Adding ability for BaseChannel to use PacketTransportInterface.

webrtc/p2p/base/fakedtlstransport.h

+/*
+ *  Copyright 2017 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_FAKEDTLSTRANSPORT_H_
+#define WEBRTC_P2P_BASE_FAKEDTLSTRANSPORT_H_
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "webrtc/base/fakesslidentity.h"
+#include "webrtc/p2p/base/dtlstransportinternal.h"
+#include "webrtc/p2p/base/fakeicetransport.h"
+
+namespace cricket {
+
+// Fake DTLS transport which is implemented by wrapping a fake ICE transport.
+// Doesn't interact directly with fake ICE transport for anything other than
+// sending packets.
+class FakeDtlsTransport : public DtlsTransportInternal {
+ public:
+  explicit FakeDtlsTransport(FakeIceTransport* ice_transport)
+      : ice_transport_(ice_transport),
+        transport_name_(ice_transport->transport_name()),
+        component_(ice_transport->component()),
+        dtls_fingerprint_("", nullptr, 0) {
+    ice_transport_->SignalReadPacket.connect(
+        this, &FakeDtlsTransport::OnIceTransportReadPacket);
+  }
+
+  // If this constructor is called, a new fake ICE transport will be created,
+  // and this FakeDtlsTransport will take the ownership.
+  explicit FakeDtlsTransport(const std::string& name, int component)
+      : owned_ice_transport_(new FakeIceTransport(name, component)),
+        transport_name_(owned_ice_transport_->transport_name()),
+        component_(owned_ice_transport_->component()),
+        dtls_fingerprint_("", nullptr, 0) {
+    ice_transport_ = owned_ice_transport_.get();
+    ice_transport_->SignalReadPacket.connect(
+        this, &FakeDtlsTransport::OnIceTransportReadPacket);
+  }
+
+  ~FakeDtlsTransport() override {
+    if (dest_ && dest_->dest_ == this) {
+      dest_->dest_ = nullptr;
+    }
+  }
+
+  // Get inner fake ICE transport.
+  FakeIceTransport* fake_ice_transport() { return ice_transport_; }
+
+  // If async, will send packets by "Post"-ing to message queue instead of
+  // synchronously "Send"-ing.
+  void SetAsync(bool async) { ice_transport_->SetAsync(async); }
+  void SetAsyncDelay(int delay_ms) { ice_transport_->SetAsyncDelay(delay_ms); }
+
+  // SetWritable, SetReceiving and SetDestination are the main methods that can
+  // be used for testing, to simulate connectivity or lack thereof.
+  void SetWritable(bool writable) {
+    ice_transport_->SetWritable(writable);
+    set_writable(writable);
+  }
+  void SetReceiving(bool receiving) {
+    ice_transport_->SetReceiving(receiving);
+    set_receiving(receiving);
+  }
+
+  // Simulates the two DTLS transports connecting to each other.
+  // If |asymmetric| is true this method only affects this FakeDtlsTransport.
+  // If false, it affects |dest| as well.
+  void SetDestination(FakeDtlsTransport* dest, bool asymmetric = false) {
+    if (dest == dest_) {
+      return;
+    }
+    RTC_DCHECK(!dest || !dest_)
+        << "Changing fake destination from one to another is not supported.";
+    if (dest && !dest_) {
+      // This simulates the DTLS handshake.
+      dest_ = dest;
+      if (local_cert_ && dest_->local_cert_) {
+        do_dtls_ = true;
+        NegotiateSrtpCiphers();
+      }
+      SetWritable(true);
+      if (!asymmetric) {
+        dest->SetDestination(this, true);
+      }
+      ice_transport_->SetDestination(
+          static_cast<FakeIceTransport*>(dest->ice_transport()), asymmetric);
+    } else {
+      // Simulates loss of connectivity, by asymmetrically forgetting dest_.
+      dest_ = nullptr;
+      SetWritable(false);
+      ice_transport_->SetDestination(nullptr, asymmetric);
+    }
+  }
+
+  // Fake DtlsTransportInternal implementation.
+  DtlsTransportState dtls_state() const override { return dtls_state_; }
+  const std::string& transport_name() const override { return transport_name_; }
+  int component() const override { return component_; }
+  const rtc::SSLFingerprint& dtls_fingerprint() const {
+    return dtls_fingerprint_;
+  }
+  bool SetRemoteFingerprint(const std::string& alg,
+                            const uint8_t* digest,
+                            size_t digest_len) override {
+    dtls_fingerprint_ = rtc::SSLFingerprint(alg, digest, digest_len);
+    return true;
+  }
+  bool SetSslRole(rtc::SSLRole role) override {
+    ssl_role_ = role;
+    return true;
+  }
+  bool GetSslRole(rtc::SSLRole* role) const override {
+    *role = ssl_role_;
+    return true;
+  }
+  bool SetLocalCertificate(
+      const rtc::scoped_refptr<rtc::RTCCertificate>& certificate) override {
+    local_cert_ = certificate;
+    return true;
+  }
+  void SetRemoteSSLCertificate(rtc::FakeSSLCertificate* cert) {
+    remote_cert_ = cert;
+  }
+  bool IsDtlsActive() const override { return do_dtls_; }
+  bool SetSrtpCryptoSuites(const std::vector<int>& ciphers) override {
+    srtp_ciphers_ = ciphers;
+    return true;
+  }
+  bool GetSrtpCryptoSuite(int* crypto_suite) override {
+    if (chosen_crypto_suite_ != rtc::SRTP_INVALID_CRYPTO_SUITE) {
+      *crypto_suite = chosen_crypto_suite_;
+      return true;
+    }
+    return false;
+  }
+  bool GetSslCipherSuite(int* cipher_suite) override { return false; }
+  rtc::scoped_refptr<rtc::RTCCertificate> GetLocalCertificate() const override {
+    return local_cert_;
+  }
+  std::unique_ptr<rtc::SSLCertificate> GetRemoteSSLCertificate()
+      const override {
+    return remote_cert_ ? std::unique_ptr<rtc::SSLCertificate>(
+                              remote_cert_->GetReference())
+                        : nullptr;
+  }
+  bool ExportKeyingMaterial(const std::string& label,
+                            const uint8_t* context,
+                            size_t context_len,
+                            bool use_context,
+                            uint8_t* result,
+                            size_t result_len) override {
+    if (chosen_crypto_suite_ != rtc::SRTP_INVALID_CRYPTO_SUITE) {
+      memset(result, 0xff, result_len);
+      return true;
+    }
+
+    return false;
+  }
+  void set_ssl_max_protocol_version(rtc::SSLProtocolVersion version) {
+    ssl_max_version_ = version;
+  }
+  rtc::SSLProtocolVersion ssl_max_protocol_version() const {
+    return ssl_max_version_;
+  }
+  bool SetSrtpCiphers(const std::vector<std::string>& ciphers) override {
+    std::vector<int> crypto_suites;
+    for (const auto cipher : ciphers) {
+      crypto_suites.push_back(rtc::SrtpCryptoSuiteFromName(cipher));
+    }
+    return SetSrtpCryptoSuites(crypto_suites);
+  }
+
+  IceTransportInternal* ice_transport() override { return ice_transport_; }
+
+  // PacketTransportInterface implementation, which passes through to fake ICE
+  // transport for sending actual packets.
+  bool writable() const override { return writable_; }
+  bool receiving() const override { return receiving_; }
+  int SendPacket(const char* data,
+                 size_t len,
+                 const rtc::PacketOptions& options,
+                 int flags) override {
+    // We expect only SRTP packets to be sent through this interface.
+    if (flags != PF_SRTP_BYPASS && flags != 0) {
+      return -1;
+    }
+    return ice_transport_->SendPacket(data, len, options, flags);
+  }
+  int SetOption(rtc::Socket::Option opt, int value) override {
+    return ice_transport_->SetOption(opt, value);
+  }
+  bool GetOption(rtc::Socket::Option opt, int* value) override {
+    return ice_transport_->GetOption(opt, value);
+  }
+  int GetError() override { return ice_transport_->GetError(); }
+
+ private:
+  void OnIceTransportReadPacket(PacketTransportInterface* ice_,
+                                const char* data,
+                                size_t len,
+                                const rtc::PacketTime& time,
+                                int flags) {
+    SignalReadPacket(this, data, len, time, flags);
+  }
+
+  void NegotiateSrtpCiphers() {
+    for (std::vector<int>::const_iterator it1 = srtp_ciphers_.begin();
+         it1 != srtp_ciphers_.end(); ++it1) {
+      for (std::vector<int>::const_iterator it2 = dest_->srtp_ciphers_.begin();
+           it2 != dest_->srtp_ciphers_.end(); ++it2) {
+        if (*it1 == *it2) {
+          chosen_crypto_suite_ = *it1;
+          return;
+        }
+      }
+    }
+  }
+
+  void set_receiving(bool receiving) {
+    if (receiving_ == receiving) {
+      return;
+    }
+    receiving_ = receiving;
+    SignalReceivingState(this);
+  }
+
+  void set_writable(bool writable) {
+    if (writable_ == writable) {
+      return;
+    }
+    writable_ = writable;
+    if (writable_) {
+      SignalReadyToSend(this);
+    }
+    SignalWritableState(this);
+  }
+
+  FakeIceTransport* ice_transport_;
+  std::unique_ptr<FakeIceTransport> owned_ice_transport_;
+  std::string transport_name_;
+  int component_;
+  FakeDtlsTransport* dest_ = nullptr;
+  rtc::scoped_refptr<rtc::RTCCertificate> local_cert_;
+  rtc::FakeSSLCertificate* remote_cert_ = nullptr;
+  bool do_dtls_ = false;
+  std::vector<int> srtp_ciphers_;
+  int chosen_crypto_suite_ = rtc::SRTP_INVALID_CRYPTO_SUITE;
+  rtc::SSLProtocolVersion ssl_max_version_ = rtc::SSL_PROTOCOL_DTLS_12;
+  rtc::SSLFingerprint dtls_fingerprint_;
+  rtc::SSLRole ssl_role_ = rtc::SSL_CLIENT;
+
+  DtlsTransportState dtls_state_ = DTLS_TRANSPORT_NEW;
+
+  bool receiving_ = false;
+  bool writable_ = false;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_FAKEDTLSTRANSPORT_H_