1 files changed, 179 insertions, 0 deletions
diff --git a/third_party/libwebrtc/rtc_base/nat_socket_factory.h b/third_party/libwebrtc/rtc_base/nat_socket_factory.h
new file mode 100644
index 0000000000..0b301b5844
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+++ b/third_party/libwebrtc/rtc_base/nat_socket_factory.h
@@ -0,0 +1,179 @@
+/*
+ *  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_SOCKET_FACTORY_H_
+#define RTC_BASE_NAT_SOCKET_FACTORY_H_
+
+#include <stddef.h>
+
+#include <map>
+#include <memory>
+#include <set>
+
+#include "rtc_base/nat_server.h"
+#include "rtc_base/nat_types.h"
+#include "rtc_base/socket.h"
+#include "rtc_base/socket_address.h"
+#include "rtc_base/socket_factory.h"
+#include "rtc_base/socket_server.h"
+#include "rtc_base/thread.h"
+
+namespace rtc {
+
+const size_t kNATEncodedIPv4AddressSize = 8U;
+const size_t kNATEncodedIPv6AddressSize = 20U;
+
+// Used by the NAT socket implementation.
+class NATInternalSocketFactory {
+ public:
+  virtual ~NATInternalSocketFactory() {}
+  virtual Socket* CreateInternalSocket(int family,
+                                       int type,
+                                       const SocketAddress& local_addr,
+                                       SocketAddress* nat_addr) = 0;
+};
+
+// Creates sockets that will send all traffic through a NAT, using an existing
+// NATServer instance running at nat_addr. The actual data is sent using sockets
+// from a socket factory, given to the constructor.
+class NATSocketFactory : public SocketFactory, public NATInternalSocketFactory {
+ public:
+  NATSocketFactory(SocketFactory* factory,
+                   const SocketAddress& nat_udp_addr,
+                   const SocketAddress& nat_tcp_addr);
+
+  NATSocketFactory(const NATSocketFactory&) = delete;
+  NATSocketFactory& operator=(const NATSocketFactory&) = delete;
+
+  // SocketFactory implementation
+  Socket* CreateSocket(int family, int type) override;
+
+  // NATInternalSocketFactory implementation
+  Socket* CreateInternalSocket(int family,
+                               int type,
+                               const SocketAddress& local_addr,
+                               SocketAddress* nat_addr) override;
+
+ private:
+  SocketFactory* factory_;
+  SocketAddress nat_udp_addr_;
+  SocketAddress nat_tcp_addr_;
+};
+
+// Creates sockets that will send traffic through a NAT depending on what
+// address they bind to. This can be used to simulate a client on a NAT sending
+// to a client that is not behind a NAT.
+// Note that the internal addresses of clients must be unique. This is because
+// there is only one socketserver per thread, and the Bind() address is used to
+// figure out which NAT (if any) the socket should talk to.
+//
+// Example with 3 NATs (2 cascaded), and 3 clients.
+// ss->AddTranslator("1.2.3.4", "192.168.0.1", NAT_ADDR_RESTRICTED);
+// ss->AddTranslator("99.99.99.99", "10.0.0.1", NAT_SYMMETRIC)->
+//     AddTranslator("10.0.0.2", "192.168.1.1", NAT_OPEN_CONE);
+// ss->GetTranslator("1.2.3.4")->AddClient("1.2.3.4", "192.168.0.2");
+// ss->GetTranslator("99.99.99.99")->AddClient("10.0.0.3");
+// ss->GetTranslator("99.99.99.99")->GetTranslator("10.0.0.2")->
+//     AddClient("192.168.1.2");
+class NATSocketServer : public SocketServer, public NATInternalSocketFactory {
+ public:
+  class Translator;
+
+  // holds a list of NATs
+  class TranslatorMap : private std::map<SocketAddress, Translator*> {
+   public:
+    ~TranslatorMap();
+    Translator* Get(const SocketAddress& ext_ip);
+    Translator* Add(const SocketAddress& ext_ip, Translator*);
+    void Remove(const SocketAddress& ext_ip);
+    Translator* FindClient(const SocketAddress& int_ip);
+  };
+
+  // a specific NAT
+  class Translator {
+   public:
+    Translator(NATSocketServer* server,
+               NATType type,
+               const SocketAddress& int_addr,
+               SocketFactory* ext_factory,
+               const SocketAddress& ext_addr);
+    ~Translator();
+
+    SocketFactory* internal_factory() { return internal_server_.get(); }
+    SocketAddress internal_udp_address() const {
+      return nat_server_->internal_udp_address();
+    }
+    SocketAddress internal_tcp_address() const {
+      return SocketAddress();  // nat_server_->internal_tcp_address();
+    }
+
+    Translator* GetTranslator(const SocketAddress& ext_ip);
+    Translator* AddTranslator(const SocketAddress& ext_ip,
+                              const SocketAddress& int_ip,
+                              NATType type);
+    void RemoveTranslator(const SocketAddress& ext_ip);
+
+    bool AddClient(const SocketAddress& int_ip);
+    void RemoveClient(const SocketAddress& int_ip);
+
+    // Looks for the specified client in this or a child NAT.
+    Translator* FindClient(const SocketAddress& int_ip);
+
+   private:
+    NATSocketServer* server_;
+    std::unique_ptr<SocketServer> internal_server_;
+    std::unique_ptr<NATServer> nat_server_;
+    TranslatorMap nats_;
+    std::set<SocketAddress> clients_;
+  };
+
+  explicit NATSocketServer(SocketServer* ss);
+
+  NATSocketServer(const NATSocketServer&) = delete;
+  NATSocketServer& operator=(const NATSocketServer&) = delete;
+
+  SocketServer* socketserver() { return server_; }
+  Thread* queue() { return msg_queue_; }
+
+  Translator* GetTranslator(const SocketAddress& ext_ip);
+  Translator* AddTranslator(const SocketAddress& ext_ip,
+                            const SocketAddress& int_ip,
+                            NATType type);
+  void RemoveTranslator(const SocketAddress& ext_ip);
+
+  // SocketServer implementation
+  Socket* CreateSocket(int family, int type) override;
+
+  void SetMessageQueue(Thread* queue) override;
+  bool Wait(webrtc::TimeDelta max_wait_duration, bool process_io) override;
+  void WakeUp() override;
+
+  // NATInternalSocketFactory implementation
+  Socket* CreateInternalSocket(int family,
+                               int type,
+                               const SocketAddress& local_addr,
+                               SocketAddress* nat_addr) override;
+
+ private:
+  SocketServer* server_;
+  Thread* msg_queue_;
+  TranslatorMap nats_;
+};
+
+// Free-standing NAT helper functions.
+size_t PackAddressForNAT(char* buf,
+                         size_t buf_size,
+                         const SocketAddress& remote_addr);
+size_t UnpackAddressFromNAT(const char* buf,
+                            size_t buf_size,
+                            SocketAddress* remote_addr);
+}  // namespace rtc
+
+#endif  // RTC_BASE_NAT_SOCKET_FACTORY_H_