Add CastSocket and implementation

This change adds a CastSocket interface to handle sending and receiving
CastMessage structures along with an implementation that uses the
platform TlsConnection for transport.

Bug: openscreen:59
Change-Id: I92dc29b45efb2b1657a2ff6d962f1ed670311370
Reviewed-on: https://chromium-review.googlesource.com/c/openscreen/+/1825511
Commit-Queue: Brandon Tolsch <btolsch@chromium.org>
Reviewed-by: Ryan Keane <rwkeane@google.com>

8 files changed, 4 insertions, 452 deletions

diff --git a/cast/sender/channel/BUILD.gn b/cast/sender/channel/BUILD.gn
index 13b061c1..85f633b0 100644
--- a/cast/sender/channel/BUILD.gn
+++ b/cast/sender/channel/BUILD.gn
@@ -6,18 +6,14 @@ source_set("channel") {
   sources = [
     "cast_auth_util.cc",
     "cast_auth_util.h",
-    "cast_framer.cc",
-    "cast_framer.h",
   ]
 
   deps = [
-    "../../../util",
-    "proto",
+    "../../common/channel/proto",
   ]
 
   public_deps = [
     "../../../platform",
-    "../../../third_party/abseil",
   ]
 }
 
@@ -25,15 +21,13 @@ source_set("unittests") {
   testonly = true
   sources = [
     "cast_auth_util_unittest.cc",
-    "cast_framer_unittest.cc",
   ]
 
   deps = [
     ":channel",
     "../../../platform",
     "../../../third_party/googletest:gtest",
-    "../../../util",
     "../../common/certificate/proto:unittest_proto",
-    "proto",
+    "../../common/channel/proto",
   ]
 }
diff --git a/cast/sender/channel/cast_auth_util.h b/cast/sender/channel/cast_auth_util.h
index b4a81e0b..35f1d028 100644
--- a/cast/sender/channel/cast_auth_util.h
+++ b/cast/sender/channel/cast_auth_util.h
@@ -10,7 +10,7 @@
 #include <string>
 
 #include "cast/common/certificate/cast_cert_validator.h"
-#include "cast/sender/channel/proto/cast_channel.pb.h"
+#include "cast/common/channel/proto/cast_channel.pb.h"
 #include "platform/base/error.h"
 
 namespace cast {
diff --git a/cast/sender/channel/cast_auth_util_unittest.cc b/cast/sender/channel/cast_auth_util_unittest.cc
index 10819362..61d49aa1 100644
--- a/cast/sender/channel/cast_auth_util_unittest.cc
+++ b/cast/sender/channel/cast_auth_util_unittest.cc
@@ -10,7 +10,7 @@
 #include "cast/common/certificate/cast_crl.h"
 #include "cast/common/certificate/proto/test_suite.pb.h"
 #include "cast/common/certificate/test_helpers.h"
-#include "cast/sender/channel/proto/cast_channel.pb.h"
+#include "cast/common/channel/proto/cast_channel.pb.h"
 #include "gtest/gtest.h"
 #include "platform/api/logging.h"
 #include "platform/api/time.h"
diff --git a/cast/sender/channel/cast_framer.cc b/cast/sender/channel/cast_framer.cc
deleted file mode 100644
index b5a8acb1..00000000
--- a/cast/sender/channel/cast_framer.cc
+++ /dev/null
@@ -1,94 +0,0 @@
-// Copyright 2019 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "cast/sender/channel/cast_framer.h"
-
-#include <stdlib.h>
-#include <string.h>
-
-#include <limits>
-
-#include "cast/sender/channel/proto/cast_channel.pb.h"
-#include "platform/api/logging.h"
-#include "util/big_endian.h"
-#include "util/std_util.h"
-
-namespace cast {
-namespace channel {
-
-using ChannelError = openscreen::Error::Code;
-
-namespace {
-
-static constexpr size_t kHeaderSize = sizeof(uint32_t);
-
-// Cast specifies a max message body size of 64 KiB.
-static constexpr size_t kMaxBodySize = 65536;
-
-}  // namespace
-
-MessageFramer::MessageFramer(absl::Span<uint8_t> input_buffer)
-    : input_buffer_(input_buffer) {}
-
-MessageFramer::~MessageFramer() = default;
-
-// static
-ErrorOr<std::string> MessageFramer::Serialize(const CastMessage& message) {
-  const size_t message_size = message.ByteSizeLong();
-  if (message_size > kMaxBodySize || message_size == 0) {
-    return ChannelError::kCastV2InvalidMessage;
-  }
-  std::string out(message_size + kHeaderSize, 0);
-  openscreen::WriteBigEndian<uint32_t>(message_size, openscreen::data(out));
-  if (!message.SerializeToArray(&out[kHeaderSize], message_size)) {
-    return ChannelError::kCastV2InvalidMessage;
-  }
-  return out;
-}
-
-ErrorOr<size_t> MessageFramer::BytesRequested() const {
-  if (message_bytes_received_ < kHeaderSize) {
-    return kHeaderSize - message_bytes_received_;
-  }
-
-  const uint32_t message_size =
-      openscreen::ReadBigEndian<uint32_t>(input_buffer_.data());
-  if (message_size > kMaxBodySize) {
-    return ChannelError::kCastV2InvalidMessage;
-  }
-  return (kHeaderSize + message_size) - message_bytes_received_;
-}
-
-ErrorOr<CastMessage> MessageFramer::TryDeserialize(size_t byte_count) {
-  message_bytes_received_ += byte_count;
-  if (message_bytes_received_ > input_buffer_.size()) {
-    return ChannelError::kCastV2InvalidMessage;
-  }
-
-  if (message_bytes_received_ < kHeaderSize) {
-    return ChannelError::kInsufficientBuffer;
-  }
-
-  const uint32_t message_size =
-      openscreen::ReadBigEndian<uint32_t>(input_buffer_.data());
-  if (message_size > kMaxBodySize) {
-    return ChannelError::kCastV2InvalidMessage;
-  }
-
-  if (message_bytes_received_ < (kHeaderSize + message_size)) {
-    return ChannelError::kInsufficientBuffer;
-  }
-
-  CastMessage parsed_message;
-  if (!parsed_message.ParseFromArray(input_buffer_.data() + kHeaderSize,
-                                     message_size)) {
-    return ChannelError::kCastV2InvalidMessage;
-  }
-
-  message_bytes_received_ = 0;
-  return parsed_message;
-}
-
-}  // namespace channel
-}  // namespace cast
diff --git a/cast/sender/channel/cast_framer.h b/cast/sender/channel/cast_framer.h
deleted file mode 100644
index 8fbabfd3..00000000
--- a/cast/sender/channel/cast_framer.h
+++ /dev/null
@@ -1,59 +0,0 @@
-// Copyright 2019 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef CAST_SENDER_CHANNEL_CAST_FRAMER_H_
-#define CAST_SENDER_CHANNEL_CAST_FRAMER_H_
-
-#include <stddef.h>
-#include <stdint.h>
-
-#include <memory>
-#include <string>
-
-#include "absl/types/span.h"
-#include "platform/base/error.h"
-
-namespace cast {
-namespace channel {
-
-class CastMessage;
-
-using openscreen::ErrorOr;
-
-// Class for constructing and parsing CastMessage packet data.
-class MessageFramer {
- public:
-  // Serializes |message_proto| into |message_data|.
-  // Returns true if the message was serialized successfully, false otherwise.
-  static ErrorOr<std::string> Serialize(const CastMessage& message);
-
-  explicit MessageFramer(absl::Span<uint8_t> input_buffer);
-  ~MessageFramer();
-
-  // The number of bytes required from the next |input_buffer| passed to
-  // TryDeserialize to complete the CastMessage being read.  Returns zero if
-  // there has been a parsing error.
-  ErrorOr<size_t> BytesRequested() const;
-
-  // Reads bytes from |input_buffer_| and returns a new CastMessage if one is
-  // fully read.
-  //
-  // |byte_count|     Number of additional bytes available in |input_buffer_|.
-  // Returns a pointer to a parsed CastMessage if a message was received in its
-  // entirety, empty unique_ptr if parsing was successful but didn't produce a
-  // complete message, and an error otherwise.
-  ErrorOr<CastMessage> TryDeserialize(size_t byte_count);
-
- private:
-  // Total size of the message received so far in bytes (head + body).
-  size_t message_bytes_received_ = 0;
-
-  // Data buffer wherein the caller should place message data for ingest.
-  absl::Span<uint8_t> input_buffer_;
-};
-
-}  // namespace channel
-}  // namespace cast
-
-#endif  // CAST_SENDER_CHANNEL_CAST_FRAMER_H_
diff --git a/cast/sender/channel/cast_framer_unittest.cc b/cast/sender/channel/cast_framer_unittest.cc
deleted file mode 100644
index 0cd10c71..00000000
--- a/cast/sender/channel/cast_framer_unittest.cc
+++ /dev/null
@@ -1,179 +0,0 @@
-// Copyright 2019 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "cast/sender/channel/cast_framer.h"
-
-#include <stddef.h>
-
-#include <algorithm>
-#include <string>
-
-#include "cast/sender/channel/proto/cast_channel.pb.h"
-#include "gtest/gtest.h"
-#include "util/big_endian.h"
-#include "util/std_util.h"
-
-namespace cast {
-namespace channel {
-
-using ChannelError = openscreen::Error::Code;
-
-namespace {
-
-static constexpr size_t kHeaderSize = sizeof(uint32_t);
-
-// Cast specifies a max message body size of 64 KiB.
-static constexpr size_t kMaxBodySize = 65536;
-
-}  // namespace
-
-class CastFramerTest : public testing::Test {
- public:
-  CastFramerTest()
-      : buffer_(kHeaderSize + kMaxBodySize),
-        framer_(absl::Span<uint8_t>(&buffer_[0], buffer_.size())) {}
-
-  void SetUp() override {
-    cast_message_.set_protocol_version(CastMessage::CASTV2_1_0);
-    cast_message_.set_source_id("source");
-    cast_message_.set_destination_id("destination");
-    cast_message_.set_namespace_("namespace");
-    cast_message_.set_payload_type(CastMessage::STRING);
-    cast_message_.set_payload_utf8("payload");
-    ErrorOr<std::string> result = MessageFramer::Serialize(cast_message_);
-    ASSERT_TRUE(result.is_value());
-    cast_message_str_ = std::move(result.value());
-  }
-
-  void WriteToBuffer(const std::string& data) {
-    memcpy(&buffer_[0], data.data(), data.size());
-  }
-
- protected:
-  CastMessage cast_message_;
-  std::string cast_message_str_;
-  std::vector<uint8_t> buffer_;
-  MessageFramer framer_;
-};
-
-TEST_F(CastFramerTest, TestMessageFramerCompleteMessage) {
-  WriteToBuffer(cast_message_str_);
-
-  // Receive 1 byte of the header, framer demands 3 more bytes.
-  EXPECT_EQ(4u, framer_.BytesRequested().value());
-  ErrorOr<CastMessage> result = framer_.TryDeserialize(1);
-  EXPECT_FALSE(result);
-  EXPECT_EQ(ChannelError::kInsufficientBuffer, result.error().code());
-  EXPECT_EQ(3u, framer_.BytesRequested().value());
-
-  // TryDeserialize remaining 3, expect that the framer has moved on to
-  // requesting the body contents.
-  result = framer_.TryDeserialize(3);
-  EXPECT_FALSE(result);
-  EXPECT_EQ(ChannelError::kInsufficientBuffer, result.error().code());
-  EXPECT_EQ(cast_message_str_.size() - kHeaderSize,
-            framer_.BytesRequested().value());
-
-  // Remainder of packet sent over the wire.
-  result = framer_.TryDeserialize(framer_.BytesRequested().value());
-  ASSERT_TRUE(result);
-  const CastMessage& message = result.value();
-  EXPECT_EQ(message.SerializeAsString(), cast_message_.SerializeAsString());
-  EXPECT_EQ(4u, framer_.BytesRequested().value());
-}
-
-TEST_F(CastFramerTest, BigEndianMessageHeader) {
-  WriteToBuffer(cast_message_str_);
-
-  EXPECT_EQ(4u, framer_.BytesRequested().value());
-  ErrorOr<CastMessage> result = framer_.TryDeserialize(4);
-  EXPECT_FALSE(result);
-  EXPECT_EQ(ChannelError::kInsufficientBuffer, result.error().code());
-
-  const uint32_t expected_size =
-      openscreen::ReadBigEndian<uint32_t>(openscreen::data(cast_message_str_));
-  EXPECT_EQ(expected_size, framer_.BytesRequested().value());
-}
-
-TEST_F(CastFramerTest, TestSerializeErrorMessageTooLarge) {
-  CastMessage big_message;
-  big_message.CopyFrom(cast_message_);
-  std::string payload;
-  payload.append(kMaxBodySize + 1, 'x');
-  big_message.set_payload_utf8(payload);
-  EXPECT_FALSE(MessageFramer::Serialize(big_message));
-}
-
-TEST_F(CastFramerTest, TestCompleteMessageAtOnce) {
-  WriteToBuffer(cast_message_str_);
-
-  ErrorOr<CastMessage> result =
-      framer_.TryDeserialize(cast_message_str_.size());
-  ASSERT_TRUE(result);
-  const CastMessage& message = result.value();
-  EXPECT_EQ(message.SerializeAsString(), cast_message_.SerializeAsString());
-  EXPECT_EQ(4u, framer_.BytesRequested().value());
-}
-
-TEST_F(CastFramerTest, TestTryDeserializeIllegalLargeMessage) {
-  std::string mangled_cast_message = cast_message_str_;
-  mangled_cast_message[0] = 88;
-  mangled_cast_message[1] = 88;
-  mangled_cast_message[2] = 88;
-  mangled_cast_message[3] = 88;
-  WriteToBuffer(mangled_cast_message);
-
-  EXPECT_EQ(4u, framer_.BytesRequested().value());
-  ErrorOr<CastMessage> result = framer_.TryDeserialize(4);
-  ASSERT_FALSE(result);
-  EXPECT_EQ(ChannelError::kCastV2InvalidMessage, result.error().code());
-  ErrorOr<size_t> bytes_requested = framer_.BytesRequested();
-  ASSERT_FALSE(bytes_requested);
-  EXPECT_EQ(ChannelError::kCastV2InvalidMessage,
-            bytes_requested.error().code());
-}
-
-TEST_F(CastFramerTest, TestTryDeserializeIllegalLargeMessage2) {
-  std::string mangled_cast_message = cast_message_str_;
-  // Header indicates body size is 0x00010001 = 65537
-  mangled_cast_message[0] = 0;
-  mangled_cast_message[1] = 0x1;
-  mangled_cast_message[2] = 0;
-  mangled_cast_message[3] = 0x1;
-  WriteToBuffer(mangled_cast_message);
-
-  EXPECT_EQ(4u, framer_.BytesRequested().value());
-  ErrorOr<CastMessage> result = framer_.TryDeserialize(4);
-  ASSERT_FALSE(result);
-  EXPECT_EQ(ChannelError::kCastV2InvalidMessage, result.error().code());
-  ErrorOr<size_t> bytes_requested = framer_.BytesRequested();
-  ASSERT_FALSE(bytes_requested);
-  EXPECT_EQ(ChannelError::kCastV2InvalidMessage,
-            bytes_requested.error().code());
-}
-
-TEST_F(CastFramerTest, TestUnparsableBodyProto) {
-  // Message header is OK, but the body is replaced with "x"es.
-  std::string mangled_cast_message = cast_message_str_;
-  for (size_t i = kHeaderSize; i < mangled_cast_message.size(); ++i) {
-    std::fill(mangled_cast_message.begin() + kHeaderSize,
-              mangled_cast_message.end(), 'x');
-  }
-  WriteToBuffer(mangled_cast_message);
-
-  // Send header.
-  EXPECT_EQ(4u, framer_.BytesRequested().value());
-  ErrorOr<CastMessage> result = framer_.TryDeserialize(4);
-  EXPECT_FALSE(result);
-  EXPECT_EQ(ChannelError::kInsufficientBuffer, result.error().code());
-  EXPECT_EQ(cast_message_str_.size() - 4, framer_.BytesRequested().value());
-
-  // Send body, expect an error.
-  result = framer_.TryDeserialize(framer_.BytesRequested().value());
-  ASSERT_FALSE(result);
-  EXPECT_EQ(ChannelError::kCastV2InvalidMessage, result.error().code());
-}
-
-}  // namespace channel
-}  // namespace cast
diff --git a/cast/sender/channel/proto/BUILD.gn b/cast/sender/channel/proto/BUILD.gn
deleted file mode 100644
index c3bfa439..00000000
--- a/cast/sender/channel/proto/BUILD.gn
+++ /dev/null
@@ -1,11 +0,0 @@
-# Copyright 2019 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-import("//third_party/protobuf/proto_library.gni")
-
-proto_library("proto") {
-  sources = [
-    "cast_channel.proto",
-  ]
-}
diff --git a/cast/sender/channel/proto/cast_channel.proto b/cast/sender/channel/proto/cast_channel.proto
deleted file mode 100644
index 57c7b3f3..00000000
--- a/cast/sender/channel/proto/cast_channel.proto
+++ /dev/null
@@ -1,99 +0,0 @@
-// Copyright 2019 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-syntax = "proto2";
-
-option optimize_for = LITE_RUNTIME;
-
-package cast.channel;
-
-message CastMessage {
-  // Always pass a version of the protocol for future compatibility
-  // requirements.
-  enum ProtocolVersion { CASTV2_1_0 = 0; }
-  required ProtocolVersion protocol_version = 1;
-
-  // source and destination ids identify the origin and destination of the
-  // message.  They are used to route messages between endpoints that share a
-  // device-to-device channel.
-  //
-  // For messages between applications:
-  //   - The sender application id is a unique identifier generated on behalf of
-  //     the sender application.
-  //   - The receiver id is always the the session id for the application.
-  //
-  // For messages to or from the sender or receiver platform, the special ids
-  // 'sender-0' and 'receiver-0' can be used.
-  //
-  // For messages intended for all endpoints using a given channel, the
-  // wildcard destination_id '*' can be used.
-  required string source_id = 2;
-  required string destination_id = 3;
-
-  // This is the core multiplexing key.  All messages are sent on a namespace
-  // and endpoints sharing a channel listen on one or more namespaces.  The
-  // namespace defines the protocol and semantics of the message.
-  required string namespace = 4;
-
-  // Encoding and payload info follows.
-
-  // What type of data do we have in this message.
-  enum PayloadType {
-    STRING = 0;
-    BINARY = 1;
-  }
-  required PayloadType payload_type = 5;
-
-  // Depending on payload_type, exactly one of the following optional fields
-  // will always be set.
-  optional string payload_utf8 = 6;
-  optional bytes payload_binary = 7;
-}
-
-enum SignatureAlgorithm {
-  UNSPECIFIED = 0;
-  RSASSA_PKCS1v15 = 1;
-  RSASSA_PSS = 2;
-}
-
-enum HashAlgorithm {
-  SHA1 = 0;
-  SHA256 = 1;
-}
-
-// Messages for authentication protocol between a sender and a receiver.
-message AuthChallenge {
-  optional SignatureAlgorithm signature_algorithm = 1
-      [default = RSASSA_PKCS1v15];
-  optional bytes sender_nonce = 2;
-  optional HashAlgorithm hash_algorithm = 3 [default = SHA1];
-}
-
-message AuthResponse {
-  required bytes signature = 1;
-  required bytes client_auth_certificate = 2;
-  repeated bytes intermediate_certificate = 3;
-  optional SignatureAlgorithm signature_algorithm = 4
-      [default = RSASSA_PKCS1v15];
-  optional bytes sender_nonce = 5;
-  optional HashAlgorithm hash_algorithm = 6 [default = SHA1];
-  optional bytes crl = 7;
-}
-
-message AuthError {
-  enum ErrorType {
-    INTERNAL_ERROR = 0;
-    NO_TLS = 1;  // The underlying connection is not TLS
-    SIGNATURE_ALGORITHM_UNAVAILABLE = 2;
-  }
-  required ErrorType error_type = 1;
-}
-
-message DeviceAuthMessage {
-  // Request fields
-  optional AuthChallenge challenge = 1;
-  // Response fields
-  optional AuthResponse response = 2;
-  optional AuthError error = 3;
-}