release/src/router/igmpproxy/src/mcgroup.c

   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 */
  44 static 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 */
  75 int 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 */
  84 int leaveMcGroup( int UdpSock, struct IfDesc *IfDp, uint32_t mcastaddr ) {
  85     return joinleave( 'l', UdpSock, IfDp, mcastaddr );
  86 }