Code

email plugin: fix check for result of malloc
[collectd.git] / src / email.c
1 /**
2  * collectd - src/email.c
3  * Copyright (C) 2006-2008  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; only version 2 of the License is applicable.
8  *
9  * This program is distributed in the hope that it will be useful, but
10  * WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12  * General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License along
15  * with this program; if not, write to the Free Software Foundation, Inc.,
16  * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
17  *
18  * Author:
19  *   Sebastian Harl <sh at tokkee.org>
20  **/
22 /*
23  * This plugin communicates with a spam filter, a virus scanner or similar
24  * software using a UNIX socket and a very simple protocol:
25  *
26  * e-mail type (e.g. ham, spam, virus, ...) and size
27  * e:<type>:<bytes>
28  *
29  * spam score
30  * s:<value>
31  *
32  * successful spam checks
33  * c:<type1>[,<type2>,...]
34  */
36 #include "collectd.h"
37 #include "common.h"
38 #include "plugin.h"
40 #include "configfile.h"
42 #include <stddef.h>
44 #if HAVE_LIBPTHREAD
45 # include <pthread.h>
46 #endif
48 #include <sys/socket.h>
49 #include <sys/un.h>
50 #include <sys/select.h>
52 /* some systems (e.g. Darwin) seem to not define UNIX_PATH_MAX at all */
53 #ifndef UNIX_PATH_MAX
54 # define UNIX_PATH_MAX sizeof (((struct sockaddr_un *)0)->sun_path)
55 #endif /* UNIX_PATH_MAX */
57 #if HAVE_GRP_H
58 #       include <grp.h>
59 #endif /* HAVE_GRP_H */
61 #define SOCK_PATH LOCALSTATEDIR"/run/"PACKAGE_NAME"-email"
62 #define MAX_CONNS 5
63 #define MAX_CONNS_LIMIT 16384
65 #define log_debug(...) DEBUG ("email: "__VA_ARGS__)
66 #define log_err(...) ERROR ("email: "__VA_ARGS__)
67 #define log_warn(...) WARNING ("email: "__VA_ARGS__)
69 /*
70  * Private data structures
71  */
72 /* linked list of email and check types */
73 typedef struct type {
74         char        *name;
75         int         value;
76         struct type *next;
77 } type_t;
79 typedef struct {
80         type_t *head;
81         type_t *tail;
82 } type_list_t;
84 /* collector thread control information */
85 typedef struct collector {
86         pthread_t thread;
88         /* socket descriptor of the current/last connection */
89         FILE *socket;
90 } collector_t;
92 /* linked list of pending connections */
93 typedef struct conn {
94         /* socket to read data from */
95         FILE *socket;
97         /* linked list of connections */
98         struct conn *next;
99 } conn_t;
101 typedef struct {
102         conn_t *head;
103         conn_t *tail;
104 } conn_list_t;
106 /*
107  * Private variables
108  */
109 /* valid configuration file keys */
110 static const char *config_keys[] =
112         "SocketFile",
113         "SocketGroup",
114         "SocketPerms",
115         "MaxConns"
116 };
117 static int config_keys_num = STATIC_ARRAY_SIZE (config_keys);
119 /* socket configuration */
120 static char *sock_file  = NULL;
121 static char *sock_group = NULL;
122 static int  sock_perms  = S_IRWXU | S_IRWXG;
123 static int  max_conns   = MAX_CONNS;
125 /* state of the plugin */
126 static int disabled = 0;
128 /* thread managing "client" connections */
129 static pthread_t connector = (pthread_t) 0;
130 static int connector_socket = -1;
132 /* tell the collector threads that a new connection is available */
133 static pthread_cond_t conn_available = PTHREAD_COND_INITIALIZER;
135 /* connections that are waiting to be processed */
136 static pthread_mutex_t conns_mutex = PTHREAD_MUTEX_INITIALIZER;
137 static conn_list_t conns;
139 /* tell the connector thread that a collector is available */
140 static pthread_cond_t collector_available = PTHREAD_COND_INITIALIZER;
142 /* collector threads */
143 static collector_t **collectors = NULL;
145 static pthread_mutex_t available_mutex = PTHREAD_MUTEX_INITIALIZER;
146 static int available_collectors;
148 static pthread_mutex_t count_mutex = PTHREAD_MUTEX_INITIALIZER;
149 static type_list_t list_count;
150 static type_list_t list_count_copy;
152 static pthread_mutex_t size_mutex = PTHREAD_MUTEX_INITIALIZER;
153 static type_list_t list_size;
154 static type_list_t list_size_copy;
156 static pthread_mutex_t score_mutex = PTHREAD_MUTEX_INITIALIZER;
157 static double score;
158 static int score_count;
160 static pthread_mutex_t check_mutex = PTHREAD_MUTEX_INITIALIZER;
161 static type_list_t list_check;
162 static type_list_t list_check_copy;
164 /*
165  * Private functions
166  */
167 static int email_config (const char *key, const char *value)
169         if (0 == strcasecmp (key, "SocketFile")) {
170                 if (NULL != sock_file)
171                         free (sock_file);
172                 sock_file = sstrdup (value);
173         }
174         else if (0 == strcasecmp (key, "SocketGroup")) {
175                 if (NULL != sock_group)
176                         free (sock_group);
177                 sock_group = sstrdup (value);
178         }
179         else if (0 == strcasecmp (key, "SocketPerms")) {
180                 /* the user is responsible for providing reasonable values */
181                 sock_perms = (int)strtol (value, NULL, 8);
182         }
183         else if (0 == strcasecmp (key, "MaxConns")) {
184                 long int tmp = strtol (value, NULL, 0);
186                 if (tmp < 1) {
187                         fprintf (stderr, "email plugin: `MaxConns' was set to invalid "
188                                         "value %li, will use default %i.\n",
189                                         tmp, MAX_CONNS);
190                         ERROR ("email plugin: `MaxConns' was set to invalid "
191                                         "value %li, will use default %i.\n",
192                                         tmp, MAX_CONNS);
193                         max_conns = MAX_CONNS;
194                 }
195                 else if (tmp > MAX_CONNS_LIMIT) {
196                         fprintf (stderr, "email plugin: `MaxConns' was set to invalid "
197                                         "value %li, will use hardcoded limit %i.\n",
198                                         tmp, MAX_CONNS_LIMIT);
199                         ERROR ("email plugin: `MaxConns' was set to invalid "
200                                         "value %li, will use hardcoded limit %i.\n",
201                                         tmp, MAX_CONNS_LIMIT);
202                         max_conns = MAX_CONNS_LIMIT;
203                 }
204                 else {
205                         max_conns = (int)tmp;
206                 }
207         }
208         else {
209                 return -1;
210         }
211         return 0;
212 } /* static int email_config (char *, char *) */
214 /* Increment the value of the given name in the given list by incr. */
215 static void type_list_incr (type_list_t *list, char *name, int incr)
217         if (NULL == list->head) {
218                 list->head = (type_t *)smalloc (sizeof (type_t));
220                 list->head->name  = sstrdup (name);
221                 list->head->value = incr;
222                 list->head->next  = NULL;
224                 list->tail = list->head;
225         }
226         else {
227                 type_t *ptr;
229                 for (ptr = list->head; NULL != ptr; ptr = ptr->next) {
230                         if (0 == strcmp (name, ptr->name))
231                                 break;
232                 }
234                 if (NULL == ptr) {
235                         list->tail->next = (type_t *)smalloc (sizeof (type_t));
236                         list->tail = list->tail->next;
238                         list->tail->name  = sstrdup (name);
239                         list->tail->value = incr;
240                         list->tail->next  = NULL;
241                 }
242                 else {
243                         ptr->value += incr;
244                 }
245         }
246         return;
247 } /* static void type_list_incr (type_list_t *, char *) */
249 static void *collect (void *arg)
251         collector_t *this = (collector_t *)arg;
253         while (1) {
254                 conn_t *connection;
256                 pthread_mutex_lock (&conns_mutex);
258                 while (NULL == conns.head) {
259                         pthread_cond_wait (&conn_available, &conns_mutex);
260                 }
262                 connection = conns.head;
263                 conns.head = conns.head->next;
265                 if (NULL == conns.head) {
266                         conns.tail = NULL;
267                 }
269                 pthread_mutex_unlock (&conns_mutex);
271                 /* make the socket available to the global
272                  * thread and connection management */
273                 this->socket = connection->socket;
275                 log_debug ("collect: handling connection on fd #%i",
276                                 fileno (this->socket));
278                 while (42) {
279                         /* 256 bytes ought to be enough for anybody ;-) */
280                         char line[256 + 1]; /* line + '\0' */
281                         int  len = 0;
283                         errno = 0;
284                         if (NULL == fgets (line, sizeof (line), this->socket)) {
285                                 if (0 != errno) {
286                                         char errbuf[1024];
287                                         log_err ("collect: reading from socket (fd #%i) "
288                                                         "failed: %s", fileno (this->socket),
289                                                         sstrerror (errno, errbuf, sizeof (errbuf)));
290                                 }
291                                 break;
292                         }
294                         len = strlen (line);
295                         if (('\n' != line[len - 1]) && ('\r' != line[len - 1])) {
296                                 log_warn ("collect: line too long (> %zu characters): "
297                                                 "'%s' (truncated)", sizeof (line) - 1, line);
299                                 while (NULL != fgets (line, sizeof (line), this->socket))
300                                         if (('\n' == line[len - 1]) || ('\r' == line[len - 1]))
301                                                 break;
302                                 continue;
303                         }
304                         if (len < 3) { /* [a-z] ':' '\n' */
305                                 continue;
306                         }
308                         line[len - 1] = 0;
310                         log_debug ("collect: line = '%s'", line);
312                         if (':' != line[1]) {
313                                 log_err ("collect: syntax error in line '%s'", line);
314                                 continue;
315                         }
317                         if ('e' == line[0]) { /* e:<type>:<bytes> */
318                                 char *ptr  = NULL;
319                                 char *type = strtok_r (line + 2, ":", &ptr);
320                                 char *tmp  = strtok_r (NULL, ":", &ptr);
321                                 int  bytes = 0;
323                                 if (NULL == tmp) {
324                                         log_err ("collect: syntax error in line '%s'", line);
325                                         continue;
326                                 }
328                                 bytes = atoi (tmp);
330                                 pthread_mutex_lock (&count_mutex);
331                                 type_list_incr (&list_count, type, /* increment = */ 1);
332                                 pthread_mutex_unlock (&count_mutex);
334                                 if (bytes > 0) {
335                                         pthread_mutex_lock (&size_mutex);
336                                         type_list_incr (&list_size, type, /* increment = */ bytes);
337                                         pthread_mutex_unlock (&size_mutex);
338                                 }
339                         }
340                         else if ('s' == line[0]) { /* s:<value> */
341                                 pthread_mutex_lock (&score_mutex);
342                                 score = (score * (double)score_count + atof (line + 2))
343                                                 / (double)(score_count + 1);
344                                 ++score_count;
345                                 pthread_mutex_unlock (&score_mutex);
346                         }
347                         else if ('c' == line[0]) { /* c:<type1>[,<type2>,...] */
348                                 char *dummy = line + 2;
349                                 char *endptr = NULL;
350                                 char *type;
352                                 pthread_mutex_lock (&check_mutex);
353                                 while ((type = strtok_r (dummy, ",", &endptr)) != NULL)
354                                 {
355                                         dummy = NULL;
356                                         type_list_incr (&list_check, type, /* increment = */ 1);
357                                 }
358                                 pthread_mutex_unlock (&check_mutex);
359                         }
360                         else {
361                                 log_err ("collect: unknown type '%c'", line[0]);
362                         }
363                 } /* while (42) */
365                 log_debug ("Shutting down connection on fd #%i",
366                                 fileno (this->socket));
368                 fclose (connection->socket);
369                 free (connection);
371                 this->socket = NULL;
373                 pthread_mutex_lock (&available_mutex);
374                 ++available_collectors;
375                 pthread_mutex_unlock (&available_mutex);
377                 pthread_cond_signal (&collector_available);
378         } /* while (1) */
380         pthread_exit ((void *)0);
381         return ((void *) 0);
382 } /* static void *collect (void *) */
384 static void *open_connection (void __attribute__((unused)) *arg)
386         struct sockaddr_un addr;
388         char *path  = (NULL == sock_file) ? SOCK_PATH : sock_file;
389         char *group = (NULL == sock_group) ? COLLECTD_GRP_NAME : sock_group;
391         /* create UNIX socket */
392         errno = 0;
393         if (-1 == (connector_socket = socket (PF_UNIX, SOCK_STREAM, 0))) {
394                 char errbuf[1024];
395                 disabled = 1;
396                 log_err ("socket() failed: %s",
397                                 sstrerror (errno, errbuf, sizeof (errbuf)));
398                 pthread_exit ((void *)1);
399         }
401         addr.sun_family = AF_UNIX;
402         sstrncpy (addr.sun_path, path, (size_t)(UNIX_PATH_MAX - 1));
404         errno = 0;
405         if (-1 == bind (connector_socket, (struct sockaddr *)&addr,
406                                 offsetof (struct sockaddr_un, sun_path)
407                                         + strlen(addr.sun_path))) {
408                 char errbuf[1024];
409                 disabled = 1;
410                 close (connector_socket);
411                 connector_socket = -1;
412                 log_err ("bind() failed: %s",
413                                 sstrerror (errno, errbuf, sizeof (errbuf)));
414                 pthread_exit ((void *)1);
415         }
417         errno = 0;
418         if (-1 == listen (connector_socket, 5)) {
419                 char errbuf[1024];
420                 disabled = 1;
421                 close (connector_socket);
422                 connector_socket = -1;
423                 log_err ("listen() failed: %s",
424                                 sstrerror (errno, errbuf, sizeof (errbuf)));
425                 pthread_exit ((void *)1);
426         }
428         {
429                 struct group sg;
430                 struct group *grp;
431                 char grbuf[2048];
432                 int status;
434                 grp = NULL;
435                 status = getgrnam_r (group, &sg, grbuf, sizeof (grbuf), &grp);
436                 if (status != 0)
437                 {
438                         char errbuf[1024];
439                         log_warn ("getgrnam_r (%s) failed: %s", group,
440                                         sstrerror (errno, errbuf, sizeof (errbuf)));
441                 }
442                 else if (grp == NULL)
443                 {
444                         log_warn ("No such group: `%s'", group);
445                 }
446                 else
447                 {
448                         status = chown (path, (uid_t) -1, grp->gr_gid);
449                         if (status != 0)
450                         {
451                                 char errbuf[1024];
452                                 log_warn ("chown (%s, -1, %i) failed: %s",
453                                                 path, (int) grp->gr_gid,
454                                                 sstrerror (errno, errbuf, sizeof (errbuf)));
455                         }
456                 }
457         }
459         errno = 0;
460         if (0 != chmod (path, sock_perms)) {
461                 char errbuf[1024];
462                 log_warn ("chmod() failed: %s",
463                                 sstrerror (errno, errbuf, sizeof (errbuf)));
464         }
466         { /* initialize collector threads */
467                 int i   = 0;
468                 int err = 0;
470                 pthread_attr_t ptattr;
472                 conns.head = NULL;
473                 conns.tail = NULL;
475                 pthread_attr_init (&ptattr);
476                 pthread_attr_setdetachstate (&ptattr, PTHREAD_CREATE_DETACHED);
478                 available_collectors = max_conns;
480                 collectors =
481                         (collector_t **)smalloc (max_conns * sizeof (collector_t *));
483                 for (i = 0; i < max_conns; ++i) {
484                         collectors[i] = (collector_t *)smalloc (sizeof (collector_t));
485                         collectors[i]->socket = NULL;
487                         if (0 != (err = plugin_thread_create (&collectors[i]->thread,
488                                                         &ptattr, collect, collectors[i]))) {
489                                 char errbuf[1024];
490                                 log_err ("pthread_create() failed: %s",
491                                                 sstrerror (errno, errbuf, sizeof (errbuf)));
492                                 collectors[i]->thread = (pthread_t) 0;
493                         }
494                 }
496                 pthread_attr_destroy (&ptattr);
497         }
499         while (1) {
500                 int remote = 0;
502                 conn_t *connection;
504                 pthread_mutex_lock (&available_mutex);
506                 while (0 == available_collectors) {
507                         pthread_cond_wait (&collector_available, &available_mutex);
508                 }
510                 --available_collectors;
512                 pthread_mutex_unlock (&available_mutex);
514                 while (42) {
515                         errno = 0;
517                         remote = accept (connector_socket, NULL, NULL);
518                         if (remote == -1) {
519                                 char errbuf[1024];
521                                 if (errno == EINTR)
522                                         continue;
524                                 disabled = 1;
525                                 close (connector_socket);
526                                 connector_socket = -1;
527                                 log_err ("accept() failed: %s",
528                                                  sstrerror (errno, errbuf, sizeof (errbuf)));
529                                 pthread_exit ((void *)1);
530                         }
532                         /* access() succeeded. */
533                         break;
534                 }
536                 connection = malloc (sizeof (*connection));
537                 if (connection == NULL)
538                 {
539                         close (remote);
540                         continue;
541                 }
542                 memset (connection, 0, sizeof (*connection));
544                 connection->socket = fdopen (remote, "r");
545                 connection->next   = NULL;
547                 if (NULL == connection->socket) {
548                         close (remote);
549                         sfree (connection);
550                         continue;
551                 }
553                 pthread_mutex_lock (&conns_mutex);
555                 if (NULL == conns.head) {
556                         conns.head = connection;
557                         conns.tail = connection;
558                 }
559                 else {
560                         conns.tail->next = connection;
561                         conns.tail = conns.tail->next;
562                 }
564                 pthread_mutex_unlock (&conns_mutex);
566                 pthread_cond_signal (&conn_available);
567         }
569         pthread_exit ((void *) 0);
570         return ((void *) 0);
571 } /* static void *open_connection (void *) */
573 static int email_init (void)
575         int err = 0;
577         if (0 != (err = plugin_thread_create (&connector, NULL,
578                                 open_connection, NULL))) {
579                 char errbuf[1024];
580                 disabled = 1;
581                 log_err ("pthread_create() failed: %s",
582                                 sstrerror (errno, errbuf, sizeof (errbuf)));
583                 return (-1);
584         }
586         return (0);
587 } /* int email_init */
589 static void type_list_free (type_list_t *t)
591         type_t *this;
593         this = t->head;
594         while (this != NULL)
595         {
596                 type_t *next = this->next;
598                 sfree (this->name);
599                 sfree (this);
601                 this = next;
602         }
604         t->head = NULL;
605         t->tail = NULL;
608 static int email_shutdown (void)
610         int i = 0;
612         if (connector != ((pthread_t) 0)) {
613                 pthread_kill (connector, SIGTERM);
614                 connector = (pthread_t) 0;
615         }
617         if (connector_socket >= 0) {
618                 close (connector_socket);
619                 connector_socket = -1;
620         }
622         /* don't allow any more connections to be processed */
623         pthread_mutex_lock (&conns_mutex);
625         available_collectors = 0;
627         if (collectors != NULL) {
628                 for (i = 0; i < max_conns; ++i) {
629                         if (collectors[i] == NULL)
630                                 continue;
632                         if (collectors[i]->thread != ((pthread_t) 0)) {
633                                 pthread_kill (collectors[i]->thread, SIGTERM);
634                                 collectors[i]->thread = (pthread_t) 0;
635                         }
637                         if (collectors[i]->socket != NULL) {
638                                 fclose (collectors[i]->socket);
639                                 collectors[i]->socket = NULL;
640                         }
642                         sfree (collectors[i]);
643                 }
644                 sfree (collectors);
645         } /* if (collectors != NULL) */
647         pthread_mutex_unlock (&conns_mutex);
649         type_list_free (&list_count);
650         type_list_free (&list_count_copy);
651         type_list_free (&list_size);
652         type_list_free (&list_size_copy);
653         type_list_free (&list_check);
654         type_list_free (&list_check_copy);
656         unlink ((NULL == sock_file) ? SOCK_PATH : sock_file);
658         sfree (sock_file);
659         sfree (sock_group);
660         return (0);
661 } /* static void email_shutdown (void) */
663 static void email_submit (const char *type, const char *type_instance, gauge_t value)
665         value_t values[1];
666         value_list_t vl = VALUE_LIST_INIT;
668         values[0].gauge = value;
670         vl.values = values;
671         vl.values_len = 1;
672         sstrncpy (vl.host, hostname_g, sizeof (vl.host));
673         sstrncpy (vl.plugin, "email", sizeof (vl.plugin));
674         sstrncpy (vl.type, type, sizeof (vl.type));
675         sstrncpy (vl.type_instance, type_instance, sizeof (vl.type_instance));
677         plugin_dispatch_values (&vl);
678 } /* void email_submit */
680 /* Copy list l1 to list l2. l2 may partly exist already, but it is assumed
681  * that neither the order nor the name of any element of either list is
682  * changed and no elements are deleted. The values of l1 are reset to zero
683  * after they have been copied to l2. */
684 static void copy_type_list (type_list_t *l1, type_list_t *l2)
686         type_t *ptr1;
687         type_t *ptr2;
689         type_t *last = NULL;
691         for (ptr1 = l1->head, ptr2 = l2->head; NULL != ptr1;
692                         ptr1 = ptr1->next, last = ptr2, ptr2 = ptr2->next) {
693                 if (NULL == ptr2) {
694                         ptr2 = (type_t *)smalloc (sizeof (type_t));
695                         ptr2->name = NULL;
696                         ptr2->next = NULL;
698                         if (NULL == last) {
699                                 l2->head = ptr2;
700                         }
701                         else {
702                                 last->next = ptr2;
703                         }
705                         l2->tail = ptr2;
706                 }
708                 if (NULL == ptr2->name) {
709                         ptr2->name = sstrdup (ptr1->name);
710                 }
712                 ptr2->value = ptr1->value;
713                 ptr1->value = 0;
714         }
715         return;
718 static int email_read (void)
720         type_t *ptr;
722         double score_old;
723         int score_count_old;
725         if (disabled)
726                 return (-1);
728         /* email count */
729         pthread_mutex_lock (&count_mutex);
731         copy_type_list (&list_count, &list_count_copy);
733         pthread_mutex_unlock (&count_mutex);
735         for (ptr = list_count_copy.head; NULL != ptr; ptr = ptr->next) {
736                 email_submit ("email_count", ptr->name, ptr->value);
737         }
739         /* email size */
740         pthread_mutex_lock (&size_mutex);
742         copy_type_list (&list_size, &list_size_copy);
744         pthread_mutex_unlock (&size_mutex);
746         for (ptr = list_size_copy.head; NULL != ptr; ptr = ptr->next) {
747                 email_submit ("email_size", ptr->name, ptr->value);
748         }
750         /* spam score */
751         pthread_mutex_lock (&score_mutex);
753         score_old = score;
754         score_count_old = score_count;
755         score = 0.0;
756         score_count = 0;
758         pthread_mutex_unlock (&score_mutex);
760         if (score_count_old > 0)
761                 email_submit ("spam_score", "", score_old);
763         /* spam checks */
764         pthread_mutex_lock (&check_mutex);
766         copy_type_list (&list_check, &list_check_copy);
768         pthread_mutex_unlock (&check_mutex);
770         for (ptr = list_check_copy.head; NULL != ptr; ptr = ptr->next)
771                 email_submit ("spam_check", ptr->name, ptr->value);
773         return (0);
774 } /* int email_read */
776 void module_register (void)
778         plugin_register_config ("email", email_config, config_keys, config_keys_num);
779         plugin_register_init ("email", email_init);
780         plugin_register_read ("email", email_read);
781         plugin_register_shutdown ("email", email_shutdown);
782 } /* void module_register */
784 /* vim: set sw=4 ts=4 tw=78 noexpandtab : */