mirror of
https://github.com/OpenVPN/openvpn3.git
synced 2024-09-20 20:13:05 +02:00
98 lines
2.8 KiB
C++
98 lines
2.8 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) 2012-2016 OpenVPN Technologies, 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 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 General Public License for more details.
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//
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// You should have received a copy of the GNU 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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// Receiver side of reliability layer
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#ifndef OPENVPN_RELIABLE_RELRECV_H
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#define OPENVPN_RELIABLE_RELRECV_H
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#include <openvpn/common/size.hpp>
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#include <openvpn/common/exception.hpp>
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#include <openvpn/common/msgwin.hpp>
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#include <openvpn/reliable/relcommon.hpp>
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namespace openvpn {
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template <typename PACKET>
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class ReliableRecvTemplate
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{
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public:
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OPENVPN_SIMPLE_EXCEPTION(rel_next_sequenced_not_ready);
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typedef reliable::id_t id_t;
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class Message : public ReliableMessageBase<PACKET>
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{
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friend class ReliableRecvTemplate;
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};
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ReliableRecvTemplate() {}
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ReliableRecvTemplate(const id_t span) { init(span); }
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void init(const id_t span)
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{
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window_.init(0, span);
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}
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// Call with unsequenced packet off of the wire.
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// Will return receive flags below.
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enum {
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ACK_TO_SENDER = (1<<0), // ACK for this packet should be returned to sender
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IN_WINDOW = (1<<1) // Packet is in-window (otherwise, packet is dropped)
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};
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unsigned int receive(const PACKET& packet, const id_t id)
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{
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if (window_.in_window(id))
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{
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Message& m = window_.ref_by_id(id);
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m.id_ = id;
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m.packet = packet;
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return ACK_TO_SENDER|IN_WINDOW;
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}
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else
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return window_.pre_window(id) ? ACK_TO_SENDER : 0;
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}
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// Return true if next_sequenced() is ready to return next message
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bool ready() const { return window_.head_defined(); }
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// Return next message in sequence.
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// Requires that ready() returns true.
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Message& next_sequenced()
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{
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return window_.ref_head();
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}
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// Call after message returned by receive is ready to
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// be disposed of.
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void advance()
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{
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window_.rm_head_nocheck();
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}
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private:
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MessageWindow<Message, id_t> window_;
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};
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} // namespace openvpn
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#endif // OPENVPN_RELIABLE_RELRECV_H
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