Socket.h

00001 
00002 /** \addtogroup netsocket */
00003 /** @{*/
00004 /* Socket
00005  * Copyright (c) 2015 ARM Limited
00006  *
00007  * Licensed under the Apache License, Version 2.0 (the "License");
00008  * you may not use this file except in compliance with the License.
00009  * You may obtain a copy of the License at
00010  *
00011  *     http://www.apache.org/licenses/LICENSE-2.0
00012  *
00013  * Unless required by applicable law or agreed to in writing, software
00014  * distributed under the License is distributed on an "AS IS" BASIS,
00015  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00016  * See the License for the specific language governing permissions and
00017  * limitations under the License.
00018  */
00019 
00020 #ifndef SOCKET_H
00021 #define SOCKET_H
00022 
00023 #include "netsocket/SocketAddress.h"
00024 #include "Callback.h"
00025 
00026 /** Abstract socket class
00027  */
00028 class Socket {
00029 public:
00030     /** Destroy a socket.
00031      *
00032      *  Closes socket if the socket is still open
00033      */
00034     virtual ~Socket() {}
00035 
00036     /** Close the socket.
00037      *
00038      *  Closes any open connection and deallocates any memory associated
00039      *  with the socket. Called from destructor if socket is not closed.
00040      *
00041      *  @return         0 on success, negative error code on failure
00042      */
00043     virtual nsapi_error_t close() = 0;
00044 
00045     /** Connects socket to a remote address.
00046      *
00047      *  Attempt to make connection on connection-mode protocol or set or reset
00048      *  the peer address on connectionless protocol.
00049      *
00050      *  Also connectionless protocols use the connected address to filter
00051      *  incoming packets for recv() and recvfrom() calls.
00052      *
00053      *  To reset the peer address, zero initialised(default constructor) SocketAddress
00054      *  object have to be in the address parameter.
00055      *
00056      *  @param address  The SocketAddress of the remote peer
00057      *  @return         0 on success, negative error code on failure
00058      */
00059     virtual nsapi_error_t connect(const SocketAddress &address) = 0;
00060 
00061     /** Send data on a socket
00062      *
00063      *  The socket must be connected to a remote host before send() call.
00064      *  Returns the number of bytes sent from the buffer.
00065      *  In case of connectionless socket, send data to pre-specified remote.
00066      *
00067      *  By default, send blocks until all data is sent. If socket is set to
00068      *  non-blocking or times out, a partial amount can be written.
00069      *  NSAPI_ERROR_WOULD_BLOCK is returned if no data was written.
00070      *
00071      *  @param data     Buffer of data to send to the host
00072      *  @param size     Size of the buffer in bytes
00073      *  @return         Number of sent bytes on success, negative error
00074      *                  code on failure.
00075      */
00076     virtual nsapi_size_or_error_t send(const void *data, nsapi_size_t size) = 0;
00077 
00078     /** Receive data from a socket.
00079      *
00080      *  Receive data from connected socket or in case of connectionless socket
00081      *  this is equivalent of calling recvfrom(NULL, data, size).
00082      *
00083      *  If socket is connected, only packets coming from connected peer address
00084      *  are accepted.
00085      *
00086      *  @note recv() is allowed write to data buffer even if error occurs.
00087      *
00088      *  By default, recv blocks until some data is received. If socket is set to
00089      *  non-blocking or times out, NSAPI_ERROR_WOULD_BLOCK can be returned to
00090      *  indicate no data.
00091      *
00092      *  @param data     Destination buffer for data received from the host
00093      *  @param size     Size of the buffer in bytes
00094      *  @return         Number of received bytes on success, negative error
00095      *                  code on failure. If no data is available to be received
00096      *                  and the peer has performed an orderly shutdown,
00097      *                  recv() returns 0.
00098      */
00099     virtual nsapi_size_or_error_t recv(void *data, nsapi_size_t size) = 0;
00100 
00101     /** Send a message on a socket.
00102      *
00103      * The sendto() function shall send a message through a connection-mode or connectionless-mode socket.
00104      * If the socket is connectionless-mode, the message shall be sent to the address specified.
00105      * If the socket is connection-mode, address shall be ignored.
00106      *
00107      * By default, sendto blocks until data is sent. If socket is set to
00108      * non-blocking or times out, NSAPI_ERROR_WOULD_BLOCK is returned
00109      * immediately.
00110      *
00111      *  @param address  Remote address
00112      *  @param data     Buffer of data to send to the host
00113      *  @param size     Size of the buffer in bytes
00114      *  @return         Number of sent bytes on success, negative error
00115      *                  code on failure
00116      */
00117     virtual nsapi_size_or_error_t sendto(const SocketAddress &address,
00118                                          const void *data, nsapi_size_t size) = 0;
00119 
00120     /** Receive a data from a socket
00121      *
00122      *  Receives a data and stores the source address in address if address
00123      *  is not NULL. Returns the number of bytes written into the buffer.
00124      *
00125      *  If socket is connected, only packets coming from connected peer address
00126      *  are accepted.
00127      *
00128      *  @note recvfrom() is allowed write to address and data buffers even if error occurs.
00129      *
00130      *  By default, recvfrom blocks until a datagram is received. If socket is set to
00131      *  non-blocking or times out with no data, NSAPI_ERROR_WOULD_BLOCK
00132      *  is returned.
00133      *
00134      *  @param address  Destination for the source address or NULL
00135      *  @param data     Destination buffer for datagram received from the host
00136      *  @param size     Size of the buffer in bytes
00137      *  @return         Number of received bytes on success, negative error
00138      *                  code on failure
00139      */
00140     virtual nsapi_size_or_error_t recvfrom(SocketAddress *address,
00141                                            void *data, nsapi_size_t size) = 0;
00142 
00143     /** Bind a specific address to a socket.
00144      *
00145      *  Binding assigns a local address to a socket.
00146      *
00147      *  @param address  Local address to bind
00148      *  @return         0 on success, negative error code on failure.
00149      */
00150     virtual nsapi_error_t bind(const SocketAddress &address) = 0;
00151 
00152     /** Set blocking or non-blocking mode of the socket.
00153      *
00154      *  Initially all sockets are in blocking mode. In non-blocking mode
00155      *  blocking operations such as send/recv/accept return
00156      *  NSAPI_ERROR_WOULD_BLOCK if they can not continue.
00157      *
00158      *  set_blocking(false) is equivalent to set_timeout(-1)
00159      *  set_blocking(true) is equivalent to set_timeout(0)
00160      *
00161      *  @param blocking true for blocking mode, false for non-blocking mode.
00162      */
00163     virtual void set_blocking(bool blocking) = 0;
00164 
00165     /** Set timeout on blocking socket operations.
00166      *
00167      *  Initially all sockets have unbounded timeouts. NSAPI_ERROR_WOULD_BLOCK
00168      *  is returned if a blocking operation takes longer than the specified
00169      *  timeout. A timeout of 0 removes the timeout from the socket. A negative
00170      *  value give the socket an unbounded timeout.
00171      *
00172      *  set_timeout(0) is equivalent to set_blocking(false)
00173      *  set_timeout(-1) is equivalent to set_blocking(true)
00174      *
00175      *  @param timeout  Timeout in milliseconds
00176      */
00177     virtual void set_timeout(int timeout) = 0;
00178 
00179     /** Register a callback on state change of the socket.
00180      *
00181      *  The specified callback will be called on state changes such as when
00182      *  the socket can recv/send/accept successfully and on when an error
00183      *  occurs. The callback may also be called spuriously without reason.
00184      *
00185      *  The callback may be called in an interrupt context and should not
00186      *  perform expensive operations such as recv/send calls.
00187      *
00188      *  Note! This is not intended as a replacement for a poll or attach-like
00189      *  asynchronous api, but rather as a building block for constructing
00190      *  such functionality. The exact timing of when the registered function
00191      *  is called is not guaranteed and susceptible to change.
00192      *
00193      *  @param func     Function to call on state change
00194      */
00195     virtual void sigio(mbed::Callback<void()> func) = 0;
00196 
00197     /*  Set socket options.
00198      *
00199      *  setsockopt() allows an application to pass stack-specific options
00200      *  to the underlying stack using stack-specific level and option names,
00201      *  or to request generic options using levels from nsapi_socket_level_t.
00202      *
00203      *  For unsupported options, NSAPI_ERROR_UNSUPPORTED is returned
00204      *  and the socket is unmodified.
00205      *
00206      *  @param level    Stack-specific protocol level or nsapi_socket_level_t
00207      *  @param optname  Level-specific option name
00208      *  @param optval   Option value
00209      *  @param optlen   Length of the option value
00210      *  @return         0 on success, negative error code on failure
00211      */
00212     virtual nsapi_error_t setsockopt(int level, int optname, const void *optval, unsigned optlen) = 0;
00213 
00214     /*  Get socket options.
00215      *
00216      *  getsockopt() allows an application to retrieve stack-specific options
00217      *  from the underlying stack using stack-specific level and option names,
00218      *  or to request generic options using levels from nsapi_socket_level_t.
00219      *
00220      *  For unsupported options, NSAPI_ERROR_UNSUPPORTED is returned
00221      *  and the socket is unmodified.
00222      *
00223      *  @param level    Stack-specific protocol level or nsapi_socket_level_t
00224      *  @param optname  Level-specific option name
00225      *  @param optval   Destination for option value
00226      *  @param optlen   Length of the option value
00227      *  @return         0 on success, negative error code on failure
00228      */
00229     virtual nsapi_error_t getsockopt(int level, int optname, void *optval, unsigned *optlen) = 0;
00230 
00231     /** Accepts a connection on a socket.
00232      *
00233      *  The server socket must be bound and set to listen for connections.
00234      *  On a new connection, returns connected network socket which user is expected to call close()
00235      *  and that deallocates the resources. Referencing a returned pointer after a close()
00236      *  call is not allowed and leads to undefined behaviour.
00237      *
00238      *  By default, accept blocks until incomming connection occurs. If socket is set to
00239      *  non-blocking or times out, error is set to NSAPI_ERROR_WOULD_BLOCK.
00240      *
00241      *  @param error      pointer to storage of the error value or NULL
00242      *  @return           pointer to a socket
00243      */
00244     virtual Socket *accept(nsapi_error_t *error = NULL) = 0;
00245 
00246     /** Listen for incoming connections.
00247      *
00248      *  Marks the socket as a passive socket that can be used to accept
00249      *  incoming connections.
00250      *
00251      *  @param backlog  Number of pending connections that can be queued
00252      *                  simultaneously, defaults to 1
00253      *  @return         0 on success, negative error code on failure
00254      */
00255     virtual nsapi_error_t listen(int backlog = 1) = 0;
00256 };
00257 
00258 
00259 #endif
00260 
00261 /** @}*/