Revert of Refactoring that removes P2PTransport and DtlsTransport classes.

webrtc/p2p/base/dtlstransport.h

+/*
+ *  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.
+ */
+
+#ifndef WEBRTC_P2P_BASE_DTLSTRANSPORT_H_
+#define WEBRTC_P2P_BASE_DTLSTRANSPORT_H_
+
+#include <memory>
+
+#include "webrtc/p2p/base/dtlstransportchannel.h"
+#include "webrtc/p2p/base/transport.h"
+
+namespace rtc {
+class SSLIdentity;
+}
+
+namespace cricket {
+
+class PortAllocator;
+
+// Base should be a descendant of cricket::Transport and have a constructor
+// that takes a transport name and PortAllocator.
+//
+// Everything in this class should be called on the network thread.
+template<class Base>
+class DtlsTransport : public Base {
+ public:
+  DtlsTransport(const std::string& name,
+                PortAllocator* allocator,
+                const rtc::scoped_refptr<rtc::RTCCertificate>& certificate)
+      : Base(name, allocator),
+        certificate_(certificate),
+        secure_role_(rtc::SSL_CLIENT),
+        ssl_max_version_(rtc::SSL_PROTOCOL_DTLS_12) {}
+
+  ~DtlsTransport() {
+    Base::DestroyAllChannels();
+  }
+
+  void SetLocalCertificate(
+      const rtc::scoped_refptr<rtc::RTCCertificate>& certificate) override {
+    certificate_ = certificate;
+  }
+  bool GetLocalCertificate(
+      rtc::scoped_refptr<rtc::RTCCertificate>* certificate) override {
+    if (!certificate_)
+      return false;
+
+    *certificate = certificate_;
+    return true;
+  }
+
+  bool SetSslMaxProtocolVersion(rtc::SSLProtocolVersion version) override {
+    ssl_max_version_ = version;
+    return true;
+  }
+
+  bool ApplyLocalTransportDescription(TransportChannelImpl* channel,
+                                      std::string* error_desc) override {
+    rtc::SSLFingerprint* local_fp =
+        Base::local_description()->identity_fingerprint.get();
+
+    if (!local_fp) {
+      certificate_ = nullptr;
+    } else if (!Base::VerifyCertificateFingerprint(certificate_.get(), local_fp,
+                                                   error_desc)) {
+      return false;
+    }
+
+    if (!channel->SetLocalCertificate(certificate_)) {
+      return BadTransportDescription("Failed to set local identity.",
+                                     error_desc);
+    }
+
+    // Apply the description in the base class.
+    return Base::ApplyLocalTransportDescription(channel, error_desc);
+  }
+
+  bool NegotiateTransportDescription(ContentAction local_role,
+                                     std::string* error_desc) override {
+    if (!Base::local_description() || !Base::remote_description()) {
+      const std::string msg = "Local and Remote description must be set before "
+                              "transport descriptions are negotiated";
+      return BadTransportDescription(msg, error_desc);
+    }
+    rtc::SSLFingerprint* local_fp =
+        Base::local_description()->identity_fingerprint.get();
+    rtc::SSLFingerprint* remote_fp =
+        Base::remote_description()->identity_fingerprint.get();
+    if (remote_fp && local_fp) {
+      remote_fingerprint_.reset(new rtc::SSLFingerprint(*remote_fp));
+      if (!Base::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));
+    }
+    // Now run the negotiation for the base class.
+    return Base::NegotiateTransportDescription(local_role, error_desc);
+  }
+
+  DtlsTransportChannelWrapper* CreateTransportChannel(int component) override {
+    DtlsTransportChannelWrapper* channel = new DtlsTransportChannelWrapper(
+        Base::CreateTransportChannel(component));
+    channel->SetSslMaxProtocolVersion(ssl_max_version_);
+    return channel;
+  }
+
+  void DestroyTransportChannel(TransportChannelImpl* channel) override {
+    // Kind of ugly, but this lets us do the exact inverse of the create.
+    DtlsTransportChannelWrapper* dtls_channel =
+        static_cast<DtlsTransportChannelWrapper*>(channel);
+    TransportChannelImpl* base_channel = dtls_channel->channel();
+    delete dtls_channel;
+    Base::DestroyTransportChannel(base_channel);
+  }
+
+  bool GetSslRole(rtc::SSLRole* ssl_role) const override {
+    ASSERT(ssl_role != NULL);
+    *ssl_role = secure_role_;
+    return true;
+  }
+
+ private:
+  bool ApplyNegotiatedTransportDescription(TransportChannelImpl* channel,
+                                           std::string* error_desc) override {
+    // 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 Base::ApplyNegotiatedTransportDescription(channel, error_desc);
+  }
+
+  rtc::scoped_refptr<rtc::RTCCertificate> certificate_;
+  rtc::SSLRole secure_role_;
+  rtc::SSLProtocolVersion ssl_max_version_;
+  std::unique_ptr<rtc::SSLFingerprint> remote_fingerprint_;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_DTLSTRANSPORT_H_