/* -*- 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 "tcp-socket.h"
#include "tcp-l4-protocol.h"
#include "ipv4-end-point.h"
#include "ipv4-l4-demux.h"
#include "ns3/simulation-singleton.h"
#include "tcp-typedefs.h"
#include "ns3/simulator.h"
#include "ns3/packet.h"
#include <algorithm>
NS_LOG_COMPONENT_DEFINE ("TcpSocket");
using namespace std;
namespace ns3 {
TcpSocket::TcpSocket ()
: m_skipRetxResched (false),
m_dupAckCount (0),
m_endPoint (0),
m_node (0),
m_tcp (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_pendingData (0),
m_rtt (0),
m_lastMeasuredRtt (Seconds(0.0))
{
NS_LOG_FUNCTION;
NS_LOG_PARAMS (this);
}
TcpSocket::~TcpSocket ()
{
NS_LOG_FUNCTION;
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
TcpSocket::SetNode (Ptr<Node> node)
{
m_node = node;
Ptr<Tcp> t = node->GetObject<Tcp> ();
m_segmentSize = t->GetDefaultSegSize ();
m_rxWindowSize = t->GetDefaultAdvWin ();
m_advertisedWindowSize = t->GetDefaultAdvWin ();
m_cWnd = t->GetDefaultInitialCwnd () * m_segmentSize;
m_ssThresh = t->GetDefaultSsThresh ();
m_initialCWnd = t->GetDefaultInitialCwnd ();
m_cnTimeout = Seconds (t->GetDefaultConnTimeout ());
m_cnCount = t->GetDefaultConnCount ();
}
void
TcpSocket::SetTcp (Ptr<TcpL4Protocol> tcp)
{
m_tcp = tcp;
}
void
TcpSocket::SetRtt (Ptr<RttEstimator> rtt)
{
m_rtt = rtt;
}
enum Socket::SocketErrno
TcpSocket::GetErrno (void) const
{
NS_LOG_FUNCTION;
return m_errno;
}
Ptr<Node>
TcpSocket::GetNode (void) const
{
NS_LOG_FUNCTION;
return m_node;
}
void
TcpSocket::Destroy (void)
{
NS_LOG_FUNCTION;
m_node = 0;
m_endPoint = 0;
m_tcp = 0;
m_retxEvent.Cancel ();
}
int
TcpSocket::FinishBind (void)
{
NS_LOG_FUNCTION;
if (m_endPoint == 0)
{
return -1;
}
m_endPoint->SetRxCallback (MakeCallback (&TcpSocket::ForwardUp, this));
m_endPoint->SetDestroyCallback (MakeCallback (&TcpSocket::Destroy, this));
return 0;
}
int
TcpSocket::Bind (void)
{
NS_LOG_FUNCTION;
m_endPoint = m_tcp->Allocate ();
return FinishBind ();
}
int
TcpSocket::Bind (const Address &address)
{
NS_LOG_FUNCTION;
NS_LOG_PARAMS (this<<address);
if (!InetSocketAddress::IsMatchingType (address))
{
return ERROR_INVAL;
}
InetSocketAddress transport = InetSocketAddress::ConvertFrom (address);
Ipv4Address ipv4 = transport.GetIpv4 ();
uint16_t port = transport.GetPort ();
Ipv4Address localInterface = Ipv4Address::GetAny ();
if (ipv4 != Ipv4Address::GetAny ())
{
Ptr<Ipv4> ipv4_api = m_node->GetObject<Ipv4> ();
// Assert that the given address matches an existing local interface
NS_ASSERT (ipv4_api->FindInterfaceForAddr (ipv4) != 0);
localInterface = ipv4;
}
if (ipv4 == Ipv4Address::GetAny () && port == 0)
{
m_endPoint = m_tcp->Allocate ();
NS_LOG_LOGIC ("TcpSocket "<<this<<" got an endpoint: "<<m_endPoint);
}
else if (ipv4 == Ipv4Address::GetAny () && port != 0)
{
m_endPoint = m_tcp->Allocate (port);
NS_LOG_LOGIC ("TcpSocket "<<this<<" got an endpoint: "<<m_endPoint);
}
else if (ipv4 != Ipv4Address::GetAny () && port == 0)
{
m_endPoint = m_tcp->Allocate (ipv4, localInterface);
NS_LOG_LOGIC ("TcpSocket "<<this<<" got an endpoint: "<<m_endPoint);
}
else if (ipv4 != Ipv4Address::GetAny () && port != 0)
{
m_endPoint = m_tcp->Allocate (ipv4, port, localInterface);
NS_LOG_LOGIC ("TcpSocket "<<this<<" got an endpoint: "<<m_endPoint);
}
return FinishBind ();
}
int
TcpSocket::ShutdownSend (void)
{
NS_LOG_FUNCTION;
m_shutdownSend = true;
return 0;
}
int
TcpSocket::ShutdownRecv (void)
{
NS_LOG_FUNCTION;
m_shutdownRecv = false;
return 0;
}
int
TcpSocket::Close (void)
{
NS_LOG_FUNCTION;
if (m_state == CLOSED)
{
return -1;
}
Actions_t action = ProcessEvent (APP_CLOSE);
if (m_pendingData)
{
if (action == FIN_TX && m_pendingData->Size () != 0 )
{
m_closeOnEmpty = true;
return 0;
}
}
ProcessAction (action);
ShutdownSend ();
return 0;
}
int
TcpSocket::Connect (const Address & address)
{
NS_LOG_FUNCTION;
NS_LOG_PARAMS (this << address);
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_defaultAddress = transport.GetIpv4 ();
m_defaultPort = transport.GetPort ();
uint32_t localIfIndex;
Ptr<Ipv4> ipv4 = m_node->GetObject<Ipv4> ();
if (ipv4->GetIfIndexForDestination (m_defaultAddress, localIfIndex))
{
m_endPoint->SetLocalAddress (ipv4->GetAddress (localIfIndex));
}
else
{
m_errno = ERROR_NOROUTETOHOST;
return -1;
}
Actions_t action = ProcessEvent (APP_CONNECT);
bool success = ProcessAction (action);
if (success)
{
return 0;
}
return -1;
}
int
TcpSocket::Send (const Ptr<Packet> p) //p here is just data, no headers
{
NS_LOG_FUNCTION;
NS_LOG_PARAMS (this << p);
if (m_state == ESTABLISHED || m_state == SYN_SENT || m_state == CLOSE_WAIT)
{ // Ok to buffer some data to send
if (!m_pendingData)
{
m_pendingData = new PendingData (0); // Create if non-existent
m_firstPendingSequence = m_nextTxSequence; // Note seq of first
}
//PendingData::Add always copies the data buffer, never modifies
m_pendingData->Add (p->GetSize (), p->PeekData ());
Actions_t action = ProcessEvent (APP_SEND);
if (!ProcessAction (action))
{
return -1; // Failed, return zero
}
return p->GetSize ();
}
else
{
m_errno = ERROR_NOTCONN;
return -1;
}
}
int TcpSocket::Send (const uint8_t* buf, uint32_t size)
{
NS_LOG_FUNCTION;
NS_LOG_PARAMS (this << buf << size);
if (m_state == ESTABLISHED || m_state == SYN_SENT || m_state == CLOSE_WAIT)
{ // Ok to buffer some data to send
if (!m_pendingData)
{
m_pendingData = new PendingData (); // Create if non-existent
m_firstPendingSequence = m_nextTxSequence; // Note seq of first
}
//PendingData::Add always copies the data buffer, never modifies
m_pendingData->Add (size,buf);
Actions_t action = ProcessEvent (APP_SEND);
if (!ProcessAction (action))
{
return -1; // Failed, return zero
}
return size;
}
else
{
m_errno = ERROR_NOTCONN;
return -1;
}
}
int TcpSocket::DoSendTo (Ptr<Packet> p, const Address &address)
{
NS_LOG_FUNCTION;
NS_LOG_PARAMS (this << p << address);
InetSocketAddress transport = InetSocketAddress::ConvertFrom (address);
Ipv4Address ipv4 = transport.GetIpv4 ();
uint16_t port = transport.GetPort ();
return DoSendTo (p, ipv4, port);
}
int TcpSocket::DoSendTo (Ptr<Packet> p, Ipv4Address ipv4, uint16_t port)
{
NS_LOG_FUNCTION;
NS_LOG_PARAMS (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
TcpSocket::SendTo (const Address &address, Ptr<Packet> p)
{
NS_LOG_FUNCTION;
NS_LOG_PARAMS (this << address << p);
if (!m_connected)
{
m_errno = ERROR_NOTCONN;
return -1;
}
else
{
return Send (p); //drop the address according to BSD manpages
}
}
int
TcpSocket::Listen (uint32_t q)
{
NS_LOG_FUNCTION;
NS_LOG_PARAMS (this << q);
Actions_t action = ProcessEvent (APP_LISTEN);
ProcessAction (action);
return 0;
}
void
TcpSocket::ForwardUp (Ptr<Packet> packet, Ipv4Address ipv4, uint16_t port)
{
NS_LOG_FUNCTION;
NS_LOG_PARAMS (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;
}
}
Events_t event = SimulationSingleton<TcpStateMachine>::Get ()->FlagsEvent (tcpHeader.GetFlags () );
Actions_t action = ProcessEvent (event); //updates the state
Address address = InetSocketAddress (ipv4, port);
ProcessPacketAction (action, packet, tcpHeader, address);
}
Actions_t TcpSocket::ProcessEvent (Events_t e)
{
NS_LOG_FUNCTION;
NS_LOG_PARAMS (this << e);
States_t saveState = m_state;
NS_LOG_LOGIC ("TcpSocket " << 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 ("TcpSocket " << 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 ("TcpSocket " << this << " moved from state " << saveState
<< " to state " <<m_state);
NS_LOG_LOGIC ("TcpSocket " << this << " pendingData " << m_pendingData);
if (saveState == SYN_SENT && m_state == ESTABLISHED)
// this means the application side has completed its portion of
// the handshaking
{
NotifyConnectionSucceeded ();
m_connected = true;
m_endPoint->SetPeer (m_defaultAddress, m_defaultPort);
NS_LOG_LOGIC ("TcpSocket " << this << " Connected!");
}
if (needCloseNotify && !m_closeNotified)
{
NS_LOG_LOGIC ("TcpSocket " << this << " transition to CLOSED from "
<< m_state << " event " << e << " closeNot " << m_closeNotified
<< " action " << stateAction.action);
NotifyCloseCompleted ();
m_closeNotified = true;
NS_LOG_LOGIC ("TcpSocket " << this << " calling Closed from PE"
<< " origState " << saveState
<< " event " << e);
NS_LOG_LOGIC ("TcpSocket " << this << " transition to CLOSED from "
<< m_state << " event " << e
<< " set CloseNotif ");
}
return stateAction.action;
}
void TcpSocket::SendEmptyPacket (uint8_t flags)
{
NS_LOG_FUNCTION;
NS_LOG_PARAMS (this << flags);
Ptr<Packet> p = Create<Packet> ();
TcpHeader header;
header.SetFlags (flags);
header.SetSequenceNumber (m_nextTxSequence);
header.SetAckNumber (m_nextRxSequence);
header.SetSourcePort (m_endPoint->GetLocalPort ());
header.SetDestinationPort (m_defaultPort);
header.SetWindowSize (m_advertisedWindowSize);
m_tcp->SendPacket (p, header, m_endPoint->GetLocalAddress (),
m_defaultAddress);
Time rto = m_rtt->RetransmitTimeout ();
if (flags & TcpHeader::SYN)
{
rto = m_cnTimeout;
m_cnTimeout = m_cnTimeout + m_cnTimeout;
m_cnCount--;
}
if (m_retxEvent.IsExpired () ) //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, &TcpSocket::ReTxTimeout, this);
}
}
bool TcpSocket::ProcessAction (Actions_t a)
{ // These actions do not require a packet or any TCP Headers
NS_LOG_FUNCTION;
NS_LOG_PARAMS (this << a);
switch (a)
{
case NO_ACT:
NS_LOG_LOGIC ("TcpSocket " << 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 ("TcpSocket " << this <<" Action RST_TX");
SendEmptyPacket (TcpHeader::RST);
break;
case SYN_TX:
NS_LOG_LOGIC ("TcpSocket " << 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 ("TcpSocket " << this <<" Action SYN_ACK_TX");
SendEmptyPacket (TcpHeader::SYN | TcpHeader::ACK);
break;
case FIN_TX:
NS_LOG_LOGIC ("TcpSocket " << this <<" Action FIN_TX");
SendEmptyPacket (TcpHeader::FIN);
break;
case FIN_ACK_TX:
NS_LOG_LOGIC ("TcpSocket " << 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 ("TcpSocket " << this <<" Action RETX");
break;
case TX_DATA:
NS_LOG_LOGIC ("TcpSocket " << this <<" Action TX_DATA");
SendPendingData ();
break;
case PEER_CLOSE:
NS_ASSERT (false); // This should be processed in ProcessPacketAction
NS_LOG_LOGIC ("TcpSocket " << this <<" Action PEER_CLOSE");
break;
case APP_CLOSED:
NS_LOG_LOGIC ("TcpSocket " << this <<" Action APP_CLOSED");
break;
case CANCEL_TM:
NS_LOG_LOGIC ("TcpSocket " << this <<" Action CANCEL_TM");
break;
case APP_NOTIFY:
NS_LOG_LOGIC ("TcpSocket " << this <<" Action APP_NOTIFY");
break;
case SERV_NOTIFY:
NS_ASSERT (false); // This should be processed in ProcessPacketAction
break;
case LAST_ACTION:
NS_LOG_LOGIC ("TcpSocket " << this <<" Action LAST_ACTION");
break;
}
return true;
}
bool TcpSocket::ProcessPacketAction (Actions_t a, Ptr<Packet> p,
const TcpHeader& tcpHeader,
const Address& fromAddress)
{
NS_LOG_FUNCTION;
NS_LOG_PARAMS (this << p << "tcpHeader " << fromAddress);
uint32_t localIfIndex;
Ptr<Ipv4> ipv4 = m_node->GetObject<Ipv4> ();
switch (a)
{
case SYN_ACK_TX:
NS_LOG_LOGIC ("TcpSocket " << this <<" Action SYN_ACK_TX");
m_defaultPort = InetSocketAddress::ConvertFrom (fromAddress).GetPort ();
m_defaultAddress =
InetSocketAddress::ConvertFrom (fromAddress).GetIpv4 ();
m_endPoint->SetPeer (m_defaultAddress, m_defaultPort);
if (ipv4->GetIfIndexForDestination (m_defaultAddress, localIfIndex))
{
m_endPoint->SetLocalAddress (ipv4->GetAddress (localIfIndex));
}
// TCP SYN consumes one byte
m_nextRxSequence = tcpHeader.GetSequenceNumber() + SequenceNumber(1);
SendEmptyPacket (TcpHeader::SYN | TcpHeader::ACK);
break;
case ACK_TX_1:
NS_LOG_LOGIC ("TcpSocket " << this <<" Action ACK_TX_1");
// TCP SYN consumes one byte
m_nextRxSequence = tcpHeader.GetSequenceNumber() + SequenceNumber(1);
SendEmptyPacket (TcpHeader::ACK);
m_rxWindowSize = tcpHeader.GetWindowSize ();
m_nextTxSequence = tcpHeader.GetAckNumber ();
if (tcpHeader.GetAckNumber () > m_highestRxAck)
{
m_highestRxAck = tcpHeader.GetAckNumber ();
}
SendPendingData ();
break;
case NEW_ACK:
NS_LOG_LOGIC ("TcpSocket " << this <<" Action NEW_ACK_TX");
if (tcpHeader.GetAckNumber () < m_highestRxAck) //old ack, do nothing
{
break;
}
if (tcpHeader.GetAckNumber () == m_highestRxAck &&
tcpHeader.GetAckNumber () < m_nextTxSequence)
{
DupAck (tcpHeader, ++m_dupAckCount);
break;
}
if (tcpHeader.GetAckNumber () > m_highestRxAck)
{
m_dupAckCount = 0;
}
NewAck (tcpHeader.GetAckNumber ());
break;
case NEW_SEQ_RX:
NS_LOG_LOGIC ("TcpSocket " << this <<" Action NEW_SEQ_TX");
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 ("TcpSocket " << 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);
}
States_t saveState = m_state; // Used to see if app responds
NS_LOG_LOGIC ("TcpSocket " << this
<< " peer close, state " << m_state);
if (!m_closeRequestNotified)
{
NS_LOG_LOGIC ("TCP " << this
<< " calling AppCloseRequest");
NotifyCloseRequested ();
m_closeRequestNotified = true;
}
NS_LOG_LOGIC ("TcpSocket " << 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 ("TcpSocket " << this << " scheduling LATO1");
m_lastAckEvent = Simulator::Schedule (m_rtt->RetransmitTimeout (),
&TcpSocket::LastAckTimeout,this);
}
break;
}
case SERV_NOTIFY:
NS_LOG_LOGIC ("TcpSocket " << this <<" Action SERV_NOTIFY");
NS_LOG_LOGIC ("TcpSocket " << this << " Connected!");
NotifyNewConnectionCreated (this, fromAddress);
m_connected = true; // ! This is bogus; fix when we clone the tcp
m_endPoint->SetPeer (m_defaultAddress, m_defaultPort);
//treat the connection orientation final ack as a newack
CommonNewAck (tcpHeader.GetAckNumber (), true);
break;
default:
break;
}
return true;
}
bool TcpSocket::SendPendingData (bool withAck)
{
NS_LOG_FUNCTION;
NS_LOG_PARAMS (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 ("TcpSocket " << 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));
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("TcpSocket " << this << " sendPendingData"
<< " txseq " << m_nextTxSequence
<< " s " << s
<< " datasize " << p->GetSize() );
uint8_t flags = 0;
if (withAck)
{
flags |= TcpHeader::ACK;
}
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;
}
TcpHeader header;
header.SetFlags (flags);
header.SetSequenceNumber (m_nextTxSequence);
header.SetAckNumber (m_nextRxSequence);
header.SetSourcePort (m_endPoint->GetLocalPort());
header.SetDestinationPort (m_defaultPort);
if (m_shutdownSend)
{
m_errno = ERROR_SHUTDOWN;
return -1;
}
Time rto = m_rtt->RetransmitTimeout ();
if (m_retxEvent.IsExpired () ) //go ahead and schedule the retransmit
{
NS_LOG_LOGIC ("Schedule retransmission timeout at time " <<
Simulator::Now ().GetSeconds () << " to expire at time " <<
(Simulator::Now () + rto).GetSeconds () );
m_retxEvent = Simulator::Schedule (rto,&TcpSocket::ReTxTimeout,this);
}
NS_LOG_LOGIC ("About to send a packet with flags: " << flags);
m_tcp->SendPacket (p, header,
m_endPoint->GetLocalAddress (),
m_defaultAddress);
m_rtt->SentSeq(m_nextTxSequence, sz); // notify the RTT
// Notify the application
Simulator::ScheduleNow(&TcpSocket::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 ("Sent "<<nPacketsSent<<" packets");
NS_LOG_LOGIC("RETURN SendPendingData");
return (nPacketsSent>0);
}
uint32_t TcpSocket::UnAckDataCount ()
{
NS_LOG_FUNCTION;
return m_nextTxSequence - m_highestRxAck;
}
uint32_t TcpSocket::BytesInFlight ()
{
NS_LOG_FUNCTION;
return m_highTxMark - m_highestRxAck;
}
uint32_t TcpSocket::Window ()
{
NS_LOG_FUNCTION;
NS_LOG_LOGIC ("TcpSocket::Window() "<<this);
return std::min (m_rxWindowSize, m_cWnd);
}
uint32_t TcpSocket::AvailableWindow ()
{
NS_LOG_FUNCTION;
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
}
void TcpSocket::NewRx (Ptr<Packet> p,
const TcpHeader& tcpHeader,
const Address& fromAddress)
{
NS_LOG_FUNCTION;
NS_LOG_PARAMS (this << p << "tcpHeader " << fromAddress);
NS_LOG_LOGIC ("TcpSocket " << this << " NewRx, p.size is " << p->GetSize () );
States_t origState = m_state;
uint32_t s = p->GetSize (); // Size of associated data
if (s == 0)
{// Nothing to do if no associated data
return;
}
// Log sequence received if enabled
// NoteTimeSeq(LOG_SEQ_RX, h->sequenceNumber);
// Three possibilities
// 1) Received seq is expected, deliver this and any buffered data
// 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
// 1) Update nextRxSeq
// 2) Deliver to application this packet
// 3) See if any buffered can be delivered
// 4) Send the ack
m_nextRxSequence += s; // Advance next expected sequence
//bytesReceived += s; // Statistics
NS_LOG_LOGIC("Case 1, advanced nrxs to " << m_nextRxSequence );
NotifyDataReceived (p, fromAddress);
if (m_closeNotified)
{
NS_LOG_LOGIC ("Tcp " << this << " HuH? Got data after closeNotif");
}
NS_LOG_LOGIC ("TcpSocket " << this << " adv rxseq by " << s);
// Look for buffered data
UnAckData_t::iterator i;
// Note that the bufferedData list DOES contain the tcp header
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 ();
Ptr<Packet> p1 = i->second;
SequenceNumber s1 = 0;
if (i->first > m_nextRxSequence)
{
break; // Not next expected
}
// already have the header as a param
//TCPHeader* h = dynamic_cast<TCPHeader*>(p1->PopPDU());
// Check non-null here...
uint8_t flags = tcpHeader.GetFlags (); // Flags (used below)
if (i->first < m_nextRxSequence)
{ // remove already delivered data
// Two cases here.
// 1) seq + length <= nextRxSeq, just discard
// 2) seq + length > nextRxSeq, can deliver partial
s1 = p->GetSize ();
if (i->first + s1 < m_nextRxSequence)
{ // Just remove from list
//bufferedData.erase(i);
p1 = 0; // Nothing to deliver
}
else
{ // Remove partial data to prepare for delivery
uint32_t dup = m_nextRxSequence - i->first;
i->second = p1->CreateFragment (0, p1->GetSize () - dup);
p1 = i->second;
}
}
else
{ // At this point i->first must equal nextRxSeq
if (i->first != m_nextRxSequence)
{
NS_FATAL_ERROR ("HuH? NexRx failure, first "
<< i->first << " nextRxSeq " << m_nextRxSequence);
}
s1 = p1->GetSize ();
}
NotifyDataReceived (p1, fromAddress);
NS_LOG_LOGIC ("TcpSocket " << this << " adv rxseq1 by " << s1 );
m_nextRxSequence += s1; // Note data received
m_bufferedData.erase (i); // Remove from list
if (flags & TcpHeader::FIN)
NS_LOG_LOGIC("TcpSocket " << this
<< " found FIN in buffered");
}
if (m_pendingClose || (origState > ESTABLISHED))
{ // See if we can close now
if (m_bufferedData.empty())
{
ProcessPacketAction (PEER_CLOSE, p, tcpHeader, fromAddress);
}
}
}
else if (SequenceNumber (tcpHeader.GetSequenceNumber ()) >= m_nextRxSequence)
{ // Need to buffer this one
NS_LOG_LOGIC ("Case 2, buffering " << tcpHeader.GetSequenceNumber () );
UnAckData_t::iterator i =
m_bufferedData.find (tcpHeader.GetSequenceNumber () );
if (i != m_bufferedData.end () )
{
i->second = 0; // relase reference to already buffered
}
// Save for later delivery
m_bufferedData[tcpHeader.GetSequenceNumber () ] = p;
}
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
SendEmptyPacket (TcpHeader::ACK);
}
void TcpSocket::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;
NS_LOG_PARAMS (this << ack << skipTimer);
//DEBUG(1,(cout << "TCP " << this << "Cancelling retx timer " << endl));
if (!skipTimer)
{
m_retxEvent.Cancel ();
}
NS_LOG_LOGIC ("TCP " << this << " NewAck " << ack
<< " numberAck " << (ack - m_highestRxAck)); // Number bytes ack'ed
m_highestRxAck = ack; // Note the highest recieved Ack
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
m_retxEvent.Cancel ();
}
}
// Try to send more data
SendPendingData();
}
void TcpSocket::NewAck (SequenceNumber seq)
{ // New acknowledgement up to sequence number "seq"
// Adjust congestion window in response to new ack's received
NS_LOG_FUNCTION;
NS_LOG_PARAMS (this << seq);
NS_LOG_LOGIC ("TcpSocket " << 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 ("TcpSocket " << 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;
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 TcpSocket::DupAck (const TcpHeader& t, uint32_t count)
{
NS_LOG_FUNCTION;
NS_LOG_PARAMS (this << "t " << count);
NS_LOG_LOGIC ("TcpSocket " << 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("TcpSocket " << 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 ();
}
}
void TcpSocket::ReTxTimeout ()
{ // Retransmit timeout
NS_LOG_FUNCTION;
NS_LOG_PARAMS (this);
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 (); // Double timeout value for next retx timer
Retransmit (); // Retransmit the packet
}
void TcpSocket::LastAckTimeout ()
{
m_lastAckEvent.Cancel ();
if (m_state == LAST_ACK)
{
Actions_t action = ProcessEvent (TIMEOUT);
ProcessAction (action);
}
if (!m_closeNotified)
{
m_closeNotified = true;
}
}
void TcpSocket::Retransmit ()
{
NS_LOG_FUNCTION;
NS_LOG_PARAMS (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 || m_state == FIN_WAIT_2)
{ // Must have lost FIN, re-send
SendEmptyPacket (TcpHeader::FIN);
}
return;
}
Ptr<Packet> p = m_pendingData->CopyFromSeq (m_segmentSize,
m_firstPendingSequence,
m_highestRxAck);
// 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 ("TcpSocket " << this << " retxing seq " << m_highestRxAck);
if (m_retxEvent.IsExpired () )
{
Time rto = m_rtt->RetransmitTimeout ();
NS_LOG_LOGIC ("Schedule retransmission timeout at time "
<< Simulator::Now ().GetSeconds () << " to expire at time "
<< (Simulator::Now () + rto).GetSeconds ());
m_retxEvent = Simulator::Schedule (rto,&TcpSocket::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_defaultPort);
tcpHeader.SetFlags (flags);
tcpHeader.SetWindowSize (m_advertisedWindowSize);
m_tcp->SendPacket (p, tcpHeader, m_endPoint->GetLocalAddress (),
m_defaultAddress);
}
}//namespace ns3