1 /* $Cambridge: exim/src/src/transports/smtp.c,v 1.21 2006/02/21 16:24:20 ph10 Exp $ */
3 /*************************************************
4 * Exim - an Internet mail transport agent *
5 *************************************************/
7 /* Copyright (c) University of Cambridge 1995 - 2006 */
8 /* See the file NOTICE for conditions of use and distribution. */
14 #define PENDING_DEFER (PENDING + DEFER)
15 #define PENDING_OK (PENDING + OK)
18 /* Options specific to the smtp transport. This transport also supports LMTP
19 over TCP/IP. The options must be in alphabetic order (note that "_" comes
20 before the lower case letters). Some live in the transport_instance block so as
21 to be publicly visible; these are flagged with opt_public. */
23 optionlist smtp_transport_options[] = {
24 { "allow_localhost", opt_bool,
25 (void *)offsetof(smtp_transport_options_block, allow_localhost) },
26 { "authenticated_sender", opt_stringptr,
27 (void *)offsetof(smtp_transport_options_block, authenticated_sender) },
28 { "command_timeout", opt_time,
29 (void *)offsetof(smtp_transport_options_block, command_timeout) },
30 { "connect_timeout", opt_time,
31 (void *)offsetof(smtp_transport_options_block, connect_timeout) },
32 { "connection_max_messages", opt_int | opt_public,
33 (void *)offsetof(transport_instance, connection_max_messages) },
34 { "data_timeout", opt_time,
35 (void *)offsetof(smtp_transport_options_block, data_timeout) },
36 { "delay_after_cutoff", opt_bool,
37 (void *)offsetof(smtp_transport_options_block, delay_after_cutoff) },
38 #ifdef EXPERIMENTAL_DOMAINKEYS
39 { "dk_canon", opt_stringptr,
40 (void *)offsetof(smtp_transport_options_block, dk_canon) },
41 { "dk_domain", opt_stringptr,
42 (void *)offsetof(smtp_transport_options_block, dk_domain) },
43 { "dk_headers", opt_stringptr,
44 (void *)offsetof(smtp_transport_options_block, dk_headers) },
45 { "dk_private_key", opt_stringptr,
46 (void *)offsetof(smtp_transport_options_block, dk_private_key) },
47 { "dk_selector", opt_stringptr,
48 (void *)offsetof(smtp_transport_options_block, dk_selector) },
49 { "dk_strict", opt_stringptr,
50 (void *)offsetof(smtp_transport_options_block, dk_strict) },
52 { "dns_qualify_single", opt_bool,
53 (void *)offsetof(smtp_transport_options_block, dns_qualify_single) },
54 { "dns_search_parents", opt_bool,
55 (void *)offsetof(smtp_transport_options_block, dns_search_parents) },
56 { "fallback_hosts", opt_stringptr,
57 (void *)offsetof(smtp_transport_options_block, fallback_hosts) },
58 { "final_timeout", opt_time,
59 (void *)offsetof(smtp_transport_options_block, final_timeout) },
60 { "gethostbyname", opt_bool,
61 (void *)offsetof(smtp_transport_options_block, gethostbyname) },
62 { "helo_data", opt_stringptr,
63 (void *)offsetof(smtp_transport_options_block, helo_data) },
64 { "hosts", opt_stringptr,
65 (void *)offsetof(smtp_transport_options_block, hosts) },
66 { "hosts_avoid_esmtp", opt_stringptr,
67 (void *)offsetof(smtp_transport_options_block, hosts_avoid_esmtp) },
69 { "hosts_avoid_tls", opt_stringptr,
70 (void *)offsetof(smtp_transport_options_block, hosts_avoid_tls) },
72 { "hosts_max_try", opt_int,
73 (void *)offsetof(smtp_transport_options_block, hosts_max_try) },
74 { "hosts_max_try_hardlimit", opt_int,
75 (void *)offsetof(smtp_transport_options_block, hosts_max_try_hardlimit) },
77 { "hosts_nopass_tls", opt_stringptr,
78 (void *)offsetof(smtp_transport_options_block, hosts_nopass_tls) },
80 { "hosts_override", opt_bool,
81 (void *)offsetof(smtp_transport_options_block, hosts_override) },
82 { "hosts_randomize", opt_bool,
83 (void *)offsetof(smtp_transport_options_block, hosts_randomize) },
84 { "hosts_require_auth", opt_stringptr,
85 (void *)offsetof(smtp_transport_options_block, hosts_require_auth) },
87 { "hosts_require_tls", opt_stringptr,
88 (void *)offsetof(smtp_transport_options_block, hosts_require_tls) },
90 { "hosts_try_auth", opt_stringptr,
91 (void *)offsetof(smtp_transport_options_block, hosts_try_auth) },
92 { "interface", opt_stringptr,
93 (void *)offsetof(smtp_transport_options_block, interface) },
94 { "keepalive", opt_bool,
95 (void *)offsetof(smtp_transport_options_block, keepalive) },
96 { "lmtp_ignore_quota", opt_bool,
97 (void *)offsetof(smtp_transport_options_block, lmtp_ignore_quota) },
98 { "max_rcpt", opt_int | opt_public,
99 (void *)offsetof(transport_instance, max_addresses) },
100 { "multi_domain", opt_bool | opt_public,
101 (void *)offsetof(transport_instance, multi_domain) },
102 { "port", opt_stringptr,
103 (void *)offsetof(smtp_transport_options_block, port) },
104 { "protocol", opt_stringptr,
105 (void *)offsetof(smtp_transport_options_block, protocol) },
106 { "retry_include_ip_address", opt_bool,
107 (void *)offsetof(smtp_transport_options_block, retry_include_ip_address) },
108 { "serialize_hosts", opt_stringptr,
109 (void *)offsetof(smtp_transport_options_block, serialize_hosts) },
110 { "size_addition", opt_int,
111 (void *)offsetof(smtp_transport_options_block, size_addition) }
113 ,{ "tls_certificate", opt_stringptr,
114 (void *)offsetof(smtp_transport_options_block, tls_certificate) },
115 { "tls_crl", opt_stringptr,
116 (void *)offsetof(smtp_transport_options_block, tls_crl) },
117 { "tls_privatekey", opt_stringptr,
118 (void *)offsetof(smtp_transport_options_block, tls_privatekey) },
119 { "tls_require_ciphers", opt_stringptr,
120 (void *)offsetof(smtp_transport_options_block, tls_require_ciphers) },
121 { "tls_tempfail_tryclear", opt_bool,
122 (void *)offsetof(smtp_transport_options_block, tls_tempfail_tryclear) },
123 { "tls_verify_certificates", opt_stringptr,
124 (void *)offsetof(smtp_transport_options_block, tls_verify_certificates) }
128 /* Size of the options list. An extern variable has to be used so that its
129 address can appear in the tables drtables.c. */
131 int smtp_transport_options_count =
132 sizeof(smtp_transport_options)/sizeof(optionlist);
134 /* Default private options block for the smtp transport. */
136 smtp_transport_options_block smtp_transport_option_defaults = {
138 NULL, /* fallback_hosts */
140 NULL, /* fallback_hostlist */
141 NULL, /* authenticated_sender */
142 US"$primary_hostname", /* helo_data */
143 NULL, /* interface */
145 US"smtp", /* protocol */
146 NULL, /* serialize_hosts */
147 NULL, /* hosts_try_auth */
148 NULL, /* hosts_require_auth */
149 NULL, /* hosts_require_tls */
150 NULL, /* hosts_avoid_tls */
151 NULL, /* hosts_avoid_esmtp */
152 NULL, /* hosts_nopass_tls */
153 5*60, /* command_timeout */
154 5*60, /* connect_timeout; shorter system default overrides */
155 5*60, /* data timeout */
156 10*60, /* final timeout */
157 1024, /* size_addition */
158 5, /* hosts_max_try */
159 50, /* hosts_max_try_hardlimit */
160 FALSE, /* allow_localhost */
161 FALSE, /* gethostbyname */
162 TRUE, /* dns_qualify_single */
163 FALSE, /* dns_search_parents */
164 TRUE, /* delay_after_cutoff */
165 FALSE, /* hosts_override */
166 FALSE, /* hosts_randomize */
167 TRUE, /* keepalive */
168 FALSE, /* lmtp_ignore_quota */
169 TRUE /* retry_include_ip_address */
171 ,NULL, /* tls_certificate */
173 NULL, /* tls_privatekey */
174 NULL, /* tls_require_ciphers */
175 NULL, /* tls_verify_certificates */
176 TRUE /* tls_tempfail_tryclear */
178 #ifdef EXPERIMENTAL_DOMAINKEYS
179 ,NULL, /* dk_canon */
180 NULL, /* dk_domain */
181 NULL, /* dk_headers */
182 NULL, /* dk_private_key */
183 NULL, /* dk_selector */
191 static uschar *smtp_command; /* Points to last cmd for error messages */
192 static uschar *mail_command; /* Points to MAIL cmd for error messages */
195 /*************************************************
196 * Setup entry point *
197 *************************************************/
199 /* This function is called when the transport is about to be used,
200 but before running it in a sub-process. It is used for two things:
202 (1) To set the fallback host list in addresses, when delivering.
203 (2) To pass back the interface, port, and protocol options, for use during
204 callout verification.
207 tblock pointer to the transport instance block
208 addrlist list of addresses about to be transported
209 tf if not NULL, pointer to block in which to return options
210 uid the uid that will be set (not used)
211 gid the gid that will be set (not used)
212 errmsg place for error message (not used)
214 Returns: OK always (FAIL, DEFER not used)
218 smtp_transport_setup(transport_instance *tblock, address_item *addrlist,
219 transport_feedback *tf, uid_t uid, gid_t gid, uschar **errmsg)
221 smtp_transport_options_block *ob =
222 (smtp_transport_options_block *)(tblock->options_block);
224 errmsg = errmsg; /* Keep picky compilers happy */
228 /* Pass back options if required. This interface is getting very messy. */
232 tf->interface = ob->interface;
234 tf->protocol = ob->protocol;
235 tf->hosts = ob->hosts;
236 tf->hosts_override = ob->hosts_override;
237 tf->hosts_randomize = ob->hosts_randomize;
238 tf->gethostbyname = ob->gethostbyname;
239 tf->qualify_single = ob->dns_qualify_single;
240 tf->search_parents = ob->dns_search_parents;
243 /* Set the fallback host list for all the addresses that don't have fallback
244 host lists, provided that the local host wasn't present in the original host
247 if (!testflag(addrlist, af_local_host_removed))
249 for (; addrlist != NULL; addrlist = addrlist->next)
250 if (addrlist->fallback_hosts == NULL)
251 addrlist->fallback_hosts = ob->fallback_hostlist;
259 /*************************************************
260 * Initialization entry point *
261 *************************************************/
263 /* Called for each instance, after its options have been read, to
264 enable consistency checks to be done, or anything else that needs
267 Argument: pointer to the transport instance block
272 smtp_transport_init(transport_instance *tblock)
274 smtp_transport_options_block *ob =
275 (smtp_transport_options_block *)(tblock->options_block);
277 /* Retry_use_local_part defaults FALSE if unset */
279 if (tblock->retry_use_local_part == TRUE_UNSET)
280 tblock->retry_use_local_part = FALSE;
282 /* Set the default port according to the protocol */
284 if (ob->port == NULL)
285 ob->port = (strcmpic(ob->protocol, US"lmtp") == 0)? US"lmtp" : US"smtp";
287 /* Set up the setup entry point, to be called before subprocesses for this
290 tblock->setup = smtp_transport_setup;
292 /* Complain if any of the timeouts are zero. */
294 if (ob->command_timeout <= 0 || ob->data_timeout <= 0 ||
295 ob->final_timeout <= 0)
296 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
297 "command, data, or final timeout value is zero for %s transport",
300 /* If hosts_override is set and there are local hosts, set the global
301 flag that stops verify from showing router hosts. */
303 if (ob->hosts_override && ob->hosts != NULL) tblock->overrides_hosts = TRUE;
305 /* If there are any fallback hosts listed, build a chain of host items
306 for them, but do not do any lookups at this time. */
308 host_build_hostlist(&(ob->fallback_hostlist), ob->fallback_hosts, FALSE);
315 /*************************************************
316 * Set delivery info into all active addresses *
317 *************************************************/
319 /* Only addresses whose status is >= PENDING are relevant. A lesser
320 status means that an address is not currently being processed.
323 addrlist points to a chain of addresses
324 errno_value to put in each address's errno field
325 msg to put in each address's message field
326 rc to put in each address's transport_return field
327 pass_message if TRUE, set the "pass message" flag in the address
329 If errno_value has the special value ERRNO_CONNECTTIMEOUT, ETIMEDOUT is put in
330 the errno field, and RTEF_CTOUT is ORed into the more_errno field, to indicate
331 this particular type of timeout.
337 set_errno(address_item *addrlist, int errno_value, uschar *msg, int rc,
342 if (errno_value == ERRNO_CONNECTTIMEOUT)
344 errno_value = ETIMEDOUT;
345 orvalue = RTEF_CTOUT;
347 for (addr = addrlist; addr != NULL; addr = addr->next)
349 if (addr->transport_return < PENDING) continue;
350 addr->basic_errno = errno_value;
351 addr->more_errno |= orvalue;
355 if (pass_message) setflag(addr, af_pass_message);
357 addr->transport_return = rc;
363 /*************************************************
364 * Check an SMTP response *
365 *************************************************/
367 /* This function is given an errno code and the SMTP response buffer
368 to analyse, together with the host identification for generating messages. It
369 sets an appropriate message and puts the first digit of the response code into
370 the yield variable. If no response was actually read, a suitable digit is
374 host the current host, to get its name for messages
375 errno_value pointer to the errno value
376 more_errno from the top address for use with ERRNO_FILTER_FAIL
377 buffer the SMTP response buffer
378 yield where to put a one-digit SMTP response code
379 message where to put an errror message
380 pass_message set TRUE if message is an SMTP response
382 Returns: TRUE if an SMTP "QUIT" command should be sent, else FALSE
385 static BOOL check_response(host_item *host, int *errno_value, int more_errno,
386 uschar *buffer, int *yield, uschar **message, BOOL *pass_message)
390 if (smtp_use_pipelining &&
391 (Ustrcmp(smtp_command, "MAIL") == 0 ||
392 Ustrcmp(smtp_command, "RCPT") == 0 ||
393 Ustrcmp(smtp_command, "DATA") == 0))
396 *yield = '4'; /* Default setting is to give a temporary error */
398 /* Handle response timeout */
400 if (*errno_value == ETIMEDOUT)
402 *message = US string_sprintf("SMTP timeout while connected to %s [%s] "
403 "after %s%s", host->name, host->address, pl, smtp_command);
404 if (transport_count > 0)
405 *message = US string_sprintf("%s (%d bytes written)", *message,
410 /* Handle malformed SMTP response */
412 if (*errno_value == ERRNO_SMTPFORMAT)
414 uschar *malfresp = string_printing(buffer);
415 while (isspace(*malfresp)) malfresp++;
417 *message = string_sprintf("Malformed SMTP reply (an empty line) from "
418 "%s [%s] in response to %s%s", host->name, host->address, pl,
421 *message = string_sprintf("Malformed SMTP reply from %s [%s] in response "
422 "to %s%s: %s", host->name, host->address, pl, smtp_command, malfresp);
426 /* Handle a failed filter process error; can't send QUIT as we mustn't
429 if (*errno_value == ERRNO_FILTER_FAIL)
431 *message = US string_sprintf("transport filter process failed (%d)%s",
433 (more_errno == EX_EXECFAILED)? ": unable to execute command" : "");
437 /* Handle a failed add_headers expansion; can't send QUIT as we mustn't
440 if (*errno_value == ERRNO_CHHEADER_FAIL)
443 US string_sprintf("failed to expand headers_add or headers_remove: %s",
444 expand_string_message);
448 /* Handle failure to write a complete data block */
450 if (*errno_value == ERRNO_WRITEINCOMPLETE)
452 *message = US string_sprintf("failed to write a data block");
456 /* Handle error responses from the remote mailer. */
460 uschar *s = string_printing(buffer);
461 *message = US string_sprintf("SMTP error from remote mail server after %s%s: "
462 "host %s [%s]: %s", pl, smtp_command, host->name, host->address, s);
463 *pass_message = TRUE;
468 /* No data was read. If there is no errno, this must be the EOF (i.e.
469 connection closed) case, which causes deferral. An explicit connection reset
470 error has the same effect. Otherwise, put the host's identity in the message,
471 leaving the errno value to be interpreted as well. In all cases, we have to
472 assume the connection is now dead. */
474 if (*errno_value == 0 || *errno_value == ECONNRESET)
476 *errno_value = ERRNO_SMTPCLOSED;
477 *message = US string_sprintf("Remote host %s [%s] closed connection "
478 "in response to %s%s", host->name, host->address, pl, smtp_command);
480 else *message = US string_sprintf("%s [%s]", host->name, host->address);
487 /*************************************************
488 * Write error message to logs *
489 *************************************************/
491 /* This writes to the main log and to the message log.
494 addr the address item containing error information
495 host the current host
501 write_logs(address_item *addr, host_item *host)
503 if (addr->message != NULL)
505 uschar *message = addr->message;
506 if (addr->basic_errno > 0)
507 message = string_sprintf("%s: %s", message, strerror(addr->basic_errno));
508 log_write(0, LOG_MAIN, "%s", message);
509 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
514 ((log_extra_selector & LX_outgoing_port) != 0)?
515 string_sprintf("%s [%s]:%d", host->name, host->address,
516 (host->port == PORT_NONE)? 25 : host->port)
518 string_sprintf("%s [%s]", host->name, host->address);
519 log_write(0, LOG_MAIN, "%s %s", msg, strerror(addr->basic_errno));
520 deliver_msglog("%s %s %s\n", tod_stamp(tod_log), msg,
521 strerror(addr->basic_errno));
527 /*************************************************
528 * Synchronize SMTP responses *
529 *************************************************/
531 /* This function is called from smtp_deliver() to receive SMTP responses from
532 the server, and match them up with the commands to which they relate. When
533 PIPELINING is not in use, this function is called after every command, and is
534 therefore somewhat over-engineered, but it is simpler to use a single scheme
535 that works both with and without PIPELINING instead of having two separate sets
538 The set of commands that are buffered up with pipelining may start with MAIL
539 and may end with DATA; in between are RCPT commands that correspond to the
540 addresses whose status is PENDING_DEFER. All other commands (STARTTLS, AUTH,
541 etc.) are never buffered.
543 Errors after MAIL or DATA abort the whole process leaving the response in the
544 buffer. After MAIL, pending responses are flushed, and the original command is
545 re-instated in big_buffer for error messages. For RCPT commands, the remote is
546 permitted to reject some recipient addresses while accepting others. However
547 certain errors clearly abort the whole process. Set the value in
548 transport_return to PENDING_OK if the address is accepted. If there is a
549 subsequent general error, it will get reset accordingly. If not, it will get
550 converted to OK at the end.
553 addrlist the complete address list
554 include_affixes TRUE if affixes include in RCPT
555 sync_addr ptr to the ptr of the one to start scanning at (updated)
556 host the host we are connected to
557 count the number of responses to read
558 pending_MAIL true if the first response is for MAIL
559 pending_DATA 0 if last command sent was not DATA
560 +1 if previously had a good recipient
561 -1 if not previously had a good recipient
562 inblock incoming SMTP block
563 timeout timeout value
564 buffer buffer for reading response
565 buffsize size of buffer
567 Returns: 3 if at least one address had 2xx and one had 5xx
568 2 if at least one address had 5xx but none had 2xx
569 1 if at least one host had a 2xx response, but none had 5xx
570 0 no address had 2xx or 5xx but no errors (all 4xx, or just DATA)
571 -1 timeout while reading RCPT response
572 -2 I/O or other non-response error for RCPT
573 -3 DATA or MAIL failed - errno and buffer set
577 sync_responses(address_item *addrlist, BOOL include_affixes,
578 address_item **sync_addr, host_item *host, int count, BOOL pending_MAIL,
579 int pending_DATA, smtp_inblock *inblock, int timeout, uschar *buffer,
582 address_item *addr = *sync_addr;
585 /* Handle the response for a MAIL command. On error, reinstate the original
586 command in big_buffer for error message use, and flush any further pending
587 responses before returning, except after I/O errors and timeouts. */
592 if (!smtp_read_response(inblock, buffer, buffsize, '2', timeout))
594 Ustrcpy(big_buffer, mail_command); /* Fits, because it came from there! */
595 if (errno == 0 && buffer[0] != 0)
597 uschar flushbuffer[4096];
600 if (!smtp_read_response(inblock, flushbuffer, sizeof(flushbuffer),
602 && (errno != 0 || flushbuffer[0] == 0))
610 if (pending_DATA) count--; /* Number of RCPT responses to come */
612 /* Read and handle the required number of RCPT responses, matching each one up
613 with an address by scanning for the next address whose status is PENDING_DEFER.
618 while (addr->transport_return != PENDING_DEFER) addr = addr->next;
620 /* The address was accepted */
622 if (smtp_read_response(inblock, buffer, buffsize, '2', timeout))
625 addr->transport_return = PENDING_OK;
627 /* If af_dr_retry_exists is set, there was a routing delay on this address;
628 ensure that any address-specific retry record is expunged. */
630 if (testflag(addr, af_dr_retry_exists))
631 retry_add_item(addr, addr->address_retry_key, rf_delete);
634 /* Timeout while reading the response */
636 else if (errno == ETIMEDOUT)
638 int save_errno = errno;
639 uschar *message = string_sprintf("SMTP timeout while connected to %s [%s] "
640 "after RCPT TO:<%s>", host->name, host->address,
641 transport_rcpt_address(addr, include_affixes));
642 set_errno(addrlist, save_errno, message, DEFER, FALSE);
643 retry_add_item(addr, addr->address_retry_key, 0);
644 host->update_waiting = FALSE;
648 /* Handle other errors in obtaining an SMTP response by returning -1. This
649 will cause all the addresses to be deferred. Restore the SMTP command in
650 big_buffer for which we are checking the response, so the error message
653 else if (errno != 0 || buffer[0] == 0)
655 string_format(big_buffer, big_buffer_size, "RCPT TO:<%s>",
656 transport_rcpt_address(addr, include_affixes));
660 /* Handle SMTP permanent and temporary response codes. */
665 string_sprintf("SMTP error from remote mail server after RCPT TO:<%s>: "
666 "host %s [%s]: %s", transport_rcpt_address(addr, include_affixes),
667 host->name, host->address, string_printing(buffer));
668 setflag(addr, af_pass_message);
669 deliver_msglog("%s %s\n", tod_stamp(tod_log), addr->message);
671 /* The response was 5xx */
673 if (buffer[0] == '5')
675 addr->transport_return = FAIL;
679 /* The response was 4xx */
683 int bincode = (buffer[1] - '0')*10 + buffer[2] - '0';
685 addr->transport_return = DEFER;
686 addr->basic_errno = ERRNO_RCPT4XX;
687 addr->more_errno |= bincode << 8;
689 /* Log temporary errors if there are more hosts to be tried. */
691 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", addr->message);
693 /* Do not put this message on the list of those waiting for this host,
694 as otherwise it is likely to be tried too often. */
696 host->update_waiting = FALSE;
698 /* Add a retry item for the address so that it doesn't get tried
701 retry_add_item(addr, addr->address_retry_key, 0);
704 } /* Loop for next RCPT response */
706 /* Update where to start at for the next block of responses, unless we
707 have already handled all the addresses. */
709 if (addr != NULL) *sync_addr = addr->next;
711 /* Handle a response to DATA. If we have not had any good recipients, either
712 previously or in this block, the response is ignored. */
714 if (pending_DATA != 0 &&
715 !smtp_read_response(inblock, buffer, buffsize, '3', timeout))
720 if (pending_DATA > 0 || (yield & 1) != 0) return -3;
721 (void)check_response(host, &errno, 0, buffer, &code, &msg, &pass_message);
722 DEBUG(D_transport) debug_printf("%s\nerror for DATA ignored: pipelining "
723 "is in use and there were no good recipients\n", msg);
726 /* All responses read and handled; MAIL (if present) received 2xx and DATA (if
727 present) received 3xx. If any RCPTs were handled and yielded anything other
728 than 4xx, yield will be set non-zero. */
735 /*************************************************
736 * Deliver address list to given host *
737 *************************************************/
739 /* If continue_hostname is not null, we get here only when continuing to
740 deliver down an existing channel. The channel was passed as the standard
743 Otherwise, we have to make a connection to the remote host, and do the
744 initial protocol exchange.
746 When running as an MUA wrapper, if the sender or any recipient is rejected,
747 temporarily or permanently, we force failure for all recipients.
750 addrlist chain of potential addresses to deliver; only those whose
751 transport_return field is set to PENDING_DEFER are currently
752 being processed; others should be skipped - they have either
753 been delivered to an earlier host or IP address, or been
754 failed by one of them.
755 host host to deliver to
756 host_af AF_INET or AF_INET6
757 port default TCP/IP port to use, in host byte order
758 interface interface to bind to, or NULL
759 tblock transport instance block
760 copy_host TRUE if host set in addr->host_used must be copied, because
761 it is specific to this call of the transport
762 message_defer set TRUE if yield is OK, but all addresses were deferred
763 because of a non-recipient, non-host failure, that is, a
764 4xx response to MAIL FROM, DATA, or ".". This is a defer
765 that is specific to the message.
766 suppress_tls if TRUE, don't attempt a TLS connection - this is set for
767 a second attempt after TLS initialization fails
769 Returns: OK - the connection was made and the delivery attempted;
770 the result for each address is in its data block.
771 DEFER - the connection could not be made, or something failed
772 while setting up the SMTP session, or there was a
773 non-message-specific error, such as a timeout.
774 ERROR - a filter command is specified for this transport,
775 and there was a problem setting it up; OR helo_data
776 or add_headers or authenticated_sender is specified
777 for this transport, and the string failed to expand
781 smtp_deliver(address_item *addrlist, host_item *host, int host_af, int port,
782 uschar *interface, transport_instance *tblock, BOOL copy_host,
783 BOOL *message_defer, BOOL suppress_tls)
786 address_item *sync_addr;
787 address_item *first_addr = addrlist;
792 time_t start_delivery_time = time(NULL);
793 smtp_transport_options_block *ob =
794 (smtp_transport_options_block *)(tblock->options_block);
795 BOOL lmtp = strcmpic(ob->protocol, US"lmtp") == 0;
797 BOOL send_rset = TRUE;
798 BOOL send_quit = TRUE;
799 BOOL setting_up = TRUE;
800 BOOL completed_address = FALSE;
803 BOOL pass_message = FALSE;
804 smtp_inblock inblock;
805 smtp_outblock outblock;
806 int max_rcpt = tblock->max_addresses;
807 uschar *igquotstr = US"";
808 uschar *local_authenticated_sender = authenticated_sender;
810 uschar *message = NULL;
811 uschar new_message_id[MESSAGE_ID_LENGTH + 1];
814 uschar inbuffer[4096];
815 uschar outbuffer[1024];
817 suppress_tls = suppress_tls; /* stop compiler warning when no TLS support */
819 *message_defer = FALSE;
820 smtp_command = US"initial connection";
821 if (max_rcpt == 0) max_rcpt = 999999;
823 /* Set up the buffer for reading SMTP response packets. */
825 inblock.buffer = inbuffer;
826 inblock.buffersize = sizeof(inbuffer);
827 inblock.ptr = inbuffer;
828 inblock.ptrend = inbuffer;
830 /* Set up the buffer for holding SMTP commands while pipelining */
832 outblock.buffer = outbuffer;
833 outblock.buffersize = sizeof(outbuffer);
834 outblock.ptr = outbuffer;
835 outblock.cmd_count = 0;
836 outblock.authenticating = FALSE;
838 /* Expand the greeting message */
840 helo_data = expand_string(ob->helo_data);
841 if (helo_data == NULL)
843 uschar *message = string_sprintf("failed to expand helo_data: %s",
844 expand_string_message);
845 set_errno(addrlist, 0, message, DEFER, FALSE);
849 /* If an authenticated_sender override has been specified for this transport
850 instance, expand it. If the expansion is forced to fail, and there was already
851 an authenticated_sender for this message, the original value will be used.
852 Other expansion failures are serious. An empty result is ignored, but there is
853 otherwise no check - this feature is expected to be used with LMTP and other
854 cases where non-standard addresses (e.g. without domains) might be required. */
856 if (ob->authenticated_sender != NULL)
858 uschar *new = expand_string(ob->authenticated_sender);
861 if (!expand_string_forcedfail)
863 uschar *message = string_sprintf("failed to expand "
864 "authenticated_sender: %s", expand_string_message);
865 set_errno(addrlist, 0, message, DEFER, FALSE);
869 else if (new[0] != 0) local_authenticated_sender = new;
872 /* Make a connection to the host if this isn't a continued delivery, and handle
873 the initial interaction and HELO/EHLO/LHLO. Connect timeout errors are handled
874 specially so they can be identified for retries. */
876 if (continue_hostname == NULL)
878 inblock.sock = outblock.sock =
879 smtp_connect(host, host_af, port, interface, ob->connect_timeout,
881 if (inblock.sock < 0)
883 set_errno(addrlist, (errno == ETIMEDOUT)? ERRNO_CONNECTTIMEOUT : errno,
888 /* The first thing is to wait for an initial OK response. The dreaded "goto"
889 is nevertheless a reasonably clean way of programming this kind of logic,
890 where you want to escape on any error. */
892 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
893 ob->command_timeout)) goto RESPONSE_FAILED;
895 /** Debugging without sending a message
896 addrlist->transport_return = DEFER;
900 /* Errors that occur after this point follow an SMTP command, which is
901 left in big_buffer by smtp_write_command() for use in error messages. */
903 smtp_command = big_buffer;
905 /* Tell the remote who we are...
907 February 1998: A convention has evolved that ESMTP-speaking MTAs include the
908 string "ESMTP" in their greeting lines, so make Exim send EHLO if the
909 greeting is of this form. The assumption was that the far end supports it
910 properly... but experience shows that there are some that give 5xx responses,
911 even though the banner includes "ESMTP" (there's a bloody-minded one that
912 says "ESMTP not spoken here"). Cope with that case.
914 September 2000: Time has passed, and it seems reasonable now to always send
915 EHLO at the start. It is also convenient to make the change while installing
918 July 2003: Joachim Wieland met a broken server that advertises "PIPELINING"
919 but times out after sending MAIL FROM, RCPT TO and DATA all together. There
920 would be no way to send out the mails, so there is now a host list
921 "hosts_avoid_esmtp" that disables ESMTP for special hosts and solves the
922 PIPELINING problem as well. Maybe it can also be useful to cure other
923 problems with broken servers.
925 Exim originally sent "Helo" at this point and ran for nearly a year that way.
926 Then somebody tried it with a Microsoft mailer... It seems that all other
927 mailers use upper case for some reason (the RFC is quite clear about case
928 independence) so, for peace of mind, I gave in. */
930 esmtp = verify_check_this_host(&(ob->hosts_avoid_esmtp), NULL,
931 host->name, host->address, NULL) != OK;
935 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n",
936 lmtp? "LHLO" : "EHLO", helo_data) < 0)
938 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
939 ob->command_timeout))
941 if (errno != 0 || buffer[0] == 0 || lmtp) goto RESPONSE_FAILED;
948 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
953 if (smtp_write_command(&outblock, FALSE, "HELO %s\r\n", helo_data) < 0)
955 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
956 ob->command_timeout)) goto RESPONSE_FAILED;
959 /* Set IGNOREQUOTA if the response to LHLO specifies support and the
960 lmtp_ignore_quota option was set. */
962 igquotstr = (lmtp && ob->lmtp_ignore_quota &&
963 pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer, Ustrlen(CS buffer), 0,
964 PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
966 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
969 tls_offered = esmtp &&
970 pcre_exec(regex_STARTTLS, NULL, CS buffer, Ustrlen(buffer), 0,
971 PCRE_EOPT, NULL, 0) >= 0;
975 /* For continuing deliveries down the same channel, the socket is the standard
976 input, and we don't need to redo EHLO here (but may need to do so for TLS - see
977 below). Set up the pointer to where subsequent commands will be left, for
978 error messages. Note that smtp_use_size and smtp_use_pipelining will have been
979 set from the command line if they were set in the process that passed the
984 inblock.sock = outblock.sock = fileno(stdin);
985 smtp_command = big_buffer;
988 /* If TLS is available on this connection, whether continued or not, attempt to
989 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
990 send another EHLO - the server may give a different answer in secure mode. We
991 use a separate buffer for reading the response to STARTTLS so that if it is
992 negative, the original EHLO data is available for subsequent analysis, should
993 the client not be required to use TLS. If the response is bad, copy the buffer
994 for error analysis. */
997 if (tls_offered && !suppress_tls &&
998 verify_check_this_host(&(ob->hosts_avoid_tls), NULL, host->name,
999 host->address, NULL) != OK)
1001 uschar buffer2[4096];
1002 if (smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") < 0)
1005 /* If there is an I/O error, transmission of this message is deferred. If
1006 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
1007 false, we also defer. However, if there is a temporary rejection of STARTTLS
1008 and tls_tempfail_tryclear is true, or if there is an outright rejection of
1009 STARTTLS, we carry on. This means we will try to send the message in clear,
1010 unless the host is in hosts_require_tls (tested below). */
1012 if (!smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
1013 ob->command_timeout))
1015 Ustrncpy(buffer, buffer2, sizeof(buffer));
1016 if (errno != 0 || buffer2[0] == 0 ||
1017 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
1018 goto RESPONSE_FAILED;
1021 /* STARTTLS accepted: try to negotiate a TLS session. */
1025 int rc = tls_client_start(inblock.sock, host, addrlist,
1026 NULL, /* No DH param */
1027 ob->tls_certificate,
1029 ob->tls_verify_certificates,
1031 ob->tls_require_ciphers,
1032 ob->command_timeout);
1034 /* TLS negotiation failed; give an error. From outside, this function may
1035 be called again to try in clear on a new connection, if the options permit
1036 it for this host. */
1040 save_errno = ERRNO_TLSFAILURE;
1041 message = US"failure while setting up TLS session";
1046 /* TLS session is set up */
1048 for (addr = addrlist; addr != NULL; addr = addr->next)
1050 if (addr->transport_return == PENDING_DEFER)
1052 addr->cipher = tls_cipher;
1053 addr->peerdn = tls_peerdn;
1059 /* If we started TLS, redo the EHLO/LHLO exchange over the secure channel. */
1061 if (tls_active >= 0)
1063 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n", lmtp? "LHLO" : "EHLO",
1066 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1067 ob->command_timeout))
1068 goto RESPONSE_FAILED;
1071 /* If the host is required to use a secure channel, ensure that we
1074 else if (verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
1075 host->address, NULL) == OK)
1077 save_errno = ERRNO_TLSREQUIRED;
1078 message = string_sprintf("a TLS session is required for %s [%s], but %s",
1079 host->name, host->address,
1080 tls_offered? "an attempt to start TLS failed" :
1081 "the server did not offer TLS support");
1086 /* If TLS is active, we have just started it up and re-done the EHLO command,
1087 so its response needs to be analyzed. If TLS is not active and this is a
1088 continued session down a previously-used socket, we haven't just done EHLO, so
1091 if (continue_hostname == NULL
1098 uschar *fail_reason = US"server did not advertise AUTH support";
1100 /* Set for IGNOREQUOTA if the response to LHLO specifies support and the
1101 lmtp_ignore_quota option was set. */
1103 igquotstr = (lmtp && ob->lmtp_ignore_quota &&
1104 pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer, Ustrlen(CS buffer), 0,
1105 PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
1107 /* If the response to EHLO specified support for the SIZE parameter, note
1108 this, provided size_addition is non-negative. */
1110 smtp_use_size = esmtp && ob->size_addition >= 0 &&
1111 pcre_exec(regex_SIZE, NULL, CS buffer, Ustrlen(CS buffer), 0,
1112 PCRE_EOPT, NULL, 0) >= 0;
1114 /* Note whether the server supports PIPELINING. If hosts_avoid_esmtp matched
1115 the current host, esmtp will be false, so PIPELINING can never be used. */
1117 smtp_use_pipelining = esmtp &&
1118 pcre_exec(regex_PIPELINING, NULL, CS buffer, Ustrlen(CS buffer), 0,
1119 PCRE_EOPT, NULL, 0) >= 0;
1121 DEBUG(D_transport) debug_printf("%susing PIPELINING\n",
1122 smtp_use_pipelining? "" : "not ");
1124 /* Note if the response to EHLO specifies support for the AUTH extension.
1125 If it has, check that this host is one we want to authenticate to, and do
1126 the business. The host name and address must be available when the
1127 authenticator's client driver is running. */
1129 smtp_authenticated = FALSE;
1130 require_auth = verify_check_this_host(&(ob->hosts_require_auth), NULL,
1131 host->name, host->address, NULL);
1133 if (esmtp && regex_match_and_setup(regex_AUTH, buffer, 0, -1))
1135 uschar *names = string_copyn(expand_nstring[1], expand_nlength[1]);
1136 expand_nmax = -1; /* reset */
1138 /* Must not do this check until after we have saved the result of the
1139 regex match above. */
1141 if (require_auth == OK ||
1142 verify_check_this_host(&(ob->hosts_try_auth), NULL, host->name,
1143 host->address, NULL) == OK)
1146 fail_reason = US"no common mechanisms were found";
1148 DEBUG(D_transport) debug_printf("scanning authentication mechanisms\n");
1150 /* Scan the configured authenticators looking for one which is configured
1151 for use as a client and whose name matches an authentication mechanism
1152 supported by the server. If one is found, attempt to authenticate by
1153 calling its client function. */
1155 for (au = auths; !smtp_authenticated && au != NULL; au = au->next)
1158 if (!au->client) continue;
1160 /* Loop to scan supported server mechanisms */
1165 int len = Ustrlen(au->public_name);
1166 while (isspace(*p)) p++;
1168 if (strncmpic(au->public_name, p, len) != 0 ||
1169 (p[len] != 0 && !isspace(p[len])))
1171 while (*p != 0 && !isspace(*p)) p++;
1175 /* Found data for a listed mechanism. Call its client entry. Set
1176 a flag in the outblock so that data is overwritten after sending so
1177 that reflections don't show it. */
1179 fail_reason = US"authentication attempt(s) failed";
1180 outblock.authenticating = TRUE;
1181 rc = (au->info->clientcode)(au, &inblock, &outblock,
1182 ob->command_timeout, buffer, sizeof(buffer));
1183 outblock.authenticating = FALSE;
1184 DEBUG(D_transport) debug_printf("%s authenticator yielded %d\n",
1187 /* A temporary authentication failure must hold up delivery to
1188 this host. After a permanent authentication failure, we carry on
1189 to try other authentication methods. If all fail hard, try to
1190 deliver the message unauthenticated unless require_auth was set. */
1195 smtp_authenticated = TRUE; /* stops the outer loop */
1198 /* Failure after writing a command */
1203 /* Failure after reading a response */
1206 if (errno != 0 || buffer[0] != '5') goto RESPONSE_FAILED;
1207 log_write(0, LOG_MAIN, "%s authenticator failed H=%s [%s] %s",
1208 au->name, host->name, host->address, buffer);
1211 /* Failure by some other means. In effect, the authenticator
1212 decided it wasn't prepared to handle this case. Typically this
1213 is the result of "fail" in an expansion string. Do we need to
1214 log anything here? */
1219 /* Internal problem, message in buffer. */
1223 set_errno(addrlist, 0, string_copy(buffer), DEFER, FALSE);
1227 break; /* If not authenticated, try next authenticator */
1228 } /* Loop for scanning supported server mechanisms */
1229 } /* Loop for further authenticators */
1233 /* If we haven't authenticated, but are required to, give up. */
1235 if (require_auth == OK && !smtp_authenticated)
1238 set_errno(addrlist, ERRNO_AUTHFAIL,
1239 string_sprintf("authentication required but %s", fail_reason), DEFER,
1245 /* The setting up of the SMTP call is now complete. Any subsequent errors are
1246 message-specific. */
1250 /* If there is a filter command specified for this transport, we can now
1251 set it up. This cannot be done until the identify of the host is known. */
1253 if (tblock->filter_command != NULL)
1257 sprintf(CS buffer, "%.50s transport", tblock->name);
1258 rc = transport_set_up_command(&transport_filter_argv, tblock->filter_command,
1259 TRUE, DEFER, addrlist, buffer, NULL);
1261 /* On failure, copy the error to all addresses, abandon the SMTP call, and
1266 set_errno(addrlist->next, addrlist->basic_errno, addrlist->message, DEFER,
1274 /* For messages that have more than the maximum number of envelope recipients,
1275 we want to send several transactions down the same SMTP connection. (See
1276 comments in deliver.c as to how this reconciles, heuristically, with
1277 remote_max_parallel.) This optimization was added to Exim after the following
1278 code was already working. The simplest way to put it in without disturbing the
1279 code was to use a goto to jump back to this point when there is another
1280 transaction to handle. */
1283 sync_addr = first_addr;
1287 completed_address = FALSE;
1290 /* Initiate a message transfer. If we know the receiving MTA supports the SIZE
1291 qualification, send it, adding something to the message size to allow for
1292 imprecision and things that get added en route. Exim keeps the number of lines
1293 in a message, so we can give an accurate value for the original message, but we
1294 need some additional to handle added headers. (Double "." characters don't get
1295 included in the count.) */
1302 sprintf(CS p, " SIZE=%d", message_size+message_linecount+ob->size_addition);
1306 /* Add the authenticated sender address if present */
1308 if (smtp_authenticated && local_authenticated_sender != NULL)
1310 string_format(p, sizeof(buffer) - (p-buffer), " AUTH=%s",
1311 auth_xtextencode(local_authenticated_sender,
1312 Ustrlen(local_authenticated_sender)));
1315 /* From here until we send the DATA command, we can make use of PIPELINING
1316 if the server host supports it. The code has to be able to check the responses
1317 at any point, for when the buffer fills up, so we write it totally generally.
1318 When PIPELINING is off, each command written reports that it has flushed the
1321 pending_MAIL = TRUE; /* The block starts with MAIL */
1323 rc = smtp_write_command(&outblock, smtp_use_pipelining,
1324 "MAIL FROM:<%s>%s\r\n", return_path, buffer);
1325 mail_command = string_copy(big_buffer); /* Save for later error message */
1329 case -1: /* Transmission error */
1332 case +1: /* Block was sent */
1333 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1334 ob->command_timeout)) goto RESPONSE_FAILED;
1335 pending_MAIL = FALSE;
1339 /* Pass over all the relevant recipient addresses for this host, which are the
1340 ones that have status PENDING_DEFER. If we are using PIPELINING, we can send
1341 several before we have to read the responses for those seen so far. This
1342 checking is done by a subroutine because it also needs to be done at the end.
1343 Send only up to max_rcpt addresses at a time, leaving first_addr pointing to
1344 the next one if not all are sent.
1346 In the MUA wrapper situation, we want to flush the PIPELINING buffer for the
1347 last address because we want to abort if any recipients have any kind of
1348 problem, temporary or permanent. We know that all recipient addresses will have
1349 the PENDING_DEFER status, because only one attempt is ever made, and we know
1350 that max_rcpt will be large, so all addresses will be done at once. */
1352 for (addr = first_addr;
1353 address_count < max_rcpt && addr != NULL;
1359 if (addr->transport_return != PENDING_DEFER) continue;
1362 no_flush = smtp_use_pipelining && (!mua_wrapper || addr->next != NULL);
1364 /* Now send the RCPT command, and process outstanding responses when
1365 necessary. After a timeout on RCPT, we just end the function, leaving the
1366 yield as OK, because this error can often mean that there is a problem with
1367 just one address, so we don't want to delay the host. */
1369 count = smtp_write_command(&outblock, no_flush, "RCPT TO:<%s>%s\r\n",
1370 transport_rcpt_address(addr, tblock->rcpt_include_affixes), igquotstr);
1371 if (count < 0) goto SEND_FAILED;
1374 switch(sync_responses(first_addr, tblock->rcpt_include_affixes,
1375 &sync_addr, host, count, pending_MAIL, 0, &inblock,
1376 ob->command_timeout, buffer, sizeof(buffer)))
1378 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1379 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1382 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1383 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1384 case 0: /* No 2xx or 5xx, but no probs */
1387 case -1: goto END_OFF; /* Timeout on RCPT */
1388 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL error */
1390 pending_MAIL = FALSE; /* Dealt with MAIL */
1392 } /* Loop for next address */
1394 /* If we are an MUA wrapper, abort if any RCPTs were rejected, either
1395 permanently or temporarily. We should have flushed and synced after the last
1400 address_item *badaddr;
1401 for (badaddr = first_addr; badaddr != NULL; badaddr = badaddr->next)
1403 if (badaddr->transport_return != PENDING_OK) break;
1405 if (badaddr != NULL)
1407 set_errno(addrlist, 0, badaddr->message, FAIL,
1408 testflag(badaddr, af_pass_message));
1413 /* If ok is TRUE, we know we have got at least one good recipient, and must now
1414 send DATA, but if it is FALSE (in the normal, non-wrapper case), we may still
1415 have a good recipient buffered up if we are pipelining. We don't want to waste
1416 time sending DATA needlessly, so we only send it if either ok is TRUE or if we
1417 are pipelining. The responses are all handled by sync_responses(). */
1419 if (ok || (smtp_use_pipelining && !mua_wrapper))
1421 int count = smtp_write_command(&outblock, FALSE, "DATA\r\n");
1422 if (count < 0) goto SEND_FAILED;
1423 switch(sync_responses(first_addr, tblock->rcpt_include_affixes, &sync_addr,
1424 host, count, pending_MAIL, ok? +1 : -1, &inblock,
1425 ob->command_timeout, buffer, sizeof(buffer)))
1427 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1428 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1431 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1432 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1433 case 0: break; /* No 2xx or 5xx, but no probs */
1435 case -1: goto END_OFF; /* Timeout on RCPT */
1436 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */
1440 /* Save the first address of the next batch. */
1444 /* If there were no good recipients (but otherwise there have been no
1445 problems), just set ok TRUE, since we have handled address-specific errors
1446 already. Otherwise, it's OK to send the message. Use the check/escape mechanism
1447 for handling the SMTP dot-handling protocol, flagging to apply to headers as
1448 well as body. Set the appropriate timeout value to be used for each chunk.
1449 (Haven't been able to make it work using select() for writing yet.) */
1451 if (!ok) ok = TRUE; else
1453 sigalrm_seen = FALSE;
1454 transport_write_timeout = ob->data_timeout;
1455 smtp_command = US"sending data block"; /* For error messages */
1456 DEBUG(D_transport|D_v)
1457 debug_printf(" SMTP>> writing message and terminating \".\"\n");
1458 transport_count = 0;
1459 #ifdef EXPERIMENTAL_DOMAINKEYS
1460 if ( (ob->dk_private_key != NULL) && (ob->dk_selector != NULL) )
1461 ok = dk_transport_write_message(addrlist, inblock.sock,
1462 topt_use_crlf | topt_end_dot | topt_escape_headers |
1463 (tblock->body_only? topt_no_headers : 0) |
1464 (tblock->headers_only? topt_no_body : 0) |
1465 (tblock->return_path_add? topt_add_return_path : 0) |
1466 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1467 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1468 0, /* No size limit */
1469 tblock->add_headers, tblock->remove_headers,
1470 US".", US"..", /* Escaping strings */
1471 tblock->rewrite_rules, tblock->rewrite_existflags,
1472 ob->dk_private_key, ob->dk_domain, ob->dk_selector,
1473 ob->dk_canon, ob->dk_headers, ob->dk_strict);
1476 ok = transport_write_message(addrlist, inblock.sock,
1477 topt_use_crlf | topt_end_dot | topt_escape_headers |
1478 (tblock->body_only? topt_no_headers : 0) |
1479 (tblock->headers_only? topt_no_body : 0) |
1480 (tblock->return_path_add? topt_add_return_path : 0) |
1481 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1482 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1483 0, /* No size limit */
1484 tblock->add_headers, tblock->remove_headers,
1485 US".", US"..", /* Escaping strings */
1486 tblock->rewrite_rules, tblock->rewrite_existflags);
1488 /* transport_write_message() uses write() because it is called from other
1489 places to write to non-sockets. This means that under some OS (e.g. Solaris)
1490 it can exit with "Broken pipe" as its error. This really means that the
1491 socket got closed at the far end. */
1493 transport_write_timeout = 0; /* for subsequent transports */
1495 /* Failure can either be some kind of I/O disaster (including timeout),
1496 or the failure of a transport filter or the expansion of added headers. */
1500 buffer[0] = 0; /* There hasn't been a response */
1501 goto RESPONSE_FAILED;
1504 /* We used to send the terminating "." explicitly here, but because of
1505 buffering effects at both ends of TCP/IP connections, you don't gain
1506 anything by keeping it separate, so it might as well go in the final
1507 data buffer for efficiency. This is now done by setting the topt_end_dot
1510 smtp_command = US"end of data";
1512 /* For SMTP, we now read a single response that applies to the whole message.
1513 If it is OK, then all the addresses have been delivered. */
1515 if (!lmtp) ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1518 /* For LMTP, we get back a response for every RCPT command that we sent;
1519 some may be accepted and some rejected. For those that get a response, their
1520 status is fixed; any that are accepted have been handed over, even if later
1521 responses crash - at least, that's how I read RFC 2033.
1523 If all went well, mark the recipient addresses as completed, record which
1524 host/IPaddress they were delivered to, and cut out RSET when sending another
1525 message down the same channel. Write the completed addresses to the journal
1526 now so that they are recorded in case there is a crash of hardware or
1527 software before the spool gets updated. Also record the final SMTP
1528 confirmation if needed (for SMTP only). */
1533 int delivery_time = (int)(time(NULL) - start_delivery_time);
1536 uschar *conf = NULL;
1539 /* Make a copy of the host if it is local to this invocation
1540 of the transport. */
1544 thost = store_get(sizeof(host_item));
1546 thost->name = string_copy(host->name);
1547 thost->address = string_copy(host->address);
1551 /* Set up confirmation if needed - applies only to SMTP */
1553 if ((log_extra_selector & LX_smtp_confirmation) != 0 && !lmtp)
1555 uschar *s = string_printing(buffer);
1556 conf = (s == buffer)? (uschar *)string_copy(s) : s;
1559 /* Process all transported addresses - for LMTP, read a status for
1562 for (addr = addrlist; addr != first_addr; addr = addr->next)
1564 if (addr->transport_return != PENDING_OK) continue;
1566 /* LMTP - if the response fails badly (e.g. timeout), use it for all the
1567 remaining addresses. Otherwise, it's a return code for just the one
1572 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1575 if (errno != 0 || buffer[0] == 0) goto RESPONSE_FAILED;
1576 addr->message = string_sprintf("LMTP error after %s: %s",
1577 big_buffer, string_printing(buffer));
1578 addr->transport_return = (buffer[0] == '5')? FAIL : DEFER;
1581 completed_address = TRUE; /* NOW we can set this flag */
1584 /* SMTP, or success return from LMTP for this address. Pass back the
1585 actual host that was used. */
1587 addr->transport_return = OK;
1588 addr->more_errno = delivery_time;
1589 addr->host_used = thost;
1590 addr->special_action = flag;
1591 addr->message = conf;
1594 /* Update the journal. For homonymic addresses, use the base address plus
1595 the transport name. See lots of comments in deliver.c about the reasons
1596 for the complications when homonyms are involved. Just carry on after
1597 write error, as it may prove possible to update the spool file later. */
1599 if (testflag(addr, af_homonym))
1600 sprintf(CS buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
1602 sprintf(CS buffer, "%.500s\n", addr->unique);
1604 DEBUG(D_deliver) debug_printf("journalling %s", buffer);
1605 len = Ustrlen(CS buffer);
1606 if (write(journal_fd, buffer, len) != len)
1607 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
1608 "%s: %s", buffer, strerror(errno));
1611 /* Ensure the journal file is pushed out to disk. */
1613 if (fsync(journal_fd) < 0)
1614 log_write(0, LOG_MAIN|LOG_PANIC, "failed to fsync journal: %s",
1620 /* Handle general (not specific to one address) failures here. The value of ok
1621 is used to skip over this code on the falling through case. A timeout causes a
1622 deferral. Other errors may defer or fail according to the response code, and
1623 may set up a special errno value, e.g. after connection chopped, which is
1624 assumed if errno == 0 and there is no text in the buffer. If control reaches
1625 here during the setting up phase (i.e. before MAIL FROM) then always defer, as
1626 the problem is not related to this specific message. */
1635 send_quit = check_response(host, &save_errno, addrlist->more_errno,
1636 buffer, &code, &message, &pass_message);
1642 message = US string_sprintf("send() to %s [%s] failed: %s",
1643 host->name, host->address, strerror(save_errno));
1647 /* This label is jumped to directly when a TLS negotiation has failed,
1648 or was not done for a host for which it is required. Values will be set
1649 in message and save_errno, and setting_up will always be true. Treat as
1650 a temporary error. */
1657 /* If the failure happened while setting up the call, see if the failure was
1658 a 5xx response (this will either be on connection, or following HELO - a 5xx
1659 after EHLO causes it to try HELO). If so, fail all addresses, as this host is
1660 never going to accept them. For other errors during setting up (timeouts or
1661 whatever), defer all addresses, and yield DEFER, so that the host is not
1662 tried again for a while. */
1665 ok = FALSE; /* For when reached by GOTO */
1671 set_errno(addrlist, save_errno, message, FAIL, pass_message);
1675 set_errno(addrlist, save_errno, message, DEFER, pass_message);
1680 /* If there was an I/O error or timeout or other transportation error,
1681 indicated by errno being non-zero, defer all addresses and yield DEFER,
1682 except for the case of failed add_headers expansion, or a transport filter
1683 failure, when the yield should be ERROR, to stop it trying other hosts.
1685 However, handle timeouts after MAIL FROM or "." and loss of connection after
1686 "." specially. They can indicate a problem with the sender address or with
1687 the contents of the message rather than a real error on the connection.
1688 Therefore, treat these cases in the same way as a 4xx response.
1690 The following condition tests for NOT these special cases. */
1692 else if (save_errno != 0 &&
1693 (save_errno != ETIMEDOUT ||
1694 (Ustrncmp(smtp_command,"MAIL",4) != 0 &&
1695 Ustrncmp(smtp_command,"end ",4) != 0)) &&
1696 (save_errno != ERRNO_SMTPCLOSED ||
1697 Ustrncmp(smtp_command,"end ",4) != 0))
1699 yield = (save_errno == ERRNO_CHHEADER_FAIL ||
1700 save_errno == ERRNO_FILTER_FAIL)? ERROR : DEFER;
1701 set_errno(addrlist, save_errno, message, DEFER, pass_message);
1704 /* Otherwise we have a message-specific error response from the remote
1705 host. This is one of
1706 (a) negative response or timeout after "mail from"
1707 (b) negative response after "data"
1708 (c) negative response or timeout or dropped connection after "."
1709 It won't be a negative response or timeout after "rcpt to", as that is dealt
1710 with separately above. The action in all cases is to set an appropriate
1711 error code for all the addresses, but to leave yield set to OK because
1712 the host itself has not failed. [It might in practice have failed for a
1713 timeout after MAIL FROM, or "." but if so, we'll discover that at the next
1714 delivery attempt.] For a temporary error, set the message_defer flag, and
1715 write to the logs for information if this is not the last host. The error for
1716 the last host will be logged as part of the address's log line. */
1720 if (mua_wrapper) code = '5'; /* Force hard failure in wrapper mode */
1722 set_errno(addrlist, save_errno, message, (code == '5')? FAIL : DEFER,
1725 /* If there's an errno, the message contains just the identity of
1728 if (code != '5') /* Anything other than 5 is treated as temporary */
1731 message = US string_sprintf("%s: %s", message, strerror(save_errno));
1732 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", message);
1733 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
1734 *message_defer = TRUE;
1740 /* If all has gone well, send_quit will be set TRUE, implying we can end the
1741 SMTP session tidily. However, if there were too many addresses to send in one
1742 message (indicated by first_addr being non-NULL) we want to carry on with the
1743 rest of them. Also, it is desirable to send more than one message down the SMTP
1744 connection if there are several waiting, provided we haven't already sent so
1745 many as to hit the configured limit. The function transport_check_waiting looks
1746 for a waiting message and returns its id. Then transport_pass_socket tries to
1747 set up a continued delivery by passing the socket on to another process. The
1748 variable send_rset is FALSE if a message has just been successfully transfered.
1750 If we are already sending down a continued channel, there may be further
1751 addresses not yet delivered that are aimed at the same host, but which have not
1752 been passed in this run of the transport. In this case, continue_more will be
1753 true, and all we should do is send RSET if necessary, and return, leaving the
1756 However, if no address was disposed of, i.e. all addresses got 4xx errors, we
1757 do not want to continue with other messages down the same channel, because that
1758 can lead to looping between two or more messages, all with the same,
1759 temporarily failing address(es). [The retry information isn't updated yet, so
1760 new processes keep on trying.] We probably also don't want to try more of this
1761 message's addresses either.
1763 If we have started a TLS session, we have to end it before passing the
1764 connection to a new process. However, not all servers can handle this (Exim
1765 can), so we do not pass such a connection on if the host matches
1766 hosts_nopass_tls. */
1769 debug_printf("ok=%d send_quit=%d send_rset=%d continue_more=%d "
1770 "yield=%d first_address is %sNULL\n", ok, send_quit, send_rset,
1771 continue_more, yield, (first_addr == NULL)? "":"not ");
1773 if (completed_address && ok && send_quit)
1776 if (first_addr != NULL || continue_more ||
1779 verify_check_this_host(&(ob->hosts_nopass_tls), NULL, host->name,
1780 host->address, NULL) != OK)
1782 transport_check_waiting(tblock->name, host->name,
1783 tblock->connection_max_messages, new_message_id, &more)
1791 if (! (ok = smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0))
1793 msg = US string_sprintf("send() to %s [%s] failed: %s", host->name,
1794 host->address, strerror(save_errno));
1797 else if (! (ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1798 ob->command_timeout)))
1801 send_quit = check_response(host, &errno, 0, buffer, &code, &msg,
1805 DEBUG(D_transport) debug_printf("%s\n", msg);
1810 /* Either RSET was not needed, or it succeeded */
1814 if (first_addr != NULL) /* More addresses still to be sent */
1815 { /* in this run of the transport */
1816 continue_sequence++; /* Causes * in logging */
1819 if (continue_more) return yield; /* More addresses for another run */
1821 /* Pass the socket to a new Exim process. Before doing so, we must shut
1822 down TLS. Not all MTAs allow for the continuation of the SMTP session
1823 when TLS is shut down. We test for this by sending a new EHLO. If we
1824 don't get a good response, we don't attempt to pass the socket on. */
1827 if (tls_active >= 0)
1830 ok = smtp_write_command(&outblock,FALSE,"EHLO %s\r\n",helo_data) >= 0 &&
1831 smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1832 ob->command_timeout);
1836 /* If the socket is successfully passed, we musn't send QUIT (or
1837 indeed anything!) from here. */
1839 if (ok && transport_pass_socket(tblock->name, host->name, host->address,
1840 new_message_id, inblock.sock))
1846 /* If RSET failed and there are addresses left, they get deferred. */
1848 else set_errno(first_addr, errno, msg, DEFER, FALSE);
1852 /* End off tidily with QUIT unless the connection has died or the socket has
1853 been passed to another process. There has been discussion on the net about what
1854 to do after sending QUIT. The wording of the RFC suggests that it is necessary
1855 to wait for a response, but on the other hand, there isn't anything one can do
1856 with an error response, other than log it. Exim used to do that. However,
1857 further discussion suggested that it is positively advantageous not to wait for
1858 the response, but to close the session immediately. This is supposed to move
1859 the TCP/IP TIME_WAIT state from the server to the client, thereby removing some
1860 load from the server. (Hosts that are both servers and clients may not see much
1861 difference, of course.) Further discussion indicated that this was safe to do
1862 on Unix systems which have decent implementations of TCP/IP that leave the
1863 connection around for a while (TIME_WAIT) after the application has gone away.
1864 This enables the response sent by the server to be properly ACKed rather than
1865 timed out, as can happen on broken TCP/IP implementations on other OS.
1867 This change is being made on 31-Jul-98. After over a year of trouble-free
1868 operation, the old commented-out code was removed on 17-Sep-99. */
1871 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1879 /* Close the socket, and return the appropriate value, first setting
1880 continue_transport and continue_hostname NULL to prevent any other addresses
1881 that may include the host from trying to re-use a continuation socket. This
1882 works because the NULL setting is passed back to the calling process, and
1883 remote_max_parallel is forced to 1 when delivering over an existing connection,
1885 If all went well and continue_more is set, we shouldn't actually get here if
1886 there are further addresses, as the return above will be taken. However,
1887 writing RSET might have failed, or there may be other addresses whose hosts are
1888 specified in the transports, and therefore not visible at top level, in which
1889 case continue_more won't get set. */
1891 (void)close(inblock.sock);
1892 continue_transport = NULL;
1893 continue_hostname = NULL;
1900 /*************************************************
1901 * Closedown entry point *
1902 *************************************************/
1904 /* This function is called when exim is passed an open smtp channel
1905 from another incarnation, but the message which it has been asked
1906 to deliver no longer exists. The channel is on stdin.
1908 We might do fancy things like looking for another message to send down
1909 the channel, but if the one we sought has gone, it has probably been
1910 delivered by some other process that itself will seek further messages,
1911 so just close down our connection.
1913 Argument: pointer to the transport instance block
1918 smtp_transport_closedown(transport_instance *tblock)
1920 smtp_transport_options_block *ob =
1921 (smtp_transport_options_block *)(tblock->options_block);
1922 smtp_inblock inblock;
1923 smtp_outblock outblock;
1925 uschar inbuffer[4096];
1926 uschar outbuffer[16];
1928 inblock.sock = fileno(stdin);
1929 inblock.buffer = inbuffer;
1930 inblock.buffersize = sizeof(inbuffer);
1931 inblock.ptr = inbuffer;
1932 inblock.ptrend = inbuffer;
1934 outblock.sock = inblock.sock;
1935 outblock.buffersize = sizeof(outbuffer);
1936 outblock.buffer = outbuffer;
1937 outblock.ptr = outbuffer;
1938 outblock.cmd_count = 0;
1939 outblock.authenticating = FALSE;
1941 (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1942 (void)smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1943 ob->command_timeout);
1944 (void)close(inblock.sock);
1949 /*************************************************
1950 * Prepare addresses for delivery *
1951 *************************************************/
1953 /* This function is called to flush out error settings from previous delivery
1954 attempts to other hosts. It also records whether we got here via an MX record
1955 or not in the more_errno field of the address. We are interested only in
1956 addresses that are still marked DEFER - others may have got delivered to a
1957 previously considered IP address. Set their status to PENDING_DEFER to indicate
1958 which ones are relevant this time.
1961 addrlist the list of addresses
1962 host the host we are delivering to
1964 Returns: the first address for this delivery
1967 static address_item *
1968 prepare_addresses(address_item *addrlist, host_item *host)
1970 address_item *first_addr = NULL;
1972 for (addr = addrlist; addr != NULL; addr = addr->next)
1974 if (addr->transport_return != DEFER) continue;
1975 if (first_addr == NULL) first_addr = addr;
1976 addr->transport_return = PENDING_DEFER;
1977 addr->basic_errno = 0;
1978 addr->more_errno = (host->mx >= 0)? 'M' : 'A';
1979 addr->message = NULL;
1981 addr->cipher = NULL;
1982 addr->peerdn = NULL;
1990 /*************************************************
1991 * Main entry point *
1992 *************************************************/
1994 /* See local README for interface details. As this is a remote transport, it is
1995 given a chain of addresses to be delivered in one connection, if possible. It
1996 always returns TRUE, indicating that each address has its own independent
1997 status set, except if there is a setting up problem, in which case it returns
2001 smtp_transport_entry(
2002 transport_instance *tblock, /* data for this instantiation */
2003 address_item *addrlist) /* addresses we are working on */
2007 int hosts_defer = 0;
2009 int hosts_looked_up = 0;
2010 int hosts_retry = 0;
2011 int hosts_serial = 0;
2012 int hosts_total = 0;
2013 int total_hosts_tried = 0;
2015 BOOL expired = TRUE;
2016 BOOL continuing = continue_hostname != NULL;
2017 uschar *expanded_hosts = NULL;
2019 uschar *tid = string_sprintf("%s transport", tblock->name);
2020 smtp_transport_options_block *ob =
2021 (smtp_transport_options_block *)(tblock->options_block);
2022 host_item *hostlist = addrlist->host_list;
2023 host_item *host = NULL;
2027 debug_printf("%s transport entered\n", tblock->name);
2028 for (addr = addrlist; addr != NULL; addr = addr->next)
2029 debug_printf(" %s\n", addr->address);
2030 if (continuing) debug_printf("already connected to %s [%s]\n",
2031 continue_hostname, continue_host_address);
2034 /* If a host list is not defined for the addresses - they must all have the
2035 same one in order to be passed to a single transport - or if the transport has
2036 a host list with hosts_override set, use the host list supplied with the
2037 transport. It is an error for this not to exist. */
2039 if (hostlist == NULL || (ob->hosts_override && ob->hosts != NULL))
2041 if (ob->hosts == NULL)
2043 addrlist->message = string_sprintf("%s transport called with no hosts set",
2045 addrlist->transport_return = PANIC;
2046 return FALSE; /* Only top address has status */
2049 DEBUG(D_transport) debug_printf("using the transport's hosts: %s\n",
2052 /* If the transport's host list contains no '$' characters, and we are not
2053 randomizing, it is fixed and therefore a chain of hosts can be built once
2054 and for all, and remembered for subsequent use by other calls to this
2055 transport. If, on the other hand, the host list does contain '$', or we are
2056 randomizing its order, we have to rebuild it each time. In the fixed case,
2057 as the hosts string will never be used again, it doesn't matter that we
2058 replace all the : characters with zeros. */
2060 if (ob->hostlist == NULL)
2062 uschar *s = ob->hosts;
2064 if (Ustrchr(s, '$') != NULL)
2066 expanded_hosts = expand_string(s);
2067 if (expanded_hosts == NULL)
2069 addrlist->message = string_sprintf("failed to expand list of hosts "
2070 "\"%s\" in %s transport: %s", s, tblock->name, expand_string_message);
2071 addrlist->transport_return = search_find_defer? DEFER : PANIC;
2072 return FALSE; /* Only top address has status */
2074 DEBUG(D_transport) debug_printf("expanded list of hosts \"%s\" to "
2075 "\"%s\"\n", s, expanded_hosts);
2079 if (ob->hosts_randomize) s = expanded_hosts = string_copy(s);
2081 host_build_hostlist(&hostlist, s, ob->hosts_randomize);
2083 /* If there was no expansion of hosts, save the host list for
2086 if (expanded_hosts == NULL) ob->hostlist = hostlist;
2089 /* This is not the first time this transport has been run in this delivery;
2090 the host list was built previously. */
2092 else hostlist = ob->hostlist;
2095 /* The host list was supplied with the address. If hosts_randomize is set, we
2096 must sort it into a random order if it did not come from MX records and has not
2097 already been randomized (but don't bother if continuing down an existing
2100 else if (ob->hosts_randomize && hostlist->mx == MX_NONE && !continuing)
2102 host_item *newlist = NULL;
2103 while (hostlist != NULL)
2105 host_item *h = hostlist;
2106 hostlist = hostlist->next;
2108 h->sort_key = random_number(100);
2110 if (newlist == NULL)
2115 else if (h->sort_key < newlist->sort_key)
2122 host_item *hh = newlist;
2123 while (hh->next != NULL)
2125 if (h->sort_key < hh->next->sort_key) break;
2133 hostlist = addrlist->host_list = newlist;
2137 /* Sort out the default port. */
2139 if (!smtp_get_port(ob->port, addrlist, &port, tid)) return FALSE;
2142 /* For each host-plus-IP-address on the list:
2144 . If this is a continued delivery and the host isn't the one with the
2145 current connection, skip.
2147 . If the status is unusable (i.e. previously failed or retry checked), skip.
2149 . If no IP address set, get the address, either by turning the name into
2150 an address, calling gethostbyname if gethostbyname is on, or by calling
2151 the DNS. The DNS may yield multiple addresses, in which case insert the
2152 extra ones into the list.
2154 . Get the retry data if not previously obtained for this address and set the
2155 field which remembers the state of this address. Skip if the retry time is
2156 not reached. If not, remember whether retry data was found. The retry string
2157 contains both the name and the IP address.
2159 . Scan the list of addresses and mark those whose status is DEFER as
2160 PENDING_DEFER. These are the only ones that will be processed in this cycle
2163 . Make a delivery attempt - addresses marked PENDING_DEFER will be tried.
2164 Some addresses may be successfully delivered, others may fail, and yet
2165 others may get temporary errors and so get marked DEFER.
2167 . The return from the delivery attempt is OK if a connection was made and a
2168 valid SMTP dialogue was completed. Otherwise it is DEFER.
2170 . If OK, add a "remove" retry item for this host/IPaddress, if any.
2172 . If fail to connect, or other defer state, add a retry item.
2174 . If there are any addresses whose status is still DEFER, carry on to the
2175 next host/IPaddress, unless we have tried the number of hosts given
2176 by hosts_max_try or hosts_max_try_hardlimit; otherwise return. Note that
2177 there is some fancy logic for hosts_max_try that means its limit can be
2178 overstepped in some circumstances.
2180 If we get to the end of the list, all hosts have deferred at least one address,
2181 or not reached their retry times. If delay_after_cutoff is unset, it requests a
2182 delivery attempt to those hosts whose last try was before the arrival time of
2183 the current message. To cope with this, we have to go round the loop a second
2184 time. After that, set the status and error data for any addresses that haven't
2185 had it set already. */
2187 for (cutoff_retry = 0; expired &&
2188 cutoff_retry < ((ob->delay_after_cutoff)? 1 : 2);
2191 host_item *nexthost = NULL;
2192 int unexpired_hosts_tried = 0;
2194 for (host = hostlist;
2196 unexpired_hosts_tried < ob->hosts_max_try &&
2197 total_hosts_tried < ob->hosts_max_try_hardlimit;
2203 BOOL serialized = FALSE;
2204 BOOL host_is_expired = FALSE;
2205 BOOL message_defer = FALSE;
2206 BOOL ifchanges = FALSE;
2207 BOOL some_deferred = FALSE;
2208 address_item *first_addr = NULL;
2209 uschar *interface = NULL;
2210 uschar *retry_host_key = NULL;
2211 uschar *retry_message_key = NULL;
2212 uschar *serialize_key = NULL;
2214 /* Default next host is next host. :-) But this can vary if the
2215 hosts_max_try limit is hit (see below). It may also be reset if a host
2216 address is looked up here (in case the host was multihomed). */
2218 nexthost = host->next;
2220 /* Set the flag requesting that this host be added to the waiting
2221 database if the delivery fails temporarily or if we are running with
2222 queue_smtp or a 2-stage queue run. This gets unset for certain
2223 kinds of error, typically those that are specific to the message. */
2225 host->update_waiting = TRUE;
2227 /* If the address hasn't yet been obtained from the host name, look it up
2228 now, unless the host is already marked as unusable. If it is marked as
2229 unusable, it means that the router was unable to find its IP address (in
2230 the DNS or wherever) OR we are in the 2nd time round the cutoff loop, and
2231 the lookup failed last time. We don't get this far if *all* MX records
2232 point to non-existent hosts; that is treated as a hard error.
2234 We can just skip this host entirely. When the hosts came from the router,
2235 the address will timeout based on the other host(s); when the address is
2236 looked up below, there is an explicit retry record added.
2238 Note that we mustn't skip unusable hosts if the address is not unset; they
2239 may be needed as expired hosts on the 2nd time round the cutoff loop. */
2241 if (host->address == NULL)
2245 uschar *canonical_name;
2247 if (host->status >= hstatus_unusable)
2249 DEBUG(D_transport) debug_printf("%s has no address and is unusable - skipping\n",
2254 DEBUG(D_transport) debug_printf("getting address for %s\n", host->name);
2256 /* The host name is permitted to have an attached port. Find it, and
2257 strip it from the name. Just remember it for now. */
2259 new_port = host_item_get_port(host);
2261 /* Count hosts looked up */
2265 /* Find by name if so configured, or if it's an IP address. We don't
2266 just copy the IP address, because we need the test-for-local to happen. */
2268 if (ob->gethostbyname || string_is_ip_address(host->name, NULL) != 0)
2269 rc = host_find_byname(host, NULL, &canonical_name, TRUE);
2272 int flags = HOST_FIND_BY_A;
2273 if (ob->dns_qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
2274 if (ob->dns_search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
2275 rc = host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
2276 &canonical_name, NULL);
2279 /* Update the host (and any additional blocks, resulting from
2280 multihoming) with a host-specific port, if any. */
2282 for (hh = host; hh != nexthost; hh = hh->next) hh->port = new_port;
2284 /* Failure to find the host at this time (usually DNS temporary failure)
2285 is really a kind of routing failure rather than a transport failure.
2286 Therefore we add a retry item of the routing kind, not to stop us trying
2287 to look this name up here again, but to ensure the address gets timed
2288 out if the failures go on long enough. A complete failure at this point
2289 commonly points to a configuration error, but the best action is still
2290 to carry on for the next host. */
2292 if (rc == HOST_FIND_AGAIN || rc == HOST_FIND_FAILED)
2294 retry_add_item(addrlist, string_sprintf("R:%s", host->name), 0);
2296 if (rc == HOST_FIND_AGAIN) hosts_defer++; else hosts_fail++;
2297 DEBUG(D_transport) debug_printf("rc = %s for %s\n", (rc == HOST_FIND_AGAIN)?
2298 "HOST_FIND_AGAIN" : "HOST_FIND_FAILED", host->name);
2299 host->status = hstatus_unusable;
2301 for (addr = addrlist; addr != NULL; addr = addr->next)
2303 if (addr->transport_return != DEFER) continue;
2304 addr->basic_errno = ERRNO_UNKNOWNHOST;
2306 string_sprintf("failed to lookup IP address for %s", host->name);
2311 /* If the host is actually the local host, we may have a problem, or
2312 there may be some cunning configuration going on. In the problem case,
2313 log things and give up. The default transport status is already DEFER. */
2315 if (rc == HOST_FOUND_LOCAL && !ob->allow_localhost)
2317 for (addr = addrlist; addr != NULL; addr = addr->next)
2319 addr->basic_errno = 0;
2320 addr->message = string_sprintf("%s transport found host %s to be "
2321 "local", tblock->name, host->name);
2325 } /* End of block for IP address lookup */
2327 /* If this is a continued delivery, we are interested only in the host
2328 which matches the name of the existing open channel. The check is put
2329 here after the local host lookup, in case the name gets expanded as a
2330 result of the lookup. Set expired FALSE, to save the outer loop executing
2333 if (continuing && (Ustrcmp(continue_hostname, host->name) != 0 ||
2334 Ustrcmp(continue_host_address, host->address) != 0))
2337 continue; /* With next host */
2340 /* Reset the default next host in case a multihomed host whose addresses
2341 are not looked up till just above added to the host list. */
2343 nexthost = host->next;
2345 /* If queue_smtp is set (-odqs or the first part of a 2-stage run), or the
2346 domain is in queue_smtp_domains, we don't actually want to attempt any
2347 deliveries. When doing a queue run, queue_smtp_domains is always unset. If
2348 there is a lookup defer in queue_smtp_domains, proceed as if the domain
2349 were not in it. We don't want to hold up all SMTP deliveries! Except when
2350 doing a two-stage queue run, don't do this if forcing. */
2352 if ((!deliver_force || queue_2stage) && (queue_smtp ||
2353 match_isinlist(addrlist->domain, &queue_smtp_domains, 0,
2354 &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL) == OK))
2357 for (addr = addrlist; addr != NULL; addr = addr->next)
2359 if (addr->transport_return != DEFER) continue;
2360 addr->message = US"domain matches queue_smtp_domains, or -odqs set";
2362 continue; /* With next host */
2365 /* Count hosts being considered - purely for an intelligent comment
2366 if none are usable. */
2370 /* Set $host and $host address now in case they are needed for the
2371 interface expansion or the serialize_hosts check; they remain set if an
2372 actual delivery happens. */
2374 deliver_host = host->name;
2375 deliver_host_address = host->address;
2377 /* Set up a string for adding to the retry key if the port number is not
2378 the standard SMTP port. A host may have its own port setting that overrides
2381 pistring = string_sprintf(":%d", (host->port == PORT_NONE)?
2383 if (Ustrcmp(pistring, ":25") == 0) pistring = US"";
2385 /* Select IPv4 or IPv6, and choose an outgoing interface. If the interface
2386 string changes upon expansion, we must add it to the key that is used for
2387 retries, because connections to the same host from a different interface
2388 should be treated separately. */
2390 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET : AF_INET6;
2391 if (!smtp_get_interface(ob->interface, host_af, addrlist, &ifchanges,
2394 if (ifchanges) pistring = string_sprintf("%s/%s", pistring, interface);
2396 /* The first time round the outer loop, check the status of the host by
2397 inspecting the retry data. The second time round, we are interested only
2398 in expired hosts that haven't been tried since this message arrived. */
2400 if (cutoff_retry == 0)
2402 /* Ensure the status of the address is set by checking retry data if
2403 necessary. There maybe host-specific retry data (applicable to all
2404 messages) and also data for retries of a specific message at this host.
2405 If either of these retry records are actually read, the keys used are
2406 returned to save recomputing them later. */
2408 host_is_expired = retry_check_address(addrlist->domain, host, pistring,
2409 ob->retry_include_ip_address, &retry_host_key, &retry_message_key);
2411 DEBUG(D_transport) debug_printf("%s [%s]%s status = %s\n", host->name,
2412 (host->address == NULL)? US"" : host->address, pistring,
2413 (host->status == hstatus_usable)? "usable" :
2414 (host->status == hstatus_unusable)? "unusable" :
2415 (host->status == hstatus_unusable_expired)? "unusable (expired)" : "?");
2417 /* Skip this address if not usable at this time, noting if it wasn't
2418 actually expired, both locally and in the address. */
2420 switch (host->status)
2422 case hstatus_unusable:
2424 setflag(addrlist, af_retry_skipped);
2427 case hstatus_unusable_expired:
2430 case hwhy_retry: hosts_retry++; break;
2431 case hwhy_failed: hosts_fail++; break;
2432 case hwhy_deferred: hosts_defer++; break;
2435 /* If there was a retry message key, implying that previously there
2436 was a message-specific defer, we don't want to update the list of
2437 messages waiting for this host. */
2439 if (retry_message_key != NULL) host->update_waiting = FALSE;
2440 continue; /* With the next host or IP address */
2444 /* Second time round the loop: if the address is set but expired, and
2445 the message is newer than the last try, let it through. */
2449 if (host->address == NULL ||
2450 host->status != hstatus_unusable_expired ||
2451 host->last_try > received_time)
2454 debug_printf("trying expired host %s [%s]%s\n",
2455 host->name, host->address, pistring);
2456 host_is_expired = TRUE;
2459 /* Setting "expired=FALSE" doesn't actually mean not all hosts are expired;
2460 it remains TRUE only if all hosts are expired and none are actually tried.
2465 /* If this host is listed as one to which access must be serialized,
2466 see if another Exim process has a connection to it, and if so, skip
2467 this host. If not, update the database to record our connection to it
2468 and remember this for later deletion. Do not do any of this if we are
2469 sending the message down a pre-existing connection. */
2472 verify_check_this_host(&(ob->serialize_hosts), NULL, host->name,
2473 host->address, NULL) == OK)
2475 serialize_key = string_sprintf("host-serialize-%s", host->name);
2476 if (!enq_start(serialize_key))
2479 debug_printf("skipping host %s because another Exim process "
2480 "is connected to it\n", host->name);
2487 /* OK, we have an IP address that is not waiting for its retry time to
2488 arrive (it might be expired) OR (second time round the loop) we have an
2489 expired host that hasn't been tried since the message arrived. Have a go
2490 at delivering the message to it. First prepare the addresses by flushing
2491 out the result of previous attempts, and finding the first address that
2492 is still to be delivered. */
2494 first_addr = prepare_addresses(addrlist, host);
2496 DEBUG(D_transport) debug_printf("delivering %s to %s [%s] (%s%s)\n",
2497 message_id, host->name, host->address, addrlist->address,
2498 (addrlist->next == NULL)? "" : ", ...");
2500 set_process_info("delivering %s to %s [%s] (%s%s)",
2501 message_id, host->name, host->address, addrlist->address,
2502 (addrlist->next == NULL)? "" : ", ...");
2504 /* This is not for real; don't do the delivery. If there are
2505 any remaining hosts, list them. */
2510 set_errno(addrlist, 0, NULL, OK, FALSE);
2511 for (addr = addrlist; addr != NULL; addr = addr->next)
2513 addr->host_used = host;
2514 addr->special_action = '*';
2515 addr->message = US"delivery bypassed by -N option";
2519 debug_printf("*** delivery by %s transport bypassed by -N option\n"
2520 "*** host and remaining hosts:\n", tblock->name);
2521 for (host2 = host; host2 != NULL; host2 = host2->next)
2522 debug_printf(" %s [%s]\n", host2->name,
2523 (host2->address == NULL)? US"unset" : host2->address);
2528 /* This is for real. If the host is expired, we don't count it for
2529 hosts_max_retry. This ensures that all hosts must expire before an address
2530 is timed out, unless hosts_max_try_hardlimit (which protects against
2531 lunatic DNS configurations) is reached.
2533 If the host is not expired and we are about to hit the hosts_max_retry
2534 limit, check to see if there is a subsequent hosts with a different MX
2535 value. If so, make that the next host, and don't count this one. This is a
2536 heuristic to make sure that different MXs do get tried. With a normal kind
2537 of retry rule, they would get tried anyway when the earlier hosts were
2538 delayed, but if the domain has a "retry every time" type of rule - as is
2539 often used for the the very large ISPs, that won't happen. */
2543 if (!host_is_expired && ++unexpired_hosts_tried >= ob->hosts_max_try)
2547 debug_printf("hosts_max_try limit reached with this host\n");
2548 for (h = host; h != NULL; h = h->next)
2549 if (h->mx != host->mx) break;
2553 unexpired_hosts_tried--;
2554 DEBUG(D_transport) debug_printf("however, a higher MX host exists "
2555 "and will be tried\n");
2559 /* Attempt the delivery. */
2561 total_hosts_tried++;
2562 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2563 expanded_hosts != NULL, &message_defer, FALSE);
2566 OK => connection made, each address contains its result;
2567 message_defer is set for message-specific defers (when all
2568 recipients are marked defer)
2569 DEFER => there was a non-message-specific delivery problem;
2570 ERROR => there was a problem setting up the arguments for a filter,
2571 or there was a problem with expanding added headers
2574 /* If the result is not OK, there was a non-message-specific problem.
2575 If the result is DEFER, we need to write to the logs saying what happened
2576 for this particular host, except in the case of authentication and TLS
2577 failures, where the log has already been written. If all hosts defer a
2578 general message is written at the end. */
2580 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL &&
2581 first_addr->basic_errno != ERRNO_TLSFAILURE)
2582 write_logs(first_addr, host);
2584 /* If STARTTLS was accepted, but there was a failure in setting up the
2585 TLS session (usually a certificate screwup), and the host is not in
2586 hosts_require_tls, and tls_tempfail_tryclear is true, try again, with
2587 TLS forcibly turned off. We have to start from scratch with a new SMTP
2588 connection. That's why the retry is done from here, not from within
2589 smtp_deliver(). [Rejections of STARTTLS itself don't screw up the
2590 session, so the in-clear transmission after those errors, if permitted,
2591 happens inside smtp_deliver().] */
2594 if (rc == DEFER && first_addr->basic_errno == ERRNO_TLSFAILURE &&
2595 ob->tls_tempfail_tryclear &&
2596 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
2597 host->address, NULL) != OK)
2599 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
2600 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
2601 first_addr = prepare_addresses(addrlist, host);
2602 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2603 expanded_hosts != NULL, &message_defer, TRUE);
2604 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL)
2605 write_logs(first_addr, host);
2610 /* Delivery attempt finished */
2612 rs = (rc == OK)? US"OK" : (rc == DEFER)? US"DEFER" : (rc == ERROR)?
2615 set_process_info("delivering %s: just tried %s [%s] for %s%s: result %s",
2616 message_id, host->name, host->address, addrlist->address,
2617 (addrlist->next == NULL)? "" : " (& others)", rs);
2619 /* Release serialization if set up */
2621 if (serialized) enq_end(serialize_key);
2623 /* If the result is DEFER, or if a host retry record is known to exist, we
2624 need to add an item to the retry chain for updating the retry database
2625 at the end of delivery. We only need to add the item to the top address,
2626 of course. Also, if DEFER, we mark the IP address unusable so as to skip it
2627 for any other delivery attempts using the same address. (It is copied into
2628 the unusable tree at the outer level, so even if different address blocks
2629 contain the same address, it still won't get tried again.) */
2631 if (rc == DEFER || retry_host_key != NULL)
2633 int delete_flag = (rc != DEFER)? rf_delete : 0;
2634 if (retry_host_key == NULL)
2636 retry_host_key = ob->retry_include_ip_address?
2637 string_sprintf("T:%S:%s%s", host->name, host->address, pistring) :
2638 string_sprintf("T:%S%s", host->name, pistring);
2641 /* If a delivery of another message over an existing SMTP connection
2642 yields DEFER, we do NOT set up retry data for the host. This covers the
2643 case when there are delays in routing the addresses in the second message
2644 that are so long that the server times out. This is alleviated by not
2645 routing addresses that previously had routing defers when handling an
2646 existing connection, but even so, this case may occur (e.g. if a
2647 previously happily routed address starts giving routing defers). If the
2648 host is genuinely down, another non-continued message delivery will
2649 notice it soon enough. */
2651 if (delete_flag != 0 || !continuing)
2652 retry_add_item(first_addr, retry_host_key, rf_host | delete_flag);
2654 /* We may have tried an expired host, if its retry time has come; ensure
2655 the status reflects the expiry for the benefit of any other addresses. */
2659 host->status = (host_is_expired)?
2660 hstatus_unusable_expired : hstatus_unusable;
2661 host->why = hwhy_deferred;
2665 /* If message_defer is set (host was OK, but every recipient got deferred
2666 because of some message-specific problem), or if that had happened
2667 previously so that a message retry key exists, add an appropriate item
2668 to the retry chain. Note that if there was a message defer but now there is
2669 a host defer, the message defer record gets deleted. That seems perfectly
2670 reasonable. Also, stop the message from being remembered as waiting
2673 if (message_defer || retry_message_key != NULL)
2675 int delete_flag = message_defer? 0 : rf_delete;
2676 if (retry_message_key == NULL)
2678 retry_message_key = ob->retry_include_ip_address?
2679 string_sprintf("T:%S:%s%s:%s", host->name, host->address, pistring,
2681 string_sprintf("T:%S%s:%s", host->name, pistring, message_id);
2683 retry_add_item(addrlist, retry_message_key,
2684 rf_message | rf_host | delete_flag);
2685 host->update_waiting = FALSE;
2688 /* Any return other than DEFER (that is, OK or ERROR) means that the
2689 addresses have got their final statuses filled in for this host. In the OK
2690 case, see if any of them are deferred. */
2694 for (addr = addrlist; addr != NULL; addr = addr->next)
2696 if (addr->transport_return == DEFER)
2698 some_deferred = TRUE;
2704 /* If no addresses deferred or the result was ERROR, return. We do this for
2705 ERROR because a failing filter set-up or add_headers expansion is likely to
2706 fail for any host we try. */
2708 if (rc == ERROR || (rc == OK && !some_deferred))
2710 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2711 return TRUE; /* Each address has its status */
2714 /* If the result was DEFER or some individual addresses deferred, let
2715 the loop run to try other hosts with the deferred addresses, except for the
2716 case when we were trying to deliver down an existing channel and failed.
2717 Don't try any other hosts in this case. */
2719 if (continuing) break;
2721 /* If the whole delivery, or some individual addresses, were deferred and
2722 there are more hosts that could be tried, do not count this host towards
2723 the hosts_max_try limit if the age of the message is greater than the
2724 maximum retry time for this host. This means we may try try all hosts,
2725 ignoring the limit, when messages have been around for some time. This is
2726 important because if we don't try all hosts, the address will never time
2727 out. NOTE: this does not apply to hosts_max_try_hardlimit. */
2729 if ((rc == DEFER || some_deferred) && nexthost != NULL)
2732 retry_config *retry = retry_find_config(host->name, NULL, 0, 0);
2734 if (retry != NULL && retry->rules != NULL)
2736 retry_rule *last_rule;
2737 for (last_rule = retry->rules;
2738 last_rule->next != NULL;
2739 last_rule = last_rule->next);
2740 timedout = time(NULL) - received_time > last_rule->timeout;
2742 else timedout = TRUE; /* No rule => timed out */
2746 unexpired_hosts_tried--;
2747 DEBUG(D_transport) debug_printf("temporary delivery error(s) override "
2748 "hosts_max_try (message older than host's retry time)\n");
2751 } /* End of loop for trying multiple hosts. */
2753 /* This is the end of the loop that repeats iff expired is TRUE and
2754 ob->delay_after_cutoff is FALSE. The second time round we will
2755 try those hosts that haven't been tried since the message arrived. */
2759 debug_printf("all IP addresses skipped or deferred at least one address\n");
2760 if (expired && !ob->delay_after_cutoff && cutoff_retry == 0)
2761 debug_printf("retrying IP addresses not tried since message arrived\n");
2766 /* Get here if all IP addresses are skipped or defer at least one address. In
2767 MUA wrapper mode, this will happen only for connection or other non-message-
2768 specific failures. Force the delivery status for all addresses to FAIL. */
2772 for (addr = addrlist; addr != NULL; addr = addr->next)
2773 addr->transport_return = FAIL;
2777 /* In the normal, non-wrapper case, add a standard message to each deferred
2778 address if there hasn't been an error, that is, if it hasn't actually been
2779 tried this time. The variable "expired" will be FALSE if any deliveries were
2780 actually tried, or if there was at least one host that was not expired. That
2781 is, it is TRUE only if no deliveries were tried and all hosts were expired. If
2782 a delivery has been tried, an error code will be set, and the failing of the
2783 message is handled by the retry code later.
2785 If queue_smtp is set, or this transport was called to send a subsequent message
2786 down an existing TCP/IP connection, and something caused the host not to be
2787 found, we end up here, but can detect these cases and handle them specially. */
2789 for (addr = addrlist; addr != NULL; addr = addr->next)
2791 /* If host is not NULL, it means that we stopped processing the host list
2792 because of hosts_max_try or hosts_max_try_hardlimit. In the former case, this
2793 means we need to behave as if some hosts were skipped because their retry
2794 time had not come. Specifically, this prevents the address from timing out.
2795 However, if we have hit hosts_max_try_hardlimit, we want to behave as if all
2796 hosts were tried. */
2800 if (total_hosts_tried >= ob->hosts_max_try_hardlimit)
2803 debug_printf("hosts_max_try_hardlimit reached: behave as if all "
2804 "hosts were tried\n");
2809 debug_printf("hosts_max_try limit caused some hosts to be skipped\n");
2810 setflag(addr, af_retry_skipped);
2814 if (queue_smtp) /* no deliveries attempted */
2816 addr->transport_return = DEFER;
2817 addr->basic_errno = 0;
2818 addr->message = US"SMTP delivery explicitly queued";
2821 else if (addr->transport_return == DEFER &&
2822 (addr->basic_errno == ERRNO_UNKNOWNERROR || addr->basic_errno == 0) &&
2823 addr->message == NULL)
2825 addr->basic_errno = ERRNO_HRETRY;
2826 if (continue_hostname != NULL)
2828 addr->message = US"no host found for existing SMTP connection";
2832 setflag(addr, af_pass_message); /* This is not a security risk */
2833 addr->message = (ob->delay_after_cutoff)?
2834 US"retry time not reached for any host after a long failure period" :
2835 US"all hosts have been failing for a long time and were last tried "
2836 "after this message arrived";
2838 /* If we are already using fallback hosts, or there are no fallback hosts
2839 defined, convert the result to FAIL to cause a bounce. */
2841 if (addr->host_list == addr->fallback_hosts ||
2842 addr->fallback_hosts == NULL)
2843 addr->transport_return = FAIL;
2847 if (hosts_retry == hosts_total)
2848 addr->message = US"retry time not reached for any host";
2849 else if (hosts_fail == hosts_total)
2850 addr->message = US"all host address lookups failed permanently";
2851 else if (hosts_defer == hosts_total)
2852 addr->message = US"all host address lookups failed temporarily";
2853 else if (hosts_serial == hosts_total)
2854 addr->message = US"connection limit reached for all hosts";
2855 else if (hosts_fail+hosts_defer == hosts_total)
2856 addr->message = US"all host address lookups failed";
2857 else addr->message = US"some host address lookups failed and retry time "
2858 "not reached for other hosts or connection limit reached";
2863 /* Update the database which keeps information about which messages are waiting
2864 for which hosts to become available. Each host in the list has a flag which is
2865 set if the data is to be updated. For some message-specific errors, the flag is
2866 turned off because we don't want follow-on deliveries in those cases. */
2868 transport_update_waiting(hostlist, tblock->name);
2872 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2874 return TRUE; /* Each address has its status */
2877 /* End of transport/smtp.c */
git://git.exim.org / exim.git / blob