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 1.41 2002/03/21 01:46:02 johnh 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::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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