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.
6 * The mrouted program is COPYRIGHT 1989 by The Board of Trustees of
7 * Leland Stanford Junior University.
10 * igmp.c,v 3.8.4.19 1998/01/06 01:57:43 fenner Exp
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 1.3 2003/11/03 19:31:38 eirikn Exp $
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 */
30 * Local function definitions.
32 /* u_char promoted to u_int */
33 static int igmp_log_level(u_int type, u_int code);
36 * Open and initialize the igmp socket, and fill in the non-changing
37 * IP header fields in the output packet buffer.
44 recv_buf = malloc(RECV_BUF_SIZE);
45 send_buf = malloc(RECV_BUF_SIZE);
47 if ((igmp_socket = socket(AF_INET, SOCK_RAW, IPPROTO_IGMP)) < 0)
48 log(LOG_ERR, errno, "IGMP socket");
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 */
55 ip = (struct ip *)send_buf;
56 bzero(ip, sizeof(struct ip));
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)
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;
69 allhosts_group = htonl(INADDR_ALLHOSTS_GROUP);
70 dvmrp_group = htonl(INADDR_DVMRP_GROUP);
71 allrtrs_group = htonl(INADDR_ALLRTRS_GROUP);
75 #define PIM_REGISTER 1
76 #define PIM_REGISTER_STOP 2
77 #define PIM_JOIN_PRUNE 3
78 #define PIM_RP_REACHABLE 4
81 #define PIM_GRAFT_ACK 7
84 igmp_packet_kind(type, code)
87 static char unknown[20];
90 case IGMP_MEMBERSHIP_QUERY: return "membership query ";
91 case IGMP_V1_MEMBERSHIP_REPORT: return "V1 member report ";
92 case IGMP_V2_MEMBERSHIP_REPORT: return "V2 member report ";
93 case IGMP_V2_LEAVE_GROUP: return "leave message ";
96 case DVMRP_PROBE: return "neighbor probe ";
97 case DVMRP_REPORT: return "route report ";
98 case DVMRP_ASK_NEIGHBORS: return "neighbor request ";
99 case DVMRP_NEIGHBORS: return "neighbor list ";
100 case DVMRP_ASK_NEIGHBORS2: return "neighbor request 2";
101 case DVMRP_NEIGHBORS2: return "neighbor list 2 ";
102 case DVMRP_PRUNE: return "prune message ";
103 case DVMRP_GRAFT: return "graft message ";
104 case DVMRP_GRAFT_ACK: return "graft message ack ";
105 case DVMRP_INFO_REQUEST: return "info request ";
106 case DVMRP_INFO_REPLY: return "info reply ";
108 sprintf(unknown, "unknown DVMRP %3d ", code);
113 case PIM_QUERY: return "PIM Router-Query ";
114 case PIM_REGISTER: return "PIM Register ";
115 case PIM_REGISTER_STOP: return "PIM Register-Stop ";
116 case PIM_JOIN_PRUNE: return "PIM Join/Prune ";
117 case PIM_RP_REACHABLE: return "PIM RP-Reachable ";
118 case PIM_ASSERT: return "PIM Assert ";
119 case PIM_GRAFT: return "PIM Graft ";
120 case PIM_GRAFT_ACK: return "PIM Graft-Ack ";
122 sprintf(unknown, "unknown PIM msg%3d", code);
125 case IGMP_MTRACE: return "IGMP trace query ";
126 case IGMP_MTRACE_RESP: return "IGMP trace reply ";
128 sprintf(unknown, "unk: 0x%02x/0x%02x ", type, code);
134 igmp_debug_kind(type, code)
138 case IGMP_MEMBERSHIP_QUERY: return DEBUG_IGMP;
139 case IGMP_V1_MEMBERSHIP_REPORT: return DEBUG_IGMP;
140 case IGMP_V2_MEMBERSHIP_REPORT: return DEBUG_IGMP;
141 case IGMP_V2_LEAVE_GROUP: return DEBUG_IGMP;
144 case DVMRP_PROBE: return DEBUG_PEER;
145 case DVMRP_REPORT: return DEBUG_ROUTE;
146 case DVMRP_ASK_NEIGHBORS: return 0;
147 case DVMRP_NEIGHBORS: return 0;
148 case DVMRP_ASK_NEIGHBORS2: return 0;
149 case DVMRP_NEIGHBORS2: return 0;
150 case DVMRP_PRUNE: return DEBUG_PRUNE;
151 case DVMRP_GRAFT: return DEBUG_PRUNE;
152 case DVMRP_GRAFT_ACK: return DEBUG_PRUNE;
153 case DVMRP_INFO_REQUEST: return 0;
154 case DVMRP_INFO_REPLY: return 0;
159 case PIM_QUERY: return 0;
160 case PIM_REGISTER: return 0;
161 case PIM_REGISTER_STOP: return 0;
162 case PIM_JOIN_PRUNE: return 0;
163 case PIM_RP_REACHABLE: return 0;
164 case PIM_ASSERT: return 0;
165 case PIM_GRAFT: return 0;
166 case PIM_GRAFT_ACK: return 0;
169 case IGMP_MTRACE: return DEBUG_TRACE;
170 case IGMP_MTRACE_RESP: return DEBUG_TRACE;
171 default: return DEBUG_IGMP;
176 * Process a newly received IGMP packet that is sitting in the input
183 register u_int32 src, dst, group;
186 int ipdatalen, iphdrlen, igmpdatalen;
188 if (recvlen < sizeof(struct ip)) {
190 "received packet too short (%u bytes) for IP header", recvlen);
194 ip = (struct ip *)recv_buf;
195 src = ip->ip_src.s_addr;
196 dst = ip->ip_dst.s_addr;
199 * this is most likely a message from the kernel indicating that
200 * a new src grp pair message has arrived and so, it would be
201 * necessary to install a route into the kernel for this.
204 if (src == 0 || dst == 0)
205 log(LOG_WARNING, 0, "kernel request not accurate");
207 add_table_entry(src, dst);
211 iphdrlen = ip->ip_hl << 2;
212 #ifdef RAW_INPUT_IS_RAW
213 ipdatalen = ntohs(ip->ip_len) - iphdrlen;
215 ipdatalen = ip->ip_len;
217 if (iphdrlen + ipdatalen != recvlen) {
219 "received packet from %s shorter (%u bytes) than hdr+data length (%u+%u)",
220 inet_fmt(src, s1), recvlen, iphdrlen, ipdatalen);
224 igmp = (struct igmp *)(recv_buf + iphdrlen);
225 group = igmp->igmp_group.s_addr;
226 igmpdatalen = ipdatalen - IGMP_MINLEN;
227 if (igmpdatalen < 0) {
229 "received IP data field too short (%u bytes) for IGMP, from %s",
230 ipdatalen, inet_fmt(src, s1));
234 IF_DEBUG(DEBUG_PKT|igmp_debug_kind(igmp->igmp_type, igmp->igmp_code))
235 log(LOG_DEBUG, 0, "RECV %s from %-15s to %s",
236 igmp_packet_kind(igmp->igmp_type, igmp->igmp_code),
237 inet_fmt(src, s1), inet_fmt(dst, s2));
239 switch (igmp->igmp_type) {
241 case IGMP_MEMBERSHIP_QUERY:
242 accept_membership_query(src, dst, group, igmp->igmp_code);
245 case IGMP_V1_MEMBERSHIP_REPORT:
246 case IGMP_V2_MEMBERSHIP_REPORT:
247 accept_group_report(src, dst, group, igmp->igmp_type);
250 case IGMP_V2_LEAVE_GROUP:
251 accept_leave_message(src, dst, group);
255 group = ntohl(group);
257 switch (igmp->igmp_code) {
259 accept_probe(src, dst,
260 (char *)(igmp+1), igmpdatalen, group);
264 accept_report(src, dst,
265 (char *)(igmp+1), igmpdatalen, group);
268 case DVMRP_ASK_NEIGHBORS:
269 accept_neighbor_request(src, dst);
272 case DVMRP_ASK_NEIGHBORS2:
273 accept_neighbor_request2(src, dst);
276 case DVMRP_NEIGHBORS:
277 accept_neighbors(src, dst, (u_char *)(igmp+1), igmpdatalen,
281 case DVMRP_NEIGHBORS2:
282 accept_neighbors2(src, dst, (u_char *)(igmp+1), igmpdatalen,
287 accept_prune(src, dst, (char *)(igmp+1), igmpdatalen);
291 accept_graft(src, dst, (char *)(igmp+1), igmpdatalen);
294 case DVMRP_GRAFT_ACK:
295 accept_g_ack(src, dst, (char *)(igmp+1), igmpdatalen);
298 case DVMRP_INFO_REQUEST:
299 accept_info_request(src, dst, (char *)(igmp+1),
303 case DVMRP_INFO_REPLY:
304 accept_info_reply(src, dst, (char *)(igmp+1), igmpdatalen);
309 "ignoring unknown DVMRP message code %u from %s to %s",
310 igmp->igmp_code, inet_fmt(src, s1),
318 case IGMP_MTRACE_RESP:
322 accept_mtrace(src, dst, group, (char *)(igmp+1),
323 igmp->igmp_code, igmpdatalen);
328 "ignoring unknown IGMP message type %x from %s to %s",
329 igmp->igmp_type, inet_fmt(src, s1),
336 * Some IGMP messages are more important than others. This routine
337 * determines the logging level at which to log a send error (often
338 * "No route to host"). This is important when there is asymmetric
339 * reachability and someone is trying to, i.e., mrinfo me periodically.
342 igmp_log_level(type, code)
346 case IGMP_MTRACE_RESP:
351 case DVMRP_NEIGHBORS:
352 case DVMRP_NEIGHBORS2:
360 * Construct an IGMP message in the output packet buffer. The caller may
361 * have already placed data in that buffer, of length 'datalen'.
364 build_igmp(src, dst, type, code, group, datalen)
374 ip = (struct ip *)send_buf;
375 ip->ip_src.s_addr = src;
376 ip->ip_dst.s_addr = dst;
377 ip->ip_len = MIN_IP_HEADER_LEN + IGMP_MINLEN + datalen;
378 #ifdef RAW_OUTPUT_IS_RAW
379 ip->ip_len = htons(ip->ip_len);
381 if (IN_MULTICAST(ntohl(dst))) {
387 igmp = (struct igmp *)(send_buf + MIN_IP_HEADER_LEN);
388 igmp->igmp_type = type;
389 igmp->igmp_code = code;
390 igmp->igmp_group.s_addr = group;
391 igmp->igmp_cksum = 0;
392 igmp->igmp_cksum = inet_cksum((u_short *)igmp,
393 IGMP_MINLEN + datalen);
397 * Call build_igmp() to build an IGMP message in the output packet buffer.
398 * Then send the message from the interface with IP address 'src' to
402 send_igmp(src, dst, type, code, group, datalen)
408 struct sockaddr_in sdst;
411 build_igmp(src, dst, type, code, group, datalen);
413 if (IN_MULTICAST(ntohl(dst))) {
415 if (type != IGMP_DVMRP || dst == allhosts_group) {
421 bzero(&sdst, sizeof(sdst));
422 sdst.sin_family = AF_INET;
424 sdst.sin_len = sizeof(sdst);
426 sdst.sin_addr.s_addr = dst;
427 if (sendto(igmp_socket, send_buf,
428 MIN_IP_HEADER_LEN + IGMP_MINLEN + datalen, 0,
429 (struct sockaddr *)&sdst, sizeof(sdst)) < 0) {
430 if (errno == ENETDOWN)
433 log(igmp_log_level(type, code), errno,
434 "sendto to %s on %s",
435 inet_fmt(dst, s1), inet_fmt(src, s2));
441 IF_DEBUG(DEBUG_PKT|igmp_debug_kind(type, code))
442 log(LOG_DEBUG, 0, "SENT %s from %-15s to %s",
443 igmp_packet_kind(type, code), src == INADDR_ANY ? "INADDR_ANY" :
444 inet_fmt(src, s1), inet_fmt(dst, s2));