mirror of
https://github.com/deneraraujo/OpenVPNAdapter.git
synced 2026-02-11 00:00:08 +08:00
120 lines
3.2 KiB
C++
120 lines
3.2 KiB
C++
// OpenVPN -- An application to securely tunnel IP networks
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// over a single port, with support for SSL/TLS-based
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// session authentication and key exchange,
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// packet encryption, packet authentication, and
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// packet compression.
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//
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// Copyright (C) 2012-2017 OpenVPN Inc.
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//
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// This program is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Affero General Public License Version 3
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// as published by the Free Software Foundation.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Affero General Public License for more details.
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//
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// You should have received a copy of the GNU Affero General Public License
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// along with this program in the COPYING file.
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// If not, see <http://www.gnu.org/licenses/>.
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#ifndef OPENVPN_COMPRESS_LZOASYM_H
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#define OPENVPN_COMPRESS_LZOASYM_H
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#include <openvpn/compress/lzoasym_impl.hpp>
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// Implement asymmetrical LZO compression (only uncompress, don't compress)
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// Should only be included by lzoselect.hpp
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namespace openvpn {
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class CompressLZOAsym : public Compress
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{
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public:
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// magic number for LZO compression
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enum {
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LZO_COMPRESS = 0x66,
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LZO_COMPRESS_SWAP = 0x67,
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};
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OPENVPN_SIMPLE_EXCEPTION(lzo_init_failed);
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CompressLZOAsym(const Frame::Ptr& frame,
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const SessionStats::Ptr& stats,
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const bool support_swap_arg,
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const bool asym_arg) // we are always asymmetrical, regardless of setting
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: Compress(frame, stats),
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support_swap(support_swap_arg)
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{
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OPENVPN_LOG_COMPRESS("LZO-ASYM init swap=" << support_swap_arg << " asym=" << asym_arg);
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}
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static void init_static()
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{
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}
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virtual const char *name() const { return "lzo-asym"; }
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void decompress_work(BufferAllocated& buf)
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{
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// initialize work buffer
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size_t zlen = frame->prepare(Frame::DECOMPRESS_WORK, work);
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// do uncompress
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const int err = lzo_asym_impl::lzo1x_decompress_safe(buf.c_data(), buf.size(), work.data(), &zlen);
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if (err != lzo_asym_impl::LZOASYM_E_OK)
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{
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error(buf);
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return;
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}
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OPENVPN_LOG_COMPRESS_VERBOSE("LZO-ASYM uncompress " << buf.size() << " -> " << zlen);
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work.set_size(zlen);
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buf.swap(work);
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}
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virtual void compress(BufferAllocated& buf, const bool hint)
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{
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// skip null packets
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if (!buf.size())
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return;
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// indicate that we didn't compress
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if (support_swap)
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do_swap(buf, NO_COMPRESS_SWAP);
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else
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buf.push_front(NO_COMPRESS);
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}
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virtual void decompress(BufferAllocated& buf)
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{
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// skip null packets
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if (!buf.size())
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return;
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const unsigned char c = buf.pop_front();
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switch (c)
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{
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case NO_COMPRESS_SWAP:
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do_unswap(buf);
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case NO_COMPRESS:
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break;
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case LZO_COMPRESS_SWAP:
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do_unswap(buf);
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case LZO_COMPRESS:
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decompress_work(buf);
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break;
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default:
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error(buf); // unknown op
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}
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}
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private:
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const bool support_swap;
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BufferAllocated work;
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};
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} // namespace openvpn
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#endif // OPENVPN_COMPRESS_LZOASYM_H
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