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) /* {{{ */
272 ssnprintf (buffer, sizeof (buffer), "%i", interval_g);
273 setenv ("COLLECTD_INTERVAL", buffer, /* overwrite = */ 1);
275 ssnprintf (buffer, sizeof (buffer), "%s", hostname_g);
276 setenv ("COLLECTD_HOSTNAME", buffer, /* overwrite = */ 1);
277 } /* }}} void set_environment */
279 __attribute__((noreturn))
280 static void exec_child (program_list_t *pl) /* {{{ */
287 struct passwd *sp_ptr;
293 status = getpwnam_r (pl->user, &sp, nambuf, sizeof (nambuf), &sp_ptr);
296 ERROR ("exec plugin: Failed to get user information for user ``%s'': %s",
297 pl->user, sstrerror (errno, errbuf, sizeof (errbuf)));
302 ERROR ("exec plugin: No such user: `%s'", pl->user);
310 ERROR ("exec plugin: Cowardly refusing to exec program as root.");
314 /* The group configured in the configfile is set as effective group, because
315 * this way the forked process can (re-)gain the user's primary group. */
317 if (NULL != pl->group)
319 if ('\0' != *pl->group) {
320 struct group *gr_ptr = NULL;
323 status = getgrnam_r (pl->group, &gr, nambuf, sizeof (nambuf), &gr_ptr);
326 ERROR ("exec plugin: Failed to get group information "
327 "for group ``%s'': %s", pl->group,
328 sstrerror (errno, errbuf, sizeof (errbuf)));
333 ERROR ("exec plugin: No such group: `%s'", pl->group);
343 } /* if (pl->group == NULL) */
354 if ((gid != egid) && (egid != -1))
360 setgroups (glist_len, glist);
362 #endif /* HAVE_SETGROUPS */
364 status = setgid (gid);
367 ERROR ("exec plugin: setgid (%i) failed: %s",
368 gid, sstrerror (errno, errbuf, sizeof (errbuf)));
374 status = setegid (egid);
377 ERROR ("exec plugin: setegid (%i) failed: %s",
378 egid, sstrerror (errno, errbuf, sizeof (errbuf)));
383 status = setuid (uid);
386 ERROR ("exec plugin: setuid (%i) failed: %s",
387 uid, sstrerror (errno, errbuf, sizeof (errbuf)));
391 status = execvp (pl->exec, pl->argv);
393 ERROR ("exec plugin: Failed to execute ``%s'': %s",
394 pl->exec, sstrerror (errno, errbuf, sizeof (errbuf)));
396 } /* void exec_child }}} */
398 static void reset_signal_mask (void) /* {{{ */
402 memset (&ss, 0, sizeof (ss));
404 sigprocmask (SIG_SETMASK, &ss, /* old mask = */ NULL);
405 } /* }}} void reset_signal_mask */
408 * Creates three pipes (one for reading, one for writing and one for errors),
409 * forks a child, sets up the pipes so that fd_in is connected to STDIN of
410 * the child and fd_out is connected to STDOUT and fd_err is connected to STDERR
411 * of the child. Then is calls `exec_child'.
413 static int fork_child (program_list_t *pl, int *fd_in, int *fd_out, int *fd_err) /* {{{ */
425 status = pipe (fd_pipe_in);
428 ERROR ("exec plugin: pipe failed: %s",
429 sstrerror (errno, errbuf, sizeof (errbuf)));
433 status = pipe (fd_pipe_out);
436 ERROR ("exec plugin: pipe failed: %s",
437 sstrerror (errno, errbuf, sizeof (errbuf)));
441 status = pipe (fd_pipe_err);
444 ERROR ("exec plugin: pipe failed: %s",
445 sstrerror (errno, errbuf, sizeof (errbuf)));
452 ERROR ("exec plugin: fork failed: %s",
453 sstrerror (errno, errbuf, sizeof (errbuf)));
461 /* Close all file descriptors but the pipe end we need. */
462 fd_num = getdtablesize ();
463 for (fd = 0; fd < fd_num; fd++)
465 if ((fd == fd_pipe_in[0])
466 || (fd == fd_pipe_out[1])
467 || (fd == fd_pipe_err[1]))
472 /* Connect the `in' pipe to STDIN */
473 if (fd_pipe_in[0] != STDIN_FILENO)
475 dup2 (fd_pipe_in[0], STDIN_FILENO);
476 close (fd_pipe_in[0]);
479 /* Now connect the `out' pipe to STDOUT */
480 if (fd_pipe_out[1] != STDOUT_FILENO)
482 dup2 (fd_pipe_out[1], STDOUT_FILENO);
483 close (fd_pipe_out[1]);
486 /* Now connect the `out' pipe to STDOUT */
487 if (fd_pipe_err[1] != STDERR_FILENO)
489 dup2 (fd_pipe_err[1], STDERR_FILENO);
490 close (fd_pipe_err[1]);
495 /* Unblock all signals */
496 reset_signal_mask ();
499 /* does not return */
502 close (fd_pipe_in[0]);
503 close (fd_pipe_out[1]);
504 close (fd_pipe_err[1]);
507 *fd_in = fd_pipe_in[1];
509 close (fd_pipe_in[1]);
512 *fd_out = fd_pipe_out[0];
514 close (fd_pipe_out[0]);
517 *fd_err = fd_pipe_err[0];
519 close (fd_pipe_err[0]);
522 } /* int fork_child }}} */
524 static int parse_line (char *buffer) /* {{{ */
526 if (strncasecmp ("PUTVAL", buffer, strlen ("PUTVAL")) == 0)
527 return (handle_putval (stdout, buffer));
528 else if (strncasecmp ("PUTNOTIF", buffer, strlen ("PUTNOTIF")) == 0)
529 return (handle_putnotif (stdout, buffer));
532 /* For backwards compatibility */
534 /* Let's annoy the user a bit.. */
535 INFO ("exec plugin: Prepending `PUTVAL' to this line: %s", buffer);
536 ssnprintf (tmp, sizeof (tmp), "PUTVAL %s", buffer);
537 return (handle_putval (stdout, tmp));
539 } /* int parse_line }}} */
541 static void *exec_read_one (void *arg) /* {{{ */
543 program_list_t *pl = (program_list_t *) arg;
544 int fd, fd_err, highest_fd;
547 char buffer[1200]; /* if not completely read */
548 char buffer_err[1024];
549 char *pbuffer = buffer;
550 char *pbuffer_err = buffer_err;
552 status = fork_child (pl, NULL, &fd, &fd_err);
555 /* Reset the "running" flag */
556 pthread_mutex_lock (&pl_lock);
557 pl->flags &= ~PL_RUNNING;
558 pthread_mutex_unlock (&pl_lock);
559 pthread_exit ((void *) 1);
563 assert (pl->pid != 0);
567 FD_SET(fd_err, &fdset);
569 /* Determine the highest file descriptor */
570 highest_fd = (fd > fd_err) ? fd : fd_err;
572 /* We use a copy of fdset, as select modifies it */
575 while (select(highest_fd + 1, ©, NULL, NULL, NULL ) > 0)
579 if (FD_ISSET(fd, ©))
583 len = read(fd, pbuffer, sizeof(buffer) - 1 - (pbuffer - buffer));
587 if (errno == EAGAIN || errno == EINTR) continue;
590 else if (len == 0) break; /* We've reached EOF */
594 len += pbuffer - buffer;
597 while ((pnl = strchr(pbuffer, '\n')))
600 if (*(pnl-1) == '\r' ) *(pnl-1) = '\0';
602 parse_line (pbuffer);
606 /* not completely read ? */
607 if (pbuffer - buffer < len)
609 len -= pbuffer - buffer;
610 memmove(buffer, pbuffer, len);
611 pbuffer = buffer + len;
616 else if (FD_ISSET(fd_err, ©))
620 len = read(fd_err, pbuffer_err, sizeof(buffer_err) - 1 - (pbuffer_err - buffer_err));
624 if (errno == EAGAIN || errno == EINTR) continue;
629 /* We've reached EOF */
630 NOTICE ("exec plugin: Program `%s' has closed STDERR.",
633 FD_CLR (fd_err, &fdset);
639 pbuffer_err[len] = '\0';
641 len += pbuffer_err - buffer_err;
642 pbuffer_err = buffer_err;
644 while ((pnl = strchr(pbuffer_err, '\n')))
647 if (*(pnl-1) == '\r' ) *(pnl-1) = '\0';
649 ERROR ("exec plugin: exec_read_one: error = %s", pbuffer_err);
653 /* not completely read ? */
654 if (pbuffer_err - buffer_err < len)
656 len -= pbuffer_err - buffer_err;
657 memmove(buffer_err, pbuffer_err, len);
658 pbuffer_err = buffer_err + len;
661 pbuffer_err = buffer_err;
667 DEBUG ("exec plugin: exec_read_one: Waiting for `%s' to exit.", pl->exec);
668 if (waitpid (pl->pid, &status, 0) > 0)
671 DEBUG ("exec plugin: Child %i exited with status %i.",
672 (int) pl->pid, pl->status);
676 pthread_mutex_lock (&pl_lock);
677 pl->flags &= ~PL_RUNNING;
678 pthread_mutex_unlock (&pl_lock);
684 pthread_exit ((void *) 0);
686 } /* void *exec_read_one }}} */
688 static void *exec_notification_one (void *arg) /* {{{ */
690 program_list_t *pl = ((program_list_and_notification_t *) arg)->pl;
691 notification_t *n = &((program_list_and_notification_t *) arg)->n;
692 notification_meta_t *meta;
697 const char *severity;
699 pid = fork_child (pl, &fd, NULL, NULL);
702 pthread_exit ((void *) 1);
705 fh = fdopen (fd, "w");
709 ERROR ("exec plugin: fdopen (%i) failed: %s", fd,
710 sstrerror (errno, errbuf, sizeof (errbuf)));
711 kill (pl->pid, SIGTERM);
715 pthread_exit ((void *) 1);
718 severity = "FAILURE";
719 if (n->severity == NOTIF_WARNING)
720 severity = "WARNING";
721 else if (n->severity == NOTIF_OKAY)
727 severity, (unsigned int) n->time);
729 /* Print the optional fields */
730 if (strlen (n->host) > 0)
731 fprintf (fh, "Host: %s\n", n->host);
732 if (strlen (n->plugin) > 0)
733 fprintf (fh, "Plugin: %s\n", n->plugin);
734 if (strlen (n->plugin_instance) > 0)
735 fprintf (fh, "PluginInstance: %s\n", n->plugin_instance);
736 if (strlen (n->type) > 0)
737 fprintf (fh, "Type: %s\n", n->type);
738 if (strlen (n->type_instance) > 0)
739 fprintf (fh, "TypeInstance: %s\n", n->type_instance);
741 for (meta = n->meta; meta != NULL; meta = meta->next)
743 if (meta->type == NM_TYPE_STRING)
744 fprintf (fh, "%s: %s\n", meta->name, meta->nm_value.nm_string);
745 else if (meta->type == NM_TYPE_SIGNED_INT)
746 fprintf (fh, "%s: %"PRIi64"\n", meta->name, meta->nm_value.nm_signed_int);
747 else if (meta->type == NM_TYPE_UNSIGNED_INT)
748 fprintf (fh, "%s: %"PRIu64"\n", meta->name, meta->nm_value.nm_unsigned_int);
749 else if (meta->type == NM_TYPE_DOUBLE)
750 fprintf (fh, "%s: %e\n", meta->name, meta->nm_value.nm_double);
751 else if (meta->type == NM_TYPE_BOOLEAN)
752 fprintf (fh, "%s: %s\n", meta->name,
753 meta->nm_value.nm_boolean ? "true" : "false");
756 fprintf (fh, "\n%s\n", n->message);
761 waitpid (pid, &status, 0);
763 DEBUG ("exec plugin: Child %i exited with status %i.",
767 plugin_notification_meta_free (n->meta);
770 pthread_exit ((void *) 0);
772 } /* void *exec_notification_one }}} */
774 static int exec_init (void) /* {{{ */
778 memset (&sa, '\0', sizeof (sa));
779 sa.sa_handler = sigchld_handler;
780 sigaction (SIGCHLD, &sa, NULL);
783 } /* int exec_init }}} */
785 static int exec_read (void) /* {{{ */
789 for (pl = pl_head; pl != NULL; pl = pl->next)
794 /* Only execute `normal' style executables here. */
795 if ((pl->flags & PL_NORMAL) == 0)
798 pthread_mutex_lock (&pl_lock);
799 /* Skip if a child is already running. */
800 if ((pl->flags & PL_RUNNING) != 0)
802 pthread_mutex_unlock (&pl_lock);
805 pl->flags |= PL_RUNNING;
806 pthread_mutex_unlock (&pl_lock);
808 pthread_attr_init (&attr);
809 pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
810 pthread_create (&t, &attr, exec_read_one, (void *) pl);
814 } /* int exec_read }}} */
816 static int exec_notification (const notification_t *n, /* {{{ */
817 user_data_t __attribute__((unused)) *user_data)
820 program_list_and_notification_t *pln;
822 for (pl = pl_head; pl != NULL; pl = pl->next)
827 /* Only execute `notification' style executables here. */
828 if ((pl->flags & PL_NOTIF_ACTION) == 0)
831 /* Skip if a child is already running. */
835 pln = (program_list_and_notification_t *) malloc (sizeof
836 (program_list_and_notification_t));
839 ERROR ("exec plugin: malloc failed.");
844 memcpy (&pln->n, n, sizeof (notification_t));
846 /* Set the `meta' member to NULL, otherwise `plugin_notification_meta_copy'
847 * will run into an endless loop. */
849 plugin_notification_meta_copy (&pln->n, n);
851 pthread_attr_init (&attr);
852 pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
853 pthread_create (&t, &attr, exec_notification_one, (void *) pln);
857 } /* }}} int exec_notification */
859 static int exec_shutdown (void) /* {{{ */
862 program_list_t *next;
871 kill (pl->pid, SIGTERM);
872 INFO ("exec plugin: Sent SIGTERM to %hu", (unsigned short int) pl->pid);
883 } /* int exec_shutdown }}} */
885 void module_register (void)
887 plugin_register_complex_config ("exec", exec_config);
888 plugin_register_init ("exec", exec_init);
889 plugin_register_read ("exec", exec_read);
890 plugin_register_notification ("exec", exec_notification,
891 /* user_data = */ NULL);
892 plugin_register_shutdown ("exec", exec_shutdown);
893 } /* void module_register */
896 * vim:shiftwidth=2:softtabstop=2:tabstop=8:fdm=marker