--- ../ns-2.1b8-ref/tcp.cc Wed May 30 02:11:04 2001 +++ tcp.cc Sat Jun 22 11:34:37 2002 @@ -37,6 +37,10 @@ "@(#) $Header: /nfs/jade/vint/CVSROOT/ns-2/tcp.cc,v 1.123 2001/05/29 23:11:04 haldar Exp $ (LBL)"; #endif +//AG: eifel stuff +//#define DEBUG(x) printf x; +#define DEBUG(x) + #include #include #include "ip.h" @@ -96,6 +100,10 @@ bind("nrexmitpack_", &nrexmitpack_); bind("nrexmitbytes_", &nrexmitbytes_); bind("singledup_", &singledup_); + bind("eifel_", &eifel_); //AG + bind("eifel_cc_", &eifel_cc_); //AG + bind("eifel_rto_", &eifel_rto_); //AG + #endif /* TCP_DELAY_BIND_ALL */ } @@ -173,6 +181,9 @@ delay_bind_init_one("nrexmitpack_"); delay_bind_init_one("nrexmitbytes_"); delay_bind_init_one("singledup_"); + delay_bind_init_one("eifel_"); //AG + delay_bind_init_one("eifel_cc_"); //AG + delay_bind_init_one("eifel_rto_"); //AG #endif /* TCP_DELAY_BIND_ALL */ Agent::delay_bind_init_all(); @@ -228,6 +239,9 @@ if (delay_bind(varName, localName, "control_increase_", &control_increase_ , tracer)) return TCL_OK; if (delay_bind_bool(varName, localName, "oldCode_", &oldCode_, tracer)) return TCL_OK; if (delay_bind_bool(varName, localName, "timerfix_", &timerfix_, tracer)) return TCL_OK; + if (delay_bind_bool(varName, localName, "eifel_", &eifel_, tracer)) return TCL_OK; //AG + if (delay_bind(varName, localName, "eifel_cc_", &eifel_cc_, tracer)) return TCL_OK; //AG + if (delay_bind(varName, localName, "eifel_rto_", &eifel_rto_, tracer)) return TCL_OK; //AG #ifdef TCP_DELAY_BIND_ALL @@ -396,6 +410,8 @@ boot_time_ = Random::uniform(tcp_tick_); first_decrease_ = 1; + cancel_timers(); //AG + /* Now these variables will be reset - Debojyoti Dutta 12th Oct'2000 */ @@ -528,7 +544,7 @@ if (ecn_) { hf->ect() = 1; // ECN-capable transport } - if (cong_action_) { + if (ecn_ && cong_action_) { //AG hf->cong_action() = TRUE; // Congestion action. cong_action_ = FALSE; } @@ -937,6 +953,11 @@ { double now = Scheduler::instance().clock(); hdr_tcp *tcph = hdr_tcp::access(pkt); + /* AG: FIXME to coexist with FullTcp which sets + t_seqno_ =highest_ack_, while TCP sets t_seqno_ = highest_ack_+ 1; */ + + eifel_ack(pkt); + /* * Wouldn't it be better to set the timer *after* * updating the RTT, instead of *before*? @@ -957,8 +978,12 @@ */ hdr_flags *fh = hdr_flags::access(pkt); if (!fh->no_ts_) { - if (ts_option_) + if (ts_option_) { rtt_update(now - tcph->ts_echo()); + /*AG: reset only if not controlled by eifel routines */ + if (eifel_rto_ != 2) + t_backoff_ = 1; //AG: wasn't reset! + } if (rtt_active_ && tcph->seqno() >= rtt_seq_) { if (!ect_ || !ecn_backoff_ || @@ -967,7 +992,10 @@ * Don't end backoff if still in ECN-Echo with * a congestion window of 1 packet. */ - t_backoff_ = 1; + + /*AG: reset only if not controlled by eifel routines */ + if (eifel_rto_ != 2) + t_backoff_ = 1; ecn_backoff_ = 0; } rtt_active_ = 0; @@ -1031,7 +1059,8 @@ if (!control_increase_ || (control_increase_ && (network_limited() == 1))) - opencwnd(); +//AG FIXME need this? if (!eifel_) + opencwnd(); } if (ect_) { if (!hdr_flags::access(pkt)->ecnecho()) @@ -1238,6 +1267,7 @@ // What if CWND_ACTION_ECN and cwnd < 1? // return; } else { + eifel_timeout(); //AG recover_ = maxseq_; if (highest_ack_ == -1 && wnd_init_option_ == 2) /* @@ -1307,7 +1337,9 @@ * invokes the Tcl finish procedure that was registered with TCP. */ void TcpAgent::finish() -{ +{ + reset(); //AG + reset_eifel(); //AG Tcl::instance().evalf("%s done", this->name()); } @@ -1551,4 +1583,132 @@ dport() // dst port id ); et_->trace(); +} + +void TcpAgent::eifel_timeout() { +//now, even when eifel is off we detect bad RTOs +// if (!eifel_) return; + + // Get the oldest unacknowledeged segment + //AG fixme iss is not used in single TCP agents + int oldest_seg = (highest_ack_ < 0) ? 0 : int(highest_ack_); + + if (eifel_rexmit_no_ == 0){ + DEBUG(("EifelFullTcpAgent::timeout_action - first retransmission %d\n",oldest_seg)); + eifel_rexmit_seq_ = oldest_seg; + eifel_rexmit_no_ = 1; + + eifel_ts_first_rexmit_ = Scheduler::instance().clock(); // that's how FullTcp implements TS + eifel_last_cwnd_ = cwnd_; + eifel_last_ssthresh_ = ssthresh_; + }else{ // eifel_rexmit_no != 0 + if (oldest_seg == eifel_rexmit_seq_){ + DEBUG(("EifelFullTcpAgent::timeout_action - Retransmission No: %d\n",eifel_rexmit_no_+1)) + eifel_rexmit_no_++; + } + } +} + +/* + * For every ACK check if 1) timeout occured 2) it was good or bad timeout + * If Eifel is enabled, respond to timeouts + */ +void TcpAgent::eifel_ack(Packet *p) { + + if (!ts_option_) return; /* cannot detect without timestamps */ + + if ( eifel_rexmit_no_ > 0) { /* check if timeout occured */ + hdr_tcp *tcph = hdr_tcp::access(p); + double ack_ts = tcph->ts_echo(); + + DEBUG(("EifelFullTcpAgent::ack_action - Rexmit Mode: t_seqn_=%d,maxseq_=%d\n",(int)t_seqno_,(int)maxseq_)) + DEBUG(("eifel_ts_first = %f, ts=%f, ts_echo=%f\n",eifel_ts_first_rexmit_,tcph->ts(),tcph->ts_echo())) + + if (ack_ts < eifel_ts_first_rexmit_) { // FIXME: Time is endless,isn't it + + DEBUG(("EifelFullTcpAgent::ack_action - Spurious Timeout: %d\n",recover_)) // so we continue with the next unsent packet + + DEBUG(("bad timeout\n")); + + /* if eifel is disabled, only detect bad timeouts, but no response */ + if (!eifel_) goto no_response; + + t_seqno_ = maxseq_; /* continue transmission from high_seq */ + + /* + * Now revert congestion control + * Note: we don't care about the number of timeouts + */ + switch (eifel_cc_) { + case 1 : /*** full undo */ + cwnd_ = eifel_last_cwnd_; + ssthresh_ = eifel_last_ssthresh_; + break; + case 2 : + /******* cwnd/=2, ssthresh=cwnd */ + cwnd_ = eifel_last_cwnd_/2; + if (int(cwnd_)<2) cwnd_ = 1; + ssthresh_ = cwnd_; //eifel_last_ssthresh_/2; + if (int(ssthresh_) <2) ssthresh_ = 2; + break; + case 3: + /******* sstresh=cwnd, cwnd=1 */ + ssthresh_ = int(eifel_last_cwnd_); + if (int(ssthresh_) <2) ssthresh_ = 2; + cwnd_ = 1; + break; + case 4: + /******* sstresh=cwnd, cwnd/=2 */ + ssthresh_ = int(eifel_last_cwnd_); + if (int(ssthresh_) <2) ssthresh_ = 2; + cwnd_ = eifel_last_cwnd_/2; + if (int(cwnd_)<2) cwnd_ = 1; + break; + case 5: + /******* sstresh=cwnd, cwnd=cwnd */ + ssthresh_ = int(eifel_last_cwnd_); + if (int(ssthresh_) <2) ssthresh_ = 2; + cwnd_ = eifel_last_cwnd_; + if (int(cwnd_)<2) cwnd_ = 1; + break; + default: + ; + /* nothing: We go on with standard TCP behavior + cwnd_ = 1; + ssthresh_ = eifel_last_ssthresh_/2; + */ + } /*switch*/ + + DEBUG(("Eifel::CC: new cwnd=%d, new ssthresh=%d\n",(int)cwnd_,(int)ssthresh_)) + + DEBUG(("Eifel::CC: old RTO %.2f\n", rtt_timeout())) + + /* eifel_rto=2 is dealed with else where */ + if (eifel_rto_==1) { + /* reseed RTO with new RTT sample (ra=rtt, va=rtt/2, t=rtt+4*va) */ + double now = Scheduler::instance().clock(); + t_srtt_=0; //this forces rtt_update to reset srtt and svar + rtt_update(now - tcph->ts_echo()); + set_rtx_timer(); + DEBUG(("Eifel::CC: new RTO %.2f\n", rtt_timeout())) + } + + } /* spurious timeout */ + else { + DEBUG(("unavoidable timeout\n")); + if (eifel_rto_==2) t_backoff_=1; + } + +no_response: + //fflush(stdout); + reset_eifel(); /* this timeout was resolved, prepare for next one */ + + } /* timeout */ +} + +/* init eifel-related variables */ +void TcpAgent::reset_eifel() { + eifel_ts_first_rexmit_ = 0; + eifel_rexmit_seq_ = 0; + eifel_rexmit_no_ = 0; } --- ../ns-2.1b8-ref/tcp.h Mon May 21 22:27:32 2001 +++ tcp.h Sat Jun 22 11:20:43 2002 @@ -263,6 +263,20 @@ * old ECN implementation, which never * reduced the congestion window below * one packet. */ + + /* AG: Eifel related stuff */ + int eifel_; /* use the Eifel algorithm or not */ + int eifel_cc_; /* 1-restore CC fully, 0-not all, etc... see tcp.cc*/ + int eifel_rto_; /* 0-standard rto, 1-reseed after timeout, 2-backoff */ + double eifel_ts_first_rexmit_; /* holds timestamp of first retransmission */ + double eifel_last_cwnd_; /* to save the current cwnd */ + int eifel_last_ssthresh_; /* same for ssthresh */ + int eifel_rexmit_seq_; /* sequence number of retransmitted segment */ + int eifel_rexmit_no_; /* number of retransmissions */ + void eifel_timeout(); + void eifel_ack(Packet*); + void reset_eifel(); + FILE *plotfile_; /* * Dynamic state. --- ../ns-2.1b8-ref/tcp-reno.cc Wed May 30 02:11:04 2001 +++ tcp-reno.cc Sat Jun 22 11:38:47 2002 @@ -1,4 +1,5 @@ -/* -*- Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*- */ +/* -*- Mode:C++; c-basic-offset:8; tab-width:8; +indent-tabs-mode:t -*- */ /* * Copyright (c) 1990, 1997 Regents of the University of California. * All rights reserved. @@ -71,6 +72,7 @@ void RenoTcpAgent::recv(Packet *pkt, Handler*) { + static int k=0; hdr_tcp *tcph = hdr_tcp::access(pkt); #ifdef notdef if (pkt->type_ != PT_ACK) { @@ -98,11 +100,29 @@ } if (++dupacks_ == numdupacks_) { dupack_action(); - dupwnd_ = numdupacks_; + //FIXME AG: ECN + //AG this fixes new segments on dupacks. + if (!bug_fix_ || highest_ack_ > recover_ ||allow_fast_retransmit(last_cwnd_action_)) //AG + dupwnd_ = numdupacks_; +/* AG: this is purely experimental, send new segments on DUPACKs + else if (k++ %2) { + send_one(); + cwnd_++; + } +*/ } else if (dupacks_ > numdupacks_) { - ++dupwnd_; // fast recovery + //AG this fixes new segments on dupacks. + if (!bug_fix_ || highest_ack_ > recover_ ||allow_fast_retransmit(last_cwnd_action_)) //AG + ++dupwnd_; // fast recovery +/* AG: this is purely experimental, send new segments on DUPACKs + else if (k++ %2) { + send_one(); + cwnd_++; + } +*/ } else if (dupacks_ < numdupacks_ && singledup_ ) { send_one(); +// cwnd_++; //AG } } Packet::free(pkt); --- ../ns-2.1b8-ref/tcp-fack.cc Fri Sep 1 06:04:07 2000 +++ tcp-fack.cc Fri May 31 16:42:29 2002 @@ -254,6 +254,7 @@ */ return; }; + eifel_timeout(); //AG // Do not clear fastrecov_ or alter recover_ variable timeout_ = FALSE; if (highest_ack_ > last_ack_) --- ../ns-2.1b8-ref/tcp-full.cc Wed May 30 19:58:36 2001 +++ tcp-full.cc Sat Jun 22 11:44:12 2002 @@ -90,6 +90,9 @@ #include "random.h" #include "template.h" +//AG uncomment to enable logging +//#include "lib-atp.h" + #define TRUE 1 #define FALSE 0 @@ -238,8 +241,9 @@ */ void -FullTcpAgent::pack_action(Packet*) +FullTcpAgent::pack_action(Packet* p) { + eifel_ack(p); //AG if (reno_fastrecov_ && fastrecov_ && cwnd_ > ssthresh_) { cwnd_ = ssthresh_; // retract window if inflated } @@ -443,7 +447,9 @@ else { fh->ecnecho() = recent_ce_; } - fh->cong_action() = cong_action_; + + if (ecn_) //AG + fh->cong_action() = cong_action_; /* actual size is data length plus header length */ @@ -463,7 +469,13 @@ nrexmitbytes_ += datalen; } - last_ack_sent_ = ackno; + last_ack_sent_ = ackno; + + //AG also add t_rtt_ ? + //uncomment to set TTL=RTO + //atp_set_ttl(p, now()+ rtt_timeout()); + //+ (int(t_srtt_) >> T_SRTT_BITS)*tcp_tick_); + send(p, 0); } @@ -818,6 +830,7 @@ recent_age_ = now(); recent_ = tcph->ts(); rtt_update(now() - tcph->ts_echo()); + t_backoff_ = 1; //AG: wasn't reset! } else if (rtt_active_ && ackno > rtt_seq_) { // got an RTT sample, record it t_backoff_ = 1; @@ -966,6 +979,11 @@ int datalen = th->size() - tcph->hlen(); // # payload bytes int ackno = tcph->ackno(); // ack # from packet int tiflags = tcph->flags() ; // tcp flags from packet + + //AG fix by Felix to retransmit lost FINs + if (state_ == TCPS_CLOSED && tiflags & TH_FIN) + goto dropafterack; + if (state_ == TCPS_CLOSED) goto drop; @@ -1357,8 +1375,8 @@ if ((tiflags & TH_ACK) == 0) { fprintf(stderr, "%f: FullTcpAgent::recv(%s) got packet lacking ACK (seq %d)\n", now(), name(), tcph->seqno()); - goto drop; - } + // goto drop; AG: this kills SYNS!! + } /* * Ack processing. @@ -1427,6 +1445,7 @@ // // do fast retransmit/recovery if at/past thresh if (ackno <= highest_ack_) { + // an ACK which doesn't advance highest_ack_ if (datalen == 0 && (!dupseg_fix_ || !dupseg)) { --pipe_; // ACK indicates pkt cached @ receiver @@ -1454,30 +1473,36 @@ ackno != highest_ack_) { // not timed, or re-ordered ACK dupacks_ = 0; - } else if (++dupacks_ == tcprexmtthresh_) { - - fastrecov_ = TRUE; - - /* re-sync the pipe_ estimate */ - pipe_ = maxseq_ - highest_ack_; - pipe_ /= maxseg_; - pipe_ -= (dupacks_ + 1); - -pipe_ = int(cwnd_) - dupacks_ - 1; - - dupack_action(); // maybe fast rexmt + } else { + + //AG fix to prevent fast recovery after RTO + if (cwnd_==1) goto drop; - } else if (dupacks_ > tcprexmtthresh_) { - if (reno_fastrecov_) { - // we just measure cwnd in - // packets, so don't scale by - // maxseg_ as real - // tcp does - cwnd_++; + if (++dupacks_ == tcprexmtthresh_) { + fastrecov_ = TRUE; + + /* re-sync the pipe_ estimate */ + pipe_ = maxseq_ - highest_ack_; + pipe_ /= maxseg_; + pipe_ -= (dupacks_ + 1); + + pipe_ = int(cwnd_) - dupacks_ - 1; + + dupack_action(); // maybe fast rexmt + goto drop; + + } else if (dupacks_ > tcprexmtthresh_) { + if (reno_fastrecov_) { + // we just measure cwnd in + // packets, so don't scale by + // maxseg_ as real + // tcp does + cwnd_++; + } + send_much(0, REASON_NORMAL, maxburst_); + goto drop; } - send_much(0, REASON_NORMAL, maxburst_); - goto drop; } } else { // non zero-length [dataful] segment @@ -1618,6 +1643,7 @@ cancel_timers(); // DOES THIS BELONG HERE?, probably (see tcp_cose #endif finish(); + reset(); //AG goto drop; } else { // should be a FIN we've seen @@ -1832,6 +1858,7 @@ void FullTcpAgent::timeout_action() { + eifel_timeout(); //AG recover_ = maxseq_; if (last_cwnd_action_ == CWND_ACTION_ECN) { slowdown(CLOSE_CWND_ONE); --- ./tcl/lib/ns-default.tcl Wed May 30 19:58:39 2001 +++ ../ns-2.1b8/tcl/lib/ns-default.tcl Thu Apr 25 16:00:16 2002 @@ -664,6 +664,11 @@ Agent/TCP set CoarseTimer_ 0 +#AG +Agent/TCP set eifel_ 0 +Agent/TCP set eifel_cc_ 1 +Agent/TCP set eifel_rto_ 0 + Agent/TCPSink set sport_ 0 Agent/TCPSink set dport_ 0