nerror for DATA ignored: pipelining "
679 "is in use and there were no good recipients\n", msg);
680 }
681
682/* All responses read and handled; MAIL (if present) received 2xx and DATA (if
683present) received 3xx. If any RCPTs were handled and yielded anything other
684than 4xx, yield will be set non-zero. */
685
686return yield;
687}
688
689
690
691/*************************************************
692* Deliver address list to given host *
693*************************************************/
694
695/* If continue_hostname is not null, we get here only when continuing to
696deliver down an existing channel. The channel was passed as the standard
697input.
698
699Otherwise, we have to make a connection to the remote host, and do the
700initial protocol exchange.
701
702When running as an MUA wrapper, if the sender or any recipient is rejected,
703temporarily or permanently, we force failure for all recipients.
704
705Arguments:
706 addrlist chain of potential addresses to deliver; only those whose
707 transport_return field is set to PENDING_DEFER are currently
708 being processed; others should be skipped - they have either
709 been delivered to an earlier host or IP address, or been
710 failed by one of them.
711 host host to deliver to
712 host_af AF_INET or AF_INET6
713 port TCP/IP port to use, in host byte order
714 interface interface to bind to, or NULL
715 tblock transport instance block
716 copy_host TRUE if host set in addr->host_used must be copied, because
717 it is specific to this call of the transport
718 message_defer set TRUE if yield is OK, but all addresses were deferred
719 because of a non-recipient, non-host failure, that is, a
720 4xx response to MAIL FROM, DATA, or ".". This is a defer
721 that is specific to the message.
722 suppress_tls if TRUE, don't attempt a TLS connection - this is set for
723 a second attempt after TLS initialization fails
724
725Returns: OK - the connection was made and the delivery attempted;
726 the result for each address is in its data block.
727 DEFER - the connection could not be made, or something failed
728 while setting up the SMTP session, or there was a
729 non-message-specific error, such as a timeout.
730 ERROR - a filter command is specified for this transport,
731 and there was a problem setting it up; OR helo_data
732 or add_headers or authenticated_sender is specified
733 for this transport, and the string failed to expand
734*/
735
736static int
737smtp_deliver(address_item *addrlist, host_item *host, int host_af, int port,
738 uschar *interface, transport_instance *tblock, BOOL copy_host,
739 BOOL *message_defer, BOOL suppress_tls)
740{
741address_item *addr;
742address_item *sync_addr;
743address_item *first_addr = addrlist;
744int yield = OK;
745int address_count;
746int save_errno;
747int rc;
748time_t start_delivery_time = time(NULL);
749smtp_transport_options_block *ob =
750 (smtp_transport_options_block *)(tblock->options_block);
751BOOL lmtp = strcmpic(ob->protocol, US"lmtp") == 0;
752BOOL ok = FALSE;
753BOOL send_rset = TRUE;
754BOOL send_quit = TRUE;
755BOOL setting_up = TRUE;
756BOOL completed_address = FALSE;
757BOOL esmtp = TRUE;
758BOOL pending_MAIL;
759smtp_inblock inblock;
760smtp_outblock outblock;
761int max_rcpt = tblock->max_addresses;
762uschar *local_authenticated_sender = authenticated_sender;
763uschar *helo_data;
764uschar *message = NULL;
765uschar new_message_id[MESSAGE_ID_LENGTH + 1];
766uschar *p;
767uschar buffer[4096];
768uschar inbuffer[4096];
769uschar outbuffer[1024];
770
771suppress_tls = suppress_tls; /* stop compiler warning when no TLS support */
772
773*message_defer = FALSE;
774smtp_command = US"initial connection";
775if (max_rcpt == 0) max_rcpt = 999999;
776
777/* Set up the buffer for reading SMTP response packets. */
778
779inblock.buffer = inbuffer;
780inblock.buffersize = sizeof(inbuffer);
781inblock.ptr = inbuffer;
782inblock.ptrend = inbuffer;
783
784/* Set up the buffer for holding SMTP commands while pipelining */
785
786outblock.buffer = outbuffer;
787outblock.buffersize = sizeof(outbuffer);
788outblock.ptr = outbuffer;
789outblock.cmd_count = 0;
790outblock.authenticating = FALSE;
791
792/* Expand the greeting message */
793
794helo_data = expand_string(ob->helo_data);
795if (helo_data == NULL)
796 {
797 uschar *message = string_sprintf("failed to expand helo_data: %s",
798 expand_string_message);
799 set_errno(addrlist, 0, message, DEFER);
800 return ERROR;
801 }
802
803/* If an authenticated_sender override has been specified for this transport
804instance, expand it. If the expansion is forced to fail, and there was already
805an authenticated_sender for this message, the original value will be used.
806Other expansion failures are serious. An empty result is ignored, but there is
807otherwise no check - this feature is expected to be used with LMTP and other
808cases where non-standard addresses (e.g. without domains) might be required. */
809
810if (ob->authenticated_sender != NULL)
811 {
812 uschar *new = expand_string(ob->authenticated_sender);
813 if (new == NULL)
814 {
815 if (!expand_string_forcedfail)
816 {
817 uschar *message = string_sprintf("failed to expand "
818 "authenticated_sender: %s", expand_string_message);
819 set_errno(addrlist, 0, message, DEFER);
820 return ERROR;
821 }
822 }
823 else if (new[0] != 0) local_authenticated_sender = new;
824 }
825
826/* Make a connection to the host if this isn't a continued delivery, and handle
827the initial interaction and HELO/EHLO/LHLO. Connect timeout errors are handled
828specially so they can be identified for retries. */
829
830if (continue_hostname == NULL)
831 {
832 inblock.sock = outblock.sock =
833 smtp_connect(host, host_af, port, interface, ob->connect_timeout,
834 ob->keepalive);
835 if (inblock.sock < 0)
836 {
837 set_errno(addrlist, (errno == ETIMEDOUT)? ERRNO_CONNECTTIMEOUT : errno,
838 NULL, DEFER);
839 return DEFER;
840 }
841
842 /* The first thing is to wait for an initial OK response. The dreaded "goto"
843 is nevertheless a reasonably clean way of programming this kind of logic,
844 where you want to escape on any error. */
845
846 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
847 ob->command_timeout)) goto RESPONSE_FAILED;
848
849/** Debugging without sending a message
850addrlist->transport_return = DEFER;
851goto SEND_QUIT;
852**/
853
854 /* Errors that occur after this point follow an SMTP command, which is
855 left in big_buffer by smtp_write_command() for use in error messages. */
856
857 smtp_command = big_buffer;
858
859 /* Tell the remote who we are...
860
861 February 1998: A convention has evolved that ESMTP-speaking MTAs include the
862 string "ESMTP" in their greeting lines, so make Exim send EHLO if the
863 greeting is of this form. The assumption was that the far end supports it
864 properly... but experience shows that there are some that give 5xx responses,
865 even though the banner includes "ESMTP" (there's a bloody-minded one that
866 says "ESMTP not spoken here"). Cope with that case.
867
868 September 2000: Time has passed, and it seems reasonable now to always send
869 EHLO at the start. It is also convenient to make the change while installing
870 the TLS stuff.
871
872 July 2003: Joachim Wieland met a broken server that advertises "PIPELINING"
873 but times out after sending MAIL FROM, RCPT TO and DATA all together. There
874 would be no way to send out the mails, so there is now a host list
875 "hosts_avoid_esmtp" that disables ESMTP for special hosts and solves the
876 PIPELINING problem as well. Maybe it can also be useful to cure other
877 problems with broken servers.
878
879 Exim originally sent "Helo" at this point and ran for nearly a year that way.
880 Then somebody tried it with a Microsoft mailer... It seems that all other
881 mailers use upper case for some reason (the RFC is quite clear about case
882 independence) so, for peace of mind, I gave in. */
883
884 esmtp = verify_check_this_host(&(ob->hosts_avoid_esmtp), NULL,
885 host->name, host->address, NULL) != OK;
886
887 if (esmtp)
888 {
889 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n",
890 lmtp? "LHLO" : "EHLO", helo_data) < 0)
891 goto SEND_FAILED;
892 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
893 ob->command_timeout))
894 {
895 if (errno != 0 || buffer[0] == 0 || lmtp) goto RESPONSE_FAILED;
896 esmtp = FALSE;
897 }
898 }
899 else
900 {
901 DEBUG(D_transport)
902 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
903 }
904
905 if (!esmtp)
906 {
907 if (smtp_write_command(&outblock, FALSE, "HELO %s\r\n", helo_data) < 0)
908 goto SEND_FAILED;
909 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
910 ob->command_timeout)) goto RESPONSE_FAILED;
911 }
912
913 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
914
915 #ifdef SUPPORT_TLS
916 tls_offered = esmtp &&
917 pcre_exec(regex_STARTTLS, NULL, CS buffer, Ustrlen(buffer), 0,
918 PCRE_EOPT, NULL, 0) >= 0;
919 #endif
920 }
921
922/* For continuing deliveries down the same channel, the socket is the standard
923input, and we don't need to redo EHLO here (but may need to do so for TLS - see
924below). Set up the pointer to where subsequent commands will be left, for
925error messages. Note that smtp_use_size and smtp_use_pipelining will have been
926set from the command line if they were set in the process that passed the
927connection on. */
928
929else
930 {
931 inblock.sock = outblock.sock = fileno(stdin);
932 smtp_command = big_buffer;
933 }
934
935/* If TLS is available on this connection, whether continued or not, attempt to
936start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
937send another EHLO - the server may give a different answer in secure mode. We
938use a separate buffer for reading the response to STARTTLS so that if it is
939negative, the original EHLO data is available for subsequent analysis, should
940the client not be required to use TLS. If the response is bad, copy the buffer
941for error analysis. */
942
943#ifdef SUPPORT_TLS
944if (tls_offered && !suppress_tls &&
945 verify_check_this_host(&(ob->hosts_avoid_tls), NULL, host->name,
946 host->address, NULL) != OK)
947 {
948 uschar buffer2[4096];
949 if (smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") < 0)
950 goto SEND_FAILED;
951
952 /* If there is an I/O error, transmission of this message is deferred. If
953 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
954 false, we also defer. However, if there is a temporary rejection of STARTTLS
955 and tls_tempfail_tryclear is true, or if there is an outright rejection of
956 STARTTLS, we carry on. This means we will try to send the message in clear,
957 unless the host is in hosts_require_tls (tested below). */
958
959 if (!smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
960 ob->command_timeout))
961 {
962 Ustrncpy(buffer, buffer2, sizeof(buffer));
963 if (errno != 0 || buffer2[0] == 0 ||
964 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
965 goto RESPONSE_FAILED;
966 }
967
968 /* STARTTLS accepted: try to negotiate a TLS session. */
969
970 else
971 {
972 int rc = tls_client_start(inblock.sock, host, addrlist,
973 NULL, /* No DH param */
974 ob->tls_certificate,
975 ob->tls_privatekey,
976 ob->tls_verify_certificates,
977 ob->tls_crl,
978 ob->tls_require_ciphers,
979 ob->command_timeout);
980
981 /* TLS negotiation failed; give an error. From outside, this function may
982 be called again to try in clear on a new connection, if the options permit
983 it for this host. */
984
985 if (rc != OK)
986 {
987 save_errno = ERRNO_TLSFAILURE;
988 message = US"failure while setting up TLS session";
989 send_quit = FALSE;
990 goto TLS_FAILED;
991 }
992
993 /* TLS session is set up */
994
995 for (addr = addrlist; addr != NULL; addr = addr->next)
996 {
997 addr->cipher = tls_cipher;
998 addr->peerdn = tls_peerdn;
999 }
1000 }
1001 }
1002
1003/* If we started TLS, redo the EHLO/LHLO exchange over the secure channel. */
1004
1005if (tls_active >= 0)
1006 {
1007 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n", lmtp? "LHLO" : "EHLO",
1008 helo_data) < 0)
1009 goto SEND_FAILED;
1010 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1011 ob->command_timeout))
1012 goto RESPONSE_FAILED;
1013 }
1014
1015/* If the host is required to use a secure channel, ensure that we
1016have one. */
1017
1018else if (verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
1019 host->address, NULL) == OK)
1020 {
1021 save_errno = ERRNO_TLSREQUIRED;
1022 message = string_sprintf("a TLS session is required for %s [%s], but %s",
1023 host->name, host->address,
1024 tls_offered? "an attempt to start TLS failed" :
1025 "the server did not offer TLS support");
1026 goto TLS_FAILED;
1027 }
1028#endif
1029
1030/* If TLS is active, we have just started it up and re-done the EHLO command,
1031so its response needs to be analyzed. If TLS is not active and this is a
1032continued session down a previously-used socket, we haven't just done EHLO, so
1033we skip this. */
1034
1035if (continue_hostname == NULL
1036 #ifdef SUPPORT_TLS
1037 || tls_active >= 0
1038 #endif
1039 )
1040 {
1041 int require_auth;
1042 uschar *fail_reason = US"server did not advertise AUTH support";
1043
1044 /* If the response to EHLO specified support for the SIZE parameter, note
1045 this, provided size_addition is non-negative. */
1046
1047 smtp_use_size = esmtp && ob->size_addition >= 0 &&
1048 pcre_exec(regex_SIZE, NULL, CS buffer, Ustrlen(CS buffer), 0,
1049 PCRE_EOPT, NULL, 0) >= 0;
1050
1051 /* Note whether the server supports PIPELINING. If hosts_avoid_esmtp matched
1052 the current host, esmtp will be false, so PIPELINING can never be used. */
1053
1054 smtp_use_pipelining = esmtp &&
1055 pcre_exec(regex_PIPELINING, NULL, CS buffer, Ustrlen(CS buffer), 0,
1056 PCRE_EOPT, NULL, 0) >= 0;
1057
1058 DEBUG(D_transport) debug_printf("%susing PIPELINING\n",
1059 smtp_use_pipelining? "" : "not ");
1060
1061 /* Note if the response to EHLO specifies support for the AUTH extension.
1062 If it has, check that this host is one we want to authenticate to, and do
1063 the business. The host name and address must be available when the
1064 authenticator's client driver is running. */
1065
1066 smtp_authenticated = FALSE;
1067 require_auth = verify_check_this_host(&(ob->hosts_require_auth), NULL,
1068 host->name, host->address, NULL);
1069
1070 if (esmtp && regex_match_and_setup(regex_AUTH, buffer, 0, -1))
1071 {
1072 uschar *names = string_copyn(expand_nstring[1], expand_nlength[1]);
1073 expand_nmax = -1; /* reset */
1074
1075 /* Must not do this check until after we have saved the result of the
1076 regex match above. */
1077
1078 if (require_auth == OK ||
1079 verify_check_this_host(&(ob->hosts_try_auth), NULL, host->name,
1080 host->address, NULL) == OK)
1081 {
1082 auth_instance *au;
1083 fail_reason = US"no common mechanisms were found";
1084
1085 DEBUG(D_transport) debug_printf("scanning authentication mechanisms\n");
1086
1087 /* Scan the configured authenticators looking for one which is configured
1088 for use as a client and whose name matches an authentication mechanism
1089 supported by the server. If one is found, attempt to authenticate by
1090 calling its client function. */
1091
1092 for (au = auths; !smtp_authenticated && au != NULL; au = au->next)
1093 {
1094 uschar *p = names;
1095 if (!au->client) continue;
1096
1097 /* Loop to scan supported server mechanisms */
1098
1099 while (*p != 0)
1100 {
1101 int rc;
1102 int len = Ustrlen(au->public_name);
1103 while (isspace(*p)) p++;
1104
1105 if (strncmpic(au->public_name, p, len) != 0 ||
1106 (p[len] != 0 && !isspace(p[len])))
1107 {
1108 while (*p != 0 && !isspace(*p)) p++;
1109 continue;
1110 }
1111
1112 /* Found data for a listed mechanism. Call its client entry. Set
1113 a flag in the outblock so that data is overwritten after sending so
1114 that reflections don't show it. */
1115
1116 fail_reason = US"authentication attempt(s) failed";
1117 outblock.authenticating = TRUE;
1118 rc = (au->info->clientcode)(au, &inblock, &outblock,
1119 ob->command_timeout, buffer, sizeof(buffer));
1120 outblock.authenticating = FALSE;
1121 DEBUG(D_transport) debug_printf("%s authenticator yielded %d\n",
1122 au->name, rc);
1123
1124 /* A temporary authentication failure must hold up delivery to
1125 this host. After a permanent authentication failure, we carry on
1126 to try other authentication methods. If all fail hard, try to
1127 deliver the message unauthenticated unless require_auth was set. */
1128
1129 switch(rc)
1130 {
1131 case OK:
1132 smtp_authenticated = TRUE; /* stops the outer loop */
1133 break;
1134
1135 /* Failure after writing a command */
1136
1137 case FAIL_SEND:
1138 goto SEND_FAILED;
1139
1140 /* Failure after reading a response */
1141
1142 case FAIL:
1143 if (errno != 0 || buffer[0] != '5') goto RESPONSE_FAILED;
1144 log_write(0, LOG_MAIN, "%s authenticator failed H=%s [%s] %s",
1145 au->name, host->name, host->address, buffer);
1146 break;
1147
1148 /* Failure by some other means. In effect, the authenticator
1149 decided it wasn't prepared to handle this case. Typically this
1150 is the result of "fail" in an expansion string. Do we need to
1151 log anything here? */
1152
1153 case CANCELLED:
1154 break;
1155
1156 /* Internal problem, message in buffer. */
1157
1158 case ERROR:
1159 yield = ERROR;
1160 set_errno(addrlist, 0, string_copy(buffer), DEFER);
1161 goto SEND_QUIT;
1162 }
1163
1164 break; /* If not authenticated, try next authenticator */
1165 } /* Loop for scanning supported server mechanisms */
1166 } /* Loop for further authenticators */
1167 }
1168 }
1169
1170 /* If we haven't authenticated, but are required to, give up. */
1171
1172 if (require_auth == OK && !smtp_authenticated)
1173 {
1174 yield = DEFER;
1175 set_errno(addrlist, ERRNO_AUTHFAIL,
1176 string_sprintf("authentication required but %s", fail_reason), DEFER);
1177 goto SEND_QUIT;
1178 }
1179 }
1180
1181/* The setting up of the SMTP call is now complete. Any subsequent errors are
1182message-specific. */
1183
1184setting_up = FALSE;
1185
1186/* If there is a filter command specified for this transport, we can now
1187set it up. This cannot be done until the identify of the host is known. */
1188
1189if (tblock->filter_command != NULL)
1190 {
1191 BOOL rc;
1192 uschar buffer[64];
1193 sprintf(CS buffer, "%.50s transport", tblock->name);
1194 rc = transport_set_up_command(&transport_filter_argv, tblock->filter_command,
1195 TRUE, DEFER, addrlist, buffer, NULL);
1196
1197 /* On failure, copy the error to all addresses, abandon the SMTP call, and
1198 yield ERROR. */
1199
1200 if (!rc)
1201 {
1202 set_errno(addrlist->next, addrlist->basic_errno, addrlist->message, DEFER);
1203 yield = ERROR;
1204 goto SEND_QUIT;
1205 }
1206 }
1207
1208
1209/* For messages that have more than the maximum number of envelope recipients,
1210we want to send several transactions down the same SMTP connection. (See
1211comments in deliver.c as to how this reconciles, heuristically, with
1212remote_max_parallel.) This optimization was added to Exim after the following
1213code was already working. The simplest way to put it in without disturbing the
1214code was to use a goto to jump back to this point when there is another
1215transaction to handle. */
1216
1217SEND_MESSAGE:
1218sync_addr = first_addr;
1219address_count = 0;
1220ok = FALSE;
1221send_rset = TRUE;
1222completed_address = FALSE;
1223
1224
1225/* Initiate a message transfer. If we know the receiving MTA supports the SIZE
1226qualification, send it, adding something to the message size to allow for
1227imprecision and things that get added en route. Exim keeps the number of lines
1228in a message, so we can give an accurate value for the original message, but we
1229need some additional to handle added headers. (Double "." characters don't get
1230included in the count.) */
1231
1232p = buffer;
1233*p = 0;
1234
1235if (smtp_use_size)
1236 {
1237 sprintf(CS p, " SIZE=%d", message_size+message_linecount+ob->size_addition);
1238 while (*p) p++;
1239 }
1240
1241/* Add the authenticated sender address if present */
1242
1243if (smtp_authenticated && local_authenticated_sender != NULL)
1244 {
1245 string_format(p, sizeof(buffer) - (p-buffer), " AUTH=%s",
1246 auth_xtextencode(local_authenticated_sender,
1247 Ustrlen(local_authenticated_sender)));
1248 }
1249
1250/* From here until we send the DATA command, we can make use of PIPELINING
1251if the server host supports it. The code has to be able to check the responses
1252at any point, for when the buffer fills up, so we write it totally generally.
1253When PIPELINING is off, each command written reports that it has flushed the
1254buffer. */
1255
1256pending_MAIL = TRUE; /* The block starts with MAIL */
1257
1258rc = smtp_write_command(&outblock, smtp_use_pipelining,
1259 "MAIL FROM:<%s>%s\r\n", return_path, buffer);
1260mail_command = string_copy(big_buffer); /* Save for later error message */
1261
1262switch(rc)
1263 {
1264 case -1: /* Transmission error */
1265 goto SEND_FAILED;
1266
1267 case +1: /* Block was sent */
1268 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1269 ob->command_timeout)) goto RESPONSE_FAILED;
1270 pending_MAIL = FALSE;
1271 break;
1272 }
1273
1274/* Pass over all the relevant recipient addresses for this host, which are the
1275ones that have status PENDING_DEFER. If we are using PIPELINING, we can send
1276several before we have to read the responses for those seen so far. This
1277checking is done by a subroutine because it also needs to be done at the end.
1278Send only up to max_rcpt addresses at a time, leaving first_addr pointing to
1279the next one if not all are sent.
1280
1281In the MUA wrapper situation, we want to flush the PIPELINING buffer for the
1282last address because we want to abort if any recipients have any kind of
1283problem, temporary or permanent. We know that all recipient addresses will have
1284the PENDING_DEFER status, because only one attempt is ever made, and we know
1285that max_rcpt will be large, so all addresses will be done at once. */
1286
1287for (addr = first_addr;
1288 address_count < max_rcpt && addr != NULL;
1289 addr = addr->next)
1290 {
1291 int count;
1292 BOOL no_flush;
1293
1294 if (addr->transport_return != PENDING_DEFER) continue;
1295
1296 address_count++;
1297 no_flush = smtp_use_pipelining && (!mua_wrapper || addr->next != NULL);
1298
1299 /* Now send the RCPT command, and process outstanding responses when
1300 necessary. After a timeout on RCPT, we just end the function, leaving the
1301 yield as OK, because this error can often mean that there is a problem with
1302 just one address, so we don't want to delay the host. */
1303
1304 count = smtp_write_command(&outblock, no_flush, "RCPT TO:<%s>\r\n",
1305 transport_rcpt_address(addr, tblock->rcpt_include_affixes));
1306 if (count < 0) goto SEND_FAILED;
1307 if (count > 0)
1308 {
1309 switch(sync_responses(first_addr, tblock->rcpt_include_affixes,
1310 &sync_addr, host, count, pending_MAIL, 0, &inblock,
1311 ob->command_timeout, buffer, sizeof(buffer)))
1312 {
1313 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1314 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1315 break;
1316
1317 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1318 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1319 case 0: /* No 2xx or 5xx, but no probs */
1320 break;
1321
1322 case -1: goto END_OFF; /* Timeout on RCPT */
1323 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL error */
1324 }
1325 pending_MAIL = FALSE; /* Dealt with MAIL */
1326 }
1327 } /* Loop for next address */
1328
1329/* If we are an MUA wrapper, abort if any RCPTs were rejected, either
1330permanently or temporarily. We should have flushed and synced after the last
1331RCPT. */
1332
1333if (mua_wrapper)
1334 {
1335 address_item *badaddr;
1336 for (badaddr = first_addr; badaddr != NULL; badaddr = badaddr->next)
1337 {
1338 if (badaddr->transport_return != PENDING_OK) break;
1339 }
1340 if (badaddr != NULL)
1341 {
1342 set_errno(addrlist, 0, badaddr->message, FAIL);
1343 ok = FALSE;
1344 }
1345 }
1346
1347/* If ok is TRUE, we know we have got at least one good recipient, and must now
1348send DATA, but if it is FALSE (in the normal, non-wrapper case), we may still
1349have a good recipient buffered up if we are pipelining. We don't want to waste
1350time sending DATA needlessly, so we only send it if either ok is TRUE or if we
1351are pipelining. The responses are all handled by sync_responses(). */
1352
1353if (ok || (smtp_use_pipelining && !mua_wrapper))
1354 {
1355 int count = smtp_write_command(&outblock, FALSE, "DATA\r\n");
1356 if (count < 0) goto SEND_FAILED;
1357 switch(sync_responses(first_addr, tblock->rcpt_include_affixes, &sync_addr,
1358 host, count, pending_MAIL, ok? +1 : -1, &inblock,
1359 ob->command_timeout, buffer, sizeof(buffer)))
1360 {
1361 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1362 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1363 break;
1364
1365 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1366 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1367 case 0: break; /* No 2xx or 5xx, but no probs */
1368
1369 case -1: goto END_OFF; /* Timeout on RCPT */
1370 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */
1371 }
1372 }
1373
1374/* Save the first address of the next batch. */
1375
1376first_addr = addr;
1377
1378/* If there were no good recipients (but otherwise there have been no
1379problems), just set ok TRUE, since we have handled address-specific errors
1380already. Otherwise, it's OK to send the message. Use the check/escape mechanism
1381for handling the SMTP dot-handling protocol, flagging to apply to headers as
1382well as body. Set the appropriate timeout value to be used for each chunk.
1383(Haven't been able to make it work using select() for writing yet.) */
1384
1385if (!ok) ok = TRUE; else
1386 {
1387 sigalrm_seen = FALSE;
1388 transport_write_timeout = ob->data_timeout;
1389 smtp_command = US"sending data block"; /* For error messages */
1390 DEBUG(D_transport|D_v)
1391 debug_printf(" SMTP>> writing message and terminating \".\"\n");
1392 transport_count = 0;
1393 ok = transport_write_message(addrlist, inblock.sock,
1394 topt_use_crlf | topt_end_dot | topt_escape_headers |
1395 (tblock->body_only? topt_no_headers : 0) |
1396 (tblock->headers_only? topt_no_body : 0) |
1397 (tblock->return_path_add? topt_add_return_path : 0) |
1398 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1399 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1400 0, /* No size limit */
1401 tblock->add_headers, tblock->remove_headers,
1402 US".", US"..", /* Escaping strings */
1403 tblock->rewrite_rules, tblock->rewrite_existflags);
1404
1405 /* transport_write_message() uses write() because it is called from other
1406 places to write to non-sockets. This means that under some OS (e.g. Solaris)
1407 it can exit with "Broken pipe" as its error. This really means that the
1408 socket got closed at the far end. */
1409
1410 transport_write_timeout = 0; /* for subsequent transports */
1411
1412 /* Failure can either be some kind of I/O disaster (including timeout),
1413 or the failure of a transport filter or the expansion of added headers. */
1414
1415 if (!ok)
1416 {
1417 buffer[0] = 0; /* There hasn't been a response */
1418 goto RESPONSE_FAILED;
1419 }
1420
1421 /* We used to send the terminating "." explicitly here, but because of
1422 buffering effects at both ends of TCP/IP connections, you don't gain
1423 anything by keeping it separate, so it might as well go in the final
1424 data buffer for efficiency. This is now done by setting the topt_end_dot
1425 flag above. */
1426
1427 smtp_command = US"end of data";
1428
1429 /* For SMTP, we now read a single response that applies to the whole message.
1430 If it is OK, then all the addresses have been delivered. */
1431
1432 if (!lmtp) ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1433 ob->final_timeout);
1434
1435 /* For LMTP, we get back a response for every RCPT command that we sent;
1436 some may be accepted and some rejected. For those that get a response, their
1437 status is fixed; any that are accepted have been handed over, even if later
1438 responses crash - at least, that's how I read RFC 2033.
1439
1440 If all went well, mark the recipient addresses as completed, record which
1441 host/IPaddress they were delivered to, and cut out RSET when sending another
1442 message down the same channel. Write the completed addresses to the journal
1443 now so that they are recorded in case there is a crash of hardware or
1444 software before the spool gets updated. Also record the final SMTP
1445 confirmation if needed (for SMTP only). */
1446
1447 if (ok)
1448 {
1449 int flag = '=';
1450 int delivery_time = (int)(time(NULL) - start_delivery_time);
1451 int len;
1452 host_item *thost;
1453 uschar *conf = NULL;
1454 send_rset = FALSE;
1455
1456 /* Make a copy of the host if it is local to this invocation
1457 of the transport. */
1458
1459 if (copy_host)
1460 {
1461 thost = store_get(sizeof(host_item));
1462 *thost = *host;
1463 thost->name = string_copy(host->name);
1464 thost->address = string_copy(host->address);
1465 }
1466 else thost = host;
1467
1468 /* Set up confirmation if needed - applies only to SMTP */
1469
1470 if ((log_extra_selector & LX_smtp_confirmation) != 0 && !lmtp)
1471 {
1472 uschar *s = string_printing(buffer);
1473 conf = (s == buffer)? (uschar *)string_copy(s) : s;
1474 }
1475
1476 /* Process all transported addresses - for LMTP, read a status for
1477 each one. */
1478
1479 for (addr = addrlist; addr != first_addr; addr = addr->next)
1480 {
1481 if (addr->transport_return != PENDING_OK) continue;
1482
1483 /* LMTP - if the response fails badly (e.g. timeout), use it for all the
1484 remaining addresses. Otherwise, it's a return code for just the one
1485 address. */
1486
1487 if (lmtp)
1488 {
1489 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1490 ob->final_timeout))
1491 {
1492 if (errno != 0 || buffer[0] == 0) goto RESPONSE_FAILED;
1493 addr->message = string_sprintf("LMTP error after %s: %s",
1494 big_buffer, string_printing(buffer));
1495 addr->transport_return = (buffer[0] == '5')? FAIL : DEFER;
1496 continue;
1497 }
1498 completed_address = TRUE; /* NOW we can set this flag */
1499 }
1500
1501 /* SMTP, or success return from LMTP for this address. Pass back the
1502 actual port used. */
1503
1504 addr->transport_return = OK;
1505 addr->more_errno = delivery_time;
1506 thost->port = port;
1507 addr->host_used = thost;
1508 addr->special_action = flag;
1509 addr->message = conf;
1510 flag = '-';
1511
1512 /* Update the journal. For homonymic addresses, use the base address plus
1513 the transport name. See lots of comments in deliver.c about the reasons
1514 for the complications when homonyms are involved. Just carry on after
1515 write error, as it may prove possible to update the spool file later. */
1516
1517 if (testflag(addr, af_homonym))
1518 sprintf(CS buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
1519 else
1520 sprintf(CS buffer, "%.500s\n", addr->unique);
1521
1522 DEBUG(D_deliver) debug_printf("journalling %s", buffer);
1523 len = Ustrlen(CS buffer);
1524 if (write(journal_fd, buffer, len) != len)
1525 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
1526 "%s: %s", buffer, strerror(errno));
1527 }
1528
1529 /* Ensure the journal file is pushed out to disk. */
1530
1531 if (fsync(journal_fd) < 0)
1532 log_write(0, LOG_MAIN|LOG_PANIC, "failed to fsync journal: %s",
1533 strerror(errno));
1534 }
1535 }
1536
1537
1538/* Handle general (not specific to one address) failures here. The value of ok
1539is used to skip over this code on the falling through case. A timeout causes a
1540deferral. Other errors may defer or fail according to the response code, and
1541may set up a special errno value, e.g. after connection chopped, which is
1542assumed if errno == 0 and there is no text in the buffer. If control reaches
1543here during the setting up phase (i.e. before MAIL FROM) then always defer, as
1544the problem is not related to this specific message. */
1545
1546if (!ok)
1547 {
1548 int code;
1549
1550 RESPONSE_FAILED:
1551 save_errno = errno;
1552 message = NULL;
1553 send_quit = check_response(host, &save_errno, addrlist->more_errno,
1554 buffer, &code, &message);
1555 goto FAILED;
1556
1557 SEND_FAILED:
1558 save_errno = errno;
1559 code = '4';
1560 message = US string_sprintf("send() to %s [%s] failed: %s",
1561 host->name, host->address, strerror(save_errno));
1562 send_quit = FALSE;
1563 goto FAILED;
1564
1565 /* This label is jumped to directly when a TLS negotiation has failed,
1566 or was not done for a host for which it is required. Values will be set
1567 in message and save_errno, and setting_up will always be true. Treat as
1568 a temporary error. */
1569
1570 #ifdef SUPPORT_TLS
1571 TLS_FAILED:
1572 code = '4';
1573 #endif
1574
1575 /* If the failure happened while setting up the call, see if the failure was
1576 a 5xx response (this will either be on connection, or following HELO - a 5xx
1577 after EHLO causes it to try HELO). If so, fail all addresses, as this host is
1578 never going to accept them. For other errors during setting up (timeouts or
1579 whatever), defer all addresses, and yield DEFER, so that the host is not
1580 tried again for a while. */
1581
1582 FAILED:
1583 ok = FALSE; /* For when reached by GOTO */
1584
1585 if (setting_up)
1586 {
1587 if (code == '5')
1588 {
1589 set_errno(addrlist, save_errno, message, FAIL);
1590 }
1591 else
1592 {
1593 set_errno(addrlist, save_errno, message, DEFER);
1594 yield = DEFER;
1595 }
1596 }
1597
1598 /* If there was an I/O error or timeout or other transportation error,
1599 indicated by errno being non-zero, defer all addresses and yield DEFER,
1600 except for the case of failed add_headers expansion, or a transport filter
1601 failure, when the yield should be ERROR, to stop it trying other hosts.
1602
1603 However, handle timeouts after MAIL FROM or "." and loss of connection after
1604 "." specially. They can indicate a problem with the sender address or with
1605 the contents of the message rather than a real error on the connection.
1606 Therefore, treat these cases in the same way as a 4xx response.
1607
1608 The following condition tests for NOT these special cases. */
1609
1610 else if (save_errno != 0 &&
1611 (save_errno != ETIMEDOUT ||
1612 (Ustrncmp(smtp_command,"MAIL",4) != 0 &&
1613 Ustrncmp(smtp_command,"end ",4) != 0)) &&
1614 (save_errno != ERRNO_SMTPCLOSED ||
1615 Ustrncmp(smtp_command,"end ",4) != 0))
1616 {
1617 yield = (save_errno == ERRNO_CHHEADER_FAIL ||
1618 save_errno == ERRNO_FILTER_FAIL)? ERROR : DEFER;
1619 set_errno(addrlist, save_errno, message, DEFER);
1620 }
1621
1622 /* Otherwise we have a message-specific error response from the remote
1623 host. This is one of
1624 (a) negative response or timeout after "mail from"
1625 (b) negative response after "data"
1626 (c) negative response or timeout or dropped connection after "."
1627 It won't be a negative response or timeout after "rcpt to", as that is dealt
1628 with separately above. The action in all cases is to set an appropriate
1629 error code for all the addresses, but to leave yield set to OK because
1630 the host itself has not failed. [It might in practice have failed for a
1631 timeout after MAIL FROM, or "." but if so, we'll discover that at the next
1632 delivery attempt.] For a temporary error, set the message_defer flag, and
1633 write to the logs for information if this is not the last host. The error for
1634 the last host will be logged as part of the address's log line. */
1635
1636 else
1637 {
1638 if (mua_wrapper) code = '5'; /* Force hard failure in wrapper mode */
1639
1640 set_errno(addrlist, save_errno, message, (code == '5')? FAIL : DEFER);
1641
1642 /* If there's an errno, the message contains just the identity of
1643 the host. */
1644
1645 if (code != '5') /* Anything other than 5 is treated as temporary */
1646 {
1647 if (save_errno > 0)
1648 message = US string_sprintf("%s: %s", message, strerror(save_errno));
1649 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", message);
1650 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
1651 *message_defer = TRUE;
1652 }
1653 }
1654 }
1655
1656
1657/* If all has gone well, send_quit will be set TRUE, implying we can end the
1658SMTP session tidily. However, if there were too many addresses to send in one
1659message (indicated by first_addr being non-NULL) we want to carry on with the
1660rest of them. Also, it is desirable to send more than one message down the SMTP
1661connection if there are several waiting, provided we haven't already sent so
1662many as to hit the configured limit. The function transport_check_waiting looks
1663for a waiting message and returns its id. Then transport_pass_socket tries to
1664set up a continued delivery by passing the socket on to another process. The
1665variable send_rset is FALSE if a message has just been successfully transfered.
1666
1667If we are already sending down a continued channel, there may be further
1668addresses not yet delivered that are aimed at the same host, but which have not
1669been passed in this run of the transport. In this case, continue_more will be
1670true, and all we should do is send RSET if necessary, and return, leaving the
1671channel open.
1672
1673However, if no address was disposed of, i.e. all addresses got 4xx errors, we
1674do not want to continue with other messages down the same channel, because that
1675can lead to looping between two or more messages, all with the same,
1676temporarily failing address(es). [The retry information isn't updated yet, so
1677new processes keep on trying.] We probably also don't want to try more of this
1678message's addresses either.
1679
1680If we have started a TLS session, we have to end it before passing the
1681connection to a new process. However, not all servers can handle this (Exim
1682can), so we do not pass such a connection on if the host matches
1683hosts_nopass_tls. */
1684
1685DEBUG(D_transport)
1686 debug_printf("ok=%d send_quit=%d send_rset=%d continue_more=%d "
1687 "yield=%d first_address is %sNULL\n", ok, send_quit, send_rset,
1688 continue_more, yield, (first_addr == NULL)? "":"not ");
1689
1690if (completed_address && ok && send_quit)
1691 {
1692 BOOL more;
1693 if (first_addr != NULL || continue_more ||
1694 (
1695 (tls_active < 0 ||
1696 verify_check_this_host(&(ob->hosts_nopass_tls), NULL, host->name,
1697 host->address, NULL) != OK)
1698 &&
1699 transport_check_waiting(tblock->name, host->name,
1700 tblock->connection_max_messages, new_message_id, &more)
1701 ))
1702 {
1703 uschar *msg;
1704
1705 if (send_rset)
1706 {
1707 if (! (ok = smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0))
1708 {
1709 msg = US string_sprintf("send() to %s [%s] failed: %s", host->name,
1710 host->address, strerror(save_errno));
1711 send_quit = FALSE;
1712 }
1713 else if (! (ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1714 ob->command_timeout)))
1715 {
1716 int code;
1717 send_quit = check_response(host, &errno, 0, buffer, &code, &msg);
1718 if (!send_quit)
1719 {
1720 DEBUG(D_transport) debug_printf("%s\n", msg);
1721 }
1722 }
1723 }
1724
1725 /* Either RSET was not needed, or it succeeded */
1726
1727 if (ok)
1728 {
1729 if (first_addr != NULL) /* More addresses still to be sent */
1730 { /* in this run of the transport */
1731 continue_sequence++; /* Causes * in logging */
1732 goto SEND_MESSAGE;
1733 }
1734 if (continue_more) return yield; /* More addresses for another run */
1735
1736 /* Pass the socket to a new Exim process. Before doing so, we must shut
1737 down TLS. Not all MTAs allow for the continuation of the SMTP session
1738 when TLS is shut down. We test for this by sending a new EHLO. If we
1739 don't get a good response, we don't attempt to pass the socket on. */
1740
1741 #ifdef SUPPORT_TLS
1742 if (tls_active >= 0)
1743 {
1744 tls_close(TRUE);
1745 ok = smtp_write_command(&outblock,FALSE,"EHLO %s\r\n",helo_data) >= 0 &&
1746 smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1747 ob->command_timeout);
1748 }
1749 #endif
1750
1751 /* If the socket is successfully passed, we musn't send QUIT (or
1752 indeed anything!) from here. */
1753
1754 if (ok && transport_pass_socket(tblock->name, host->name, host->address,
1755 new_message_id, inblock.sock))
1756 {
1757 send_quit = FALSE;
1758 }
1759 }
1760
1761 /* If RSET failed and there are addresses left, they get deferred. */
1762
1763 else set_errno(first_addr, errno, msg, DEFER);
1764 }
1765 }
1766
1767/* End off tidily with QUIT unless the connection has died or the socket has
1768been passed to another process. There has been discussion on the net about what
1769to do after sending QUIT. The wording of the RFC suggests that it is necessary
1770to wait for a response, but on the other hand, there isn't anything one can do
1771with an error response, other than log it. Exim used to do that. However,
1772further discussion suggested that it is positively advantageous not to wait for
1773the response, but to close the session immediately. This is supposed to move
1774the TCP/IP TIME_WAIT state from the server to the client, thereby removing some
1775load from the server. (Hosts that are both servers and clients may not see much
1776difference, of course.) Further discussion indicated that this was safe to do
1777on Unix systems which have decent implementations of TCP/IP that leave the
1778connection around for a while (TIME_WAIT) after the application has gone away.
1779This enables the response sent by the server to be properly ACKed rather than
1780timed out, as can happen on broken TCP/IP implementations on other OS.
1781
1782This change is being made on 31-Jul-98. After over a year of trouble-free
1783operation, the old commented-out code was removed on 17-Sep-99. */
1784
1785SEND_QUIT:
1786if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1787
1788END_OFF:
1789
1790#ifdef SUPPORT_TLS
1791tls_close(TRUE);
1792#endif
1793
1794/* Close the socket, and return the appropriate value, first setting
1795continue_transport and continue_hostname NULL to prevent any other addresses
1796that may include the host from trying to re-use a continuation socket. This
1797works because the NULL setting is passed back to the calling process, and
1798remote_max_parallel is forced to 1 when delivering over an existing connection,
1799
1800If all went well and continue_more is set, we shouldn't actually get here if
1801there are further addresses, as the return above will be taken. However,
1802writing RSET might have failed, or there may be other addresses whose hosts are
1803specified in the transports, and therefore not visible at top level, in which
1804case continue_more won't get set. */
1805
1806close(inblock.sock);
1807continue_transport = NULL;
1808continue_hostname = NULL;
1809return yield;
1810}
1811
1812
1813
1814
1815/*************************************************
1816* Closedown entry point *
1817*************************************************/
1818
1819/* This function is called when exim is passed an open smtp channel
1820from another incarnation, but the message which it has been asked
1821to deliver no longer exists. The channel is on stdin.
1822
1823We might do fancy things like looking for another message to send down
1824the channel, but if the one we sought has gone, it has probably been
1825delivered by some other process that itself will seek further messages,
1826so just close down our connection.
1827
1828Argument: pointer to the transport instance block
1829Returns: nothing
1830*/
1831
1832void
1833smtp_transport_closedown(transport_instance *tblock)
1834{
1835smtp_transport_options_block *ob =
1836 (smtp_transport_options_block *)(tblock->options_block);
1837smtp_inblock inblock;
1838smtp_outblock outblock;
1839uschar buffer[256];
1840uschar inbuffer[4096];
1841uschar outbuffer[16];
1842
1843inblock.sock = fileno(stdin);
1844inblock.buffer = inbuffer;
1845inblock.buffersize = sizeof(inbuffer);
1846inblock.ptr = inbuffer;
1847inblock.ptrend = inbuffer;
1848
1849outblock.sock = inblock.sock;
1850outblock.buffersize = sizeof(outbuffer);
1851outblock.buffer = outbuffer;
1852outblock.ptr = outbuffer;
1853outblock.cmd_count = 0;
1854outblock.authenticating = FALSE;
1855
1856(void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1857(void)smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1858 ob->command_timeout);
1859close(inblock.sock);
1860}
1861
1862
1863
1864/*************************************************
1865* Prepare addresses for delivery *
1866*************************************************/
1867
1868/* This function is called to flush out error settings from previous delivery
1869attempts to other hosts. It also records whether we got here via an MX record
1870or not in the more_errno field of the address. We are interested only in
1871addresses that are still marked DEFER - others may have got delivered to a
1872previously considered IP address. Set their status to PENDING_DEFER to indicate
1873which ones are relevant this time.
1874
1875Arguments:
1876 addrlist the list of addresses
1877 host the host we are delivering to
1878
1879Returns: the first address for this delivery
1880*/
1881
1882static address_item *
1883prepare_addresses(address_item *addrlist, host_item *host)
1884{
1885address_item *first_addr = NULL;
1886address_item *addr;
1887for (addr = addrlist; addr != NULL; addr = addr->next)
1888 {
1889 if (addr->transport_return != DEFER) continue;
1890 if (first_addr == NULL) first_addr = addr;
1891 addr->transport_return = PENDING_DEFER;
1892 addr->basic_errno = 0;
1893 addr->more_errno = (host->mx >= 0)? 'M' : 'A';
1894 addr->message = NULL;
1895 #ifdef SUPPORT_TLS
1896 addr->cipher = NULL;
1897 addr->peerdn = NULL;
1898 #endif
1899 }
1900return first_addr;
1901}
1902
1903
1904
1905/*************************************************
1906* Main entry point *
1907*************************************************/
1908
1909/* See local README for interface details. As this is a remote transport, it is
1910given a chain of addresses to be delivered in one connection, if possible. It
1911always returns TRUE, indicating that each address has its own independent
1912status set, except if there is a setting up problem, in which case it returns
1913FALSE. */
1914
1915BOOL
1916smtp_transport_entry(
1917 transport_instance *tblock, /* data for this instantiation */
1918 address_item *addrlist) /* addresses we are working on */
1919{
1920int cutoff_retry;
1921int port;
1922int hosts_defer = 0;
1923int hosts_fail = 0;
1924int hosts_looked_up = 0;
1925int hosts_retry = 0;
1926int hosts_serial = 0;
1927int hosts_total = 0;
1928address_item *addr;
1929BOOL expired = TRUE;
1930BOOL continuing = continue_hostname != NULL;
1931uschar *expanded_hosts = NULL;
1932uschar *pistring;
1933uschar *tid = string_sprintf("%s transport", tblock->name);
1934smtp_transport_options_block *ob =
1935 (smtp_transport_options_block *)(tblock->options_block);
1936host_item *hostlist = addrlist->host_list;
1937host_item *host = NULL;
1938
1939DEBUG(D_transport)
1940 {
1941 debug_printf("%s transport entered\n", tblock->name);
1942 for (addr = addrlist; addr != NULL; addr = addr->next)
1943 debug_printf(" %s\n", addr->address);
1944 if (continuing) debug_printf("already connected to %s [%s]\n",
1945 continue_hostname, continue_host_address);
1946 }
1947
1948/* If a host list is not defined for the addresses - they must all have the
1949same one in order to be passed to a single transport - or if the transport has
1950a host list with hosts_override set, use the host list supplied with the
1951transport. It is an error for this not to exist. */
1952
1953if (hostlist == NULL || (ob->hosts_override && ob->hosts != NULL))
1954 {
1955 if (ob->hosts == NULL)
1956 {
1957 addrlist->message = string_sprintf("%s transport called with no hosts set",
1958 tblock->name);
1959 addrlist->transport_return = PANIC;
1960 return FALSE; /* Only top address has status */
1961 }
1962
1963 DEBUG(D_transport) debug_printf("using the transport's hosts: %s\n",
1964 ob->hosts);
1965
1966 /* If the transport's host list contains no '$' characters, and we are not
1967 randomizing, it is fixed and therefore a chain of hosts can be built once
1968 and for all, and remembered for subsequent use by other calls to this
1969 transport. If, on the other hand, the host list does contain '$', or we are
1970 randomizing its order, we have to rebuild it each time. In the fixed case,
1971 as the hosts string will never be used again, it doesn't matter that we
1972 replace all the : characters with zeros. */
1973
1974 if (ob->hostlist == NULL)
1975 {
1976 uschar *s = ob->hosts;
1977
1978 if (Ustrchr(s, '$') != NULL)
1979 {
1980 expanded_hosts = expand_string(s);
1981 if (expanded_hosts == NULL)
1982 {
1983 addrlist->message = string_sprintf("failed to expand list of hosts "
1984 "\"%s\" in %s transport: %s", s, tblock->name, expand_string_message);
1985 addrlist->transport_return = search_find_defer? DEFER : PANIC;
1986 return FALSE; /* Only top address has status */
1987 }
1988 DEBUG(D_transport) debug_printf("expanded list of hosts \"%s\" to "
1989 "\"%s\"\n", s, expanded_hosts);
1990 s = expanded_hosts;
1991 }
1992 else
1993 if (ob->hosts_randomize) s = expanded_hosts = string_copy(s);
1994
1995 host_build_hostlist(&hostlist, s, ob->hosts_randomize);
1996
1997 /* If there was no expansion of hosts, save the host list for
1998 next time. */
1999
2000 if (expanded_hosts == NULL) ob->hostlist = hostlist;
2001 }
2002
2003 /* This is not the first time this transport has been run in this delivery;
2004 the host list was built previously. */
2005
2006 else hostlist = ob->hostlist;
2007 }
2008
2009/* The host list was supplied with the address. If hosts_randomize is set, we
2010must sort it into a random order if it did not come from MX records and has not
2011already been randomized (but don't bother if continuing down an existing
2012connection). */
2013
2014else if (ob->hosts_randomize && hostlist->mx == MX_NONE && !continuing)
2015 {
2016 host_item *newlist = NULL;
2017 while (hostlist != NULL)
2018 {
2019 host_item *h = hostlist;
2020 hostlist = hostlist->next;
2021
2022 h->sort_key = random_number(100);
2023
2024 if (newlist == NULL)
2025 {
2026 h->next = NULL;
2027 newlist = h;
2028 }
2029 else if (h->sort_key < newlist->sort_key)
2030 {
2031 h->next = newlist;
2032 newlist = h;
2033 }
2034 else
2035 {
2036 host_item *hh = newlist;
2037 while (hh->next != NULL)
2038 {
2039 if (h->sort_key < hh->next->sort_key) break;
2040 hh = hh->next;
2041 }
2042 h->next = hh->next;
2043 hh->next = h;
2044 }
2045 }
2046
2047 hostlist = addrlist->host_list = newlist;
2048 }
2049
2050
2051/* Sort out the port. Set up a string for adding to the retry key if the port
2052number is not the standard SMTP port. */
2053
2054if (!smtp_get_port(ob->port, addrlist, &port, tid)) return FALSE;
2055pistring = string_sprintf(":%d", port);
2056if (Ustrcmp(pistring, ":25") == 0) pistring = US"";
2057
2058
2059/* For each host-plus-IP-address on the list:
2060
2061. If this is a continued delivery and the host isn't the one with the
2062 current connection, skip.
2063
2064. If the status is unusable (i.e. previously failed or retry checked), skip.
2065
2066. If no IP address set, get the address, either by turning the name into
2067 an address, calling gethostbyname if gethostbyname is on, or by calling
2068 the DNS. The DNS may yield multiple addresses, in which case insert the
2069 extra ones into the list.
2070
2071. Get the retry data if not previously obtained for this address and set the
2072 field which remembers the state of this address. Skip if the retry time is
2073 not reached. If not, remember whether retry data was found. The retry string
2074 contains both the name and the IP address.
2075
2076. Scan the list of addresses and mark those whose status is DEFER as
2077 PENDING_DEFER. These are the only ones that will be processed in this cycle
2078 of the hosts loop.
2079
2080. Make a delivery attempt - addresses marked PENDING_DEFER will be tried.
2081 Some addresses may be successfully delivered, others may fail, and yet
2082 others may get temporary errors and so get marked DEFER.
2083
2084. The return from the delivery attempt is OK if a connection was made and a
2085 valid SMTP dialogue was completed. Otherwise it is DEFER.
2086
2087. If OK, add a "remove" retry item for this host/IPaddress, if any.
2088
2089. If fail to connect, or other defer state, add a retry item.
2090
2091. If there are any addresses whose status is still DEFER, carry on to the
2092 next host/IPaddress, unless we have tried the number of hosts given
2093 by hosts_max_try; otherwise return.
2094
2095If we get to the end of the list, all hosts have deferred at least one address,
2096or not reached their retry times. If delay_after_cutoff is unset, it requests a
2097delivery attempt to those hosts whose last try was before the arrival time of
2098the current message. To cope with this, we have to go round the loop a second
2099time. After that, set the status and error data for any addresses that haven't
2100had it set already. */
2101
2102for (cutoff_retry = 0; expired &&
2103 cutoff_retry < ((ob->delay_after_cutoff)? 1 : 2);
2104 cutoff_retry++)
2105 {
2106 host_item *nexthost = NULL;
2107 int unexpired_hosts_tried = 0;
2108
2109 for (host = hostlist;
2110 host != NULL && unexpired_hosts_tried < ob->hosts_max_try;
2111 host = nexthost)
2112 {
2113 int rc;
2114 int host_af;
2115 uschar *rs;
2116 BOOL serialized = FALSE;
2117 BOOL host_is_expired = FALSE;
2118 BOOL message_defer = FALSE;
2119 BOOL ifchanges = FALSE;
2120 BOOL some_deferred = FALSE;
2121 address_item *first_addr = NULL;
2122 uschar *interface = NULL;
2123 uschar *retry_host_key = NULL;
2124 uschar *retry_message_key = NULL;
2125 uschar *serialize_key = NULL;
2126
2127 /* Default next host is next host. :-) But this can vary if the
2128 hosts_max_try limit is hit (see below). */
2129
2130 nexthost = host->next;
2131
2132 /* Set the flag requesting that this host be added to the waiting
2133 database if the delivery fails temporarily or if we are running with
2134 queue_smtp or a 2-stage queue run. This gets unset for certain
2135 kinds of error, typically those that are specific to the message. */
2136
2137 host->update_waiting = TRUE;
2138
2139 /* If the address hasn't yet been obtained from the host name, look it up
2140 now, unless the host is already marked as unusable. If it is marked as
2141 unusable, it means that the router was unable to find its IP address (in
2142 the DNS or wherever) OR we are in the 2nd time round the cutoff loop, and
2143 the lookup failed last time. We don't get this far if *all* MX records
2144 point to non-existent hosts; that is treated as a hard error.
2145
2146 We can just skip this host entirely. When the hosts came from the router,
2147 the address will timeout based on the other host(s); when the address is
2148 looked up below, there is an explicit retry record added.
2149
2150 Note that we mustn't skip unusable hosts if the address is not unset; they
2151 may be needed as expired hosts on the 2nd time round the cutoff loop. */
2152
2153 if (host->address == NULL)
2154 {
2155 uschar *canonical_name;
2156
2157 if (host->status >= hstatus_unusable)
2158 {
2159 DEBUG(D_transport) debug_printf("%s has no address and is unusable - skipping\n",
2160 host->name);
2161 continue;
2162 }
2163
2164 DEBUG(D_transport) debug_printf("getting address for %s\n", host->name);
2165
2166 hosts_looked_up++;
2167
2168 /* Find by name if so configured, or if it's an IP address. We don't
2169 just copy the IP address, because we need the test-for-local to happen. */
2170
2171 if (ob->gethostbyname || string_is_ip_address(host->name, NULL))
2172 rc = host_find_byname(host, NULL, &canonical_name, TRUE);
2173 else
2174 {
2175 int flags = HOST_FIND_BY_A;
2176 if (ob->dns_qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
2177 if (ob->dns_search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
2178 rc = host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
2179 &canonical_name, NULL);
2180 }
2181
2182 /* Failure to find the host at this time (usually DNS temporary failure)
2183 is really a kind of routing failure rather than a transport failure.
2184 Therefore we add a retry item of the routing kind, not to stop us trying
2185 to look this name up here again, but to ensure the address gets timed
2186 out if the failures go on long enough. A complete failure at this point
2187 commonly points to a configuration error, but the best action is still
2188 to carry on for the next host. */
2189
2190 if (rc == HOST_FIND_AGAIN || rc == HOST_FIND_FAILED)
2191 {
2192 retry_add_item(addrlist, string_sprintf("R:%s", host->name), 0);
2193 expired = FALSE;
2194 if (rc == HOST_FIND_AGAIN) hosts_defer++; else hosts_fail++;
2195 DEBUG(D_transport) debug_printf("rc = %s for %s\n", (rc == HOST_FIND_AGAIN)?
2196 "HOST_FIND_AGAIN" : "HOST_FIND_FAILED", host->name);
2197 host->status = hstatus_unusable;
2198
2199 for (addr = addrlist; addr != NULL; addr = addr->next)
2200 {
2201 if (addr->transport_return != DEFER) continue;
2202 addr->basic_errno = ERRNO_UNKNOWNHOST;
2203 addr->message =
2204 string_sprintf("failed to lookup IP address for %s", host->name);
2205 }
2206 continue;
2207 }
2208
2209 /* If the host is actually the local host, we may have a problem, or
2210 there may be some cunning configuration going on. In the problem case,
2211 log things and give up. The default transport status is already DEFER. */
2212
2213 if (rc == HOST_FOUND_LOCAL && !ob->allow_localhost)
2214 {
2215 for (addr = addrlist; addr != NULL; addr = addr->next)
2216 {
2217 addr->basic_errno = 0;
2218 addr->message = string_sprintf("%s transport found host %s to be "
2219 "local", tblock->name, host->name);
2220 }
2221 goto END_TRANSPORT;
2222 }
2223 } /* End of block for IP address lookup */
2224
2225 /* If this is a continued delivery, we are interested only in the host
2226 which matches the name of the existing open channel. The check is put
2227 here after the local host lookup, in case the name gets expanded as a
2228 result of the lookup. Set expired FALSE, to save the outer loop executing
2229 twice. */
2230
2231 if (continuing && (Ustrcmp(continue_hostname, host->name) != 0 ||
2232 Ustrcmp(continue_host_address, host->address) != 0))
2233 {
2234 expired = FALSE;
2235 continue; /* With next host */
2236 }
2237
2238 /* If queue_smtp is set (-odqs or the first part of a 2-stage run), or the
2239 domain is in queue_smtp_domains, we don't actually want to attempt any
2240 deliveries. When doing a queue run, queue_smtp_domains is always unset. If
2241 there is a lookup defer in queue_smtp_domains, proceed as if the domain
2242 were not in it. We don't want to hold up all SMTP deliveries! Except when
2243 doing a two-stage queue run, don't do this if forcing. */
2244
2245 if ((!deliver_force || queue_2stage) && (queue_smtp ||
2246 match_isinlist(addrlist->domain, &queue_smtp_domains, 0, NULL, NULL,
2247 MCL_DOMAIN, TRUE, NULL) == OK))
2248 {
2249 expired = FALSE;
2250 for (addr = addrlist; addr != NULL; addr = addr->next)
2251 {
2252 if (addr->transport_return != DEFER) continue;
2253 addr->message = US"domain matches queue_smtp_domains, or -odqs set";
2254 }
2255 continue; /* With next host */
2256 }
2257
2258 /* Count hosts being considered - purely for an intelligent comment
2259 if none are usable. */
2260
2261 hosts_total++;
2262
2263 /* Set $host and $host address now in case they are needed for the
2264 interface expansion or the serialize_hosts check; they remain set if an
2265 actual delivery happens. */
2266
2267 deliver_host = host->name;
2268 deliver_host_address = host->address;
2269
2270 /* Select IPv4 or IPv6, and choose an outgoing interface. If the interface
2271 string changes upon expansion, we must add it to the key that is used for
2272 retries, because connections to the same host from a different interface
2273 should be treated separately. */
2274
2275 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET : AF_INET6;
2276 if (!smtp_get_interface(ob->interface, host_af, addrlist, &ifchanges,
2277 &interface, tid))
2278 return FALSE;
2279 if (ifchanges) pistring = string_sprintf("%s/%s", pistring, interface);
2280
2281 /* The first time round the outer loop, check the status of the host by
2282 inspecting the retry data. The second time round, we are interested only
2283 in expired hosts that haven't been tried since this message arrived. */
2284
2285 if (cutoff_retry == 0)
2286 {
2287 /* Ensure the status of the address is set by checking retry data if
2288 necessary. There maybe host-specific retry data (applicable to all
2289 messages) and also data for retries of a specific message at this host.
2290 If either of these retry records are actually read, the keys used are
2291 returned to save recomputing them later. */
2292
2293 host_is_expired = retry_check_address(addrlist->domain, host, pistring,
2294 ob->retry_include_ip_address, &retry_host_key, &retry_message_key);
2295
2296 DEBUG(D_transport) debug_printf("%s [%s]%s status = %s\n", host->name,
2297 (host->address == NULL)? US"" : host->address, pistring,
2298 (host->status == hstatus_usable)? "usable" :
2299 (host->status == hstatus_unusable)? "unusable" :
2300 (host->status == hstatus_unusable_expired)? "unusable (expired)" : "?");
2301
2302 /* Skip this address if not usable at this time, noting if it wasn't
2303 actually expired, both locally and in the address. */
2304
2305 switch (host->status)
2306 {
2307 case hstatus_unusable:
2308 expired = FALSE;
2309 setflag(addrlist, af_retry_skipped);
2310 /* Fall through */
2311
2312 case hstatus_unusable_expired:
2313 switch (host->why)
2314 {
2315 case hwhy_retry: hosts_retry++; break;
2316 case hwhy_failed: hosts_fail++; break;
2317 case hwhy_deferred: hosts_defer++; break;
2318 }
2319
2320 /* If there was a retry message key, implying that previously there
2321 was a message-specific defer, we don't want to update the list of
2322 messages waiting for this host. */
2323
2324 if (retry_message_key != NULL) host->update_waiting = FALSE;
2325 continue; /* With the next host or IP address */
2326 }
2327 }
2328
2329 /* Second time round the loop: if the address is set but expired, and
2330 the message is newer than the last try, let it through. */
2331
2332 else
2333 {
2334 if (host->address == NULL ||
2335 host->status != hstatus_unusable_expired ||
2336 host->last_try > received_time)
2337 continue;
2338 DEBUG(D_transport)
2339 debug_printf("trying expired host %s [%s]%s\n",
2340 host->name, host->address, pistring);
2341 host_is_expired = TRUE;
2342 }
2343
2344 /* Setting "expired=FALSE" doesn't actually mean not all hosts are expired;
2345 it remains TRUE only if all hosts are expired and none are actually tried.
2346 */
2347
2348 expired = FALSE;
2349
2350 /* If this host is listed as one to which access must be serialized,
2351 see if another Exim process has a connection to it, and if so, skip
2352 this host. If not, update the database to record our connection to it
2353 and remember this for later deletion. Do not do any of this if we are
2354 sending the message down a pre-existing connection. */
2355
2356 if (!continuing &&
2357 verify_check_this_host(&(ob->serialize_hosts), NULL, host->name,
2358 host->address, NULL) == OK)
2359 {
2360 serialize_key = string_sprintf("host-serialize-%s", host->name);
2361 if (!enq_start(serialize_key))
2362 {
2363 DEBUG(D_transport)
2364 debug_printf("skipping host %s because another Exim process "
2365 "is connected to it\n", host->name);
2366 hosts_serial++;
2367 continue;
2368 }
2369 serialized = TRUE;
2370 }
2371
2372 /* OK, we have an IP address that is not waiting for its retry time to
2373 arrive (it might be expired) OR (second time round the loop) we have an
2374 expired host that hasn't been tried since the message arrived. Have a go
2375 at delivering the message to it. First prepare the addresses by flushing
2376 out the result of previous attempts, and finding the first address that
2377 is still to be delivered. */
2378
2379 first_addr = prepare_addresses(addrlist, host);
2380
2381 DEBUG(D_transport) debug_printf("delivering %s to %s [%s] (%s%s)\n",
2382 message_id, host->name, host->address, addrlist->address,
2383 (addrlist->next == NULL)? "" : ", ...");
2384
2385 set_process_info("delivering %s to %s [%s] (%s%s)",
2386 message_id, host->name, host->address, addrlist->address,
2387 (addrlist->next == NULL)? "" : ", ...");
2388
2389 /* This is not for real; don't do the delivery. If there are
2390 any remaining hosts, list them. */
2391
2392 if (dont_deliver)
2393 {
2394 host_item *host2;
2395 set_errno(addrlist, 0, NULL, OK);
2396 for (addr = addrlist; addr != NULL; addr = addr->next)
2397 {
2398 addr->host_used = host;
2399 addr->special_action = '*';
2400 addr->message = US"delivery bypassed by -N option";
2401 }
2402 DEBUG(D_transport)
2403 {
2404 debug_printf("*** delivery by %s transport bypassed by -N option\n"
2405 "*** host and remaining hosts:\n", tblock->name);
2406 for (host2 = host; host2 != NULL; host2 = host2->next)
2407 debug_printf(" %s [%s]\n", host2->name,
2408 (host2->address == NULL)? US"unset" : host2->address);
2409 }
2410 rc = OK;
2411 }
2412
2413 /* This is for real. If the host is expired, we don't count it for
2414 hosts_max_retry. This ensures that all hosts must expire before an address
2415 is timed out. Otherwise, if we are about to hit the hosts_max_retry limit,
2416 check to see if there is a subsequent hosts with a different MX value. If
2417 so, make that the next host, and don't count this one. This is a heuristic
2418 to make sure that different MXs do get tried. With a normal kind of retry
2419 rule, they would get tried anyway when the earlier hosts were delayed, but
2420 if the domain has a "retry every time" type of rule - as is often used for
2421 the the very large ISPs, that won't happen. */
2422
2423 else
2424 {
2425 if (!host_is_expired && ++unexpired_hosts_tried >= ob->hosts_max_try)
2426 {
2427 host_item *h;
2428 DEBUG(D_transport)
2429 debug_printf("hosts_max_try limit reached with this host\n");
2430 for (h = host; h != NULL; h = h->next)
2431 if (h->mx != host->mx) break;
2432 if (h != NULL)
2433 {
2434 nexthost = h;
2435 unexpired_hosts_tried--;
2436 DEBUG(D_transport) debug_printf("however, a higher MX host exists "
2437 "and will be tried\n");
2438 }
2439 }
2440
2441 /* Attempt the delivery. */
2442
2443 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2444 expanded_hosts != NULL, &message_defer, FALSE);
2445
2446 /* Yield is one of:
2447 OK => connection made, each address contains its result;
2448 message_defer is set for message-specific defers (when all
2449 recipients are marked defer)
2450 DEFER => there was a non-message-specific delivery problem;
2451 ERROR => there was a problem setting up the arguments for a filter,
2452 or there was a problem with expanding added headers
2453 */
2454
2455 /* If the result is not OK, there was a non-message-specific problem.
2456 If the result is DEFER, we need to write to the logs saying what happened
2457 for this particular host, except in the case of authentication and TLS
2458 failures, where the log has already been written. If all hosts defer a
2459 general message is written at the end. */
2460
2461 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL &&
2462 first_addr->basic_errno != ERRNO_TLSFAILURE)
2463 write_logs(first_addr, host);
2464
2465 /* If STARTTLS was accepted, but there was a failure in setting up the
2466 TLS session (usually a certificate screwup), and the host is not in
2467 hosts_require_tls, and tls_tempfail_tryclear is true, try again, with
2468 TLS forcibly turned off. We have to start from scratch with a new SMTP
2469 connection. That's why the retry is done from here, not from within
2470 smtp_deliver(). [Rejections of STARTTLS itself don't screw up the
2471 session, so the in-clear transmission after those errors, if permitted,
2472 happens inside smtp_deliver().] */
2473
2474 #ifdef SUPPORT_TLS
2475 if (rc == DEFER && first_addr->basic_errno == ERRNO_TLSFAILURE &&
2476 ob->tls_tempfail_tryclear &&
2477 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
2478 host->address, NULL) != OK)
2479 {
2480 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
2481 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
2482 first_addr = prepare_addresses(addrlist, host);
2483 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2484 expanded_hosts != NULL, &message_defer, TRUE);
2485 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL)
2486 write_logs(first_addr, host);
2487 }
2488 #endif
2489 }
2490
2491 /* Delivery attempt finished */
2492
2493 rs = (rc == OK)? US"OK" : (rc == DEFER)? US"DEFER" : (rc == ERROR)?
2494 US"ERROR" : US"?";
2495
2496 set_process_info("delivering %s: just tried %s [%s] for %s%s: result %s",
2497 message_id, host->name, host->address, addrlist->address,
2498 (addrlist->next == NULL)? "" : " (& others)", rs);
2499
2500 /* Release serialization if set up */
2501
2502 if (serialized) enq_end(serialize_key);
2503
2504 /* If the result is DEFER, or if a host retry record is known to exist, we
2505 need to add an item to the retry chain for updating the retry database
2506 at the end of delivery. We only need to add the item to the top address,
2507 of course. Also, if DEFER, we mark the IP address unusable so as to skip it
2508 for any other delivery attempts using the same address. (It is copied into
2509 the unusable tree at the outer level, so even if different address blocks
2510 contain the same address, it still won't get tried again.) */
2511
2512 if (rc == DEFER || retry_host_key != NULL)
2513 {
2514 int delete_flag = (rc != DEFER)? rf_delete : 0;
2515 if (retry_host_key == NULL)
2516 {
2517 retry_host_key = ob->retry_include_ip_address?
2518 string_sprintf("T:%S:%s%s", host->name, host->address, pistring) :
2519 string_sprintf("T:%S%s", host->name, pistring);
2520 }
2521
2522 /* If a delivery of another message over an existing SMTP connection
2523 yields DEFER, we do NOT set up retry data for the host. This covers the
2524 case when there are delays in routing the addresses in the second message
2525 that are so long that the server times out. This is alleviated by not
2526 routing addresses that previously had routing defers when handling an
2527 existing connection, but even so, this case may occur (e.g. if a
2528 previously happily routed address starts giving routing defers). If the
2529 host is genuinely down, another non-continued message delivery will
2530 notice it soon enough. */
2531
2532 if (delete_flag != 0 || !continuing)
2533 retry_add_item(first_addr, retry_host_key, rf_host | delete_flag);
2534
2535 /* We may have tried an expired host, if its retry time has come; ensure
2536 the status reflects the expiry for the benefit of any other addresses. */
2537
2538 if (rc == DEFER)
2539 {
2540 host->status = (host_is_expired)?
2541 hstatus_unusable_expired : hstatus_unusable;
2542 host->why = hwhy_deferred;
2543 }
2544 }
2545
2546 /* If message_defer is set (host was OK, but every recipient got deferred
2547 because of some message-specific problem), or if that had happened
2548 previously so that a message retry key exists, add an appropriate item
2549 to the retry chain. Note that if there was a message defer but now there is
2550 a host defer, the message defer record gets deleted. That seems perfectly
2551 reasonable. Also, stop the message from being remembered as waiting
2552 for this host. */
2553
2554 if (message_defer || retry_message_key != NULL)
2555 {
2556 int delete_flag = message_defer? 0 : rf_delete;
2557 if (retry_message_key == NULL)
2558 {
2559 retry_message_key = ob->retry_include_ip_address?
2560 string_sprintf("T:%S:%s%s:%s", host->name, host->address, pistring,
2561 message_id) :
2562 string_sprintf("T:%S%s:%s", host->name, pistring, message_id);
2563 }
2564 retry_add_item(addrlist, retry_message_key,
2565 rf_message | rf_host | delete_flag);
2566 host->update_waiting = FALSE;
2567 }
2568
2569 /* Any return other than DEFER (that is, OK or ERROR) means that the
2570 addresses have got their final statuses filled in for this host. In the OK
2571 case, see if any of them are deferred. */
2572
2573 if (rc == OK)
2574 {
2575 for (addr = addrlist; addr != NULL; addr = addr->next)
2576 {
2577 if (addr->transport_return == DEFER)
2578 {
2579 some_deferred = TRUE;
2580 break;
2581 }
2582 }
2583 }
2584
2585 /* If no addresses deferred or the result was ERROR, return. We do this for
2586 ERROR because a failing filter set-up or add_headers expansion is likely to
2587 fail for any host we try. */
2588
2589 if (rc == ERROR || (rc == OK && !some_deferred))
2590 {
2591 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2592 return TRUE; /* Each address has its status */
2593 }
2594
2595 /* If the result was DEFER or some individual addresses deferred, let
2596 the loop run to try other hosts with the deferred addresses, except for the
2597 case when we were trying to deliver down an existing channel and failed.
2598 Don't try any other hosts in this case. */
2599
2600 if (continuing) break;
2601
2602 /* If the whole delivery, or some individual addresses, were deferred and
2603 there are more hosts that could be tried, do not count this host towards
2604 the hosts_max_try limit if the age of the message is greater than the
2605 maximum retry time for this host. This means we may try try all hosts,
2606 ignoring the limit, when messages have been around for some time. This is
2607 important because if we don't try all hosts, the address will never time
2608 out. */
2609
2610 if ((rc == DEFER || some_deferred) && nexthost != NULL)
2611 {
2612 BOOL timedout;
2613 retry_config *retry = retry_find_config(host->name, NULL, 0, 0);
2614
2615 if (retry != NULL && retry->rules != NULL)
2616 {
2617 retry_rule *last_rule;
2618 for (last_rule = retry->rules;
2619 last_rule->next != NULL;
2620 last_rule = last_rule->next);
2621 timedout = time(NULL) - received_time > last_rule->timeout;
2622 }
2623 else timedout = TRUE; /* No rule => timed out */
2624
2625 if (timedout)
2626 {
2627 unexpired_hosts_tried--;
2628 DEBUG(D_transport) debug_printf("temporary delivery error(s) override "
2629 "hosts_max_try (message older than host's retry time)\n");
2630 }
2631 }
2632 } /* End of loop for trying multiple hosts. */
2633
2634 /* This is the end of the loop that repeats iff expired is TRUE and
2635 ob->delay_after_cutoff is FALSE. The second time round we will
2636 try those hosts that haven't been tried since the message arrived. */
2637
2638 DEBUG(D_transport)
2639 {
2640 debug_printf("all IP addresses skipped or deferred at least one address\n");
2641 if (expired && !ob->delay_after_cutoff && cutoff_retry == 0)
2642 debug_printf("retrying IP addresses not tried since message arrived\n");
2643 }
2644 }
2645
2646
2647/* Get here if all IP addresses are skipped or defer at least one address. In
2648MUA wrapper mode, this will happen only for connection or other non-message-
2649specific failures. Force the delivery status for all addresses to FAIL. */
2650
2651if (mua_wrapper)
2652 {
2653 for (addr = addrlist; addr != NULL; addr = addr->next)
2654 addr->transport_return = FAIL;
2655 goto END_TRANSPORT;
2656 }
2657
2658/* In the normal, non-wrapper case, add a standard message to each deferred
2659address if there hasn't been an error, that is, if it hasn't actually been
2660tried this time. The variable "expired" will be FALSE if any deliveries were
2661actually tried, or if there was at least one host that was not expired. That
2662is, it is TRUE only if no deliveries were tried and all hosts were expired. If
2663a delivery has been tried, an error code will be set, and the failing of the
2664message is handled by the retry code later.
2665
2666If queue_smtp is set, or this transport was called to send a subsequent message
2667down an existing TCP/IP connection, and something caused the host not to be
2668found, we end up here, but can detect these cases and handle them specially. */
2669
2670for (addr = addrlist; addr != NULL; addr = addr->next)
2671 {
2672 /* If host is not NULL, it means that we stopped processing the host list
2673 because of hosts_max_try. This means we need to behave as if some hosts were
2674 skipped because their retry time had not come. Specifically, this prevents
2675 the address from timing out. */
2676
2677 if (host != NULL)
2678 {
2679 DEBUG(D_transport)
2680 debug_printf("hosts_max_try limit caused some hosts to be skipped\n");
2681 setflag(addr, af_retry_skipped);
2682 }
2683
2684 if (queue_smtp) /* no deliveries attempted */
2685 {
2686 addr->transport_return = DEFER;
2687 addr->basic_errno = 0;
2688 addr->message = US"SMTP delivery explicitly queued";
2689 }
2690
2691 else if (addr->transport_return == DEFER &&
2692 (addr->basic_errno == ERRNO_UNKNOWNERROR || addr->basic_errno == 0) &&
2693 addr->message == NULL)
2694 {
2695 addr->basic_errno = ERRNO_HRETRY;
2696 if (continue_hostname != NULL)
2697 {
2698 addr->message = US"no host found for existing SMTP connection";
2699 }
2700 else if (expired)
2701 {
2702 addr->message = (ob->delay_after_cutoff)?
2703 US"retry time not reached for any host after a long failure period" :
2704 US"all hosts have been failing for a long time and were last tried "
2705 "after this message arrived";
2706
2707 /* If we are already using fallback hosts, or there are no fallback hosts
2708 defined, convert the result to FAIL to cause a bounce. */
2709
2710 if (addr->host_list == addr->fallback_hosts ||
2711 addr->fallback_hosts == NULL)
2712 addr->transport_return = FAIL;
2713 }
2714 else
2715 {
2716 if (hosts_retry == hosts_total)
2717 addr->message = US"retry time not reached for any host";
2718 else if (hosts_fail == hosts_total)
2719 addr->message = US"all host address lookups failed permanently";
2720 else if (hosts_defer == hosts_total)
2721 addr->message = US"all host address lookups failed temporarily";
2722 else if (hosts_serial == hosts_total)
2723 addr->message = US"connection limit reached for all hosts";
2724 else if (hosts_fail+hosts_defer == hosts_total)
2725 addr->message = US"all host address lookups failed";
2726 else addr->message = US"some host address lookups failed and retry time "
2727 "not reached for other hosts or connection limit reached";
2728 }
2729 }
2730 }
2731
2732/* Update the database which keeps information about which messages are waiting
2733for which hosts to become available. Each host in the list has a flag which is
2734set if the data is to be updated. For some message-specific errors, the flag is
2735turned off because we don't want follow-on deliveries in those cases. */
2736
2737transport_update_waiting(hostlist, tblock->name);
2738
2739END_TRANSPORT:
2740
2741DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2742
2743return TRUE; /* Each address has its status */
2744}
2745
2746/* End of transport/smtp.c */