release/src/router/igmpproxy/src/request.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 *   request.c
  35 *
  36 *   Functions for recieveing and processing IGMP requests.
  37 *
  38 */
  39
  40 #include "igmpproxy.h"
  41
  42 // Prototypes...
  43 void sendGroupSpecificMemberQuery(void *argument);
  44
  45 typedef struct {
  46     uint32_t      group;
  47     uint32_t      vifAddr;
  48     short       started;
  49 } GroupVifDesc;
  50
  51
  52 /**
  53 *   Handles incoming membership reports, and
  54 *   appends them to the routing table.
  55 */
  56 void acceptGroupReport(uint32_t src, uint32_t group, uint8_t type) {
  57     struct IfDesc  *sourceVif;
  58
  59     // Sanitycheck the group adress...
  60     if(!IN_MULTICAST( ntohl(group) )) {
  61         my_log(LOG_WARNING, 0, "The group address %s is not a valid Multicast group.",
  62             inetFmt(group, s1));
  63         return;
  64     }
  65
  66     // Find the interface on which the report was recieved.
  67     sourceVif = getIfByAddress( src );
  68     if(sourceVif == NULL) {
  69         my_log(LOG_WARNING, 0, "No interfaces found for source %s",
  70             inetFmt(src,s1));
  71         return;
  72     }
  73
  74     if(sourceVif->InAdr.s_addr == src) {
  75         my_log(LOG_NOTICE, 0, "The IGMP message was from myself. Ignoring.");
  76         return;
  77     }
  78
  79     // We have a IF so check that it's an downstream IF.
  80     if(sourceVif->state == IF_STATE_DOWNSTREAM) {
  81
  82         my_log(LOG_DEBUG, 0, "Should insert group %s (from: %s) to route table. Vif Ix : %d",
  83             inetFmt(group,s1), inetFmt(src,s2), sourceVif->index);
  84
  85         // If we don't have a whitelist we insertRoute and done
  86         if(sourceVif->allowedgroups == NULL)
  87         {
  88             insertRoute(group, sourceVif->index);
  89             return;
  90         }
  91         // Check if this Request is legit on this interface
  92         struct SubnetList *sn;
  93         for(sn = sourceVif->allowedgroups; sn != NULL; sn = sn->next)
  94             if((group & sn->subnet_mask) == sn->subnet_addr)
  95             {
  96                 // The membership report was OK... Insert it into the route table..
  97                 insertRoute(group, sourceVif->index);
  98                 return;
  99             }
 100         my_log(LOG_INFO, 0, "The group address %s may not be requested from this interface. Ignoring.", inetFmt(group, s1));
 101     } else {
 102         // Log the state of the interface the report was recieved on.
 103         my_log(LOG_INFO, 0, "Membership report was recieved on %s. Ignoring.",
 104             sourceVif->state==IF_STATE_UPSTREAM?"the upstream interface":"a disabled interface");
 105     }
 106
 107 }
 108
 109 /**
 110 *   Recieves and handles a group leave message.
 111 */
 112 void acceptLeaveMessage(uint32_t src, uint32_t group) {
 113     struct IfDesc   *sourceVif;
 114
 115     my_log(LOG_DEBUG, 0,
 116             "Got leave message from %s to %s. Starting last member detection.",
 117             inetFmt(src, s1), inetFmt(group, s2));
 118
 119     // Sanitycheck the group adress...
 120     if(!IN_MULTICAST( ntohl(group) )) {
 121         my_log(LOG_WARNING, 0, "The group address %s is not a valid Multicast group.",
 122             inetFmt(group, s1));
 123         return;
 124     }
 125
 126     // Find the interface on which the report was recieved.
 127     sourceVif = getIfByAddress( src );
 128     if(sourceVif == NULL) {
 129         my_log(LOG_WARNING, 0, "No interfaces found for source %s",
 130             inetFmt(src,s1));
 131         return;
 132     }
 133
 134     // We have a IF so check that it's an downstream IF.
 135     if(sourceVif->state == IF_STATE_DOWNSTREAM) {
 136
 137         GroupVifDesc   *gvDesc;
 138         gvDesc = (GroupVifDesc*) malloc(sizeof(GroupVifDesc));
 139
 140         // Tell the route table that we are checking for remaining members...
 141         setRouteLastMemberMode(group);
 142
 143         // Call the group spesific membership querier...
 144         gvDesc->group = group;
 145         gvDesc->vifAddr = sourceVif->InAdr.s_addr;
 146         gvDesc->started = 0;
 147
 148         sendGroupSpecificMemberQuery(gvDesc);
 149
 150     } else {
 151         // just ignore the leave request...
 152         my_log(LOG_DEBUG, 0, "The found if for %s was not downstream. Ignoring leave request.", inetFmt(src, s1));
 153     }
 154 }
 155
 156 /**
 157 *   Sends a group specific member report query until the
 158 *   group times out...
 159 */
 160 void sendGroupSpecificMemberQuery(void *argument) {
 161     struct  Config  *conf = getCommonConfig();
 162
 163     // Cast argument to correct type...
 164     GroupVifDesc   *gvDesc = (GroupVifDesc*) argument;
 165
 166     if(gvDesc->started) {
 167         // If aging returns false, we don't do any further action...
 168         if(!lastMemberGroupAge(gvDesc->group)) {
 169             return;
 170         }
 171     } else {
 172         gvDesc->started = 1;
 173     }
 174
 175     // Send a group specific membership query...
 176     sendIgmp(gvDesc->vifAddr, gvDesc->group,
 177              IGMP_MEMBERSHIP_QUERY,
 178              conf->lastMemberQueryInterval * IGMP_TIMER_SCALE,
 179              gvDesc->group, 0);
 180
 181     my_log(LOG_DEBUG, 0, "Sent membership query from %s to %s. Delay: %d",
 182         inetFmt(gvDesc->vifAddr,s1), inetFmt(gvDesc->group,s2),
 183         conf->lastMemberQueryInterval);
 184
 185     // Set timeout for next round...
 186     timer_setTimer(conf->lastMemberQueryInterval, sendGroupSpecificMemberQuery, gvDesc);
 187
 188 }
 189
 190
 191 /**
 192 *   Sends a general membership query on downstream VIFs
 193 */
 194 void sendGeneralMembershipQuery() {
 195     struct  Config  *conf = getCommonConfig();
 196     struct  IfDesc  *Dp;
 197     int             Ix;
 198
 199     // Loop through all downstream vifs...
 200     for ( Ix = 0; (Dp = getIfByIx(Ix)); Ix++ ) {
 201         if ( Dp->InAdr.s_addr && ! (Dp->Flags & IFF_LOOPBACK) ) {
 202             if(Dp->state == IF_STATE_DOWNSTREAM) {
 203                 // Send the membership query...
 204                 sendIgmp(Dp->InAdr.s_addr, allhosts_group,
 205                          IGMP_MEMBERSHIP_QUERY,
 206                          conf->queryResponseInterval * IGMP_TIMER_SCALE, 0, 0);
 207
 208                 my_log(LOG_DEBUG, 0,
 209                         "Sent membership query from %s to %s. Delay: %d",
 210                         inetFmt(Dp->InAdr.s_addr,s1),
 211                         inetFmt(allhosts_group,s2),
 212                         conf->queryResponseInterval);
 213             }
 214         }
 215     }
 216
 217     // Install timer for aging active routes.
 218     timer_setTimer(conf->queryResponseInterval, ageActiveRoutes, NULL);
 219
 220     // Install timer for next general query...
 221     if(conf->startupQueryCount>0) {
 222         // Use quick timer...
 223         timer_setTimer(conf->startupQueryInterval, sendGeneralMembershipQuery, NULL);
 224         // Decrease startup counter...
 225         conf->startupQueryCount--;
 226     }
 227     else {
 228         // Use slow timer...
 229         timer_setTimer(conf->queryInterval, sendGeneralMembershipQuery, NULL);
 230     }
 231
 232
 233 }
 234