classifier.cc

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/* -*-  Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*- */
/*
 * Copyright (c) 1996 Regents of the University of California.
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 * 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
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#ifndef lint
static const char rcsid[] =
    "@(#) $Header: /nfs/jade/vint/CVSROOT/ns-2/classifier/classifier.cc,v 1.42 2005/09/26 09:12:46 lacage Exp $";
#endif

#include <stdlib.h>
#include "config.h"
#include "classifier.h"
#include "packet.h"

static class ClassifierClass : public TclClass {
public:
    ClassifierClass() : TclClass("Classifier") {}
    TclObject* create(int, const char*const*) {
        return (new Classifier());
    }
} class_classifier;


Classifier::Classifier() : 
    slot_(0), nslot_(0), maxslot_(-1), shift_(0), mask_(0xffffffff), nsize_(0)
{
    default_target_ = 0;

    bind("offset_", &offset_);
    bind("shift_", &shift_);
    bind("mask_", &mask_);
}

int Classifier::classify(Packet *p)
{
    return (mshift(*((int*) p->access(offset_))));
}

Classifier::~Classifier()
{
    delete [] slot_;
}

void Classifier::set_table_size(int nn)
{
    nsize_ = nn;
}

void Classifier::alloc(int slot)
{
    NsObject** old = slot_;
    int n = nslot_;
    if (old == 0) 
        if (nsize_ != 0) {
            //printf("classifier %x set to %d....%dth visit\n", this, nsize_, i++);
            nslot_ = nsize_;
        }
        else {
            //printf("classifier %x set to 32....%dth visit\n", this, j++);
            nslot_ = 32;
        }
    while (nslot_ <= slot) 
        nslot_ <<= 1;
    slot_ = new NsObject*[nslot_];
    memset(slot_, 0, nslot_ * sizeof(NsObject*));
    for (int i = 0; i < n; ++i)
        slot_[i] = old[i];
    delete [] old;
}


void Classifier::install(int slot, NsObject* p)
{
    if (slot >= nslot_)
        alloc(slot);
    slot_[slot] = p;
    if (slot >= maxslot_)
        maxslot_ = slot;
}

void Classifier::clear(int slot)
{
    slot_[slot] = 0;
    if (slot == maxslot_) {
        while (--maxslot_ >= 0 && slot_[maxslot_] == 0)
            ;
    }
}

int Classifier::allocPort (NsObject *nullagent)
{
    return getnxt (nullagent);
}

int Classifier::getnxt(NsObject *nullagent)
{
    int i;
    for (i=0; i < nslot_; i++)
        if (slot_[i]==0 || slot_[i]==nullagent)
            return i;
    i=nslot_;
    alloc(nslot_);
    return i;
}

/*
 * objects only ever see "packet" events, which come either
 * from an incoming link or a local agent (i.e., packet source).
 */
void Classifier::recv(Packet* p, Handler*h)
{
    NsObject* node = find(p);
    if (node == NULL) {
        /*
         * XXX this should be "dropped" somehow.  Right now,
         * these events aren't traced.
         */
        Packet::free(p);
        return;
    }
    node->recv(p,h);
}

/*
 * perform the mapping from packet to object
 * perform upcall if no mapping
 */

NsObject* Classifier::find(Packet* p)
{
    NsObject* node = NULL;
    int cl = classify(p);
    if (cl < 0 || cl >= nslot_ || (node = slot_[cl]) == 0) { 
        if (default_target_) 
            return default_target_;
        /*
         * Sigh.  Can't pass the pkt out to tcl because it's
         * not an object.
         */
        Tcl::instance().evalf("%s no-slot %ld", name(), cl);
        if (cl == TWICE) {
            /*
             * Try again.  Maybe callback patched up the table.
             */
            cl = classify(p);
            if (cl < 0 || cl >= nslot_ || (node = slot_[cl]) == 0)
                return (NULL);
        }
    }
    return (node);
}

int Classifier::install_next(NsObject *node) {
    int slot = maxslot_ + 1;
    install(slot, node);
    return (slot);
}

int Classifier::command(int argc, const char*const* argv)
{
    Tcl& tcl = Tcl::instance();
    if(argc == 2) {
                if (strcmp(argv[1], "defaulttarget") == 0) {
                        if (default_target_ != 0)
                                tcl.result(default_target_->name());
                        return (TCL_OK);
                }
        } else if (argc == 3) {
        /*
         * $classifier alloc-port nullagent
         */
        if (strcmp(argv[1],"alloc-port") == 0) {
            int slot;
            NsObject* nullagent =
                (NsObject*)TclObject::lookup(argv[2]);
            slot = getnxt(nullagent);
            tcl.resultf("%u",slot);
            return(TCL_OK);
        }
        /*
         * $classifier clear $slot
         */
        if (strcmp(argv[1], "clear") == 0) {
            int slot = atoi(argv[2]);
            clear(slot);
            return (TCL_OK);
        }
        /*
         * $classifier installNext $node
         */
        if (strcmp(argv[1], "installNext") == 0) {
            //int slot = maxslot_ + 1;
            NsObject* node = (NsObject*)TclObject::lookup(argv[2]);
            if (node == NULL) {
                tcl.resultf("Classifier::installNext attempt "
            "to install non-object %s into classifier", argv[2]);
                return TCL_ERROR;
            };
            int slot = install_next(node);
            tcl.resultf("%u", slot);
            return TCL_OK;
        }
        /*
         * $classifier slot snum
         * returns the name of the object in slot # snum
         */
        if (strcmp(argv[1], "slot") == 0) {
            int slot = atoi(argv[2]);
            if (slot >= 0 && slot < nslot_ && slot_[slot] != NULL) {
                tcl.resultf("%s", slot_[slot]->name());
                return TCL_OK;
            }
            tcl.resultf("Classifier: no object at slot %d", slot);
            return (TCL_ERROR);
        }
        /*
         * $classifier findslot $node
         * finds the slot containing $node
         */
        if (strcmp(argv[1], "findslot") == 0) {
            int slot = 0;
            NsObject* node = (NsObject*)TclObject::lookup(argv[2]);
            if (node == NULL) {
                return (TCL_ERROR);
            }
            while (slot < nslot_) {
                // check if the slot is empty (xuanc, 1/14/02) 
                // fix contributed by Frank A. Zdarsky 
                // <frank.zdarsky@kom.tu-darmstadt.de>
                if (slot_[slot] && 
                    strcmp(slot_[slot]->name(), argv[2]) == 0){
                    tcl.resultf("%u", slot);
                    return (TCL_OK);
                }
                slot++;
            }
            tcl.result("-1");
            return (TCL_OK);
        }
        if (strcmp(argv[1], "defaulttarget") == 0) {
            default_target_=(NsObject*)TclObject::lookup(argv[2]);
            if (default_target_ == 0)
                return TCL_ERROR;
            return TCL_OK;
        }
    } else if (argc == 4) {
        /*
         * $classifier install $slot $node
         */
        if (strcmp(argv[1], "install") == 0) {
            int slot = atoi(argv[2]);
            NsObject* node = (NsObject*)TclObject::lookup(argv[3]);
            install(slot, node);
            return (TCL_OK);
        }
    }
    return (NsObject::command(argc, argv));
}

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