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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/rawtransportchannel.h"
     29 
     30 #include <string>
     31 #include <vector>
     32 #include "talk/base/common.h"
     33 #include "talk/p2p/base/constants.h"
     34 #include "talk/p2p/base/portallocator.h"
     35 #include "talk/p2p/base/portinterface.h"
     36 #include "talk/p2p/base/rawtransport.h"
     37 #include "talk/p2p/base/relayport.h"
     38 #include "talk/p2p/base/sessionmanager.h"
     39 #include "talk/p2p/base/stunport.h"
     40 #include "talk/xmllite/qname.h"
     41 #include "talk/xmllite/xmlelement.h"
     42 #include "talk/xmpp/constants.h"
     43 
     44 #if defined(FEATURE_ENABLE_PSTN)
     45 
     46 namespace {
     47 
     48 const uint32 MSG_DESTROY_UNUSED_PORTS = 1;
     49 
     50 }  // namespace
     51 
     52 namespace cricket {
     53 
     54 RawTransportChannel::RawTransportChannel(const std::string& content_name,
     55                                          int component,
     56                                          RawTransport* transport,
     57                                          talk_base::Thread *worker_thread,
     58                                          PortAllocator *allocator)
     59   : TransportChannelImpl(content_name, component),
     60     raw_transport_(transport),
     61     allocator_(allocator),
     62     allocator_session_(NULL),
     63     stun_port_(NULL),
     64     relay_port_(NULL),
     65     port_(NULL),
     66     use_relay_(false) {
     67   if (worker_thread == NULL)
     68     worker_thread_ = raw_transport_->worker_thread();
     69   else
     70     worker_thread_ = worker_thread;
     71 }
     72 
     73 RawTransportChannel::~RawTransportChannel() {
     74   delete allocator_session_;
     75 }
     76 
     77 int RawTransportChannel::SendPacket(const char *data, size_t size,
     78                                     const talk_base::PacketOptions& options,
     79                                     int flags) {
     80   if (port_ == NULL)
     81     return -1;
     82   if (remote_address_.IsNil())
     83     return -1;
     84   if (flags != 0)
     85     return -1;
     86   return port_->SendTo(data, size, remote_address_, options, true);
     87 }
     88 
     89 int RawTransportChannel::SetOption(talk_base::Socket::Option opt, int value) {
     90   // TODO: allow these to be set before we have a port
     91   if (port_ == NULL)
     92     return -1;
     93   return port_->SetOption(opt, value);
     94 }
     95 
     96 int RawTransportChannel::GetError() {
     97   return (port_ != NULL) ? port_->GetError() : 0;
     98 }
     99 
    100 void RawTransportChannel::Connect() {
    101   // Create an allocator that only returns stun and relay ports.
    102   // Use empty string for ufrag and pwd here. There won't be any STUN or relay
    103   // interactions when using RawTC.
    104   // TODO: Change raw to only use local udp ports.
    105   allocator_session_ = allocator_->CreateSession(
    106       SessionId(), content_name(), component(), "", "");
    107 
    108   uint32 flags = PORTALLOCATOR_DISABLE_UDP | PORTALLOCATOR_DISABLE_TCP;
    109 
    110 #if !defined(FEATURE_ENABLE_STUN_CLASSIFICATION)
    111   flags |= PORTALLOCATOR_DISABLE_RELAY;
    112 #endif
    113   allocator_session_->set_flags(flags);
    114   allocator_session_->SignalPortReady.connect(
    115       this, &RawTransportChannel::OnPortReady);
    116   allocator_session_->SignalCandidatesReady.connect(
    117       this, &RawTransportChannel::OnCandidatesReady);
    118 
    119   // The initial ports will include stun.
    120   allocator_session_->StartGettingPorts();
    121 }
    122 
    123 void RawTransportChannel::Reset() {
    124   set_readable(false);
    125   set_writable(false);
    126 
    127   delete allocator_session_;
    128 
    129   allocator_session_ = NULL;
    130   stun_port_ = NULL;
    131   relay_port_ = NULL;
    132   port_ = NULL;
    133   remote_address_ = talk_base::SocketAddress();
    134 }
    135 
    136 void RawTransportChannel::OnCandidate(const Candidate& candidate) {
    137   remote_address_ = candidate.address();
    138   ASSERT(!remote_address_.IsNil());
    139   set_readable(true);
    140 
    141   // We can write once we have a port and a remote address.
    142   if (port_ != NULL)
    143     SetWritable();
    144 }
    145 
    146 void RawTransportChannel::OnRemoteAddress(
    147     const talk_base::SocketAddress& remote_address) {
    148   remote_address_ = remote_address;
    149   set_readable(true);
    150 
    151   if (port_ != NULL)
    152     SetWritable();
    153 }
    154 
    155 // Note about stun classification
    156 // Code to classify our NAT type and use the relay port if we are behind an
    157 // asymmetric NAT is under a FEATURE_ENABLE_STUN_CLASSIFICATION #define.
    158 // To turn this one we will have to enable a second stun address and make sure
    159 // that the relay server works for raw UDP.
    160 //
    161 // Another option is to classify the NAT type early and not offer the raw
    162 // transport type at all if we can't support it.
    163 
    164 void RawTransportChannel::OnPortReady(
    165     PortAllocatorSession* session, PortInterface* port) {
    166   ASSERT(session == allocator_session_);
    167 
    168   if (port->Type() == STUN_PORT_TYPE) {
    169     stun_port_ = static_cast<StunPort*>(port);
    170   } else if (port->Type() == RELAY_PORT_TYPE) {
    171     relay_port_ = static_cast<RelayPort*>(port);
    172   } else {
    173     ASSERT(false);
    174   }
    175 }
    176 
    177 void RawTransportChannel::OnCandidatesReady(
    178     PortAllocatorSession *session, const std::vector<Candidate>& candidates) {
    179   ASSERT(session == allocator_session_);
    180   ASSERT(candidates.size() >= 1);
    181 
    182   // The most recent candidate is the one we haven't seen yet.
    183   Candidate c = candidates[candidates.size() - 1];
    184 
    185   if (c.type() == STUN_PORT_TYPE) {
    186     ASSERT(stun_port_ != NULL);
    187 
    188 #if defined(FEATURE_ENABLE_STUN_CLASSIFICATION)
    189     // We need to wait until we have two addresses.
    190     if (stun_port_->candidates().size() < 2)
    191       return;
    192 
    193     // This is the second address.  If these addresses are the same, then we
    194     // are not behind a symmetric NAT.  Hence, a stun port should be sufficient.
    195     if (stun_port_->candidates()[0].address() ==
    196         stun_port_->candidates()[1].address()) {
    197       SetPort(stun_port_);
    198       return;
    199     }
    200 
    201     // We will need to use relay.
    202     use_relay_ = true;
    203 
    204     // If we already have a relay address, we're good.  Otherwise, we will need
    205     // to wait until one arrives.
    206     if (relay_port_->candidates().size() > 0)
    207       SetPort(relay_port_);
    208 #else  // defined(FEATURE_ENABLE_STUN_CLASSIFICATION)
    209     // Always use the stun port.  We don't classify right now so just assume it
    210     // will work fine.
    211     SetPort(stun_port_);
    212 #endif
    213   } else if (c.type() == RELAY_PORT_TYPE) {
    214     if (use_relay_)
    215       SetPort(relay_port_);
    216   } else {
    217     ASSERT(false);
    218   }
    219 }
    220 
    221 void RawTransportChannel::SetPort(PortInterface* port) {
    222   ASSERT(port_ == NULL);
    223   port_ = port;
    224 
    225   // We don't need any ports other than the one we picked.
    226   allocator_session_->StopGettingPorts();
    227   worker_thread_->Post(
    228       this, MSG_DESTROY_UNUSED_PORTS, NULL);
    229 
    230   // Send a message to the other client containing our address.
    231 
    232   ASSERT(port_->Candidates().size() >= 1);
    233   ASSERT(port_->Candidates()[0].protocol() == "udp");
    234   SignalCandidateReady(this, port_->Candidates()[0]);
    235 
    236   // Read all packets from this port.
    237   port_->EnablePortPackets();
    238   port_->SignalReadPacket.connect(this, &RawTransportChannel::OnReadPacket);
    239 
    240   // We can write once we have a port and a remote address.
    241   if (!remote_address_.IsAny())
    242     SetWritable();
    243 }
    244 
    245 void RawTransportChannel::SetWritable() {
    246   ASSERT(port_ != NULL);
    247   ASSERT(!remote_address_.IsAny());
    248 
    249   set_writable(true);
    250 
    251   Candidate remote_candidate;
    252   remote_candidate.set_address(remote_address_);
    253   SignalRouteChange(this, remote_candidate);
    254 }
    255 
    256 void RawTransportChannel::OnReadPacket(
    257     PortInterface* port, const char* data, size_t size,
    258     const talk_base::SocketAddress& addr) {
    259   ASSERT(port_ == port);
    260   SignalReadPacket(this, data, size, talk_base::CreatePacketTime(0), 0);
    261 }
    262 
    263 void RawTransportChannel::OnMessage(talk_base::Message* msg) {
    264   ASSERT(msg->message_id == MSG_DESTROY_UNUSED_PORTS);
    265   ASSERT(port_ != NULL);
    266   if (port_ != stun_port_) {
    267     stun_port_->Destroy();
    268     stun_port_ = NULL;
    269   }
    270   if (port_ != relay_port_ && relay_port_ != NULL) {
    271     relay_port_->Destroy();
    272     relay_port_ = NULL;
    273   }
    274 }
    275 
    276 }  // namespace cricket
    277 #endif  // defined(FEATURE_ENABLE_PSTN)
    278