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28 #include "talk/base/natsocketfactory.h"
30 #include "talk/base/logging.h"
31 #include "talk/base/natserver.h"
32 #include "talk/base/virtualsocketserver.h"
36 // Packs the given socketaddress into the buffer in buf, in the quasi-STUN
37 // format that the natserver uses.
38 // Returns 0 if an invalid address is passed.
39 size_t PackAddressForNAT(char* buf, size_t buf_size,
40 const SocketAddress& remote_addr) {
41 const IPAddress& ip = remote_addr.ipaddr();
42 int family = ip.family();
46 *(reinterpret_cast<uint16*>(&buf[2])) = HostToNetwork16(remote_addr.port());
47 if (family == AF_INET) {
48 ASSERT(buf_size >= kNATEncodedIPv4AddressSize);
49 in_addr v4addr = ip.ipv4_address();
50 memcpy(&buf[4], &v4addr, kNATEncodedIPv4AddressSize - 4);
51 return kNATEncodedIPv4AddressSize;
52 } else if (family == AF_INET6) {
53 ASSERT(buf_size >= kNATEncodedIPv6AddressSize);
54 in6_addr v6addr = ip.ipv6_address();
55 memcpy(&buf[4], &v6addr, kNATEncodedIPv6AddressSize - 4);
56 return kNATEncodedIPv6AddressSize;
61 // Decodes the remote address from a packet that has been encoded with the nat's
62 // quasi-STUN format. Returns the length of the address (i.e., the offset into
63 // data where the original packet starts).
64 size_t UnpackAddressFromNAT(const char* buf, size_t buf_size,
65 SocketAddress* remote_addr) {
66 ASSERT(buf_size >= 8);
69 uint16 port = NetworkToHost16(*(reinterpret_cast<const uint16*>(&buf[2])));
70 if (family == AF_INET) {
71 const in_addr* v4addr = reinterpret_cast<const in_addr*>(&buf[4]);
72 *remote_addr = SocketAddress(IPAddress(*v4addr), port);
73 return kNATEncodedIPv4AddressSize;
74 } else if (family == AF_INET6) {
75 ASSERT(buf_size >= 20);
76 const in6_addr* v6addr = reinterpret_cast<const in6_addr*>(&buf[4]);
77 *remote_addr = SocketAddress(IPAddress(*v6addr), port);
78 return kNATEncodedIPv6AddressSize;
85 class NATSocket : public AsyncSocket, public sigslot::has_slots<> {
87 explicit NATSocket(NATInternalSocketFactory* sf, int family, int type)
88 : sf_(sf), family_(family), type_(type), connected_(false),
89 socket_(NULL), buf_(NULL), size_(0) {
92 virtual ~NATSocket() {
97 virtual SocketAddress GetLocalAddress() const {
98 return (socket_) ? socket_->GetLocalAddress() : SocketAddress();
101 virtual SocketAddress GetRemoteAddress() const {
102 return remote_addr_; // will be NIL if not connected
105 virtual int Bind(const SocketAddress& addr) {
106 if (socket_) { // already bound, bubble up error
111 socket_ = sf_->CreateInternalSocket(family_, type_, addr, &server_addr_);
112 result = (socket_) ? socket_->Bind(addr) : -1;
114 socket_->SignalConnectEvent.connect(this, &NATSocket::OnConnectEvent);
115 socket_->SignalReadEvent.connect(this, &NATSocket::OnReadEvent);
116 socket_->SignalWriteEvent.connect(this, &NATSocket::OnWriteEvent);
117 socket_->SignalCloseEvent.connect(this, &NATSocket::OnCloseEvent);
119 server_addr_.Clear();
127 virtual int Connect(const SocketAddress& addr) {
128 if (!socket_) { // socket must be bound, for now
133 if (type_ == SOCK_STREAM) {
134 result = socket_->Connect(server_addr_.IsNil() ? addr : server_addr_);
146 virtual int Send(const void* data, size_t size) {
148 return SendTo(data, size, remote_addr_);
151 virtual int SendTo(const void* data, size_t size, const SocketAddress& addr) {
152 ASSERT(!connected_ || addr == remote_addr_);
153 if (server_addr_.IsNil() || type_ == SOCK_STREAM) {
154 return socket_->SendTo(data, size, addr);
156 // This array will be too large for IPv4 packets, but only by 12 bytes.
157 scoped_ptr<char[]> buf(new char[size + kNATEncodedIPv6AddressSize]);
158 size_t addrlength = PackAddressForNAT(buf.get(),
159 size + kNATEncodedIPv6AddressSize,
161 size_t encoded_size = size + addrlength;
162 memcpy(buf.get() + addrlength, data, size);
163 int result = socket_->SendTo(buf.get(), encoded_size, server_addr_);
165 ASSERT(result == static_cast<int>(encoded_size));
166 result = result - static_cast<int>(addrlength);
171 virtual int Recv(void* data, size_t size) {
173 return RecvFrom(data, size, &addr);
176 virtual int RecvFrom(void* data, size_t size, SocketAddress *out_addr) {
177 if (server_addr_.IsNil() || type_ == SOCK_STREAM) {
178 return socket_->RecvFrom(data, size, out_addr);
180 // Make sure we have enough room to read the requested amount plus the
181 // largest possible header address.
182 SocketAddress remote_addr;
183 Grow(size + kNATEncodedIPv6AddressSize);
185 // Read the packet from the socket.
186 int result = socket_->RecvFrom(buf_, size_, &remote_addr);
188 ASSERT(remote_addr == server_addr_);
190 // TODO: we need better framing so we know how many bytes we can
191 // return before we need to read the next address. For UDP, this will be
192 // fine as long as the reader always reads everything in the packet.
193 ASSERT((size_t)result < size_);
195 // Decode the wire packet into the actual results.
196 SocketAddress real_remote_addr;
198 UnpackAddressFromNAT(buf_, result, &real_remote_addr);
199 memcpy(data, buf_ + addrlength, result - addrlength);
201 // Make sure this packet should be delivered before returning it.
202 if (!connected_ || (real_remote_addr == remote_addr_)) {
204 *out_addr = real_remote_addr;
205 result = result - static_cast<int>(addrlength);
207 LOG(LS_ERROR) << "Dropping packet from unknown remote address: "
208 << real_remote_addr.ToString();
209 result = 0; // Tell the caller we didn't read anything
216 virtual int Close() {
219 result = socket_->Close();
222 remote_addr_ = SocketAddress();
230 virtual int Listen(int backlog) {
231 return socket_->Listen(backlog);
233 virtual AsyncSocket* Accept(SocketAddress *paddr) {
234 return socket_->Accept(paddr);
236 virtual int GetError() const {
237 return socket_->GetError();
239 virtual void SetError(int error) {
240 socket_->SetError(error);
242 virtual ConnState GetState() const {
243 return connected_ ? CS_CONNECTED : CS_CLOSED;
245 virtual int EstimateMTU(uint16* mtu) {
246 return socket_->EstimateMTU(mtu);
248 virtual int GetOption(Option opt, int* value) {
249 return socket_->GetOption(opt, value);
251 virtual int SetOption(Option opt, int value) {
252 return socket_->SetOption(opt, value);
255 void OnConnectEvent(AsyncSocket* socket) {
256 // If we're NATed, we need to send a request with the real addr to use.
257 ASSERT(socket == socket_);
258 if (server_addr_.IsNil()) {
260 SignalConnectEvent(this);
262 SendConnectRequest();
265 void OnReadEvent(AsyncSocket* socket) {
266 // If we're NATed, we need to process the connect reply.
267 ASSERT(socket == socket_);
268 if (type_ == SOCK_STREAM && !server_addr_.IsNil() && !connected_) {
269 HandleConnectReply();
271 SignalReadEvent(this);
274 void OnWriteEvent(AsyncSocket* socket) {
275 ASSERT(socket == socket_);
276 SignalWriteEvent(this);
278 void OnCloseEvent(AsyncSocket* socket, int error) {
279 ASSERT(socket == socket_);
280 SignalCloseEvent(this, error);
284 // Makes sure the buffer is at least the given size.
285 void Grow(size_t new_size) {
286 if (size_ < new_size) {
289 buf_ = new char[size_];
293 // Sends the destination address to the server to tell it to connect.
294 void SendConnectRequest() {
296 size_t length = PackAddressForNAT(buf, ARRAY_SIZE(buf), remote_addr_);
297 socket_->Send(buf, length);
300 // Handles the byte sent back from the server and fires the appropriate event.
301 void HandleConnectReply() {
303 socket_->Recv(&code, sizeof(code));
305 SignalConnectEvent(this);
308 SignalCloseEvent(this, code);
312 NATInternalSocketFactory* sf_;
316 SocketAddress remote_addr_;
317 SocketAddress server_addr_; // address of the NAT server
318 AsyncSocket* socket_;
324 NATSocketFactory::NATSocketFactory(SocketFactory* factory,
325 const SocketAddress& nat_addr)
326 : factory_(factory), nat_addr_(nat_addr) {
329 Socket* NATSocketFactory::CreateSocket(int type) {
330 return CreateSocket(AF_INET, type);
333 Socket* NATSocketFactory::CreateSocket(int family, int type) {
334 return new NATSocket(this, family, type);
337 AsyncSocket* NATSocketFactory::CreateAsyncSocket(int type) {
338 return CreateAsyncSocket(AF_INET, type);
341 AsyncSocket* NATSocketFactory::CreateAsyncSocket(int family, int type) {
342 return new NATSocket(this, family, type);
345 AsyncSocket* NATSocketFactory::CreateInternalSocket(int family, int type,
346 const SocketAddress& local_addr, SocketAddress* nat_addr) {
347 *nat_addr = nat_addr_;
348 return factory_->CreateAsyncSocket(family, type);
352 NATSocketServer::NATSocketServer(SocketServer* server)
353 : server_(server), msg_queue_(NULL) {
356 NATSocketServer::Translator* NATSocketServer::GetTranslator(
357 const SocketAddress& ext_ip) {
358 return nats_.Get(ext_ip);
361 NATSocketServer::Translator* NATSocketServer::AddTranslator(
362 const SocketAddress& ext_ip, const SocketAddress& int_ip, NATType type) {
363 // Fail if a translator already exists with this extternal address.
364 if (nats_.Get(ext_ip))
367 return nats_.Add(ext_ip, new Translator(this, type, int_ip, server_, ext_ip));
370 void NATSocketServer::RemoveTranslator(
371 const SocketAddress& ext_ip) {
372 nats_.Remove(ext_ip);
375 Socket* NATSocketServer::CreateSocket(int type) {
376 return CreateSocket(AF_INET, type);
379 Socket* NATSocketServer::CreateSocket(int family, int type) {
380 return new NATSocket(this, family, type);
383 AsyncSocket* NATSocketServer::CreateAsyncSocket(int type) {
384 return CreateAsyncSocket(AF_INET, type);
387 AsyncSocket* NATSocketServer::CreateAsyncSocket(int family, int type) {
388 return new NATSocket(this, family, type);
391 AsyncSocket* NATSocketServer::CreateInternalSocket(int family, int type,
392 const SocketAddress& local_addr, SocketAddress* nat_addr) {
393 AsyncSocket* socket = NULL;
394 Translator* nat = nats_.FindClient(local_addr);
396 socket = nat->internal_factory()->CreateAsyncSocket(family, type);
397 *nat_addr = (type == SOCK_STREAM) ?
398 nat->internal_tcp_address() : nat->internal_address();
400 socket = server_->CreateAsyncSocket(family, type);
405 // NATSocketServer::Translator
406 NATSocketServer::Translator::Translator(
407 NATSocketServer* server, NATType type, const SocketAddress& int_ip,
408 SocketFactory* ext_factory, const SocketAddress& ext_ip)
410 // Create a new private network, and a NATServer running on the private
411 // network that bridges to the external network. Also tell the private
412 // network to use the same message queue as us.
413 VirtualSocketServer* internal_server = new VirtualSocketServer(server_);
414 internal_server->SetMessageQueue(server_->queue());
415 internal_factory_.reset(internal_server);
416 nat_server_.reset(new NATServer(type, internal_server, int_ip,
417 ext_factory, ext_ip));
421 NATSocketServer::Translator* NATSocketServer::Translator::GetTranslator(
422 const SocketAddress& ext_ip) {
423 return nats_.Get(ext_ip);
426 NATSocketServer::Translator* NATSocketServer::Translator::AddTranslator(
427 const SocketAddress& ext_ip, const SocketAddress& int_ip, NATType type) {
428 // Fail if a translator already exists with this extternal address.
429 if (nats_.Get(ext_ip))
433 return nats_.Add(ext_ip,
434 new Translator(server_, type, int_ip, server_, ext_ip));
436 void NATSocketServer::Translator::RemoveTranslator(
437 const SocketAddress& ext_ip) {
438 nats_.Remove(ext_ip);
439 RemoveClient(ext_ip);
442 bool NATSocketServer::Translator::AddClient(
443 const SocketAddress& int_ip) {
444 // Fail if a client already exists with this internal address.
445 if (clients_.find(int_ip) != clients_.end())
448 clients_.insert(int_ip);
452 void NATSocketServer::Translator::RemoveClient(
453 const SocketAddress& int_ip) {
454 std::set<SocketAddress>::iterator it = clients_.find(int_ip);
455 if (it != clients_.end()) {
460 NATSocketServer::Translator* NATSocketServer::Translator::FindClient(
461 const SocketAddress& int_ip) {
462 // See if we have the requested IP, or any of our children do.
463 return (clients_.find(int_ip) != clients_.end()) ?
464 this : nats_.FindClient(int_ip);
467 // NATSocketServer::TranslatorMap
468 NATSocketServer::TranslatorMap::~TranslatorMap() {
469 for (TranslatorMap::iterator it = begin(); it != end(); ++it) {
474 NATSocketServer::Translator* NATSocketServer::TranslatorMap::Get(
475 const SocketAddress& ext_ip) {
476 TranslatorMap::iterator it = find(ext_ip);
477 return (it != end()) ? it->second : NULL;
480 NATSocketServer::Translator* NATSocketServer::TranslatorMap::Add(
481 const SocketAddress& ext_ip, Translator* nat) {
482 (*this)[ext_ip] = nat;
486 void NATSocketServer::TranslatorMap::Remove(
487 const SocketAddress& ext_ip) {
488 TranslatorMap::iterator it = find(ext_ip);
495 NATSocketServer::Translator* NATSocketServer::TranslatorMap::FindClient(
496 const SocketAddress& int_ip) {
497 Translator* nat = NULL;
498 for (TranslatorMap::iterator it = begin(); it != end() && !nat; ++it) {
499 nat = it->second->FindClient(int_ip);
504 } // namespace talk_base