src/common/uuid.c

   1 /*
   2  * Copyright (C) 2019 Michael Jeanson <mjeanson@efficios.com>
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a copy
   5  * of this software and associated documentation files (the "Software"), to deal
   6  * in the Software without restriction, including without limitation the rights
   7  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   8  * copies of the Software, and to permit persons to whom the Software is
   9  * furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included in
  12  * all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  17  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  19  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  20  * SOFTWARE.
  21  */
  22
  23 #include <glib.h>
  24 #include <stdio.h>
  25 #include <string.h>
  26 #include <inttypes.h>
  27
  28 #include "common/assert.h"
  29 #include "common/uuid.h"
  30
  31
  32 /*
  33  * Generate a random UUID according to RFC4122, section 4.4.
  34  */
  35 BT_HIDDEN
  36 void bt_uuid_generate(bt_uuid_t uuid_out)
  37 {
  38         int i;
  39         GRand *rand;
  40
  41         BT_ASSERT(uuid_out);
  42
  43         rand = g_rand_new();
  44
  45         /*
  46          * Generate 16 bytes of random bits.
  47          */
  48         for (i = 0; i < BT_UUID_LEN; i++) {
  49                 uuid_out[i] = (uint8_t) g_rand_int(rand);
  50         }
  51
  52         /*
  53          * Set the two most significant bits (bits 6 and 7) of the
  54          * clock_seq_hi_and_reserved to zero and one, respectively.
  55          */
  56         uuid_out[8] &= ~(1 << 6);
  57         uuid_out[8] |= (1 << 7);
  58
  59         /*
  60          * Set the four most significant bits (bits 12 through 15) of the
  61          * time_hi_and_version field to the 4-bit version number from
  62          * Section 4.1.3.
  63          */
  64         uuid_out[6] &= 0x0f;
  65         uuid_out[6] |= (BT_UUID_VER << 4);
  66
  67         g_rand_free(rand);
  68 }
  69
  70 BT_HIDDEN
  71 void bt_uuid_to_str(const bt_uuid_t uuid_in, char *str_out)
  72 {
  73         BT_ASSERT(uuid_in);
  74         BT_ASSERT(str_out);
  75
  76         sprintf(str_out, BT_UUID_FMT, BT_UUID_FMT_VALUES(uuid_in));
  77 }
  78
  79 BT_HIDDEN
  80 int bt_uuid_from_str(const char *str_in, bt_uuid_t uuid_out)
  81 {
  82         int ret = 0;
  83         bt_uuid_t uuid_scan;
  84
  85         BT_ASSERT(uuid_out);
  86         BT_ASSERT(str_in);
  87
  88         if (strnlen(str_in, BT_UUID_STR_LEN + 1) != BT_UUID_STR_LEN) {
  89                 ret = -1;
  90                 goto end;
  91         }
  92
  93         /* Scan to a temporary location in case of a partial match. */
  94         if (sscanf(str_in, BT_UUID_FMT, BT_UUID_SCAN_VALUES(uuid_scan)) != BT_UUID_LEN) {
  95                 ret = -1;
  96         }
  97
  98         bt_uuid_copy(uuid_out, uuid_scan);
  99 end:
 100         return ret;
 101 }
 102
 103 BT_HIDDEN
 104 int bt_uuid_compare(const bt_uuid_t uuid_a, const bt_uuid_t uuid_b)
 105 {
 106         return memcmp(uuid_a, uuid_b, BT_UUID_LEN);
 107 }
 108
 109 BT_HIDDEN
 110 void bt_uuid_copy(bt_uuid_t uuid_dest, const bt_uuid_t uuid_src)
 111 {
 112         BT_ASSERT(uuid_dest);
 113         BT_ASSERT(uuid_src);
 114         BT_ASSERT(uuid_dest != uuid_src);
 115
 116         memcpy(uuid_dest, uuid_src, BT_UUID_LEN);
 117 }