relayport.cc

本人收集整理的一份c/c++跨平台网络库

  }
  options_.push_back(OptionValue(opt, value));
  return result;
}

int RelayPort::GetError() {
  return error_;
}

void RelayPort::OnReadPacket(
    const char* data, size_t size, 
    const talk_base::SocketAddress& remote_addr) {
  if (Connection* conn = GetConnection(remote_addr)) {
    conn->OnReadPacket(data, size);
  } else {
    Port::OnReadPacket(data, size, remote_addr);
  }
}

void RelayPort::DisposeSocket(talk_base::AsyncPacketSocket * socket) {
  thread_->Dispose(socket);
}

RelayEntry::RelayEntry(RelayPort* port, 
                       const talk_base::SocketAddress& ext_addr,
                       const talk_base::SocketAddress& local_addr)
  : port_(port), ext_addr_(ext_addr), local_addr_(local_addr), server_index_(0),
    socket_(0), connected_(false), locked_(false), requests_(port->thread()) {

  requests_.SignalSendPacket.connect(this, &RelayEntry::OnSendPacket);
}

RelayEntry::~RelayEntry() {
  delete socket_;
}

void RelayEntry::Connect() {
  assert(socket_ == 0);
  const ProtocolAddress * ra = port()->ServerAddress(server_index_);
  if (!ra) {
    LOG(INFO) << "Out of relay server connections";
    return;
  }

  LOG(INFO) << "Connecting to relay via " << ProtoToString(ra->proto) << " @ " << ra->address.ToString();

  socket_ = port_->CreatePacketSocket(ra->proto);
  assert(socket_ != 0);

  socket_->SignalReadPacket.connect(this, &RelayEntry::OnReadPacket);
  if (socket_->Bind(local_addr_) < 0)
    LOG(INFO) << "bind: " << std::strerror(socket_->GetError());

  for (unsigned i = 0; i < port_->options().size(); ++i)
    socket_->SetOption(port_->options()[i].first, port_->options()[i].second);

  if ((ra->proto == PROTO_TCP) || (ra->proto == PROTO_SSLTCP)) {
    talk_base::AsyncTCPSocket * tcp 
      = static_cast<talk_base::AsyncTCPSocket *>(socket_);
    tcp->SignalClose.connect(this, &RelayEntry::OnSocketClose);
    tcp->SignalConnect.connect(this, &RelayEntry::OnSocketConnect);
    tcp->Connect(ra->address);
  } else {
    requests_.Send(new AllocateRequest(this));
  }
}

void RelayEntry::OnConnect(const talk_base::SocketAddress& mapped_addr) {
  ProtocolType proto = PROTO_UDP;
  LOG(INFO) << "Relay allocate succeeded: " << ProtoToString(proto) << " @ " << mapped_addr.ToString();
  connected_ = true;

  port_->AddExternalAddress(ProtocolAddress(mapped_addr, proto));
  port_->SetReady();
}

int RelayEntry::SendTo(const void* data, size_t size,
                        const talk_base::SocketAddress& addr) {

  // If this connection is locked to the address given, then we can send the
  // packet with no wrapper.
  if (locked_ && (ext_addr_ == addr))
    return SendPacket(data, size);

  // Otherwise, we must wrap the given data in a STUN SEND request so that we
  // can communicate the destination address to the server.
  //
  // Note that we do not use a StunRequest here.  This is because there is
  // likely no reason to resend this packet. If it is late, we just drop it.
  // The next send to this address will try again.

  StunMessage request;
  request.SetType(STUN_SEND_REQUEST);
  request.SetTransactionID(CreateRandomString(16));

  StunByteStringAttribute* magic_cookie_attr =
      StunAttribute::CreateByteString(STUN_ATTR_MAGIC_COOKIE);
  magic_cookie_attr->CopyBytes(port_->magic_cookie().c_str(),
                               (uint16)port_->magic_cookie().size());
  request.AddAttribute(magic_cookie_attr);

  StunByteStringAttribute* username_attr =
      StunAttribute::CreateByteString(STUN_ATTR_USERNAME);
  username_attr->CopyBytes(port_->username_fragment().c_str(),
                           (uint16)port_->username_fragment().size());
  request.AddAttribute(username_attr);

  StunAddressAttribute* addr_attr =
      StunAttribute::CreateAddress(STUN_ATTR_DESTINATION_ADDRESS);
  addr_attr->SetFamily(1);
  addr_attr->SetIP(addr.ip());
  addr_attr->SetPort(addr.port());
  request.AddAttribute(addr_attr);

  // Attempt to lock
  if (ext_addr_ == addr) {
    StunUInt32Attribute* options_attr =
      StunAttribute::CreateUInt32(STUN_ATTR_OPTIONS);
    options_attr->SetValue(0x1);
    request.AddAttribute(options_attr);
  }

  StunByteStringAttribute* data_attr =
      StunAttribute::CreateByteString(STUN_ATTR_DATA);
  data_attr->CopyBytes(data, (uint16)size);
  request.AddAttribute(data_attr);

  // TODO: compute the HMAC.

  talk_base::ByteBuffer buf;
  request.Write(&buf);

  return SendPacket(buf.Data(), buf.Length());
}

void RelayEntry::ScheduleKeepAlive() {
  requests_.SendDelayed(new AllocateRequest(this), KEEPALIVE_DELAY);
}

void RelayEntry::HandleConnectFailure() {
  //if (GetMillisecondCount() - start_time_ > RETRY_TIMEOUT)
  //  return;
  //ScheduleKeepAlive();

  connected_ = false;
  port()->DisposeSocket(socket_);
  socket_ = 0;
  requests_.Clear();

  server_index_ += 1;
  Connect();
}

void RelayEntry::OnSocketConnect(talk_base::AsyncTCPSocket* socket) {
  assert(socket == socket_);
  LOG(INFO) << "relay tcp connected to " << socket->GetRemoteAddress().ToString();
  requests_.Send(new AllocateRequest(this));
}

void RelayEntry::OnSocketClose(talk_base::AsyncTCPSocket* socket, int error) {
  assert(socket == socket_);
  PLOG(LERROR, error) << "relay tcp connect failed";
  HandleConnectFailure();
}

void RelayEntry::OnReadPacket(const char* data, size_t size,
                              const talk_base::SocketAddress& remote_addr,
                              talk_base::AsyncPacketSocket* socket) {
  assert(socket == socket_);
  //assert(remote_addr == port_->server_addr()); TODO: are we worried about this?

  // If the magic cookie is not present, then this is an unwrapped packet sent
  // by the server,  The actual remote address is the one we recorded.
  if (!port_->HasMagicCookie(data, size)) {
    if (locked_) {
      port_->OnReadPacket(data, size, ext_addr_);
    } else {
      LOG(WARNING) << "Dropping packet: entry not locked";
    }
    return;
  }

  talk_base::ByteBuffer buf(data, size);
  StunMessage msg;
  if (!msg.Read(&buf)) {
    LOG(INFO) << "Incoming packet was not STUN";
    return;
  }

  // The incoming packet should be a STUN ALLOCATE response, SEND response, or
  // DATA indication.
  if (requests_.CheckResponse(&msg)) {
    return;
  } else if (msg.type() == STUN_SEND_RESPONSE) {
    if (const StunUInt32Attribute* options_attr = msg.GetUInt32(STUN_ATTR_OPTIONS)) {
      if (options_attr->value() & 0x1) {
        locked_ = true;
      }
    }
    return;
  } else if (msg.type() != STUN_DATA_INDICATION) {
    LOG(INFO) << "Received BAD stun type from server: " << msg.type()
             ;
    return;
  }

  // This must be a data indication.

  const StunAddressAttribute* addr_attr =
      msg.GetAddress(STUN_ATTR_SOURCE_ADDRESS2);
  if (!addr_attr) {
    LOG(INFO) << "Data indication has no source address";
    return;
  } else if (addr_attr->family() != 1) {
    LOG(INFO) << "Source address has bad family";
    return;
  }

  talk_base::SocketAddress remote_addr2(addr_attr->ip(), addr_attr->port());

  const StunByteStringAttribute* data_attr = msg.GetByteString(STUN_ATTR_DATA);
  if (!data_attr) {
    LOG(INFO) << "Data indication has no data";
    return;
  }

  // Process the actual data and remote address in the normal manner.
  port_->OnReadPacket(data_attr->bytes(), data_attr->length(), remote_addr2);
}

void RelayEntry::OnSendPacket(const void* data, size_t size, StunRequest* req) {
  SendPacket(data, size);
}

int RelayEntry::SendPacket(const void* data, size_t size) {
  const ProtocolAddress * ra = port_->ServerAddress(server_index_);
  if (!ra) {
    if (socket_)
      socket_->SetError(ENOTCONN);
    return SOCKET_ERROR;
  }
  int sent = socket_->SendTo(data, size, ra->address);
  if (sent <= 0) {
    LOG(LS_VERBOSE) << "sendto: " << std::strerror(socket_->GetError());
    assert(sent < 0);
  }
  return sent;
}

AllocateRequest::AllocateRequest(RelayEntry* entry) : entry_(entry) {
  start_time_ = talk_base::GetMillisecondCount();
}

void AllocateRequest::Prepare(StunMessage* request) {
  request->SetType(STUN_ALLOCATE_REQUEST);

  StunByteStringAttribute* magic_cookie_attr =
      StunAttribute::CreateByteString(STUN_ATTR_MAGIC_COOKIE);
  magic_cookie_attr->CopyBytes(
      entry_->port()->magic_cookie().c_str(),
      (uint16)entry_->port()->magic_cookie().size());
  request->AddAttribute(magic_cookie_attr);

  StunByteStringAttribute* username_attr =
      StunAttribute::CreateByteString(STUN_ATTR_USERNAME);
  username_attr->CopyBytes(
      entry_->port()->username_fragment().c_str(),
      (uint16)entry_->port()->username_fragment().size());
  request->AddAttribute(username_attr);
}

int AllocateRequest::GetNextDelay() {
  int delay = 100 * talk_base::_max(1 << count_, 2);
  count_ += 1;
  if (count_ == 5)
    timeout_ = true;
  return delay;
}

void AllocateRequest::OnResponse(StunMessage* response) {
  const StunAddressAttribute* addr_attr =
      response->GetAddress(STUN_ATTR_MAPPED_ADDRESS);
  if (!addr_attr) {
    LOG(INFO) << "Allocate response missing mapped address.";
  } else if (addr_attr->family() != 1) {
    LOG(INFO) << "Mapped address has bad family";
  } else {
    talk_base::SocketAddress addr(addr_attr->ip(), addr_attr->port());
    entry_->OnConnect(addr);
  }

  // We will do a keep-alive regardless of whether this request suceeds.
  // This should have almost no impact on network usage.
  entry_->ScheduleKeepAlive();
}

void AllocateRequest::OnErrorResponse(StunMessage* response) {
  const StunErrorCodeAttribute* attr = response->GetErrorCode();
  if (!attr) {
    LOG(INFO) << "Bad allocate response error code";
  } else {
    LOG(INFO) << "Allocate error response:"
              << " code=" << static_cast<int>(attr->error_code())
              << " reason='" << attr->reason() << "'";
  }

  if (talk_base::GetMillisecondCount() - start_time_ <= RETRY_TIMEOUT)
    entry_->ScheduleKeepAlive();
}

void AllocateRequest::OnTimeout() {
  LOG(INFO) << "Allocate request timed out";
  entry_->HandleConnectFailure();
}

} // namespace cricket