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https://github.com/OpenVPN/openvpn3.git
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dde1574596
This is the result after running 'clang-format -i' on all C++ files and headers, with the defined formatting rules in .clang-format. Only the openvpn/common/unicode-impl.hpp has been excluded, as that is mostly a copy of an external project. Signed-off-by: David Sommerseth <davids@openvpn.net>
93 lines
2.4 KiB
C++
93 lines
2.4 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) 2012-2022 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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#pragma once
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#include <openvpn/common/endian.hpp>
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#include <openvpn/ip/ipcommon.hpp>
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namespace openvpn {
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#pragma pack(push)
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#pragma pack(1)
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struct TCPHeader
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{
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static unsigned int length(const std::uint8_t doff_res)
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{
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return ((doff_res)&0xF0) >> 2;
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}
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std::uint16_t source;
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std::uint16_t dest;
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std::uint32_t seq;
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std::uint32_t ack_seq;
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std::uint8_t doff_res;
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std::uint8_t flags;
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std::uint16_t window;
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std::uint16_t check;
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std::uint16_t urgent_p;
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// helper enum to parse options in TCP header
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enum
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{
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OPT_EOL = 0,
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OPT_NOP = 1,
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OPT_MAXSEG = 2,
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OPTLEN_MAXSEG = 4
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};
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enum
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{
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FLAG_SYN = 1 << 1
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};
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};
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#pragma pack(pop)
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/*
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* The following routine is used to update an
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* internet checksum. "acc" is a 32-bit
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* accumulation of all the changes to the
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* checksum (adding in old 16-bit words and
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* subtracting out new words), and "cksum"
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* is the checksum value to be updated.
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*/
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inline void tcp_adjust_checksum(int acc, std::uint16_t &cksum)
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{
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int _acc = acc;
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_acc += cksum;
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if (_acc < 0)
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{
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_acc = -_acc;
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_acc = (_acc >> 16) + (_acc & 0xffff);
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_acc += _acc >> 16;
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cksum = (uint16_t)~_acc;
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}
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else
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{
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_acc = (_acc >> 16) + (_acc & 0xffff);
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_acc += _acc >> 16;
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cksum = (uint16_t)_acc;
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}
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}
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} // namespace openvpn
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