1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) University of Cambridge 1995 - 2018 */
6 /* See the file NOTICE for conditions of use and distribution. */
8 /* Functions concerned with running Exim as a daemon */
14 /* Structure for holding data for each SMTP connection */
16 typedef struct smtp_slot
{
17 pid_t pid
; /* pid of the spawned reception process */
18 uschar
*host_address
; /* address of the client host */
21 /* An empty slot for initializing (Standard C does not allow constructor
22 expressions in assignments except as initializers in declarations). */
24 static smtp_slot empty_smtp_slot
= { .pid
= 0, .host_address
= NULL
};
28 /*************************************************
29 * Local static variables *
30 *************************************************/
32 static SIGNAL_BOOL sigchld_seen
;
33 static SIGNAL_BOOL sighup_seen
;
34 static SIGNAL_BOOL sigterm_seen
;
36 static int accept_retry_count
= 0;
37 static int accept_retry_errno
;
38 static BOOL accept_retry_select_failed
;
40 static int queue_run_count
= 0;
41 static pid_t
*queue_pid_slots
= NULL
;
42 static smtp_slot
*smtp_slots
= NULL
;
44 static BOOL write_pid
= TRUE
;
48 /*************************************************
50 *************************************************/
52 /* All this handler does is to set a flag and re-enable the signal.
54 Argument: the signal number
59 sighup_handler(int sig
)
61 sig
= sig
; /* Keep picky compilers happy */
63 signal(SIGHUP
, sighup_handler
);
68 /*************************************************
69 * SIGCHLD handler for main daemon process *
70 *************************************************/
72 /* Don't re-enable the handler here, since we aren't doing the
73 waiting here. If the signal is re-enabled, there will just be an
74 infinite sequence of calls to this handler. The SIGCHLD signal is
75 used just as a means of waking up the daemon so that it notices
76 terminated subprocesses as soon as possible.
78 Argument: the signal number
83 main_sigchld_handler(int sig
)
85 sig
= sig
; /* Keep picky compilers happy */
86 os_non_restarting_signal(SIGCHLD
, SIG_DFL
);
91 /* SIGTERM handler. Try to get the damon pif file removed
95 main_sigterm_handler(int sig
)
103 /*************************************************
104 * Unexpected errors in SMTP calls *
105 *************************************************/
107 /* This function just saves a bit of repetitious coding.
110 log_msg Text of message to be logged
111 smtp_msg Text of SMTP error message
112 was_errno The failing errno
118 never_error(uschar
*log_msg
, uschar
*smtp_msg
, int was_errno
)
120 uschar
*emsg
= was_errno
<= 0
121 ? US
"" : string_sprintf(": %s", strerror(was_errno
));
122 log_write(0, LOG_MAIN
|LOG_PANIC
, "%s%s", log_msg
, emsg
);
123 if (smtp_out
) smtp_printf("421 %s\r\n", FALSE
, smtp_msg
);
129 /*************************************************
130 *************************************************/
133 close_daemon_sockets(int daemon_notifier_fd
,
134 int * listen_sockets
, int listen_socket_count
)
136 if (daemon_notifier_fd
>= 0) (void) close(daemon_notifier_fd
);
137 for (int i
= 0; i
< listen_socket_count
; i
++) (void) close(listen_sockets
[i
]);
141 /*************************************************
142 * Handle a connected SMTP call *
143 *************************************************/
145 /* This function is called when an SMTP connection has been accepted.
146 If there are too many, give an error message and close down. Otherwise
147 spin off a sub-process to handle the call. The list of listening sockets
148 is required so that they can be closed in the sub-process. Take care not to
149 leak store in this process - reset the stacking pool at the end.
152 listen_sockets sockets which are listening for incoming calls
153 listen_socket_count count of listening sockets
154 accept_socket socket of the current accepted call
155 accepted socket information about the current call
161 handle_smtp_call(int *listen_sockets
, int listen_socket_count
,
162 int accept_socket
, struct sockaddr
*accepted
)
165 union sockaddr_46 interface_sockaddr
;
166 EXIM_SOCKLEN_T ifsize
= sizeof(interface_sockaddr
);
167 int dup_accept_socket
= -1;
168 int max_for_this_host
= 0;
169 int save_log_selector
= *log_selector
;
172 rmark reset_point
= store_mark();
174 /* Make the address available in ASCII representation, and also fish out
177 sender_host_address
= host_ntoa(-1, accepted
, NULL
, &sender_host_port
);
178 DEBUG(D_any
) debug_printf("Connection request from %s port %d\n",
179 sender_host_address
, sender_host_port
);
181 /* Set up the output stream, check the socket has duplicated, and set up the
182 input stream. These operations fail only the exceptional circumstances. Note
183 that never_error() won't use smtp_out if it is NULL. */
185 if (!(smtp_out
= fdopen(accept_socket
, "wb")))
187 never_error(US
"daemon: fdopen() for smtp_out failed", US
"", errno
);
191 if ((dup_accept_socket
= dup(accept_socket
)) < 0)
193 never_error(US
"daemon: couldn't dup socket descriptor",
194 US
"Connection setup failed", errno
);
198 if (!(smtp_in
= fdopen(dup_accept_socket
, "rb")))
200 never_error(US
"daemon: fdopen() for smtp_in failed",
201 US
"Connection setup failed", errno
);
205 /* Get the data for the local interface address. Panic for most errors, but
206 "connection reset by peer" just means the connection went away. */
208 if (getsockname(accept_socket
, (struct sockaddr
*)(&interface_sockaddr
),
211 log_write(0, LOG_MAIN
| ((errno
== ECONNRESET
)? 0 : LOG_PANIC
),
212 "getsockname() failed: %s", strerror(errno
));
213 smtp_printf("421 Local problem: getsockname() failed; please try again later\r\n", FALSE
);
217 interface_address
= host_ntoa(-1, &interface_sockaddr
, NULL
, &interface_port
);
218 DEBUG(D_interface
) debug_printf("interface address=%s port=%d\n",
219 interface_address
, interface_port
);
221 /* Build a string identifying the remote host and, if requested, the port and
222 the local interface data. This is for logging; at the end of this function the
223 memory is reclaimed. */
225 whofrom
= string_append(NULL
, 3, "[", sender_host_address
, "]");
227 if (LOGGING(incoming_port
))
228 whofrom
= string_fmt_append(whofrom
, ":%d", sender_host_port
);
230 if (LOGGING(incoming_interface
))
231 whofrom
= string_fmt_append(whofrom
, " I=[%s]:%d",
232 interface_address
, interface_port
);
234 (void) string_from_gstring(whofrom
); /* Terminate the newly-built string */
236 /* Check maximum number of connections. We do not check for reserved
237 connections or unacceptable hosts here. That is done in the subprocess because
238 it might take some time. */
240 if (smtp_accept_max
> 0 && smtp_accept_count
>= smtp_accept_max
)
242 DEBUG(D_any
) debug_printf("rejecting SMTP connection: count=%d max=%d\n",
243 smtp_accept_count
, smtp_accept_max
);
244 smtp_printf("421 Too many concurrent SMTP connections; "
245 "please try again later.\r\n", FALSE
);
246 log_write(L_connection_reject
,
247 LOG_MAIN
, "Connection from %s refused: too many connections",
252 /* If a load limit above which only reserved hosts are acceptable is defined,
253 get the load average here, and if there are in fact no reserved hosts, do
254 the test right away (saves a fork). If there are hosts, do the check in the
255 subprocess because it might take time. */
257 if (smtp_load_reserve
>= 0)
259 load_average
= OS_GETLOADAVG();
260 if (smtp_reserve_hosts
== NULL
&& load_average
> smtp_load_reserve
)
262 DEBUG(D_any
) debug_printf("rejecting SMTP connection: load average = %.2f\n",
263 (double)load_average
/1000.0);
264 smtp_printf("421 Too much load; please try again later.\r\n", FALSE
);
265 log_write(L_connection_reject
,
266 LOG_MAIN
, "Connection from %s refused: load average = %.2f",
267 whofrom
->s
, (double)load_average
/1000.0);
272 /* Check that one specific host (strictly, IP address) is not hogging
273 resources. This is done here to prevent a denial of service attack by someone
274 forcing you to fork lots of times before denying service. The value of
275 smtp_accept_max_per_host is a string which is expanded. This makes it possible
276 to provide host-specific limits according to $sender_host address, but because
277 this is in the daemon mainline, only fast expansions (such as inline address
278 checks) should be used. The documentation is full of warnings. */
280 if (smtp_accept_max_per_host
!= NULL
)
282 uschar
*expanded
= expand_string(smtp_accept_max_per_host
);
283 if (expanded
== NULL
)
285 if (!f
.expand_string_forcedfail
)
286 log_write(0, LOG_MAIN
|LOG_PANIC
, "expansion of smtp_accept_max_per_host "
287 "failed for %s: %s", whofrom
->s
, expand_string_message
);
289 /* For speed, interpret a decimal number inline here */
292 uschar
*s
= expanded
;
294 max_for_this_host
= max_for_this_host
* 10 + *s
++ - '0';
296 log_write(0, LOG_MAIN
|LOG_PANIC
, "expansion of smtp_accept_max_per_host "
297 "for %s contains non-digit: %s", whofrom
->s
, expanded
);
301 /* If we have fewer connections than max_for_this_host, we can skip the tedious
302 per host_address checks. Note that at this stage smtp_accept_count contains the
303 count of *other* connections, not including this one. */
305 if ((max_for_this_host
> 0) &&
306 (smtp_accept_count
>= max_for_this_host
))
308 int host_accept_count
= 0;
309 int other_host_count
= 0; /* keep a count of non matches to optimise */
311 for (int i
= 0; i
< smtp_accept_max
; ++i
)
312 if (smtp_slots
[i
].host_address
)
314 if (Ustrcmp(sender_host_address
, smtp_slots
[i
].host_address
) == 0)
319 /* Testing all these strings is expensive - see if we can drop out
320 early, either by hitting the target, or finding there are not enough
321 connections left to make the target. */
323 if ((host_accept_count
>= max_for_this_host
) ||
324 ((smtp_accept_count
- other_host_count
) < max_for_this_host
))
328 if (host_accept_count
>= max_for_this_host
)
330 DEBUG(D_any
) debug_printf("rejecting SMTP connection: too many from this "
331 "IP address: count=%d max=%d\n",
332 host_accept_count
, max_for_this_host
);
333 smtp_printf("421 Too many concurrent SMTP connections "
334 "from this IP address; please try again later.\r\n", FALSE
);
335 log_write(L_connection_reject
,
336 LOG_MAIN
, "Connection from %s refused: too many connections "
337 "from that IP address", whofrom
->s
);
342 /* OK, the connection count checks have been passed. Before we can fork the
343 accepting process, we must first log the connection if requested. This logging
344 used to happen in the subprocess, but doing that means that the value of
345 smtp_accept_count can be out of step by the time it is logged. So we have to do
346 the logging here and accept the performance cost. Note that smtp_accept_count
347 hasn't yet been incremented to take account of this connection.
349 In order to minimize the cost (because this is going to happen for every
350 connection), do a preliminary selector test here. This saves ploughing through
351 the generalized logging code each time when the selector is false. If the
352 selector is set, check whether the host is on the list for logging. If not,
353 arrange to unset the selector in the subprocess. */
355 if (LOGGING(smtp_connection
))
357 uschar
*list
= hosts_connection_nolog
;
358 memset(sender_host_cache
, 0, sizeof(sender_host_cache
));
359 if (list
!= NULL
&& verify_check_host(&list
) == OK
)
360 save_log_selector
&= ~L_smtp_connection
;
362 log_write(L_smtp_connection
, LOG_MAIN
, "SMTP connection from %s "
363 "(TCP/IP connection count = %d)", whofrom
->s
, smtp_accept_count
+ 1);
366 /* Now we can fork the accepting process; do a lookup tidy, just in case any
367 expansion above did a lookup. */
372 /* Handle the child process */
377 int queue_only_reason
= 0;
378 int old_pool
= store_pool
;
379 int save_debug_selector
= debug_selector
;
380 BOOL local_queue_only
;
381 BOOL session_local_queue_only
;
383 struct sigaction act
;
386 smtp_accept_count
++; /* So that it includes this process */
388 /* May have been modified for the subprocess */
390 *log_selector
= save_log_selector
;
392 /* Get the local interface address into permanent store */
394 store_pool
= POOL_PERM
;
395 interface_address
= string_copy(interface_address
);
396 store_pool
= old_pool
;
398 /* Check for a tls-on-connect port */
400 if (host_is_tls_on_connect_port(interface_port
)) tls_in
.on_connect
= TRUE
;
402 /* Expand smtp_active_hostname if required. We do not do this any earlier,
403 because it may depend on the local interface address (indeed, that is most
404 likely what it depends on.) */
406 smtp_active_hostname
= primary_hostname
;
407 if (raw_active_hostname
)
409 uschar
* nah
= expand_string(raw_active_hostname
);
412 if (!f
.expand_string_forcedfail
)
414 log_write(0, LOG_MAIN
|LOG_PANIC
, "failed to expand \"%s\" "
415 "(smtp_active_hostname): %s", raw_active_hostname
,
416 expand_string_message
);
417 smtp_printf("421 Local configuration error; "
418 "please try again later.\r\n", FALSE
);
421 exim_underbar_exit(EXIT_FAILURE
);
424 else if (*nah
) smtp_active_hostname
= nah
;
427 /* Initialize the queueing flags */
430 session_local_queue_only
= queue_only
;
432 /* Close the listening sockets, and set the SIGCHLD handler to SIG_IGN.
433 We also attempt to set things up so that children are automatically reaped,
434 but just in case this isn't available, there's a paranoid waitpid() in the
435 loop too (except for systems where we are sure it isn't needed). See the more
436 extensive comment before the reception loop in exim.c for a fuller
437 explanation of this logic. */
439 close_daemon_sockets(daemon_notifier_fd
, listen_sockets
, listen_socket_count
);
441 /* Set FD_CLOEXEC on the SMTP socket. We don't want any rogue child processes
442 to be able to communicate with them, under any circumstances. */
443 (void)fcntl(accept_socket
, F_SETFD
,
444 fcntl(accept_socket
, F_GETFD
) | FD_CLOEXEC
);
445 (void)fcntl(dup_accept_socket
, F_SETFD
,
446 fcntl(dup_accept_socket
, F_GETFD
) | FD_CLOEXEC
);
449 act
.sa_handler
= SIG_IGN
;
450 sigemptyset(&(act
.sa_mask
));
451 act
.sa_flags
= SA_NOCLDWAIT
;
452 sigaction(SIGCHLD
, &act
, NULL
);
454 signal(SIGCHLD
, SIG_IGN
);
456 signal(SIGTERM
, SIG_DFL
);
458 /* Attempt to get an id from the sending machine via the RFC 1413
459 protocol. We do this in the sub-process in order not to hold up the
460 main process if there is any delay. Then set up the fullhost information
461 in case there is no HELO/EHLO.
463 If debugging is enabled only for the daemon, we must turn if off while
464 finding the id, but turn it on again afterwards so that information about the
465 incoming connection is output. */
467 if (f
.debug_daemon
) debug_selector
= 0;
468 verify_get_ident(IDENT_PORT
);
469 host_build_sender_fullhost();
470 debug_selector
= save_debug_selector
;
473 debug_printf("Process %d is handling incoming connection from %s\n",
474 (int)getpid(), sender_fullhost
);
476 /* Now disable debugging permanently if it's required only for the daemon
479 if (f
.debug_daemon
) debug_selector
= 0;
481 /* If there are too many child processes for immediate delivery,
482 set the session_local_queue_only flag, which is initialized from the
483 configured value and may therefore already be TRUE. Leave logging
484 till later so it will have a message id attached. Note that there is no
485 possibility of re-calculating this per-message, because the value of
486 smtp_accept_count does not change in this subprocess. */
488 if (smtp_accept_queue
> 0 && smtp_accept_count
> smtp_accept_queue
)
490 session_local_queue_only
= TRUE
;
491 queue_only_reason
= 1;
494 /* Handle the start of the SMTP session, then loop, accepting incoming
495 messages from the SMTP connection. The end will come at the QUIT command,
496 when smtp_setup_msg() returns 0. A break in the connection causes the
497 process to die (see accept.c).
499 NOTE: We do *not* call smtp_log_no_mail() if smtp_start_session() fails,
500 because a log line has already been written for all its failure exists
501 (usually "connection refused: <reason>") and writing another one is
502 unnecessary clutter. */
504 if (!smtp_start_session())
508 exim_underbar_exit(EXIT_SUCCESS
);
514 message_id
[0] = 0; /* Clear out any previous message_id */
515 reset_point
= store_mark(); /* Save current store high water point */
518 debug_printf("Process %d is ready for new message\n", (int)getpid());
520 /* Smtp_setup_msg() returns 0 on QUIT or if the call is from an
521 unacceptable host or if an ACL "drop" command was triggered, -1 on
522 connection lost, and +1 on validly reaching DATA. Receive_msg() almost
523 always returns TRUE when smtp_input is true; just retry if no message was
524 accepted (can happen for invalid message parameters). However, it can yield
525 FALSE if the connection was forcibly dropped by the DATA ACL. */
527 if ((rc
= smtp_setup_msg()) > 0)
529 BOOL ok
= receive_msg(FALSE
);
530 search_tidyup(); /* Close cached databases */
531 if (!ok
) /* Connection was dropped */
533 cancel_cutthrough_connection(TRUE
, US
"receive dropped");
535 smtp_log_no_mail(); /* Log no mail if configured */
536 exim_underbar_exit(EXIT_SUCCESS
);
538 if (message_id
[0] == 0) continue; /* No message was accepted */
544 int fd
= fileno(smtp_in
);
548 /* drain socket, for clean TCP FINs */
549 if (fcntl(fd
, F_SETFL
, O_NONBLOCK
) == 0)
550 for(int i
= 16; read(fd
, buf
, sizeof(buf
)) > 0 && i
> 0; ) i
--;
552 cancel_cutthrough_connection(TRUE
, US
"message setup dropped");
554 smtp_log_no_mail(); /* Log no mail if configured */
556 /*XXX should we pause briefly, hoping that the client will be the
557 active TCP closer hence get the TCP_WAIT endpoint? */
558 DEBUG(D_receive
) debug_printf("SMTP>>(close on process exit)\n");
559 exim_underbar_exit(rc
? EXIT_FAILURE
: EXIT_SUCCESS
);
562 /* Show the recipients when debugging */
567 debug_printf("Sender: %s\n", sender_address
);
570 debug_printf("Recipients:\n");
571 for (int i
= 0; i
< recipients_count
; i
++)
572 debug_printf(" %s\n", recipients_list
[i
].address
);
576 /* A message has been accepted. Clean up any previous delivery processes
577 that have completed and are defunct, on systems where they don't go away
578 by themselves (see comments when setting SIG_IGN above). On such systems
579 (if any) these delivery processes hang around after termination until
580 the next message is received. */
582 #ifndef SIG_IGN_WORKS
583 while (waitpid(-1, NULL
, WNOHANG
) > 0);
586 /* Reclaim up the store used in accepting this message */
589 int r
= receive_messagecount
;
590 BOOL q
= f
.queue_only_policy
;
591 smtp_reset(reset_point
);
593 f
.queue_only_policy
= q
;
594 receive_messagecount
= r
;
597 /* If queue_only is set or if there are too many incoming connections in
598 existence, session_local_queue_only will be TRUE. If it is not, check
599 whether we have received too many messages in this session for immediate
602 if (!session_local_queue_only
&&
603 smtp_accept_queue_per_connection
> 0 &&
604 receive_messagecount
> smtp_accept_queue_per_connection
)
606 session_local_queue_only
= TRUE
;
607 queue_only_reason
= 2;
610 /* Initialize local_queue_only from session_local_queue_only. If it is not
611 true, and queue_only_load is set, check that the load average is below it.
612 If local_queue_only is set by this means, we also set if for the session if
613 queue_only_load_latch is true (the default). This means that, once set,
614 local_queue_only remains set for any subsequent messages on the same SMTP
615 connection. This is a deliberate choice; even though the load average may
616 fall, it doesn't seem right to deliver later messages on the same call when
617 not delivering earlier ones. However, the are special circumstances such as
618 very long-lived connections from scanning appliances where this is not the
619 best strategy. In such cases, queue_only_load_latch should be set false. */
621 if ( !(local_queue_only
= session_local_queue_only
)
622 && queue_only_load
>= 0
623 && (local_queue_only
= (load_average
= OS_GETLOADAVG()) > queue_only_load
)
626 queue_only_reason
= 3;
627 if (queue_only_load_latch
) session_local_queue_only
= TRUE
;
630 /* Log the queueing here, when it will get a message id attached, but
631 not if queue_only is set (case 0). */
633 if (local_queue_only
) switch(queue_only_reason
)
635 case 1: log_write(L_delay_delivery
,
636 LOG_MAIN
, "no immediate delivery: too many connections "
637 "(%d, max %d)", smtp_accept_count
, smtp_accept_queue
);
640 case 2: log_write(L_delay_delivery
,
641 LOG_MAIN
, "no immediate delivery: more than %d messages "
642 "received in one connection", smtp_accept_queue_per_connection
);
645 case 3: log_write(L_delay_delivery
,
646 LOG_MAIN
, "no immediate delivery: load average %.2f",
647 (double)load_average
/1000.0);
651 /* If a delivery attempt is required, spin off a new process to handle it.
652 If we are not root, we have to re-exec exim unless deliveries are being
653 done unprivileged. */
655 else if ( (!f
.queue_only_policy
|| f
.queue_smtp
)
656 && !f
.deliver_freeze
)
660 /* Before forking, ensure that the C output buffer is flushed. Otherwise
661 anything that it in it will get duplicated, leading to duplicate copies
662 of the pending output. */
666 if ((dpid
= fork()) == 0)
668 (void)fclose(smtp_in
);
669 (void)fclose(smtp_out
);
671 /* Don't ever molest the parent's SSL connection, but do clean up
672 the data structures if necessary. */
675 tls_close(NULL
, TLS_NO_SHUTDOWN
);
678 /* Reset SIGHUP and SIGCHLD in the child in both cases. */
680 signal(SIGHUP
, SIG_DFL
);
681 signal(SIGCHLD
, SIG_DFL
);
682 signal(SIGTERM
, SIG_DFL
);
684 if (geteuid() != root_uid
&& !deliver_drop_privilege
)
686 signal(SIGALRM
, SIG_DFL
);
687 delivery_re_exec(CEE_EXEC_PANIC
);
688 /* Control does not return here. */
691 /* No need to re-exec; SIGALRM remains set to the default handler */
693 (void) deliver_message(message_id
, FALSE
, FALSE
);
695 exim_underbar_exit(EXIT_SUCCESS
);
700 release_cutthrough_connection(US
"passed for delivery");
701 DEBUG(D_any
) debug_printf("forked delivery process %d\n", (int)dpid
);
705 cancel_cutthrough_connection(TRUE
, US
"delivery fork failed");
706 log_write(0, LOG_MAIN
|LOG_PANIC
, "daemon: delivery process fork "
707 "failed: %s", strerror(errno
));
714 /* Carrying on in the parent daemon process... Can't do much if the fork
715 failed. Otherwise, keep count of the number of accepting processes and
716 remember the pid for ticking off when the child completes. */
719 never_error(US
"daemon: accept process fork failed", US
"Fork failed", errno
);
722 for (int i
= 0; i
< smtp_accept_max
; ++i
)
723 if (smtp_slots
[i
].pid
<= 0)
725 smtp_slots
[i
].pid
= pid
;
726 /* Connection closes come asyncronously, so we cannot stack this store */
727 if (smtp_accept_max_per_host
)
728 smtp_slots
[i
].host_address
= string_copy_malloc(sender_host_address
);
732 DEBUG(D_any
) debug_printf("%d SMTP accept process%s running\n",
733 smtp_accept_count
, smtp_accept_count
== 1 ? "" : "es");
736 /* Get here via goto in error cases */
740 /* Close the streams associated with the socket which will also close the
741 socket fds in this process. We can't do anything if fclose() fails, but
742 logging brings it to someone's attention. However, "connection reset by peer"
743 isn't really a problem, so skip that one. On Solaris, a dropped connection can
744 manifest itself as a broken pipe, so drop that one too. If the streams don't
745 exist, something went wrong while setting things up. Make sure the socket
746 descriptors are closed, in order to drop the connection. */
750 if (fclose(smtp_out
) != 0 && errno
!= ECONNRESET
&& errno
!= EPIPE
)
751 log_write(0, LOG_MAIN
|LOG_PANIC
, "daemon: fclose(smtp_out) failed: %s",
755 else (void)close(accept_socket
);
759 if (fclose(smtp_in
) != 0 && errno
!= ECONNRESET
&& errno
!= EPIPE
)
760 log_write(0, LOG_MAIN
|LOG_PANIC
, "daemon: fclose(smtp_in) failed: %s",
764 else (void)close(dup_accept_socket
);
766 /* Release any store used in this process, including the store used for holding
767 the incoming host address and an expanded active_hostname. */
771 sender_host_address
= NULL
;
772 store_reset(reset_point
);
773 sender_host_address
= NULL
;
779 /*************************************************
780 * Check wildcard listen special cases *
781 *************************************************/
783 /* This function is used when binding and listening on lists of addresses and
784 ports. It tests for special cases of wildcard listening, when IPv4 and IPv6
785 sockets may interact in different ways in different operating systems. It is
786 passed an error number, the list of listening addresses, and the current
787 address. Two checks are available: for a previous wildcard IPv6 address, or for
788 a following wildcard IPv4 address, in both cases on the same port.
790 In practice, pairs of wildcard addresses should be adjacent in the address list
791 because they are sorted that way below.
795 addresses the list of addresses
796 ipa the current IP address
797 back if TRUE, check for previous wildcard IPv6 address
798 if FALSE, check for a following wildcard IPv4 address
800 Returns: TRUE or FALSE
804 check_special_case(int eno
, ip_address_item
*addresses
, ip_address_item
*ipa
,
807 ip_address_item
*ipa2
;
809 /* For the "back" case, if the failure was "address in use" for a wildcard IPv4
810 address, seek a previous IPv6 wildcard address on the same port. As it is
811 previous, it must have been successfully bound and be listening. Flag it as a
812 "6 including 4" listener. */
816 if (eno
!= EADDRINUSE
|| ipa
->address
[0] != 0) return FALSE
;
817 for (ipa2
= addresses
; ipa2
!= ipa
; ipa2
= ipa2
->next
)
819 if (ipa2
->address
[1] == 0 && ipa2
->port
== ipa
->port
)
821 ipa2
->v6_include_v4
= TRUE
;
827 /* For the "forward" case, if the current address is a wildcard IPv6 address,
828 we seek a following wildcard IPv4 address on the same port. */
832 if (ipa
->address
[0] != ':' || ipa
->address
[1] != 0) return FALSE
;
833 for (ipa2
= ipa
->next
; ipa2
!= NULL
; ipa2
= ipa2
->next
)
834 if (ipa2
->address
[0] == 0 && ipa
->port
== ipa2
->port
) return TRUE
;
843 /*************************************************
844 * Handle terminating subprocesses *
845 *************************************************/
847 /* Handle the termination of child processes. Theoretically, this need be done
848 only when sigchld_seen is TRUE, but rumour has it that some systems lose
849 SIGCHLD signals at busy times, so to be on the safe side, this function is
850 called each time round. It shouldn't be too expensive.
857 handle_ending_processes(void)
862 while ((pid
= waitpid(-1, &status
, WNOHANG
)) > 0)
866 debug_printf("child %d ended: status=0x%x\n", (int)pid
, status
);
868 if (WIFEXITED(status
))
869 debug_printf(" normal exit, %d\n", WEXITSTATUS(status
));
870 else if (WIFSIGNALED(status
))
871 debug_printf(" signal exit, signal %d%s\n", WTERMSIG(status
),
872 WCOREDUMP(status
) ? " (core dumped)" : "");
876 /* If it's a listening daemon for which we are keeping track of individual
877 subprocesses, deal with an accepting process that has terminated. */
882 for (i
= 0; i
< smtp_accept_max
; i
++)
883 if (smtp_slots
[i
].pid
== pid
)
885 if (smtp_slots
[i
].host_address
)
886 store_free(smtp_slots
[i
].host_address
);
887 smtp_slots
[i
] = empty_smtp_slot
;
888 if (--smtp_accept_count
< 0) smtp_accept_count
= 0;
889 DEBUG(D_any
) debug_printf("%d SMTP accept process%s now running\n",
890 smtp_accept_count
, (smtp_accept_count
== 1)? "" : "es");
893 if (i
< smtp_accept_max
) continue; /* Found an accepting process */
896 /* If it wasn't an accepting process, see if it was a queue-runner
897 process that we are tracking. */
901 int max
= atoi(CS
expand_string(queue_run_max
));
902 for (int i
= 0; i
< max
; i
++)
903 if (queue_pid_slots
[i
] == pid
)
905 queue_pid_slots
[i
] = 0;
906 if (--queue_run_count
< 0) queue_run_count
= 0;
907 DEBUG(D_any
) debug_printf("%d queue-runner process%s now running\n",
908 queue_run_count
, (queue_run_count
== 1)? "" : "es");
918 set_pid_file_path(void)
920 if (override_pid_file_path
)
921 pid_file_path
= override_pid_file_path
;
924 pid_file_path
= string_sprintf("%s/exim-daemon.pid", spool_directory
);
928 /* Remove the daemon's pidfile. Note: runs with root privilege,
929 as a direct child of the daemon. Does not return. */
932 delete_pid_file(void)
934 uschar
* daemon_pid
= string_sprintf("%d\n", (int)getppid());
938 if ((f
= Ufopen(pid_file_path
, "rb")))
940 if ( fgets(CS big_buffer
, big_buffer_size
, f
)
941 && Ustrcmp(daemon_pid
, big_buffer
) == 0
943 if (Uunlink(pid_file_path
) == 0)
946 debug_printf("%s unlink: %s\n", pid_file_path
, strerror(errno
));
950 debug_printf("unlinked %s\n", pid_file_path
);
955 debug_printf("%s\n", string_open_failed(errno
, "pid file %s",
957 exim_exit(EXIT_SUCCESS
, US
"pid file remover");
961 /* Called by the daemon; exec a child to get the pid file deleted
962 since we may require privs for the containing directory */
969 if (daemon_notifier_fd
>= 0)
971 close(daemon_notifier_fd
);
972 daemon_notifier_fd
= -1;
973 #ifndef EXIM_HAVE_ABSTRACT_UNIX_SOCKETS
975 uschar
* s
= string_sprintf("%s/%s", spool_directory
, NOTIFIER_SOCKET_NAME
);
976 DEBUG(D_any
) debug_printf("unlinking notifier socket %s\n", s
);
982 if (f
.running_in_test_harness
|| write_pid
)
984 if ((pid
= fork()) == 0)
986 if (override_pid_file_path
)
987 (void)child_exec_exim(CEE_EXEC_PANIC
, FALSE
, NULL
, FALSE
, 3,
988 "-oP", override_pid_file_path
, "-oPX");
990 (void)child_exec_exim(CEE_EXEC_PANIC
, FALSE
, NULL
, FALSE
, 1, "-oPX");
992 /* Control never returns here. */
997 exim_exit(EXIT_SUCCESS
, US
"daemon");
1001 /*************************************************
1002 * Listener socket for local work prompts *
1003 *************************************************/
1006 daemon_notifier_socket(void)
1009 const uschar
* where
;
1010 struct sockaddr_un sa_un
= {.sun_family
= AF_UNIX
};
1013 DEBUG(D_any
) debug_printf("creating notifier socket ");
1016 if ((fd
= socket(PF_UNIX
, SOCK_DGRAM
|SOCK_CLOEXEC
, 0)) < 0)
1017 { where
= US
"socket"; goto bad
; }
1019 if ((fd
= socket(PF_UNIX
, SOCK_DGRAM
, 0)) < 0)
1020 { where
= US
"socket"; goto bad
; }
1021 (void)fcntl(fd
, F_SETFD
, fcntl(fd
, F_GETFD
) | FD_CLOEXEC
);
1024 #ifdef EXIM_HAVE_ABSTRACT_UNIX_SOCKETS
1025 sa_un
.sun_path
[0] = 0; /* Abstract local socket addr - Linux-specific? */
1026 len
= offsetof(struct sockaddr_un
, sun_path
) + 1
1027 + snprintf(sa_un
.sun_path
+1, sizeof(sa_un
.sun_path
)-1, "%s", NOTIFIER_SOCKET_NAME
);
1028 DEBUG(D_any
) debug_printf("@%s\n", sa_un
.sun_path
+1);
1029 #else /* filesystem-visible and persistent; will neeed removal */
1030 len
= offsetof(struct sockaddr_un
, sun_path
)
1031 + snprintf(sa_un
.sun_path
, sizeof(sa_un
.sun_path
), "%s/%s",
1032 spool_directory
, NOTIFIER_SOCKET_NAME
);
1033 DEBUG(D_any
) debug_printf("%s\n", sa_un
.sun_path
);
1036 if (bind(fd
, (const struct sockaddr
*)&sa_un
, len
) < 0)
1037 { where
= US
"bind"; goto bad
; }
1039 #ifdef SO_PASSCRED /* Linux */
1040 if (setsockopt(fd
, SOL_SOCKET
, SO_PASSCRED
, &on
, sizeof(on
)) < 0)
1041 { where
= US
"SO_PASSCRED"; goto bad2
; }
1042 #elif defined(LOCAL_CREDS) /* FreeBSD-ish */
1043 if (setsockopt(fd
, 0, LOCAL_CREDS
, &on
, sizeof(on
)) < 0)
1044 { where
= US
"LOCAL_CREDS"; goto bad2
; }
1047 /* debug_printf("%s: fd %d\n", __FUNCTION__, fd); */
1048 daemon_notifier_fd
= fd
;
1052 #ifndef EXIM_HAVE_ABSTRACT_UNIX_SOCKETS
1053 Uunlink(sa_un
.sun_path
);
1056 log_write(0, LOG_MAIN
|LOG_PANIC
, "%s %s: %s",
1057 __FUNCTION__
, where
, strerror(errno
));
1063 static uschar queuerun_msgid
[MESSAGE_ID_LENGTH
+1];
1065 /* Return TRUE if a sigalrm should be emulated */
1067 daemon_notification(void)
1069 uschar buf
[256], cbuf
[256];
1070 struct sockaddr_un sa_un
;
1071 struct iovec iov
= {.iov_base
= buf
, .iov_len
= sizeof(buf
)-1};
1072 struct msghdr msg
= { .msg_name
= &sa_un
,
1073 .msg_namelen
= sizeof(sa_un
),
1076 .msg_control
= cbuf
,
1077 .msg_controllen
= sizeof(cbuf
)
1080 struct cmsghdr
* cp
;
1082 buf
[sizeof(buf
)-1] = 0;
1083 if ((sz
= recvmsg(daemon_notifier_fd
, &msg
, 0)) <= 0) return FALSE
;
1084 if (sz
>= sizeof(buf
)) return FALSE
;
1087 debug_printf("addrlen %d\n", msg
.msg_namelen
);
1089 DEBUG(D_queue_run
) debug_printf("%s from addr '%s%.*s'\n", __FUNCTION__
,
1090 *sa_un
.sun_path
? "" : "@",
1091 (int)msg
.msg_namelen
- (*sa_un
.sun_path
? 0 : 1),
1092 sa_un
.sun_path
+ (*sa_un
.sun_path
? 0 : 1));
1094 /* Refuse to handle the item unless the peer has good credentials */
1095 #ifdef SCM_CREDENTIALS
1096 # define EXIM_SCM_CR_TYPE SCM_CREDENTIALS
1097 #elif defined(LOCAL_CREDS) && defined(SCM_CREDS)
1098 # define EXIM_SCM_CR_TYPE SCM_CREDS
1100 /* The OS has no way to get the creds of the caller (for a unix/datagram socket.
1101 Punt; don't try to check. */
1104 #ifdef EXIM_SCM_CR_TYPE
1105 for (struct cmsghdr
* cp
= CMSG_FIRSTHDR(&msg
);
1107 cp
= CMSG_NXTHDR(&msg
, cp
))
1108 if (cp
->cmsg_level
== SOL_SOCKET
&& cp
->cmsg_type
== EXIM_SCM_CR_TYPE
)
1110 # ifdef SCM_CREDENTIALS /* Linux */
1111 struct ucred
* cr
= (struct ucred
*) CMSG_DATA(cp
);
1112 if (cr
->uid
&& cr
->uid
!= exim_uid
)
1114 DEBUG(D_queue_run
) debug_printf("%s: sender creds pid %d uid %d gid %d\n",
1115 __FUNCTION__
, (int)cr
->pid
, (int)cr
->uid
, (int)cr
->gid
);
1118 # elif defined(LOCAL_CREDS) /* BSD-ish */
1119 struct sockcred
* cr
= (struct sockcred
*) CMSG_DATA(cp
);
1120 if (cr
->sc_uid
&& cr
->sc_uid
!= exim_uid
)
1122 DEBUG(D_queue_run
) debug_printf("%s: sender creds pid ??? uid %d gid %d\n",
1123 __FUNCTION__
, (int)cr
->sc_uid
, (int)cr
->sc_gid
);
1134 #ifdef EXPERIMENTAL_QUEUE_RAMP
1135 case NOTIFY_MSG_QRUN
:
1136 /* this should be a message_id */
1138 debug_printf("%s: qrunner trigger: %s\n", __FUNCTION__
, buf
+1);
1139 memcpy(queuerun_msgid
, buf
+1, MESSAGE_ID_LENGTH
+1);
1141 #endif /*EXPERIMENTAL_QUEUE_RAMP*/
1143 case NOTIFY_QUEUE_SIZE_REQ
:
1146 int len
= snprintf(CS buf
, sizeof(buf
), "%u", queue_count_cached());
1149 debug_printf("%s: queue size request: %s\n", __FUNCTION__
, buf
);
1151 if (sendto(daemon_notifier_fd
, buf
, len
, 0,
1152 (const struct sockaddr
*)&sa_un
, msg
.msg_namelen
) < 0)
1153 log_write(0, LOG_MAIN
|LOG_PANIC
,
1154 "%s: sendto: %s\n", __FUNCTION__
, strerror(errno
));
1162 /*************************************************
1163 * Exim Daemon Mainline *
1164 *************************************************/
1166 /* The daemon can do two jobs, either of which is optional:
1168 (1) Listens for incoming SMTP calls and spawns off a sub-process to handle
1169 each one. This is requested by the -bd option, with -oX specifying the SMTP
1170 port on which to listen (for testing).
1172 (2) Spawns a queue-running process every so often. This is controlled by the
1173 -q option with a an interval time. (If no time is given, a single queue run
1174 is done from the main function, and control doesn't get here.)
1176 Root privilege is required in order to attach to port 25. Some systems require
1177 it when calling socket() rather than bind(). To cope with all cases, we run as
1178 root for both socket() and bind(). Some systems also require root in order to
1179 write to the pid file directory. This function must therefore be called as root
1180 if it is to work properly in all circumstances. Once the socket is bound and
1181 the pid file written, root privilege is given up if there is an exim uid.
1183 There are no arguments to this function, and it never returns. */
1189 int *listen_sockets
= NULL
;
1190 int listen_socket_count
= 0;
1191 ip_address_item
*addresses
= NULL
;
1192 time_t last_connection_time
= (time_t)0;
1193 int local_queue_run_max
= atoi(CS
expand_string(queue_run_max
));
1195 /* If any debugging options are set, turn on the D_pid bit so that all
1196 debugging lines get the pid added. */
1198 DEBUG(D_any
|D_v
) debug_selector
|= D_pid
;
1200 if (f
.inetd_wait_mode
)
1202 listen_socket_count
= 1;
1203 listen_sockets
= store_get(sizeof(int), FALSE
);
1205 if (dup2(0, 3) == -1)
1206 log_write(0, LOG_MAIN
|LOG_PANIC_DIE
,
1207 "failed to dup inetd socket safely away: %s", strerror(errno
));
1209 listen_sockets
[0] = 3;
1215 if (debug_file
== stderr
)
1217 /* need a call to log_write before call to open debug_file, so that
1218 log.c:file_path has been initialised. This is unfortunate. */
1219 log_write(0, LOG_MAIN
, "debugging Exim in inetd wait mode starting");
1223 exim_nullstd(); /* re-open fd2 after we just closed it again */
1224 debug_logging_activate(US
"-wait", NULL
);
1227 DEBUG(D_any
) debug_printf("running in inetd wait mode\n");
1229 /* As per below, when creating sockets ourselves, we handle tcp_nodelay for
1230 our own buffering; we assume though that inetd set the socket REUSEADDR. */
1233 if (setsockopt(3, IPPROTO_TCP
, TCP_NODELAY
, US
&on
, sizeof(on
)))
1234 log_write(0, LOG_MAIN
|LOG_PANIC_DIE
, "failed to set socket NODELAY: %s",
1239 if (f
.inetd_wait_mode
|| f
.daemon_listen
)
1241 /* If any option requiring a load average to be available during the
1242 reception of a message is set, call os_getloadavg() while we are root
1243 for those OS for which this is necessary the first time it is called (in
1244 order to perform an "open" on the kernel memory file). */
1246 #ifdef LOAD_AVG_NEEDS_ROOT
1247 if (queue_only_load
>= 0 || smtp_load_reserve
>= 0 ||
1248 (deliver_queue_load_max
>= 0 && deliver_drop_privilege
))
1249 (void)os_getloadavg();
1254 /* Do the preparation for setting up a listener on one or more interfaces, and
1255 possible on various ports. This is controlled by the combination of
1256 local_interfaces (which can set IP addresses and ports) and daemon_smtp_port
1257 (which is a list of default ports to use for those items in local_interfaces
1258 that do not specify a port). The -oX command line option can be used to
1259 override one or both of these options.
1261 If local_interfaces is not set, the default is to listen on all interfaces.
1262 When it is set, it can include "all IPvx interfaces" as an item. This is useful
1263 when different ports are in use.
1265 It turns out that listening on all interfaces is messy in an IPv6 world,
1266 because several different implementation approaches have been taken. This code
1267 is now supposed to work with all of them. The point of difference is whether an
1268 IPv6 socket that is listening on all interfaces will receive incoming IPv4
1269 calls or not. We also have to cope with the case when IPv6 libraries exist, but
1270 there is no IPv6 support in the kernel.
1272 . On Solaris, an IPv6 socket will accept IPv4 calls, and give them as mapped
1273 addresses. However, if an IPv4 socket is also listening on all interfaces,
1274 calls are directed to the appropriate socket.
1276 . On (some versions of) Linux, an IPv6 socket will accept IPv4 calls, and
1277 give them as mapped addresses, but an attempt also to listen on an IPv4
1278 socket on all interfaces causes an error.
1280 . On OpenBSD, an IPv6 socket will not accept IPv4 calls. You have to set up
1281 two sockets if you want to accept both kinds of call.
1283 . FreeBSD is like OpenBSD, but it has the IPV6_V6ONLY socket option, which
1284 can be turned off, to make it behave like the versions of Linux described
1287 . I heard a report that the USAGI IPv6 stack for Linux has implemented
1290 So, what we do when IPv6 is supported is as follows:
1292 (1) After it is set up, the list of interfaces is scanned for wildcard
1293 addresses. If an IPv6 and an IPv4 wildcard are both found for the same
1294 port, the list is re-arranged so that they are together, with the IPv6
1297 (2) If the creation of a wildcard IPv6 socket fails, we just log the error and
1298 carry on if an IPv4 wildcard socket for the same port follows later in the
1299 list. This allows Exim to carry on in the case when the kernel has no IPv6
1302 (3) Having created an IPv6 wildcard socket, we try to set IPV6_V6ONLY if that
1303 option is defined. However, if setting fails, carry on regardless (but log
1306 (4) If binding or listening on an IPv6 wildcard socket fails, it is a serious
1309 (5) If binding or listening on an IPv4 wildcard socket fails with the error
1310 EADDRINUSE, and a previous interface was an IPv6 wildcard for the same
1311 port (which must have succeeded or we wouldn't have got this far), we
1312 assume we are in the situation where just a single socket is permitted,
1313 and ignore the error.
1317 The preparation code decodes options and sets up the relevant data. We do this
1318 first, so that we can return non-zero if there are any syntax errors, and also
1321 if (f
.daemon_listen
&& !f
.inetd_wait_mode
)
1323 int *default_smtp_port
;
1327 const uschar
* list
;
1328 uschar
*local_iface_source
= US
"local_interfaces";
1329 ip_address_item
*ipa
;
1330 ip_address_item
**pipa
;
1332 /* If -oX was used, disable the writing of a pid file unless -oP was
1333 explicitly used to force it. Then scan the string given to -oX. Any items
1334 that contain neither a dot nor a colon are used to override daemon_smtp_port.
1335 Any other items are used to override local_interfaces. */
1337 if (override_local_interfaces
)
1339 gstring
* new_smtp_port
= NULL
;
1340 gstring
* new_local_interfaces
= NULL
;
1342 if (!override_pid_file_path
) write_pid
= FALSE
;
1344 list
= override_local_interfaces
;
1346 while ((s
= string_nextinlist(&list
, &sep
, big_buffer
, big_buffer_size
)))
1349 gstring
** gp
= Ustrpbrk(s
, ".:") ? &new_local_interfaces
: &new_smtp_port
;
1355 *gp
= string_catn(*gp
, US
"<", 1);
1358 *gp
= string_catn(*gp
, joinstr
, 2);
1359 *gp
= string_cat (*gp
, s
);
1364 daemon_smtp_port
= string_from_gstring(new_smtp_port
);
1365 DEBUG(D_any
) debug_printf("daemon_smtp_port overridden by -oX:\n %s\n",
1369 if (new_local_interfaces
)
1371 local_interfaces
= string_from_gstring(new_local_interfaces
);
1372 local_iface_source
= US
"-oX data";
1373 DEBUG(D_any
) debug_printf("local_interfaces overridden by -oX:\n %s\n",
1378 /* Create a list of default SMTP ports, to be used if local_interfaces
1379 contains entries without explicit ports. First count the number of ports, then
1380 build a translated list in a vector. */
1382 list
= daemon_smtp_port
;
1384 while ((s
= string_nextinlist(&list
, &sep
, big_buffer
, big_buffer_size
)))
1386 default_smtp_port
= store_get((pct
+1) * sizeof(int), FALSE
);
1387 list
= daemon_smtp_port
;
1390 (s
= string_nextinlist(&list
, &sep
, big_buffer
, big_buffer_size
));
1396 default_smtp_port
[pct
] = Ustrtol(s
, &end
, 0);
1397 if (end
!= s
+ Ustrlen(s
))
1398 log_write(0, LOG_PANIC_DIE
|LOG_CONFIG
, "invalid SMTP port: %s", s
);
1402 struct servent
*smtp_service
= getservbyname(CS s
, "tcp");
1404 log_write(0, LOG_PANIC_DIE
|LOG_CONFIG
, "TCP port \"%s\" not found", s
);
1405 default_smtp_port
[pct
] = ntohs(smtp_service
->s_port
);
1408 default_smtp_port
[pct
] = 0;
1410 /* Check the list of TLS-on-connect ports and do name lookups if needed */
1412 list
= tls_in
.on_connect_ports
;
1414 while ((s
= string_nextinlist(&list
, &sep
, big_buffer
, big_buffer_size
)))
1419 list
= tls_in
.on_connect_ports
;
1420 tls_in
.on_connect_ports
= NULL
;
1422 while ((s
= string_nextinlist(&list
, &sep
, big_buffer
, big_buffer_size
)))
1426 struct servent
* smtp_service
= getservbyname(CS s
, "tcp");
1428 log_write(0, LOG_PANIC_DIE
|LOG_CONFIG
, "TCP port \"%s\" not found", s
);
1429 s
= string_sprintf("%d", (int)ntohs(smtp_service
->s_port
));
1431 g
= string_append_listele(g
, ':', s
);
1434 tls_in
.on_connect_ports
= g
->s
;
1438 /* Create the list of local interfaces, possibly with ports included. This
1439 list may contain references to 0.0.0.0 and ::0 as wildcards. These special
1440 values are converted below. */
1442 addresses
= host_build_ifacelist(local_interfaces
, local_iface_source
);
1444 /* In the list of IP addresses, convert 0.0.0.0 into an empty string, and ::0
1445 into the string ":". We use these to recognize wildcards in IPv4 and IPv6. In
1446 fact, many IP stacks recognize 0.0.0.0 and ::0 and handle them as wildcards
1447 anyway, but we need to know which are the wildcard addresses, and the shorter
1450 In the same scan, fill in missing port numbers from the default list. When
1451 there is more than one item in the list, extra items are created. */
1453 for (ipa
= addresses
; ipa
; ipa
= ipa
->next
)
1455 if (Ustrcmp(ipa
->address
, "0.0.0.0") == 0)
1456 ipa
->address
[0] = 0;
1457 else if (Ustrcmp(ipa
->address
, "::0") == 0)
1459 ipa
->address
[0] = ':';
1460 ipa
->address
[1] = 0;
1463 if (ipa
->port
> 0) continue;
1465 if (daemon_smtp_port
[0] <= 0)
1466 log_write(0, LOG_MAIN
|LOG_PANIC_DIE
, "no port specified for interface "
1467 "%s and daemon_smtp_port is unset; cannot start daemon",
1468 ipa
->address
[0] == 0 ? US
"\"all IPv4\"" :
1469 ipa
->address
[1] == 0 ? US
"\"all IPv6\"" : ipa
->address
);
1471 ipa
->port
= default_smtp_port
[0];
1472 for (int i
= 1; default_smtp_port
[i
] > 0; i
++)
1474 ip_address_item
*new = store_get(sizeof(ip_address_item
), FALSE
);
1476 memcpy(new->address
, ipa
->address
, Ustrlen(ipa
->address
) + 1);
1477 new->port
= default_smtp_port
[i
];
1478 new->next
= ipa
->next
;
1484 /* Scan the list of addresses for wildcards. If we find an IPv4 and an IPv6
1485 wildcard for the same port, ensure that (a) they are together and (b) the
1486 IPv6 address comes first. This makes handling the messy features easier, and
1487 also simplifies the construction of the "daemon started" log line. */
1490 for (ipa
= addresses
; ipa
; pipa
= &ipa
->next
, ipa
= ipa
->next
)
1492 ip_address_item
*ipa2
;
1494 /* Handle an IPv4 wildcard */
1496 if (ipa
->address
[0] == 0)
1497 for (ipa2
= ipa
; ipa2
->next
; ipa2
= ipa2
->next
)
1499 ip_address_item
*ipa3
= ipa2
->next
;
1500 if (ipa3
->address
[0] == ':' &&
1501 ipa3
->address
[1] == 0 &&
1502 ipa3
->port
== ipa
->port
)
1504 ipa2
->next
= ipa3
->next
;
1511 /* Handle an IPv6 wildcard. */
1513 else if (ipa
->address
[0] == ':' && ipa
->address
[1] == 0)
1514 for (ipa2
= ipa
; ipa2
->next
; ipa2
= ipa2
->next
)
1516 ip_address_item
*ipa3
= ipa2
->next
;
1517 if (ipa3
->address
[0] == 0 && ipa3
->port
== ipa
->port
)
1519 ipa2
->next
= ipa3
->next
;
1520 ipa3
->next
= ipa
->next
;
1528 /* Get a vector to remember all the sockets in */
1530 for (ipa
= addresses
; ipa
; ipa
= ipa
->next
)
1531 listen_socket_count
++;
1532 listen_sockets
= store_get(sizeof(int) * listen_socket_count
, FALSE
);
1534 } /* daemon_listen but not inetd_wait_mode */
1536 if (f
.daemon_listen
)
1539 /* Do a sanity check on the max connects value just to save us from getting
1540 a huge amount of store. */
1542 if (smtp_accept_max
> 4095) smtp_accept_max
= 4096;
1544 /* There's no point setting smtp_accept_queue unless it is less than the max
1545 connects limit. The configuration reader ensures that the max is set if the
1546 queue-only option is set. */
1548 if (smtp_accept_queue
> smtp_accept_max
) smtp_accept_queue
= 0;
1550 /* Get somewhere to keep the list of SMTP accepting pids if we are keeping
1551 track of them for total number and queue/host limits. */
1553 if (smtp_accept_max
> 0)
1555 smtp_slots
= store_get(smtp_accept_max
* sizeof(smtp_slot
), FALSE
);
1556 for (int i
= 0; i
< smtp_accept_max
; i
++) smtp_slots
[i
] = empty_smtp_slot
;
1560 /* The variable background_daemon is always false when debugging, but
1561 can also be forced false in order to keep a non-debugging daemon in the
1562 foreground. If background_daemon is true, close all open file descriptors that
1563 we know about, but then re-open stdin, stdout, and stderr to /dev/null. Also
1564 do this for inetd_wait mode.
1566 This is protection against any called functions (in libraries, or in
1567 Perl, or whatever) that think they can write to stderr (or stdout). Before this
1568 was added, it was quite likely that an SMTP connection would use one of these
1569 file descriptors, in which case writing random stuff to it caused chaos.
1571 Then disconnect from the controlling terminal, Most modern Unixes seem to have
1572 setsid() for getting rid of the controlling terminal. For any OS that doesn't,
1573 setsid() can be #defined as a no-op, or as something else. */
1575 if (f
.background_daemon
|| f
.inetd_wait_mode
)
1577 log_close_all(); /* Just in case anything was logged earlier */
1578 search_tidyup(); /* Just in case any were used in reading the config. */
1579 (void)close(0); /* Get rid of stdin/stdout/stderr */
1582 exim_nullstd(); /* Connect stdin/stdout/stderr to /dev/null */
1583 log_stderr
= NULL
; /* So no attempt to copy paniclog output */
1586 if (f
.background_daemon
)
1588 /* If the parent process of this one has pid == 1, we are re-initializing the
1589 daemon as the result of a SIGHUP. In this case, there is no need to do
1590 anything, because the controlling terminal has long gone. Otherwise, fork, in
1591 case current process is a process group leader (see 'man setsid' for an
1592 explanation) before calling setsid(). */
1597 if (pid
< 0) log_write(0, LOG_MAIN
|LOG_PANIC_DIE
,
1598 "fork() failed when starting daemon: %s", strerror(errno
));
1599 if (pid
> 0) exit(EXIT_SUCCESS
); /* in parent process, just exit */
1600 (void)setsid(); /* release controlling terminal */
1604 /* We are now in the disconnected, daemon process (unless debugging). Set up
1605 the listening sockets if required. */
1607 daemon_notifier_socket();
1609 if (f
.daemon_listen
&& !f
.inetd_wait_mode
)
1612 ip_address_item
*ipa
;
1614 /* For each IP address, create a socket, bind it to the appropriate port, and
1615 start listening. See comments above about IPv6 sockets that may or may not
1616 accept IPv4 calls when listening on all interfaces. We also have to cope with
1617 the case of a system with IPv6 libraries, but no IPv6 support in the kernel.
1618 listening, provided a wildcard IPv4 socket for the same port follows. */
1620 for (ipa
= addresses
, sk
= 0; sk
< listen_socket_count
; ipa
= ipa
->next
, sk
++)
1623 ip_address_item
*ipa2
;
1626 if (Ustrchr(ipa
->address
, ':') != NULL
)
1629 wildcard
= ipa
->address
[1] == 0;
1634 wildcard
= ipa
->address
[0] == 0;
1637 if ((listen_sockets
[sk
] = ip_socket(SOCK_STREAM
, af
)) < 0)
1639 if (check_special_case(0, addresses
, ipa
, FALSE
))
1641 log_write(0, LOG_MAIN
, "Failed to create IPv6 socket for wildcard "
1642 "listening (%s): will use IPv4", strerror(errno
));
1645 log_write(0, LOG_PANIC_DIE
, "IPv%c socket creation failed: %s",
1646 (af
== AF_INET6
)? '6' : '4', strerror(errno
));
1649 /* If this is an IPv6 wildcard socket, set IPV6_V6ONLY if that option is
1650 available. Just log failure (can get protocol not available, just like
1651 socket creation can). */
1654 if (af
== AF_INET6
&& wildcard
&&
1655 setsockopt(listen_sockets
[sk
], IPPROTO_IPV6
, IPV6_V6ONLY
, CS (&on
),
1657 log_write(0, LOG_MAIN
, "Setting IPV6_V6ONLY on daemon's IPv6 wildcard "
1658 "socket failed (%s): carrying on without it", strerror(errno
));
1659 #endif /* IPV6_V6ONLY */
1661 /* Set SO_REUSEADDR so that the daemon can be restarted while a connection
1662 is being handled. Without this, a connection will prevent reuse of the
1663 smtp port for listening. */
1665 if (setsockopt(listen_sockets
[sk
], SOL_SOCKET
, SO_REUSEADDR
,
1666 US (&on
), sizeof(on
)) < 0)
1667 log_write(0, LOG_MAIN
|LOG_PANIC_DIE
, "setting SO_REUSEADDR on socket "
1668 "failed when starting daemon: %s", strerror(errno
));
1670 /* Set TCP_NODELAY; Exim does its own buffering. There is a switch to
1671 disable this because it breaks some broken clients. */
1673 if (tcp_nodelay
) setsockopt(listen_sockets
[sk
], IPPROTO_TCP
, TCP_NODELAY
,
1674 US (&on
), sizeof(on
));
1676 /* Now bind the socket to the required port; if Exim is being restarted
1677 it may not always be possible to bind immediately, even with SO_REUSEADDR
1678 set, so try 10 times, waiting between each try. After 10 failures, we give
1679 up. In an IPv6 environment, if bind () fails with the error EADDRINUSE and
1680 we are doing wildcard IPv4 listening and there was a previous IPv6 wildcard
1681 address for the same port, ignore the error on the grounds that we must be
1682 in a system where the IPv6 socket accepts both kinds of call. This is
1683 necessary for (some release of) USAGI Linux; other IP stacks fail at the
1684 listen() stage instead. */
1687 f
.tcp_fastopen_ok
= TRUE
;
1692 if (ip_bind(listen_sockets
[sk
], af
, ipa
->address
, ipa
->port
) >= 0) break;
1693 if (check_special_case(errno
, addresses
, ipa
, TRUE
))
1695 DEBUG(D_any
) debug_printf("wildcard IPv4 bind() failed after IPv6 "
1696 "listen() success; EADDRINUSE ignored\n");
1697 (void)close(listen_sockets
[sk
]);
1700 msg
= US
strerror(errno
);
1706 if (daemon_startup_retries
<= 0)
1707 log_write(0, LOG_MAIN
|LOG_PANIC_DIE
,
1708 "socket bind() to port %d for address %s failed: %s: "
1709 "daemon abandoned", ipa
->port
, addr
, msg
);
1710 log_write(0, LOG_MAIN
, "socket bind() to port %d for address %s "
1711 "failed: %s: waiting %s before trying again (%d more %s)",
1712 ipa
->port
, addr
, msg
, readconf_printtime(daemon_startup_sleep
),
1713 daemon_startup_retries
, (daemon_startup_retries
> 1)? "tries" : "try");
1714 daemon_startup_retries
--;
1715 sleep(daemon_startup_sleep
);
1720 debug_printf("listening on all interfaces (IPv%c) port %d\n",
1721 af
== AF_INET6
? '6' : '4', ipa
->port
);
1723 debug_printf("listening on %s port %d\n", ipa
->address
, ipa
->port
);
1725 #if defined(TCP_FASTOPEN) && !defined(__APPLE__)
1726 if ( f
.tcp_fastopen_ok
1727 && setsockopt(listen_sockets
[sk
], IPPROTO_TCP
, TCP_FASTOPEN
,
1728 &smtp_connect_backlog
, sizeof(smtp_connect_backlog
)))
1730 DEBUG(D_any
) debug_printf("setsockopt FASTOPEN: %s\n", strerror(errno
));
1731 f
.tcp_fastopen_ok
= FALSE
;
1735 /* Start listening on the bound socket, establishing the maximum backlog of
1736 connections that is allowed. On success, continue to the next address. */
1738 if (listen(listen_sockets
[sk
], smtp_connect_backlog
) >= 0)
1740 #if defined(TCP_FASTOPEN) && defined(__APPLE__)
1741 if ( f
.tcp_fastopen_ok
1742 && setsockopt(listen_sockets
[sk
], IPPROTO_TCP
, TCP_FASTOPEN
,
1745 DEBUG(D_any
) debug_printf("setsockopt FASTOPEN: %s\n", strerror(errno
));
1746 f
.tcp_fastopen_ok
= FALSE
;
1752 /* Listening has failed. In an IPv6 environment, as for bind(), if listen()
1753 fails with the error EADDRINUSE and we are doing IPv4 wildcard listening
1754 and there was a previous successful IPv6 wildcard listen on the same port,
1755 we want to ignore the error on the grounds that we must be in a system
1756 where the IPv6 socket accepts both kinds of call. */
1758 if (!check_special_case(errno
, addresses
, ipa
, TRUE
))
1759 log_write(0, LOG_PANIC_DIE
, "listen() failed on interface %s: %s",
1761 ? af
== AF_INET6
? US
"(any IPv6)" : US
"(any IPv4)" : ipa
->address
,
1764 DEBUG(D_any
) debug_printf("wildcard IPv4 listen() failed after IPv6 "
1765 "listen() success; EADDRINUSE ignored\n");
1766 (void)close(listen_sockets
[sk
]);
1768 /* Come here if there has been a problem with the socket which we
1769 are going to ignore. We remove the address from the chain, and back up the
1773 sk
--; /* Back up the count */
1774 listen_socket_count
--; /* Reduce the total */
1775 if (ipa
== addresses
) addresses
= ipa
->next
; else
1777 for (ipa2
= addresses
; ipa2
->next
!= ipa
; ipa2
= ipa2
->next
);
1778 ipa2
->next
= ipa
->next
;
1781 } /* End of bind/listen loop for each address */
1782 } /* End of setup for listening */
1785 /* If we are not listening, we want to write a pid file only if -oP was
1786 explicitly given. */
1788 else if (!override_pid_file_path
)
1791 /* Write the pid to a known file for assistance in identification, if required.
1792 We do this before giving up root privilege, because on some systems it is
1793 necessary to be root in order to write into the pid file directory. There's
1794 nothing to stop multiple daemons running, as long as no more than one listens
1795 on a given TCP/IP port on the same interface(s). However, in these
1796 circumstances it gets far too complicated to mess with pid file names
1797 automatically. Consequently, Exim 4 writes a pid file only
1799 (a) When running in the test harness, or
1800 (b) When -bd is used and -oX is not used, or
1801 (c) When -oP is used to supply a path.
1803 The variable daemon_write_pid is used to control this. */
1805 if (f
.running_in_test_harness
|| write_pid
)
1809 set_pid_file_path();
1810 if ((f
= modefopen(pid_file_path
, "wb", 0644)))
1812 (void)fprintf(f
, "%d\n", (int)getpid());
1814 DEBUG(D_any
) debug_printf("pid written to %s\n", pid_file_path
);
1818 debug_printf("%s\n", string_open_failed(errno
, "pid file %s",
1822 /* Set up the handler for SIGHUP, which causes a restart of the daemon. */
1824 sighup_seen
= FALSE
;
1825 signal(SIGHUP
, sighup_handler
);
1827 /* Give up root privilege at this point (assuming that exim_uid and exim_gid
1828 are not root). The third argument controls the running of initgroups().
1829 Normally we do this, in order to set up the groups for the Exim user. However,
1830 if we are not root at this time - some odd installations run that way - we
1833 exim_setugid(exim_uid
, exim_gid
, geteuid()==root_uid
, US
"running as a daemon");
1835 /* Update the originator_xxx fields so that received messages as listed as
1836 coming from Exim, not whoever started the daemon. */
1838 originator_uid
= exim_uid
;
1839 originator_gid
= exim_gid
;
1840 originator_login
= (pw
= getpwuid(exim_uid
))
1841 ? string_copy_perm(US pw
->pw_name
, FALSE
) : US
"exim";
1843 /* Get somewhere to keep the list of queue-runner pids if we are keeping track
1844 of them (and also if we are doing queue runs). */
1846 if (queue_interval
> 0 && local_queue_run_max
> 0)
1848 queue_pid_slots
= store_get(local_queue_run_max
* sizeof(pid_t
), FALSE
);
1849 for (int i
= 0; i
< local_queue_run_max
; i
++) queue_pid_slots
[i
] = 0;
1852 /* Set up the handler for termination of child processes, and the one
1853 telling us to die. */
1855 sigchld_seen
= FALSE
;
1856 os_non_restarting_signal(SIGCHLD
, main_sigchld_handler
);
1858 sigterm_seen
= FALSE
;
1859 os_non_restarting_signal(SIGTERM
, main_sigterm_handler
);
1861 /* If we are to run the queue periodically, pretend the alarm has just gone
1862 off. This will cause the first queue-runner to get kicked off straight away. */
1864 sigalrm_seen
= (queue_interval
> 0);
1866 /* Log the start up of a daemon - at least one of listening or queue running
1869 if (f
.inetd_wait_mode
)
1871 uschar
*p
= big_buffer
;
1873 if (inetd_wait_timeout
>= 0)
1874 sprintf(CS p
, "terminating after %d seconds", inetd_wait_timeout
);
1876 sprintf(CS p
, "with no wait timeout");
1878 log_write(0, LOG_MAIN
,
1879 "exim %s daemon started: pid=%d, launched with listening socket, %s",
1880 version_string
, getpid(), big_buffer
);
1881 set_process_info("daemon(%s): pre-listening socket", version_string
);
1883 /* set up the timeout logic */
1884 sigalrm_seen
= TRUE
;
1887 else if (f
.daemon_listen
)
1890 int smtps_ports
= 0;
1891 ip_address_item
* ipa
;
1893 uschar
* qinfo
= queue_interval
> 0
1894 ? string_sprintf("-q%s", readconf_printtime(queue_interval
))
1895 : US
"no queue runs";
1897 /* Build a list of listening addresses in big_buffer, but limit it to 10
1898 items. The style is for backwards compatibility.
1900 It is now possible to have some ports listening for SMTPS (the old,
1901 deprecated protocol that starts TLS without using STARTTLS), and others
1902 listening for standard SMTP. Keep their listings separate. */
1904 for (int j
= 0, i
; j
< 2; j
++)
1906 for (i
= 0, ipa
= addresses
; i
< 10 && ipa
; i
++, ipa
= ipa
->next
)
1908 /* First time round, look for SMTP ports; second time round, look for
1909 SMTPS ports. Build IP+port strings. */
1911 if (host_is_tls_on_connect_port(ipa
->port
) == (j
> 0))
1918 /* Now the information about the port (and sometimes interface) */
1920 if (ipa
->address
[0] == ':' && ipa
->address
[1] == 0)
1922 if (ipa
->next
&& ipa
->next
->address
[0] == 0 &&
1923 ipa
->next
->port
== ipa
->port
)
1925 ipa
->log
= string_sprintf(" port %d (IPv6 and IPv4)", ipa
->port
);
1926 (ipa
= ipa
->next
)->log
= NULL
;
1928 else if (ipa
->v6_include_v4
)
1929 ipa
->log
= string_sprintf(" port %d (IPv6 with IPv4)", ipa
->port
);
1931 ipa
->log
= string_sprintf(" port %d (IPv6)", ipa
->port
);
1933 else if (ipa
->address
[0] == 0) /* v4 wildcard */
1934 ipa
->log
= string_sprintf(" port %d (IPv4)", ipa
->port
);
1935 else /* check for previously-seen IP */
1937 ip_address_item
* i2
;
1938 for (i2
= addresses
; i2
!= ipa
; i2
= i2
->next
)
1939 if ( host_is_tls_on_connect_port(i2
->port
) == (j
> 0)
1940 && Ustrcmp(ipa
->address
, i2
->address
) == 0
1942 { /* found; append port to list */
1943 for (p
= i2
->log
; *p
; ) p
++; /* end of existing string */
1944 if (*--p
== '}') *p
= '\0'; /* drop EOL */
1945 while (isdigit(*--p
)) ; /* char before port */
1947 i2
->log
= *p
== ':' /* no list yet? */
1948 ? string_sprintf("%.*s{%s,%d}",
1949 (int)(p
- i2
->log
+ 1), i2
->log
, p
+1, ipa
->port
)
1950 : string_sprintf("%s,%d}", i2
->log
, ipa
->port
);
1954 if (i2
== ipa
) /* first-time IP */
1955 ipa
->log
= string_sprintf(" [%s]:%d", ipa
->address
, ipa
->port
);
1962 for (int j
= 0, i
; j
< 2; j
++)
1964 /* First time round, look for SMTP ports; second time round, look for
1965 SMTPS ports. For the first one of each, insert leading text. */
1970 p
+= sprintf(CS p
, "SMTP on");
1973 if (smtps_ports
> 0)
1974 p
+= sprintf(CS p
, "%sSMTPS on",
1975 smtp_ports
== 0 ? "" : " and for ");
1977 /* Now the information about the port (and sometimes interface) */
1979 for (i
= 0, ipa
= addresses
; i
< 10 && ipa
; i
++, ipa
= ipa
->next
)
1980 if (host_is_tls_on_connect_port(ipa
->port
) == (j
> 0))
1982 p
+= sprintf(CS p
, "%s", ipa
->log
);
1985 p
+= sprintf(CS p
, " ...");
1988 log_write(0, LOG_MAIN
,
1989 "exim %s daemon started: pid=%d, %s, listening for %s",
1990 version_string
, getpid(), qinfo
, big_buffer
);
1991 set_process_info("daemon(%s): %s, listening for %s",
1992 version_string
, qinfo
, big_buffer
);
1997 uschar
* s
= *queue_name
1998 ? string_sprintf("-qG%s/%s", queue_name
, readconf_printtime(queue_interval
))
1999 : string_sprintf("-q%s", readconf_printtime(queue_interval
));
2000 log_write(0, LOG_MAIN
,
2001 "exim %s daemon started: pid=%d, %s, not listening for SMTP",
2002 version_string
, getpid(), s
);
2003 set_process_info("daemon(%s): %s, not listening", version_string
, s
);
2006 /* Do any work it might be useful to amortize over our children
2007 (eg: compile regex) */
2010 smtp_deliver_init(); /* Used for callouts */
2012 #ifndef DISABLE_DKIM
2014 # ifdef MEASURE_TIMING
2016 gettimeofday(&t0
, NULL
);
2019 # ifdef MEASURE_TIMING
2020 report_time_since(&t0
, US
"dkim_exim_init (delta)");
2025 #ifdef WITH_CONTENT_SCAN
2032 /* Close the log so it can be renamed and moved. In the few cases below where
2033 this long-running process writes to the log (always exceptional conditions), it
2034 closes the log afterwards, for the same reason. */
2038 DEBUG(D_any
) debug_print_ids(US
"daemon running with");
2040 /* Any messages accepted via this route are going to be SMTP. */
2044 #ifdef MEASURE_TIMING
2045 report_time_since(×tamp_startup
, US
"daemon loop start"); /* testcase 0022 */
2048 /* Enter the never-ending loop... */
2053 struct sockaddr_in6 accepted
;
2055 struct sockaddr_in accepted
;
2062 daemon_die(); /* Does not return */
2064 /* This code is placed first in the loop, so that it gets obeyed at the
2065 start, before the first wait, for the queue-runner case, so that the first
2066 one can be started immediately.
2068 The other option is that we have an inetd wait timeout specified to -bw. */
2072 if (inetd_wait_timeout
> 0)
2074 time_t resignal_interval
= inetd_wait_timeout
;
2076 if (last_connection_time
== (time_t)0)
2079 debug_printf("inetd wait timeout expired, but still not seen first message, ignoring\n");
2083 time_t now
= time(NULL
);
2084 if (now
== (time_t)-1)
2086 DEBUG(D_any
) debug_printf("failed to get time: %s\n", strerror(errno
));
2090 if ((now
- last_connection_time
) >= inetd_wait_timeout
)
2093 debug_printf("inetd wait timeout %d expired, ending daemon\n",
2094 inetd_wait_timeout
);
2095 log_write(0, LOG_MAIN
, "exim %s daemon terminating, inetd wait timeout reached.\n",
2101 resignal_interval
-= (now
- last_connection_time
);
2106 sigalrm_seen
= FALSE
;
2107 ALARM(resignal_interval
);
2112 DEBUG(D_any
) debug_printf("%s received\n",
2113 #ifdef EXPERIMENTAL_QUEUE_RAMP
2114 *queuerun_msgid
? "qrun notification" :
2118 /* Do a full queue run in a child process, if required, unless we already
2119 have enough queue runners on the go. If we are not running as root, a
2120 re-exec is required. */
2122 if (queue_interval
> 0 &&
2123 (local_queue_run_max
<= 0 || queue_run_count
< local_queue_run_max
))
2125 if ((pid
= fork()) == 0)
2127 DEBUG(D_any
) debug_printf("Starting queue-runner: pid %d\n",
2130 /* Disable debugging if it's required only for the daemon process. We
2131 leave the above message, because it ties up with the "child ended"
2132 debugging messages. */
2134 if (f
.debug_daemon
) debug_selector
= 0;
2136 /* Close any open listening sockets in the child */
2138 close_daemon_sockets(daemon_notifier_fd
,
2139 listen_sockets
, listen_socket_count
);
2141 /* Reset SIGHUP and SIGCHLD in the child in both cases. */
2143 signal(SIGHUP
, SIG_DFL
);
2144 signal(SIGCHLD
, SIG_DFL
);
2145 signal(SIGTERM
, SIG_DFL
);
2147 /* Re-exec if privilege has been given up, unless deliver_drop_
2148 privilege is set. Reset SIGALRM before exec(). */
2150 if (geteuid() != root_uid
&& !deliver_drop_privilege
)
2157 signal(SIGALRM
, SIG_DFL
);
2161 #ifdef EXPERIMENTAL_QUEUE_RAMP
2165 if (f
.queue_run_first_delivery
) *p
++ = 'i';
2166 if (f
.queue_run_force
) *p
++ = 'f';
2167 if (f
.deliver_force_thaw
) *p
++ = 'f';
2168 if (f
.queue_run_local
) *p
++ = 'l';
2170 extra
[0] = *queue_name
2171 ? string_sprintf("%sG%s", opt
, queue_name
) : opt
;
2173 #ifdef EXPERIMENTAL_QUEUE_RAMP
2174 if (*queuerun_msgid
)
2176 extra
[extracount
++] = queuerun_msgid
; /* Trigger only the */
2177 extra
[extracount
++] = queuerun_msgid
; /* one message */
2181 /* If -R or -S were on the original command line, ensure they get
2184 if (deliver_selectstring
)
2186 extra
[extracount
++] = f
.deliver_selectstring_regex
? US
"-Rr" : US
"-R";
2187 extra
[extracount
++] = deliver_selectstring
;
2190 if (deliver_selectstring_sender
)
2192 extra
[extracount
++] = f
.deliver_selectstring_sender_regex
2194 extra
[extracount
++] = deliver_selectstring_sender
;
2197 /* Overlay this process with a new execution. */
2199 (void)child_exec_exim(CEE_EXEC_PANIC
, FALSE
, NULL
, FALSE
, extracount
,
2200 extra
[0], extra
[1], extra
[2], extra
[3], extra
[4], extra
[5], extra
[6]);
2202 /* Control never returns here. */
2205 /* No need to re-exec; SIGALRM remains set to the default handler */
2207 #ifdef EXPERIMENTAL_QUEUE_RAMP
2208 if (*queuerun_msgid
)
2210 f
.queue_2stage
= FALSE
;
2211 queue_run(queuerun_msgid
, queuerun_msgid
, FALSE
);
2215 queue_run(NULL
, NULL
, FALSE
);
2216 exim_underbar_exit(EXIT_SUCCESS
);
2221 log_write(0, LOG_MAIN
|LOG_PANIC
, "daemon: fork of queue-runner "
2222 "process failed: %s", strerror(errno
));
2227 for (int i
= 0; i
< local_queue_run_max
; ++i
)
2228 if (queue_pid_slots
[i
] <= 0)
2230 queue_pid_slots
[i
] = pid
;
2234 DEBUG(D_any
) debug_printf("%d queue-runner process%s running\n",
2235 queue_run_count
, queue_run_count
== 1 ? "" : "es");
2239 /* Reset the alarm clock */
2241 sigalrm_seen
= FALSE
;
2242 #ifdef EXPERIMENTAL_QUEUE_RAMP
2243 if (*queuerun_msgid
)
2244 *queuerun_msgid
= 0;
2247 ALARM(queue_interval
);
2250 } /* sigalrm_seen */
2253 /* Sleep till a connection happens if listening, and handle the connection if
2254 that is why we woke up. The FreeBSD operating system requires the use of
2255 select() before accept() because the latter function is not interrupted by
2256 a signal, and we want to wake up for SIGCHLD and SIGALRM signals. Some other
2257 OS do notice signals in accept() but it does no harm to have the select()
2258 in for all of them - and it won't then be a lurking problem for ports to
2259 new OS. In fact, the later addition of listening on specific interfaces only
2260 requires this way of working anyway. */
2262 if (f
.daemon_listen
)
2264 int lcount
, select_errno
;
2266 BOOL select_failed
= FALSE
;
2267 fd_set select_listen
;
2269 FD_ZERO(&select_listen
);
2270 if (daemon_notifier_fd
>= 0)
2271 FD_SET(daemon_notifier_fd
, &select_listen
);
2272 for (int sk
= 0; sk
< listen_socket_count
; sk
++)
2274 FD_SET(listen_sockets
[sk
], &select_listen
);
2275 if (listen_sockets
[sk
] > max_socket
) max_socket
= listen_sockets
[sk
];
2278 DEBUG(D_any
) debug_printf("Listening...\n");
2280 /* In rare cases we may have had a SIGCHLD signal in the time between
2281 setting the handler (below) and getting back here. If so, pretend that the
2282 select() was interrupted so that we reap the child. This might still leave
2283 a small window when a SIGCHLD could get lost. However, since we use SIGCHLD
2284 only to do the reaping more quickly, it shouldn't result in anything other
2285 than a delay until something else causes a wake-up. */
2293 lcount
= select(max_socket
+ 1, (SELECT_ARG2_TYPE
*)&select_listen
,
2298 select_failed
= TRUE
;
2302 /* Clean up any subprocesses that may have terminated. We need to do this
2303 here so that smtp_accept_max_per_host works when a connection to that host
2304 has completed, and we are about to accept a new one. When this code was
2305 later in the sequence, a new connection could be rejected, even though an
2306 old one had just finished. Preserve the errno from any select() failure for
2307 the use of the common select/accept error processing below. */
2309 select_errno
= errno
;
2310 handle_ending_processes();
2311 errno
= select_errno
;
2314 /* Create or rotate any required keys */
2318 /* Loop for all the sockets that are currently ready to go. If select
2319 actually failed, we have set the count to 1 and select_failed=TRUE, so as
2320 to use the common error code for select/accept below. */
2322 while (lcount
-- > 0)
2324 int accept_socket
= -1;
2328 if ( daemon_notifier_fd
>= 0
2329 && FD_ISSET(daemon_notifier_fd
, &select_listen
))
2331 FD_CLR(daemon_notifier_fd
, &select_listen
);
2332 sigalrm_seen
= daemon_notification();
2333 break; /* to top of daemon loop */
2335 for (int sk
= 0; sk
< listen_socket_count
; sk
++)
2336 if (FD_ISSET(listen_sockets
[sk
], &select_listen
))
2338 len
= sizeof(accepted
);
2339 accept_socket
= accept(listen_sockets
[sk
],
2340 (struct sockaddr
*)&accepted
, &len
);
2341 FD_CLR(listen_sockets
[sk
], &select_listen
);
2346 /* If select or accept has failed and this was not caused by an
2347 interruption, log the incident and try again. With asymmetric TCP/IP
2348 routing errors such as "No route to network" have been seen here. Also
2349 "connection reset by peer" has been seen. These cannot be classed as
2350 disastrous errors, but they could fill up a lot of log. The code in smail
2351 crashes the daemon after 10 successive failures of accept, on the grounds
2352 that some OS fail continuously. Exim originally followed suit, but this
2353 appears to have caused problems. Now it just keeps going, but instead of
2354 logging each error, it batches them up when they are continuous. */
2356 if (accept_socket
< 0 && errno
!= EINTR
)
2358 if (accept_retry_count
== 0)
2360 accept_retry_errno
= errno
;
2361 accept_retry_select_failed
= select_failed
;
2365 if (errno
!= accept_retry_errno
||
2366 select_failed
!= accept_retry_select_failed
||
2367 accept_retry_count
>= 50)
2369 log_write(0, LOG_MAIN
| ((accept_retry_count
>= 50)? LOG_PANIC
: 0),
2370 "%d %s() failure%s: %s",
2372 accept_retry_select_failed
? "select" : "accept",
2373 (accept_retry_count
== 1)? "" : "s",
2374 strerror(accept_retry_errno
));
2376 accept_retry_count
= 0;
2377 accept_retry_errno
= errno
;
2378 accept_retry_select_failed
= select_failed
;
2381 accept_retry_count
++;
2386 if (accept_retry_count
> 0)
2388 log_write(0, LOG_MAIN
, "%d %s() failure%s: %s",
2390 accept_retry_select_failed
? "select" : "accept",
2391 (accept_retry_count
== 1)? "" : "s",
2392 strerror(accept_retry_errno
));
2394 accept_retry_count
= 0;
2398 /* If select/accept succeeded, deal with the connection. */
2400 if (accept_socket
>= 0)
2402 if (inetd_wait_timeout
)
2403 last_connection_time
= time(NULL
);
2404 handle_smtp_call(listen_sockets
, listen_socket_count
, accept_socket
,
2405 (struct sockaddr
*)&accepted
);
2410 /* If not listening, then just sleep for the queue interval. If we woke
2411 up early the last time for some other signal, it won't matter because
2412 the alarm signal will wake at the right time. This code originally used
2413 sleep() but it turns out that on the FreeBSD system, sleep() is not inter-
2414 rupted by signals, so it wasn't waking up for SIGALRM or SIGCHLD. Luckily
2415 select() can be used as an interruptible sleep() on all versions of Unix. */
2420 tv
.tv_sec
= queue_interval
;
2422 select(0, NULL
, NULL
, NULL
, &tv
);
2423 handle_ending_processes();
2426 /* Re-enable the SIGCHLD handler if it has been run. It can't do it
2427 for itself, because it isn't doing the waiting itself. */
2431 sigchld_seen
= FALSE
;
2432 os_non_restarting_signal(SIGCHLD
, main_sigchld_handler
);
2435 /* Handle being woken by SIGHUP. We know at this point that the result
2436 of accept() has been dealt with, so we can re-exec exim safely, first
2437 closing the listening sockets so that they can be reused. Cancel any pending
2438 alarm in case it is just about to go off, and set SIGHUP to be ignored so
2439 that another HUP in quick succession doesn't clobber the new daemon before it
2440 gets going. All log files get closed by the close-on-exec flag; however, if
2441 the exec fails, we need to close the logs. */
2445 log_write(0, LOG_MAIN
, "pid %d: SIGHUP received: re-exec daemon",
2447 close_daemon_sockets(daemon_notifier_fd
,
2448 listen_sockets
, listen_socket_count
);
2450 signal(SIGHUP
, SIG_IGN
);
2451 sighup_argv
[0] = exim_path
;
2453 execv(CS exim_path
, (char *const *)sighup_argv
);
2454 log_write(0, LOG_MAIN
|LOG_PANIC_DIE
, "pid %d: exec of %s failed: %s",
2455 getpid(), exim_path
, strerror(errno
));
2459 } /* End of main loop */
2461 /* Control never reaches here */
2466 /* End of exim_daemon.c */