chiark / gitweb /
first attempt at proper service/socket logic
[elogind.git] / socket.c
1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
2
3 #include <sys/types.h>
4 #include <sys/stat.h>
5 #include <unistd.h>
6 #include <errno.h>
7 #include <fcntl.h>
8 #include <sys/poll.h>
9 #include <signal.h>
10
11 #include "name.h"
12 #include "socket.h"
13 #include "log.h"
14
15 static const NameActiveState state_table[_SOCKET_STATE_MAX] = {
16         [SOCKET_DEAD] = NAME_INACTIVE,
17         [SOCKET_START_PRE] = NAME_ACTIVATING,
18         [SOCKET_START_POST] = NAME_ACTIVATING,
19         [SOCKET_LISTENING] = NAME_ACTIVE,
20         [SOCKET_RUNNING] = NAME_ACTIVE,
21         [SOCKET_STOP_PRE] = NAME_DEACTIVATING,
22         [SOCKET_STOP_PRE_SIGTERM] = NAME_DEACTIVATING,
23         [SOCKET_STOP_PRE_SIGKILL] = NAME_DEACTIVATING,
24         [SOCKET_STOP_POST] = NAME_DEACTIVATING,
25         [SOCKET_STOP_POST_SIGTERM] = NAME_DEACTIVATING,
26         [SOCKET_STOP_POST_SIGKILL] = NAME_DEACTIVATING,
27         [SOCKET_MAINTAINANCE] = NAME_INACTIVE,
28 };
29
30 static int socket_init(Name *n) {
31         Socket *s = SOCKET(n);
32         char *t;
33         int r;
34
35         /* First, reset everything to the defaults, in case this is a
36          * reload */
37
38         s->bind_ipv6_only = false;
39         s->backlog = SOMAXCONN;
40         s->timeout_usec = DEFAULT_TIMEOUT_USEC;
41         exec_context_init(&s->exec_context);
42
43         if ((r = name_load_fragment_and_dropin(n)) < 0)
44                 return r;
45
46         if (!(t = name_change_suffix(name_id(n), ".service")))
47                 return -ENOMEM;
48
49         r = manager_load_name(n->meta.manager, t, (Name**) &s->service);
50         free(t);
51
52         if (r < 0)
53                 return r;
54
55         if ((r = set_ensure_allocated(n->meta.dependencies + NAME_BEFORE, trivial_hash_func, trivial_compare_func)) < 0)
56                 return r;
57
58         if ((r = set_put(n->meta.dependencies[NAME_BEFORE], s->service)) < 0)
59                 return r;
60
61         return 0;
62 }
63
64 static void socket_done(Name *n) {
65         Socket *s = SOCKET(n);
66         SocketPort *p;
67
68         assert(s);
69
70         while ((p = s->ports)) {
71                 LIST_REMOVE(SocketPort, port, s->ports, p);
72
73                 if (p->fd >= 0)
74                         close_nointr(p->fd);
75                 free(p->path);
76                 free(p);
77         }
78
79         exec_context_done(&s->exec_context);
80         exec_command_free_array(s->exec_command, _SOCKET_EXEC_MAX);
81         s->control_command = NULL;
82
83         if (s->control_pid > 0) {
84                 name_unwatch_pid(n, s->control_pid);
85                 s->control_pid = 0;
86         }
87
88         s->service = NULL;
89
90         name_unwatch_timer(n, &s->timer_id);
91 }
92
93 static const char* listen_lookup(int type) {
94
95         if (type == SOCK_STREAM)
96                 return "ListenStream";
97         else if (type == SOCK_DGRAM)
98                 return "ListenDatagram";
99         else if (type == SOCK_SEQPACKET)
100                 return "ListenSequentialPacket";
101
102         assert_not_reached("Unknown socket type");
103         return NULL;
104 }
105
106 static void socket_dump(Name *n, FILE *f, const char *prefix) {
107
108         static const char* const state_table[_SOCKET_STATE_MAX] = {
109                 [SOCKET_DEAD] = "dead",
110                 [SOCKET_START_PRE] = "start-pre",
111                 [SOCKET_START_POST] = "start-post",
112                 [SOCKET_LISTENING] = "listening",
113                 [SOCKET_RUNNING] = "running",
114                 [SOCKET_STOP_PRE] = "stop-pre",
115                 [SOCKET_STOP_PRE_SIGTERM] = "stop-pre-sigterm",
116                 [SOCKET_STOP_PRE_SIGKILL] = "stop-pre-sigkill",
117                 [SOCKET_STOP_POST] = "stop-post",
118                 [SOCKET_STOP_POST_SIGTERM] = "stop-post-sigterm",
119                 [SOCKET_STOP_POST_SIGKILL] = "stop-post-sigkill",
120                 [SOCKET_MAINTAINANCE] = "maintainance"
121         };
122
123         static const char* const command_table[_SOCKET_EXEC_MAX] = {
124                 [SOCKET_EXEC_START_PRE] = "StartPre",
125                 [SOCKET_EXEC_START_POST] = "StartPost",
126                 [SOCKET_EXEC_STOP_PRE] = "StopPre",
127                 [SOCKET_EXEC_STOP_POST] = "StopPost"
128         };
129
130         SocketExecCommand c;
131         Socket *s = SOCKET(n);
132         SocketPort *p;
133
134         assert(s);
135
136         fprintf(f,
137                 "%sSocket State: %s\n"
138                 "%sBindIPv6Only: %s\n"
139                 "%sBacklog: %u\n",
140                 prefix, state_table[s->state],
141                 prefix, yes_no(s->bind_ipv6_only),
142                 prefix, s->backlog);
143
144         LIST_FOREACH(port, p, s->ports) {
145
146                 if (p->type == SOCKET_SOCKET) {
147                         const char *t;
148                         int r;
149                         char *k;
150
151                         if ((r = socket_address_print(&p->address, &k)) < 0)
152                                 t = strerror(-r);
153                         else
154                                 t = k;
155
156                         fprintf(f, "%s%s: %s\n", prefix, listen_lookup(p->address.type), k);
157                         free(k);
158                 } else
159                         fprintf(f, "%sListenFIFO: %s\n", prefix, p->path);
160         }
161
162         exec_context_dump(&s->exec_context, f, prefix);
163
164         for (c = 0; c < _SOCKET_EXEC_MAX; c++) {
165                 ExecCommand *i;
166
167                 LIST_FOREACH(command, i, s->exec_command[c])
168                         fprintf(f, "%s%s: %s\n", prefix, command_table[c], i->path);
169         }
170 }
171
172 static void socket_close_fds(Socket *s) {
173         SocketPort *p;
174
175         assert(s);
176
177         LIST_FOREACH(port, p, s->ports) {
178                 if (p->fd < 0)
179                         continue;
180
181                 name_unwatch_fd(NAME(s), p->fd);
182                 assert_se(close_nointr(p->fd) >= 0);
183
184                 p->fd = -1;
185         }
186 }
187
188 static int socket_open_fds(Socket *s) {
189         SocketPort *p;
190         int r;
191
192         assert(s);
193
194         LIST_FOREACH(port, p, s->ports) {
195
196                 if (p->fd >= 0)
197                         continue;
198
199                 if (p->type == SOCKET_SOCKET) {
200
201                         if ((r = socket_address_listen(&p->address, s->backlog, s->bind_ipv6_only, &p->fd)) < 0)
202                                 goto rollback;
203
204                 } else {
205                         struct stat st;
206                         assert(p->type == SOCKET_FIFO);
207
208                         if (mkfifo(p->path, 0666 & ~s->exec_context.umask) < 0 && errno != EEXIST) {
209                                 r = -errno;
210                                 goto rollback;
211                         }
212
213                         if ((p->fd = open(p->path, O_RDWR|O_CLOEXEC|O_NOCTTY|O_NONBLOCK|O_NOFOLLOW)) < 0) {
214                                 r = -errno;
215                                 goto rollback;
216                         }
217
218                         if (fstat(p->fd, &st) < 0) {
219                                 r = -errno;
220                                 goto rollback;
221                         }
222
223                         /* FIXME verify user, access mode */
224
225                         if (!S_ISFIFO(st.st_mode)) {
226                                 r = -EEXIST;
227                                 goto rollback;
228                         }
229                 }
230         }
231
232         return 0;
233
234 rollback:
235         socket_close_fds(s);
236         return r;
237 }
238
239 static void socket_unwatch_fds(Socket *s) {
240         SocketPort *p;
241
242         assert(s);
243
244         LIST_FOREACH(port, p, s->ports) {
245                 if (p->fd < 0)
246                         continue;
247
248                 name_unwatch_fd(NAME(s), p->fd);
249         }
250 }
251
252 static int socket_watch_fds(Socket *s) {
253         SocketPort *p;
254         int r;
255
256         assert(s);
257
258         LIST_FOREACH(port, p, s->ports) {
259                 if (p->fd < 0)
260                         continue;
261
262                 if ((r = name_watch_fd(NAME(s), p->fd, POLLIN)) < 0)
263                         goto fail;
264         }
265
266         return 0;
267
268 fail:
269         socket_unwatch_fds(s);
270         return r;
271 }
272
273 static void socket_set_state(Socket *s, SocketState state) {
274         SocketState old_state;
275         assert(s);
276
277         old_state = s->state;
278         s->state = state;
279
280         if (state != SOCKET_START_PRE &&
281             state != SOCKET_START_POST &&
282             state != SOCKET_STOP_PRE &&
283             state != SOCKET_STOP_PRE_SIGTERM &&
284             state != SOCKET_STOP_PRE_SIGKILL &&
285             state != SOCKET_STOP_POST &&
286             state != SOCKET_STOP_POST_SIGTERM &&
287             state != SOCKET_STOP_POST_SIGKILL)
288                 name_unwatch_timer(NAME(s), &s->timer_id);
289
290         if (state != SOCKET_START_PRE &&
291             state != SOCKET_START_POST &&
292             state != SOCKET_STOP_PRE &&
293             state != SOCKET_STOP_PRE_SIGTERM &&
294             state != SOCKET_STOP_PRE_SIGKILL &&
295             state != SOCKET_STOP_POST &&
296             state != SOCKET_STOP_POST_SIGTERM &&
297             state != SOCKET_STOP_POST_SIGKILL)
298                 if (s->control_pid >= 0) {
299                         name_unwatch_pid(NAME(s), s->control_pid);
300                         s->control_pid = 0;
301                 }
302
303         if (state != SOCKET_START_PRE &&
304             state != SOCKET_START_POST &&
305             state != SOCKET_STOP_PRE &&
306             state != SOCKET_STOP_POST)
307                 s->control_command = NULL;
308
309         if (state != SOCKET_START_POST &&
310             state != SOCKET_LISTENING &&
311             state != SOCKET_RUNNING &&
312             state != SOCKET_STOP_PRE &&
313             state != SOCKET_STOP_PRE_SIGTERM &&
314             state != SOCKET_STOP_PRE_SIGKILL)
315                 socket_close_fds(s);
316
317         if (state != SOCKET_LISTENING)
318                 socket_unwatch_fds(s);
319
320         name_notify(NAME(s), state_table[old_state], state_table[s->state]);
321 }
322
323 static int socket_spawn(Socket *s, ExecCommand *c, bool timeout, pid_t *_pid) {
324         pid_t pid;
325         int r;
326
327         assert(s);
328         assert(c);
329         assert(_pid);
330
331         if (timeout) {
332                 if ((r = name_watch_timer(NAME(s), s->timeout_usec, &s->timer_id)) < 0)
333                         goto fail;
334         } else
335                 name_unwatch_timer(NAME(s), &s->timer_id);
336
337         if ((r = exec_spawn(c, &s->exec_context, NULL, 0, &pid)) < 0)
338                 goto fail;
339
340         if ((r = name_watch_pid(NAME(s), pid)) < 0)
341                 /* FIXME: we need to do something here */
342                 goto fail;
343
344         *_pid = pid;
345
346         return 0;
347
348 fail:
349         if (timeout)
350                 name_unwatch_timer(NAME(s), &s->timer_id);
351
352         return r;
353 }
354
355 static void socket_enter_dead(Socket *s, bool success) {
356         assert(s);
357
358         if (!success)
359                 s->failure = true;
360
361         socket_set_state(s, s->failure ? SOCKET_MAINTAINANCE : SOCKET_DEAD);
362 }
363
364 static void socket_enter_stop_post(Socket *s, bool success) {
365         int r;
366         assert(s);
367
368         if (!success)
369                 s->failure = true;
370
371         if ((s->control_command = s->exec_command[SOCKET_EXEC_STOP_POST])) {
372
373                 if ((r = socket_spawn(s, s->control_command, true, &s->control_pid)) < 0)
374                         goto fail;
375
376                 socket_set_state(s, SOCKET_STOP_POST);
377         } else
378                 socket_enter_dead(s, true);
379
380         return;
381
382 fail:
383         log_warning("%s failed to run stop-post executable: %s", name_id(NAME(s)), strerror(-r));
384         socket_enter_dead(s, false);
385 }
386
387 static void socket_enter_signal(Socket *s, SocketState state, bool success) {
388         int r;
389
390         assert(s);
391
392         if (!success)
393                 s->failure = true;
394
395         if (s->control_pid > 0) {
396                 int sig;
397
398                 sig = (state == SOCKET_STOP_PRE_SIGTERM || state == SOCKET_STOP_POST_SIGTERM) ? SIGTERM : SIGKILL;
399
400                 if (kill(s->control_pid, sig) < 0 && errno != ESRCH) {
401                         r = -errno;
402                         goto fail;
403                 }
404
405                 socket_set_state(s, state);
406         } else
407                 socket_enter_dead(s, true);
408
409         return;
410
411 fail:
412         log_warning("%s failed to kill processes: %s", name_id(NAME(s)), strerror(-r));
413
414         if (state == SOCKET_STOP_PRE_SIGTERM || state == SOCKET_STOP_PRE_SIGKILL)
415                 socket_enter_stop_post(s, false);
416         else
417                 socket_enter_dead(s, false);
418 }
419
420 static void socket_enter_stop_pre(Socket *s, bool success) {
421         int r;
422         assert(s);
423
424         if (!success)
425                 s->failure = true;
426
427         if ((s->control_command = s->exec_command[SOCKET_EXEC_STOP_PRE])) {
428
429                 if ((r = socket_spawn(s, s->control_command, true, &s->control_pid)) < 0)
430                         goto fail;
431
432                 socket_set_state(s, SOCKET_STOP_PRE);
433         } else
434                 socket_enter_stop_post(s, true);
435
436         return;
437
438 fail:
439         log_warning("%s failed to run stop-pre executable: %s", name_id(NAME(s)), strerror(-r));
440         socket_enter_stop_post(s, false);
441 }
442
443 static void socket_enter_start_post(Socket *s) {
444         int r;
445         assert(s);
446
447         if ((r = socket_open_fds(s)) < 0 ||
448             (r = socket_watch_fds(s)) < 0) {
449                 log_warning("%s failed to listen on sockets: %s", name_id(NAME(s)), strerror(-r));
450                 goto fail;
451         }
452
453         if ((s->control_command = s->exec_command[SOCKET_EXEC_START_POST])) {
454
455                 if ((r = socket_spawn(s, s->control_command, true, &s->control_pid)) < 0) {
456                         log_warning("%s failed to run start-post executable: %s", name_id(NAME(s)), strerror(-r));
457                         goto fail;
458                 }
459
460                 socket_set_state(s, SOCKET_START_POST);
461         } else
462                 socket_set_state(s, SOCKET_LISTENING);
463
464         return;
465
466 fail:
467         socket_enter_stop_pre(s, false);
468 }
469
470 static void socket_enter_start_pre(Socket *s) {
471         int r;
472         assert(s);
473
474         if ((s->control_command = s->exec_command[SOCKET_EXEC_START_PRE])) {
475
476                 if ((r = socket_spawn(s, s->control_command, true, &s->control_pid)) < 0)
477                         goto fail;
478
479                 socket_set_state(s, SOCKET_START_PRE);
480         } else
481                 socket_enter_start_post(s);
482
483         return;
484
485 fail:
486         log_warning("%s failed to run start-pre exectuable: %s", name_id(NAME(s)), strerror(-r));
487         socket_enter_dead(s, false);
488 }
489
490 static void socket_enter_running(Socket *s) {
491         int r;
492
493         assert(s);
494
495         if ((r = manager_add_job(NAME(s)->meta.manager, JOB_START, NAME(s->service), JOB_REPLACE, true, NULL)) < 0)
496                 goto fail;
497
498         socket_set_state(s, SOCKET_RUNNING);
499         return;
500
501 fail:
502         log_warning("%s failed to queue socket startup job: %s", name_id(NAME(s)), strerror(-r));
503         socket_enter_dead(s, false);
504 }
505
506 static void socket_run_next(Socket *s, bool success) {
507         int r;
508
509         assert(s);
510         assert(s->control_command);
511         assert(s->control_command->command_next);
512
513         if (!success)
514                 s->failure = true;
515
516         s->control_command = s->control_command->command_next;
517
518         if ((r = socket_spawn(s, s->control_command, true, &s->control_pid)) < 0)
519                 goto fail;
520
521         return;
522
523 fail:
524         if (s->state == SOCKET_STOP_PRE)
525                 socket_enter_stop_post(s, false);
526         else if (s->state == SOCKET_STOP_POST)
527                 socket_enter_dead(s, false);
528         else
529                 socket_enter_stop_pre(s, false);
530 }
531
532 static int socket_start(Name *n) {
533         Socket *s = SOCKET(n);
534
535         assert(s);
536
537         /* We cannot fulfill this request right now, try again later
538          * please! */
539         if (s->state == SOCKET_STOP_PRE ||
540             s->state == SOCKET_STOP_PRE_SIGKILL ||
541             s->state == SOCKET_STOP_PRE_SIGTERM ||
542             s->state == SOCKET_STOP_POST ||
543             s->state == SOCKET_STOP_POST_SIGTERM ||
544             s->state == SOCKET_STOP_POST_SIGKILL)
545                 return -EAGAIN;
546
547         if (s->state == SOCKET_START_PRE ||
548             s->state == SOCKET_START_POST)
549                 return 0;
550
551         /* Cannot run this without the service being around */
552         if (s->service->meta.load_state != NAME_LOADED)
553                 return -ENOENT;
554
555         assert(s->state == SOCKET_DEAD || s->state == SOCKET_MAINTAINANCE);
556
557         s->failure = false;
558         socket_enter_start_pre(s);
559         return 0;
560 }
561
562 static int socket_stop(Name *n) {
563         Socket *s = SOCKET(n);
564
565         assert(s);
566
567         /* We cannot fulfill this request right now, try again later
568          * please! */
569         if (s->state == SOCKET_START_PRE ||
570             s->state == SOCKET_START_POST)
571                 return -EAGAIN;
572
573         assert(s->state == SOCKET_LISTENING || s->state == SOCKET_RUNNING);
574
575         socket_enter_stop_pre(s, true);
576         return 0;
577 }
578
579 static NameActiveState socket_active_state(Name *n) {
580         assert(n);
581
582         return state_table[SOCKET(n)->state];
583 }
584
585 static void socket_fd_event(Name *n, int fd, uint32_t events) {
586         Socket *s = SOCKET(n);
587
588         assert(s);
589
590         log_info("Incoming traffic on %s", name_id(n));
591
592         if (events != POLLIN)
593                 socket_enter_stop_pre(s, false);
594
595         socket_enter_running(s);
596 }
597
598 static void socket_sigchld_event(Name *n, pid_t pid, int code, int status) {
599         Socket *s = SOCKET(n);
600         bool success;
601
602         assert(s);
603         assert(pid >= 0);
604
605         success = code == CLD_EXITED || status == 0;
606         s->failure = s->failure || !success;
607
608         assert(s->control_pid == pid);
609         assert(s->control_command);
610
611         exec_status_fill(&s->control_command->exec_status, pid, code, status);
612         s->control_pid = 0;
613
614         log_debug("%s: control process exited, code=%s status=%i", name_id(n), sigchld_code(code), status);
615
616         if (s->control_command->command_next &&
617             (success || (s->state == SOCKET_EXEC_STOP_PRE || s->state == SOCKET_EXEC_STOP_POST)))
618                 socket_run_next(s, success);
619         else {
620                 /* No further commands for this step, so let's figure
621                  * out what to do next */
622
623                 switch (s->state) {
624
625                 case SOCKET_START_PRE:
626                         if (success)
627                                 socket_enter_start_pre(s);
628                         else
629                                 socket_enter_stop_pre(s, false);
630                         break;
631
632                 case SOCKET_START_POST:
633                         if (success)
634                                 socket_set_state(s, SOCKET_LISTENING);
635                         else
636                                 socket_enter_stop_pre(s, false);
637                         break;
638
639                 case SOCKET_STOP_PRE:
640                 case SOCKET_STOP_PRE_SIGTERM:
641                 case SOCKET_STOP_PRE_SIGKILL:
642                         socket_enter_stop_post(s, success);
643                         break;
644
645                 case SOCKET_STOP_POST:
646                 case SOCKET_STOP_POST_SIGTERM:
647                 case SOCKET_STOP_POST_SIGKILL:
648                         socket_enter_dead(s, success);
649                         break;
650
651                 default:
652                         assert_not_reached("Uh, control process died at wrong time.");
653                 }
654         }
655 }
656
657 static void socket_timer_event(Name *n, int id, uint64_t elapsed) {
658         Socket *s = SOCKET(n);
659
660         assert(s);
661         assert(elapsed == 1);
662
663         assert(s->timer_id == id);
664
665         switch (s->state) {
666
667         case SOCKET_START_PRE:
668         case SOCKET_START_POST:
669                 log_warning("%s operation timed out. Stopping.", name_id(n));
670                 socket_enter_stop_pre(s, false);
671                 break;
672
673         case SOCKET_STOP_PRE:
674                 log_warning("%s stopping timed out. Terminating.", name_id(n));
675                 socket_enter_signal(s, SOCKET_STOP_PRE_SIGTERM, false);
676                 break;
677
678         case SOCKET_STOP_PRE_SIGTERM:
679                 log_warning("%s stopping timed out. Killing.", name_id(n));
680                 socket_enter_signal(s, SOCKET_STOP_PRE_SIGKILL, false);
681                 break;
682
683         case SOCKET_STOP_PRE_SIGKILL:
684                 log_warning("%s still around after SIGKILL. Ignoring.", name_id(n));
685                 socket_enter_stop_post(s, false);
686                 break;
687
688         case SOCKET_STOP_POST:
689                 log_warning("%s stopping timed out (2). Terminating.", name_id(n));
690                 socket_enter_signal(s, SOCKET_STOP_POST_SIGTERM, false);
691                 break;
692
693         case SOCKET_STOP_POST_SIGTERM:
694                 log_warning("%s stopping timed out (2). Killing.", name_id(n));
695                 socket_enter_signal(s, SOCKET_STOP_POST_SIGKILL, false);
696                 break;
697
698         case SOCKET_STOP_POST_SIGKILL:
699                 log_warning("%s still around after SIGKILL (2). Entering maintainance mode.", name_id(n));
700                 socket_enter_dead(s, false);
701                 break;
702
703         default:
704                 assert_not_reached("Timeout at wrong time.");
705         }
706 }
707
708 const NameVTable socket_vtable = {
709         .suffix = ".socket",
710
711         .init = socket_init,
712         .done = socket_done,
713
714         .dump = socket_dump,
715
716         .start = socket_start,
717         .stop = socket_stop,
718
719         .active_state = socket_active_state,
720
721         .fd_event = socket_fd_event,
722         .sigchld_event = socket_sigchld_event,
723         .timer_event = socket_timer_event
724 };