2 * collectd - src/exec.c
3 * Copyright (C) 2007-2009 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 exec_child (program_list_t *pl) /* {{{ */
275 struct passwd *sp_ptr;
281 status = getpwnam_r (pl->user, &sp, nambuf, sizeof (nambuf), &sp_ptr);
284 ERROR ("exec plugin: getpwnam_r failed: %s",
285 sstrerror (errno, errbuf, sizeof (errbuf)));
290 ERROR ("exec plugin: No such user: `%s'", pl->user);
298 ERROR ("exec plugin: Cowardly refusing to exec program as root.");
302 /* The group configured in the configfile is set as effective group, because
303 * this way the forked process can (re-)gain the user's primary group. */
305 if (NULL != pl->group)
307 if ('\0' != *pl->group) {
308 struct group *gr_ptr = NULL;
311 status = getgrnam_r (pl->group, &gr, nambuf, sizeof (nambuf), &gr_ptr);
314 ERROR ("exec plugin: getgrnam_r failed: %s",
315 sstrerror (errno, errbuf, sizeof (errbuf)));
320 ERROR ("exec plugin: No such group: `%s'", pl->group);
330 } /* if (pl->group == NULL) */
341 if ((gid != egid) && (egid != -1))
347 setgroups (glist_len, glist);
349 #endif /* HAVE_SETGROUPS */
351 status = setgid (gid);
354 ERROR ("exec plugin: setgid (%i) failed: %s",
355 gid, sstrerror (errno, errbuf, sizeof (errbuf)));
361 status = setegid (egid);
364 ERROR ("exec plugin: setegid (%i) failed: %s",
365 egid, sstrerror (errno, errbuf, sizeof (errbuf)));
370 status = setuid (uid);
373 ERROR ("exec plugin: setuid (%i) failed: %s",
374 uid, sstrerror (errno, errbuf, sizeof (errbuf)));
378 status = execvp (pl->exec, pl->argv);
380 ERROR ("exec plugin: exec failed: %s",
381 sstrerror (errno, errbuf, sizeof (errbuf)));
383 } /* void exec_child }}} */
385 static void reset_signal_mask (void) /* {{{ */
389 memset (&ss, 0, sizeof (ss));
391 sigprocmask (SIG_SETMASK, &ss, /* old mask = */ NULL);
392 } /* }}} void reset_signal_mask */
395 * Creates three pipes (one for reading, one for writing and one for errors),
396 * forks a child, sets up the pipes so that fd_in is connected to STDIN of
397 * the child and fd_out is connected to STDOUT and fd_err is connected to STDERR
398 * of the child. Then is calls `exec_child'.
400 static int fork_child (program_list_t *pl, int *fd_in, int *fd_out, int *fd_err) /* {{{ */
412 status = pipe (fd_pipe_in);
415 ERROR ("exec plugin: pipe failed: %s",
416 sstrerror (errno, errbuf, sizeof (errbuf)));
420 status = pipe (fd_pipe_out);
423 ERROR ("exec plugin: pipe failed: %s",
424 sstrerror (errno, errbuf, sizeof (errbuf)));
428 status = pipe (fd_pipe_err);
431 ERROR ("exec plugin: pipe failed: %s",
432 sstrerror (errno, errbuf, sizeof (errbuf)));
439 ERROR ("exec plugin: fork failed: %s",
440 sstrerror (errno, errbuf, sizeof (errbuf)));
448 /* Close all file descriptors but the pipe end we need. */
449 fd_num = getdtablesize ();
450 for (fd = 0; fd < fd_num; fd++)
452 if ((fd == fd_pipe_in[0])
453 || (fd == fd_pipe_out[1])
454 || (fd == fd_pipe_err[1]))
459 /* Connect the `in' pipe to STDIN */
460 if (fd_pipe_in[0] != STDIN_FILENO)
462 dup2 (fd_pipe_in[0], STDIN_FILENO);
463 close (fd_pipe_in[0]);
466 /* Now connect the `out' pipe to STDOUT */
467 if (fd_pipe_out[1] != STDOUT_FILENO)
469 dup2 (fd_pipe_out[1], STDOUT_FILENO);
470 close (fd_pipe_out[1]);
473 /* Now connect the `out' pipe to STDOUT */
474 if (fd_pipe_err[1] != STDERR_FILENO)
476 dup2 (fd_pipe_err[1], STDERR_FILENO);
477 close (fd_pipe_err[1]);
480 /* Unblock all signals */
481 reset_signal_mask ();
484 /* does not return */
487 close (fd_pipe_in[0]);
488 close (fd_pipe_out[1]);
489 close (fd_pipe_err[1]);
492 *fd_in = fd_pipe_in[1];
494 close (fd_pipe_in[1]);
497 *fd_out = fd_pipe_out[0];
499 close (fd_pipe_out[0]);
502 *fd_err = fd_pipe_err[0];
504 close (fd_pipe_err[0]);
507 } /* int fork_child }}} */
509 static int parse_line (char *buffer) /* {{{ */
511 if (strncasecmp ("PUTVAL", buffer, strlen ("PUTVAL")) == 0)
512 return (handle_putval (stdout, buffer));
513 else if (strncasecmp ("PUTNOTIF", buffer, strlen ("PUTNOTIF")) == 0)
514 return (handle_putnotif (stdout, buffer));
517 /* For backwards compatibility */
519 /* Let's annoy the user a bit.. */
520 INFO ("exec plugin: Prepending `PUTVAL' to this line: %s", buffer);
521 ssnprintf (tmp, sizeof (tmp), "PUTVAL %s", buffer);
522 return (handle_putval (stdout, tmp));
524 } /* int parse_line }}} */
526 static void *exec_read_one (void *arg) /* {{{ */
528 program_list_t *pl = (program_list_t *) arg;
529 int fd, fd_err, highest_fd;
532 char buffer[1200]; /* if not completely read */
533 char buffer_err[1024];
534 char *pbuffer = buffer;
535 char *pbuffer_err = buffer_err;
537 status = fork_child (pl, NULL, &fd, &fd_err);
539 pthread_exit ((void *) 1);
542 assert (pl->pid != 0);
546 FD_SET(fd_err, &fdset);
548 /* Determine the highest file descriptor */
549 highest_fd = (fd > fd_err) ? fd : fd_err;
551 /* We use a copy of fdset, as select modifies it */
554 while (select(highest_fd + 1, ©, NULL, NULL, NULL ) > 0)
558 if (FD_ISSET(fd, ©))
562 len = read(fd, pbuffer, sizeof(buffer) - 1 - (pbuffer - buffer));
566 if (errno == EAGAIN || errno == EINTR) continue;
569 else if (len == 0) break; /* We've reached EOF */
573 len += pbuffer - buffer;
576 while ((pnl = strchr(pbuffer, '\n')))
579 if (*(pnl-1) == '\r' ) *(pnl-1) = '\0';
581 parse_line (pbuffer);
585 /* not completely read ? */
586 if (pbuffer - buffer < len)
588 len -= pbuffer - buffer;
589 memmove(buffer, pbuffer, len);
590 pbuffer = buffer + len;
595 else if (FD_ISSET(fd_err, ©))
599 len = read(fd_err, pbuffer_err, sizeof(buffer_err) - 1 - (pbuffer_err - buffer_err));
603 if (errno == EAGAIN || errno == EINTR) continue;
608 /* We've reached EOF */
609 NOTICE ("exec plugin: Program `%s' has closed STDERR.",
612 FD_CLR (fd_err, &fdset);
618 pbuffer_err[len] = '\0';
620 len += pbuffer_err - buffer_err;
621 pbuffer_err = buffer_err;
623 while ((pnl = strchr(pbuffer_err, '\n')))
626 if (*(pnl-1) == '\r' ) *(pnl-1) = '\0';
628 ERROR ("exec plugin: exec_read_one: error = %s", pbuffer_err);
632 /* not completely read ? */
633 if (pbuffer_err - buffer_err < len)
635 len -= pbuffer_err - buffer_err;
636 memmove(buffer_err, pbuffer_err, len);
637 pbuffer_err = buffer_err + len;
640 pbuffer_err = buffer_err;
646 DEBUG ("exec plugin: exec_read_one: Waiting for `%s' to exit.", pl->exec);
647 if (waitpid (pl->pid, &status, 0) > 0)
650 DEBUG ("exec plugin: Child %i exited with status %i.",
651 (int) pl->pid, pl->status);
655 pthread_mutex_lock (&pl_lock);
656 pl->flags &= ~PL_RUNNING;
657 pthread_mutex_unlock (&pl_lock);
663 pthread_exit ((void *) 0);
665 } /* void *exec_read_one }}} */
667 static void *exec_notification_one (void *arg) /* {{{ */
669 program_list_t *pl = ((program_list_and_notification_t *) arg)->pl;
670 notification_t *n = &((program_list_and_notification_t *) arg)->n;
671 notification_meta_t *meta;
676 const char *severity;
678 pid = fork_child (pl, &fd, NULL, NULL);
681 pthread_exit ((void *) 1);
684 fh = fdopen (fd, "w");
688 ERROR ("exec plugin: fdopen (%i) failed: %s", fd,
689 sstrerror (errno, errbuf, sizeof (errbuf)));
690 kill (pl->pid, SIGTERM);
694 pthread_exit ((void *) 1);
697 severity = "FAILURE";
698 if (n->severity == NOTIF_WARNING)
699 severity = "WARNING";
700 else if (n->severity == NOTIF_OKAY)
706 severity, (unsigned int) n->time);
708 /* Print the optional fields */
709 if (strlen (n->host) > 0)
710 fprintf (fh, "Host: %s\n", n->host);
711 if (strlen (n->plugin) > 0)
712 fprintf (fh, "Plugin: %s\n", n->plugin);
713 if (strlen (n->plugin_instance) > 0)
714 fprintf (fh, "PluginInstance: %s\n", n->plugin_instance);
715 if (strlen (n->type) > 0)
716 fprintf (fh, "Type: %s\n", n->type);
717 if (strlen (n->type_instance) > 0)
718 fprintf (fh, "TypeInstance: %s\n", n->type_instance);
720 for (meta = n->meta; meta != NULL; meta = meta->next)
722 if (meta->type == NM_TYPE_STRING)
723 fprintf (fh, "%s: %s\n", meta->name, meta->nm_value.nm_string);
724 else if (meta->type == NM_TYPE_SIGNED_INT)
725 fprintf (fh, "%s: %"PRIi64"\n", meta->name, meta->nm_value.nm_signed_int);
726 else if (meta->type == NM_TYPE_UNSIGNED_INT)
727 fprintf (fh, "%s: %"PRIu64"\n", meta->name, meta->nm_value.nm_unsigned_int);
728 else if (meta->type == NM_TYPE_DOUBLE)
729 fprintf (fh, "%s: %e\n", meta->name, meta->nm_value.nm_double);
730 else if (meta->type == NM_TYPE_BOOLEAN)
731 fprintf (fh, "%s: %s\n", meta->name,
732 meta->nm_value.nm_boolean ? "true" : "false");
735 fprintf (fh, "\n%s\n", n->message);
740 waitpid (pid, &status, 0);
742 DEBUG ("exec plugin: Child %i exited with status %i.",
746 plugin_notification_meta_free (n->meta);
749 pthread_exit ((void *) 0);
751 } /* void *exec_notification_one }}} */
753 static int exec_init (void) /* {{{ */
757 memset (&sa, '\0', sizeof (sa));
758 sa.sa_handler = sigchld_handler;
759 sigaction (SIGCHLD, &sa, NULL);
762 } /* int exec_init }}} */
764 static int exec_read (void) /* {{{ */
768 for (pl = pl_head; pl != NULL; pl = pl->next)
773 /* Only execute `normal' style executables here. */
774 if ((pl->flags & PL_NORMAL) == 0)
777 pthread_mutex_lock (&pl_lock);
778 /* Skip if a child is already running. */
779 if ((pl->flags & PL_RUNNING) != 0)
781 pthread_mutex_unlock (&pl_lock);
784 pl->flags |= PL_RUNNING;
785 pthread_mutex_unlock (&pl_lock);
787 pthread_attr_init (&attr);
788 pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
789 pthread_create (&t, &attr, exec_read_one, (void *) pl);
793 } /* int exec_read }}} */
795 static int exec_notification (const notification_t *n,
796 user_data_t __attribute__((unused)) *user_data)
799 program_list_and_notification_t *pln;
801 for (pl = pl_head; pl != NULL; pl = pl->next)
806 /* Only execute `notification' style executables here. */
807 if ((pl->flags & PL_NOTIF_ACTION) == 0)
810 /* Skip if a child is already running. */
814 pln = (program_list_and_notification_t *) malloc (sizeof
815 (program_list_and_notification_t));
818 ERROR ("exec plugin: malloc failed.");
823 memcpy (&pln->n, n, sizeof (notification_t));
825 /* Set the `meta' member to NULL, otherwise `plugin_notification_meta_copy'
826 * will run into an endless loop. */
828 plugin_notification_meta_copy (&pln->n, n);
830 pthread_attr_init (&attr);
831 pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
832 pthread_create (&t, &attr, exec_notification_one, (void *) pln);
836 } /* }}} int exec_notification */
838 static int exec_shutdown (void) /* {{{ */
841 program_list_t *next;
850 kill (pl->pid, SIGTERM);
851 INFO ("exec plugin: Sent SIGTERM to %hu", (unsigned short int) pl->pid);
862 } /* int exec_shutdown }}} */
864 void module_register (void)
866 plugin_register_complex_config ("exec", exec_config);
867 plugin_register_init ("exec", exec_init);
868 plugin_register_read ("exec", exec_read);
869 plugin_register_notification ("exec", exec_notification,
870 /* user_data = */ NULL);
871 plugin_register_shutdown ("exec", exec_shutdown);
872 } /* void module_register */
875 * vim:shiftwidth=2:softtabstop=2:tabstop=8:fdm=marker