1 /* $Cambridge: exim/src/src/transports/smtp.c,v 1.20 2006/02/07 11:19:03 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 errmsg place for error message (not used)
212 Returns: OK always (FAIL, DEFER not used)
216 smtp_transport_setup(transport_instance *tblock, address_item *addrlist,
217 transport_feedback *tf, uschar **errmsg)
219 smtp_transport_options_block *ob =
220 (smtp_transport_options_block *)(tblock->options_block);
222 errmsg = errmsg; /* Keep picky compilers happy */
224 /* Pass back options if required. This interface is getting very messy. */
228 tf->interface = ob->interface;
230 tf->protocol = ob->protocol;
231 tf->hosts = ob->hosts;
232 tf->hosts_override = ob->hosts_override;
233 tf->hosts_randomize = ob->hosts_randomize;
234 tf->gethostbyname = ob->gethostbyname;
235 tf->qualify_single = ob->dns_qualify_single;
236 tf->search_parents = ob->dns_search_parents;
239 /* Set the fallback host list for all the addresses that don't have fallback
240 host lists, provided that the local host wasn't present in the original host
243 if (!testflag(addrlist, af_local_host_removed))
245 for (; addrlist != NULL; addrlist = addrlist->next)
246 if (addrlist->fallback_hosts == NULL)
247 addrlist->fallback_hosts = ob->fallback_hostlist;
255 /*************************************************
256 * Initialization entry point *
257 *************************************************/
259 /* Called for each instance, after its options have been read, to
260 enable consistency checks to be done, or anything else that needs
263 Argument: pointer to the transport instance block
268 smtp_transport_init(transport_instance *tblock)
270 smtp_transport_options_block *ob =
271 (smtp_transport_options_block *)(tblock->options_block);
273 /* Retry_use_local_part defaults FALSE if unset */
275 if (tblock->retry_use_local_part == TRUE_UNSET)
276 tblock->retry_use_local_part = FALSE;
278 /* Set the default port according to the protocol */
280 if (ob->port == NULL)
281 ob->port = (strcmpic(ob->protocol, US"lmtp") == 0)? US"lmtp" : US"smtp";
283 /* Set up the setup entry point, to be called before subprocesses for this
286 tblock->setup = smtp_transport_setup;
288 /* Complain if any of the timeouts are zero. */
290 if (ob->command_timeout <= 0 || ob->data_timeout <= 0 ||
291 ob->final_timeout <= 0)
292 log_write(0, LOG_PANIC_DIE|LOG_CONFIG,
293 "command, data, or final timeout value is zero for %s transport",
296 /* If hosts_override is set and there are local hosts, set the global
297 flag that stops verify from showing router hosts. */
299 if (ob->hosts_override && ob->hosts != NULL) tblock->overrides_hosts = TRUE;
301 /* If there are any fallback hosts listed, build a chain of host items
302 for them, but do not do any lookups at this time. */
304 host_build_hostlist(&(ob->fallback_hostlist), ob->fallback_hosts, FALSE);
311 /*************************************************
312 * Set delivery info into all active addresses *
313 *************************************************/
315 /* Only addresses whose status is >= PENDING are relevant. A lesser
316 status means that an address is not currently being processed.
319 addrlist points to a chain of addresses
320 errno_value to put in each address's errno field
321 msg to put in each address's message field
322 rc to put in each address's transport_return field
323 pass_message if TRUE, set the "pass message" flag in the address
325 If errno_value has the special value ERRNO_CONNECTTIMEOUT, ETIMEDOUT is put in
326 the errno field, and RTEF_CTOUT is ORed into the more_errno field, to indicate
327 this particular type of timeout.
333 set_errno(address_item *addrlist, int errno_value, uschar *msg, int rc,
338 if (errno_value == ERRNO_CONNECTTIMEOUT)
340 errno_value = ETIMEDOUT;
341 orvalue = RTEF_CTOUT;
343 for (addr = addrlist; addr != NULL; addr = addr->next)
345 if (addr->transport_return < PENDING) continue;
346 addr->basic_errno = errno_value;
347 addr->more_errno |= orvalue;
351 if (pass_message) setflag(addr, af_pass_message);
353 addr->transport_return = rc;
359 /*************************************************
360 * Check an SMTP response *
361 *************************************************/
363 /* This function is given an errno code and the SMTP response buffer
364 to analyse, together with the host identification for generating messages. It
365 sets an appropriate message and puts the first digit of the response code into
366 the yield variable. If no response was actually read, a suitable digit is
370 host the current host, to get its name for messages
371 errno_value pointer to the errno value
372 more_errno from the top address for use with ERRNO_FILTER_FAIL
373 buffer the SMTP response buffer
374 yield where to put a one-digit SMTP response code
375 message where to put an errror message
376 pass_message set TRUE if message is an SMTP response
378 Returns: TRUE if an SMTP "QUIT" command should be sent, else FALSE
381 static BOOL check_response(host_item *host, int *errno_value, int more_errno,
382 uschar *buffer, int *yield, uschar **message, BOOL *pass_message)
386 if (smtp_use_pipelining &&
387 (Ustrcmp(smtp_command, "MAIL") == 0 ||
388 Ustrcmp(smtp_command, "RCPT") == 0 ||
389 Ustrcmp(smtp_command, "DATA") == 0))
392 *yield = '4'; /* Default setting is to give a temporary error */
394 /* Handle response timeout */
396 if (*errno_value == ETIMEDOUT)
398 *message = US string_sprintf("SMTP timeout while connected to %s [%s] "
399 "after %s%s", host->name, host->address, pl, smtp_command);
400 if (transport_count > 0)
401 *message = US string_sprintf("%s (%d bytes written)", *message,
406 /* Handle malformed SMTP response */
408 if (*errno_value == ERRNO_SMTPFORMAT)
410 uschar *malfresp = string_printing(buffer);
411 while (isspace(*malfresp)) malfresp++;
413 *message = string_sprintf("Malformed SMTP reply (an empty line) from "
414 "%s [%s] in response to %s%s", host->name, host->address, pl,
417 *message = string_sprintf("Malformed SMTP reply from %s [%s] in response "
418 "to %s%s: %s", host->name, host->address, pl, smtp_command, malfresp);
422 /* Handle a failed filter process error; can't send QUIT as we mustn't
425 if (*errno_value == ERRNO_FILTER_FAIL)
427 *message = US string_sprintf("transport filter process failed (%d)%s",
429 (more_errno == EX_EXECFAILED)? ": unable to execute command" : "");
433 /* Handle a failed add_headers expansion; can't send QUIT as we mustn't
436 if (*errno_value == ERRNO_CHHEADER_FAIL)
439 US string_sprintf("failed to expand headers_add or headers_remove: %s",
440 expand_string_message);
444 /* Handle failure to write a complete data block */
446 if (*errno_value == ERRNO_WRITEINCOMPLETE)
448 *message = US string_sprintf("failed to write a data block");
452 /* Handle error responses from the remote mailer. */
456 uschar *s = string_printing(buffer);
457 *message = US string_sprintf("SMTP error from remote mail server after %s%s: "
458 "host %s [%s]: %s", pl, smtp_command, host->name, host->address, s);
459 *pass_message = TRUE;
464 /* No data was read. If there is no errno, this must be the EOF (i.e.
465 connection closed) case, which causes deferral. An explicit connection reset
466 error has the same effect. Otherwise, put the host's identity in the message,
467 leaving the errno value to be interpreted as well. In all cases, we have to
468 assume the connection is now dead. */
470 if (*errno_value == 0 || *errno_value == ECONNRESET)
472 *errno_value = ERRNO_SMTPCLOSED;
473 *message = US string_sprintf("Remote host %s [%s] closed connection "
474 "in response to %s%s", host->name, host->address, pl, smtp_command);
476 else *message = US string_sprintf("%s [%s]", host->name, host->address);
483 /*************************************************
484 * Write error message to logs *
485 *************************************************/
487 /* This writes to the main log and to the message log.
490 addr the address item containing error information
491 host the current host
497 write_logs(address_item *addr, host_item *host)
499 if (addr->message != NULL)
501 uschar *message = addr->message;
502 if (addr->basic_errno > 0)
503 message = string_sprintf("%s: %s", message, strerror(addr->basic_errno));
504 log_write(0, LOG_MAIN, "%s", message);
505 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
510 ((log_extra_selector & LX_outgoing_port) != 0)?
511 string_sprintf("%s [%s]:%d", host->name, host->address,
512 (host->port == PORT_NONE)? 25 : host->port)
514 string_sprintf("%s [%s]", host->name, host->address);
515 log_write(0, LOG_MAIN, "%s %s", msg, strerror(addr->basic_errno));
516 deliver_msglog("%s %s %s\n", tod_stamp(tod_log), msg,
517 strerror(addr->basic_errno));
523 /*************************************************
524 * Synchronize SMTP responses *
525 *************************************************/
527 /* This function is called from smtp_deliver() to receive SMTP responses from
528 the server, and match them up with the commands to which they relate. When
529 PIPELINING is not in use, this function is called after every command, and is
530 therefore somewhat over-engineered, but it is simpler to use a single scheme
531 that works both with and without PIPELINING instead of having two separate sets
534 The set of commands that are buffered up with pipelining may start with MAIL
535 and may end with DATA; in between are RCPT commands that correspond to the
536 addresses whose status is PENDING_DEFER. All other commands (STARTTLS, AUTH,
537 etc.) are never buffered.
539 Errors after MAIL or DATA abort the whole process leaving the response in the
540 buffer. After MAIL, pending responses are flushed, and the original command is
541 re-instated in big_buffer for error messages. For RCPT commands, the remote is
542 permitted to reject some recipient addresses while accepting others. However
543 certain errors clearly abort the whole process. Set the value in
544 transport_return to PENDING_OK if the address is accepted. If there is a
545 subsequent general error, it will get reset accordingly. If not, it will get
546 converted to OK at the end.
549 addrlist the complete address list
550 include_affixes TRUE if affixes include in RCPT
551 sync_addr ptr to the ptr of the one to start scanning at (updated)
552 host the host we are connected to
553 count the number of responses to read
554 pending_MAIL true if the first response is for MAIL
555 pending_DATA 0 if last command sent was not DATA
556 +1 if previously had a good recipient
557 -1 if not previously had a good recipient
558 inblock incoming SMTP block
559 timeout timeout value
560 buffer buffer for reading response
561 buffsize size of buffer
563 Returns: 3 if at least one address had 2xx and one had 5xx
564 2 if at least one address had 5xx but none had 2xx
565 1 if at least one host had a 2xx response, but none had 5xx
566 0 no address had 2xx or 5xx but no errors (all 4xx, or just DATA)
567 -1 timeout while reading RCPT response
568 -2 I/O or other non-response error for RCPT
569 -3 DATA or MAIL failed - errno and buffer set
573 sync_responses(address_item *addrlist, BOOL include_affixes,
574 address_item **sync_addr, host_item *host, int count, BOOL pending_MAIL,
575 int pending_DATA, smtp_inblock *inblock, int timeout, uschar *buffer,
578 address_item *addr = *sync_addr;
581 /* Handle the response for a MAIL command. On error, reinstate the original
582 command in big_buffer for error message use, and flush any further pending
583 responses before returning, except after I/O errors and timeouts. */
588 if (!smtp_read_response(inblock, buffer, buffsize, '2', timeout))
590 Ustrcpy(big_buffer, mail_command); /* Fits, because it came from there! */
591 if (errno == 0 && buffer[0] != 0)
593 uschar flushbuffer[4096];
596 if (!smtp_read_response(inblock, flushbuffer, sizeof(flushbuffer),
598 && (errno != 0 || flushbuffer[0] == 0))
606 if (pending_DATA) count--; /* Number of RCPT responses to come */
608 /* Read and handle the required number of RCPT responses, matching each one up
609 with an address by scanning for the next address whose status is PENDING_DEFER.
614 while (addr->transport_return != PENDING_DEFER) addr = addr->next;
616 /* The address was accepted */
618 if (smtp_read_response(inblock, buffer, buffsize, '2', timeout))
621 addr->transport_return = PENDING_OK;
623 /* If af_dr_retry_exists is set, there was a routing delay on this address;
624 ensure that any address-specific retry record is expunged. */
626 if (testflag(addr, af_dr_retry_exists))
627 retry_add_item(addr, addr->address_retry_key, rf_delete);
630 /* Timeout while reading the response */
632 else if (errno == ETIMEDOUT)
634 int save_errno = errno;
635 uschar *message = string_sprintf("SMTP timeout while connected to %s [%s] "
636 "after RCPT TO:<%s>", host->name, host->address,
637 transport_rcpt_address(addr, include_affixes));
638 set_errno(addrlist, save_errno, message, DEFER, FALSE);
639 retry_add_item(addr, addr->address_retry_key, 0);
640 host->update_waiting = FALSE;
644 /* Handle other errors in obtaining an SMTP response by returning -1. This
645 will cause all the addresses to be deferred. Restore the SMTP command in
646 big_buffer for which we are checking the response, so the error message
649 else if (errno != 0 || buffer[0] == 0)
651 string_format(big_buffer, big_buffer_size, "RCPT TO:<%s>",
652 transport_rcpt_address(addr, include_affixes));
656 /* Handle SMTP permanent and temporary response codes. */
661 string_sprintf("SMTP error from remote mail server after RCPT TO:<%s>: "
662 "host %s [%s]: %s", transport_rcpt_address(addr, include_affixes),
663 host->name, host->address, string_printing(buffer));
664 setflag(addr, af_pass_message);
665 deliver_msglog("%s %s\n", tod_stamp(tod_log), addr->message);
667 /* The response was 5xx */
669 if (buffer[0] == '5')
671 addr->transport_return = FAIL;
675 /* The response was 4xx */
679 int bincode = (buffer[1] - '0')*10 + buffer[2] - '0';
681 addr->transport_return = DEFER;
682 addr->basic_errno = ERRNO_RCPT4XX;
683 addr->more_errno |= bincode << 8;
685 /* Log temporary errors if there are more hosts to be tried. */
687 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", addr->message);
689 /* Do not put this message on the list of those waiting for this host,
690 as otherwise it is likely to be tried too often. */
692 host->update_waiting = FALSE;
694 /* Add a retry item for the address so that it doesn't get tried
697 retry_add_item(addr, addr->address_retry_key, 0);
700 } /* Loop for next RCPT response */
702 /* Update where to start at for the next block of responses, unless we
703 have already handled all the addresses. */
705 if (addr != NULL) *sync_addr = addr->next;
707 /* Handle a response to DATA. If we have not had any good recipients, either
708 previously or in this block, the response is ignored. */
710 if (pending_DATA != 0 &&
711 !smtp_read_response(inblock, buffer, buffsize, '3', timeout))
716 if (pending_DATA > 0 || (yield & 1) != 0) return -3;
717 (void)check_response(host, &errno, 0, buffer, &code, &msg, &pass_message);
718 DEBUG(D_transport) debug_printf("%s\nerror for DATA ignored: pipelining "
719 "is in use and there were no good recipients\n", msg);
722 /* All responses read and handled; MAIL (if present) received 2xx and DATA (if
723 present) received 3xx. If any RCPTs were handled and yielded anything other
724 than 4xx, yield will be set non-zero. */
731 /*************************************************
732 * Deliver address list to given host *
733 *************************************************/
735 /* If continue_hostname is not null, we get here only when continuing to
736 deliver down an existing channel. The channel was passed as the standard
739 Otherwise, we have to make a connection to the remote host, and do the
740 initial protocol exchange.
742 When running as an MUA wrapper, if the sender or any recipient is rejected,
743 temporarily or permanently, we force failure for all recipients.
746 addrlist chain of potential addresses to deliver; only those whose
747 transport_return field is set to PENDING_DEFER are currently
748 being processed; others should be skipped - they have either
749 been delivered to an earlier host or IP address, or been
750 failed by one of them.
751 host host to deliver to
752 host_af AF_INET or AF_INET6
753 port default TCP/IP port to use, in host byte order
754 interface interface to bind to, or NULL
755 tblock transport instance block
756 copy_host TRUE if host set in addr->host_used must be copied, because
757 it is specific to this call of the transport
758 message_defer set TRUE if yield is OK, but all addresses were deferred
759 because of a non-recipient, non-host failure, that is, a
760 4xx response to MAIL FROM, DATA, or ".". This is a defer
761 that is specific to the message.
762 suppress_tls if TRUE, don't attempt a TLS connection - this is set for
763 a second attempt after TLS initialization fails
765 Returns: OK - the connection was made and the delivery attempted;
766 the result for each address is in its data block.
767 DEFER - the connection could not be made, or something failed
768 while setting up the SMTP session, or there was a
769 non-message-specific error, such as a timeout.
770 ERROR - a filter command is specified for this transport,
771 and there was a problem setting it up; OR helo_data
772 or add_headers or authenticated_sender is specified
773 for this transport, and the string failed to expand
777 smtp_deliver(address_item *addrlist, host_item *host, int host_af, int port,
778 uschar *interface, transport_instance *tblock, BOOL copy_host,
779 BOOL *message_defer, BOOL suppress_tls)
782 address_item *sync_addr;
783 address_item *first_addr = addrlist;
788 time_t start_delivery_time = time(NULL);
789 smtp_transport_options_block *ob =
790 (smtp_transport_options_block *)(tblock->options_block);
791 BOOL lmtp = strcmpic(ob->protocol, US"lmtp") == 0;
793 BOOL send_rset = TRUE;
794 BOOL send_quit = TRUE;
795 BOOL setting_up = TRUE;
796 BOOL completed_address = FALSE;
799 BOOL pass_message = FALSE;
800 smtp_inblock inblock;
801 smtp_outblock outblock;
802 int max_rcpt = tblock->max_addresses;
803 uschar *igquotstr = US"";
804 uschar *local_authenticated_sender = authenticated_sender;
806 uschar *message = NULL;
807 uschar new_message_id[MESSAGE_ID_LENGTH + 1];
810 uschar inbuffer[4096];
811 uschar outbuffer[1024];
813 suppress_tls = suppress_tls; /* stop compiler warning when no TLS support */
815 *message_defer = FALSE;
816 smtp_command = US"initial connection";
817 if (max_rcpt == 0) max_rcpt = 999999;
819 /* Set up the buffer for reading SMTP response packets. */
821 inblock.buffer = inbuffer;
822 inblock.buffersize = sizeof(inbuffer);
823 inblock.ptr = inbuffer;
824 inblock.ptrend = inbuffer;
826 /* Set up the buffer for holding SMTP commands while pipelining */
828 outblock.buffer = outbuffer;
829 outblock.buffersize = sizeof(outbuffer);
830 outblock.ptr = outbuffer;
831 outblock.cmd_count = 0;
832 outblock.authenticating = FALSE;
834 /* Expand the greeting message */
836 helo_data = expand_string(ob->helo_data);
837 if (helo_data == NULL)
839 uschar *message = string_sprintf("failed to expand helo_data: %s",
840 expand_string_message);
841 set_errno(addrlist, 0, message, DEFER, FALSE);
845 /* If an authenticated_sender override has been specified for this transport
846 instance, expand it. If the expansion is forced to fail, and there was already
847 an authenticated_sender for this message, the original value will be used.
848 Other expansion failures are serious. An empty result is ignored, but there is
849 otherwise no check - this feature is expected to be used with LMTP and other
850 cases where non-standard addresses (e.g. without domains) might be required. */
852 if (ob->authenticated_sender != NULL)
854 uschar *new = expand_string(ob->authenticated_sender);
857 if (!expand_string_forcedfail)
859 uschar *message = string_sprintf("failed to expand "
860 "authenticated_sender: %s", expand_string_message);
861 set_errno(addrlist, 0, message, DEFER, FALSE);
865 else if (new[0] != 0) local_authenticated_sender = new;
868 /* Make a connection to the host if this isn't a continued delivery, and handle
869 the initial interaction and HELO/EHLO/LHLO. Connect timeout errors are handled
870 specially so they can be identified for retries. */
872 if (continue_hostname == NULL)
874 inblock.sock = outblock.sock =
875 smtp_connect(host, host_af, port, interface, ob->connect_timeout,
877 if (inblock.sock < 0)
879 set_errno(addrlist, (errno == ETIMEDOUT)? ERRNO_CONNECTTIMEOUT : errno,
884 /* The first thing is to wait for an initial OK response. The dreaded "goto"
885 is nevertheless a reasonably clean way of programming this kind of logic,
886 where you want to escape on any error. */
888 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
889 ob->command_timeout)) goto RESPONSE_FAILED;
891 /** Debugging without sending a message
892 addrlist->transport_return = DEFER;
896 /* Errors that occur after this point follow an SMTP command, which is
897 left in big_buffer by smtp_write_command() for use in error messages. */
899 smtp_command = big_buffer;
901 /* Tell the remote who we are...
903 February 1998: A convention has evolved that ESMTP-speaking MTAs include the
904 string "ESMTP" in their greeting lines, so make Exim send EHLO if the
905 greeting is of this form. The assumption was that the far end supports it
906 properly... but experience shows that there are some that give 5xx responses,
907 even though the banner includes "ESMTP" (there's a bloody-minded one that
908 says "ESMTP not spoken here"). Cope with that case.
910 September 2000: Time has passed, and it seems reasonable now to always send
911 EHLO at the start. It is also convenient to make the change while installing
914 July 2003: Joachim Wieland met a broken server that advertises "PIPELINING"
915 but times out after sending MAIL FROM, RCPT TO and DATA all together. There
916 would be no way to send out the mails, so there is now a host list
917 "hosts_avoid_esmtp" that disables ESMTP for special hosts and solves the
918 PIPELINING problem as well. Maybe it can also be useful to cure other
919 problems with broken servers.
921 Exim originally sent "Helo" at this point and ran for nearly a year that way.
922 Then somebody tried it with a Microsoft mailer... It seems that all other
923 mailers use upper case for some reason (the RFC is quite clear about case
924 independence) so, for peace of mind, I gave in. */
926 esmtp = verify_check_this_host(&(ob->hosts_avoid_esmtp), NULL,
927 host->name, host->address, NULL) != OK;
931 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n",
932 lmtp? "LHLO" : "EHLO", helo_data) < 0)
934 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
935 ob->command_timeout))
937 if (errno != 0 || buffer[0] == 0 || lmtp) goto RESPONSE_FAILED;
944 debug_printf("not sending EHLO (host matches hosts_avoid_esmtp)\n");
949 if (smtp_write_command(&outblock, FALSE, "HELO %s\r\n", helo_data) < 0)
951 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
952 ob->command_timeout)) goto RESPONSE_FAILED;
955 /* Set IGNOREQUOTA if the response to LHLO specifies support and the
956 lmtp_ignore_quota option was set. */
958 igquotstr = (lmtp && ob->lmtp_ignore_quota &&
959 pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer, Ustrlen(CS buffer), 0,
960 PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
962 /* Set tls_offered if the response to EHLO specifies support for STARTTLS. */
965 tls_offered = esmtp &&
966 pcre_exec(regex_STARTTLS, NULL, CS buffer, Ustrlen(buffer), 0,
967 PCRE_EOPT, NULL, 0) >= 0;
971 /* For continuing deliveries down the same channel, the socket is the standard
972 input, and we don't need to redo EHLO here (but may need to do so for TLS - see
973 below). Set up the pointer to where subsequent commands will be left, for
974 error messages. Note that smtp_use_size and smtp_use_pipelining will have been
975 set from the command line if they were set in the process that passed the
980 inblock.sock = outblock.sock = fileno(stdin);
981 smtp_command = big_buffer;
984 /* If TLS is available on this connection, whether continued or not, attempt to
985 start up a TLS session, unless the host is in hosts_avoid_tls. If successful,
986 send another EHLO - the server may give a different answer in secure mode. We
987 use a separate buffer for reading the response to STARTTLS so that if it is
988 negative, the original EHLO data is available for subsequent analysis, should
989 the client not be required to use TLS. If the response is bad, copy the buffer
990 for error analysis. */
993 if (tls_offered && !suppress_tls &&
994 verify_check_this_host(&(ob->hosts_avoid_tls), NULL, host->name,
995 host->address, NULL) != OK)
997 uschar buffer2[4096];
998 if (smtp_write_command(&outblock, FALSE, "STARTTLS\r\n") < 0)
1001 /* If there is an I/O error, transmission of this message is deferred. If
1002 there is a temporary rejection of STARRTLS and tls_tempfail_tryclear is
1003 false, we also defer. However, if there is a temporary rejection of STARTTLS
1004 and tls_tempfail_tryclear is true, or if there is an outright rejection of
1005 STARTTLS, we carry on. This means we will try to send the message in clear,
1006 unless the host is in hosts_require_tls (tested below). */
1008 if (!smtp_read_response(&inblock, buffer2, sizeof(buffer2), '2',
1009 ob->command_timeout))
1011 Ustrncpy(buffer, buffer2, sizeof(buffer));
1012 if (errno != 0 || buffer2[0] == 0 ||
1013 (buffer2[0] == '4' && !ob->tls_tempfail_tryclear))
1014 goto RESPONSE_FAILED;
1017 /* STARTTLS accepted: try to negotiate a TLS session. */
1021 int rc = tls_client_start(inblock.sock, host, addrlist,
1022 NULL, /* No DH param */
1023 ob->tls_certificate,
1025 ob->tls_verify_certificates,
1027 ob->tls_require_ciphers,
1028 ob->command_timeout);
1030 /* TLS negotiation failed; give an error. From outside, this function may
1031 be called again to try in clear on a new connection, if the options permit
1032 it for this host. */
1036 save_errno = ERRNO_TLSFAILURE;
1037 message = US"failure while setting up TLS session";
1042 /* TLS session is set up */
1044 for (addr = addrlist; addr != NULL; addr = addr->next)
1046 if (addr->transport_return == PENDING_DEFER)
1048 addr->cipher = tls_cipher;
1049 addr->peerdn = tls_peerdn;
1055 /* If we started TLS, redo the EHLO/LHLO exchange over the secure channel. */
1057 if (tls_active >= 0)
1059 if (smtp_write_command(&outblock, FALSE, "%s %s\r\n", lmtp? "LHLO" : "EHLO",
1062 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1063 ob->command_timeout))
1064 goto RESPONSE_FAILED;
1067 /* If the host is required to use a secure channel, ensure that we
1070 else if (verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
1071 host->address, NULL) == OK)
1073 save_errno = ERRNO_TLSREQUIRED;
1074 message = string_sprintf("a TLS session is required for %s [%s], but %s",
1075 host->name, host->address,
1076 tls_offered? "an attempt to start TLS failed" :
1077 "the server did not offer TLS support");
1082 /* If TLS is active, we have just started it up and re-done the EHLO command,
1083 so its response needs to be analyzed. If TLS is not active and this is a
1084 continued session down a previously-used socket, we haven't just done EHLO, so
1087 if (continue_hostname == NULL
1094 uschar *fail_reason = US"server did not advertise AUTH support";
1096 /* Set for IGNOREQUOTA if the response to LHLO specifies support and the
1097 lmtp_ignore_quota option was set. */
1099 igquotstr = (lmtp && ob->lmtp_ignore_quota &&
1100 pcre_exec(regex_IGNOREQUOTA, NULL, CS buffer, Ustrlen(CS buffer), 0,
1101 PCRE_EOPT, NULL, 0) >= 0)? US" IGNOREQUOTA" : US"";
1103 /* If the response to EHLO specified support for the SIZE parameter, note
1104 this, provided size_addition is non-negative. */
1106 smtp_use_size = esmtp && ob->size_addition >= 0 &&
1107 pcre_exec(regex_SIZE, NULL, CS buffer, Ustrlen(CS buffer), 0,
1108 PCRE_EOPT, NULL, 0) >= 0;
1110 /* Note whether the server supports PIPELINING. If hosts_avoid_esmtp matched
1111 the current host, esmtp will be false, so PIPELINING can never be used. */
1113 smtp_use_pipelining = esmtp &&
1114 pcre_exec(regex_PIPELINING, NULL, CS buffer, Ustrlen(CS buffer), 0,
1115 PCRE_EOPT, NULL, 0) >= 0;
1117 DEBUG(D_transport) debug_printf("%susing PIPELINING\n",
1118 smtp_use_pipelining? "" : "not ");
1120 /* Note if the response to EHLO specifies support for the AUTH extension.
1121 If it has, check that this host is one we want to authenticate to, and do
1122 the business. The host name and address must be available when the
1123 authenticator's client driver is running. */
1125 smtp_authenticated = FALSE;
1126 require_auth = verify_check_this_host(&(ob->hosts_require_auth), NULL,
1127 host->name, host->address, NULL);
1129 if (esmtp && regex_match_and_setup(regex_AUTH, buffer, 0, -1))
1131 uschar *names = string_copyn(expand_nstring[1], expand_nlength[1]);
1132 expand_nmax = -1; /* reset */
1134 /* Must not do this check until after we have saved the result of the
1135 regex match above. */
1137 if (require_auth == OK ||
1138 verify_check_this_host(&(ob->hosts_try_auth), NULL, host->name,
1139 host->address, NULL) == OK)
1142 fail_reason = US"no common mechanisms were found";
1144 DEBUG(D_transport) debug_printf("scanning authentication mechanisms\n");
1146 /* Scan the configured authenticators looking for one which is configured
1147 for use as a client and whose name matches an authentication mechanism
1148 supported by the server. If one is found, attempt to authenticate by
1149 calling its client function. */
1151 for (au = auths; !smtp_authenticated && au != NULL; au = au->next)
1154 if (!au->client) continue;
1156 /* Loop to scan supported server mechanisms */
1161 int len = Ustrlen(au->public_name);
1162 while (isspace(*p)) p++;
1164 if (strncmpic(au->public_name, p, len) != 0 ||
1165 (p[len] != 0 && !isspace(p[len])))
1167 while (*p != 0 && !isspace(*p)) p++;
1171 /* Found data for a listed mechanism. Call its client entry. Set
1172 a flag in the outblock so that data is overwritten after sending so
1173 that reflections don't show it. */
1175 fail_reason = US"authentication attempt(s) failed";
1176 outblock.authenticating = TRUE;
1177 rc = (au->info->clientcode)(au, &inblock, &outblock,
1178 ob->command_timeout, buffer, sizeof(buffer));
1179 outblock.authenticating = FALSE;
1180 DEBUG(D_transport) debug_printf("%s authenticator yielded %d\n",
1183 /* A temporary authentication failure must hold up delivery to
1184 this host. After a permanent authentication failure, we carry on
1185 to try other authentication methods. If all fail hard, try to
1186 deliver the message unauthenticated unless require_auth was set. */
1191 smtp_authenticated = TRUE; /* stops the outer loop */
1194 /* Failure after writing a command */
1199 /* Failure after reading a response */
1202 if (errno != 0 || buffer[0] != '5') goto RESPONSE_FAILED;
1203 log_write(0, LOG_MAIN, "%s authenticator failed H=%s [%s] %s",
1204 au->name, host->name, host->address, buffer);
1207 /* Failure by some other means. In effect, the authenticator
1208 decided it wasn't prepared to handle this case. Typically this
1209 is the result of "fail" in an expansion string. Do we need to
1210 log anything here? */
1215 /* Internal problem, message in buffer. */
1219 set_errno(addrlist, 0, string_copy(buffer), DEFER, FALSE);
1223 break; /* If not authenticated, try next authenticator */
1224 } /* Loop for scanning supported server mechanisms */
1225 } /* Loop for further authenticators */
1229 /* If we haven't authenticated, but are required to, give up. */
1231 if (require_auth == OK && !smtp_authenticated)
1234 set_errno(addrlist, ERRNO_AUTHFAIL,
1235 string_sprintf("authentication required but %s", fail_reason), DEFER,
1241 /* The setting up of the SMTP call is now complete. Any subsequent errors are
1242 message-specific. */
1246 /* If there is a filter command specified for this transport, we can now
1247 set it up. This cannot be done until the identify of the host is known. */
1249 if (tblock->filter_command != NULL)
1253 sprintf(CS buffer, "%.50s transport", tblock->name);
1254 rc = transport_set_up_command(&transport_filter_argv, tblock->filter_command,
1255 TRUE, DEFER, addrlist, buffer, NULL);
1257 /* On failure, copy the error to all addresses, abandon the SMTP call, and
1262 set_errno(addrlist->next, addrlist->basic_errno, addrlist->message, DEFER,
1270 /* For messages that have more than the maximum number of envelope recipients,
1271 we want to send several transactions down the same SMTP connection. (See
1272 comments in deliver.c as to how this reconciles, heuristically, with
1273 remote_max_parallel.) This optimization was added to Exim after the following
1274 code was already working. The simplest way to put it in without disturbing the
1275 code was to use a goto to jump back to this point when there is another
1276 transaction to handle. */
1279 sync_addr = first_addr;
1283 completed_address = FALSE;
1286 /* Initiate a message transfer. If we know the receiving MTA supports the SIZE
1287 qualification, send it, adding something to the message size to allow for
1288 imprecision and things that get added en route. Exim keeps the number of lines
1289 in a message, so we can give an accurate value for the original message, but we
1290 need some additional to handle added headers. (Double "." characters don't get
1291 included in the count.) */
1298 sprintf(CS p, " SIZE=%d", message_size+message_linecount+ob->size_addition);
1302 /* Add the authenticated sender address if present */
1304 if (smtp_authenticated && local_authenticated_sender != NULL)
1306 string_format(p, sizeof(buffer) - (p-buffer), " AUTH=%s",
1307 auth_xtextencode(local_authenticated_sender,
1308 Ustrlen(local_authenticated_sender)));
1311 /* From here until we send the DATA command, we can make use of PIPELINING
1312 if the server host supports it. The code has to be able to check the responses
1313 at any point, for when the buffer fills up, so we write it totally generally.
1314 When PIPELINING is off, each command written reports that it has flushed the
1317 pending_MAIL = TRUE; /* The block starts with MAIL */
1319 rc = smtp_write_command(&outblock, smtp_use_pipelining,
1320 "MAIL FROM:<%s>%s\r\n", return_path, buffer);
1321 mail_command = string_copy(big_buffer); /* Save for later error message */
1325 case -1: /* Transmission error */
1328 case +1: /* Block was sent */
1329 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1330 ob->command_timeout)) goto RESPONSE_FAILED;
1331 pending_MAIL = FALSE;
1335 /* Pass over all the relevant recipient addresses for this host, which are the
1336 ones that have status PENDING_DEFER. If we are using PIPELINING, we can send
1337 several before we have to read the responses for those seen so far. This
1338 checking is done by a subroutine because it also needs to be done at the end.
1339 Send only up to max_rcpt addresses at a time, leaving first_addr pointing to
1340 the next one if not all are sent.
1342 In the MUA wrapper situation, we want to flush the PIPELINING buffer for the
1343 last address because we want to abort if any recipients have any kind of
1344 problem, temporary or permanent. We know that all recipient addresses will have
1345 the PENDING_DEFER status, because only one attempt is ever made, and we know
1346 that max_rcpt will be large, so all addresses will be done at once. */
1348 for (addr = first_addr;
1349 address_count < max_rcpt && addr != NULL;
1355 if (addr->transport_return != PENDING_DEFER) continue;
1358 no_flush = smtp_use_pipelining && (!mua_wrapper || addr->next != NULL);
1360 /* Now send the RCPT command, and process outstanding responses when
1361 necessary. After a timeout on RCPT, we just end the function, leaving the
1362 yield as OK, because this error can often mean that there is a problem with
1363 just one address, so we don't want to delay the host. */
1365 count = smtp_write_command(&outblock, no_flush, "RCPT TO:<%s>%s\r\n",
1366 transport_rcpt_address(addr, tblock->rcpt_include_affixes), igquotstr);
1367 if (count < 0) goto SEND_FAILED;
1370 switch(sync_responses(first_addr, tblock->rcpt_include_affixes,
1371 &sync_addr, host, count, pending_MAIL, 0, &inblock,
1372 ob->command_timeout, buffer, sizeof(buffer)))
1374 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1375 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1378 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1379 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1380 case 0: /* No 2xx or 5xx, but no probs */
1383 case -1: goto END_OFF; /* Timeout on RCPT */
1384 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL error */
1386 pending_MAIL = FALSE; /* Dealt with MAIL */
1388 } /* Loop for next address */
1390 /* If we are an MUA wrapper, abort if any RCPTs were rejected, either
1391 permanently or temporarily. We should have flushed and synced after the last
1396 address_item *badaddr;
1397 for (badaddr = first_addr; badaddr != NULL; badaddr = badaddr->next)
1399 if (badaddr->transport_return != PENDING_OK) break;
1401 if (badaddr != NULL)
1403 set_errno(addrlist, 0, badaddr->message, FAIL,
1404 testflag(badaddr, af_pass_message));
1409 /* If ok is TRUE, we know we have got at least one good recipient, and must now
1410 send DATA, but if it is FALSE (in the normal, non-wrapper case), we may still
1411 have a good recipient buffered up if we are pipelining. We don't want to waste
1412 time sending DATA needlessly, so we only send it if either ok is TRUE or if we
1413 are pipelining. The responses are all handled by sync_responses(). */
1415 if (ok || (smtp_use_pipelining && !mua_wrapper))
1417 int count = smtp_write_command(&outblock, FALSE, "DATA\r\n");
1418 if (count < 0) goto SEND_FAILED;
1419 switch(sync_responses(first_addr, tblock->rcpt_include_affixes, &sync_addr,
1420 host, count, pending_MAIL, ok? +1 : -1, &inblock,
1421 ob->command_timeout, buffer, sizeof(buffer)))
1423 case 3: ok = TRUE; /* 2xx & 5xx => OK & progress made */
1424 case 2: completed_address = TRUE; /* 5xx (only) => progress made */
1427 case 1: ok = TRUE; /* 2xx (only) => OK, but if LMTP, */
1428 if (!lmtp) completed_address = TRUE; /* can't tell about progress yet */
1429 case 0: break; /* No 2xx or 5xx, but no probs */
1431 case -1: goto END_OFF; /* Timeout on RCPT */
1432 default: goto RESPONSE_FAILED; /* I/O error, or any MAIL/DATA error */
1436 /* Save the first address of the next batch. */
1440 /* If there were no good recipients (but otherwise there have been no
1441 problems), just set ok TRUE, since we have handled address-specific errors
1442 already. Otherwise, it's OK to send the message. Use the check/escape mechanism
1443 for handling the SMTP dot-handling protocol, flagging to apply to headers as
1444 well as body. Set the appropriate timeout value to be used for each chunk.
1445 (Haven't been able to make it work using select() for writing yet.) */
1447 if (!ok) ok = TRUE; else
1449 sigalrm_seen = FALSE;
1450 transport_write_timeout = ob->data_timeout;
1451 smtp_command = US"sending data block"; /* For error messages */
1452 DEBUG(D_transport|D_v)
1453 debug_printf(" SMTP>> writing message and terminating \".\"\n");
1454 transport_count = 0;
1455 #ifdef EXPERIMENTAL_DOMAINKEYS
1456 if ( (ob->dk_private_key != NULL) && (ob->dk_selector != NULL) )
1457 ok = dk_transport_write_message(addrlist, inblock.sock,
1458 topt_use_crlf | topt_end_dot | topt_escape_headers |
1459 (tblock->body_only? topt_no_headers : 0) |
1460 (tblock->headers_only? topt_no_body : 0) |
1461 (tblock->return_path_add? topt_add_return_path : 0) |
1462 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1463 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1464 0, /* No size limit */
1465 tblock->add_headers, tblock->remove_headers,
1466 US".", US"..", /* Escaping strings */
1467 tblock->rewrite_rules, tblock->rewrite_existflags,
1468 ob->dk_private_key, ob->dk_domain, ob->dk_selector,
1469 ob->dk_canon, ob->dk_headers, ob->dk_strict);
1472 ok = transport_write_message(addrlist, inblock.sock,
1473 topt_use_crlf | topt_end_dot | topt_escape_headers |
1474 (tblock->body_only? topt_no_headers : 0) |
1475 (tblock->headers_only? topt_no_body : 0) |
1476 (tblock->return_path_add? topt_add_return_path : 0) |
1477 (tblock->delivery_date_add? topt_add_delivery_date : 0) |
1478 (tblock->envelope_to_add? topt_add_envelope_to : 0),
1479 0, /* No size limit */
1480 tblock->add_headers, tblock->remove_headers,
1481 US".", US"..", /* Escaping strings */
1482 tblock->rewrite_rules, tblock->rewrite_existflags);
1484 /* transport_write_message() uses write() because it is called from other
1485 places to write to non-sockets. This means that under some OS (e.g. Solaris)
1486 it can exit with "Broken pipe" as its error. This really means that the
1487 socket got closed at the far end. */
1489 transport_write_timeout = 0; /* for subsequent transports */
1491 /* Failure can either be some kind of I/O disaster (including timeout),
1492 or the failure of a transport filter or the expansion of added headers. */
1496 buffer[0] = 0; /* There hasn't been a response */
1497 goto RESPONSE_FAILED;
1500 /* We used to send the terminating "." explicitly here, but because of
1501 buffering effects at both ends of TCP/IP connections, you don't gain
1502 anything by keeping it separate, so it might as well go in the final
1503 data buffer for efficiency. This is now done by setting the topt_end_dot
1506 smtp_command = US"end of data";
1508 /* For SMTP, we now read a single response that applies to the whole message.
1509 If it is OK, then all the addresses have been delivered. */
1511 if (!lmtp) ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1514 /* For LMTP, we get back a response for every RCPT command that we sent;
1515 some may be accepted and some rejected. For those that get a response, their
1516 status is fixed; any that are accepted have been handed over, even if later
1517 responses crash - at least, that's how I read RFC 2033.
1519 If all went well, mark the recipient addresses as completed, record which
1520 host/IPaddress they were delivered to, and cut out RSET when sending another
1521 message down the same channel. Write the completed addresses to the journal
1522 now so that they are recorded in case there is a crash of hardware or
1523 software before the spool gets updated. Also record the final SMTP
1524 confirmation if needed (for SMTP only). */
1529 int delivery_time = (int)(time(NULL) - start_delivery_time);
1532 uschar *conf = NULL;
1535 /* Make a copy of the host if it is local to this invocation
1536 of the transport. */
1540 thost = store_get(sizeof(host_item));
1542 thost->name = string_copy(host->name);
1543 thost->address = string_copy(host->address);
1547 /* Set up confirmation if needed - applies only to SMTP */
1549 if ((log_extra_selector & LX_smtp_confirmation) != 0 && !lmtp)
1551 uschar *s = string_printing(buffer);
1552 conf = (s == buffer)? (uschar *)string_copy(s) : s;
1555 /* Process all transported addresses - for LMTP, read a status for
1558 for (addr = addrlist; addr != first_addr; addr = addr->next)
1560 if (addr->transport_return != PENDING_OK) continue;
1562 /* LMTP - if the response fails badly (e.g. timeout), use it for all the
1563 remaining addresses. Otherwise, it's a return code for just the one
1568 if (!smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1571 if (errno != 0 || buffer[0] == 0) goto RESPONSE_FAILED;
1572 addr->message = string_sprintf("LMTP error after %s: %s",
1573 big_buffer, string_printing(buffer));
1574 addr->transport_return = (buffer[0] == '5')? FAIL : DEFER;
1577 completed_address = TRUE; /* NOW we can set this flag */
1580 /* SMTP, or success return from LMTP for this address. Pass back the
1581 actual host that was used. */
1583 addr->transport_return = OK;
1584 addr->more_errno = delivery_time;
1585 addr->host_used = thost;
1586 addr->special_action = flag;
1587 addr->message = conf;
1590 /* Update the journal. For homonymic addresses, use the base address plus
1591 the transport name. See lots of comments in deliver.c about the reasons
1592 for the complications when homonyms are involved. Just carry on after
1593 write error, as it may prove possible to update the spool file later. */
1595 if (testflag(addr, af_homonym))
1596 sprintf(CS buffer, "%.500s/%s\n", addr->unique + 3, tblock->name);
1598 sprintf(CS buffer, "%.500s\n", addr->unique);
1600 DEBUG(D_deliver) debug_printf("journalling %s", buffer);
1601 len = Ustrlen(CS buffer);
1602 if (write(journal_fd, buffer, len) != len)
1603 log_write(0, LOG_MAIN|LOG_PANIC, "failed to write journal for "
1604 "%s: %s", buffer, strerror(errno));
1607 /* Ensure the journal file is pushed out to disk. */
1609 if (fsync(journal_fd) < 0)
1610 log_write(0, LOG_MAIN|LOG_PANIC, "failed to fsync journal: %s",
1616 /* Handle general (not specific to one address) failures here. The value of ok
1617 is used to skip over this code on the falling through case. A timeout causes a
1618 deferral. Other errors may defer or fail according to the response code, and
1619 may set up a special errno value, e.g. after connection chopped, which is
1620 assumed if errno == 0 and there is no text in the buffer. If control reaches
1621 here during the setting up phase (i.e. before MAIL FROM) then always defer, as
1622 the problem is not related to this specific message. */
1631 send_quit = check_response(host, &save_errno, addrlist->more_errno,
1632 buffer, &code, &message, &pass_message);
1638 message = US string_sprintf("send() to %s [%s] failed: %s",
1639 host->name, host->address, strerror(save_errno));
1643 /* This label is jumped to directly when a TLS negotiation has failed,
1644 or was not done for a host for which it is required. Values will be set
1645 in message and save_errno, and setting_up will always be true. Treat as
1646 a temporary error. */
1653 /* If the failure happened while setting up the call, see if the failure was
1654 a 5xx response (this will either be on connection, or following HELO - a 5xx
1655 after EHLO causes it to try HELO). If so, fail all addresses, as this host is
1656 never going to accept them. For other errors during setting up (timeouts or
1657 whatever), defer all addresses, and yield DEFER, so that the host is not
1658 tried again for a while. */
1661 ok = FALSE; /* For when reached by GOTO */
1667 set_errno(addrlist, save_errno, message, FAIL, pass_message);
1671 set_errno(addrlist, save_errno, message, DEFER, pass_message);
1676 /* If there was an I/O error or timeout or other transportation error,
1677 indicated by errno being non-zero, defer all addresses and yield DEFER,
1678 except for the case of failed add_headers expansion, or a transport filter
1679 failure, when the yield should be ERROR, to stop it trying other hosts.
1681 However, handle timeouts after MAIL FROM or "." and loss of connection after
1682 "." specially. They can indicate a problem with the sender address or with
1683 the contents of the message rather than a real error on the connection.
1684 Therefore, treat these cases in the same way as a 4xx response.
1686 The following condition tests for NOT these special cases. */
1688 else if (save_errno != 0 &&
1689 (save_errno != ETIMEDOUT ||
1690 (Ustrncmp(smtp_command,"MAIL",4) != 0 &&
1691 Ustrncmp(smtp_command,"end ",4) != 0)) &&
1692 (save_errno != ERRNO_SMTPCLOSED ||
1693 Ustrncmp(smtp_command,"end ",4) != 0))
1695 yield = (save_errno == ERRNO_CHHEADER_FAIL ||
1696 save_errno == ERRNO_FILTER_FAIL)? ERROR : DEFER;
1697 set_errno(addrlist, save_errno, message, DEFER, pass_message);
1700 /* Otherwise we have a message-specific error response from the remote
1701 host. This is one of
1702 (a) negative response or timeout after "mail from"
1703 (b) negative response after "data"
1704 (c) negative response or timeout or dropped connection after "."
1705 It won't be a negative response or timeout after "rcpt to", as that is dealt
1706 with separately above. The action in all cases is to set an appropriate
1707 error code for all the addresses, but to leave yield set to OK because
1708 the host itself has not failed. [It might in practice have failed for a
1709 timeout after MAIL FROM, or "." but if so, we'll discover that at the next
1710 delivery attempt.] For a temporary error, set the message_defer flag, and
1711 write to the logs for information if this is not the last host. The error for
1712 the last host will be logged as part of the address's log line. */
1716 if (mua_wrapper) code = '5'; /* Force hard failure in wrapper mode */
1718 set_errno(addrlist, save_errno, message, (code == '5')? FAIL : DEFER,
1721 /* If there's an errno, the message contains just the identity of
1724 if (code != '5') /* Anything other than 5 is treated as temporary */
1727 message = US string_sprintf("%s: %s", message, strerror(save_errno));
1728 if (host->next != NULL) log_write(0, LOG_MAIN, "%s", message);
1729 deliver_msglog("%s %s\n", tod_stamp(tod_log), message);
1730 *message_defer = TRUE;
1736 /* If all has gone well, send_quit will be set TRUE, implying we can end the
1737 SMTP session tidily. However, if there were too many addresses to send in one
1738 message (indicated by first_addr being non-NULL) we want to carry on with the
1739 rest of them. Also, it is desirable to send more than one message down the SMTP
1740 connection if there are several waiting, provided we haven't already sent so
1741 many as to hit the configured limit. The function transport_check_waiting looks
1742 for a waiting message and returns its id. Then transport_pass_socket tries to
1743 set up a continued delivery by passing the socket on to another process. The
1744 variable send_rset is FALSE if a message has just been successfully transfered.
1746 If we are already sending down a continued channel, there may be further
1747 addresses not yet delivered that are aimed at the same host, but which have not
1748 been passed in this run of the transport. In this case, continue_more will be
1749 true, and all we should do is send RSET if necessary, and return, leaving the
1752 However, if no address was disposed of, i.e. all addresses got 4xx errors, we
1753 do not want to continue with other messages down the same channel, because that
1754 can lead to looping between two or more messages, all with the same,
1755 temporarily failing address(es). [The retry information isn't updated yet, so
1756 new processes keep on trying.] We probably also don't want to try more of this
1757 message's addresses either.
1759 If we have started a TLS session, we have to end it before passing the
1760 connection to a new process. However, not all servers can handle this (Exim
1761 can), so we do not pass such a connection on if the host matches
1762 hosts_nopass_tls. */
1765 debug_printf("ok=%d send_quit=%d send_rset=%d continue_more=%d "
1766 "yield=%d first_address is %sNULL\n", ok, send_quit, send_rset,
1767 continue_more, yield, (first_addr == NULL)? "":"not ");
1769 if (completed_address && ok && send_quit)
1772 if (first_addr != NULL || continue_more ||
1775 verify_check_this_host(&(ob->hosts_nopass_tls), NULL, host->name,
1776 host->address, NULL) != OK)
1778 transport_check_waiting(tblock->name, host->name,
1779 tblock->connection_max_messages, new_message_id, &more)
1787 if (! (ok = smtp_write_command(&outblock, FALSE, "RSET\r\n") >= 0))
1789 msg = US string_sprintf("send() to %s [%s] failed: %s", host->name,
1790 host->address, strerror(save_errno));
1793 else if (! (ok = smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1794 ob->command_timeout)))
1797 send_quit = check_response(host, &errno, 0, buffer, &code, &msg,
1801 DEBUG(D_transport) debug_printf("%s\n", msg);
1806 /* Either RSET was not needed, or it succeeded */
1810 if (first_addr != NULL) /* More addresses still to be sent */
1811 { /* in this run of the transport */
1812 continue_sequence++; /* Causes * in logging */
1815 if (continue_more) return yield; /* More addresses for another run */
1817 /* Pass the socket to a new Exim process. Before doing so, we must shut
1818 down TLS. Not all MTAs allow for the continuation of the SMTP session
1819 when TLS is shut down. We test for this by sending a new EHLO. If we
1820 don't get a good response, we don't attempt to pass the socket on. */
1823 if (tls_active >= 0)
1826 ok = smtp_write_command(&outblock,FALSE,"EHLO %s\r\n",helo_data) >= 0 &&
1827 smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1828 ob->command_timeout);
1832 /* If the socket is successfully passed, we musn't send QUIT (or
1833 indeed anything!) from here. */
1835 if (ok && transport_pass_socket(tblock->name, host->name, host->address,
1836 new_message_id, inblock.sock))
1842 /* If RSET failed and there are addresses left, they get deferred. */
1844 else set_errno(first_addr, errno, msg, DEFER, FALSE);
1848 /* End off tidily with QUIT unless the connection has died or the socket has
1849 been passed to another process. There has been discussion on the net about what
1850 to do after sending QUIT. The wording of the RFC suggests that it is necessary
1851 to wait for a response, but on the other hand, there isn't anything one can do
1852 with an error response, other than log it. Exim used to do that. However,
1853 further discussion suggested that it is positively advantageous not to wait for
1854 the response, but to close the session immediately. This is supposed to move
1855 the TCP/IP TIME_WAIT state from the server to the client, thereby removing some
1856 load from the server. (Hosts that are both servers and clients may not see much
1857 difference, of course.) Further discussion indicated that this was safe to do
1858 on Unix systems which have decent implementations of TCP/IP that leave the
1859 connection around for a while (TIME_WAIT) after the application has gone away.
1860 This enables the response sent by the server to be properly ACKed rather than
1861 timed out, as can happen on broken TCP/IP implementations on other OS.
1863 This change is being made on 31-Jul-98. After over a year of trouble-free
1864 operation, the old commented-out code was removed on 17-Sep-99. */
1867 if (send_quit) (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1875 /* Close the socket, and return the appropriate value, first setting
1876 continue_transport and continue_hostname NULL to prevent any other addresses
1877 that may include the host from trying to re-use a continuation socket. This
1878 works because the NULL setting is passed back to the calling process, and
1879 remote_max_parallel is forced to 1 when delivering over an existing connection,
1881 If all went well and continue_more is set, we shouldn't actually get here if
1882 there are further addresses, as the return above will be taken. However,
1883 writing RSET might have failed, or there may be other addresses whose hosts are
1884 specified in the transports, and therefore not visible at top level, in which
1885 case continue_more won't get set. */
1887 (void)close(inblock.sock);
1888 continue_transport = NULL;
1889 continue_hostname = NULL;
1896 /*************************************************
1897 * Closedown entry point *
1898 *************************************************/
1900 /* This function is called when exim is passed an open smtp channel
1901 from another incarnation, but the message which it has been asked
1902 to deliver no longer exists. The channel is on stdin.
1904 We might do fancy things like looking for another message to send down
1905 the channel, but if the one we sought has gone, it has probably been
1906 delivered by some other process that itself will seek further messages,
1907 so just close down our connection.
1909 Argument: pointer to the transport instance block
1914 smtp_transport_closedown(transport_instance *tblock)
1916 smtp_transport_options_block *ob =
1917 (smtp_transport_options_block *)(tblock->options_block);
1918 smtp_inblock inblock;
1919 smtp_outblock outblock;
1921 uschar inbuffer[4096];
1922 uschar outbuffer[16];
1924 inblock.sock = fileno(stdin);
1925 inblock.buffer = inbuffer;
1926 inblock.buffersize = sizeof(inbuffer);
1927 inblock.ptr = inbuffer;
1928 inblock.ptrend = inbuffer;
1930 outblock.sock = inblock.sock;
1931 outblock.buffersize = sizeof(outbuffer);
1932 outblock.buffer = outbuffer;
1933 outblock.ptr = outbuffer;
1934 outblock.cmd_count = 0;
1935 outblock.authenticating = FALSE;
1937 (void)smtp_write_command(&outblock, FALSE, "QUIT\r\n");
1938 (void)smtp_read_response(&inblock, buffer, sizeof(buffer), '2',
1939 ob->command_timeout);
1940 (void)close(inblock.sock);
1945 /*************************************************
1946 * Prepare addresses for delivery *
1947 *************************************************/
1949 /* This function is called to flush out error settings from previous delivery
1950 attempts to other hosts. It also records whether we got here via an MX record
1951 or not in the more_errno field of the address. We are interested only in
1952 addresses that are still marked DEFER - others may have got delivered to a
1953 previously considered IP address. Set their status to PENDING_DEFER to indicate
1954 which ones are relevant this time.
1957 addrlist the list of addresses
1958 host the host we are delivering to
1960 Returns: the first address for this delivery
1963 static address_item *
1964 prepare_addresses(address_item *addrlist, host_item *host)
1966 address_item *first_addr = NULL;
1968 for (addr = addrlist; addr != NULL; addr = addr->next)
1970 if (addr->transport_return != DEFER) continue;
1971 if (first_addr == NULL) first_addr = addr;
1972 addr->transport_return = PENDING_DEFER;
1973 addr->basic_errno = 0;
1974 addr->more_errno = (host->mx >= 0)? 'M' : 'A';
1975 addr->message = NULL;
1977 addr->cipher = NULL;
1978 addr->peerdn = NULL;
1986 /*************************************************
1987 * Main entry point *
1988 *************************************************/
1990 /* See local README for interface details. As this is a remote transport, it is
1991 given a chain of addresses to be delivered in one connection, if possible. It
1992 always returns TRUE, indicating that each address has its own independent
1993 status set, except if there is a setting up problem, in which case it returns
1997 smtp_transport_entry(
1998 transport_instance *tblock, /* data for this instantiation */
1999 address_item *addrlist) /* addresses we are working on */
2003 int hosts_defer = 0;
2005 int hosts_looked_up = 0;
2006 int hosts_retry = 0;
2007 int hosts_serial = 0;
2008 int hosts_total = 0;
2009 int total_hosts_tried = 0;
2011 BOOL expired = TRUE;
2012 BOOL continuing = continue_hostname != NULL;
2013 uschar *expanded_hosts = NULL;
2015 uschar *tid = string_sprintf("%s transport", tblock->name);
2016 smtp_transport_options_block *ob =
2017 (smtp_transport_options_block *)(tblock->options_block);
2018 host_item *hostlist = addrlist->host_list;
2019 host_item *host = NULL;
2023 debug_printf("%s transport entered\n", tblock->name);
2024 for (addr = addrlist; addr != NULL; addr = addr->next)
2025 debug_printf(" %s\n", addr->address);
2026 if (continuing) debug_printf("already connected to %s [%s]\n",
2027 continue_hostname, continue_host_address);
2030 /* If a host list is not defined for the addresses - they must all have the
2031 same one in order to be passed to a single transport - or if the transport has
2032 a host list with hosts_override set, use the host list supplied with the
2033 transport. It is an error for this not to exist. */
2035 if (hostlist == NULL || (ob->hosts_override && ob->hosts != NULL))
2037 if (ob->hosts == NULL)
2039 addrlist->message = string_sprintf("%s transport called with no hosts set",
2041 addrlist->transport_return = PANIC;
2042 return FALSE; /* Only top address has status */
2045 DEBUG(D_transport) debug_printf("using the transport's hosts: %s\n",
2048 /* If the transport's host list contains no '$' characters, and we are not
2049 randomizing, it is fixed and therefore a chain of hosts can be built once
2050 and for all, and remembered for subsequent use by other calls to this
2051 transport. If, on the other hand, the host list does contain '$', or we are
2052 randomizing its order, we have to rebuild it each time. In the fixed case,
2053 as the hosts string will never be used again, it doesn't matter that we
2054 replace all the : characters with zeros. */
2056 if (ob->hostlist == NULL)
2058 uschar *s = ob->hosts;
2060 if (Ustrchr(s, '$') != NULL)
2062 expanded_hosts = expand_string(s);
2063 if (expanded_hosts == NULL)
2065 addrlist->message = string_sprintf("failed to expand list of hosts "
2066 "\"%s\" in %s transport: %s", s, tblock->name, expand_string_message);
2067 addrlist->transport_return = search_find_defer? DEFER : PANIC;
2068 return FALSE; /* Only top address has status */
2070 DEBUG(D_transport) debug_printf("expanded list of hosts \"%s\" to "
2071 "\"%s\"\n", s, expanded_hosts);
2075 if (ob->hosts_randomize) s = expanded_hosts = string_copy(s);
2077 host_build_hostlist(&hostlist, s, ob->hosts_randomize);
2079 /* If there was no expansion of hosts, save the host list for
2082 if (expanded_hosts == NULL) ob->hostlist = hostlist;
2085 /* This is not the first time this transport has been run in this delivery;
2086 the host list was built previously. */
2088 else hostlist = ob->hostlist;
2091 /* The host list was supplied with the address. If hosts_randomize is set, we
2092 must sort it into a random order if it did not come from MX records and has not
2093 already been randomized (but don't bother if continuing down an existing
2096 else if (ob->hosts_randomize && hostlist->mx == MX_NONE && !continuing)
2098 host_item *newlist = NULL;
2099 while (hostlist != NULL)
2101 host_item *h = hostlist;
2102 hostlist = hostlist->next;
2104 h->sort_key = random_number(100);
2106 if (newlist == NULL)
2111 else if (h->sort_key < newlist->sort_key)
2118 host_item *hh = newlist;
2119 while (hh->next != NULL)
2121 if (h->sort_key < hh->next->sort_key) break;
2129 hostlist = addrlist->host_list = newlist;
2133 /* Sort out the default port. */
2135 if (!smtp_get_port(ob->port, addrlist, &port, tid)) return FALSE;
2138 /* For each host-plus-IP-address on the list:
2140 . If this is a continued delivery and the host isn't the one with the
2141 current connection, skip.
2143 . If the status is unusable (i.e. previously failed or retry checked), skip.
2145 . If no IP address set, get the address, either by turning the name into
2146 an address, calling gethostbyname if gethostbyname is on, or by calling
2147 the DNS. The DNS may yield multiple addresses, in which case insert the
2148 extra ones into the list.
2150 . Get the retry data if not previously obtained for this address and set the
2151 field which remembers the state of this address. Skip if the retry time is
2152 not reached. If not, remember whether retry data was found. The retry string
2153 contains both the name and the IP address.
2155 . Scan the list of addresses and mark those whose status is DEFER as
2156 PENDING_DEFER. These are the only ones that will be processed in this cycle
2159 . Make a delivery attempt - addresses marked PENDING_DEFER will be tried.
2160 Some addresses may be successfully delivered, others may fail, and yet
2161 others may get temporary errors and so get marked DEFER.
2163 . The return from the delivery attempt is OK if a connection was made and a
2164 valid SMTP dialogue was completed. Otherwise it is DEFER.
2166 . If OK, add a "remove" retry item for this host/IPaddress, if any.
2168 . If fail to connect, or other defer state, add a retry item.
2170 . If there are any addresses whose status is still DEFER, carry on to the
2171 next host/IPaddress, unless we have tried the number of hosts given
2172 by hosts_max_try or hosts_max_try_hardlimit; otherwise return. Note that
2173 there is some fancy logic for hosts_max_try that means its limit can be
2174 overstepped in some circumstances.
2176 If we get to the end of the list, all hosts have deferred at least one address,
2177 or not reached their retry times. If delay_after_cutoff is unset, it requests a
2178 delivery attempt to those hosts whose last try was before the arrival time of
2179 the current message. To cope with this, we have to go round the loop a second
2180 time. After that, set the status and error data for any addresses that haven't
2181 had it set already. */
2183 for (cutoff_retry = 0; expired &&
2184 cutoff_retry < ((ob->delay_after_cutoff)? 1 : 2);
2187 host_item *nexthost = NULL;
2188 int unexpired_hosts_tried = 0;
2190 for (host = hostlist;
2192 unexpired_hosts_tried < ob->hosts_max_try &&
2193 total_hosts_tried < ob->hosts_max_try_hardlimit;
2199 BOOL serialized = FALSE;
2200 BOOL host_is_expired = FALSE;
2201 BOOL message_defer = FALSE;
2202 BOOL ifchanges = FALSE;
2203 BOOL some_deferred = FALSE;
2204 address_item *first_addr = NULL;
2205 uschar *interface = NULL;
2206 uschar *retry_host_key = NULL;
2207 uschar *retry_message_key = NULL;
2208 uschar *serialize_key = NULL;
2210 /* Default next host is next host. :-) But this can vary if the
2211 hosts_max_try limit is hit (see below). It may also be reset if a host
2212 address is looked up here (in case the host was multihomed). */
2214 nexthost = host->next;
2216 /* Set the flag requesting that this host be added to the waiting
2217 database if the delivery fails temporarily or if we are running with
2218 queue_smtp or a 2-stage queue run. This gets unset for certain
2219 kinds of error, typically those that are specific to the message. */
2221 host->update_waiting = TRUE;
2223 /* If the address hasn't yet been obtained from the host name, look it up
2224 now, unless the host is already marked as unusable. If it is marked as
2225 unusable, it means that the router was unable to find its IP address (in
2226 the DNS or wherever) OR we are in the 2nd time round the cutoff loop, and
2227 the lookup failed last time. We don't get this far if *all* MX records
2228 point to non-existent hosts; that is treated as a hard error.
2230 We can just skip this host entirely. When the hosts came from the router,
2231 the address will timeout based on the other host(s); when the address is
2232 looked up below, there is an explicit retry record added.
2234 Note that we mustn't skip unusable hosts if the address is not unset; they
2235 may be needed as expired hosts on the 2nd time round the cutoff loop. */
2237 if (host->address == NULL)
2241 uschar *canonical_name;
2243 if (host->status >= hstatus_unusable)
2245 DEBUG(D_transport) debug_printf("%s has no address and is unusable - skipping\n",
2250 DEBUG(D_transport) debug_printf("getting address for %s\n", host->name);
2252 /* The host name is permitted to have an attached port. Find it, and
2253 strip it from the name. Just remember it for now. */
2255 new_port = host_item_get_port(host);
2257 /* Count hosts looked up */
2261 /* Find by name if so configured, or if it's an IP address. We don't
2262 just copy the IP address, because we need the test-for-local to happen. */
2264 if (ob->gethostbyname || string_is_ip_address(host->name, NULL) != 0)
2265 rc = host_find_byname(host, NULL, &canonical_name, TRUE);
2268 int flags = HOST_FIND_BY_A;
2269 if (ob->dns_qualify_single) flags |= HOST_FIND_QUALIFY_SINGLE;
2270 if (ob->dns_search_parents) flags |= HOST_FIND_SEARCH_PARENTS;
2271 rc = host_find_bydns(host, NULL, flags, NULL, NULL, NULL,
2272 &canonical_name, NULL);
2275 /* Update the host (and any additional blocks, resulting from
2276 multihoming) with a host-specific port, if any. */
2278 for (hh = host; hh != nexthost; hh = hh->next) hh->port = new_port;
2280 /* Failure to find the host at this time (usually DNS temporary failure)
2281 is really a kind of routing failure rather than a transport failure.
2282 Therefore we add a retry item of the routing kind, not to stop us trying
2283 to look this name up here again, but to ensure the address gets timed
2284 out if the failures go on long enough. A complete failure at this point
2285 commonly points to a configuration error, but the best action is still
2286 to carry on for the next host. */
2288 if (rc == HOST_FIND_AGAIN || rc == HOST_FIND_FAILED)
2290 retry_add_item(addrlist, string_sprintf("R:%s", host->name), 0);
2292 if (rc == HOST_FIND_AGAIN) hosts_defer++; else hosts_fail++;
2293 DEBUG(D_transport) debug_printf("rc = %s for %s\n", (rc == HOST_FIND_AGAIN)?
2294 "HOST_FIND_AGAIN" : "HOST_FIND_FAILED", host->name);
2295 host->status = hstatus_unusable;
2297 for (addr = addrlist; addr != NULL; addr = addr->next)
2299 if (addr->transport_return != DEFER) continue;
2300 addr->basic_errno = ERRNO_UNKNOWNHOST;
2302 string_sprintf("failed to lookup IP address for %s", host->name);
2307 /* If the host is actually the local host, we may have a problem, or
2308 there may be some cunning configuration going on. In the problem case,
2309 log things and give up. The default transport status is already DEFER. */
2311 if (rc == HOST_FOUND_LOCAL && !ob->allow_localhost)
2313 for (addr = addrlist; addr != NULL; addr = addr->next)
2315 addr->basic_errno = 0;
2316 addr->message = string_sprintf("%s transport found host %s to be "
2317 "local", tblock->name, host->name);
2321 } /* End of block for IP address lookup */
2323 /* If this is a continued delivery, we are interested only in the host
2324 which matches the name of the existing open channel. The check is put
2325 here after the local host lookup, in case the name gets expanded as a
2326 result of the lookup. Set expired FALSE, to save the outer loop executing
2329 if (continuing && (Ustrcmp(continue_hostname, host->name) != 0 ||
2330 Ustrcmp(continue_host_address, host->address) != 0))
2333 continue; /* With next host */
2336 /* Reset the default next host in case a multihomed host whose addresses
2337 are not looked up till just above added to the host list. */
2339 nexthost = host->next;
2341 /* If queue_smtp is set (-odqs or the first part of a 2-stage run), or the
2342 domain is in queue_smtp_domains, we don't actually want to attempt any
2343 deliveries. When doing a queue run, queue_smtp_domains is always unset. If
2344 there is a lookup defer in queue_smtp_domains, proceed as if the domain
2345 were not in it. We don't want to hold up all SMTP deliveries! Except when
2346 doing a two-stage queue run, don't do this if forcing. */
2348 if ((!deliver_force || queue_2stage) && (queue_smtp ||
2349 match_isinlist(addrlist->domain, &queue_smtp_domains, 0,
2350 &domainlist_anchor, NULL, MCL_DOMAIN, TRUE, NULL) == OK))
2353 for (addr = addrlist; addr != NULL; addr = addr->next)
2355 if (addr->transport_return != DEFER) continue;
2356 addr->message = US"domain matches queue_smtp_domains, or -odqs set";
2358 continue; /* With next host */
2361 /* Count hosts being considered - purely for an intelligent comment
2362 if none are usable. */
2366 /* Set $host and $host address now in case they are needed for the
2367 interface expansion or the serialize_hosts check; they remain set if an
2368 actual delivery happens. */
2370 deliver_host = host->name;
2371 deliver_host_address = host->address;
2373 /* Set up a string for adding to the retry key if the port number is not
2374 the standard SMTP port. A host may have its own port setting that overrides
2377 pistring = string_sprintf(":%d", (host->port == PORT_NONE)?
2379 if (Ustrcmp(pistring, ":25") == 0) pistring = US"";
2381 /* Select IPv4 or IPv6, and choose an outgoing interface. If the interface
2382 string changes upon expansion, we must add it to the key that is used for
2383 retries, because connections to the same host from a different interface
2384 should be treated separately. */
2386 host_af = (Ustrchr(host->address, ':') == NULL)? AF_INET : AF_INET6;
2387 if (!smtp_get_interface(ob->interface, host_af, addrlist, &ifchanges,
2390 if (ifchanges) pistring = string_sprintf("%s/%s", pistring, interface);
2392 /* The first time round the outer loop, check the status of the host by
2393 inspecting the retry data. The second time round, we are interested only
2394 in expired hosts that haven't been tried since this message arrived. */
2396 if (cutoff_retry == 0)
2398 /* Ensure the status of the address is set by checking retry data if
2399 necessary. There maybe host-specific retry data (applicable to all
2400 messages) and also data for retries of a specific message at this host.
2401 If either of these retry records are actually read, the keys used are
2402 returned to save recomputing them later. */
2404 host_is_expired = retry_check_address(addrlist->domain, host, pistring,
2405 ob->retry_include_ip_address, &retry_host_key, &retry_message_key);
2407 DEBUG(D_transport) debug_printf("%s [%s]%s status = %s\n", host->name,
2408 (host->address == NULL)? US"" : host->address, pistring,
2409 (host->status == hstatus_usable)? "usable" :
2410 (host->status == hstatus_unusable)? "unusable" :
2411 (host->status == hstatus_unusable_expired)? "unusable (expired)" : "?");
2413 /* Skip this address if not usable at this time, noting if it wasn't
2414 actually expired, both locally and in the address. */
2416 switch (host->status)
2418 case hstatus_unusable:
2420 setflag(addrlist, af_retry_skipped);
2423 case hstatus_unusable_expired:
2426 case hwhy_retry: hosts_retry++; break;
2427 case hwhy_failed: hosts_fail++; break;
2428 case hwhy_deferred: hosts_defer++; break;
2431 /* If there was a retry message key, implying that previously there
2432 was a message-specific defer, we don't want to update the list of
2433 messages waiting for this host. */
2435 if (retry_message_key != NULL) host->update_waiting = FALSE;
2436 continue; /* With the next host or IP address */
2440 /* Second time round the loop: if the address is set but expired, and
2441 the message is newer than the last try, let it through. */
2445 if (host->address == NULL ||
2446 host->status != hstatus_unusable_expired ||
2447 host->last_try > received_time)
2450 debug_printf("trying expired host %s [%s]%s\n",
2451 host->name, host->address, pistring);
2452 host_is_expired = TRUE;
2455 /* Setting "expired=FALSE" doesn't actually mean not all hosts are expired;
2456 it remains TRUE only if all hosts are expired and none are actually tried.
2461 /* If this host is listed as one to which access must be serialized,
2462 see if another Exim process has a connection to it, and if so, skip
2463 this host. If not, update the database to record our connection to it
2464 and remember this for later deletion. Do not do any of this if we are
2465 sending the message down a pre-existing connection. */
2468 verify_check_this_host(&(ob->serialize_hosts), NULL, host->name,
2469 host->address, NULL) == OK)
2471 serialize_key = string_sprintf("host-serialize-%s", host->name);
2472 if (!enq_start(serialize_key))
2475 debug_printf("skipping host %s because another Exim process "
2476 "is connected to it\n", host->name);
2483 /* OK, we have an IP address that is not waiting for its retry time to
2484 arrive (it might be expired) OR (second time round the loop) we have an
2485 expired host that hasn't been tried since the message arrived. Have a go
2486 at delivering the message to it. First prepare the addresses by flushing
2487 out the result of previous attempts, and finding the first address that
2488 is still to be delivered. */
2490 first_addr = prepare_addresses(addrlist, host);
2492 DEBUG(D_transport) debug_printf("delivering %s to %s [%s] (%s%s)\n",
2493 message_id, host->name, host->address, addrlist->address,
2494 (addrlist->next == NULL)? "" : ", ...");
2496 set_process_info("delivering %s to %s [%s] (%s%s)",
2497 message_id, host->name, host->address, addrlist->address,
2498 (addrlist->next == NULL)? "" : ", ...");
2500 /* This is not for real; don't do the delivery. If there are
2501 any remaining hosts, list them. */
2506 set_errno(addrlist, 0, NULL, OK, FALSE);
2507 for (addr = addrlist; addr != NULL; addr = addr->next)
2509 addr->host_used = host;
2510 addr->special_action = '*';
2511 addr->message = US"delivery bypassed by -N option";
2515 debug_printf("*** delivery by %s transport bypassed by -N option\n"
2516 "*** host and remaining hosts:\n", tblock->name);
2517 for (host2 = host; host2 != NULL; host2 = host2->next)
2518 debug_printf(" %s [%s]\n", host2->name,
2519 (host2->address == NULL)? US"unset" : host2->address);
2524 /* This is for real. If the host is expired, we don't count it for
2525 hosts_max_retry. This ensures that all hosts must expire before an address
2526 is timed out, unless hosts_max_try_hardlimit (which protects against
2527 lunatic DNS configurations) is reached.
2529 If the host is not expired and we are about to hit the hosts_max_retry
2530 limit, check to see if there is a subsequent hosts with a different MX
2531 value. If so, make that the next host, and don't count this one. This is a
2532 heuristic to make sure that different MXs do get tried. With a normal kind
2533 of retry rule, they would get tried anyway when the earlier hosts were
2534 delayed, but if the domain has a "retry every time" type of rule - as is
2535 often used for the the very large ISPs, that won't happen. */
2539 if (!host_is_expired && ++unexpired_hosts_tried >= ob->hosts_max_try)
2543 debug_printf("hosts_max_try limit reached with this host\n");
2544 for (h = host; h != NULL; h = h->next)
2545 if (h->mx != host->mx) break;
2549 unexpired_hosts_tried--;
2550 DEBUG(D_transport) debug_printf("however, a higher MX host exists "
2551 "and will be tried\n");
2555 /* Attempt the delivery. */
2557 total_hosts_tried++;
2558 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2559 expanded_hosts != NULL, &message_defer, FALSE);
2562 OK => connection made, each address contains its result;
2563 message_defer is set for message-specific defers (when all
2564 recipients are marked defer)
2565 DEFER => there was a non-message-specific delivery problem;
2566 ERROR => there was a problem setting up the arguments for a filter,
2567 or there was a problem with expanding added headers
2570 /* If the result is not OK, there was a non-message-specific problem.
2571 If the result is DEFER, we need to write to the logs saying what happened
2572 for this particular host, except in the case of authentication and TLS
2573 failures, where the log has already been written. If all hosts defer a
2574 general message is written at the end. */
2576 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL &&
2577 first_addr->basic_errno != ERRNO_TLSFAILURE)
2578 write_logs(first_addr, host);
2580 /* If STARTTLS was accepted, but there was a failure in setting up the
2581 TLS session (usually a certificate screwup), and the host is not in
2582 hosts_require_tls, and tls_tempfail_tryclear is true, try again, with
2583 TLS forcibly turned off. We have to start from scratch with a new SMTP
2584 connection. That's why the retry is done from here, not from within
2585 smtp_deliver(). [Rejections of STARTTLS itself don't screw up the
2586 session, so the in-clear transmission after those errors, if permitted,
2587 happens inside smtp_deliver().] */
2590 if (rc == DEFER && first_addr->basic_errno == ERRNO_TLSFAILURE &&
2591 ob->tls_tempfail_tryclear &&
2592 verify_check_this_host(&(ob->hosts_require_tls), NULL, host->name,
2593 host->address, NULL) != OK)
2595 log_write(0, LOG_MAIN, "TLS session failure: delivering unencrypted "
2596 "to %s [%s] (not in hosts_require_tls)", host->name, host->address);
2597 first_addr = prepare_addresses(addrlist, host);
2598 rc = smtp_deliver(addrlist, host, host_af, port, interface, tblock,
2599 expanded_hosts != NULL, &message_defer, TRUE);
2600 if (rc == DEFER && first_addr->basic_errno != ERRNO_AUTHFAIL)
2601 write_logs(first_addr, host);
2606 /* Delivery attempt finished */
2608 rs = (rc == OK)? US"OK" : (rc == DEFER)? US"DEFER" : (rc == ERROR)?
2611 set_process_info("delivering %s: just tried %s [%s] for %s%s: result %s",
2612 message_id, host->name, host->address, addrlist->address,
2613 (addrlist->next == NULL)? "" : " (& others)", rs);
2615 /* Release serialization if set up */
2617 if (serialized) enq_end(serialize_key);
2619 /* If the result is DEFER, or if a host retry record is known to exist, we
2620 need to add an item to the retry chain for updating the retry database
2621 at the end of delivery. We only need to add the item to the top address,
2622 of course. Also, if DEFER, we mark the IP address unusable so as to skip it
2623 for any other delivery attempts using the same address. (It is copied into
2624 the unusable tree at the outer level, so even if different address blocks
2625 contain the same address, it still won't get tried again.) */
2627 if (rc == DEFER || retry_host_key != NULL)
2629 int delete_flag = (rc != DEFER)? rf_delete : 0;
2630 if (retry_host_key == NULL)
2632 retry_host_key = ob->retry_include_ip_address?
2633 string_sprintf("T:%S:%s%s", host->name, host->address, pistring) :
2634 string_sprintf("T:%S%s", host->name, pistring);
2637 /* If a delivery of another message over an existing SMTP connection
2638 yields DEFER, we do NOT set up retry data for the host. This covers the
2639 case when there are delays in routing the addresses in the second message
2640 that are so long that the server times out. This is alleviated by not
2641 routing addresses that previously had routing defers when handling an
2642 existing connection, but even so, this case may occur (e.g. if a
2643 previously happily routed address starts giving routing defers). If the
2644 host is genuinely down, another non-continued message delivery will
2645 notice it soon enough. */
2647 if (delete_flag != 0 || !continuing)
2648 retry_add_item(first_addr, retry_host_key, rf_host | delete_flag);
2650 /* We may have tried an expired host, if its retry time has come; ensure
2651 the status reflects the expiry for the benefit of any other addresses. */
2655 host->status = (host_is_expired)?
2656 hstatus_unusable_expired : hstatus_unusable;
2657 host->why = hwhy_deferred;
2661 /* If message_defer is set (host was OK, but every recipient got deferred
2662 because of some message-specific problem), or if that had happened
2663 previously so that a message retry key exists, add an appropriate item
2664 to the retry chain. Note that if there was a message defer but now there is
2665 a host defer, the message defer record gets deleted. That seems perfectly
2666 reasonable. Also, stop the message from being remembered as waiting
2669 if (message_defer || retry_message_key != NULL)
2671 int delete_flag = message_defer? 0 : rf_delete;
2672 if (retry_message_key == NULL)
2674 retry_message_key = ob->retry_include_ip_address?
2675 string_sprintf("T:%S:%s%s:%s", host->name, host->address, pistring,
2677 string_sprintf("T:%S%s:%s", host->name, pistring, message_id);
2679 retry_add_item(addrlist, retry_message_key,
2680 rf_message | rf_host | delete_flag);
2681 host->update_waiting = FALSE;
2684 /* Any return other than DEFER (that is, OK or ERROR) means that the
2685 addresses have got their final statuses filled in for this host. In the OK
2686 case, see if any of them are deferred. */
2690 for (addr = addrlist; addr != NULL; addr = addr->next)
2692 if (addr->transport_return == DEFER)
2694 some_deferred = TRUE;
2700 /* If no addresses deferred or the result was ERROR, return. We do this for
2701 ERROR because a failing filter set-up or add_headers expansion is likely to
2702 fail for any host we try. */
2704 if (rc == ERROR || (rc == OK && !some_deferred))
2706 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2707 return TRUE; /* Each address has its status */
2710 /* If the result was DEFER or some individual addresses deferred, let
2711 the loop run to try other hosts with the deferred addresses, except for the
2712 case when we were trying to deliver down an existing channel and failed.
2713 Don't try any other hosts in this case. */
2715 if (continuing) break;
2717 /* If the whole delivery, or some individual addresses, were deferred and
2718 there are more hosts that could be tried, do not count this host towards
2719 the hosts_max_try limit if the age of the message is greater than the
2720 maximum retry time for this host. This means we may try try all hosts,
2721 ignoring the limit, when messages have been around for some time. This is
2722 important because if we don't try all hosts, the address will never time
2723 out. NOTE: this does not apply to hosts_max_try_hardlimit. */
2725 if ((rc == DEFER || some_deferred) && nexthost != NULL)
2728 retry_config *retry = retry_find_config(host->name, NULL, 0, 0);
2730 if (retry != NULL && retry->rules != NULL)
2732 retry_rule *last_rule;
2733 for (last_rule = retry->rules;
2734 last_rule->next != NULL;
2735 last_rule = last_rule->next);
2736 timedout = time(NULL) - received_time > last_rule->timeout;
2738 else timedout = TRUE; /* No rule => timed out */
2742 unexpired_hosts_tried--;
2743 DEBUG(D_transport) debug_printf("temporary delivery error(s) override "
2744 "hosts_max_try (message older than host's retry time)\n");
2747 } /* End of loop for trying multiple hosts. */
2749 /* This is the end of the loop that repeats iff expired is TRUE and
2750 ob->delay_after_cutoff is FALSE. The second time round we will
2751 try those hosts that haven't been tried since the message arrived. */
2755 debug_printf("all IP addresses skipped or deferred at least one address\n");
2756 if (expired && !ob->delay_after_cutoff && cutoff_retry == 0)
2757 debug_printf("retrying IP addresses not tried since message arrived\n");
2762 /* Get here if all IP addresses are skipped or defer at least one address. In
2763 MUA wrapper mode, this will happen only for connection or other non-message-
2764 specific failures. Force the delivery status for all addresses to FAIL. */
2768 for (addr = addrlist; addr != NULL; addr = addr->next)
2769 addr->transport_return = FAIL;
2773 /* In the normal, non-wrapper case, add a standard message to each deferred
2774 address if there hasn't been an error, that is, if it hasn't actually been
2775 tried this time. The variable "expired" will be FALSE if any deliveries were
2776 actually tried, or if there was at least one host that was not expired. That
2777 is, it is TRUE only if no deliveries were tried and all hosts were expired. If
2778 a delivery has been tried, an error code will be set, and the failing of the
2779 message is handled by the retry code later.
2781 If queue_smtp is set, or this transport was called to send a subsequent message
2782 down an existing TCP/IP connection, and something caused the host not to be
2783 found, we end up here, but can detect these cases and handle them specially. */
2785 for (addr = addrlist; addr != NULL; addr = addr->next)
2787 /* If host is not NULL, it means that we stopped processing the host list
2788 because of hosts_max_try or hosts_max_try_hardlimit. In the former case, this
2789 means we need to behave as if some hosts were skipped because their retry
2790 time had not come. Specifically, this prevents the address from timing out.
2791 However, if we have hit hosts_max_try_hardlimit, we want to behave as if all
2792 hosts were tried. */
2796 if (total_hosts_tried >= ob->hosts_max_try_hardlimit)
2799 debug_printf("hosts_max_try_hardlimit reached: behave as if all "
2800 "hosts were tried\n");
2805 debug_printf("hosts_max_try limit caused some hosts to be skipped\n");
2806 setflag(addr, af_retry_skipped);
2810 if (queue_smtp) /* no deliveries attempted */
2812 addr->transport_return = DEFER;
2813 addr->basic_errno = 0;
2814 addr->message = US"SMTP delivery explicitly queued";
2817 else if (addr->transport_return == DEFER &&
2818 (addr->basic_errno == ERRNO_UNKNOWNERROR || addr->basic_errno == 0) &&
2819 addr->message == NULL)
2821 addr->basic_errno = ERRNO_HRETRY;
2822 if (continue_hostname != NULL)
2824 addr->message = US"no host found for existing SMTP connection";
2828 setflag(addr, af_pass_message); /* This is not a security risk */
2829 addr->message = (ob->delay_after_cutoff)?
2830 US"retry time not reached for any host after a long failure period" :
2831 US"all hosts have been failing for a long time and were last tried "
2832 "after this message arrived";
2834 /* If we are already using fallback hosts, or there are no fallback hosts
2835 defined, convert the result to FAIL to cause a bounce. */
2837 if (addr->host_list == addr->fallback_hosts ||
2838 addr->fallback_hosts == NULL)
2839 addr->transport_return = FAIL;
2843 if (hosts_retry == hosts_total)
2844 addr->message = US"retry time not reached for any host";
2845 else if (hosts_fail == hosts_total)
2846 addr->message = US"all host address lookups failed permanently";
2847 else if (hosts_defer == hosts_total)
2848 addr->message = US"all host address lookups failed temporarily";
2849 else if (hosts_serial == hosts_total)
2850 addr->message = US"connection limit reached for all hosts";
2851 else if (hosts_fail+hosts_defer == hosts_total)
2852 addr->message = US"all host address lookups failed";
2853 else addr->message = US"some host address lookups failed and retry time "
2854 "not reached for other hosts or connection limit reached";
2859 /* Update the database which keeps information about which messages are waiting
2860 for which hosts to become available. Each host in the list has a flag which is
2861 set if the data is to be updated. For some message-specific errors, the flag is
2862 turned off because we don't want follow-on deliveries in those cases. */
2864 transport_update_waiting(hostlist, tblock->name);
2868 DEBUG(D_transport) debug_printf("Leaving %s transport\n", tblock->name);
2870 return TRUE; /* Each address has its status */
2873 /* End of transport/smtp.c */
git://git.exim.org / exim.git / blob