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      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 #include "talk/p2p/base/stunport.h"
     29 
     30 #include "talk/base/common.h"
     31 #include "talk/base/logging.h"
     32 #include "talk/base/helpers.h"
     33 #include "talk/base/nethelpers.h"
     34 #include "talk/p2p/base/common.h"
     35 
     36 namespace cricket {
     37 
     38 // TODO: Move these to a common place (used in relayport too)
     39 const int KEEPALIVE_DELAY = 10 * 1000;  // 10 seconds - sort timeouts
     40 const int RETRY_DELAY = 50;             // 50ms, from ICE spec
     41 const int RETRY_TIMEOUT = 50 * 1000;    // ICE says 50 secs
     42 
     43 // Handles a binding request sent to the STUN server.
     44 class StunPortBindingRequest : public StunRequest {
     45  public:
     46   StunPortBindingRequest(StunPort* port, bool keep_alive,
     47                          const talk_base::SocketAddress& addr)
     48     : port_(port), keep_alive_(keep_alive), server_addr_(addr) {
     49     start_time_ = talk_base::Time();
     50   }
     51 
     52   virtual ~StunPortBindingRequest() {
     53   }
     54 
     55   const talk_base::SocketAddress& server_addr() const { return server_addr_; }
     56 
     57   virtual void Prepare(StunMessage* request) {
     58     request->SetType(STUN_BINDING_REQUEST);
     59   }
     60 
     61   virtual void OnResponse(StunMessage* response) {
     62     const StunAddressAttribute* addr_attr =
     63         response->GetAddress(STUN_ATTR_MAPPED_ADDRESS);
     64     if (!addr_attr) {
     65       LOG(LS_ERROR) << "Binding response missing mapped address.";
     66     } else if (addr_attr->family() != 1) {
     67       LOG(LS_ERROR) << "Binding address has bad family";
     68     } else {
     69       talk_base::SocketAddress addr(addr_attr->ip(), addr_attr->port());
     70       port_->AddAddress(addr, "udp", true);
     71     }
     72 
     73     // We will do a keep-alive regardless of whether this request suceeds.
     74     // This should have almost no impact on network usage.
     75     if (keep_alive_) {
     76       port_->requests_.SendDelayed(
     77           new StunPortBindingRequest(port_, true, server_addr_),
     78           KEEPALIVE_DELAY);
     79     }
     80   }
     81 
     82   virtual void OnErrorResponse(StunMessage* response) {
     83     const StunErrorCodeAttribute* attr = response->GetErrorCode();
     84     if (!attr) {
     85       LOG(LS_ERROR) << "Bad allocate response error code";
     86     } else {
     87       LOG(LS_ERROR) << "Binding error response:"
     88                  << " class=" << attr->error_class()
     89                  << " number=" << attr->number()
     90                  << " reason='" << attr->reason() << "'";
     91     }
     92 
     93     port_->SignalAddressError(port_);
     94 
     95     if (keep_alive_
     96         && (talk_base::TimeSince(start_time_) <= RETRY_TIMEOUT)) {
     97       port_->requests_.SendDelayed(
     98           new StunPortBindingRequest(port_, true, server_addr_),
     99           KEEPALIVE_DELAY);
    100     }
    101   }
    102 
    103   virtual void OnTimeout() {
    104     LOG(LS_ERROR) << "Binding request timed out from "
    105                   << port_->socket_->GetLocalAddress(NULL).ToString()
    106                   << " (" << port_->network()->name() << ")";
    107 
    108     port_->SignalAddressError(port_);
    109 
    110     if (keep_alive_
    111         && (talk_base::TimeSince(start_time_) <= RETRY_TIMEOUT)) {
    112       port_->requests_.SendDelayed(
    113           new StunPortBindingRequest(port_, true, server_addr_),
    114           RETRY_DELAY);
    115     }
    116   }
    117 
    118  private:
    119   StunPort* port_;
    120   bool keep_alive_;
    121   talk_base::SocketAddress server_addr_;
    122   uint32 start_time_;
    123 };
    124 
    125 const std::string STUN_PORT_TYPE("stun");
    126 
    127 StunPort::StunPort(talk_base::Thread* thread,
    128                    talk_base::PacketSocketFactory* factory,
    129                    talk_base::Network* network,
    130                    uint32 ip, int min_port, int max_port,
    131                    const talk_base::SocketAddress& server_addr)
    132     : Port(thread, STUN_PORT_TYPE, factory, network, ip, min_port, max_port),
    133       server_addr_(server_addr),
    134       requests_(thread),
    135       socket_(NULL),
    136       error_(0),
    137       resolver_(NULL) {
    138   requests_.SignalSendPacket.connect(this, &StunPort::OnSendPacket);
    139 }
    140 
    141 bool StunPort::Init() {
    142   socket_ = factory_->CreateUdpSocket(
    143       talk_base::SocketAddress(ip_, 0), min_port_, max_port_);
    144   if (!socket_) {
    145     LOG_J(LS_WARNING, this) << "UDP socket creation failed";
    146     return false;
    147   }
    148   socket_->SignalReadPacket.connect(this, &StunPort::OnReadPacket);
    149   return true;
    150 }
    151 
    152 StunPort::~StunPort() {
    153   if (resolver_) {
    154     resolver_->Destroy(false);
    155   }
    156   delete socket_;
    157 }
    158 
    159 void StunPort::PrepareAddress() {
    160   // We will keep pinging the stun server to make sure our NAT pin-hole stays
    161   // open during the call.
    162   if (server_addr_.IsUnresolved()) {
    163     ResolveStunAddress();
    164   } else {
    165     requests_.Send(new StunPortBindingRequest(this, true, server_addr_));
    166   }
    167 }
    168 
    169 void StunPort::PrepareSecondaryAddress() {
    170   // DNS resolution of the secondary address is not currently supported.
    171   ASSERT(!server_addr2_.IsAny());
    172   requests_.Send(new StunPortBindingRequest(this, false, server_addr2_));
    173 }
    174 
    175 Connection* StunPort::CreateConnection(const Candidate& address,
    176                                        CandidateOrigin origin) {
    177   if (address.protocol() != "udp")
    178     return NULL;
    179 
    180   Connection* conn = new ProxyConnection(this, 0, address);
    181   AddConnection(conn);
    182   return conn;
    183 }
    184 
    185 int StunPort::SendTo(const void* data, size_t size,
    186                      const talk_base::SocketAddress& addr, bool payload) {
    187   int sent = socket_->SendTo(data, size, addr);
    188   if (sent < 0) {
    189     error_ = socket_->GetError();
    190     LOG_J(LS_ERROR, this) << "UDP send of " << size
    191                           << " bytes failed with error " << error_;
    192   }
    193   return sent;
    194 }
    195 
    196 int StunPort::SetOption(talk_base::Socket::Option opt, int value) {
    197   return socket_->SetOption(opt, value);
    198 }
    199 
    200 int StunPort::GetError() {
    201   return error_;
    202 }
    203 
    204 void StunPort::OnReadPacket(talk_base::AsyncPacketSocket* socket,
    205                             const char* data, size_t size,
    206                             const talk_base::SocketAddress& remote_addr) {
    207   ASSERT(socket == socket_);
    208 
    209   // Look for a response from the STUN server.
    210   // Even if the response doesn't match one of our outstanding requests, we
    211   // will eat it because it might be a response to a retransmitted packet, and
    212   // we already cleared the request when we got the first response.
    213   ASSERT(!server_addr_.IsUnresolved());
    214   if (remote_addr == server_addr_ || remote_addr == server_addr2_) {
    215     requests_.CheckResponse(data, size);
    216     return;
    217   }
    218 
    219   if (Connection* conn = GetConnection(remote_addr)) {
    220     conn->OnReadPacket(data, size);
    221   } else {
    222     Port::OnReadPacket(data, size, remote_addr);
    223   }
    224 }
    225 
    226 void StunPort::ResolveStunAddress() {
    227   if (resolver_)
    228     return;
    229 
    230   resolver_ = new talk_base::AsyncResolver();
    231   resolver_->SignalWorkDone.connect(this, &StunPort::OnResolveResult);
    232   resolver_->set_address(server_addr_);
    233   resolver_->Start();
    234 }
    235 
    236 void StunPort::OnResolveResult(talk_base::SignalThread* t) {
    237   ASSERT(t == resolver_);
    238   if (resolver_->error() != 0) {
    239     LOG_J(LS_WARNING, this) << "StunPort: stun host lookup received error "
    240                             << resolver_->error();
    241     SignalAddressError(this);
    242   }
    243 
    244   server_addr_ = resolver_->address();
    245   PrepareAddress();
    246 }
    247 
    248 // TODO: merge this with SendTo above.
    249 void StunPort::OnSendPacket(const void* data, size_t size, StunRequest* req) {
    250   StunPortBindingRequest* sreq = static_cast<StunPortBindingRequest*>(req);
    251   if (socket_->SendTo(data, size, sreq->server_addr()) < 0)
    252     PLOG(LERROR, socket_->GetError()) << "sendto";
    253 }
    254 
    255 }  // namespace cricket
    256