release/src/router/igmpproxy/src/ifvc.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 #include "igmpproxy.h"
  35
  36 struct IfDesc IfDescVc[ MAX_IF ], *IfDescEp = IfDescVc;
  37
  38 /*
  39 ** Builds up a vector with the interface of the machine. Calls to the other functions of
  40 ** the module will fail if they are called before the vector is build.
  41 **
  42 */
  43 void buildIfVc() {
  44     struct ifreq IfVc[ sizeof( IfDescVc ) / sizeof( IfDescVc[ 0 ] )  ];
  45     struct ifreq *IfEp;
  46
  47     int Sock;
  48
  49     if ( (Sock = socket( AF_INET, SOCK_DGRAM, 0 )) < 0 )
  50         my_log( LOG_ERR, errno, "RAW socket open" );
  51
  52     /* get If vector
  53      */
  54     {
  55         struct ifconf IoCtlReq;
  56
  57         IoCtlReq.ifc_buf = (void *)IfVc;
  58         IoCtlReq.ifc_len = sizeof( IfVc );
  59
  60         if ( ioctl( Sock, SIOCGIFCONF, &IoCtlReq ) < 0 )
  61             my_log( LOG_ERR, errno, "ioctl SIOCGIFCONF" );
  62
  63         IfEp = (void *)((char *)IfVc + IoCtlReq.ifc_len);
  64     }
  65
  66     /* loop over interfaces and copy interface info to IfDescVc
  67      */
  68     {
  69         struct ifreq  *IfPt, *IfNext;
  70
  71         // Temp keepers of interface params...
  72         uint32_t addr, subnet, mask;
  73
  74         for ( IfPt = IfVc; IfPt < IfEp; IfPt = IfNext ) {
  75             struct ifreq IfReq;
  76             char FmtBu[ 32 ];
  77
  78             IfNext = (struct ifreq *)((char *)&IfPt->ifr_addr +
  79 #ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
  80                                     IfPt->ifr_addr.sa_len
  81 #else
  82                                     sizeof(struct sockaddr_in)
  83 #endif
  84                     );
  85             if (IfNext < IfPt + 1)
  86                     IfNext = IfPt + 1;
  87
  88             strncpy( IfDescEp->Name, IfPt->ifr_name, sizeof( IfDescEp->Name ) );
  89
  90             // Currently don't set any allowed nets...
  91             //IfDescEp->allowednets = NULL;
  92
  93             // Set the index to -1 by default.
  94             IfDescEp->index = -1;
  95
  96             /* don't retrieve more info for non-IP interfaces
  97              */
  98             if ( IfPt->ifr_addr.sa_family != AF_INET ) {
  99                 IfDescEp->InAdr.s_addr = 0;  /* mark as non-IP interface */
 100                 IfDescEp++;
 101                 continue;
 102             }
 103
 104             // Get the interface adress...
 105             IfDescEp->InAdr = ((struct sockaddr_in *)&IfPt->ifr_addr)->sin_addr;
 106             addr = IfDescEp->InAdr.s_addr;
 107
 108             memcpy( IfReq.ifr_name, IfDescEp->Name, sizeof( IfReq.ifr_name ) );
 109             IfReq.ifr_addr.sa_family = AF_INET;
 110             ((struct sockaddr_in *)&IfReq.ifr_addr)->sin_addr.s_addr = addr;
 111
 112             // Get the subnet mask...
 113             if (ioctl(Sock, SIOCGIFNETMASK, &IfReq ) < 0)
 114                 my_log(LOG_ERR, errno, "ioctl SIOCGIFNETMASK for %s", IfReq.ifr_name);
 115             mask = ((struct sockaddr_in *)&IfReq.ifr_addr)->sin_addr.s_addr;
 116             subnet = addr & mask;
 117
 118             /* get if flags
 119             **
 120             ** typical flags:
 121             ** lo    0x0049 -> Running, Loopback, Up
 122             ** ethx  0x1043 -> Multicast, Running, Broadcast, Up
 123             ** ipppx 0x0091 -> NoArp, PointToPoint, Up
 124             ** grex  0x00C1 -> NoArp, Running, Up
 125             ** ipipx 0x00C1 -> NoArp, Running, Up
 126             */
 127             if ( ioctl( Sock, SIOCGIFFLAGS, &IfReq ) < 0 )
 128                 my_log( LOG_ERR, errno, "ioctl SIOCGIFFLAGS" );
 129
 130             IfDescEp->Flags = IfReq.ifr_flags;
 131
 132             // Insert the verified subnet as an allowed net...
 133             IfDescEp->allowednets = (struct SubnetList *)malloc(sizeof(struct SubnetList));
 134             if(IfDescEp->allowednets == NULL) my_log(LOG_ERR, 0, "Out of memory !");
 135
 136             // Create the network address for the IF..
 137             IfDescEp->allowednets->next = NULL;
 138             IfDescEp->allowednets->subnet_mask = mask;
 139             IfDescEp->allowednets->subnet_addr = subnet;
 140
 141             // Set the default params for the IF...
 142             IfDescEp->state         = IF_STATE_DISABLED;
 143             IfDescEp->robustness    = DEFAULT_ROBUSTNESS;
 144             IfDescEp->threshold     = DEFAULT_THRESHOLD;   /* ttl limit */
 145             IfDescEp->ratelimit     = DEFAULT_RATELIMIT;
 146
 147
 148             // Debug log the result...
 149             my_log( LOG_DEBUG, 0, "buildIfVc: Interface %s Addr: %s, Flags: 0x%04x, Network: %s",
 150                  IfDescEp->Name,
 151                  fmtInAdr( FmtBu, IfDescEp->InAdr ),
 152                  IfDescEp->Flags,
 153                  inetFmts(subnet,mask, s1));
 154
 155             IfDescEp++;
 156         }
 157     }
 158
 159     close( Sock );
 160 }
 161
 162 /*
 163 ** Returns a pointer to the IfDesc of the interface 'IfName'
 164 **
 165 ** returns: - pointer to the IfDesc of the requested interface
 166 **          - NULL if no interface 'IfName' exists
 167 **
 168 */
 169 struct IfDesc *getIfByName( const char *IfName ) {
 170     struct IfDesc *Dp;
 171
 172     for ( Dp = IfDescVc; Dp < IfDescEp; Dp++ )
 173         if ( ! strcmp( IfName, Dp->Name ) )
 174             return Dp;
 175
 176     return NULL;
 177 }
 178
 179 /*
 180 ** Returns a pointer to the IfDesc of the interface 'Ix'
 181 **
 182 ** returns: - pointer to the IfDesc of the requested interface
 183 **          - NULL if no interface 'Ix' exists
 184 **
 185 */
 186 struct IfDesc *getIfByIx( unsigned Ix ) {
 187     struct IfDesc *Dp = &IfDescVc[ Ix ];
 188     return Dp < IfDescEp ? Dp : NULL;
 189 }
 190
 191 /**
 192 *   Returns a pointer to the IfDesc whose subnet matches
 193 *   the supplied IP adress. The IP must match a interfaces
 194 *   subnet, or any configured allowed subnet on a interface.
 195 */
 196 struct IfDesc *getIfByAddress( uint32_t ipaddr ) {
 197
 198     struct IfDesc       *Dp;
 199     struct SubnetList   *currsubnet;
 200     struct IfDesc       *res = NULL;
 201     uint32_t            last_subnet_mask = 0;
 202
 203     for ( Dp = IfDescVc; Dp < IfDescEp; Dp++ ) {
 204         // Loop through all registered allowed nets of the VIF...
 205         for(currsubnet = Dp->allowednets; currsubnet != NULL; currsubnet = currsubnet->next) {
 206             // Check if the ip falls in under the subnet....
 207             if(currsubnet->subnet_mask > last_subnet_mask && (ipaddr & currsubnet->subnet_mask) == currsubnet->subnet_addr) {
 208                 res = Dp;
 209                 last_subnet_mask = currsubnet->subnet_mask;
 210             }
 211         }
 212     }
 213     return res;
 214 }
 215
 216
 217 /**
 218 *   Returns a pointer to the IfDesc whose subnet matches
 219 *   the supplied IP adress. The IP must match a interfaces
 220 *   subnet, or any configured allowed subnet on a interface.
 221 */
 222 struct IfDesc *getIfByVifIndex( unsigned vifindex ) {
 223     struct IfDesc       *Dp;
 224     if(vifindex>0) {
 225         for ( Dp = IfDescVc; Dp < IfDescEp; Dp++ ) {
 226             if(Dp->index == vifindex) {
 227                 return Dp;
 228             }
 229         }
 230     }
 231     return NULL;
 232 }
 233
 234
 235 /**
 236 *   Function that checks if a given ipaddress is a valid
 237 *   address for the supplied VIF.
 238 */
 239 int isAdressValidForIf( struct IfDesc* intrface, uint32_t ipaddr ) {
 240     struct SubnetList   *currsubnet;
 241
 242     if(intrface == NULL) {
 243         return 0;
 244     }
 245     // Loop through all registered allowed nets of the VIF...
 246     for(currsubnet = intrface->allowednets; currsubnet != NULL; currsubnet = currsubnet->next) {
 247         // Check if the ip falls in under the subnet....
 248         if((ipaddr & currsubnet->subnet_mask) == currsubnet->subnet_addr) {
 249             return 1;
 250         }
 251     }
 252     return 0;
 253 }
 254
 255