create_socket

SFL
Version 2.11

`create_socket`

#include "sflsock.h"
sock_t
create_socket (
    const char *protocol                /*  Protocol "tcp" or "udp"          */
)

Synopsis

Creates a TCP or UDP socket. The socket is not connected. To use with TCP services you must bind or connect the socket. You can use the socket with UDP services - e.g. read UDP () - immediately. Returns a socket number or INVALID_SOCKET, in which case you can get the reason for the error by calling connect error (). This may be one of:

IP NOSOCKETS Sockets not supported on this system
IP BADPROTOCOL Cannot understand protocol name
IP SOCKETERROR Cannot create the socket

Source Code - (sflsock.c)

{
#if (defined (DOES_SOCKETS))
    struct protoent
        *ppe;                           /*  Protocol information entry       */
    int
#   if (!defined (__WINDOWS__))
        true_value = 1,                 /*  Boolean value for setsockopt()   */
#   endif
        sock_type;                      /*  Type of socket we want           */
    sock_t
        handle;                         /*  Socket from socket() call        */

    ASSERT (protocol && *protocol);
    connect_error_value = IP_NOERROR;   /*  Assume no errors                 */

    /*  Map protocol name to protocol number                                 */
    ppe = getprotobyname (protocol);
    if (ppe == NULL)                    /*  Cannot get protocol entry        */
      {
        connect_error_value = IP_BADPROTOCOL;
        return (INVALID_SOCKET);
      }
    /*  Use protocol string to choose a socket type                          */
    if (streq (protocol, "udp"))
        sock_type = SOCK_DGRAM;
    else
        sock_type = SOCK_STREAM;

    /*  Allocate a socket                                                    */
    handle = (sock_t) socket (AF_INET, sock_type, ppe-> p_proto);
    if (handle == INVALID_SOCKET)       /*  Cannot create passive socket     */
      {
        connect_error_value = IP_SOCKETERROR;
        return (INVALID_SOCKET);
      }
#   if (!defined (__WINDOWS__))
    /*  On BSD-socket systems we need to do this to allow the server to
     *  restart on a previously-used socket, without an annoying timeout
     *  of several minutes.  With winsock the reuseaddr option lets the
     *  server work with an already-used socket (!), so we don't do it.
     */
    setsockopt ((SOCKET) handle, SOL_SOCKET, SO_REUSEADDR,
                (char *) &true_value, sizeof (true_value));
#   endif
    prepare_socket (handle);            /*  Ready socket for use             */
    ip_sockets++;
    return (handle);

#elif (defined (FAKE_SOCKETS))
    return (1);                         /*  Return dummy handle              */

#else
    connect_error_value = IP_NOSOCKETS;
    return (INVALID_SOCKET);            /*  Sockets not supported            */
#endif
}

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IP NOSOCKETS	Sockets not supported on this system
IP BADPROTOCOL	Cannot understand protocol name
IP SOCKETERROR	Cannot create the socket