/src/internet/model/tcp-socket-base.cc
C++ | 2293 lines | 1904 code | 157 blank | 232 comment | 491 complexity | 36f750ef4f764a953e53febbbcc2be36 MD5 | raw file
Possible License(s): GPL-2.0
- /* -*- 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 <cstdlib>
- #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 (std::rand ()),
- // 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 (this);
- m_endPoint = m_tcp->Allocate ();
- if (0 == m_endPoint)
- {
- m_errno = ERROR_ADDRNOTAVAIL;
- return -1;
- }
- m_tcp->m_sockets.push_back (this);
- return SetupCallback ();
- }
- int
- TcpSocketBase::Bind6 (void)
- {
- NS_LOG_FUNCTION (this);
- m_endPoint6 = m_tcp->Allocate6 ();
- if (0 == m_endPoint6)
- {
- m_errno = ERROR_ADDRNOTAVAIL;
- return -1;
- }
- m_tcp->m_sockets.push_back (this);
- return SetupCallback ();
- }
- /** 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) && m_endPoint6 == 0)
- {
- 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) && m_endPoint == 0)
- {
- // 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::Destroy6, 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_endPoint = 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);
- }
- }
- NS_LOG_LOGIC (this << " Cancelled ReTxTimeout event which was set to expire at " <<
- (Simulator::Now () + Simulator::GetDelayLeft (m_retxEvent)).GetSeconds ());
- CancelAllTimers ();
- }
- /** Kill this socket. This is a callback function configured to m_endpoint in
- SetupCallback(), invoked when the endpoint is destroyed. */
- void
- TcpSocketBase::Destroy6 (void)
- {
- NS_LOG_FUNCTION (this);
- 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);
- }
- }
- 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