1/* 2 * libjingle 3 * Copyright 2004--2005, Google Inc. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright notice, 9 * this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright notice, 11 * this list of conditions and the following disclaimer in the documentation 12 * and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 17 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 18 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 19 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28#ifndef TALK_BASE_NATSERVER_H_ 29#define TALK_BASE_NATSERVER_H_ 30 31#include <map> 32#include <set> 33 34#include "talk/base/asyncudpsocket.h" 35#include "talk/base/socketaddresspair.h" 36#include "talk/base/thread.h" 37#include "talk/base/socketfactory.h" 38#include "talk/base/nattypes.h" 39 40namespace talk_base { 41 42// Change how routes (socketaddress pairs) are compared based on the type of 43// NAT. The NAT server maintains a hashtable of the routes that it knows 44// about. So these affect which routes are treated the same. 45struct RouteCmp { 46 explicit RouteCmp(NAT* nat); 47 size_t operator()(const SocketAddressPair& r) const; 48 bool operator()( 49 const SocketAddressPair& r1, const SocketAddressPair& r2) const; 50 51 bool symmetric; 52}; 53 54// Changes how addresses are compared based on the filtering rules of the NAT. 55struct AddrCmp { 56 explicit AddrCmp(NAT* nat); 57 size_t operator()(const SocketAddress& r) const; 58 bool operator()(const SocketAddress& r1, const SocketAddress& r2) const; 59 60 bool use_ip; 61 bool use_port; 62}; 63 64// Implements the NAT device. It listens for packets on the internal network, 65// translates them, and sends them out over the external network. 66 67const int NAT_SERVER_PORT = 4237; 68 69class NATServer : public sigslot::has_slots<> { 70 public: 71 NATServer( 72 NATType type, SocketFactory* internal, const SocketAddress& internal_addr, 73 SocketFactory* external, const SocketAddress& external_ip); 74 ~NATServer(); 75 76 SocketAddress internal_address() const { 77 return server_socket_->GetLocalAddress(); 78 } 79 80 // Packets received on one of the networks. 81 void OnInternalPacket(AsyncPacketSocket* socket, const char* buf, 82 size_t size, const SocketAddress& addr); 83 void OnExternalPacket(AsyncPacketSocket* socket, const char* buf, 84 size_t size, const SocketAddress& remote_addr); 85 86 private: 87 typedef std::set<SocketAddress, AddrCmp> AddressSet; 88 89 /* Records a translation and the associated external socket. */ 90 struct TransEntry { 91 TransEntry(const SocketAddressPair& r, AsyncUDPSocket* s, NAT* nat); 92 ~TransEntry(); 93 94 SocketAddressPair route; 95 AsyncUDPSocket* socket; 96 AddressSet* whitelist; 97 }; 98 99 typedef std::map<SocketAddressPair, TransEntry*, RouteCmp> InternalMap; 100 typedef std::map<SocketAddress, TransEntry*> ExternalMap; 101 102 /* Creates a new entry that translates the given route. */ 103 void Translate(const SocketAddressPair& route); 104 105 /* Determines whether the NAT would filter out a packet from this address. */ 106 bool Filter(TransEntry* entry, const SocketAddress& ext_addr); 107 108 NAT* nat_; 109 SocketFactory* internal_; 110 SocketFactory* external_; 111 SocketAddress external_ip_; 112 AsyncUDPSocket* server_socket_; 113 AsyncSocket* tcp_server_socket_; 114 InternalMap* int_map_; 115 ExternalMap* ext_map_; 116 DISALLOW_EVIL_CONSTRUCTORS(NATServer); 117}; 118 119} // namespace talk_base 120 121#endif // TALK_BASE_NATSERVER_H_ 122