uuid.c

   1 /*
   2  * mdadm - manage Linux "md" devices aka RAID arrays.
   3  *
   4  * Copyright (C) 2001-2013 Neil Brown <neilb@suse.de>
   5  *
   6  *
   7  *    This program is free software; you can redistribute it and/or modify
   8  *    it under the terms of the GNU General Public License as published by
   9  *    the Free Software Foundation; either version 2 of the License, or
  10  *    (at your option) any later version.
  11  *
  12  *    This program is distributed in the hope that it will be useful,
  13  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *    GNU General Public License for more details.
  16  *
  17  *    You should have received a copy of the GNU General Public License
  18  *    along with this program; if not, write to the Free Software
  19  *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  *
  21  *    Author: Neil Brown
  22  *    Email: <neilb@suse.de>
  23  */
  24
  25 #include        <string.h>
  26
  27 const int uuid_zero[4] = { 0, 0, 0, 0 };
  28
  29 int same_uuid(int a[4], int b[4], int swapuuid)
  30 {
  31         if (swapuuid) {
  32                 /* parse uuids are hostendian.
  33                  * uuid's from some superblocks are big-ending
  34                  * if there is a difference, we need to swap..
  35                  */
  36                 unsigned char *ac = (unsigned char *)a;
  37                 unsigned char *bc = (unsigned char *)b;
  38                 int i;
  39                 for (i = 0; i < 16; i += 4) {
  40                         if (ac[i+0] != bc[i+3] ||
  41                             ac[i+1] != bc[i+2] ||
  42                             ac[i+2] != bc[i+1] ||
  43                             ac[i+3] != bc[i+0])
  44                                 return 0;
  45                 }
  46                 return 1;
  47         } else {
  48                 if (a[0]==b[0] &&
  49                     a[1]==b[1] &&
  50                     a[2]==b[2] &&
  51                     a[3]==b[3])
  52                         return 1;
  53                 return 0;
  54         }
  55 }
  56
  57 void copy_uuid(void *a, int b[4], int swapuuid)
  58 {
  59         if (swapuuid) {
  60                 /* parse uuids are hostendian.
  61                  * uuid's from some superblocks are big-ending
  62                  * if there is a difference, we need to swap..
  63                  */
  64                 unsigned char *ac = (unsigned char *)a;
  65                 unsigned char *bc = (unsigned char *)b;
  66                 int i;
  67                 for (i = 0; i < 16; i += 4) {
  68                         ac[i+0] = bc[i+3];
  69                         ac[i+1] = bc[i+2];
  70                         ac[i+2] = bc[i+1];
  71                         ac[i+3] = bc[i+0];
  72                 }
  73         } else
  74                 memcpy(a, b, 16);
  75 }
  76
  77 /*
  78  * Parse a 128 bit uuid in 4 integers
  79  * format is 32 hexx nibbles with options :.<space> separator
  80  * If not exactly 32 hex digits are found, return 0
  81  * else return 1
  82  */
  83 int parse_uuid(char *str, int uuid[4])
  84 {
  85         int hit = 0; /* number of Hex digIT */
  86         int i;
  87         char c;
  88         for (i = 0; i < 4; i++)
  89                 uuid[i] = 0;
  90
  91         while ((c = *str++) != 0) {
  92                 int n;
  93                 if (c >= '0' && c <= '9')
  94                         n = c-'0';
  95                 else if (c >= 'a' && c <= 'f')
  96                         n = 10 + c - 'a';
  97                 else if (c >= 'A' && c <= 'F')
  98                         n = 10 + c - 'A';
  99                 else if (strchr(":. -", c))
 100                         continue;
 101                 else return 0;
 102
 103                 if (hit<32) {
 104                         uuid[hit/8] <<= 4;
 105                         uuid[hit/8] += n;
 106                 }
 107                 hit++;
 108         }
 109         if (hit == 32)
 110                 return 1;
 111         return 0;
 112 }