/* -*-	Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*- *//* * Copyright (c) 1991-1997 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 Computer Systems *	Engineering Group at Lawrence Berkeley Laboratory. * 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 * 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. */ /* 8/02 Tom Kelly - Dynamic resizing of seen buffer */#include "flags.h"#include "ip.h"#include "tcp-sink.h"#include "hdr_qs.h"static class TcpSinkClass : public TclClass {public:	TcpSinkClass() : TclClass("Agent/TCPSink") {}	TclObject* create(int, const char*const*) {		return (new TcpSink(new Acker));	}} class_tcpsink;Acker::Acker() : next_(0), maxseen_(0), wndmask_(MWM), ecn_unacked_(0), 	ts_to_echo_(0), last_ack_sent_(0){	seen_ = new int[MWS];	memset(seen_, 0, (sizeof(int) * (MWS)));}void Acker::reset() {	next_ = 0;	maxseen_ = 0;	memset(seen_, 0, (sizeof(int) * (wndmask_ + 1)));}	// dynamically increase the seen buffer as needed// size must be a factor of two for the wndmask_ to work...void Acker::resize_buffers(int sz) { 	int* new_seen = new int[sz];	int new_wndmask = sz - 1;		if(!new_seen){		fprintf(stderr, "Unable to allocate buffer seen_[%i]\n", sz);		exit(1);	}		memset(new_seen, 0, (sizeof(int) * (sz)));		for(int i = next_; i <= maxseen_+1; i++){		new_seen[i & new_wndmask] = seen_[i&wndmask_];	}		delete[] seen_;	seen_ = new_seen;      	wndmask_ = new_wndmask;	return; }void Acker::update_ts(int seqno, double ts, int rfc1323){	// update timestamp if segment advances with ACK.        // Code changed by Andrei Gurtov.        if (rfc1323 && seqno == last_ack_sent_ + 1)               ts_to_echo_ = ts;        else if (ts >= ts_to_echo_ && seqno <= last_ack_sent_ + 1)               //rfc1323-bis, update timestamps from duplicate segments               ts_to_echo_ = ts;}// returns number of bytes that can be "delivered" to application// also updates the receive window (i.e. next_, maxseen, and seen_ array)int Acker::update(int seq, int numBytes){	bool just_marked_as_seen = FALSE;	is_dup_ = FALSE;	// start by assuming the segment hasn't been received before	if (numBytes <= 0)		printf("Error, received TCP packet size <= 0\n");	int numToDeliver = 0;	while(seq + 1 - next_ >= wndmask_) {		// next_ is next packet expected; wndmask_ is the maximum		// window size minus 1; if somehow the seqno of the		// packet is greater than the one we're expecting+wndmask_,		// then resize the buffer.		resize_buffers((wndmask_+1)*2);	}	if (seq > maxseen_) {		// the packet is the highest one we've seen so far		int i;		for (i = maxseen_ + 1; i < seq; ++i)			seen_[i & wndmask_] = 0;		// we record the packets between the old maximum and		// the new max as being "unseen" i.e. 0 bytes of each		// packet have been received		maxseen_ = seq;		seen_[maxseen_ & wndmask_] = numBytes;		// store how many bytes have been seen for this packet		seen_[(maxseen_ + 1) & wndmask_] = 0;		// clear the array entry for the packet immediately		// after this one		just_marked_as_seen = TRUE;		// necessary so this packet isn't confused as being a duplicate	}	int next = next_;	if (seq < next) {		// Duplicate packet case 1: the packet is to the left edge of		// the receive window; therefore we must have seen it		// before#ifdef DEBUGDSACK		printf("%f\t Received duplicate packet %d\n",Scheduler::instance().clock(),seq);#endif		is_dup_ = TRUE;	}	if (seq >= next && seq <= maxseen_) {		// next is the left edge of the recv window; maxseen_		// is the right edge; execute this block if there are		// missing packets in the recv window AND if current		// packet falls within those gaps		if (seen_[seq & wndmask_] && !just_marked_as_seen) {		// Duplicate case 2: the segment has already been		// recorded as being received (AND not because we just		// marked it as such)			is_dup_ = TRUE;#ifdef DEBUGDSACK			printf("%f\t Received duplicate packet %d\n",Scheduler::instance().clock(),seq);#endif		}		seen_[seq & wndmask_] = numBytes;		// record the packet as being seen		while (seen_[next & wndmask_]) {			// this loop first gets executed if seq==next;			// i.e., this is the next packet in order that			// we've been waiting for.  the loop sets how			// many bytes we can now deliver to the			// application, due to this packet arriving			// (and the prior arrival of any segments			// immediately to the right)			numToDeliver += seen_[next & wndmask_];			++next;		}		next_ = next;		// store the new left edge of the window	}	return numToDeliver;}TcpSink::TcpSink(Acker* acker) : Agent(PT_ACK), acker_(acker), save_(NULL),	lastreset_(0.0){	bytes_ = 0; 	bind("bytes_", &bytes_);	/*	 * maxSackBlocks_ does wierd tracing things.	 * don't make it delay-bound yet.	 */#if defined(TCP_DELAY_BIND_ALL) && 0#else /* ! TCP_DELAY_BIND_ALL */	bind("maxSackBlocks_", &max_sack_blocks_); // used only by sack#endif /* TCP_DELAY_BIND_ALL */}voidTcpSink::delay_bind_init_all(){        delay_bind_init_one("packetSize_");        delay_bind_init_one("ts_echo_bugfix_");	delay_bind_init_one("ts_echo_rfc1323_");	delay_bind_init_one("bytes_"); // For throughput measurements in JOBS        delay_bind_init_one("generateDSacks_"); // used only by sack	delay_bind_init_one("qs_enabled_");	delay_bind_init_one("RFC2581_immediate_ack_");#if defined(TCP_DELAY_BIND_ALL) && 0        delay_bind_init_one("maxSackBlocks_");#endif /* TCP_DELAY_BIND_ALL */	Agent::delay_bind_init_all();}intTcpSink::delay_bind_dispatch(const char *varName, const char *localName, TclObject *tracer){        if (delay_bind(varName, localName, "packetSize_", &size_, tracer)) return TCL_OK;        if (delay_bind_bool(varName, localName, "ts_echo_bugfix_", &ts_echo_bugfix_, tracer)) return TCL_OK;	if (delay_bind_bool(varName, localName, "ts_echo_rfc1323_", &ts_echo_rfc1323_, tracer)) return TCL_OK;        if (delay_bind_bool(varName, localName, "generateDSacks_", &generate_dsacks_, tracer)) return TCL_OK;        if (delay_bind_bool(varName, localName, "qs_enabled_", &qs_enabled_, tracer)) return TCL_OK;        if (delay_bind_bool(varName, localName, "RFC2581_immediate_ack_", &RFC2581_immediate_ack_, tracer)) return TCL_OK;#if defined(TCP_DELAY_BIND_ALL) && 0        if (delay_bind(varName, localName, "maxSackBlocks_", &max_sack_blocks_, tracer)) return TCL_OK;#endif /* TCP_DELAY_BIND_ALL */        return Agent::delay_bind_dispatch(varName, localName, tracer);}void Acker::append_ack(hdr_cmn*, hdr_tcp*, int) const{}void Acker::update_ecn_unacked(int value){	ecn_unacked_ = value;}int TcpSink::command(int argc, const char*const* argv){	if (argc == 2) {		if (strcmp(argv[1], "reset") == 0) {			reset();			return (TCL_OK);		}		if (strcmp(argv[1], "resize_buffers") == 0) {			// no need for this as seen buffer set dynamically			fprintf(stderr,"DEPRECIATED: resize_buffers\n");			return (TCL_OK);		}	}	return (Agent::command(argc, argv));}void TcpSink::reset() {	acker_->reset();		save_ = NULL;	lastreset_ = Scheduler::instance().clock(); /* W.N. - for detecting */				/* packets from previous incarnations */}void TcpSink::ack(Packet* opkt){	Packet* npkt = allocpkt();	// opkt is the "old" packet that was received	// npkt is the "new" packet being constructed (for the ACK)	double now = Scheduler::instance().clock();	hdr_tcp *otcp = hdr_tcp::access(opkt);	hdr_ip *oiph = hdr_ip::access(opkt);	hdr_tcp *ntcp = hdr_tcp::access(npkt);	if (qs_enabled_) {		// QuickStart code from Srikanth Sundarrajan.		hdr_qs *oqsh = hdr_qs::access(opkt);		hdr_qs *nqsh = hdr_qs::access(npkt);	        if (otcp->seqno() == 0 && oqsh->flag() == QS_REQUEST) {	                nqsh->flag() = QS_RESPONSE;	                nqsh->ttl() = (oiph->ttl() - oqsh->ttl()) % 256;	                nqsh->rate() = (oqsh->rate() < MWS) ? oqsh->rate() : MWS;	        }	        else {	                nqsh->flag() = QS_DISABLE;	        }	}	// get the tcp headers	ntcp->seqno() = acker_->Seqno();	// get the cumulative sequence number to put in the ACK; this	// is just the left edge of the receive window - 1	ntcp->ts() = now;	// timestamp the packet	if (ts_echo_bugfix_)  /* TCP/IP Illustrated, Vol. 2, pg. 870 */		ntcp->ts_echo() = acker_->ts_to_echo();	else		ntcp->ts_echo() = otcp->ts();	// echo the original's time stamp	hdr_ip* oip = hdr_ip::access(opkt);	hdr_ip* nip = hdr_ip::access(npkt);	// get the ip headers	nip->flowid() = oip->flowid();	// copy the flow id		hdr_flags* of = hdr_flags::access(opkt);	hdr_flags* nf = hdr_flags::access(npkt);	hdr_flags* sf;	if (save_ != NULL)		sf = hdr_flags::access(save_);	else 		sf = 0;		// Look at delayed packet being acked. 	if ( (sf != 0 && sf->cong_action()) || of->cong_action() ) 		// Sender has responsed to congestion. 		acker_->update_ecn_unacked(0);	if ( (sf != 0 && sf->ect() && sf->ce())  || 			(of->ect() && of->ce()) )		// New report of congestion.  		acker_->update_ecn_unacked(1);	if ( (sf != 0 && sf->ect()) || of->ect() )		// Set EcnEcho bit.  		nf->ecnecho() = acker_->ecn_unacked();	if (!of->ect() && of->ecnecho() ||		(sf != 0 && !sf->ect() && sf->ecnecho()) ) 		 // This is the negotiation for ECN-capability.		 // We are not checking for of->cong_action() also. 		 // In this respect, this does not conform to the 		 // specifications in the internet draft 		nf->ecnecho() = 1;	acker_->append_ack(hdr_cmn::access(npkt),			   ntcp, otcp->seqno());	add_to_ack(npkt);	// the above function is used in TcpAsymSink        // Andrei Gurtov        acker_->last_ack_sent_ = ntcp->seqno();        // printf("ACK %d ts %f\n", ntcp->seqno(), ntcp->ts_echo());		send(npkt, 0);	// send it}void TcpSink::add_to_ack(Packet*){	return;}void TcpSink::recv(Packet* pkt, Handler*){	int numToDeliver;	int numBytes = hdr_cmn::access(pkt)->size();	// number of bytes in the packet just received	hdr_tcp *th = hdr_tcp::access(pkt);	/* W.N. Check if packet is from previous incarnation */	if (th->ts() < lastreset_) {		// Remove packet and do nothing		Packet::free(pkt);		return;	}	acker_->update_ts(th->seqno(),th->ts(),ts_echo_rfc1323_);	// update the timestamp to echo	      	numToDeliver = acker_->update(th->seqno(), numBytes);	// update the recv window; figure out how many in-order-bytes	// (if any) can be removed from the window and handed to the	// application	if (numToDeliver) {		bytes_ += numToDeliver;		recvBytes(numToDeliver);	}	// send any packets to the application