/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */
/*
* Copyright (c) 2007 Georgia Tech Research Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation;
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Author: Raj Bhattacharjea <raj.b@gatech.edu>
*/
#include "ns3/node.h"
#include "ns3/inet-socket-address.h"
#include "ns3/log.h"
#include "ns3/ipv4.h"
#include "ns3/ipv4-interface-address.h"
#include "ns3/ipv4-route.h"
#include "tcp-socket-impl.h"
#include "tcp-l4-protocol.h"
#include "ipv4-end-point.h"
#include "ns3/simulation-singleton.h"
#include "tcp-typedefs.h"
#include "ns3/simulator.h"
#include "ns3/packet.h"
#include "ns3/uinteger.h"
#include "ns3/trace-source-accessor.h"
#include <algorithm>
NS_LOG_COMPONENT_DEFINE ("TcpSocketImpl");
using namespace std;
namespace ns3 {
NS_OBJECT_ENSURE_REGISTERED (TcpSocketImpl);
TypeId
TcpSocketImpl::GetTypeId ()
{
static TypeId tid = TypeId("ns3::TcpSocketImpl")
.SetParent<TcpSocket> ()
.AddTraceSource ("CongestionWindow",
"The TCP connection's congestion window",
MakeTraceSourceAccessor (&TcpSocketImpl::m_cWnd))
;
return tid;
}
TcpSocketImpl::TcpSocketImpl ()
: m_skipRetxResched (false),
m_dupAckCount (0),
m_delAckCount (0),
m_endPoint (0),
m_node (0),
m_tcp (0),
m_localAddress (Ipv4Address::GetZero ()),
m_localPort (0),
m_errno (ERROR_NOTERROR),
m_shutdownSend (false),
m_shutdownRecv (false),
m_connected (false),
m_state (CLOSED),
m_closeNotified (false),
m_closeRequestNotified (false),
m_closeOnEmpty (false),
m_pendingClose (false),
m_nextTxSequence (0),
m_highTxMark (0),
m_highestRxAck (0),
m_lastRxAck (0),
m_nextRxSequence (0),
m_rxAvailable (0),
m_rxBufSize (0),
m_pendingData (0),
m_rxWindowSize (0),
m_persistTime (Seconds(6)), //XXX hook this into attributes?
m_rtt (0),
m_lastMeasuredRtt (Seconds(0.0))
{
NS_LOG_FUNCTION (this);
}
TcpSocketImpl::TcpSocketImpl(const TcpSocketImpl& sock)
: TcpSocket(sock), //copy object::m_tid, copy socket::callbacks
m_skipRetxResched (sock.m_skipRetxResched),
m_dupAckCount (sock.m_dupAckCount),
m_delAckCount (0),
m_delAckMaxCount (sock.m_delAckMaxCount),
m_delAckTimeout (sock.m_delAckTimeout),
m_endPoint (0),
m_node (sock.m_node),
m_tcp (sock.m_tcp),
m_remoteAddress (sock.m_remoteAddress),
m_remotePort (sock.m_remotePort),
m_localAddress (sock.m_localAddress),
m_localPort (sock.m_localPort),
m_errno (sock.m_errno),
m_shutdownSend (sock.m_shutdownSend),
m_shutdownRecv (sock.m_shutdownRecv),
m_connected (sock.m_connected),
m_state (sock.m_state),
m_closeNotified (sock.m_closeNotified),
m_closeRequestNotified (sock.m_closeRequestNotified),
m_closeOnEmpty (sock.m_closeOnEmpty),
m_pendingClose (sock.m_pendingClose),
m_nextTxSequence (sock.m_nextTxSequence),
m_highTxMark (sock.m_highTxMark),
m_highestRxAck (sock.m_highestRxAck),
m_lastRxAck (sock.m_lastRxAck),
m_nextRxSequence (sock.m_nextRxSequence),
m_rxAvailable (0),
m_rxBufSize (0),
m_pendingData (0),
m_segmentSize (sock.m_segmentSize),
m_rxWindowSize (sock.m_rxWindowSize),
m_cWnd (sock.m_cWnd),
m_ssThresh (sock.m_ssThresh),
m_initialCWnd (sock.m_initialCWnd),
m_persistTime (sock.m_persistTime),
m_rtt (0),
m_lastMeasuredRtt (Seconds(0.0)),
m_cnTimeout (sock.m_cnTimeout),
m_cnCount (sock.m_cnCount),
m_sndBufSize (sock.m_sndBufSize),
m_rxBufMaxSize(sock.m_rxBufMaxSize)
{
NS_LOG_FUNCTION_NOARGS ();
NS_LOG_LOGIC("Invoked the copy constructor");
//copy the pending data if necessary
if(sock.m_pendingData)
{
m_pendingData = sock.m_pendingData->Copy();
}
//copy the rtt if necessary
if (sock.m_rtt)
{
m_rtt = sock.m_rtt->Copy();
}
//null out the socket base class callbacks,
//make user of the socket register this explicitly
Callback<void, Ptr< Socket > > vPS =
MakeNullCallback<void, Ptr<Socket> > ();
Callback<void, Ptr<Socket>, const Address &> vPSA =
MakeNullCallback<void, Ptr<Socket>, const Address &> ();
Callback<void, Ptr<Socket>, uint32_t> vPSUI =
MakeNullCallback<void, Ptr<Socket>, uint32_t> ();
SetConnectCallback (vPS, vPS);
SetDataSentCallback (vPSUI);
SetSendCallback (vPSUI);
SetRecvCallback (vPS);
//can't "copy" the endpoint just yes, must do this when we know the peer info
//too; this is in SYN_ACK_TX
}
TcpSocketImpl::~TcpSocketImpl ()
{
NS_LOG_FUNCTION(this);
m_node = 0;
if (m_endPoint != 0)
{
NS_ASSERT (m_tcp != 0);
/**
* Note that this piece of code is a bit tricky:
* when DeAllocate is called, it will call into
* Ipv4EndPointDemux::Deallocate which triggers
* a delete of the associated endPoint which triggers
* in turn a call to the method ::Destroy below
* will will zero the m_endPoint field.
*/
NS_ASSERT (m_endPoint != 0);
m_tcp->DeAllocate (m_endPoint);
NS_ASSERT (m_endPoint == 0);
}
m_tcp = 0;
delete m_pendingData; //prevents leak
m_pendingData = 0;
}
void
TcpSocketImpl::SetNode (Ptr<Node> node)
{
m_node = node;
// Initialize some variables
m_cWnd = m_initialCWnd * m_segmentSize;
}
void
TcpSocketImpl::SetTcp (Ptr<TcpL4Protocol> tcp)
{
m_tcp = tcp;
}
void
TcpSocketImpl::SetRtt (Ptr<RttEstimator> rtt)
{
m_rtt = rtt;
}
enum Socket::SocketErrno
TcpSocketImpl::GetErrno (void) const
{
NS_LOG_FUNCTION_NOARGS ();
return m_errno;
}
Ptr<Node>
TcpSocketImpl::GetNode (void) const
{
NS_LOG_FUNCTION_NOARGS ();
return m_node;
}
void
TcpSocketImpl::Destroy (void)
{
NS_LOG_FUNCTION_NOARGS ();
m_node = 0;
m_endPoint = 0;
m_tcp = 0;
NS_LOG_LOGIC (this<<" Cancelled ReTxTimeout event which was set to expire at "
<< (Simulator::Now () +
Simulator::GetDelayLeft (m_retxEvent)).GetSeconds());
m_retxEvent.Cancel ();
}
int
TcpSocketImpl::FinishBind (void)
{
NS_LOG_FUNCTION_NOARGS ();
if (m_endPoint == 0)
{
return -1;
}
m_endPoint->SetRxCallback (MakeCallback (&TcpSocketImpl::ForwardUp, Ptr<TcpSocketImpl>(this)));
m_endPoint->SetDestroyCallback (MakeCallback (&TcpSocketImpl::Destroy, Ptr<TcpSocketImpl>(this)));
m_localAddress = m_endPoint->GetLocalAddress ();
m_localPort = m_endPoint->GetLocalPort ();
return 0;
}
int
TcpSocketImpl::Bind (void)
{
NS_LOG_FUNCTION_NOARGS ();
m_endPoint = m_tcp->Allocate ();
return FinishBind ();
}
int
TcpSocketImpl::Bind (const Address &address)
{
NS_LOG_FUNCTION (this<<address);
if (!InetSocketAddress::IsMatchingType (address))
{
m_errno = ERROR_INVAL;
return -1;
}
InetSocketAddress transport = InetSocketAddress::ConvertFrom (address);
Ipv4Address ipv4 = transport.GetIpv4 ();
uint16_t port = transport.GetPort ();
if (ipv4 == Ipv4Address::GetAny () && port == 0)
{
m_endPoint = m_tcp->Allocate ();
NS_LOG_LOGIC ("TcpSocketImpl "<<this<<" got an endpoint: "<<m_endPoint);
}
else if (ipv4 == Ipv4Address::GetAny () && port != 0)
{
m_endPoint = m_tcp->Allocate (port);
NS_LOG_LOGIC ("TcpSocketImpl "<<this<<" got an endpoint: "<<m_endPoint);
}
else if (ipv4 != Ipv4Address::GetAny () && port == 0)
{
m_endPoint = m_tcp->Allocate (ipv4);
NS_LOG_LOGIC ("TcpSocketImpl "<<this<<" got an endpoint: "<<m_endPoint);
}
else if (ipv4 != Ipv4Address::GetAny () && port != 0)
{
m_endPoint = m_tcp->Allocate (ipv4, port);
NS_LOG_LOGIC ("TcpSocketImpl "<<this<<" got an endpoint: "<<m_endPoint);
}
return FinishBind ();
}
int
TcpSocketImpl::ShutdownSend (void)
{
NS_LOG_FUNCTION_NOARGS ();
m_shutdownSend = true;
return 0;
}
int
TcpSocketImpl::ShutdownRecv (void)
{
NS_LOG_FUNCTION_NOARGS ();
m_shutdownRecv = true;
return 0;
}
int
TcpSocketImpl::Close (void)
{
NS_LOG_FUNCTION_NOARGS ();
if (m_pendingData && m_pendingData->Size() != 0)
{ // App close with pending data must wait until all data transmitted
m_closeOnEmpty = true;
NS_LOG_LOGIC("Socket " << this <<
" deferring close, state " << m_state);
return 0;
}
Actions_t action = ProcessEvent (APP_CLOSE);
ProcessAction (action);
ShutdownSend ();
return 0;
}
int
TcpSocketImpl::Connect (const Address & address)
{
NS_LOG_FUNCTION (this << address);
Ptr<Ipv4> ipv4 = m_node->GetObject<Ipv4> ();
if (m_endPoint == 0)
{
if (Bind () == -1)
{
NS_ASSERT (m_endPoint == 0);
return -1;
}
NS_ASSERT (m_endPoint != 0);
}
InetSocketAddress transport = InetSocketAddress::ConvertFrom (address);
m_remoteAddress = transport.GetIpv4 ();
m_remotePort = transport.GetPort ();
if (ipv4->GetRoutingProtocol () != 0)
{
Ipv4Header header;
header.SetDestination (m_remoteAddress);
Socket::SocketErrno errno;
Ptr<Ipv4Route> route;
uint32_t oif = 0; //specify non-zero if bound to a source address
// XXX here, cache the route in the endpoint?
route = ipv4->GetRoutingProtocol ()->RouteOutput (header, oif, errno);
if (route != 0)
{
NS_LOG_LOGIC ("Route exists");
m_endPoint->SetLocalAddress (route->GetSource ());
}
else
{
NS_LOG_LOGIC ("TcpSocketImpl::Connect(): Route to " << m_remoteAddress << " does not exist");
NS_LOG_ERROR (errno);
m_errno = errno;
return -1;
}
}
else
{
NS_FATAL_ERROR ("No Ipv4RoutingProtocol in the node");
}
Actions_t action = ProcessEvent (APP_CONNECT);
bool success = ProcessAction (action);
if (success)
{
return 0;
}
return -1;
}
//p here is just data, no headers
int
TcpSocketImpl::Send (Ptr<Packet> p, uint32_t flags)
{
NS_LOG_FUNCTION (this << p);
if (m_state == ESTABLISHED || m_state == SYN_SENT || m_state == CLOSE_WAIT)
{
if (p->GetSize() > GetTxAvailable ())
{
m_errno = ERROR_MSGSIZE;
return -1;
}
if (!m_pendingData)
{
m_pendingData = new PendingData (); // Create if non-existent
m_firstPendingSequence = m_nextTxSequence; // Note seq of first
}
//PendingData::Add stores a copy of the Ptr p
m_pendingData->Add (p);
NS_LOG_DEBUG("TcpSock::Send, pdsize " << m_pendingData->Size() <<
" state " << m_state);
Actions_t action = ProcessEvent (APP_SEND);
NS_LOG_DEBUG(" action " << action);
if (!ProcessAction (action))
{
return -1; // Failed, return zero
}
return p->GetSize();
}
else
{
m_errno = ERROR_NOTCONN;
return -1;
}
}
int TcpSocketImpl::DoSendTo (Ptr<Packet> p, const Address &address)
{
NS_LOG_FUNCTION (this << p << address);
InetSocketAddress transport = InetSocketAddress::ConvertFrom (address);
Ipv4Address ipv4 = transport.GetIpv4 ();
uint16_t port = transport.GetPort ();
return DoSendTo (p, ipv4, port);
}
int TcpSocketImpl::DoSendTo (Ptr<Packet> p, Ipv4Address ipv4, uint16_t port)
{
NS_LOG_FUNCTION (this << p << ipv4 << port);
if (m_endPoint == 0)
{
if (Bind () == -1)
{
NS_ASSERT (m_endPoint == 0);
return -1;
}
NS_ASSERT (m_endPoint != 0);
}
if (m_shutdownSend)
{
m_errno = ERROR_SHUTDOWN;
return -1;
}
m_tcp->Send (p, m_endPoint->GetLocalAddress (), ipv4,
m_endPoint->GetLocalPort (), port);
NotifyDataSent (p->GetSize ());
return 0;
}
int
TcpSocketImpl::SendTo (Ptr<Packet> p, uint32_t flags, const Address &address)
{
NS_LOG_FUNCTION (this << address << p);
if (!m_connected)
{
m_errno = ERROR_NOTCONN;
return -1;
}
else
{
return Send (p, flags); //drop the address according to BSD manpages
}
}
uint32_t
TcpSocketImpl::GetTxAvailable (void) const
{
NS_LOG_FUNCTION_NOARGS ();
if (m_pendingData != 0)
{
uint32_t unAckedDataSize =
m_pendingData->SizeFromSeq (m_firstPendingSequence, m_highestRxAck);
NS_ASSERT (m_sndBufSize >= unAckedDataSize); //else a logical error
return m_sndBufSize-unAckedDataSize;
}
else
{
return m_sndBufSize;
}
}
int
TcpSocketImpl::Listen (void)
{
NS_LOG_FUNCTION (this);
// Linux quits EINVAL if we're not closed, so match what they do
if (m_state != CLOSED)
{
m_errno = ERROR_INVAL;
return -1;
}
Actions_t action = ProcessEvent (APP_LISTEN);
ProcessAction (action);
return 0;
}
Ptr<Packet>
TcpSocketImpl::Recv (uint32_t maxSize, uint32_t flags)
{
NS_LOG_FUNCTION_NOARGS ();
if(m_bufferedData.empty())
{
if(m_state == CLOSE_WAIT) //means EOF
{
return Create<Packet>();
}
//else, means nothing to read
return 0;
}
UnAckData_t out; //serves as buffer to return up to the user
UnAckData_t::iterator i;
while (!m_bufferedData.empty ())
{ // Check the buffered data for delivery
NS_LOG_LOGIC("TCP " << this << " bufferedData.size() "
<< m_bufferedData.size ()
<< " time " << Simulator::Now ());
i = m_bufferedData.begin ();
SequenceNumber s1 = 0;
if (i->first > m_nextRxSequence)
{
break; // we're done, no more in-sequence data exits
}
else // (i->first <= m_nextRxSequence)
{ // Two cases here.
// 1) seq + length > nextRxSeq, can deliver partial
// 2) seq + length <= nextRxSeq, deliver whole
s1 = i->second->GetSize ();
if (i->first + s1 > m_nextRxSequence)
{ // Remove partial data to prepare for delivery
uint32_t avail = s1 + i->first - m_nextRxSequence;
i->second = i->second->CreateFragment (0, avail);
}
// else this packet is okay to deliver whole
// so don't do anything else and output it
out[i->first] = i->second;
}
m_rxAvailable -= i->second->GetSize ();
m_rxBufSize -= i->second->GetSize ();
m_bufferedData.erase (i); // Remove from list
}
if (out.size() == 0)
{
return 0;
}
Ptr<Packet> outPacket = Create<Packet>();
for(i = out.begin(); i!=out.end(); ++i)
{
if (outPacket->GetSize() + i->second->GetSize() <= maxSize )
{
outPacket->AddAtEnd(i->second);
}
else
{
//only append as much as will fit
uint32_t avail = maxSize - outPacket->GetSize();
outPacket->AddAtEnd(i->second->CreateFragment(0,avail));
//put the rest back into the buffer
m_bufferedData[i->first+SequenceNumber(avail)]
= i->second->CreateFragment(avail,i->second->GetSize()-avail);
m_rxAvailable += i->second->GetSize()-avail;
m_rxBufSize += i->second->GetSize()-avail;
}
}
return outPacket;
}
uint32_t
TcpSocketImpl::GetRxAvailable (void) const
{
NS_LOG_FUNCTION_NOARGS ();
// We separately maintain this state to avoid walking the queue
// every time this might be called
return m_rxAvailable;
}
Ptr<Packet>
TcpSocketImpl::RecvFrom (uint32_t maxSize, uint32_t flags,
Address &fromAddress)
{
NS_LOG_FUNCTION (this << maxSize << flags);
Ptr<Packet> packet = Recv (maxSize, flags);
//Null packet means no data to read, and an empty packet indicates EOF
if (packet != 0 && packet->GetSize() != 0)
{
SocketAddressTag tag;
bool found;
found = packet->FindFirstMatchingTag (tag);
NS_ASSERT (found);
fromAddress = tag.GetAddress ();
}
return packet;
}
int
TcpSocketImpl::GetSockName (Address &address) const
{
NS_LOG_FUNCTION_NOARGS ();
address = InetSocketAddress(m_localAddress, m_localPort);
return 0;
}
void
TcpSocketImpl::ForwardUp (Ptr<Packet> packet, Ipv4Address ipv4, uint16_t port)
{
NS_LOG_DEBUG("Socket " << this << " got forward up" <<
" dport " << m_endPoint->GetLocalPort() <<
" daddr " << m_endPoint->GetLocalAddress() <<
" sport " << m_endPoint->GetPeerPort() <<
" saddr " << m_endPoint->GetPeerAddress());
NS_LOG_FUNCTION (this << packet << ipv4 << port);
if (m_shutdownRecv)
{
return;
}
TcpHeader tcpHeader;
packet->RemoveHeader (tcpHeader);
if (tcpHeader.GetFlags () & TcpHeader::ACK)
{
Time m = m_rtt->AckSeq (tcpHeader.GetAckNumber () );
if (m != Seconds (0.0))
{
m_lastMeasuredRtt = m;
}
}
if (m_rxWindowSize == 0 && tcpHeader.GetWindowSize () != 0)
{ //persist probes end
NS_LOG_LOGIC (this<<" Leaving zerowindow persist state");
m_persistEvent.Cancel ();
}
m_rxWindowSize = tcpHeader.GetWindowSize (); //update the flow control window
Events_t event = SimulationSingleton<TcpStateMachine>::Get ()->FlagsEvent (tcpHeader.GetFlags () );
Actions_t action = ProcessEvent (event); //updates the state
Address address = InetSocketAddress (ipv4, port);
NS_LOG_DEBUG("Socket " << this <<
" processing pkt action, " << action <<
" current state " << m_state);
ProcessPacketAction (action, packet, tcpHeader, address);
}
Actions_t TcpSocketImpl::ProcessEvent (Events_t e)
{
NS_LOG_FUNCTION (this << e);
States_t saveState = m_state;
NS_LOG_LOGIC ("TcpSocketImpl " << this << " processing event " << e);
// simulation singleton is a way to get a single global static instance of a
// class intended to be a singleton; see simulation-singleton.h
SA stateAction = SimulationSingleton<TcpStateMachine>::Get ()->Lookup (m_state,e);
// debug
if (stateAction.action == RST_TX)
{
NS_LOG_LOGIC ("TcpSocketImpl " << this << " sending RST from state "
<< saveState << " event " << e);
}
bool needCloseNotify = (stateAction.state == CLOSED && m_state != CLOSED
&& e != TIMEOUT);
m_state = stateAction.state;
NS_LOG_LOGIC ("TcpSocketImpl " << this << " moved from state " << saveState
<< " to state " <<m_state);
NS_LOG_LOGIC ("TcpSocketImpl " << this << " pendingData " << m_pendingData);
//extra event logic is here for RX events
//e = SYN_ACK_RX
if (saveState == SYN_SENT && m_state == ESTABLISHED)
// this means the application side has completed its portion of
// the handshaking
{
Simulator::ScheduleNow(&TcpSocketImpl::ConnectionSucceeded, this);
//NotifyConnectionSucceeded ();
m_connected = true;
m_endPoint->SetPeer (m_remoteAddress, m_remotePort);
NS_LOG_LOGIC ("TcpSocketImpl " << this << " Connected!");
}
if (needCloseNotify && !m_closeNotified)
{
NS_LOG_LOGIC ("TcpSocketImpl " << this << " transition to CLOSED from "
<< m_state << " event " << e << " closeNot " << m_closeNotified
<< " action " << stateAction.action);
m_closeNotified = true;
NS_LOG_LOGIC ("TcpSocketImpl " << this << " calling Closed from PE"
<< " origState " << saveState
<< " event " << e);
NS_LOG_LOGIC ("TcpSocketImpl " << this << " transition to CLOSED from "
<< m_state << " event " << e
<< " set CloseNotif ");
}
return stateAction.action;
}
void TcpSocketImpl::SendEmptyPacket (uint8_t flags)
{
NS_LOG_FUNCTION (this << (uint32_t)flags);
Ptr<Packet> p = Create<Packet> ();
TcpHeader header;
if (flags & TcpHeader::FIN)
{
flags |= TcpHeader::ACK;
}
header.SetFlags (flags);
header.SetSequenceNumber (m_nextTxSequence);
header.SetAckNumber (m_nextRxSequence);
header.SetSourcePort (m_endPoint->GetLocalPort ());
header.SetDestinationPort (m_remotePort);
header.SetWindowSize (AdvertisedWindowSize());
m_tcp->SendPacket (p, header, m_endPoint->GetLocalAddress (),
m_remoteAddress);
Time rto = m_rtt->RetransmitTimeout ();
bool hasSyn = flags & TcpHeader::SYN;
bool hasFin = flags & TcpHeader::FIN;
bool isAck = flags == TcpHeader::ACK;
if (hasSyn)
{
rto = m_cnTimeout;
m_cnTimeout = m_cnTimeout + m_cnTimeout;
m_cnCount--;
}
if (m_retxEvent.IsExpired () && (hasSyn || hasFin) && !isAck )
//no outstanding timer
{
NS_LOG_LOGIC ("Schedule retransmission timeout at time "
<< Simulator::Now ().GetSeconds () << " to expire at time "
<< (Simulator::Now () + rto).GetSeconds ());
m_retxEvent = Simulator::Schedule (rto, &TcpSocketImpl::ReTxTimeout, this);
}
}
bool TcpSocketImpl::ProcessAction (Actions_t a)
{ // These actions do not require a packet or any TCP Headers
NS_LOG_FUNCTION (this << a);
switch (a)
{
case NO_ACT:
NS_LOG_LOGIC ("TcpSocketImpl " << this <<" Action: NO_ACT");
break;
case ACK_TX:
SendEmptyPacket (TcpHeader::ACK);
break;
case ACK_TX_1:
NS_ASSERT (false); // This should be processed in ProcessPacketAction
break;
case RST_TX:
NS_LOG_LOGIC ("TcpSocketImpl " << this <<" Action RST_TX");
SendEmptyPacket (TcpHeader::RST);
break;
case SYN_TX:
NS_LOG_LOGIC ("TcpSocketImpl " << this <<" Action SYN_TX");
// TCP SYN Flag consumes one byte
// is the above correct? we're SENDING a syn, not acking back -- Raj
// commented out for now
// m_nextTxSequence+= 1;
SendEmptyPacket (TcpHeader::SYN);
break;
case SYN_ACK_TX:
NS_LOG_LOGIC ("TcpSocketImpl " << this <<" Action SYN_ACK_TX");
// TCP SYN Flag consumes one byte
++m_nextRxSequence;
SendEmptyPacket (TcpHeader::SYN | TcpHeader::ACK);
break;
case FIN_TX:
NS_LOG_LOGIC ("TcpSocketImpl " << this <<" Action FIN_TX");
SendEmptyPacket (TcpHeader::FIN);
break;
case FIN_ACK_TX:
NS_LOG_LOGIC ("TcpSocketImpl " << this <<" Action FIN_ACK_TX");
SendEmptyPacket (TcpHeader::FIN | TcpHeader::ACK);
break;
case NEW_ACK:
NS_ASSERT (false); // This should be processed in ProcessPacketAction
break;
case NEW_SEQ_RX:
NS_ASSERT (false); // This should be processed in ProcessPacketAction
break;
case RETX:
NS_LOG_LOGIC ("TcpSocketImpl " << this <<" Action RETX");
break;
case TX_DATA:
NS_LOG_LOGIC ("TcpSocketImpl " << this <<" Action TX_DATA");
SendPendingData (m_connected);
break;
case PEER_CLOSE:
NS_ASSERT (false); // This should be processed in ProcessPacketAction
NS_LOG_LOGIC ("TcpSocketImpl " << this <<" Action PEER_CLOSE");
break;
case APP_CLOSED:
NS_LOG_LOGIC ("TcpSocketImpl " << this <<" Action APP_CLOSED");
break;
case CANCEL_TM:
NS_LOG_LOGIC ("TcpSocketImpl " << this <<" Action CANCEL_TM");
break;
case APP_NOTIFY:
NS_LOG_LOGIC ("TcpSocketImpl " << this <<" Action APP_NOTIFY");
break;
case SERV_NOTIFY:
NS_ASSERT (false); // This should be processed in ProcessPacketAction
break;
case LAST_ACTION:
NS_LOG_LOGIC ("TcpSocketImpl " << this <<" Action LAST_ACTION");
break;
}
return true;
}
bool TcpSocketImpl::ProcessPacketAction (Actions_t a, Ptr<Packet> p,
const TcpHeader& tcpHeader,
const Address& fromAddress)
{
NS_LOG_FUNCTION (this << a << p << fromAddress);
Ptr<Ipv4> ipv4 = m_node->GetObject<Ipv4> ();
switch (a)
{
case ACK_TX:
if(tcpHeader.GetFlags() & TcpHeader::FIN)
{
++m_nextRxSequence; //bump this to account for the FIN
}
SendEmptyPacket (TcpHeader::ACK);
break;
case SYN_ACK_TX:
NS_LOG_LOGIC ("TcpSocketImpl " << this <<" Action SYN_ACK_TX");
if (m_state == LISTEN) //this means we should fork a new TcpSocketImpl
{
NS_LOG_DEBUG("In SYN_ACK_TX, m_state is LISTEN, this " << this);
//notify the server that we got a SYN
// If server refuses connection do nothing
if (!NotifyConnectionRequest(fromAddress)) return true;
// Clone the socket
Ptr<TcpSocketImpl> newSock = Copy ();
NS_LOG_LOGIC ("Cloned a TcpSocketImpl " << newSock);
//this listening socket should do nothing more
Simulator::ScheduleNow (&TcpSocketImpl::CompleteFork, newSock,
p, tcpHeader,fromAddress);
return true;
}
// This is the cloned endpoint
m_endPoint->SetPeer (m_remoteAddress, m_remotePort);
// Look up the source address
if (ipv4->GetRoutingProtocol () != 0)
{
Ipv4Header header;
Socket::SocketErrno errno;
Ptr<Ipv4Route> route;
uint32_t oif = 0; //specify non-zero if bound to a source address
header.SetDestination (m_remoteAddress);
route = ipv4->GetRoutingProtocol ()->RouteOutput (header, oif, errno);
if (route != 0)
{
NS_LOG_LOGIC ("Route exists");
m_endPoint->SetLocalAddress (route->GetSource ());
}
else
{
NS_LOG_ERROR (errno);
m_errno = errno;
return -1;
}
}
else
{
NS_FATAL_ERROR ("No Ipv4RoutingProtocol in the node");
}
// TCP SYN consumes one byte
m_nextRxSequence = tcpHeader.GetSequenceNumber() + SequenceNumber(1);
SendEmptyPacket (TcpHeader::SYN | TcpHeader::ACK);
break;
case ACK_TX_1:
NS_LOG_LOGIC ("TcpSocketImpl " << this <<" Action ACK_TX_1");
// TCP SYN consumes one byte
m_nextRxSequence = tcpHeader.GetSequenceNumber() + SequenceNumber(1);
m_nextTxSequence = tcpHeader.GetAckNumber ();
m_firstPendingSequence = m_nextTxSequence; //bug 166
NS_LOG_DEBUG ("TcpSocketImpl " << this << " ACK_TX_1" <<
" nextRxSeq " << m_nextRxSequence);
SendEmptyPacket (TcpHeader::ACK);
if (tcpHeader.GetAckNumber () > m_highestRxAck)
{
m_highestRxAck = tcpHeader.GetAckNumber ();
// Data freed from the send buffer; notify any blocked sender
if (GetTxAvailable () > 0)
{
NotifySend (GetTxAvailable ());
}
}
SendPendingData (m_connected); //send acks if we are connected
break;
case NEW_ACK:
NS_LOG_LOGIC ("TcpSocketImpl " << this <<" Action NEW_ACK_TX");
//check to see of the ACK had data with it; if so, pass it along
//to NEW_SEQ_RX
if(p->GetSize () > 0)
{
Simulator::ScheduleNow(&TcpSocketImpl::ProcessPacketAction,
this,
NEW_SEQ_RX,
p,
tcpHeader,
fromAddress);
}
if (tcpHeader.GetAckNumber () < m_highestRxAck) //old ack, do nothing
{
break;
}
if (tcpHeader.GetAckNumber () == m_highestRxAck)
{
if (tcpHeader.GetAckNumber () < m_nextTxSequence)
{
DupAck (tcpHeader, ++m_dupAckCount);
}
NS_ASSERT(tcpHeader.GetAckNumber () <= m_nextTxSequence);
//if the ack is precisely equal to the nextTxSequence
break;
}
if (tcpHeader.GetAckNumber () > m_highestRxAck)
{
m_dupAckCount = 0;
}
NewAck (tcpHeader.GetAckNumber ());
break;
case NEW_SEQ_RX:
NS_LOG_LOGIC ("TcpSocketImpl " << this <<" Action NEW_SEQ_RX");
NewRx (p, tcpHeader, fromAddress); // Process new data received
break;
case PEER_CLOSE:
{
// First we have to be sure the FIN packet was not received
// out of sequence. If so, note pending close and process
// new sequence rx
if (tcpHeader.GetSequenceNumber () != m_nextRxSequence)
{ // process close later
m_pendingClose = true;
NS_LOG_LOGIC ("TcpSocketImpl " << this << " setting pendingClose"
<< " rxseq " << tcpHeader.GetSequenceNumber ()
<< " nextRxSeq " << m_nextRxSequence);
NewRx (p, tcpHeader, fromAddress);
return true;
}
// Now we need to see if any data came with the FIN
// if so, call NewRx
if (p->GetSize () != 0)
{
NewRx (p, tcpHeader, fromAddress);
}
++m_nextRxSequence; //bump this to account for the FIN
States_t saveState = m_state; // Used to see if app responds
NS_LOG_LOGIC ("TcpSocketImpl " << this
<< " peer close, state " << m_state);
if (!m_closeRequestNotified)
{
NS_LOG_LOGIC ("TCP " << this
<< " calling AppCloseRequest");
m_closeRequestNotified = true;
}
NS_LOG_LOGIC ("TcpSocketImpl " << this
<< " peer close, state after " << m_state);
if (m_state == saveState)
{ // Need to ack, the application will close later
SendEmptyPacket (TcpHeader::ACK);
// // Also need to re-tx the ack if we
}
if (m_state == LAST_ACK)
{
NS_LOG_LOGIC ("TcpSocketImpl " << this << " scheduling LATO1");
m_lastAckEvent = Simulator::Schedule (m_rtt->RetransmitTimeout (),
&TcpSocketImpl::LastAckTimeout,this);
}
break;
}
case SERV_NOTIFY:
NS_LOG_LOGIC ("TcpSocketImpl " << this <<" Action SERV_NOTIFY");
NS_LOG_LOGIC ("TcpSocketImpl " << this << " Connected!");
m_connected = true; // ! This is bogus; fix when we clone the tcp
m_endPoint->SetPeer (m_remoteAddress, m_remotePort);
//treat the connection orientation final ack as a newack
CommonNewAck (tcpHeader.GetAckNumber (), true);
NotifyNewConnectionCreated (this, fromAddress);
break;
default:
return ProcessAction (a);
}
return true;
}
void TcpSocketImpl::CompleteFork(Ptr<Packet> p, const TcpHeader& h, const Address& fromAddress)
{
// Get port and address from peer (connecting host)
m_remotePort = InetSocketAddress::ConvertFrom (fromAddress).GetPort ();
m_remoteAddress = InetSocketAddress::ConvertFrom (fromAddress).GetIpv4 ();
m_endPoint = m_tcp->Allocate (m_localAddress,
m_localPort,
m_remoteAddress,
m_remotePort);
//the cloned socket with be in listen state, so manually change state
m_state = SYN_RCVD;
//equivalent to FinishBind
m_endPoint->SetRxCallback (MakeCallback (&TcpSocketImpl::ForwardUp, Ptr<TcpSocketImpl>(this)));
m_endPoint->SetDestroyCallback (MakeCallback (&TcpSocketImpl::Destroy, Ptr<TcpSocketImpl>(this)));
ProcessPacketAction(SYN_ACK_TX, p, h, fromAddress);
}
void TcpSocketImpl::ConnectionSucceeded()
{ // We would preferred to have scheduled an event directly to
// NotifyConnectionSucceeded, but (sigh) these are protected
// and we can get the address of it :(
NotifyConnectionSucceeded();
}
bool TcpSocketImpl::SendPendingData (bool withAck)
{
NS_LOG_FUNCTION (this << withAck);
NS_LOG_LOGIC ("ENTERING SendPendingData");
if (!m_pendingData)
{
return false; // No data exists
}
uint32_t nPacketsSent = 0;
while (m_pendingData->SizeFromSeq (m_firstPendingSequence, m_nextTxSequence))
{
uint32_t w = AvailableWindow ();// Get available window size
NS_LOG_LOGIC ("TcpSocketImpl " << this << " SendPendingData"
<< " w " << w
<< " rxwin " << m_rxWindowSize
<< " cWnd " << m_cWnd
<< " segsize " << m_segmentSize
<< " nextTxSeq " << m_nextTxSequence
<< " highestRxAck " << m_highestRxAck
<< " pd->Size " << m_pendingData->Size ()
<< " pd->SFS " << m_pendingData->SizeFromSeq (m_firstPendingSequence, m_nextTxSequence));
//XXX pd->Size is probably a bug, should be SizeFromSeq(...)
if (w < m_segmentSize && m_pendingData->Size () > w)
{
break; // No more
}
uint32_t s = std::min (w, m_segmentSize); // Send no more than window
Ptr<Packet> p = m_pendingData->CopyFromSeq (s, m_firstPendingSequence,
m_nextTxSequence);
NS_LOG_LOGIC("TcpSocketImpl " << this << " SendPendingData"
<< " txseq " << m_nextTxSequence
<< " s " << s
<< " datasize " << p->GetSize() );
uint8_t flags = 0;
uint32_t sz = p->GetSize (); // Size of packet
uint32_t remainingData = m_pendingData->SizeFromSeq(
m_firstPendingSequence,
m_nextTxSequence + SequenceNumber (sz));
if (m_closeOnEmpty && (remainingData == 0))
{
flags = TcpHeader::FIN;
m_state = FIN_WAIT_1;
}
if (withAck)
{
flags |= TcpHeader::ACK;
}
TcpHeader header;
header.SetFlags (flags);
header.SetSequenceNumber (m_nextTxSequence);
header.SetAckNumber (m_nextRxSequence);
header.SetSourcePort (m_endPoint->GetLocalPort());
header.SetDestinationPort (m_remotePort);
header.SetWindowSize (AdvertisedWindowSize());
if (m_shutdownSend)
{
m_errno = ERROR_SHUTDOWN;
return -1;
}
if (m_retxEvent.IsExpired () ) //go ahead and schedule the retransmit
{
Time rto = m_rtt->RetransmitTimeout ();
NS_LOG_LOGIC (this<<" SendPendingData Schedule ReTxTimeout at time " <<
Simulator::Now ().GetSeconds () << " to expire at time " <<
(Simulator::Now () + rto).GetSeconds () );
m_retxEvent = Simulator::Schedule (rto,&TcpSocketImpl::ReTxTimeout,this);
}
NS_LOG_LOGIC ("About to send a packet with flags: " << flags);
m_tcp->SendPacket (p, header,
m_endPoint->GetLocalAddress (),
m_remoteAddress);
m_rtt->SentSeq(m_nextTxSequence, sz); // notify the RTT
// Notify the application
Simulator::ScheduleNow(&TcpSocketImpl::NotifyDataSent, this, p->GetSize ());
nPacketsSent++; // Count sent this loop
m_nextTxSequence += sz; // Advance next tx sequence
// Note the high water mark
m_highTxMark = std::max (m_nextTxSequence, m_highTxMark);
}
NS_LOG_LOGIC ("SendPendingData Sent "<<nPacketsSent<<" packets");
NS_LOG_LOGIC("RETURN SendPendingData");
return (nPacketsSent>0);
}
uint32_t TcpSocketImpl::UnAckDataCount ()
{
NS_LOG_FUNCTION_NOARGS ();
return m_nextTxSequence - m_highestRxAck;
}
uint32_t TcpSocketImpl::BytesInFlight ()
{
NS_LOG_FUNCTION_NOARGS ();
return m_highTxMark - m_highestRxAck;
}
uint32_t TcpSocketImpl::Window ()
{
NS_LOG_FUNCTION_NOARGS ();
NS_LOG_LOGIC ("TcpSocketImpl::Window() "<<this);
return std::min (m_rxWindowSize, m_cWnd.Get());
}
uint32_t TcpSocketImpl::AvailableWindow ()
{
NS_LOG_FUNCTION_NOARGS ();
uint32_t unack = UnAckDataCount (); // Number of outstanding bytes
uint32_t win = Window ();
if (win < unack)
{
return 0; // No space available
}
return (win - unack); // Amount of window space available
}
uint32_t TcpSocketImpl::RxBufferFreeSpace()
{
return m_rxBufMaxSize - m_rxBufSize;
}
uint16_t TcpSocketImpl::AdvertisedWindowSize()
{
uint32_t max = 0xffff;
return std::min(RxBufferFreeSpace(), max);
}
void TcpSocketImpl::NewRx (Ptr<Packet> p,
const TcpHeader& tcpHeader,
const Address& fromAddress)
{
NS_LOG_FUNCTION (this << p << "tcpHeader " << fromAddress);
NS_LOG_LOGIC ("TcpSocketImpl " << this << " NewRx,"
<< " seq " << tcpHeader.GetSequenceNumber()
<< " ack " << tcpHeader.GetAckNumber()
<< " p.size is " << p->GetSize () );
NS_LOG_DEBUG ("TcpSocketImpl " << this <<
" NewRx," <<
" seq " << tcpHeader.GetSequenceNumber() <<
" ack " << tcpHeader.GetAckNumber() <<
" p.size is " << p->GetSize());
States_t origState = m_state;
if (RxBufferFreeSpace() < p->GetSize())
{ //if not enough room, fragment
p = p->CreateFragment(0, RxBufferFreeSpace());
}
//XXX
//fragmenting here MIGHT not be the right thing to do, since possibly we trim
//the front and back off the packet below if it isn't all new data, so the
//check against RxBufferFreeSpace and fragmentation should ideally occur
//just before insertion into m_bufferedData, but this strategy is more
//agressive in rejecting oversized packets and still gives acceptable TCP
uint32_t s = p->GetSize (); // Size of associated data
if (s == 0)
{//if there is no data or no rx buffer space, just ack anyway
SendEmptyPacket (TcpHeader::ACK);
return;
}
// Log sequence received if enabled
// NoteTimeSeq(LOG_SEQ_RX, h->sequenceNumber);
// Three possibilities
// 1) Received seq is expected, buffer this, update rxAvailable, and ack
// 2) Received seq is < expected, just re-ack previous
// 3) Received seq is > expected, just re-ack previous and buffer data
if (tcpHeader.GetSequenceNumber () == m_nextRxSequence)
{ // If seq is expected seq
// Trim the end if necessary
// 1) Update nextRxSeq
// 2) Buffer this packet so Recv can read it
// 3) Send the ack
UnAckData_t::iterator next = m_bufferedData.upper_bound (m_nextRxSequence);
if (next != m_bufferedData.end ())
{
SequenceNumber nextBufferedSeq = next->first;
if (m_nextRxSequence + SequenceNumber(s) > nextBufferedSeq)
{//tail end isn't all new, trim enough off the end
s = nextBufferedSeq - m_nextRxSequence;
}
}
p = p->CreateFragment (0,s);
m_nextRxSequence += s; // Advance next expected sequence
NS_LOG_LOGIC("Case 1, advanced nrxs to " << m_nextRxSequence );
SocketAddressTag tag;
tag.SetAddress (fromAddress);
p->AddTag (tag);
//buffer this, it'll be read by call to Recv
UnAckData_t::iterator i =
m_bufferedData.find (tcpHeader.GetSequenceNumber () );
NS_ASSERT(i == m_bufferedData.end ()); //no way it should have been found
// Save for later delivery if there is room
m_bufferedData[tcpHeader.GetSequenceNumber () ] = p;
m_rxAvailable += p->GetSize ();
RxBufFinishInsert (tcpHeader.GetSequenceNumber ());
m_rxBufSize += p->GetSize ();
NotifyDataRecv ();
if (m_closeNotified)
{
NS_LOG_LOGIC ("Tcp " << this << " HuH? Got data after closeNotif");
}
NS_LOG_LOGIC ("TcpSocketImpl " << this << " adv rxseq by " << s);
if (m_pendingClose || (origState > ESTABLISHED))
{ // See if we can close now
if (m_bufferedData.empty())
{
ProcessPacketAction (PEER_CLOSE, p, tcpHeader, fromAddress);
}
}
}
else if (tcpHeader.GetSequenceNumber () > m_nextRxSequence)
{ // Need to buffer this one, but trim off the front and back if necessary
NS_LOG_LOGIC ("Case 2, buffering " << tcpHeader.GetSequenceNumber () );
UnAckData_t::iterator previous =
m_bufferedData.lower_bound (tcpHeader.GetSequenceNumber ());
SequenceNumber startSeq = tcpHeader.GetSequenceNumber();
if (previous != m_bufferedData.begin ())
{
--previous;
startSeq = previous->first + SequenceNumber(previous->second->GetSize());
if (startSeq > tcpHeader.GetSequenceNumber ())
{
s = tcpHeader.GetSequenceNumber () + SequenceNumber(s) - startSeq;
}
else
{
startSeq = tcpHeader.GetSequenceNumber();
}
}
//possibly trim off the end
UnAckData_t::iterator next = m_bufferedData.upper_bound (tcpHeader.GetSequenceNumber());
if (next != m_bufferedData.end ())
{
SequenceNumber nextBufferedSeq = next->first;
if (startSeq + SequenceNumber(s) > nextBufferedSeq)
{//tail end isn't all new either, trim enough off the end
s = nextBufferedSeq - startSeq;
}
}
p = p->CreateFragment (startSeq - tcpHeader.GetSequenceNumber (),s);
UnAckData_t::iterator i =
m_bufferedData.find (startSeq);
if (i != m_bufferedData.end () )
{
if(p->GetSize() > i->second->GetSize())
{
i->second = 0; // relase reference to already buffered
}
else
{
p = i->second;
}
}
// Save for later delivery
SocketAddressTag tag;
tag.SetAddress (fromAddress);
p->AddTag (tag);
m_bufferedData[startSeq] = p;
i = m_bufferedData.find (startSeq);
next = i;
++next;
if(next != m_bufferedData.end())
{
NS_ASSERT(next->first >= i->first + SequenceNumber(i->second->GetSize ()));
}
}
else if (tcpHeader.GetSequenceNumber () + SequenceNumber(s) > m_nextRxSequence)
{//parial new data case, only part of the packet is new data
//trim the beginning
s = tcpHeader.GetSequenceNumber () + SequenceNumber(s) - m_nextRxSequence; //how much new
//possibly trim off the end
UnAckData_t::iterator next = m_bufferedData.upper_bound (m_nextRxSequence);
if (next != m_bufferedData.end ())
{
SequenceNumber nextBufferedSeq = next->first;
if (m_nextRxSequence + SequenceNumber(s) > nextBufferedSeq)
{//tail end isn't all new either, trim enough off the end
s = nextBufferedSeq - m_nextRxSequence;
}
}
p = p->CreateFragment (m_nextRxSequence - tcpHeader.GetSequenceNumber (),s);
SequenceNumber start = m_nextRxSequence;
m_nextRxSequence += s; // Advance next expected sequence
SocketAddressTag tag;
tag.SetAddress (fromAddress);
p->AddTag (tag);
//buffer the new fragment, it'll be read by call to Recv
UnAckData_t::iterator i = m_bufferedData.find (start);
if (i != m_bufferedData.end () ) //we found it already in the buffer
{
i->second = 0; // relase reference to already buffered
}
// Save for later delivery
m_bufferedData[start] = p;
m_rxAvailable += p->GetSize ();
m_rxBufSize += p->GetSize();
RxBufFinishInsert(start);
NotifyDataRecv ();
}
else
{ // debug
NS_LOG_LOGIC("TCP " << this
<< " got seq " << tcpHeader.GetSequenceNumber ()
<< " expected " << m_nextRxSequence
<< " flags " << tcpHeader.GetFlags ());
}
// Now send a new ack packet acknowledging all received and delivered data
if(++m_delAckCount >= m_delAckMaxCount)
{
m_delAckEvent.Cancel();
m_delAckCount = 0;
SendEmptyPacket (TcpHeader::ACK);
}
else
{
if (m_delAckEvent.IsExpired())
{
m_delAckEvent = Simulator::Schedule (m_delAckTimeout, &TcpSocketImpl::DelAckTimeout, this);
}
}
}
void TcpSocketImpl::RxBufFinishInsert (SequenceNumber seq)
{
//putting data into the buffer might have filled in a sequence gap so we have
//to iterate through the list to find the largest contiguous sequenced chunk,
//and update m_rxAvailable and m_nextRxSequence appropriately
UnAckData_t::iterator i = m_bufferedData.find (seq);
UnAckData_t::iterator next = i;
++next;
//make sure the buffer is logically sequenced
if(next != m_bufferedData.end())
{
NS_ASSERT(next->first >= i->first + SequenceNumber(i->second->GetSize ()));
}
while(next != m_bufferedData.end())
{
if(i->first + SequenceNumber(i->second->GetSize ()) == next->first)
{
//next packet is in sequence, count it
m_rxAvailable += next->second->GetSize();
m_nextRxSequence += next->second->GetSize();
}
else
{
break; //no more in this contiguous chunk
}
++i;
++next;
}
}
void TcpSocketImpl::DelAckTimeout ()
{
m_delAckCount = 0;
SendEmptyPacket (TcpHeader::ACK);
}
void TcpSocketImpl::CommonNewAck (SequenceNumber ack, bool skipTimer)
{ // CommonNewAck is called only for "New" (non-duplicate) acks
// and MUST be called by any subclass, from the NewAck function
// Always cancel any pending re-tx timer on new acknowledgement
NS_LOG_FUNCTION (this << ack << skipTimer);
//DEBUG(1,(cout << "TCP " << this << "Cancelling retx timer " << endl));
if (!skipTimer)
{
NS_LOG_LOGIC (this<<" Cancelled ReTxTimeout event which was set to expire at "
<< (Simulator::Now () +
Simulator::GetDelayLeft (m_retxEvent)).GetSeconds());
m_retxEvent.Cancel ();
//On recieving a "New" ack we restart retransmission timer .. RFC 2988
Time rto = m_rtt->RetransmitTimeout ();
NS_LOG_LOGIC (this<<" Schedule ReTxTimeout at time "
<< Simulator::Now ().GetSeconds () << " to expire at time "
<< (Simulator::Now () + rto).GetSeconds ());
m_retxEvent =
Simulator::Schedule (rto, &TcpSocketImpl::ReTxTimeout, this);
}
if (m_rxWindowSize == 0 && m_persistEvent.IsExpired ()) //zerowindow
{
NS_LOG_LOGIC (this<<"Enter zerowindow persist state");
NS_LOG_LOGIC (this<<" Cancelled ReTxTimeout event which was set to expire at "
<< (Simulator::Now () +
Simulator::GetDelayLeft (m_retxEvent)).GetSeconds());
m_retxEvent.Cancel ();
NS_LOG_LOGIC ("Schedule persist timeout at time "
<<Simulator::Now ().GetSeconds () << " to expire at time "
<< (Simulator::Now () + m_persistTime).GetSeconds());
m_persistEvent =
Simulator::Schedule (m_persistTime, &TcpSocketImpl::PersistTimeout, this);
NS_ASSERT (m_persistTime == Simulator::GetDelayLeft (m_persistEvent));
}
NS_LOG_LOGIC ("TCP " << this << " NewAck " << ack
<< " numberAck " << (ack - m_highestRxAck)); // Number bytes ack'ed
m_highestRxAck = ack; // Note the highest recieved Ack
if (GetTxAvailable () > 0)
{
NotifySend (GetTxAvailable ());
}
if (ack > m_nextTxSequence)
{
m_nextTxSequence = ack; // If advanced
}
// See if all pending ack'ed; if so we can delete the data
if (m_pendingData)
{ // Data exists, see if can be deleted
if (m_pendingData->SizeFromSeq (m_firstPendingSequence, m_highestRxAck) == 0)
{ // All pending acked, can be deleted
m_pendingData->Clear ();
delete m_pendingData;
m_pendingData = 0;
// Insure no re-tx timer
NS_LOG_LOGIC (this<<" Cancelled ReTxTimeout event which was set to expire at "
<< (Simulator::Now () +
Simulator::GetDelayLeft (m_retxEvent)).GetSeconds());
m_retxEvent.Cancel ();
}
}
// Try to send more data
SendPendingData (m_connected);
}
Ptr<TcpSocketImpl> TcpSocketImpl::Copy ()
{
return CopyObject<TcpSocketImpl> (this);
}
void TcpSocketImpl::NewAck (SequenceNumber seq)
{ // New acknowledgement up to sequence number "seq"
// Adjust congestion window in response to new ack's received
NS_LOG_FUNCTION (this << seq);
NS_LOG_LOGIC ("TcpSocketImpl " << this << " NewAck "
<< " seq " << seq
<< " cWnd " << m_cWnd
<< " ssThresh " << m_ssThresh);
if (m_cWnd < m_ssThresh)
{ // Slow start mode, add one segSize to cWnd
m_cWnd += m_segmentSize;
NS_LOG_LOGIC ("TcpSocketImpl " << this << " NewCWnd SlowStart, cWnd " << m_cWnd
<< " sst " << m_ssThresh);
}
else
{ // Congestion avoidance mode, adjust by (ackBytes*segSize) / cWnd
double adder = ((double) m_segmentSize * m_segmentSize) / m_cWnd.Get();
if (adder < 1.0)
{
adder = 1.0;
}
m_cWnd += (uint32_t) adder;
NS_LOG_LOGIC ("NewCWnd CongAvoid, cWnd " << m_cWnd
<< " sst " << m_ssThresh);
}
CommonNewAck (seq, false); // Complete newAck processing
}
void TcpSocketImpl::DupAck (const TcpHeader& t, uint32_t count)
{
NS_LOG_FUNCTION (this << "t " << count);
NS_LOG_LOGIC ("TcpSocketImpl " << this << " DupAck " << t.GetAckNumber ()
<< ", count " << count
<< ", time " << Simulator::Now ());
if (count == 3)
{ // Count of three indicates triple duplicate ack
m_ssThresh = Window () / 2; // Per RFC2581
m_ssThresh = std::max (m_ssThresh, 2 * m_segmentSize);
NS_LOG_LOGIC("TcpSocketImpl " << this << "Tahoe TDA, time " << Simulator::Now ()
<< " seq " << t.GetAckNumber ()
<< " in flight " << BytesInFlight ()
<< " new ssthresh " << m_ssThresh);
m_cWnd = m_segmentSize; // Collapse cwnd (re-enter slowstart)
// For Tahoe, we also reset nextTxSeq
m_nextTxSequence = m_highestRxAck;
SendPendingData (m_connected);
}
}
void TcpSocketImpl::ReTxTimeout ()
{ // Retransmit timeout
NS_LOG_FUNCTION (this);
NS_LOG_LOGIC (this<<" ReTxTimeout Expired at time "<<Simulator::Now ().GetSeconds());
m_ssThresh = Window () / 2; // Per RFC2581
m_ssThresh = std::max (m_ssThresh, 2 * m_segmentSize);
// Set cWnd to segSize on timeout, per rfc2581
// Collapse congestion window (re-enter slowstart)
m_cWnd = m_segmentSize;
m_nextTxSequence = m_highestRxAck; // Start from highest Ack
m_rtt->IncreaseMultiplier (); // DoubleValue timeout value for next retx timer
Retransmit (); // Retransmit the packet
}
void TcpSocketImpl::LastAckTimeout ()
{
m_lastAckEvent.Cancel ();
if (m_state == LAST_ACK)
{
Actions_t action = ProcessEvent (TIMEOUT);
ProcessAction (action);
}
if (!m_closeNotified)
{
m_closeNotified = true;
}
}
void TcpSocketImpl::PersistTimeout ()
{
NS_LOG_LOGIC ("PersistTimeout expired at "<<Simulator::Now ().GetSeconds ());
m_persistTime = Scalar(2)*m_persistTime;
m_persistTime = std::min(Seconds(60),m_persistTime); //maxes out at 60
//the persist timeout sends exactly one byte probes
//this is explicit in stevens, and kind of in rfc793 p42, rfc1122 sec4.2.2.17
Ptr<Packet> p =
m_pendingData->CopyFromSeq(1,m_firstPendingSequence,m_nextTxSequence);
TcpHeader tcpHeader;
tcpHeader.SetSequenceNumber (m_nextTxSequence);
tcpHeader.SetAckNumber (m_nextRxSequence);
tcpHeader.SetSourcePort (m_endPoint->GetLocalPort());
tcpHeader.SetDestinationPort (m_remotePort);
tcpHeader.SetWindowSize (AdvertisedWindowSize());
m_tcp->SendPacket (p, tcpHeader, m_endPoint->GetLocalAddress (),
m_remoteAddress);
NS_LOG_LOGIC ("Schedule persist timeout at time "
<<Simulator::Now ().GetSeconds () << " to expire at time "
<< (Simulator::Now () + m_persistTime).GetSeconds());
m_persistEvent =
Simulator::Schedule (m_persistTime, &TcpSocketImpl::PersistTimeout, this);
}
void TcpSocketImpl::Retransmit ()
{
NS_LOG_FUNCTION (this);
uint8_t flags = TcpHeader::NONE;
if (m_state == SYN_SENT)
{
if (m_cnCount > 0)
{
SendEmptyPacket (TcpHeader::SYN);
return;
}
else
{
NotifyConnectionFailed ();
return;
}
}
if (!m_pendingData)
{
if (m_state == FIN_WAIT_1)
{ // Must have lost FIN, re-send
SendEmptyPacket (TcpHeader::FIN);
}
return;
}
NS_ASSERT(m_nextTxSequence == m_highestRxAck);
Ptr<Packet> p = m_pendingData->CopyFromSeq (m_segmentSize,
m_firstPendingSequence,
m_nextTxSequence);
// Calculate remaining data for COE check
uint32_t remainingData = m_pendingData->SizeFromSeq (
m_firstPendingSequence,
m_nextTxSequence + SequenceNumber(p->GetSize ()));
if (m_closeOnEmpty && remainingData == 0)
{ // Add the FIN flag
flags = flags | TcpHeader::FIN;
}
NS_LOG_LOGIC ("TcpSocketImpl " << this << " retxing seq " << m_highestRxAck);
if (m_retxEvent.IsExpired () )
{
Time rto = m_rtt->RetransmitTimeout ();
NS_LOG_LOGIC (this<<" Schedule ReTxTimeout at time "
<< Simulator::Now ().GetSeconds () << " to expire at time "
<< (Simulator::Now () + rto).GetSeconds ());
m_retxEvent = Simulator::Schedule (rto,&TcpSocketImpl::ReTxTimeout,this);
}
m_rtt->SentSeq (m_highestRxAck,p->GetSize ());
// And send the packet
TcpHeader tcpHeader;
tcpHeader.SetSequenceNumber (m_nextTxSequence);
tcpHeader.SetAckNumber (m_nextRxSequence);
tcpHeader.SetSourcePort (m_endPoint->GetLocalPort());
tcpHeader.SetDestinationPort (m_remotePort);
tcpHeader.SetFlags (flags);
tcpHeader.SetWindowSize (AdvertisedWindowSize());
m_tcp->SendPacket (p, tcpHeader, m_endPoint->GetLocalAddress (),
m_remoteAddress);
}
void
TcpSocketImpl::SetSndBufSize (uint32_t size)
{
m_sndBufSize = size;
}
uint32_t
TcpSocketImpl::GetSndBufSize (void) const
{
return m_sndBufSize;
}
void
TcpSocketImpl::SetRcvBufSize (uint32_t size)
{
m_rxBufMaxSize = size;
}
uint32_t
TcpSocketImpl::GetRcvBufSize (void) const
{
return m_rxBufMaxSize;
}
void
TcpSocketImpl::SetSegSize (uint32_t size)
{
m_segmentSize = size;
}
uint32_t
TcpSocketImpl::GetSegSize (void) const
{
return m_segmentSize;
}
void
TcpSocketImpl::SetSSThresh (uint32_t threshold)
{
m_ssThresh = threshold;
}
uint32_t
TcpSocketImpl::GetSSThresh (void) const
{
return m_ssThresh;
}
void
TcpSocketImpl::SetInitialCwnd (uint32_t cwnd)
{
m_initialCWnd = cwnd;
}
uint32_t
TcpSocketImpl::GetInitialCwnd (void) const
{
return m_initialCWnd;
}
void
TcpSocketImpl::SetConnTimeout (Time timeout)
{
m_cnTimeout = timeout;
}
Time
TcpSocketImpl::GetConnTimeout (void) const
{
return m_cnTimeout;
}
void
TcpSocketImpl::SetConnCount (uint32_t count)
{
m_cnCount = count;
}
uint32_t
TcpSocketImpl::GetConnCount (void) const
{
return m_cnCount;
}
void
TcpSocketImpl::SetDelAckTimeout (Time timeout)
{
m_delAckTimeout = timeout;
}
Time
TcpSocketImpl::GetDelAckTimeout (void) const
{
return m_delAckTimeout;
}
void
TcpSocketImpl::SetDelAckMaxCount (uint32_t count)
{
m_delAckMaxCount = count;
}
uint32_t
TcpSocketImpl::GetDelAckMaxCount (void) const
{
return m_delAckMaxCount;
}
}//namespace ns3