| 1 | /* |
| 2 | * SPDX-License-Identifier: MIT |
| 3 | * |
| 4 | * Copyright (C) 2019 Michael Jeanson <mjeanson@efficios.com> |
| 5 | */ |
| 6 | |
| 7 | #include <glib.h> |
| 8 | #include <stdio.h> |
| 9 | #include <string.h> |
| 10 | #include <inttypes.h> |
| 11 | |
| 12 | #include "common/assert.h" |
| 13 | #include "common/uuid.h" |
| 14 | |
| 15 | |
| 16 | /* |
| 17 | * Generate a random UUID according to RFC4122, section 4.4. |
| 18 | */ |
| 19 | void bt_uuid_generate(bt_uuid_t uuid_out) |
| 20 | { |
| 21 | int i; |
| 22 | GRand *rand; |
| 23 | |
| 24 | BT_ASSERT(uuid_out); |
| 25 | |
| 26 | rand = g_rand_new(); |
| 27 | |
| 28 | /* |
| 29 | * Generate 16 bytes of random bits. |
| 30 | */ |
| 31 | for (i = 0; i < BT_UUID_LEN; i++) { |
| 32 | uuid_out[i] = (uint8_t) g_rand_int(rand); |
| 33 | } |
| 34 | |
| 35 | /* |
| 36 | * Set the two most significant bits (bits 6 and 7) of the |
| 37 | * clock_seq_hi_and_reserved to zero and one, respectively. |
| 38 | */ |
| 39 | uuid_out[8] &= ~(1 << 6); |
| 40 | uuid_out[8] |= (1 << 7); |
| 41 | |
| 42 | /* |
| 43 | * Set the four most significant bits (bits 12 through 15) of the |
| 44 | * time_hi_and_version field to the 4-bit version number from |
| 45 | * Section 4.1.3. |
| 46 | */ |
| 47 | uuid_out[6] &= 0x0f; |
| 48 | uuid_out[6] |= (BT_UUID_VER << 4); |
| 49 | |
| 50 | g_rand_free(rand); |
| 51 | } |
| 52 | |
| 53 | void bt_uuid_to_str(const bt_uuid_t uuid_in, char *str_out) |
| 54 | { |
| 55 | BT_ASSERT_DBG(uuid_in); |
| 56 | BT_ASSERT_DBG(str_out); |
| 57 | |
| 58 | snprintf(str_out, BT_UUID_STR_LEN + 1, BT_UUID_FMT, BT_UUID_FMT_VALUES(uuid_in)); |
| 59 | } |
| 60 | |
| 61 | int bt_uuid_from_str(const char *str_in, bt_uuid_t uuid_out) |
| 62 | { |
| 63 | int ret = 0; |
| 64 | bt_uuid_t uuid_scan; |
| 65 | |
| 66 | BT_ASSERT_DBG(uuid_out); |
| 67 | BT_ASSERT_DBG(str_in); |
| 68 | |
| 69 | if (strnlen(str_in, BT_UUID_STR_LEN + 1) != BT_UUID_STR_LEN) { |
| 70 | ret = -1; |
| 71 | goto end; |
| 72 | } |
| 73 | |
| 74 | /* Scan to a temporary location in case of a partial match. */ |
| 75 | if (sscanf(str_in, BT_UUID_FMT, BT_UUID_SCAN_VALUES(uuid_scan)) != BT_UUID_LEN) { |
| 76 | ret = -1; |
| 77 | } |
| 78 | |
| 79 | bt_uuid_copy(uuid_out, uuid_scan); |
| 80 | end: |
| 81 | return ret; |
| 82 | } |
| 83 | |
| 84 | int bt_uuid_compare(const bt_uuid_t uuid_a, const bt_uuid_t uuid_b) |
| 85 | { |
| 86 | return memcmp(uuid_a, uuid_b, BT_UUID_LEN); |
| 87 | } |
| 88 | |
| 89 | void bt_uuid_copy(bt_uuid_t uuid_dest, const bt_uuid_t uuid_src) |
| 90 | { |
| 91 | BT_ASSERT(uuid_dest); |
| 92 | BT_ASSERT(uuid_src); |
| 93 | BT_ASSERT(uuid_dest != uuid_src); |
| 94 | |
| 95 | memcpy(uuid_dest, uuid_src, BT_UUID_LEN); |
| 96 | } |