ns3::TcpSocketImpl Class Reference
[Socket, Tcp]
An implementation of a stream socket using TCP.
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#include <tcp-socket-impl.h>
Public Member Functions | |
| TcpSocketImpl () | |
| virtual enum SocketErrno | GetErrno (void) const |
| virtual Ptr< Node > | GetNode (void) const |
| virtual int | Bind (void) |
| virtual int | Bind (const Address &address) |
| virtual int | Close (void) |
| Close a socket. | |
| virtual int | ShutdownSend (void) |
| virtual int | ShutdownRecv (void) |
| virtual int | Connect (const Address &address) |
| Initiate a connection to a remote host. | |
| virtual int | Listen (void) |
| Listen for incoming connections. | |
| virtual uint32_t | GetTxAvailable (void) const |
| Returns the number of bytes which can be sent in a single call to Send. | |
| virtual int | Send (Ptr< Packet > p, uint32_t flags) |
| Send data (or dummy data) to the remote host. | |
| virtual int | SendTo (Ptr< Packet > p, uint32_t flags, const Address &toAddress) |
| Send data to a specified peer. | |
| virtual uint32_t | GetRxAvailable (void) const |
| virtual Ptr< Packet > | Recv (uint32_t maxSize, uint32_t flags) |
| Read data from the socket. | |
| virtual Ptr< Packet > | RecvFrom (uint32_t maxSize, uint32_t flags, Address &fromAddress) |
| Read a single packet from the socket and retrieve the sender address. | |
| virtual int | GetSockName (Address &address) const |
Static Public Member Functions | |
| static TypeId | GetTypeId (void) |
| This method returns the TypeId associated to ns3::TcpSocketImpl. | |
Detailed Description
An implementation of a stream socket using TCP.This class contains an implementation of TCP Tahoe, as well as a sockets interface for talking to TCP. Features include connection orientation, reliability through cumulative acknowledgements, congestion and flow control. Finite send buffer semantics are modeled, but as of yet, finite receive buffer modelling is unimplemented.
The closedown of these sockets is as of yet not compliant with the relevent RFCs, i.e. the FIN handshaking isn't correct. While this is visible at the PCAP tracing level, it has no effect on the statistics users are interested in, i.e. throughput, delay, etc. of actual payload data.
Asynchronous callbacks to provide notifications to higher layers that a protocol event has occured, such as space freeing up in the send buffer or new data arriving in the receive buffer.
Constructor & Destructor Documentation
| ns3::TcpSocketImpl::TcpSocketImpl | ( | ) |
Create an unbound tcp socket.
Member Function Documentation
| virtual int ns3::TcpSocketImpl::Bind | ( | const Address & | address | ) | [virtual] |
- Parameters:
-
address the address to try to allocate
- Returns:
- 0 on success, -1 on failure.
Implements ns3::Socket.
| virtual int ns3::TcpSocketImpl::Bind | ( | void | ) | [virtual] |
Allocate a local endpoint for this socket.
- Returns:
- 0 on success, -1 on failure.
Implements ns3::Socket.
| virtual int ns3::TcpSocketImpl::Close | ( | void | ) | [virtual] |
Close a socket.
After the Close call, the socket is no longer valid, and cannot safely be used for subsequent operations.
Implements ns3::Socket.
| virtual int ns3::TcpSocketImpl::Connect | ( | const Address & | address | ) | [virtual] |
Initiate a connection to a remote host.
- Parameters:
-
address Address of remote.
Implements ns3::Socket.
| virtual enum SocketErrno ns3::TcpSocketImpl::GetErrno | ( | void | ) | const [virtual] |
- Returns:
- the errno associated to the last call which failed in this socket. Each socket's errno is initialized to zero when the socket is created.
Implements ns3::Socket.
| virtual uint32_t ns3::TcpSocketImpl::GetRxAvailable | ( | void | ) | const [virtual] |
Return number of bytes which can be returned from one or multiple calls to Recv. Must be possible to call this method from the Recv callback.
Implements ns3::Socket.
| virtual int ns3::TcpSocketImpl::GetSockName | ( | Address & | address | ) | const [virtual] |
| virtual uint32_t ns3::TcpSocketImpl::GetTxAvailable | ( | void | ) | const [virtual] |
Returns the number of bytes which can be sent in a single call to Send.
For datagram sockets, this returns the number of bytes that can be passed atomically through the underlying protocol.
For stream sockets, this returns the available space in bytes left in the transmit buffer.
Implements ns3::Socket.
| static TypeId ns3::TcpSocketImpl::GetTypeId | ( | void | ) | [static] |
This method returns the TypeId associated to ns3::TcpSocketImpl.
No Attributes defined for this type.
Attributes defined in parent class ns3::TcpSocket:
-
SndBufSize: TcpSocket maximum transmit buffer size (bytes)
- Set with class: ns3::UintegerValue
- Underlying type: uint32_t 0:4294967295
- Initial value: 131072
- Flags: construct write read
-
RcvBufSize: TcpSocket maximum receive buffer size (bytes)
- Set with class: ns3::UintegerValue
- Underlying type: uint32_t 0:4294967295
- Initial value: 4294967295
- Flags: construct write read
-
SegmentSize: TCP maximum segment size in bytes (may be adjusted based on MTU discovery)
- Set with class: ns3::UintegerValue
- Underlying type: uint32_t 0:4294967295
- Initial value: 536
- Flags: construct write read
-
SlowStartThreshold: TCP slow start threshold (bytes)
- Set with class: ns3::UintegerValue
- Underlying type: uint32_t 0:4294967295
- Initial value: 65535
- Flags: construct write read
-
InitialCwnd: TCP initial congestion window size (segments)
- Set with class: ns3::UintegerValue
- Underlying type: uint32_t 0:4294967295
- Initial value: 1
- Flags: construct write read
- ConnTimeout: TCP retransmission timeout when opening connection (seconds)
-
ConnCount: Number of connection attempts (SYN retransmissions) before returning failure
- Set with class: ns3::UintegerValue
- Underlying type: uint32_t 0:4294967295
- Initial value: 6
- Flags: construct write read
- DelAckTimeout: Timeout value for TCP delayed acks, in seconds
-
DelAckCount: Number of packets to wait before sending a TCP ack
- Set with class: ns3::UintegerValue
- Underlying type: uint32_t 0:4294967295
- Initial value: 2
- Flags: construct write read
- CongestionWindow: The TCP connection's congestion window
Reimplemented from ns3::TcpSocket.
| virtual int ns3::TcpSocketImpl::Listen | ( | void | ) | [virtual] |
Listen for incoming connections.
- Returns:
- 0 on success, -1 on error (in which case errno is set).
Implements ns3::Socket.
Read data from the socket.
This function matches closely in semantics to the recv() function call in the standard C library (libc): ssize_t recv (int s, void *buf, size_t len, int flags); except that the receive I/O is asynchronous. This is the primary Recv method at this low-level API and must be implemented by subclasses.
This method is normally used only on a connected socket. In a typical blocking sockets model, this call would block until at least one byte is returned or the connection closes. In ns-3 at this API, the call returns immediately in such a case and returns 0 if nothing is available to be read. However, an application can set a callback, ns3::SetRecvCallback, to be notified of data being available to be read (when it conceptually unblocks); this is an asynchronous I/O model for recv().
This variant of Recv() uses class ns3::Packet to encapsulate data, rather than providing a raw pointer and length field. This allows an ns-3 application to attach tags if desired (such as a flow ID) and may allow the simulator to avoid some data copies. Despite the appearance of receiving Packets on a stream socket, just think of it as a fancy byte buffer with streaming semantics.
The semantics depend on the type of socket. For a datagram socket, each Recv() returns the data from at most one Send(), and order is not necessarily preserved. For a stream socket, the bytes are delivered in order, and on-the-wire packet boundaries are not preserved.
The flags argument is formed by or'ing one or more of the values: MSG_OOB process out-of-band data MSG_PEEK peek at incoming message None of these flags are supported for now.
Some variants of Recv() are supported as additional API, including RecvFrom(), overloaded Recv() without arguments, and variants that use raw character buffers.
- Parameters:
-
maxSize reader will accept packet up to maxSize flags Socket control flags
- Returns:
- Ptr<Packet> of the next in-sequence packet. Returns 0 if the socket cannot return a next in-sequence packet conforming to the maxSize and flags.
- See also:
- SetRecvCallback
Implements ns3::Socket.
| virtual Ptr<Packet> ns3::TcpSocketImpl::RecvFrom | ( | uint32_t | maxSize, | |
| uint32_t | flags, | |||
| Address & | fromAddress | |||
| ) | [virtual] |
Read a single packet from the socket and retrieve the sender address.
Calls Recv(maxSize, flags) with maxSize implicitly set to maximum sized integer, and flags set to zero.
This method has similar semantics to Recv () but subclasses may want to provide checks on socket state, so the implementation is pushed to subclasses.
- Parameters:
-
maxSize reader will accept packet up to maxSize flags Socket control flags fromAddress output parameter that will return the address of the sender of the received packet, if any. Remains untouched if no packet is received.
- Returns:
- Ptr<Packet> of the next in-sequence packet. Returns 0 if the socket cannot return a next in-sequence packet.
Implements ns3::Socket.
Send data (or dummy data) to the remote host.
This function matches closely in semantics to the send() function call in the standard C library (libc): ssize_t send (int s, const void *msg, size_t len, int flags); except that the send I/O is asynchronous. This is the primary Send method at this low-level API and must be implemented by subclasses.
In a typical blocking sockets model, this call would block upon lack of space to hold the message to be sent. In ns-3 at this API, the call returns immediately in such a case, but the callback registered with SetSendCallback() is invoked when the socket has space (when it conceptually unblocks); this is an asynchronous I/O model for send().
This variant of Send() uses class ns3::Packet to encapsulate data, rather than providing a raw pointer and length field. This allows an ns-3 application to attach tags if desired (such as a flow ID) and may allow the simulator to avoid some data copies. Despite the appearance of sending Packets on a stream socket, just think of it as a fancy byte buffer with streaming semantics.
If either the message buffer within the Packet is too long to pass atomically through the underlying protocol (for datagram sockets), or the message buffer cannot entirely fit in the transmit buffer (for stream sockets), -1 is returned and SocketErrno is set to ERROR_MSGSIZE. If the packet does not fit, the caller can split the Packet (based on information obtained from GetTxAvailable) and reattempt to send the data.
The flags argument is formed by or'ing one or more of the values: MSG_OOB process out-of-band data MSG_DONTROUTE bypass routing, use direct interface These flags are _unsupported_ as of ns-3.1.
- Parameters:
-
p ns3::Packet to send flags Socket control flags
- Returns:
- the number of bytes accepted for transmission if no error occurs, and -1 otherwise.
- See also:
- SetSendCallback
Implements ns3::Socket.
| virtual int ns3::TcpSocketImpl::SendTo | ( | Ptr< Packet > | p, | |
| uint32_t | flags, | |||
| const Address & | toAddress | |||
| ) | [virtual] |
Send data to a specified peer.
This method has similar semantics to Send () but subclasses may want to provide checks on socket state, so the implementation is pushed to subclasses.
- Returns:
- -1 in case of error or the number of bytes copied in the internal buffer and accepted for transmission.
Implements ns3::Socket.
| virtual int ns3::TcpSocketImpl::ShutdownRecv | ( | void | ) | [virtual] |
- Returns:
- zero on success, -1 on failure.
Implements ns3::Socket.
| virtual int ns3::TcpSocketImpl::ShutdownSend | ( | void | ) | [virtual] |
- Returns:
- zero on success, -1 on failure.
Implements ns3::Socket.
The documentation for this class was generated from the following files:
- src/internet-stack/tcp-socket-impl.h
- doc/introspected-doxygen.h
