uuid.c

/*
 * mdadm - manage Linux "md" devices aka RAID arrays.
 *
 * Copyright (C) 2001-2013 Neil Brown <neilb@suse.de>
 *
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *    Author: Neil Brown
 *    Email: <neilb@suse.de>
 */

#include	<string.h>

const int uuid_zero[4] = { 0, 0, 0, 0 };

int same_uuid(int a[4], int b[4], int swapuuid)
{
	if (swapuuid) {
		/* parse uuids are hostendian.
		 * uuid's from some superblocks are big-ending
		 * if there is a difference, we need to swap..
		 */
		unsigned char *ac = (unsigned char *)a;
		unsigned char *bc = (unsigned char *)b;
		int i;
		for (i = 0; i < 16; i += 4) {
			if (ac[i+0] != bc[i+3] ||
			    ac[i+1] != bc[i+2] ||
			    ac[i+2] != bc[i+1] ||
			    ac[i+3] != bc[i+0])
				return 0;
		}
		return 1;
	} else {
		if (a[0]==b[0] &&
		    a[1]==b[1] &&
		    a[2]==b[2] &&
		    a[3]==b[3])
			return 1;
		return 0;
	}
}

void copy_uuid(void *a, int b[4], int swapuuid)
{
	if (swapuuid) {
		/* parse uuids are hostendian.
		 * uuid's from some superblocks are big-ending
		 * if there is a difference, we need to swap..
		 */
		unsigned char *ac = (unsigned char *)a;
		unsigned char *bc = (unsigned char *)b;
		int i;
		for (i = 0; i < 16; i += 4) {
			ac[i+0] = bc[i+3];
			ac[i+1] = bc[i+2];
			ac[i+2] = bc[i+1];
			ac[i+3] = bc[i+0];
		}
	} else
		memcpy(a, b, 16);
}

/*
 * Parse a 128 bit uuid in 4 integers
 * format is 32 hexx nibbles with options :.<space> separator
 * If not exactly 32 hex digits are found, return 0
 * else return 1
 */
int parse_uuid(char *str, int uuid[4])
{
	int hit = 0; /* number of Hex digIT */
	int i;
	char c;
	for (i = 0; i < 4; i++)
		uuid[i] = 0;

	while ((c = *str++) != 0) {
		int n;
		if (c >= '0' && c <= '9')
			n = c-'0';
		else if (c >= 'a' && c <= 'f')
			n = 10 + c - 'a';
		else if (c >= 'A' && c <= 'F')
			n = 10 + c - 'A';
		else if (strchr(":. -", c))
			continue;
		else return 0;

		if (hit<32) {
			uuid[hit/8] <<= 4;
			uuid[hit/8] += n;
		}
		hit++;
	}
	if (hit == 32)
		return 1;
	return 0;
}