ipmodule.cc

/*
 * Copyright (c) 2007 Regents of the SIGNET lab, University of Padova.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. Neither the name of the University of Padova (SIGNET lab) 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 THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
 * "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 THE COPYRIGHT OWNER OR 
 * CONTRIBUTORS 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.
 */

#include "ipmodule.h"
#include "ip.h"
#include "ip-clmsg.h"

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

}
} class_ipmodule;

nsaddr_t lastIP = 0;

IPModule::IPModule() : Module()
{
        ipAddr_ = ++lastIP;
}

IPModule::~IPModule()
{
}

int IPModule::command(int argc, const char*const* argv)
{
        Tcl& tcl = Tcl::instance();
        if(argc == 2)
        {
                if (strcasecmp(argv[1],"addr")==0)
                {
                        tcl.resultf("%d", ipAddr_);
                        return TCL_OK;
                }
                else if (strcasecmp(argv[1],"subnet")==0)
                {
                        tcl.resultf("%d", subnet_);
                        return TCL_OK;
                }
                else if (strcasecmp(argv[1],"addr-string")==0)
                {
                        tcl.resultf("%d.%d.%d.%d", (ipAddr_ & 0xff000000)>>24,(ipAddr_ & 0x00ff0000)>>16, (ipAddr_ & 0x0000ff00)>>8, (ipAddr_ & 0x000000ff));
                        return TCL_OK;
                }
                else if (strcasecmp(argv[1],"subnet-string")==0)
                {
                        tcl.resultf("%d.%d.%d.%d", (subnet_ & 0xff000000)>>24,(subnet_ & 0x00ff0000)>>16, (subnet_ & 0x0000ff00)>>8, (subnet_ & 0x000000ff));
                        return TCL_OK;
                }
        }
        else if (argc == 3) {
                if (strcasecmp (argv[1], "addr") == 0) {
                        ipAddr_ = str2addr((char *)argv[2]);
                        if (ipAddr_ == 0)
                          {
                            fprintf(stderr,"0.0.0.0 is not a valid IP address");
                            return TCL_ERROR;
                          }
                        subnet_ = get_subnetaddr(ipAddr_);
                        return TCL_OK;
                }
                else if (strcasecmp (argv[1], "subnet") == 0) {
                        subnet_ = str2sub((char *)argv[2]);
                        return TCL_OK;
                }
        }
        return Module::command(argc, argv);
}

void IPModule::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_ || iph->daddr() == IP_BROADCAST)
                {
                        ch->size() -= IP_HDR_LEN;
                        sendUp(p);
                }
                else
                {
                        /*
                        This is a simple IP module. If you want to add routing feature, put here the code for forward the packets.
                        */
                        drop(p, NOT_FOR_ME_DEPTH, NOT_FOR_ME_REASON);
                }
        }
        else
        {

                iph->saddr() = ipAddr_;
                iph->ttl() = IP_DEF_TTL;
                ch->addr_type() = NS_AF_INET;
                ch->size() += IP_HDR_LEN;
                if ((u_int32_t)iph->daddr() == IP_BROADCAST)
                        ch->next_hop()  = IP_BROADCAST;
                else {
                        ch->next_hop() = iph->daddr();
                }
                sendDown(p);
        }
}

nsaddr_t IPModule::str2addr(const char *str)
{
        int level[4] = {0,0,0,0};
        char tmp[20];
        strncpy(tmp,str,19);
        tmp[19] = '\0';
        char *p = strtok(tmp, ".");
        for(int i = 0; p && i < 4; p = strtok(NULL, "."), i++)
        {
                level[i] = atoi(p);
                if(level[i] > 255)
                        level[i] = 255;
                else if(level[i] < 0)
                        level[i] = 0;
        }
        nsaddr_t addr = 0;
        for(int i = 0; i < 4; i++)
        {
                addr += (level[i] << 8 * (3 - i));
        }
        return addr;
}

nsaddr_t IPModule::str2sub(const char *str)
{
        int level[4] = {0,0,0,0};
        char tmp[20];
        strncpy(tmp,str,19);
        tmp[19] = '\0';
        char *p = strtok(tmp, ".");
        for(int i = 0; p && i < 4; p = strtok(NULL, "."), i++)
        {
                level[i] = atoi(p);
                if(level[i] > 255)
                        level[i] = 255;
                else if(level[i] < 0)
                        level[i] = 0;
        }
        nsaddr_t sub = 0;
        for(int i = 0; i < 4; i++)
        {
                sub += (level[i] << 8 * (3 - i));
        }
        return sub;
}

nsaddr_t IPModule::get_subnetaddr(nsaddr_t addr)
{
        int c = 0;
        nsaddr_t a = (addr & 0xff000000)>>24;
        if (a < 128)
                c = 1;
        else if (a < 192)
                c = 2;
        else if (a < 224)
                c = 3;
        else if (a < 240)
                c = 4;
        else
                c = 5;
        
        if (c > 3)
                return 0;
        
        switch(c)
        {
                case 1:
                        return (nsaddr_t)0xff000000;
                case 2:
                        return (nsaddr_t)0xffff0000;
                case 3:
                        return (nsaddr_t)0xffffff00;
        }
}


int IPModule::recvSyncClMsg(ClMessage* m)
{
        if(m->type() == IP_CLMSG_SEND_ADDR)
        {
                IPClMsgSendAddr *c = new IPClMsgSendAddr(UNICAST, m->getSource());
                c->setAddr(ipAddr_);
//              sendDown(m->getSource(), c);            // DEPRECATED method
                sendAsyncClMsgDown(c);
                return 0;
        }
        return Module::recvSyncClMsg(m);
}

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