Commit | Line | Data |
---|---|---|
059ec3d9 PH |
1 | /************************************************* |
2 | * Exim - an Internet mail transport agent * | |
3 | *************************************************/ | |
4 | ||
80fea873 | 5 | /* Copyright (c) University of Cambridge 1995 - 2016 */ |
059ec3d9 PH |
6 | /* See the file NOTICE for conditions of use and distribution. */ |
7 | ||
8 | /* Functions concerned with running Exim as a daemon */ | |
9 | ||
10 | ||
11 | #include "exim.h" | |
12 | ||
13 | ||
14 | /* Structure for holding data for each SMTP connection */ | |
15 | ||
16 | typedef struct smtp_slot { | |
17 | pid_t pid; /* pid of the spawned reception process */ | |
18 | uschar *host_address; /* address of the client host */ | |
19 | } smtp_slot; | |
20 | ||
21 | /* An empty slot for initializing (Standard C does not allow constructor | |
22 | expressions in assigments except as initializers in declarations). */ | |
23 | ||
24 | static smtp_slot empty_smtp_slot = { 0, NULL }; | |
25 | ||
26 | ||
27 | ||
28 | /************************************************* | |
29 | * Local static variables * | |
30 | *************************************************/ | |
31 | ||
cd59ab18 PP |
32 | static SIGNAL_BOOL sigchld_seen; |
33 | static SIGNAL_BOOL sighup_seen; | |
059ec3d9 PH |
34 | |
35 | static int accept_retry_count = 0; | |
36 | static int accept_retry_errno; | |
37 | static BOOL accept_retry_select_failed; | |
38 | ||
39 | static int queue_run_count = 0; | |
bb6e88ff PH |
40 | static pid_t *queue_pid_slots = NULL; |
41 | static smtp_slot *smtp_slots = NULL; | |
059ec3d9 PH |
42 | |
43 | static BOOL write_pid = TRUE; | |
44 | ||
45 | ||
46 | ||
47 | /************************************************* | |
48 | * SIGHUP Handler * | |
49 | *************************************************/ | |
50 | ||
51 | /* All this handler does is to set a flag and re-enable the signal. | |
52 | ||
53 | Argument: the signal number | |
54 | Returns: nothing | |
55 | */ | |
56 | ||
57 | static void | |
58 | sighup_handler(int sig) | |
59 | { | |
60 | sig = sig; /* Keep picky compilers happy */ | |
61 | sighup_seen = TRUE; | |
62 | signal(SIGHUP, sighup_handler); | |
63 | } | |
64 | ||
65 | ||
66 | ||
67 | /************************************************* | |
68 | * SIGCHLD handler for main daemon process * | |
69 | *************************************************/ | |
70 | ||
71 | /* Don't re-enable the handler here, since we aren't doing the | |
72 | waiting here. If the signal is re-enabled, there will just be an | |
73 | infinite sequence of calls to this handler. The SIGCHLD signal is | |
74 | used just as a means of waking up the daemon so that it notices | |
75 | terminated subprocesses as soon as possible. | |
76 | ||
77 | Argument: the signal number | |
78 | Returns: nothing | |
79 | */ | |
80 | ||
81 | static void | |
82 | main_sigchld_handler(int sig) | |
83 | { | |
84 | sig = sig; /* Keep picky compilers happy */ | |
7d468ab8 | 85 | os_non_restarting_signal(SIGCHLD, SIG_DFL); |
059ec3d9 | 86 | sigchld_seen = TRUE; |
059ec3d9 PH |
87 | } |
88 | ||
89 | ||
90 | ||
91 | ||
92 | /************************************************* | |
93 | * Unexpected errors in SMTP calls * | |
94 | *************************************************/ | |
95 | ||
96 | /* This function just saves a bit of repetitious coding. | |
97 | ||
98 | Arguments: | |
99 | log_msg Text of message to be logged | |
100 | smtp_msg Text of SMTP error message | |
101 | was_errno The failing errno | |
102 | ||
103 | Returns: nothing | |
104 | */ | |
105 | ||
106 | static void | |
107 | never_error(uschar *log_msg, uschar *smtp_msg, int was_errno) | |
108 | { | |
109 | uschar *emsg = (was_errno <= 0)? US"" : | |
110 | string_sprintf(": %s", strerror(was_errno)); | |
111 | log_write(0, LOG_MAIN|LOG_PANIC, "%s%s", log_msg, emsg); | |
112 | if (smtp_out != NULL) smtp_printf("421 %s\r\n", smtp_msg); | |
113 | } | |
114 | ||
115 | ||
116 | ||
117 | ||
118 | /************************************************* | |
119 | * Handle a connected SMTP call * | |
120 | *************************************************/ | |
121 | ||
122 | /* This function is called when an SMTP connection has been accepted. | |
123 | If there are too many, give an error message and close down. Otherwise | |
124 | spin off a sub-process to handle the call. The list of listening sockets | |
125 | is required so that they can be closed in the sub-process. Take care not to | |
126 | leak store in this process - reset the stacking pool at the end. | |
127 | ||
128 | Arguments: | |
129 | listen_sockets sockets which are listening for incoming calls | |
130 | listen_socket_count count of listening sockets | |
131 | accept_socket socket of the current accepted call | |
132 | accepted socket information about the current call | |
133 | ||
134 | Returns: nothing | |
135 | */ | |
136 | ||
137 | static void | |
138 | handle_smtp_call(int *listen_sockets, int listen_socket_count, | |
139 | int accept_socket, struct sockaddr *accepted) | |
140 | { | |
141 | pid_t pid; | |
142 | union sockaddr_46 interface_sockaddr; | |
36a3b041 | 143 | EXIM_SOCKLEN_T ifsize = sizeof(interface_sockaddr); |
059ec3d9 PH |
144 | int dup_accept_socket = -1; |
145 | int max_for_this_host = 0; | |
146 | int wfsize = 0; | |
147 | int wfptr = 0; | |
6c6d6e48 | 148 | int save_log_selector = *log_selector; |
059ec3d9 PH |
149 | uschar *whofrom = NULL; |
150 | ||
151 | void *reset_point = store_get(0); | |
152 | ||
153 | /* Make the address available in ASCII representation, and also fish out | |
154 | the remote port. */ | |
155 | ||
156 | sender_host_address = host_ntoa(-1, accepted, NULL, &sender_host_port); | |
157 | DEBUG(D_any) debug_printf("Connection request from %s port %d\n", | |
158 | sender_host_address, sender_host_port); | |
159 | ||
160 | /* Set up the output stream, check the socket has duplicated, and set up the | |
161 | input stream. These operations fail only the exceptional circumstances. Note | |
162 | that never_error() won't use smtp_out if it is NULL. */ | |
163 | ||
f5d25c2b | 164 | if (!(smtp_out = fdopen(accept_socket, "wb"))) |
059ec3d9 PH |
165 | { |
166 | never_error(US"daemon: fdopen() for smtp_out failed", US"", errno); | |
167 | goto ERROR_RETURN; | |
168 | } | |
169 | ||
f5d25c2b | 170 | if ((dup_accept_socket = dup(accept_socket)) < 0) |
059ec3d9 PH |
171 | { |
172 | never_error(US"daemon: couldn't dup socket descriptor", | |
173 | US"Connection setup failed", errno); | |
174 | goto ERROR_RETURN; | |
175 | } | |
176 | ||
f5d25c2b | 177 | if (!(smtp_in = fdopen(dup_accept_socket, "rb"))) |
059ec3d9 PH |
178 | { |
179 | never_error(US"daemon: fdopen() for smtp_in failed", | |
180 | US"Connection setup failed", errno); | |
181 | goto ERROR_RETURN; | |
182 | } | |
183 | ||
520de300 PH |
184 | /* Get the data for the local interface address. Panic for most errors, but |
185 | "connection reset by peer" just means the connection went away. */ | |
059ec3d9 PH |
186 | |
187 | if (getsockname(accept_socket, (struct sockaddr *)(&interface_sockaddr), | |
188 | &ifsize) < 0) | |
189 | { | |
520de300 PH |
190 | log_write(0, LOG_MAIN | ((errno == ECONNRESET)? 0 : LOG_PANIC), |
191 | "getsockname() failed: %s", strerror(errno)); | |
059ec3d9 PH |
192 | smtp_printf("421 Local problem: getsockname() failed; please try again later\r\n"); |
193 | goto ERROR_RETURN; | |
194 | } | |
195 | ||
196 | interface_address = host_ntoa(-1, &interface_sockaddr, NULL, &interface_port); | |
197 | DEBUG(D_interface) debug_printf("interface address=%s port=%d\n", | |
198 | interface_address, interface_port); | |
199 | ||
200 | /* Build a string identifying the remote host and, if requested, the port and | |
201 | the local interface data. This is for logging; at the end of this function the | |
202 | memory is reclaimed. */ | |
203 | ||
204 | whofrom = string_append(whofrom, &wfsize, &wfptr, 3, "[", sender_host_address, "]"); | |
205 | ||
6c6d6e48 | 206 | if (LOGGING(incoming_port)) |
059ec3d9 PH |
207 | whofrom = string_append(whofrom, &wfsize, &wfptr, 2, ":", string_sprintf("%d", |
208 | sender_host_port)); | |
209 | ||
6c6d6e48 | 210 | if (LOGGING(incoming_interface)) |
059ec3d9 PH |
211 | whofrom = string_append(whofrom, &wfsize, &wfptr, 4, " I=[", |
212 | interface_address, "]:", string_sprintf("%d", interface_port)); | |
213 | ||
214 | whofrom[wfptr] = 0; /* Terminate the newly-built string */ | |
215 | ||
216 | /* Check maximum number of connections. We do not check for reserved | |
217 | connections or unacceptable hosts here. That is done in the subprocess because | |
218 | it might take some time. */ | |
219 | ||
220 | if (smtp_accept_max > 0 && smtp_accept_count >= smtp_accept_max) | |
221 | { | |
222 | DEBUG(D_any) debug_printf("rejecting SMTP connection: count=%d max=%d\n", | |
223 | smtp_accept_count, smtp_accept_max); | |
224 | smtp_printf("421 Too many concurrent SMTP connections; " | |
225 | "please try again later.\r\n"); | |
226 | log_write(L_connection_reject, | |
227 | LOG_MAIN, "Connection from %s refused: too many connections", | |
228 | whofrom); | |
229 | goto ERROR_RETURN; | |
230 | } | |
231 | ||
232 | /* If a load limit above which only reserved hosts are acceptable is defined, | |
233 | get the load average here, and if there are in fact no reserved hosts, do | |
234 | the test right away (saves a fork). If there are hosts, do the check in the | |
235 | subprocess because it might take time. */ | |
236 | ||
237 | if (smtp_load_reserve >= 0) | |
238 | { | |
8669f003 | 239 | load_average = OS_GETLOADAVG(); |
059ec3d9 PH |
240 | if (smtp_reserve_hosts == NULL && load_average > smtp_load_reserve) |
241 | { | |
242 | DEBUG(D_any) debug_printf("rejecting SMTP connection: load average = %.2f\n", | |
243 | (double)load_average/1000.0); | |
244 | smtp_printf("421 Too much load; please try again later.\r\n"); | |
245 | log_write(L_connection_reject, | |
246 | LOG_MAIN, "Connection from %s refused: load average = %.2f", | |
247 | whofrom, (double)load_average/1000.0); | |
248 | goto ERROR_RETURN; | |
249 | } | |
250 | } | |
251 | ||
252 | /* Check that one specific host (strictly, IP address) is not hogging | |
253 | resources. This is done here to prevent a denial of service attack by someone | |
254 | forcing you to fork lots of times before denying service. The value of | |
255 | smtp_accept_max_per_host is a string which is expanded. This makes it possible | |
256 | to provide host-specific limits according to $sender_host address, but because | |
257 | this is in the daemon mainline, only fast expansions (such as inline address | |
258 | checks) should be used. The documentation is full of warnings. */ | |
259 | ||
260 | if (smtp_accept_max_per_host != NULL) | |
261 | { | |
262 | uschar *expanded = expand_string(smtp_accept_max_per_host); | |
263 | if (expanded == NULL) | |
264 | { | |
265 | if (!expand_string_forcedfail) | |
266 | log_write(0, LOG_MAIN|LOG_PANIC, "expansion of smtp_accept_max_per_host " | |
267 | "failed for %s: %s", whofrom, expand_string_message); | |
268 | } | |
269 | /* For speed, interpret a decimal number inline here */ | |
270 | else | |
271 | { | |
272 | uschar *s = expanded; | |
273 | while (isdigit(*s)) | |
274 | max_for_this_host = max_for_this_host * 10 + *s++ - '0'; | |
275 | if (*s != 0) | |
276 | log_write(0, LOG_MAIN|LOG_PANIC, "expansion of smtp_accept_max_per_host " | |
277 | "for %s contains non-digit: %s", whofrom, expanded); | |
278 | } | |
279 | } | |
280 | ||
281 | /* If we have fewer connections than max_for_this_host, we can skip the tedious | |
282 | per host_address checks. Note that at this stage smtp_accept_count contains the | |
283 | count of *other* connections, not including this one. */ | |
284 | ||
285 | if ((max_for_this_host > 0) && | |
286 | (smtp_accept_count >= max_for_this_host)) | |
287 | { | |
288 | int i; | |
289 | int host_accept_count = 0; | |
290 | int other_host_count = 0; /* keep a count of non matches to optimise */ | |
291 | ||
292 | for (i = 0; i < smtp_accept_max; ++i) | |
059ec3d9 PH |
293 | if (smtp_slots[i].host_address != NULL) |
294 | { | |
295 | if (Ustrcmp(sender_host_address, smtp_slots[i].host_address) == 0) | |
296 | host_accept_count++; | |
297 | else | |
298 | other_host_count++; | |
299 | ||
300 | /* Testing all these strings is expensive - see if we can drop out | |
301 | early, either by hitting the target, or finding there are not enough | |
302 | connections left to make the target. */ | |
303 | ||
304 | if ((host_accept_count >= max_for_this_host) || | |
305 | ((smtp_accept_count - other_host_count) < max_for_this_host)) | |
306 | break; | |
307 | } | |
059ec3d9 PH |
308 | |
309 | if (host_accept_count >= max_for_this_host) | |
310 | { | |
311 | DEBUG(D_any) debug_printf("rejecting SMTP connection: too many from this " | |
312 | "IP address: count=%d max=%d\n", | |
313 | host_accept_count, max_for_this_host); | |
314 | smtp_printf("421 Too many concurrent SMTP connections " | |
315 | "from this IP address; please try again later.\r\n"); | |
316 | log_write(L_connection_reject, | |
317 | LOG_MAIN, "Connection from %s refused: too many connections " | |
318 | "from that IP address", whofrom); | |
319 | goto ERROR_RETURN; | |
320 | } | |
321 | } | |
322 | ||
323 | /* OK, the connection count checks have been passed. Before we can fork the | |
324 | accepting process, we must first log the connection if requested. This logging | |
325 | used to happen in the subprocess, but doing that means that the value of | |
326 | smtp_accept_count can be out of step by the time it is logged. So we have to do | |
327 | the logging here and accept the performance cost. Note that smtp_accept_count | |
328 | hasn't yet been incremented to take account of this connection. | |
329 | ||
330 | In order to minimize the cost (because this is going to happen for every | |
331 | connection), do a preliminary selector test here. This saves ploughing through | |
332 | the generalized logging code each time when the selector is false. If the | |
333 | selector is set, check whether the host is on the list for logging. If not, | |
334 | arrange to unset the selector in the subprocess. */ | |
335 | ||
6c6d6e48 | 336 | if (LOGGING(smtp_connection)) |
059ec3d9 PH |
337 | { |
338 | uschar *list = hosts_connection_nolog; | |
ce325893 | 339 | memset(sender_host_cache, 0, sizeof(sender_host_cache)); |
059ec3d9 | 340 | if (list != NULL && verify_check_host(&list) == OK) |
6c6d6e48 | 341 | save_log_selector &= ~L_smtp_connection; |
059ec3d9 PH |
342 | else |
343 | log_write(L_smtp_connection, LOG_MAIN, "SMTP connection from %s " | |
344 | "(TCP/IP connection count = %d)", whofrom, smtp_accept_count + 1); | |
345 | } | |
346 | ||
347 | /* Now we can fork the accepting process; do a lookup tidy, just in case any | |
348 | expansion above did a lookup. */ | |
349 | ||
350 | search_tidyup(); | |
351 | pid = fork(); | |
352 | ||
353 | /* Handle the child process */ | |
354 | ||
355 | if (pid == 0) | |
356 | { | |
357 | int i; | |
358 | int queue_only_reason = 0; | |
359 | int old_pool = store_pool; | |
8e669ac1 | 360 | int save_debug_selector = debug_selector; |
059ec3d9 | 361 | BOOL local_queue_only; |
8669f003 | 362 | BOOL session_local_queue_only; |
059ec3d9 PH |
363 | #ifdef SA_NOCLDWAIT |
364 | struct sigaction act; | |
365 | #endif | |
366 | ||
b01dd148 PH |
367 | smtp_accept_count++; /* So that it includes this process */ |
368 | ||
059ec3d9 PH |
369 | /* May have been modified for the subprocess */ |
370 | ||
6c6d6e48 | 371 | *log_selector = save_log_selector; |
059ec3d9 PH |
372 | |
373 | /* Get the local interface address into permanent store */ | |
374 | ||
375 | store_pool = POOL_PERM; | |
376 | interface_address = string_copy(interface_address); | |
377 | store_pool = old_pool; | |
378 | ||
379 | /* Check for a tls-on-connect port */ | |
380 | ||
817d9f57 | 381 | if (host_is_tls_on_connect_port(interface_port)) tls_in.on_connect = TRUE; |
059ec3d9 PH |
382 | |
383 | /* Expand smtp_active_hostname if required. We do not do this any earlier, | |
384 | because it may depend on the local interface address (indeed, that is most | |
385 | likely what it depends on.) */ | |
386 | ||
387 | smtp_active_hostname = primary_hostname; | |
ad7fc6eb | 388 | if (raw_active_hostname) |
059ec3d9 | 389 | { |
ad7fc6eb JH |
390 | uschar * nah = expand_string(raw_active_hostname); |
391 | if (!nah) | |
059ec3d9 PH |
392 | { |
393 | if (!expand_string_forcedfail) | |
394 | { | |
395 | log_write(0, LOG_MAIN|LOG_PANIC, "failed to expand \"%s\" " | |
396 | "(smtp_active_hostname): %s", raw_active_hostname, | |
397 | expand_string_message); | |
398 | smtp_printf("421 Local configuration error; " | |
399 | "please try again later.\r\n"); | |
400 | mac_smtp_fflush(); | |
401 | search_tidyup(); | |
402 | _exit(EXIT_FAILURE); | |
403 | } | |
404 | } | |
ad7fc6eb | 405 | else if (*nah) smtp_active_hostname = nah; |
059ec3d9 PH |
406 | } |
407 | ||
408 | /* Initialize the queueing flags */ | |
409 | ||
410 | queue_check_only(); | |
8669f003 | 411 | session_local_queue_only = queue_only; |
059ec3d9 PH |
412 | |
413 | /* Close the listening sockets, and set the SIGCHLD handler to SIG_IGN. | |
414 | We also attempt to set things up so that children are automatically reaped, | |
415 | but just in case this isn't available, there's a paranoid waitpid() in the | |
416 | loop too (except for systems where we are sure it isn't needed). See the more | |
417 | extensive comment before the reception loop in exim.c for a fuller | |
418 | explanation of this logic. */ | |
419 | ||
f1e894f3 | 420 | for (i = 0; i < listen_socket_count; i++) (void)close(listen_sockets[i]); |
059ec3d9 | 421 | |
fa32850b DW |
422 | /* Set FD_CLOEXEC on the SMTP socket. We don't want any rogue child processes |
423 | to be able to communicate with them, under any circumstances. */ | |
424 | (void)fcntl(accept_socket, F_SETFD, | |
425 | fcntl(accept_socket, F_GETFD) | FD_CLOEXEC); | |
426 | (void)fcntl(dup_accept_socket, F_SETFD, | |
427 | fcntl(dup_accept_socket, F_GETFD) | FD_CLOEXEC); | |
428 | ||
059ec3d9 PH |
429 | #ifdef SA_NOCLDWAIT |
430 | act.sa_handler = SIG_IGN; | |
431 | sigemptyset(&(act.sa_mask)); | |
432 | act.sa_flags = SA_NOCLDWAIT; | |
433 | sigaction(SIGCHLD, &act, NULL); | |
434 | #else | |
435 | signal(SIGCHLD, SIG_IGN); | |
436 | #endif | |
437 | ||
438 | /* Attempt to get an id from the sending machine via the RFC 1413 | |
439 | protocol. We do this in the sub-process in order not to hold up the | |
440 | main process if there is any delay. Then set up the fullhost information | |
8e669ac1 PH |
441 | in case there is no HELO/EHLO. |
442 | ||
443 | If debugging is enabled only for the daemon, we must turn if off while | |
444 | finding the id, but turn it on again afterwards so that information about the | |
3d235903 | 445 | incoming connection is output. */ |
8e669ac1 | 446 | |
3d235903 | 447 | if (debug_daemon) debug_selector = 0; |
059ec3d9 PH |
448 | verify_get_ident(IDENT_PORT); |
449 | host_build_sender_fullhost(); | |
8e669ac1 | 450 | debug_selector = save_debug_selector; |
059ec3d9 PH |
451 | |
452 | DEBUG(D_any) | |
453 | debug_printf("Process %d is handling incoming connection from %s\n", | |
454 | (int)getpid(), sender_fullhost); | |
455 | ||
3d235903 PH |
456 | /* Now disable debugging permanently if it's required only for the daemon |
457 | process. */ | |
458 | ||
459 | if (debug_daemon) debug_selector = 0; | |
460 | ||
059ec3d9 | 461 | /* If there are too many child processes for immediate delivery, |
8669f003 | 462 | set the session_local_queue_only flag, which is initialized from the |
059ec3d9 | 463 | configured value and may therefore already be TRUE. Leave logging |
8669f003 PH |
464 | till later so it will have a message id attached. Note that there is no |
465 | possibility of re-calculating this per-message, because the value of | |
466 | smtp_accept_count does not change in this subprocess. */ | |
059ec3d9 | 467 | |
b01dd148 | 468 | if (smtp_accept_queue > 0 && smtp_accept_count > smtp_accept_queue) |
059ec3d9 | 469 | { |
8669f003 | 470 | session_local_queue_only = TRUE; |
059ec3d9 PH |
471 | queue_only_reason = 1; |
472 | } | |
473 | ||
474 | /* Handle the start of the SMTP session, then loop, accepting incoming | |
475 | messages from the SMTP connection. The end will come at the QUIT command, | |
476 | when smtp_setup_msg() returns 0. A break in the connection causes the | |
24796b8d PH |
477 | process to die (see accept.c). |
478 | ||
479 | NOTE: We do *not* call smtp_log_no_mail() if smtp_start_session() fails, | |
480 | because a log line has already been written for all its failure exists | |
481 | (usually "connection refused: <reason>") and writing another one is | |
482 | unnecessary clutter. */ | |
059ec3d9 PH |
483 | |
484 | if (!smtp_start_session()) | |
485 | { | |
486 | mac_smtp_fflush(); | |
487 | search_tidyup(); | |
488 | _exit(EXIT_SUCCESS); | |
489 | } | |
490 | ||
491 | for (;;) | |
492 | { | |
493 | int rc; | |
494 | message_id[0] = 0; /* Clear out any previous message_id */ | |
495 | reset_point = store_get(0); /* Save current store high water point */ | |
496 | ||
497 | DEBUG(D_any) | |
498 | debug_printf("Process %d is ready for new message\n", (int)getpid()); | |
499 | ||
500 | /* Smtp_setup_msg() returns 0 on QUIT or if the call is from an | |
501 | unacceptable host or if an ACL "drop" command was triggered, -1 on | |
502 | connection lost, and +1 on validly reaching DATA. Receive_msg() almost | |
503 | always returns TRUE when smtp_input is true; just retry if no message was | |
504 | accepted (can happen for invalid message parameters). However, it can yield | |
505 | FALSE if the connection was forcibly dropped by the DATA ACL. */ | |
506 | ||
507 | if ((rc = smtp_setup_msg()) > 0) | |
508 | { | |
509 | BOOL ok = receive_msg(FALSE); | |
510 | search_tidyup(); /* Close cached databases */ | |
511 | if (!ok) /* Connection was dropped */ | |
512 | { | |
513 | mac_smtp_fflush(); | |
b4ed4da0 | 514 | smtp_log_no_mail(); /* Log no mail if configured */ |
059ec3d9 PH |
515 | _exit(EXIT_SUCCESS); |
516 | } | |
517 | if (message_id[0] == 0) continue; /* No message was accepted */ | |
518 | } | |
519 | else | |
520 | { | |
ad7fc6eb JH |
521 | if (smtp_out) |
522 | { | |
5ddc9771 | 523 | int i, fd = fileno(smtp_in); |
ad7fc6eb JH |
524 | uschar buf[128]; |
525 | ||
526 | mac_smtp_fflush(); | |
527 | /* drain socket, for clean TCP FINs */ | |
5ddc9771 JH |
528 | if (fcntl(fd, F_SETFL, O_NONBLOCK) == 0) |
529 | for(i = 16; read(fd, buf, sizeof(buf)) > 0 && i > 0; ) i--; | |
ad7fc6eb | 530 | } |
059ec3d9 | 531 | search_tidyup(); |
b4ed4da0 | 532 | smtp_log_no_mail(); /* Log no mail if configured */ |
60d10ce7 JH |
533 | |
534 | /*XXX should we pause briefly, hoping that the client will be the | |
535 | active TCP closer hence get the TCP_WAIT endpoint? */ | |
536 | DEBUG(D_receive) debug_printf("SMTP>>(close on process exit)\n"); | |
f5d25c2b | 537 | _exit(rc ? EXIT_FAILURE : EXIT_SUCCESS); |
059ec3d9 PH |
538 | } |
539 | ||
540 | /* Show the recipients when debugging */ | |
541 | ||
542 | DEBUG(D_receive) | |
543 | { | |
544 | int i; | |
545 | if (sender_address != NULL) | |
546 | debug_printf("Sender: %s\n", sender_address); | |
547 | if (recipients_list != NULL) | |
548 | { | |
549 | debug_printf("Recipients:\n"); | |
550 | for (i = 0; i < recipients_count; i++) | |
551 | debug_printf(" %s\n", recipients_list[i].address); | |
552 | } | |
553 | } | |
554 | ||
555 | /* A message has been accepted. Clean up any previous delivery processes | |
556 | that have completed and are defunct, on systems where they don't go away | |
557 | by themselves (see comments when setting SIG_IGN above). On such systems | |
558 | (if any) these delivery processes hang around after termination until | |
559 | the next message is received. */ | |
560 | ||
561 | #ifndef SIG_IGN_WORKS | |
562 | while (waitpid(-1, NULL, WNOHANG) > 0); | |
563 | #endif | |
564 | ||
565 | /* Reclaim up the store used in accepting this message */ | |
566 | ||
567 | store_reset(reset_point); | |
568 | ||
569 | /* If queue_only is set or if there are too many incoming connections in | |
8669f003 PH |
570 | existence, session_local_queue_only will be TRUE. If it is not, check |
571 | whether we have received too many messages in this session for immediate | |
572 | delivery. */ | |
573 | ||
574 | if (!session_local_queue_only && | |
575 | smtp_accept_queue_per_connection > 0 && | |
576 | receive_messagecount > smtp_accept_queue_per_connection) | |
059ec3d9 | 577 | { |
8669f003 PH |
578 | session_local_queue_only = TRUE; |
579 | queue_only_reason = 2; | |
580 | } | |
581 | ||
582 | /* Initialize local_queue_only from session_local_queue_only. If it is not | |
583 | true, and queue_only_load is set, check that the load average is below it. | |
584 | If local_queue_only is set by this means, we also set if for the session if | |
585 | queue_only_load_latch is true (the default). This means that, once set, | |
586 | local_queue_only remains set for any subsequent messages on the same SMTP | |
587 | connection. This is a deliberate choice; even though the load average may | |
588 | fall, it doesn't seem right to deliver later messages on the same call when | |
589 | not delivering earlier ones. However, the are special circumstances such as | |
590 | very long-lived connections from scanning appliances where this is not the | |
591 | best strategy. In such cases, queue_only_load_latch should be set false. */ | |
592 | ||
f5d25c2b JH |
593 | if ( !(local_queue_only = session_local_queue_only) |
594 | && queue_only_load >= 0 | |
595 | && (local_queue_only = (load_average = OS_GETLOADAVG()) > queue_only_load) | |
596 | ) | |
8669f003 | 597 | { |
f5d25c2b JH |
598 | queue_only_reason = 3; |
599 | if (queue_only_load_latch) session_local_queue_only = TRUE; | |
059ec3d9 PH |
600 | } |
601 | ||
602 | /* Log the queueing here, when it will get a message id attached, but | |
603 | not if queue_only is set (case 0). */ | |
604 | ||
605 | if (local_queue_only) switch(queue_only_reason) | |
606 | { | |
f5d25c2b | 607 | case 1: log_write(L_delay_delivery, |
059ec3d9 PH |
608 | LOG_MAIN, "no immediate delivery: too many connections " |
609 | "(%d, max %d)", smtp_accept_count, smtp_accept_queue); | |
f5d25c2b | 610 | break; |
059ec3d9 | 611 | |
f5d25c2b | 612 | case 2: log_write(L_delay_delivery, |
059ec3d9 PH |
613 | LOG_MAIN, "no immediate delivery: more than %d messages " |
614 | "received in one connection", smtp_accept_queue_per_connection); | |
f5d25c2b | 615 | break; |
059ec3d9 | 616 | |
f5d25c2b | 617 | case 3: log_write(L_delay_delivery, |
059ec3d9 PH |
618 | LOG_MAIN, "no immediate delivery: load average %.2f", |
619 | (double)load_average/1000.0); | |
f5d25c2b | 620 | break; |
059ec3d9 PH |
621 | } |
622 | ||
623 | /* If a delivery attempt is required, spin off a new process to handle it. | |
624 | If we are not root, we have to re-exec exim unless deliveries are being | |
625 | done unprivileged. */ | |
626 | ||
627 | else if (!queue_only_policy && !deliver_freeze) | |
628 | { | |
629 | pid_t dpid; | |
630 | ||
631 | /* Before forking, ensure that the C output buffer is flushed. Otherwise | |
632 | anything that it in it will get duplicated, leading to duplicate copies | |
633 | of the pending output. */ | |
634 | ||
635 | mac_smtp_fflush(); | |
636 | ||
637 | if ((dpid = fork()) == 0) | |
638 | { | |
f1e894f3 PH |
639 | (void)fclose(smtp_in); |
640 | (void)fclose(smtp_out); | |
059ec3d9 PH |
641 | |
642 | /* Don't ever molest the parent's SSL connection, but do clean up | |
643 | the data structures if necessary. */ | |
644 | ||
645 | #ifdef SUPPORT_TLS | |
a400eccf | 646 | tls_close(TRUE, FALSE); |
059ec3d9 PH |
647 | #endif |
648 | ||
649 | /* Reset SIGHUP and SIGCHLD in the child in both cases. */ | |
650 | ||
651 | signal(SIGHUP, SIG_DFL); | |
652 | signal(SIGCHLD, SIG_DFL); | |
653 | ||
654 | if (geteuid() != root_uid && !deliver_drop_privilege) | |
655 | { | |
656 | signal(SIGALRM, SIG_DFL); | |
e37f8a84 JH |
657 | (void)child_exec_exim(CEE_EXEC_PANIC, FALSE, NULL, FALSE, |
658 | 2, US"-Mc", message_id); | |
059ec3d9 PH |
659 | /* Control does not return here. */ |
660 | } | |
661 | ||
662 | /* No need to re-exec; SIGALRM remains set to the default handler */ | |
663 | ||
664 | (void)deliver_message(message_id, FALSE, FALSE); | |
665 | search_tidyup(); | |
666 | _exit(EXIT_SUCCESS); | |
667 | } | |
668 | ||
669 | if (dpid > 0) | |
670 | { | |
671 | DEBUG(D_any) debug_printf("forked delivery process %d\n", (int)dpid); | |
672 | } | |
673 | else | |
059ec3d9 PH |
674 | log_write(0, LOG_MAIN|LOG_PANIC, "daemon: delivery process fork " |
675 | "failed: %s", strerror(errno)); | |
059ec3d9 PH |
676 | } |
677 | } | |
678 | } | |
679 | ||
680 | ||
681 | /* Carrying on in the parent daemon process... Can't do much if the fork | |
682 | failed. Otherwise, keep count of the number of accepting processes and | |
683 | remember the pid for ticking off when the child completes. */ | |
684 | ||
685 | if (pid < 0) | |
059ec3d9 | 686 | never_error(US"daemon: accept process fork failed", US"Fork failed", errno); |
059ec3d9 PH |
687 | else |
688 | { | |
689 | int i; | |
690 | for (i = 0; i < smtp_accept_max; ++i) | |
059ec3d9 PH |
691 | if (smtp_slots[i].pid <= 0) |
692 | { | |
693 | smtp_slots[i].pid = pid; | |
694 | if (smtp_accept_max_per_host != NULL) | |
695 | smtp_slots[i].host_address = string_copy_malloc(sender_host_address); | |
696 | smtp_accept_count++; | |
697 | break; | |
698 | } | |
059ec3d9 PH |
699 | DEBUG(D_any) debug_printf("%d SMTP accept process%s running\n", |
700 | smtp_accept_count, (smtp_accept_count == 1)? "" : "es"); | |
701 | } | |
702 | ||
703 | /* Get here via goto in error cases */ | |
704 | ||
705 | ERROR_RETURN: | |
706 | ||
707 | /* Close the streams associated with the socket which will also close the | |
708 | socket fds in this process. We can't do anything if fclose() fails, but | |
709 | logging brings it to someone's attention. However, "connection reset by peer" | |
1f872c80 PH |
710 | isn't really a problem, so skip that one. On Solaris, a dropped connection can |
711 | manifest itself as a broken pipe, so drop that one too. If the streams don't | |
712 | exist, something went wrong while setting things up. Make sure the socket | |
713 | descriptors are closed, in order to drop the connection. */ | |
059ec3d9 | 714 | |
f5d25c2b | 715 | if (smtp_out) |
059ec3d9 | 716 | { |
1f872c80 | 717 | if (fclose(smtp_out) != 0 && errno != ECONNRESET && errno != EPIPE) |
059ec3d9 PH |
718 | log_write(0, LOG_MAIN|LOG_PANIC, "daemon: fclose(smtp_out) failed: %s", |
719 | strerror(errno)); | |
720 | smtp_out = NULL; | |
721 | } | |
f1e894f3 | 722 | else (void)close(accept_socket); |
059ec3d9 | 723 | |
f5d25c2b | 724 | if (smtp_in) |
059ec3d9 | 725 | { |
1f872c80 | 726 | if (fclose(smtp_in) != 0 && errno != ECONNRESET && errno != EPIPE) |
059ec3d9 PH |
727 | log_write(0, LOG_MAIN|LOG_PANIC, "daemon: fclose(smtp_in) failed: %s", |
728 | strerror(errno)); | |
729 | smtp_in = NULL; | |
730 | } | |
f1e894f3 | 731 | else (void)close(dup_accept_socket); |
059ec3d9 PH |
732 | |
733 | /* Release any store used in this process, including the store used for holding | |
734 | the incoming host address and an expanded active_hostname. */ | |
735 | ||
c8899c20 | 736 | log_close_all(); |
059ec3d9 PH |
737 | store_reset(reset_point); |
738 | sender_host_address = NULL; | |
739 | } | |
740 | ||
741 | ||
742 | ||
743 | ||
744 | /************************************************* | |
745 | * Check wildcard listen special cases * | |
746 | *************************************************/ | |
747 | ||
748 | /* This function is used when binding and listening on lists of addresses and | |
749 | ports. It tests for special cases of wildcard listening, when IPv4 and IPv6 | |
750 | sockets may interact in different ways in different operating systems. It is | |
751 | passed an error number, the list of listening addresses, and the current | |
752 | address. Two checks are available: for a previous wildcard IPv6 address, or for | |
753 | a following wildcard IPv4 address, in both cases on the same port. | |
754 | ||
755 | In practice, pairs of wildcard addresses should be adjacent in the address list | |
756 | because they are sorted that way below. | |
757 | ||
758 | Arguments: | |
759 | eno the error number | |
760 | addresses the list of addresses | |
761 | ipa the current IP address | |
762 | back if TRUE, check for previous wildcard IPv6 address | |
763 | if FALSE, check for a following wildcard IPv4 address | |
764 | ||
765 | Returns: TRUE or FALSE | |
766 | */ | |
767 | ||
768 | static BOOL | |
769 | check_special_case(int eno, ip_address_item *addresses, ip_address_item *ipa, | |
770 | BOOL back) | |
771 | { | |
772 | ip_address_item *ipa2; | |
773 | ||
774 | /* For the "back" case, if the failure was "address in use" for a wildcard IPv4 | |
775 | address, seek a previous IPv6 wildcard address on the same port. As it is | |
776 | previous, it must have been successfully bound and be listening. Flag it as a | |
777 | "6 including 4" listener. */ | |
778 | ||
779 | if (back) | |
780 | { | |
781 | if (eno != EADDRINUSE || ipa->address[0] != 0) return FALSE; | |
782 | for (ipa2 = addresses; ipa2 != ipa; ipa2 = ipa2->next) | |
783 | { | |
784 | if (ipa2->address[1] == 0 && ipa2->port == ipa->port) | |
785 | { | |
786 | ipa2->v6_include_v4 = TRUE; | |
787 | return TRUE; | |
788 | } | |
789 | } | |
790 | } | |
791 | ||
792 | /* For the "forward" case, if the current address is a wildcard IPv6 address, | |
793 | we seek a following wildcard IPv4 address on the same port. */ | |
794 | ||
795 | else | |
796 | { | |
797 | if (ipa->address[0] != ':' || ipa->address[1] != 0) return FALSE; | |
798 | for (ipa2 = ipa->next; ipa2 != NULL; ipa2 = ipa2->next) | |
799 | if (ipa2->address[0] == 0 && ipa->port == ipa2->port) return TRUE; | |
800 | } | |
801 | ||
802 | return FALSE; | |
803 | } | |
804 | ||
805 | ||
806 | ||
807 | ||
bb6e88ff PH |
808 | /************************************************* |
809 | * Handle terminating subprocesses * | |
810 | *************************************************/ | |
811 | ||
812 | /* Handle the termination of child processes. Theoretically, this need be done | |
813 | only when sigchld_seen is TRUE, but rumour has it that some systems lose | |
814 | SIGCHLD signals at busy times, so to be on the safe side, this function is | |
815 | called each time round. It shouldn't be too expensive. | |
816 | ||
817 | Arguments: none | |
818 | Returns: nothing | |
819 | */ | |
820 | ||
821 | static void | |
822 | handle_ending_processes(void) | |
823 | { | |
824 | int status; | |
825 | pid_t pid; | |
826 | ||
827 | while ((pid = waitpid(-1, &status, WNOHANG)) > 0) | |
828 | { | |
829 | int i; | |
7be682ca PP |
830 | DEBUG(D_any) |
831 | { | |
832 | debug_printf("child %d ended: status=0x%x\n", (int)pid, status); | |
833 | #ifdef WCOREDUMP | |
834 | if (WIFEXITED(status)) | |
835 | debug_printf(" normal exit, %d\n", WEXITSTATUS(status)); | |
836 | else if (WIFSIGNALED(status)) | |
837 | debug_printf(" signal exit, signal %d%s\n", WTERMSIG(status), | |
838 | WCOREDUMP(status) ? " (core dumped)" : ""); | |
839 | #endif | |
840 | } | |
bb6e88ff | 841 | |
8e669ac1 | 842 | /* If it's a listening daemon for which we are keeping track of individual |
bb6e88ff PH |
843 | subprocesses, deal with an accepting process that has terminated. */ |
844 | ||
845 | if (smtp_slots != NULL) | |
846 | { | |
847 | for (i = 0; i < smtp_accept_max; i++) | |
848 | { | |
849 | if (smtp_slots[i].pid == pid) | |
850 | { | |
851 | if (smtp_slots[i].host_address != NULL) | |
852 | store_free(smtp_slots[i].host_address); | |
853 | smtp_slots[i] = empty_smtp_slot; | |
854 | if (--smtp_accept_count < 0) smtp_accept_count = 0; | |
855 | DEBUG(D_any) debug_printf("%d SMTP accept process%s now running\n", | |
856 | smtp_accept_count, (smtp_accept_count == 1)? "" : "es"); | |
857 | break; | |
858 | } | |
859 | } | |
860 | if (i < smtp_accept_max) continue; /* Found an accepting process */ | |
861 | } | |
862 | ||
863 | /* If it wasn't an accepting process, see if it was a queue-runner | |
864 | process that we are tracking. */ | |
865 | ||
0cd5fd23 | 866 | if (queue_pid_slots) |
bb6e88ff | 867 | { |
4dc2379a | 868 | int max = atoi(CS expand_string(queue_run_max)); |
0cd5fd23 | 869 | for (i = 0; i < max; i++) |
bb6e88ff PH |
870 | if (queue_pid_slots[i] == pid) |
871 | { | |
872 | queue_pid_slots[i] = 0; | |
873 | if (--queue_run_count < 0) queue_run_count = 0; | |
874 | DEBUG(D_any) debug_printf("%d queue-runner process%s now running\n", | |
875 | queue_run_count, (queue_run_count == 1)? "" : "es"); | |
876 | break; | |
877 | } | |
bb6e88ff PH |
878 | } |
879 | } | |
880 | } | |
881 | ||
059ec3d9 PH |
882 | |
883 | ||
884 | /************************************************* | |
885 | * Exim Daemon Mainline * | |
886 | *************************************************/ | |
887 | ||
888 | /* The daemon can do two jobs, either of which is optional: | |
889 | ||
890 | (1) Listens for incoming SMTP calls and spawns off a sub-process to handle | |
891 | each one. This is requested by the -bd option, with -oX specifying the SMTP | |
892 | port on which to listen (for testing). | |
893 | ||
894 | (2) Spawns a queue-running process every so often. This is controlled by the | |
895 | -q option with a an interval time. (If no time is given, a single queue run | |
896 | is done from the main function, and control doesn't get here.) | |
897 | ||
898 | Root privilege is required in order to attach to port 25. Some systems require | |
899 | it when calling socket() rather than bind(). To cope with all cases, we run as | |
900 | root for both socket() and bind(). Some systems also require root in order to | |
901 | write to the pid file directory. This function must therefore be called as root | |
902 | if it is to work properly in all circumstances. Once the socket is bound and | |
903 | the pid file written, root privilege is given up if there is an exim uid. | |
904 | ||
905 | There are no arguments to this function, and it never returns. */ | |
906 | ||
907 | void | |
908 | daemon_go(void) | |
909 | { | |
ebeaf996 | 910 | struct passwd *pw; |
059ec3d9 PH |
911 | int *listen_sockets = NULL; |
912 | int listen_socket_count = 0; | |
913 | ip_address_item *addresses = NULL; | |
9ee44efb | 914 | time_t last_connection_time = (time_t)0; |
4dc2379a | 915 | int local_queue_run_max = atoi(CS expand_string(queue_run_max)); |
059ec3d9 PH |
916 | |
917 | /* If any debugging options are set, turn on the D_pid bit so that all | |
918 | debugging lines get the pid added. */ | |
919 | ||
920 | DEBUG(D_any|D_v) debug_selector |= D_pid; | |
921 | ||
9ee44efb PP |
922 | if (inetd_wait_mode) |
923 | { | |
9ee44efb | 924 | listen_socket_count = 1; |
96f5fe4c | 925 | listen_sockets = store_get(sizeof(int)); |
9ee44efb PP |
926 | (void) close(3); |
927 | if (dup2(0, 3) == -1) | |
9ee44efb PP |
928 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, |
929 | "failed to dup inetd socket safely away: %s", strerror(errno)); | |
d4ff61d1 | 930 | |
9ee44efb PP |
931 | listen_sockets[0] = 3; |
932 | (void) close(0); | |
933 | (void) close(1); | |
934 | (void) close(2); | |
935 | exim_nullstd(); | |
936 | ||
937 | if (debug_file == stderr) | |
938 | { | |
939 | /* need a call to log_write before call to open debug_file, so that | |
940 | log.c:file_path has been initialised. This is unfortunate. */ | |
941 | log_write(0, LOG_MAIN, "debugging Exim in inetd wait mode starting"); | |
942 | ||
943 | fclose(debug_file); | |
944 | debug_file = NULL; | |
945 | exim_nullstd(); /* re-open fd2 after we just closed it again */ | |
946 | debug_logging_activate(US"-wait", NULL); | |
947 | } | |
948 | ||
949 | DEBUG(D_any) debug_printf("running in inetd wait mode\n"); | |
950 | ||
951 | /* As per below, when creating sockets ourselves, we handle tcp_nodelay for | |
952 | our own buffering; we assume though that inetd set the socket REUSEADDR. */ | |
953 | ||
d4ff61d1 JH |
954 | if (tcp_nodelay) |
955 | if (setsockopt(3, IPPROTO_TCP, TCP_NODELAY, US &on, sizeof(on))) | |
956 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "failed to set socket NODELAY: %s", | |
957 | strerror(errno)); | |
9ee44efb PP |
958 | } |
959 | ||
960 | ||
961 | if (inetd_wait_mode || daemon_listen) | |
962 | { | |
963 | /* If any option requiring a load average to be available during the | |
964 | reception of a message is set, call os_getloadavg() while we are root | |
965 | for those OS for which this is necessary the first time it is called (in | |
966 | order to perform an "open" on the kernel memory file). */ | |
967 | ||
968 | #ifdef LOAD_AVG_NEEDS_ROOT | |
969 | if (queue_only_load >= 0 || smtp_load_reserve >= 0 || | |
970 | (deliver_queue_load_max >= 0 && deliver_drop_privilege)) | |
971 | (void)os_getloadavg(); | |
972 | #endif | |
973 | } | |
974 | ||
059ec3d9 PH |
975 | |
976 | /* Do the preparation for setting up a listener on one or more interfaces, and | |
977 | possible on various ports. This is controlled by the combination of | |
978 | local_interfaces (which can set IP addresses and ports) and daemon_smtp_port | |
979 | (which is a list of default ports to use for those items in local_interfaces | |
980 | that do not specify a port). The -oX command line option can be used to | |
981 | override one or both of these options. | |
982 | ||
983 | If local_interfaces is not set, the default is to listen on all interfaces. | |
984 | When it is set, it can include "all IPvx interfaces" as an item. This is useful | |
985 | when different ports are in use. | |
986 | ||
987 | It turns out that listening on all interfaces is messy in an IPv6 world, | |
988 | because several different implementation approaches have been taken. This code | |
989 | is now supposed to work with all of them. The point of difference is whether an | |
990 | IPv6 socket that is listening on all interfaces will receive incoming IPv4 | |
991 | calls or not. We also have to cope with the case when IPv6 libraries exist, but | |
992 | there is no IPv6 support in the kernel. | |
993 | ||
994 | . On Solaris, an IPv6 socket will accept IPv4 calls, and give them as mapped | |
995 | addresses. However, if an IPv4 socket is also listening on all interfaces, | |
996 | calls are directed to the appropriate socket. | |
997 | ||
998 | . On (some versions of) Linux, an IPv6 socket will accept IPv4 calls, and | |
999 | give them as mapped addresses, but an attempt also to listen on an IPv4 | |
1000 | socket on all interfaces causes an error. | |
1001 | ||
1002 | . On OpenBSD, an IPv6 socket will not accept IPv4 calls. You have to set up | |
1003 | two sockets if you want to accept both kinds of call. | |
1004 | ||
1005 | . FreeBSD is like OpenBSD, but it has the IPV6_V6ONLY socket option, which | |
1006 | can be turned off, to make it behave like the versions of Linux described | |
1007 | above. | |
1008 | ||
1009 | . I heard a report that the USAGI IPv6 stack for Linux has implemented | |
1010 | IPV6_V6ONLY. | |
1011 | ||
1012 | So, what we do when IPv6 is supported is as follows: | |
1013 | ||
1014 | (1) After it is set up, the list of interfaces is scanned for wildcard | |
1015 | addresses. If an IPv6 and an IPv4 wildcard are both found for the same | |
1016 | port, the list is re-arranged so that they are together, with the IPv6 | |
1017 | wildcard first. | |
1018 | ||
1019 | (2) If the creation of a wildcard IPv6 socket fails, we just log the error and | |
1020 | carry on if an IPv4 wildcard socket for the same port follows later in the | |
1021 | list. This allows Exim to carry on in the case when the kernel has no IPv6 | |
1022 | support. | |
1023 | ||
1024 | (3) Having created an IPv6 wildcard socket, we try to set IPV6_V6ONLY if that | |
1025 | option is defined. However, if setting fails, carry on regardless (but log | |
1026 | the incident). | |
1027 | ||
1028 | (4) If binding or listening on an IPv6 wildcard socket fails, it is a serious | |
1029 | error. | |
1030 | ||
1031 | (5) If binding or listening on an IPv4 wildcard socket fails with the error | |
1032 | EADDRINUSE, and a previous interface was an IPv6 wildcard for the same | |
1033 | port (which must have succeeded or we wouldn't have got this far), we | |
1034 | assume we are in the situation where just a single socket is permitted, | |
1035 | and ignore the error. | |
1036 | ||
1037 | Phew! | |
1038 | ||
1039 | The preparation code decodes options and sets up the relevant data. We do this | |
1040 | first, so that we can return non-zero if there are any syntax errors, and also | |
1041 | write to stderr. */ | |
1042 | ||
602e0254 | 1043 | if (daemon_listen && !inetd_wait_mode) |
059ec3d9 PH |
1044 | { |
1045 | int *default_smtp_port; | |
1046 | int sep; | |
1047 | int pct = 0; | |
1048 | uschar *s; | |
55414b25 | 1049 | const uschar * list; |
059ec3d9 PH |
1050 | uschar *local_iface_source = US"local_interfaces"; |
1051 | ip_address_item *ipa; | |
1052 | ip_address_item **pipa; | |
1053 | ||
059ec3d9 PH |
1054 | /* If -oX was used, disable the writing of a pid file unless -oP was |
1055 | explicitly used to force it. Then scan the string given to -oX. Any items | |
1056 | that contain neither a dot nor a colon are used to override daemon_smtp_port. | |
1057 | Any other items are used to override local_interfaces. */ | |
1058 | ||
1059 | if (override_local_interfaces != NULL) | |
1060 | { | |
1061 | uschar *new_smtp_port = NULL; | |
1062 | uschar *new_local_interfaces = NULL; | |
1063 | int portsize = 0; | |
1064 | int portptr = 0; | |
1065 | int ifacesize = 0; | |
1066 | int ifaceptr = 0; | |
1067 | ||
1068 | if (override_pid_file_path == NULL) write_pid = FALSE; | |
1069 | ||
1070 | list = override_local_interfaces; | |
1071 | sep = 0; | |
55414b25 | 1072 | while ((s = string_nextinlist(&list, &sep, big_buffer, big_buffer_size))) |
059ec3d9 PH |
1073 | { |
1074 | uschar joinstr[4]; | |
1075 | uschar **ptr; | |
1076 | int *sizeptr; | |
1077 | int *ptrptr; | |
1078 | ||
1079 | if (Ustrpbrk(s, ".:") == NULL) | |
1080 | { | |
1081 | ptr = &new_smtp_port; | |
1082 | sizeptr = &portsize; | |
1083 | ptrptr = &portptr; | |
1084 | } | |
1085 | else | |
1086 | { | |
1087 | ptr = &new_local_interfaces; | |
1088 | sizeptr = &ifacesize; | |
1089 | ptrptr = &ifaceptr; | |
1090 | } | |
1091 | ||
1092 | if (*ptr == NULL) | |
1093 | { | |
1094 | joinstr[0] = sep; | |
1095 | joinstr[1] = ' '; | |
c2f669a4 | 1096 | *ptr = string_catn(*ptr, sizeptr, ptrptr, US"<", 1); |
059ec3d9 PH |
1097 | } |
1098 | ||
c2f669a4 JH |
1099 | *ptr = string_catn(*ptr, sizeptr, ptrptr, joinstr, 2); |
1100 | *ptr = string_cat (*ptr, sizeptr, ptrptr, s); | |
059ec3d9 PH |
1101 | } |
1102 | ||
1103 | if (new_smtp_port != NULL) | |
1104 | { | |
1105 | new_smtp_port[portptr] = 0; | |
1106 | daemon_smtp_port = new_smtp_port; | |
1107 | DEBUG(D_any) debug_printf("daemon_smtp_port overridden by -oX:\n %s\n", | |
1108 | daemon_smtp_port); | |
1109 | } | |
1110 | ||
1111 | if (new_local_interfaces != NULL) | |
1112 | { | |
1113 | new_local_interfaces[ifaceptr] = 0; | |
1114 | local_interfaces = new_local_interfaces; | |
1115 | local_iface_source = US"-oX data"; | |
1116 | DEBUG(D_any) debug_printf("local_interfaces overridden by -oX:\n %s\n", | |
1117 | local_interfaces); | |
1118 | } | |
1119 | } | |
1120 | ||
1121 | /* Create a list of default SMTP ports, to be used if local_interfaces | |
1122 | contains entries without explict ports. First count the number of ports, then | |
1123 | build a translated list in a vector. */ | |
1124 | ||
1125 | list = daemon_smtp_port; | |
1126 | sep = 0; | |
55414b25 | 1127 | while ((s = string_nextinlist(&list, &sep, big_buffer, big_buffer_size))) |
059ec3d9 PH |
1128 | pct++; |
1129 | default_smtp_port = store_get((pct+1) * sizeof(int)); | |
1130 | list = daemon_smtp_port; | |
1131 | sep = 0; | |
1132 | for (pct = 0; | |
55414b25 | 1133 | (s = string_nextinlist(&list, &sep, big_buffer, big_buffer_size)); |
059ec3d9 PH |
1134 | pct++) |
1135 | { | |
1136 | if (isdigit(*s)) | |
1137 | { | |
1138 | uschar *end; | |
1139 | default_smtp_port[pct] = Ustrtol(s, &end, 0); | |
1140 | if (end != s + Ustrlen(s)) | |
1141 | log_write(0, LOG_PANIC_DIE|LOG_CONFIG, "invalid SMTP port: %s", s); | |
1142 | } | |
1143 | else | |
1144 | { | |
1145 | struct servent *smtp_service = getservbyname(CS s, "tcp"); | |
071c51f7 | 1146 | if (!smtp_service) |
059ec3d9 PH |
1147 | log_write(0, LOG_PANIC_DIE|LOG_CONFIG, "TCP port \"%s\" not found", s); |
1148 | default_smtp_port[pct] = ntohs(smtp_service->s_port); | |
1149 | } | |
1150 | } | |
1151 | default_smtp_port[pct] = 0; | |
1152 | ||
071c51f7 JH |
1153 | /* Check the list of TLS-on-connect ports and do name lookups if needed */ |
1154 | ||
1155 | list = tls_in.on_connect_ports; | |
1156 | sep = 0; | |
1157 | while ((s = string_nextinlist(&list, &sep, big_buffer, big_buffer_size))) | |
1158 | if (!isdigit(*s)) | |
1159 | { | |
1160 | list = tls_in.on_connect_ports; | |
1161 | tls_in.on_connect_ports = NULL; | |
1162 | sep = 0; | |
1163 | while ((s = string_nextinlist(&list, &sep, big_buffer, big_buffer_size))) | |
1164 | { | |
1165 | if (!isdigit(*s)) | |
1166 | { | |
1167 | struct servent *smtp_service = getservbyname(CS s, "tcp"); | |
1168 | if (!smtp_service) | |
1169 | log_write(0, LOG_PANIC_DIE|LOG_CONFIG, "TCP port \"%s\" not found", s); | |
1170 | s= string_sprintf("%d", (int)ntohs(smtp_service->s_port)); | |
1171 | } | |
1172 | tls_in.on_connect_ports = string_append_listele(tls_in.on_connect_ports, | |
1173 | ':', s); | |
1174 | } | |
1175 | break; | |
1176 | } | |
1177 | ||
059ec3d9 PH |
1178 | /* Create the list of local interfaces, possibly with ports included. This |
1179 | list may contain references to 0.0.0.0 and ::0 as wildcards. These special | |
1180 | values are converted below. */ | |
1181 | ||
1182 | addresses = host_build_ifacelist(local_interfaces, local_iface_source); | |
1183 | ||
1184 | /* In the list of IP addresses, convert 0.0.0.0 into an empty string, and ::0 | |
1185 | into the string ":". We use these to recognize wildcards in IPv4 and IPv6. In | |
1186 | fact, many IP stacks recognize 0.0.0.0 and ::0 and handle them as wildcards | |
1187 | anyway, but we need to know which are the wildcard addresses, and the shorter | |
1188 | strings are neater. | |
1189 | ||
1190 | In the same scan, fill in missing port numbers from the default list. When | |
1191 | there is more than one item in the list, extra items are created. */ | |
1192 | ||
1193 | for (ipa = addresses; ipa != NULL; ipa = ipa->next) | |
1194 | { | |
1195 | int i; | |
1196 | ||
1197 | if (Ustrcmp(ipa->address, "0.0.0.0") == 0) ipa->address[0] = 0; | |
1198 | else if (Ustrcmp(ipa->address, "::0") == 0) | |
1199 | { | |
1200 | ipa->address[0] = ':'; | |
1201 | ipa->address[1] = 0; | |
1202 | } | |
1203 | ||
1204 | if (ipa->port > 0) continue; | |
1205 | ||
1206 | if (daemon_smtp_port[0] <= 0) | |
1207 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "no port specified for interface " | |
1208 | "%s and daemon_smtp_port is unset; cannot start daemon", | |
1209 | (ipa->address[0] == 0)? US"\"all IPv4\"" : | |
1210 | (ipa->address[1] == 0)? US"\"all IPv6\"" : ipa->address); | |
1211 | ipa->port = default_smtp_port[0]; | |
1212 | for (i = 1; default_smtp_port[i] > 0; i++) | |
1213 | { | |
1214 | ip_address_item *new = store_get(sizeof(ip_address_item)); | |
1215 | memcpy(new->address, ipa->address, Ustrlen(ipa->address) + 1); | |
1216 | new->port = default_smtp_port[i]; | |
1217 | new->next = ipa->next; | |
1218 | ipa->next = new; | |
1219 | ipa = new; | |
1220 | } | |
1221 | } | |
1222 | ||
1223 | /* Scan the list of addresses for wildcards. If we find an IPv4 and an IPv6 | |
1224 | wildcard for the same port, ensure that (a) they are together and (b) the | |
1225 | IPv6 address comes first. This makes handling the messy features easier, and | |
1226 | also simplifies the construction of the "daemon started" log line. */ | |
1227 | ||
1228 | pipa = &addresses; | |
1229 | for (ipa = addresses; ipa != NULL; pipa = &(ipa->next), ipa = ipa->next) | |
1230 | { | |
1231 | ip_address_item *ipa2; | |
1232 | ||
1233 | /* Handle an IPv4 wildcard */ | |
1234 | ||
1235 | if (ipa->address[0] == 0) | |
1236 | { | |
1237 | for (ipa2 = ipa; ipa2->next != NULL; ipa2 = ipa2->next) | |
1238 | { | |
1239 | ip_address_item *ipa3 = ipa2->next; | |
1240 | if (ipa3->address[0] == ':' && | |
1241 | ipa3->address[1] == 0 && | |
1242 | ipa3->port == ipa->port) | |
1243 | { | |
1244 | ipa2->next = ipa3->next; | |
1245 | ipa3->next = ipa; | |
1246 | *pipa = ipa3; | |
1247 | break; | |
1248 | } | |
1249 | } | |
1250 | } | |
1251 | ||
1252 | /* Handle an IPv6 wildcard. */ | |
1253 | ||
1254 | else if (ipa->address[0] == ':' && ipa->address[1] == 0) | |
1255 | { | |
1256 | for (ipa2 = ipa; ipa2->next != NULL; ipa2 = ipa2->next) | |
1257 | { | |
1258 | ip_address_item *ipa3 = ipa2->next; | |
1259 | if (ipa3->address[0] == 0 && ipa3->port == ipa->port) | |
1260 | { | |
1261 | ipa2->next = ipa3->next; | |
1262 | ipa3->next = ipa->next; | |
1263 | ipa->next = ipa3; | |
1264 | ipa = ipa3; | |
1265 | break; | |
1266 | } | |
1267 | } | |
1268 | } | |
1269 | } | |
1270 | ||
1271 | /* Get a vector to remember all the sockets in */ | |
1272 | ||
1273 | for (ipa = addresses; ipa != NULL; ipa = ipa->next) | |
1274 | listen_socket_count++; | |
96f5fe4c | 1275 | listen_sockets = store_get(sizeof(int) * listen_socket_count); |
059ec3d9 | 1276 | |
9ee44efb PP |
1277 | } /* daemon_listen but not inetd_wait_mode */ |
1278 | ||
1279 | if (daemon_listen) | |
1280 | { | |
1281 | ||
059ec3d9 PH |
1282 | /* Do a sanity check on the max connects value just to save us from getting |
1283 | a huge amount of store. */ | |
1284 | ||
1285 | if (smtp_accept_max > 4095) smtp_accept_max = 4096; | |
1286 | ||
1287 | /* There's no point setting smtp_accept_queue unless it is less than the max | |
1288 | connects limit. The configuration reader ensures that the max is set if the | |
1289 | queue-only option is set. */ | |
1290 | ||
1291 | if (smtp_accept_queue > smtp_accept_max) smtp_accept_queue = 0; | |
1292 | ||
1293 | /* Get somewhere to keep the list of SMTP accepting pids if we are keeping | |
1294 | track of them for total number and queue/host limits. */ | |
1295 | ||
1296 | if (smtp_accept_max > 0) | |
1297 | { | |
1298 | int i; | |
1299 | smtp_slots = store_get(smtp_accept_max * sizeof(smtp_slot)); | |
1300 | for (i = 0; i < smtp_accept_max; i++) smtp_slots[i] = empty_smtp_slot; | |
1301 | } | |
1302 | } | |
1303 | ||
76a2d7ba PH |
1304 | /* The variable background_daemon is always false when debugging, but |
1305 | can also be forced false in order to keep a non-debugging daemon in the | |
1306 | foreground. If background_daemon is true, close all open file descriptors that | |
9ee44efb PP |
1307 | we know about, but then re-open stdin, stdout, and stderr to /dev/null. Also |
1308 | do this for inetd_wait mode. | |
76a2d7ba PH |
1309 | |
1310 | This is protection against any called functions (in libraries, or in | |
1311 | Perl, or whatever) that think they can write to stderr (or stdout). Before this | |
1312 | was added, it was quite likely that an SMTP connection would use one of these | |
1313 | file descriptors, in which case writing random stuff to it caused chaos. | |
1314 | ||
1315 | Then disconnect from the controlling terminal, Most modern Unixes seem to have | |
1316 | setsid() for getting rid of the controlling terminal. For any OS that doesn't, | |
1317 | setsid() can be #defined as a no-op, or as something else. */ | |
059ec3d9 | 1318 | |
9ee44efb | 1319 | if (background_daemon || inetd_wait_mode) |
059ec3d9 | 1320 | { |
76a2d7ba PH |
1321 | log_close_all(); /* Just in case anything was logged earlier */ |
1322 | search_tidyup(); /* Just in case any were used in reading the config. */ | |
f1e894f3 PH |
1323 | (void)close(0); /* Get rid of stdin/stdout/stderr */ |
1324 | (void)close(1); | |
1325 | (void)close(2); | |
8e669ac1 | 1326 | exim_nullstd(); /* Connect stdin/stdout/stderr to /dev/null */ |
059ec3d9 | 1327 | log_stderr = NULL; /* So no attempt to copy paniclog output */ |
9ee44efb | 1328 | } |
059ec3d9 | 1329 | |
9ee44efb PP |
1330 | if (background_daemon) |
1331 | { | |
059ec3d9 | 1332 | /* If the parent process of this one has pid == 1, we are re-initializing the |
8e669ac1 | 1333 | daemon as the result of a SIGHUP. In this case, there is no need to do |
76a2d7ba PH |
1334 | anything, because the controlling terminal has long gone. Otherwise, fork, in |
1335 | case current process is a process group leader (see 'man setsid' for an | |
1336 | explanation) before calling setsid(). */ | |
059ec3d9 PH |
1337 | |
1338 | if (getppid() != 1) | |
1339 | { | |
1340 | pid_t pid = fork(); | |
1341 | if (pid < 0) log_write(0, LOG_MAIN|LOG_PANIC_DIE, | |
1342 | "fork() failed when starting daemon: %s", strerror(errno)); | |
1343 | if (pid > 0) exit(EXIT_SUCCESS); /* in parent process, just exit */ | |
1344 | (void)setsid(); /* release controlling terminal */ | |
1345 | } | |
1346 | } | |
1347 | ||
1348 | /* We are now in the disconnected, daemon process (unless debugging). Set up | |
1349 | the listening sockets if required. */ | |
1350 | ||
9ee44efb | 1351 | if (daemon_listen && !inetd_wait_mode) |
059ec3d9 PH |
1352 | { |
1353 | int sk; | |
059ec3d9 PH |
1354 | ip_address_item *ipa; |
1355 | ||
1356 | /* For each IP address, create a socket, bind it to the appropriate port, and | |
1357 | start listening. See comments above about IPv6 sockets that may or may not | |
1358 | accept IPv4 calls when listening on all interfaces. We also have to cope with | |
1359 | the case of a system with IPv6 libraries, but no IPv6 support in the kernel. | |
1360 | listening, provided a wildcard IPv4 socket for the same port follows. */ | |
1361 | ||
1362 | for (ipa = addresses, sk = 0; sk < listen_socket_count; ipa = ipa->next, sk++) | |
1363 | { | |
1364 | BOOL wildcard; | |
1365 | ip_address_item *ipa2; | |
059ec3d9 PH |
1366 | int af; |
1367 | ||
1368 | if (Ustrchr(ipa->address, ':') != NULL) | |
1369 | { | |
1370 | af = AF_INET6; | |
1371 | wildcard = ipa->address[1] == 0; | |
1372 | } | |
1373 | else | |
1374 | { | |
1375 | af = AF_INET; | |
1376 | wildcard = ipa->address[0] == 0; | |
1377 | } | |
1378 | ||
96f5fe4c | 1379 | if ((listen_sockets[sk] = ip_socket(SOCK_STREAM, af)) < 0) |
059ec3d9 PH |
1380 | { |
1381 | if (check_special_case(0, addresses, ipa, FALSE)) | |
1382 | { | |
1383 | log_write(0, LOG_MAIN, "Failed to create IPv6 socket for wildcard " | |
1384 | "listening (%s): will use IPv4", strerror(errno)); | |
1385 | goto SKIP_SOCKET; | |
1386 | } | |
1387 | log_write(0, LOG_PANIC_DIE, "IPv%c socket creation failed: %s", | |
1388 | (af == AF_INET6)? '6' : '4', strerror(errno)); | |
1389 | } | |
1390 | ||
1391 | /* If this is an IPv6 wildcard socket, set IPV6_V6ONLY if that option is | |
1392 | available. Just log failure (can get protocol not available, just like | |
1393 | socket creation can). */ | |
1394 | ||
1395 | #ifdef IPV6_V6ONLY | |
1396 | if (af == AF_INET6 && wildcard && | |
1397 | setsockopt(listen_sockets[sk], IPPROTO_IPV6, IPV6_V6ONLY, (char *)(&on), | |
1398 | sizeof(on)) < 0) | |
1399 | log_write(0, LOG_MAIN, "Setting IPV6_V6ONLY on daemon's IPv6 wildcard " | |
1400 | "socket failed (%s): carrying on without it", strerror(errno)); | |
1401 | #endif /* IPV6_V6ONLY */ | |
1402 | ||
1403 | /* Set SO_REUSEADDR so that the daemon can be restarted while a connection | |
1404 | is being handled. Without this, a connection will prevent reuse of the | |
1405 | smtp port for listening. */ | |
1406 | ||
1407 | if (setsockopt(listen_sockets[sk], SOL_SOCKET, SO_REUSEADDR, | |
1408 | (uschar *)(&on), sizeof(on)) < 0) | |
1409 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "setting SO_REUSEADDR on socket " | |
1410 | "failed when starting daemon: %s", strerror(errno)); | |
1411 | ||
1412 | /* Set TCP_NODELAY; Exim does its own buffering. There is a switch to | |
1413 | disable this because it breaks some broken clients. */ | |
1414 | ||
1415 | if (tcp_nodelay) setsockopt(listen_sockets[sk], IPPROTO_TCP, TCP_NODELAY, | |
1416 | (uschar *)(&on), sizeof(on)); | |
1417 | ||
1418 | /* Now bind the socket to the required port; if Exim is being restarted | |
1419 | it may not always be possible to bind immediately, even with SO_REUSEADDR | |
1420 | set, so try 10 times, waiting between each try. After 10 failures, we give | |
1421 | up. In an IPv6 environment, if bind () fails with the error EADDRINUSE and | |
1422 | we are doing wildcard IPv4 listening and there was a previous IPv6 wildcard | |
1423 | address for the same port, ignore the error on the grounds that we must be | |
1424 | in a system where the IPv6 socket accepts both kinds of call. This is | |
1425 | necessary for (some release of) USAGI Linux; other IP stacks fail at the | |
1426 | listen() stage instead. */ | |
1427 | ||
1428 | for(;;) | |
1429 | { | |
1430 | uschar *msg, *addr; | |
1431 | if (ip_bind(listen_sockets[sk], af, ipa->address, ipa->port) >= 0) break; | |
1432 | if (check_special_case(errno, addresses, ipa, TRUE)) | |
1433 | { | |
1434 | DEBUG(D_any) debug_printf("wildcard IPv4 bind() failed after IPv6 " | |
1435 | "listen() success; EADDRINUSE ignored\n"); | |
f1e894f3 | 1436 | (void)close(listen_sockets[sk]); |
059ec3d9 PH |
1437 | goto SKIP_SOCKET; |
1438 | } | |
1439 | msg = US strerror(errno); | |
1440 | addr = wildcard? ((af == AF_INET6)? US"(any IPv6)" : US"(any IPv4)") : | |
1441 | ipa->address; | |
4aee0225 | 1442 | if (daemon_startup_retries <= 0) |
059ec3d9 PH |
1443 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, |
1444 | "socket bind() to port %d for address %s failed: %s: " | |
1445 | "daemon abandoned", ipa->port, addr, msg); | |
1446 | log_write(0, LOG_MAIN, "socket bind() to port %d for address %s " | |
4aee0225 PH |
1447 | "failed: %s: waiting %s before trying again (%d more %s)", |
1448 | ipa->port, addr, msg, readconf_printtime(daemon_startup_sleep), | |
1449 | daemon_startup_retries, (daemon_startup_retries > 1)? "tries" : "try"); | |
1450 | daemon_startup_retries--; | |
1451 | sleep(daemon_startup_sleep); | |
059ec3d9 PH |
1452 | } |
1453 | ||
1454 | DEBUG(D_any) | |
059ec3d9 PH |
1455 | if (wildcard) |
1456 | debug_printf("listening on all interfaces (IPv%c) port %d\n", | |
fb05276a | 1457 | af == AF_INET6 ? '6' : '4', ipa->port); |
059ec3d9 PH |
1458 | else |
1459 | debug_printf("listening on %s port %d\n", ipa->address, ipa->port); | |
fb05276a JH |
1460 | |
1461 | #ifdef TCP_FASTOPEN | |
4670e9d3 JH |
1462 | if (setsockopt(listen_sockets[sk], IPPROTO_TCP, TCP_FASTOPEN, |
1463 | &smtp_connect_backlog, sizeof(smtp_connect_backlog))) | |
a23ff3b4 | 1464 | DEBUG(D_any) debug_printf("setsockopt FASTOPEN: %s\n", strerror(errno)); |
fb05276a | 1465 | #endif |
059ec3d9 PH |
1466 | |
1467 | /* Start listening on the bound socket, establishing the maximum backlog of | |
1468 | connections that is allowed. On success, continue to the next address. */ | |
1469 | ||
1470 | if (listen(listen_sockets[sk], smtp_connect_backlog) >= 0) continue; | |
1471 | ||
1472 | /* Listening has failed. In an IPv6 environment, as for bind(), if listen() | |
1473 | fails with the error EADDRINUSE and we are doing IPv4 wildcard listening | |
1474 | and there was a previous successful IPv6 wildcard listen on the same port, | |
1475 | we want to ignore the error on the grounds that we must be in a system | |
1476 | where the IPv6 socket accepts both kinds of call. */ | |
1477 | ||
1478 | if (!check_special_case(errno, addresses, ipa, TRUE)) | |
1479 | log_write(0, LOG_PANIC_DIE, "listen() failed on interface %s: %s", | |
fb05276a JH |
1480 | wildcard |
1481 | ? af == AF_INET6 ? US"(any IPv6)" : US"(any IPv4)" : ipa->address, | |
059ec3d9 PH |
1482 | strerror(errno)); |
1483 | ||
1484 | DEBUG(D_any) debug_printf("wildcard IPv4 listen() failed after IPv6 " | |
1485 | "listen() success; EADDRINUSE ignored\n"); | |
f1e894f3 | 1486 | (void)close(listen_sockets[sk]); |
059ec3d9 PH |
1487 | |
1488 | /* Come here if there has been a problem with the socket which we | |
1489 | are going to ignore. We remove the address from the chain, and back up the | |
1490 | counts. */ | |
1491 | ||
1492 | SKIP_SOCKET: | |
1493 | sk--; /* Back up the count */ | |
1494 | listen_socket_count--; /* Reduce the total */ | |
1495 | if (ipa == addresses) addresses = ipa->next; else | |
1496 | { | |
1497 | for (ipa2 = addresses; ipa2->next != ipa; ipa2 = ipa2->next); | |
1498 | ipa2->next = ipa->next; | |
1499 | ipa = ipa2; | |
1500 | } | |
1501 | } /* End of bind/listen loop for each address */ | |
1502 | } /* End of setup for listening */ | |
1503 | ||
1504 | ||
1505 | /* If we are not listening, we want to write a pid file only if -oP was | |
1506 | explicitly given. */ | |
1507 | ||
1508 | else if (override_pid_file_path == NULL) write_pid = FALSE; | |
1509 | ||
1510 | /* Write the pid to a known file for assistance in identification, if required. | |
1511 | We do this before giving up root privilege, because on some systems it is | |
1512 | necessary to be root in order to write into the pid file directory. There's | |
1513 | nothing to stop multiple daemons running, as long as no more than one listens | |
1514 | on a given TCP/IP port on the same interface(s). However, in these | |
1515 | circumstances it gets far too complicated to mess with pid file names | |
1516 | automatically. Consequently, Exim 4 writes a pid file only | |
1517 | ||
1518 | (a) When running in the test harness, or | |
1519 | (b) When -bd is used and -oX is not used, or | |
1520 | (c) When -oP is used to supply a path. | |
1521 | ||
1522 | The variable daemon_write_pid is used to control this. */ | |
1523 | ||
1524 | if (running_in_test_harness || write_pid) | |
1525 | { | |
1526 | FILE *f; | |
1527 | ||
1528 | if (override_pid_file_path != NULL) | |
1529 | pid_file_path = override_pid_file_path; | |
1530 | ||
1531 | if (pid_file_path[0] == 0) | |
1532 | pid_file_path = string_sprintf("%s/exim-daemon.pid", spool_directory); | |
1533 | ||
2632889e | 1534 | f = modefopen(pid_file_path, "wb", 0644); |
059ec3d9 PH |
1535 | if (f != NULL) |
1536 | { | |
ff790e47 | 1537 | (void)fprintf(f, "%d\n", (int)getpid()); |
ff790e47 | 1538 | (void)fclose(f); |
059ec3d9 PH |
1539 | DEBUG(D_any) debug_printf("pid written to %s\n", pid_file_path); |
1540 | } | |
1541 | else | |
1542 | { | |
1543 | DEBUG(D_any) | |
1544 | debug_printf("%s\n", string_open_failed(errno, "pid file %s", | |
1545 | pid_file_path)); | |
1546 | } | |
1547 | } | |
1548 | ||
1549 | /* Set up the handler for SIGHUP, which causes a restart of the daemon. */ | |
1550 | ||
1551 | sighup_seen = FALSE; | |
1552 | signal(SIGHUP, sighup_handler); | |
1553 | ||
1554 | /* Give up root privilege at this point (assuming that exim_uid and exim_gid | |
1555 | are not root). The third argument controls the running of initgroups(). | |
1556 | Normally we do this, in order to set up the groups for the Exim user. However, | |
1557 | if we are not root at this time - some odd installations run that way - we | |
1558 | cannot do this. */ | |
1559 | ||
1560 | exim_setugid(exim_uid, exim_gid, geteuid()==root_uid, US"running as a daemon"); | |
1561 | ||
ebeaf996 PH |
1562 | /* Update the originator_xxx fields so that received messages as listed as |
1563 | coming from Exim, not whoever started the daemon. */ | |
1564 | ||
1565 | originator_uid = exim_uid; | |
1566 | originator_gid = exim_gid; | |
1567 | originator_login = ((pw = getpwuid(exim_uid)) != NULL)? | |
1568 | string_copy_malloc(US pw->pw_name) : US"exim"; | |
1569 | ||
059ec3d9 PH |
1570 | /* Get somewhere to keep the list of queue-runner pids if we are keeping track |
1571 | of them (and also if we are doing queue runs). */ | |
1572 | ||
0cd5fd23 | 1573 | if (queue_interval > 0 && local_queue_run_max > 0) |
059ec3d9 PH |
1574 | { |
1575 | int i; | |
0cd5fd23 JH |
1576 | queue_pid_slots = store_get(local_queue_run_max * sizeof(pid_t)); |
1577 | for (i = 0; i < local_queue_run_max; i++) queue_pid_slots[i] = 0; | |
059ec3d9 PH |
1578 | } |
1579 | ||
1580 | /* Set up the handler for termination of child processes. */ | |
1581 | ||
1582 | sigchld_seen = FALSE; | |
7d468ab8 | 1583 | os_non_restarting_signal(SIGCHLD, main_sigchld_handler); |
059ec3d9 PH |
1584 | |
1585 | /* If we are to run the queue periodically, pretend the alarm has just gone | |
1586 | off. This will cause the first queue-runner to get kicked off straight away. */ | |
1587 | ||
1588 | sigalrm_seen = (queue_interval > 0); | |
1589 | ||
1590 | /* Log the start up of a daemon - at least one of listening or queue running | |
1591 | must be set up. */ | |
1592 | ||
9ee44efb PP |
1593 | if (inetd_wait_mode) |
1594 | { | |
1595 | uschar *p = big_buffer; | |
1596 | ||
1597 | if (inetd_wait_timeout >= 0) | |
1598 | sprintf(CS p, "terminating after %d seconds", inetd_wait_timeout); | |
1599 | else | |
1600 | sprintf(CS p, "with no wait timeout"); | |
1601 | ||
1602 | log_write(0, LOG_MAIN, | |
1603 | "exim %s daemon started: pid=%d, launched with listening socket, %s", | |
1604 | version_string, getpid(), big_buffer); | |
2f21487f | 1605 | set_process_info("daemon(%s): pre-listening socket", version_string); |
9ee44efb PP |
1606 | |
1607 | /* set up the timeout logic */ | |
1608 | sigalrm_seen = 1; | |
1609 | } | |
1610 | ||
1611 | else if (daemon_listen) | |
059ec3d9 PH |
1612 | { |
1613 | int i, j; | |
1614 | int smtp_ports = 0; | |
1615 | int smtps_ports = 0; | |
e37f8a84 JH |
1616 | ip_address_item * ipa; |
1617 | uschar * p = big_buffer; | |
1618 | uschar * qinfo = queue_interval > 0 | |
1619 | ? string_sprintf("-q%s", readconf_printtime(queue_interval)) | |
1620 | : US"no queue runs"; | |
059ec3d9 PH |
1621 | |
1622 | /* Build a list of listening addresses in big_buffer, but limit it to 10 | |
1623 | items. The style is for backwards compatibility. | |
1624 | ||
1625 | It is now possible to have some ports listening for SMTPS (the old, | |
1626 | deprecated protocol that starts TLS without using STARTTLS), and others | |
1627 | listening for standard SMTP. Keep their listings separate. */ | |
1628 | ||
1629 | for (j = 0; j < 2; j++) | |
1630 | { | |
e37f8a84 | 1631 | for (i = 0, ipa = addresses; i < 10 && ipa; i++, ipa = ipa->next) |
059ec3d9 PH |
1632 | { |
1633 | /* First time round, look for SMTP ports; second time round, look for | |
1634 | SMTPS ports. For the first one of each, insert leading text. */ | |
1635 | ||
1636 | if (host_is_tls_on_connect_port(ipa->port) == (j > 0)) | |
1637 | { | |
e37f8a84 JH |
1638 | if (j == 0) |
1639 | { | |
1640 | if (smtp_ports++ == 0) | |
059ec3d9 PH |
1641 | { |
1642 | memcpy(p, "SMTP on", 8); | |
1643 | p += 7; | |
1644 | } | |
e37f8a84 JH |
1645 | } |
1646 | else | |
1647 | { | |
1648 | if (smtps_ports++ == 0) | |
059ec3d9 PH |
1649 | { |
1650 | (void)sprintf(CS p, "%sSMTPS on", | |
e37f8a84 JH |
1651 | smtp_ports == 0 ? "" : " and for "); |
1652 | while (*p) p++; | |
059ec3d9 | 1653 | } |
e37f8a84 | 1654 | } |
059ec3d9 PH |
1655 | |
1656 | /* Now the information about the port (and sometimes interface) */ | |
1657 | ||
1658 | if (ipa->address[0] == ':' && ipa->address[1] == 0) | |
1659 | { | |
1660 | if (ipa->next != NULL && ipa->next->address[0] == 0 && | |
1661 | ipa->next->port == ipa->port) | |
1662 | { | |
1663 | (void)sprintf(CS p, " port %d (IPv6 and IPv4)", ipa->port); | |
1664 | ipa = ipa->next; | |
1665 | } | |
1666 | else if (ipa->v6_include_v4) | |
1667 | (void)sprintf(CS p, " port %d (IPv6 with IPv4)", ipa->port); | |
1668 | else | |
1669 | (void)sprintf(CS p, " port %d (IPv6)", ipa->port); | |
1670 | } | |
1671 | else if (ipa->address[0] == 0) | |
1672 | (void)sprintf(CS p, " port %d (IPv4)", ipa->port); | |
1673 | else | |
1674 | (void)sprintf(CS p, " [%s]:%d", ipa->address, ipa->port); | |
1675 | while (*p != 0) p++; | |
1676 | } | |
1677 | } | |
1678 | ||
e37f8a84 | 1679 | if (ipa) |
059ec3d9 PH |
1680 | { |
1681 | memcpy(p, " ...", 5); | |
1682 | p += 4; | |
1683 | } | |
1684 | } | |
1685 | ||
1686 | log_write(0, LOG_MAIN, | |
1687 | "exim %s daemon started: pid=%d, %s, listening for %s", | |
1688 | version_string, getpid(), qinfo, big_buffer); | |
44915474 JH |
1689 | set_process_info("daemon(%s): %s, listening for %s", |
1690 | version_string, qinfo, big_buffer); | |
059ec3d9 PH |
1691 | } |
1692 | ||
1693 | else | |
1694 | { | |
44915474 JH |
1695 | uschar * s = *queue_name |
1696 | ? string_sprintf("-qG%s/%s", queue_name, readconf_printtime(queue_interval)) | |
1697 | : string_sprintf("-q%s", readconf_printtime(queue_interval)); | |
059ec3d9 | 1698 | log_write(0, LOG_MAIN, |
44915474 JH |
1699 | "exim %s daemon started: pid=%d, %s, not listening for SMTP", |
1700 | version_string, getpid(), s); | |
1701 | set_process_info("daemon(%s): %s, not listening", version_string, s); | |
059ec3d9 PH |
1702 | } |
1703 | ||
476be7e2 JH |
1704 | /* Do any work it might be useful to amortize over our children |
1705 | (eg: compile regex) */ | |
1706 | ||
476be7e2 JH |
1707 | dns_pattern_init(); |
1708 | ||
1709 | #ifdef WITH_CONTENT_SCAN | |
1710 | malware_init(); | |
1711 | #endif | |
059ec3d9 PH |
1712 | |
1713 | /* Close the log so it can be renamed and moved. In the few cases below where | |
1714 | this long-running process writes to the log (always exceptional conditions), it | |
1715 | closes the log afterwards, for the same reason. */ | |
1716 | ||
1717 | log_close_all(); | |
1718 | ||
1719 | DEBUG(D_any) debug_print_ids(US"daemon running with"); | |
1720 | ||
1721 | /* Any messages accepted via this route are going to be SMTP. */ | |
1722 | ||
1723 | smtp_input = TRUE; | |
1724 | ||
1725 | /* Enter the never-ending loop... */ | |
1726 | ||
1727 | for (;;) | |
1728 | { | |
1729 | #if HAVE_IPV6 | |
1730 | struct sockaddr_in6 accepted; | |
1731 | #else | |
1732 | struct sockaddr_in accepted; | |
1733 | #endif | |
1734 | ||
cf73943b | 1735 | EXIM_SOCKLEN_T len; |
059ec3d9 PH |
1736 | pid_t pid; |
1737 | ||
1738 | /* This code is placed first in the loop, so that it gets obeyed at the | |
9ee44efb PP |
1739 | start, before the first wait, for the queue-runner case, so that the first |
1740 | one can be started immediately. | |
1741 | ||
1742 | The other option is that we have an inetd wait timeout specified to -bw. */ | |
059ec3d9 PH |
1743 | |
1744 | if (sigalrm_seen) | |
1745 | { | |
9ee44efb PP |
1746 | if (inetd_wait_timeout > 0) |
1747 | { | |
1748 | time_t resignal_interval = inetd_wait_timeout; | |
1749 | ||
1750 | if (last_connection_time == (time_t)0) | |
1751 | { | |
1752 | DEBUG(D_any) | |
1753 | debug_printf("inetd wait timeout expired, but still not seen first message, ignoring\n"); | |
1754 | } | |
1755 | else | |
1756 | { | |
1757 | time_t now = time(NULL); | |
1758 | if (now == (time_t)-1) | |
1759 | { | |
1760 | DEBUG(D_any) debug_printf("failed to get time: %s\n", strerror(errno)); | |
1761 | } | |
1762 | else | |
1763 | { | |
1764 | if ((now - last_connection_time) >= inetd_wait_timeout) | |
1765 | { | |
1766 | DEBUG(D_any) | |
1767 | debug_printf("inetd wait timeout %d expired, ending daemon\n", | |
1768 | inetd_wait_timeout); | |
1769 | log_write(0, LOG_MAIN, "exim %s daemon terminating, inetd wait timeout reached.\n", | |
1770 | version_string); | |
1771 | exit(EXIT_SUCCESS); | |
1772 | } | |
1773 | else | |
1774 | { | |
1775 | resignal_interval -= (now - last_connection_time); | |
1776 | } | |
1777 | } | |
1778 | } | |
059ec3d9 | 1779 | |
9ee44efb PP |
1780 | sigalrm_seen = FALSE; |
1781 | alarm(resignal_interval); | |
1782 | } | |
059ec3d9 | 1783 | |
9ee44efb | 1784 | else |
059ec3d9 | 1785 | { |
9ee44efb | 1786 | DEBUG(D_any) debug_printf("SIGALRM received\n"); |
8e669ac1 | 1787 | |
9ee44efb PP |
1788 | /* Do a full queue run in a child process, if required, unless we already |
1789 | have enough queue runners on the go. If we are not running as root, a | |
1790 | re-exec is required. */ | |
059ec3d9 | 1791 | |
9ee44efb | 1792 | if (queue_interval > 0 && |
0cd5fd23 | 1793 | (local_queue_run_max <= 0 || queue_run_count < local_queue_run_max)) |
9ee44efb PP |
1794 | { |
1795 | if ((pid = fork()) == 0) | |
1796 | { | |
1797 | int sk; | |
3d235903 | 1798 | |
9ee44efb PP |
1799 | DEBUG(D_any) debug_printf("Starting queue-runner: pid %d\n", |
1800 | (int)getpid()); | |
8e669ac1 | 1801 | |
9ee44efb PP |
1802 | /* Disable debugging if it's required only for the daemon process. We |
1803 | leave the above message, because it ties up with the "child ended" | |
1804 | debugging messages. */ | |
059ec3d9 | 1805 | |
9ee44efb | 1806 | if (debug_daemon) debug_selector = 0; |
059ec3d9 | 1807 | |
9ee44efb | 1808 | /* Close any open listening sockets in the child */ |
059ec3d9 | 1809 | |
9ee44efb PP |
1810 | for (sk = 0; sk < listen_socket_count; sk++) |
1811 | (void)close(listen_sockets[sk]); | |
059ec3d9 | 1812 | |
9ee44efb | 1813 | /* Reset SIGHUP and SIGCHLD in the child in both cases. */ |
059ec3d9 | 1814 | |
9ee44efb PP |
1815 | signal(SIGHUP, SIG_DFL); |
1816 | signal(SIGCHLD, SIG_DFL); | |
059ec3d9 | 1817 | |
9ee44efb PP |
1818 | /* Re-exec if privilege has been given up, unless deliver_drop_ |
1819 | privilege is set. Reset SIGALRM before exec(). */ | |
4fbcfc2e | 1820 | |
9ee44efb | 1821 | if (geteuid() != root_uid && !deliver_drop_privilege) |
4fbcfc2e | 1822 | { |
9ee44efb PP |
1823 | uschar opt[8]; |
1824 | uschar *p = opt; | |
1825 | uschar *extra[5]; | |
1826 | int extracount = 1; | |
1827 | ||
1828 | signal(SIGALRM, SIG_DFL); | |
1829 | *p++ = '-'; | |
1830 | *p++ = 'q'; | |
1831 | if (queue_2stage) *p++ = 'q'; | |
1832 | if (queue_run_first_delivery) *p++ = 'i'; | |
1833 | if (queue_run_force) *p++ = 'f'; | |
1834 | if (deliver_force_thaw) *p++ = 'f'; | |
1835 | if (queue_run_local) *p++ = 'l'; | |
1836 | *p = 0; | |
e37f8a84 JH |
1837 | extra[0] = queue_name |
1838 | ? string_sprintf("%sG%s", opt, queue_name) : opt; | |
9ee44efb PP |
1839 | |
1840 | /* If -R or -S were on the original command line, ensure they get | |
1841 | passed on. */ | |
1842 | ||
e37f8a84 | 1843 | if (deliver_selectstring) |
9ee44efb | 1844 | { |
e37f8a84 | 1845 | extra[extracount++] = deliver_selectstring_regex ? US"-Rr" : US"-R"; |
9ee44efb PP |
1846 | extra[extracount++] = deliver_selectstring; |
1847 | } | |
1848 | ||
e37f8a84 | 1849 | if (deliver_selectstring_sender) |
9ee44efb | 1850 | { |
e37f8a84 JH |
1851 | extra[extracount++] = deliver_selectstring_sender_regex |
1852 | ? US"-Sr" : US"-S"; | |
9ee44efb PP |
1853 | extra[extracount++] = deliver_selectstring_sender; |
1854 | } | |
1855 | ||
1856 | /* Overlay this process with a new execution. */ | |
1857 | ||
1858 | (void)child_exec_exim(CEE_EXEC_PANIC, FALSE, NULL, TRUE, extracount, | |
1859 | extra[0], extra[1], extra[2], extra[3], extra[4]); | |
1860 | ||
1861 | /* Control never returns here. */ | |
4fbcfc2e PH |
1862 | } |
1863 | ||
9ee44efb | 1864 | /* No need to re-exec; SIGALRM remains set to the default handler */ |
059ec3d9 | 1865 | |
9ee44efb PP |
1866 | queue_run(NULL, NULL, FALSE); |
1867 | _exit(EXIT_SUCCESS); | |
059ec3d9 PH |
1868 | } |
1869 | ||
9ee44efb | 1870 | if (pid < 0) |
059ec3d9 | 1871 | { |
9ee44efb PP |
1872 | log_write(0, LOG_MAIN|LOG_PANIC, "daemon: fork of queue-runner " |
1873 | "process failed: %s", strerror(errno)); | |
1874 | log_close_all(); | |
1875 | } | |
1876 | else | |
1877 | { | |
1878 | int i; | |
0cd5fd23 | 1879 | for (i = 0; i < local_queue_run_max; ++i) |
9ee44efb PP |
1880 | if (queue_pid_slots[i] <= 0) |
1881 | { | |
1882 | queue_pid_slots[i] = pid; | |
1883 | queue_run_count++; | |
1884 | break; | |
1885 | } | |
9ee44efb PP |
1886 | DEBUG(D_any) debug_printf("%d queue-runner process%s running\n", |
1887 | queue_run_count, (queue_run_count == 1)? "" : "es"); | |
059ec3d9 | 1888 | } |
059ec3d9 | 1889 | } |
059ec3d9 | 1890 | |
9ee44efb | 1891 | /* Reset the alarm clock */ |
059ec3d9 | 1892 | |
9ee44efb PP |
1893 | sigalrm_seen = FALSE; |
1894 | alarm(queue_interval); | |
1895 | } | |
1896 | ||
1897 | } /* sigalrm_seen */ | |
059ec3d9 PH |
1898 | |
1899 | ||
1900 | /* Sleep till a connection happens if listening, and handle the connection if | |
1901 | that is why we woke up. The FreeBSD operating system requires the use of | |
1902 | select() before accept() because the latter function is not interrupted by | |
1903 | a signal, and we want to wake up for SIGCHLD and SIGALRM signals. Some other | |
1904 | OS do notice signals in accept() but it does no harm to have the select() | |
1905 | in for all of them - and it won't then be a lurking problem for ports to | |
1906 | new OS. In fact, the later addition of listening on specific interfaces only | |
1907 | requires this way of working anyway. */ | |
1908 | ||
1909 | if (daemon_listen) | |
1910 | { | |
bb6e88ff | 1911 | int sk, lcount, select_errno; |
059ec3d9 PH |
1912 | int max_socket = 0; |
1913 | BOOL select_failed = FALSE; | |
1914 | fd_set select_listen; | |
1915 | ||
1916 | FD_ZERO(&select_listen); | |
1917 | for (sk = 0; sk < listen_socket_count; sk++) | |
1918 | { | |
1919 | FD_SET(listen_sockets[sk], &select_listen); | |
1920 | if (listen_sockets[sk] > max_socket) max_socket = listen_sockets[sk]; | |
1921 | } | |
1922 | ||
1923 | DEBUG(D_any) debug_printf("Listening...\n"); | |
8e669ac1 PH |
1924 | |
1925 | /* In rare cases we may have had a SIGCHLD signal in the time between | |
1926 | setting the handler (below) and getting back here. If so, pretend that the | |
7d468ab8 | 1927 | select() was interrupted so that we reap the child. This might still leave |
8e669ac1 | 1928 | a small window when a SIGCHLD could get lost. However, since we use SIGCHLD |
7d468ab8 PH |
1929 | only to do the reaping more quickly, it shouldn't result in anything other |
1930 | than a delay until something else causes a wake-up. */ | |
1931 | ||
1932 | if (sigchld_seen) | |
1933 | { | |
1934 | lcount = -1; | |
8e669ac1 | 1935 | errno = EINTR; |
7d468ab8 PH |
1936 | } |
1937 | else | |
8e669ac1 | 1938 | { |
7d468ab8 PH |
1939 | lcount = select(max_socket + 1, (SELECT_ARG2_TYPE *)&select_listen, |
1940 | NULL, NULL, NULL); | |
8e669ac1 | 1941 | } |
059ec3d9 | 1942 | |
7d468ab8 | 1943 | if (lcount < 0) |
059ec3d9 PH |
1944 | { |
1945 | select_failed = TRUE; | |
1946 | lcount = 1; | |
1947 | } | |
8e669ac1 PH |
1948 | |
1949 | /* Clean up any subprocesses that may have terminated. We need to do this | |
1950 | here so that smtp_accept_max_per_host works when a connection to that host | |
1951 | has completed, and we are about to accept a new one. When this code was | |
1952 | later in the sequence, a new connection could be rejected, even though an | |
1953 | old one had just finished. Preserve the errno from any select() failure for | |
bb6e88ff | 1954 | the use of the common select/accept error processing below. */ |
8e669ac1 | 1955 | |
bb6e88ff PH |
1956 | select_errno = errno; |
1957 | handle_ending_processes(); | |
8e669ac1 PH |
1958 | errno = select_errno; |
1959 | ||
059ec3d9 | 1960 | /* Loop for all the sockets that are currently ready to go. If select |
7d468ab8 PH |
1961 | actually failed, we have set the count to 1 and select_failed=TRUE, so as |
1962 | to use the common error code for select/accept below. */ | |
059ec3d9 PH |
1963 | |
1964 | while (lcount-- > 0) | |
1965 | { | |
1966 | int accept_socket = -1; | |
1967 | if (!select_failed) | |
1968 | { | |
1969 | for (sk = 0; sk < listen_socket_count; sk++) | |
1970 | { | |
1971 | if (FD_ISSET(listen_sockets[sk], &select_listen)) | |
1972 | { | |
cf73943b | 1973 | len = sizeof(accepted); |
059ec3d9 PH |
1974 | accept_socket = accept(listen_sockets[sk], |
1975 | (struct sockaddr *)&accepted, &len); | |
1976 | FD_CLR(listen_sockets[sk], &select_listen); | |
1977 | break; | |
1978 | } | |
1979 | } | |
1980 | } | |
1981 | ||
1982 | /* If select or accept has failed and this was not caused by an | |
1983 | interruption, log the incident and try again. With asymmetric TCP/IP | |
1984 | routing errors such as "No route to network" have been seen here. Also | |
1985 | "connection reset by peer" has been seen. These cannot be classed as | |
1986 | disastrous errors, but they could fill up a lot of log. The code in smail | |
1987 | crashes the daemon after 10 successive failures of accept, on the grounds | |
1988 | that some OS fail continuously. Exim originally followed suit, but this | |
1989 | appears to have caused problems. Now it just keeps going, but instead of | |
1990 | logging each error, it batches them up when they are continuous. */ | |
1991 | ||
1992 | if (accept_socket < 0 && errno != EINTR) | |
1993 | { | |
1994 | if (accept_retry_count == 0) | |
1995 | { | |
1996 | accept_retry_errno = errno; | |
1997 | accept_retry_select_failed = select_failed; | |
1998 | } | |
1999 | else | |
2000 | { | |
2001 | if (errno != accept_retry_errno || | |
2002 | select_failed != accept_retry_select_failed || | |
2003 | accept_retry_count >= 50) | |
2004 | { | |
2005 | log_write(0, LOG_MAIN | ((accept_retry_count >= 50)? LOG_PANIC : 0), | |
2006 | "%d %s() failure%s: %s", | |
2007 | accept_retry_count, | |
2008 | accept_retry_select_failed? "select" : "accept", | |
2009 | (accept_retry_count == 1)? "" : "s", | |
2010 | strerror(accept_retry_errno)); | |
2011 | log_close_all(); | |
2012 | accept_retry_count = 0; | |
2013 | accept_retry_errno = errno; | |
2014 | accept_retry_select_failed = select_failed; | |
2015 | } | |
2016 | } | |
2017 | accept_retry_count++; | |
2018 | } | |
2019 | ||
2020 | else | |
2021 | { | |
2022 | if (accept_retry_count > 0) | |
2023 | { | |
2024 | log_write(0, LOG_MAIN, "%d %s() failure%s: %s", | |
2025 | accept_retry_count, | |
2026 | accept_retry_select_failed? "select" : "accept", | |
2027 | (accept_retry_count == 1)? "" : "s", | |
2028 | strerror(accept_retry_errno)); | |
2029 | log_close_all(); | |
2030 | accept_retry_count = 0; | |
2031 | } | |
2032 | } | |
2033 | ||
2034 | /* If select/accept succeeded, deal with the connection. */ | |
2035 | ||
2036 | if (accept_socket >= 0) | |
9ee44efb PP |
2037 | { |
2038 | if (inetd_wait_timeout) | |
2039 | last_connection_time = time(NULL); | |
059ec3d9 PH |
2040 | handle_smtp_call(listen_sockets, listen_socket_count, accept_socket, |
2041 | (struct sockaddr *)&accepted); | |
9ee44efb | 2042 | } |
059ec3d9 PH |
2043 | } |
2044 | } | |
2045 | ||
2046 | /* If not listening, then just sleep for the queue interval. If we woke | |
2047 | up early the last time for some other signal, it won't matter because | |
2048 | the alarm signal will wake at the right time. This code originally used | |
2049 | sleep() but it turns out that on the FreeBSD system, sleep() is not inter- | |
2050 | rupted by signals, so it wasn't waking up for SIGALRM or SIGCHLD. Luckily | |
2051 | select() can be used as an interruptible sleep() on all versions of Unix. */ | |
2052 | ||
2053 | else | |
2054 | { | |
2055 | struct timeval tv; | |
2056 | tv.tv_sec = queue_interval; | |
2057 | tv.tv_usec = 0; | |
2058 | select(0, NULL, NULL, NULL, &tv); | |
8e669ac1 | 2059 | handle_ending_processes(); |
059ec3d9 PH |
2060 | } |
2061 | ||
2062 | /* Re-enable the SIGCHLD handler if it has been run. It can't do it | |
2063 | for itself, because it isn't doing the waiting itself. */ | |
2064 | ||
2065 | if (sigchld_seen) | |
2066 | { | |
2067 | sigchld_seen = FALSE; | |
7d468ab8 | 2068 | os_non_restarting_signal(SIGCHLD, main_sigchld_handler); |
059ec3d9 PH |
2069 | } |
2070 | ||
2071 | /* Handle being woken by SIGHUP. We know at this point that the result | |
2072 | of accept() has been dealt with, so we can re-exec exim safely, first | |
2073 | closing the listening sockets so that they can be reused. Cancel any pending | |
2074 | alarm in case it is just about to go off, and set SIGHUP to be ignored so | |
2075 | that another HUP in quick succession doesn't clobber the new daemon before it | |
2076 | gets going. All log files get closed by the close-on-exec flag; however, if | |
2077 | the exec fails, we need to close the logs. */ | |
2078 | ||
2079 | if (sighup_seen) | |
2080 | { | |
2081 | int sk; | |
2082 | log_write(0, LOG_MAIN, "pid %d: SIGHUP received: re-exec daemon", | |
2083 | getpid()); | |
f1e894f3 PH |
2084 | for (sk = 0; sk < listen_socket_count; sk++) |
2085 | (void)close(listen_sockets[sk]); | |
059ec3d9 PH |
2086 | alarm(0); |
2087 | signal(SIGHUP, SIG_IGN); | |
2088 | sighup_argv[0] = exim_path; | |
2089 | exim_nullstd(); | |
2090 | execv(CS exim_path, (char *const *)sighup_argv); | |
2091 | log_write(0, LOG_MAIN|LOG_PANIC_DIE, "pid %d: exec of %s failed: %s", | |
2092 | getpid(), exim_path, strerror(errno)); | |
2093 | log_close_all(); | |
2094 | } | |
2095 | ||
2096 | } /* End of main loop */ | |
2097 | ||
2098 | /* Control never reaches here */ | |
2099 | } | |
2100 | ||
071c51f7 JH |
2101 | /* vi: aw ai sw=2 |
2102 | */ | |
059ec3d9 | 2103 | /* End of exim_daemon.c */ |