Build fix: missing initializer for member 'payload'
[lttng-tools.git] / src / common / uuid.cpp
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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 *
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7 */
8
c9e313bc 9#include <common/compat/string.hpp>
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10#include <stddef.h>
11#include <stdint.h>
12#include <stdio.h>
13#include <stdlib.h>
14#include <string.h>
15#include <time.h>
16
c9e313bc 17#include "uuid.hpp"
c70636a7 18
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19namespace {
20const lttng_uuid nil_uuid = {};
21bool lttng_uuid_is_init;
22} /* namespace */
c70636a7 23
328c2fe7 24void lttng_uuid_to_str(const lttng_uuid& uuid, char *uuid_str)
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25{
26 sprintf(uuid_str, LTTNG_UUID_FMT, LTTNG_UUID_FMT_VALUES(uuid));
27}
28
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29std::string lttng::utils::uuid_to_str(const lttng_uuid& uuid)
30{
31 std::string uuid_str(LTTNG_UUID_STR_LEN, '\0');
32
33 ::lttng_uuid_to_str(uuid, &uuid_str[0]);
34
35 /* Don't include '\0' in the C++ string. */
36 uuid_str.resize(uuid_str.size() - 1);
37
38 return uuid_str;
39}
40
328c2fe7 41int lttng_uuid_from_str(const char *str_in, lttng_uuid& uuid_out)
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42{
43 int ret = 0;
44 lttng_uuid uuid_scan;
45
328c2fe7 46 if (str_in == nullptr) {
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47 ret = -1;
48 goto end;
49 }
50
a1298db6 51 if (lttng_strnlen(str_in, LTTNG_UUID_STR_LEN) != LTTNG_UUID_STR_LEN - 1) {
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52 ret = -1;
53 goto end;
54 }
55
56 /* Scan to a temporary location in case of a partial match. */
57 if (sscanf(str_in, LTTNG_UUID_FMT, LTTNG_UUID_SCAN_VALUES(uuid_scan)) !=
58 LTTNG_UUID_LEN) {
59 ret = -1;
52cb8c0f 60 goto end;
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61 }
62
328c2fe7 63 uuid_out = uuid_scan;
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64end:
65 return ret;
66}
67
328c2fe7 68bool lttng_uuid_is_nil(const lttng_uuid& uuid)
c70636a7 69{
328c2fe7 70 return uuid == nil_uuid;
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71}
72
73/*
74 * Generate a random UUID according to RFC4122, section 4.4.
75 */
328c2fe7 76int lttng_uuid_generate(lttng_uuid& uuid_out)
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77{
78 int i, ret = 0;
79
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80 if (!lttng_uuid_is_init) {
81 /*
82 * We don't need cryptographic quality randomness to
83 * generate UUIDs, seed rand with the epoch.
84 */
85 const time_t epoch = time(NULL);
86
87 if (epoch == (time_t) -1) {
88 ret = -1;
89 goto end;
90 }
c70636a7 91
aeeb48c6 92 srand(epoch);
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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
118end:
119 return ret;
120}
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