1 /* 2 * Copyright 2004 The WebRTC Project Authors. All rights reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #ifndef WEBRTC_BASE_NATSERVER_H_ 12 #define WEBRTC_BASE_NATSERVER_H_ 13 14 #include <map> 15 #include <set> 16 17 #include "webrtc/base/asyncudpsocket.h" 18 #include "webrtc/base/socketaddresspair.h" 19 #include "webrtc/base/thread.h" 20 #include "webrtc/base/socketfactory.h" 21 #include "webrtc/base/nattypes.h" 22 23 namespace rtc { 24 25 // Change how routes (socketaddress pairs) are compared based on the type of 26 // NAT. The NAT server maintains a hashtable of the routes that it knows 27 // about. So these affect which routes are treated the same. 28 struct RouteCmp { 29 explicit RouteCmp(NAT* nat); 30 size_t operator()(const SocketAddressPair& r) const; 31 bool operator()( 32 const SocketAddressPair& r1, const SocketAddressPair& r2) const; 33 34 bool symmetric; 35 }; 36 37 // Changes how addresses are compared based on the filtering rules of the NAT. 38 struct AddrCmp { 39 explicit AddrCmp(NAT* nat); 40 size_t operator()(const SocketAddress& r) const; 41 bool operator()(const SocketAddress& r1, const SocketAddress& r2) const; 42 43 bool use_ip; 44 bool use_port; 45 }; 46 47 // Implements the NAT device. It listens for packets on the internal network, 48 // translates them, and sends them out over the external network. 49 50 const int NAT_SERVER_PORT = 4237; 51 52 class NATServer : public sigslot::has_slots<> { 53 public: 54 NATServer( 55 NATType type, SocketFactory* internal, const SocketAddress& internal_addr, 56 SocketFactory* external, const SocketAddress& external_ip); 57 ~NATServer(); 58 internal_address()59 SocketAddress internal_address() const { 60 return server_socket_->GetLocalAddress(); 61 } 62 63 // Packets received on one of the networks. 64 void OnInternalPacket(AsyncPacketSocket* socket, const char* buf, 65 size_t size, const SocketAddress& addr, 66 const PacketTime& packet_time); 67 void OnExternalPacket(AsyncPacketSocket* socket, const char* buf, 68 size_t size, const SocketAddress& remote_addr, 69 const PacketTime& packet_time); 70 71 private: 72 typedef std::set<SocketAddress, AddrCmp> AddressSet; 73 74 /* Records a translation and the associated external socket. */ 75 struct TransEntry { 76 TransEntry(const SocketAddressPair& r, AsyncUDPSocket* s, NAT* nat); 77 ~TransEntry(); 78 79 void WhitelistInsert(const SocketAddress& addr); 80 bool WhitelistContains(const SocketAddress& ext_addr); 81 82 SocketAddressPair route; 83 AsyncUDPSocket* socket; 84 AddressSet* whitelist; 85 CriticalSection crit_; 86 }; 87 88 typedef std::map<SocketAddressPair, TransEntry*, RouteCmp> InternalMap; 89 typedef std::map<SocketAddress, TransEntry*> ExternalMap; 90 91 /* Creates a new entry that translates the given route. */ 92 void Translate(const SocketAddressPair& route); 93 94 /* Determines whether the NAT would filter out a packet from this address. */ 95 bool ShouldFilterOut(TransEntry* entry, const SocketAddress& ext_addr); 96 97 NAT* nat_; 98 SocketFactory* internal_; 99 SocketFactory* external_; 100 SocketAddress external_ip_; 101 AsyncUDPSocket* server_socket_; 102 AsyncSocket* tcp_server_socket_; 103 InternalMap* int_map_; 104 ExternalMap* ext_map_; 105 DISALLOW_EVIL_CONSTRUCTORS(NATServer); 106 }; 107 108 } // namespace rtc 109 110 #endif // WEBRTC_BASE_NATSERVER_H_ 111