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c70636a7 MJ |
1 | /* |
2 | * Copyright (C) 2018 Jérémie Galarneau <jeremie.galarneau@efficios.com> | |
3 | * Copyright (C) 2019 Michael Jeanson <mjeanson@efficios.com> | |
4 | * | |
ab5be9fa | 5 | * SPDX-License-Identifier: LGPL-2.1-only |
c70636a7 | 6 | * |
c70636a7 MJ |
7 | */ |
8 | ||
28ab034a JG |
9 | #include "uuid.hpp" |
10 | ||
c9e313bc | 11 | #include <common/compat/string.hpp> |
57b90af7 JG |
12 | #include <common/error.hpp> |
13 | #include <common/format.hpp> | |
14 | #include <common/random.hpp> | |
15 | ||
c70636a7 MJ |
16 | #include <stddef.h> |
17 | #include <stdint.h> | |
18 | #include <stdio.h> | |
19 | #include <stdlib.h> | |
20 | #include <string.h> | |
21 | #include <time.h> | |
22 | ||
328c2fe7 JG |
23 | namespace { |
24 | const lttng_uuid nil_uuid = {}; | |
25 | bool lttng_uuid_is_init; | |
26 | } /* namespace */ | |
c70636a7 | 27 | |
328c2fe7 | 28 | void lttng_uuid_to_str(const lttng_uuid& uuid, char *uuid_str) |
c70636a7 MJ |
29 | { |
30 | sprintf(uuid_str, LTTNG_UUID_FMT, LTTNG_UUID_FMT_VALUES(uuid)); | |
31 | } | |
32 | ||
23083fa0 JG |
33 | std::string lttng::utils::uuid_to_str(const lttng_uuid& uuid) |
34 | { | |
35 | std::string uuid_str(LTTNG_UUID_STR_LEN, '\0'); | |
36 | ||
37 | ::lttng_uuid_to_str(uuid, &uuid_str[0]); | |
38 | ||
39 | /* Don't include '\0' in the C++ string. */ | |
40 | uuid_str.resize(uuid_str.size() - 1); | |
41 | ||
42 | return uuid_str; | |
43 | } | |
44 | ||
328c2fe7 | 45 | int lttng_uuid_from_str(const char *str_in, lttng_uuid& uuid_out) |
c70636a7 MJ |
46 | { |
47 | int ret = 0; | |
00c2aa6f | 48 | lttng_uuid uuid_scan = {}; |
c70636a7 | 49 | |
328c2fe7 | 50 | if (str_in == nullptr) { |
c70636a7 MJ |
51 | ret = -1; |
52 | goto end; | |
53 | } | |
54 | ||
a1298db6 | 55 | if (lttng_strnlen(str_in, LTTNG_UUID_STR_LEN) != LTTNG_UUID_STR_LEN - 1) { |
c70636a7 MJ |
56 | ret = -1; |
57 | goto end; | |
58 | } | |
59 | ||
60 | /* Scan to a temporary location in case of a partial match. */ | |
28ab034a | 61 | if (sscanf(str_in, LTTNG_UUID_FMT, LTTNG_UUID_SCAN_VALUES(uuid_scan)) != LTTNG_UUID_LEN) { |
c70636a7 | 62 | ret = -1; |
52cb8c0f | 63 | goto end; |
c70636a7 MJ |
64 | } |
65 | ||
328c2fe7 | 66 | uuid_out = uuid_scan; |
c70636a7 MJ |
67 | end: |
68 | return ret; | |
69 | } | |
70 | ||
328c2fe7 | 71 | bool lttng_uuid_is_nil(const lttng_uuid& uuid) |
c70636a7 | 72 | { |
328c2fe7 | 73 | return uuid == nil_uuid; |
c70636a7 MJ |
74 | } |
75 | ||
76 | /* | |
77 | * Generate a random UUID according to RFC4122, section 4.4. | |
78 | */ | |
328c2fe7 | 79 | int lttng_uuid_generate(lttng_uuid& uuid_out) |
c70636a7 MJ |
80 | { |
81 | int i, ret = 0; | |
82 | ||
c70636a7 | 83 | if (!lttng_uuid_is_init) { |
57b90af7 JG |
84 | try { |
85 | srand(lttng::random::produce_best_effort_random_seed()); | |
5b9eda8a | 86 | } catch (const std::exception& e) { |
88277a52 | 87 | ERR("Failed to initialize random seed during generation of UUID: %s", |
28ab034a | 88 | e.what()); |
c70636a7 MJ |
89 | ret = -1; |
90 | goto end; | |
91 | } | |
c70636a7 MJ |
92 | |
93 | lttng_uuid_is_init = true; | |
94 | } | |
95 | ||
96 | /* | |
97 | * Generate 16 bytes of random bits. | |
98 | */ | |
99 | for (i = 0; i < LTTNG_UUID_LEN; i++) { | |
100 | uuid_out[i] = (uint8_t) rand(); | |
101 | } | |
102 | ||
103 | /* | |
104 | * Set the two most significant bits (bits 6 and 7) of the | |
105 | * clock_seq_hi_and_reserved to zero and one, respectively. | |
106 | */ | |
107 | uuid_out[8] &= ~(1 << 6); | |
108 | uuid_out[8] |= (1 << 7); | |
109 | ||
110 | /* | |
111 | * Set the four most significant bits (bits 12 through 15) of the | |
112 | * time_hi_and_version field to the 4-bit version number from | |
113 | * Section 4.1.3. | |
114 | */ | |
115 | uuid_out[6] &= 0x0f; | |
116 | uuid_out[6] |= (LTTNG_UUID_VER << 4); | |
117 | ||
118 | end: | |
119 | return ret; | |
120 | } |