mirror of
https://github.com/deneraraujo/OpenVPNAdapter.git
synced 2026-01-31 00:00:06 +08:00
120 lines
3.5 KiB
C++
120 lines
3.5 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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// Handle ACK tracking for reliability layer
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#ifndef OPENVPN_RELIABLE_RELACK_H
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#define OPENVPN_RELIABLE_RELACK_H
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#include <deque>
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#include <algorithm>
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#include <limits>
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#include <openvpn/common/socktypes.hpp>
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#include <openvpn/buffer/buffer.hpp>
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#include <openvpn/crypto/packet_id.hpp>
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#include <openvpn/reliable/relcommon.hpp>
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namespace openvpn {
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class ReliableAck
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{
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public:
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typedef reliable::id_t id_t;
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ReliableAck(const size_t max_ack_list)
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: max_ack_list_(max_ack_list ? max_ack_list : std::numeric_limits<size_t>::max()) {}
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size_t size() const { return data.size(); }
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bool empty() const { return data.empty(); }
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void push_back(id_t value) { data.push_back(value); }
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id_t front() const { return data.front(); }
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void pop_front() { data.pop_front(); }
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// Called to read incoming ACK IDs from buf and mark them as ACKed in rel_send.
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// If live is false, read the ACK IDs, but don't modify rel_send.
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// Return the number of ACK IDs read.
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template <typename REL_SEND>
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static size_t ack(REL_SEND& rel_send, Buffer& buf, const bool live)
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{
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const size_t len = buf.pop_front();
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for (size_t i = 0; i < len; ++i)
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{
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const id_t id = read_id(buf);
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if (live)
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rel_send.ack(id);
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}
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return len;
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}
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static size_t ack_skip(Buffer& buf)
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{
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const size_t len = buf.pop_front();
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for (size_t i = 0; i < len; ++i)
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read_id(buf);
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return len;
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}
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// copy ACKs from buffer to self
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void read(Buffer& buf)
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{
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const size_t len = buf.pop_front();
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for (size_t i = 0; i < len; ++i)
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{
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const id_t id = read_id(buf);
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data.push_back(id);
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}
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}
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// called to write outgoing ACKs to buf
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void prepend(Buffer& buf)
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{
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const size_t len = std::min(data.size(), max_ack_list_);
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for (size_t i = len; i > 0; --i)
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{
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prepend_id(buf, data[i-1]);
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}
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buf.push_front((unsigned char)len);
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data.erase (data.begin(), data.begin()+len);
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}
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static void prepend_id(Buffer& buf, const id_t id)
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{
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const id_t net_id = htonl(id);
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buf.prepend ((unsigned char *)&net_id, sizeof (net_id));
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}
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static id_t read_id(Buffer& buf)
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{
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id_t net_id;
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buf.read ((unsigned char *)&net_id, sizeof (net_id));
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return ntohl(net_id);
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}
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private:
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size_t max_ack_list_; // Maximum number of ACKs placed in a single message by prepend_acklist()
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std::deque<id_t> data;
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};
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} // namespace openvpn
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#endif // OPENVPN_RELIABLE_RELACK_H
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