1 /*

     2  * Sockets for TCP networking.

     3  *

     4  * This layer offers some functionality over what SDL_net offers directly: listening

     5  * sockets (called acceptors here) can be bound to port 0, which will make them listen

     6  * on a random unused port, if one can be found. To support this feature, you can also

     7  * query the local port that an acceptor is listening on.

     8  *

     9  * Further, we support nonblocking reads and writes here. The writes are buffered (TODO),

    10  * so that all data will be accepted, and you can configure a maximum buffer size

    11  * where the connection will be terminated.

    12  *

    13  * In order to ensure buffered data is actually sent out, you should regularly call

    14  * the tick function on your sockets.

    15  */

    16 

    17 #ifndef SOCKET_H_

    18 #define SOCKET_H_

    19 

    20 #include <stdbool.h>

    21 #include <stdint.h>

    22 

    23 struct _flib_tcpsocket;

    24 typedef struct _flib_tcpsocket *flib_tcpsocket;

    25 

    26 struct _flib_acceptor;

    27 typedef struct _flib_acceptor *flib_acceptor;

    28 

    29 /**

    30  * Create a new acceptor which will listen for incoming TCP connections

    31  * on the given port. If port is 0, this will listen on a random

    32  * unused port which can then be queried with flib_acceptor_listenport.

    33  *

    34  * Can return NULL on error.

    35  */

    36 flib_acceptor flib_acceptor_create(uint16_t port);

    37 

    38 /**

    39  * Return the port on which the acceptor is listening.

    40  */

    41 uint16_t flib_acceptor_listenport(flib_acceptor acceptor);

    42 

    43 /**

    44  * Close the acceptor, free its memory and set it to NULL.

    45  * If the acceptor is already NULL, nothing happens.

    46  */

    47 void flib_acceptor_close(flib_acceptor *acceptorptr);

    48 

    49 /**

    50  * Try to accept a connection from an acceptor (listening socket).

    51  * if localOnly is true, this will only accept connections which came from 127.0.0.1

    52  * Returns NULL if nothing can be accepted.

    53  */

    54 flib_tcpsocket flib_socket_accept(flib_acceptor acceptor, bool localOnly);

    55 

    56 /**

    57  * Close the socket, free its memory and set it to NULL.

    58  * If the socket is already NULL, nothing happens.

    59  */

    60 void flib_socket_close(flib_tcpsocket *socket);

    61 

    62 /**

    63  * Attempt to receive up to maxlen bytes from the socket, but does not

    64  * block if nothing is available.

    65  * Returns the ammount of data received, 0 if there was nothing to receive,

    66  * or a negative number if the connection was closed or an error occurred.

    67  */

    68 int flib_socket_nbrecv(flib_tcpsocket sock, void *data, int maxlen);

    69 

    70 int flib_socket_send(flib_tcpsocket sock, void *data, int len);

    71 

    72 #endif /* SOCKET_H_ */