sa.cc

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/* -*-  Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*- */
/*
 * Copyright (c) Xerox Corporation 1997. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Linking this file statically or dynamically with other modules is making
 * a combined work based on this file.  Thus, the terms and conditions of
 * the GNU General Public License cover the whole combination.
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 * In addition, as a special exception, the copyright holders of this file
 * give you permission to combine this file with free software programs or
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 * requires distribution of source code.
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 * Note that people who make modified versions of this file are not
 * obligated to grant this special exception for their modified versions;
 * it is their choice whether to do so.  The GNU General Public License
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 * $Header: /nfs/jade/vint/CVSROOT/ns-2/adc/sa.cc,v 1.16 2005/08/26 05:05:28 tomh Exp $
 */

//packets after it succeeds in a3-way handshake from the receiver
// should be connected with Agent/SignalAck class

#include "udp.h"
#include "sa.h"
#include "ip.h"
#include "random.h"

#define SAMPLERATE 8000

SA_Agent::SA_Agent() : Agent(PT_UDP), trafgen_(0), rtd_(0), callback_(0), 
    sa_timer_(this), nextPkttime_(-1), running_(0), seqno_(-1)
{
    bind_bw("rate_",&rate_);
    bind("bucket_",&bucket_);
    bind("packetSize_", &size_);
}

SA_Agent::~SA_Agent()
{
        if (callback_) 
                delete[] callback_;

}


static class SA_AgentClass : public TclClass {
public:
    SA_AgentClass() : TclClass("Agent/SA") {}
    TclObject* create(int, const char*const*) {
        return (new SA_Agent());
    }
} class_signalsource_agent;

int SA_Agent::command(int argc, const char*const* argv)
{
    Tcl& tcl = Tcl::instance();
    if (argc==3) {
        if (strcmp(argv[1], "target") == 0) {
            target_ = (NsObject*)TclObject::lookup(argv[2]);
            if (target_ == 0) {
                tcl.resultf("no such object %s", argv[2]);
                return (TCL_ERROR);
            }
            ctrl_target_=target_;
            return (TCL_OK);
        } 
        else if (strcmp(argv[1],"ctrl-target")== 0) {
            ctrl_target_=(NsObject*)TclObject::lookup(argv[2]);
            if (ctrl_target_ == 0) {
                tcl.resultf("no such object %s", argv[2]);
                return (TCL_ERROR);
            }
            return (TCL_OK);
        }
            if (strcmp(argv[1], "stoponidle") == 0) {
                stoponidle(argv[2]);
            return(TCL_OK);
        }
                if (strcmp(argv[1], "attach-traffic") == 0) {
                        trafgen_ =(TrafficGenerator*)TclObject::lookup(argv[2]);
                        if (trafgen_ == 0) {
                                tcl.resultf("no such node %s", argv[2]);
                                return(TCL_ERROR);
                        }
                        return(TCL_OK);
                }

    }
        if (argc == 2) {
                if (strcmp(argv[1], "start") == 0) {
                        start();
                        return(TCL_OK);
                } else if (strcmp(argv[1], "stop") == 0) {
                        stop();
                        return(TCL_OK);
                }
        }
    return (Agent::command(argc,argv));
}


void SA_Agent::start()
{
    //send the request packet
    if (trafgen_) {
        trafgen_->init();
        //running_=1;
        sendreq();
    }
}

void SA_Agent::stop()
{
    sendteardown();
    if (running_ != 0) {
        sa_timer_.cancel();
        running_ =0;
    }
}


void SA_Agent::sendreq()
{
    Packet *p = allocpkt();
    hdr_cmn* ch= hdr_cmn::access(p);
    ch->ptype()=PT_REQUEST;
    ch->size()=20;
    //also put in the r,b parameters for the flow in the packet
    hdr_resv* rv=hdr_resv::access(p);
    rv->decision() =1;
    rv->rate()=rate_;
    rv->bucket()=bucket_;
    ctrl_target_->recv(p);
}

void SA_Agent::sendteardown()
{
    Packet *p = allocpkt();
    hdr_cmn* ch= hdr_cmn::access(p);
    ch->ptype()=PT_TEARDOWN;
    ch->size()=20;
    //also put in the r,b parameters for the flow in the packet
    hdr_resv* rv=hdr_resv::access(p);
    rv->decision() =1;
    rv->rate()=rate_;
    rv->bucket()=bucket_;
    ctrl_target_->recv(p);
}


void SA_Agent::recv(Packet *p, Handler *) 
{
    hdr_cmn *ch= hdr_cmn::access(p);
    hdr_resv *rv=hdr_resv::access(p);
    hdr_ip * iph = hdr_ip::access(p);
    if ( ch->ptype() == PT_ACCEPT || ch->ptype() == PT_REJECT ) {
        ch->ptype() = PT_CONFIRM;

        // turn the packet around by swapping src and dst
        // (address and port)
        ns_addr_t tmp;
        tmp = iph->src();
        iph->src() = iph->dst();
        iph->dst() = tmp;
        ctrl_target_->recv(p);
    }
    
    // put an additional check here to see if admission was granted
    if (rv->decision()) {
        //printf("Flow %d accepted @ %f\n",iph->flowid(),Scheduler::instance().clock());
        fflush(stdout);
        double t = trafgen_->next_interval(size_);
        running_=1;
        sa_timer_.resched(t);
    }
    else {
        //printf("Flow %d rejected @ %f\n",iph->flowid(),Scheduler::instance().clock());
        fflush(stdout);
        //Currently the flow is stopped if rejected
        running_=0;
    }
    //make an upcall to sched a stoptime for this flow from now
    Tcl::instance().evalf("%s sched-stop %d",name(),rv->decision());
}

void SA_Agent::stoponidle(const char *s)
{
        callback_ = new char[strlen(s)+1];
        strcpy(callback_, s);

        if (trafgen_->on()) {
                // Tcl::instance().evalf("puts \"%s waiting for burst at %f\"", name(), Scheduler::instance().clock());
                rtd_ = 1;
        }
        else {
                stop();
                Tcl::instance().evalf("%s %s", name(), callback_);
        }

}

void SA_Timer::expire(Event* /*e*/) {
        a_->timeout(0);
}

void SA_Agent::timeout(int)
{
        if (running_) {
                /* send a packet */
                sendpkt();
                /* figure out when to send the next one */
                nextPkttime_ = trafgen_->next_interval(size_);
                /* schedule it */
                sa_timer_.resched(nextPkttime_);

                /* hack: if we are waiting for a current burst to end
                 * before stopping . . .
                 */
                if (rtd_) {
                        if (trafgen_->on() == 0) {
                                stop();
                                //Tcl::instance().evalf("puts \"%s burst over at %f\"",
                                // name(), Scheduler::instance().clock());
                                Tcl::instance().evalf("%s sched-stop %d", name(), 0);
                        }
                }
        }
}

void SA_Agent::sendpkt()
{
        Packet* p = allocpkt();
        hdr_rtp* rh = hdr_rtp::access(p);
        rh->seqno() = ++seqno_;
        rh->flags()=0;

        double local_time=Scheduler::instance().clock();
        /*put in "rtp timestamps" and begining of talkspurt labels */
        hdr_cmn* ch = hdr_cmn::access(p);
        ch->timestamp()=(u_int32_t)(SAMPLERATE*local_time);
        ch->size()=size_;
        if ((nextPkttime_ != trafgen_->interval()) || (nextPkttime_ == -1))
                rh->flags() |= RTP_M;

        target_->recv(p);
}

void SA_Agent::sendmsg(int nbytes, const char* /*flags*/)
{
        Packet *p;
        int n;

    assert (size_ > 0);

    n = nbytes / size_;

        if (nbytes == -1) {
                start();
                return;
        }
        while (n-- > 0) {
            p = allocpkt();
                hdr_rtp* rh = hdr_rtp::access(p);
                rh->seqno() = seqno_;
                target_->recv(p);
        }
        n = nbytes % size_;
        if (n > 0) {
            p = allocpkt();
            hdr_rtp* rh = hdr_rtp::access(p);
            rh->seqno() = seqno_;
            target_->recv(p);
        }
        idle();
}

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