Merge commit '86cc97e55fe346502462284d2e636a2b3708163e' as 'Sources/OpenVPN3'

2026-04-24 00:00:05 +08:00 · 2020-02-24 14:43:11 +03:00
parent 133b3756e6 86cc97e55f
commit 32f1555929
655 changed files with 146468 additions and 0 deletions
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+//    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) 2012-2017 OpenVPN Inc.
+//
+//    This program is free software: you can redistribute it and/or modify
+//    it under the terms of the GNU Affero 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 Affero General Public License for more details.
+//
+//    You should have received a copy of the GNU Affero General Public License
+//    along with this program in the COPYING file.
+//    If not, see <http://www.gnu.org/licenses/>.
+
+// Handle ACK tracking for reliability layer
+
+#ifndef OPENVPN_RELIABLE_RELACK_H
+#define OPENVPN_RELIABLE_RELACK_H
+
+#include <deque>
+#include <algorithm>
+#include <limits>
+
+#include <openvpn/common/socktypes.hpp>
+#include <openvpn/buffer/buffer.hpp>
+#include <openvpn/crypto/packet_id.hpp>
+#include <openvpn/reliable/relcommon.hpp>
+
+namespace openvpn {
+
+  class ReliableAck
+  {
+  public:
+    typedef reliable::id_t id_t;
+
+    ReliableAck(const size_t max_ack_list)
+      : max_ack_list_(max_ack_list ? max_ack_list : std::numeric_limits<size_t>::max()) {}
+
+    size_t size() const        { return data.size(); }
+    bool empty() const         { return data.empty(); }
+    void push_back(id_t value) { data.push_back(value); }
+    id_t front() const         { return data.front(); }
+    void pop_front()           { data.pop_front(); }
+
+    // Called to read incoming ACK IDs from buf and mark them as ACKed in rel_send.
+    // If live is false, read the ACK IDs, but don't modify rel_send.
+    // Return the number of ACK IDs read.
+    template <typename REL_SEND>
+    static size_t ack(REL_SEND& rel_send, Buffer& buf, const bool live)
+    {
+      const size_t len = buf.pop_front();
+      for (size_t i = 0; i < len; ++i)
+	{
+	  const id_t id = read_id(buf);
+	  if (live)
+	    rel_send.ack(id);
+	}
+      return len;
+    }
+
+    static size_t ack_skip(Buffer& buf)
+    {
+      const size_t len = buf.pop_front();
+      for (size_t i = 0; i < len; ++i)
+	read_id(buf);
+      return len;
+    }
+
+    // copy ACKs from buffer to self
+    void read(Buffer& buf)
+    {
+      const size_t len = buf.pop_front();
+      for (size_t i = 0; i < len; ++i)
+	{
+	  const id_t id = read_id(buf);
+	  data.push_back(id);
+	}
+    }
+
+    // called to write outgoing ACKs to buf
+    void prepend(Buffer& buf)
+    {
+      const size_t len = std::min(data.size(), max_ack_list_);
+      for (size_t i = len; i > 0; --i)
+	{
+	  prepend_id(buf, data[i-1]);
+	}
+      buf.push_front((unsigned char)len);
+      data.erase (data.begin(), data.begin()+len);
+    }
+
+    static void prepend_id(Buffer& buf, const id_t id)
+    {
+      const id_t net_id = htonl(id);
+      buf.prepend ((unsigned char *)&net_id, sizeof (net_id));
+    }
+
+    static id_t read_id(Buffer& buf)
+    {
+      id_t net_id;
+      buf.read ((unsigned char *)&net_id, sizeof (net_id));
+      return ntohl(net_id);
+    }
+
+  private:
+    size_t max_ack_list_; // Maximum number of ACKs placed in a single message by prepend_acklist()
+    std::deque<id_t> data;
+  };
+
+} // namespace openvpn
+
+#endif // OPENVPN_RELIABLE_RELACK_H