Refactoring that removes P2PTransport and DtlsTransport classes.

webrtc/p2p/base/jseptransport.cc

Index: webrtc/p2p/base/jseptransport.cc
diff --git a/webrtc/p2p/base/transport.cc b/webrtc/p2p/base/jseptransport.cc
similarity index 62%
rename from webrtc/p2p/base/transport.cc
rename to webrtc/p2p/base/jseptransport.cc
index 7bd14c4cad1b8989755c7e6eba61f7ffcaf74c37..abfe0449a48f93e9d5a15806133f7d17e01e43be 100644
--- a/webrtc/p2p/base/transport.cc
+++ b/webrtc/p2p/base/jseptransport.cc
@@ -11,10 +11,12 @@
 #include <memory>
 #include <utility>  // for std::pair
 
-#include "webrtc/p2p/base/transport.h"
+#include "webrtc/p2p/base/jseptransport.h"
 
 #include "webrtc/p2p/base/candidate.h"
+#include "webrtc/p2p/base/dtlstransportchannel.h"
 #include "webrtc/p2p/base/p2pconstants.h"
+#include "webrtc/p2p/base/p2ptransportchannel.h"
 #include "webrtc/p2p/base/port.h"
 #include "webrtc/p2p/base/transportchannelimpl.h"
 #include "webrtc/base/bind.h"
@@ -58,37 +60,112 @@ bool IceCredentialsChanged(const std::string& old_ufrag,
   return (old_ufrag != new_ufrag) || (old_pwd != new_pwd);
 }
 
-Transport::Transport(const std::string& name, PortAllocator* allocator)
-    : name_(name), allocator_(allocator) {}
+bool VerifyCandidate(const Candidate& cand, std::string* error) {
+  // No address zero.
+  if (cand.address().IsNil() || cand.address().IsAnyIP()) {
+    *error = "candidate has address of zero";
+    return false;
+  }
+
+  // Disallow all ports below 1024, except for 80 and 443 on public addresses.
+  int port = cand.address().port();
+  if (cand.protocol() == TCP_PROTOCOL_NAME &&
+      (cand.tcptype() == TCPTYPE_ACTIVE_STR || port == 0)) {
+    // Expected for active-only candidates per
+    // http://tools.ietf.org/html/rfc6544#section-4.5 so no error.
+    // Libjingle clients emit port 0, in "active" mode.
+    return true;
+  }
+  if (port < 1024) {
+    if ((port != 80) && (port != 443)) {
+      *error = "candidate has port below 1024, but not 80 or 443";
+      return false;
+    }
+
+    if (cand.address().IsPrivateIP()) {
+      *error = "candidate has port of 80 or 443 with private IP address";
+      return false;
+    }
+  }
 
-Transport::~Transport() {
-  RTC_DCHECK(channels_destroyed_);
+  return true;
 }
 
-void Transport::SetIceRole(IceRole role) {
-  ice_role_ = role;
-  for (const auto& kv : channels_) {
-    kv.second->SetIceRole(ice_role_);
+bool VerifyCandidates(const Candidates& candidates, std::string* error) {
+  for (const Candidate& candidate : candidates) {
+    if (!VerifyCandidate(candidate, error)) {
+      return false;
+    }
   }
+  return true;
 }
 
-std::unique_ptr<rtc::SSLCertificate> Transport::GetRemoteSSLCertificate() {
-  if (channels_.empty()) {
-    return nullptr;
+JsepTransport::JsepTransport(
+    const std::string& mid,
+    const rtc::scoped_refptr<rtc::RTCCertificate>& certificate)
+    : mid_(mid), certificate_(certificate) {}
+
+bool JsepTransport::AddChannel(TransportChannelImpl* dtls, int component) {
+  if (channels_.find(component) != channels_.end()) {
+    LOG(LS_ERROR) << "Adding channel for component " << component << " twice.";
+    return false;
+  }
+  channels_[component] = dtls;
+  // Something's wrong if a channel is being added after a description is set.
+  // This may currently occur if rtcp-mux is negotiated, then a new m= section
+  // is added in a later offer/answer. But this is suboptimal and should be
+  // changed; we shouldn't support going from muxed to non-muxed.
+  // TODO(deadbeef): Once this is fixed, make the warning an error, and remove
+  // the calls to "ApplyXTransportDescription" below.
+  if (local_description_set_ || remote_description_set_) {
+    LOG(LS_WARNING) << "Adding new transport channel after "
+                       "transport description already applied.";
+  }
+  bool ret = true;
+  std::string err;
+  if (local_description_set_) {
+    ret &= ApplyLocalTransportDescription(channels_[component], &err);
   }
+  if (remote_description_set_) {
+    ret &= ApplyRemoteTransportDescription(channels_[component], &err);
+  }
+  if (local_description_set_ && remote_description_set_) {
+    ret &= ApplyNegotiatedTransportDescription(channels_[component], &err);
+  }
+  return ret;
+}
+
+bool JsepTransport::RemoveChannel(int component) {
+  auto it = channels_.find(component);
+  if (it == channels_.end()) {
+    LOG(LS_ERROR) << "Trying to remove channel for component " << component
+                  << ", which doesn't exist.";
+    return false;
+  }
+  channels_.erase(component);
+  return true;
+}
 
-  auto iter = channels_.begin();
-  return iter->second->GetRemoteSSLCertificate();
+bool JsepTransport::HasChannels() const {
+  return !channels_.empty();
 }
 
-void Transport::SetIceConfig(const IceConfig& config) {
-  ice_config_ = config;
-  for (const auto& kv : channels_) {
-    kv.second->SetIceConfig(ice_config_);
+void JsepTransport::SetLocalCertificate(
+    const rtc::scoped_refptr<rtc::RTCCertificate>& certificate) {
+  certificate_ = certificate;
+}
+
+bool JsepTransport::GetLocalCertificate(
+    rtc::scoped_refptr<rtc::RTCCertificate>* certificate) const {
+  if (!certificate_) {
+    return false;
   }
+
+  *certificate = certificate_;
+  return true;
 }
 
-bool Transport::SetLocalTransportDescription(
+bool JsepTransport::SetLocalTransportDescription(
     const TransportDescription& description,
     ContentAction action,
     std::string* error_desc) {
@@ -101,6 +178,16 @@ bool Transport::SetLocalTransportDescription(
 
   local_description_.reset(new TransportDescription(description));
 
+  rtc::SSLFingerprint* local_fp =
+      local_description_->identity_fingerprint.get();
+
+  if (!local_fp) {
+    certificate_ = nullptr;
+  } else if (!VerifyCertificateFingerprint(certificate_.get(), local_fp,
+                                           error_desc)) {
+    return false;
+  }
+
   for (const auto& kv : channels_) {
     ret &= ApplyLocalTransportDescription(kv.second, error_desc);
   }
@@ -119,7 +206,7 @@ bool Transport::SetLocalTransportDescription(
   return ret;
 }
 
-bool Transport::SetRemoteTransportDescription(
+bool JsepTransport::SetRemoteTransportDescription(
     const TransportDescription& description,
     ContentAction action,
     std::string* error_desc) {
@@ -146,135 +233,18 @@ bool Transport::SetRemoteTransportDescription(
   return ret;
 }
 
-TransportChannelImpl* Transport::CreateChannel(int component) {
-  TransportChannelImpl* channel;
-
-  // Create the entry if it does not exist.
-  bool channel_exists = false;
-  auto iter = channels_.find(component);
-  if (iter == channels_.end()) {
-    channel = CreateTransportChannel(component);
-    channels_.insert(std::pair<int, TransportChannelImpl*>(component, channel));
-  } else {
-    channel = iter->second;
-    channel_exists = true;
-  }
-
-  channels_destroyed_ = false;
-
-  if (channel_exists) {
-    // If this is an existing channel, we should just return it.
-    return channel;
-  }
-
-  // Push down our transport state to the new channel.
-  channel->SetIceRole(ice_role_);
-  channel->SetIceTiebreaker(tiebreaker_);
-  channel->SetIceConfig(ice_config_);
-  // TODO(ronghuawu): Change CreateChannel to be able to return error since
-  // below Apply**Description calls can fail.
-  if (local_description_)
-    ApplyLocalTransportDescription(channel, nullptr);
-  if (remote_description_)
-    ApplyRemoteTransportDescription(channel, nullptr);
-  if (local_description_ && remote_description_)
-    ApplyNegotiatedTransportDescription(channel, nullptr);
-
-  return channel;
-}
-
-TransportChannelImpl* Transport::GetChannel(int component) {
-  auto iter = channels_.find(component);
-  return (iter != channels_.end()) ? iter->second : nullptr;
-}
-
-bool Transport::HasChannels() {
-  return !channels_.empty();
-}
-
-void Transport::DestroyChannel(int component) {
-  auto iter = channels_.find(component);
-  if (iter == channels_.end())
-    return;
-
-  TransportChannelImpl* channel = iter->second;
-  channels_.erase(iter);
-  DestroyTransportChannel(channel);
-}
-
-void Transport::MaybeStartGathering() {
-  CallChannels(&TransportChannelImpl::MaybeStartGathering);
-}
-
-void Transport::DestroyAllChannels() {
-  for (const auto& kv : channels_) {
-    DestroyTransportChannel(kv.second);
-  }
-  channels_.clear();
-  channels_destroyed_ = true;
-}
-
-void Transport::CallChannels(TransportChannelFunc func) {
-  for (const auto& kv : channels_) {
-    (kv.second->*func)();
-  }
-}
-
-bool Transport::VerifyCandidate(const Candidate& cand, std::string* error) {
-  // No address zero.
-  if (cand.address().IsNil() || cand.address().IsAnyIP()) {
-    *error = "candidate has address of zero";
-    return false;
-  }
-
-  // Disallow all ports below 1024, except for 80 and 443 on public addresses.
-  int port = cand.address().port();
-  if (cand.protocol() == TCP_PROTOCOL_NAME &&
-      (cand.tcptype() == TCPTYPE_ACTIVE_STR || port == 0)) {
-    // Expected for active-only candidates per
-    // http://tools.ietf.org/html/rfc6544#section-4.5 so no error.
-    // Libjingle clients emit port 0, in "active" mode.
-    return true;
-  }
-  if (port < 1024) {
-    if ((port != 80) && (port != 443)) {
-      *error = "candidate has port below 1024, but not 80 or 443";
-      return false;
-    }
-
-    if (cand.address().IsPrivateIP()) {
-      *error = "candidate has port of 80 or 443 with private IP address";
-      return false;
-    }
-  }
-
-  if (!HasChannel(cand.component())) {
-    *error = "Candidate has an unknown component: " + cand.ToString() +
-             " for content: " + name();
-    return false;
-  }
-
-  return true;
-}
-
-bool Transport::VerifyCandidates(const Candidates& candidates,
-                                 std::string* error) {
-  for (const Candidate& candidate : candidates) {
-    if (!VerifyCandidate(candidate, error)) {
-      return false;
-    }
-  }
-  return true;
+void JsepTransport::GetSslRole(rtc::SSLRole* ssl_role) const {
+  RTC_DCHECK(ssl_role);
+  *ssl_role = secure_role_;
 }
 
-
-bool Transport::GetStats(TransportStats* stats) {
-  stats->transport_name = name();
+bool JsepTransport::GetStats(TransportStats* stats) {
+  stats->transport_name = mid();
   stats->channel_stats.clear();
-  for (auto kv : channels_) {
+  for (auto& kv : channels_) {
     TransportChannelImpl* channel = kv.second;
     TransportChannelStats substats;
-    substats.component = channel->component();
+    substats.component = kv.first;
     channel->GetSrtpCryptoSuite(&substats.srtp_crypto_suite);
     channel->GetSslCipherSuite(&substats.ssl_cipher_suite);
     if (!channel->GetStats(&substats.connection_infos)) {
@@ -285,74 +255,95 @@ bool Transport::GetStats(TransportStats* stats) {
   return true;
 }
 
-bool Transport::AddRemoteCandidates(const std::vector<Candidate>& candidates,
-                                    std::string* error) {
-  ASSERT(!channels_destroyed_);
-  // Verify each candidate before passing down to the transport layer.
-  if (!VerifyCandidates(candidates, error)) {
-    return false;
-  }
-
-  for (const Candidate& candidate : candidates) {
-    TransportChannelImpl* channel = GetChannel(candidate.component());
-    if (channel != nullptr) {
-      channel->AddRemoteCandidate(candidate);
-    }
+bool JsepTransport::VerifyCertificateFingerprint(
+    const rtc::RTCCertificate* certificate,
+    const rtc::SSLFingerprint* fingerprint,
+    std::string* error_desc) const {
+  if (!fingerprint) {
+    return BadTransportDescription("No fingerprint.", error_desc);
   }
-  return true;
-}
-
-bool Transport::RemoveRemoteCandidates(const std::vector<Candidate>& candidates,
-                                       std::string* error) {
-  ASSERT(!channels_destroyed_);
-  // Verify each candidate before passing down to the transport layer.
-  if (!VerifyCandidates(candidates, error)) {
-    return false;
+  if (!certificate) {
+    return BadTransportDescription(
+        "Fingerprint provided but no identity available.", error_desc);
   }
-
-  for (const Candidate& candidate : candidates) {
-    TransportChannelImpl* channel = GetChannel(candidate.component());
-    if (channel != nullptr) {
-      channel->RemoveRemoteCandidate(candidate);
-    }
+  std::unique_ptr<rtc::SSLFingerprint> fp_tmp(rtc::SSLFingerprint::Create(
+      fingerprint->algorithm, certificate->identity()));
+  ASSERT(fp_tmp.get() != NULL);
+  if (*fp_tmp == *fingerprint) {
+    return true;
   }
-  return true;
+  std::ostringstream desc;
+  desc << "Local fingerprint does not match identity. Expected: ";
+  desc << fp_tmp->ToString();
+  desc << " Got: " << fingerprint->ToString();
+  return BadTransportDescription(desc.str(), error_desc);
 }
 
-bool Transport::ApplyLocalTransportDescription(TransportChannelImpl* ch,
-                                               std::string* error_desc) {
-  ch->SetIceParameters(local_description_->GetIceParameters());
+bool JsepTransport::ApplyLocalTransportDescription(
+    TransportChannelImpl* channel,
+    std::string* error_desc) {
+  channel->SetIceParameters(local_description_->GetIceParameters());
   return true;
 }
 
-bool Transport::ApplyRemoteTransportDescription(TransportChannelImpl* ch,
-                                                std::string* error_desc) {
-  ch->SetRemoteIceParameters(remote_description_->GetIceParameters());
+bool JsepTransport::ApplyRemoteTransportDescription(
+    TransportChannelImpl* channel,
+    std::string* error_desc) {
+  // Currently, all ICE-related calls still go through this DTLS channel. But
+  // that will change once we get rid of TransportChannelImpl, and the DTLS
+  // channel interface no longer includes ICE-specific methods. Then this class
+  // will need to call dtls->ice()->SetIceRole(), for example, assuming the Dtls
+  // interface will expose its inner ICE channel.
+  channel->SetRemoteIceParameters(remote_description_->GetIceParameters());
+  channel->SetRemoteIceMode(remote_description_->ice_mode);
   return true;
 }
 
-bool Transport::ApplyNegotiatedTransportDescription(
+bool JsepTransport::ApplyNegotiatedTransportDescription(
     TransportChannelImpl* channel,
     std::string* error_desc) {
-  channel->SetRemoteIceMode(remote_ice_mode_);
+  // Set SSL role. Role must be set before fingerprint is applied, which
+  // initiates DTLS setup.
+  if (!channel->SetSslRole(secure_role_)) {
+    return BadTransportDescription("Failed to set SSL role for the channel.",
+                                   error_desc);
+  }
+  // Apply remote fingerprint.
+  if (!channel->SetRemoteFingerprint(
+          remote_fingerprint_->algorithm,
+          reinterpret_cast<const uint8_t*>(remote_fingerprint_->digest.data()),
+          remote_fingerprint_->digest.size())) {
+    return BadTransportDescription("Failed to apply remote fingerprint.",
+                                   error_desc);
+  }
   return true;
 }
 
-bool Transport::NegotiateTransportDescription(ContentAction local_role,
-                                              std::string* error_desc) {
-  // TODO(ekr@rtfm.com): This is ICE-specific stuff. Refactor into
-  // P2PTransport.
-
-  // If transport is in ICEROLE_CONTROLLED and remote end point supports only
-  // ice_lite, this local end point should take CONTROLLING role.
-  if (ice_role_ == ICEROLE_CONTROLLED &&
-      remote_description_->ice_mode == ICEMODE_LITE) {
-    SetIceRole(ICEROLE_CONTROLLING);
+bool JsepTransport::NegotiateTransportDescription(ContentAction local_role,
+                                                  std::string* error_desc) {
+  if (!local_description_ || !remote_description_) {
+    const std::string msg =
+        "Applying an answer transport description "
+        "without applying any offer.";
+    return BadTransportDescription(msg, error_desc);
+  }
+  rtc::SSLFingerprint* local_fp =
+      local_description_->identity_fingerprint.get();
+  rtc::SSLFingerprint* remote_fp =
+      remote_description_->identity_fingerprint.get();
+  if (remote_fp && local_fp) {
+    remote_fingerprint_.reset(new rtc::SSLFingerprint(*remote_fp));
+    if (!NegotiateRole(local_role, &secure_role_, error_desc)) {
+      return false;
+    }
+  } else if (local_fp && (local_role == CA_ANSWER)) {
+    return BadTransportDescription(
+        "Local fingerprint supplied when caller didn't offer DTLS.",
+        error_desc);
+  } else {
+    // We are not doing DTLS
+    remote_fingerprint_.reset(new rtc::SSLFingerprint("", nullptr, 0));
   }
-
-  // Update remote ice_mode to all existing channels.
-  remote_ice_mode_ = remote_description_->ice_mode;
-
   // Now that we have negotiated everything, push it downward.
   // Note that we cache the result so that if we have race conditions
   // between future SetRemote/SetLocal invocations and new channel
@@ -366,35 +357,11 @@ bool Transport::NegotiateTransportDescription(ContentAction local_role,
   return true;
 }
 
-bool Transport::VerifyCertificateFingerprint(
-    const rtc::RTCCertificate* certificate,
-    const rtc::SSLFingerprint* fingerprint,
-    std::string* error_desc) const {
-  if (!fingerprint) {
-    return BadTransportDescription("No fingerprint.", error_desc);
-  }
-  if (!certificate) {
-    return BadTransportDescription(
-        "Fingerprint provided but no identity available.", error_desc);
-  }
-  std::unique_ptr<rtc::SSLFingerprint> fp_tmp(rtc::SSLFingerprint::Create(
-      fingerprint->algorithm, certificate->identity()));
-  ASSERT(fp_tmp.get() != NULL);
-  if (*fp_tmp == *fingerprint) {
-    return true;
-  }
-  std::ostringstream desc;
-  desc << "Local fingerprint does not match identity. Expected: ";
-  desc << fp_tmp->ToString();
-  desc << " Got: " << fingerprint->ToString();
-  return BadTransportDescription(desc.str(), error_desc);
-}
-
-bool Transport::NegotiateRole(ContentAction local_role,
-                              rtc::SSLRole* ssl_role,
-                              std::string* error_desc) const {
+bool JsepTransport::NegotiateRole(ContentAction local_role,
+                                  rtc::SSLRole* ssl_role,
+                                  std::string* error_desc) const {
   RTC_DCHECK(ssl_role);
-  if (!local_description() || !remote_description()) {
+  if (!local_description_ || !remote_description_) {
     const std::string msg =
         "Local and Remote description must be set before "
         "transport descriptions are negotiated";
@@ -424,8 +391,8 @@ bool Transport::NegotiateRole(ContentAction local_role,
   // ClientHello over each flow (host/port quartet).
   // IOW - actpass and passive modes should be treated as server and
   // active as client.
-  ConnectionRole local_connection_role = local_description()->connection_role;
-  ConnectionRole remote_connection_role = remote_description()->connection_role;
+  ConnectionRole local_connection_role = local_description_->connection_role;
+  ConnectionRole remote_connection_role = remote_description_->connection_role;
 
   bool is_remote_server = false;
   if (local_role == CA_OFFER) {