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MFC r1.6 r1.30 r1.28 (HEAD):
[dragonfly.git] / usr.sbin / mrouted / igmp.c
blob1bc21779efb20ab8f36adf6f824ed0d5248d3c3e
1 /*
2 * The mrouted program is covered by the license in the accompanying file
3 * named "LICENSE". Use of the mrouted program represents acceptance of
4 * the terms and conditions listed in that file.
5 *
6 * The mrouted program is COPYRIGHT 1989 by The Board of Trustees of
7 * Leland Stanford Junior University.
8 *
9 *
10 * igmp.c,v 3.8.4.19 1998/01/06 01:57:43 fenner Exp
11 *
12 * $FreeBSD: src/usr.sbin/mrouted/igmp.c,v 1.16 1999/08/28 01:17:04 peter Exp $
13 * $DragonFly: src/usr.sbin/mrouted/igmp.c,v 1.4 2004/03/15 18:10:28 dillon Exp $
14 */
15
16 #include "defs.h"
17
18 /*
19 * Exported variables.
20 */
21 char *recv_buf; /* input packet buffer */
22 char *send_buf; /* output packet buffer */
23 int igmp_socket; /* socket for all network I/O */
24 u_int32 allhosts_group; /* All hosts addr in net order */
25 u_int32 allrtrs_group; /* All-Routers " in net order */
26 u_int32 dvmrp_group; /* DVMRP grp addr in net order */
27 u_int32 dvmrp_genid; /* IGMP generation id */
28
29 /*
30 * Local function definitions.
31 */
32 /* u_char promoted to u_int */
33 static int igmp_log_level(u_int type, u_int code);
34
35 /*
36 * Open and initialize the igmp socket, and fill in the non-changing
37 * IP header fields in the output packet buffer.
38 */
39 void
40 init_igmp(void)
41 {
42 struct ip *ip;
43
44 recv_buf = malloc(RECV_BUF_SIZE);
45 send_buf = malloc(RECV_BUF_SIZE);
46
47 if ((igmp_socket = socket(AF_INET, SOCK_RAW, IPPROTO_IGMP)) < 0)
48 log(LOG_ERR, errno, "IGMP socket");
49
50 k_hdr_include(TRUE); /* include IP header when sending */
51 k_set_rcvbuf(256*1024,48*1024); /* lots of input buffering */
52 k_set_ttl(1); /* restrict multicasts to one hop */
53 k_set_loop(FALSE); /* disable multicast loopback */
54
55 ip = (struct ip *)send_buf;
56 bzero(ip, sizeof(struct ip));
57 /*
58 * Fields zeroed that aren't filled in later:
59 * - IP ID (let the kernel fill it in)
60 * - Offset (we don't send fragments)
61 * - Checksum (let the kernel fill it in)
62 */
63 ip->ip_v = IPVERSION;
64 ip->ip_hl = sizeof(struct ip) >> 2;
65 ip->ip_tos = 0xc0; /* Internet Control */
66 ip->ip_ttl = MAXTTL; /* applies to unicasts only */
67 ip->ip_p = IPPROTO_IGMP;
68
69 allhosts_group = htonl(INADDR_ALLHOSTS_GROUP);
70 dvmrp_group = htonl(INADDR_DVMRP_GROUP);
71 allrtrs_group = htonl(INADDR_ALLRTRS_GROUP);
72 }
73
74 #define PIM_QUERY 0
75 #define PIM_REGISTER 1
76 #define PIM_REGISTER_STOP 2
77 #define PIM_JOIN_PRUNE 3
78 #define PIM_RP_REACHABLE 4
79 #define PIM_ASSERT 5
80 #define PIM_GRAFT 6
81 #define PIM_GRAFT_ACK 7
82
83 char *
84 igmp_packet_kind(u_int type, u_int code)
85 {
86 static char unknown[20];
87
88 switch (type) {
89 case IGMP_MEMBERSHIP_QUERY: return "membership query ";
90 case IGMP_V1_MEMBERSHIP_REPORT: return "V1 member report ";
91 case IGMP_V2_MEMBERSHIP_REPORT: return "V2 member report ";
92 case IGMP_V2_LEAVE_GROUP: return "leave message ";
93 case IGMP_DVMRP:
94 switch (code) {
95 case DVMRP_PROBE: return "neighbor probe ";
96 case DVMRP_REPORT: return "route report ";
97 case DVMRP_ASK_NEIGHBORS: return "neighbor request ";
98 case DVMRP_NEIGHBORS: return "neighbor list ";
99 case DVMRP_ASK_NEIGHBORS2: return "neighbor request 2";
100 case DVMRP_NEIGHBORS2: return "neighbor list 2 ";
101 case DVMRP_PRUNE: return "prune message ";
102 case DVMRP_GRAFT: return "graft message ";
103 case DVMRP_GRAFT_ACK: return "graft message ack ";
104 case DVMRP_INFO_REQUEST: return "info request ";
105 case DVMRP_INFO_REPLY: return "info reply ";
106 default:
107 sprintf(unknown, "unknown DVMRP %3d ", code);
108 return unknown;
109 }
110 case IGMP_PIM:
111 switch (code) {
112 case PIM_QUERY: return "PIM Router-Query ";
113 case PIM_REGISTER: return "PIM Register ";
114 case PIM_REGISTER_STOP: return "PIM Register-Stop ";
115 case PIM_JOIN_PRUNE: return "PIM Join/Prune ";
116 case PIM_RP_REACHABLE: return "PIM RP-Reachable ";
117 case PIM_ASSERT: return "PIM Assert ";
118 case PIM_GRAFT: return "PIM Graft ";
119 case PIM_GRAFT_ACK: return "PIM Graft-Ack ";
120 default:
121 sprintf(unknown, "unknown PIM msg%3d", code);
122 return unknown;
123 }
124 case IGMP_MTRACE: return "IGMP trace query ";
125 case IGMP_MTRACE_RESP: return "IGMP trace reply ";
126 default:
127 sprintf(unknown, "unk: 0x%02x/0x%02x ", type, code);
128 return unknown;
129 }
130 }
131
132 int
133 igmp_debug_kind(u_int type, u_int code)
134 {
135 switch (type) {
136 case IGMP_MEMBERSHIP_QUERY: return DEBUG_IGMP;
137 case IGMP_V1_MEMBERSHIP_REPORT: return DEBUG_IGMP;
138 case IGMP_V2_MEMBERSHIP_REPORT: return DEBUG_IGMP;
139 case IGMP_V2_LEAVE_GROUP: return DEBUG_IGMP;
140 case IGMP_DVMRP:
141 switch (code) {
142 case DVMRP_PROBE: return DEBUG_PEER;
143 case DVMRP_REPORT: return DEBUG_ROUTE;
144 case DVMRP_ASK_NEIGHBORS: return 0;
145 case DVMRP_NEIGHBORS: return 0;
146 case DVMRP_ASK_NEIGHBORS2: return 0;
147 case DVMRP_NEIGHBORS2: return 0;
148 case DVMRP_PRUNE: return DEBUG_PRUNE;
149 case DVMRP_GRAFT: return DEBUG_PRUNE;
150 case DVMRP_GRAFT_ACK: return DEBUG_PRUNE;
151 case DVMRP_INFO_REQUEST: return 0;
152 case DVMRP_INFO_REPLY: return 0;
153 default: return 0;
154 }
155 case IGMP_PIM:
156 switch (code) {
157 case PIM_QUERY: return 0;
158 case PIM_REGISTER: return 0;
159 case PIM_REGISTER_STOP: return 0;
160 case PIM_JOIN_PRUNE: return 0;
161 case PIM_RP_REACHABLE: return 0;
162 case PIM_ASSERT: return 0;
163 case PIM_GRAFT: return 0;
164 case PIM_GRAFT_ACK: return 0;
165 default: return 0;
166 }
167 case IGMP_MTRACE: return DEBUG_TRACE;
168 case IGMP_MTRACE_RESP: return DEBUG_TRACE;
169 default: return DEBUG_IGMP;
170 }
171 }
172
173 /*
174 * Process a newly received IGMP packet that is sitting in the input
175 * packet buffer.
176 */
177 void
178 accept_igmp(int recvlen)
179 {
180 u_int32 src, dst, group;
181 struct ip *ip;
182 struct igmp *igmp;
183 int ipdatalen, iphdrlen, igmpdatalen;
184
185 if (recvlen < sizeof(struct ip)) {
186 log(LOG_WARNING, 0,
187 "received packet too short (%u bytes) for IP header", recvlen);
188 return;
189 }
190
191 ip = (struct ip *)recv_buf;
192 src = ip->ip_src.s_addr;
193 dst = ip->ip_dst.s_addr;
194
195 /*
196 * this is most likely a message from the kernel indicating that
197 * a new src grp pair message has arrived and so, it would be
198 * necessary to install a route into the kernel for this.
199 */
200 if (ip->ip_p == 0) {
201 if (src == 0 || dst == 0)
202 log(LOG_WARNING, 0, "kernel request not accurate");
203 else
204 add_table_entry(src, dst);
205 return;
206 }
207
208 iphdrlen = ip->ip_hl << 2;
209 #ifdef RAW_INPUT_IS_RAW
210 ipdatalen = ntohs(ip->ip_len) - iphdrlen;
211 #else
212 ipdatalen = ip->ip_len;
213 #endif
214 if (iphdrlen + ipdatalen != recvlen) {
215 log(LOG_WARNING, 0,
216 "received packet from %s shorter (%u bytes) than hdr+data length (%u+%u)",
217 inet_fmt(src, s1), recvlen, iphdrlen, ipdatalen);
218 return;
219 }
220
221 igmp = (struct igmp *)(recv_buf + iphdrlen);
222 group = igmp->igmp_group.s_addr;
223 igmpdatalen = ipdatalen - IGMP_MINLEN;
224 if (igmpdatalen < 0) {
225 log(LOG_WARNING, 0,
226 "received IP data field too short (%u bytes) for IGMP, from %s",
227 ipdatalen, inet_fmt(src, s1));
228 return;
229 }
230
231 IF_DEBUG(DEBUG_PKT|igmp_debug_kind(igmp->igmp_type, igmp->igmp_code))
232 log(LOG_DEBUG, 0, "RECV %s from %-15s to %s",
233 igmp_packet_kind(igmp->igmp_type, igmp->igmp_code),
234 inet_fmt(src, s1), inet_fmt(dst, s2));
235
236 switch (igmp->igmp_type) {
237
238 case IGMP_MEMBERSHIP_QUERY:
239 accept_membership_query(src, dst, group, igmp->igmp_code);
240 return;
241
242 case IGMP_V1_MEMBERSHIP_REPORT:
243 case IGMP_V2_MEMBERSHIP_REPORT:
244 accept_group_report(src, dst, group, igmp->igmp_type);
245 return;
246
247 case IGMP_V2_LEAVE_GROUP:
248 accept_leave_message(src, dst, group);
249 return;
250
251 case IGMP_DVMRP:
252 group = ntohl(group);
253
254 switch (igmp->igmp_code) {
255 case DVMRP_PROBE:
256 accept_probe(src, dst,
257 (char *)(igmp+1), igmpdatalen, group);
258 return;
259
260 case DVMRP_REPORT:
261 accept_report(src, dst,
262 (char *)(igmp+1), igmpdatalen, group);
263 return;
264
265 case DVMRP_ASK_NEIGHBORS:
266 accept_neighbor_request(src, dst);
267 return;
268
269 case DVMRP_ASK_NEIGHBORS2:
270 accept_neighbor_request2(src, dst);
271 return;
272
273 case DVMRP_NEIGHBORS:
274 accept_neighbors(src, dst, (u_char *)(igmp+1), igmpdatalen,
275 group);
276 return;
277
278 case DVMRP_NEIGHBORS2:
279 accept_neighbors2(src, dst, (u_char *)(igmp+1), igmpdatalen,
280 group);
281 return;
282
283 case DVMRP_PRUNE:
284 accept_prune(src, dst, (char *)(igmp+1), igmpdatalen);
285 return;
286
287 case DVMRP_GRAFT:
288 accept_graft(src, dst, (char *)(igmp+1), igmpdatalen);
289 return;
290
291 case DVMRP_GRAFT_ACK:
292 accept_g_ack(src, dst, (char *)(igmp+1), igmpdatalen);
293 return;
294
295 case DVMRP_INFO_REQUEST:
296 accept_info_request(src, dst, (char *)(igmp+1),
297 igmpdatalen);
298 return;
299
300 case DVMRP_INFO_REPLY:
301 accept_info_reply(src, dst, (char *)(igmp+1), igmpdatalen);
302 return;
303
304 default:
305 log(LOG_INFO, 0,
306 "ignoring unknown DVMRP message code %u from %s to %s",
307 igmp->igmp_code, inet_fmt(src, s1),
308 inet_fmt(dst, s2));
309 return;
310 }
311
312 case IGMP_PIM:
313 return;
314
315 case IGMP_MTRACE_RESP:
316 return;
317
318 case IGMP_MTRACE:
319 accept_mtrace(src, dst, group, (char *)(igmp+1),
320 igmp->igmp_code, igmpdatalen);
321 return;
322
323 default:
324 log(LOG_INFO, 0,
325 "ignoring unknown IGMP message type %x from %s to %s",
326 igmp->igmp_type, inet_fmt(src, s1),
327 inet_fmt(dst, s2));
328 return;
329 }
330 }
331
332 /*
333 * Some IGMP messages are more important than others. This routine
334 * determines the logging level at which to log a send error (often
335 * "No route to host"). This is important when there is asymmetric
336 * reachability and someone is trying to, i.e., mrinfo me periodically.
337 */
338 static int
339 igmp_log_level(u_int type, u_int code)
340 {
341 switch (type) {
342 case IGMP_MTRACE_RESP:
343 return LOG_INFO;
344
345 case IGMP_DVMRP:
346 switch (code) {
347 case DVMRP_NEIGHBORS:
348 case DVMRP_NEIGHBORS2:
349 return LOG_INFO;
350 }
351 }
352 return LOG_WARNING;
353 }
354
355 /*
356 * Construct an IGMP message in the output packet buffer. The caller may
357 * have already placed data in that buffer, of length 'datalen'.
358 */
359 void
360 build_igmp(u_int32 src, u_int32 dst, int type, int code, u_int32 group,
361 int datalen)
362 {
363 struct ip *ip;
364 struct igmp *igmp;
365 extern int curttl;
366
367 ip = (struct ip *)send_buf;
368 ip->ip_src.s_addr = src;
369 ip->ip_dst.s_addr = dst;
370 ip->ip_len = MIN_IP_HEADER_LEN + IGMP_MINLEN + datalen;
371 #ifdef RAW_OUTPUT_IS_RAW
372 ip->ip_len = htons(ip->ip_len);
373 #endif
374 if (IN_MULTICAST(ntohl(dst))) {
375 ip->ip_ttl = curttl;
376 } else {
377 ip->ip_ttl = MAXTTL;
378 }
379
380 igmp = (struct igmp *)(send_buf + MIN_IP_HEADER_LEN);
381 igmp->igmp_type = type;
382 igmp->igmp_code = code;
383 igmp->igmp_group.s_addr = group;
384 igmp->igmp_cksum = 0;
385 igmp->igmp_cksum = inet_cksum((u_short *)igmp,
386 IGMP_MINLEN + datalen);
387 }
388
389 /*
390 * Call build_igmp() to build an IGMP message in the output packet buffer.
391 * Then send the message from the interface with IP address 'src' to
392 * destination 'dst'.
393 */
394 void
395 send_igmp(u_int32 src, u_int32 dst, int type, int code, u_int32 group,
396 int datalen)
397 {
398 struct sockaddr_in sdst;
399 int setloop = 0;
400
401 build_igmp(src, dst, type, code, group, datalen);
402
403 if (IN_MULTICAST(ntohl(dst))) {
404 k_set_if(src);
405 if (type != IGMP_DVMRP || dst == allhosts_group) {
406 setloop = 1;
407 k_set_loop(TRUE);
408 }
409 }
410
411 bzero(&sdst, sizeof(sdst));
412 sdst.sin_family = AF_INET;
413 #ifdef HAVE_SA_LEN
414 sdst.sin_len = sizeof(sdst);
415 #endif
416 sdst.sin_addr.s_addr = dst;
417 if (sendto(igmp_socket, send_buf,
418 MIN_IP_HEADER_LEN + IGMP_MINLEN + datalen, 0,
419 (struct sockaddr *)&sdst, sizeof(sdst)) < 0) {
420 if (errno == ENETDOWN)
421 check_vif_state();
422 else
423 log(igmp_log_level(type, code), errno,
424 "sendto to %s on %s",
425 inet_fmt(dst, s1), inet_fmt(src, s2));
426 }
427
428 if (setloop)
429 k_set_loop(FALSE);
430
431 IF_DEBUG(DEBUG_PKT|igmp_debug_kind(type, code))
432 log(LOG_DEBUG, 0, "SENT %s from %-15s to %s",
433 igmp_packet_kind(type, code), src == INADDR_ANY ? "INADDR_ANY" :
434 inet_fmt(src, s1), inet_fmt(dst, s2));
435 }
DragonFly BSD