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
|
// OpenVPN -- An application to securely tunnel IP networks
// over a single port, with support for SSL/TLS-based
// session authentication and key exchange,
// packet encryption, packet authentication, and
// packet compression.
//
// Copyright (C) 2012- OpenVPN Inc.
//
// SPDX-License-Identifier: MPL-2.0 OR AGPL-3.0-only WITH openvpn3-openssl-exception
//
#ifndef OPENVPN_COMPRESS_LZOASYM_H
#define OPENVPN_COMPRESS_LZOASYM_H
#include <openvpn/buffer/buffer.hpp>
#include <openvpn/compress/lzoasym_impl.hpp>
// Implement asymmetrical LZO compression (only uncompress, don't compress)
// Should only be included by lzoselect.hpp
namespace openvpn {
class CompressLZOAsym : public Compress
{
public:
// magic number for LZO compression
enum
{
LZO_COMPRESS = 0x66,
LZO_COMPRESS_SWAP = 0x67,
};
OPENVPN_SIMPLE_EXCEPTION(lzo_init_failed);
CompressLZOAsym(const Frame::Ptr &frame,
const SessionStats::Ptr &stats,
const bool support_swap_arg,
const bool asym_arg) // we are always asymmetrical, regardless of setting
: Compress(frame, stats),
support_swap(support_swap_arg)
{
OVPN_LOG_INFO("LZO-ASYM init swap=" << support_swap_arg << " asym=" << asym_arg);
}
static void init_static()
{
}
const char *name() const override
{
return "lzo-asym";
}
void decompress_work(BufferAllocated &buf)
{
// initialize work buffer
size_t zlen = frame->prepare(Frame::DECOMPRESS_WORK, work);
// do uncompress
const int err = lzo_asym_impl::lzo1x_decompress_safe(buf.c_data(), buf.size(), work.data(), &zlen);
if (err != lzo_asym_impl::LZOASYM_E_OK)
{
error(buf);
return;
}
OVPN_LOG_VERBOSE("LZO-ASYM uncompress " << buf.size() << " -> " << zlen);
work.set_size(zlen);
buf.swap(work);
}
void compress(BufferAllocated &buf, const bool hint) override
{
// skip null packets
if (!buf.size())
return;
// indicate that we didn't compress
if (support_swap)
do_swap(buf, NO_COMPRESS_SWAP);
else
buf.push_front(NO_COMPRESS);
}
void decompress(BufferAllocated &buf) override
{
// skip null packets
if (!buf.size())
return;
const unsigned char c = buf.pop_front();
switch (c)
{
case NO_COMPRESS_SWAP:
do_unswap(buf);
[[fallthrough]];
case NO_COMPRESS:
break;
case LZO_COMPRESS_SWAP:
do_unswap(buf);
[[fallthrough]];
case LZO_COMPRESS:
decompress_work(buf);
break;
default:
error(buf); // unknown op
}
}
private:
const bool support_swap;
BufferAllocated work;
};
} // namespace openvpn
#endif // OPENVPN_COMPRESS_LZOASYM_H
|
