Clean & integrate force_command.
[exim.git] / src / src / transports / smtp.c
... / ...
CommitLineData
1/*************************************************
2* Exim - an Internet mail transport agent *
3*************************************************/
4
5/* Copyright (c) University of Cambridge 1995 - 2012 */
6/* See the file NOTICE for conditions of use and distribution. */
7
8#include "../exim.h"
9#include "smtp.h"
10
11#define PENDING 256
12#define PENDING_DEFER (PENDING + DEFER)
13#define PENDING_OK (PENDING + OK)
14
15
16/* Options specific to the smtp transport. This transport also supports LMTP
17over TCP/IP. The options must be in alphabetic order (note that "_" comes
18before the lower case letters). Some live in the transport_instance block so as
19to be publicly visible; these are flagged with opt_public. */
20
21optionlist smtp_transport_options[] = {
22 { "address_retry_include_sender", opt_bool,
23 (void *)offsetof(smtp_transport_options_block, address_retry_include_sender) },
24 { "allow_localhost", opt_bool,
25 (void *)offsetof(smtp_transport_options_block, allow_localhost) },
26 { "authenticated_sender", opt_stringptr,
27 (void *)offsetof(smtp_transport_options_block, authenticated_sender) },
28 { "authenticated_sender_force", opt_bool,
29 (void *)offsetof(smtp_transport_options_block, authenticated_sender_force) },
30 { "command_timeout", opt_time,
31 (void *)offsetof(smtp_transport_options_block, command_timeout) },
32 { "connect_timeout", opt_time,
33 (void *)offsetof(smtp_transport_options_block, connect_timeout) },
34 { "connection_max_messages", opt_int | opt_public,
35 (void *)offsetof(transport_instance, connection_max_messages) },
36 { "data_timeout", opt_time,
37 (void *)offsetof(smtp_transport_options_block, data_timeout) },
38 { "delay_after_cutoff", opt_bool,
39 (void *)offsetof(smtp_transport_options_block, delay_after_cutoff) },
40#ifndef DISABLE_DKIM
41 { "dkim_canon", opt_stringptr,
42 (void *)offsetof(smtp_transport_options_block, dkim_canon) },
43 { "dkim_domain", opt_stringptr,
44 (void *)offsetof(smtp_transport_options_block, dkim_domain) },
45 { "dkim_private_key", opt_stringptr,
46 (void *)offsetof(smtp_transport_options_block, dkim_private_key) },
47 { "dkim_selector", opt_stringptr,
48 (void *)offsetof(smtp_transport_options_block, dkim_selector) },
49 { "dkim_sign_headers", opt_stringptr,
50 (void *)offsetof(smtp_transport_options_block, dkim_sign_headers) },
51 { "dkim_strict", opt_stringptr,
52 (void *)offsetof(smtp_transport_options_block, dkim_strict) },
53#endif
54 { "dns_qualify_single", opt_bool,
55 (void *)offsetof(smtp_transport_options_block, dns_qualify_single) },
56 { "dns_search_parents", opt_bool,
57 (void *)offsetof(smtp_transport_options_block, dns_search_parents) },
58 { "dscp", opt_stringptr,
59 (void *)offsetof(smtp_transport_options_block, dscp) },
60 { "fallback_hosts", opt_stringptr,
61 (void *)offsetof(smtp_transport_options_block, fallback_hosts) },
62 { "final_timeout", opt_time,
63 (void *)offsetof(smtp_transport_options_block, final_timeout) },
64 { "gethostbyname", opt_bool,
65 (void *)offsetof(smtp_transport_options_block, gethostbyname) },
66#ifdef SUPPORT_TLS
67 /* These are no longer honoured, as of Exim 4.80; for now, we silently
68 ignore; a later release will warn, and a later-still release will remove
69 these options, so that using them becomes an error. */
70 { "gnutls_require_kx", opt_stringptr,
71 (void *)offsetof(smtp_transport_options_block, gnutls_require_kx) },
72 { "gnutls_require_mac", opt_stringptr,
73 (void *)offsetof(smtp_transport_options_block, gnutls_require_mac) },
74 { "gnutls_require_protocols", opt_stringptr,
75 (void *)offsetof(smtp_transport_options_block, gnutls_require_proto) },
76#endif
77 { "helo_data", opt_stringptr,
78 (void *)offsetof(smtp_transport_options_block, helo_data) },
79 { "hosts", opt_stringptr,
80 (void *)offsetof(smtp_transport_options_block, hosts) },
81 { "hosts_avoid_esmtp", opt_stringptr,
82 (void *)offsetof(smtp_transport_options_block, hosts_avoid_esmtp) },
83 { "hosts_avoid_pipelining", opt_stringptr,
84 (void *)offsetof(smtp_transport_options_block, hosts_avoid_pipelining) },
85#ifdef SUPPORT_TLS
86 { "hosts_avoid_tls", opt_stringptr,
87 (void *)offsetof(smtp_transport_options_block, hosts_avoid_tls) },
88#endif
89 { "hosts_max_try", opt_int,
90 (void *)offsetof(smtp_transport_options_block, hosts_max_try) },
91 { "hosts_max_try_hardlimit", opt_int,
92 (void *)offsetof(smtp_transport_options_block, hosts_max_try_hardlimit) },
93#ifdef SUPPORT_TLS
94 { "hosts_nopass_tls", opt_stringptr,
95 (void *)offsetof(smtp_transport_options_block, hosts_nopass_tls) },
96#endif
97 { "hosts_override", opt_bool,
98 (void *)offsetof(smtp_transport_options_block, hosts_override) },
99 { "hosts_randomize", opt_bool,
100 (void *)offsetof(smtp_transport_options_block, hosts_randomize) },
101 { "hosts_require_auth", opt_stringptr,
102 (void *)offsetof(smtp_transport_options_block, hosts_require_auth) },
103#ifdef SUPPORT_TLS
104 { "hosts_require_tls", opt_stringptr,
105 (void *)offsetof(smtp_transport_options_block, hosts_require_tls) },
106#endif
107 { "hosts_try_auth", opt_stringptr,
108 (void *)offsetof(smtp_transport_options_block, hosts_try_auth) },
109#ifdef EXPERIMENTAL_PRDR
110 { "hosts_try_prdr", opt_stringptr,
111 (void *)offsetof(smtp_transport_options_block, hosts_try_prdr) },
112#endif
113#ifdef SUPPORT_TLS
114 { "hosts_verify_avoid_tls", opt_stringptr,
115 (void *)offsetof(smtp_transport_options_block, hosts_verify_avoid_tls) },
116#endif
117 { "interface", opt_stringptr,
118 (void *)offsetof(smtp_transport_options_block, interface) },
119 { "keepalive", opt_bool,
120 (void *)offsetof(smtp_transport_options_block, keepalive) },
121 { "lmtp_ignore_quota", opt_bool,
122 (void *)offsetof(smtp_transport_options_block, lmtp_ignore_quota) },
123 { "max_rcpt", opt_int | opt_public,
124 (void *)offsetof(transport_instance, max_addresses) },
125 { "multi_domain", opt_bool | opt_public,
126 (void *)offsetof(transport_instance, multi_domain) },
127 { "port", opt_stringptr,
128 (void *)offsetof(smtp_transport_options_block, port) },
129 { "protocol", opt_stringptr,
130 (void *)offsetof(smtp_transport_options_block, protocol) },
131 { "retry_include_ip_address", opt_bool,
132 (void *)offsetof(smtp_transport_options_block, retry_include_ip_address) },
133 { "serialize_hosts", opt_stringptr,
134 (void *)offsetof(smtp_transport_options_block, serialize_hosts) },
135 { "size_addition", opt_int,
136 (void *)offsetof(smtp_transport_options_block, size_addition) }
137#ifdef SUPPORT_TLS
138 ,{ "tls_certificate", opt_stringptr,
139 (void *)offsetof(smtp_transport_options_block, tls_certificate) },
140 { "tls_crl", opt_stringptr,
141 (void *)offsetof(smtp_transport_options_block, tls_crl) },
142 { "tls_dh_min_bits", opt_int,
143 (void *)offsetof(smtp_transport_options_block, tls_dh_min_bits) },
144 { "tls_privatekey", opt_stringptr,
145 (void *)offsetof(smtp_transport_options_block, tls_privatekey) },
146 { "tls_require_ciphers", opt_stringptr,
147 (void *)offsetof(smtp_transport_options_block, tls_require_ciphers) },
148 { "tls_sni", opt_stringptr,
149 (void *)offsetof(smtp_transport_options_block, tls_sni) },
150 { "tls_tempfail_tryclear", opt_bool,
151 (void *)offsetof(smtp_transport_options_block, tls_tempfail_tryclear) },
152 { "tls_verify_certificates", opt_stringptr,
153 (void *)offsetof(smtp_transport_options_block, tls_verify_certificates) }
154#endif
155};
156
157/* Size of the options list. An extern variable has to be used so that its
158address can appear in the tables drtables.c. */
159
160int smtp_transport_options_count =
161 sizeof(smtp_transport_options)/sizeof(optionlist);
162
163/* Default private options block for the smtp transport. */
164
165smtp_transport_options_block smtp_transport_option_defaults = {
166 NULL, /* hosts */
167 NULL, /* fallback_hosts */
168 NULL, /* hostlist */
169 NULL, /* fallback_hostlist */
170 NULL, /* authenticated_sender */
171 US"$primary_hostname", /* helo_data */
172 NULL, /* interface */
173 NULL, /* port */
174 US"smtp", /* protocol */
175 NULL, /* DSCP */
176 NULL, /* serialize_hosts */
177 NULL, /* hosts_try_auth */
178 NULL, /* hosts_require_auth */
179#ifdef EXPERIMENTAL_PRDR
180 NULL, /* hosts_try_prdr */
181#endif
182 NULL, /* hosts_require_tls */
183 NULL, /* hosts_avoid_tls */
184 US"*", /* hosts_verify_avoid_tls */
185 NULL, /* hosts_avoid_pipelining */
186 NULL, /* hosts_avoid_esmtp */
187 NULL, /* hosts_nopass_tls */
188 5*60, /* command_timeout */
189 5*60, /* connect_timeout; shorter system default overrides */
190 5*60, /* data timeout */
191 10*60, /* final timeout */
192 1024, /* size_addition */
193 5, /* hosts_max_try */
194 50, /* hosts_max_try_hardlimit */
195 TRUE, /* address_retry_include_sender */
196 FALSE, /* allow_localhost */
197 FALSE, /* authenticated_sender_force */
198 FALSE, /* gethostbyname */
199 TRUE, /* dns_qualify_single */
200 FALSE, /* dns_search_parents */
201 TRUE, /* delay_after_cutoff */
202 FALSE, /* hosts_override */
203 FALSE, /* hosts_randomize */
204 TRUE, /* keepalive */
205 FALSE, /* lmtp_ignore_quota */
206 TRUE /* retry_include_ip_address */
207#ifdef SUPPORT_TLS
208 ,NULL, /* tls_certificate */
209 NULL, /* tls_crl */
210 NULL, /* tls_privatekey */
211 NULL, /* tls_require_ciphers */
212 NULL, /* gnutls_require_kx */
213 NULL, /* gnutls_require_mac */
214 NULL, /* gnutls_require_proto */
215 NULL, /* tls_sni */
216 NULL, /* tls_verify_certificates */
217 EXIM_CLIENT_DH_DEFAULT_MIN_BITS,
218 /* tls_dh_min_bits */
219 TRUE /* tls_tempfail_tryclear */
220#endif
221#ifndef DISABLE_DKIM
222 ,NULL, /* dkim_canon */
223 NULL, /* dkim_domain */
224 NULL, /* dkim_private_key */
225 NULL, /* dkim_selector */
226 NULL, /* dkim_sign_headers */
227 NULL /* dkim_strict */
228#endif
229};
230
231
232/* Local statics */
233
234static uschar *smtp_command; /* Points to last cmd for error messages */
235static uschar *mail_command; /* Points to MAIL cmd for error messages */
236static BOOL update_waiting; /* TRUE to update the "wait" database */
237
238
239/*************************************************
240* Setup entry point *
241*************************************************/
242
243/* This function is called when the transport is about to be used,
244but before running it in a sub-process. It is used for two things:
245
246 (1) To set the fallback host list in addresses, when delivering.
247 (2) To pass back the interface, port, protocol, and other options, for use
248 during callout verification.
249
250Arguments:
251 tblock pointer to the transport instance block
252 addrlist list of addresses about to be transported
253 tf if not NULL, pointer to block in which to return options
254 uid the uid that will be set (not used)
255 gid the gid that will be set (not used)
256 errmsg place for error message (not used)
257
258Returns: OK always (FAIL, DEFER not used)
259*/
260
261static int
262smtp_transport_setup(transport_instance *tblock, address_item *addrlist,
263 transport_feedback *tf, uid_t uid, gid_t gid, uschar **errmsg)
264{
265smtp_transport_options_block *ob =
266 (smtp_transport_options_block *)(tblock->options_block);
267
268errmsg = errmsg; /* Keep picky compilers happy */
269uid = uid;
270gid = gid;
271
272/* Pass back options if required. This interface is getting very messy. */
273
274if (tf != NULL)
275 {
276 tf->interface = ob->interface;
277 tf->port = ob->port;
278 tf->protocol = ob->protocol;
279 tf->hosts = ob->hosts;
280 tf->hosts_override = ob->hosts_override;
281 tf->hosts_randomize = ob->hosts_randomize;
282 tf->gethostbyname = ob->gethostbyname;
283 tf->qualify_single = ob->dns_qualify_single;
284 tf->search_parents = ob->dns_search_parents;
285 tf->helo_data = ob->helo_data;
286 }
287
288/* Set the fallback host list for all the addresses that don't have fallback
289host lists, provided that the local host wasn't present in the original host
290list. */
291
292if (!testflag(addrlist, af_local_host_removed))
293 {
294 for (; addrlist != NULL; addrlist = addrlist->next)
295 if (addrlist->fallback_hosts == NULL)
296 addrlist->fallback_hosts = ob->fallback_hostlist;
297 }
298
299return OK;
300}
301
302
303
304/*************************************************
305* Initialization entry point *
306*************************************************/
307
308/* Called for each instance, after its options have been read, to
309enable consistency checks to be done, or anything else that needs
310to be set up.
311
312Argument: pointer to the transport instance block
313Returns: nothing
314*/
315
316void
317smtp_transport_init(transport_instance *tblock)
318{
319smtp_transport_options_block *ob =
320 (smtp_transport_options_block *)(tblock->options_block);
321
322/* Retry_use_local_part defaults FALSE if unset */
323
324if (tblock->retry_use_local_part == TRUE_UNSET)
325 tblock->retry_use_local_part = FALSE;
326
327/* Set the default port according to the protocol */
328
329if (ob->port == NULL)
330 ob->port = (strcmpic(ob->protocol, US"lmtp") == 0)? US"lmtp" :
331 (strcmpic(ob->protocol, US"smtps") == 0)? US"smtps" : US"smtp";
332
333/* Set up the setup entry point, to be called before subprocesses for this
334transport. */
335
336tblock->setup = smtp_transport_setup;
337
338/* Complain if any of the timeouts are zero. */
339
340if (ob->command_timeout <= 0 || ob->data_timeout <= 0 ||
341 ob->final_timeout <= 0)
342 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
343 "command, data, or final timeout value is zero for %s transport",
344 tblock->name);
345
346/* If hosts_override is set and there are local hosts, set the global
347flag that stops verify from showing router hosts. */
348
349if (ob->hosts_override && ob->hosts != NULL) tblock->overrides_hosts = TRUE;
350
351/* If there are any fallback hosts listed, build a chain of host items
352for them, but do not do any lookups at this time. */
353
354host_build_hostlist(&(ob->fallback_hostlist), ob->fallback_hosts, FALSE);
355}
356
357
358
359
360
361/*************************************************
362* Set delivery info into all active addresses *
363*************************************************/
364
365/* Only addresses whose status is >= PENDING are relevant. A lesser
366status means that an address is not currently being processed.
367
368Arguments:
369 addrlist points to a chain of addresses
370 errno_value to put in each address's errno field
371 msg to put in each address's message field
372 rc to put in each address's transport_return field
373 pass_message if TRUE, set the "pass message" flag in the address
374
375If errno_value has the special value ERRNO_CONNECTTIMEOUT, ETIMEDOUT is put in
376the errno field, and RTEF_CTOUT is ORed into the more_errno field, to indicate
377this particular type of timeout.
378
379Returns: nothing
380*/
381
382static void
383set_errno(address_item *addrlist, int errno_value, uschar *msg, int rc,
384 BOOL pass_message)
385{
386address_item *addr;
387int orvalue = 0;
388if (errno_value == ERRNO_CONNECTTIMEOUT)
389 {
390 errno_value = ETIMEDOUT;
391 orvalue = RTEF_CTOUT;
392 }
393for (addr = addrlist; addr != NULL; addr = addr->next)
394 {
395 if (addr->transport_return < PENDING) continue;
396 addr->basic_errno = errno_value;
397 addr->more_errno |= orvalue;
398 if (msg != NULL)
399 {
400 addr->message = msg;
401 if (pass_message) setflag(addr, af_pass_message);
402 }
403 addr->transport_return = rc;
404 }
405}
406
407
408
409/*************************************************
410* Check an SMTP response *
411*************************************************/
412
413/* This function is given an errno code and the SMTP response buffer
414to analyse, together with the host identification for generating messages. It
415sets an appropriate message and puts the first digit of the response code into
416the yield variable. If no response was actually read, a suitable digit is
417chosen.
418
419Arguments:
420 host the current host, to get its name for messages
421 errno_value pointer to the errno value
422 more_errno from the top address for use with ERRNO_FILTER_FAIL
423 buffer the SMTP response buffer
424 yield where to put a one-digit SMTP response code
425 message where to put an errror message
426 pass_message set TRUE if message is an SMTP response
427
428Returns: TRUE if an SMTP "QUIT" command should be sent, else FALSE
429*/
430
431static BOOL check_response(host_item *host, int *errno_value, int more_errno,
432 uschar *buffer, int *yield, uschar **message, BOOL *pass_message)
433{
434uschar *pl = US"";
435
436if (smtp_use_pipelining &&
437 (Ustrcmp(smtp_command, "MAIL") == 0 ||
438 Ustrcmp(smtp_command, "RCPT") == 0 ||
439 Ustrcmp(smtp_command, "DATA") == 0))
440 pl = US"pipelined ";
441
442*yield = '4'; /* Default setting is to give a temporary error */
443
444/* Handle response timeout */
445
446if (*errno_value == ETIMEDOUT)
447 {
448 *message = US string_sprintf("SMTP timeout while connected to %s [%s] "
449 "after %s%s", host->name, host->address, pl, smtp_command);
450 if (transport_count > 0)
451 *message = US string_sprintf("%s (%d bytes written)", *message,
452 transport_count);
453 return FALSE;
454 }
455
456/* Handle malformed SMTP response */
457
458if (*errno_value == ERRNO_SMTPFORMAT)
459 {
460 uschar *malfresp = string_printing(buffer);
461 while (isspace(*malfresp)) malfresp++;
462 if (*malfresp == 0)
463 *message = string_sprintf("Malformed SMTP reply (an empty line) from "
464 "%s [%s] in response to %s%s", host->name, host->address, pl,
465 smtp_command);
466 else
467 *message = string_sprintf("Malformed SMTP reply from %s [%s] in response "
468 "to %s%s: %s", host->name, host->address, pl, smtp_command, malfresp);
469 return FALSE;
470 }
471
472/* Handle a failed filter process error; can't send QUIT as we mustn't
473end the DATA. */
474
475if (*errno_value == ERRNO_FILTER_FAIL)
476 {
477 *message = US string_sprintf("transport filter process failed (%d)%s",
478 more_errno,
479 (more_errno == EX_EXECFAILED)? ": unable to execute command" : "");
480 return FALSE;
481 }
482
483/* Handle a failed add_headers expansion; can't send QUIT as we mustn't
484end the DATA. */
485
486if (*errno_value == ERRNO_CHHEADER_FAIL)
487 {
488 *message =
489 US string_sprintf("failed to expand headers_add or headers_remove: %s",
490 expand_string_message);
491 return FALSE;
492 }
493
494/* Handle failure to write a complete data block */
495
496if (*errno_value == ERRNO_WRITEINCOMPLETE)
497 {
498 *message = US string_sprintf("failed to write a data block");
499 return FALSE;
500 }
501
502/* Handle error responses from the remote mailer. */
503
504if (buffer[0] != 0)
505 {
506 uschar *s = string_printing(buffer);
507 *message = US string_sprintf("SMTP error from remote mail server after %s%s: "
508 "host %s [%s]: %s", pl, smtp_command, host->name, host->address, s);
509 *pass_message = TRUE;
510 *yield = buffer[0];
511 return TRUE;
512 }
513
514/* No data was read. If there is no errno, this must be the EOF (i.e.
515connection closed) case, which causes deferral. An explicit connection reset
516error has the same effect. Otherwise, put the host's identity in the message,
517leaving the errno value to be interpreted as well. In all cases, we have to
518assume the connection is now dead. */
519
520if (*errno_value == 0 || *errno_value == ECONNRESET)
521 {
522 *errno_value = ERRNO_SMTPCLOSED;
523 *message = US string_sprintf("Remote host %s [%s] closed connection "
524 "in response to %s%s", host->name, host->address, pl, smtp_command);
525 }
526else *message = US string_sprintf("%s [%s]", host->name, host->address);
527
528return FALSE;
529}
530
531
532
533/*************************************************
534* Write error message to logs *
535*************************************************/
536
537/* This writes to the main log and to the message log.
538
539Arguments:
540 addr the address item containing error information
541 host the current host
542
543Returns: nothing
544*/
545
546static void
547write_logs(address_item *addr, host_item *host)
548{
549if (addr->message != NULL)
550 {
551 uschar *message = addr->message;
552 if (addr->basic_errno > 0)
553 message = string_sprintf("%s: %s", message, strerror(addr->basic_errno));
554 log_write(0, LOG_MAIN, "%s", message);
555 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
556 }
557else
558 {
559 uschar *msg =
560 ((log_extra_selector & LX_outgoing_port) != 0)?
561 string_sprintf("%s [%s]:%d", host->name, host->address,
562 (host->port == PORT_NONE)? 25 : host->port)
563 :
564 string_sprintf("%s [%s]", host->name, host->address);
565 log_write(0, LOG_MAIN, "%s %s", msg, strerror(addr->basic_errno));
566 deliver_msglog("%s %s %s\n", tod_stamp(tod_log), msg,
567 strerror(addr->basic_errno));
568 }
569}
570
571
572
573/*************************************************
574* Synchronize SMTP responses *
575*************************************************/
576
577/* This function is called from smtp_deliver() to receive SMTP responses from
578the server, and match them up with the commands to which they relate. When
579PIPELINING is not in use, this function is called after every command, and is
580therefore somewhat over-engineered, but it is simpler to use a single scheme
581that works both with and without PIPELINING instead of having two separate sets
582of code.
583
584The set of commands that are buffered up with pipelining may start with MAIL
585and may end with DATA; in between are RCPT commands that correspond to the
586addresses whose status is PENDING_DEFER. All other commands (STARTTLS, AUTH,
587etc.) are never buffered.
588
589Errors after MAIL or DATA abort the whole process leaving the response in the
590buffer. After MAIL, pending responses are flushed, and the original command is
591re-instated in big_buffer for error messages. For RCPT commands, the remote is
592permitted to reject some recipient addresses while accepting others. However
593certain errors clearly abort the whole process. Set the value in
594transport_return to PENDING_OK if the address is accepted. If there is a
595subsequent general error, it will get reset accordingly. If not, it will get
596converted to OK at the end.
597
598Arguments:
599 addrlist the complete address list
600 include_affixes TRUE if affixes include in RCPT
601 sync_addr ptr to the ptr of the one to start scanning at (updated)
602 host the host we are connected to
603 count the number of responses to read
604 address_retry_
605 include_sender true if 4xx retry is to include the sender it its key
606 pending_MAIL true if the first response is for MAIL
607 pending_DATA 0 if last command sent was not DATA
608 +1 if previously had a good recipient
609 -1 if not previously had a good recipient
610 inblock incoming SMTP block
611 timeout timeout value
612 buffer buffer for reading response
613 buffsize size of buffer
614
615Returns: 3 if at least one address had 2xx and one had 5xx
616 2 if at least one address had 5xx but none had 2xx
617 1 if at least one host had a 2xx response, but none had 5xx
618 0 no address had 2xx or 5xx but no errors (all 4xx, or just DATA)
619 -1 timeout while reading RCPT response
620 -2 I/O or other non-response error for RCPT
621 -3 DATA or MAIL failed - errno and buffer set
622*/
623
624static int
625sync_responses(address_item *addrlist, BOOL include_affixes,
626 address_item **sync_addr, host_item *host, int count,
627 BOOL address_retry_include_sender, BOOL pending_MAIL,
628 int pending_DATA, smtp_inblock *inblock, int timeout, uschar *buffer,
629 int buffsize)
630{
631address_item *addr = *sync_addr;
632int yield = 0;
633
634/* Handle the response for a MAIL command. On error, reinstate the original
635command in big_buffer for error message use, and flush any further pending
636responses before returning, except after I/O errors and timeouts. */
637
638if (pending_MAIL)
639 {
640 count--;
641 if (!smtp_read_response(inblock, buffer, buffsize, '2', timeout))
642 {
643 Ustrcpy(big_buffer, mail_command); /* Fits, because it came from there! */
644 if (errno == 0 && buffer[0] != 0)
645 {
646 uschar flushbuffer[4096];
647 int save_errno = 0;
648 if (buffer[0] == '4')
649 {
650 save_errno = ERRNO_MAIL4XX;
651 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
652 }
653 while (count-- > 0)
654 {
655 if (!smtp_read_response(inblock, flushbuffer, sizeof(flushbuffer),
656 '2', timeout)
657 && (errno != 0 || flushbuffer[0] == 0))
658 break;
659 }
660 errno = save_errno;
661 }
662 return -3;
663 }
664 }
665
666if (pending_DATA) count--; /* Number of RCPT responses to come */
667
668/* Read and handle the required number of RCPT responses, matching each one up
669with an address by scanning for the next address whose status is PENDING_DEFER.
670*/
671
672while (count-- > 0)
673 {
674 while (addr->transport_return != PENDING_DEFER) addr = addr->next;
675
676 /* The address was accepted */
677
678 if (smtp_read_response(inblock, buffer, buffsize, '2', timeout))
679 {
680 yield |= 1;
681 addr->transport_return = PENDING_OK;
682
683 /* If af_dr_retry_exists is set, there was a routing delay on this address;
684 ensure that any address-specific retry record is expunged. We do this both
685 for the basic key and for the version that also includes the sender. */
686
687 if (testflag(addr, af_dr_retry_exists))
688 {
689 uschar *altkey = string_sprintf("%s:<%s>", addr->address_retry_key,
690 sender_address);
691 retry_add_item(addr, altkey, rf_delete);
692 retry_add_item(addr, addr->address_retry_key, rf_delete);
693 }
694 }
695
696 /* Timeout while reading the response */
697
698 else if (errno == ETIMEDOUT)
699 {
700 int save_errno = errno;
701 uschar *message = string_sprintf("SMTP timeout while connected to %s [%s] "
702 "after RCPT TO:<%s>", host->name, host->address,
703 transport_rcpt_address(addr, include_affixes));
704 set_errno(addrlist, save_errno, message, DEFER, FALSE);
705 retry_add_item(addr, addr->address_retry_key, 0);
706 update_waiting = FALSE;
707 return -1;
708 }
709
710 /* Handle other errors in obtaining an SMTP response by returning -1. This
711 will cause all the addresses to be deferred. Restore the SMTP command in
712 big_buffer for which we are checking the response, so the error message
713 makes sense. */
714
715 else if (errno != 0 || buffer[0] == 0)
716 {
717 string_format(big_buffer, big_buffer_size, "RCPT TO:<%s>",
718 transport_rcpt_address(addr, include_affixes));
719 return -2;
720 }
721
722 /* Handle SMTP permanent and temporary response codes. */
723
724 else
725 {
726 addr->message =
727 string_sprintf("SMTP error from remote mail server after RCPT TO:<%s>: "
728 "host %s [%s]: %s", transport_rcpt_address(addr, include_affixes),
729 host->name, host->address, string_printing(buffer));
730 setflag(addr, af_pass_message);
731 deliver_msglog("%s %s\n", tod_stamp(tod_log), addr->message);
732
733 /* The response was 5xx */
734
735 if (buffer[0] == '5')
736 {
737 addr->transport_return = FAIL;
738 yield |= 2;
739 }
740
741 /* The response was 4xx */
742
743 else
744 {
745 addr->transport_return = DEFER;
746 addr->basic_errno = ERRNO_RCPT4XX;
747 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
748
749 /* Log temporary errors if there are more hosts to be tried. */
750
751 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", addr->message);
752
753 /* Do not put this message on the list of those waiting for specific
754 hosts, as otherwise it is likely to be tried too often. */
755
756 update_waiting = FALSE;
757
758 /* Add a retry item for the address so that it doesn't get tried again
759 too soon. If address_retry_include_sender is true, add the sender address
760 to the retry key. */
761
762 if (address_retry_include_sender)
763 {
764 uschar *altkey = string_sprintf("%s:<%s>", addr->address_retry_key,
765 sender_address);
766 retry_add_item(addr, altkey, 0);
767 }
768 else retry_add_item(addr, addr->address_retry_key, 0);
769 }
770 }
771 } /* Loop for next RCPT response */
772
773/* Update where to start at for the next block of responses, unless we
774have already handled all the addresses. */
775
776if (addr != NULL) *sync_addr = addr->next;
777
778/* Handle a response to DATA. If we have not had any good recipients, either
779previously or in this block, the response is ignored. */
780
781if (pending_DATA != 0 &&
782 !smtp_read_response(inblock, buffer, buffsize, '3', timeout))
783 {
784 int code;
785 uschar *msg;
786 BOOL pass_message;
787 if (pending_DATA > 0 || (yield & 1) != 0)
788 {
789 if (errno == 0 && buffer[0] == '4')
790 {
791 errno = ERRNO_DATA4XX;
792 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
793 }
794 return -3;
795 }
796 (void)check_response(host, &errno, 0, buffer, &code, &msg, &pass_message);
797 DEBUG(D_transport) debug_printf("%s\nerror for DATA ignored: pipelining "
798 "is in use and there were no good recipients\n", msg);
799 }
800
801/* All responses read and handled; MAIL (if present) received 2xx and DATA (if
802present) received 3xx. If any RCPTs were handled and yielded anything other
803than 4xx, yield will be set non-zero. */
804
805return yield;
806}
807
808
809
810/*************************************************
811* Deliver address list to given host *
812*************************************************/
813
814/* If continue_hostname is not null, we get here only when continuing to
815deliver down an existing channel. The channel was passed as the standard
816input. TLS is never active on a passed channel; the previous process always
817closes it down before passing the connection on.
818
819Otherwise, we have to make a connection to the remote host, and do the
820initial protocol exchange.
821
822When running as an MUA wrapper, if the sender or any recipient is rejected,
823temporarily or permanently, we force failure for all recipients.
824
825Arguments:
826 addrlist chain of potential addresses to deliver; only those whose
827 transport_return field is set to PENDING_DEFER are currently
828 being processed; others should be skipped - they have either
829 been delivered to an earlier host or IP address, or been
830 failed by one of them.
831 host host to deliver to
832 host_af AF_INET or AF_INET6
833 port default TCP/IP port to use, in host byte order
834 interface interface to bind to, or NULL
835 tblock transport instance block
836 copy_host TRUE if host set in addr->host_used must be copied, because
837 it is specific to this call of the transport
838 message_defer set TRUE if yield is OK, but all addresses were deferred
839 because of a non-recipient, non-host failure, that is, a
840 4xx response to MAIL FROM, DATA, or ".". This is a defer
841 that is specific to the message.
842 suppress_tls if TRUE, don't attempt a TLS connection - this is set for
843 a second attempt after TLS initialization fails
844
845Returns: OK - the connection was made and the delivery attempted;
846 the result for each address is in its data block.
847 DEFER - the connection could not be made, or something failed
848 while setting up the SMTP session, or there was a
849 non-message-specific error, such as a timeout.
850 ERROR - a filter command is specified for this transport,
851 and there was a problem setting it up; OR helo_data
852 or add_headers or authenticated_sender is specified
853 for this transport, and the string failed to expand
854*/
855
856static int
857smtp_deliver(address_item *addrlist, host_item *host, int host_af, int port,
858 uschar *interface, transport_instance *tblock, BOOL copy_host,
859 BOOL *message_defer, BOOL suppress_tls)
860{
861address_item *addr;
862address_item *sync_addr;
863address_item *first_addr = addrlist;
864int yield = OK;
865int address_count;
866int save_errno;
867int rc;
868time_t start_delivery_time = time(NULL);
869smtp_transport_options_block *ob =
870 (smtp_transport_options_block *)(tblock->options_block);
871BOOL lmtp = strcmpic(ob->protocol, US"lmtp") == 0;
872BOOL smtps = strcmpic(ob->protocol, US"smtps") == 0;
873BOOL ok = FALSE;
874BOOL send_rset = TRUE;
875BOOL send_quit = TRUE;
876BOOL setting_up = TRUE;
877BOOL completed_address = FALSE;
878BOOL esmtp = TRUE;
879BOOL pending_MAIL;
880BOOL pass_message = FALSE;
881#ifdef EXPERIMENTAL_PRDR
882BOOL prdr_offered = FALSE;
883BOOL prdr_active;
884#endif
885smtp_inblock inblock;
886smtp_outblock outblock;
887int max_rcpt = tblock->max_addresses;
888uschar *igquotstr = US"";
889uschar *local_authenticated_sender = authenticated_sender;
890uschar *helo_data = NULL;
891uschar *message = NULL;
892uschar new_message_id[MESSAGE_ID_LENGTH + 1];
893uschar *p;
894uschar buffer[4096];
895uschar inbuffer[4096];
896uschar outbuffer[1024];
897
898suppress_tls = suppress_tls; /* stop compiler warning when no TLS support */
899
900*message_defer = FALSE;
901smtp_command = US"initial connection";
902if (max_rcpt == 0) max_rcpt = 999999;
903
904/* Set up the buffer for reading SMTP response packets. */
905
906inblock.buffer = inbuffer;
907inblock.buffersize = sizeof(inbuffer);
908inblock.ptr = inbuffer;
909inblock.ptrend = inbuffer;
910
911/* Set up the buffer for holding SMTP commands while pipelining */
912
913outblock.buffer = outbuffer;
914outblock.buffersize = sizeof(outbuffer);
915outblock.ptr = outbuffer;
916outblock.cmd_count = 0;
917outblock.authenticating = FALSE;
918
919/* Reset the parameters of a TLS session. */
920
921tls_in.bits = 0;
922tls_in.cipher = NULL; /* for back-compatible behaviour */
923tls_in.peerdn = NULL;
924#if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
925tls_in.sni = NULL;
926#endif
927
928tls_out.bits = 0;
929tls_out.cipher = NULL; /* the one we may use for this transport */
930tls_out.peerdn = NULL;
931#if defined(SUPPORT_TLS) && !defined(USE_GNUTLS)
932tls_out.sni = NULL;
933#endif
934
935#ifndef SUPPORT_TLS
936if (smtps)
937 {
938 set_errno(addrlist, 0, US"TLS support not available", DEFER, FALSE);
939 return ERROR;
940 }
941#endif
942
943/* Make a connection to the host if this isn't a continued delivery, and handle
944the initial interaction and HELO/EHLO/LHLO. Connect timeout errors are handled
945specially so they can be identified for retries. */
946
947if (continue_hostname == NULL)
948 {
949 inblock.sock = outblock.sock =
950 smtp_connect(host, host_af, port, interface, ob->connect_timeout,
951 ob->keepalive, ob->dscp); /* This puts port into host->port */
952
953 if (inblock.sock < 0)
954 {
955 set_errno(addrlist, (errno == ETIMEDOUT)? ERRNO_CONNECTTIMEOUT : errno,
956 NULL, DEFER, FALSE);
957 return DEFER;
958 }
959
960 /* Expand the greeting message while waiting for the initial response. (Makes
961 sense if helo_data contains ${lookup dnsdb ...} stuff). The expansion is
962 delayed till here so that $sending_interface and $sending_port are set. */
963
964 helo_data = expand_string(ob->helo_data);
965
966 /* The first thing is to wait for an initial OK response. The dreaded "goto"
967 is nevertheless a reasonably clean way of programming this kind of logic,
968 where you want to escape on any error. */
969
970 if (!smtps)
971 {
972 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
973 ob->command_timeout)) goto RESPONSE_FAILED;
974
975 /* Now check if the helo_data expansion went well, and sign off cleanly if
976 it didn't. */
977
978 if (helo_data == NULL)
979 {
980 uschar *message = string_sprintf("failed to expand helo_data: %s",
981 expand_string_message);
982 set_errno(addrlist, 0, message, DEFER, FALSE);
983 yield = DEFER;
984 goto SEND_QUIT;
985 }
986 }
987
988/** Debugging without sending a message
989addrlist->transport_return = DEFER;
990goto SEND_QUIT;
991**/
992
993 /* Errors that occur after this point follow an SMTP command, which is
994 left in big_buffer by smtp_write_command() for use in error messages. */
995
996 smtp_command = big_buffer;
997
998 /* Tell the remote who we are...
999
1000 February 1998: A convention has evolved that ESMTP-speaking MTAs include the
1001 string "ESMTP" in their greeting lines, so make Exim send EHLO if the
1002 greeting is of this form. The assumption was that the far end supports it
1003 properly... but experience shows that there are some that give 5xx responses,
1004 even though the banner includes "ESMTP" (there's a bloody-minded one that
1005 says "ESMTP not spoken here"). Cope with that case.
1006
1007 September 2000: Time has passed, and it seems reasonable now to always send
1008 EHLO at the start. It is also convenient to make the change while installing
1009 the TLS stuff.
1010
1011 July 2003: Joachim Wieland met a broken server that advertises "PIPELINING"
1012 but times out after sending MAIL FROM, RCPT TO and DATA all together. There
1013 would be no way to send out the mails, so there is now a host list
1014 "hosts_avoid_esmtp" that disables ESMTP for special hosts and solves the
1015 PIPELINING problem as well. Maybe it can also be useful to cure other
1016 problems with broken servers.
1017
1018 Exim originally sent "Helo" at this point and ran for nearly a year that way.
1019 Then somebody tried it with a Microsoft mailer... It seems that all other
1020 mailers use upper case for some reason (the RFC is quite clear about case
1021 independence) so, for peace of mind, I gave in. */
1022
1023 esmtp = verify_check_this_host(&(ob->hosts_avoid_esmtp), NULL,
1024 host->name, host->address, NULL) != OK;
1025
1026 /* Alas; be careful, since this goto is not an error-out, so conceivably
1027 we might set data between here and the target which we assume to exist
1028 and be usable. I can see this coming back to bite us. */
1029 #ifdef SUPPORT_TLS
1030 if (smtps)
1031 {
1032 tls_offered = TRUE;
1033 suppress_tls = FALSE;
1034 ob->tls_tempfail_tryclear = FALSE;
1035 smtp_command = US"SSL-on-connect";
1036 goto TLS_NEGOTIATE;
1037 }
1038 #endif
1039
1040 if (esmtp)
1041 {
1042 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n",
1043 lmtp? "LHLO" : "EHLO", helo_data) < 0)
1044 goto SEND_FAILED;
1045 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1046 ob->command_timeout))
1047 {
1048 if (errno != 0 || buffer[0] == 0 || lmtp) goto RESPONSE_FAILED;
1049 esmtp = FALSE;
1050 }
1051 }
1052 else
1053 {
1054 DEBUG(D_transport)
1055 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
1056 }
1057
1058 if (!esmtp)
1059 {
1060 if (smtp_write_command(&outblock, FALSE, "HELO %s\r\n", helo_data) < 0)
1061 goto SEND_FAILED;
1062 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1063 ob->command_timeout)) goto RESPONSE_FAILED;
1064 }
1065
1066 /* Set IGNOREQUOTA if the response to LHLO specifies support and the
1067 lmtp_ignore_quota option was set. */
1068
1069 igquotstr = (lmtp && ob->lmtp_ignore_quota &&
1070 pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer, Ustrlen(CS buffer), 0,
1071 PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
1072
1073 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
1074
1075 #ifdef SUPPORT_TLS
1076 tls_offered = esmtp &&
1077 pcre_exec(regex_STARTTLS, NULL, CS buffer, Ustrlen(buffer), 0,
1078 PCRE_EOPT, NULL, 0) >= 0;
1079 #endif
1080
1081 #ifdef EXPERIMENTAL_PRDR
1082 prdr_offered = esmtp &&
1083 (pcre_exec(regex_PRDR, NULL, CS buffer, Ustrlen(buffer), 0,
1084 PCRE_EOPT, NULL, 0) >= 0) &&
1085 (verify_check_this_host(&(ob->hosts_try_prdr), NULL, host->name,
1086 host->address, NULL) == OK);
1087
1088 if (prdr_offered)
1089 {DEBUG(D_transport) debug_printf("PRDR usable\n");}
1090 #endif
1091 }
1092
1093/* For continuing deliveries down the same channel, the socket is the standard
1094input, and we don't need to redo EHLO here (but may need to do so for TLS - see
1095below). Set up the pointer to where subsequent commands will be left, for
1096error messages. Note that smtp_use_size and smtp_use_pipelining will have been
1097set from the command line if they were set in the process that passed the
1098connection on. */
1099
1100else
1101 {
1102 inblock.sock = outblock.sock = fileno(stdin);
1103 smtp_command = big_buffer;
1104 host->port = port; /* Record the port that was used */
1105 }
1106
1107/* If TLS is available on this connection, whether continued or not, attempt to
1108start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
1109send another EHLO - the server may give a different answer in secure mode. We
1110use a separate buffer for reading the response to STARTTLS so that if it is
1111negative, the original EHLO data is available for subsequent analysis, should
1112the client not be required to use TLS. If the response is bad, copy the buffer
1113for error analysis. */
1114
1115#ifdef SUPPORT_TLS
1116if (tls_offered && !suppress_tls &&
1117 verify_check_this_host(&(ob->hosts_avoid_tls), NULL, host->name,
1118 host->address, NULL) != OK)
1119 {
1120 uschar buffer2[4096];
1121 if (smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") < 0)
1122 goto SEND_FAILED;
1123
1124 /* If there is an I/O error, transmission of this message is deferred. If
1125 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
1126 false, we also defer. However, if there is a temporary rejection of STARTTLS
1127 and tls_tempfail_tryclear is true, or if there is an outright rejection of
1128 STARTTLS, we carry on. This means we will try to send the message in clear,
1129 unless the host is in hosts_require_tls (tested below). */
1130
1131 if (!smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
1132 ob->command_timeout))
1133 {
1134 if (errno != 0 || buffer2[0] == 0 ||
1135 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
1136 {
1137 Ustrncpy(buffer, buffer2, sizeof(buffer));
1138 goto RESPONSE_FAILED;
1139 }
1140 }
1141
1142 /* STARTTLS accepted: try to negotiate a TLS session. */
1143
1144 else
1145 TLS_NEGOTIATE:
1146 {
1147 int rc = tls_client_start(inblock.sock,
1148 host,
1149 addrlist,
1150 NULL, /* No DH param */
1151 ob->tls_certificate,
1152 ob->tls_privatekey,
1153 ob->tls_sni,
1154 ob->tls_verify_certificates,
1155 ob->tls_crl,
1156 ob->tls_require_ciphers,
1157 ob->tls_dh_min_bits,
1158 ob->command_timeout);
1159
1160 /* TLS negotiation failed; give an error. From outside, this function may
1161 be called again to try in clear on a new connection, if the options permit
1162 it for this host. */
1163
1164 if (rc != OK)
1165 {
1166 save_errno = ERRNO_TLSFAILURE;
1167 message = US"failure while setting up TLS session";
1168 send_quit = FALSE;
1169 goto TLS_FAILED;
1170 }
1171
1172 /* TLS session is set up */
1173
1174 for (addr = addrlist; addr != NULL; addr = addr->next)
1175 {
1176 if (addr->transport_return == PENDING_DEFER)
1177 {
1178 addr->cipher = tls_out.cipher;
1179 addr->peerdn = tls_out.peerdn;
1180 }
1181 }
1182 }
1183 }
1184
1185/* if smtps, we'll have smtp_command set to something else; always safe to
1186reset it here. */
1187smtp_command = big_buffer;
1188
1189/* If we started TLS, redo the EHLO/LHLO exchange over the secure channel. If
1190helo_data is null, we are dealing with a connection that was passed from
1191another process, and so we won't have expanded helo_data above. We have to
1192expand it here. $sending_ip_address and $sending_port are set up right at the
1193start of the Exim process (in exim.c). */
1194
1195if (tls_out.active >= 0)
1196 {
1197 char *greeting_cmd;
1198 if (helo_data == NULL)
1199 {
1200 helo_data = expand_string(ob->helo_data);
1201 if (helo_data == NULL)
1202 {
1203 uschar *message = string_sprintf("failed to expand helo_data: %s",
1204 expand_string_message);
1205 set_errno(addrlist, 0, message, DEFER, FALSE);
1206 yield = DEFER;
1207 goto SEND_QUIT;
1208 }
1209 }
1210
1211 /* For SMTPS we need to wait for the initial OK response. */
1212 if (smtps)
1213 {
1214 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1215 ob->command_timeout)) goto RESPONSE_FAILED;
1216 }
1217
1218 if (esmtp)
1219 greeting_cmd = "EHLO";
1220 else
1221 {
1222 greeting_cmd = "HELO";
1223 DEBUG(D_transport)
1224 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
1225 }
1226
1227 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n",
1228 lmtp? "LHLO" : greeting_cmd, helo_data) < 0)
1229 goto SEND_FAILED;
1230 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1231 ob->command_timeout))
1232 goto RESPONSE_FAILED;
1233 }
1234
1235/* If the host is required to use a secure channel, ensure that we
1236have one. */
1237
1238else if (verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
1239 host->address, NULL) == OK)
1240 {
1241 save_errno = ERRNO_TLSREQUIRED;
1242 message = string_sprintf("a TLS session is required for %s [%s], but %s",
1243 host->name, host->address,
1244 tls_offered? "an attempt to start TLS failed" :
1245 "the server did not offer TLS support");
1246 goto TLS_FAILED;
1247 }
1248#endif
1249
1250/* If TLS is active, we have just started it up and re-done the EHLO command,
1251so its response needs to be analyzed. If TLS is not active and this is a
1252continued session down a previously-used socket, we haven't just done EHLO, so
1253we skip this. */
1254
1255if (continue_hostname == NULL
1256 #ifdef SUPPORT_TLS
1257 || tls_out.active >= 0
1258 #endif
1259 )
1260 {
1261 int require_auth;
1262 uschar *fail_reason = US"server did not advertise AUTH support";
1263
1264 /* Set for IGNOREQUOTA if the response to LHLO specifies support and the
1265 lmtp_ignore_quota option was set. */
1266
1267 igquotstr = (lmtp && ob->lmtp_ignore_quota &&
1268 pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer, Ustrlen(CS buffer), 0,
1269 PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
1270
1271 /* If the response to EHLO specified support for the SIZE parameter, note
1272 this, provided size_addition is non-negative. */
1273
1274 smtp_use_size = esmtp && ob->size_addition >= 0 &&
1275 pcre_exec(regex_SIZE, NULL, CS buffer, Ustrlen(CS buffer), 0,
1276 PCRE_EOPT, NULL, 0) >= 0;
1277
1278 /* Note whether the server supports PIPELINING. If hosts_avoid_esmtp matched
1279 the current host, esmtp will be false, so PIPELINING can never be used. If
1280 the current host matches hosts_avoid_pipelining, don't do it. */
1281
1282 smtp_use_pipelining = esmtp &&
1283 verify_check_this_host(&(ob->hosts_avoid_pipelining), NULL, host->name,
1284 host->address, NULL) != OK &&
1285 pcre_exec(regex_PIPELINING, NULL, CS buffer, Ustrlen(CS buffer), 0,
1286 PCRE_EOPT, NULL, 0) >= 0;
1287
1288 DEBUG(D_transport) debug_printf("%susing PIPELINING\n",
1289 smtp_use_pipelining? "" : "not ");
1290
1291#ifdef EXPERIMENTAL_PRDR
1292 prdr_offered = esmtp &&
1293 pcre_exec(regex_PRDR, NULL, CS buffer, Ustrlen(CS buffer), 0,
1294 PCRE_EOPT, NULL, 0) >= 0 &&
1295 verify_check_this_host(&(ob->hosts_try_prdr), NULL, host->name,
1296 host->address, NULL) == OK;
1297
1298 if (prdr_offered)
1299 {DEBUG(D_transport) debug_printf("PRDR usable\n");}
1300#endif
1301
1302 /* Note if the response to EHLO specifies support for the AUTH extension.
1303 If it has, check that this host is one we want to authenticate to, and do
1304 the business. The host name and address must be available when the
1305 authenticator's client driver is running. */
1306
1307 smtp_authenticated = FALSE;
1308 client_authenticator = client_authenticated_id = client_authenticated_sender = NULL;
1309 require_auth = verify_check_this_host(&(ob->hosts_require_auth), NULL,
1310 host->name, host->address, NULL);
1311
1312 if (esmtp && regex_match_and_setup(regex_AUTH, buffer, 0, -1))
1313 {
1314 uschar *names = string_copyn(expand_nstring[1], expand_nlength[1]);
1315 expand_nmax = -1; /* reset */
1316
1317 /* Must not do this check until after we have saved the result of the
1318 regex match above. */
1319
1320 if (require_auth == OK ||
1321 verify_check_this_host(&(ob->hosts_try_auth), NULL, host->name,
1322 host->address, NULL) == OK)
1323 {
1324 auth_instance *au;
1325 fail_reason = US"no common mechanisms were found";
1326
1327 DEBUG(D_transport) debug_printf("scanning authentication mechanisms\n");
1328
1329 /* Scan the configured authenticators looking for one which is configured
1330 for use as a client, which is not suppressed by client_condition, and
1331 whose name matches an authentication mechanism supported by the server.
1332 If one is found, attempt to authenticate by calling its client function.
1333 */
1334
1335 for (au = auths; !smtp_authenticated && au != NULL; au = au->next)
1336 {
1337 uschar *p = names;
1338 if (!au->client ||
1339 (au->client_condition != NULL &&
1340 !expand_check_condition(au->client_condition, au->name,
1341 US"client authenticator")))
1342 {
1343 DEBUG(D_transport) debug_printf("skipping %s authenticator: %s\n",
1344 au->name,
1345 (au->client)? "client_condition is false" :
1346 "not configured as a client");
1347 continue;
1348 }
1349
1350 /* Loop to scan supported server mechanisms */
1351
1352 while (*p != 0)
1353 {
1354 int rc;
1355 int len = Ustrlen(au->public_name);
1356 while (isspace(*p)) p++;
1357
1358 if (strncmpic(au->public_name, p, len) != 0 ||
1359 (p[len] != 0 && !isspace(p[len])))
1360 {
1361 while (*p != 0 && !isspace(*p)) p++;
1362 continue;
1363 }
1364
1365 /* Found data for a listed mechanism. Call its client entry. Set
1366 a flag in the outblock so that data is overwritten after sending so
1367 that reflections don't show it. */
1368
1369 fail_reason = US"authentication attempt(s) failed";
1370 outblock.authenticating = TRUE;
1371 rc = (au->info->clientcode)(au, &inblock, &outblock,
1372 ob->command_timeout, buffer, sizeof(buffer));
1373 outblock.authenticating = FALSE;
1374 DEBUG(D_transport) debug_printf("%s authenticator yielded %d\n",
1375 au->name, rc);
1376
1377 /* A temporary authentication failure must hold up delivery to
1378 this host. After a permanent authentication failure, we carry on
1379 to try other authentication methods. If all fail hard, try to
1380 deliver the message unauthenticated unless require_auth was set. */
1381
1382 switch(rc)
1383 {
1384 case OK:
1385 smtp_authenticated = TRUE; /* stops the outer loop */
1386 client_authenticator = au->name;
1387 if (au->set_client_id != NULL)
1388 client_authenticated_id = expand_string(au->set_client_id);
1389 break;
1390
1391 /* Failure after writing a command */
1392
1393 case FAIL_SEND:
1394 goto SEND_FAILED;
1395
1396 /* Failure after reading a response */
1397
1398 case FAIL:
1399 if (errno != 0 || buffer[0] != '5') goto RESPONSE_FAILED;
1400 log_write(0, LOG_MAIN, "%s authenticator failed H=%s [%s] %s",
1401 au->name, host->name, host->address, buffer);
1402 break;
1403
1404 /* Failure by some other means. In effect, the authenticator
1405 decided it wasn't prepared to handle this case. Typically this
1406 is the result of "fail" in an expansion string. Do we need to
1407 log anything here? Feb 2006: a message is now put in the buffer
1408 if logging is required. */
1409
1410 case CANCELLED:
1411 if (*buffer != 0)
1412 log_write(0, LOG_MAIN, "%s authenticator cancelled "
1413 "authentication H=%s [%s] %s", au->name, host->name,
1414 host->address, buffer);
1415 break;
1416
1417 /* Internal problem, message in buffer. */
1418
1419 case ERROR:
1420 yield = ERROR;
1421 set_errno(addrlist, 0, string_copy(buffer), DEFER, FALSE);
1422 goto SEND_QUIT;
1423 }
1424
1425 break; /* If not authenticated, try next authenticator */
1426 } /* Loop for scanning supported server mechanisms */
1427 } /* Loop for further authenticators */
1428 }
1429 }
1430
1431 /* If we haven't authenticated, but are required to, give up. */
1432
1433 if (require_auth == OK && !smtp_authenticated)
1434 {
1435 yield = DEFER;
1436 set_errno(addrlist, ERRNO_AUTHFAIL,
1437 string_sprintf("authentication required but %s", fail_reason), DEFER,
1438 FALSE);
1439 goto SEND_QUIT;
1440 }
1441 }
1442
1443/* The setting up of the SMTP call is now complete. Any subsequent errors are
1444message-specific. */
1445
1446setting_up = FALSE;
1447
1448/* If there is a filter command specified for this transport, we can now
1449set it up. This cannot be done until the identify of the host is known. */
1450
1451if (tblock->filter_command != NULL)
1452 {
1453 BOOL rc;
1454 uschar buffer[64];
1455 sprintf(CS buffer, "%.50s transport", tblock->name);
1456 rc = transport_set_up_command(&transport_filter_argv, tblock->filter_command,
1457 TRUE, DEFER, addrlist, buffer, NULL);
1458 transport_filter_timeout = tblock->filter_timeout;
1459
1460 /* On failure, copy the error to all addresses, abandon the SMTP call, and
1461 yield ERROR. */
1462
1463 if (!rc)
1464 {
1465 set_errno(addrlist->next, addrlist->basic_errno, addrlist->message, DEFER,
1466 FALSE);
1467 yield = ERROR;
1468 goto SEND_QUIT;
1469 }
1470 }
1471
1472
1473/* For messages that have more than the maximum number of envelope recipients,
1474we want to send several transactions down the same SMTP connection. (See
1475comments in deliver.c as to how this reconciles, heuristically, with
1476remote_max_parallel.) This optimization was added to Exim after the following
1477code was already working. The simplest way to put it in without disturbing the
1478code was to use a goto to jump back to this point when there is another
1479transaction to handle. */
1480
1481SEND_MESSAGE:
1482sync_addr = first_addr;
1483address_count = 0;
1484ok = FALSE;
1485send_rset = TRUE;
1486completed_address = FALSE;
1487
1488
1489/* Initiate a message transfer. If we know the receiving MTA supports the SIZE
1490qualification, send it, adding something to the message size to allow for
1491imprecision and things that get added en route. Exim keeps the number of lines
1492in a message, so we can give an accurate value for the original message, but we
1493need some additional to handle added headers. (Double "." characters don't get
1494included in the count.) */
1495
1496p = buffer;
1497*p = 0;
1498
1499if (smtp_use_size)
1500 {
1501 sprintf(CS p, " SIZE=%d", message_size+message_linecount+ob->size_addition);
1502 while (*p) p++;
1503 }
1504
1505#ifdef EXPERIMENTAL_PRDR
1506prdr_active = FALSE;
1507if (prdr_offered)
1508 {
1509 for (addr = first_addr; addr; addr = addr->next)
1510 if (addr->transport_return == PENDING_DEFER)
1511 {
1512 for (addr = addr->next; addr; addr = addr->next)
1513 if (addr->transport_return == PENDING_DEFER)
1514 { /* at least two recipients to send */
1515 prdr_active = TRUE;
1516 sprintf(CS p, " PRDR"); p += 5;
1517 goto prdr_is_active;
1518 }
1519 break;
1520 }
1521 }
1522prdr_is_active:
1523#endif
1524
1525/* If an authenticated_sender override has been specified for this transport
1526instance, expand it. If the expansion is forced to fail, and there was already
1527an authenticated_sender for this message, the original value will be used.
1528Other expansion failures are serious. An empty result is ignored, but there is
1529otherwise no check - this feature is expected to be used with LMTP and other
1530cases where non-standard addresses (e.g. without domains) might be required. */
1531
1532if (ob->authenticated_sender != NULL)
1533 {
1534 uschar *new = expand_string(ob->authenticated_sender);
1535 if (new == NULL)
1536 {
1537 if (!expand_string_forcedfail)
1538 {
1539 uschar *message = string_sprintf("failed to expand "
1540 "authenticated_sender: %s", expand_string_message);
1541 set_errno(addrlist, 0, message, DEFER, FALSE);
1542 return ERROR;
1543 }
1544 }
1545 else if (new[0] != 0) local_authenticated_sender = new;
1546 }
1547
1548/* Add the authenticated sender address if present */
1549
1550if ((smtp_authenticated || ob->authenticated_sender_force) &&
1551 local_authenticated_sender != NULL)
1552 {
1553 string_format(p, sizeof(buffer) - (p-buffer), " AUTH=%s",
1554 auth_xtextencode(local_authenticated_sender,
1555 Ustrlen(local_authenticated_sender)));
1556 client_authenticated_sender = string_copy(local_authenticated_sender);
1557 }
1558
1559/* From here until we send the DATA command, we can make use of PIPELINING
1560if the server host supports it. The code has to be able to check the responses
1561at any point, for when the buffer fills up, so we write it totally generally.
1562When PIPELINING is off, each command written reports that it has flushed the
1563buffer. */
1564
1565pending_MAIL = TRUE; /* The block starts with MAIL */
1566
1567rc = smtp_write_command(&outblock, smtp_use_pipelining,
1568 "MAIL FROM:<%s>%s\r\n", return_path, buffer);
1569mail_command = string_copy(big_buffer); /* Save for later error message */
1570
1571switch(rc)
1572 {
1573 case -1: /* Transmission error */
1574 goto SEND_FAILED;
1575
1576 case +1: /* Block was sent */
1577 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1578 ob->command_timeout))
1579 {
1580 if (errno == 0 && buffer[0] == '4')
1581 {
1582 errno = ERRNO_MAIL4XX;
1583 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1584 }
1585 goto RESPONSE_FAILED;
1586 }
1587 pending_MAIL = FALSE;
1588 break;
1589 }
1590
1591/* Pass over all the relevant recipient addresses for this host, which are the
1592ones that have status PENDING_DEFER. If we are using PIPELINING, we can send
1593several before we have to read the responses for those seen so far. This
1594checking is done by a subroutine because it also needs to be done at the end.
1595Send only up to max_rcpt addresses at a time, leaving first_addr pointing to
1596the next one if not all are sent.
1597
1598In the MUA wrapper situation, we want to flush the PIPELINING buffer for the
1599last address because we want to abort if any recipients have any kind of
1600problem, temporary or permanent. We know that all recipient addresses will have
1601the PENDING_DEFER status, because only one attempt is ever made, and we know
1602that max_rcpt will be large, so all addresses will be done at once. */
1603
1604for (addr = first_addr;
1605 address_count < max_rcpt && addr != NULL;
1606 addr = addr->next)
1607 {
1608 int count;
1609 BOOL no_flush;
1610
1611 if (addr->transport_return != PENDING_DEFER) continue;
1612
1613 address_count++;
1614 no_flush = smtp_use_pipelining && (!mua_wrapper || addr->next != NULL);
1615
1616 /* Now send the RCPT command, and process outstanding responses when
1617 necessary. After a timeout on RCPT, we just end the function, leaving the
1618 yield as OK, because this error can often mean that there is a problem with
1619 just one address, so we don't want to delay the host. */
1620
1621 count = smtp_write_command(&outblock, no_flush, "RCPT TO:<%s>%s\r\n",
1622 transport_rcpt_address(addr, tblock->rcpt_include_affixes), igquotstr);
1623 if (count < 0) goto SEND_FAILED;
1624 if (count > 0)
1625 {
1626 switch(sync_responses(first_addr, tblock->rcpt_include_affixes,
1627 &sync_addr, host, count, ob->address_retry_include_sender,
1628 pending_MAIL, 0, &inblock, ob->command_timeout, buffer,
1629 sizeof(buffer)))
1630 {
1631 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1632 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1633 break;
1634
1635 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1636 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1637 case 0: /* No 2xx or 5xx, but no probs */
1638 break;
1639
1640 case -1: goto END_OFF; /* Timeout on RCPT */
1641 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL error */
1642 }
1643 pending_MAIL = FALSE; /* Dealt with MAIL */
1644 }
1645 } /* Loop for next address */
1646
1647/* If we are an MUA wrapper, abort if any RCPTs were rejected, either
1648permanently or temporarily. We should have flushed and synced after the last
1649RCPT. */
1650
1651if (mua_wrapper)
1652 {
1653 address_item *badaddr;
1654 for (badaddr = first_addr; badaddr != NULL; badaddr = badaddr->next)
1655 {
1656 if (badaddr->transport_return != PENDING_OK) break;
1657 }
1658 if (badaddr != NULL)
1659 {
1660 set_errno(addrlist, 0, badaddr->message, FAIL,
1661 testflag(badaddr, af_pass_message));
1662 ok = FALSE;
1663 }
1664 }
1665
1666/* If ok is TRUE, we know we have got at least one good recipient, and must now
1667send DATA, but if it is FALSE (in the normal, non-wrapper case), we may still
1668have a good recipient buffered up if we are pipelining. We don't want to waste
1669time sending DATA needlessly, so we only send it if either ok is TRUE or if we
1670are pipelining. The responses are all handled by sync_responses(). */
1671
1672if (ok || (smtp_use_pipelining && !mua_wrapper))
1673 {
1674 int count = smtp_write_command(&outblock, FALSE, "DATA\r\n");
1675 if (count < 0) goto SEND_FAILED;
1676 switch(sync_responses(first_addr, tblock->rcpt_include_affixes, &sync_addr,
1677 host, count, ob->address_retry_include_sender, pending_MAIL,
1678 ok? +1 : -1, &inblock, ob->command_timeout, buffer, sizeof(buffer)))
1679 {
1680 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1681 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1682 break;
1683
1684 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1685 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1686 case 0: break; /* No 2xx or 5xx, but no probs */
1687
1688 case -1: goto END_OFF; /* Timeout on RCPT */
1689 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */
1690 }
1691 }
1692
1693/* Save the first address of the next batch. */
1694
1695first_addr = addr;
1696
1697/* If there were no good recipients (but otherwise there have been no
1698problems), just set ok TRUE, since we have handled address-specific errors
1699already. Otherwise, it's OK to send the message. Use the check/escape mechanism
1700for handling the SMTP dot-handling protocol, flagging to apply to headers as
1701well as body. Set the appropriate timeout value to be used for each chunk.
1702(Haven't been able to make it work using select() for writing yet.) */
1703
1704if (!ok) ok = TRUE; else
1705 {
1706 sigalrm_seen = FALSE;
1707 transport_write_timeout = ob->data_timeout;
1708 smtp_command = US"sending data block"; /* For error messages */
1709 DEBUG(D_transport|D_v)
1710 debug_printf(" SMTP>> writing message and terminating \".\"\n");
1711 transport_count = 0;
1712#ifndef DISABLE_DKIM
1713 ok = dkim_transport_write_message(addrlist, inblock.sock,
1714 topt_use_crlf | topt_end_dot | topt_escape_headers |
1715 (tblock->body_only? topt_no_headers : 0) |
1716 (tblock->headers_only? topt_no_body : 0) |
1717 (tblock->return_path_add? topt_add_return_path : 0) |
1718 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1719 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1720 0, /* No size limit */
1721 tblock->add_headers, tblock->remove_headers,
1722 US".", US"..", /* Escaping strings */
1723 tblock->rewrite_rules, tblock->rewrite_existflags,
1724 ob->dkim_private_key, ob->dkim_domain, ob->dkim_selector,
1725 ob->dkim_canon, ob->dkim_strict, ob->dkim_sign_headers
1726 );
1727#else
1728 ok = transport_write_message(addrlist, inblock.sock,
1729 topt_use_crlf | topt_end_dot | topt_escape_headers |
1730 (tblock->body_only? topt_no_headers : 0) |
1731 (tblock->headers_only? topt_no_body : 0) |
1732 (tblock->return_path_add? topt_add_return_path : 0) |
1733 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1734 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1735 0, /* No size limit */
1736 tblock->add_headers, tblock->remove_headers,
1737 US".", US"..", /* Escaping strings */
1738 tblock->rewrite_rules, tblock->rewrite_existflags);
1739#endif
1740
1741 /* transport_write_message() uses write() because it is called from other
1742 places to write to non-sockets. This means that under some OS (e.g. Solaris)
1743 it can exit with "Broken pipe" as its error. This really means that the
1744 socket got closed at the far end. */
1745
1746 transport_write_timeout = 0; /* for subsequent transports */
1747
1748 /* Failure can either be some kind of I/O disaster (including timeout),
1749 or the failure of a transport filter or the expansion of added headers. */
1750
1751 if (!ok)
1752 {
1753 buffer[0] = 0; /* There hasn't been a response */
1754 goto RESPONSE_FAILED;
1755 }
1756
1757 /* We used to send the terminating "." explicitly here, but because of
1758 buffering effects at both ends of TCP/IP connections, you don't gain
1759 anything by keeping it separate, so it might as well go in the final
1760 data buffer for efficiency. This is now done by setting the topt_end_dot
1761 flag above. */
1762
1763 smtp_command = US"end of data";
1764
1765#ifdef EXPERIMENTAL_PRDR
1766 /* For PRDR we optionally get a partial-responses warning
1767 * followed by the individual responses, before going on with
1768 * the overall response. If we don't get the warning then deal
1769 * with per non-PRDR. */
1770 if(prdr_active)
1771 {
1772 ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '3',
1773 ob->final_timeout);
1774 if (!ok && errno == 0)
1775 switch(buffer[0])
1776 {
1777 case '2': prdr_active = FALSE;
1778 ok = TRUE;
1779 break;
1780 case '4': errno = ERRNO_DATA4XX;
1781 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1782 break;
1783 }
1784 }
1785 else
1786#endif
1787
1788 /* For non-PRDR SMTP, we now read a single response that applies to the
1789 whole message. If it is OK, then all the addresses have been delivered. */
1790
1791 if (!lmtp)
1792 {
1793 ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1794 ob->final_timeout);
1795 if (!ok && errno == 0 && buffer[0] == '4')
1796 {
1797 errno = ERRNO_DATA4XX;
1798 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1799 }
1800 }
1801
1802 /* For LMTP, we get back a response for every RCPT command that we sent;
1803 some may be accepted and some rejected. For those that get a response, their
1804 status is fixed; any that are accepted have been handed over, even if later
1805 responses crash - at least, that's how I read RFC 2033.
1806
1807 If all went well, mark the recipient addresses as completed, record which
1808 host/IPaddress they were delivered to, and cut out RSET when sending another
1809 message down the same channel. Write the completed addresses to the journal
1810 now so that they are recorded in case there is a crash of hardware or
1811 software before the spool gets updated. Also record the final SMTP
1812 confirmation if needed (for SMTP only). */
1813
1814 if (ok)
1815 {
1816 int flag = '=';
1817 int delivery_time = (int)(time(NULL) - start_delivery_time);
1818 int len;
1819 host_item *thost;
1820 uschar *conf = NULL;
1821 send_rset = FALSE;
1822
1823 /* Make a copy of the host if it is local to this invocation
1824 of the transport. */
1825
1826 if (copy_host)
1827 {
1828 thost = store_get(sizeof(host_item));
1829 *thost = *host;
1830 thost->name = string_copy(host->name);
1831 thost->address = string_copy(host->address);
1832 }
1833 else thost = host;
1834
1835 /* Set up confirmation if needed - applies only to SMTP */
1836
1837 if ((log_extra_selector & LX_smtp_confirmation) != 0 && !lmtp)
1838 {
1839 uschar *s = string_printing(buffer);
1840 conf = (s == buffer)? (uschar *)string_copy(s) : s;
1841 }
1842
1843 /* Process all transported addresses - for LMTP or PRDR, read a status for
1844 each one. */
1845
1846 for (addr = addrlist; addr != first_addr; addr = addr->next)
1847 {
1848 if (addr->transport_return != PENDING_OK) continue;
1849
1850 /* LMTP - if the response fails badly (e.g. timeout), use it for all the
1851 remaining addresses. Otherwise, it's a return code for just the one
1852 address. For temporary errors, add a retry item for the address so that
1853 it doesn't get tried again too soon. */
1854
1855#ifdef EXPERIMENTAL_PRDR
1856 if (lmtp || prdr_active)
1857#else
1858 if (lmtp)
1859#endif
1860 {
1861 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1862 ob->final_timeout))
1863 {
1864 if (errno != 0 || buffer[0] == 0) goto RESPONSE_FAILED;
1865 addr->message = string_sprintf(
1866#ifdef EXPERIMENTAL_PRDR
1867 "%s error after %s: %s", prdr_active ? "PRDR":"LMTP",
1868#else
1869 "LMTP error after %s: %s",
1870#endif
1871 big_buffer, string_printing(buffer));
1872 setflag(addr, af_pass_message); /* Allow message to go to user */
1873 if (buffer[0] == '5')
1874 addr->transport_return = FAIL;
1875 else
1876 {
1877 errno = ERRNO_DATA4XX;
1878 addr->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1879 addr->transport_return = DEFER;
1880#ifdef EXPERIMENTAL_PRDR
1881 if (!prdr_active)
1882#endif
1883 retry_add_item(addr, addr->address_retry_key, 0);
1884 }
1885 continue;
1886 }
1887 completed_address = TRUE; /* NOW we can set this flag */
1888 if ((log_extra_selector & LX_smtp_confirmation) != 0)
1889 {
1890 uschar *s = string_printing(buffer);
1891 conf = (s == buffer)? (uschar *)string_copy(s) : s;
1892 }
1893 }
1894
1895 /* SMTP, or success return from LMTP for this address. Pass back the
1896 actual host that was used. */
1897
1898 addr->transport_return = OK;
1899 addr->more_errno = delivery_time;
1900 addr->host_used = thost;
1901 addr->special_action = flag;
1902 addr->message = conf;
1903#ifdef EXPERIMENTAL_PRDR
1904 if (prdr_active) addr->flags |= af_prdr_used;
1905#endif
1906 flag = '-';
1907
1908#ifdef EXPERIMENTAL_PRDR
1909 if (!prdr_active)
1910#endif
1911 {
1912 /* Update the journal. For homonymic addresses, use the base address plus
1913 the transport name. See lots of comments in deliver.c about the reasons
1914 for the complications when homonyms are involved. Just carry on after
1915 write error, as it may prove possible to update the spool file later. */
1916
1917 if (testflag(addr, af_homonym))
1918 sprintf(CS buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
1919 else
1920 sprintf(CS buffer, "%.500s\n", addr->unique);
1921
1922 DEBUG(D_deliver) debug_printf("journalling %s", buffer);
1923 len = Ustrlen(CS buffer);
1924 if (write(journal_fd, buffer, len) != len)
1925 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
1926 "%s: %s", buffer, strerror(errno));
1927 }
1928 }
1929
1930#ifdef EXPERIMENTAL_PRDR
1931 if (prdr_active)
1932 {
1933 /* PRDR - get the final, overall response. For any non-success
1934 upgrade all the address statuses. */
1935 ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1936 ob->final_timeout);
1937 if (!ok)
1938 {
1939 if(errno == 0 && buffer[0] == '4')
1940 {
1941 errno = ERRNO_DATA4XX;
1942 addrlist->more_errno |= ((buffer[1] - '0')*10 + buffer[2] - '0') << 8;
1943 }
1944 for (addr = addrlist; addr != first_addr; addr = addr->next)
1945 if (buffer[0] == '5' || addr->transport_return == OK)
1946 addr->transport_return = PENDING_OK; /* allow set_errno action */
1947 goto RESPONSE_FAILED;
1948 }
1949
1950 /* Update the journal, or setup retry. */
1951 for (addr = addrlist; addr != first_addr; addr = addr->next)
1952 if (addr->transport_return == OK)
1953 {
1954 if (testflag(addr, af_homonym))
1955 sprintf(CS buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
1956 else
1957 sprintf(CS buffer, "%.500s\n", addr->unique);
1958
1959 DEBUG(D_deliver) debug_printf("journalling(PRDR) %s", buffer);
1960 len = Ustrlen(CS buffer);
1961 if (write(journal_fd, buffer, len) != len)
1962 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
1963 "%s: %s", buffer, strerror(errno));
1964 }
1965 else if (addr->transport_return == DEFER)
1966 retry_add_item(addr, addr->address_retry_key, -2);
1967 }
1968#endif
1969
1970 /* Ensure the journal file is pushed out to disk. */
1971
1972 if (EXIMfsync(journal_fd) < 0)
1973 log_write(0, LOG_MAIN|LOG_PANIC, "failed to fsync journal: %s",
1974 strerror(errno));
1975 }
1976 }
1977
1978
1979/* Handle general (not specific to one address) failures here. The value of ok
1980is used to skip over this code on the falling through case. A timeout causes a
1981deferral. Other errors may defer or fail according to the response code, and
1982may set up a special errno value, e.g. after connection chopped, which is
1983assumed if errno == 0 and there is no text in the buffer. If control reaches
1984here during the setting up phase (i.e. before MAIL FROM) then always defer, as
1985the problem is not related to this specific message. */
1986
1987if (!ok)
1988 {
1989 int code;
1990
1991 RESPONSE_FAILED:
1992 save_errno = errno;
1993 message = NULL;
1994 send_quit = check_response(host, &save_errno, addrlist->more_errno,
1995 buffer, &code, &message, &pass_message);
1996 goto FAILED;
1997
1998 SEND_FAILED:
1999 save_errno = errno;
2000 code = '4';
2001 message = US string_sprintf("send() to %s [%s] failed: %s",
2002 host->name, host->address, strerror(save_errno));
2003 send_quit = FALSE;
2004 goto FAILED;
2005
2006 /* This label is jumped to directly when a TLS negotiation has failed,
2007 or was not done for a host for which it is required. Values will be set
2008 in message and save_errno, and setting_up will always be true. Treat as
2009 a temporary error. */
2010
2011 #ifdef SUPPORT_TLS
2012 TLS_FAILED:
2013 code = '4';
2014 #endif
2015
2016 /* If the failure happened while setting up the call, see if the failure was
2017 a 5xx response (this will either be on connection, or following HELO - a 5xx
2018 after EHLO causes it to try HELO). If so, fail all addresses, as this host is
2019 never going to accept them. For other errors during setting up (timeouts or
2020 whatever), defer all addresses, and yield DEFER, so that the host is not
2021 tried again for a while. */
2022
2023 FAILED:
2024 ok = FALSE; /* For when reached by GOTO */
2025
2026 if (setting_up)
2027 {
2028 if (code == '5')
2029 {
2030 set_errno(addrlist, save_errno, message, FAIL, pass_message);
2031 }
2032 else
2033 {
2034 set_errno(addrlist, save_errno, message, DEFER, pass_message);
2035 yield = DEFER;
2036 }
2037 }
2038
2039 /* We want to handle timeouts after MAIL or "." and loss of connection after
2040 "." specially. They can indicate a problem with the sender address or with
2041 the contents of the message rather than a real error on the connection. These
2042 cases are treated in the same way as a 4xx response. This next bit of code
2043 does the classification. */
2044
2045 else
2046 {
2047 BOOL message_error;
2048
2049 switch(save_errno)
2050 {
2051 case 0:
2052 case ERRNO_MAIL4XX:
2053 case ERRNO_DATA4XX:
2054 message_error = TRUE;
2055 break;
2056
2057 case ETIMEDOUT:
2058 message_error = Ustrncmp(smtp_command,"MAIL",4) == 0 ||
2059 Ustrncmp(smtp_command,"end ",4) == 0;
2060 break;
2061
2062 case ERRNO_SMTPCLOSED:
2063 message_error = Ustrncmp(smtp_command,"end ",4) == 0;
2064 break;
2065
2066 default:
2067 message_error = FALSE;
2068 break;
2069 }
2070
2071 /* Handle the cases that are treated as message errors. These are:
2072
2073 (a) negative response or timeout after MAIL
2074 (b) negative response after DATA
2075 (c) negative response or timeout or dropped connection after "."
2076
2077 It won't be a negative response or timeout after RCPT, as that is dealt
2078 with separately above. The action in all cases is to set an appropriate
2079 error code for all the addresses, but to leave yield set to OK because the
2080 host itself has not failed. Of course, it might in practice have failed
2081 when we've had a timeout, but if so, we'll discover that at the next
2082 delivery attempt. For a temporary error, set the message_defer flag, and
2083 write to the logs for information if this is not the last host. The error
2084 for the last host will be logged as part of the address's log line. */
2085
2086 if (message_error)
2087 {
2088 if (mua_wrapper) code = '5'; /* Force hard failure in wrapper mode */
2089 set_errno(addrlist, save_errno, message, (code == '5')? FAIL : DEFER,
2090 pass_message);
2091
2092 /* If there's an errno, the message contains just the identity of
2093 the host. */
2094
2095 if (code != '5') /* Anything other than 5 is treated as temporary */
2096 {
2097 if (save_errno > 0)
2098 message = US string_sprintf("%s: %s", message, strerror(save_errno));
2099 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", message);
2100 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
2101 *message_defer = TRUE;
2102 }
2103 }
2104
2105 /* Otherwise, we have an I/O error or a timeout other than after MAIL or
2106 ".", or some other transportation error. We defer all addresses and yield
2107 DEFER, except for the case of failed add_headers expansion, or a transport
2108 filter failure, when the yield should be ERROR, to stop it trying other
2109 hosts. */
2110
2111 else
2112 {
2113 yield = (save_errno == ERRNO_CHHEADER_FAIL ||
2114 save_errno == ERRNO_FILTER_FAIL)? ERROR : DEFER;
2115 set_errno(addrlist, save_errno, message, DEFER, pass_message);
2116 }
2117 }
2118 }
2119
2120
2121/* If all has gone well, send_quit will be set TRUE, implying we can end the
2122SMTP session tidily. However, if there were too many addresses to send in one
2123message (indicated by first_addr being non-NULL) we want to carry on with the
2124rest of them. Also, it is desirable to send more than one message down the SMTP
2125connection if there are several waiting, provided we haven't already sent so
2126many as to hit the configured limit. The function transport_check_waiting looks
2127for a waiting message and returns its id. Then transport_pass_socket tries to
2128set up a continued delivery by passing the socket on to another process. The
2129variable send_rset is FALSE if a message has just been successfully transfered.
2130
2131If we are already sending down a continued channel, there may be further
2132addresses not yet delivered that are aimed at the same host, but which have not
2133been passed in this run of the transport. In this case, continue_more will be
2134true, and all we should do is send RSET if necessary, and return, leaving the
2135channel open.
2136
2137However, if no address was disposed of, i.e. all addresses got 4xx errors, we
2138do not want to continue with other messages down the same channel, because that
2139can lead to looping between two or more messages, all with the same,
2140temporarily failing address(es). [The retry information isn't updated yet, so
2141new processes keep on trying.] We probably also don't want to try more of this
2142message's addresses either.
2143
2144If we have started a TLS session, we have to end it before passing the
2145connection to a new process. However, not all servers can handle this (Exim
2146can), so we do not pass such a connection on if the host matches
2147hosts_nopass_tls. */
2148
2149DEBUG(D_transport)
2150 debug_printf("ok=%d send_quit=%d send_rset=%d continue_more=%d "
2151 "yield=%d first_address is %sNULL\n", ok, send_quit, send_rset,
2152 continue_more, yield, (first_addr == NULL)? "":"not ");
2153
2154if (completed_address && ok && send_quit)
2155 {
2156 BOOL more;
2157 if (first_addr != NULL || continue_more ||
2158 (
2159 (tls_out.active < 0 ||
2160 verify_check_this_host(&(ob->hosts_nopass_tls), NULL, host->name,
2161 host->address, NULL) != OK)
2162 &&
2163 transport_check_waiting(tblock->name, host->name,
2164 tblock->connection_max_messages, new_message_id, &more)
2165 ))
2166 {
2167 uschar *msg;
2168 BOOL pass_message;
2169
2170 if (send_rset)
2171 {
2172 if (! (ok = smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0))
2173 {
2174 msg = US string_sprintf("send() to %s [%s] failed: %s", host->name,
2175 host->address, strerror(save_errno));
2176 send_quit = FALSE;
2177 }
2178 else if (! (ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2179 ob->command_timeout)))
2180 {
2181 int code;
2182 send_quit = check_response(host, &errno, 0, buffer, &code, &msg,
2183 &pass_message);
2184 if (!send_quit)
2185 {
2186 DEBUG(D_transport) debug_printf("%s\n", msg);
2187 }
2188 }
2189 }
2190
2191 /* Either RSET was not needed, or it succeeded */
2192
2193 if (ok)
2194 {
2195 if (first_addr != NULL) /* More addresses still to be sent */
2196 { /* in this run of the transport */
2197 continue_sequence++; /* Causes * in logging */
2198 goto SEND_MESSAGE;
2199 }
2200 if (continue_more) return yield; /* More addresses for another run */
2201
2202 /* Pass the socket to a new Exim process. Before doing so, we must shut
2203 down TLS. Not all MTAs allow for the continuation of the SMTP session
2204 when TLS is shut down. We test for this by sending a new EHLO. If we
2205 don't get a good response, we don't attempt to pass the socket on. */
2206
2207 #ifdef SUPPORT_TLS
2208 if (tls_out.active >= 0)
2209 {
2210 tls_close(FALSE, TRUE);
2211 if (smtps)
2212 ok = FALSE;
2213 else
2214 ok = smtp_write_command(&outblock,FALSE,"EHLO %s\r\n",helo_data) >= 0 &&
2215 smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2216 ob->command_timeout);
2217 }
2218 #endif
2219
2220 /* If the socket is successfully passed, we musn't send QUIT (or
2221 indeed anything!) from here. */
2222
2223 if (ok && transport_pass_socket(tblock->name, host->name, host->address,
2224 new_message_id, inblock.sock))
2225 {
2226 send_quit = FALSE;
2227 }
2228 }
2229
2230 /* If RSET failed and there are addresses left, they get deferred. */
2231
2232 else set_errno(first_addr, errno, msg, DEFER, FALSE);
2233 }
2234 }
2235
2236/* End off tidily with QUIT unless the connection has died or the socket has
2237been passed to another process. There has been discussion on the net about what
2238to do after sending QUIT. The wording of the RFC suggests that it is necessary
2239to wait for a response, but on the other hand, there isn't anything one can do
2240with an error response, other than log it. Exim used to do that. However,
2241further discussion suggested that it is positively advantageous not to wait for
2242the response, but to close the session immediately. This is supposed to move
2243the TCP/IP TIME_WAIT state from the server to the client, thereby removing some
2244load from the server. (Hosts that are both servers and clients may not see much
2245difference, of course.) Further discussion indicated that this was safe to do
2246on Unix systems which have decent implementations of TCP/IP that leave the
2247connection around for a while (TIME_WAIT) after the application has gone away.
2248This enables the response sent by the server to be properly ACKed rather than
2249timed out, as can happen on broken TCP/IP implementations on other OS.
2250
2251This change is being made on 31-Jul-98. After over a year of trouble-free
2252operation, the old commented-out code was removed on 17-Sep-99. */
2253
2254SEND_QUIT:
2255if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
2256
2257END_OFF:
2258
2259#ifdef SUPPORT_TLS
2260tls_close(FALSE, TRUE);
2261#endif
2262
2263/* Close the socket, and return the appropriate value, first setting
2264continue_transport and continue_hostname NULL to prevent any other addresses
2265that may include the host from trying to re-use a continuation socket. This
2266works because the NULL setting is passed back to the calling process, and
2267remote_max_parallel is forced to 1 when delivering over an existing connection,
2268
2269If all went well and continue_more is set, we shouldn't actually get here if
2270there are further addresses, as the return above will be taken. However,
2271writing RSET might have failed, or there may be other addresses whose hosts are
2272specified in the transports, and therefore not visible at top level, in which
2273case continue_more won't get set. */
2274
2275(void)close(inblock.sock);
2276continue_transport = NULL;
2277continue_hostname = NULL;
2278return yield;
2279}
2280
2281
2282
2283
2284/*************************************************
2285* Closedown entry point *
2286*************************************************/
2287
2288/* This function is called when exim is passed an open smtp channel
2289from another incarnation, but the message which it has been asked
2290to deliver no longer exists. The channel is on stdin.
2291
2292We might do fancy things like looking for another message to send down
2293the channel, but if the one we sought has gone, it has probably been
2294delivered by some other process that itself will seek further messages,
2295so just close down our connection.
2296
2297Argument: pointer to the transport instance block
2298Returns: nothing
2299*/
2300
2301void
2302smtp_transport_closedown(transport_instance *tblock)
2303{
2304smtp_transport_options_block *ob =
2305 (smtp_transport_options_block *)(tblock->options_block);
2306smtp_inblock inblock;
2307smtp_outblock outblock;
2308uschar buffer[256];
2309uschar inbuffer[4096];
2310uschar outbuffer[16];
2311
2312inblock.sock = fileno(stdin);
2313inblock.buffer = inbuffer;
2314inblock.buffersize = sizeof(inbuffer);
2315inblock.ptr = inbuffer;
2316inblock.ptrend = inbuffer;
2317
2318outblock.sock = inblock.sock;
2319outblock.buffersize = sizeof(outbuffer);
2320outblock.buffer = outbuffer;
2321outblock.ptr = outbuffer;
2322outblock.cmd_count = 0;
2323outblock.authenticating = FALSE;
2324
2325(void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
2326(void)smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
2327 ob->command_timeout);
2328(void)close(inblock.sock);
2329}
2330
2331
2332
2333/*************************************************
2334* Prepare addresses for delivery *
2335*************************************************/
2336
2337/* This function is called to flush out error settings from previous delivery
2338attempts to other hosts. It also records whether we got here via an MX record
2339or not in the more_errno field of the address. We are interested only in
2340addresses that are still marked DEFER - others may have got delivered to a
2341previously considered IP address. Set their status to PENDING_DEFER to indicate
2342which ones are relevant this time.
2343
2344Arguments:
2345 addrlist the list of addresses
2346 host the host we are delivering to
2347
2348Returns: the first address for this delivery
2349*/
2350
2351static address_item *
2352prepare_addresses(address_item *addrlist, host_item *host)
2353{
2354address_item *first_addr = NULL;
2355address_item *addr;
2356for (addr = addrlist; addr != NULL; addr = addr->next)
2357 {
2358 if (addr->transport_return != DEFER) continue;
2359 if (first_addr == NULL) first_addr = addr;
2360 addr->transport_return = PENDING_DEFER;
2361 addr->basic_errno = 0;
2362 addr->more_errno = (host->mx >= 0)? 'M' : 'A';
2363 addr->message = NULL;
2364 #ifdef SUPPORT_TLS
2365 addr->cipher = NULL;
2366 addr->peerdn = NULL;
2367 #endif
2368 }
2369return first_addr;
2370}
2371
2372
2373
2374/*************************************************
2375* Main entry point *
2376*************************************************/
2377
2378/* See local README for interface details. As this is a remote transport, it is
2379given a chain of addresses to be delivered in one connection, if possible. It
2380always returns TRUE, indicating that each address has its own independent
2381status set, except if there is a setting up problem, in which case it returns
2382FALSE. */
2383
2384BOOL
2385smtp_transport_entry(
2386 transport_instance *tblock, /* data for this instantiation */
2387 address_item *addrlist) /* addresses we are working on */
2388{
2389int cutoff_retry;
2390int port;
2391int hosts_defer = 0;
2392int hosts_fail = 0;
2393int hosts_looked_up = 0;
2394int hosts_retry = 0;
2395int hosts_serial = 0;
2396int hosts_total = 0;
2397int total_hosts_tried = 0;
2398address_item *addr;
2399BOOL expired = TRUE;
2400BOOL continuing = continue_hostname != NULL;
2401uschar *expanded_hosts = NULL;
2402uschar *pistring;
2403uschar *tid = string_sprintf("%s transport", tblock->name);
2404smtp_transport_options_block *ob =
2405 (smtp_transport_options_block *)(tblock->options_block);
2406host_item *hostlist = addrlist->host_list;
2407host_item *host = NULL;
2408
2409DEBUG(D_transport)
2410 {
2411 debug_printf("%s transport entered\n", tblock->name);
2412 for (addr = addrlist; addr != NULL; addr = addr->next)
2413 debug_printf(" %s\n", addr->address);
2414 if (continuing) debug_printf("already connected to %s [%s]\n",
2415 continue_hostname, continue_host_address);
2416 }
2417
2418/* Set the flag requesting that these hosts be added to the waiting
2419database if the delivery fails temporarily or if we are running with
2420queue_smtp or a 2-stage queue run. This gets unset for certain
2421kinds of error, typically those that are specific to the message. */
2422
2423update_waiting = TRUE;
2424
2425/* If a host list is not defined for the addresses - they must all have the
2426same one in order to be passed to a single transport - or if the transport has
2427a host list with hosts_override set, use the host list supplied with the
2428transport. It is an error for this not to exist. */
2429
2430if (hostlist == NULL || (ob->hosts_override && ob->hosts != NULL))
2431 {
2432 if (ob->hosts == NULL)
2433 {
2434 addrlist->message = string_sprintf("%s transport called with no hosts set",
2435 tblock->name);
2436 addrlist->transport_return = PANIC;
2437 return FALSE; /* Only top address has status */
2438 }
2439
2440 DEBUG(D_transport) debug_printf("using the transport's hosts: %s\n",
2441 ob->hosts);
2442
2443 /* If the transport's host list contains no '$' characters, and we are not
2444 randomizing, it is fixed and therefore a chain of hosts can be built once
2445 and for all, and remembered for subsequent use by other calls to this
2446 transport. If, on the other hand, the host list does contain '$', or we are
2447 randomizing its order, we have to rebuild it each time. In the fixed case,
2448 as the hosts string will never be used again, it doesn't matter that we
2449 replace all the : characters with zeros. */
2450
2451 if (ob->hostlist == NULL)
2452 {
2453 uschar *s = ob->hosts;
2454
2455 if (Ustrchr(s, '$') != NULL)
2456 {
2457 expanded_hosts = expand_string(s);
2458 if (expanded_hosts == NULL)
2459 {
2460 addrlist->message = string_sprintf("failed to expand list of hosts "
2461 "\"%s\" in %s transport: %s", s, tblock->name, expand_string_message);
2462 addrlist->transport_return = search_find_defer? DEFER : PANIC;
2463 return FALSE; /* Only top address has status */
2464 }
2465 DEBUG(D_transport) debug_printf("expanded list of hosts \"%s\" to "
2466 "\"%s\"\n", s, expanded_hosts);
2467 s = expanded_hosts;
2468 }
2469 else
2470 if (ob->hosts_randomize) s = expanded_hosts = string_copy(s);
2471
2472 host_build_hostlist(&hostlist, s, ob->hosts_randomize);
2473
2474 /* Check that the expansion yielded something useful. */
2475 if (hostlist == NULL)
2476 {
2477 addrlist->message =
2478 string_sprintf("%s transport has empty hosts setting", tblock->name);
2479 addrlist->transport_return = PANIC;
2480 return FALSE; /* Only top address has status */
2481 }
2482
2483 /* If there was no expansion of hosts, save the host list for
2484 next time. */
2485
2486 if (expanded_hosts == NULL) ob->hostlist = hostlist;
2487 }
2488
2489 /* This is not the first time this transport has been run in this delivery;
2490 the host list was built previously. */
2491
2492 else hostlist = ob->hostlist;
2493 }
2494
2495/* The host list was supplied with the address. If hosts_randomize is set, we
2496must sort it into a random order if it did not come from MX records and has not
2497already been randomized (but don't bother if continuing down an existing
2498connection). */
2499
2500else if (ob->hosts_randomize && hostlist->mx == MX_NONE && !continuing)
2501 {
2502 host_item *newlist = NULL;
2503 while (hostlist != NULL)
2504 {
2505 host_item *h = hostlist;
2506 hostlist = hostlist->next;
2507
2508 h->sort_key = random_number(100);
2509
2510 if (newlist == NULL)
2511 {
2512 h->next = NULL;
2513 newlist = h;
2514 }
2515 else if (h->sort_key < newlist->sort_key)
2516 {
2517 h->next = newlist;
2518 newlist = h;
2519 }
2520 else
2521 {
2522 host_item *hh = newlist;
2523 while (hh->next != NULL)
2524 {
2525 if (h->sort_key < hh->next->sort_key) break;
2526 hh = hh->next;
2527 }
2528 h->next = hh->next;
2529 hh->next = h;
2530 }
2531 }
2532
2533 hostlist = addrlist->host_list = newlist;
2534 }
2535
2536
2537/* Sort out the default port. */
2538
2539if (!smtp_get_port(ob->port, addrlist, &port, tid)) return FALSE;
2540
2541
2542/* For each host-plus-IP-address on the list:
2543
2544. If this is a continued delivery and the host isn't the one with the
2545 current connection, skip.
2546
2547. If the status is unusable (i.e. previously failed or retry checked), skip.
2548
2549. If no IP address set, get the address, either by turning the name into
2550 an address, calling gethostbyname if gethostbyname is on, or by calling
2551 the DNS. The DNS may yield multiple addresses, in which case insert the
2552 extra ones into the list.
2553
2554. Get the retry data if not previously obtained for this address and set the
2555 field which remembers the state of this address. Skip if the retry time is
2556 not reached. If not, remember whether retry data was found. The retry string
2557 contains both the name and the IP address.
2558
2559. Scan the list of addresses and mark those whose status is DEFER as
2560 PENDING_DEFER. These are the only ones that will be processed in this cycle
2561 of the hosts loop.
2562
2563. Make a delivery attempt - addresses marked PENDING_DEFER will be tried.
2564 Some addresses may be successfully delivered, others may fail, and yet
2565 others may get temporary errors and so get marked DEFER.
2566
2567. The return from the delivery attempt is OK if a connection was made and a
2568 valid SMTP dialogue was completed. Otherwise it is DEFER.
2569
2570. If OK, add a "remove" retry item for this host/IPaddress, if any.
2571
2572. If fail to connect, or other defer state, add a retry item.
2573
2574. If there are any addresses whose status is still DEFER, carry on to the
2575 next host/IPaddress, unless we have tried the number of hosts given
2576 by hosts_max_try or hosts_max_try_hardlimit; otherwise return. Note that
2577 there is some fancy logic for hosts_max_try that means its limit can be
2578 overstepped in some circumstances.
2579
2580If we get to the end of the list, all hosts have deferred at least one address,
2581or not reached their retry times. If delay_after_cutoff is unset, it requests a
2582delivery attempt to those hosts whose last try was before the arrival time of
2583the current message. To cope with this, we have to go round the loop a second
2584time. After that, set the status and error data for any addresses that haven't
2585had it set already. */
2586
2587for (cutoff_retry = 0; expired &&
2588 cutoff_retry < ((ob->delay_after_cutoff)? 1 : 2);
2589 cutoff_retry++)
2590 {
2591 host_item *nexthost = NULL;
2592 int unexpired_hosts_tried = 0;
2593
2594 for (host = hostlist;
2595 host != NULL &&
2596 unexpired_hosts_tried < ob->hosts_max_try &&
2597 total_hosts_tried < ob->hosts_max_try_hardlimit;
2598 host = nexthost)
2599 {
2600 int rc;
2601 int host_af;
2602 uschar *rs;
2603 BOOL serialized = FALSE;
2604 BOOL host_is_expired = FALSE;
2605 BOOL message_defer = FALSE;
2606 BOOL ifchanges = FALSE;
2607 BOOL some_deferred = FALSE;
2608 address_item *first_addr = NULL;
2609 uschar *interface = NULL;
2610 uschar *retry_host_key = NULL;
2611 uschar *retry_message_key = NULL;
2612 uschar *serialize_key = NULL;
2613
2614 /* Default next host is next host. :-) But this can vary if the
2615 hosts_max_try limit is hit (see below). It may also be reset if a host
2616 address is looked up here (in case the host was multihomed). */
2617
2618 nexthost = host->next;
2619
2620 /* If the address hasn't yet been obtained from the host name, look it up
2621 now, unless the host is already marked as unusable. If it is marked as
2622 unusable, it means that the router was unable to find its IP address (in
2623 the DNS or wherever) OR we are in the 2nd time round the cutoff loop, and
2624 the lookup failed last time. We don't get this far if *all* MX records
2625 point to non-existent hosts; that is treated as a hard error.
2626
2627 We can just skip this host entirely. When the hosts came from the router,
2628 the address will timeout based on the other host(s); when the address is
2629 looked up below, there is an explicit retry record added.
2630
2631 Note that we mustn't skip unusable hosts if the address is not unset; they
2632 may be needed as expired hosts on the 2nd time round the cutoff loop. */
2633
2634 if (host->address == NULL)
2635 {
2636 int new_port, flags;
2637 host_item *hh;
2638 uschar *canonical_name;
2639
2640 if (host->status >= hstatus_unusable)
2641 {
2642 DEBUG(D_transport) debug_printf("%s has no address and is unusable - skipping\n",
2643 host->name);
2644 continue;
2645 }
2646
2647 DEBUG(D_transport) debug_printf("getting address for %s\n", host->name);
2648
2649 /* The host name is permitted to have an attached port. Find it, and
2650 strip it from the name. Just remember it for now. */
2651
2652 new_port = host_item_get_port(host);
2653
2654 /* Count hosts looked up */
2655
2656 hosts_looked_up++;
2657
2658 /* Find by name if so configured, or if it's an IP address. We don't
2659 just copy the IP address, because we need the test-for-local to happen. */
2660
2661 flags = HOST_FIND_BY_A;
2662 if (ob->dns_qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
2663 if (ob->dns_search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
2664
2665 if (ob->gethostbyname || string_is_ip_address(host->name, NULL) != 0)
2666 rc = host_find_byname(host, NULL, flags, &canonical_name, TRUE);
2667 else
2668 rc = host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
2669 &canonical_name, NULL);
2670
2671 /* Update the host (and any additional blocks, resulting from
2672 multihoming) with a host-specific port, if any. */
2673
2674 for (hh = host; hh != nexthost; hh = hh->next) hh->port = new_port;
2675
2676 /* Failure to find the host at this time (usually DNS temporary failure)
2677 is really a kind of routing failure rather than a transport failure.
2678 Therefore we add a retry item of the routing kind, not to stop us trying
2679 to look this name up here again, but to ensure the address gets timed
2680 out if the failures go on long enough. A complete failure at this point
2681 commonly points to a configuration error, but the best action is still
2682 to carry on for the next host. */
2683
2684 if (rc == HOST_FIND_AGAIN || rc == HOST_FIND_FAILED)
2685 {
2686 retry_add_item(addrlist, string_sprintf("R:%s", host->name), 0);
2687 expired = FALSE;
2688 if (rc == HOST_FIND_AGAIN) hosts_defer++; else hosts_fail++;
2689 DEBUG(D_transport) debug_printf("rc = %s for %s\n", (rc == HOST_FIND_AGAIN)?
2690 "HOST_FIND_AGAIN" : "HOST_FIND_FAILED", host->name);
2691 host->status = hstatus_unusable;
2692
2693 for (addr = addrlist; addr != NULL; addr = addr->next)
2694 {
2695 if (addr->transport_return != DEFER) continue;
2696 addr->basic_errno = ERRNO_UNKNOWNHOST;
2697 addr->message =
2698 string_sprintf("failed to lookup IP address for %s", host->name);
2699 }
2700 continue;
2701 }
2702
2703 /* If the host is actually the local host, we may have a problem, or
2704 there may be some cunning configuration going on. In the problem case,
2705 log things and give up. The default transport status is already DEFER. */
2706
2707 if (rc == HOST_FOUND_LOCAL && !ob->allow_localhost)
2708 {
2709 for (addr = addrlist; addr != NULL; addr = addr->next)
2710 {
2711 addr->basic_errno = 0;
2712 addr->message = string_sprintf("%s transport found host %s to be "
2713 "local", tblock->name, host->name);
2714 }
2715 goto END_TRANSPORT;
2716 }
2717 } /* End of block for IP address lookup */
2718
2719 /* If this is a continued delivery, we are interested only in the host
2720 which matches the name of the existing open channel. The check is put
2721 here after the local host lookup, in case the name gets expanded as a
2722 result of the lookup. Set expired FALSE, to save the outer loop executing
2723 twice. */
2724
2725 if (continuing && (Ustrcmp(continue_hostname, host->name) != 0 ||
2726 Ustrcmp(continue_host_address, host->address) != 0))
2727 {
2728 expired = FALSE;
2729 continue; /* With next host */
2730 }
2731
2732 /* Reset the default next host in case a multihomed host whose addresses
2733 are not looked up till just above added to the host list. */
2734
2735 nexthost = host->next;
2736
2737 /* If queue_smtp is set (-odqs or the first part of a 2-stage run), or the
2738 domain is in queue_smtp_domains, we don't actually want to attempt any
2739 deliveries. When doing a queue run, queue_smtp_domains is always unset. If
2740 there is a lookup defer in queue_smtp_domains, proceed as if the domain
2741 were not in it. We don't want to hold up all SMTP deliveries! Except when
2742 doing a two-stage queue run, don't do this if forcing. */
2743
2744 if ((!deliver_force || queue_2stage) && (queue_smtp ||
2745 match_isinlist(addrlist->domain, &queue_smtp_domains, 0,
2746 &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL) == OK))
2747 {
2748 expired = FALSE;
2749 for (addr = addrlist; addr != NULL; addr = addr->next)
2750 {
2751 if (addr->transport_return != DEFER) continue;
2752 addr->message = US"domain matches queue_smtp_domains, or -odqs set";
2753 }
2754 continue; /* With next host */
2755 }
2756
2757 /* Count hosts being considered - purely for an intelligent comment
2758 if none are usable. */
2759
2760 hosts_total++;
2761
2762 /* Set $host and $host address now in case they are needed for the
2763 interface expansion or the serialize_hosts check; they remain set if an
2764 actual delivery happens. */
2765
2766 deliver_host = host->name;
2767 deliver_host_address = host->address;
2768
2769 /* Set up a string for adding to the retry key if the port number is not
2770 the standard SMTP port. A host may have its own port setting that overrides
2771 the default. */
2772
2773 pistring = string_sprintf(":%d", (host->port == PORT_NONE)?
2774 port : host->port);
2775 if (Ustrcmp(pistring, ":25") == 0) pistring = US"";
2776
2777 /* Select IPv4 or IPv6, and choose an outgoing interface. If the interface
2778 string changes upon expansion, we must add it to the key that is used for
2779 retries, because connections to the same host from a different interface
2780 should be treated separately. */
2781
2782 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET : AF_INET6;
2783 if (!smtp_get_interface(ob->interface, host_af, addrlist, &ifchanges,
2784 &interface, tid))
2785 return FALSE;
2786 if (ifchanges) pistring = string_sprintf("%s/%s", pistring, interface);
2787
2788 /* The first time round the outer loop, check the status of the host by
2789 inspecting the retry data. The second time round, we are interested only
2790 in expired hosts that haven't been tried since this message arrived. */
2791
2792 if (cutoff_retry == 0)
2793 {
2794 /* Ensure the status of the address is set by checking retry data if
2795 necessary. There maybe host-specific retry data (applicable to all
2796 messages) and also data for retries of a specific message at this host.
2797 If either of these retry records are actually read, the keys used are
2798 returned to save recomputing them later. */
2799
2800 host_is_expired = retry_check_address(addrlist->domain, host, pistring,
2801 ob->retry_include_ip_address, &retry_host_key, &retry_message_key);
2802
2803 DEBUG(D_transport) debug_printf("%s [%s]%s status = %s\n", host->name,
2804 (host->address == NULL)? US"" : host->address, pistring,
2805 (host->status == hstatus_usable)? "usable" :
2806 (host->status == hstatus_unusable)? "unusable" :
2807 (host->status == hstatus_unusable_expired)? "unusable (expired)" : "?");
2808
2809 /* Skip this address if not usable at this time, noting if it wasn't
2810 actually expired, both locally and in the address. */
2811
2812 switch (host->status)
2813 {
2814 case hstatus_unusable:
2815 expired = FALSE;
2816 setflag(addrlist, af_retry_skipped);
2817 /* Fall through */
2818
2819 case hstatus_unusable_expired:
2820 switch (host->why)
2821 {
2822 case hwhy_retry: hosts_retry++; break;
2823 case hwhy_failed: hosts_fail++; break;
2824 case hwhy_deferred: hosts_defer++; break;
2825 }
2826
2827 /* If there was a retry message key, implying that previously there
2828 was a message-specific defer, we don't want to update the list of
2829 messages waiting for these hosts. */
2830
2831 if (retry_message_key != NULL) update_waiting = FALSE;
2832 continue; /* With the next host or IP address */
2833 }
2834 }
2835
2836 /* Second time round the loop: if the address is set but expired, and
2837 the message is newer than the last try, let it through. */
2838
2839 else
2840 {
2841 if (host->address == NULL ||
2842 host->status != hstatus_unusable_expired ||
2843 host->last_try > received_time)
2844 continue;
2845 DEBUG(D_transport)
2846 debug_printf("trying expired host %s [%s]%s\n",
2847 host->name, host->address, pistring);
2848 host_is_expired = TRUE;
2849 }
2850
2851 /* Setting "expired=FALSE" doesn't actually mean not all hosts are expired;
2852 it remains TRUE only if all hosts are expired and none are actually tried.
2853 */
2854
2855 expired = FALSE;
2856
2857 /* If this host is listed as one to which access must be serialized,
2858 see if another Exim process has a connection to it, and if so, skip
2859 this host. If not, update the database to record our connection to it
2860 and remember this for later deletion. Do not do any of this if we are
2861 sending the message down a pre-existing connection. */
2862
2863 if (!continuing &&
2864 verify_check_this_host(&(ob->serialize_hosts), NULL, host->name,
2865 host->address, NULL) == OK)
2866 {
2867 serialize_key = string_sprintf("host-serialize-%s", host->name);
2868 if (!enq_start(serialize_key))
2869 {
2870 DEBUG(D_transport)
2871 debug_printf("skipping host %s because another Exim process "
2872 "is connected to it\n", host->name);
2873 hosts_serial++;
2874 continue;
2875 }
2876 serialized = TRUE;
2877 }
2878
2879 /* OK, we have an IP address that is not waiting for its retry time to
2880 arrive (it might be expired) OR (second time round the loop) we have an
2881 expired host that hasn't been tried since the message arrived. Have a go
2882 at delivering the message to it. First prepare the addresses by flushing
2883 out the result of previous attempts, and finding the first address that
2884 is still to be delivered. */
2885
2886 first_addr = prepare_addresses(addrlist, host);
2887
2888 DEBUG(D_transport) debug_printf("delivering %s to %s [%s] (%s%s)\n",
2889 message_id, host->name, host->address, addrlist->address,
2890 (addrlist->next == NULL)? "" : ", ...");
2891
2892 set_process_info("delivering %s to %s [%s] (%s%s)",
2893 message_id, host->name, host->address, addrlist->address,
2894 (addrlist->next == NULL)? "" : ", ...");
2895
2896 /* This is not for real; don't do the delivery. If there are
2897 any remaining hosts, list them. */
2898
2899 if (dont_deliver)
2900 {
2901 host_item *host2;
2902 set_errno(addrlist, 0, NULL, OK, FALSE);
2903 for (addr = addrlist; addr != NULL; addr = addr->next)
2904 {
2905 addr->host_used = host;
2906 addr->special_action = '*';
2907 addr->message = US"delivery bypassed by -N option";
2908 }
2909 DEBUG(D_transport)
2910 {
2911 debug_printf("*** delivery by %s transport bypassed by -N option\n"
2912 "*** host and remaining hosts:\n", tblock->name);
2913 for (host2 = host; host2 != NULL; host2 = host2->next)
2914 debug_printf(" %s [%s]\n", host2->name,
2915 (host2->address == NULL)? US"unset" : host2->address);
2916 }
2917 rc = OK;
2918 }
2919
2920 /* This is for real. If the host is expired, we don't count it for
2921 hosts_max_retry. This ensures that all hosts must expire before an address
2922 is timed out, unless hosts_max_try_hardlimit (which protects against
2923 lunatic DNS configurations) is reached.
2924
2925 If the host is not expired and we are about to hit the hosts_max_retry
2926 limit, check to see if there is a subsequent hosts with a different MX
2927 value. If so, make that the next host, and don't count this one. This is a
2928 heuristic to make sure that different MXs do get tried. With a normal kind
2929 of retry rule, they would get tried anyway when the earlier hosts were
2930 delayed, but if the domain has a "retry every time" type of rule - as is
2931 often used for the the very large ISPs, that won't happen. */
2932
2933 else
2934 {
2935 if (!host_is_expired && ++unexpired_hosts_tried >= ob->hosts_max_try)
2936 {
2937 host_item *h;
2938 DEBUG(D_transport)
2939 debug_printf("hosts_max_try limit reached with this host\n");
2940 for (h = host; h != NULL; h = h->next)
2941 if (h->mx != host->mx) break;
2942 if (h != NULL)
2943 {
2944 nexthost = h;
2945 unexpired_hosts_tried--;
2946 DEBUG(D_transport) debug_printf("however, a higher MX host exists "
2947 "and will be tried\n");
2948 }
2949 }
2950
2951 /* Attempt the delivery. */
2952
2953 total_hosts_tried++;
2954 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2955 expanded_hosts != NULL, &message_defer, FALSE);
2956
2957 /* Yield is one of:
2958 OK => connection made, each address contains its result;
2959 message_defer is set for message-specific defers (when all
2960 recipients are marked defer)
2961 DEFER => there was a non-message-specific delivery problem;
2962 ERROR => there was a problem setting up the arguments for a filter,
2963 or there was a problem with expanding added headers
2964 */
2965
2966 /* If the result is not OK, there was a non-message-specific problem.
2967 If the result is DEFER, we need to write to the logs saying what happened
2968 for this particular host, except in the case of authentication and TLS
2969 failures, where the log has already been written. If all hosts defer a
2970 general message is written at the end. */
2971
2972 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL &&
2973 first_addr->basic_errno != ERRNO_TLSFAILURE)
2974 write_logs(first_addr, host);
2975
2976 /* If STARTTLS was accepted, but there was a failure in setting up the
2977 TLS session (usually a certificate screwup), and the host is not in
2978 hosts_require_tls, and tls_tempfail_tryclear is true, try again, with
2979 TLS forcibly turned off. We have to start from scratch with a new SMTP
2980 connection. That's why the retry is done from here, not from within
2981 smtp_deliver(). [Rejections of STARTTLS itself don't screw up the
2982 session, so the in-clear transmission after those errors, if permitted,
2983 happens inside smtp_deliver().] */
2984
2985 #ifdef SUPPORT_TLS
2986 if (rc == DEFER && first_addr->basic_errno == ERRNO_TLSFAILURE &&
2987 ob->tls_tempfail_tryclear &&
2988 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
2989 host->address, NULL) != OK)
2990 {
2991 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
2992 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
2993 first_addr = prepare_addresses(addrlist, host);
2994 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2995 expanded_hosts != NULL, &message_defer, TRUE);
2996 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL)
2997 write_logs(first_addr, host);
2998 }
2999 #endif
3000 }
3001
3002 /* Delivery attempt finished */
3003
3004 rs = (rc == OK)? US"OK" : (rc == DEFER)? US"DEFER" : (rc == ERROR)?
3005 US"ERROR" : US"?";
3006
3007 set_process_info("delivering %s: just tried %s [%s] for %s%s: result %s",
3008 message_id, host->name, host->address, addrlist->address,
3009 (addrlist->next == NULL)? "" : " (& others)", rs);
3010
3011 /* Release serialization if set up */
3012
3013 if (serialized) enq_end(serialize_key);
3014
3015 /* If the result is DEFER, or if a host retry record is known to exist, we
3016 need to add an item to the retry chain for updating the retry database
3017 at the end of delivery. We only need to add the item to the top address,
3018 of course. Also, if DEFER, we mark the IP address unusable so as to skip it
3019 for any other delivery attempts using the same address. (It is copied into
3020 the unusable tree at the outer level, so even if different address blocks
3021 contain the same address, it still won't get tried again.) */
3022
3023 if (rc == DEFER || retry_host_key != NULL)
3024 {
3025 int delete_flag = (rc != DEFER)? rf_delete : 0;
3026 if (retry_host_key == NULL)
3027 {
3028 retry_host_key = ob->retry_include_ip_address?
3029 string_sprintf("T:%S:%s%s", host->name, host->address, pistring) :
3030 string_sprintf("T:%S%s", host->name, pistring);
3031 }
3032
3033 /* If a delivery of another message over an existing SMTP connection
3034 yields DEFER, we do NOT set up retry data for the host. This covers the
3035 case when there are delays in routing the addresses in the second message
3036 that are so long that the server times out. This is alleviated by not
3037 routing addresses that previously had routing defers when handling an
3038 existing connection, but even so, this case may occur (e.g. if a
3039 previously happily routed address starts giving routing defers). If the
3040 host is genuinely down, another non-continued message delivery will
3041 notice it soon enough. */
3042
3043 if (delete_flag != 0 || !continuing)
3044 retry_add_item(first_addr, retry_host_key, rf_host | delete_flag);
3045
3046 /* We may have tried an expired host, if its retry time has come; ensure
3047 the status reflects the expiry for the benefit of any other addresses. */
3048
3049 if (rc == DEFER)
3050 {
3051 host->status = (host_is_expired)?
3052 hstatus_unusable_expired : hstatus_unusable;
3053 host->why = hwhy_deferred;
3054 }
3055 }
3056
3057 /* If message_defer is set (host was OK, but every recipient got deferred
3058 because of some message-specific problem), or if that had happened
3059 previously so that a message retry key exists, add an appropriate item
3060 to the retry chain. Note that if there was a message defer but now there is
3061 a host defer, the message defer record gets deleted. That seems perfectly
3062 reasonable. Also, stop the message from being remembered as waiting
3063 for specific hosts. */
3064
3065 if (message_defer || retry_message_key != NULL)
3066 {
3067 int delete_flag = message_defer? 0 : rf_delete;
3068 if (retry_message_key == NULL)
3069 {
3070 retry_message_key = ob->retry_include_ip_address?
3071 string_sprintf("T:%S:%s%s:%s", host->name, host->address, pistring,
3072 message_id) :
3073 string_sprintf("T:%S%s:%s", host->name, pistring, message_id);
3074 }
3075 retry_add_item(addrlist, retry_message_key,
3076 rf_message | rf_host | delete_flag);
3077 update_waiting = FALSE;
3078 }
3079
3080 /* Any return other than DEFER (that is, OK or ERROR) means that the
3081 addresses have got their final statuses filled in for this host. In the OK
3082 case, see if any of them are deferred. */
3083
3084 if (rc == OK)
3085 {
3086 for (addr = addrlist; addr != NULL; addr = addr->next)
3087 {
3088 if (addr->transport_return == DEFER)
3089 {
3090 some_deferred = TRUE;
3091 break;
3092 }
3093 }
3094 }
3095
3096 /* If no addresses deferred or the result was ERROR, return. We do this for
3097 ERROR because a failing filter set-up or add_headers expansion is likely to
3098 fail for any host we try. */
3099
3100 if (rc == ERROR || (rc == OK && !some_deferred))
3101 {
3102 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
3103 return TRUE; /* Each address has its status */
3104 }
3105
3106 /* If the result was DEFER or some individual addresses deferred, let
3107 the loop run to try other hosts with the deferred addresses, except for the
3108 case when we were trying to deliver down an existing channel and failed.
3109 Don't try any other hosts in this case. */
3110
3111 if (continuing) break;
3112
3113 /* If the whole delivery, or some individual addresses, were deferred and
3114 there are more hosts that could be tried, do not count this host towards
3115 the hosts_max_try limit if the age of the message is greater than the
3116 maximum retry time for this host. This means we may try try all hosts,
3117 ignoring the limit, when messages have been around for some time. This is
3118 important because if we don't try all hosts, the address will never time
3119 out. NOTE: this does not apply to hosts_max_try_hardlimit. */
3120
3121 if ((rc == DEFER || some_deferred) && nexthost != NULL)
3122 {
3123 BOOL timedout;
3124 retry_config *retry = retry_find_config(host->name, NULL, 0, 0);
3125
3126 if (retry != NULL && retry->rules != NULL)
3127 {
3128 retry_rule *last_rule;
3129 for (last_rule = retry->rules;
3130 last_rule->next != NULL;
3131 last_rule = last_rule->next);
3132 timedout = time(NULL) - received_time > last_rule->timeout;
3133 }
3134 else timedout = TRUE; /* No rule => timed out */
3135
3136 if (timedout)
3137 {
3138 unexpired_hosts_tried--;
3139 DEBUG(D_transport) debug_printf("temporary delivery error(s) override "
3140 "hosts_max_try (message older than host's retry time)\n");
3141 }
3142 }
3143 } /* End of loop for trying multiple hosts. */
3144
3145 /* This is the end of the loop that repeats iff expired is TRUE and
3146 ob->delay_after_cutoff is FALSE. The second time round we will
3147 try those hosts that haven't been tried since the message arrived. */
3148
3149 DEBUG(D_transport)
3150 {
3151 debug_printf("all IP addresses skipped or deferred at least one address\n");
3152 if (expired && !ob->delay_after_cutoff && cutoff_retry == 0)
3153 debug_printf("retrying IP addresses not tried since message arrived\n");
3154 }
3155 }
3156
3157
3158/* Get here if all IP addresses are skipped or defer at least one address. In
3159MUA wrapper mode, this will happen only for connection or other non-message-
3160specific failures. Force the delivery status for all addresses to FAIL. */
3161
3162if (mua_wrapper)
3163 {
3164 for (addr = addrlist; addr != NULL; addr = addr->next)
3165 addr->transport_return = FAIL;
3166 goto END_TRANSPORT;
3167 }
3168
3169/* In the normal, non-wrapper case, add a standard message to each deferred
3170address if there hasn't been an error, that is, if it hasn't actually been
3171tried this time. The variable "expired" will be FALSE if any deliveries were
3172actually tried, or if there was at least one host that was not expired. That
3173is, it is TRUE only if no deliveries were tried and all hosts were expired. If
3174a delivery has been tried, an error code will be set, and the failing of the
3175message is handled by the retry code later.
3176
3177If queue_smtp is set, or this transport was called to send a subsequent message
3178down an existing TCP/IP connection, and something caused the host not to be
3179found, we end up here, but can detect these cases and handle them specially. */
3180
3181for (addr = addrlist; addr != NULL; addr = addr->next)
3182 {
3183 /* If host is not NULL, it means that we stopped processing the host list
3184 because of hosts_max_try or hosts_max_try_hardlimit. In the former case, this
3185 means we need to behave as if some hosts were skipped because their retry
3186 time had not come. Specifically, this prevents the address from timing out.
3187 However, if we have hit hosts_max_try_hardlimit, we want to behave as if all
3188 hosts were tried. */
3189
3190 if (host != NULL)
3191 {
3192 if (total_hosts_tried >= ob->hosts_max_try_hardlimit)
3193 {
3194 DEBUG(D_transport)
3195 debug_printf("hosts_max_try_hardlimit reached: behave as if all "
3196 "hosts were tried\n");
3197 }
3198 else
3199 {
3200 DEBUG(D_transport)
3201 debug_printf("hosts_max_try limit caused some hosts to be skipped\n");
3202 setflag(addr, af_retry_skipped);
3203 }
3204 }
3205
3206 if (queue_smtp) /* no deliveries attempted */
3207 {
3208 addr->transport_return = DEFER;
3209 addr->basic_errno = 0;
3210 addr->message = US"SMTP delivery explicitly queued";
3211 }
3212
3213 else if (addr->transport_return == DEFER &&
3214 (addr->basic_errno == ERRNO_UNKNOWNERROR || addr->basic_errno == 0) &&
3215 addr->message == NULL)
3216 {
3217 addr->basic_errno = ERRNO_HRETRY;
3218 if (continue_hostname != NULL)
3219 {
3220 addr->message = US"no host found for existing SMTP connection";
3221 }
3222 else if (expired)
3223 {
3224 setflag(addr, af_pass_message); /* This is not a security risk */
3225 addr->message = (ob->delay_after_cutoff)?
3226 US"retry time not reached for any host after a long failure period" :
3227 US"all hosts have been failing for a long time and were last tried "
3228 "after this message arrived";
3229
3230 /* If we are already using fallback hosts, or there are no fallback hosts
3231 defined, convert the result to FAIL to cause a bounce. */
3232
3233 if (addr->host_list == addr->fallback_hosts ||
3234 addr->fallback_hosts == NULL)
3235 addr->transport_return = FAIL;
3236 }
3237 else
3238 {
3239 if (hosts_retry == hosts_total)
3240 addr->message = US"retry time not reached for any host";
3241 else if (hosts_fail == hosts_total)
3242 addr->message = US"all host address lookups failed permanently";
3243 else if (hosts_defer == hosts_total)
3244 addr->message = US"all host address lookups failed temporarily";
3245 else if (hosts_serial == hosts_total)
3246 addr->message = US"connection limit reached for all hosts";
3247 else if (hosts_fail+hosts_defer == hosts_total)
3248 addr->message = US"all host address lookups failed";
3249 else addr->message = US"some host address lookups failed and retry time "
3250 "not reached for other hosts or connection limit reached";
3251 }
3252 }
3253 }
3254
3255/* Update the database which keeps information about which messages are waiting
3256for which hosts to become available. For some message-specific errors, the
3257update_waiting flag is turned off because we don't want follow-on deliveries in
3258those cases. If this transport instance is explicitly limited to one message
3259per connection then follow-on deliveries are not possible and there's no need
3260to create/update the per-transport wait-<transport_name> database. */
3261
3262if (update_waiting && tblock->connection_max_messages != 1)
3263 transport_update_waiting(hostlist, tblock->name);
3264
3265END_TRANSPORT:
3266
3267DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
3268
3269return TRUE; /* Each address has its status */
3270}
3271
3272/* End of transport/smtp.c */