mbed-os/features/netsocket/TCPSocket.h

/*
 * Copyright (c) 2015 ARM Limited
 *
 * 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 TCPSocket.h TCPSocket class */
/** \addtogroup netsocket
 * @{*/

#ifndef TCPSOCKET_H
#define TCPSOCKET_H

#include "netsocket/InternetSocket.h"
#include "netsocket/NetworkStack.h"
#include "netsocket/NetworkInterface.h"
#include "rtos/EventFlags.h"


/** TCP socket connection
 */
class TCPSocket : public InternetSocket {
public:
    /** Create an uninitialized socket
     *
     *  Must call open to initialize the socket on a network stack.
     */
    TCPSocket();

    /** Create a socket on a network interface
     *
     *  Creates and opens a socket on the network stack of the given
     *  network interface.
     *
     *  @param stack    Network stack as target for socket
     *
     *  @deprecated since mbed-os-5.11
     */
    template <typename S>
    MBED_DEPRECATED_SINCE("mbed-os-5.11",
                          "The TCPSocket(S *stack) constructor is deprecated."
                          "It discards the open() call return value."
                          "Use another constructor and call open() explicitly, instead.")
    TCPSocket(S *stack)
    {
        open(stack);
    }

    /** Destroy a socket
     *
     *  Closes socket if the socket is still open
     */
    virtual ~TCPSocket();

    /** Override multicast functions to return error for TCP
     *
     */
    virtual int join_multicast_group(const SocketAddress &address)
    {
        return NSAPI_ERROR_UNSUPPORTED;
    }

    /** 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.
     *
     *  @param host     Hostname of the remote host
     *  @param port     Port of the remote host
     *  @return         0 on success, negative error code on failure
     */
    nsapi_error_t connect(const char *host, uint16_t port);

    /** Connects TCP socket to a remote host
     *
     *  Initiates a connection to a remote server specified by the
     *  indicated address.
     *
     *  @param address  The SocketAddress of the remote host
     *  @return         0 on success, negative error code on failure
     */
    virtual nsapi_error_t connect(const SocketAddress &address);

    /** 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.
     *
     *  @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 error
     *                  code on failure
     */
    virtual nsapi_size_or_error_t send(const void *data, nsapi_size_t size);

    /** 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.
     *
     *  @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 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);

    /** 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.
     *
     *  @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 error
     *                  code on failure
     */
    virtual nsapi_size_or_error_t sendto(const SocketAddress &address,
                                         const void *data, nsapi_size_t size);

    /** 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.
     *
     *  @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 error
     *                  code on failure
     */
    virtual nsapi_size_or_error_t recvfrom(SocketAddress *address,
                                           void *data, nsapi_size_t size);

    /** 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.
     *
     *  @param error      pointer to storage of the error value or NULL
     *  @return           pointer to a socket
     */
    virtual TCPSocket *accept(nsapi_error_t *error = NULL);

    /** 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         0 on success, negative error code on failure
     */
    virtual nsapi_error_t listen(int backlog = 1);

protected:
    friend class TCPServer;
    virtual nsapi_protocol_t get_proto();

private:
    /** Create a socket out of a given socket
     *
     *  To be used within accept() function. Close() will clean this up.
     */
    TCPSocket(TCPSocket *parent, nsapi_socket_t socket, SocketAddress address);
};


#endif

/** @}*/