xref: /src/sys/stand/efiboot/efidev.c

/*	$NetBSD: efidev.c,v 1.2 2020/07/15 00:51:40 jmcneill Exp $	*/
/*	$OpenBSD: efiboot.c,v 1.28 2017/11/25 19:02:07 patrick Exp $	*/

/*
 * Copyright (c) 2015 YASUOKA Masahiko <yasuoka (at) yasuoka.net>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "efiboot.h"

/*
 * Determine the number of nodes up to, but not including, the first
 * node of the specified type.
 */
int
efi_device_path_depth(EFI_DEVICE_PATH *dp, int dptype)
{
	int	i;

	for (i = 0; !IsDevicePathEnd(dp); dp = NextDevicePathNode(dp), i++) {
		if (DevicePathType(dp) == dptype)
			return (i);
	}

	return (-1);
}

int
efi_device_path_count(EFI_DEVICE_PATH *dp)
{
	int	count;

	for (count = 0; ; dp = NextDevicePathNode(dp), count++) {
		if (IsDevicePathEnd(dp))
			break;
	}

	return (count);
}

int
efi_device_path_ncmp(EFI_DEVICE_PATH *dpa, EFI_DEVICE_PATH *dpb, int deptn)
{
	int	 i, cmp;

	for (i = 0; i < deptn; i++) {
		if (IsDevicePathEnd(dpa) || IsDevicePathEnd(dpb))
			return ((IsDevicePathEnd(dpa) && IsDevicePathEnd(dpb))
			    ? 0 : (IsDevicePathEnd(dpa))? -1 : 1);
		cmp = DevicePathNodeLength(dpa) - DevicePathNodeLength(dpb);
		if (cmp)
			return (cmp);
		cmp = memcmp(dpa, dpb, DevicePathNodeLength(dpa));
		if (cmp)
			return (cmp);
		dpa = NextDevicePathNode(dpa);
		dpb = NextDevicePathNode(dpb);
	}

	return (0);
}