igmp.c revision 1.4
1 /* $NetBSD: igmp.c,v 1.4 1995/10/09 03:51:40 thorpej Exp $ */ 2 3 /* 4 * The mrouted program is covered by the license in the accompanying file 5 * named "LICENSE". Use of the mrouted program represents acceptance of 6 * the terms and conditions listed in that file. 7 * 8 * The mrouted program is COPYRIGHT 1989 by The Board of Trustees of 9 * Leland Stanford Junior University. 10 */ 11 12 13 #include "defs.h" 14 15 16 /* 17 * Exported variables. 18 */ 19 char *recv_buf; /* input packet buffer */ 20 char *send_buf; /* output packet buffer */ 21 int igmp_socket; /* socket for all network I/O */ 22 u_int32_t allhosts_group; /* All hosts addr in net order */ 23 u_int32_t allrtrs_group; /* All-Routers " in net order */ 24 u_int32_t dvmrp_group; /* DVMRP grp addr in net order */ 25 u_int32_t dvmrp_genid; /* IGMP generation id */ 26 27 /* 28 * Open and initialize the igmp socket, and fill in the non-changing 29 * IP header fields in the output packet buffer. 30 */ 31 void init_igmp() 32 { 33 struct ip *ip; 34 35 recv_buf = malloc(RECV_BUF_SIZE); 36 send_buf = malloc(RECV_BUF_SIZE); 37 38 if ((igmp_socket = socket(AF_INET, SOCK_RAW, IPPROTO_IGMP)) < 0) 39 log(LOG_ERR, errno, "IGMP socket"); 40 41 k_hdr_include(TRUE); /* include IP header when sending */ 42 k_set_rcvbuf(48*1024); /* lots of input buffering */ 43 k_set_ttl(1); /* restrict multicasts to one hop */ 44 k_set_loop(FALSE); /* disable multicast loopback */ 45 46 ip = (struct ip *)send_buf; 47 ip->ip_hl = sizeof(struct ip) >> 2; 48 ip->ip_v = IPVERSION; 49 ip->ip_tos = 0; 50 ip->ip_off = 0; 51 ip->ip_p = IPPROTO_IGMP; 52 ip->ip_ttl = MAXTTL; /* applies to unicasts only */ 53 54 allhosts_group = htonl(INADDR_ALLHOSTS_GROUP); 55 dvmrp_group = htonl(INADDR_DVMRP_GROUP); 56 allrtrs_group = htonl(INADDR_ALLRTRS_GROUP); 57 } 58 59 #define PIM_QUERY 0 60 #define PIM_REGISTER 1 61 #define PIM_REGISTER_STOP 2 62 #define PIM_JOIN_PRUNE 3 63 #define PIM_RP_REACHABLE 4 64 #define PIM_ASSERT 5 65 #define PIM_GRAFT 6 66 #define PIM_GRAFT_ACK 7 67 68 static char *packet_kind(type, code) 69 u_char type, code; 70 { 71 switch (type) { 72 case IGMP_HOST_MEMBERSHIP_QUERY: return "membership query "; 73 case IGMP_v1_HOST_MEMBERSHIP_REPORT: return "membership report "; 74 case IGMP_v2_HOST_MEMBERSHIP_REPORT: return "new member report "; 75 case IGMP_HOST_LEAVE_MESSAGE: return "leave message "; 76 case IGMP_DVMRP: 77 switch (code) { 78 case DVMRP_PROBE: return "neighbor probe "; 79 case DVMRP_REPORT: return "route report "; 80 case DVMRP_ASK_NEIGHBORS: return "neighbor request "; 81 case DVMRP_NEIGHBORS: return "neighbor list "; 82 case DVMRP_ASK_NEIGHBORS2: return "neighbor request 2"; 83 case DVMRP_NEIGHBORS2: return "neighbor list 2 "; 84 case DVMRP_PRUNE: return "prune message "; 85 case DVMRP_GRAFT: return "graft message "; 86 case DVMRP_GRAFT_ACK: return "graft message ack "; 87 default: return "unknown DVMRP msg "; 88 } 89 case IGMP_PIM: 90 switch (code) { 91 case PIM_QUERY: return "PIM Router-Query "; 92 case PIM_REGISTER: return "PIM Register "; 93 case PIM_REGISTER_STOP: return "PIM Register-Stop "; 94 case PIM_JOIN_PRUNE: return "PIM Join/Prune "; 95 case PIM_RP_REACHABLE: return "PIM RP-Reachable "; 96 case PIM_ASSERT: return "PIM Assert "; 97 case PIM_GRAFT: return "PIM Graft "; 98 case PIM_GRAFT_ACK: return "PIM Graft-Ack "; 99 default: return "unknown PIM msg "; 100 } 101 case IGMP_MTRACE_QUERY: return "IGMP trace query "; 102 case IGMP_MTRACE_REPLY: return "IGMP trace reply "; 103 default: return "unknown IGMP msg "; 104 } 105 } 106 107 /* 108 * Process a newly received IGMP packet that is sitting in the input 109 * packet buffer. 110 */ 111 void accept_igmp(recvlen) 112 int recvlen; 113 { 114 register u_int32_t src, dst, group; 115 struct ip *ip; 116 struct igmp *igmp; 117 int ipdatalen, iphdrlen, igmpdatalen; 118 119 if (recvlen < sizeof(struct ip)) { 120 log(LOG_WARNING, 0, 121 "received packet too short (%u bytes) for IP header", recvlen); 122 return; 123 } 124 125 ip = (struct ip *)recv_buf; 126 src = ip->ip_src.s_addr; 127 dst = ip->ip_dst.s_addr; 128 129 /* 130 * this is most likely a message from the kernel indicating that 131 * a new src grp pair message has arrived and so, it would be 132 * necessary to install a route into the kernel for this. 133 */ 134 if (ip->ip_p == 0) { 135 if (src == 0 || dst == 0) 136 log(LOG_WARNING, 0, "kernel request not accurate"); 137 else 138 add_table_entry(src, dst); 139 return; 140 } 141 142 iphdrlen = ip->ip_hl << 2; 143 ipdatalen = ip->ip_len; 144 if (iphdrlen + ipdatalen != recvlen) { 145 log(LOG_WARNING, 0, 146 "received packet shorter (%u bytes) than hdr+data length (%u+%u)", 147 recvlen, iphdrlen, ipdatalen); 148 return; 149 } 150 151 igmp = (struct igmp *)(recv_buf + iphdrlen); 152 group = igmp->igmp_group.s_addr; 153 igmpdatalen = ipdatalen - IGMP_MINLEN; 154 if (igmpdatalen < 0) { 155 log(LOG_WARNING, 0, 156 "received IP data field too short (%u bytes) for IGMP, from %s", 157 ipdatalen, inet_fmt(src, s1)); 158 return; 159 } 160 161 log(LOG_DEBUG, 0, "RECV %s from %-15s to %s", 162 packet_kind(igmp->igmp_type, igmp->igmp_code), 163 inet_fmt(src, s1), inet_fmt(dst, s2)); 164 165 switch (igmp->igmp_type) { 166 167 case IGMP_HOST_MEMBERSHIP_QUERY: 168 accept_membership_query(src, dst, group, igmp->igmp_code); 169 return; 170 171 case IGMP_v1_HOST_MEMBERSHIP_REPORT: 172 case IGMP_v2_HOST_MEMBERSHIP_REPORT: 173 accept_group_report(src, dst, group, igmp->igmp_type); 174 return; 175 176 case IGMP_HOST_LEAVE_MESSAGE: 177 accept_leave_message(src, dst, group); 178 return; 179 180 case IGMP_DVMRP: 181 group = ntohl(group); 182 183 switch (igmp->igmp_code) { 184 case DVMRP_PROBE: 185 accept_probe(src, dst, 186 (char *)(igmp+1), igmpdatalen, group); 187 return; 188 189 case DVMRP_REPORT: 190 accept_report(src, dst, 191 (char *)(igmp+1), igmpdatalen, group); 192 return; 193 194 case DVMRP_ASK_NEIGHBORS: 195 accept_neighbor_request(src, dst); 196 return; 197 198 case DVMRP_ASK_NEIGHBORS2: 199 accept_neighbor_request2(src, dst); 200 return; 201 202 case DVMRP_NEIGHBORS: 203 accept_neighbors(src, dst, (char *)(igmp+1), igmpdatalen, 204 group); 205 return; 206 207 case DVMRP_NEIGHBORS2: 208 accept_neighbors2(src, dst, (char *)(igmp+1), igmpdatalen, 209 group); 210 return; 211 212 case DVMRP_PRUNE: 213 accept_prune(src, dst, (char *)(igmp+1), igmpdatalen); 214 return; 215 216 case DVMRP_GRAFT: 217 accept_graft(src, dst, (char *)(igmp+1), igmpdatalen); 218 return; 219 220 case DVMRP_GRAFT_ACK: 221 accept_g_ack(src, dst, (char *)(igmp+1), igmpdatalen); 222 return; 223 224 default: 225 log(LOG_INFO, 0, 226 "ignoring unknown DVMRP message code %u from %s to %s", 227 igmp->igmp_code, inet_fmt(src, s1), 228 inet_fmt(dst, s2)); 229 return; 230 } 231 232 case IGMP_PIM: 233 return; 234 235 case IGMP_MTRACE_REPLY: 236 return; 237 238 case IGMP_MTRACE_QUERY: 239 accept_mtrace(src, dst, group, (char *)(igmp+1), 240 igmp->igmp_code, igmpdatalen); 241 return; 242 243 default: 244 log(LOG_INFO, 0, 245 "ignoring unknown IGMP message type %x from %s to %s", 246 igmp->igmp_type, inet_fmt(src, s1), 247 inet_fmt(dst, s2)); 248 return; 249 } 250 } 251 252 253 /* 254 * Construct an IGMP message in the output packet buffer. The caller may 255 * have already placed data in that buffer, of length 'datalen'. Then send 256 * the message from the interface with IP address 'src' to destination 'dst'. 257 */ 258 void 259 send_igmp(src, dst, type, code, group, datalen) 260 u_int32_t src, dst; 261 int type, code; 262 u_int32_t group; 263 int datalen; 264 { 265 static struct sockaddr_in sdst; 266 struct ip *ip; 267 struct igmp *igmp; 268 269 ip = (struct ip *)send_buf; 270 ip->ip_src.s_addr = src; 271 ip->ip_dst.s_addr = dst; 272 ip->ip_len = MIN_IP_HEADER_LEN + IGMP_MINLEN + datalen; 273 274 igmp = (struct igmp *)(send_buf + MIN_IP_HEADER_LEN); 275 igmp->igmp_type = type; 276 igmp->igmp_code = code; 277 igmp->igmp_group.s_addr = group; 278 igmp->igmp_cksum = 0; 279 igmp->igmp_cksum = inet_cksum((u_short *)igmp, 280 IGMP_MINLEN + datalen); 281 282 if (IN_MULTICAST(ntohl(dst))) k_set_if(src); 283 if (dst == allhosts_group) k_set_loop(TRUE); 284 285 bzero(&sdst, sizeof(sdst)); 286 sdst.sin_family = AF_INET; 287 #if (defined(BSD) && (BSD >= 199103)) 288 sdst.sin_len = sizeof(sdst); 289 #endif 290 sdst.sin_addr.s_addr = dst; 291 if (sendto(igmp_socket, send_buf, ip->ip_len, 0, 292 (struct sockaddr *)&sdst, sizeof(sdst)) < 0) { 293 if (errno == ENETDOWN) 294 check_vif_state(); 295 else 296 log(LOG_WARNING, errno, 297 "sendto to %s on %s", 298 inet_fmt(dst, s1), inet_fmt(src, s2)); 299 } 300 301 if (dst == allhosts_group) k_set_loop(FALSE); 302 303 log(LOG_DEBUG, 0, "SENT %s from %-15s to %s", 304 packet_kind(type, code), inet_fmt(src, s1), inet_fmt(dst, s2)); 305 } 306
Indexes created Thu Sep 25 16:09:42 GMT 2025