mirror of
https://github.com/OpenVPN/openvpn3.git
synced 2024-09-20 12:12:15 +02:00
04b2a3c9b7
Signed-off-by: Samuli Seppänen <samuli@openvpn.net>
137 lines
3.5 KiB
C++
137 lines
3.5 KiB
C++
// 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) 2012-2016 OpenVPN Technologies, Inc.
|
|
//
|
|
// This program is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU General Public License Version 3
|
|
// 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 in the COPYING file.
|
|
// If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
#ifndef OPENVPN_COMPRESS_SNAPPY_H
|
|
#define OPENVPN_COMPRESS_SNAPPY_H
|
|
|
|
// Implement Snappy compression.
|
|
// Should only be included by compress.hpp
|
|
|
|
#include <snappy.h>
|
|
|
|
namespace openvpn {
|
|
|
|
class CompressSnappy : public Compress
|
|
{
|
|
// magic number for Snappy compression
|
|
enum {
|
|
SNAPPY_COMPRESS = 0x68,
|
|
};
|
|
|
|
public:
|
|
CompressSnappy(const Frame::Ptr& frame, const SessionStats::Ptr& stats, const bool asym_arg)
|
|
: Compress(frame, stats),
|
|
asym(asym_arg)
|
|
{
|
|
OPENVPN_LOG_COMPRESS("SNAPPY init asym=" << asym_arg);
|
|
}
|
|
|
|
virtual const char *name() const { return "snappy"; }
|
|
|
|
virtual void compress(BufferAllocated& buf, const bool hint)
|
|
{
|
|
// skip null packets
|
|
if (!buf.size())
|
|
return;
|
|
|
|
if (hint && !asym)
|
|
{
|
|
// initialize work buffer
|
|
frame->prepare(Frame::COMPRESS_WORK, work);
|
|
|
|
// verify that input data length is not too large
|
|
if (snappy::MaxCompressedLength(buf.size()) > work.max_size())
|
|
{
|
|
error(buf);
|
|
return;
|
|
}
|
|
|
|
// do compress
|
|
size_t comp_size;
|
|
snappy::RawCompress((const char *)buf.c_data(), buf.size(), (char *)work.data(), &comp_size);
|
|
|
|
// did compression actually reduce data length?
|
|
if (comp_size < buf.size())
|
|
{
|
|
OPENVPN_LOG_COMPRESS_VERBOSE("SNAPPY compress " << buf.size() << " -> " << comp_size);
|
|
work.set_size(comp_size);
|
|
do_swap(work, SNAPPY_COMPRESS);
|
|
buf.swap(work);
|
|
return;
|
|
}
|
|
}
|
|
|
|
// indicate that we didn't compress
|
|
do_swap(buf, NO_COMPRESS_SWAP);
|
|
}
|
|
|
|
virtual void decompress(BufferAllocated& buf)
|
|
{
|
|
// skip null packets
|
|
if (!buf.size())
|
|
return;
|
|
|
|
const unsigned char c = buf.pop_front();
|
|
switch (c)
|
|
{
|
|
case NO_COMPRESS_SWAP:
|
|
do_unswap(buf);
|
|
break;
|
|
case SNAPPY_COMPRESS:
|
|
{
|
|
do_unswap(buf);
|
|
|
|
// initialize work buffer
|
|
const size_t payload_size = frame->prepare(Frame::DECOMPRESS_WORK, work);
|
|
|
|
// do uncompress
|
|
size_t decomp_size;
|
|
if (!snappy::GetUncompressedLength((const char *)buf.c_data(), buf.size(), &decomp_size)
|
|
|| decomp_size > payload_size)
|
|
{
|
|
error(buf);
|
|
break;
|
|
}
|
|
if (!snappy::RawUncompress((const char *)buf.c_data(), buf.size(), (char *)work.data()))
|
|
{
|
|
error(buf);
|
|
break;
|
|
}
|
|
OPENVPN_LOG_COMPRESS_VERBOSE("SNAPPY uncompress " << buf.size() << " -> " << decomp_size);
|
|
work.set_size(decomp_size);
|
|
buf.swap(work);
|
|
}
|
|
break;
|
|
default:
|
|
error(buf); // unknown op
|
|
break;
|
|
}
|
|
}
|
|
|
|
private:
|
|
const bool asym;
|
|
BufferAllocated work;
|
|
};
|
|
|
|
} // namespace openvpn
|
|
|
|
#endif // OPENVPN_COMPRESS_SNAPPY_H
|