replicator.cc

Go to the documentation of this file.

/* -*-  Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*- */
/*
 * Copyright (c) 1996 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 MASH Research
 *  Group at the University of California Berkeley.
 * 4. Neither the name of the University nor of the Research Group 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
 * 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.
 */

#ifndef lint
static const char rcsid[] =
    "@(#) $Header: /nfs/jade/vint/CVSROOT/ns-2/mcast/replicator.cc,v 1.21 2000/12/20 10:12:48 alefiyah Exp $";
#endif

#include "classifier.h"
#include "packet.h"
#include "ip.h"

/*
 * A replicator is not really a packet classifier but
 * we simply find convenience in leveraging its slot table.
 * (this object used to implement fan-out on a multicast
 * router as well as broadcast LANs)
 */
class Replicator : public Classifier {
public:
    Replicator();
    void recv(Packet*, Handler* h = 0);
    virtual int classify(Packet*) {/*NOTREACHED*/ return -1;};
protected:
    virtual int command(int argc, const char*const* argv);
    int ignore_;
    int direction_;
};

static class ReplicatorClass : public TclClass {
public:
    ReplicatorClass() : TclClass("Classifier/Replicator") {}
    TclObject* create(int, const char*const*) {
        return (new Replicator());
    }
} class_replicator;

Replicator::Replicator() : ignore_(0),direction_(0)
{
    bind("ignore_", &ignore_);
    bind_bool("direction_",&direction_);
}

void Replicator::recv(Packet* p, Handler*)
{
    hdr_ip* iph = hdr_ip::access(p);
    hdr_cmn* ch = hdr_cmn::access(p);
    if (maxslot_ < 0) {
        if (!ignore_) 
            Tcl::instance().evalf("%s drop %ld %ld %d", name(), 
                iph->saddr(), iph->daddr(), ch->iface());
        Packet::free(p);
        return;
    }
    
    //If the direction of the packet is DOWN, 
    // now that is has reached the end of the stack 
    // change the direction to UP
    if(direction_){
        if( HDR_CMN(p)->direction() == hdr_cmn::DOWN){
            ch->direction() = hdr_cmn::UP; // Up the stack 
        }
    }
    for (int i = 0; i < maxslot_; ++i) {
        NsObject* o = slot_[i];
        if (o != 0)
            o->recv(p->copy());
    }
    /* we know that maxslot is non-null */
    slot_[maxslot_]->recv(p);
}

int Replicator::command(int argc, const char*const* argv)
{
    Tcl& tcl = Tcl::instance();
    if (argc == 2) {
        /*
         * $replicator slot
         */
        if (strcmp(argv[1], "slots") == 0) {
            if (maxslot_ < 0) {
                tcl.result("");
                return (TCL_OK);
            }
            for (int i = 0; i <= maxslot_; i++) {
                if (slot_[i] == 0) 
                    continue;
                tcl.resultf("%s %s", tcl.result(),
                        slot_[i]->name());
            }
            return (TCL_OK);
        }
        
    }
    return Classifier::command(argc, argv);
}

---