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 */
34 #include "utils_cmd_putval.h"
35 #include "utils_cmd_putnotif.h"
37 #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 = calloc (1, sizeof (*pl));
131 ERROR ("exec plugin: calloc failed.");
135 if (strcasecmp ("NotificationExec", ci->key) == 0)
136 pl->flags |= PL_NOTIF_ACTION;
138 pl->flags |= PL_NORMAL;
140 pl->user = strdup (ci->values[0].value.string);
141 if (pl->user == NULL)
143 ERROR ("exec plugin: strdup failed.");
148 pl->group = strchr (pl->user, ':');
149 if (pl->group != NULL)
155 pl->exec = strdup (ci->values[1].value.string);
156 if (pl->exec == NULL)
158 ERROR ("exec plugin: strdup failed.");
164 pl->argv = calloc (ci->values_num, sizeof (*pl->argv));
165 if (pl->argv == NULL)
167 ERROR ("exec plugin: calloc failed.");
175 char *tmp = strrchr (ci->values[1].value.string, '/');
177 sstrncpy (buffer, ci->values[1].value.string, sizeof (buffer));
179 sstrncpy (buffer, tmp + 1, sizeof (buffer));
181 pl->argv[0] = strdup (buffer);
182 if (pl->argv[0] == NULL)
184 ERROR ("exec plugin: strdup failed.");
192 for (i = 1; i < (ci->values_num - 1); i++)
194 if (ci->values[i + 1].type == OCONFIG_TYPE_STRING)
196 pl->argv[i] = strdup (ci->values[i + 1].value.string);
200 if (ci->values[i + 1].type == OCONFIG_TYPE_NUMBER)
202 ssnprintf (buffer, sizeof (buffer), "%lf",
203 ci->values[i + 1].value.number);
207 if (ci->values[i + 1].value.boolean)
208 sstrncpy (buffer, "true", sizeof (buffer));
210 sstrncpy (buffer, "false", sizeof (buffer));
213 pl->argv[i] = strdup (buffer);
216 if (pl->argv[i] == NULL)
218 ERROR ("exec plugin: strdup failed.");
223 if (i < (ci->values_num - 1))
236 for (i = 0; pl->argv[i] != NULL; i++)
238 DEBUG ("exec plugin: argv[%i] = %s", i, pl->argv[i]);
245 } /* int exec_config_exec }}} */
247 static int exec_config (oconfig_item_t *ci) /* {{{ */
249 for (int i = 0; i < ci->children_num; i++)
251 oconfig_item_t *child = ci->children + i;
252 if ((strcasecmp ("Exec", child->key) == 0)
253 || (strcasecmp ("NotificationExec", child->key) == 0))
254 exec_config_exec (child);
257 WARNING ("exec plugin: Unknown config option `%s'.", child->key);
262 } /* int exec_config }}} */
264 static void set_environment (void) /* {{{ */
269 ssnprintf (buffer, sizeof (buffer), "%.3f",
270 CDTIME_T_TO_DOUBLE (plugin_get_interval ()));
271 setenv ("COLLECTD_INTERVAL", buffer, /* overwrite = */ 1);
273 ssnprintf (buffer, sizeof (buffer), "%s", hostname_g);
274 setenv ("COLLECTD_HOSTNAME", buffer, /* overwrite = */ 1);
276 ssnprintf (buffer, sizeof (buffer), "COLLECTD_INTERVAL=%.3f",
277 CDTIME_T_TO_DOUBLE (plugin_get_interval ()));
280 ssnprintf (buffer, sizeof (buffer), "COLLECTD_HOSTNAME=%s", hostname_g);
283 } /* }}} void set_environment */
285 __attribute__((noreturn))
286 static void exec_child (program_list_t *pl, int uid, int gid, int egid) /* {{{ */
300 if ((gid != egid) && (egid != -1))
306 setgroups (glist_len, glist);
308 #endif /* HAVE_SETGROUPS */
310 status = setgid (gid);
313 ERROR ("exec plugin: setgid (%i) failed: %s",
314 gid, sstrerror (errno, errbuf, sizeof (errbuf)));
320 status = setegid (egid);
323 ERROR ("exec plugin: setegid (%i) failed: %s",
324 egid, sstrerror (errno, errbuf, sizeof (errbuf)));
329 status = setuid (uid);
332 ERROR ("exec plugin: setuid (%i) failed: %s",
333 uid, sstrerror (errno, errbuf, sizeof (errbuf)));
337 execvp (pl->exec, pl->argv);
339 ERROR ("exec plugin: Failed to execute ``%s'': %s",
340 pl->exec, sstrerror (errno, errbuf, sizeof (errbuf)));
342 } /* void exec_child }}} */
344 static void reset_signal_mask (void) /* {{{ */
349 sigprocmask (SIG_SETMASK, &ss, /* old mask = */ NULL);
350 } /* }}} void reset_signal_mask */
352 static int create_pipe (int fd_pipe[2]) /* {{{ */
357 status = pipe (fd_pipe);
360 ERROR ("exec plugin: pipe failed: %s",
361 sstrerror (errno, errbuf, sizeof (errbuf)));
366 } /* }}} int create_pipe */
368 static void close_pipe (int fd_pipe[2]) /* {{{ */
370 if (fd_pipe[0] != -1)
373 if (fd_pipe[1] != -1)
375 } /* }}} void close_pipe */
378 * Creates three pipes (one for reading, one for writing and one for errors),
379 * forks a child, sets up the pipes so that fd_in is connected to STDIN of
380 * the child and fd_out is connected to STDOUT and fd_err is connected to STDERR
381 * of the child. Then is calls `exec_child'.
383 static int fork_child (program_list_t *pl, int *fd_in, int *fd_out, int *fd_err) /* {{{ */
385 int fd_pipe_in[2] = {-1, -1};
386 int fd_pipe_out[2] = {-1, -1};
387 int fd_pipe_err[2] = {-1, -1};
396 struct passwd *sp_ptr;
403 if ((create_pipe(fd_pipe_in) == -1)
404 || (create_pipe(fd_pipe_out) == -1)
405 || (create_pipe(fd_pipe_err) == -1))
409 status = getpwnam_r (pl->user, &sp, nambuf, sizeof (nambuf), &sp_ptr);
412 ERROR ("exec plugin: Failed to get user information for user ``%s'': %s",
413 pl->user, sstrerror (errno, errbuf, sizeof (errbuf)));
419 ERROR ("exec plugin: No such user: `%s'", pl->user);
427 ERROR ("exec plugin: Cowardly refusing to exec program as root.");
431 /* The group configured in the configfile is set as effective group, because
432 * this way the forked process can (re-)gain the user's primary group. */
434 if (NULL != pl->group)
436 if ('\0' != *pl->group) {
437 struct group *gr_ptr = NULL;
440 status = getgrnam_r (pl->group, &gr, nambuf, sizeof (nambuf), &gr_ptr);
443 ERROR ("exec plugin: Failed to get group information "
444 "for group ``%s'': %s", pl->group,
445 sstrerror (errno, errbuf, sizeof (errbuf)));
450 ERROR ("exec plugin: No such group: `%s'", pl->group);
460 } /* if (pl->group == NULL) */
465 ERROR ("exec plugin: fork failed: %s",
466 sstrerror (errno, errbuf, sizeof (errbuf)));
473 /* Close all file descriptors but the pipe end we need. */
474 fd_num = getdtablesize ();
475 for (int fd = 0; fd < fd_num; fd++)
477 if ((fd == fd_pipe_in[0])
478 || (fd == fd_pipe_out[1])
479 || (fd == fd_pipe_err[1]))
484 /* Connect the `in' pipe to STDIN */
485 if (fd_pipe_in[0] != STDIN_FILENO)
487 dup2 (fd_pipe_in[0], STDIN_FILENO);
488 close (fd_pipe_in[0]);
491 /* Now connect the `out' pipe to STDOUT */
492 if (fd_pipe_out[1] != STDOUT_FILENO)
494 dup2 (fd_pipe_out[1], STDOUT_FILENO);
495 close (fd_pipe_out[1]);
498 /* Now connect the `err' pipe to STDERR */
499 if (fd_pipe_err[1] != STDERR_FILENO)
501 dup2 (fd_pipe_err[1], STDERR_FILENO);
502 close (fd_pipe_err[1]);
507 /* Unblock all signals */
508 reset_signal_mask ();
510 exec_child (pl, uid, gid, egid);
511 /* does not return */
514 close (fd_pipe_in[0]);
515 close (fd_pipe_out[1]);
516 close (fd_pipe_err[1]);
519 *fd_in = fd_pipe_in[1];
521 close (fd_pipe_in[1]);
524 *fd_out = fd_pipe_out[0];
526 close (fd_pipe_out[0]);
529 *fd_err = fd_pipe_err[0];
531 close (fd_pipe_err[0]);
536 close_pipe(fd_pipe_in);
537 close_pipe(fd_pipe_out);
538 close_pipe(fd_pipe_err);
541 } /* int fork_child }}} */
543 static int parse_line (char *buffer) /* {{{ */
545 if (strncasecmp ("PUTVAL", buffer, strlen ("PUTVAL")) == 0)
546 return (handle_putval (stdout, buffer));
547 else if (strncasecmp ("PUTNOTIF", buffer, strlen ("PUTNOTIF")) == 0)
548 return (handle_putnotif (stdout, buffer));
551 ERROR ("exec plugin: Unable to parse command, ignoring line: \"%s\"",
555 } /* int parse_line }}} */
557 static void *exec_read_one (void *arg) /* {{{ */
559 program_list_t *pl = (program_list_t *) arg;
560 int fd, fd_err, highest_fd;
563 char buffer[1200]; /* if not completely read */
564 char buffer_err[1024];
565 char *pbuffer = buffer;
566 char *pbuffer_err = buffer_err;
568 status = fork_child (pl, NULL, &fd, &fd_err);
571 /* Reset the "running" flag */
572 pthread_mutex_lock (&pl_lock);
573 pl->flags &= ~PL_RUNNING;
574 pthread_mutex_unlock (&pl_lock);
575 pthread_exit ((void *) 1);
579 assert (pl->pid != 0);
583 FD_SET(fd_err, &fdset);
585 /* Determine the highest file descriptor */
586 highest_fd = (fd > fd_err) ? fd : fd_err;
588 /* We use a copy of fdset, as select modifies it */
595 status = select (highest_fd + 1, ©, NULL, NULL, NULL);
603 if (FD_ISSET(fd, ©))
607 len = read(fd, pbuffer, sizeof(buffer) - 1 - (pbuffer - buffer));
611 if (errno == EAGAIN || errno == EINTR) continue;
614 else if (len == 0) break; /* We've reached EOF */
618 len += pbuffer - buffer;
621 while ((pnl = strchr(pbuffer, '\n')))
624 if (*(pnl-1) == '\r' ) *(pnl-1) = '\0';
626 parse_line (pbuffer);
630 /* not completely read ? */
631 if (pbuffer - buffer < len)
633 len -= pbuffer - buffer;
634 memmove(buffer, pbuffer, len);
635 pbuffer = buffer + len;
640 else if (FD_ISSET(fd_err, ©))
644 len = read(fd_err, pbuffer_err, sizeof(buffer_err) - 1 - (pbuffer_err - buffer_err));
648 if (errno == EAGAIN || errno == EINTR)
654 /* We've reached EOF */
655 NOTICE ("exec plugin: Program `%s' has closed STDERR.", pl->exec);
657 /* Remove file descriptor form select() set. */
658 FD_CLR (fd_err, &fdset);
662 /* Clean up file descriptor */
668 pbuffer_err[len] = '\0';
670 len += pbuffer_err - buffer_err;
671 pbuffer_err = buffer_err;
673 while ((pnl = strchr(pbuffer_err, '\n')))
676 if (*(pnl-1) == '\r' ) *(pnl-1) = '\0';
678 ERROR ("exec plugin: exec_read_one: error = %s", pbuffer_err);
682 /* not completely read ? */
683 if (pbuffer_err - buffer_err < len)
685 len -= pbuffer_err - buffer_err;
686 memmove(buffer_err, pbuffer_err, len);
687 pbuffer_err = buffer_err + len;
690 pbuffer_err = buffer_err;
696 DEBUG ("exec plugin: exec_read_one: Waiting for `%s' to exit.", pl->exec);
697 if (waitpid (pl->pid, &status, 0) > 0)
700 DEBUG ("exec plugin: Child %i exited with status %i.",
701 (int) pl->pid, pl->status);
705 pthread_mutex_lock (&pl_lock);
706 pl->flags &= ~PL_RUNNING;
707 pthread_mutex_unlock (&pl_lock);
713 pthread_exit ((void *) 0);
715 } /* void *exec_read_one }}} */
717 static void *exec_notification_one (void *arg) /* {{{ */
719 program_list_t *pl = ((program_list_and_notification_t *) arg)->pl;
720 notification_t *n = &((program_list_and_notification_t *) arg)->n;
725 const char *severity;
727 pid = fork_child (pl, &fd, NULL, NULL);
730 pthread_exit ((void *) 1);
733 fh = fdopen (fd, "w");
737 ERROR ("exec plugin: fdopen (%i) failed: %s", fd,
738 sstrerror (errno, errbuf, sizeof (errbuf)));
742 pthread_exit ((void *) 1);
745 severity = "FAILURE";
746 if (n->severity == NOTIF_WARNING)
747 severity = "WARNING";
748 else if (n->severity == NOTIF_OKAY)
754 severity, CDTIME_T_TO_DOUBLE (n->time));
756 /* Print the optional fields */
757 if (strlen (n->host) > 0)
758 fprintf (fh, "Host: %s\n", n->host);
759 if (strlen (n->plugin) > 0)
760 fprintf (fh, "Plugin: %s\n", n->plugin);
761 if (strlen (n->plugin_instance) > 0)
762 fprintf (fh, "PluginInstance: %s\n", n->plugin_instance);
763 if (strlen (n->type) > 0)
764 fprintf (fh, "Type: %s\n", n->type);
765 if (strlen (n->type_instance) > 0)
766 fprintf (fh, "TypeInstance: %s\n", n->type_instance);
768 for (notification_meta_t *meta = n->meta; meta != NULL; meta = meta->next)
770 if (meta->type == NM_TYPE_STRING)
771 fprintf (fh, "%s: %s\n", meta->name, meta->nm_value.nm_string);
772 else if (meta->type == NM_TYPE_SIGNED_INT)
773 fprintf (fh, "%s: %"PRIi64"\n", meta->name, meta->nm_value.nm_signed_int);
774 else if (meta->type == NM_TYPE_UNSIGNED_INT)
775 fprintf (fh, "%s: %"PRIu64"\n", meta->name, meta->nm_value.nm_unsigned_int);
776 else if (meta->type == NM_TYPE_DOUBLE)
777 fprintf (fh, "%s: %e\n", meta->name, meta->nm_value.nm_double);
778 else if (meta->type == NM_TYPE_BOOLEAN)
779 fprintf (fh, "%s: %s\n", meta->name,
780 meta->nm_value.nm_boolean ? "true" : "false");
783 fprintf (fh, "\n%s\n", n->message);
788 waitpid (pid, &status, 0);
790 DEBUG ("exec plugin: Child %i exited with status %i.",
794 plugin_notification_meta_free (n->meta);
797 pthread_exit ((void *) 0);
799 } /* void *exec_notification_one }}} */
801 static int exec_init (void) /* {{{ */
803 struct sigaction sa = {
804 .sa_handler = sigchld_handler
807 sigaction (SIGCHLD, &sa, NULL);
810 } /* int exec_init }}} */
812 static int exec_read (void) /* {{{ */
814 for (program_list_t *pl = pl_head; pl != NULL; pl = pl->next)
819 /* Only execute `normal' style executables here. */
820 if ((pl->flags & PL_NORMAL) == 0)
823 pthread_mutex_lock (&pl_lock);
824 /* Skip if a child is already running. */
825 if ((pl->flags & PL_RUNNING) != 0)
827 pthread_mutex_unlock (&pl_lock);
830 pl->flags |= PL_RUNNING;
831 pthread_mutex_unlock (&pl_lock);
833 pthread_attr_init (&attr);
834 pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
835 plugin_thread_create (&t, &attr, exec_read_one, (void *) pl);
836 pthread_attr_destroy (&attr);
840 } /* int exec_read }}} */
842 static int exec_notification (const notification_t *n, /* {{{ */
843 user_data_t __attribute__((unused)) *user_data)
845 program_list_and_notification_t *pln;
847 for (program_list_t *pl = pl_head; pl != NULL; pl = pl->next)
852 /* Only execute `notification' style executables here. */
853 if ((pl->flags & PL_NOTIF_ACTION) == 0)
856 /* Skip if a child is already running. */
860 pln = malloc (sizeof (*pln));
863 ERROR ("exec plugin: malloc failed.");
868 memcpy (&pln->n, n, sizeof (notification_t));
870 /* Set the `meta' member to NULL, otherwise `plugin_notification_meta_copy'
871 * will run into an endless loop. */
873 plugin_notification_meta_copy (&pln->n, n);
875 pthread_attr_init (&attr);
876 pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
877 plugin_thread_create (&t, &attr, exec_notification_one, (void *) pln);
878 pthread_attr_destroy (&attr);
882 } /* }}} int exec_notification */
884 static int exec_shutdown (void) /* {{{ */
887 program_list_t *next;
896 kill (pl->pid, SIGTERM);
897 INFO ("exec plugin: Sent SIGTERM to %hu", (unsigned short int) pl->pid);
908 } /* int exec_shutdown }}} */
910 void module_register (void)
912 plugin_register_complex_config ("exec", exec_config);
913 plugin_register_init ("exec", exec_init);
914 plugin_register_read ("exec", exec_read);
915 plugin_register_notification ("exec", exec_notification,
916 /* user_data = */ NULL);
917 plugin_register_shutdown ("exec", exec_shutdown);
918 } /* void module_register */
921 * vim:shiftwidth=2:softtabstop=2:tabstop=8:fdm=marker