1/* 2** igmpproxy - IGMP proxy based multicast router 3** Copyright (C) 2005 Johnny Egeland <johnny@rlo.org> 4** 5** This program is free software; you can redistribute it and/or modify 6** it under the terms of the GNU General Public License as published by 7** the Free Software Foundation; either version 2 of the License, or 8** (at your option) any later version. 9** 10** This program is distributed in the hope that it will be useful, 11** but WITHOUT ANY WARRANTY; without even the implied warranty of 12** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13** GNU General Public License for more details. 14** 15** You should have received a copy of the GNU General Public License 16** along with this program; if not, write to the Free Software 17** Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18** 19**---------------------------------------------------------------------------- 20** 21** This software is derived work from the following software. The original 22** source code has been modified from it's original state by the author 23** of igmpproxy. 24** 25** smcroute 0.92 - Copyright (C) 2001 Carsten Schill <carsten@cschill.de> 26** - Licensed under the GNU General Public License, version 2 27** 28** mrouted 3.9-beta3 - COPYRIGHT 1989 by The Board of Trustees of 29** Leland Stanford Junior University. 30** - Original license can be found in the Stanford.txt file. 31** 32*/ 33/** 34* mcgroup contains functions for joining and leaving multicast groups. 35* 36*/ 37 38#include "igmpproxy.h" 39 40 41/** 42* Common function for joining or leaving a MCast group. 43*/ 44static int joinleave( int Cmd, int UdpSock, struct IfDesc *IfDp, uint32_t mcastaddr ) { 45 struct ip_mreq CtlReq; 46 const char *CmdSt = Cmd == 'j' ? "join" : "leave"; 47 48 memset(&CtlReq, 0, sizeof(CtlReq)); 49 CtlReq.imr_multiaddr.s_addr = mcastaddr; 50 CtlReq.imr_interface.s_addr = IfDp->InAdr.s_addr; 51 52 { 53 my_log( LOG_NOTICE, 0, "%sMcGroup: %s on %s", CmdSt, 54 inetFmt( mcastaddr, s1 ), IfDp ? IfDp->Name : "<any>" ); 55 } 56 57 if( setsockopt( UdpSock, IPPROTO_IP, 58 Cmd == 'j' ? IP_ADD_MEMBERSHIP : IP_DROP_MEMBERSHIP, 59 (void *)&CtlReq, sizeof( CtlReq ) ) ) 60 { 61 my_log( LOG_WARNING, errno, "MRT_%s_MEMBERSHIP failed", Cmd == 'j' ? "ADD" : "DROP" ); 62 return 1; 63 } 64 65 return 0; 66} 67 68/** 69* Joins the MC group with the address 'McAdr' on the interface 'IfName'. 70* The join is bound to the UDP socket 'UdpSock', so if this socket is 71* closed the membership is dropped. 72* 73* @return 0 if the function succeeds, 1 if parameters are wrong or the join fails 74*/ 75int joinMcGroup( int UdpSock, struct IfDesc *IfDp, uint32_t mcastaddr ) { 76 return joinleave( 'j', UdpSock, IfDp, mcastaddr ); 77} 78 79/** 80* Leaves the MC group with the address 'McAdr' on the interface 'IfName'. 81* 82* @return 0 if the function succeeds, 1 if parameters are wrong or the join fails 83*/ 84int leaveMcGroup( int UdpSock, struct IfDesc *IfDp, uint32_t mcastaddr ) { 85 return joinleave( 'l', UdpSock, IfDp, mcastaddr ); 86} 87