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>
41 #define PL_NORMAL 0x01
42 #define PL_NOTIF_ACTION 0x02
44 #define PL_RUNNING 0x10
50 * Access to this structure is serialized using the `pl_lock' lock and the
51 * `PL_RUNNING' flag. The execution of notifications is *not* serialized, so
52 * all functions used to handle notifications MUST NOT write to this structure.
53 * The `pid' and `status' fields are thus unused if the `PL_NOTIF_ACTION' flag
55 * The `PL_RUNNING' flag is set in `exec_read' and unset in `exec_read_one'.
57 struct program_list_s;
58 typedef struct program_list_s program_list_t;
71 typedef struct program_list_and_notification_s
75 } program_list_and_notification_t;
80 static program_list_t *pl_head = NULL;
81 static pthread_mutex_t pl_lock = PTHREAD_MUTEX_INITIALIZER;
86 static void sigchld_handler (int __attribute__((unused)) signal) /* {{{ */
90 while ((pid = waitpid (-1, &status, WNOHANG)) > 0)
93 for (pl = pl_head; pl != NULL; pl = pl->next)
98 } /* while (waitpid) */
99 } /* void sigchld_handler }}} */
101 static int exec_config_exec (oconfig_item_t *ci) /* {{{ */
107 if (ci->children_num != 0)
109 WARNING ("exec plugin: The config option `%s' may not be a block.",
113 if (ci->values_num < 2)
115 WARNING ("exec plugin: The config option `%s' needs at least two "
116 "arguments.", ci->key);
119 if ((ci->values[0].type != OCONFIG_TYPE_STRING)
120 || (ci->values[1].type != OCONFIG_TYPE_STRING))
122 WARNING ("exec plugin: The first two arguments to the `%s' option must "
123 "be string arguments.", ci->key);
127 pl = calloc (1, sizeof (*pl));
130 ERROR ("exec plugin: calloc failed.");
134 if (strcasecmp ("NotificationExec", ci->key) == 0)
135 pl->flags |= PL_NOTIF_ACTION;
137 pl->flags |= PL_NORMAL;
139 pl->user = strdup (ci->values[0].value.string);
140 if (pl->user == NULL)
142 ERROR ("exec plugin: strdup failed.");
147 pl->group = strchr (pl->user, ':');
148 if (pl->group != NULL)
154 pl->exec = strdup (ci->values[1].value.string);
155 if (pl->exec == NULL)
157 ERROR ("exec plugin: strdup failed.");
163 pl->argv = calloc (ci->values_num, sizeof (*pl->argv));
164 if (pl->argv == NULL)
166 ERROR ("exec plugin: calloc failed.");
174 char *tmp = strrchr (ci->values[1].value.string, '/');
176 sstrncpy (buffer, ci->values[1].value.string, sizeof (buffer));
178 sstrncpy (buffer, tmp + 1, sizeof (buffer));
180 pl->argv[0] = strdup (buffer);
181 if (pl->argv[0] == NULL)
183 ERROR ("exec plugin: strdup failed.");
191 for (i = 1; i < (ci->values_num - 1); i++)
193 if (ci->values[i + 1].type == OCONFIG_TYPE_STRING)
195 pl->argv[i] = strdup (ci->values[i + 1].value.string);
199 if (ci->values[i + 1].type == OCONFIG_TYPE_NUMBER)
201 ssnprintf (buffer, sizeof (buffer), "%lf",
202 ci->values[i + 1].value.number);
206 if (ci->values[i + 1].value.boolean)
207 sstrncpy (buffer, "true", sizeof (buffer));
209 sstrncpy (buffer, "false", sizeof (buffer));
212 pl->argv[i] = strdup (buffer);
215 if (pl->argv[i] == NULL)
217 ERROR ("exec plugin: strdup failed.");
222 if (i < (ci->values_num - 1))
235 for (i = 0; pl->argv[i] != NULL; i++)
237 DEBUG ("exec plugin: argv[%i] = %s", i, pl->argv[i]);
244 } /* int exec_config_exec }}} */
246 static int exec_config (oconfig_item_t *ci) /* {{{ */
250 for (i = 0; i < ci->children_num; i++)
252 oconfig_item_t *child = ci->children + i;
253 if ((strcasecmp ("Exec", child->key) == 0)
254 || (strcasecmp ("NotificationExec", child->key) == 0))
255 exec_config_exec (child);
258 WARNING ("exec plugin: Unknown config option `%s'.", child->key);
263 } /* int exec_config }}} */
265 static void set_environment (void) /* {{{ */
270 ssnprintf (buffer, sizeof (buffer), "%.3f",
271 CDTIME_T_TO_DOUBLE (plugin_get_interval ()));
272 setenv ("COLLECTD_INTERVAL", buffer, /* overwrite = */ 1);
274 ssnprintf (buffer, sizeof (buffer), "%s", hostname_g);
275 setenv ("COLLECTD_HOSTNAME", buffer, /* overwrite = */ 1);
277 ssnprintf (buffer, sizeof (buffer), "COLLECTD_INTERVAL=%.3f",
278 CDTIME_T_TO_DOUBLE (plugin_get_interval ()));
281 ssnprintf (buffer, sizeof (buffer), "COLLECTD_HOSTNAME=%s", hostname_g);
284 } /* }}} void set_environment */
286 __attribute__((noreturn))
287 static void exec_child (program_list_t *pl, int uid, int gid, int egid) /* {{{ */
301 if ((gid != egid) && (egid != -1))
307 setgroups (glist_len, glist);
309 #endif /* HAVE_SETGROUPS */
311 status = setgid (gid);
314 ERROR ("exec plugin: setgid (%i) failed: %s",
315 gid, sstrerror (errno, errbuf, sizeof (errbuf)));
321 status = setegid (egid);
324 ERROR ("exec plugin: setegid (%i) failed: %s",
325 egid, sstrerror (errno, errbuf, sizeof (errbuf)));
330 status = setuid (uid);
333 ERROR ("exec plugin: setuid (%i) failed: %s",
334 uid, sstrerror (errno, errbuf, sizeof (errbuf)));
338 execvp (pl->exec, pl->argv);
340 ERROR ("exec plugin: Failed to execute ``%s'': %s",
341 pl->exec, sstrerror (errno, errbuf, sizeof (errbuf)));
343 } /* void exec_child }}} */
345 static void reset_signal_mask (void) /* {{{ */
349 memset (&ss, 0, sizeof (ss));
351 sigprocmask (SIG_SETMASK, &ss, /* old mask = */ NULL);
352 } /* }}} void reset_signal_mask */
354 static int create_pipe (int fd_pipe[2]) /* {{{ */
359 status = pipe (fd_pipe);
362 ERROR ("exec plugin: pipe failed: %s",
363 sstrerror (errno, errbuf, sizeof (errbuf)));
368 } /* }}} int create_pipe */
370 static void close_pipe (int fd_pipe[2]) /* {{{ */
372 if (fd_pipe[0] != -1)
375 if (fd_pipe[1] != -1)
377 } /* }}} void close_pipe */
380 * Creates three pipes (one for reading, one for writing and one for errors),
381 * forks a child, sets up the pipes so that fd_in is connected to STDIN of
382 * the child and fd_out is connected to STDOUT and fd_err is connected to STDERR
383 * of the child. Then is calls `exec_child'.
385 static int fork_child (program_list_t *pl, int *fd_in, int *fd_out, int *fd_err) /* {{{ */
387 int fd_pipe_in[2] = {-1, -1};
388 int fd_pipe_out[2] = {-1, -1};
389 int fd_pipe_err[2] = {-1, -1};
398 struct passwd *sp_ptr;
405 if ((create_pipe(fd_pipe_in) == -1)
406 || (create_pipe(fd_pipe_out) == -1)
407 || (create_pipe(fd_pipe_err) == -1))
411 status = getpwnam_r (pl->user, &sp, nambuf, sizeof (nambuf), &sp_ptr);
414 ERROR ("exec plugin: Failed to get user information for user ``%s'': %s",
415 pl->user, sstrerror (errno, errbuf, sizeof (errbuf)));
421 ERROR ("exec plugin: No such user: `%s'", pl->user);
429 ERROR ("exec plugin: Cowardly refusing to exec program as root.");
433 /* The group configured in the configfile is set as effective group, because
434 * this way the forked process can (re-)gain the user's primary group. */
436 if (NULL != pl->group)
438 if ('\0' != *pl->group) {
439 struct group *gr_ptr = NULL;
442 status = getgrnam_r (pl->group, &gr, nambuf, sizeof (nambuf), &gr_ptr);
445 ERROR ("exec plugin: Failed to get group information "
446 "for group ``%s'': %s", pl->group,
447 sstrerror (errno, errbuf, sizeof (errbuf)));
452 ERROR ("exec plugin: No such group: `%s'", pl->group);
462 } /* if (pl->group == NULL) */
467 ERROR ("exec plugin: fork failed: %s",
468 sstrerror (errno, errbuf, sizeof (errbuf)));
476 /* Close all file descriptors but the pipe end we need. */
477 fd_num = getdtablesize ();
478 for (fd = 0; fd < fd_num; fd++)
480 if ((fd == fd_pipe_in[0])
481 || (fd == fd_pipe_out[1])
482 || (fd == fd_pipe_err[1]))
487 /* Connect the `in' pipe to STDIN */
488 if (fd_pipe_in[0] != STDIN_FILENO)
490 dup2 (fd_pipe_in[0], STDIN_FILENO);
491 close (fd_pipe_in[0]);
494 /* Now connect the `out' pipe to STDOUT */
495 if (fd_pipe_out[1] != STDOUT_FILENO)
497 dup2 (fd_pipe_out[1], STDOUT_FILENO);
498 close (fd_pipe_out[1]);
501 /* Now connect the `err' pipe to STDERR */
502 if (fd_pipe_err[1] != STDERR_FILENO)
504 dup2 (fd_pipe_err[1], STDERR_FILENO);
505 close (fd_pipe_err[1]);
510 /* Unblock all signals */
511 reset_signal_mask ();
513 exec_child (pl, uid, gid, egid);
514 /* does not return */
517 close (fd_pipe_in[0]);
518 close (fd_pipe_out[1]);
519 close (fd_pipe_err[1]);
522 *fd_in = fd_pipe_in[1];
524 close (fd_pipe_in[1]);
527 *fd_out = fd_pipe_out[0];
529 close (fd_pipe_out[0]);
532 *fd_err = fd_pipe_err[0];
534 close (fd_pipe_err[0]);
539 close_pipe(fd_pipe_in);
540 close_pipe(fd_pipe_out);
541 close_pipe(fd_pipe_err);
544 } /* int fork_child }}} */
546 static int parse_line (char *buffer) /* {{{ */
548 if (strncasecmp ("PUTVAL", buffer, strlen ("PUTVAL")) == 0)
549 return (handle_putval (stdout, buffer));
550 else if (strncasecmp ("PUTNOTIF", buffer, strlen ("PUTNOTIF")) == 0)
551 return (handle_putnotif (stdout, buffer));
554 ERROR ("exec plugin: Unable to parse command, ignoring line: \"%s\"",
558 } /* int parse_line }}} */
560 static void *exec_read_one (void *arg) /* {{{ */
562 program_list_t *pl = (program_list_t *) arg;
563 int fd, fd_err, highest_fd;
566 char buffer[1200]; /* if not completely read */
567 char buffer_err[1024];
568 char *pbuffer = buffer;
569 char *pbuffer_err = buffer_err;
571 status = fork_child (pl, NULL, &fd, &fd_err);
574 /* Reset the "running" flag */
575 pthread_mutex_lock (&pl_lock);
576 pl->flags &= ~PL_RUNNING;
577 pthread_mutex_unlock (&pl_lock);
578 pthread_exit ((void *) 1);
582 assert (pl->pid != 0);
586 FD_SET(fd_err, &fdset);
588 /* Determine the highest file descriptor */
589 highest_fd = (fd > fd_err) ? fd : fd_err;
591 /* We use a copy of fdset, as select modifies it */
598 status = select (highest_fd + 1, ©, NULL, NULL, NULL);
606 if (FD_ISSET(fd, ©))
610 len = read(fd, pbuffer, sizeof(buffer) - 1 - (pbuffer - buffer));
614 if (errno == EAGAIN || errno == EINTR) continue;
617 else if (len == 0) break; /* We've reached EOF */
621 len += pbuffer - buffer;
624 while ((pnl = strchr(pbuffer, '\n')))
627 if (*(pnl-1) == '\r' ) *(pnl-1) = '\0';
629 parse_line (pbuffer);
633 /* not completely read ? */
634 if (pbuffer - buffer < len)
636 len -= pbuffer - buffer;
637 memmove(buffer, pbuffer, len);
638 pbuffer = buffer + len;
643 else if (FD_ISSET(fd_err, ©))
647 len = read(fd_err, pbuffer_err, sizeof(buffer_err) - 1 - (pbuffer_err - buffer_err));
651 if (errno == EAGAIN || errno == EINTR)
657 /* We've reached EOF */
658 NOTICE ("exec plugin: Program `%s' has closed STDERR.", pl->exec);
660 /* Remove file descriptor form select() set. */
661 FD_CLR (fd_err, &fdset);
665 /* Clean up file descriptor */
671 pbuffer_err[len] = '\0';
673 len += pbuffer_err - buffer_err;
674 pbuffer_err = buffer_err;
676 while ((pnl = strchr(pbuffer_err, '\n')))
679 if (*(pnl-1) == '\r' ) *(pnl-1) = '\0';
681 ERROR ("exec plugin: exec_read_one: error = %s", pbuffer_err);
685 /* not completely read ? */
686 if (pbuffer_err - buffer_err < len)
688 len -= pbuffer_err - buffer_err;
689 memmove(buffer_err, pbuffer_err, len);
690 pbuffer_err = buffer_err + len;
693 pbuffer_err = buffer_err;
699 DEBUG ("exec plugin: exec_read_one: Waiting for `%s' to exit.", pl->exec);
700 if (waitpid (pl->pid, &status, 0) > 0)
703 DEBUG ("exec plugin: Child %i exited with status %i.",
704 (int) pl->pid, pl->status);
708 pthread_mutex_lock (&pl_lock);
709 pl->flags &= ~PL_RUNNING;
710 pthread_mutex_unlock (&pl_lock);
716 pthread_exit ((void *) 0);
718 } /* void *exec_read_one }}} */
720 static void *exec_notification_one (void *arg) /* {{{ */
722 program_list_t *pl = ((program_list_and_notification_t *) arg)->pl;
723 notification_t *n = &((program_list_and_notification_t *) arg)->n;
724 notification_meta_t *meta;
729 const char *severity;
731 pid = fork_child (pl, &fd, NULL, NULL);
734 pthread_exit ((void *) 1);
737 fh = fdopen (fd, "w");
741 ERROR ("exec plugin: fdopen (%i) failed: %s", fd,
742 sstrerror (errno, errbuf, sizeof (errbuf)));
746 pthread_exit ((void *) 1);
749 severity = "FAILURE";
750 if (n->severity == NOTIF_WARNING)
751 severity = "WARNING";
752 else if (n->severity == NOTIF_OKAY)
758 severity, CDTIME_T_TO_DOUBLE (n->time));
760 /* Print the optional fields */
761 if (strlen (n->host) > 0)
762 fprintf (fh, "Host: %s\n", n->host);
763 if (strlen (n->plugin) > 0)
764 fprintf (fh, "Plugin: %s\n", n->plugin);
765 if (strlen (n->plugin_instance) > 0)
766 fprintf (fh, "PluginInstance: %s\n", n->plugin_instance);
767 if (strlen (n->type) > 0)
768 fprintf (fh, "Type: %s\n", n->type);
769 if (strlen (n->type_instance) > 0)
770 fprintf (fh, "TypeInstance: %s\n", n->type_instance);
772 for (meta = n->meta; meta != NULL; meta = meta->next)
774 if (meta->type == NM_TYPE_STRING)
775 fprintf (fh, "%s: %s\n", meta->name, meta->nm_value.nm_string);
776 else if (meta->type == NM_TYPE_SIGNED_INT)
777 fprintf (fh, "%s: %"PRIi64"\n", meta->name, meta->nm_value.nm_signed_int);
778 else if (meta->type == NM_TYPE_UNSIGNED_INT)
779 fprintf (fh, "%s: %"PRIu64"\n", meta->name, meta->nm_value.nm_unsigned_int);
780 else if (meta->type == NM_TYPE_DOUBLE)
781 fprintf (fh, "%s: %e\n", meta->name, meta->nm_value.nm_double);
782 else if (meta->type == NM_TYPE_BOOLEAN)
783 fprintf (fh, "%s: %s\n", meta->name,
784 meta->nm_value.nm_boolean ? "true" : "false");
787 fprintf (fh, "\n%s\n", n->message);
792 waitpid (pid, &status, 0);
794 DEBUG ("exec plugin: Child %i exited with status %i.",
798 plugin_notification_meta_free (n->meta);
801 pthread_exit ((void *) 0);
803 } /* void *exec_notification_one }}} */
805 static int exec_init (void) /* {{{ */
809 memset (&sa, '\0', sizeof (sa));
810 sa.sa_handler = sigchld_handler;
811 sigaction (SIGCHLD, &sa, NULL);
814 } /* int exec_init }}} */
816 static int exec_read (void) /* {{{ */
820 for (pl = pl_head; pl != NULL; pl = pl->next)
825 /* Only execute `normal' style executables here. */
826 if ((pl->flags & PL_NORMAL) == 0)
829 pthread_mutex_lock (&pl_lock);
830 /* Skip if a child is already running. */
831 if ((pl->flags & PL_RUNNING) != 0)
833 pthread_mutex_unlock (&pl_lock);
836 pl->flags |= PL_RUNNING;
837 pthread_mutex_unlock (&pl_lock);
839 pthread_attr_init (&attr);
840 pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
841 plugin_thread_create (&t, &attr, exec_read_one, (void *) pl);
842 pthread_attr_destroy (&attr);
846 } /* int exec_read }}} */
848 static int exec_notification (const notification_t *n, /* {{{ */
849 user_data_t __attribute__((unused)) *user_data)
852 program_list_and_notification_t *pln;
854 for (pl = pl_head; pl != NULL; pl = pl->next)
859 /* Only execute `notification' style executables here. */
860 if ((pl->flags & PL_NOTIF_ACTION) == 0)
863 /* Skip if a child is already running. */
867 pln = malloc (sizeof (*pln));
870 ERROR ("exec plugin: malloc failed.");
875 memcpy (&pln->n, n, sizeof (notification_t));
877 /* Set the `meta' member to NULL, otherwise `plugin_notification_meta_copy'
878 * will run into an endless loop. */
880 plugin_notification_meta_copy (&pln->n, n);
882 pthread_attr_init (&attr);
883 pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
884 plugin_thread_create (&t, &attr, exec_notification_one, (void *) pln);
885 pthread_attr_destroy (&attr);
889 } /* }}} int exec_notification */
891 static int exec_shutdown (void) /* {{{ */
894 program_list_t *next;
903 kill (pl->pid, SIGTERM);
904 INFO ("exec plugin: Sent SIGTERM to %hu", (unsigned short int) pl->pid);
915 } /* int exec_shutdown }}} */
917 void module_register (void)
919 plugin_register_complex_config ("exec", exec_config);
920 plugin_register_init ("exec", exec_init);
921 plugin_register_read ("exec", exec_read);
922 plugin_register_notification ("exec", exec_notification,
923 /* user_data = */ NULL);
924 plugin_register_shutdown ("exec", exec_shutdown);
925 } /* void module_register */
928 * vim:shiftwidth=2:softtabstop=2:tabstop=8:fdm=marker