2 This file is part of GNUnet.
3 (C) 2009 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 2, or (at your
8 option) any later version.
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11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
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16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 * @file arm/gnunet-service-arm.c
23 * @brief the automated restart manager service
24 * @author Christian Grothoff
27 * - multiple start-stop requests with RC>1 can result
28 * in UP/DOWN signals based on "pending" that are inaccurate...
29 * => have list of clients waiting for a resolution instead of
30 * giving instant (but incorrect) replies
31 * - code could go into restart-loop for a service
32 * if service crashes instantly -- need exponential back-off
33 * - need to test auto-restart code on configuration changes;
34 * - should refine restart code to check if *relevant* parts of the
35 * configuration were changed (anything in the section for the service)
36 * - should have a way to specify dependencies between services and
37 * manage restarts of groups of services
40 #include "gnunet_client_lib.h"
41 #include "gnunet_getopt_lib.h"
42 #include "gnunet_os_lib.h"
43 #include "gnunet_protocols.h"
44 #include "gnunet_service_lib.h"
49 * Run maintenance every second.
51 #define MAINT_FREQUENCY GNUNET_TIME_UNIT_SECONDS
54 * How long do we wait until we decide that a service
57 #define CHECK_TIMEOUT GNUNET_TIME_UNIT_MINUTES
61 typedef void (*CleanCallback) (void *cls, struct ServiceList * pos);
64 * List of our services.
69 * This is a linked list.
71 struct ServiceList *next;
74 * Name of the service.
79 * Name of the binary used.
84 * Name of the configuration file used.
89 * Function to call upon kill completion (waitpid), NULL
90 * if we should simply restart the process.
92 CleanCallback kill_continuation;
95 * Closure for kill_continuation.
97 void *kill_continuation_cls;
100 * Process ID of the child.
105 * Last time the config of this service was
111 * Reference counter (counts how many times we've been
112 * asked to start the service). We only actually stop
113 * it once rc hits zero.
120 * List of running services.
122 static struct ServiceList *running;
127 static struct GNUNET_CONFIGURATION_Handle *cfg;
132 static struct GNUNET_SCHEDULER_Handle *sched;
135 * Command to prepend to each actual command.
137 static char *prefix_command;
141 write_result (void *cls, size_t size, void *buf)
144 struct GNUNET_MessageHeader *msg;
147 return 0; /* error, not much we can do */
148 GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
150 msg->size = htons (sizeof (struct GNUNET_MessageHeader));
151 msg->type = htons (*res);
153 return sizeof (struct GNUNET_MessageHeader);
159 * Signal our client that we will start or stop the
162 * @return NULL if it was not found
165 signal_result (struct GNUNET_SERVER_Client *client,
166 const char *name, uint16_t result)
171 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
172 "Telling client that service `%s' is now %s\n",
174 result == GNUNET_MESSAGE_TYPE_ARM_IS_DOWN ? "down" : "up");
176 res = GNUNET_malloc (sizeof (uint16_t));
178 GNUNET_SERVER_notify_transmit_ready (client,
179 sizeof (struct GNUNET_MessageHeader),
180 GNUNET_TIME_UNIT_FOREVER_REL,
186 * Find the process with the given service
187 * name in the given list, remove it and return it.
189 * @return NULL if it was not found
191 static struct ServiceList *
192 find_name (const char *name)
194 struct ServiceList *pos;
195 struct ServiceList *prev;
201 if (0 == strcmp (pos->name, name))
206 prev->next = pos->next;
218 free_entry (struct ServiceList *pos)
220 GNUNET_free_non_null (pos->config);
221 GNUNET_free_non_null (pos->binary);
222 GNUNET_free (pos->name);
230 * Actually start the process for the given service.
232 * @param sl identifies service to start
235 start_process (struct ServiceList *sl)
240 unsigned int argv_size;
243 const char *firstarg;
248 GNUNET_CONFIGURATION_get_value_string (cfg,
249 sl->name, "PREFIX", &loprefix))
250 loprefix = GNUNET_strdup (prefix_command);
252 GNUNET_CONFIGURATION_get_value_string (cfg,
253 sl->name, "OPTIONS", &options))
254 options = GNUNET_strdup ("");
255 use_debug = GNUNET_CONFIGURATION_get_value_yesno (cfg, sl->name, "DEBUG");
257 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Starting service `%s'\n"), sl->name);
259 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
260 "Starting service `%s' using binary `%s' and configuration `%s'\n",
261 sl->name, sl->binary, sl->config);
267 while ('\0' != *lopos)
274 while ('\0' != *optpos)
281 argv = GNUNET_malloc (argv_size * sizeof (char *));
285 while ('\0' != *lopos)
287 while (*lopos == ' ')
293 argv[argv_size++] = lopos;
294 while (('\0' != *lopos) && (' ' != *lopos))
302 firstarg = sl->binary;
303 argv[argv_size++] = sl->binary;
304 argv[argv_size++] = "-c";
305 argv[argv_size++] = sl->config;
306 if (GNUNET_YES == use_debug)
308 argv[argv_size++] = "-L";
309 argv[argv_size++] = "DEBUG";
312 while ('\0' != *optpos)
314 while (*optpos == ' ')
318 argv[argv_size++] = optpos;
319 while (('\0' != *optpos) && (' ' != *optpos))
326 argv[argv_size++] = NULL;
327 sl->pid = GNUNET_OS_start_process_v (firstarg, argv);
329 GNUNET_free (loprefix);
330 GNUNET_free (options);
335 * Start the specified service.
338 start_service (struct GNUNET_SERVER_Client *client, const char *servicename)
340 struct ServiceList *sl;
344 sl = find_name (servicename);
347 /* already running, just increment RC */
348 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
349 _("Service `%s' already running.\n"), servicename);
353 signal_result (client, servicename, GNUNET_MESSAGE_TYPE_ARM_IS_UP);
357 GNUNET_CONFIGURATION_get_value_string (cfg,
358 servicename, "BINARY", &binary))
360 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
361 _("Binary implementing service `%s' not known!\n"),
363 signal_result (client, servicename, GNUNET_MESSAGE_TYPE_ARM_IS_DOWN);
367 GNUNET_CONFIGURATION_get_value_filename (cfg,
371 (0 != STAT (config, &sbuf)))
373 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
374 _("Configuration file `%s' for service `%s' not known!\n"),
375 config, servicename);
376 signal_result (client, servicename, GNUNET_MESSAGE_TYPE_ARM_IS_DOWN);
377 GNUNET_free (binary);
378 GNUNET_free (config);
381 sl = GNUNET_malloc (sizeof (struct ServiceList));
382 sl->name = GNUNET_strdup (servicename);
387 sl->mtime = sbuf.st_mtime;
390 signal_result (client, servicename, GNUNET_MESSAGE_TYPE_ARM_IS_UP);
395 free_and_signal (void *cls, struct ServiceList *pos)
397 struct GNUNET_SERVER_Client *client = cls;
398 /* find_name will remove "pos" from the list! */
399 GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Service `%s' stopped\n", pos->name);
400 signal_result (client, pos->name, GNUNET_MESSAGE_TYPE_ARM_IS_DOWN);
401 GNUNET_SERVER_receive_done (client, GNUNET_OK);
402 GNUNET_SERVER_client_drop (client);
408 * Stop the specified service.
411 stop_service (struct GNUNET_SERVER_Client *client, const char *servicename)
413 struct ServiceList *pos;
414 struct GNUNET_CLIENT_Connection *sc;
416 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
417 "Preparing to stop `%s'\n", servicename);
418 pos = find_name (servicename);
419 if ((pos != NULL) && (pos->kill_continuation != NULL))
421 /* killing already in progress */
422 signal_result (client, servicename, GNUNET_MESSAGE_TYPE_ARM_IS_DOWN);
425 if ((pos != NULL) && (pos->rc > 1))
427 /* RC>1, just decrement RC */
431 signal_result (client, servicename, GNUNET_MESSAGE_TYPE_ARM_IS_UP);
432 GNUNET_SERVER_receive_done (client, GNUNET_OK);
437 if (0 != PLIBC_KILL (pos->pid, SIGTERM))
438 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "kill");
441 pos->kill_continuation = &free_and_signal;
442 pos->kill_continuation_cls = client;
443 GNUNET_SERVER_client_keep (client);
447 sc = GNUNET_CLIENT_connect (sched, servicename, cfg);
448 GNUNET_CLIENT_service_shutdown (sc);
449 GNUNET_CLIENT_disconnect (sc);
450 signal_result (client, servicename, GNUNET_MESSAGE_TYPE_ARM_IS_DOWN);
451 GNUNET_SERVER_receive_done (client, GNUNET_OK);
457 * Handle START-message.
459 * @param cls closure (always NULL)
460 * @param client identification of the client
461 * @param message the actual message
462 * @return GNUNET_OK to keep the connection open,
463 * GNUNET_SYSERR to close it (signal serious error)
466 handle_start (void *cls,
467 struct GNUNET_SERVER_Client *client,
468 const struct GNUNET_MessageHeader *message)
470 const char *servicename;
473 size = ntohs (message->size);
474 size -= sizeof (struct GNUNET_MessageHeader);
475 servicename = (const char *) &message[1];
476 if ((size == 0) || (servicename[size - 1] != '\0'))
479 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
482 start_service (client, servicename);
483 GNUNET_SERVER_receive_done (client, GNUNET_OK);
488 * Handle STOP-message.
490 * @param cls closure (always NULL)
491 * @param client identification of the client
492 * @param message the actual message
493 * @return GNUNET_OK to keep the connection open,
494 * GNUNET_SYSERR to close it (signal serious error)
497 handle_stop (void *cls,
498 struct GNUNET_SERVER_Client *client,
499 const struct GNUNET_MessageHeader *message)
501 const char *servicename;
504 size = ntohs (message->size);
505 size -= sizeof (struct GNUNET_MessageHeader);
506 servicename = (const char *) &message[1];
507 if ((size == 0) || (servicename[size - 1] != '\0'))
510 GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
513 stop_service (client, servicename);
519 * Background task doing maintenance.
525 maint (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
527 struct ServiceList *pos;
528 struct ServiceList *prev;
529 struct ServiceList *next;
535 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
537 GNUNET_log (GNUNET_ERROR_TYPE_INFO, _("Stopping all services\n"));
538 while (NULL != (pos = running))
541 if (0 != PLIBC_KILL (pos->pid, SIGTERM))
542 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "kill");
543 if (GNUNET_OK != GNUNET_OS_process_wait(pos->pid))
544 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "waitpid");
549 GNUNET_SCHEDULER_add_delayed (tc->sched,
551 GNUNET_SCHEDULER_PRIORITY_IDLE,
552 GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
553 MAINT_FREQUENCY, &maint, cfg);
555 /* check for services that died (WAITPID) */
558 while (NULL != (pos = next))
560 enum GNUNET_OS_ProcessStatusType statusType;
561 unsigned long statusCode;
566 if (NULL != pos->kill_continuation)
572 pos->kill_continuation (pos->kill_continuation_cls, pos);
576 if ( (GNUNET_SYSERR == (ret = GNUNET_OS_process_status(pos->pid,
579 ( (ret == GNUNET_NO) ||
580 (statusType == GNUNET_OS_PROCESS_STOPPED) ||
581 (statusType == GNUNET_OS_PROCESS_RUNNING) ) )
586 if (statusType == GNUNET_OS_PROCESS_EXITED)
588 statstr = _( /* process termination method */ "exit");
589 statcode = statusCode;
591 else if (statusType == GNUNET_OS_PROCESS_SIGNALED)
593 statstr = _( /* process termination method */ "signal");
594 statcode = statusCode;
598 statstr = _( /* process termination method */ "unknown");
601 if (NULL != pos->kill_continuation)
607 pos->kill_continuation (pos->kill_continuation_cls, pos);
610 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
611 _("Service `%s' terminated with status %s/%d, will try to restart it!\n"),
612 pos->name, statstr, statcode);
613 /* schedule restart */
618 /* check for services that need to be restarted due to
619 configuration changes or because the last restart failed */
623 if ((0 == STAT (pos->config, &sbuf)) && (pos->mtime < sbuf.st_mtime))
625 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
626 _("Restarting service `%s' due to configuration file change.\n"));
627 if (0 != PLIBC_KILL (pos->pid, SIGTERM))
628 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "kill");
632 GNUNET_log (GNUNET_ERROR_TYPE_INFO,
633 _("Restarting service `%s'.\n"), pos->name);
634 /* FIXME: should have some exponentially
635 increasing timer to avoid tight restart loops */
644 * List of handlers for the messages understood by this
647 static struct GNUNET_SERVER_MessageHandler handlers[] = {
648 {&handle_start, NULL, GNUNET_MESSAGE_TYPE_ARM_START, 0},
649 {&handle_stop, NULL, GNUNET_MESSAGE_TYPE_ARM_STOP, 0},
655 * Process arm requests.
658 * @param s scheduler to use
659 * @param server the initialized server
660 * @param c configuration to use
664 struct GNUNET_SCHEDULER_Handle *s,
665 struct GNUNET_SERVER_Handle *server,
666 struct GNUNET_CONFIGURATION_Handle *c)
668 char *defaultservices;
671 GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Starting...\n");
675 GNUNET_CONFIGURATION_get_value_string (cfg,
679 prefix_command = GNUNET_strdup ("");
680 /* start default services... */
682 GNUNET_CONFIGURATION_get_value_string (cfg,
688 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
689 "Starting default services `%s'\n", defaultservices);
691 pos = strtok (defaultservices, " ");
694 start_service (NULL, pos);
695 pos = strtok (NULL, " ");
697 GNUNET_free (defaultservices);
702 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
703 "No default services configured.\n");
707 /* process client requests */
708 GNUNET_SERVER_add_handlers (server, handlers);
710 /* manage services */
711 GNUNET_SCHEDULER_add_delayed (sched,
713 GNUNET_SCHEDULER_PRIORITY_IDLE,
714 GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
715 MAINT_FREQUENCY, &maint, NULL);
720 * The main function for the arm service.
722 * @param argc number of arguments from the command line
723 * @param argv command line arguments
724 * @return 0 ok, 1 on error
727 main (int argc, char *const *argv)
730 GNUNET_SERVICE_run (argc,
731 argv, "arm", &run, NULL, NULL, NULL)) ? 0 : 1;
734 /* end of gnunet-service-arm.c */