source: downloads/tcl8.5.2/generic/tclIOSock.c @ 25

/*
 * tclIOSock.c --
 *
 *      Common routines used by all socket based channel types.
 *
 * Copyright (c) 1995-1997 Sun Microsystems, Inc.
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: tclIOSock.c,v 1.11 2007/02/20 23:24:04 nijtmans Exp $
 */

#include "tclInt.h"

/*
 *---------------------------------------------------------------------------
 *
 * TclSockGetPort --
 *
 *      Maps from a string, which could be a service name, to a port. Used by
 *      socket creation code to get port numbers and resolve registered
 *      service names to port numbers.
 *
 * Results:
 *      A standard Tcl result. On success, the port number is returned in
 *      portPtr. On failure, an error message is left in the interp's result.
 *
 * Side effects:
 *      None.
 *
 *---------------------------------------------------------------------------
 */

int
TclSockGetPort(
    Tcl_Interp *interp,
    const char *string, /* Integer or service name */
    const char *proto, /* "tcp" or "udp", typically */
    int *portPtr)               /* Return port number */
{
    struct servent *sp;         /* Protocol info for named services */
    Tcl_DString ds;
    const char *native;

    if (Tcl_GetInt(NULL, string, portPtr) != TCL_OK) {
        /*
         * Don't bother translating 'proto' to native.
         */

        native = Tcl_UtfToExternalDString(NULL, string, -1, &ds);
        sp = getservbyname(native, proto);              /* INTL: Native. */
        Tcl_DStringFree(&ds);
        if (sp != NULL) {
            *portPtr = ntohs((unsigned short) sp->s_port);
            return TCL_OK;
        }
    }
    if (Tcl_GetInt(interp, string, portPtr) != TCL_OK) {
        return TCL_ERROR;
    }
    if (*portPtr > 0xFFFF) {
        Tcl_AppendResult(interp, "couldn't open socket: port number too high",
                NULL);
        return TCL_ERROR;
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * TclSockMinimumBuffers --
 *
 *      Ensure minimum buffer sizes (non zero).
 *
 * Results:
 *      A standard Tcl result.
 *
 * Side effects:
 *      Sets SO_SNDBUF and SO_RCVBUF sizes.
 *
 *----------------------------------------------------------------------
 */

int
TclSockMinimumBuffers(
    int sock,                   /* Socket file descriptor */
    int size)                   /* Minimum buffer size */
{
    int current;
    socklen_t len;

    len = sizeof(int);
    getsockopt(sock, SOL_SOCKET, SO_SNDBUF, (char *)&current, &len);
    if (current < size) {
        len = sizeof(int);
        setsockopt(sock, SOL_SOCKET, SO_SNDBUF, (char *)&size, len);
    }
    len = sizeof(int);
    getsockopt(sock, SOL_SOCKET, SO_RCVBUF, (char *)&current, &len);
    if (current < size) {
        len = sizeof(int);
        setsockopt(sock, SOL_SOCKET, SO_RCVBUF, (char *)&size, len);
    }
    return TCL_OK;
}

/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */