1 /**
2 * collectd - src/email.c
3 * Copyright (C) 2006-2008 Sebastian Harl
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be included in
13 * all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 *
23 * Authors:
24 * Sebastian Harl <sh at tokkee.org>
25 **/
27 /*
28 * This plugin communicates with a spam filter, a virus scanner or similar
29 * software using a UNIX socket and a very simple protocol:
30 *
31 * e-mail type (e.g. ham, spam, virus, ...) and size
32 * e:<type>:<bytes>
33 *
34 * spam score
35 * s:<value>
36 *
37 * successful spam checks
38 * c:<type1>[,<type2>,...]
39 */
41 #include "collectd.h"
42 #include "common.h"
43 #include "plugin.h"
45 #include "configfile.h"
47 #include <stddef.h>
49 #if HAVE_LIBPTHREAD
50 # include <pthread.h>
51 #endif
53 #include <sys/un.h>
54 #include <sys/select.h>
56 /* some systems (e.g. Darwin) seem to not define UNIX_PATH_MAX at all */
57 #ifndef UNIX_PATH_MAX
58 # define UNIX_PATH_MAX sizeof (((struct sockaddr_un *)0)->sun_path)
59 #endif /* UNIX_PATH_MAX */
61 #if HAVE_GRP_H
62 # include <grp.h>
63 #endif /* HAVE_GRP_H */
65 #define SOCK_PATH LOCALSTATEDIR"/run/"PACKAGE_NAME"-email"
66 #define MAX_CONNS 5
67 #define MAX_CONNS_LIMIT 16384
69 #define log_debug(...) DEBUG ("email: "__VA_ARGS__)
70 #define log_err(...) ERROR ("email: "__VA_ARGS__)
71 #define log_warn(...) WARNING ("email: "__VA_ARGS__)
73 /*
74 * Private data structures
75 */
76 /* linked list of email and check types */
77 typedef struct type {
78 char *name;
79 int value;
80 struct type *next;
81 } type_t;
83 typedef struct {
84 type_t *head;
85 type_t *tail;
86 } type_list_t;
88 /* collector thread control information */
89 typedef struct collector {
90 pthread_t thread;
92 /* socket descriptor of the current/last connection */
93 FILE *socket;
94 } collector_t;
96 /* linked list of pending connections */
97 typedef struct conn {
98 /* socket to read data from */
99 FILE *socket;
101 /* linked list of connections */
102 struct conn *next;
103 } conn_t;
105 typedef struct {
106 conn_t *head;
107 conn_t *tail;
108 } conn_list_t;
110 /*
111 * Private variables
112 */
113 /* valid configuration file keys */
114 static const char *config_keys[] =
115 {
116 "SocketFile",
117 "SocketGroup",
118 "SocketPerms",
119 "MaxConns"
120 };
121 static int config_keys_num = STATIC_ARRAY_SIZE (config_keys);
123 /* socket configuration */
124 static char *sock_file = NULL;
125 static char *sock_group = NULL;
126 static int sock_perms = S_IRWXU | S_IRWXG;
127 static int max_conns = MAX_CONNS;
129 /* state of the plugin */
130 static int disabled = 0;
132 /* thread managing "client" connections */
133 static pthread_t connector = (pthread_t) 0;
134 static int connector_socket = -1;
136 /* tell the collector threads that a new connection is available */
137 static pthread_cond_t conn_available = PTHREAD_COND_INITIALIZER;
139 /* connections that are waiting to be processed */
140 static pthread_mutex_t conns_mutex = PTHREAD_MUTEX_INITIALIZER;
141 static conn_list_t conns;
143 /* tell the connector thread that a collector is available */
144 static pthread_cond_t collector_available = PTHREAD_COND_INITIALIZER;
146 /* collector threads */
147 static collector_t **collectors = NULL;
149 static pthread_mutex_t available_mutex = PTHREAD_MUTEX_INITIALIZER;
150 static int available_collectors;
152 static pthread_mutex_t count_mutex = PTHREAD_MUTEX_INITIALIZER;
153 static type_list_t list_count;
154 static type_list_t list_count_copy;
156 static pthread_mutex_t size_mutex = PTHREAD_MUTEX_INITIALIZER;
157 static type_list_t list_size;
158 static type_list_t list_size_copy;
160 static pthread_mutex_t score_mutex = PTHREAD_MUTEX_INITIALIZER;
161 static double score;
162 static int score_count;
164 static pthread_mutex_t check_mutex = PTHREAD_MUTEX_INITIALIZER;
165 static type_list_t list_check;
166 static type_list_t list_check_copy;
168 /*
169 * Private functions
170 */
171 static int email_config (const char *key, const char *value)
172 {
173 if (0 == strcasecmp (key, "SocketFile")) {
174 if (NULL != sock_file)
175 free (sock_file);
176 sock_file = sstrdup (value);
177 }
178 else if (0 == strcasecmp (key, "SocketGroup")) {
179 if (NULL != sock_group)
180 free (sock_group);
181 sock_group = sstrdup (value);
182 }
183 else if (0 == strcasecmp (key, "SocketPerms")) {
184 /* the user is responsible for providing reasonable values */
185 sock_perms = (int)strtol (value, NULL, 8);
186 }
187 else if (0 == strcasecmp (key, "MaxConns")) {
188 long int tmp = strtol (value, NULL, 0);
190 if (tmp < 1) {
191 fprintf (stderr, "email plugin: `MaxConns' was set to invalid "
192 "value %li, will use default %i.\n",
193 tmp, MAX_CONNS);
194 ERROR ("email plugin: `MaxConns' was set to invalid "
195 "value %li, will use default %i.\n",
196 tmp, MAX_CONNS);
197 max_conns = MAX_CONNS;
198 }
199 else if (tmp > MAX_CONNS_LIMIT) {
200 fprintf (stderr, "email plugin: `MaxConns' was set to invalid "
201 "value %li, will use hardcoded limit %i.\n",
202 tmp, MAX_CONNS_LIMIT);
203 ERROR ("email plugin: `MaxConns' was set to invalid "
204 "value %li, will use hardcoded limit %i.\n",
205 tmp, MAX_CONNS_LIMIT);
206 max_conns = MAX_CONNS_LIMIT;
207 }
208 else {
209 max_conns = (int)tmp;
210 }
211 }
212 else {
213 return -1;
214 }
215 return 0;
216 } /* static int email_config (char *, char *) */
218 /* Increment the value of the given name in the given list by incr. */
219 static void type_list_incr (type_list_t *list, char *name, int incr)
220 {
221 if (NULL == list->head) {
222 list->head = smalloc (sizeof (*list->head));
224 list->head->name = sstrdup (name);
225 list->head->value = incr;
226 list->head->next = NULL;
228 list->tail = list->head;
229 }
230 else {
231 type_t *ptr;
233 for (ptr = list->head; NULL != ptr; ptr = ptr->next) {
234 if (0 == strcmp (name, ptr->name))
235 break;
236 }
238 if (NULL == ptr) {
239 list->tail->next = smalloc (sizeof (*list->tail->next));
240 list->tail = list->tail->next;
242 list->tail->name = sstrdup (name);
243 list->tail->value = incr;
244 list->tail->next = NULL;
245 }
246 else {
247 ptr->value += incr;
248 }
249 }
250 return;
251 } /* static void type_list_incr (type_list_t *, char *) */
253 static void *collect (void *arg)
254 {
255 collector_t *this = (collector_t *)arg;
257 while (1) {
258 conn_t *connection;
260 pthread_mutex_lock (&conns_mutex);
262 while (NULL == conns.head) {
263 pthread_cond_wait (&conn_available, &conns_mutex);
264 }
266 connection = conns.head;
267 conns.head = conns.head->next;
269 if (NULL == conns.head) {
270 conns.tail = NULL;
271 }
273 pthread_mutex_unlock (&conns_mutex);
275 /* make the socket available to the global
276 * thread and connection management */
277 this->socket = connection->socket;
279 log_debug ("collect: handling connection on fd #%i",
280 fileno (this->socket));
282 while (42) {
283 /* 256 bytes ought to be enough for anybody ;-) */
284 char line[256 + 1]; /* line + '\0' */
285 int len = 0;
287 errno = 0;
288 if (NULL == fgets (line, sizeof (line), this->socket)) {
289 if (0 != errno) {
290 char errbuf[1024];
291 log_err ("collect: reading from socket (fd #%i) "
292 "failed: %s", fileno (this->socket),
293 sstrerror (errno, errbuf, sizeof (errbuf)));
294 }
295 break;
296 }
298 len = strlen (line);
299 if (('\n' != line[len - 1]) && ('\r' != line[len - 1])) {
300 log_warn ("collect: line too long (> %zu characters): "
301 "'%s' (truncated)", sizeof (line) - 1, line);
303 while (NULL != fgets (line, sizeof (line), this->socket))
304 if (('\n' == line[len - 1]) || ('\r' == line[len - 1]))
305 break;
306 continue;
307 }
308 if (len < 3) { /* [a-z] ':' '\n' */
309 continue;
310 }
312 line[len - 1] = 0;
314 log_debug ("collect: line = '%s'", line);
316 if (':' != line[1]) {
317 log_err ("collect: syntax error in line '%s'", line);
318 continue;
319 }
321 if ('e' == line[0]) { /* e:<type>:<bytes> */
322 char *ptr = NULL;
323 char *type = strtok_r (line + 2, ":", &ptr);
324 char *tmp = strtok_r (NULL, ":", &ptr);
325 int bytes = 0;
327 if (NULL == tmp) {
328 log_err ("collect: syntax error in line '%s'", line);
329 continue;
330 }
332 bytes = atoi (tmp);
334 pthread_mutex_lock (&count_mutex);
335 type_list_incr (&list_count, type, /* increment = */ 1);
336 pthread_mutex_unlock (&count_mutex);
338 if (bytes > 0) {
339 pthread_mutex_lock (&size_mutex);
340 type_list_incr (&list_size, type, /* increment = */ bytes);
341 pthread_mutex_unlock (&size_mutex);
342 }
343 }
344 else if ('s' == line[0]) { /* s:<value> */
345 pthread_mutex_lock (&score_mutex);
346 score = (score * (double)score_count + atof (line + 2))
347 / (double)(score_count + 1);
348 ++score_count;
349 pthread_mutex_unlock (&score_mutex);
350 }
351 else if ('c' == line[0]) { /* c:<type1>[,<type2>,...] */
352 char *dummy = line + 2;
353 char *endptr = NULL;
354 char *type;
356 pthread_mutex_lock (&check_mutex);
357 while ((type = strtok_r (dummy, ",", &endptr)) != NULL)
358 {
359 dummy = NULL;
360 type_list_incr (&list_check, type, /* increment = */ 1);
361 }
362 pthread_mutex_unlock (&check_mutex);
363 }
364 else {
365 log_err ("collect: unknown type '%c'", line[0]);
366 }
367 } /* while (42) */
369 log_debug ("Shutting down connection on fd #%i",
370 fileno (this->socket));
372 fclose (connection->socket);
373 free (connection);
375 this->socket = NULL;
377 pthread_mutex_lock (&available_mutex);
378 ++available_collectors;
379 pthread_mutex_unlock (&available_mutex);
381 pthread_cond_signal (&collector_available);
382 } /* while (1) */
384 pthread_exit ((void *)0);
385 return ((void *) 0);
386 } /* static void *collect (void *) */
388 static void *open_connection (void __attribute__((unused)) *arg)
389 {
390 struct sockaddr_un addr;
392 const char *path = (NULL == sock_file) ? SOCK_PATH : sock_file;
393 const char *group = (NULL == sock_group) ? COLLECTD_GRP_NAME : sock_group;
395 /* create UNIX socket */
396 errno = 0;
397 if (-1 == (connector_socket = socket (PF_UNIX, SOCK_STREAM, 0))) {
398 char errbuf[1024];
399 disabled = 1;
400 log_err ("socket() failed: %s",
401 sstrerror (errno, errbuf, sizeof (errbuf)));
402 pthread_exit ((void *)1);
403 }
405 addr.sun_family = AF_UNIX;
406 sstrncpy (addr.sun_path, path, (size_t)(UNIX_PATH_MAX - 1));
408 errno = 0;
409 if (-1 == bind (connector_socket, (struct sockaddr *)&addr,
410 offsetof (struct sockaddr_un, sun_path)
411 + strlen(addr.sun_path))) {
412 char errbuf[1024];
413 disabled = 1;
414 close (connector_socket);
415 connector_socket = -1;
416 log_err ("bind() failed: %s",
417 sstrerror (errno, errbuf, sizeof (errbuf)));
418 pthread_exit ((void *)1);
419 }
421 errno = 0;
422 if (-1 == listen (connector_socket, 5)) {
423 char errbuf[1024];
424 disabled = 1;
425 close (connector_socket);
426 connector_socket = -1;
427 log_err ("listen() failed: %s",
428 sstrerror (errno, errbuf, sizeof (errbuf)));
429 pthread_exit ((void *)1);
430 }
432 {
433 struct group sg;
434 struct group *grp;
435 char grbuf[2048];
436 int status;
438 grp = NULL;
439 status = getgrnam_r (group, &sg, grbuf, sizeof (grbuf), &grp);
440 if (status != 0)
441 {
442 char errbuf[1024];
443 log_warn ("getgrnam_r (%s) failed: %s", group,
444 sstrerror (errno, errbuf, sizeof (errbuf)));
445 }
446 else if (grp == NULL)
447 {
448 log_warn ("No such group: `%s'", group);
449 }
450 else
451 {
452 status = chown (path, (uid_t) -1, grp->gr_gid);
453 if (status != 0)
454 {
455 char errbuf[1024];
456 log_warn ("chown (%s, -1, %i) failed: %s",
457 path, (int) grp->gr_gid,
458 sstrerror (errno, errbuf, sizeof (errbuf)));
459 }
460 }
461 }
463 errno = 0;
464 if (0 != chmod (path, sock_perms)) {
465 char errbuf[1024];
466 log_warn ("chmod() failed: %s",
467 sstrerror (errno, errbuf, sizeof (errbuf)));
468 }
470 { /* initialize collector threads */
471 int i = 0;
472 int err = 0;
474 pthread_attr_t ptattr;
476 conns.head = NULL;
477 conns.tail = NULL;
479 pthread_attr_init (&ptattr);
480 pthread_attr_setdetachstate (&ptattr, PTHREAD_CREATE_DETACHED);
482 available_collectors = max_conns;
484 collectors =
485 smalloc (max_conns * sizeof (*collectors));
487 for (i = 0; i < max_conns; ++i) {
488 collectors[i] = smalloc (sizeof (*collectors[i]));
489 collectors[i]->socket = NULL;
491 if (0 != (err = plugin_thread_create (&collectors[i]->thread,
492 &ptattr, collect, collectors[i]))) {
493 char errbuf[1024];
494 log_err ("pthread_create() failed: %s",
495 sstrerror (errno, errbuf, sizeof (errbuf)));
496 collectors[i]->thread = (pthread_t) 0;
497 }
498 }
500 pthread_attr_destroy (&ptattr);
501 }
503 while (1) {
504 int remote = 0;
506 conn_t *connection;
508 pthread_mutex_lock (&available_mutex);
510 while (0 == available_collectors) {
511 pthread_cond_wait (&collector_available, &available_mutex);
512 }
514 --available_collectors;
516 pthread_mutex_unlock (&available_mutex);
518 while (42) {
519 errno = 0;
521 remote = accept (connector_socket, NULL, NULL);
522 if (remote == -1) {
523 char errbuf[1024];
525 if (errno == EINTR)
526 continue;
528 disabled = 1;
529 close (connector_socket);
530 connector_socket = -1;
531 log_err ("accept() failed: %s",
532 sstrerror (errno, errbuf, sizeof (errbuf)));
533 pthread_exit ((void *)1);
534 }
536 /* access() succeeded. */
537 break;
538 }
540 connection = calloc (1, sizeof (*connection));
541 if (connection == NULL)
542 {
543 close (remote);
544 continue;
545 }
547 connection->socket = fdopen (remote, "r");
548 connection->next = NULL;
550 if (NULL == connection->socket) {
551 close (remote);
552 sfree (connection);
553 continue;
554 }
556 pthread_mutex_lock (&conns_mutex);
558 if (NULL == conns.head) {
559 conns.head = connection;
560 conns.tail = connection;
561 }
562 else {
563 conns.tail->next = connection;
564 conns.tail = conns.tail->next;
565 }
567 pthread_mutex_unlock (&conns_mutex);
569 pthread_cond_signal (&conn_available);
570 }
572 pthread_exit ((void *) 0);
573 return ((void *) 0);
574 } /* static void *open_connection (void *) */
576 static int email_init (void)
577 {
578 int err = 0;
580 if (0 != (err = plugin_thread_create (&connector, NULL,
581 open_connection, NULL))) {
582 char errbuf[1024];
583 disabled = 1;
584 log_err ("pthread_create() failed: %s",
585 sstrerror (errno, errbuf, sizeof (errbuf)));
586 return (-1);
587 }
589 return (0);
590 } /* int email_init */
592 static void type_list_free (type_list_t *t)
593 {
594 type_t *this;
596 this = t->head;
597 while (this != NULL)
598 {
599 type_t *next = this->next;
601 sfree (this->name);
602 sfree (this);
604 this = next;
605 }
607 t->head = NULL;
608 t->tail = NULL;
609 }
611 static int email_shutdown (void)
612 {
613 int i = 0;
615 if (connector != ((pthread_t) 0)) {
616 pthread_kill (connector, SIGTERM);
617 connector = (pthread_t) 0;
618 }
620 if (connector_socket >= 0) {
621 close (connector_socket);
622 connector_socket = -1;
623 }
625 /* don't allow any more connections to be processed */
626 pthread_mutex_lock (&conns_mutex);
628 available_collectors = 0;
630 if (collectors != NULL) {
631 for (i = 0; i < max_conns; ++i) {
632 if (collectors[i] == NULL)
633 continue;
635 if (collectors[i]->thread != ((pthread_t) 0)) {
636 pthread_kill (collectors[i]->thread, SIGTERM);
637 collectors[i]->thread = (pthread_t) 0;
638 }
640 if (collectors[i]->socket != NULL) {
641 fclose (collectors[i]->socket);
642 collectors[i]->socket = NULL;
643 }
645 sfree (collectors[i]);
646 }
647 sfree (collectors);
648 } /* if (collectors != NULL) */
650 pthread_mutex_unlock (&conns_mutex);
652 type_list_free (&list_count);
653 type_list_free (&list_count_copy);
654 type_list_free (&list_size);
655 type_list_free (&list_size_copy);
656 type_list_free (&list_check);
657 type_list_free (&list_check_copy);
659 unlink ((NULL == sock_file) ? SOCK_PATH : sock_file);
661 sfree (sock_file);
662 sfree (sock_group);
663 return (0);
664 } /* static void email_shutdown (void) */
666 static void email_submit (const char *type, const char *type_instance, gauge_t value)
667 {
668 value_t values[1];
669 value_list_t vl = VALUE_LIST_INIT;
671 values[0].gauge = value;
673 vl.values = values;
674 vl.values_len = 1;
675 sstrncpy (vl.host, hostname_g, sizeof (vl.host));
676 sstrncpy (vl.plugin, "email", sizeof (vl.plugin));
677 sstrncpy (vl.type, type, sizeof (vl.type));
678 sstrncpy (vl.type_instance, type_instance, sizeof (vl.type_instance));
680 plugin_dispatch_values (&vl);
681 } /* void email_submit */
683 /* Copy list l1 to list l2. l2 may partly exist already, but it is assumed
684 * that neither the order nor the name of any element of either list is
685 * changed and no elements are deleted. The values of l1 are reset to zero
686 * after they have been copied to l2. */
687 static void copy_type_list (type_list_t *l1, type_list_t *l2)
688 {
689 type_t *ptr1;
690 type_t *ptr2;
692 type_t *last = NULL;
694 for (ptr1 = l1->head, ptr2 = l2->head; NULL != ptr1;
695 ptr1 = ptr1->next, last = ptr2, ptr2 = ptr2->next) {
696 if (NULL == ptr2) {
697 ptr2 = smalloc (sizeof (*ptr2));
698 ptr2->name = NULL;
699 ptr2->next = NULL;
701 if (NULL == last) {
702 l2->head = ptr2;
703 }
704 else {
705 last->next = ptr2;
706 }
708 l2->tail = ptr2;
709 }
711 if (NULL == ptr2->name) {
712 ptr2->name = sstrdup (ptr1->name);
713 }
715 ptr2->value = ptr1->value;
716 ptr1->value = 0;
717 }
718 return;
719 }
721 static int email_read (void)
722 {
723 type_t *ptr;
725 double score_old;
726 int score_count_old;
728 if (disabled)
729 return (-1);
731 /* email count */
732 pthread_mutex_lock (&count_mutex);
734 copy_type_list (&list_count, &list_count_copy);
736 pthread_mutex_unlock (&count_mutex);
738 for (ptr = list_count_copy.head; NULL != ptr; ptr = ptr->next) {
739 email_submit ("email_count", ptr->name, ptr->value);
740 }
742 /* email size */
743 pthread_mutex_lock (&size_mutex);
745 copy_type_list (&list_size, &list_size_copy);
747 pthread_mutex_unlock (&size_mutex);
749 for (ptr = list_size_copy.head; NULL != ptr; ptr = ptr->next) {
750 email_submit ("email_size", ptr->name, ptr->value);
751 }
753 /* spam score */
754 pthread_mutex_lock (&score_mutex);
756 score_old = score;
757 score_count_old = score_count;
758 score = 0.0;
759 score_count = 0;
761 pthread_mutex_unlock (&score_mutex);
763 if (score_count_old > 0)
764 email_submit ("spam_score", "", score_old);
766 /* spam checks */
767 pthread_mutex_lock (&check_mutex);
769 copy_type_list (&list_check, &list_check_copy);
771 pthread_mutex_unlock (&check_mutex);
773 for (ptr = list_check_copy.head; NULL != ptr; ptr = ptr->next)
774 email_submit ("spam_check", ptr->name, ptr->value);
776 return (0);
777 } /* int email_read */
779 void module_register (void)
780 {
781 plugin_register_config ("email", email_config, config_keys, config_keys_num);
782 plugin_register_init ("email", email_init);
783 plugin_register_read ("email", email_read);
784 plugin_register_shutdown ("email", email_shutdown);
785 } /* void module_register */
787 /* vim: set sw=4 ts=4 tw=78 noexpandtab : */