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 <netdb.h>
27 #include <sys/types.h>
28 #include <sys/socket.h>
29 #include <netinet/in.h>
30 #include <arpa/inet.h>
31 #include <syslog.h>
32 #include <errno.h>
33 #include <assert.h>
35 #include "network.h"
36 #include "common.h"
37 #include "utils_debug.h"
39 /* 1500 - 40 - 8 = Ethernet packet - IPv6 header - UDP header */
40 /* #define BUFF_SIZE 1452 */
42 #define BUFF_SIZE 4096
44 #ifdef HAVE_LIBRRD
45 extern int operating_mode;
46 #else
47 static int operating_mode = MODE_CLIENT;
48 #endif
50 typedef struct sockent
51 {
52 int fd;
53 int mode;
54 struct sockaddr_storage *addr;
55 socklen_t addrlen;
56 struct sockent *next;
57 } sockent_t;
59 static sockent_t *socklist_head = NULL;
61 static int network_bind_socket (const sockent_t *se, const struct addrinfo *ai)
62 {
63 int loop = 1;
65 DBG ("fd = %i; calling `bind'", se->fd);
67 if (bind (se->fd, ai->ai_addr, ai->ai_addrlen) == -1)
68 {
69 syslog (LOG_ERR, "bind: %s", strerror (errno));
70 return (-1);
71 }
73 if (ai->ai_family == AF_INET)
74 {
75 struct sockaddr_in *addr = (struct sockaddr_in *) ai->ai_addr;
76 if (IN_MULTICAST (ntohl (addr->sin_addr.s_addr)))
77 {
78 struct ip_mreq mreq;
80 DBG ("fd = %i; IPv4 multicast address found", se->fd);
82 mreq.imr_multiaddr.s_addr = addr->sin_addr.s_addr;
83 mreq.imr_interface.s_addr = htonl (INADDR_ANY);
85 if (setsockopt (se->fd, IPPROTO_IP, IP_MULTICAST_LOOP,
86 &loop, sizeof (loop)) == -1)
87 {
88 syslog (LOG_ERR, "setsockopt: %s", strerror (errno));
89 return (-1);
90 }
92 if (setsockopt (se->fd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
93 &mreq, sizeof (mreq)) == -1)
94 {
95 syslog (LOG_ERR, "setsockopt: %s", strerror (errno));
96 return (-1);
97 }
98 }
99 }
100 else if (ai->ai_family == AF_INET6)
101 {
102 /* Useful example: http://gsyc.escet.urjc.es/~eva/IPv6-web/examples/mcast.html */
103 struct sockaddr_in6 *addr = (struct sockaddr_in6 *) ai->ai_addr;
104 if (IN6_IS_ADDR_MULTICAST (&addr->sin6_addr))
105 {
106 struct ipv6_mreq mreq;
108 DBG ("fd = %i; IPv6 multicast address found", se->fd);
110 memcpy (&mreq.ipv6mr_multiaddr,
111 &addr->sin6_addr,
112 sizeof (addr->sin6_addr));
114 /* http://developer.apple.com/documentation/Darwin/Reference/ManPages/man4/ip6.4.html
115 * ipv6mr_interface may be set to zeroes to
116 * choose the default multicast interface or to
117 * the index of a particular multicast-capable
118 * interface if the host is multihomed.
119 * Membership is associ-associated with a
120 * single interface; programs running on
121 * multihomed hosts may need to join the same
122 * group on more than one interface.*/
123 mreq.ipv6mr_interface = 0;
125 if (setsockopt (se->fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP,
126 &loop, sizeof (loop)) == -1)
127 {
128 syslog (LOG_ERR, "setsockopt: %s", strerror (errno));
129 return (-1);
130 }
132 if (setsockopt (se->fd, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP,
133 &mreq, sizeof (mreq)) == -1)
134 {
135 syslog (LOG_ERR, "setsockopt: %s", strerror (errno));
136 return (-1);
137 }
138 }
139 }
141 return (0);
142 }
144 int network_create_socket (const char *node, const char *service)
145 {
146 sockent_t *socklist_tail;
148 struct addrinfo ai_hints;
149 struct addrinfo *ai_list, *ai_ptr;
150 int ai_return;
152 int num_added = 0;
154 DBG ("node = %s, service = %s", node, service);
156 if (operating_mode == MODE_LOCAL)
157 return (-1);
159 socklist_tail = socklist_head;
160 while ((socklist_tail != NULL) && (socklist_tail->next != NULL))
161 socklist_tail = socklist_tail->next;
163 memset (&ai_hints, '\0', sizeof (ai_hints));
164 ai_hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG;
165 ai_hints.ai_family = PF_UNSPEC;
166 ai_hints.ai_socktype = SOCK_DGRAM;
167 ai_hints.ai_protocol = IPPROTO_UDP; /* XXX is this right here?!? */
169 if ((ai_return = getaddrinfo (node, service, &ai_hints, &ai_list)) != 0)
170 {
171 syslog (LOG_ERR, "getaddrinfo (%s, %s): %s",
172 node == NULL ? "(null)" : node,
173 service == NULL ? "(null)" : service,
174 ai_return == EAI_SYSTEM ? strerror (errno) : gai_strerror (ai_return));
175 return (-1);
176 }
178 for (ai_ptr = ai_list; ai_ptr != NULL; ai_ptr = ai_ptr->ai_next)
179 {
180 sockent_t *se;
182 if ((se = (sockent_t *) malloc (sizeof (sockent_t))) == NULL)
183 {
184 syslog (LOG_EMERG, "malloc: %s", strerror (errno));
185 continue;
186 }
188 if ((se->addr = (struct sockaddr_storage *) malloc (sizeof (struct sockaddr_storage))) == NULL)
189 {
190 syslog (LOG_EMERG, "malloc: %s", strerror (errno));
191 free (se);
192 continue;
193 }
195 assert (sizeof (struct sockaddr_storage) >= ai_ptr->ai_addrlen);
196 memset (se->addr, '\0', sizeof (struct sockaddr_storage));
197 memcpy (se->addr, ai_ptr->ai_addr, ai_ptr->ai_addrlen);
198 se->addrlen = ai_ptr->ai_addrlen;
200 se->mode = operating_mode;
201 se->fd = socket (ai_ptr->ai_family, ai_ptr->ai_socktype, ai_ptr->ai_protocol);
202 se->next = NULL;
204 if (se->fd == -1)
205 {
206 syslog (LOG_ERR, "socket: %s", strerror (errno));
207 free (se->addr);
208 free (se);
209 continue;
210 }
212 if (operating_mode == MODE_SERVER)
213 if (network_bind_socket (se, ai_ptr) != 0)
214 {
215 free (se->addr);
216 free (se);
217 continue;
218 }
220 if (socklist_tail == NULL)
221 {
222 socklist_head = se;
223 socklist_tail = se;
224 }
225 else
226 {
227 socklist_tail->next = se;
228 socklist_tail = se;
229 }
231 num_added++;
233 /* We don't open more than one write-socket per node/service pair.. */
234 if (operating_mode == MODE_CLIENT)
235 break;
236 }
238 freeaddrinfo (ai_list);
240 return (num_added);
241 }
243 static int network_connect_default (void)
244 {
245 int ret;
247 if (socklist_head != NULL)
248 return (0);
250 DBG ("socklist_head is NULL");
252 ret = 0;
254 if (network_create_socket (NET_DEFAULT_V6_ADDR, NET_DEFAULT_PORT) > 0)
255 ret++;
257 /* Don't use IPv4 and IPv6 in parallel by default.. */
258 if ((operating_mode == MODE_CLIENT) && (ret != 0))
259 return (ret);
261 if (network_create_socket (NET_DEFAULT_V4_ADDR, NET_DEFAULT_PORT) > 0)
262 ret++;
264 if (ret == 0)
265 ret = -1;
267 return (ret);
268 }
270 static int network_get_listen_socket (void)
271 {
272 int fd;
273 int max_fd;
274 int status;
276 fd_set readfds;
277 sockent_t *se;
279 if (socklist_head == NULL)
280 network_connect_default ();
282 FD_ZERO (&readfds);
283 max_fd = -1;
284 for (se = socklist_head; se != NULL; se = se->next)
285 {
286 if (se->mode != operating_mode)
287 continue;
289 FD_SET (se->fd, &readfds);
290 if (se->fd >= max_fd)
291 max_fd = se->fd + 1;
292 }
294 if (max_fd == -1)
295 {
296 syslog (LOG_WARNING, "No listen sockets found!");
297 return (-1);
298 }
300 status = select (max_fd, &readfds, NULL, NULL, NULL);
302 if (status == -1)
303 {
304 if (errno != EINTR)
305 syslog (LOG_ERR, "select: %s", strerror (errno));
306 return (-1);
307 }
309 fd = -1;
310 for (se = socklist_head; se != NULL; se = se->next)
311 {
312 if (se->mode != operating_mode)
313 continue;
315 if (FD_ISSET (se->fd, &readfds))
316 {
317 fd = se->fd;
318 break;
319 }
320 }
322 if (fd == -1)
323 syslog (LOG_WARNING, "No socket ready..?");
325 DBG ("fd = %i", fd);
326 return (fd);
327 }
329 int network_receive (char **host, char **type, char **inst, char **value)
330 {
331 int fd;
332 char buffer[BUFF_SIZE];
334 struct sockaddr_storage addr;
335 socklen_t addrlen;
336 int status;
338 char *fields[4];
340 assert (operating_mode == MODE_SERVER);
342 *host = NULL;
343 *type = NULL;
344 *inst = NULL;
345 *value = NULL;
347 if ((fd = network_get_listen_socket ()) < 0)
348 return (-1);
350 if (recvfrom (fd, buffer, BUFF_SIZE, 0, (struct sockaddr *) &addr, &addrlen) == -1)
351 {
352 syslog (LOG_ERR, "recvfrom: %s", strerror (errno));
353 return (-1);
354 }
356 if ((*host = (char *) malloc (BUFF_SIZE)) == NULL)
357 {
358 syslog (LOG_EMERG, "malloc: %s", strerror (errno));
359 return (-1);
360 }
362 status = getnameinfo ((struct sockaddr *) &addr, addrlen,
363 *host, BUFF_SIZE, NULL, 0, 0);
364 if (status != 0)
365 {
366 free (*host); *host = NULL;
367 syslog (LOG_ERR, "getnameinfo: %s",
368 status == EAI_SYSTEM ? strerror (errno) : gai_strerror (status));
369 return (-1);
370 }
372 if (strsplit (buffer, fields, 4) != 3)
373 {
374 syslog (LOG_WARNING, "Invalid message from `%s'", *host);
375 free (*host); *host = NULL;
376 return (-1);
377 }
379 if ((*type = strdup (fields[0])) == NULL)
380 {
381 syslog (LOG_EMERG, "strdup: %s", strerror (errno));
382 free (*host); *host = NULL;
383 return (-1);
384 }
386 if ((*inst = strdup (fields[1])) == NULL)
387 {
388 syslog (LOG_EMERG, "strdup: %s", strerror (errno));
389 free (*host); *host = NULL;
390 free (*type); *type = NULL;
391 return (-1);
392 }
394 if ((*value = strdup (fields[2])) == NULL)
395 {
396 syslog (LOG_EMERG, "strdup: %s", strerror (errno));
397 free (*host); *host = NULL;
398 free (*type); *type = NULL;
399 free (*inst); *inst = NULL;
400 return (-1);
401 }
403 DBG ("host = %s, type = %s, inst = %s, value = %s",
404 *host, *type, *inst, *value);
406 return (0);
407 }
409 int network_send (char *type, char *inst, char *value)
410 {
411 char buf[BUFF_SIZE];
412 int buflen;
414 sockent_t *se;
416 int ret;
417 int status;
419 DBG ("type = %s, inst = %s, value = %s", type, inst, value);
421 assert (operating_mode == MODE_CLIENT);
423 buflen = snprintf (buf, BUFF_SIZE, "%s %s %s", type, inst, value);
424 if ((buflen >= BUFF_SIZE) || (buflen < 1))
425 {
426 syslog (LOG_WARNING, "network_send: snprintf failed..");
427 return (-1);
428 }
429 buf[buflen] = '\0';
430 buflen++;
432 if (socklist_head == NULL)
433 network_connect_default ();
435 ret = 0;
436 for (se = socklist_head; se != NULL; se = se->next)
437 {
438 if (se->mode != operating_mode)
439 continue;
441 DBG ("fd = %i", se->fd);
443 while (1)
444 {
445 status = sendto (se->fd, buf, buflen, 0,
446 (struct sockaddr *) se->addr, se->addrlen);
448 if (status == -1)
449 {
450 if (errno == EINTR)
451 {
452 DBG ("sendto was interrupted");
453 continue;
454 }
455 else
456 {
457 syslog (LOG_ERR, "sendto: %s", strerror (errno));
458 ret = -1;
459 break;
460 }
461 }
462 else if (ret >= 0)
463 ret++;
464 break;
465 }
466 }
468 if (ret == 0)
469 syslog (LOG_WARNING, "Message wasn't sent to anybody..");
471 return (ret);
472 }