1 /**
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
6 *
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.
10 *
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.
15 *
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
19 *
20 * Authors:
21 * Florian octo Forster <octo at collectd.org>
22 * Sebastian Harl <sh at tokkee.org>
23 * Peter Holik <peter at holik.at>
24 **/
26 #define _DEFAULT_SOURCE
27 #define _BSD_SOURCE /* For setgroups */
29 #include "collectd.h"
31 #include "common.h"
32 #include "plugin.h"
34 #include "utils_cmd_putnotif.h"
35 #include "utils_cmd_putval.h"
37 #include <grp.h>
38 #include <pwd.h>
39 #include <signal.h>
40 #include <sys/types.h>
42 #ifdef HAVE_SYS_CAPABILITY_H
43 #include <sys/capability.h>
44 #endif
46 #define PL_NORMAL 0x01
47 #define PL_NOTIF_ACTION 0x02
49 #define PL_RUNNING 0x10
51 /*
52 * Private data types
53 */
54 /*
55 * Access to this structure is serialized using the `pl_lock' lock and the
56 * `PL_RUNNING' flag. The execution of notifications is *not* serialized, so
57 * all functions used to handle notifications MUST NOT write to this structure.
58 * The `pid' and `status' fields are thus unused if the `PL_NOTIF_ACTION' flag
59 * is set.
60 * The `PL_RUNNING' flag is set in `exec_read' and unset in `exec_read_one'.
61 */
62 struct program_list_s;
63 typedef struct program_list_s program_list_t;
64 struct program_list_s {
65 char *user;
66 char *group;
67 char *exec;
68 char **argv;
69 int pid;
70 int status;
71 int flags;
72 program_list_t *next;
73 };
75 typedef struct program_list_and_notification_s {
76 program_list_t *pl;
77 notification_t n;
78 } program_list_and_notification_t;
80 /*
81 * Private variables
82 */
83 static program_list_t *pl_head = NULL;
84 static pthread_mutex_t pl_lock = PTHREAD_MUTEX_INITIALIZER;
86 /*
87 * Functions
88 */
89 static void sigchld_handler(int __attribute__((unused)) signal) /* {{{ */
90 {
91 pid_t pid;
92 int status;
93 while ((pid = waitpid(-1, &status, WNOHANG)) > 0) {
94 program_list_t *pl;
95 for (pl = pl_head; pl != NULL; pl = pl->next)
96 if (pl->pid == pid)
97 break;
98 if (pl != NULL)
99 pl->status = status;
100 } /* while (waitpid) */
101 } /* void sigchld_handler }}} */
103 static int exec_config_exec(oconfig_item_t *ci) /* {{{ */
104 {
105 program_list_t *pl;
106 char buffer[128];
107 int i;
109 if (ci->children_num != 0) {
110 WARNING("exec plugin: The config option `%s' may not be a block.", ci->key);
111 return -1;
112 }
113 if (ci->values_num < 2) {
114 WARNING("exec plugin: The config option `%s' needs at least two "
115 "arguments.",
116 ci->key);
117 return -1;
118 }
119 if ((ci->values[0].type != OCONFIG_TYPE_STRING) ||
120 (ci->values[1].type != OCONFIG_TYPE_STRING)) {
121 WARNING("exec plugin: The first two arguments to the `%s' option must "
122 "be string arguments.",
123 ci->key);
124 return -1;
125 }
127 pl = calloc(1, sizeof(*pl));
128 if (pl == NULL) {
129 ERROR("exec plugin: calloc failed.");
130 return -1;
131 }
133 if (strcasecmp("NotificationExec", ci->key) == 0)
134 pl->flags |= PL_NOTIF_ACTION;
135 else
136 pl->flags |= PL_NORMAL;
138 pl->user = strdup(ci->values[0].value.string);
139 if (pl->user == NULL) {
140 ERROR("exec plugin: strdup failed.");
141 sfree(pl);
142 return -1;
143 }
145 pl->group = strchr(pl->user, ':');
146 if (pl->group != NULL) {
147 *pl->group = '\0';
148 pl->group++;
149 }
151 pl->exec = strdup(ci->values[1].value.string);
152 if (pl->exec == NULL) {
153 ERROR("exec plugin: strdup failed.");
154 sfree(pl->user);
155 sfree(pl);
156 return -1;
157 }
159 pl->argv = calloc(ci->values_num, sizeof(*pl->argv));
160 if (pl->argv == NULL) {
161 ERROR("exec plugin: calloc failed.");
162 sfree(pl->exec);
163 sfree(pl->user);
164 sfree(pl);
165 return -1;
166 }
168 {
169 char *tmp = strrchr(ci->values[1].value.string, '/');
170 if (tmp == NULL)
171 sstrncpy(buffer, ci->values[1].value.string, sizeof(buffer));
172 else
173 sstrncpy(buffer, tmp + 1, sizeof(buffer));
174 }
175 pl->argv[0] = strdup(buffer);
176 if (pl->argv[0] == NULL) {
177 ERROR("exec plugin: strdup failed.");
178 sfree(pl->argv);
179 sfree(pl->exec);
180 sfree(pl->user);
181 sfree(pl);
182 return -1;
183 }
185 for (i = 1; i < (ci->values_num - 1); i++) {
186 if (ci->values[i + 1].type == OCONFIG_TYPE_STRING) {
187 pl->argv[i] = strdup(ci->values[i + 1].value.string);
188 } else {
189 if (ci->values[i + 1].type == OCONFIG_TYPE_NUMBER) {
190 snprintf(buffer, sizeof(buffer), "%lf", ci->values[i + 1].value.number);
191 } else {
192 if (ci->values[i + 1].value.boolean)
193 sstrncpy(buffer, "true", sizeof(buffer));
194 else
195 sstrncpy(buffer, "false", sizeof(buffer));
196 }
198 pl->argv[i] = strdup(buffer);
199 }
201 if (pl->argv[i] == NULL) {
202 ERROR("exec plugin: strdup failed.");
203 break;
204 }
205 } /* for (i) */
207 if (i < (ci->values_num - 1)) {
208 while ((--i) >= 0) {
209 sfree(pl->argv[i]);
210 }
211 sfree(pl->argv);
212 sfree(pl->exec);
213 sfree(pl->user);
214 sfree(pl);
215 return -1;
216 }
218 for (i = 0; pl->argv[i] != NULL; i++) {
219 DEBUG("exec plugin: argv[%i] = %s", i, pl->argv[i]);
220 }
222 pl->next = pl_head;
223 pl_head = pl;
225 return 0;
226 } /* int exec_config_exec }}} */
228 static int exec_config(oconfig_item_t *ci) /* {{{ */
229 {
230 for (int i = 0; i < ci->children_num; i++) {
231 oconfig_item_t *child = ci->children + i;
232 if ((strcasecmp("Exec", child->key) == 0) ||
233 (strcasecmp("NotificationExec", child->key) == 0))
234 exec_config_exec(child);
235 else {
236 WARNING("exec plugin: Unknown config option `%s'.", child->key);
237 }
238 } /* for (i) */
240 return 0;
241 } /* int exec_config }}} */
243 static void set_environment(void) /* {{{ */
244 {
245 char buffer[1024];
247 #ifdef HAVE_SETENV
248 snprintf(buffer, sizeof(buffer), "%.3f",
249 CDTIME_T_TO_DOUBLE(plugin_get_interval()));
250 setenv("COLLECTD_INTERVAL", buffer, /* overwrite = */ 1);
252 sstrncpy(buffer, hostname_g, sizeof(buffer));
253 setenv("COLLECTD_HOSTNAME", buffer, /* overwrite = */ 1);
254 #else
255 snprintf(buffer, sizeof(buffer), "COLLECTD_INTERVAL=%.3f",
256 CDTIME_T_TO_DOUBLE(plugin_get_interval()));
257 putenv(buffer);
259 snprintf(buffer, sizeof(buffer), "COLLECTD_HOSTNAME=%s", hostname_g);
260 putenv(buffer);
261 #endif
262 } /* }}} void set_environment */
264 __attribute__((noreturn)) static void exec_child(program_list_t *pl, int uid,
265 int gid, int egid) /* {{{ */
266 {
267 int status;
268 char errbuf[1024];
270 #if HAVE_SETGROUPS
271 if (getuid() == 0) {
272 gid_t glist[2];
273 size_t glist_len;
275 glist[0] = gid;
276 glist_len = 1;
278 if ((gid != egid) && (egid != -1)) {
279 glist[1] = egid;
280 glist_len = 2;
281 }
283 setgroups(glist_len, glist);
284 }
285 #endif /* HAVE_SETGROUPS */
287 status = setgid(gid);
288 if (status != 0) {
289 ERROR("exec plugin: setgid (%i) failed: %s", gid,
290 sstrerror(errno, errbuf, sizeof(errbuf)));
291 exit(-1);
292 }
294 if (egid != -1) {
295 status = setegid(egid);
296 if (status != 0) {
297 ERROR("exec plugin: setegid (%i) failed: %s", egid,
298 sstrerror(errno, errbuf, sizeof(errbuf)));
299 exit(-1);
300 }
301 }
303 status = setuid(uid);
304 if (status != 0) {
305 ERROR("exec plugin: setuid (%i) failed: %s", uid,
306 sstrerror(errno, errbuf, sizeof(errbuf)));
307 exit(-1);
308 }
310 execvp(pl->exec, pl->argv);
312 ERROR("exec plugin: Failed to execute ``%s'': %s", pl->exec,
313 sstrerror(errno, errbuf, sizeof(errbuf)));
314 exit(-1);
315 } /* void exec_child }}} */
317 static void reset_signal_mask(void) /* {{{ */
318 {
319 sigset_t ss;
321 sigemptyset(&ss);
322 sigprocmask(SIG_SETMASK, &ss, /* old mask = */ NULL);
323 } /* }}} void reset_signal_mask */
325 static int create_pipe(int fd_pipe[2]) /* {{{ */
326 {
327 char errbuf[1024];
328 int status;
330 status = pipe(fd_pipe);
331 if (status != 0) {
332 ERROR("exec plugin: pipe failed: %s",
333 sstrerror(errno, errbuf, sizeof(errbuf)));
334 return -1;
335 }
337 return 0;
338 } /* }}} int create_pipe */
340 static void close_pipe(int fd_pipe[2]) /* {{{ */
341 {
342 if (fd_pipe[0] != -1)
343 close(fd_pipe[0]);
345 if (fd_pipe[1] != -1)
346 close(fd_pipe[1]);
347 } /* }}} void close_pipe */
349 /*
350 * Creates three pipes (one for reading, one for writing and one for errors),
351 * forks a child, sets up the pipes so that fd_in is connected to STDIN of
352 * the child and fd_out is connected to STDOUT and fd_err is connected to STDERR
353 * of the child. Then is calls `exec_child'.
354 */
355 static int fork_child(program_list_t *pl, int *fd_in, int *fd_out,
356 int *fd_err) /* {{{ */
357 {
358 int fd_pipe_in[2] = {-1, -1};
359 int fd_pipe_out[2] = {-1, -1};
360 int fd_pipe_err[2] = {-1, -1};
361 char errbuf[1024];
362 int status;
363 int pid;
365 int uid;
366 int gid;
367 int egid;
369 struct passwd *sp_ptr;
370 struct passwd sp;
372 if (pl->pid != 0)
373 return -1;
375 long int nambuf_size = sysconf(_SC_GETPW_R_SIZE_MAX);
376 if (nambuf_size <= 0)
377 nambuf_size = sysconf(_SC_PAGESIZE);
378 if (nambuf_size <= 0)
379 nambuf_size = 4096;
380 char nambuf[nambuf_size];
382 if ((create_pipe(fd_pipe_in) == -1) || (create_pipe(fd_pipe_out) == -1) ||
383 (create_pipe(fd_pipe_err) == -1))
384 goto failed;
386 sp_ptr = NULL;
387 status = getpwnam_r(pl->user, &sp, nambuf, sizeof(nambuf), &sp_ptr);
388 if (status != 0) {
389 ERROR("exec plugin: Failed to get user information for user ``%s'': %s",
390 pl->user, sstrerror(status, errbuf, sizeof(errbuf)));
391 goto failed;
392 }
394 if (sp_ptr == NULL) {
395 ERROR("exec plugin: No such user: `%s'", pl->user);
396 goto failed;
397 }
399 uid = sp.pw_uid;
400 gid = sp.pw_gid;
401 if (uid == 0) {
402 ERROR("exec plugin: Cowardly refusing to exec program as root.");
403 goto failed;
404 }
406 /* The group configured in the configfile is set as effective group, because
407 * this way the forked process can (re-)gain the user's primary group. */
408 egid = -1;
409 if (pl->group != NULL) {
410 if (*pl->group != '\0') {
411 struct group *gr_ptr = NULL;
412 struct group gr;
414 long int grbuf_size = sysconf(_SC_GETGR_R_SIZE_MAX);
415 if (grbuf_size <= 0)
416 grbuf_size = sysconf(_SC_PAGESIZE);
417 if (grbuf_size <= 0)
418 grbuf_size = 4096;
419 char grbuf[grbuf_size];
421 status = getgrnam_r(pl->group, &gr, grbuf, sizeof(grbuf), &gr_ptr);
422 if (status != 0) {
423 ERROR("exec plugin: Failed to get group information "
424 "for group ``%s'': %s",
425 pl->group, sstrerror(status, errbuf, sizeof(errbuf)));
426 goto failed;
427 }
428 if (gr_ptr == NULL) {
429 ERROR("exec plugin: No such group: `%s'", pl->group);
430 goto failed;
431 }
433 egid = gr.gr_gid;
434 } else {
435 egid = gid;
436 }
437 } /* if (pl->group == NULL) */
439 pid = fork();
440 if (pid < 0) {
441 ERROR("exec plugin: fork failed: %s",
442 sstrerror(errno, errbuf, sizeof(errbuf)));
443 goto failed;
444 } else if (pid == 0) {
445 int fd_num;
447 /* Close all file descriptors but the pipe end we need. */
448 fd_num = getdtablesize();
449 for (int fd = 0; fd < fd_num; fd++) {
450 if ((fd == fd_pipe_in[0]) || (fd == fd_pipe_out[1]) ||
451 (fd == fd_pipe_err[1]))
452 continue;
453 close(fd);
454 }
456 /* Connect the `in' pipe to STDIN */
457 if (fd_pipe_in[0] != STDIN_FILENO) {
458 dup2(fd_pipe_in[0], STDIN_FILENO);
459 close(fd_pipe_in[0]);
460 }
462 /* Now connect the `out' pipe to STDOUT */
463 if (fd_pipe_out[1] != STDOUT_FILENO) {
464 dup2(fd_pipe_out[1], STDOUT_FILENO);
465 close(fd_pipe_out[1]);
466 }
468 /* Now connect the `err' pipe to STDERR */
469 if (fd_pipe_err[1] != STDERR_FILENO) {
470 dup2(fd_pipe_err[1], STDERR_FILENO);
471 close(fd_pipe_err[1]);
472 }
474 set_environment();
476 /* Unblock all signals */
477 reset_signal_mask();
479 exec_child(pl, uid, gid, egid);
480 /* does not return */
481 }
483 close(fd_pipe_in[0]);
484 close(fd_pipe_out[1]);
485 close(fd_pipe_err[1]);
487 if (fd_in != NULL)
488 *fd_in = fd_pipe_in[1];
489 else
490 close(fd_pipe_in[1]);
492 if (fd_out != NULL)
493 *fd_out = fd_pipe_out[0];
494 else
495 close(fd_pipe_out[0]);
497 if (fd_err != NULL)
498 *fd_err = fd_pipe_err[0];
499 else
500 close(fd_pipe_err[0]);
502 return pid;
504 failed:
505 close_pipe(fd_pipe_in);
506 close_pipe(fd_pipe_out);
507 close_pipe(fd_pipe_err);
509 return -1;
510 } /* int fork_child }}} */
512 static int parse_line(char *buffer) /* {{{ */
513 {
514 if (strncasecmp("PUTVAL", buffer, strlen("PUTVAL")) == 0)
515 return cmd_handle_putval(stdout, buffer);
516 else if (strncasecmp("PUTNOTIF", buffer, strlen("PUTNOTIF")) == 0)
517 return handle_putnotif(stdout, buffer);
518 else {
519 ERROR("exec plugin: Unable to parse command, ignoring line: \"%s\"",
520 buffer);
521 return -1;
522 }
523 } /* int parse_line }}} */
525 static void *exec_read_one(void *arg) /* {{{ */
526 {
527 program_list_t *pl = (program_list_t *)arg;
528 int fd, fd_err, highest_fd;
529 fd_set fdset, copy;
530 int status;
531 char buffer[1200]; /* if not completely read */
532 char buffer_err[1024];
533 char *pbuffer = buffer;
534 char *pbuffer_err = buffer_err;
536 status = fork_child(pl, NULL, &fd, &fd_err);
537 if (status < 0) {
538 /* Reset the "running" flag */
539 pthread_mutex_lock(&pl_lock);
540 pl->flags &= ~PL_RUNNING;
541 pthread_mutex_unlock(&pl_lock);
542 pthread_exit((void *)1);
543 }
544 pl->pid = status;
546 assert(pl->pid != 0);
548 FD_ZERO(&fdset);
549 FD_SET(fd, &fdset);
550 FD_SET(fd_err, &fdset);
552 /* Determine the highest file descriptor */
553 highest_fd = (fd > fd_err) ? fd : fd_err;
555 /* We use a copy of fdset, as select modifies it */
556 copy = fdset;
558 while (1) {
559 int len;
561 status = select(highest_fd + 1, ©, NULL, NULL, NULL);
562 if (status < 0) {
563 if (errno == EINTR)
564 continue;
565 break;
566 }
568 if (FD_ISSET(fd, ©)) {
569 char *pnl;
571 len = read(fd, pbuffer, sizeof(buffer) - 1 - (pbuffer - buffer));
573 if (len < 0) {
574 if (errno == EAGAIN || errno == EINTR)
575 continue;
576 break;
577 } else if (len == 0)
578 break; /* We've reached EOF */
580 pbuffer[len] = '\0';
582 len += pbuffer - buffer;
583 pbuffer = buffer;
585 while ((pnl = strchr(pbuffer, '\n'))) {
586 *pnl = '\0';
587 if (*(pnl - 1) == '\r')
588 *(pnl - 1) = '\0';
590 parse_line(pbuffer);
592 pbuffer = ++pnl;
593 }
594 /* not completely read ? */
595 if (pbuffer - buffer < len) {
596 len -= pbuffer - buffer;
597 memmove(buffer, pbuffer, len);
598 pbuffer = buffer + len;
599 } else
600 pbuffer = buffer;
601 } else if (FD_ISSET(fd_err, ©)) {
602 char *pnl;
604 len = read(fd_err, pbuffer_err,
605 sizeof(buffer_err) - 1 - (pbuffer_err - buffer_err));
607 if (len < 0) {
608 if (errno == EAGAIN || errno == EINTR)
609 continue;
610 break;
611 } else if (len == 0) {
612 /* We've reached EOF */
613 NOTICE("exec plugin: Program `%s' has closed STDERR.", pl->exec);
615 /* Remove file descriptor form select() set. */
616 FD_CLR(fd_err, &fdset);
617 copy = fdset;
618 highest_fd = fd;
620 /* Clean up file descriptor */
621 close(fd_err);
622 fd_err = -1;
623 continue;
624 }
626 pbuffer_err[len] = '\0';
628 len += pbuffer_err - buffer_err;
629 pbuffer_err = buffer_err;
631 while ((pnl = strchr(pbuffer_err, '\n'))) {
632 *pnl = '\0';
633 if (*(pnl - 1) == '\r')
634 *(pnl - 1) = '\0';
636 ERROR("exec plugin: exec_read_one: error = %s", pbuffer_err);
638 pbuffer_err = ++pnl;
639 }
640 /* not completely read ? */
641 if (pbuffer_err - buffer_err < len) {
642 len -= pbuffer_err - buffer_err;
643 memmove(buffer_err, pbuffer_err, len);
644 pbuffer_err = buffer_err + len;
645 } else
646 pbuffer_err = buffer_err;
647 }
648 /* reset copy */
649 copy = fdset;
650 }
652 DEBUG("exec plugin: exec_read_one: Waiting for `%s' to exit.", pl->exec);
653 if (waitpid(pl->pid, &status, 0) > 0)
654 pl->status = status;
656 DEBUG("exec plugin: Child %i exited with status %i.", (int)pl->pid,
657 pl->status);
659 pl->pid = 0;
661 pthread_mutex_lock(&pl_lock);
662 pl->flags &= ~PL_RUNNING;
663 pthread_mutex_unlock(&pl_lock);
665 close(fd);
666 if (fd_err >= 0)
667 close(fd_err);
669 pthread_exit((void *)0);
670 return NULL;
671 } /* void *exec_read_one }}} */
673 static void *exec_notification_one(void *arg) /* {{{ */
674 {
675 program_list_t *pl = ((program_list_and_notification_t *)arg)->pl;
676 notification_t *n = &((program_list_and_notification_t *)arg)->n;
677 int fd;
678 FILE *fh;
679 int pid;
680 int status;
681 const char *severity;
683 pid = fork_child(pl, &fd, NULL, NULL);
684 if (pid < 0) {
685 sfree(arg);
686 pthread_exit((void *)1);
687 }
689 fh = fdopen(fd, "w");
690 if (fh == NULL) {
691 char errbuf[1024];
692 ERROR("exec plugin: fdopen (%i) failed: %s", fd,
693 sstrerror(errno, errbuf, sizeof(errbuf)));
694 kill(pid, SIGTERM);
695 close(fd);
696 sfree(arg);
697 pthread_exit((void *)1);
698 }
700 severity = "FAILURE";
701 if (n->severity == NOTIF_WARNING)
702 severity = "WARNING";
703 else if (n->severity == NOTIF_OKAY)
704 severity = "OKAY";
706 fprintf(fh, "Severity: %s\n"
707 "Time: %.3f\n",
708 severity, CDTIME_T_TO_DOUBLE(n->time));
710 /* Print the optional fields */
711 if (strlen(n->host) > 0)
712 fprintf(fh, "Host: %s\n", n->host);
713 if (strlen(n->plugin) > 0)
714 fprintf(fh, "Plugin: %s\n", n->plugin);
715 if (strlen(n->plugin_instance) > 0)
716 fprintf(fh, "PluginInstance: %s\n", n->plugin_instance);
717 if (strlen(n->type) > 0)
718 fprintf(fh, "Type: %s\n", n->type);
719 if (strlen(n->type_instance) > 0)
720 fprintf(fh, "TypeInstance: %s\n", n->type_instance);
722 for (notification_meta_t *meta = n->meta; meta != NULL; meta = meta->next) {
723 if (meta->type == NM_TYPE_STRING)
724 fprintf(fh, "%s: %s\n", meta->name, meta->nm_value.nm_string);
725 else if (meta->type == NM_TYPE_SIGNED_INT)
726 fprintf(fh, "%s: %" PRIi64 "\n", meta->name,
727 meta->nm_value.nm_signed_int);
728 else if (meta->type == NM_TYPE_UNSIGNED_INT)
729 fprintf(fh, "%s: %" PRIu64 "\n", meta->name,
730 meta->nm_value.nm_unsigned_int);
731 else if (meta->type == NM_TYPE_DOUBLE)
732 fprintf(fh, "%s: %e\n", meta->name, meta->nm_value.nm_double);
733 else if (meta->type == NM_TYPE_BOOLEAN)
734 fprintf(fh, "%s: %s\n", meta->name,
735 meta->nm_value.nm_boolean ? "true" : "false");
736 }
738 fprintf(fh, "\n%s\n", n->message);
740 fflush(fh);
741 fclose(fh);
743 waitpid(pid, &status, 0);
745 DEBUG("exec plugin: Child %i exited with status %i.", pid, status);
747 if (n->meta != NULL)
748 plugin_notification_meta_free(n->meta);
749 n->meta = NULL;
750 sfree(arg);
751 pthread_exit((void *)0);
752 return NULL;
753 } /* void *exec_notification_one }}} */
755 static int exec_init(void) /* {{{ */
756 {
757 struct sigaction sa = {.sa_handler = sigchld_handler};
759 sigaction(SIGCHLD, &sa, NULL);
761 #if defined(HAVE_SYS_CAPABILITY_H) && defined(CAP_SETUID) && defined(CAP_SETGID)
762 if ((check_capability(CAP_SETUID) != 0) ||
763 (check_capability(CAP_SETGID) != 0)) {
764 if (getuid() == 0)
765 WARNING(
766 "exec plugin: Running collectd as root, but the CAP_SETUID "
767 "or CAP_SETGID capabilities are missing. The plugin's read function "
768 "will probably fail. Is your init system dropping capabilities?");
769 else
770 WARNING(
771 "exec plugin: collectd doesn't have the CAP_SETUID or "
772 "CAP_SETGID capabilities. If you don't want to run collectd as root, "
773 "try running \"setcap 'cap_setuid=ep cap_setgid=ep'\" on the "
774 "collectd binary.");
775 }
776 #endif
778 return 0;
779 } /* int exec_init }}} */
781 static int exec_read(void) /* {{{ */
782 {
783 for (program_list_t *pl = pl_head; pl != NULL; pl = pl->next) {
784 pthread_t t;
785 pthread_attr_t attr;
787 /* Only execute `normal' style executables here. */
788 if ((pl->flags & PL_NORMAL) == 0)
789 continue;
791 pthread_mutex_lock(&pl_lock);
792 /* Skip if a child is already running. */
793 if ((pl->flags & PL_RUNNING) != 0) {
794 pthread_mutex_unlock(&pl_lock);
795 continue;
796 }
797 pl->flags |= PL_RUNNING;
798 pthread_mutex_unlock(&pl_lock);
800 pthread_attr_init(&attr);
801 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
802 plugin_thread_create(&t, &attr, exec_read_one, (void *)pl, "exec read");
803 pthread_attr_destroy(&attr);
804 } /* for (pl) */
806 return 0;
807 } /* int exec_read }}} */
809 static int exec_notification(const notification_t *n, /* {{{ */
810 user_data_t __attribute__((unused)) * user_data) {
811 program_list_and_notification_t *pln;
813 for (program_list_t *pl = pl_head; pl != NULL; pl = pl->next) {
814 pthread_t t;
815 pthread_attr_t attr;
817 /* Only execute `notification' style executables here. */
818 if ((pl->flags & PL_NOTIF_ACTION) == 0)
819 continue;
821 /* Skip if a child is already running. */
822 if (pl->pid != 0)
823 continue;
825 pln = malloc(sizeof(*pln));
826 if (pln == NULL) {
827 ERROR("exec plugin: malloc failed.");
828 continue;
829 }
831 pln->pl = pl;
832 memcpy(&pln->n, n, sizeof(notification_t));
834 /* Set the `meta' member to NULL, otherwise `plugin_notification_meta_copy'
835 * will run into an endless loop. */
836 pln->n.meta = NULL;
837 plugin_notification_meta_copy(&pln->n, n);
839 pthread_attr_init(&attr);
840 pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
841 plugin_thread_create(&t, &attr, exec_notification_one, (void *)pln,
842 "exec notify");
843 pthread_attr_destroy(&attr);
844 } /* for (pl) */
846 return 0;
847 } /* }}} int exec_notification */
849 static int exec_shutdown(void) /* {{{ */
850 {
851 program_list_t *pl;
852 program_list_t *next;
854 pl = pl_head;
855 while (pl != NULL) {
856 next = pl->next;
858 if (pl->pid > 0) {
859 kill(pl->pid, SIGTERM);
860 INFO("exec plugin: Sent SIGTERM to %hu", (unsigned short int)pl->pid);
861 }
863 sfree(pl->user);
864 sfree(pl);
866 pl = next;
867 } /* while (pl) */
868 pl_head = NULL;
870 return 0;
871 } /* int exec_shutdown }}} */
873 void module_register(void) {
874 plugin_register_complex_config("exec", exec_config);
875 plugin_register_init("exec", exec_init);
876 plugin_register_read("exec", exec_read);
877 plugin_register_notification("exec", exec_notification,
878 /* user_data = */ NULL);
879 plugin_register_shutdown("exec", exec_shutdown);
880 } /* void module_register */