1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
|
/* SPDX-License-Identifier: GPL-3.0-or-later
* Copyright © 2016-2018 The TokTok team.
* Copyright © 2014 Tox project.
*/
/*
* Implementation of an efficient array to store that we pinged something.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "ping_array.h"
#include <stdlib.h>
#include <string.h>
#include "crypto_core.h"
#include "mono_time.h"
#include "util.h"
typedef struct Ping_Array_Entry {
void *data;
uint32_t length;
uint64_t time;
uint64_t ping_id;
} Ping_Array_Entry;
struct Ping_Array {
Ping_Array_Entry *entries;
uint32_t last_deleted; /* number representing the next entry to be deleted. */
uint32_t last_added; /* number representing the last entry to be added. */
uint32_t total_size; /* The length of entries */
uint32_t timeout; /* The timeout after which entries are cleared. */
};
Ping_Array *ping_array_new(uint32_t size, uint32_t timeout)
{
if (size == 0 || timeout == 0) {
return nullptr;
}
if ((size & (size - 1)) != 0) {
// Not a power of 2.
return nullptr;
}
Ping_Array *const empty_array = (Ping_Array *)calloc(1, sizeof(Ping_Array));
if (empty_array == nullptr) {
return nullptr;
}
empty_array->entries = (Ping_Array_Entry *)calloc(size, sizeof(Ping_Array_Entry));
if (empty_array->entries == nullptr) {
free(empty_array);
return nullptr;
}
empty_array->last_deleted = 0;
empty_array->last_added = 0;
empty_array->total_size = size;
empty_array->timeout = timeout;
return empty_array;
}
static void clear_entry(Ping_Array *array, uint32_t index)
{
const Ping_Array_Entry empty = {nullptr};
free(array->entries[index].data);
array->entries[index] = empty;
}
void ping_array_kill(Ping_Array *array)
{
while (array->last_deleted != array->last_added) {
const uint32_t index = array->last_deleted % array->total_size;
clear_entry(array, index);
++array->last_deleted;
}
free(array->entries);
free(array);
}
/* Clear timed out entries.
*/
static void ping_array_clear_timedout(Ping_Array *array, const Mono_Time *mono_time)
{
while (array->last_deleted != array->last_added) {
const uint32_t index = array->last_deleted % array->total_size;
if (!mono_time_is_timeout(mono_time, array->entries[index].time, array->timeout)) {
break;
}
clear_entry(array, index);
++array->last_deleted;
}
}
uint64_t ping_array_add(Ping_Array *array, const Mono_Time *mono_time, const uint8_t *data,
uint32_t length)
{
ping_array_clear_timedout(array, mono_time);
const uint32_t index = array->last_added % array->total_size;
if (array->entries[index].data != nullptr) {
array->last_deleted = array->last_added - array->total_size;
clear_entry(array, index);
}
array->entries[index].data = malloc(length);
if (array->entries[index].data == nullptr) {
return 0;
}
memcpy(array->entries[index].data, data, length);
array->entries[index].length = length;
array->entries[index].time = mono_time_get(mono_time);
++array->last_added;
uint64_t ping_id = random_u64();
ping_id /= array->total_size;
ping_id *= array->total_size;
ping_id += index;
if (ping_id == 0) {
ping_id += array->total_size;
}
array->entries[index].ping_id = ping_id;
return ping_id;
}
int32_t ping_array_check(Ping_Array *array, const Mono_Time *mono_time, uint8_t *data,
size_t length, uint64_t ping_id)
{
if (ping_id == 0) {
return -1;
}
const uint32_t index = ping_id % array->total_size;
if (array->entries[index].ping_id != ping_id) {
return -1;
}
if (mono_time_is_timeout(mono_time, array->entries[index].time, array->timeout)) {
return -1;
}
if (array->entries[index].length > length) {
return -1;
}
// TODO(iphydf): This can't happen? If it indeed can't, turn it into an assert.
if (array->entries[index].data == nullptr) {
return -1;
}
memcpy(data, array->entries[index].data, array->entries[index].length);
const uint32_t len = array->entries[index].length;
clear_entry(array, index);
return len;
}
|
