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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_SOCKET_FACTORY_H_
#define RTC_BASE_NAT_SOCKET_FACTORY_H_
#include <stddef.h>
#include <map>
#include <memory>
#include <set>
#include "rtc_base/async_socket.h"
#include "rtc_base/constructor_magic.h"
#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 AsyncSocket* 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);
// SocketFactory implementation
Socket* CreateSocket(int family, int type) override;
AsyncSocket* CreateAsyncSocket(int family, int type) override;
// NATInternalSocketFactory implementation
AsyncSocket* CreateInternalSocket(int family,
int type,
const SocketAddress& local_addr,
SocketAddress* nat_addr) override;
private:
SocketFactory* factory_;
SocketAddress nat_udp_addr_;
SocketAddress nat_tcp_addr_;
RTC_DISALLOW_COPY_AND_ASSIGN(NATSocketFactory);
};
// 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_factory_.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<SocketFactory> internal_factory_;
std::unique_ptr<NATServer> nat_server_;
TranslatorMap nats_;
std::set<SocketAddress> clients_;
};
explicit NATSocketServer(SocketServer* ss);
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;
AsyncSocket* CreateAsyncSocket(int family, int type) override;
void SetMessageQueue(Thread* queue) override;
bool Wait(int cms, bool process_io) override;
void WakeUp() override;
// NATInternalSocketFactory implementation
AsyncSocket* CreateInternalSocket(int family,
int type,
const SocketAddress& local_addr,
SocketAddress* nat_addr) override;
private:
SocketServer* server_;
Thread* msg_queue_;
TranslatorMap nats_;
RTC_DISALLOW_COPY_AND_ASSIGN(NATSocketServer);
};
// 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_
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