Create an uninitialized socket.

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

Create a socket on a network interface.

Creates and opens a socket on the network stack of the given network interface.

Parameters

stack

Network stack as target for socket

Deprecated:

since mbed-os-5.11

Definition at line 54 of file TCPSocket.h.

Destroy a socket.

Closes socket if the socket is still open

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

error

pointer to storage of the error value or NULL

Returns

pointer to a socket

Implements Socket.

Register a callback on state change of the socket.

See also

Socket::sigio

Deprecated:

The behavior of Socket::attach differs from other attach functions in Mbed OS and has been known to cause confusion. Replaced by Socket::sigio.

Register a callback on state change of the socket.

See also

Socket::sigio

Deprecated:

The attach function does not support cv-qualifiers. Replaced by attach(callback(obj, method)).

Definition at line 192 of file InternetSocket.h.

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

Parameters

port	Local port to bind.

Return values

NSAPI_ERROR_OK	on success.
NSAPI_ERROR_NO_SOCKET	if socket is not open.
int	negative error codes for stack-related failures. See NetworkStack::socket_bind.

Bind the socket to a specific address and port on which to receive data.

If the IP address is zeroed, only the port is bound.

Parameters

address	Null-terminated local address to bind.
port	Local port to bind.

Return values

NSAPI_ERROR_OK	on success.
NSAPI_ERROR_NO_SOCKET	if socket is not open.
int	negative error codes for stack-related failures. See NetworkStack::socket_bind.

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

address

Local address to bind.

Returns

NSAPI_ERROR_OK on success, negative subclass-dependent error code on failure.

Implements Socket.

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_OK	on success.
NSAPI_ERROR_NO_SOCKET	if socket is not open.
int	negative error codes for stack-related failures. See NetworkStack::socket_close.

Implements Socket.

Connects TCP socket to a remote host.

Initiates a connection to a remote server specified by either a domain name or an IP address and a port.

Parameters

host	Hostname of the remote host
port	Port of the remote host

Return values

NSAPI_ERROR_OK	on success
NSAPI_ERROR_IN_PROGRESS	if the operation is ongoing
NSAPI_ERROR_NO_SOCKET	if the socket has not been allocated
NSAPI_ERROR_DNS_FAILURE	if the DNS address of host could not be resolved
NSAPI_ERROR_IS_CONNECTED	if the connection is already established
int	Other negative error codes for stack-related failures. See NetworkStack::socket_connect().

Connects TCP socket to a remote host.

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

Parameters

address

The SocketAddress of the remote host

Return values

NSAPI_ERROR_OK	on success
NSAPI_ERROR_IN_PROGRESS	if the operation is ongoing
NSAPI_ERROR_NO_SOCKET	if the socket has not been allocated
NSAPI_ERROR_DNS_FAILURE	if the DNS address of host could not be resolved
NSAPI_ERROR_IS_CONNECTED	if the connection is already established
int	Other negative error codes for stack-related failures. See NetworkStack::socket_connect().

Implements Socket.

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

address	Destination address to use in rtt estimate.
rtt_estimate	Returned 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).

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

address	Destination added used to estimate stagger value.
data_amount	Amount of bytes to transfer in kilobytes.
stagger_min	Minimum stagger value in seconds.
stagger_max	Maximum stagger value in seconds.
stagger_rand	Randomized 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).

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

address

Pointer to SocketAddress structure.

Return values

NSAPI_ERROR_OK	on success.
NSAPI_ERROR_NO_SOCKET	if socket is not connected.
NSAPI_ERROR_NO_CONNECTION	if the remote peer was not set.

Implements Socket.

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

level	Stack-specific protocol level or nsapi_socket_level_t.
optname	Level-specific option name.
optval	Destination for option value.
optlen	Length of the option value.

Return values

NSAPI_ERROR_OK	on success.
NSAPI_ERROR_NO_SOCKET	if socket is not open.
int	Negative error code on failure, see NetworkStack::getsockopt.

Implements Socket.

Override multicast functions to return error for TCP.

Definition at line 68 of file TCPSocket.h.

Leave an IP multicast group.

Parameters

address

Multicast group IP address.

Returns

NSAPI_ERROR_OK on success, negative error code on failure (

See also

InternetSocket::setsockopt).

Listen for incoming connections.

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

Parameters

backlog

Number of pending connections that can be queued simultaneously, defaults to 1

Return values

NSAPI_ERROR_OK	on success
NSAPI_ERROR_NO_SOCKET	in case socket was not created correctly
int	Other negative error codes for stack-related failures. See NetworkStack::socket_listen.

Implements Socket.

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

stack

Network stack as target for socket.

Return values

NSAPI_ERROR_OK	on success.
NSAPI_ERROR_PARAMETER	in case the provided stack was invalid or a stack was already created and socket opened successfully.
int	negative error codes for stack-related failures. See NetworkStack::socket_open.

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

data	Destination buffer for data received from the host
size	Size of the buffer in bytes

Return values

int	Number of received bytes on success
NSAPI_ERROR_NO_SOCKET	in case socket was not created correctly
NSAPI_ERROR_WOULD_BLOCK	in case non-blocking mode is enabled and send cannot be performed immediately
int	Other negative error codes for stack-related failures. See NetworkStack::socket_recv.

Implements Socket.

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

address	Destination for the source address or NULL
data	Destination buffer for datagram received from the host
size	Size of the buffer in bytes

Return values

int	Number of received bytes on success
NSAPI_ERROR_NO_SOCKET	in case socket was not created correctly
NSAPI_ERROR_WOULD_BLOCK	in case non-blocking mode is enabled and send cannot be performed immediately
int	Other negative error codes for stack-related failures. See NetworkStack::socket_recv.

Implements Socket.

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

data	Buffer of data to send to the host
size	Size of the buffer in bytes

Return values

int	Number of sent bytes on success
NSAPI_ERROR_NO_SOCKET	in case socket was not created correctly
NSAPI_ERROR_WOULD_BLOCK	in case non-blocking mode is enabled and send cannot be performed immediately
int	Other negative error codes for stack-related failures. See NetworkStack::socket_send.

Implements Socket.

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

address	Remote address
data	Buffer of data to send to the host
size	Size of the buffer in bytes

Return values

int	Number of sent bytes on success
NSAPI_ERROR_NO_SOCKET	in case socket was not created correctly
NSAPI_ERROR_WOULD_BLOCK	in case non-blocking mode is enabled and send cannot be performed immediately
int	Other negative error codes for stack-related failures. See NetworkStack::socket_send.

Implements Socket.

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

blocking

true for blocking mode, false for non-blocking mode.

Implements Socket.

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

timeout

Timeout in milliseconds

Implements Socket.

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

level	Stack-specific protocol level or nsapi_socket_level_t.
optname	Level-specific option name.
optval	Option value.
optlen	Length of the option value.

Return values

NSAPI_ERROR_OK	on success.
NSAPI_ERROR_NO_SOCKET	if socket is not open.
int	Negative error code on failure, see NetworkStack::setsockopt.

Implements Socket.

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

func	Function to call on state change.

Implements Socket.