Socket Class Reference
[Netsocket]

Destroy a socket.

Closes socket if the socket is still open.

Definition at line 45 of file Socket.h.

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 CellularNonIPSocket, InternetDatagramSocket, TCPSocket, and TLSSocketWrapper.

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.

Implemented in CellularNonIPSocket, InternetSocket, and TLSSocketWrapper.

Closes the socket.

Closes any open connection and deallocates any memory associated with the socket. Called from destructor if socket is not closed.

Returns:

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

Implemented in CellularNonIPSocket, InternetSocket, and TLSSocketWrapper.

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 CellularNonIPSocket, InternetDatagramSocket, TCPSocket, TLSSocket, and TLSSocketWrapper.

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.

Implemented in CellularNonIPSocket, InternetSocket, and TLSSocketWrapper.

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.

Implemented in CellularNonIPSocket, InternetSocket, and TLSSocketWrapper.

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 CellularNonIPSocket, InternetDatagramSocket, TCPSocket, and TLSSocketWrapper.

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 CellularNonIPSocket, InternetDatagramSocket, TCPSocket, and TLSSocketWrapper.

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 CellularNonIPSocket, InternetDatagramSocket, TCPSocket, and TLSSocketWrapper.

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 CellularNonIPSocket, InternetDatagramSocket, TCPSocket, and TLSSocketWrapper.

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 CellularNonIPSocket, InternetDatagramSocket, TCPSocket, and TLSSocketWrapper.

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.

Implemented in CellularNonIPSocket, InternetSocket, and TLSSocketWrapper.

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

Implemented in CellularNonIPSocket, InternetSocket, and TLSSocketWrapper.

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.

Implemented in CellularNonIPSocket, InternetSocket, and TLSSocketWrapper.

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.

Implemented in CellularNonIPSocket, InternetSocket, and TLSSocketWrapper.