Revert "Reland "Remove GICE (gone forever!) and PORTALLOCATOR_ENABLE_SHARED_UFRAG (enabled forever)…

webrtc/p2p/base/transportdescriptionfactory.cc

 /*
  *  Copyright 2012 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.
  */
 
 #include "webrtc/p2p/base/transportdescriptionfactory.h"
 
 #include "webrtc/p2p/base/transportdescription.h"
 #include "webrtc/base/helpers.h"
 #include "webrtc/base/logging.h"
 #include "webrtc/base/messagedigest.h"
 #include "webrtc/base/scoped_ptr.h"
 #include "webrtc/base/sslfingerprint.h"
 
 namespace cricket {
 
+static TransportProtocol kDefaultProtocol = ICEPROTO_RFC5245;
+
 TransportDescriptionFactory::TransportDescriptionFactory()
-    : secure_(SEC_DISABLED),
+    : protocol_(kDefaultProtocol),
+      secure_(SEC_DISABLED),
       identity_(NULL) {
 }
 
 TransportDescription* TransportDescriptionFactory::CreateOffer(
     const TransportOptions& options,
     const TransportDescription* current_description) const {
   rtc::scoped_ptr<TransportDescription> desc(new TransportDescription());
 
+  // Set the transport type depending on the selected protocol.
+  if (protocol_ == ICEPROTO_RFC5245) {
+    desc->transport_type = NS_JINGLE_ICE_UDP;
+  } else if (protocol_ == ICEPROTO_HYBRID) {
+    desc->transport_type = NS_JINGLE_ICE_UDP;
+    desc->AddOption(ICE_OPTION_GICE);
+  } else if (protocol_ == ICEPROTO_GOOGLE) {
+    desc->transport_type = NS_GINGLE_P2P;
+  }
+
   // Generate the ICE credentials if we don't already have them.
   if (!current_description || options.ice_restart) {
     desc->ice_ufrag = rtc::CreateRandomString(ICE_UFRAG_LENGTH);
     desc->ice_pwd = rtc::CreateRandomString(ICE_PWD_LENGTH);
   } else {
     desc->ice_ufrag = current_description->ice_ufrag;
     desc->ice_pwd = current_description->ice_pwd;
   }
 
   // If we are trying to establish a secure transport, add a fingerprint.
   if (secure_ == SEC_ENABLED || secure_ == SEC_REQUIRED) {
     // Fail if we can't create the fingerprint.
     // If we are the initiator set role to "actpass".
     if (!SetSecurityInfo(desc.get(), CONNECTIONROLE_ACTPASS)) {
       return NULL;
     }
   }
 
   return desc.release();
 }
 
 TransportDescription* TransportDescriptionFactory::CreateAnswer(
     const TransportDescription* offer,
     const TransportOptions& options,
     const TransportDescription* current_description) const {
+  // A NULL offer is treated as a GICE transport description.
   // TODO(juberti): Figure out why we get NULL offers, and fix this upstream.
-  if (!offer) {
-    LOG(LS_WARNING) << "Failed to create TransportDescription answer " <<
-        "because offer is NULL";
+  rtc::scoped_ptr<TransportDescription> desc(new TransportDescription());
+
+  // Figure out which ICE variant to negotiate; prefer RFC 5245 ICE, but fall
+  // back to G-ICE if needed. Note that we never create a hybrid answer, since
+  // we know what the other side can support already.
+  if (offer && offer->transport_type == NS_JINGLE_ICE_UDP &&
+      (protocol_ == ICEPROTO_RFC5245 || protocol_ == ICEPROTO_HYBRID)) {
+    // Offer is ICE or hybrid, we support ICE or hybrid: use ICE.
+    desc->transport_type = NS_JINGLE_ICE_UDP;
+  } else if (offer && offer->transport_type == NS_JINGLE_ICE_UDP &&
+             offer->HasOption(ICE_OPTION_GICE) &&
+             protocol_ == ICEPROTO_GOOGLE) {
+    desc->transport_type = NS_GINGLE_P2P;
+    // Offer is hybrid, we support GICE: use GICE.
+  } else if ((!offer || offer->transport_type == NS_GINGLE_P2P) &&
+             (protocol_ == ICEPROTO_HYBRID || protocol_ == ICEPROTO_GOOGLE)) {
+    // Offer is GICE, we support hybrid or GICE: use GICE.
+    desc->transport_type = NS_GINGLE_P2P;
+  } else {
+    // Mismatch.
+    LOG(LS_WARNING) << "Failed to create TransportDescription answer "
+                       "because of incompatible transport types";
     return NULL;
   }
 
-  rtc::scoped_ptr<TransportDescription> desc(new TransportDescription());
   // Generate the ICE credentials if we don't already have them or ice is
   // being restarted.
   if (!current_description || options.ice_restart) {
     desc->ice_ufrag = rtc::CreateRandomString(ICE_UFRAG_LENGTH);
     desc->ice_pwd = rtc::CreateRandomString(ICE_PWD_LENGTH);
   } else {
     desc->ice_ufrag = current_description->ice_ufrag;
     desc->ice_pwd = current_description->ice_pwd;
   }
 
@@ skipping 43 matching lines @@
                   << digest_alg;
     return false;
   }
 
   // Assign security role.
   desc->connection_role = role;
   return true;
 }
 
 }  // namespace cricket
+