include/linux/uuid.h

   1 /*
   2  * UUID/GUID definition
   3  *
   4  * Copyright (C) 2010, 2016 Intel Corp.
   5  *      Huang Ying <ying.huang@intel.com>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License version
   9  * 2 as published by the Free Software Foundation;
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  */
  16 #ifndef _LINUX_UUID_H_
  17 #define _LINUX_UUID_H_
  18
  19 #include <uapi/linux/uuid.h>
  20
  21 /*
  22  * V1 (time-based) UUID definition [RFC 4122].
  23  * - the timestamp is a 60-bit value, split 32/16/12, and goes in 100ns
  24  *   increments since midnight 15th October 1582
  25  *   - add AFS_UUID_TO_UNIX_TIME to convert unix time in 100ns units to UUID
  26  *     time
  27  * - the clock sequence is a 14-bit counter to avoid duplicate times
  28  */
  29 struct uuid_v1 {
  30         __be32          time_low;                       /* low part of timestamp */
  31         __be16          time_mid;                       /* mid part of timestamp */
  32         __be16          time_hi_and_version;            /* high part of timestamp and version  */
  33 #define UUID_TO_UNIX_TIME       0x01b21dd213814000ULL
  34 #define UUID_TIMEHI_MASK        0x0fff
  35 #define UUID_VERSION_TIME       0x1000  /* time-based UUID */
  36 #define UUID_VERSION_NAME       0x3000  /* name-based UUID */
  37 #define UUID_VERSION_RANDOM     0x4000  /* (pseudo-)random generated UUID */
  38         u8              clock_seq_hi_and_reserved;      /* clock seq hi and variant */
  39 #define UUID_CLOCKHI_MASK       0x3f
  40 #define UUID_VARIANT_STD        0x80
  41         u8              clock_seq_low;                  /* clock seq low */
  42         u8              node[6];                        /* spatially unique node ID (MAC addr) */
  43 };
  44
  45 /*
  46  * The length of a UUID string ("aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee")
  47  * not including trailing NUL.
  48  */
  49 #define UUID_STRING_LEN         36
  50
  51 static inline int uuid_le_cmp(const uuid_le u1, const uuid_le u2)
  52 {
  53         return memcmp(&u1, &u2, sizeof(uuid_le));
  54 }
  55
  56 static inline int uuid_be_cmp(const uuid_be u1, const uuid_be u2)
  57 {
  58         return memcmp(&u1, &u2, sizeof(uuid_be));
  59 }
  60
  61 void generate_random_uuid(unsigned char uuid[16]);
  62
  63 extern void uuid_le_gen(uuid_le *u);
  64 extern void uuid_be_gen(uuid_be *u);
  65
  66 bool __must_check uuid_is_valid(const char *uuid);
  67
  68 extern const u8 uuid_le_index[16];
  69 extern const u8 uuid_be_index[16];
  70
  71 int uuid_le_to_bin(const char *uuid, uuid_le *u);
  72 int uuid_be_to_bin(const char *uuid, uuid_be *u);
  73
  74 #endif