Destroy the socket.

Note

Closes socket if it's 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 to call close() 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.

Implemented in TCPSocket, TLSSocketWrapper, InternetDatagramSocket, and CellularNonIPSocket.

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 socket to a remote address.

Attempts to make connection on connection-mode protocol or set or reset the peer address on connectionless protocol.

Connectionless protocols also use the connected address to filter incoming packets for recv() and recvfrom() calls.

To reset the peer address, there must be zero initialized(default constructor) SocketAddress objects in the address parameter.

Note

If connect() fails it is recommended to close the Socket and create a new one before attempting to reconnect.

Parameters

address

The SocketAddress of the remote peer.

Returns

NSAPI_ERROR_OK on success. Negative subclass-dependent error code on failure.

Implemented in TLSSocketWrapper, CellularNonIPSocket, InternetDatagramSocket, and TCPSocket.

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.

Subscribe to 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).

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.

Returns

NSAPI_ERROR_OK on success, negative error code on failure.

Implemented in TCPSocket, TLSSocketWrapper, InternetDatagramSocket, and CellularNonIPSocket.

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 from a socket.

Receive data from connected socket, or in the case of connectionless socket, equivalent to calling recvfrom(NULL, data, size).

If socket is connected, only packets coming from connected peer address are accepted.

Note

recv() is allowed write to data buffer even if an error occurs.

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.

Returns

Number of received bytes on success, negative, subclass-dependent error code on failure. If no data is available to be received and the peer has performed an orderly shutdown, recv() returns 0.

Implemented in TLSSocketWrapper, InternetDatagramSocket, TCPSocket, and CellularNonIPSocket.

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.

If socket is connected, only packets coming from connected peer address are accepted.

Note

recvfrom() is allowed write to address and data buffers even if error occurs.

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

Returns

Number of received bytes on success, negative subclass-dependent error code on failure

Implemented in TCPSocket, TLSSocketWrapper, CellularNonIPSocket, and InternetDatagramSocket.

Send data on a socket.

The socket must be connected to a remote host before send() call. Returns the number of bytes sent from the buffer. In case of connectionless socket, sends data to pre-specified remote.

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.

Returns

NSAPI_ERROR_OK on success. Negative subclass-dependent error code on failure.

Implemented in TLSSocketWrapper, InternetDatagramSocket, TCPSocket, and CellularNonIPSocket.

Send a message on a socket.

The sendto() function sends a message through a connection-mode or connectionless-mode socket. If the socket is a connectionless-mode socket, the message is sent to the address specified. If the socket is a connected-mode socket, 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

Returns

Number of sent bytes on success, negative subclass-dependent error code on failure

Implemented in TLSSocketWrapper, TCPSocket, CellularNonIPSocket, and InternetDatagramSocket.

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.