1 /**
2 * collectd - src/network.c
3 * Copyright (C) 2006 Florian octo Forster
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 * Authors:
20 * Florian octo Forster <octo at verplant.org>
21 **/
23 #include <stdlib.h>
24 #include <stdio.h>
25 #include <string.h>
26 #include <sys/types.h>
27 #include <sys/socket.h>
28 #include <netdb.h>
29 #include <netinet/in.h>
30 #include <arpa/inet.h>
31 #include <syslog.h>
32 #include <errno.h>
34 #include "network.h"
35 #include "common.h"
36 #include "configfile.h"
37 #include "utils_debug.h"
39 /* 1500 - 40 - 8 = Ethernet packet - IPv6 header - UDP header */
40 /* #define BUFF_SIZE 1452 */
42 #ifndef IPV6_ADD_MEMBERSHIP
43 # ifdef IPV6_JOIN_GROUP
44 # define IPV6_ADD_MEMBERSHIP IPV6_JOIN_GROUP
45 # else
46 # error "Neither IP_ADD_MEMBERSHIP nor IPV6_JOIN_GROUP is defined"
47 # endif
48 #endif /* !IP_ADD_MEMBERSHIP */
50 #define BUFF_SIZE 4096
52 #ifdef HAVE_LIBRRD
53 extern int operating_mode;
54 #else
55 static int operating_mode = MODE_CLIENT;
56 #endif
58 typedef struct sockent
59 {
60 int fd;
61 int mode;
62 struct sockaddr_storage *addr;
63 socklen_t addrlen;
64 struct sockent *next;
65 } sockent_t;
67 static sockent_t *socklist_head = NULL;
69 static int network_set_ttl (const sockent_t *se, const struct addrinfo *ai)
70 {
71 char *ttl_str;
72 int ttl_int;
74 ttl_str = cf_get_option ("TimeToLive", NULL);
75 if (ttl_str == NULL)
76 return (-1);
78 ttl_int = atoi (ttl_str);
79 if ((ttl_int < 1) || (ttl_int > 255))
80 {
81 syslog (LOG_WARNING, "A TTL value of %i is invalid.", ttl_int);
82 return (-1);
83 }
85 DBG ("ttl = %i", ttl_int);
87 if (ai->ai_family == AF_INET)
88 {
89 struct sockaddr_in *addr = (struct sockaddr_in *) ai->ai_addr;
90 int optname;
92 if (IN_MULTICAST (ntohl (addr->sin_addr.s_addr)))
93 optname = IP_MULTICAST_TTL;
94 else
95 optname = IP_TTL;
97 if (setsockopt (se->fd, IPPROTO_IP, optname,
98 &ttl_int, sizeof (ttl_int)) == -1)
99 {
100 syslog (LOG_ERR, "setsockopt: %s", strerror (errno));
101 return (-1);
102 }
103 }
104 else if (ai->ai_family == AF_INET6)
105 {
106 /* Useful example: http://gsyc.escet.urjc.es/~eva/IPv6-web/examples/mcast.html */
107 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) ai->ai_addr;
108 int optname;
110 if (IN6_IS_ADDR_MULTICAST (&addr->sin6_addr))
111 optname = IPV6_MULTICAST_HOPS;
112 else
113 optname = IPV6_UNICAST_HOPS;
115 if (setsockopt (se->fd, IPPROTO_IPV6, optname,
116 &ttl_int, sizeof (ttl_int)) == -1)
117 {
118 syslog (LOG_ERR, "setsockopt: %s", strerror (errno));
119 return (-1);
120 }
121 }
123 return (0);
124 }
126 static int network_bind_socket (const sockent_t *se, const struct addrinfo *ai)
127 {
128 int loop = 1;
130 DBG ("fd = %i; calling `bind'", se->fd);
132 if (bind (se->fd, ai->ai_addr, ai->ai_addrlen) == -1)
133 {
134 syslog (LOG_ERR, "bind: %s", strerror (errno));
135 return (-1);
136 }
138 if (ai->ai_family == AF_INET)
139 {
140 struct sockaddr_in *addr = (struct sockaddr_in *) ai->ai_addr;
141 if (IN_MULTICAST (ntohl (addr->sin_addr.s_addr)))
142 {
143 struct ip_mreq mreq;
145 DBG ("fd = %i; IPv4 multicast address found", se->fd);
147 mreq.imr_multiaddr.s_addr = addr->sin_addr.s_addr;
148 mreq.imr_interface.s_addr = htonl (INADDR_ANY);
150 if (setsockopt (se->fd, IPPROTO_IP, IP_MULTICAST_LOOP,
151 &loop, sizeof (loop)) == -1)
152 {
153 syslog (LOG_ERR, "setsockopt: %s", strerror (errno));
154 return (-1);
155 }
157 if (setsockopt (se->fd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
158 &mreq, sizeof (mreq)) == -1)
159 {
160 syslog (LOG_ERR, "setsockopt: %s", strerror (errno));
161 return (-1);
162 }
163 }
164 }
165 else if (ai->ai_family == AF_INET6)
166 {
167 /* Useful example: http://gsyc.escet.urjc.es/~eva/IPv6-web/examples/mcast.html */
168 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) ai->ai_addr;
169 if (IN6_IS_ADDR_MULTICAST (&addr->sin6_addr))
170 {
171 struct ipv6_mreq mreq;
173 DBG ("fd = %i; IPv6 multicast address found", se->fd);
175 memcpy (&mreq.ipv6mr_multiaddr,
176 &addr->sin6_addr,
177 sizeof (addr->sin6_addr));
179 /* http://developer.apple.com/documentation/Darwin/Reference/ManPages/man4/ip6.4.html
180 * ipv6mr_interface may be set to zeroes to
181 * choose the default multicast interface or to
182 * the index of a particular multicast-capable
183 * interface if the host is multihomed.
184 * Membership is associ-associated with a
185 * single interface; programs running on
186 * multihomed hosts may need to join the same
187 * group on more than one interface.*/
188 mreq.ipv6mr_interface = 0;
190 if (setsockopt (se->fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP,
191 &loop, sizeof (loop)) == -1)
192 {
193 syslog (LOG_ERR, "setsockopt: %s", strerror (errno));
194 return (-1);
195 }
197 if (setsockopt (se->fd, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP,
198 &mreq, sizeof (mreq)) == -1)
199 {
200 syslog (LOG_ERR, "setsockopt: %s", strerror (errno));
201 return (-1);
202 }
203 }
204 }
206 return (0);
207 }
209 int network_create_socket (const char *node, const char *service)
210 {
211 sockent_t *socklist_tail;
213 struct addrinfo ai_hints;
214 struct addrinfo *ai_list, *ai_ptr;
215 int ai_return;
217 int num_added = 0;
219 DBG ("node = %s, service = %s", node, service);
221 if (operating_mode == MODE_LOCAL)
222 return (-1);
224 socklist_tail = socklist_head;
225 while ((socklist_tail != NULL) && (socklist_tail->next != NULL))
226 socklist_tail = socklist_tail->next;
228 memset (&ai_hints, '\0', sizeof (ai_hints));
229 ai_hints.ai_flags = 0;
230 #ifdef AI_PASSIVE
231 ai_hints.ai_flags |= AI_PASSIVE;
232 #endif
233 #ifdef AI_ADDRCONFIG
234 ai_hints.ai_flags |= AI_ADDRCONFIG;
235 #endif
236 ai_hints.ai_family = PF_UNSPEC;
237 ai_hints.ai_socktype = SOCK_DGRAM;
238 ai_hints.ai_protocol = IPPROTO_UDP;
240 if ((ai_return = getaddrinfo (node, service, &ai_hints, &ai_list)) != 0)
241 {
242 syslog (LOG_ERR, "getaddrinfo (%s, %s): %s",
243 node == NULL ? "(null)" : node,
244 service == NULL ? "(null)" : service,
245 ai_return == EAI_SYSTEM ? strerror (errno) : gai_strerror (ai_return));
246 return (-1);
247 }
249 for (ai_ptr = ai_list; ai_ptr != NULL; ai_ptr = ai_ptr->ai_next)
250 {
251 sockent_t *se;
253 if ((se = (sockent_t *) malloc (sizeof (sockent_t))) == NULL)
254 {
255 syslog (LOG_EMERG, "malloc: %s", strerror (errno));
256 continue;
257 }
259 if ((se->addr = (struct sockaddr_storage *) malloc (sizeof (struct sockaddr_storage))) == NULL)
260 {
261 syslog (LOG_EMERG, "malloc: %s", strerror (errno));
262 free (se);
263 continue;
264 }
266 assert (sizeof (struct sockaddr_storage) >= ai_ptr->ai_addrlen);
267 memset (se->addr, '\0', sizeof (struct sockaddr_storage));
268 memcpy (se->addr, ai_ptr->ai_addr, ai_ptr->ai_addrlen);
269 se->addrlen = ai_ptr->ai_addrlen;
271 se->mode = operating_mode;
272 se->fd = socket (ai_ptr->ai_family, ai_ptr->ai_socktype, ai_ptr->ai_protocol);
273 se->next = NULL;
275 if (se->fd == -1)
276 {
277 syslog (LOG_ERR, "socket: %s", strerror (errno));
278 free (se->addr);
279 free (se);
280 continue;
281 }
283 if (operating_mode == MODE_SERVER)
284 {
285 if (network_bind_socket (se, ai_ptr) != 0)
286 {
287 free (se->addr);
288 free (se);
289 continue;
290 }
291 }
292 else if (operating_mode == MODE_CLIENT)
293 {
294 network_set_ttl (se, ai_ptr);
295 }
297 if (socklist_tail == NULL)
298 {
299 socklist_head = se;
300 socklist_tail = se;
301 }
302 else
303 {
304 socklist_tail->next = se;
305 socklist_tail = se;
306 }
308 num_added++;
310 /* We don't open more than one write-socket per node/service pair.. */
311 if (operating_mode == MODE_CLIENT)
312 break;
313 }
315 freeaddrinfo (ai_list);
317 return (num_added);
318 }
320 static int network_connect_default (void)
321 {
322 int ret;
324 if (socklist_head != NULL)
325 return (0);
327 DBG ("socklist_head is NULL");
329 ret = 0;
331 if (network_create_socket (NET_DEFAULT_V6_ADDR, NET_DEFAULT_PORT) > 0)
332 ret++;
334 /* Don't use IPv4 and IPv6 in parallel by default.. */
335 if ((operating_mode == MODE_CLIENT) && (ret != 0))
336 return (ret);
338 if (network_create_socket (NET_DEFAULT_V4_ADDR, NET_DEFAULT_PORT) > 0)
339 ret++;
341 if (ret == 0)
342 ret = -1;
344 return (ret);
345 }
347 static int network_get_listen_socket (void)
348 {
349 int fd;
350 int max_fd;
351 int status;
353 fd_set readfds;
354 sockent_t *se;
356 if (socklist_head == NULL)
357 network_connect_default ();
359 FD_ZERO (&readfds);
360 max_fd = -1;
361 for (se = socklist_head; se != NULL; se = se->next)
362 {
363 if (se->mode != operating_mode)
364 continue;
366 FD_SET (se->fd, &readfds);
367 if (se->fd >= max_fd)
368 max_fd = se->fd + 1;
369 }
371 if (max_fd == -1)
372 {
373 syslog (LOG_WARNING, "No listen sockets found!");
374 return (-1);
375 }
377 status = select (max_fd, &readfds, NULL, NULL, NULL);
379 if (status == -1)
380 {
381 if (errno != EINTR)
382 syslog (LOG_ERR, "select: %s", strerror (errno));
383 return (-1);
384 }
386 fd = -1;
387 for (se = socklist_head; se != NULL; se = se->next)
388 {
389 if (se->mode != operating_mode)
390 continue;
392 if (FD_ISSET (se->fd, &readfds))
393 {
394 fd = se->fd;
395 break;
396 }
397 }
399 if (fd == -1)
400 syslog (LOG_WARNING, "No socket ready..?");
402 DBG ("fd = %i", fd);
403 return (fd);
404 }
406 int network_receive (char **host, char **type, char **inst, char **value)
407 {
408 int fd;
409 char buffer[BUFF_SIZE];
411 struct sockaddr_storage addr;
412 socklen_t addrlen;
413 int status;
415 char *fields[4];
417 assert (operating_mode == MODE_SERVER);
419 *host = NULL;
420 *type = NULL;
421 *inst = NULL;
422 *value = NULL;
424 if ((fd = network_get_listen_socket ()) < 0)
425 return (-1);
427 addrlen = sizeof (addr);
428 if (recvfrom (fd, buffer, BUFF_SIZE, 0, (struct sockaddr *) &addr, &addrlen) == -1)
429 {
430 syslog (LOG_ERR, "recvfrom: %s", strerror (errno));
431 return (-1);
432 }
434 if ((*host = (char *) malloc (BUFF_SIZE)) == NULL)
435 {
436 syslog (LOG_EMERG, "malloc: %s", strerror (errno));
437 return (-1);
438 }
440 status = getnameinfo ((struct sockaddr *) &addr, addrlen,
441 *host, BUFF_SIZE, NULL, 0, 0);
442 if (status != 0)
443 {
444 free (*host); *host = NULL;
445 syslog (LOG_ERR, "getnameinfo: %s",
446 status == EAI_SYSTEM ? strerror (errno) : gai_strerror (status));
447 return (-1);
448 }
450 if (strsplit (buffer, fields, 4) != 3)
451 {
452 syslog (LOG_WARNING, "Invalid message from `%s'", *host);
453 free (*host); *host = NULL;
454 return (-1);
455 }
457 if ((*type = strdup (fields[0])) == NULL)
458 {
459 syslog (LOG_EMERG, "strdup: %s", strerror (errno));
460 free (*host); *host = NULL;
461 return (-1);
462 }
464 if ((*inst = strdup (fields[1])) == NULL)
465 {
466 syslog (LOG_EMERG, "strdup: %s", strerror (errno));
467 free (*host); *host = NULL;
468 free (*type); *type = NULL;
469 return (-1);
470 }
472 if ((*value = strdup (fields[2])) == NULL)
473 {
474 syslog (LOG_EMERG, "strdup: %s", strerror (errno));
475 free (*host); *host = NULL;
476 free (*type); *type = NULL;
477 free (*inst); *inst = NULL;
478 return (-1);
479 }
481 DBG ("host = %s, type = %s, inst = %s, value = %s",
482 *host, *type, *inst, *value);
484 return (0);
485 }
487 int network_send (char *type, char *inst, char *value)
488 {
489 char buf[BUFF_SIZE];
490 int buflen;
492 sockent_t *se;
494 int ret;
495 int status;
497 DBG ("type = %s, inst = %s, value = %s", type, inst, value);
499 assert (operating_mode == MODE_CLIENT);
501 buflen = snprintf (buf, BUFF_SIZE, "%s %s %s", type, inst, value);
502 if ((buflen >= BUFF_SIZE) || (buflen < 1))
503 {
504 syslog (LOG_WARNING, "network_send: snprintf failed..");
505 return (-1);
506 }
507 buf[buflen] = '\0';
508 buflen++;
510 if (socklist_head == NULL)
511 network_connect_default ();
513 ret = 0;
514 for (se = socklist_head; se != NULL; se = se->next)
515 {
516 if (se->mode != operating_mode)
517 continue;
519 DBG ("fd = %i", se->fd);
521 while (1)
522 {
523 status = sendto (se->fd, buf, buflen, 0,
524 (struct sockaddr *) se->addr, se->addrlen);
526 if (status == -1)
527 {
528 if (errno == EINTR)
529 {
530 DBG ("sendto was interrupted");
531 continue;
532 }
533 else
534 {
535 syslog (LOG_ERR, "sendto: %s", strerror (errno));
536 ret = -1;
537 break;
538 }
539 }
540 else if (ret >= 0)
541 ret++;
542 break;
543 }
544 }
546 if (ret == 0)
547 syslog (LOG_WARNING, "Message wasn't sent to anybody..");
549 return (ret);
550 }