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
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
|
/*
* Implementation of an efficient array to store that we pinged something.
*/
/*
* Copyright © 2016-2017 The TokTok team.
* Copyright © 2014 Tox project.
*
* This file is part of Tox, the free peer to peer instant messenger.
*
* Tox is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Tox is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Tox. If not, see <http://www.gnu.org/licenses/>.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "ping_array.h"
#include "crypto_core.h"
#include "util.h"
typedef struct {
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. */
};
/* Initialize a Ping_Array.
* size represents the total size of the array and should be a power of 2.
* timeout represents the maximum timeout in seconds for the entry.
*
* return 0 on success.
* return -1 on failure.
*/
Ping_Array *ping_array_new(uint32_t size, uint32_t timeout)
{
if (size == 0 || timeout == 0) {
return NULL;
}
Ping_Array *empty_array = (Ping_Array *)calloc(1, sizeof(Ping_Array));
if (empty_array == NULL) {
return NULL;
}
empty_array->entries = (Ping_Array_Entry *)calloc(size, sizeof(Ping_Array_Entry));
if (empty_array->entries == NULL) {
free(empty_array);
return NULL;
}
empty_array->last_deleted = 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)
{
free(array->entries[index].data);
array->entries[index].data = NULL;
array->entries[index].length =
array->entries[index].time =
array->entries[index].ping_id = 0;
}
/* Free all the allocated memory in a Ping_Array.
*/
void ping_array_kill(Ping_Array *array)
{
while (array->last_deleted != array->last_added) {
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)
{
while (array->last_deleted != array->last_added) {
uint32_t index = array->last_deleted % array->total_size;
if (!is_timeout(array->entries[index].time, array->timeout)) {
break;
}
clear_entry(array, index);
++array->last_deleted;
}
}
/* Add a data with length to the Ping_Array list and return a ping_id.
*
* return ping_id on success.
* return 0 on failure.
*/
uint64_t ping_array_add(Ping_Array *array, const uint8_t *data, uint32_t length)
{
ping_array_clear_timedout(array);
uint32_t index = array->last_added % array->total_size;
if (array->entries[index].data != NULL) {
array->last_deleted = array->last_added - array->total_size;
clear_entry(array, index);
}
array->entries[index].data = malloc(length);
if (array->entries[index].data == NULL) {
return 0;
}
memcpy(array->entries[index].data, data, length);
array->entries[index].length = length;
array->entries[index].time = unix_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;
}
/* Check if ping_id is valid and not timed out.
*
* On success, copies the data into data of length,
*
* return length of data copied on success.
* return -1 on failure.
*/
int32_t ping_array_check(Ping_Array *array, uint8_t *data, size_t length, uint64_t ping_id)
{
if (ping_id == 0) {
return -1;
}
uint32_t index = ping_id % array->total_size;
if (array->entries[index].ping_id != ping_id) {
return -1;
}
if (is_timeout(array->entries[index].time, array->timeout)) {
return -1;
}
if (array->entries[index].length > length) {
return -1;
}
if (array->entries[index].data == NULL) {
return -1;
}
memcpy(data, array->entries[index].data, array->entries[index].length);
uint32_t len = array->entries[index].length;
clear_entry(array, index);
return len;
}
|