ll.cc

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/* -*-  Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*- */
/*
 * Copyright (c) 1997 Regents of the University of California.
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *  This product includes software developed by the Daedalus Research
 *  Group at the University of California Berkeley.
 * 4. Neither the name of the University nor of the Laboratory may be used
 *    to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS OR CONTRIBUTORS BE LIABLE
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 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * Contributed by the Daedalus Research Group, http://daedalus.cs.berkeley.edu
 */

#ifndef lint
static const char rcsid[] =
    "@(#) $Header: /nfs/jade/vint/CVSROOT/ns-2/mac/ll.cc,v 1.46 2002/03/14 01:12:52 haldar Exp $ (UCB)";
#endif

#include <errmodel.h>
#include <mac.h>
#include <ll.h>
#include <address.h>
#include <dsr/hdr_sr.h>

int hdr_ll::offset_;

static class LLHeaderClass : public PacketHeaderClass {
public:
    LLHeaderClass() : PacketHeaderClass("PacketHeader/LL",
                        sizeof(hdr_ll)) {
        bind_offset(&hdr_ll::offset_);
    }
} class_hdr_ll;


static class LLClass : public TclClass {
public:
    LLClass() : TclClass("LL") {}
    TclObject* create(int, const char*const*) {
        return (new LL);
    }
} class_ll;


LL::LL() : LinkDelay(), seqno_(0), ackno_(0), macDA_(0), ifq_(0),
    mac_(0), lanrouter_(0), arptable_(0), varp_(0),
    downtarget_(0), uptarget_(0)
{
    bind("macDA_", &macDA_);
}

int LL::command(int argc, const char*const* argv)
{
    Tcl& tcl = Tcl::instance();
    if (argc == 3) {
        if (strcmp(argv[1], "ifq") == 0) {
            ifq_ = (Queue*) TclObject::lookup(argv[2]);
            return (TCL_OK);
        }
        if(strcmp(argv[1], "arptable") == 0) {
                        arptable_ = (ARPTable*)TclObject::lookup(argv[2]);
                        assert(arptable_);
                        return TCL_OK;
                }
        if(strcmp(argv[1], "varp") == 0) {
                        varp_ = (VARPTable*)TclObject::lookup(argv[2]);
                        assert(varp_);
                        return TCL_OK;
                }
        if (strcmp(argv[1], "mac") == 0) {
            mac_ = (Mac*) TclObject::lookup(argv[2]);
                        assert(mac_);
            return (TCL_OK);
        }
        if (strcmp(argv[1], "down-target") == 0) {
            downtarget_ = (NsObject*) TclObject::lookup(argv[2]);
            return (TCL_OK);
        }
        if (strcmp(argv[1], "up-target") == 0) {
            uptarget_ = (NsObject*) TclObject::lookup(argv[2]);
            return (TCL_OK);
        }
        if (strcmp(argv[1], "lanrouter") == 0) {
            lanrouter_ = (LanRouter*) TclObject::lookup(argv[2]);
            return (TCL_OK);
        }

    }
    else if (argc == 2) {
        if (strcmp(argv[1], "ifq") == 0) {
            tcl.resultf("%s", ifq_->name());
            return (TCL_OK);
        }
        if (strcmp(argv[1], "mac") == 0) {
            tcl.resultf("%s", mac_->name());
            return (TCL_OK);
        }
        if (strcmp(argv[1], "down-target") == 0) {
            tcl.resultf("%s", downtarget_->name());
            return (TCL_OK);
        }
        if (strcmp(argv[1], "up-target") == 0) {
            tcl.resultf("%s", uptarget_->name());
            return (TCL_OK);
        }
    }
    return LinkDelay::command(argc, argv);
}



void LL::recv(Packet* p, Handler* /*h*/)
{
    hdr_cmn *ch = HDR_CMN(p);
    //char *mh = (char*) HDR_MAC(p);
    //struct hdr_sr *hsr = HDR_SR(p);

    /*
     * Sanity Check
     */
    assert(initialized());

    //if(p->incoming) {
    //p->incoming = 0;
    //}
    // XXXXX NOTE: use of incoming flag has been depracated; In order to track direction of pkt flow, direction_ in hdr_cmn is used instead. see packet.h for details.

    // If direction = UP, then pass it up the stack
    // Otherwise, set direction to DOWN and pass it down the stack
    if(ch->direction() == hdr_cmn::UP) {
        //if(mac_->hdr_type(mh) == ETHERTYPE_ARP)
        if(ch->ptype_ == PT_ARP)
            arptable_->arpinput(p, this);
        else
            uptarget_ ? sendUp(p) : drop(p);
        return;
    }

    ch->direction() = hdr_cmn::DOWN;
    sendDown(p);
}


void LL::sendDown(Packet* p)
{   
    hdr_cmn *ch = HDR_CMN(p);
    hdr_ip *ih = HDR_IP(p);

    nsaddr_t dst = (nsaddr_t)Address::instance().get_nodeaddr(ih->daddr());
    //nsaddr_t dst = ih->dst();
    hdr_ll *llh = HDR_LL(p);
    char *mh = (char*)p->access(hdr_mac::offset_);
    
    llh->seqno_ = ++seqno_;
    llh->lltype() = LL_DATA;

    mac_->hdr_src(mh, mac_->addr());
    mac_->hdr_type(mh, ETHERTYPE_IP);
    int tx = 0;
    
    switch(ch->addr_type()) {

    case NS_AF_ILINK:
        mac_->hdr_dst((char*) HDR_MAC(p), ch->next_hop());
        break;

    case NS_AF_INET:
        dst = ch->next_hop();
        /* FALL THROUGH */
        
    case NS_AF_NONE:
        
        if (IP_BROADCAST == (u_int32_t) dst)
        {
            mac_->hdr_dst((char*) HDR_MAC(p), MAC_BROADCAST);
            break;
        }
        /* Assuming arptable is present, send query */
        if (arptable_) {
            tx = arptable_->arpresolve(dst, p, this);
            break;
        }
        //if (varp_) {
        //tx = varp_->arpresolve(dst, p);
        //break;
            
        //}         
        /* FALL THROUGH */

    default:
        
        int IPnh = (lanrouter_) ? lanrouter_->next_hop(p) : -1;
        if (IPnh < 0)
            mac_->hdr_dst((char*) HDR_MAC(p),macDA_);
        else if (varp_)
            tx = varp_->arpresolve(IPnh, p);
        else
            mac_->hdr_dst((char*) HDR_MAC(p), IPnh);
        break;
    }
    
    if (tx == 0) {
        Scheduler& s = Scheduler::instance();
    // let mac decide when to take a new packet from the queue.
        s.schedule(downtarget_, p, delay_);
    }
}



void LL::sendUp(Packet* p)
{

    Scheduler& s = Scheduler::instance();
    if (hdr_cmn::access(p)->error() > 0)
        drop(p);
    else
        s.schedule(uptarget_, p, delay_);
}

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