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
|
/*
* OpenVPN -- An application to securely tunnel IP networks
* over a single UDP port, with support for SSL/TLS-based
* session authentication and key exchange,
* packet encryption, packet authentication, and
* packet compression.
*
* Copyright (C) 2002-2021 OpenVPN Inc <sales@openvpn.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* This program 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 this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#elif defined(_MSC_VER)
#include "config-msvc.h"
#endif
#include "syshead.h"
#if defined(USE_COMP)
#include "comp.h"
#include "error.h"
#include "otime.h"
#include "memdbg.h"
static void
stub_compress_init(struct compress_context *compctx)
{
}
static void
stub_compress_uninit(struct compress_context *compctx)
{
}
static void
stub_compress(struct buffer *buf, struct buffer work,
struct compress_context *compctx,
const struct frame *frame)
{
if (buf->len <= 0)
{
return;
}
if (compctx->flags & COMP_F_SWAP)
{
uint8_t *head = BPTR(buf);
uint8_t *tail = BEND(buf);
ASSERT(buf_safe(buf, 1));
++buf->len;
/* move head byte of payload to tail */
*tail = *head;
*head = NO_COMPRESS_BYTE_SWAP;
}
else
{
uint8_t *header = buf_prepend(buf, 1);
*header = NO_COMPRESS_BYTE;
}
}
static void
stub_decompress(struct buffer *buf, struct buffer work,
struct compress_context *compctx,
const struct frame *frame)
{
uint8_t c;
if (buf->len <= 0)
{
return;
}
if (compctx->flags & COMP_F_SWAP)
{
uint8_t *head = BPTR(buf);
c = *head;
--buf->len;
*head = *BEND(buf);
if (c != NO_COMPRESS_BYTE_SWAP)
{
dmsg(D_COMP_ERRORS, "Bad compression stub (swap) decompression header byte: %d", c);
buf->len = 0;
}
}
else
{
c = *BPTR(buf);
ASSERT(buf_advance(buf, 1));
if (c != NO_COMPRESS_BYTE)
{
dmsg(D_COMP_ERRORS, "Bad compression stub decompression header byte: %d", c);
buf->len = 0;
}
}
}
static void
stubv2_compress(struct buffer *buf, struct buffer work,
struct compress_context *compctx,
const struct frame *frame)
{
if (buf->len <= 0)
{
return;
}
compv2_escape_data_ifneeded(buf);
}
static void
stubv2_decompress(struct buffer *buf, struct buffer work,
struct compress_context *compctx,
const struct frame *frame)
{
if (buf->len <= 0)
{
return;
}
uint8_t *head = BPTR(buf);
/* no compression or packet to short*/
if (head[0] != COMP_ALGV2_INDICATOR_BYTE)
{
return;
}
/* compression header (0x50) is present */
buf_advance(buf, 1);
/* Packet buffer too short (only 1 byte) */
if (buf->len <= 0)
{
return;
}
head = BPTR(buf);
buf_advance(buf, 1);
if (head[0] != COMP_ALGV2_UNCOMPRESSED_BYTE)
{
dmsg(D_COMP_ERRORS, "Bad compression stubv2 decompression header byte: %d", *head);
buf->len = 0;
return;
}
}
const struct compress_alg compv2_stub_alg = {
"stubv2",
stub_compress_init,
stub_compress_uninit,
stubv2_compress,
stubv2_decompress
};
const struct compress_alg comp_stub_alg = {
"stub",
stub_compress_init,
stub_compress_uninit,
stub_compress,
stub_decompress
};
#else /* if defined(USE_COMP) */
static void
dummy(void)
{
}
#endif /* USE_STUB */
|
