aodv-interface.cc

AODV version of Uppsala University

/*
 * Copyright (c) 2008, Karlstad University
 * Erik Andersson, Emil Ljungdahl
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the <organization> nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY COPYRIGHT HOLDERS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL <copyright holder> BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This software is based on the original NS-Miracle code found at
 * http://www.dei.unipd.it/wdyn/?IDsezione=3966
 */

#include <ip.h>

#include "aodv-interface.h"

#define NEXT_HOP_UNREACHABLE_DEPHT  5
#define NEXT_HOP_UNREACHABLE_REASON "NHU"

static class AODVInterfaceModuleClass : public TclClass {
	public:
		AODVInterfaceModuleClass() : TclClass("Module/IP/AODVInterface") {}
		TclObject* create(int, const char*const*) {
			return (new AODVInterfaceModule);

		}
} class_aodvinterface_module;


AODVInterfaceModule::AODVInterfaceModule()
{
}

AODVInterfaceModule::~AODVInterfaceModule()
{
}

void AODVInterfaceModule::recv(Packet *p)
{
	hdr_ip *iph = HDR_IP(p);
	hdr_cmn *ch = HDR_CMN(p);

	if(ch->direction() == hdr_cmn::UP)
	{

		if (iph->daddr() == ipAddr_ )
		{
	   // I am the final destination
	   // Unfortunately current IpRouting implementation is not
	   // aware of the IP address of each underlying interface, so
	   // it can only see if the destination is equal to the next
	   // hop. For this reason, the IP Interface module must
	   // explicitly perform the following operation to let
	   // IpRouting do the right thing(TM).
			ch->next_hop_ = iph->daddr();	   
		}

		if  ( (ch->next_hop_ == ipAddr_ )
					 || (iph->daddr() == IP_BROADCAST ) )
		{ // I am either the next hop or the destination,
	  // so I'll forward this packet up
			sendUp(p);
		}
		else
		{ // I am NOT the next hop	  
			drop(p, NOT_FOR_ME_DEPTH, NOT_FOR_ME_REASON);
		}
	}
	else
	{ /* direction DOWN */

		/* Check if next hop can be reached through this interface */
		if ( ! ((ch->next_hop_ & subnet_) == (ipAddr_ & subnet_) || ch->next_hop_ == IP_BROADCAST))
		{
			drop(p,NEXT_HOP_UNREACHABLE_DEPHT, NEXT_HOP_UNREACHABLE_REASON);
		}
		else
		{ // next hop is reachable, packet will be sent through this interface	 


	  		// Set source IP ONLY IF it was not set before 
	  		// (0.0.0.0 is not a valid address)
			if (iph->saddr() == 0)
				iph->saddr() = ipAddr_;

	  		// Mark this IP interface as the previous hop
			ch-> prev_hop_ = ipAddr_;
	
			sendDown(p);
		}
	}
}

int AODVInterfaceModule::command(int argc, const char*const* argv)
{
	Tcl& tcl = Tcl::instance();
	if(argc == 2)
	{
		if(strcasecmp(argv[1],"subnet")==0)
		{
			tcl.resultf("%d", subnet_);
			return TCL_OK;
		}
	}
	else if(argc == 3)
	{
		if (strcasecmp (argv[1], "subnet") == 0) {
			subnet_ = str2sub((char *)argv[2]);
			return TCL_OK;
		}
	}
	return IPModule::command(argc, argv);
}