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Public Member Functions
TCPSocket Class Reference

TCP socket connection. More...

#include <TCPSocket.h>

Inheritance diagram for TCPSocket:
InternetSocket Socket

Public Member Functions

 TCPSocket ()
 Create an uninitialized socket. More...
 
int join_multicast_group (const SocketAddress &address)
 Override multicast functions to return error for TCP. More...
 
nsapi_error_t connect (const SocketAddress &address) override
 Connects TCP socket to a remote host. More...
 
nsapi_size_or_error_t send (const void *data, nsapi_size_t size) override
 Send data over a TCP socket. More...
 
nsapi_size_or_error_t recv (void *data, nsapi_size_t size) override
 Receive data over a TCP socket. More...
 
nsapi_size_or_error_t sendto (const SocketAddress &address, const void *data, nsapi_size_t size) override
 Send data on a socket. More...
 
nsapi_size_or_error_t recvfrom (SocketAddress *address, void *data, nsapi_size_t size) override
 Receive a data from a socket. More...
 
TCPSocketaccept (nsapi_error_t *error=NULL) override
 Accepts a connection on a socket. More...
 
nsapi_error_t listen (int backlog=1) override
 Listen for incoming connections. More...
 
nsapi_error_t open (NetworkStack *stack)
 Open a network socket on the network stack of the given network interface. More...
 
nsapi_error_t close () override
 defined(DOXYGEN_ONLY) More...
 
int leave_multicast_group (const SocketAddress &address)
 Leave an IP multicast group. More...
 
int get_rtt_estimate_to_address (const SocketAddress &address, uint32_t *rtt_estimate)
 Get estimated round trip time to destination address. More...
 
int get_stagger_estimate_to_address (const SocketAddress &address, uint16_t data_amount, uint16_t *stagger_min, uint16_t *stagger_max, uint16_t *stagger_rand)
 Get estimated stagger value. More...
 
nsapi_error_t bind (uint16_t port)
 Bind the socket to a port on which to receive data. More...
 
nsapi_error_t bind (const SocketAddress &address) override
 Bind a specific address to a socket. More...
 
void set_blocking (bool blocking) override
 Set blocking or non-blocking mode of the socket. More...
 
void set_timeout (int timeout) override
 Set timeout on blocking socket operations. More...
 
nsapi_error_t setsockopt (int level, int optname, const void *optval, unsigned optlen) override
 Set socket options. More...
 
nsapi_error_t getsockopt (int level, int optname, void *optval, unsigned *optlen) override
 Get socket options. More...
 
void sigio (mbed::Callback< void()> func) override
 Register a callback on state change of the socket. More...
 
nsapi_error_t getpeername (SocketAddress *address) override
 Get the remote-end peer associated with this socket. More...
 

Detailed Description

TCP socket connection.

Definition at line 32 of file TCPSocket.h.

Constructor & Destructor Documentation

TCPSocket ( )

Create an uninitialized socket.

Must call open to initialize the socket on a network stack.

Member Function Documentation

TCPSocket* accept ( nsapi_error_t error = NULL)
overridevirtual

Accepts a connection on a socket.

The server socket must be bound and set to listen for connections. On a new connection, returns connected network socket which user is expected to call close() and that deallocates the resources. Referencing a returned pointer after a close() call is not allowed and leads to undefined behavior.

By default, accept blocks until incoming connection occurs. If socket is set to non-blocking or times out, error is set to NSAPI_ERROR_WOULD_BLOCK.

Parameters
errorpointer to storage of the error value or NULL: NSAPI_ERROR_OK on success NSAPI_ERROR_WOULD_BLOCK if socket is set to non-blocking and would block NSAPI_ERROR_NO_SOCKET if the socket was not open
Returns
pointer to a socket

Implements Socket.

nsapi_error_t bind ( uint16_t  port)
inherited

Bind the socket to a port on which to receive data.

Parameters
portLocal port to bind.
Return values
NSAPI_ERROR_OKon success.
NSAPI_ERROR_NO_SOCKETif socket is not open.
intnegative error codes for stack-related failures. See NetworkStack::socket_bind.
nsapi_error_t bind ( const SocketAddress address)
overridevirtualinherited

Bind a specific address to a socket.

Binding a socket specifies the address and port on which to receive data. If the IP address is zeroed, only the port is bound.

Parameters
addressLocal address to bind.
Returns
NSAPI_ERROR_OK on success, negative subclass-dependent error code on failure.

Implements Socket.

nsapi_error_t close ( )
overridevirtualinherited

defined(DOXYGEN_ONLY)

Close any open connection, and deallocate any memory associated with the socket. Called from destructor if socket is not closed.

Return values
NSAPI_ERROR_OKon success.
NSAPI_ERROR_NO_SOCKETif socket is not open.
intnegative error codes for stack-related failures. See NetworkStack::socket_close.

Implements Socket.

nsapi_error_t connect ( const SocketAddress address)
overridevirtual

Connects TCP socket to a remote host.

Initiates a connection to a remote server specified by the indicated address.

Parameters
addressThe SocketAddress of the remote host
Return values
NSAPI_ERROR_OKon success
NSAPI_ERROR_IN_PROGRESSif the operation is ongoing
NSAPI_ERROR_NO_SOCKETif the socket has not been allocated
NSAPI_ERROR_DNS_FAILUREif the DNS address of host could not be resolved
NSAPI_ERROR_IS_CONNECTEDif the connection is already established
intOther negative error codes for stack-related failures. See NetworkStack::socket_connect().

Implements Socket.

int get_rtt_estimate_to_address ( const SocketAddress address,
uint32_t *  rtt_estimate 
)
inherited

Get estimated round trip time to destination address.

Use estimated round trip time to adjust application retry timers to work in networks that have low data rate and high latency.

Parameters
addressDestination address to use in rtt estimate.
rtt_estimateReturned round trip time value in milliseconds.
Returns
NSAPI_ERROR_OK on success.
NSAPI_ERROR_PARAMETER if the provided pointer is invalid.
negative error code on other failures (
See also
InternetSocket::getsockopt).
int get_stagger_estimate_to_address ( const SocketAddress address,
uint16_t  data_amount,
uint16_t *  stagger_min,
uint16_t *  stagger_max,
uint16_t *  stagger_rand 
)
inherited

Get estimated stagger value.

Stagger value is a time that application should wait before using heavy network operations after connecting to network. Purpose of staggering is to avoid network congestion that may happen in low bandwith networks if multiple applications simultaneously start heavy network usage after joining to the network.

Parameters
addressDestination added used to estimate stagger value.
data_amountAmount of bytes to transfer in kilobytes.
stagger_minMinimum stagger value in seconds.
stagger_maxMaximum stagger value in seconds.
stagger_randRandomized stagger value between stagger_min and stagger_max in seconds.
Returns
NSAPI_ERROR_OK on success.
negative error code on other failures (
See also
InternetSocket::getsockopt).
nsapi_error_t getpeername ( SocketAddress address)
overridevirtualinherited

Get the remote-end peer associated with this socket.

Copy the remote peer address to a SocketAddress structure pointed by address parameter. Socket must be connected to have a peer address associated.

Parameters
addressPointer to SocketAddress structure.
Return values
NSAPI_ERROR_OKon success.
NSAPI_ERROR_NO_SOCKETif socket is not connected.
NSAPI_ERROR_NO_CONNECTIONif the remote peer was not set.

Implements Socket.

nsapi_error_t getsockopt ( int  level,
int  optname,
void *  optval,
unsigned *  optlen 
)
overridevirtualinherited

Get socket options.

getsockopt() allows an application to retrieve stack-specific options from the underlying stack using stack-specific level and option names, or to request generic options using levels from nsapi_socket_level_t.

For unsupported options, NSAPI_ERROR_UNSUPPORTED is returned and the socket is unmodified.

Parameters
levelStack-specific protocol level or nsapi_socket_level_t.
optnameLevel-specific option name.
optvalDestination for option value.
optlenLength of the option value.
Return values
NSAPI_ERROR_OKon success.
NSAPI_ERROR_NO_SOCKETif socket is not open.
intNegative error code on failure, see NetworkStack::getsockopt.

Implements Socket.

int join_multicast_group ( const SocketAddress address)

Override multicast functions to return error for TCP.

Definition at line 43 of file TCPSocket.h.

int leave_multicast_group ( const SocketAddress address)
inherited

Leave an IP multicast group.

Parameters
addressMulticast group IP address.
Returns
NSAPI_ERROR_OK on success, negative error code on failure (
See also
InternetSocket::setsockopt).
nsapi_error_t listen ( int  backlog = 1)
overridevirtual

Listen for incoming connections.

Marks the socket as a passive socket that can be used to accept incoming connections.

Parameters
backlogNumber of pending connections that can be queued simultaneously, defaults to 1
Return values
NSAPI_ERROR_OKon success
NSAPI_ERROR_NO_SOCKETin case socket was not created correctly
intOther negative error codes for stack-related failures. See NetworkStack::socket_listen.

Implements Socket.

nsapi_error_t open ( NetworkStack stack)
inherited

Open a network socket on the network stack of the given network interface.

Note
Not needed if stack is passed to the socket's constructor.
Parameters
stackNetwork stack as target for socket.
Return values
NSAPI_ERROR_OKon success.
NSAPI_ERROR_PARAMETERin case the provided stack was invalid or a stack was already created and socket opened successfully.
intnegative error codes for stack-related failures. See NetworkStack::socket_open.
nsapi_size_or_error_t recv ( void *  data,
nsapi_size_t  size 
)
overridevirtual

Receive data over a TCP socket.

The socket must be connected to a remote host. Returns the number of bytes received into the buffer.

By default, recv blocks until some data is received. If socket is set to non-blocking or times out, NSAPI_ERROR_WOULD_BLOCK can be returned to indicate no data.

Parameters
dataDestination buffer for data received from the host
sizeSize of the buffer in bytes
Return values
intNumber of received bytes on success
NSAPI_ERROR_NO_SOCKETin case socket was not created correctly
NSAPI_ERROR_WOULD_BLOCKin case non-blocking mode is enabled and send cannot be performed immediately
intOther negative error codes for stack-related failures. See NetworkStack::socket_recv.

Implements Socket.

nsapi_size_or_error_t recvfrom ( SocketAddress address,
void *  data,
nsapi_size_t  size 
)
overridevirtual

Receive a data from a socket.

Receives a data and stores the source address in address if address is not NULL. Returns the number of bytes written into the buffer.

By default, recvfrom blocks until a data is received. If socket is set to non-blocking or times out with no datagram, NSAPI_ERROR_WOULD_BLOCK is returned.

Parameters
addressDestination for the source address or NULL
dataDestination buffer for datagram received from the host
sizeSize of the buffer in bytes
Return values
intNumber of received bytes on success
NSAPI_ERROR_NO_SOCKETin case socket was not created correctly
NSAPI_ERROR_WOULD_BLOCKin case non-blocking mode is enabled and send cannot be performed immediately
intOther negative error codes for stack-related failures. See NetworkStack::socket_recv.

Implements Socket.

nsapi_size_or_error_t send ( const void *  data,
nsapi_size_t  size 
)
overridevirtual

Send data over a TCP socket.

The socket must be connected to a remote host. Returns the number of bytes sent from the buffer.

By default, send blocks until all data is sent. If socket is set to non-blocking or times out, a partial amount can be written. NSAPI_ERROR_WOULD_BLOCK is returned if no data was written.

Parameters
dataBuffer of data to send to the host
sizeSize of the buffer in bytes
Return values
intNumber of sent bytes on success
NSAPI_ERROR_NO_SOCKETin case socket was not created correctly
NSAPI_ERROR_WOULD_BLOCKin case non-blocking mode is enabled and send cannot be performed immediately
intOther negative error codes for stack-related failures. See NetworkStack::socket_send.

Implements Socket.

nsapi_size_or_error_t sendto ( const SocketAddress address,
const void *  data,
nsapi_size_t  size 
)
overridevirtual

Send data on a socket.

TCP socket is connection oriented protocol, so address is ignored.

By default, sendto blocks until data is sent. If socket is set to non-blocking or times out, NSAPI_ERROR_WOULD_BLOCK is returned immediately.

Parameters
addressRemote address
dataBuffer of data to send to the host
sizeSize of the buffer in bytes
Return values
intNumber of sent bytes on success
NSAPI_ERROR_NO_SOCKETin case socket was not created correctly
NSAPI_ERROR_WOULD_BLOCKin case non-blocking mode is enabled and send cannot be performed immediately
intOther negative error codes for stack-related failures. See NetworkStack::socket_send.

Implements Socket.

void set_blocking ( bool  blocking)
overridevirtualinherited

Set blocking or non-blocking mode of the socket.

Initially all sockets are in blocking mode. In non-blocking mode blocking operations such as send/recv/accept return NSAPI_ERROR_WOULD_BLOCK if they cannot continue.

set_blocking(false) is equivalent to set_timeout(0) set_blocking(true) is equivalent to set_timeout(-1)

Parameters
blockingtrue for blocking mode, false for non-blocking mode.

Implements Socket.

void set_timeout ( int  timeout)
overridevirtualinherited

Set timeout on blocking socket operations.

Initially all sockets have unbounded timeouts. NSAPI_ERROR_WOULD_BLOCK is returned if a blocking operation takes longer than the specified timeout. A timeout of 0 removes the timeout from the socket. A negative value gives the socket an unbounded timeout.

set_timeout(0) is equivalent to set_blocking(false) set_timeout(-1) is equivalent to set_blocking(true)

Parameters
timeoutTimeout in milliseconds

Implements Socket.

nsapi_error_t setsockopt ( int  level,
int  optname,
const void *  optval,
unsigned  optlen 
)
overridevirtualinherited

Set socket options.

setsockopt() allows an application to pass stack-specific options to the underlying stack using stack-specific level and option names, or to request generic options using levels from nsapi_socket_level_t.

For unsupported options, NSAPI_ERROR_UNSUPPORTED is returned and the socket is unmodified.

Parameters
levelStack-specific protocol level or nsapi_socket_level_t.
optnameLevel-specific option name.
optvalOption value.
optlenLength of the option value.
Return values
NSAPI_ERROR_OKon success.
NSAPI_ERROR_NO_SOCKETif socket is not open.
intNegative error code on failure, see NetworkStack::setsockopt.

Implements Socket.

void sigio ( mbed::Callback< void()>  func)
overridevirtualinherited

Register a callback on state change of the socket.

The specified callback is called on state changes, such as when the socket can receive/send/accept successfully and when an error occurs. The callback may also be called spuriously without reason.

The callback may be called in an interrupt context and should not perform expensive operations such as receive/send calls.

Note! This is not intended as a replacement for a poll or attach-like asynchronous API, but rather as a building block for constructing such functionality. The exact timing of the registered function is not guaranteed and susceptible to change.

Parameters
funcFunction to call on state change.

Implements Socket.

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