/* ** igmpproxy - IGMP proxy based multicast router ** Copyright (C) 2005 Johnny Egeland ** ** This program is free software; you can redistribute it and/or modify ** it under the terms of the GNU General Public License as published by ** the Free Software Foundation; either version 2 of the License, or ** (at your option) any later version. ** ** This program is distributed in the hope that it will be useful, ** but WITHOUT ANY WARRANTY; without even the implied warranty of ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ** GNU General Public License for more details. ** ** You should have received a copy of the GNU General Public License ** along with this program; if not, write to the Free Software ** Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA ** **---------------------------------------------------------------------------- ** ** This software is derived work from the following software. The original ** source code has been modified from it's original state by the author ** of igmpproxy. ** ** smcroute 0.92 - Copyright (C) 2001 Carsten Schill ** - Licensed under the GNU General Public License, version 2 ** ** mrouted 3.9-beta3 - COPYRIGHT 1989 by The Board of Trustees of ** Leland Stanford Junior University. ** - Original license can be found in the Stanford.txt file. ** */ /** * request.c * * Functions for recieveing and processing IGMP requests. * */ #include "igmpproxy.h" // Prototypes... void sendGroupSpecificMemberQuery(void *argument); typedef struct { uint32_t group; uint32_t vifAddr; short started; } GroupVifDesc; /** * Handles incoming membership reports, and * appends them to the routing table. */ void acceptGroupReport(uint32_t src, uint32_t group, uint8_t type) { struct IfDesc *sourceVif; // Sanitycheck the group adress... if(!IN_MULTICAST( ntohl(group) )) { my_log(LOG_WARNING, 0, "The group address %s is not a valid Multicast group.", inetFmt(group, s1)); return; } // Find the interface on which the report was recieved. sourceVif = getIfByAddress( src ); if(sourceVif == NULL) { my_log(LOG_WARNING, 0, "No interfaces found for source %s", inetFmt(src,s1)); return; } if(sourceVif->InAdr.s_addr == src) { my_log(LOG_NOTICE, 0, "The IGMP message was from myself. Ignoring."); return; } // We have a IF so check that it's an downstream IF. if(sourceVif->state == IF_STATE_DOWNSTREAM) { my_log(LOG_DEBUG, 0, "Should insert group %s (from: %s) to route table. Vif Ix : %d", inetFmt(group,s1), inetFmt(src,s2), sourceVif->index); // The membership report was OK... Insert it into the route table.. insertRoute(group, sourceVif->index); } else { // Log the state of the interface the report was recieved on. my_log(LOG_INFO, 0, "Mebership report was recieved on %s. Ignoring.", sourceVif->state==IF_STATE_UPSTREAM?"the upstream interface":"a disabled interface"); } } /** * Recieves and handles a group leave message. */ void acceptLeaveMessage(uint32_t src, uint32_t group) { struct IfDesc *sourceVif; my_log(LOG_DEBUG, 0, "Got leave message from %s to %s. Starting last member detection.", inetFmt(src, s1), inetFmt(group, s2)); // Sanitycheck the group adress... if(!IN_MULTICAST( ntohl(group) )) { my_log(LOG_WARNING, 0, "The group address %s is not a valid Multicast group.", inetFmt(group, s1)); return; } // Find the interface on which the report was recieved. sourceVif = getIfByAddress( src ); if(sourceVif == NULL) { my_log(LOG_WARNING, 0, "No interfaces found for source %s", inetFmt(src,s1)); return; } // We have a IF so check that it's an downstream IF. if(sourceVif->state == IF_STATE_DOWNSTREAM) { GroupVifDesc *gvDesc; gvDesc = (GroupVifDesc*) malloc(sizeof(GroupVifDesc)); // Tell the route table that we are checking for remaining members... setRouteLastMemberMode(group); // Call the group spesific membership querier... gvDesc->group = group; gvDesc->vifAddr = sourceVif->InAdr.s_addr; gvDesc->started = 0; sendGroupSpecificMemberQuery(gvDesc); } else { // just ignore the leave request... my_log(LOG_DEBUG, 0, "The found if for %s was not downstream. Ignoring leave request.", inetFmt(src, s1)); } } /** * Sends a group specific member report query until the * group times out... */ void sendGroupSpecificMemberQuery(void *argument) { struct Config *conf = getCommonConfig(); // Cast argument to correct type... GroupVifDesc *gvDesc = (GroupVifDesc*) argument; if(gvDesc->started) { // If aging returns false, we don't do any further action... if(!lastMemberGroupAge(gvDesc->group)) { return; } } else { gvDesc->started = 1; } // Send a group specific membership query... sendIgmp(gvDesc->vifAddr, gvDesc->group, IGMP_MEMBERSHIP_QUERY, conf->lastMemberQueryInterval * IGMP_TIMER_SCALE, gvDesc->group, 0); my_log(LOG_DEBUG, 0, "Sent membership query from %s to %s. Delay: %d", inetFmt(gvDesc->vifAddr,s1), inetFmt(gvDesc->group,s2), conf->lastMemberQueryInterval); // Set timeout for next round... timer_setTimer(conf->lastMemberQueryInterval, sendGroupSpecificMemberQuery, gvDesc); } /** * Sends a general membership query on downstream VIFs */ void sendGeneralMembershipQuery() { struct Config *conf = getCommonConfig(); struct IfDesc *Dp; int Ix; // Loop through all downstream vifs... for ( Ix = 0; (Dp = getIfByIx(Ix)); Ix++ ) { if ( Dp->InAdr.s_addr && ! (Dp->Flags & IFF_LOOPBACK) ) { if(Dp->state == IF_STATE_DOWNSTREAM) { // Send the membership query... sendIgmp(Dp->InAdr.s_addr, allhosts_group, IGMP_MEMBERSHIP_QUERY, conf->queryResponseInterval * IGMP_TIMER_SCALE, 0, 0); my_log(LOG_DEBUG, 0, "Sent membership query from %s to %s. Delay: %d", inetFmt(Dp->InAdr.s_addr,s1), inetFmt(allhosts_group,s2), conf->queryResponseInterval); } } } // Install timer for aging active routes. timer_setTimer(conf->queryResponseInterval, ageActiveRoutes, NULL); // Install timer for next general query... if(conf->startupQueryCount>0) { // Use quick timer... timer_setTimer(conf->startupQueryInterval, sendGeneralMembershipQuery, NULL); // Decrease startup counter... conf->startupQueryCount--; } else { // Use slow timer... timer_setTimer(conf->queryInterval, sendGeneralMembershipQuery, NULL); } }