/*	$NetBSD: linux_pipe.c,v 1.65 2011/04/14 00:59:06 christos Exp $	*/

/*-
 * Copyright (c) 1995, 1998 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Frank van der Linden and Eric Haszlakiewicz.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: linux_pipe.c,v 1.65 2011/04/14 00:59:06 christos Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/mman.h>
#include <sys/mount.h>
#include <sys/fcntl.h>
#include <sys/filedesc.h>

#include <sys/sched.h>
#include <sys/syscallargs.h>

#include <compat/linux/common/linux_types.h>
#include <compat/linux/common/linux_mmap.h>
#include <compat/linux/common/linux_signal.h>
#include <compat/linux/common/linux_ipc.h>
#include <compat/linux/common/linux_sem.h>
#include <compat/linux/common/linux_fcntl.h>

#include <compat/linux/linux_syscallargs.h>

/* Used on: arm, i386, m68k, ppc, amd64 */
/* Not used on: alpha, mips, sparc, sparc64 */
/* Alpha, mips, sparc and sparc64 pass one of the fds in a register */

/*
 * NetBSD passes fd[0] in retval[0], and fd[1] in retval[1].
 * Linux directly passes the pointer.
 */
static int
linux_pipe_return(struct lwp *l, int *pfds, register_t *retval, int flags)
{
	int error;

	if (sizeof(*retval) != sizeof(*pfds)) {
		/* On amd64, sizeof(register_t) != sizeof(int) */
		int rpfds[2];
		rpfds[0] = (int)retval[0];
		rpfds[1] = (int)retval[1];

		if ((error = copyout(rpfds, pfds, sizeof(rpfds))))
			return error;
	} else {
		if ((error = copyout(retval, pfds, 2 * sizeof(*pfds))))
			return error;
	}
	if (flags & LINUX_O_CLOEXEC) {
		fd_set_exclose(l, retval[0], true);
		fd_set_exclose(l, retval[1], true);
	}
	retval[0] = 0;
	return 0;
}

int
linux_sys_pipe(struct lwp *l, const struct linux_sys_pipe_args *uap,
    register_t *retval)
{
	/* {
		syscallarg(int *) pfds;
	} */
	int error;

	if ((error = pipe1(l, retval, 0)))
		return error;

	return linux_pipe_return(l, SCARG(uap, pfds), retval, 0);
}

int
linux_sys_pipe2(struct lwp *l, const struct linux_sys_pipe2_args *uap,
    register_t *retval)
{
	/* {
		syscallarg(int *) pfds;
		syscallarg(int) flags;
	} */
	int error;
	int flag = 0;

	switch (SCARG(uap, flags)) {
	case LINUX_O_CLOEXEC:
		break;
	case LINUX_O_NONBLOCK:
	case LINUX_O_NONBLOCK|LINUX_O_CLOEXEC:
		flag = O_NONBLOCK;
		break;
	default:
		return EINVAL;
	}

	if ((error = pipe1(l, retval, flag)))
		return error;

	return linux_pipe_return(l, SCARG(uap, pfds), retval,
	    SCARG(uap, flags));
}
