/*
* Copyright (c) 2015 ARM Limited
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/** @file Socket.h Abstract Socket interface */
/** @addtogroup NetSocket
* Mbed OS Socket API
* @{ */
#ifndef SOCKET_H
#define SOCKET_H
#include "netsocket/SocketAddress.h"
#include "Callback.h"
/** Socket interface.
*
* This class defines the Mbed OS Socket API.
* Socket is an abstract interface for communicating with remote endpoints.
*
* This API is intended for applications and libraries instead of
* protocol-specific implementations. For example, TCPSocket
* and UDPSocket are implementations of the Socket interface.
* Socket API is intentionally not protocol-specific, and allows all protocol
* to provide the same API regardless of the underlying transport mechanism.
*/
class Socket {
public:
/** Destroy a socket.
*
* Closes socket if the socket is still open.
*/
virtual ~Socket() = default;
/** Closes the socket.
*
* Closes any open connection and deallocates any memory associated
* with the socket. Called from destructor if socket is not closed.
*
* @return NSAPI_ERROR_OK on success.
* Negative subclass-dependent error code on failure.
*/
virtual nsapi_error_t close() = 0;
/** 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.
*
* @param address The SocketAddress of the remote peer.
* @return NSAPI_ERROR_OK on success.
* Negative subclass-dependent error code on failure.
*/
virtual nsapi_error_t connect(const SocketAddress &address) = 0;
/** 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.
*
* @param data Buffer of data to send to the host.
* @param size Size of the buffer in bytes.
* @return NSAPI_ERROR_OK on success.
* Negative subclass-dependent error code on failure.
*/
virtual nsapi_size_or_error_t send(const void *data, nsapi_size_t size) = 0;
/** 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.
*
* @param data Destination buffer for data received from the host.
* @param size Size of the buffer in bytes.
* @return 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.
*/
virtual nsapi_size_or_error_t recv(void *data, nsapi_size_t size) = 0;
/** 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.
*
* @param address Remote address
* @param data Buffer of data to send to the host
* @param size Size of the buffer in bytes
* @return Number of sent bytes on success, negative subclass-dependent error
* code on failure
*/
virtual nsapi_size_or_error_t sendto(const SocketAddress &address,
const void *data, nsapi_size_t size) = 0;
/** 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.
*
* @param address Destination for the source address or NULL
* @param data Destination buffer for datagram received from the host
* @param size Size of the buffer in bytes
* @return Number of received bytes on success, negative subclass-dependent
* error code on failure
*/
virtual nsapi_size_or_error_t recvfrom(SocketAddress *address,
void *data, nsapi_size_t size) = 0;
/** Send a message on a socket.
*
* The sendto_control() 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.
*
* Additional control information can be passed to the stack for specific operations.
*
* 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.
*
* @param address Remote address
* @param data Buffer of data to send to the host
* @param size Size of the buffer in bytes
* @param control Control data, for instance a populated #nsapi_pktinfo structure.
* @param control_size Size of \c control in bytes.
* @return Number of sent bytes on success, negative subclass-dependent error
* code on failure
*/
virtual nsapi_size_or_error_t sendto_control(const SocketAddress &address,
const void *data, nsapi_size_t size,
nsapi_msghdr_t *control, nsapi_size_t control_size) = 0;
/** 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.
*
* Ancillary data is stored into \c control. The caller needs to allocate a buffer
* that is large enough to contain the data they want to receive, then pass the pointer in
* through the \c control member. The data will be filled into \c control, beginning with a header
* specifying what data was received. See #MsgHeaderIterator for how to parse this data.
*
* @note recvfrom_control() 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.
*
* @param address Destination for the source address or NULL
* @param data Destination buffer for datagram received from the host
* @param size Size of the buffer in bytes
* @param control Caller-allocated buffer to store ancillary data.
* @param control_size Size of the \c control buffer that the caller has allocated.
* @return Number of received bytes on success, negative subclass-dependent
* error code on failure
*/
virtual nsapi_size_or_error_t recvfrom_control(SocketAddress *address,
void *data, nsapi_size_t size,
nsapi_msghdr_t *control, nsapi_size_t control_size) = 0;
/** 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.
*
* @param address Local address to bind.
* @return NSAPI_ERROR_OK on success, negative subclass-dependent error
* code on failure.
*/
virtual nsapi_error_t bind(const SocketAddress &address) = 0;
/** 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)
*
* @param blocking true for blocking mode, false for non-blocking mode.
*/
virtual void set_blocking(bool blocking) = 0;
/** 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)
*
* @param timeout Timeout in milliseconds
*/
virtual void set_timeout(int timeout) = 0;
/** 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.
*
* @param func Function to call on state change.
*/
virtual void sigio(mbed::Callback<void()> func) = 0;
/** 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.
*
* @param level Stack-specific protocol level or nsapi_socket_level_t.
* @param optname Level-specific option name.
* @param optval Option value.
* @param optlen Length of the option value.
* @retval NSAPI_ERROR_OK on success.
* @retval NSAPI_ERROR_NO_SOCKET if socket is not open.
* @retval int Negative error code on failure, see @ref NetworkStack::setsockopt.
*/
virtual nsapi_error_t setsockopt(int level, int optname, const void *optval, unsigned optlen) = 0;
/** 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.
*
* @param level Stack-specific protocol level or nsapi_socket_level_t.
* @param optname Level-specific option name.
* @param optval Destination for option value.
* @param optlen Length of the option value.
* @retval NSAPI_ERROR_OK on success.
* @retval NSAPI_ERROR_NO_SOCKET if socket is not open.
* @retval int Negative error code on failure, see @ref NetworkStack::getsockopt.
*/
virtual nsapi_error_t getsockopt(int level, int optname, void *optval, unsigned *optlen) = 0;
/** 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.
*
* @param error Pointer to storage of the error value or NULL.
* @return Pointer to a socket.
*/
virtual Socket *accept(nsapi_error_t *error = NULL) = 0;
/** Listen for incoming connections.
*
* Marks the socket as a passive socket that can be used to accept
* incoming connections.
*
* @param backlog Number of pending connections that can be queued
* simultaneously, defaults to 1.
* @return NSAPI_ERROR_OK on success, negative error code on failure.
*/
virtual nsapi_error_t listen(int backlog = 1) = 0;
/** 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.
*
* @param address Pointer to SocketAddress structure.
* @retval NSAPI_ERROR_OK on success.
* @retval NSAPI_ERROR_NO_SOCKET if socket is not connected.
* @retval NSAPI_ERROR_NO_CONNECTION if the remote peer was not set.
*/
virtual nsapi_error_t getpeername(SocketAddress *address) = 0;
};
#endif
/** @}*/
