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 collectd.org>
22 * Sebastian Harl <sh at tokkee.org>
23 * Peter Holik <peter at holik.at>
26 #define _DEFAULT_SOURCE
27 #define _BSD_SOURCE /* For setgroups */
33 #include "utils_cmd_putval.h"
34 #include "utils_cmd_putnotif.h"
36 #include <sys/types.h>
43 #define PL_NORMAL 0x01
44 #define PL_NOTIF_ACTION 0x02
46 #define PL_RUNNING 0x10
52 * Access to this structure is serialized using the `pl_lock' lock and the
53 * `PL_RUNNING' flag. The execution of notifications is *not* serialized, so
54 * all functions used to handle notifications MUST NOT write to this structure.
55 * The `pid' and `status' fields are thus unused if the `PL_NOTIF_ACTION' flag
57 * The `PL_RUNNING' flag is set in `exec_read' and unset in `exec_read_one'.
59 struct program_list_s;
60 typedef struct program_list_s program_list_t;
73 typedef struct program_list_and_notification_s
77 } program_list_and_notification_t;
82 static program_list_t *pl_head = NULL;
83 static pthread_mutex_t pl_lock = PTHREAD_MUTEX_INITIALIZER;
88 static void sigchld_handler (int __attribute__((unused)) signal) /* {{{ */
92 while ((pid = waitpid (-1, &status, WNOHANG)) > 0)
95 for (pl = pl_head; pl != NULL; pl = pl->next)
100 } /* while (waitpid) */
101 } /* void sigchld_handler }}} */
103 static int exec_config_exec (oconfig_item_t *ci) /* {{{ */
109 if (ci->children_num != 0)
111 WARNING ("exec plugin: The config option `%s' may not be a block.",
115 if (ci->values_num < 2)
117 WARNING ("exec plugin: The config option `%s' needs at least two "
118 "arguments.", ci->key);
121 if ((ci->values[0].type != OCONFIG_TYPE_STRING)
122 || (ci->values[1].type != OCONFIG_TYPE_STRING))
124 WARNING ("exec plugin: The first two arguments to the `%s' option must "
125 "be string arguments.", ci->key);
129 pl = calloc (1, sizeof (*pl));
132 ERROR ("exec plugin: calloc failed.");
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 = calloc (ci->values_num, sizeof (*pl->argv));
166 if (pl->argv == NULL)
168 ERROR ("exec plugin: calloc failed.");
176 char *tmp = strrchr (ci->values[1].value.string, '/');
178 sstrncpy (buffer, ci->values[1].value.string, sizeof (buffer));
180 sstrncpy (buffer, tmp + 1, sizeof (buffer));
182 pl->argv[0] = strdup (buffer);
183 if (pl->argv[0] == NULL)
185 ERROR ("exec plugin: strdup failed.");
193 for (i = 1; i < (ci->values_num - 1); i++)
195 if (ci->values[i + 1].type == OCONFIG_TYPE_STRING)
197 pl->argv[i] = strdup (ci->values[i + 1].value.string);
201 if (ci->values[i + 1].type == OCONFIG_TYPE_NUMBER)
203 ssnprintf (buffer, sizeof (buffer), "%lf",
204 ci->values[i + 1].value.number);
208 if (ci->values[i + 1].value.boolean)
209 sstrncpy (buffer, "true", sizeof (buffer));
211 sstrncpy (buffer, "false", sizeof (buffer));
214 pl->argv[i] = strdup (buffer);
217 if (pl->argv[i] == NULL)
219 ERROR ("exec plugin: strdup failed.");
224 if (i < (ci->values_num - 1))
237 for (i = 0; pl->argv[i] != NULL; i++)
239 DEBUG ("exec plugin: argv[%i] = %s", i, pl->argv[i]);
246 } /* int exec_config_exec }}} */
248 static int exec_config (oconfig_item_t *ci) /* {{{ */
252 for (i = 0; i < ci->children_num; i++)
254 oconfig_item_t *child = ci->children + i;
255 if ((strcasecmp ("Exec", child->key) == 0)
256 || (strcasecmp ("NotificationExec", child->key) == 0))
257 exec_config_exec (child);
260 WARNING ("exec plugin: Unknown config option `%s'.", child->key);
265 } /* int exec_config }}} */
267 static void set_environment (void) /* {{{ */
272 ssnprintf (buffer, sizeof (buffer), "%.3f",
273 CDTIME_T_TO_DOUBLE (plugin_get_interval ()));
274 setenv ("COLLECTD_INTERVAL", buffer, /* overwrite = */ 1);
276 ssnprintf (buffer, sizeof (buffer), "%s", hostname_g);
277 setenv ("COLLECTD_HOSTNAME", buffer, /* overwrite = */ 1);
279 ssnprintf (buffer, sizeof (buffer), "COLLECTD_INTERVAL=%.3f",
280 CDTIME_T_TO_DOUBLE (plugin_get_interval ()));
283 ssnprintf (buffer, sizeof (buffer), "COLLECTD_HOSTNAME=%s", hostname_g);
286 } /* }}} void set_environment */
288 __attribute__((noreturn))
289 static void exec_child (program_list_t *pl, int uid, int gid, int egid) /* {{{ */
303 if ((gid != egid) && (egid != -1))
309 setgroups (glist_len, glist);
311 #endif /* HAVE_SETGROUPS */
313 status = setgid (gid);
316 ERROR ("exec plugin: setgid (%i) failed: %s",
317 gid, sstrerror (errno, errbuf, sizeof (errbuf)));
323 status = setegid (egid);
326 ERROR ("exec plugin: setegid (%i) failed: %s",
327 egid, sstrerror (errno, errbuf, sizeof (errbuf)));
332 status = setuid (uid);
335 ERROR ("exec plugin: setuid (%i) failed: %s",
336 uid, sstrerror (errno, errbuf, sizeof (errbuf)));
340 execvp (pl->exec, pl->argv);
342 ERROR ("exec plugin: Failed to execute ``%s'': %s",
343 pl->exec, sstrerror (errno, errbuf, sizeof (errbuf)));
345 } /* void exec_child }}} */
347 static void reset_signal_mask (void) /* {{{ */
351 memset (&ss, 0, sizeof (ss));
353 sigprocmask (SIG_SETMASK, &ss, /* old mask = */ NULL);
354 } /* }}} void reset_signal_mask */
356 static int create_pipe (int fd_pipe[2]) /* {{{ */
361 status = pipe (fd_pipe);
364 ERROR ("exec plugin: pipe failed: %s",
365 sstrerror (errno, errbuf, sizeof (errbuf)));
370 } /* }}} int create_pipe */
372 static void close_pipe (int fd_pipe[2]) /* {{{ */
374 if (fd_pipe[0] != -1)
377 if (fd_pipe[1] != -1)
379 } /* }}} void close_pipe */
382 * Creates three pipes (one for reading, one for writing and one for errors),
383 * forks a child, sets up the pipes so that fd_in is connected to STDIN of
384 * the child and fd_out is connected to STDOUT and fd_err is connected to STDERR
385 * of the child. Then is calls `exec_child'.
387 static int fork_child (program_list_t *pl, int *fd_in, int *fd_out, int *fd_err) /* {{{ */
389 int fd_pipe_in[2] = {-1, -1};
390 int fd_pipe_out[2] = {-1, -1};
391 int fd_pipe_err[2] = {-1, -1};
400 struct passwd *sp_ptr;
407 if ((create_pipe(fd_pipe_in) == -1)
408 || (create_pipe(fd_pipe_out) == -1)
409 || (create_pipe(fd_pipe_err) == -1))
413 status = getpwnam_r (pl->user, &sp, nambuf, sizeof (nambuf), &sp_ptr);
416 ERROR ("exec plugin: Failed to get user information for user ``%s'': %s",
417 pl->user, sstrerror (errno, errbuf, sizeof (errbuf)));
423 ERROR ("exec plugin: No such user: `%s'", pl->user);
431 ERROR ("exec plugin: Cowardly refusing to exec program as root.");
435 /* The group configured in the configfile is set as effective group, because
436 * this way the forked process can (re-)gain the user's primary group. */
438 if (NULL != pl->group)
440 if ('\0' != *pl->group) {
441 struct group *gr_ptr = NULL;
444 status = getgrnam_r (pl->group, &gr, nambuf, sizeof (nambuf), &gr_ptr);
447 ERROR ("exec plugin: Failed to get group information "
448 "for group ``%s'': %s", pl->group,
449 sstrerror (errno, errbuf, sizeof (errbuf)));
454 ERROR ("exec plugin: No such group: `%s'", pl->group);
464 } /* if (pl->group == NULL) */
469 ERROR ("exec plugin: fork failed: %s",
470 sstrerror (errno, errbuf, sizeof (errbuf)));
478 /* Close all file descriptors but the pipe end we need. */
479 fd_num = getdtablesize ();
480 for (fd = 0; fd < fd_num; fd++)
482 if ((fd == fd_pipe_in[0])
483 || (fd == fd_pipe_out[1])
484 || (fd == fd_pipe_err[1]))
489 /* Connect the `in' pipe to STDIN */
490 if (fd_pipe_in[0] != STDIN_FILENO)
492 dup2 (fd_pipe_in[0], STDIN_FILENO);
493 close (fd_pipe_in[0]);
496 /* Now connect the `out' pipe to STDOUT */
497 if (fd_pipe_out[1] != STDOUT_FILENO)
499 dup2 (fd_pipe_out[1], STDOUT_FILENO);
500 close (fd_pipe_out[1]);
503 /* Now connect the `err' pipe to STDERR */
504 if (fd_pipe_err[1] != STDERR_FILENO)
506 dup2 (fd_pipe_err[1], STDERR_FILENO);
507 close (fd_pipe_err[1]);
512 /* Unblock all signals */
513 reset_signal_mask ();
515 exec_child (pl, uid, gid, egid);
516 /* does not return */
519 close (fd_pipe_in[0]);
520 close (fd_pipe_out[1]);
521 close (fd_pipe_err[1]);
524 *fd_in = fd_pipe_in[1];
526 close (fd_pipe_in[1]);
529 *fd_out = fd_pipe_out[0];
531 close (fd_pipe_out[0]);
534 *fd_err = fd_pipe_err[0];
536 close (fd_pipe_err[0]);
541 close_pipe(fd_pipe_in);
542 close_pipe(fd_pipe_out);
543 close_pipe(fd_pipe_err);
546 } /* int fork_child }}} */
548 static int parse_line (char *buffer) /* {{{ */
550 if (strncasecmp ("PUTVAL", buffer, strlen ("PUTVAL")) == 0)
551 return (handle_putval (stdout, buffer));
552 else if (strncasecmp ("PUTNOTIF", buffer, strlen ("PUTNOTIF")) == 0)
553 return (handle_putnotif (stdout, buffer));
556 ERROR ("exec plugin: Unable to parse command, ignoring line: \"%s\"",
560 } /* int parse_line }}} */
562 static void *exec_read_one (void *arg) /* {{{ */
564 program_list_t *pl = (program_list_t *) arg;
565 int fd, fd_err, highest_fd;
568 char buffer[1200]; /* if not completely read */
569 char buffer_err[1024];
570 char *pbuffer = buffer;
571 char *pbuffer_err = buffer_err;
573 status = fork_child (pl, NULL, &fd, &fd_err);
576 /* Reset the "running" flag */
577 pthread_mutex_lock (&pl_lock);
578 pl->flags &= ~PL_RUNNING;
579 pthread_mutex_unlock (&pl_lock);
580 pthread_exit ((void *) 1);
584 assert (pl->pid != 0);
588 FD_SET(fd_err, &fdset);
590 /* Determine the highest file descriptor */
591 highest_fd = (fd > fd_err) ? fd : fd_err;
593 /* We use a copy of fdset, as select modifies it */
600 status = select (highest_fd + 1, ©, NULL, NULL, NULL);
608 if (FD_ISSET(fd, ©))
612 len = read(fd, pbuffer, sizeof(buffer) - 1 - (pbuffer - buffer));
616 if (errno == EAGAIN || errno == EINTR) continue;
619 else if (len == 0) break; /* We've reached EOF */
623 len += pbuffer - buffer;
626 while ((pnl = strchr(pbuffer, '\n')))
629 if (*(pnl-1) == '\r' ) *(pnl-1) = '\0';
631 parse_line (pbuffer);
635 /* not completely read ? */
636 if (pbuffer - buffer < len)
638 len -= pbuffer - buffer;
639 memmove(buffer, pbuffer, len);
640 pbuffer = buffer + len;
645 else if (FD_ISSET(fd_err, ©))
649 len = read(fd_err, pbuffer_err, sizeof(buffer_err) - 1 - (pbuffer_err - buffer_err));
653 if (errno == EAGAIN || errno == EINTR)
659 /* We've reached EOF */
660 NOTICE ("exec plugin: Program `%s' has closed STDERR.", pl->exec);
662 /* Remove file descriptor form select() set. */
663 FD_CLR (fd_err, &fdset);
667 /* Clean up file descriptor */
673 pbuffer_err[len] = '\0';
675 len += pbuffer_err - buffer_err;
676 pbuffer_err = buffer_err;
678 while ((pnl = strchr(pbuffer_err, '\n')))
681 if (*(pnl-1) == '\r' ) *(pnl-1) = '\0';
683 ERROR ("exec plugin: exec_read_one: error = %s", pbuffer_err);
687 /* not completely read ? */
688 if (pbuffer_err - buffer_err < len)
690 len -= pbuffer_err - buffer_err;
691 memmove(buffer_err, pbuffer_err, len);
692 pbuffer_err = buffer_err + len;
695 pbuffer_err = buffer_err;
701 DEBUG ("exec plugin: exec_read_one: Waiting for `%s' to exit.", pl->exec);
702 if (waitpid (pl->pid, &status, 0) > 0)
705 DEBUG ("exec plugin: Child %i exited with status %i.",
706 (int) pl->pid, pl->status);
710 pthread_mutex_lock (&pl_lock);
711 pl->flags &= ~PL_RUNNING;
712 pthread_mutex_unlock (&pl_lock);
718 pthread_exit ((void *) 0);
720 } /* void *exec_read_one }}} */
722 static void *exec_notification_one (void *arg) /* {{{ */
724 program_list_t *pl = ((program_list_and_notification_t *) arg)->pl;
725 notification_t *n = &((program_list_and_notification_t *) arg)->n;
726 notification_meta_t *meta;
731 const char *severity;
733 pid = fork_child (pl, &fd, NULL, NULL);
736 pthread_exit ((void *) 1);
739 fh = fdopen (fd, "w");
743 ERROR ("exec plugin: fdopen (%i) failed: %s", fd,
744 sstrerror (errno, errbuf, sizeof (errbuf)));
745 kill (pl->pid, SIGTERM);
749 pthread_exit ((void *) 1);
752 severity = "FAILURE";
753 if (n->severity == NOTIF_WARNING)
754 severity = "WARNING";
755 else if (n->severity == NOTIF_OKAY)
761 severity, CDTIME_T_TO_DOUBLE (n->time));
763 /* Print the optional fields */
764 if (strlen (n->host) > 0)
765 fprintf (fh, "Host: %s\n", n->host);
766 if (strlen (n->plugin) > 0)
767 fprintf (fh, "Plugin: %s\n", n->plugin);
768 if (strlen (n->plugin_instance) > 0)
769 fprintf (fh, "PluginInstance: %s\n", n->plugin_instance);
770 if (strlen (n->type) > 0)
771 fprintf (fh, "Type: %s\n", n->type);
772 if (strlen (n->type_instance) > 0)
773 fprintf (fh, "TypeInstance: %s\n", n->type_instance);
775 for (meta = n->meta; meta != NULL; meta = meta->next)
777 if (meta->type == NM_TYPE_STRING)
778 fprintf (fh, "%s: %s\n", meta->name, meta->nm_value.nm_string);
779 else if (meta->type == NM_TYPE_SIGNED_INT)
780 fprintf (fh, "%s: %"PRIi64"\n", meta->name, meta->nm_value.nm_signed_int);
781 else if (meta->type == NM_TYPE_UNSIGNED_INT)
782 fprintf (fh, "%s: %"PRIu64"\n", meta->name, meta->nm_value.nm_unsigned_int);
783 else if (meta->type == NM_TYPE_DOUBLE)
784 fprintf (fh, "%s: %e\n", meta->name, meta->nm_value.nm_double);
785 else if (meta->type == NM_TYPE_BOOLEAN)
786 fprintf (fh, "%s: %s\n", meta->name,
787 meta->nm_value.nm_boolean ? "true" : "false");
790 fprintf (fh, "\n%s\n", n->message);
795 waitpid (pid, &status, 0);
797 DEBUG ("exec plugin: Child %i exited with status %i.",
801 plugin_notification_meta_free (n->meta);
804 pthread_exit ((void *) 0);
806 } /* void *exec_notification_one }}} */
808 static int exec_init (void) /* {{{ */
812 memset (&sa, '\0', sizeof (sa));
813 sa.sa_handler = sigchld_handler;
814 sigaction (SIGCHLD, &sa, NULL);
817 } /* int exec_init }}} */
819 static int exec_read (void) /* {{{ */
823 for (pl = pl_head; pl != NULL; pl = pl->next)
828 /* Only execute `normal' style executables here. */
829 if ((pl->flags & PL_NORMAL) == 0)
832 pthread_mutex_lock (&pl_lock);
833 /* Skip if a child is already running. */
834 if ((pl->flags & PL_RUNNING) != 0)
836 pthread_mutex_unlock (&pl_lock);
839 pl->flags |= PL_RUNNING;
840 pthread_mutex_unlock (&pl_lock);
842 pthread_attr_init (&attr);
843 pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
844 plugin_thread_create (&t, &attr, exec_read_one, (void *) pl);
845 pthread_attr_destroy (&attr);
849 } /* int exec_read }}} */
851 static int exec_notification (const notification_t *n, /* {{{ */
852 user_data_t __attribute__((unused)) *user_data)
855 program_list_and_notification_t *pln;
857 for (pl = pl_head; pl != NULL; pl = pl->next)
862 /* Only execute `notification' style executables here. */
863 if ((pl->flags & PL_NOTIF_ACTION) == 0)
866 /* Skip if a child is already running. */
870 pln = malloc (sizeof (*pln));
873 ERROR ("exec plugin: malloc failed.");
878 memcpy (&pln->n, n, sizeof (notification_t));
880 /* Set the `meta' member to NULL, otherwise `plugin_notification_meta_copy'
881 * will run into an endless loop. */
883 plugin_notification_meta_copy (&pln->n, n);
885 pthread_attr_init (&attr);
886 pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
887 plugin_thread_create (&t, &attr, exec_notification_one, (void *) pln);
888 pthread_attr_destroy (&attr);
892 } /* }}} int exec_notification */
894 static int exec_shutdown (void) /* {{{ */
897 program_list_t *next;
906 kill (pl->pid, SIGTERM);
907 INFO ("exec plugin: Sent SIGTERM to %hu", (unsigned short int) pl->pid);
918 } /* int exec_shutdown }}} */
920 void module_register (void)
922 plugin_register_complex_config ("exec", exec_config);
923 plugin_register_init ("exec", exec_init);
924 plugin_register_read ("exec", exec_read);
925 plugin_register_notification ("exec", exec_notification,
926 /* user_data = */ NULL);
927 plugin_register_shutdown ("exec", exec_shutdown);
928 } /* void module_register */
931 * vim:shiftwidth=2:softtabstop=2:tabstop=8:fdm=marker