2 * collectd - src/exec.c
3 * Copyright (C) 2007-2010 Florian octo Forster
4 * Copyright (C) 2007-2009 Sebastian Harl
5 * Copyright (C) 2008 Peter Holik
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; only version 2 of the License is applicable.
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * General Public License for more details.
16 * You should have received a copy of the GNU General Public License along
17 * with this program; if not, write to the Free Software Foundation, Inc.,
18 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 * Florian octo Forster <octo at verplant.org>
22 * Sebastian Harl <sh at tokkee.org>
23 * Peter Holik <peter at holik.at>
26 #define _BSD_SOURCE /* For setgroups */
32 #include "utils_cmd_putval.h"
33 #include "utils_cmd_putnotif.h"
35 #include <sys/types.h>
42 #define PL_NORMAL 0x01
43 #define PL_NOTIF_ACTION 0x02
45 #define PL_RUNNING 0x10
51 * Access to this structure is serialized using the `pl_lock' lock and the
52 * `PL_RUNNING' flag. The execution of notifications is *not* serialized, so
53 * all functions used to handle notifications MUST NOT write to this structure.
54 * The `pid' and `status' fields are thus unused if the `PL_NOTIF_ACTION' flag
56 * The `PL_RUNNING' flag is set in `exec_read' and unset in `exec_read_one'.
58 struct program_list_s;
59 typedef struct program_list_s program_list_t;
72 typedef struct program_list_and_notification_s
76 } program_list_and_notification_t;
81 static program_list_t *pl_head = NULL;
82 static pthread_mutex_t pl_lock = PTHREAD_MUTEX_INITIALIZER;
87 static void sigchld_handler (int __attribute__((unused)) signal) /* {{{ */
91 while ((pid = waitpid (-1, &status, WNOHANG)) > 0)
94 for (pl = pl_head; pl != NULL; pl = pl->next)
99 } /* while (waitpid) */
100 } /* void sigchld_handler }}} */
102 static int exec_config_exec (oconfig_item_t *ci) /* {{{ */
108 if (ci->children_num != 0)
110 WARNING ("exec plugin: The config option `%s' may not be a block.",
114 if (ci->values_num < 2)
116 WARNING ("exec plugin: The config option `%s' needs at least two "
117 "arguments.", ci->key);
120 if ((ci->values[0].type != OCONFIG_TYPE_STRING)
121 || (ci->values[1].type != OCONFIG_TYPE_STRING))
123 WARNING ("exec plugin: The first two arguments to the `%s' option must "
124 "be string arguments.", ci->key);
128 pl = (program_list_t *) malloc (sizeof (program_list_t));
131 ERROR ("exec plugin: malloc failed.");
134 memset (pl, '\0', sizeof (program_list_t));
136 if (strcasecmp ("NotificationExec", ci->key) == 0)
137 pl->flags |= PL_NOTIF_ACTION;
139 pl->flags |= PL_NORMAL;
141 pl->user = strdup (ci->values[0].value.string);
142 if (pl->user == NULL)
144 ERROR ("exec plugin: strdup failed.");
149 pl->group = strchr (pl->user, ':');
150 if (pl->group != NULL)
156 pl->exec = strdup (ci->values[1].value.string);
157 if (pl->exec == NULL)
159 ERROR ("exec plugin: strdup failed.");
165 pl->argv = (char **) malloc (ci->values_num * sizeof (char *));
166 if (pl->argv == NULL)
168 ERROR ("exec plugin: malloc failed.");
174 memset (pl->argv, '\0', ci->values_num * sizeof (char *));
177 char *tmp = strrchr (ci->values[1].value.string, '/');
179 sstrncpy (buffer, ci->values[1].value.string, sizeof (buffer));
181 sstrncpy (buffer, tmp + 1, sizeof (buffer));
183 pl->argv[0] = strdup (buffer);
184 if (pl->argv[0] == NULL)
186 ERROR ("exec plugin: malloc failed.");
194 for (i = 1; i < (ci->values_num - 1); i++)
196 if (ci->values[i + 1].type == OCONFIG_TYPE_STRING)
198 pl->argv[i] = strdup (ci->values[i + 1].value.string);
202 if (ci->values[i + 1].type == OCONFIG_TYPE_NUMBER)
204 ssnprintf (buffer, sizeof (buffer), "%lf",
205 ci->values[i + 1].value.number);
209 if (ci->values[i + 1].value.boolean)
210 sstrncpy (buffer, "true", sizeof (buffer));
212 sstrncpy (buffer, "false", sizeof (buffer));
215 pl->argv[i] = strdup (buffer);
218 if (pl->argv[i] == NULL)
220 ERROR ("exec plugin: strdup failed.");
225 if (i < (ci->values_num - 1))
238 for (i = 0; pl->argv[i] != NULL; i++)
240 DEBUG ("exec plugin: argv[%i] = %s", i, pl->argv[i]);
247 } /* int exec_config_exec }}} */
249 static int exec_config (oconfig_item_t *ci) /* {{{ */
253 for (i = 0; i < ci->children_num; i++)
255 oconfig_item_t *child = ci->children + i;
256 if ((strcasecmp ("Exec", child->key) == 0)
257 || (strcasecmp ("NotificationExec", child->key) == 0))
258 exec_config_exec (child);
261 WARNING ("exec plugin: Unknown config option `%s'.", child->key);
266 } /* int exec_config }}} */
268 static void set_environment (void) /* {{{ */
273 ssnprintf (buffer, sizeof (buffer), "%.3f",
274 CDTIME_T_TO_DOUBLE (plugin_get_interval ()));
275 setenv ("COLLECTD_INTERVAL", buffer, /* overwrite = */ 1);
277 ssnprintf (buffer, sizeof (buffer), "%s", hostname_g);
278 setenv ("COLLECTD_HOSTNAME", buffer, /* overwrite = */ 1);
280 ssnprintf (buffer, sizeof (buffer), "COLLECTD_INTERVAL=%.3f",
281 CDTIME_T_TO_DOUBLE (plugin_get_interval ()));
284 ssnprintf (buffer, sizeof (buffer), "COLLECTD_HOSTNAME=%s", hostname_g);
287 } /* }}} void set_environment */
289 __attribute__((noreturn))
290 static void exec_child (program_list_t *pl) /* {{{ */
297 struct passwd *sp_ptr;
303 status = getpwnam_r (pl->user, &sp, nambuf, sizeof (nambuf), &sp_ptr);
306 ERROR ("exec plugin: Failed to get user information for user ``%s'': %s",
307 pl->user, sstrerror (errno, errbuf, sizeof (errbuf)));
312 ERROR ("exec plugin: No such user: `%s'", pl->user);
320 ERROR ("exec plugin: Cowardly refusing to exec program as root.");
324 /* The group configured in the configfile is set as effective group, because
325 * this way the forked process can (re-)gain the user's primary group. */
327 if (NULL != pl->group)
329 if ('\0' != *pl->group) {
330 struct group *gr_ptr = NULL;
333 status = getgrnam_r (pl->group, &gr, nambuf, sizeof (nambuf), &gr_ptr);
336 ERROR ("exec plugin: Failed to get group information "
337 "for group ``%s'': %s", pl->group,
338 sstrerror (errno, errbuf, sizeof (errbuf)));
343 ERROR ("exec plugin: No such group: `%s'", pl->group);
353 } /* if (pl->group == NULL) */
364 if ((gid != egid) && (egid != -1))
370 setgroups (glist_len, glist);
372 #endif /* HAVE_SETGROUPS */
374 status = setgid (gid);
377 ERROR ("exec plugin: setgid (%i) failed: %s",
378 gid, sstrerror (errno, errbuf, sizeof (errbuf)));
384 status = setegid (egid);
387 ERROR ("exec plugin: setegid (%i) failed: %s",
388 egid, sstrerror (errno, errbuf, sizeof (errbuf)));
393 status = setuid (uid);
396 ERROR ("exec plugin: setuid (%i) failed: %s",
397 uid, sstrerror (errno, errbuf, sizeof (errbuf)));
401 status = execvp (pl->exec, pl->argv);
403 ERROR ("exec plugin: Failed to execute ``%s'': %s",
404 pl->exec, sstrerror (errno, errbuf, sizeof (errbuf)));
406 } /* void exec_child }}} */
408 static void reset_signal_mask (void) /* {{{ */
412 memset (&ss, 0, sizeof (ss));
414 sigprocmask (SIG_SETMASK, &ss, /* old mask = */ NULL);
415 } /* }}} void reset_signal_mask */
418 * Creates three pipes (one for reading, one for writing and one for errors),
419 * forks a child, sets up the pipes so that fd_in is connected to STDIN of
420 * the child and fd_out is connected to STDOUT and fd_err is connected to STDERR
421 * of the child. Then is calls `exec_child'.
423 static int fork_child (program_list_t *pl, int *fd_in, int *fd_out, int *fd_err) /* {{{ */
435 status = pipe (fd_pipe_in);
438 ERROR ("exec plugin: pipe failed: %s",
439 sstrerror (errno, errbuf, sizeof (errbuf)));
443 status = pipe (fd_pipe_out);
446 ERROR ("exec plugin: pipe failed: %s",
447 sstrerror (errno, errbuf, sizeof (errbuf)));
451 status = pipe (fd_pipe_err);
454 ERROR ("exec plugin: pipe failed: %s",
455 sstrerror (errno, errbuf, sizeof (errbuf)));
462 ERROR ("exec plugin: fork failed: %s",
463 sstrerror (errno, errbuf, sizeof (errbuf)));
471 /* Close all file descriptors but the pipe end we need. */
472 fd_num = getdtablesize ();
473 for (fd = 0; fd < fd_num; fd++)
475 if ((fd == fd_pipe_in[0])
476 || (fd == fd_pipe_out[1])
477 || (fd == fd_pipe_err[1]))
482 /* Connect the `in' pipe to STDIN */
483 if (fd_pipe_in[0] != STDIN_FILENO)
485 dup2 (fd_pipe_in[0], STDIN_FILENO);
486 close (fd_pipe_in[0]);
489 /* Now connect the `out' pipe to STDOUT */
490 if (fd_pipe_out[1] != STDOUT_FILENO)
492 dup2 (fd_pipe_out[1], STDOUT_FILENO);
493 close (fd_pipe_out[1]);
496 /* Now connect the `out' pipe to STDOUT */
497 if (fd_pipe_err[1] != STDERR_FILENO)
499 dup2 (fd_pipe_err[1], STDERR_FILENO);
500 close (fd_pipe_err[1]);
505 /* Unblock all signals */
506 reset_signal_mask ();
509 /* does not return */
512 close (fd_pipe_in[0]);
513 close (fd_pipe_out[1]);
514 close (fd_pipe_err[1]);
517 *fd_in = fd_pipe_in[1];
519 close (fd_pipe_in[1]);
522 *fd_out = fd_pipe_out[0];
524 close (fd_pipe_out[0]);
527 *fd_err = fd_pipe_err[0];
529 close (fd_pipe_err[0]);
532 } /* int fork_child }}} */
534 static int parse_line (char *buffer) /* {{{ */
536 if (strncasecmp ("PUTVAL", buffer, strlen ("PUTVAL")) == 0)
537 return (handle_putval (stdout, buffer));
538 else if (strncasecmp ("PUTNOTIF", buffer, strlen ("PUTNOTIF")) == 0)
539 return (handle_putnotif (stdout, buffer));
542 ERROR ("exec plugin: Unable to parse command, ignoring line: \"%s\"",
546 } /* int parse_line }}} */
548 static void *exec_read_one (void *arg) /* {{{ */
550 program_list_t *pl = (program_list_t *) arg;
551 int fd, fd_err, highest_fd;
554 char buffer[1200]; /* if not completely read */
555 char buffer_err[1024];
556 char *pbuffer = buffer;
557 char *pbuffer_err = buffer_err;
559 status = fork_child (pl, NULL, &fd, &fd_err);
562 /* Reset the "running" flag */
563 pthread_mutex_lock (&pl_lock);
564 pl->flags &= ~PL_RUNNING;
565 pthread_mutex_unlock (&pl_lock);
566 pthread_exit ((void *) 1);
570 assert (pl->pid != 0);
574 FD_SET(fd_err, &fdset);
576 /* Determine the highest file descriptor */
577 highest_fd = (fd > fd_err) ? fd : fd_err;
579 /* We use a copy of fdset, as select modifies it */
586 status = select (highest_fd + 1, ©, NULL, NULL, NULL);
594 if (FD_ISSET(fd, ©))
598 len = read(fd, pbuffer, sizeof(buffer) - 1 - (pbuffer - buffer));
602 if (errno == EAGAIN || errno == EINTR) continue;
605 else if (len == 0) break; /* We've reached EOF */
609 len += pbuffer - buffer;
612 while ((pnl = strchr(pbuffer, '\n')))
615 if (*(pnl-1) == '\r' ) *(pnl-1) = '\0';
617 parse_line (pbuffer);
621 /* not completely read ? */
622 if (pbuffer - buffer < len)
624 len -= pbuffer - buffer;
625 memmove(buffer, pbuffer, len);
626 pbuffer = buffer + len;
631 else if (FD_ISSET(fd_err, ©))
635 len = read(fd_err, pbuffer_err, sizeof(buffer_err) - 1 - (pbuffer_err - buffer_err));
639 if (errno == EAGAIN || errno == EINTR)
645 /* We've reached EOF */
646 NOTICE ("exec plugin: Program `%s' has closed STDERR.", pl->exec);
648 /* Remove file descriptor form select() set. */
649 FD_CLR (fd_err, &fdset);
653 /* Clean up file descriptor */
659 pbuffer_err[len] = '\0';
661 len += pbuffer_err - buffer_err;
662 pbuffer_err = buffer_err;
664 while ((pnl = strchr(pbuffer_err, '\n')))
667 if (*(pnl-1) == '\r' ) *(pnl-1) = '\0';
669 ERROR ("exec plugin: exec_read_one: error = %s", pbuffer_err);
673 /* not completely read ? */
674 if (pbuffer_err - buffer_err < len)
676 len -= pbuffer_err - buffer_err;
677 memmove(buffer_err, pbuffer_err, len);
678 pbuffer_err = buffer_err + len;
681 pbuffer_err = buffer_err;
687 DEBUG ("exec plugin: exec_read_one: Waiting for `%s' to exit.", pl->exec);
688 if (waitpid (pl->pid, &status, 0) > 0)
691 DEBUG ("exec plugin: Child %i exited with status %i.",
692 (int) pl->pid, pl->status);
696 pthread_mutex_lock (&pl_lock);
697 pl->flags &= ~PL_RUNNING;
698 pthread_mutex_unlock (&pl_lock);
704 pthread_exit ((void *) 0);
706 } /* void *exec_read_one }}} */
708 static void *exec_notification_one (void *arg) /* {{{ */
710 program_list_t *pl = ((program_list_and_notification_t *) arg)->pl;
711 notification_t *n = &((program_list_and_notification_t *) arg)->n;
712 notification_meta_t *meta;
717 const char *severity;
719 pid = fork_child (pl, &fd, NULL, NULL);
722 pthread_exit ((void *) 1);
725 fh = fdopen (fd, "w");
729 ERROR ("exec plugin: fdopen (%i) failed: %s", fd,
730 sstrerror (errno, errbuf, sizeof (errbuf)));
731 kill (pl->pid, SIGTERM);
735 pthread_exit ((void *) 1);
738 severity = "FAILURE";
739 if (n->severity == NOTIF_WARNING)
740 severity = "WARNING";
741 else if (n->severity == NOTIF_OKAY)
747 severity, CDTIME_T_TO_DOUBLE (n->time));
749 /* Print the optional fields */
750 if (strlen (n->host) > 0)
751 fprintf (fh, "Host: %s\n", n->host);
752 if (strlen (n->plugin) > 0)
753 fprintf (fh, "Plugin: %s\n", n->plugin);
754 if (strlen (n->plugin_instance) > 0)
755 fprintf (fh, "PluginInstance: %s\n", n->plugin_instance);
756 if (strlen (n->type) > 0)
757 fprintf (fh, "Type: %s\n", n->type);
758 if (strlen (n->type_instance) > 0)
759 fprintf (fh, "TypeInstance: %s\n", n->type_instance);
761 for (meta = n->meta; meta != NULL; meta = meta->next)
763 if (meta->type == NM_TYPE_STRING)
764 fprintf (fh, "%s: %s\n", meta->name, meta->nm_value.nm_string);
765 else if (meta->type == NM_TYPE_SIGNED_INT)
766 fprintf (fh, "%s: %"PRIi64"\n", meta->name, meta->nm_value.nm_signed_int);
767 else if (meta->type == NM_TYPE_UNSIGNED_INT)
768 fprintf (fh, "%s: %"PRIu64"\n", meta->name, meta->nm_value.nm_unsigned_int);
769 else if (meta->type == NM_TYPE_DOUBLE)
770 fprintf (fh, "%s: %e\n", meta->name, meta->nm_value.nm_double);
771 else if (meta->type == NM_TYPE_BOOLEAN)
772 fprintf (fh, "%s: %s\n", meta->name,
773 meta->nm_value.nm_boolean ? "true" : "false");
776 fprintf (fh, "\n%s\n", n->message);
781 waitpid (pid, &status, 0);
783 DEBUG ("exec plugin: Child %i exited with status %i.",
787 plugin_notification_meta_free (n->meta);
790 pthread_exit ((void *) 0);
792 } /* void *exec_notification_one }}} */
794 static int exec_init (void) /* {{{ */
798 memset (&sa, '\0', sizeof (sa));
799 sa.sa_handler = sigchld_handler;
800 sigaction (SIGCHLD, &sa, NULL);
803 } /* int exec_init }}} */
805 static int exec_read (void) /* {{{ */
809 for (pl = pl_head; pl != NULL; pl = pl->next)
814 /* Only execute `normal' style executables here. */
815 if ((pl->flags & PL_NORMAL) == 0)
818 pthread_mutex_lock (&pl_lock);
819 /* Skip if a child is already running. */
820 if ((pl->flags & PL_RUNNING) != 0)
822 pthread_mutex_unlock (&pl_lock);
825 pl->flags |= PL_RUNNING;
826 pthread_mutex_unlock (&pl_lock);
828 pthread_attr_init (&attr);
829 pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
830 plugin_thread_create (&t, &attr, exec_read_one, (void *) pl);
831 pthread_attr_destroy (&attr);
835 } /* int exec_read }}} */
837 static int exec_notification (const notification_t *n, /* {{{ */
838 user_data_t __attribute__((unused)) *user_data)
841 program_list_and_notification_t *pln;
843 for (pl = pl_head; pl != NULL; pl = pl->next)
848 /* Only execute `notification' style executables here. */
849 if ((pl->flags & PL_NOTIF_ACTION) == 0)
852 /* Skip if a child is already running. */
856 pln = (program_list_and_notification_t *) malloc (sizeof
857 (program_list_and_notification_t));
860 ERROR ("exec plugin: malloc failed.");
865 memcpy (&pln->n, n, sizeof (notification_t));
867 /* Set the `meta' member to NULL, otherwise `plugin_notification_meta_copy'
868 * will run into an endless loop. */
870 plugin_notification_meta_copy (&pln->n, n);
872 pthread_attr_init (&attr);
873 pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
874 plugin_thread_create (&t, &attr, exec_notification_one, (void *) pln);
875 pthread_attr_destroy (&attr);
879 } /* }}} int exec_notification */
881 static int exec_shutdown (void) /* {{{ */
884 program_list_t *next;
893 kill (pl->pid, SIGTERM);
894 INFO ("exec plugin: Sent SIGTERM to %hu", (unsigned short int) pl->pid);
905 } /* int exec_shutdown }}} */
907 void module_register (void)
909 plugin_register_complex_config ("exec", exec_config);
910 plugin_register_init ("exec", exec_init);
911 plugin_register_read ("exec", exec_read);
912 plugin_register_notification ("exec", exec_notification,
913 /* user_data = */ NULL);
914 plugin_register_shutdown ("exec", exec_shutdown);
915 } /* void module_register */
918 * vim:shiftwidth=2:softtabstop=2:tabstop=8:fdm=marker