packet_input.c

支持IPv6的adov路由协议（本人修改后）

    DEBUG(LOG_INFO, 0, "packet_input: pkt to %s", ip6_to_str(dest_addr));
	printf("ZJH:packet_input: pkt to %s\n", ip6_to_str(dest_addr));
#else
    DEBUG(LOG_INFO, 0, "packet_input: pkt to %s", ip_to_str(dest_addr));
#endif /* _IPV6 */

#endif /* DEBUG_PACKET */

    if (dev_name){
	ifindex = name2index(dev_name);
//	printf("ZJH:dev_name:%s if_index:%d\n",dev_name,ifindex);
	}
    else
	ifindex = 0;
#endif				/* NS_PORT */

    /* If the packet is not interesting we just let it go through... */
    //PL:
#ifdef _IPV6
    
    if ((memcmp(&dest_addr, &ipv6_multicast_addr, sizeof(struct in6_addr)) == 0) ||
	/*(memcmp(&dest_addr, &(DEV_IFINDEX(ifindex).ipaddr), 
		sizeof(struct in6_addr)) == 0)  ||*/
	to_my_address(dest_addr)||
	(memcmp(&dest_addr, &(DEV_IFINDEX(ifindex).multicast),
		sizeof(struct in6_addr)) == 0)  ||
	(dest_addr.s6_addr[0]==256) /*multicast address*/
	/* PL: Not sure about this, we don't have netmask
	|| ((internet_gw_mode && this_host.gateway_mode)
	 && ((dest_addr & DEV_IFINDEX(ifindex).netmask) !=
	     DEV_IFINDEX(ifindex).broadcast))
	*/
	)
      {
	//PL: debug
	printf("**** dest_addr = %s, src_addr = %s *****\n", ip6_to_str(dest_addr),
	       ip6_to_str(src_addr));
	printf("goto accept\n");
	goto accept;
      }
#else
    if ((dest_addr == AODV_BROADCAST) ||
	(dest_addr == DEV_IFINDEX(ifindex).ipaddr) ||
	(dest_addr == DEV_IFINDEX(ifindex).broadcast) ||
	((internet_gw_mode && this_host.gateway_mode)
	 && ((dest_addr & DEV_IFINDEX(ifindex).netmask) !=
	     DEV_IFINDEX(ifindex).broadcast)))
	goto accept;
#endif /* _IPV6 */

    /* Find the entry of the neighboring node and the destination  (if any). */
    rev_rt = rt_table_find_active(src_addr);
    fwd_rt = rt_table_find_active(dest_addr);

    //PL: debug
    /*
    printf("dest_addr = %s, src_addr = %s\n", ip6_to_str(dest_addr), ip6_to_str(src_addr));
    
    if(rev_rt != NULL)
      printf("rev_rt != NULL\n");
    else
      printf("rev_rt == NULL\n");

    if(fwd_rt != NULL)
      printf("fwd_rt != NULL\n");
    else
      printf("fwd_rt == NULL\n");
    */

    /* If a packet is received on the NF_IP_PRE_ROUTING hook,
       i.e. inbound on the interface and we don't have a route to the
       destination, we should send an RERR to the source and then drop
       the package... */
    /* NF_IP_PRE_ROUTING = 0 */

#ifdef NS_PORT
#define PACKET_IS_INBOUND ch->direction() == hdr_cmn::UP
#else
#define PACKET_IS_INBOUND pkt->hook == 0
#endif

    //PL:
#ifdef _IPV6
    //if ((memcmp(&dest_addr, &(DEV_IFINDEX(ifindex).ipaddr), sizeof(dest_addr)) != 0)
    if(!to_my_address(dest_addr)
	&& (!fwd_rt && PACKET_IS_INBOUND))
#else
    if ((dest_addr != DEV_IFINDEX(ifindex).ipaddr)
	&& (!fwd_rt && PACKET_IS_INBOUND))
#endif /* _IPV6 */
      {
	rt_table_t *rt_entry;
	RERR *rerr;

	//PL:
#ifdef _IPV6
	struct in6_addr rerr_dest;

	DEBUG(LOG_DEBUG, 0, "packet_input: Sending RERR for unknown dest %s",
	      ip6_to_str(dest_addr));
#else
	u_int32_t rerr_dest;

	DEBUG(LOG_DEBUG, 0, "packet_input: Sending RERR for unknown dest %s",
	      ip_to_str(dest_addr));
#endif /* _IPV6 */


	/* There is an expired entry in the routing table we want to send
	   along the seqno in the RERR... */
	rt_entry = rt_table_find(dest_addr);

	if (rt_entry)
	  {
	    rerr = rerr_create(0, rt_entry->dest_addr, rt_entry->dest_seqno);
	    rt_table_update_timeout(rt_entry, DELETE_PERIOD);
	  } 
	else
	    rerr = rerr_create(0, dest_addr, 0);

	/* Unicast the RERR to the source of the data transmission if
	 * possible, otherwise we broadcast it. */
	//PL:
#ifdef _IPV6
	if (rev_rt)
	    memcpy(&rerr_dest, &rev_rt->next_hop, sizeof(struct in6_addr));
	else
	    memcpy(&rerr_dest, &ipv6_multicast_addr, sizeof(struct in6_addr));
#else
	if (rev_rt)
	    rerr_dest = rev_rt->next_hop;
	else
	    rerr_dest = AODV_BROADCAST;
#endif /* _IPV6 */

	aodv_socket_send((AODV_msg *) rerr, rerr_dest,
			 RERR_CALC_SIZE(rerr), 1, &DEV_IFINDEX(ifindex));

	if (wait_on_reboot) 
	  {
	    DEBUG(LOG_DEBUG, 0, "packet_input: Wait on reboot timer reset.");
	    timer_add_msec(&worb_timer, DELETE_PERIOD);
	  }
#ifdef NS_PORT
	drop(p, DROP_RTR_NO_ROUTE);
#else
	status = ipq_set_verdict(h, pkt->packet_id, NF_DROP, 0, NULL);
	if (status < 0)
	    die(h);
#endif
	return;
      }

    /* Check if the route is currently in repair. In that case just
       buffer the packet */
    repair_rt = rt_table_find(dest_addr);

    if (repair_rt && (repair_rt->flags & LREPAIR)) {
#ifdef NS_PORT
	packet_queue_add(p, dest_addr);
#else
	packet_queue_add(pkt->packet_id, dest_addr);
#endif
	return;
    }
    /*  update_timers:  */
    /* When forwarding a packet, we update the lifetime of the
       destination's routing table entry, as well as the entry for the
       next hop neighbor (if not the same). AODV draft 10, section
       6.2. */
    //PL:
#ifdef _IPV6
    if (fwd_rt &&
	//(memcmp(&dest_addr, &(DEV_IFINDEX(ifindex).ipaddr), sizeof(struct in6_addr)) != 0))
	!to_my_address(dest_addr))
#else
    if (fwd_rt && dest_addr != DEV_IFINDEX(ifindex).ipaddr)
#endif /* _IPV6 */
      {
	rt_table_update_timeout(fwd_rt, ACTIVE_ROUTE_TIMEOUT);

	next_hop_rt = rt_table_find_active(fwd_rt->next_hop);

	//PL:
#ifdef _IPV6
	if (next_hop_rt && 
	    (memcmp(&(next_hop_rt->dest_addr), &(fwd_rt->dest_addr), 
		    sizeof(struct in6_addr)) != 0))
#else
	if (next_hop_rt && next_hop_rt->dest_addr != fwd_rt->dest_addr)
#endif /* _IPV6 */
	  {
	    //PL:
	    /*
	    printf("packet_input: rt_table_update_timeout\n");
	    */
	    rt_table_update_timeout(next_hop_rt, ACTIVE_ROUTE_TIMEOUT);
	  }
      }

    /* Also update the reverse route and reverse next hop along the
       path back, since routes between originators and the destination
       are expected to be symmetric. */
    if (rev_rt) {
	rt_table_update_timeout(rev_rt, ACTIVE_ROUTE_TIMEOUT);

	next_hop_rt = rt_table_find_active(rev_rt->next_hop);

	//PL:
#ifdef _IPV6
	if (next_hop_rt && 
	    (memcmp(&(next_hop_rt->dest_addr), &(fwd_rt->dest_addr),
		    sizeof(struct in6_addr)) != 0))

#else
	if (next_hop_rt && next_hop_rt->dest_addr != fwd_rt->dest_addr)
#endif /* _IPV6 */
	    rt_table_update_timeout(next_hop_rt, ACTIVE_ROUTE_TIMEOUT);
    }
#ifdef DEBUG_PACKET
    //PL:
#ifdef _IPV6
    DEBUG(LOG_INFO, 0, "packet_input: d=%s s=%s",
	  ip6_to_str(dest_addr), ip6_to_str(src_addr));
#else
    DEBUG(LOG_INFO, 0, "packet_input: d=%s s=%s",
	  ip_to_str(dest_addr), ip_to_str(src_addr));
#endif /* _IPV6 */
#endif				/* DEBUG_PACKET */

    if (!fwd_rt || (fwd_rt->hcnt == 1 && (fwd_rt->flags & UNIDIR))) {
	/* Buffer packets... Packets are queued by the ip_queue_aodv.o module
	   already. We only need to save the handle id, and return the proper
	   verdict when we know what to do... */
#ifdef NS_PORT
	packet_queue_add(p, dest_addr);
#else
	seek_entry=seek_list_find(dest_addr);
        /*if (seek_entry&&seek_entry->to_internet) {
		//DEBUG(LOG_INFO, 0, "rreq_route_discovery: Already seeking %s",ip_to_str(dest_addr)); 
		
			packet_queue_add(pkt->packet_id,dest_addr,1);
	}else{
		packet_queue_add(pkt->packet_id, dest_addr,0);
	*/
	
	if(seek_entry){
		packet_queue_add(pkt->packet_id,dest_addr);
	}else{
		packet_queue_add(pkt->packet_id,dest_addr);
	/* If the request is generated locally by an application, we save
	   the IP header + 64 bits of data for sending an ICMP Destination
	   Host Unreachable in case we don't find a route... */
	//PL:
#ifdef _IPV6
		//if (memcmp(&src_addr, &(DEV_IFINDEX(ifindex).ipaddr),sizeof(struct in6_addr)) == 0) 
		if(to_my_address(src_addr))
#else
		if (src_addr == DEV_IFINDEX(ifindex).ipaddr)
#endif /* _IPV6 */
	  	{
	    	ipd = (struct ip_data *) malloc(sizeof(struct ip_data));
	    	if (ipd < 0)
	      	{
			perror("Malloc for IP data failed!");
			exit(-1);
	      	}
	    //PL:
#ifdef _IPV6
	    //PL: No idea at all, just guessing here....
	    	ipd->len = 40 + 8;
#else
	    	ipd->len = (ip->ihl << 2) + 8;	/* IP header + 64 bits data (8 bytes) */
#endif /* _IPV6 */
	    	memcpy(ipd->data, ip, ipd->len);
	  	} 
		else
	  	ipd = NULL;
#endif
		/* Whether need gateway or not */
    		if((internet_gw_mode==0)||
		   (memcmp(&(new_ip6addr_head->ip6_in6addr),&dest_addr,(int)((new_ip6addr_head->plen)/8))==0)){
    			gw_find_flag=GW_FIND_NO_NEED;
			printf("no need gateway!\n");
		}
    		else{
    			gw_find_flag=GW_FIND_NEED;
			printf("need gateway!\n");
		}
	
		rreq_route_discovery(dest_addr, rreq_flags, ipd);
	}
	return;
    }

  accept:

#ifdef NS_PORT
    if (fwd_rt)
	sendPacket(p, fwd_rt->next_hop, 0.0);
    else
	drop(p, DROP_RTR_NO_ROUTE);
#else
    status = ipq_set_verdict(h, pkt->packet_id, NF_ACCEPT, 0, NULL);
    if (status < 0)
	die(h);
#endif
    return;
}