/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
* Copyright (c) 2007 Georgia Tech Research Corporation
* Copyright (c) 2010 Adrian Sai-wah Tam
*
* 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: Adrian Sai-wah Tam <adrian.sw.tam@gmail.com>
*/
#define NS_LOG_APPEND_CONTEXT \
if (m_node) { std::clog << Simulator::Now ().GetSeconds () << " [node " << m_node->GetId () << "] "; }
#include "ns3/abort.h"
#include "ns3/node.h"
#include "ns3/inet-socket-address.h"
#include "ns3/inet6-socket-address.h"
#include "ns3/log.h"
#include "ns3/ipv4.h"
#include "ns3/ipv6.h"
#include "ns3/ipv4-interface-address.h"
#include "ns3/ipv4-route.h"
#include "ns3/ipv6-route.h"
#include "ns3/ipv4-routing-protocol.h"
#include "ns3/ipv6-routing-protocol.h"
#include "ns3/simulation-singleton.h"
#include "ns3/simulator.h"
#include "ns3/packet.h"
#include "ns3/uinteger.h"
#include "ns3/double.h"
#include "ns3/trace-source-accessor.h"
#include "tcp-socket-base.h"
#include "tcp-l4-protocol.h"
#include "ipv4-end-point.h"
#include "ipv6-end-point.h"
#include "ipv6-l3-protocol.h"
#include "tcp-header.h"
#include "rtt-estimator.h"
#include <algorithm>
NS_LOG_COMPONENT_DEFINE ("TcpSocketBase");
namespace ns3 {
NS_OBJECT_ENSURE_REGISTERED (TcpSocketBase);
TypeId
TcpSocketBase::GetTypeId (void)
{
static TypeId tid = TypeId ("ns3::TcpSocketBase")
.SetParent<TcpSocket> ()
// .AddAttribute ("TcpState", "State in TCP state machine",
// TypeId::ATTR_GET,
// EnumValue (CLOSED),
// MakeEnumAccessor (&TcpSocketBase::m_state),
// MakeEnumChecker (CLOSED, "Closed"))
.AddAttribute ("MaxSegLifetime",
"Maximum segment lifetime in seconds, use for TIME_WAIT state transition to CLOSED state",
DoubleValue (120), /* RFC793 says MSL=2 minutes*/
MakeDoubleAccessor (&TcpSocketBase::m_msl),
MakeDoubleChecker<double> (0))
.AddAttribute ("MaxWindowSize", "Max size of advertised window",
UintegerValue (65535),
MakeUintegerAccessor (&TcpSocketBase::m_maxWinSize),
MakeUintegerChecker<uint16_t> ())
.AddTraceSource ("RTO",
"Retransmission timeout",
MakeTraceSourceAccessor (&TcpSocketBase::m_rto))
.AddTraceSource ("RTT",
"Last RTT sample",
MakeTraceSourceAccessor (&TcpSocketBase::m_lastRtt))
.AddTraceSource ("NextTxSequence",
"Next sequence number to send (SND.NXT)",
MakeTraceSourceAccessor (&TcpSocketBase::m_nextTxSequence))
.AddTraceSource ("HighestSequence",
"Highest sequence number ever sent in socket's life time",
MakeTraceSourceAccessor (&TcpSocketBase::m_highTxMark))
.AddTraceSource ("State",
"TCP state",
MakeTraceSourceAccessor (&TcpSocketBase::m_state))
.AddTraceSource ("RWND",
"Remote side's flow control window",
MakeTraceSourceAccessor (&TcpSocketBase::m_rWnd))
;
return tid;
}
TcpSocketBase::TcpSocketBase (void)
: m_dupAckCount (0),
m_delAckCount (0),
m_endPoint (0),
m_endPoint6 (0),
m_node (0),
m_tcp (0),
m_rtt (0),
m_nextTxSequence (0), // Change this for non-zero initial sequence number
m_highTxMark (0),
m_rxBuffer (0),
m_txBuffer (0),
m_state (CLOSED),
m_errno (ERROR_NOTERROR),
m_closeNotified (false),
m_closeOnEmpty (false),
m_shutdownSend (false),
m_shutdownRecv (false),
m_connected (false),
m_segmentSize (0), // For attribute initialization consistency (quiet valgrind)
m_rWnd (0)
{
NS_LOG_FUNCTION (this);
}
TcpSocketBase::TcpSocketBase (const TcpSocketBase& sock)
: TcpSocket (sock), //copy object::m_tid and socket::callbacks
m_dupAckCount (sock.m_dupAckCount),
m_delAckCount (0),
m_delAckMaxCount (sock.m_delAckMaxCount),
m_noDelay (sock.m_noDelay),
m_cnRetries (sock.m_cnRetries),
m_delAckTimeout (sock.m_delAckTimeout),
m_persistTimeout (sock.m_persistTimeout),
m_cnTimeout (sock.m_cnTimeout),
m_endPoint (0),
m_endPoint6 (0),
m_node (sock.m_node),
m_tcp (sock.m_tcp),
m_rtt (0),
m_nextTxSequence (sock.m_nextTxSequence),
m_highTxMark (sock.m_highTxMark),
m_rxBuffer (sock.m_rxBuffer),
m_txBuffer (sock.m_txBuffer),
m_state (sock.m_state),
m_errno (sock.m_errno),
m_closeNotified (sock.m_closeNotified),
m_closeOnEmpty (sock.m_closeOnEmpty),
m_shutdownSend (sock.m_shutdownSend),
m_shutdownRecv (sock.m_shutdownRecv),
m_connected (sock.m_connected),
m_msl (sock.m_msl),
m_segmentSize (sock.m_segmentSize),
m_maxWinSize (sock.m_maxWinSize),
m_rWnd (sock.m_rWnd)
{
NS_LOG_FUNCTION (this);
NS_LOG_LOGIC ("Invoked the copy constructor");
// Copy the rtt estimator if it is set
if (sock.m_rtt)
{
m_rtt = sock.m_rtt->Copy ();
}
// Reset all callbacks to null
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);
}
TcpSocketBase::~TcpSocketBase (void)
{
NS_LOG_FUNCTION (this);
m_node = 0;
if (m_endPoint != 0)
{
NS_ASSERT (m_tcp != 0);
/*
* Upon Bind, an Ipv4Endpoint is allocated and set to m_endPoint, and
* DestroyCallback is set to TcpSocketBase::Destroy. If we called
* m_tcp->DeAllocate, it wil destroy its Ipv4EndpointDemux::DeAllocate,
* which in turn destroys my m_endPoint, and in turn invokes
* TcpSocketBase::Destroy to nullify m_node, m_endPoint, and m_tcp.
*/
NS_ASSERT (m_endPoint != 0);
m_tcp->DeAllocate (m_endPoint);
NS_ASSERT (m_endPoint == 0);
}
if (m_endPoint6 != 0)
{
NS_ASSERT (m_tcp != 0);
NS_ASSERT (m_endPoint6 != 0);
m_tcp->DeAllocate (m_endPoint6);
NS_ASSERT (m_endPoint6 == 0);
}
m_tcp = 0;
CancelAllTimers ();
}
/** Associate a node with this TCP socket */
void
TcpSocketBase::SetNode (Ptr<Node> node)
{
m_node = node;
}
/** Associate the L4 protocol (e.g. mux/demux) with this socket */
void
TcpSocketBase::SetTcp (Ptr<TcpL4Protocol> tcp)
{
m_tcp = tcp;
}
/** Set an RTT estimator with this socket */
void
TcpSocketBase::SetRtt (Ptr<RttEstimator> rtt)
{
m_rtt = rtt;
}
/** Inherit from Socket class: Returns error code */
enum Socket::SocketErrno
TcpSocketBase::GetErrno (void) const
{
return m_errno;
}
/** Inherit from Socket class: Returns socket type, NS3_SOCK_STREAM */
enum Socket::SocketType
TcpSocketBase::GetSocketType (void) const
{
return NS3_SOCK_STREAM;
}
/** Inherit from Socket class: Returns associated node */
Ptr<Node>
TcpSocketBase::GetNode (void) const
{
NS_LOG_FUNCTION_NOARGS ();
return m_node;
}
/** Inherit from Socket class: Bind socket to an end-point in TcpL4Protocol */
int
TcpSocketBase::Bind (void)
{
NS_LOG_FUNCTION_NOARGS ();
m_endPoint = m_tcp->Allocate ();
m_endPoint6 = m_tcp->Allocate6 ();
if (0 == m_endPoint || 0 == m_endPoint6)
{
m_errno = ERROR_ADDRNOTAVAIL;
return -1;
}
m_tcp->m_sockets.push_back (this);
return SetupCallback ();
}
int
TcpSocketBase::Bind6 (void)
{
return Bind ();
}
/** Inherit from Socket class: Bind socket (with specific address) to an end-point in TcpL4Protocol */
int
TcpSocketBase::Bind (const Address &address)
{
NS_LOG_FUNCTION (this << address);
if (InetSocketAddress::IsMatchingType (address))
{
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 ();
}
else if (ipv4 == Ipv4Address::GetAny () && port != 0)
{
m_endPoint = m_tcp->Allocate (port);
}
else if (ipv4 != Ipv4Address::GetAny () && port == 0)
{
m_endPoint = m_tcp->Allocate (ipv4);
}
else if (ipv4 != Ipv4Address::GetAny () && port != 0)
{
m_endPoint = m_tcp->Allocate (ipv4, port);
}
if (0 == m_endPoint)
{
m_errno = port ? ERROR_ADDRINUSE : ERROR_ADDRNOTAVAIL;
return -1;
}
}
else if (Inet6SocketAddress::IsMatchingType (address))
{
Inet6SocketAddress transport = Inet6SocketAddress::ConvertFrom (address);
Ipv6Address ipv6 = transport.GetIpv6 ();
uint16_t port = transport.GetPort ();
if (ipv6 == Ipv6Address::GetAny () && port == 0)
{
m_endPoint6 = m_tcp->Allocate6 ();
}
else if (ipv6 == Ipv6Address::GetAny () && port != 0)
{
m_endPoint6 = m_tcp->Allocate6 (port);
}
else if (ipv6 != Ipv6Address::GetAny () && port == 0)
{
m_endPoint6 = m_tcp->Allocate6 (ipv6);
}
else if (ipv6 != Ipv6Address::GetAny () && port != 0)
{
m_endPoint6 = m_tcp->Allocate6 (ipv6, port);
}
if (0 == m_endPoint6)
{
m_errno = port ? ERROR_ADDRINUSE : ERROR_ADDRNOTAVAIL;
return -1;
}
}
else
{
m_errno = ERROR_INVAL;
return -1;
}
m_tcp->m_sockets.push_back (this);
NS_LOG_LOGIC ("TcpSocketBase " << this << " got an endpoint: " << m_endPoint);
return SetupCallback ();
}
/** Inherit from Socket class: Initiate connection to a remote address:port */
int
TcpSocketBase::Connect (const Address & address)
{
NS_LOG_FUNCTION (this << address);
// If haven't do so, Bind() this socket first
if (InetSocketAddress::IsMatchingType (address))
{
if (m_endPoint == 0)
{
if (Bind () == -1)
{
NS_ASSERT (m_endPoint == 0);
return -1; // Bind() failed
}
NS_ASSERT (m_endPoint != 0);
}
InetSocketAddress transport = InetSocketAddress::ConvertFrom (address);
m_endPoint->SetPeer (transport.GetIpv4 (), transport.GetPort ());
m_endPoint6 = 0;
// Get the appropriate local address and port number from the routing protocol and set up endpoint
if (SetupEndpoint () != 0)
{ // Route to destination does not exist
return -1;
}
}
else if (Inet6SocketAddress::IsMatchingType (address) )
{
// If we are operating on a v4-mapped address, translate the address to
// a v4 address and re-call this function
Inet6SocketAddress transport = Inet6SocketAddress::ConvertFrom (address);
Ipv6Address v6Addr = transport.GetIpv6 ();
if (v6Addr.IsIpv4MappedAddress () == true)
{
Ipv4Address v4Addr = v6Addr.GetIpv4MappedAddress ();
return Connect(InetSocketAddress(v4Addr, transport.GetPort ()));
}
if (m_endPoint6 == 0)
{
if (Bind6 () == -1)
{
NS_ASSERT (m_endPoint6 == 0);
return -1; // Bind() failed
}
NS_ASSERT (m_endPoint6 != 0);
}
m_endPoint6->SetPeer (v6Addr, transport.GetPort ());
m_endPoint = 0;
// Get the appropriate local address and port number from the routing protocol and set up endpoint
if (SetupEndpoint6 () != 0)
{ // Route to destination does not exist
return -1;
}
}
else
{
m_errno = ERROR_INVAL;
return -1;
}
// Re-initialize parameters in case this socket is being reused after CLOSE
m_rtt->Reset ();
m_cnCount = m_cnRetries;
// DoConnect() will do state-checking and send a SYN packet
return DoConnect ();
}
/** Inherit from Socket class: Listen on the endpoint for an incoming connection */
int
TcpSocketBase::Listen (void)
{
NS_LOG_FUNCTION (this);
// Linux quits EINVAL if we're not in CLOSED state, so match what they do
if (m_state != CLOSED)
{
m_errno = ERROR_INVAL;
return -1;
}
// In other cases, set the state to LISTEN and done
NS_LOG_INFO ("CLOSED -> LISTEN");
m_state = LISTEN;
return 0;
}
/** Inherit from Socket class: Kill this socket and signal the peer (if any) */
int
TcpSocketBase::Close (void)
{
NS_LOG_FUNCTION (this);
// First we check to see if there is any unread rx data
// Bug number 426 claims we should send reset in this case.
if (m_rxBuffer.Size () != 0)
{
SendRST ();
return 0;
}
if (m_txBuffer.SizeFromSequence (m_nextTxSequence) > 0)
{ // App close with pending data must wait until all data transmitted
if (m_closeOnEmpty == false)
{
m_closeOnEmpty = true;
NS_LOG_INFO ("Socket " << this << " deferring close, state " << TcpStateName[m_state]);
}
return 0;
}
return DoClose ();
}
/** Inherit from Socket class: Signal a termination of send */
int
TcpSocketBase::ShutdownSend (void)
{
NS_LOG_FUNCTION (this);
m_shutdownSend = true;
return 0;
}
/** Inherit from Socket class: Signal a termination of receive */
int
TcpSocketBase::ShutdownRecv (void)
{
NS_LOG_FUNCTION (this);
m_shutdownRecv = true;
return 0;
}
/** Inherit from Socket class: Send a packet. Parameter flags is not used.
Packet has no TCP header. Invoked by upper-layer application */
int
TcpSocketBase::Send (Ptr<Packet> p, uint32_t flags)
{
NS_LOG_FUNCTION (this << p);
NS_ABORT_MSG_IF (flags, "use of flags is not supported in TcpSocketBase::Send()");
if (m_state == ESTABLISHED || m_state == SYN_SENT || m_state == CLOSE_WAIT)
{
// Store the packet into Tx buffer
if (!m_txBuffer.Add (p))
{ // TxBuffer overflow, send failed
m_errno = ERROR_MSGSIZE;
return -1;
}
// Submit the data to lower layers
NS_LOG_LOGIC ("txBufSize=" << m_txBuffer.Size () << " state " << TcpStateName[m_state]);
if (m_state == ESTABLISHED || m_state == CLOSE_WAIT)
{ // Try to send the data out
SendPendingData (m_connected);
}
return p->GetSize ();
}
else
{ // Connection not established yet
m_errno = ERROR_NOTCONN;
return -1; // Send failure
}
}
/** Inherit from Socket class: In TcpSocketBase, it is same as Send() call */
int
TcpSocketBase::SendTo (Ptr<Packet> p, uint32_t flags, const Address &address)
{
return Send (p, flags); // SendTo() and Send() are the same
}
/** Inherit from Socket class: Return data to upper-layer application. Parameter flags
is not used. Data is returned as a packet of size no larger than maxSize */
Ptr<Packet>
TcpSocketBase::Recv (uint32_t maxSize, uint32_t flags)
{
NS_LOG_FUNCTION (this);
NS_ABORT_MSG_IF (flags, "use of flags is not supported in TcpSocketBase::Recv()");
if (m_rxBuffer.Size () == 0 && m_state == CLOSE_WAIT)
{
return Create<Packet> (); // Send EOF on connection close
}
Ptr<Packet> outPacket = m_rxBuffer.Extract (maxSize);
if (outPacket != 0 && outPacket->GetSize () != 0)
{
SocketAddressTag tag;
if (m_endPoint != 0)
{
tag.SetAddress (InetSocketAddress (m_endPoint->GetPeerAddress (), m_endPoint->GetPeerPort ()));
}
else if (m_endPoint6 != 0)
{
tag.SetAddress (Inet6SocketAddress (m_endPoint6->GetPeerAddress (), m_endPoint6->GetPeerPort ()));
}
outPacket->AddPacketTag (tag);
}
return outPacket;
}
/** Inherit from Socket class: Recv and return the remote's address */
Ptr<Packet>
TcpSocketBase::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)
{
if (m_endPoint != 0)
{
fromAddress = InetSocketAddress (m_endPoint->GetPeerAddress (), m_endPoint->GetPeerPort ());
}
else if (m_endPoint6 != 0)
{
fromAddress = Inet6SocketAddress (m_endPoint6->GetPeerAddress (), m_endPoint6->GetPeerPort ());
}
else
{
fromAddress = InetSocketAddress (Ipv4Address::GetZero (), 0);
}
}
return packet;
}
/** Inherit from Socket class: Get the max number of bytes an app can send */
uint32_t
TcpSocketBase::GetTxAvailable (void) const
{
NS_LOG_FUNCTION (this);
return m_txBuffer.Available ();
}
/** Inherit from Socket class: Get the max number of bytes an app can read */
uint32_t
TcpSocketBase::GetRxAvailable (void) const
{
NS_LOG_FUNCTION (this);
return m_rxBuffer.Available ();
}
/** Inherit from Socket class: Return local address:port */
int
TcpSocketBase::GetSockName (Address &address) const
{
NS_LOG_FUNCTION (this);
if (m_endPoint != 0)
{
address = InetSocketAddress (m_endPoint->GetLocalAddress (), m_endPoint->GetLocalPort ());
}
else if (m_endPoint6 != 0)
{
address = Inet6SocketAddress (m_endPoint6->GetLocalAddress (), m_endPoint6->GetLocalPort ());
}
else
{ // It is possible to call this method on a socket without a name
// in which case, behavior is unspecified
// Should this return an InetSocketAddress or an Inet6SocketAddress?
address = InetSocketAddress (Ipv4Address::GetZero (), 0);
}
return 0;
}
/** Inherit from Socket class: Bind this socket to the specified NetDevice */
void
TcpSocketBase::BindToNetDevice (Ptr<NetDevice> netdevice)
{
NS_LOG_FUNCTION (netdevice);
Socket::BindToNetDevice (netdevice); // Includes sanity check
if (m_endPoint == 0 && m_endPoint6 == 0)
{
if (Bind () == -1)
{
NS_ASSERT ((m_endPoint == 0 && m_endPoint6 == 0));
return;
}
NS_ASSERT ((m_endPoint != 0 && m_endPoint6 != 0));
}
if (m_endPoint != 0)
{
m_endPoint->BindToNetDevice (netdevice);
}
// No BindToNetDevice() for Ipv6EndPoint
return;
}
/** Clean up after Bind. Set up callback functions in the end-point. */
int
TcpSocketBase::SetupCallback (void)
{
NS_LOG_FUNCTION (this);
if (m_endPoint == 0 && m_endPoint6 == 0)
{
return -1;
}
if (m_endPoint != 0)
{
m_endPoint->SetRxCallback (MakeCallback (&TcpSocketBase::ForwardUp, Ptr<TcpSocketBase> (this)));
m_endPoint->SetDestroyCallback (MakeCallback (&TcpSocketBase::Destroy, Ptr<TcpSocketBase> (this)));
}
if (m_endPoint6 != 0)
{
m_endPoint6->SetRxCallback (MakeCallback (&TcpSocketBase::ForwardUp6, Ptr<TcpSocketBase> (this)));
m_endPoint6->SetDestroyCallback (MakeCallback (&TcpSocketBase::Destroy, Ptr<TcpSocketBase> (this)));
}
return 0;
}
/** Perform the real connection tasks: Send SYN if allowed, RST if invalid */
int
TcpSocketBase::DoConnect (void)
{
NS_LOG_FUNCTION (this);
// A new connection is allowed only if this socket does not have a connection
if (m_state == CLOSED || m_state == LISTEN || m_state == SYN_SENT || m_state == LAST_ACK || m_state == CLOSE_WAIT)
{ // send a SYN packet and change state into SYN_SENT
SendEmptyPacket (TcpHeader::SYN);
NS_LOG_INFO (TcpStateName[m_state] << " -> SYN_SENT");
m_state = SYN_SENT;
}
else if (m_state != TIME_WAIT)
{ // In states SYN_RCVD, ESTABLISHED, FIN_WAIT_1, FIN_WAIT_2, and CLOSING, an connection
// exists. We send RST, tear down everything, and close this socket.
SendRST ();
CloseAndNotify ();
}
return 0;
}
/** Do the action to close the socket. Usually send a packet with appropriate
flags depended on the current m_state. */
int
TcpSocketBase::DoClose (void)
{
NS_LOG_FUNCTION (this);
switch (m_state)
{
case SYN_RCVD:
case ESTABLISHED:
// send FIN to close the peer
SendEmptyPacket (TcpHeader::FIN);
NS_LOG_INFO ("ESTABLISHED -> FIN_WAIT_1");
m_state = FIN_WAIT_1;
break;
case CLOSE_WAIT:
// send FIN+ACK to close the peer
SendEmptyPacket (TcpHeader::FIN | TcpHeader::ACK);
NS_LOG_INFO ("CLOSE_WAIT -> LAST_ACK");
m_state = LAST_ACK;
break;
case SYN_SENT:
case CLOSING:
// Send RST if application closes in SYN_SENT and CLOSING
SendRST ();
CloseAndNotify ();
break;
case LISTEN:
case LAST_ACK:
// In these three states, move to CLOSED and tear down the end point
CloseAndNotify ();
break;
case CLOSED:
case FIN_WAIT_1:
case FIN_WAIT_2:
case TIME_WAIT:
default: /* mute compiler */
// Do nothing in these four states
break;
}
return 0;
}
/** Peacefully close the socket by notifying the upper layer and deallocate end point */
void
TcpSocketBase::CloseAndNotify (void)
{
NS_LOG_FUNCTION (this);
if (!m_closeNotified) NotifyNormalClose ();
if (m_state != TIME_WAIT) DeallocateEndPoint ();
m_closeNotified = true;
NS_LOG_INFO (TcpStateName[m_state] << " -> CLOSED");
CancelAllTimers ();
m_state = CLOSED;
}
/** Tell if a sequence number range is out side the range that my rx buffer can
accpet */
bool
TcpSocketBase::OutOfRange (SequenceNumber32 head, SequenceNumber32 tail) const
{
if (m_state == LISTEN || m_state == SYN_SENT || m_state == SYN_RCVD)
{ // Rx buffer in these states are not initialized.
return false;
}
if (m_state == LAST_ACK || m_state == CLOSING || m_state == CLOSE_WAIT)
{ // In LAST_ACK and CLOSING states, it only wait for an ACK and the
// sequence number must equals to m_rxBuffer.NextRxSequence ()
return (m_rxBuffer.NextRxSequence () != head);
};
// In all other cases, check if the sequence number is in range
return (tail < m_rxBuffer.NextRxSequence () || m_rxBuffer.MaxRxSequence () <= head);
}
/** Function called by the L3 protocol when it received a packet to pass on to
the TCP. This function is registered as the "RxCallback" function in
SetupCallback(), which invoked by Bind(), and CompleteFork() */
void
TcpSocketBase::ForwardUp (Ptr<Packet> packet, Ipv4Header header, uint16_t port,
Ptr<Ipv4Interface> incomingInterface)
{
DoForwardUp (packet, header, port, incomingInterface);
}
void
TcpSocketBase::ForwardUp6 (Ptr<Packet> packet, Ipv6Address saddr, Ipv6Address daddr, uint16_t port)
{
DoForwardUp (packet, saddr, daddr, port);
}
/** The real function to handle the incoming packet from lower layers. This is
wrapped by ForwardUp() so that this function can be overloaded by daughter
classes. */
void
TcpSocketBase::DoForwardUp (Ptr<Packet> packet, Ipv4Header header, uint16_t port,
Ptr<Ipv4Interface> incomingInterface)
{
NS_LOG_LOGIC ("Socket " << this << " forward up " <<
m_endPoint->GetPeerAddress () <<
":" << m_endPoint->GetPeerPort () <<
" to " << m_endPoint->GetLocalAddress () <<
":" << m_endPoint->GetLocalPort ());
Address fromAddress = InetSocketAddress (header.GetSource (), port);
Address toAddress = InetSocketAddress (header.GetDestination (), m_endPoint->GetLocalPort ());
// Peel off TCP header and do validity checking
TcpHeader tcpHeader;
packet->RemoveHeader (tcpHeader);
if (tcpHeader.GetFlags () & TcpHeader::ACK)
{
EstimateRtt (tcpHeader);
}
ReadOptions (tcpHeader);
// Update Rx window size, i.e. the flow control window
if (m_rWnd.Get () == 0 && tcpHeader.GetWindowSize () != 0)
{ // persist probes end
NS_LOG_LOGIC (this << " Leaving zerowindow persist state");
m_persistEvent.Cancel ();
}
m_rWnd = tcpHeader.GetWindowSize ();
// Discard fully out of range data packets
if (packet->GetSize () &&
OutOfRange (tcpHeader.GetSequenceNumber (), tcpHeader.GetSequenceNumber () + packet->GetSize ()))
{
NS_LOG_LOGIC ("At state " << TcpStateName[m_state] <<
" received packet of seq [" << tcpHeader.GetSequenceNumber () <<
":" << tcpHeader.GetSequenceNumber () + packet->GetSize() <<
") out of range [" << m_rxBuffer.NextRxSequence () << ":" <<
m_rxBuffer.MaxRxSequence () << ")");
// Acknowledgement should be sent for all unacceptable packets (RFC793, p.69)
if (m_state == ESTABLISHED && !(tcpHeader.GetFlags () & TcpHeader::RST))
{
SendEmptyPacket (TcpHeader::ACK);
}
return;
}
// TCP state machine code in different process functions
// C.f.: tcp_rcv_state_process() in tcp_input.c in Linux kernel
switch (m_state)
{
case ESTABLISHED:
ProcessEstablished (packet, tcpHeader);
break;
case LISTEN:
ProcessListen (packet, tcpHeader, fromAddress, toAddress);
break;
case TIME_WAIT:
// Do nothing
break;
case CLOSED:
// Send RST if the incoming packet is not a RST
if ((tcpHeader.GetFlags () & ~(TcpHeader::PSH | TcpHeader::URG)) != TcpHeader::RST)
{ // Since m_endPoint is not configured yet, we cannot use SendRST here
TcpHeader h;
h.SetFlags (TcpHeader::RST);
h.SetSequenceNumber (m_nextTxSequence);
h.SetAckNumber (m_rxBuffer.NextRxSequence ());
h.SetSourcePort (tcpHeader.GetDestinationPort ());
h.SetDestinationPort (tcpHeader.GetSourcePort ());
h.SetWindowSize (AdvertisedWindowSize ());
AddOptions (h);
m_tcp->SendPacket (Create<Packet> (), h, header.GetDestination (), header.GetSource (), m_boundnetdevice);
}
break;
case SYN_SENT:
ProcessSynSent (packet, tcpHeader);
break;
case SYN_RCVD:
ProcessSynRcvd (packet, tcpHeader, fromAddress, toAddress);
break;
case FIN_WAIT_1:
case FIN_WAIT_2:
case CLOSE_WAIT:
ProcessWait (packet, tcpHeader);
break;
case CLOSING:
ProcessClosing (packet, tcpHeader);
break;
case LAST_ACK:
ProcessLastAck (packet, tcpHeader);
break;
default: // mute compiler
break;
}
}
void
TcpSocketBase::DoForwardUp (Ptr<Packet> packet, Ipv6Address saddr, Ipv6Address daddr, uint16_t port)
{
NS_LOG_LOGIC ("Socket " << this << " forward up " <<
m_endPoint6->GetPeerAddress () <<
":" << m_endPoint6->GetPeerPort () <<
" to " << m_endPoint6->GetLocalAddress () <<
":" << m_endPoint6->GetLocalPort ());
Address fromAddress = Inet6SocketAddress (saddr, port);
Address toAddress = Inet6SocketAddress (daddr, m_endPoint6->GetLocalPort ());
// Peel off TCP header and do validity checking
TcpHeader tcpHeader;
packet->RemoveHeader (tcpHeader);
if (tcpHeader.GetFlags () & TcpHeader::ACK)
{
EstimateRtt (tcpHeader);
}
ReadOptions (tcpHeader);
// Update Rx window size, i.e. the flow control window
if (m_rWnd.Get () == 0 && tcpHeader.GetWindowSize () != 0)
{ // persist probes end
NS_LOG_LOGIC (this << " Leaving zerowindow persist state");
m_persistEvent.Cancel ();
}
m_rWnd = tcpHeader.GetWindowSize ();
// Discard fully out of range packets
if (packet->GetSize () &&
OutOfRange (tcpHeader.GetSequenceNumber (), tcpHeader.GetSequenceNumber () + packet->GetSize ()))
{
NS_LOG_LOGIC ("At state " << TcpStateName[m_state] <<
" received packet of seq [" << tcpHeader.GetSequenceNumber () <<
":" << tcpHeader.GetSequenceNumber () + packet->GetSize() <<
") out of range [" << m_rxBuffer.NextRxSequence () << ":" <<
m_rxBuffer.MaxRxSequence () << ")");
// Acknowledgement should be sent for all unacceptable packets (RFC793, p.69)
if (m_state == ESTABLISHED && !(tcpHeader.GetFlags () & TcpHeader::RST))
{
SendEmptyPacket (TcpHeader::ACK);
}
return;
}
// TCP state machine code in different process functions
// C.f.: tcp_rcv_state_process() in tcp_input.c in Linux kernel
switch (m_state)
{
case ESTABLISHED:
ProcessEstablished (packet, tcpHeader);
break;
case LISTEN:
ProcessListen (packet, tcpHeader, fromAddress, toAddress);
break;
case TIME_WAIT:
// Do nothing
break;
case CLOSED:
// Send RST if the incoming packet is not a RST
if ((tcpHeader.GetFlags () & ~(TcpHeader::PSH | TcpHeader::URG)) != TcpHeader::RST)
{ // Since m_endPoint is not configured yet, we cannot use SendRST here
TcpHeader h;
h.SetFlags (TcpHeader::RST);
h.SetSequenceNumber (m_nextTxSequence);
h.SetAckNumber (m_rxBuffer.NextRxSequence ());
h.SetSourcePort (tcpHeader.GetDestinationPort ());
h.SetDestinationPort (tcpHeader.GetSourcePort ());
h.SetWindowSize (AdvertisedWindowSize ());
AddOptions (h);
m_tcp->SendPacket (Create<Packet> (), h, daddr, saddr, m_boundnetdevice);
}
break;
case SYN_SENT:
ProcessSynSent (packet, tcpHeader);
break;
case SYN_RCVD:
ProcessSynRcvd (packet, tcpHeader, fromAddress, toAddress);
break;
case FIN_WAIT_1:
case FIN_WAIT_2:
case CLOSE_WAIT:
ProcessWait (packet, tcpHeader);
break;
case CLOSING:
ProcessClosing (packet, tcpHeader);
break;
case LAST_ACK:
ProcessLastAck (packet, tcpHeader);
break;
default: // mute compiler
break;
}
}
/** Received a packet upon ESTABLISHED state. This function is mimicking the
role of tcp_rcv_established() in tcp_input.c in Linux kernel. */
void
TcpSocketBase::ProcessEstablished (Ptr<Packet> packet, const TcpHeader& tcpHeader)
{
NS_LOG_FUNCTION (this << tcpHeader);
// Extract the flags. PSH and URG are not honoured.
uint8_t tcpflags = tcpHeader.GetFlags () & ~(TcpHeader::PSH | TcpHeader::URG);
// Different flags are different events
if (tcpflags == TcpHeader::ACK)
{
ReceivedAck (packet, tcpHeader);
}
else if (tcpflags == TcpHeader::SYN)
{ // Received SYN, old NS-3 behaviour is to set state to SYN_RCVD and
// respond with a SYN+ACK. But it is not a legal state transition as of
// RFC793. Thus this is ignored.
}
else if (tcpflags == (TcpHeader::SYN | TcpHeader::ACK))
{ // No action for received SYN+ACK, it is probably a duplicated packet
}
else if (tcpflags == TcpHeader::FIN || tcpflags == (TcpHeader::FIN | TcpHeader::ACK))
{ // Received FIN or FIN+ACK, bring down this socket nicely
PeerClose (packet, tcpHeader);
}
else if (tcpflags == 0)
{ // No flags means there is only data
ReceivedData (packet, tcpHeader);
if (m_rxBuffer.Finished ())
{
PeerClose (packet, tcpHeader);
}
}
else
{ // Received RST or the TCP flags is invalid, in either case, terminate this socket
if (tcpflags != TcpHeader::RST)
{ // this must be an invalid flag, send reset
NS_LOG_LOGIC ("Illegal flag " << tcpflags << " received. Reset packet is sent.");
SendRST ();
}
CloseAndNotify ();
}
}
/** Process the newly received ACK */
void
TcpSocketBase::ReceivedAck (Ptr<Packet> packet, const TcpHeader& tcpHeader)
{
NS_LOG_FUNCTION (this << tcpHeader);
// Received ACK. Compare the ACK number against highest unacked seqno
if (0 == (tcpHeader.GetFlags () & TcpHeader::ACK))
{ // Ignore if no ACK flag
}
else if (tcpHeader.GetAckNumber () < m_txBuffer.HeadSequence ())
{ // Case 1: Old ACK, ignored.
NS_LOG_LOGIC ("Ignored ack of " << tcpHeader.GetAckNumber ());
}
else if (tcpHeader.GetAckNumber () == m_txBuffer.HeadSequence ())
{ // Case 2: Potentially a duplicated ACK
if (tcpHeader.GetAckNumber () < m_nextTxSequence)
{
NS_LOG_LOGIC ("Dupack of " << tcpHeader.GetAckNumber ());
DupAck (tcpHeader, ++m_dupAckCount);
}
// otherwise, the ACK is precisely equal to the nextTxSequence
NS_ASSERT (tcpHeader.GetAckNumber () <= m_nextTxSequence);
}
else if (tcpHeader.GetAckNumber () > m_txBuffer.HeadSequence ())
{ // Case 3: New ACK, reset m_dupAckCount and update m_txBuffer
NS_LOG_LOGIC ("New ack of " << tcpHeader.GetAckNumber ());
NewAck (tcpHeader.GetAckNumber ());
m_dupAckCount = 0;
}
// If there is any data piggybacked, store it into m_rxBuffer
if (packet->GetSize () > 0)
{
ReceivedData (packet, tcpHeader);
}
}
/** Received a packet upon LISTEN state. */
void
TcpSocketBase::ProcessListen (Ptr<Packet> packet, const TcpHeader& tcpHeader,
const Address& fromAddress, const Address& toAddress)
{
NS_LOG_FUNCTION (this << tcpHeader);
// Extract the flags. PSH and URG are not honoured.
uint8_t tcpflags = tcpHeader.GetFlags () & ~(TcpHeader::PSH | TcpHeader::URG);
// Fork a socket if received a SYN. Do nothing otherwise.
// C.f.: the LISTEN part in tcp_v4_do_rcv() in tcp_ipv4.c in Linux kernel
if (tcpflags != TcpHeader::SYN) return;
// Call socket's notify function to let the server app know we got a SYN
// If the server app refuses the connection, do nothing
if (!NotifyConnectionRequest (fromAddress)) return;
// Clone the socket, simulate fork
Ptr<TcpSocketBase> newSock = Fork ();
NS_LOG_LOGIC ("Cloned a TcpSocketBase " << newSock);
Simulator::ScheduleNow (&TcpSocketBase::CompleteFork, newSock,
packet, tcpHeader, fromAddress, toAddress);
}
/** Received a packet upon SYN_SENT */
void
TcpSocketBase::ProcessSynSent (Ptr<Packet> packet, const TcpHeader& tcpHeader)
{
NS_LOG_FUNCTION (this << tcpHeader);
// Extract the flags. PSH and URG are not honoured.
uint8_t tcpflags = tcpHeader.GetFlags () & ~(TcpHeader::PSH | TcpHeader::URG);
if (tcpflags == 0)
{ // Bare data, accept it and move to ESTABLISHED state. This is not a normal behaviour. Remove this?
NS_LOG_INFO ("SYN_SENT -> ESTABLISHED");
m_state = ESTABLISHED;
m_connected = true;
m_retxEvent.Cancel ();
m_delAckCount = m_delAckMaxCount;
ReceivedData (packet, tcpHeader);
Simulator::ScheduleNow (&TcpSocketBase::ConnectionSucceeded, this);
}
else if (tcpflags == TcpHeader::ACK)
{ // Ignore ACK in SYN_SENT
}
else if (tcpflags == TcpHeader::SYN)
{ // Received SYN, move to SYN_RCVD state and respond with SYN+ACK
NS_LOG_INFO ("SYN_SENT -> SYN_RCVD");
m_state = SYN_RCVD;
m_cnCount = m_cnRetries;
m_rxBuffer.SetNextRxSequence (tcpHeader.GetSequenceNumber () + SequenceNumber32 (1));
SendEmptyPacket (TcpHeader::SYN | TcpHeader::ACK);
}
else if (tcpflags == (TcpHeader::SYN | TcpHeader::ACK)
&& m_nextTxSequence + SequenceNumber32 (1) == tcpHeader.GetAckNumber ())
{ // Handshake completed
NS_LOG_INFO ("SYN_SENT -> ESTABLISHED");
m_state = ESTABLISHED;
m_connected = true;
m_retxEvent.Cancel ();
m_rxBuffer.SetNextRxSequence (tcpHeader.GetSequenceNumber () + SequenceNumber32 (1));
m_highTxMark = ++m_nextTxSequence;
m_txBuffer.SetHeadSequence (m_nextTxSequence);
SendEmptyPacket (TcpHeader::ACK);
SendPendingData (m_connected);
Simulator::ScheduleNow (&TcpSocketBase::ConnectionSucceeded, this);
// Always respond to first data packet to speed up the connection.
// Remove to get the behaviour of old NS-3 code.
m_delAckCount = m_delAckMaxCount;
}
else
{ // Other in-sequence input
if (tcpflags != TcpHeader::RST)
{ // When (1) rx of FIN+ACK; (2) rx of FIN; (3) rx of bad flags
NS_LOG_LOGIC ("Illegal flag " << std::hex << static_cast<uint32_t>(tcpflags) << std::dec << " received. Reset packet is sent.");
SendRST ();
}
CloseAndNotify ();
}
}
/** Received a packet upon SYN_RCVD */
void
TcpSocketBase::ProcessSynRcvd (Ptr<Packet> packet, const TcpHeader& tcpHeader,
const Address& fromAddress, const Address& toAddress)
{
NS_LOG_FUNCTION (this << tcpHeader);
// Extract the flags. PSH and URG are not honoured.
uint8_t tcpflags = tcpHeader.GetFlags () & ~(TcpHeader::PSH | TcpHeader::URG);
if (tcpflags == 0 ||
(tcpflags == TcpHeader::ACK
&& m_nextTxSequence + SequenceNumber32 (1) == tcpHeader.GetAckNumber ()))
{ // If it is bare data, accept it and move to ESTABLISHED state. This is
// possibly due to ACK lost in 3WHS. If in-sequence ACK is received, the
// handshake is completed nicely.
NS_LOG_INFO ("SYN_RCVD -> ESTABLISHED");
m_state = ESTABLISHED;
m_connected = true;
m_retxEvent.Cancel ();
m_highTxMark = ++m_nextTxSequence;
m_txBuffer.SetHeadSequence (m_nextTxSequence);
if (m_endPoint)
{
m_endPoint->SetPeer (InetSocketAddress::ConvertFrom (fromAddress).GetIpv4 (),
InetSocketAddress::ConvertFrom (fromAddress).GetPort ());
}
else if (m_endPoint6)
{
m_endPoint6->SetPeer (Inet6SocketAddress::ConvertFrom (fromAddress).GetIpv6 (),
Inet6SocketAddress::ConvertFrom (fromAddress).GetPort ());
}
// Always respond to first data packet to speed up the connection.
// Remove to get the behaviour of old NS-3 code.
m_delAckCount = m_delAckMaxCount;
ReceivedAck (packet, tcpHeader);
NotifyNewConnectionCreated (this, fromAddress);
// As this connection is established, the socket is available to send data now
if (GetTxAvailable () > 0)
{
NotifySend (GetTxAvailable ());
}
}
else if (tcpflags == TcpHeader::SYN)
{ // Probably the peer lost my SYN+ACK
m_rxBuffer.SetNextRxSequence (tcpHeader.GetSequenceNumber () + SequenceNumber32 (1));
SendEmptyPacket (TcpHeader::SYN | TcpHeader::ACK);
}
else if (tcpflags == (TcpHeader::FIN | TcpHeader::ACK))
{
if (tcpHeader.GetSequenceNumber () == m_rxBuffer.NextRxSequence ())
{ // In-sequence FIN before connection complete. Set up connection and close.
m_connected = true;
m_retxEvent.Cancel ();
m_highTxMark = ++m_nextTxSequence;
m_txBuffer.SetHeadSequence (m_nextTxSequence);
if (m_endPoint)
{
m_endPoint->SetPeer (InetSocketAddress::ConvertFrom (fromAddress).GetIpv4 (),
InetSocketAddress::ConvertFrom (fromAddress).GetPort ());
}
else if (m_endPoint6)
{
m_endPoint6->SetPeer (Inet6SocketAddress::ConvertFrom (fromAddress).GetIpv6 (),
Inet6SocketAddress::ConvertFrom (fromAddress).GetPort ());
}
PeerClose (packet, tcpHeader);
}
}
else
{ // Other in-sequence input
if (tcpflags != TcpHeader::RST)
{ // When (1) rx of SYN+ACK; (2) rx of FIN; (3) rx of bad flags
NS_LOG_LOGIC ("Illegal flag " << tcpflags << " received. Reset packet is sent.");
if (m_endPoint)
{
m_endPoint->SetPeer (InetSocketAddress::ConvertFrom (fromAddress).GetIpv4 (),
InetSocketAddress::ConvertFrom (fromAddress).GetPort ());
}
else if (m_endPoint6)
{
m_endPoint6->SetPeer (Inet6SocketAddress::ConvertFrom (fromAddress).GetIpv6 (),
Inet6SocketAddress::ConvertFrom (fromAddress).GetPort ());
}
SendRST ();
}
CloseAndNotify ();
}
}
/** Received a packet upon CLOSE_WAIT, FIN_WAIT_1, or FIN_WAIT_2 states */
void
TcpSocketBase::ProcessWait (Ptr<Packet> packet, const TcpHeader& tcpHeader)
{
NS_LOG_FUNCTION (this << tcpHeader);
// Extract the flags. PSH and URG are not honoured.
uint8_t tcpflags = tcpHeader.GetFlags () & ~(TcpHeader::PSH | TcpHeader::URG);
if (packet->GetSize () > 0)
{ // Bare data, accept it
ReceivedData (packet, tcpHeader);
}
else if (tcpflags == TcpHeader::ACK)
{ // Process the ACK, and if in FIN_WAIT_1, conditionally move to FIN_WAIT_2
ReceivedAck (packet, tcpHeader);
if (m_state == FIN_WAIT_1 && m_txBuffer.Size () == 0 &&
tcpHeader.GetAckNumber () == m_highTxMark + SequenceNumber32 (1))
{ // This ACK corresponds to the FIN sent
NS_LOG_INFO ("FIN_WAIT_1 -> FIN_WAIT_2");
m_state = FIN_WAIT_2;
}
}
else if (tcpflags == TcpHeader::FIN || tcpflags == (TcpHeader::FIN | TcpHeader::ACK))
{ // Got FIN, respond with ACK and move to next state
if (tcpflags & TcpHeader::ACK)
{ // Process the ACK first
ReceivedAck (packet, tcpHeader);
}
m_rxBuffer.SetFinSequence (tcpHeader.GetSequenceNumber ());
}
else if (tcpflags == TcpHeader::SYN || tcpflags == (TcpHeader::SYN | TcpHeader::ACK))
{ // Duplicated SYN or SYN+ACK, possibly due to spurious retransmission
return;
}
else
{ // This is a RST or bad flags
if (tcpflags != TcpHeader::RST)
{
NS_LOG_LOGIC ("Illegal flag " << tcpflags << " received. Reset packet is sent.");
SendRST ();
}
CloseAndNotify ();
return;
}
// Check if the close responder sent an in-sequence FIN, if so, respond ACK
if ((m_state == FIN_WAIT_1 || m_state == FIN_WAIT_2) && m_rxBuffer.Finished ())
{
if (m_state == FIN_WAIT_1)
{
NS_LOG_INFO ("FIN_WAIT_1 -> CLOSING");
m_state = CLOSING;
if (m_txBuffer.Size () == 0 &&
tcpHeader.GetAckNumber () == m_highTxMark + SequenceNumber32 (1))
{ // This ACK corresponds to the FIN sent
TimeWait ();
}
}
else if (m_state == FIN_WAIT_2)
{
TimeWait ();
};
SendEmptyPacket (TcpHeader::ACK);
if (!m_shutdownRecv) NotifyDataRecv ();
}
}
/** Received a packet upon CLOSING */
void
TcpSocketBase::ProcessClosing (Ptr<Packet> packet, const TcpHeader& tcpHeader)
{
NS_LOG_FUNCTION (this << tcpHeader);
// Extract the flags. PSH and URG are not honoured.
uint8_t tcpflags = tcpHeader.GetFlags () & ~(TcpHeader::PSH | TcpHeader::URG);
if (tcpflags == TcpHeader::ACK)
{
if (tcpHeader.GetSequenceNumber () == m_rxBuffer.NextRxSequence ())
{ // This ACK corresponds to the FIN sent
TimeWait ();
}
}
else
{ // CLOSING state means simultaneous close, i.e. no one is sending data to
// anyone. If anything other than ACK is received, respond with a reset.
if (tcpflags == TcpHeader::FIN || tcpflags == (TcpHeader::FIN | TcpHeader::ACK))
{ // FIN from the peer as well. We can close immediately.
SendEmptyPacket (TcpHeader::ACK);
}
else if (tcpflags != TcpHeader::RST)
{ // Receive of SYN or SYN+ACK or bad flags or pure data
NS_LOG_LOGIC ("Illegal flag " << tcpflags << " received. Reset packet is sent.");
SendRST ();
}
CloseAndNotify ();
}
}
/** Received a packet upon LAST_ACK */
void
TcpSocketBase::ProcessLastAck (Ptr<Packet> packet, const TcpHeader& tcpHeader)
{
NS_LOG_FUNCTION (this << tcpHeader);
// Extract the flags. PSH and URG are not honoured.
uint8_t tcpflags = tcpHeader.GetFlags () & ~(TcpHeader::PSH | TcpHeader::URG);
if (tcpflags == 0)
{
ReceivedData (packet, tcpHeader);
}
else if (tcpflags == TcpHeader::ACK)
{
if (tcpHeader.GetSequenceNumber () == m_rxBuffer.NextRxSequence ())
{ // This ACK corresponds to the FIN sent. This socket closed peacefully.
CloseAndNotify ();
}
}
else if (tcpflags == TcpHeader::FIN)
{ // Received FIN again, the peer probably lost the FIN+ACK
SendEmptyPacket (TcpHeader::FIN | TcpHeader::ACK);
}
else if (tcpflags == (TcpHeader::FIN | TcpHeader::ACK) || tcpflags == TcpHeader::RST)
{
CloseAndNotify ();
}
else
{ // Received a SYN or SYN+ACK or bad flags
NS_LOG_LOGIC ("Illegal flag " << tcpflags << " received. Reset packet is sent.");
SendRST ();
CloseAndNotify ();
}
}
/** Peer sent me a FIN. Remember its sequence in rx buffer. */
void
TcpSocketBase::PeerClose (Ptr<Packet> p, const TcpHeader& tcpHeader)
{
NS_LOG_FUNCTION (this << tcpHeader);
// Ignore all out of range packets
if (tcpHeader.GetSequenceNumber () < m_rxBuffer.NextRxSequence () ||
tcpHeader.GetSequenceNumber () > m_rxBuffer.MaxRxSequence ())
{
return;
};
// For any case, remember the FIN position in rx buffer first
m_rxBuffer.SetFinSequence (tcpHeader.GetSequenceNumber () + SequenceNumber32 (p->GetSize ()));
NS_LOG_LOGIC ("Accepted FIN at seq " << tcpHeader.GetSequenceNumber () + SequenceNumber32 (p->GetSize ()));
// If there is any piggybacked data, process it
if (p->GetSize ())
{
ReceivedData (p, tcpHeader);
}
// Return if FIN is out of sequence, otherwise move to CLOSE_WAIT state by DoPeerClose
if (!m_rxBuffer.Finished ())
{
return;
};
// Simultaneous close: Application invoked Close() when we are processing this FIN packet
if (m_state == FIN_WAIT_1)
{
NS_LOG_INFO ("FIN_WAIT_1 -> CLOSING");
m_state = CLOSING;
return;
}
DoPeerClose (); // Change state, respond with ACK
}
/** Received a in-sequence FIN. Close down this socket. */
void
TcpSocketBase::DoPeerClose (void)
{
NS_ASSERT (m_state == ESTABLISHED || m_state == SYN_RCVD);
// Move the state to CLOSE_WAIT
NS_LOG_INFO (TcpStateName[m_state] << " -> CLOSE_WAIT");
m_state = CLOSE_WAIT;
if (!m_closeNotified)
{
// The normal behaviour for an application is that, when the peer sent a in-sequence
// FIN, the app should prepare to close. The app has two choices at this point: either
// respond with ShutdownSend() call to declare that it has nothing more to send and
// the socket can be closed immediately; or remember the peer's close request, wait
// until all its existing data are pushed into the TCP socket, then call Close()
// explicitly.
NS_LOG_LOGIC ("TCP " << this << " calling NotifyNormalClose");
NotifyNormalClose ();
m_closeNotified = true;
}
if (m_shutdownSend)
{ // The application declares that it would not sent any more, close this socket
Close ();
}
else
{ // Need to ack, the application will close later
SendEmptyPacket (TcpHeader::ACK);
}
if (m_state == LAST_ACK)
{
NS_LOG_LOGIC ("TcpSocketBase " << this << " scheduling LATO1");
m_lastAckEvent = Simulator::Schedule (m_rtt->RetransmitTimeout (),
&TcpSocketBase::LastAckTimeout, this);
}
}
/** Kill this socket. This is a callback function configured to m_endpoint in
SetupCallback(), invoked when the endpoint is destroyed. */
void
TcpSocketBase::Destroy (void)
{
NS_LOG_FUNCTION (this);
m_node = 0;
m_endPoint = 0;
m_endPoint6 = 0;
if (m_tcp != 0)
{
std::vector<Ptr<TcpSocketBase> >::iterator it
= std::find (m_tcp->m_sockets.begin (), m_tcp->m_sockets.end (), this);
if (it != m_tcp->m_sockets.end ())
{
m_tcp->m_sockets.erase (it);
}
m_tcp = 0;
}
NS_LOG_LOGIC (this << " Cancelled ReTxTimeout event which was set to expire at " <<
(Simulator::Now () + Simulator::GetDelayLeft (m_retxEvent)).GetSeconds ());
CancelAllTimers ();
}
/** Send an empty packet with specified TCP flags */
void
TcpSocketBase::SendEmptyPacket (uint8_t flags)
{
NS_LOG_FUNCTION (this << (uint32_t)flags);
Ptr<Packet> p = Create<Packet> ();
TcpHeader header;
SequenceNumber32 s = m_nextTxSequence;
if (m_endPoint == 0 && m_endPoint6 == 0)
{
NS_LOG_WARN ("Failed to send empty packet due to null endpoint");
return;
}
if (flags & TcpHeader::FIN)
{
flags |= TcpHeader::ACK;
}
else if (m_state == FIN_WAIT_1 || m_state == LAST_ACK || m_state == CLOSING)
{
++s;
}
header.SetFlags (flags);
header.SetSequenceNumber (s);
header.SetAckNumber (m_rxBuffer.NextRxSequence ());
if (m_endPoint != 0)
{
header.SetSourcePort (m_endPoint->GetLocalPort ());
header.SetDestinationPort (m_endPoint->GetPeerPort ());
}
else
{
header.SetSourcePort (m_endPoint6->GetLocalPort ());
header.SetDestinationPort (m_endPoint6->GetPeerPort ());
}
header.SetWindowSize (AdvertisedWindowSize ());
AddOptions (header);
m_rto = m_rtt->RetransmitTimeout ();
bool hasSyn = flags & TcpHeader::SYN;
bool hasFin = flags & TcpHeader::FIN;
bool isAck = flags == TcpHeader::ACK;
if (hasSyn)
{
if (m_cnCount == 0)
{ // No more connection retries, give up
NS_LOG_LOGIC ("Connection failed.");
CloseAndNotify ();
return;
}
else
{ // Exponential backoff of connection time out
int backoffCount = 0x1 << (m_cnRetries - m_cnCount);
m_rto = m_cnTimeout * backoffCount;
m_cnCount--;
}
}
if (m_endPoint != 0)
{
m_tcp->SendPacket (p, header, m_endPoint->GetLocalAddress (),
m_endPoint->GetPeerAddress (), m_boundnetdevice);
}
else
{
m_tcp->SendPacket (p, header, m_endPoint6->GetLocalAddress (),
m_endPoint6->GetPeerAddress (), m_boundnetdevice);
}
if (flags & TcpHeader::ACK)
{ // If sending an ACK, cancel the delay ACK as well
m_delAckEvent.Cancel ();
m_delAckCount = 0;
}
if (m_retxEvent.IsExpired () && (hasSyn || hasFin) && !isAck )
{ // Retransmit SYN / SYN+ACK / FIN / FIN+ACK to guard against lost
NS_LOG_LOGIC ("Schedule retransmission timeout at time "
<< Simulator::Now ().GetSeconds () << " to expire at time "
<< (Simulator::Now () + m_rto.Get ()).GetSeconds ());
m_retxEvent = Simulator::Schedule (m_rto, &TcpSocketBase::SendEmptyPacket, this, flags);
}
}
/** This function closes the endpoint completely. Called upon RST_TX action. */
void
TcpSocketBase::SendRST (void)
{
NS_LOG_FUNCTION (this);
SendEmptyPacket (TcpHeader::RST);
NotifyErrorClose ();
DeallocateEndPoint ();
}
/** Deallocate the end point and cancel all the timers */
void
TcpSocketBase::DeallocateEndPoint (void)
{
if (m_endPoint != 0)
{
m_endPoint->SetDestroyCallback (MakeNullCallback<void> ());
m_tcp->DeAllocate (m_endPoint);
m_endPoint = 0;
std::vector<Ptr<TcpSocketBase> >::iterator it
= std::find (m_tcp->m_sockets.begin (), m_tcp->m_sockets.end (), this);
if (it != m_tcp->m_sockets.end ())
{
m_tcp->m_sockets.erase (it);
}
CancelAllTimers ();
}
if (m_endPoint6 != 0)
{
m_endPoint6->SetDestroyCallback (MakeNullCallback<void> ());
m_tcp->DeAllocate (m_endPoint6);
m_endPoint6 = 0;
std::vector<Ptr<TcpSocketBase> >::iterator it
= std::find (m_tcp->m_sockets.begin (), m_tcp->m_sockets.end (), this);
if (it != m_tcp->m_sockets.end ())
{
m_tcp->m_sockets.erase (it);
}
CancelAllTimers ();
}
}
/** Configure the endpoint to a local address. Called by Connect() if Bind() didn't specify one. */
int
TcpSocketBase::SetupEndpoint ()
{
NS_LOG_FUNCTION (this);
Ptr<Ipv4> ipv4 = m_node->GetObject<Ipv4> ();
NS_ASSERT (ipv4 != 0);
if (ipv4->GetRoutingProtocol () == 0)
{
NS_FATAL_ERROR ("No Ipv4RoutingProtocol in the node");
}
// Create a dummy packet, then ask the routing function for the best output
// interface's address
Ipv4Header header;
header.SetDestination (m_endPoint->GetPeerAddress ());
Socket::SocketErrno errno_;
Ptr<Ipv4Route> route;
Ptr<NetDevice> oif = m_boundnetdevice;
route = ipv4->GetRoutingProtocol ()->RouteOutput (Ptr<Packet> (), header, oif, errno_);
if (route == 0)
{
NS_LOG_LOGIC ("Route to " << m_endPoint->GetPeerAddress () << " does not exist");
NS_LOG_ERROR (errno_);
m_errno = errno_;
return -1;
}
NS_LOG_LOGIC ("Route exists");
m_endPoint->SetLocalAddress (route->GetSource ());
return 0;
}
int
TcpSocketBase::SetupEndpoint6 ()
{
NS_LOG_FUNCTION (this);
Ptr<Ipv6L3Protocol> ipv6 = m_node->GetObject<Ipv6L3Protocol> ();
NS_ASSERT (ipv6 != 0);
if (ipv6->GetRoutingProtocol () == 0)
{
NS_FATAL_ERROR ("No Ipv6RoutingProtocol in the node");
}
// Create a dummy packet, then ask the routing function for the best output
// interface's address
Ipv6Header header;
header.SetDestinationAddress (m_endPoint6->GetPeerAddress ());
Socket::SocketErrno errno_;
Ptr<Ipv6Route> route;
Ptr<NetDevice> oif = m_boundnetdevice;
route = ipv6->GetRoutingProtocol ()->RouteOutput (Ptr<Packet> (), header, oif, errno_);
if (route == 0)
{
NS_LOG_LOGIC ("Route to " << m_endPoint6->GetPeerAddress () << " does not exist");
NS_LOG_ERROR (errno_);
m_errno = errno_;
return -1;
}
NS_LOG_LOGIC ("Route exists");
m_endPoint6->SetLocalAddress (route->GetSource ());
return 0;
}
/** This function is called only if a SYN received in LISTEN state. After
TcpSocketBase cloned, allocate a new end point to handle the incoming
connection and send a SYN+ACK to complete the handshake. */
void
TcpSocketBase::CompleteFork (Ptr<Packet> p, const TcpHeader& h,
const Address& fromAddress, const Address& toAddress)
{
// Get port and address from peer (connecting host)
if (InetSocketAddress::IsMatchingType (toAddress))
{
m_endPoint = m_tcp->Allocate (InetSocketAddress::ConvertFrom (toAddress).GetIpv4 (),
InetSocketAddress::ConvertFrom (toAddress).GetPort (),
InetSocketAddress::ConvertFrom (fromAddress).GetIpv4 (),
InetSocketAddress::ConvertFrom (fromAddress).GetPort ());
m_endPoint6 = 0;
}
else if (Inet6SocketAddress::IsMatchingType (toAddress))
{
m_endPoint6 = m_tcp->Allocate6 (Inet6SocketAddress::ConvertFrom (toAddress).GetIpv6 (),
Inet6SocketAddress::ConvertFrom (toAddress).GetPort (),
Inet6SocketAddress::ConvertFrom (fromAddress).GetIpv6 (),
Inet6SocketAddress::ConvertFrom (fromAddress).GetPort ());
m_endPoint = 0;
}
m_tcp->m_sockets.push_back (this);
// Change the cloned socket from LISTEN state to SYN_RCVD
NS_LOG_INFO ("LISTEN -> SYN_RCVD");
m_state = SYN_RCVD;
m_cnCount = m_cnRetries;
SetupCallback ();
// Set the sequence number and send SYN+ACK
m_rxBuffer.SetNextRxSequence (h.GetSequenceNumber () + SequenceNumber32 (1));
SendEmptyPacket (TcpHeader::SYN | TcpHeader::ACK);
}
void
TcpSocketBase::ConnectionSucceeded ()
{ // Wrapper to protected function NotifyConnectionSucceeded() so that it can
// be called as a scheduled event
NotifyConnectionSucceeded ();
// The if-block below was moved from ProcessSynSent() to here because we need
// to invoke the NotifySend() only after NotifyConnectionSucceeded() to
// reflect the behaviour in the real world.
if (GetTxAvailable () > 0)
{
NotifySend (GetTxAvailable ());
}
}
/** Extract at most maxSize bytes from the TxBuffer at sequence seq, add the
TCP header, and send to TcpL4Protocol */
uint32_t
TcpSocketBase::SendDataPacket (SequenceNumber32 seq, uint32_t maxSize, bool withAck)
{
NS_LOG_FUNCTION (this << seq << maxSize << withAck);
Ptr<Packet> p = m_txBuffer.CopyFromSequence (maxSize, seq);
uint32_t sz = p->GetSize (); // Size of packet
uint8_t flags = withAck ? TcpHeader::ACK : 0;
uint32_t remainingData = m_txBuffer.SizeFromSequence (seq + SequenceNumber32 (sz));
if (m_closeOnEmpty && (remainingData == 0))
{
flags |= TcpHeader::FIN;
if (m_state == ESTABLISHED)
{ // On active close: I am the first one to send FIN
NS_LOG_INFO ("ESTABLISHED -> FIN_WAIT_1");
m_state = FIN_WAIT_1;
}
else if (m_state == CLOSE_WAIT)
{ // On passive close: Peer sent me FIN already
NS_LOG_INFO ("CLOSE_WAIT -> LAST_ACK");
m_state = LAST_ACK;
}
}
TcpHeader header;
header.SetFlags (flags);
header.SetSequenceNumber (seq);
header.SetAckNumber (m_rxBuffer.NextRxSequence ());
if (m_endPoint)
{
header.SetSourcePort (m_endPoint->GetLocalPort ());
header.SetDestinationPort (m_endPoint->GetPeerPort ());
}
else
{
header.SetSourcePort (m_endPoint6->GetLocalPort ());
header.SetDestinationPort (m_endPoint6->GetPeerPort ());
}
header.SetWindowSize (AdvertisedWindowSize ());
AddOptions (header);
if (m_retxEvent.IsExpired () )
{ // Schedule retransmit
m_rto = m_rtt->RetransmitTimeout ();
NS_LOG_LOGIC (this << " SendDataPacket Schedule ReTxTimeout at time " <<
Simulator::Now ().GetSeconds () << " to expire at time " <<
(Simulator::Now () + m_rto.Get ()).GetSeconds () );
m_retxEvent = Simulator::Schedule (m_rto, &TcpSocketBase::ReTxTimeout, this);
}
NS_LOG_LOGIC ("Send packet via TcpL4Protocol with flags 0x" << std::hex << static_cast<uint32_t> (flags) << std::dec);
if (m_endPoint)
{
m_tcp->SendPacket (p, header, m_endPoint->GetLocalAddress (),
m_endPoint->GetPeerAddress (), m_boundnetdevice);
}
else
{
m_tcp->SendPacket (p, header, m_endPoint6->GetLocalAddress (),
m_endPoint6->GetPeerAddress (), m_boundnetdevice);
}
m_rtt->SentSeq (seq, sz); // notify the RTT
// Notify the application of the data being sent unless this is a retransmit
if (seq == m_nextTxSequence)
{
Simulator::ScheduleNow (&TcpSocketBase::NotifyDataSent, this, sz);
}
// Update highTxMark
m_highTxMark = std::max (seq + sz, m_highTxMark.Get ());
return sz;
}
/** Send as much pending data as possible according to the Tx window. Note that
* this function did not implement the PSH flag
*/
bool
TcpSocketBase::SendPendingData (bool withAck)
{
NS_LOG_FUNCTION (this << withAck);
if (m_txBuffer.Size () == 0) return false; // Nothing to send
if (m_endPoint == 0 && m_endPoint6 == 0)
{
NS_LOG_INFO ("TcpSocketBase::SendPendingData: No endpoint; m_shutdownSend=" << m_shutdownSend);
return false; // Is this the right way to handle this condition?
}
uint32_t nPacketsSent = 0;
while (m_txBuffer.SizeFromSequence (m_nextTxSequence))
{
uint32_t w = AvailableWindow (); // Get available window size
NS_LOG_LOGIC ("TcpSocketBase " << this << " SendPendingData" <<
" w " << w <<
" rxwin " << m_rWnd <<
" segsize " << m_segmentSize <<
" nextTxSeq " << m_nextTxSequence <<
" highestRxAck " << m_txBuffer.HeadSequence () <<
" pd->Size " << m_txBuffer.Size () <<
" pd->SFS " << m_txBuffer.SizeFromSequence (m_nextTxSequence));
// Quit if send disallowed
if (m_shutdownSend)
{
m_errno = ERROR_SHUTDOWN;
return false;
}
// Stop sending if we need to wait for a larger Tx window (prevent silly window syndrome)
if (w < m_segmentSize && m_txBuffer.SizeFromSequence (m_nextTxSequence) > w)
{
break; // No more
}
// Nagle's algorithm (RFC896): Hold off sending if there is unacked data
// in the buffer and the amount of data to send is less than one segment
if (!m_noDelay && UnAckDataCount () > 0 &&
m_txBuffer.SizeFromSequence (m_nextTxSequence) < m_segmentSize)
{
NS_LOG_LOGIC ("Invoking Nagle's algorithm. Wait to send.");
break;
}
uint32_t s = std::min (w, m_segmentSize); // Send no more than window
uint32_t sz = SendDataPacket (m_nextTxSequence, s, withAck);
nPacketsSent++; // Count sent this loop
m_nextTxSequence += sz; // Advance next tx sequence
}
NS_LOG_LOGIC ("SendPendingData sent " << nPacketsSent << " packets");
return (nPacketsSent > 0);
}
uint32_t
TcpSocketBase::UnAckDataCount ()
{
NS_LOG_FUNCTION (this);
return m_nextTxSequence.Get () - m_txBuffer.HeadSequence ();
}
uint32_t
TcpSocketBase::BytesInFlight ()
{
NS_LOG_FUNCTION (this);
return m_highTxMark.Get () - m_txBuffer.HeadSequence ();
}
uint32_t
TcpSocketBase::Window ()
{
NS_LOG_FUNCTION (this);
return m_rWnd;
}
uint32_t
TcpSocketBase::AvailableWindow ()
{
NS_LOG_FUNCTION_NOARGS ();
uint32_t unack = UnAckDataCount (); // Number of outstanding bytes
uint32_t win = Window (); // Number of bytes allowed to be outstanding
NS_LOG_LOGIC ("UnAckCount=" << unack << ", Win=" << win);
return (win < unack) ? 0 : (win - unack);
}
uint16_t
TcpSocketBase::AdvertisedWindowSize ()
{
return std::min (m_rxBuffer.MaxBufferSize () - m_rxBuffer.Size (), (uint32_t)m_maxWinSize);
}
// Receipt of new packet, put into Rx buffer
void
TcpSocketBase::ReceivedData (Ptr<Packet> p, const TcpHeader& tcpHeader)
{
NS_LOG_FUNCTION (this << tcpHeader);
NS_LOG_LOGIC ("seq " << tcpHeader.GetSequenceNumber () <<
" ack " << tcpHeader.GetAckNumber () <<
" pkt size " << p->GetSize () );
// Put into Rx buffer
SequenceNumber32 expectedSeq = m_rxBuffer.NextRxSequence ();
if (!m_rxBuffer.Add (p, tcpHeader))
{ // Insert failed: No data or RX buffer full
SendEmptyPacket (TcpHeader::ACK);
return;
}
// Now send a new ACK packet acknowledging all received and delivered data
if (m_rxBuffer.Size () > m_rxBuffer.Available () || m_rxBuffer.NextRxSequence () > expectedSeq + p->GetSize ())
{ // A gap exists in the buffer, or we filled a gap: Always ACK
SendEmptyPacket (TcpHeader::ACK);
}
else
{ // In-sequence packet: ACK if delayed ack count allows
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,
&TcpSocketBase::DelAckTimeout, this);
NS_LOG_LOGIC (this << " scheduled delayed ACK at " << (Simulator::Now () + Simulator::GetDelayLeft (m_delAckEvent)).GetSeconds ());
}
}
// Notify app to receive if necessary
if (expectedSeq < m_rxBuffer.NextRxSequence ())
{ // NextRxSeq advanced, we have something to send to the app
if (!m_shutdownRecv) NotifyDataRecv ();
// Handle exceptions
if (m_closeNotified)
{
NS_LOG_WARN ("Why TCP " << this << " got data after close notification?");
}
// If we received FIN before and now completed all "holes" in rx buffer,
// invoke peer close procedure
if (m_rxBuffer.Finished () && (tcpHeader.GetFlags () & TcpHeader::FIN) == 0)
{
DoPeerClose ();
}
}
}
/** Called by ForwardUp() to estimate RTT */
void
TcpSocketBase::EstimateRtt (const TcpHeader& tcpHeader)
{
// Use m_rtt for the estimation. Note, RTT of duplicated acknowledgement
// (which should be ignored) is handled by m_rtt. Once timestamp option
// is implemented, this function would be more elaborated.
m_lastRtt = m_rtt->AckSeq (tcpHeader.GetAckNumber () );
};
// Called by the ReceivedAck() when new ACK received and by ProcessSynRcvd()
// when the three-way handshake completed. This cancels retransmission timer
// and advances Tx window
void
TcpSocketBase::NewAck (SequenceNumber32 const& ack)
{
NS_LOG_FUNCTION (this << ack);
if (m_state != SYN_RCVD)
{ // Set RTO unless the ACK is received in SYN_RCVD state
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
m_rto = m_rtt->RetransmitTimeout ();
NS_LOG_LOGIC (this << " Schedule ReTxTimeout at time " <<
Simulator::Now ().GetSeconds () << " to expire at time " <<
(Simulator::Now () + m_rto.Get ()).GetSeconds ());
m_retxEvent = Simulator::Schedule (m_rto, &TcpSocketBase::ReTxTimeout, this);
}
if (m_rWnd.Get () == 0 && m_persistEvent.IsExpired ())
{ // Zero window: Enter persist state to send 1 byte to probe
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_persistTimeout).GetSeconds ());
m_persistEvent = Simulator::Schedule (m_persistTimeout, &TcpSocketBase::PersistTimeout, this);
NS_ASSERT (m_persistTimeout == Simulator::GetDelayLeft (m_persistEvent));
}
// Note the highest ACK and tell app to send more
NS_LOG_LOGIC ("TCP " << this << " NewAck " << ack <<
" numberAck " << (ack - m_txBuffer.HeadSequence ())); // Number bytes ack'ed
m_txBuffer.DiscardUpTo (ack);
if (GetTxAvailable () > 0)
{
NotifySend (GetTxAvailable ());
}
if (ack > m_nextTxSequence)
{
m_nextTxSequence = ack; // If advanced
}
if (m_txBuffer.Size () == 0 && m_state != FIN_WAIT_1 && m_state != CLOSING)
{ // No retransmit timer if no data to retransmit
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);
}
// Retransmit timeout
void
TcpSocketBase::ReTxTimeout ()
{
NS_LOG_FUNCTION (this);
NS_LOG_LOGIC (this << " ReTxTimeout Expired at time " << Simulator::Now ().GetSeconds ());
// If erroneous timeout in closed/timed-wait state, just return
if (m_state == CLOSED || m_state == TIME_WAIT) return;
// If all data are received (non-closing socket and nothing to send), just return
if (m_state <= ESTABLISHED && m_txBuffer.HeadSequence () >= m_highTxMark) return;
Retransmit ();
}
void
TcpSocketBase::DelAckTimeout (void)
{
m_delAckCount = 0;
SendEmptyPacket (TcpHeader::ACK);
}
void
TcpSocketBase::LastAckTimeout (void)
{
NS_LOG_FUNCTION (this);
m_lastAckEvent.Cancel ();
if (m_state == LAST_ACK)
{
CloseAndNotify ();
}
if (!m_closeNotified)
{
m_closeNotified = true;
}
}
// Send 1-byte data to probe for the window size at the receiver when
// the local knowledge tells that the receiver has zero window size
// C.f.: RFC793 p.42, RFC1112 sec.4.2.2.17
void
TcpSocketBase::PersistTimeout ()
{
NS_LOG_LOGIC ("PersistTimeout expired at " << Simulator::Now ().GetSeconds ());
m_persistTimeout = std::min (Seconds (60), Time (2 * m_persistTimeout)); // max persist timeout = 60s
Ptr<Packet> p = m_txBuffer.CopyFromSequence (1, m_nextTxSequence);
TcpHeader tcpHeader;
tcpHeader.SetSequenceNumber (m_nextTxSequence);
tcpHeader.SetAckNumber (m_rxBuffer.NextRxSequence ());
tcpHeader.SetWindowSize (AdvertisedWindowSize ());
if (m_endPoint != 0)
{
tcpHeader.SetSourcePort (m_endPoint->GetLocalPort ());
tcpHeader.SetDestinationPort (m_endPoint->GetPeerPort ());
}
else
{
tcpHeader.SetSourcePort (m_endPoint6->GetLocalPort ());
tcpHeader.SetDestinationPort (m_endPoint6->GetPeerPort ());
}
AddOptions (tcpHeader);
if (m_endPoint != 0)
{
m_tcp->SendPacket (p, tcpHeader, m_endPoint->GetLocalAddress (),
m_endPoint->GetPeerAddress (), m_boundnetdevice);
}
else
{
m_tcp->SendPacket (p, tcpHeader, m_endPoint6->GetLocalAddress (),
m_endPoint6->GetPeerAddress (), m_boundnetdevice);
}
NS_LOG_LOGIC ("Schedule persist timeout at time "
<< Simulator::Now ().GetSeconds () << " to expire at time "
<< (Simulator::Now () + m_persistTimeout).GetSeconds ());
m_persistEvent = Simulator::Schedule (m_persistTimeout, &TcpSocketBase::PersistTimeout, this);
}
void
TcpSocketBase::Retransmit ()
{
m_nextTxSequence = m_txBuffer.HeadSequence (); // Start from highest Ack
m_rtt->IncreaseMultiplier (); // Double the timeout value for next retx timer
m_dupAckCount = 0;
DoRetransmit (); // Retransmit the packet
}
void
TcpSocketBase::DoRetransmit ()
{
NS_LOG_FUNCTION (this);
// Retransmit SYN packet
if (m_state == SYN_SENT)
{
if (m_cnCount > 0)
{
SendEmptyPacket (TcpHeader::SYN);
}
else
{
NotifyConnectionFailed ();
}
return;
}
// Retransmit non-data packet: Only if in FIN_WAIT_1 or CLOSING state
if (m_txBuffer.Size () == 0)
{
if (m_state == FIN_WAIT_1 || m_state == CLOSING)
{ // Must have lost FIN, re-send
SendEmptyPacket (TcpHeader::FIN);
}
return;
}
// Retransmit a data packet: Call SendDataPacket
NS_LOG_LOGIC ("TcpSocketBase " << this << " retxing seq " << m_txBuffer.HeadSequence ());
uint32_t sz = SendDataPacket (m_txBuffer.HeadSequence (), m_segmentSize, true);
// In case of RTO, advance m_nextTxSequence
m_nextTxSequence = std::max (m_nextTxSequence.Get (), m_txBuffer.HeadSequence () + sz);
}
void
TcpSocketBase::CancelAllTimers ()
{
m_retxEvent.Cancel ();
m_persistEvent.Cancel ();
m_delAckEvent.Cancel ();
m_lastAckEvent.Cancel ();
m_timewaitEvent.Cancel ();
}
/** Move TCP to Time_Wait state and schedule a transition to Closed state */
void
TcpSocketBase::TimeWait ()
{
NS_LOG_INFO (TcpStateName[m_state] << " -> TIME_WAIT");
m_state = TIME_WAIT;
CancelAllTimers ();
// Move from TIME_WAIT to CLOSED after 2*MSL. Max segment lifetime is 2 min
// according to RFC793, p.28
m_timewaitEvent = Simulator::Schedule (Seconds (2*m_msl),
&TcpSocketBase::CloseAndNotify, this);
}
/** Below are the attribute get/set functions */
void
TcpSocketBase::SetSndBufSize (uint32_t size)
{
m_txBuffer.SetMaxBufferSize (size);
}
uint32_t
TcpSocketBase::GetSndBufSize (void) const
{
return m_txBuffer.MaxBufferSize ();
}
void
TcpSocketBase::SetRcvBufSize (uint32_t size)
{
m_rxBuffer.SetMaxBufferSize (size);
}
uint32_t
TcpSocketBase::GetRcvBufSize (void) const
{
return m_rxBuffer.MaxBufferSize ();
}
void
TcpSocketBase::SetSegSize (uint32_t size)
{
m_segmentSize = size;
NS_ABORT_MSG_UNLESS (m_state == CLOSED, "Cannot change segment size dynamically.");
}
uint32_t
TcpSocketBase::GetSegSize (void) const
{
return m_segmentSize;
}
void
TcpSocketBase::SetConnTimeout (Time timeout)
{
m_cnTimeout = timeout;
}
Time
TcpSocketBase::GetConnTimeout (void) const
{
return m_cnTimeout;
}
void
TcpSocketBase::SetConnCount (uint32_t count)
{
m_cnRetries = count;
}
uint32_t
TcpSocketBase::GetConnCount (void) const
{
return m_cnRetries;
}
void
TcpSocketBase::SetDelAckTimeout (Time timeout)
{
m_delAckTimeout = timeout;
}
Time
TcpSocketBase::GetDelAckTimeout (void) const
{
return m_delAckTimeout;
}
void
TcpSocketBase::SetDelAckMaxCount (uint32_t count)
{
m_delAckMaxCount = count;
}
uint32_t
TcpSocketBase::GetDelAckMaxCount (void) const
{
return m_delAckMaxCount;
}
void
TcpSocketBase::SetTcpNoDelay (bool noDelay)
{
m_noDelay = noDelay;
}
bool
TcpSocketBase::GetTcpNoDelay (void) const
{
return m_noDelay;
}
void
TcpSocketBase::SetPersistTimeout (Time timeout)
{
m_persistTimeout = timeout;
}
Time
TcpSocketBase::GetPersistTimeout (void) const
{
return m_persistTimeout;
}
bool
TcpSocketBase::SetAllowBroadcast (bool allowBroadcast)
{
// Broadcast is not implemented. Return true only if allowBroadcast==false
return (!allowBroadcast);
}
bool
TcpSocketBase::GetAllowBroadcast (void) const
{
return false;
}
/** Placeholder function for future extension that reads more from the TCP header */
void
TcpSocketBase::ReadOptions (const TcpHeader&)
{
}
/** Placeholder function for future extension that changes the TCP header */
void
TcpSocketBase::AddOptions (TcpHeader&)
{
}
} // namespace ns3