Add config to prune TURN ports

webrtc/p2p/client/basicportallocator.cc

 /*
  *  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.
  */
 
@@ skipping 29 matching lines @@
   MSG_CONFIG_STOP,
 };
 
 const int PHASE_UDP = 0;
 const int PHASE_RELAY = 1;
 const int PHASE_TCP = 2;
 const int PHASE_SSLTCP = 3;
 
 const int kNumPhases = 4;
 
+// Gets address family priority:  Unspecified < IPv4 < IPv6.

[pthatcher1, 2016/06/29 00:33:11]

Can you write this as IPv6 > IPv4 > Unspecified?

[honghaiz3, 2016/06/29 01:34:15]

Done.

+int GetAddressFamilyPriority(int ip_family) {
+  switch (ip_family) {
+    case AF_UNSPEC:
+      return 0;
+    case AF_INET:
+      return 1;
+    case AF_INET6:
+      return 2;
+    default:
+      RTC_DCHECK(false);

[pthatcher1, 2016/06/29 00:33:11]

Shouldn't we have RTC_DCHECK for AF_UNSPEC as well?

[honghaiz3, 2016/06/29 01:34:16]

Agree. put it together with default. 

+      return 0;

[pthatcher1, 2016/06/29 00:33:11]

Can you put highest first?

case AF_INET6:
  return 2;
case AF_INET:
  return 1;
...

[honghaiz3, 2016/06/29 01:34:15]

Done.

+  }
+}
+
+// Returns positive if a is better, negative if b is better, and 0 otherwise.
+int ComparePort(const cricket::Port* a, const cricket::Port* b) {
+  static constexpr int a_is_better = 1;
+  static constexpr int b_is_better = -1;
+  // Protocol type is defined as UDP = 0, TCP = 1, SSLTCP = 2.
+  if (a->GetProtocol() < b->GetProtocol()) {
+    return a_is_better;
+  }
+  if (a->GetProtocol() > b->GetProtocol()) {
+    return b_is_better;
+  }
+
+  int a_family = GetAddressFamilyPriority(a->Network()->GetBestIP().family());
+  int b_family = GetAddressFamilyPriority(b->Network()->GetBestIP().family());
+  return a_family - b_family;
+}
+
 }  // namespace
 
 namespace cricket {
 const uint32_t DISABLE_ALL_PHASES =
     PORTALLOCATOR_DISABLE_UDP | PORTALLOCATOR_DISABLE_TCP |
     PORTALLOCATOR_DISABLE_STUN | PORTALLOCATOR_DISABLE_RELAY;
 
 // BasicPortAllocator
 BasicPortAllocator::BasicPortAllocator(rtc::NetworkManager* network_manager,
                                        rtc::PacketSocketFactory* socket_factory)
     : network_manager_(network_manager), socket_factory_(socket_factory) {
   ASSERT(network_manager_ != nullptr);
   ASSERT(socket_factory_ != nullptr);
   Construct();
 }
 
 BasicPortAllocator::BasicPortAllocator(rtc::NetworkManager* network_manager)
     : network_manager_(network_manager), socket_factory_(nullptr) {
   ASSERT(network_manager_ != nullptr);
   Construct();
 }
 
 BasicPortAllocator::BasicPortAllocator(rtc::NetworkManager* network_manager,
                                        rtc::PacketSocketFactory* socket_factory,
                                        const ServerAddresses& stun_servers)
     : network_manager_(network_manager), socket_factory_(socket_factory) {
   ASSERT(socket_factory_ != NULL);
-  SetConfiguration(stun_servers, std::vector<RelayServerConfig>(), 0);
+  SetConfiguration(stun_servers, std::vector<RelayServerConfig>(), 0, false);
   Construct();
 }
 
 BasicPortAllocator::BasicPortAllocator(
     rtc::NetworkManager* network_manager,
     const ServerAddresses& stun_servers,
     const rtc::SocketAddress& relay_address_udp,
     const rtc::SocketAddress& relay_address_tcp,
     const rtc::SocketAddress& relay_address_ssl)
     : network_manager_(network_manager), socket_factory_(NULL) {
   std::vector<RelayServerConfig> turn_servers;
   RelayServerConfig config(RELAY_GTURN);
   if (!relay_address_udp.IsNil()) {
     config.ports.push_back(ProtocolAddress(relay_address_udp, PROTO_UDP));
   }
   if (!relay_address_tcp.IsNil()) {
     config.ports.push_back(ProtocolAddress(relay_address_tcp, PROTO_TCP));
   }
   if (!relay_address_ssl.IsNil()) {
     config.ports.push_back(ProtocolAddress(relay_address_ssl, PROTO_SSLTCP));
   }
 
   if (!config.ports.empty()) {
     turn_servers.push_back(config);
   }
 
-  SetConfiguration(stun_servers, turn_servers, 0);
+  SetConfiguration(stun_servers, turn_servers, 0, false);
   Construct();
 }
 
 void BasicPortAllocator::Construct() {
   allow_tcp_listen_ = true;
 }
 
 BasicPortAllocator::~BasicPortAllocator() {
 }
 
 PortAllocatorSession* BasicPortAllocator::CreateSessionInternal(
     const std::string& content_name, int component,
     const std::string& ice_ufrag, const std::string& ice_pwd) {
   return new BasicPortAllocatorSession(
       this, content_name, component, ice_ufrag, ice_pwd);
 }
 
 void BasicPortAllocator::AddTurnServer(const RelayServerConfig& turn_server) {
   std::vector<RelayServerConfig> new_turn_servers = turn_servers();
   new_turn_servers.push_back(turn_server);
-  SetConfiguration(stun_servers(), new_turn_servers, candidate_pool_size());
+  SetConfiguration(stun_servers(), new_turn_servers, candidate_pool_size(),
+                   prune_turn_ports());
 }
 
 // BasicPortAllocatorSession
 BasicPortAllocatorSession::BasicPortAllocatorSession(
     BasicPortAllocator *allocator,
     const std::string& content_name,
     int component,
     const std::string& ice_ufrag,
     const std::string& ice_pwd)
     : PortAllocatorSession(content_name, component,
@@ skipping 74 matching lines @@
 }
 
 void BasicPortAllocatorSession::ClearGettingPorts() {
   network_thread_->Clear(this, MSG_ALLOCATE);
   for (uint32_t i = 0; i < sequences_.size(); ++i)
     sequences_[i]->Stop();
 }
 
 std::vector<PortInterface*> BasicPortAllocatorSession::ReadyPorts() const {
   std::vector<PortInterface*> ret;
-  for (const PortData& port : ports_) {
-    if (port.has_pairable_candidate() && !port.error()) {
-      ret.push_back(port.port());
+  for (const PortData& data : ports_) {
+    if (data.ready()) {
+      ret.push_back(data.port());
     }
   }
   return ret;
 }
 
 std::vector<Candidate> BasicPortAllocatorSession::ReadyCandidates() const {
   std::vector<Candidate> candidates;
   for (const PortData& data : ports_) {
+    if (!data.ready()) {
+      continue;
+    }
+
     for (const Candidate& candidate : data.port()->Candidates()) {
       if (!CheckCandidateFilter(candidate)) {
         continue;
       }
       ProtocolType pvalue;
       if (!StringToProto(candidate.protocol().c_str(), &pvalue) ||
           !data.sequence()->ProtocolEnabled(pvalue)) {
         continue;
       }
       candidates.push_back(SanitizeRelatedAddress(candidate));
@@ skipping 30 matching lines @@
   }
 
   // Check that all port allocation sequences are complete (not running).
   if (std::any_of(sequences_.begin(), sequences_.end(),
                   [](const AllocationSequence* sequence) {
                     return sequence->state() == AllocationSequence::kRunning;
                   })) {
     return false;
   }
 
-  // If all allocated ports are in complete state, session must have got all
+  // If all allocated ports are no longer gathering, session must have got all
   // expected candidates. Session will trigger candidates allocation complete
   // signal.
-  if (!std::all_of(ports_.begin(), ports_.end(), [](const PortData& port) {
-        return (port.complete() || port.error());
-      })) {
-    return false;
-  }
-
-  return true;
+  return std::none_of(ports_.begin(), ports_.end(),
+                      [](const PortData& port) { return port.inprogress(); });
 }
 
 void BasicPortAllocatorSession::OnMessage(rtc::Message *message) {
   switch (message->message_id) {
   case MSG_CONFIG_START:
     ASSERT(rtc::Thread::Current() == network_thread_);
     GetPortConfigurations();
     break;
   case MSG_CONFIG_READY:
     ASSERT(rtc::Thread::Current() == network_thread_);
@@ skipping 49 matching lines @@
 
 void BasicPortAllocatorSession::OnConfigStop() {
   ASSERT(rtc::Thread::Current() == network_thread_);
 
   // If any of the allocated ports have not completed the candidates allocation,
   // mark those as error. Since session doesn't need any new candidates
   // at this stage of the allocation, it's safe to discard any new candidates.
   bool send_signal = false;
   for (std::vector<PortData>::iterator it = ports_.begin();
        it != ports_.end(); ++it) {
-    if (!it->complete() && !it->error()) {
+    if (it->inprogress()) {
       // Updating port state to error, which didn't finish allocating candidates
       // yet.
       it->set_error();
       send_signal = true;
     }
   }
 
   // Did we stop any running sequences?
   for (std::vector<AllocationSequence*>::iterator it = sequences_.begin();
        it != sequences_.end() && !send_signal; ++it) {
@@ skipping 65 matching lines @@
 // create a new sequence to create the appropriate ports.
 void BasicPortAllocatorSession::DoAllocate() {
   bool done_signal_needed = false;
   std::vector<rtc::Network*> networks;
   GetNetworks(&networks);
 
   if (networks.empty()) {
     LOG(LS_WARNING) << "Machine has no networks; no ports will be allocated";
     done_signal_needed = true;
   } else {
+    PortConfiguration* config = configs_.empty() ? nullptr : configs_.back();
     for (uint32_t i = 0; i < networks.size(); ++i) {
-      PortConfiguration* config = NULL;
-      if (configs_.size() > 0)
-        config = configs_.back();
-
       uint32_t sequence_flags = flags();
       if ((sequence_flags & DISABLE_ALL_PHASES) == DISABLE_ALL_PHASES) {
         // If all the ports are disabled we should just fire the allocation
         // done event and return.
         done_signal_needed = true;
         break;
       }
 
       if (!config || config->relays.empty()) {
         // No relay ports specified in this config.
@@ skipping 100 matching lines @@
   // Send candidate allocation complete signal if we have no sequences.
   MaybeSignalCandidatesAllocationDone();
 }
 
 void BasicPortAllocatorSession::OnCandidateReady(
     Port* port, const Candidate& c) {
   ASSERT(rtc::Thread::Current() == network_thread_);
   PortData* data = FindPort(port);
   ASSERT(data != NULL);
   // Discarding any candidate signal if port allocation status is
-  // already in completed state.
-  if (data->complete() || data->error()) {
+  // already done with gathering.
+  if (!data->inprogress()) {
     return;
   }
 
+  // Mark that the port has a pairable candidate, either because we have a
+  // usable candidate from the port, or simply because the port is bound to the
+  // any address and therefore has no host candidate. This will trigger the port
+  // to start creating candidate pairs (connections) and issue connectivity
+  // checks. If port has already been marked as having a pairable candidate,
+  // do nothing here.
+  // Note: We should check whether any candidates may become ready after this
+  // because there we will check whether the candidate is generated by the ready
+  // ports, which may include this port.
+  if (CandidatePairable(c, port)) {
+    OnPortPairable(data);
+  }
+
   ProtocolType pvalue;
   bool candidate_protocol_enabled =
       StringToProto(c.protocol().c_str(), &pvalue) &&
       data->sequence()->ProtocolEnabled(pvalue);
 
-  if (CheckCandidateFilter(c) && candidate_protocol_enabled) {
+  if (data->ready() && CheckCandidateFilter(c) && candidate_protocol_enabled) {
     std::vector<Candidate> candidates;
     candidates.push_back(SanitizeRelatedAddress(c));
     SignalCandidatesReady(this, candidates);
   }
+}
 
-  // Port has already been marked as having a pairable candidate.
-  // Nothing to do here.
+void BasicPortAllocatorSession::OnPortPairable(PortData* data) {
   if (data->has_pairable_candidate()) {
     return;
   }
+  data->set_has_pairable_candidate(true);

[pthatcher1, 2016/06/29 00:33:11]

Actually, this makes it seem like the method should be called
OnPairableCandidateReady, and that makes me think we should move the
has_pairable_candidate/set_has_pairable_candidate thing back to OnCandidateReady
and call this method OnFirstPairableCandidateReady, like so:

if (CandidatePairable(c, port) && data->has_pairable_candidate()) {
  data->set_has_pairable_candidate(true);
  OnFirstPairableCandidateReady();
}


Sorry for the churn on this one.

[honghaiz3, 2016/06/29 01:34:15]

Done. 

 
-  // Mark that the port has a pairable candidate, either because we have a
-  // usable candidate from the port, or simply because the port is bound to the
-  // any address and therefore has no host candidate. This will trigger the port
-  // to start creating candidate pairs (connections) and issue connectivity
-  // checks.
-  if (CandidatePairable(c, port)) {
-    data->set_has_pairable_candidate(true);
+  if (data->pruned()) {
+    // A port may have been pruned before it becomes ready. In that case,
+    // do not need to do anything here.
+    return;
+  }
+
+  Port* port = data->port();
+  if (!allocator_->prune_turn_ports() || port->Type() != RELAY_PORT_TYPE) {
     SignalPortReady(this, port);
+    return;
+  }
+
+  // Note: We determine the same network based only on their network names. So
+  // if an IPv4 address and an IPv6 address have the same network name, they
+  // are considered the same network here.
+  Port* best_turn_port_on_same_network =
+      GetBestTurnPortForNetwork(port->Network()->name());
+
+  // |port| is already in the list of ports, so the best port cannot be nullptr.
+  RTC_CHECK(best_turn_port_on_same_network != nullptr);
+  bool pruned_port = false;
+  if (ComparePort(port, best_turn_port_on_same_network) >= 0) {
+    SignalPortReady(this, port);
+    // Prune existing ports that have lower priorities.
+    pruned_port = PruneTurnPortsWorseThan(best_turn_port_on_same_network);
+  } else {
+    // Don't need to send SignalPortPruned for the current port because it was
+    // not signaled for being ready yet.
+    data->set_pruned();
+    pruned_port = true;
+  }
+  if (pruned_port) {
+    MaybeSignalCandidatesAllocationDone();
   }

[pthatcher1, 2016/06/29 00:33:11]

I feel like we could also be more readable by sticking this in a separate
method.  I'm trying to think of a good name, though.  Perhaps something like
this:

PruneTurnPortsForNetwork(port->Network()->name());
if (!data->pruned()) {
  SignalPortReady(this, port);
}


And PruneTurnPortsForNetwork could just be be:

Port* best_port = GetBestTurnPortForNetwork(name);
PruneTurnPortsWorseThan(best_port);
MaybeSignalCandidatesAllocationDone();


Then this whole method could just be:

if (port->Type() == RELAY_PORT_TYPE && allocator_->prune_turn_ports()) {
  PruneTurnPortsForNetwork(port->Network()->name());
}
if (!data->pruned()) {
  SignalPortReady(this, port);
}


And then we could perhaps just inline it after all.

[honghaiz3, 2016/06/29 01:34:15]

Done and inlined it. 

 }
 
+Port* BasicPortAllocatorSession::GetBestTurnPortForNetwork(
+    const std::string& network_name) const {
+  Port* best_turn_port = nullptr;
+  for (const PortData& data : ports_) {
+    if (data.port()->Network()->name() == network_name &&
+        data.port()->Type() == RELAY_PORT_TYPE && data.ready() &&
+        (!best_turn_port || ComparePort(data.port(), best_turn_port) > 0)) {
+      best_turn_port = data.port();
+    }
+  }
+  return best_turn_port;
+}
+
+bool BasicPortAllocatorSession::PruneTurnPortsWorseThan(Port* best_turn_port) {
+  bool pruned_port = false;
+  for (PortData& data : ports_) {
+    if (data.port()->Network()->name() == best_turn_port->Network()->name() &&
+        data.port()->Type() == RELAY_PORT_TYPE && !data.pruned() &&
+        ComparePort(data.port(), best_turn_port) < 0) {
+      data.set_pruned();
+      SignalPortPruned(this, data.port());
+      pruned_port = true;
+    }
+  }
+  return pruned_port;
+}
+
 void BasicPortAllocatorSession::OnPortComplete(Port* port) {
   ASSERT(rtc::Thread::Current() == network_thread_);
   PortData* data = FindPort(port);
   ASSERT(data != NULL);
 
   // Ignore any late signals.
-  if (data->complete() || data->error()) {
+  if (!data->inprogress()) {
     return;
   }
 
   // Moving to COMPLETE state.
   data->set_complete();
   // Send candidate allocation complete signal if this was the last port.
   MaybeSignalCandidatesAllocationDone();
 }
 
 void BasicPortAllocatorSession::OnPortError(Port* port) {
   ASSERT(rtc::Thread::Current() == network_thread_);
   PortData* data = FindPort(port);
   ASSERT(data != NULL);
   // We might have already given up on this port and stopped it.
-  if (data->complete() || data->error()) {
+  if (!data->inprogress()) {
     return;
   }
 
   // SignalAddressError is currently sent from StunPort/TurnPort.
   // But this signal itself is generic.
   data->set_error();
   // Send candidate allocation complete signal if this was the last port.
   MaybeSignalCandidatesAllocationDone();
 }
 
@@ skipping 385 matching lines @@
 
   // If BasicPortAllocatorSession::OnAllocate left relay ports enabled then we
   // ought to have a relay list for them here.
   ASSERT(config_ && !config_->relays.empty());
   if (!(config_ && !config_->relays.empty())) {
     LOG(LS_WARNING)
         << "AllocationSequence: No relay server configured, skipping.";
     return;
   }
 
-  PortConfiguration::RelayList::const_iterator relay;
-  for (relay = config_->relays.begin();
-       relay != config_->relays.end(); ++relay) {
-    if (relay->type == RELAY_GTURN) {
-      CreateGturnPort(*relay);
-    } else if (relay->type == RELAY_TURN) {
-      CreateTurnPort(*relay);
+  for (RelayServerConfig& relay : config_->relays) {
+    if (relay.type == RELAY_GTURN) {
+      CreateGturnPort(relay);
+    } else if (relay.type == RELAY_TURN) {
+      CreateTurnPort(relay);
     } else {
       ASSERT(false);
     }
   }
 }
 
 void AllocationSequence::CreateGturnPort(const RelayServerConfig& config) {
   // TODO(mallinath) - Rename RelayPort to GTurnPort.
   RelayPort* port = RelayPort::Create(session_->network_thread(),
                                       session_->socket_factory(),
@@ skipping 187 matching lines @@
   ServerAddresses servers;
   for (size_t i = 0; i < relays.size(); ++i) {
     if (relays[i].type == turn_type && SupportsProtocol(relays[i], type)) {
       servers.insert(relays[i].ports.front().address);
     }
   }
   return servers;
 }
 
 }  // namespace cricket