358 lines
9.9 KiB
C
358 lines
9.9 KiB
C
/*
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* The mrouted program is covered by the license in the accompanying file
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* named "LICENSE". Use of the mrouted program represents acceptance of
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* the terms and conditions listed in that file.
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*
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* The mrouted program is COPYRIGHT 1989 by The Board of Trustees of
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* Leland Stanford Junior University.
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*
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*
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* $Id: igmp.c,v 1.9 1996/01/06 21:09:44 peter Exp $
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*/
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#include "defs.h"
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/*
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* Exported variables.
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*/
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char *recv_buf; /* input packet buffer */
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char *send_buf; /* output packet buffer */
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int igmp_socket; /* socket for all network I/O */
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u_int32 allhosts_group; /* All hosts addr in net order */
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u_int32 allrtrs_group; /* All-Routers " in net order */
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u_int32 dvmrp_group; /* DVMRP grp addr in net order */
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u_int32 dvmrp_genid; /* IGMP generation id */
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/*
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* Local function definitions.
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*/
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/* u_char promoted to u_int */
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static char * packet_kind __P((u_int type, u_int code));
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static int igmp_log_level __P((u_int type, u_int code));
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/*
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* Open and initialize the igmp socket, and fill in the non-changing
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* IP header fields in the output packet buffer.
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*/
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void
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init_igmp()
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{
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struct ip *ip;
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recv_buf = malloc(RECV_BUF_SIZE);
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send_buf = malloc(RECV_BUF_SIZE);
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if ((igmp_socket = socket(AF_INET, SOCK_RAW, IPPROTO_IGMP)) < 0)
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log(LOG_ERR, errno, "IGMP socket");
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k_hdr_include(TRUE); /* include IP header when sending */
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k_set_rcvbuf(48*1024); /* lots of input buffering */
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k_set_ttl(1); /* restrict multicasts to one hop */
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k_set_loop(FALSE); /* disable multicast loopback */
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ip = (struct ip *)send_buf;
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ip->ip_hl = sizeof(struct ip) >> 2;
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ip->ip_v = IPVERSION;
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ip->ip_tos = 0;
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ip->ip_off = 0;
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ip->ip_p = IPPROTO_IGMP;
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ip->ip_ttl = MAXTTL; /* applies to unicasts only */
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allhosts_group = htonl(INADDR_ALLHOSTS_GROUP);
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dvmrp_group = htonl(INADDR_DVMRP_GROUP);
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allrtrs_group = htonl(INADDR_ALLRTRS_GROUP);
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}
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#define PIM_QUERY 0
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#define PIM_REGISTER 1
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#define PIM_REGISTER_STOP 2
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#define PIM_JOIN_PRUNE 3
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#define PIM_RP_REACHABLE 4
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#define PIM_ASSERT 5
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#define PIM_GRAFT 6
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#define PIM_GRAFT_ACK 7
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static char *
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packet_kind(type, code)
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u_int type, code;
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{
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switch (type) {
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case IGMP_HOST_MEMBERSHIP_QUERY: return "membership query ";
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case IGMP_HOST_MEMBERSHIP_REPORT: return "membership report ";
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case IGMP_HOST_NEW_MEMBERSHIP_REPORT: return "new member report ";
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case IGMP_HOST_LEAVE_MESSAGE: return "leave message ";
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case IGMP_DVMRP:
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switch (code) {
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case DVMRP_PROBE: return "neighbor probe ";
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case DVMRP_REPORT: return "route report ";
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case DVMRP_ASK_NEIGHBORS: return "neighbor request ";
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case DVMRP_NEIGHBORS: return "neighbor list ";
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case DVMRP_ASK_NEIGHBORS2: return "neighbor request 2";
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case DVMRP_NEIGHBORS2: return "neighbor list 2 ";
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case DVMRP_PRUNE: return "prune message ";
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case DVMRP_GRAFT: return "graft message ";
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case DVMRP_GRAFT_ACK: return "graft message ack ";
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case DVMRP_INFO_REQUEST: return "info request ";
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case DVMRP_INFO_REPLY: return "info reply ";
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default: return "unknown DVMRP msg ";
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}
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case IGMP_PIM:
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switch (code) {
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case PIM_QUERY: return "PIM Router-Query ";
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case PIM_REGISTER: return "PIM Register ";
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case PIM_REGISTER_STOP: return "PIM Register-Stop ";
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case PIM_JOIN_PRUNE: return "PIM Join/Prune ";
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case PIM_RP_REACHABLE: return "PIM RP-Reachable ";
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case PIM_ASSERT: return "PIM Assert ";
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case PIM_GRAFT: return "PIM Graft ";
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case PIM_GRAFT_ACK: return "PIM Graft-Ack ";
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default: return "unknown PIM msg ";
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}
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case IGMP_MTRACE: return "IGMP trace query ";
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case IGMP_MTRACE_RESP: return "IGMP trace reply ";
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default: return "unknown IGMP msg ";
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}
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}
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/*
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* Process a newly received IGMP packet that is sitting in the input
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* packet buffer.
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*/
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void
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accept_igmp(recvlen)
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int recvlen;
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{
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register u_int32 src, dst, group;
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struct ip *ip;
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struct igmp *igmp;
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int ipdatalen, iphdrlen, igmpdatalen;
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if (recvlen < sizeof(struct ip)) {
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log(LOG_WARNING, 0,
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"received packet too short (%u bytes) for IP header", recvlen);
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return;
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}
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ip = (struct ip *)recv_buf;
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src = ip->ip_src.s_addr;
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dst = ip->ip_dst.s_addr;
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/*
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* this is most likely a message from the kernel indicating that
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* a new src grp pair message has arrived and so, it would be
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* necessary to install a route into the kernel for this.
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*/
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if (ip->ip_p == 0) {
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if (src == 0 || dst == 0)
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log(LOG_WARNING, 0, "kernel request not accurate");
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else
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add_table_entry(src, dst);
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return;
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}
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iphdrlen = ip->ip_hl << 2;
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ipdatalen = ip->ip_len;
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if (iphdrlen + ipdatalen != recvlen) {
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log(LOG_WARNING, 0,
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"received packet from %s shorter (%u bytes) than hdr+data length (%u+%u)",
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inet_fmt(src, s1), recvlen, iphdrlen, ipdatalen);
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return;
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}
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igmp = (struct igmp *)(recv_buf + iphdrlen);
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group = igmp->igmp_group.s_addr;
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igmpdatalen = ipdatalen - IGMP_MINLEN;
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if (igmpdatalen < 0) {
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log(LOG_WARNING, 0,
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"received IP data field too short (%u bytes) for IGMP, from %s",
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ipdatalen, inet_fmt(src, s1));
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return;
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}
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log(LOG_DEBUG, 0, "RECV %s from %-15s to %s",
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packet_kind(igmp->igmp_type, igmp->igmp_code),
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inet_fmt(src, s1), inet_fmt(dst, s2));
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switch (igmp->igmp_type) {
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case IGMP_HOST_MEMBERSHIP_QUERY:
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accept_membership_query(src, dst, group, igmp->igmp_code);
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return;
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case IGMP_HOST_MEMBERSHIP_REPORT:
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case IGMP_HOST_NEW_MEMBERSHIP_REPORT:
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accept_group_report(src, dst, group, igmp->igmp_type);
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return;
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case IGMP_HOST_LEAVE_MESSAGE:
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accept_leave_message(src, dst, group);
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return;
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case IGMP_DVMRP:
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group = ntohl(group);
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switch (igmp->igmp_code) {
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case DVMRP_PROBE:
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accept_probe(src, dst,
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(char *)(igmp+1), igmpdatalen, group);
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return;
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case DVMRP_REPORT:
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accept_report(src, dst,
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(char *)(igmp+1), igmpdatalen, group);
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return;
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case DVMRP_ASK_NEIGHBORS:
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accept_neighbor_request(src, dst);
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return;
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case DVMRP_ASK_NEIGHBORS2:
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accept_neighbor_request2(src, dst);
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return;
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case DVMRP_NEIGHBORS:
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accept_neighbors(src, dst, (u_char *)(igmp+1), igmpdatalen,
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group);
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return;
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case DVMRP_NEIGHBORS2:
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accept_neighbors2(src, dst, (u_char *)(igmp+1), igmpdatalen,
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group);
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return;
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case DVMRP_PRUNE:
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accept_prune(src, dst, (char *)(igmp+1), igmpdatalen);
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return;
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case DVMRP_GRAFT:
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accept_graft(src, dst, (char *)(igmp+1), igmpdatalen);
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return;
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case DVMRP_GRAFT_ACK:
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accept_g_ack(src, dst, (char *)(igmp+1), igmpdatalen);
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return;
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case DVMRP_INFO_REQUEST:
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accept_info_request(src, dst, (char *)(igmp+1),
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igmpdatalen);
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return;
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case DVMRP_INFO_REPLY:
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accept_info_reply(src, dst, (char *)(igmp+1), igmpdatalen);
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return;
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default:
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log(LOG_INFO, 0,
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"ignoring unknown DVMRP message code %u from %s to %s",
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igmp->igmp_code, inet_fmt(src, s1),
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inet_fmt(dst, s2));
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return;
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}
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case IGMP_PIM:
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return;
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case IGMP_MTRACE_RESP:
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return;
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case IGMP_MTRACE:
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accept_mtrace(src, dst, group, (char *)(igmp+1),
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igmp->igmp_code, igmpdatalen);
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return;
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default:
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log(LOG_INFO, 0,
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"ignoring unknown IGMP message type %x from %s to %s",
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igmp->igmp_type, inet_fmt(src, s1),
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inet_fmt(dst, s2));
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return;
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}
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}
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/*
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* Some IGMP messages are more important than others. This routine
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* determines the logging level at which to log a send error (often
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* "No route to host"). This is important when there is asymmetric
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* reachability and someone is trying to, i.e., mrinfo me periodically.
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*/
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static int
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igmp_log_level(type, code)
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u_int type, code;
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{
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switch (type) {
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case IGMP_MTRACE_RESP:
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return LOG_INFO;
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case IGMP_DVMRP:
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switch (code) {
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case DVMRP_NEIGHBORS:
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case DVMRP_NEIGHBORS2:
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return LOG_INFO;
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}
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}
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return LOG_WARNING;
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}
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/*
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* Construct an IGMP message in the output packet buffer. The caller may
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* have already placed data in that buffer, of length 'datalen'. Then send
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* the message from the interface with IP address 'src' to destination 'dst'.
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*/
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void
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send_igmp(src, dst, type, code, group, datalen)
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u_int32 src, dst;
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int type, code;
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u_int32 group;
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int datalen;
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{
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struct sockaddr_in sdst;
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struct ip *ip;
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struct igmp *igmp;
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int setloop;
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ip = (struct ip *)send_buf;
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ip->ip_src.s_addr = src;
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ip->ip_dst.s_addr = dst;
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ip->ip_len = MIN_IP_HEADER_LEN + IGMP_MINLEN + datalen;
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igmp = (struct igmp *)(send_buf + MIN_IP_HEADER_LEN);
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igmp->igmp_type = type;
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igmp->igmp_code = code;
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igmp->igmp_group.s_addr = group;
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igmp->igmp_cksum = 0;
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igmp->igmp_cksum = inet_cksum((u_short *)igmp,
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IGMP_MINLEN + datalen);
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if (IN_MULTICAST(ntohl(dst))) {
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k_set_if(src);
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if (type != IGMP_DVMRP || dst == allhosts_group) {
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setloop = 1;
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k_set_loop(TRUE);
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}
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}
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bzero(&sdst, sizeof(sdst));
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sdst.sin_family = AF_INET;
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#if (defined(BSD) && (BSD >= 199103))
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sdst.sin_len = sizeof(sdst);
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#endif
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sdst.sin_addr.s_addr = dst;
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if (sendto(igmp_socket, send_buf, ip->ip_len, 0,
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(struct sockaddr *)&sdst, sizeof(sdst)) < 0) {
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if (errno == ENETDOWN)
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check_vif_state();
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else
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log(igmp_log_level(type, code), errno,
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"sendto to %s on %s",
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inet_fmt(dst, s1), inet_fmt(src, s2));
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}
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if (setloop)
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k_set_loop(FALSE);
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log(LOG_DEBUG, 0, "SENT %s from %-15s to %s",
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packet_kind(type, code), inet_fmt(src, s1), inet_fmt(dst, s2));
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}
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