#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdarg.h>

#include <fcntl.h>

#include "../internal/syscall.h"

/*
 * fcntl over SYS_fcntl (72). The third argument is read from the varargs
 * only for the commands POSIX defines one for (F_DUPFD, F_DUPFD_CLOEXEC,
 * F_SETFD, F_SETFL, the lock commands, and the owner/signal commands);
 * every other command passes 0, which the kernel ignores. Pointers (the
 * struct flock * of F_GETLK/F_SETLK/F_SETLKW/F_OFD_*) ride the varargs
 * slot as a long — on x86_64 long and void * share one GPR slot, so the
 * read is ABI-exact.
 *
 * F_DUPFD_CLOEXEC passes straight through: the x86_64 kernel has supported
 * it as a single native operation since 2.6.24, so no F_DUPFD + F_SETFD
 * fallback is needed. F_SETFL needs no O_LARGEFILE massaging on x86_64
 * (that is a 32-bit compat concern only).
 */
int
fcntl(int fildes, int cmd, ...)
{
    long arg = 0;
    va_list ap;

    switch (cmd)
    {
    case F_DUPFD:
    case F_DUPFD_CLOEXEC:
    case F_SETFD:
    case F_SETFL:
    case F_GETLK:
    case F_SETLK:
    case F_SETLKW:
    case F_SETOWN:
    case F_SETSIG:
    case F_GETOWN_EX:
    case F_SETOWN_EX:
    case F_OFD_GETLK:
    case F_OFD_SETLK:
    case F_OFD_SETLKW:
        va_start(ap, cmd);
        arg = va_arg(ap, long);
        va_end(ap);
        break;
    default:
        break;
    }
    return syscall_ret(__syscall3(SYS_fcntl, fildes, cmd, arg));
}