source/lib/util_uuid.c

   1 /*
   2  *  Unix SMB/CIFS implementation.
   3  *  UUID server routines
   4  *  Copyright (C) Theodore Ts'o               1996, 1997,
   5  *  Copyright (C) Jim McDonough                     2002.
   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., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  */
  21
  22 #include "includes.h"
  23
  24 /*
  25  * Offset between 15-Oct-1582 and 1-Jan-70
  26  */
  27 #define TIME_OFFSET_HIGH 0x01B21DD2
  28 #define TIME_OFFSET_LOW  0x13814000
  29
  30 struct uuid {
  31         uint32   time_low;
  32         uint16   time_mid;
  33         uint16   time_hi_and_version;
  34         uint16   clock_seq;
  35         uint8    node[6];
  36 };
  37
  38
  39 static void uuid_pack(const struct uuid *uu, GUID *ptr)
  40 {
  41         uint32 tmp;
  42         uint8 *out = ptr->info;
  43
  44         tmp = uu->time_low;
  45         out[3] = (uint8) tmp;
  46         tmp >>= 8;
  47         out[2] = (uint8) tmp;
  48         tmp >>= 8;
  49         out[1] = (uint8) tmp;
  50         tmp >>= 8;
  51         out[0] = (uint8) tmp;
  52
  53         tmp = uu->time_mid;
  54         out[5] = (uint8) tmp;
  55         tmp >>= 8;
  56         out[4] = (uint8) tmp;
  57
  58         tmp = uu->time_hi_and_version;
  59         out[7] = (uint8) tmp;
  60         tmp >>= 8;
  61         out[6] = (uint8) tmp;
  62
  63         tmp = uu->clock_seq;
  64         out[9] = (uint8) tmp;
  65         tmp >>= 8;
  66         out[8] = (uint8) tmp;
  67
  68         memcpy(out+10, uu->node, 6);
  69 }
  70
  71 static void uuid_unpack(const GUID in, struct uuid *uu)
  72 {
  73         const uint8 *ptr = in.info;
  74         uint32 tmp;
  75
  76         tmp = *ptr++;
  77         tmp = (tmp << 8) | *ptr++;
  78         tmp = (tmp << 8) | *ptr++;
  79         tmp = (tmp << 8) | *ptr++;
  80         uu->time_low = tmp;
  81
  82         tmp = *ptr++;
  83         tmp = (tmp << 8) | *ptr++;
  84         uu->time_mid = tmp;
  85
  86         tmp = *ptr++;
  87         tmp = (tmp << 8) | *ptr++;
  88         uu->time_hi_and_version = tmp;
  89
  90         tmp = *ptr++;
  91         tmp = (tmp << 8) | *ptr++;
  92         uu->clock_seq = tmp;
  93
  94         memcpy(uu->node, ptr, 6);
  95 }
  96
  97 void uuid_generate_random(GUID *out)
  98 {
  99         GUID tmp;
 100         struct uuid uu;
 101
 102         generate_random_buffer(tmp.info, sizeof(tmp.info), True);
 103         uuid_unpack(tmp, &uu);
 104
 105         uu.clock_seq = (uu.clock_seq & 0x3FFF) | 0x8000;
 106         uu.time_hi_and_version = (uu.time_hi_and_version & 0x0FFF) | 0x4000;
 107         uuid_pack(&uu, out);
 108 }