/*
 *              f c n t l
 *
 * Routine to get and set various file parameters
 * such as file flags, type of I/O device etc.
 *
 * AMENDMENT HISTORY
 * ~~~~~~~~~~~~~~~~~
 *  26 Aug 93   DJW   - Merged routines l1_to_c() and c_to_l1() into main
 *                      body to avoid function call overheads.
 *
 *  25 Sep 93   DJW   - Added support for Posix O_NONBLOCK and O_SYNC modes.
 *
 *  12 Nov 95   DJW   - Added support for O_NONBLOCK mode correctly in its own
 *                      right rather than a synonym for O_NDELAY.
 *                    - Switched to using support routines for mode translation.
 */

#define __LIBRARY__

#include <fcntl.h>
#include <stdarg.h>
#include <errno.h>
#include <stddef.h>

/*
 *  UFB flags we are allowed to touch
 */
#define TOUCH_MASK (UFB_WA|UFB_RA|UFB_NT|UFB_AP|UFB_ND|UFB_NB|UFB_SY)


int fcntl ( int  fd, int  action,  ...)
{
    va_list ap;
    UFB_t * uptr;
    struct  flock *flock;
    int   flags;

    /*
     *  Start with a sanity check
    */
    if ( (uptr = _Chkufb( fd )) == NULL) {
        return -1;
    }

    va_start (ap,action);
    flags =  *((int *)ap);
    flock = *((struct flock **)ap);
    va_end(ap);

    /*
     *  Now take the required action
     */
    switch( action ) {
        case F_GETFD:
            return (int)uptr->ufbtyp;

        case F_SETFD:
            uptr->ufbtyp = (char)flags;
            return 0;

        case F_GETFL:
            return (int)_ModeFd(uptr->ufbflg);

        case F_SETFL:
            uptr->ufbflg &= (short)~((short)TOUCH_MASK);
            uptr->ufbflg |= (short)(_ModeUfb(flags) & (short)TOUCH_MASK);
            return 0;

        case F_GETLK:
            /* Dummy - pretend it works */
            flock->l_type = F_UNLCK;
            flock->l_whence = SEEK_SET;
            return 0;

        case F_SETLK:
            /* Dummy - pretend it works */
            return 0;

        case F_SETLKW:
            /* Dummy - pretend it works */
            return 0;

        default:
            errno = EINVAL;
            return -1;
    }
    /*  NOT REACHED */
}