text: /* PPPoE support library "libpppoe"
   *
   * Copyright 2000 Michal Ostrowski <mostrows@styx.uwaterloo.ca>,
   *		  Jamal Hadi Salim <hadi@cyberus.ca>
   *
   *  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.
   */
  
  #include "pppoe.h"
  
  static int relay_init_disc(struct session* ses,
  			   struct pppoe_packet *p_in,
  			   struct pppoe_packet **p_out){
  
      ses->state = 0;
      ses->retransmits = -1 ;
      ses->retries = -1;
  
      (*p_out) = NULL;
      return 0;
  }
  
  static int pcid=0;
  static int relay_rcv_padi(struct session* ses,
  			  struct pppoe_packet *p_in,
  			  struct pppoe_packet **p_out){
      char tag_buf[32];
      struct pppoe_con *newpc = NULL;
      struct pppoe_tag *tag = (struct pppoe_tag *) tag_buf;
  
  
      tag->tag_type = PTT_RELAY_SID;
      tag->tag_len  = htons(ETH_ALEN + sizeof(struct session *));
  
      memcpy(tag->tag_data, p_in->addr.sll_addr, ETH_ALEN);
      memcpy(tag->tag_data + ETH_ALEN, &ses, sizeof(struct session *));
  
      if(! p_in->tags[TAG_RELAY_SID] ){
  	copy_tag(p_in, tag);
      }
  
  
      poe_dbglog(ses, "Recv'd PADI: %P",p_in);
      poe_dbglog(ses, "Recv'd packet: %P",p_in);
      newpc = get_con( ntohs(tag->tag_len), tag->tag_data );
      if(!newpc){
  	
  	newpc = (struct pppoe_con *) malloc(sizeof(struct pppoe_con));
  	memset(newpc , 0, sizeof(struct pppoe_con));
  	
  	newpc->id = pcid++;
  	
  	newpc->key_len = ntohs(p_in->tags[TAG_RELAY_SID]->tag_len);
  	memcpy(newpc->key, p_in->tags[TAG_RELAY_SID]->tag_data, newpc->key_len);
  	memcpy(newpc->client, p_in->addr.sll_addr, ETH_ALEN);
  	
  	memcpy(newpc->server, MAC_BCAST_ADDR, ETH_ALEN);
  	
  	store_con(newpc);
  	
      }
  
      ++newpc->ref_count;
  
      memset(p_in->addr.sll_addr, 0xff, ETH_ALEN);
  
      p_in->addr.sll_ifindex = ses->remote.sll_ifindex;
  
      send_disc(ses, p_in);
      return 0;
  }
  
  static int relay_rcv_pkt(struct session* ses,
  			 struct pppoe_packet *p_in,
  			 struct pppoe_packet **p_out){
      struct pppoe_con *pc;
      char tag_buf[32];
      struct pppoe_tag *tag = p_in->tags[TAG_RELAY_SID];
  
      if( !tag ) return 0;
  
      pc = get_con(ntohs(tag->tag_len),tag->tag_data);
  
      if( !pc ) return 0;
  
      poe_dbglog(ses, "Recv'd packet: %P",p_in);
  
      if( memcmp(pc->client , p_in->addr.sll_addr , ETH_ALEN ) == 0 ){
  	
  	memcpy(p_in->addr.sll_addr, pc->server, ETH_ALEN);
  	p_in->addr.sll_ifindex = ses->remote.sll_ifindex;
  	
      }else{
  	if( memcmp(pc->server, MAC_BCAST_ADDR, ETH_ALEN) == 0 ){
  	    memcpy(pc->server, p_in->addr.sll_addr, ETH_ALEN);
  	
  	}else if( memcmp(pc->server, p_in->addr.sll_addr, ETH_ALEN) !=0){
  	    return 0;
  	}
  	
  	memcpy(p_in->addr.sll_addr, pc->client, ETH_ALEN);
  	p_in->addr.sll_ifindex = ses->local.sll_ifindex;
  	
  	
      }
  
  
      send_disc(ses, p_in);
      return 0;
  }
  
  static int relay_rcv_pads(struct session* ses,
  			  struct pppoe_packet *p_in,
  			  struct pppoe_packet **p_out){
  
      struct pppoe_con *pc;
      char tag_buf[32];
      struct pppoe_tag *tag = p_in->tags[TAG_RELAY_SID];
      struct sockaddr_pppox sp_cl= { AF_PPPOX, PX_PROTO_OE,
  				   { p_in->hdr->sid, {0,},{0,}}};
  
      struct sockaddr_pppox sp_sv= { AF_PPPOX, PX_PROTO_OE,
  				   { p_in->hdr->sid, {0,},{0,}}};
  
      int ret;
  
  
      if( !tag ) return 0;
  
      pc = get_con(ntohs(tag->tag_len),tag->tag_data);
  
      if( !pc ) return 0;
  
  
      if(!pc->connected){
  	
  	pc->sv_sock = socket( AF_PPPOX, SOCK_DGRAM, PX_PROTO_OE);
  	if( pc->sv_sock < 0){
  	    poe_fatal(ses,"Cannot open PPPoE socket: %i",errno);
  	}
  	
  	pc->cl_sock = socket( AF_PPPOX, SOCK_DGRAM, PX_PROTO_OE);
  	if( pc->cl_sock < 0){
  	    poe_fatal(ses,"Cannot open PPPoE socket: %i",errno);
  	}
  	
  	memcpy( sp_sv.sa_addr.pppoe.dev, ses->fwd_name, IFNAMSIZ);
  	memcpy( sp_sv.sa_addr.pppoe.remote, pc->server, ETH_ALEN);
  	
  	ret = connect( pc->sv_sock,
  		       (struct sockaddr*)&sp_sv,
  		       sizeof(struct sockaddr_pppox));
  	if( ret < 0){
  	    poe_fatal(ses,"Cannot connect PPPoE socket: %i",errno);
  	}
  	
  	memcpy( sp_cl.sa_addr.pppoe.dev, ses->name, IFNAMSIZ);
  	memcpy( sp_cl.sa_addr.pppoe.remote, pc->client, ETH_ALEN);
  	
  	ret = connect( pc->cl_sock,
  		       (struct sockaddr*)&sp_cl,
  		       sizeof(struct sockaddr_pppox));
  	if( ret < 0){
  	    poe_fatal(ses,"Cannot connect PPPoE socket: %i",errno);
  	}
  	
  	
  	ret = ioctl( pc->sv_sock, PPPOEIOCSFWD, &sp_cl);
  	if( ret < 0){
  	    poe_fatal(ses,"Cannot set forwarding on PPPoE socket: %i",errno);
  	}
  	
  	ret = ioctl( pc->cl_sock, PPPOEIOCSFWD, &sp_sv);
  	if( ret < 0){
  	    poe_fatal(ses,"Cannot set forwarding on PPPoE socket: %i",errno);
  	}
  	
  	pc->connected = 1;
      }
  
      poe_info(ses,"PPPoE relay for %E established to %E (sid=%04x)\n",
  	     pc->client,pc->server, p_in->hdr->sid);
  
      return relay_rcv_pkt(ses,p_in,p_out);
  }
  
  
  static int relay_rcv_padt(struct session* ses,
  			  struct pppoe_packet *p_in,
  			  struct pppoe_packet **p_out){
  
      int ret;
      struct pppoe_con *pc;
      char tag_buf[32];
      struct pppoe_tag *tag = p_in->tags[TAG_RELAY_SID];
  
      if( !tag ) return 0;
  
      pc = get_con(ntohs(tag->tag_len),tag->tag_data);
  
      if( !pc ) return 0;
  
      ret = relay_rcv_pkt(ses,p_in,p_out);
  
  
      if(pc->cl_sock>0){
  	close(pc->cl_sock);
      }
  
      if(pc->sv_sock>0){
  	close(pc->sv_sock);
      }
  
      --pc->ref_count;
      if( pc->ref_count == 0 ){
  	delete_con(pc->key_len, pc->key);
  	
  	free(pc);
      }
  }
  
  
  int relay_init_ses(struct session *ses, char* from, char* to)
  {
      int retval = client_init_ses(ses, from);
  
      if(retval<0) return retval;
  
      ses->fwd_sock =  socket(PF_PACKET, SOCK_DGRAM, 0);
      if( ses->fwd_sock < 0 ) {
  	poe_fatal(ses,"Cannot create PF_PACKET socket for PPPoE forwarding\n");
      }
  
      /* Verify the device name , construct ses->local */
      retval = get_sockaddr_ll(to, &ses->remote);
      if (retval < 0)
  	poe_fatal(ses,"relay_init_ses:get_sockaddr_ll failed %m");
  
      retval = bind( ses->fwd_sock ,
  		   (struct sockaddr*)&ses->remote,
  		   sizeof(struct sockaddr_ll));
  
      if( retval < 0 ){
  	poe_fatal(ses,"bind to PF_PACKET socket failed: %m");
      }
  
      memcpy(ses->fwd_name, to, IFNAMSIZ);
      memcpy(ses->name, from, IFNAMSIZ);
  
  
      ses->init_disc = relay_init_disc;
      ses->rcv_padi  = relay_rcv_padi;
      ses->rcv_pado  = relay_rcv_pkt;
      ses->rcv_padr  = relay_rcv_pkt;
      ses->rcv_pads  = relay_rcv_pads;
      ses->rcv_padt  = relay_rcv_padt;
  }
  