1 /**
2 * collectd - src/email.c
3 * Copyright (C) 2006 Sebastian Harl
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18 *
19 * Author:
20 * Sebastian Harl <sh at tokkee.org>
21 **/
23 /*
24 * This plugin communicates with a spam filter, a virus scanner or similar
25 * software using a UNIX socket and a very simple protocol:
26 *
27 * e-mail type (e.g. ham, spam, virus, ...) and size
28 * e:<type>:<bytes>
29 *
30 * spam score
31 * s:<value>
32 *
33 * successful spam checks
34 * c:<type1>[,<type2>,...]
35 */
37 #include "collectd.h"
38 #include "common.h"
39 #include "plugin.h"
41 #include <pthread.h>
43 #if HAVE_SYS_SELECT_H
44 # include <sys/select.h>
45 #endif /* HAVE_SYS_SELECT_H */
47 #if HAVE_SYS_SOCKET_H
48 # include <sys/socket.h>
49 #endif /* HAVE_SYS_SOCKET_H */
51 /* *sigh* glibc does not define UNIX_PATH_MAX in sys/un.h ... */
52 #if HAVE_LINUX_UN_H
53 # include <linux/un.h>
54 #elif HAVE_SYS_UN_H
55 # include <sys/un.h>
56 #endif /* HAVE_LINUX_UN_H | HAVE_SYS_UN_H */
58 #if HAVE_GRP_H
59 # include <grp.h>
60 #endif /* HAVE_GRP_H */
62 #define MODULE_NAME "email"
64 /* 256 bytes ought to be enough for anybody ;-) */
65 #define BUFSIZE 256
67 #define SOCK_PATH "/tmp/.collectd-email"
68 #define MAX_CONNS 5
70 /* linked list of email and check types */
71 typedef struct type {
72 char *name;
73 int value;
74 struct type *next;
75 } type_t;
77 typedef struct {
78 type_t *head;
79 type_t *tail;
80 } type_list_t;
82 /* linked list of collector thread control information */
83 typedef struct collector {
84 pthread_t thread;
86 /* socket to read data from */
87 int socket;
89 /* buffer to read data to */
90 char buffer[BUFSIZE];
91 int idx; /* current position in buffer */
93 struct collector *next;
94 } collector_t;
96 typedef struct {
97 collector_t *head;
98 collector_t *tail;
99 } collector_list_t;
101 /* state of the plugin */
102 static int disabled = 0;
104 /* thread managing "client" connections */
105 static pthread_t connector;
107 /* tell the connector thread that a collector is available */
108 static pthread_cond_t collector_available = PTHREAD_COND_INITIALIZER;
110 /* collector threads that are in use */
111 static pthread_mutex_t active_mutex = PTHREAD_MUTEX_INITIALIZER;
112 static collector_list_t active;
114 /* collector threads that are available for use */
115 static pthread_mutex_t available_mutex = PTHREAD_MUTEX_INITIALIZER;
116 static collector_list_t available;
118 #define COUNT_FILE "email/email-%s.rrd"
119 static char *count_ds_def[] =
120 {
121 "DS:count:GAUGE:"COLLECTD_HEARTBEAT":0:U",
122 NULL
123 };
124 static int count_ds_num = 1;
126 static pthread_mutex_t count_mutex = PTHREAD_MUTEX_INITIALIZER;
127 static type_list_t count;
129 #define SIZE_FILE "email/email_size-%s.rrd"
130 static char *size_ds_def[] =
131 {
132 "DS:size:GAUGE:"COLLECTD_HEARTBEAT":0:U",
133 NULL
134 };
135 static int size_ds_num = 1;
137 static pthread_mutex_t size_mutex = PTHREAD_MUTEX_INITIALIZER;
138 static type_list_t size;
140 #define SCORE_FILE "email/spam_score.rrd"
141 static char *score_ds_def[] =
142 {
143 "DS:score:GAUGE:"COLLECTD_HEARTBEAT":U:U",
144 NULL
145 };
146 static int score_ds_num = 1;
148 static pthread_mutex_t score_mutex = PTHREAD_MUTEX_INITIALIZER;
149 static double score;
150 static int score_count;
152 #define CHECK_FILE "email/spam_check-%s.rrd"
153 static char *check_ds_def[] =
154 {
155 "DS:hits:GAUGE:"COLLECTD_HEARTBEAT":0:U",
156 NULL
157 };
158 static int check_ds_num = 1;
160 static pthread_mutex_t check_mutex = PTHREAD_MUTEX_INITIALIZER;
161 static type_list_t check;
163 /* Increment the value of the given name in the given list by incr. */
164 static void type_list_incr (type_list_t *list, char *name, int incr)
165 {
166 if (NULL == list->head) {
167 list->head = (type_t *)smalloc (sizeof (type_t));
169 list->head->name = sstrdup (name);
170 list->head->value = incr;
171 list->head->next = NULL;
173 list->tail = list->head;
174 }
175 else {
176 type_t *ptr;
178 for (ptr = list->head; NULL != ptr; ptr = ptr->next) {
179 if (0 == strcmp (name, ptr->name))
180 break;
181 }
183 if (NULL == ptr) {
184 list->tail->next = (type_t *)smalloc (sizeof (type_t));
185 list->tail = list->tail->next;
187 list->tail->name = sstrdup (name);
188 list->tail->value = incr;
189 list->tail->next = NULL;
190 }
191 else {
192 ptr->value += incr;
193 }
194 }
195 return;
196 } /* static void type_list_incr (type_list_t *, char *) */
198 /* Read a single character from the socket. If an error occurs or end-of-file
199 * is reached return '\0'. */
200 char read_char (collector_t *src)
201 {
202 char ret = '\0';
204 fd_set fdset;
206 FD_ZERO (&fdset);
207 FD_SET (src->socket, &fdset);
209 if (-1 == select (src->socket + 1, &fdset, NULL, NULL, NULL)) {
210 syslog (LOG_ERR, "select() failed: %s", strerror (errno));
211 return '\0';
212 }
214 assert (FD_ISSET (src->socket, &fdset));
216 do {
217 ssize_t len = 0;
219 errno = 0;
220 if (0 > (len = read (src->socket, (void *)&ret, 1))) {
221 if (EINTR != errno) {
222 syslog (LOG_ERR, "read() failed: %s", strerror (errno));
223 return '\0';
224 }
225 }
227 if (0 == len)
228 return '\0';
229 } while (EINTR == errno);
230 return ret;
231 } /* char read_char (collector_t *) */
233 /* Read a single line (terminated by '\n') from the the socket.
234 *
235 * The return value is zero terminated and does not contain any newline
236 * characters. In case that no complete line is available (non-blocking mode
237 * should be enabled) an empty string is returned.
238 *
239 * If an error occurs or end-of-file is reached return NULL.
240 *
241 * IMPORTANT NOTE: If there is no newline character found in BUFSIZE
242 * characters of the input stream, the line will will be ignored! By
243 * definition we should not get any longer input lines, thus this is
244 * acceptable in this case ;-) */
245 char *read_line (collector_t *src)
246 {
247 int i = 0;
248 char *ret;
250 assert (BUFSIZE > src->idx);
252 for (i = 0; i < src->idx; ++i) {
253 if ('\n' == src->buffer[i])
254 break;
255 }
257 if ('\n' != src->buffer[i]) {
258 fd_set fdset;
260 ssize_t len = 0;
262 FD_ZERO (&fdset);
263 FD_SET (src->socket, &fdset);
265 if (-1 == select (src->socket + 1, &fdset, NULL, NULL, NULL)) {
266 syslog (LOG_ERR, "select() failed: %s", strerror (errno));
267 return NULL;
268 }
270 assert (FD_ISSET (src->socket, &fdset));
272 do {
273 errno = 0;
274 if (0 > (len = read (src->socket,
275 (void *)(&(src->buffer[0]) + src->idx),
276 BUFSIZE - src->idx))) {
277 if (EINTR != errno) {
278 syslog (LOG_ERR, "read() failed: %s", strerror (errno));
279 return NULL;
280 }
281 }
283 if (0 == len)
284 return NULL;
285 } while (EINTR == errno);
287 src->idx += len;
289 for (i = src->idx - len; i < src->idx; ++i) {
290 if ('\n' == src->buffer[i])
291 break;
292 }
294 if ('\n' != src->buffer[i]) {
295 ret = (char *)smalloc (1);
297 ret[0] = '\0';
299 if (BUFSIZE == src->idx) { /* no space left in buffer */
300 while ('\n' != read_char (src))
301 /* ignore complete line */;
303 src->idx = 0;
304 }
305 return ret;
306 }
307 }
309 ret = (char *)smalloc (i + 1);
310 memcpy (ret, &(src->buffer[0]), i + 1);
311 ret[i] = '\0';
313 src->idx -= (i + 1);
315 if (0 == src->idx)
316 src->buffer[0] = '\0';
317 else
318 memmove (&(src->buffer[0]), &(src->buffer[i + 1]), src->idx);
319 return ret;
320 } /* char *read_line (collector_t *) */
322 static void *collect (void *arg)
323 {
324 collector_t *this = (collector_t *)arg;
326 int loop = 1;
328 { /* put the socket in non-blocking mode */
329 int flags = 0;
331 errno = 0;
332 if (-1 == fcntl (this->socket, F_GETFL, &flags)) {
333 syslog (LOG_ERR, "fcntl() failed: %s", strerror (errno));
334 loop = 0;
335 }
337 errno = 0;
338 if (-1 == fcntl (this->socket, F_SETFL, flags | O_NONBLOCK)) {
339 syslog (LOG_ERR, "fcntl() failed: %s", strerror (errno));
340 loop = 0;
341 }
342 }
344 while (loop) {
345 char *line = read_line (this);
347 if (NULL == line) {
348 loop = 0;
349 break;
350 }
352 if ('\0' == line[0]) {
353 free (line);
354 continue;
355 }
357 if (':' != line[1]) {
358 syslog (LOG_ERR, "email: syntax error in line '%s'", line);
359 free (line);
360 continue;
361 }
363 if ('e' == line[0]) { /* e:<type>:<bytes> */
364 char *ptr = NULL;
365 char *type = strtok_r (line + 2, ":", &ptr);
366 char *tmp = strtok_r (NULL, ":", &ptr);
367 int bytes = 0;
369 if (NULL == tmp) {
370 syslog (LOG_ERR, "email: syntax error in line '%s'", line);
371 free (line);
372 continue;
373 }
375 bytes = atoi (tmp);
377 pthread_mutex_lock (&count_mutex);
378 type_list_incr (&count, type, 1);
379 pthread_mutex_unlock (&count_mutex);
381 pthread_mutex_lock (&size_mutex);
382 type_list_incr (&size, type, bytes);
383 pthread_mutex_unlock (&size_mutex);
384 }
385 else if ('s' == line[0]) { /* s:<value> */
386 pthread_mutex_lock (&score_mutex);
387 score = (score * (double)score_count + atof (line + 2))
388 / (double)(score_count + 1);
389 ++score_count;
390 pthread_mutex_unlock (&score_mutex);
391 }
392 else if ('c' == line[0]) { /* c:<type1>[,<type2>,...] */
393 char *ptr = NULL;
394 char *type = strtok_r (line + 2, ",", &ptr);
396 do {
397 pthread_mutex_lock (&check_mutex);
398 type_list_incr (&check, type, 1);
399 pthread_mutex_unlock (&check_mutex);
400 } while (NULL != (type = strtok_r (NULL, ",", &ptr)));
401 }
402 else {
403 syslog (LOG_ERR, "email: unknown type '%c'", line[0]);
404 }
406 free (line);
407 }
409 /* put this thread back into the available list */
410 pthread_mutex_lock (&active_mutex);
411 {
412 collector_t *last;
413 collector_t *ptr;
415 last = NULL;
417 for (ptr = active.head; NULL != ptr; last = ptr, ptr = ptr->next) {
418 if (0 != pthread_equal (ptr->thread, this->thread))
419 break;
420 }
422 /* the current thread _has_ to be in the active list */
423 assert (NULL != ptr);
425 if (NULL == last) {
426 active.head = ptr->next;
427 }
428 else {
429 last->next = ptr->next;
431 if (NULL == last->next) {
432 active.tail = last;
433 }
434 }
435 }
436 pthread_mutex_unlock (&active_mutex);
438 this->next = NULL;
440 pthread_mutex_lock (&available_mutex);
442 if (NULL == available.head) {
443 available.head = this;
444 available.tail = this;
445 }
446 else {
447 available.tail->next = this;
448 available.tail = this;
449 }
451 pthread_mutex_unlock (&available_mutex);
453 pthread_cond_signal (&collector_available);
454 pthread_exit ((void *)0);
455 } /* void *collect (void *) */
457 static void *open_connection (void *arg)
458 {
459 int local = 0;
461 struct sockaddr_un addr;
463 /* create UNIX socket */
464 errno = 0;
465 if (-1 == (local = socket (PF_UNIX, SOCK_STREAM, 0))) {
466 disabled = 1;
467 syslog (LOG_ERR, "socket() failed: %s", strerror (errno));
468 pthread_exit ((void *)1);
469 }
471 addr.sun_family = AF_UNIX;
473 strncpy (addr.sun_path, SOCK_PATH, (size_t)(UNIX_PATH_MAX - 1));
474 addr.sun_path[UNIX_PATH_MAX - 1] = '\0';
475 unlink (addr.sun_path);
477 errno = 0;
478 if (-1 == bind (local, (struct sockaddr *)&addr,
479 offsetof (struct sockaddr_un, sun_path)
480 + strlen(addr.sun_path))) {
481 disabled = 1;
482 syslog (LOG_ERR, "bind() failed: %s", strerror (errno));
483 pthread_exit ((void *)1);
484 }
486 errno = 0;
487 if (-1 == listen (local, 5)) {
488 disabled = 1;
489 syslog (LOG_ERR, "listen() failed: %s", strerror (errno));
490 pthread_exit ((void *)1);
491 }
493 if ((uid_t)0 == geteuid ()) {
494 struct group *grp;
496 errno = 0;
497 if (NULL != (grp = getgrnam (COLLECTD_GRP_NAME))) {
498 errno = 0;
499 if (0 != chown (SOCK_PATH, (uid_t)-1, grp->gr_gid)) {
500 syslog (LOG_WARNING, "chown() failed: %s", strerror (errno));
501 }
502 }
503 else {
504 syslog (LOG_WARNING, "getgrnam() failed: %s", strerror (errno));
505 }
506 }
507 else {
508 syslog (LOG_WARNING, "not running as root");
509 }
511 errno = 0;
512 if (0 != chmod (SOCK_PATH, S_IRWXU | S_IRWXG)) {
513 syslog (LOG_WARNING, "chmod() failed: %s", strerror (errno));
514 }
516 { /* initialize queue of available threads */
517 int i = 0;
519 collector_t *last;
521 active.head = NULL;
522 active.tail = NULL;
524 available.head = (collector_t *)smalloc (sizeof (collector_t));
525 available.tail = available.head;
526 available.tail->next = NULL;
528 last = available.head;
530 for (i = 1; i < MAX_CONNS; ++i) {
531 last->next = (collector_t *)smalloc (sizeof (collector_t));
532 last = last->next;
533 available.tail = last;
534 available.tail->next = NULL;
535 }
536 }
538 while (1) {
539 int remote = 0;
540 int err = 0;
542 collector_t *collector;
544 pthread_attr_t ptattr;
546 pthread_mutex_lock (&available_mutex);
547 while (NULL == available.head) {
548 pthread_cond_wait (&collector_available, &available_mutex);
549 }
550 pthread_mutex_unlock (&available_mutex);
552 do {
553 errno = 0;
554 if (-1 == (remote = accept (local, NULL, NULL))) {
555 if (EINTR != errno) {
556 disabled = 1;
557 syslog (LOG_ERR, "accept() failed: %s", strerror (errno));
558 pthread_exit ((void *)1);
559 }
560 }
561 } while (EINTR == errno);
563 /* assign connection to next available thread */
564 pthread_mutex_lock (&available_mutex);
566 collector = available.head;
567 collector->socket = remote;
569 if (available.head == available.tail) {
570 available.head = NULL;
571 available.tail = NULL;
572 }
573 else {
574 available.head = available.head->next;
575 }
577 pthread_mutex_unlock (&available_mutex);
579 collector->idx = 0;
580 collector->next = NULL;
582 pthread_attr_init (&ptattr);
583 pthread_attr_setdetachstate (&ptattr, PTHREAD_CREATE_DETACHED);
585 if (0 == (err = pthread_create (&collector->thread, &ptattr, collect,
586 (void *)collector))) {
587 pthread_mutex_lock (&active_mutex);
589 if (NULL == active.head) {
590 active.head = collector;
591 active.tail = collector;
592 }
593 else {
594 active.tail->next = collector;
595 active.tail = collector;
596 }
598 pthread_mutex_unlock (&active_mutex);
599 }
600 else {
601 pthread_mutex_lock (&available_mutex);
603 if (NULL == available.head) {
604 available.head = collector;
605 available.tail = collector;
606 }
607 else {
608 available.tail->next = collector;
609 available.tail = collector;
610 }
612 pthread_mutex_unlock (&available_mutex);
614 close (remote);
615 syslog (LOG_ERR, "pthread_create() failed: %s", strerror (err));
616 }
618 pthread_attr_destroy (&ptattr);
619 }
620 pthread_exit ((void *)0);
621 } /* void *open_connection (void *) */
623 static void email_init (void)
624 {
625 int err = 0;
627 if (0 != (err = pthread_create (&connector, NULL,
628 open_connection, NULL))) {
629 disabled = 1;
630 syslog (LOG_ERR, "pthread_create() failed: %s", strerror (err));
631 return;
632 }
633 return;
634 } /* static void email_init (void) */
636 static void count_write (char *host, char *inst, char *val)
637 {
638 char file[BUFSIZE] = "";
639 int len = 0;
641 len = snprintf (file, BUFSIZE, COUNT_FILE, inst);
642 if ((len < 0) || (len >= BUFSIZE))
643 return;
645 rrd_update_file (host, file, val, count_ds_def, count_ds_num);
646 return;
647 } /* static void email_write (char *host, char *inst, char *val) */
649 static void size_write (char *host, char *inst, char *val)
650 {
651 char file[BUFSIZE] = "";
652 int len = 0;
654 len = snprintf (file, BUFSIZE, SIZE_FILE, inst);
655 if ((len < 0) || (len >= BUFSIZE))
656 return;
658 rrd_update_file (host, file, val, size_ds_def, size_ds_num);
659 return;
660 } /* static void size_write (char *host, char *inst, char *val) */
662 static void score_write (char *host, char *inst, char *val)
663 {
664 rrd_update_file (host, SCORE_FILE, val, score_ds_def, score_ds_num);
665 return;
666 } /* static void score_write (char *host, char *inst, char *val) */
668 static void check_write (char *host, char *inst, char *val)
669 {
670 char file[BUFSIZE] = "";
671 int len = 0;
673 len = snprintf (file, BUFSIZE, CHECK_FILE, inst);
674 if ((len < 0) || (len >= BUFSIZE))
675 return;
677 rrd_update_file (host, file, val, check_ds_def, check_ds_num);
678 return;
679 } /* static void check_write (char *host, char *inst, char *val) */
681 static void type_submit (char *plugin, char *inst, int value)
682 {
683 char buf[BUFSIZE] = "";
684 int len = 0;
686 if (0 == value)
687 return;
689 len = snprintf (buf, BUFSIZE, "%u:%i", (unsigned int)curtime, value);
690 if ((len < 0) || (len >= BUFSIZE))
691 return;
693 plugin_submit (plugin, inst, buf);
694 return;
695 } /* static void type_submit (char *, char *, int) */
697 static void score_submit (double value)
698 {
699 char buf[BUFSIZE] = "";
700 int len = 0;
702 if (0.0 == value)
703 return;
705 len = snprintf (buf, BUFSIZE, "%u:%.2f", (unsigned int)curtime, value);
706 if ((len < 0) || (len >= BUFSIZE))
707 return;
709 plugin_submit ("email_spam_score", NULL, buf);
710 return;
711 }
713 static void email_read (void)
714 {
715 type_t *ptr;
717 if (disabled)
718 return;
720 pthread_mutex_lock (&count_mutex);
722 for (ptr = count.head; NULL != ptr; ptr = ptr->next) {
723 type_submit ("email_count", ptr->name, ptr->value);
724 ptr->value = 0;
725 }
727 pthread_mutex_unlock (&count_mutex);
729 pthread_mutex_lock (&size_mutex);
731 for (ptr = size.head; NULL != ptr; ptr = ptr->next) {
732 type_submit ("email_size", ptr->name, ptr->value);
733 ptr->value = 0;
734 }
736 pthread_mutex_unlock (&size_mutex);
738 pthread_mutex_lock (&score_mutex);
740 score_submit (score);
741 score = 0.0;
742 score_count = 0;
744 pthread_mutex_unlock (&score_mutex);
746 pthread_mutex_lock (&check_mutex);
748 for (ptr = check.head; NULL != ptr; ptr = ptr->next) {
749 type_submit ("email_spam_check", ptr->name, ptr->value);
750 ptr->value = 0;
751 }
753 pthread_mutex_unlock (&check_mutex);
754 return;
755 } /* static void read (void) */
757 void module_register (void)
758 {
759 plugin_register (MODULE_NAME, email_init, email_read, NULL);
760 plugin_register ("email_count", NULL, NULL, count_write);
761 plugin_register ("email_size", NULL, NULL, size_write);
762 plugin_register ("email_spam_score", NULL, NULL, score_write);
763 plugin_register ("email_spam_check", NULL, NULL, check_write);
764 return;
765 } /* void module_register (void) */
767 /* vim: set sw=4 ts=4 tw=78 noexpandtab : */