Repo created

TMessagesProj/jni/voip/webrtc/rtc_base/nat_server.h

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+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef RTC_BASE_NAT_SERVER_H_
+#define RTC_BASE_NAT_SERVER_H_
+
+#include <map>
+#include <set>
+
+#include "rtc_base/async_udp_socket.h"
+#include "rtc_base/nat_types.h"
+#include "rtc_base/proxy_server.h"
+#include "rtc_base/socket_address_pair.h"
+#include "rtc_base/socket_factory.h"
+#include "rtc_base/synchronization/mutex.h"
+#include "rtc_base/thread.h"
+
+namespace rtc {
+
+// Change how routes (socketaddress pairs) are compared based on the type of
+// NAT.  The NAT server maintains a hashtable of the routes that it knows
+// about.  So these affect which routes are treated the same.
+struct RouteCmp {
+  explicit RouteCmp(NAT* nat);
+  size_t operator()(const SocketAddressPair& r) const;
+  bool operator()(const SocketAddressPair& r1,
+                  const SocketAddressPair& r2) const;
+
+  bool symmetric;
+};
+
+// Changes how addresses are compared based on the filtering rules of the NAT.
+struct AddrCmp {
+  explicit AddrCmp(NAT* nat);
+  size_t operator()(const SocketAddress& r) const;
+  bool operator()(const SocketAddress& r1, const SocketAddress& r2) const;
+
+  bool use_ip;
+  bool use_port;
+};
+
+// Implements the NAT device.  It listens for packets on the internal network,
+// translates them, and sends them out over the external network.
+//
+// TCP connections initiated from the internal side of the NAT server are
+// also supported, by making a connection to the NAT server's TCP address and
+// then sending the remote address in quasi-STUN format. The connection status
+// will be indicated back to the client as a 1 byte status code, where '0'
+// indicates success.
+
+const int NAT_SERVER_UDP_PORT = 4237;
+const int NAT_SERVER_TCP_PORT = 4238;
+
+class NATServer {
+ public:
+  NATServer(NATType type,
+            rtc::Thread& internal_socket_thread,
+            SocketFactory* internal,
+            const SocketAddress& internal_udp_addr,
+            const SocketAddress& internal_tcp_addr,
+            rtc::Thread& external_socket_thread,
+            SocketFactory* external,
+            const SocketAddress& external_ip);
+  ~NATServer();
+
+  NATServer(const NATServer&) = delete;
+  NATServer& operator=(const NATServer&) = delete;
+
+  SocketAddress internal_udp_address() const {
+    return udp_server_socket_->GetLocalAddress();
+  }
+
+  SocketAddress internal_tcp_address() const {
+    return tcp_proxy_server_->GetServerAddress();
+  }
+
+  // Packets received on one of the networks.
+  void OnInternalUDPPacket(AsyncPacketSocket* socket,
+                           const rtc::ReceivedPacket& packet);
+  void OnExternalUDPPacket(AsyncPacketSocket* socket,
+                           const rtc::ReceivedPacket& packet);
+
+ private:
+  typedef std::set<SocketAddress, AddrCmp> AddressSet;
+
+  /* Records a translation and the associated external socket. */
+  struct TransEntry {
+    TransEntry(const SocketAddressPair& r, AsyncUDPSocket* s, NAT* nat);
+    ~TransEntry();
+
+    void AllowlistInsert(const SocketAddress& addr);
+    bool AllowlistContains(const SocketAddress& ext_addr);
+
+    SocketAddressPair route;
+    AsyncUDPSocket* socket;
+    AddressSet* allowlist;
+    webrtc::Mutex mutex_;
+  };
+
+  typedef std::map<SocketAddressPair, TransEntry*, RouteCmp> InternalMap;
+  typedef std::map<SocketAddress, TransEntry*> ExternalMap;
+
+  /* Creates a new entry that translates the given route. */
+  void Translate(const SocketAddressPair& route);
+
+  /* Determines whether the NAT would filter out a packet from this address. */
+  bool ShouldFilterOut(TransEntry* entry, const SocketAddress& ext_addr);
+
+  NAT* nat_;
+  rtc::Thread& internal_socket_thread_;
+  rtc::Thread& external_socket_thread_;
+  SocketFactory* external_;
+  SocketAddress external_ip_;
+  AsyncUDPSocket* udp_server_socket_;
+  ProxyServer* tcp_proxy_server_;
+  InternalMap* int_map_;
+  ExternalMap* ext_map_;
+};
+
+}  // namespace rtc
+
+#endif  // RTC_BASE_NAT_SERVER_H_