src/ifvc.c - manifest_repos/igmpproxy - Git at Google

 /*
 **  igmpproxy - IGMP proxy based multicast router
 **  Copyright (C) 2005 Johnny Egeland <johnny@rlo.org>
 **
 **  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 <carsten@cschill.de>
 **  - Licensed under the GNU General Public License, either version 2 or
 **    any later version.
 **
 **  mrouted 3.9-beta3 - Copyright (C) 2002 by The Board of Trustees of
 **  Leland Stanford Junior University.
 **  - Licensed under the 3-clause BSD license, see Stanford.txt file.
 **
 */

 #include "igmpproxy.h"

 /* We need a temporary copy to not break strict aliasing rules */
 static inline uint32_t s_addr_from_sockaddr(const struct sockaddr *addr) {
     struct sockaddr_in addr_in;
     memcpy(&addr_in, addr, sizeof(addr_in));
     return addr_in.sin_addr.s_addr;
 }

 struct IfDesc IfDescVc[ MAX_IF ], *IfDescEp = IfDescVc;

 /* aimwang: add for detect interface and rebuild IfVc record */
 /***************************************************
  * TODO:    Only need run me when detect downstream changed.
  *          For example: /etc/ppp/ip-up & ip-down can touch a file /tmp/ppp_changed
  *          So I can check if the file exist then run me and delete the file.
  ***************************************************/
 void rebuildIfVc () {
     struct ifreq IfVc[ sizeof( IfDescVc ) / sizeof( IfDescVc[ 0 ] )  ];
     struct ifreq *IfEp;
     struct ifconf IoCtlReq;
     struct IfDesc *Dp;
     struct ifreq  *IfPt, *IfNext;
     uint32_t addr, subnet, mask;
     int Sock;

     // Get the config.
     struct Config *config = getCommonConfig();

     if ( (Sock = socket( AF_INET, SOCK_DGRAM, 0 )) < 0 )
         my_log( LOG_ERR, errno, "RAW socket open" );

     // aimwang: set all downstream IF as lost, for check IF exist or gone.
     for (Dp = IfDescVc; Dp < IfDescEp; Dp++) {
         if (Dp->state == IF_STATE_DOWNSTREAM) {
             Dp->state = IF_STATE_LOST;
         }
     }

     IoCtlReq.ifc_buf = (void *)IfVc;
     IoCtlReq.ifc_len = sizeof( IfVc );

     if ( ioctl( Sock, SIOCGIFCONF, &IoCtlReq ) < 0 )
         my_log( LOG_ERR, errno, "ioctl SIOCGIFCONF" );

     IfEp = (void *)((char *)IfVc + IoCtlReq.ifc_len);

     for ( IfPt = IfVc; IfPt < IfEp; IfPt = IfNext ) {
         struct ifreq IfReq;
         char FmtBu[ 32 ];

         IfNext = (struct ifreq *)((char *)&IfPt->ifr_addr +
 #ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
                 IfPt->ifr_addr.sa_len
 #else
                 sizeof(struct sockaddr_in)
 #endif
         );
         if (IfNext < IfPt + 1)
             IfNext = IfPt + 1;

         for (Dp = IfDescVc; Dp < IfDescEp; Dp++) {
             if (0 == strcmp(Dp->Name, IfPt->ifr_name)) {
                 break;
             }
         }

         if (Dp == IfDescEp) {
             strncpy( Dp->Name, IfPt->ifr_name, sizeof( IfDescEp->Name ) );
         }

         if ( IfPt->ifr_addr.sa_family != AF_INET ) {
             if (Dp == IfDescEp) {
                 IfDescEp++;
             }
             Dp->InAdr.s_addr = 0;  /* mark as non-IP interface */
             continue;
         }

         // Get the interface adress...
         Dp->InAdr.s_addr = s_addr_from_sockaddr(&IfPt->ifr_addr);
         addr = Dp->InAdr.s_addr;

         memcpy( IfReq.ifr_name, Dp->Name, sizeof( IfReq.ifr_name ) );

         // Get the subnet mask...
         if (ioctl(Sock, SIOCGIFNETMASK, &IfReq ) < 0)
             my_log(LOG_ERR, errno, "ioctl SIOCGIFNETMASK for %s", IfReq.ifr_name);
         mask = s_addr_from_sockaddr(&IfReq.ifr_netmask);
         subnet = addr & mask;

         if ( ioctl( Sock, SIOCGIFFLAGS, &IfReq ) < 0 )
             my_log( LOG_ERR, errno, "ioctl SIOCGIFFLAGS" );
         Dp->Flags = IfReq.ifr_flags;

         if (0x10d1 == Dp->Flags)
         {
             if ( ioctl( Sock, SIOCGIFDSTADDR, &IfReq ) < 0 )
                 my_log(LOG_ERR, errno, "ioctl SIOCGIFDSTADDR for %s", IfReq.ifr_name);
             addr = s_addr_from_sockaddr(&IfReq.ifr_dstaddr);
             subnet = addr & mask;
         }

         if (Dp == IfDescEp) {
             // Insert the verified subnet as an allowed net...
             Dp->allowednets = (struct SubnetList *)malloc(sizeof(struct SubnetList));
             if(IfDescEp->allowednets == NULL) {
                 my_log(LOG_ERR, 0, "Out of memory !");
             }
             Dp->allowednets->next = NULL;
             Dp->state         = IF_STATE_DOWNSTREAM;
             Dp->robustness    = DEFAULT_ROBUSTNESS;
             Dp->threshold     = DEFAULT_THRESHOLD;   /* ttl limit */
             Dp->ratelimit     = DEFAULT_RATELIMIT;
         }

         // Set the network address for the IF..
         Dp->allowednets->subnet_mask = mask;
         Dp->allowednets->subnet_addr = subnet;

         // Set the state for the IF...
         if (Dp->state == IF_STATE_LOST) {
             Dp->state         = IF_STATE_DOWNSTREAM;
         }

         // when IF become enabeld from downstream, addVIF to enable its VIF
         if (Dp->state == IF_STATE_HIDDEN) {
             my_log(LOG_NOTICE, 0, "%s [Hidden -> Downstream]", Dp->Name);
             Dp->state = IF_STATE_DOWNSTREAM;
             addVIF(Dp);
             joinMcGroup(getMcGroupSock(), Dp, allrouters_group);
         }

         // addVIF when found new IF
         if (Dp == IfDescEp) {
             my_log(LOG_NOTICE, 0, "%s [New]", Dp->Name);
             Dp->state = config->defaultInterfaceState;
             addVIF(Dp);
             joinMcGroup(getMcGroupSock(), Dp, allrouters_group);
             IfDescEp++;
         }

         // Debug log the result...
         my_log( LOG_DEBUG, 0, "rebuildIfVc: Interface %s Addr: %s, Flags: 0x%04x, Network: %s",
             Dp->Name,
             fmtInAdr( FmtBu, Dp->InAdr ),
             Dp->Flags,
             inetFmts(subnet, mask, s1));
     }

     // aimwang: search not longer exist IF, set as hidden and call delVIF
     for (Dp = IfDescVc; Dp < IfDescEp; Dp++) {
         if (IF_STATE_LOST == Dp->state) {
             my_log(LOG_NOTICE, 0, "%s [Downstream -> Hidden]", Dp->Name);
             Dp->state = IF_STATE_HIDDEN;
             leaveMcGroup( getMcGroupSock(), Dp, allrouters_group );
             delVIF(Dp);
         }
     }

     close( Sock );
 }

 /*
 ** Builds up a vector with the interface of the machine. Calls to the other functions of
 ** the module will fail if they are called before the vector is build.
 **
 */
 void buildIfVc(void) {
     struct ifreq IfVc[ sizeof( IfDescVc ) / sizeof( IfDescVc[ 0 ] )  ];
     struct ifreq *IfEp;
     struct Config *config = getCommonConfig();

     int Sock;

     if ( (Sock = socket( AF_INET, SOCK_DGRAM, 0 )) < 0 )
         my_log( LOG_ERR, errno, "RAW socket open" );

     /* get If vector
      */
     {
         struct ifconf IoCtlReq;

         IoCtlReq.ifc_buf = (void *)IfVc;
         IoCtlReq.ifc_len = sizeof( IfVc );

         if ( ioctl( Sock, SIOCGIFCONF, &IoCtlReq ) < 0 )
             my_log( LOG_ERR, errno, "ioctl SIOCGIFCONF" );

         IfEp = (void *)((char *)IfVc + IoCtlReq.ifc_len);
     }

     /* loop over interfaces and copy interface info to IfDescVc
      */
     {
         struct ifreq  *IfPt, *IfNext;

         // Temp keepers of interface params...
         uint32_t addr, subnet, mask;

         for ( IfPt = IfVc; IfPt < IfEp; IfPt = IfNext ) {
             struct ifreq IfReq;
             char FmtBu[ 32 ];

             IfNext = (struct ifreq *)((char *)&IfPt->ifr_addr +
 #ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
                     IfPt->ifr_addr.sa_len
 #else
                     sizeof(struct sockaddr_in)
 #endif
             );
             if (IfNext < IfPt + 1)
                 IfNext = IfPt + 1;

             strncpy( IfDescEp->Name, IfPt->ifr_name, sizeof( IfDescEp->Name ) );

             // Currently don't set any allowed nets...
             //IfDescEp->allowednets = NULL;

             // Set the index to -1 by default.
             IfDescEp->index = (unsigned int)-1;

             /* don't retrieve more info for non-IP interfaces
              */
             if ( IfPt->ifr_addr.sa_family != AF_INET ) {
                 IfDescEp->InAdr.s_addr = 0;  /* mark as non-IP interface */
                 IfDescEp++;
                 continue;
             }

             // Get the interface adress...
             IfDescEp->InAdr.s_addr = s_addr_from_sockaddr(&IfPt->ifr_addr);
             addr = IfDescEp->InAdr.s_addr;

             memcpy( IfReq.ifr_name, IfDescEp->Name, sizeof( IfReq.ifr_name ) );

             // Get the subnet mask...
             if (ioctl(Sock, SIOCGIFNETMASK, &IfReq ) < 0)
                 my_log(LOG_ERR, errno, "ioctl SIOCGIFNETMASK for %s", IfReq.ifr_name);
             mask = s_addr_from_sockaddr(&IfReq.ifr_netmask);
             subnet = addr & mask;

             /* get if flags
             **
             ** typical flags:
             ** lo    0x0049 -> Running, Loopback, Up
             ** ethx  0x1043 -> Multicast, Running, Broadcast, Up
             ** ipppx 0x0091 -> NoArp, PointToPoint, Up
             ** grex  0x00C1 -> NoArp, Running, Up
             ** ipipx 0x00C1 -> NoArp, Running, Up
             */
             if ( ioctl( Sock, SIOCGIFFLAGS, &IfReq ) < 0 )
                 my_log( LOG_ERR, errno, "ioctl SIOCGIFFLAGS" );

             IfDescEp->Flags = IfReq.ifr_flags;

             // aimwang: when pppx get dstaddr for use
             if (0x10d1 == IfDescEp->Flags)
             {
                 if ( ioctl( Sock, SIOCGIFDSTADDR, &IfReq ) < 0 )
                     my_log(LOG_ERR, errno, "ioctl SIOCGIFDSTADDR for %s", IfReq.ifr_name);
                 addr = s_addr_from_sockaddr(&IfReq.ifr_dstaddr);
                 subnet = addr & mask;
             }

             // Insert the verified subnet as an allowed net...
             IfDescEp->allowednets = (struct SubnetList *)malloc(sizeof(struct SubnetList));
             if(IfDescEp->allowednets == NULL) my_log(LOG_ERR, 0, "Out of memory !");

             // Create the network address for the IF..
             IfDescEp->allowednets->next = NULL;
             IfDescEp->allowednets->subnet_mask = mask;
             IfDescEp->allowednets->subnet_addr = subnet;

             // Set the default params for the IF...
             IfDescEp->state         = config->defaultInterfaceState;
             IfDescEp->robustness    = DEFAULT_ROBUSTNESS;
             IfDescEp->threshold     = DEFAULT_THRESHOLD;   /* ttl limit */
             IfDescEp->ratelimit     = DEFAULT_RATELIMIT;

             // Debug log the result...
             my_log( LOG_DEBUG, 0, "buildIfVc: Interface %s Addr: %s, Flags: 0x%04x, Network: %s",
                  IfDescEp->Name,
                  fmtInAdr( FmtBu, IfDescEp->InAdr ),
                  IfDescEp->Flags,
                  inetFmts(subnet,mask, s1));

             IfDescEp++;
         }
     }

     close( Sock );
 }

 /*
 ** Returns a pointer to the IfDesc of the interface 'IfName'
 **
 ** returns: - pointer to the IfDesc of the requested interface
 **          - NULL if no interface 'IfName' exists
 **
 */
 struct IfDesc *getIfByName( const char *IfName ) {
     struct IfDesc *Dp;

     for ( Dp = IfDescVc; Dp < IfDescEp; Dp++ )
         if ( ! strcmp( IfName, Dp->Name ) )
             return Dp;

     return NULL;
 }

 /*
 ** Returns a pointer to the IfDesc of the interface 'Ix'
 **
 ** returns: - pointer to the IfDesc of the requested interface
 **          - NULL if no interface 'Ix' exists
 **
 */
 struct IfDesc *getIfByIx( unsigned Ix ) {
     struct IfDesc *Dp = &IfDescVc[ Ix ];
     return Dp < IfDescEp ? Dp : NULL;
 }

 /**
 *   Returns a pointer to the IfDesc whose subnet matches
 *   the supplied IP adress. The IP must match a interfaces
 *   subnet, or any configured allowed subnet on a interface.
 */
 struct IfDesc *getIfByAddress( uint32_t ipaddr ) {

     struct IfDesc       *Dp;
     struct SubnetList   *currsubnet;
     struct IfDesc       *res = NULL;
     uint32_t            last_subnet_mask = 0;

     for ( Dp = IfDescVc; Dp < IfDescEp; Dp++ ) {
         // Loop through all registered allowed nets of the VIF...
         for(currsubnet = Dp->allowednets; currsubnet != NULL; currsubnet = currsubnet->next) {
             // Check if the ip falls in under the subnet....
             if(currsubnet->subnet_mask > last_subnet_mask && (ipaddr & currsubnet->subnet_mask) == currsubnet->subnet_addr) {
                 res = Dp;
                 last_subnet_mask = currsubnet->subnet_mask;
             }
         }
     }
     return res;
 }


 /**
 *   Returns a pointer to the IfDesc whose subnet matches
 *   the supplied IP adress. The IP must match a interfaces
 *   subnet, or any configured allowed subnet on a interface.
 */
 struct IfDesc *getIfByVifIndex( unsigned vifindex ) {
     struct IfDesc       *Dp;
     if(vifindex>0) {
         for ( Dp = IfDescVc; Dp < IfDescEp; Dp++ ) {
             if(Dp->index == vifindex) {
                 return Dp;
             }
         }
     }
     return NULL;
 }


 /**
 *   Function that checks if a given ipaddress is a valid
 *   address for the supplied VIF.
 */
 int isAdressValidForIf( struct IfDesc* intrface, uint32_t ipaddr ) {
     struct SubnetList   *currsubnet;

     if(intrface == NULL) {
         return 0;
     }

     // Loop through all registered allowed nets of the VIF...
     for(currsubnet = intrface->allowednets; currsubnet != NULL; currsubnet = currsubnet->next) {
         // Check if the ip falls in under the subnet....
         if((ipaddr & currsubnet->subnet_mask) == (currsubnet->subnet_addr& currsubnet->subnet_mask)) {
             return 1;
         }
     }
     return 0;
 }
	/*
	** igmpproxy - IGMP proxy based multicast router
	** Copyright (C) 2005 Johnny Egeland <johnny@rlo.org>
	**
	** 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 <carsten@cschill.de>
	** - Licensed under the GNU General Public License, either version 2 or
	** any later version.
	**
	** mrouted 3.9-beta3 - Copyright (C) 2002 by The Board of Trustees of
	** Leland Stanford Junior University.
	** - Licensed under the 3-clause BSD license, see Stanford.txt file.
	**
	*/

	#include "igmpproxy.h"

	/* We need a temporary copy to not break strict aliasing rules */
	static inline uint32_t s_addr_from_sockaddr(const struct sockaddr *addr) {
	struct sockaddr_in addr_in;
	memcpy(&addr_in, addr, sizeof(addr_in));
	return addr_in.sin_addr.s_addr;
	}

	struct IfDesc IfDescVc[ MAX_IF ], *IfDescEp = IfDescVc;

	/* aimwang: add for detect interface and rebuild IfVc record */
	/***************************************************
	* TODO: Only need run me when detect downstream changed.
	* For example: /etc/ppp/ip-up & ip-down can touch a file /tmp/ppp_changed
	* So I can check if the file exist then run me and delete the file.
	***************************************************/
	void rebuildIfVc () {
	struct ifreq IfVc[ sizeof( IfDescVc ) / sizeof( IfDescVc[ 0 ] ) ];
	struct ifreq *IfEp;
	struct ifconf IoCtlReq;
	struct IfDesc *Dp;
	struct ifreq IfPt, IfNext;
	uint32_t addr, subnet, mask;
	int Sock;

	// Get the config.
	struct Config *config = getCommonConfig();

	if ( (Sock = socket( AF_INET, SOCK_DGRAM, 0 )) < 0 )
	my_log( LOG_ERR, errno, "RAW socket open" );

	// aimwang: set all downstream IF as lost, for check IF exist or gone.
	for (Dp = IfDescVc; Dp < IfDescEp; Dp++) {
	if (Dp->state == IF_STATE_DOWNSTREAM) {
	Dp->state = IF_STATE_LOST;
	}
	}

	IoCtlReq.ifc_buf = (void *)IfVc;
	IoCtlReq.ifc_len = sizeof( IfVc );

	if ( ioctl( Sock, SIOCGIFCONF, &IoCtlReq ) < 0 )
	my_log( LOG_ERR, errno, "ioctl SIOCGIFCONF" );

	IfEp = (void )((char )IfVc + IoCtlReq.ifc_len);

	for ( IfPt = IfVc; IfPt < IfEp; IfPt = IfNext ) {
	struct ifreq IfReq;
	char FmtBu[ 32 ];

	IfNext = (struct ifreq )((char )&IfPt->ifr_addr +
	#ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
	IfPt->ifr_addr.sa_len
	#else
	sizeof(struct sockaddr_in)
	#endif
	);
	if (IfNext < IfPt + 1)
	IfNext = IfPt + 1;

	for (Dp = IfDescVc; Dp < IfDescEp; Dp++) {
	if (0 == strcmp(Dp->Name, IfPt->ifr_name)) {
	break;
	}
	}

	if (Dp == IfDescEp) {
	strncpy( Dp->Name, IfPt->ifr_name, sizeof( IfDescEp->Name ) );
	}

	if ( IfPt->ifr_addr.sa_family != AF_INET ) {
	if (Dp == IfDescEp) {
	IfDescEp++;
	}
	Dp->InAdr.s_addr = 0; /* mark as non-IP interface */
	continue;
	}

	// Get the interface adress...
	Dp->InAdr.s_addr = s_addr_from_sockaddr(&IfPt->ifr_addr);
	addr = Dp->InAdr.s_addr;

	memcpy( IfReq.ifr_name, Dp->Name, sizeof( IfReq.ifr_name ) );

	// Get the subnet mask...
	if (ioctl(Sock, SIOCGIFNETMASK, &IfReq ) < 0)
	my_log(LOG_ERR, errno, "ioctl SIOCGIFNETMASK for %s", IfReq.ifr_name);
	mask = s_addr_from_sockaddr(&IfReq.ifr_netmask);
	subnet = addr & mask;

	if ( ioctl( Sock, SIOCGIFFLAGS, &IfReq ) < 0 )
	my_log( LOG_ERR, errno, "ioctl SIOCGIFFLAGS" );
	Dp->Flags = IfReq.ifr_flags;

	if (0x10d1 == Dp->Flags)
	{
	if ( ioctl( Sock, SIOCGIFDSTADDR, &IfReq ) < 0 )
	my_log(LOG_ERR, errno, "ioctl SIOCGIFDSTADDR for %s", IfReq.ifr_name);
	addr = s_addr_from_sockaddr(&IfReq.ifr_dstaddr);
	subnet = addr & mask;
	}

	if (Dp == IfDescEp) {
	// Insert the verified subnet as an allowed net...
	Dp->allowednets = (struct SubnetList *)malloc(sizeof(struct SubnetList));
	if(IfDescEp->allowednets == NULL) {
	my_log(LOG_ERR, 0, "Out of memory !");
	}
	Dp->allowednets->next = NULL;
	Dp->state = IF_STATE_DOWNSTREAM;
	Dp->robustness = DEFAULT_ROBUSTNESS;
	Dp->threshold = DEFAULT_THRESHOLD; /* ttl limit */
	Dp->ratelimit = DEFAULT_RATELIMIT;
	}

	// Set the network address for the IF..
	Dp->allowednets->subnet_mask = mask;
	Dp->allowednets->subnet_addr = subnet;

	// Set the state for the IF...
	if (Dp->state == IF_STATE_LOST) {
	Dp->state = IF_STATE_DOWNSTREAM;
	}

	// when IF become enabeld from downstream, addVIF to enable its VIF
	if (Dp->state == IF_STATE_HIDDEN) {
	my_log(LOG_NOTICE, 0, "%s [Hidden -> Downstream]", Dp->Name);
	Dp->state = IF_STATE_DOWNSTREAM;
	addVIF(Dp);
	joinMcGroup(getMcGroupSock(), Dp, allrouters_group);
	}

	// addVIF when found new IF
	if (Dp == IfDescEp) {
	my_log(LOG_NOTICE, 0, "%s [New]", Dp->Name);
	Dp->state = config->defaultInterfaceState;
	addVIF(Dp);
	joinMcGroup(getMcGroupSock(), Dp, allrouters_group);
	IfDescEp++;
	}

	// Debug log the result...
	my_log( LOG_DEBUG, 0, "rebuildIfVc: Interface %s Addr: %s, Flags: 0x%04x, Network: %s",
	Dp->Name,
	fmtInAdr( FmtBu, Dp->InAdr ),
	Dp->Flags,
	inetFmts(subnet, mask, s1));
	}

	// aimwang: search not longer exist IF, set as hidden and call delVIF
	for (Dp = IfDescVc; Dp < IfDescEp; Dp++) {
	if (IF_STATE_LOST == Dp->state) {
	my_log(LOG_NOTICE, 0, "%s [Downstream -> Hidden]", Dp->Name);
	Dp->state = IF_STATE_HIDDEN;
	leaveMcGroup( getMcGroupSock(), Dp, allrouters_group );
	delVIF(Dp);
	}
	}

	close( Sock );
	}

	/*
	** Builds up a vector with the interface of the machine. Calls to the other functions of
	** the module will fail if they are called before the vector is build.
	**
	*/
	void buildIfVc(void) {
	struct ifreq IfVc[ sizeof( IfDescVc ) / sizeof( IfDescVc[ 0 ] ) ];
	struct ifreq *IfEp;
	struct Config *config = getCommonConfig();

	int Sock;

	if ( (Sock = socket( AF_INET, SOCK_DGRAM, 0 )) < 0 )
	my_log( LOG_ERR, errno, "RAW socket open" );

	/* get If vector
	*/
	{
	struct ifconf IoCtlReq;

	IoCtlReq.ifc_buf = (void *)IfVc;
	IoCtlReq.ifc_len = sizeof( IfVc );

	if ( ioctl( Sock, SIOCGIFCONF, &IoCtlReq ) < 0 )
	my_log( LOG_ERR, errno, "ioctl SIOCGIFCONF" );

	IfEp = (void )((char )IfVc + IoCtlReq.ifc_len);
	}

	/* loop over interfaces and copy interface info to IfDescVc
	*/
	{
	struct ifreq IfPt, IfNext;

	// Temp keepers of interface params...
	uint32_t addr, subnet, mask;

	for ( IfPt = IfVc; IfPt < IfEp; IfPt = IfNext ) {
	struct ifreq IfReq;
	char FmtBu[ 32 ];

	IfNext = (struct ifreq )((char )&IfPt->ifr_addr +
	#ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
	IfPt->ifr_addr.sa_len
	#else
	sizeof(struct sockaddr_in)
	#endif
	);
	if (IfNext < IfPt + 1)
	IfNext = IfPt + 1;

	strncpy( IfDescEp->Name, IfPt->ifr_name, sizeof( IfDescEp->Name ) );

	// Currently don't set any allowed nets...
	//IfDescEp->allowednets = NULL;

	// Set the index to -1 by default.
	IfDescEp->index = (unsigned int)-1;

	/* don't retrieve more info for non-IP interfaces
	*/
	if ( IfPt->ifr_addr.sa_family != AF_INET ) {
	IfDescEp->InAdr.s_addr = 0; /* mark as non-IP interface */
	IfDescEp++;
	continue;
	}

	// Get the interface adress...
	IfDescEp->InAdr.s_addr = s_addr_from_sockaddr(&IfPt->ifr_addr);
	addr = IfDescEp->InAdr.s_addr;

	memcpy( IfReq.ifr_name, IfDescEp->Name, sizeof( IfReq.ifr_name ) );

	// Get the subnet mask...
	if (ioctl(Sock, SIOCGIFNETMASK, &IfReq ) < 0)
	my_log(LOG_ERR, errno, "ioctl SIOCGIFNETMASK for %s", IfReq.ifr_name);
	mask = s_addr_from_sockaddr(&IfReq.ifr_netmask);
	subnet = addr & mask;

	/* get if flags
	**
	** typical flags:
	** lo 0x0049 -> Running, Loopback, Up
	** ethx 0x1043 -> Multicast, Running, Broadcast, Up
	** ipppx 0x0091 -> NoArp, PointToPoint, Up
	** grex 0x00C1 -> NoArp, Running, Up
	** ipipx 0x00C1 -> NoArp, Running, Up
	*/
	if ( ioctl( Sock, SIOCGIFFLAGS, &IfReq ) < 0 )
	my_log( LOG_ERR, errno, "ioctl SIOCGIFFLAGS" );

	IfDescEp->Flags = IfReq.ifr_flags;

	// aimwang: when pppx get dstaddr for use
	if (0x10d1 == IfDescEp->Flags)
	{
	if ( ioctl( Sock, SIOCGIFDSTADDR, &IfReq ) < 0 )
	my_log(LOG_ERR, errno, "ioctl SIOCGIFDSTADDR for %s", IfReq.ifr_name);
	addr = s_addr_from_sockaddr(&IfReq.ifr_dstaddr);
	subnet = addr & mask;
	}

	// Insert the verified subnet as an allowed net...
	IfDescEp->allowednets = (struct SubnetList *)malloc(sizeof(struct SubnetList));
	if(IfDescEp->allowednets == NULL) my_log(LOG_ERR, 0, "Out of memory !");

	// Create the network address for the IF..
	IfDescEp->allowednets->next = NULL;
	IfDescEp->allowednets->subnet_mask = mask;
	IfDescEp->allowednets->subnet_addr = subnet;

	// Set the default params for the IF...
	IfDescEp->state = config->defaultInterfaceState;
	IfDescEp->robustness = DEFAULT_ROBUSTNESS;
	IfDescEp->threshold = DEFAULT_THRESHOLD; /* ttl limit */
	IfDescEp->ratelimit = DEFAULT_RATELIMIT;

	// Debug log the result...
	my_log( LOG_DEBUG, 0, "buildIfVc: Interface %s Addr: %s, Flags: 0x%04x, Network: %s",
	IfDescEp->Name,
	fmtInAdr( FmtBu, IfDescEp->InAdr ),
	IfDescEp->Flags,
	inetFmts(subnet,mask, s1));

	IfDescEp++;
	}
	}

	close( Sock );
	}

	/*
	** Returns a pointer to the IfDesc of the interface 'IfName'
	**
	** returns: - pointer to the IfDesc of the requested interface
	** - NULL if no interface 'IfName' exists
	**
	*/
	struct IfDesc getIfByName( const char IfName ) {
	struct IfDesc *Dp;

	for ( Dp = IfDescVc; Dp < IfDescEp; Dp++ )
	if ( ! strcmp( IfName, Dp->Name ) )
	return Dp;

	return NULL;
	}

	/*
	** Returns a pointer to the IfDesc of the interface 'Ix'
	**
	** returns: - pointer to the IfDesc of the requested interface
	** - NULL if no interface 'Ix' exists
	**
	*/
	struct IfDesc *getIfByIx( unsigned Ix ) {
	struct IfDesc *Dp = &IfDescVc[ Ix ];
	return Dp < IfDescEp ? Dp : NULL;
	}

	/**
	* Returns a pointer to the IfDesc whose subnet matches
	* the supplied IP adress. The IP must match a interfaces
	* subnet, or any configured allowed subnet on a interface.
	*/
	struct IfDesc *getIfByAddress( uint32_t ipaddr ) {

	struct IfDesc *Dp;
	struct SubnetList *currsubnet;
	struct IfDesc *res = NULL;
	uint32_t last_subnet_mask = 0;

	for ( Dp = IfDescVc; Dp < IfDescEp; Dp++ ) {
	// Loop through all registered allowed nets of the VIF...
	for(currsubnet = Dp->allowednets; currsubnet != NULL; currsubnet = currsubnet->next) {
	// Check if the ip falls in under the subnet....
	if(currsubnet->subnet_mask > last_subnet_mask && (ipaddr & currsubnet->subnet_mask) == currsubnet->subnet_addr) {
	res = Dp;
	last_subnet_mask = currsubnet->subnet_mask;
	}
	}
	}
	return res;
	}


	/**
	* Returns a pointer to the IfDesc whose subnet matches
	* the supplied IP adress. The IP must match a interfaces
	* subnet, or any configured allowed subnet on a interface.
	*/
	struct IfDesc *getIfByVifIndex( unsigned vifindex ) {
	struct IfDesc *Dp;
	if(vifindex>0) {
	for ( Dp = IfDescVc; Dp < IfDescEp; Dp++ ) {
	if(Dp->index == vifindex) {
	return Dp;
	}
	}
	}
	return NULL;
	}


	/**
	* Function that checks if a given ipaddress is a valid
	* address for the supplied VIF.
	*/
	int isAdressValidForIf( struct IfDesc* intrface, uint32_t ipaddr ) {
	struct SubnetList *currsubnet;

	if(intrface == NULL) {
	return 0;
	}

	// Loop through all registered allowed nets of the VIF...
	for(currsubnet = intrface->allowednets; currsubnet != NULL; currsubnet = currsubnet->next) {
	// Check if the ip falls in under the subnet....
	if((ipaddr & currsubnet->subnet_mask) == (currsubnet->subnet_addr& currsubnet->subnet_mask)) {
	return 1;
	}
	}
	return 0;
	}