Discovery: CastV2 Struct

This CL introduces a new CastV2 specific struct to hold all service-
instance related information. It is intended for use with the top-level
discovery API shown here:
https://chromium-review.googlesource.com/c/openscreen/+/1959588

Change-Id: I47230dc785e557598c7f56754f247e873d1dd433
Reviewed-on: https://chromium-review.googlesource.com/c/openscreen/+/1961045
Commit-Queue: Ryan Keane <rwkeane@google.com>
Reviewed-by: mark a. foltz <mfoltz@chromium.org>

6 files changed, 114 insertions, 2 deletions

diff --git a/BUILD.gn b/BUILD.gn
index 45c89852..056c7d0d 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -11,6 +11,7 @@ group("gn_all") {
   deps = [
     "cast/common:certificate",
     "cast/common:channel",
+    "cast/common:discovery",
     "cast/sender:channel",
     "cast/streaming:receiver",
     "cast/streaming:sender",
diff --git a/cast/common/BUILD.gn b/cast/common/BUILD.gn
index 537153bd..5e3227da 100644
--- a/cast/common/BUILD.gn
+++ b/cast/common/BUILD.gn
@@ -59,6 +59,18 @@ source_set("channel") {
   ]
 }
 
+source_set("discovery") {
+  sources = [
+    "discovery/service_info.h",
+  ]
+
+  deps = []
+
+  public_deps = [
+    "../../platform",
+  ]
+}
+
 source_set("test_helpers") {
   testonly = true
   sources = [
diff --git a/cast/common/discovery/service_info.h b/cast/common/discovery/service_info.h
new file mode 100644
index 00000000..cd028f86
--- /dev/null
+++ b/cast/common/discovery/service_info.h
@@ -0,0 +1,72 @@
+// 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_COMMON_DISCOVERY_SERVICE_INFO_H_
+#define CAST_COMMON_DISCOVERY_SERVICE_INFO_H_
+
+#include <memory>
+#include <string>
+
+#include "platform/base/ip_address.h"
+
+namespace openscreen {
+namespace cast {
+
+// This represents the ‘st’ flag in the CastV2 TXT record.
+enum ReceiverStatus {
+  // The receiver is idle and does not need to be connected now.
+  kIdle = 0,
+
+  // The receiver is hosting an activity and invites the sender to join.  The
+  // receiver should connect to the running activity using the channel
+  // establishment protocol, and then query the activity to determine the next
+  // step, such as showing a description of the activity and prompting the user
+  // to launch the corresponding app.
+  kBusy = 1,
+  kJoin = kBusy
+};
+
+// This represents the ‘ca’ field in the CastV2 spec.
+enum ReceiverCapabilities : uint64_t {
+  kHasVideoOutput = 0x01 << 0,
+  kHasVideoInput = 0x01 << 1,
+  kHasAudioOutput = 0x01 << 2,
+  kHasAudioInput = 0x01 << 3,
+  kIsDevModeEnabled = 0x01 << 4,
+};
+
+// This is the top-level service info class for CastV2. It describes a specific
+// service instance.
+struct ServiceInfo {
+  // Endpoints for the service. Present if an endpoint of this address type
+  // exists and empty otherwise.
+  IPEndpoint v4_address;
+  IPEndpoint v6_address;
+
+  // A UUID for the Cast receiver. This should be a universally unique
+  // identifier for the receiver, and should (but does not have to be) be stable
+  // across factory resets.
+  std::string unique_id;
+
+  // Cast protocol version supported. Begins at 2 and is incremented by 1 with
+  // each version.
+  uint8_t protocol_version;
+
+  // Capabilities supported by this service instance.
+  ReceiverCapabilities capabilities;
+
+  // Status of the service instance.
+  ReceiverStatus status;
+
+  // The model name of the device, e.g. “Eureka v1”, “Mollie”.
+  std::string model_name;
+
+  // The friendly name of the device, e.g. “Living Room TV".
+  std::string friendly_name;
+};
+
+}  // namespace cast
+}  // namespace openscreen
+
+#endif  // CAST_COMMON_DISCOVERY_SERVICE_INFO_H_
diff --git a/platform/base/ip_address.cc b/platform/base/ip_address.cc
index b95a443e..97870f6c 100644
--- a/platform/base/ip_address.cc
+++ b/platform/base/ip_address.cc
@@ -203,6 +203,10 @@ ErrorOr<IPAddress> IPAddress::ParseV6(const std::string& s) {
   return IPAddress(hextets);
 }
 
+IPEndpoint::operator bool() const {
+  return address || port;
+}
+
 bool operator==(const IPEndpoint& a, const IPEndpoint& b) {
   return (a.address == b.address) && (a.port == b.port);
 }
diff --git a/platform/base/ip_address.h b/platform/base/ip_address.h
index 2cd35352..aae3a13c 100644
--- a/platform/base/ip_address.h
+++ b/platform/base/ip_address.h
@@ -90,9 +90,10 @@ class IPAddress {
 struct IPEndpoint {
  public:
   IPAddress address;
-  uint16_t port;
-};
+  uint16_t port = 0;
 
+  explicit operator bool() const;
+};
 bool operator==(const IPEndpoint& a, const IPEndpoint& b);
 bool operator!=(const IPEndpoint& a, const IPEndpoint& b);
 
diff --git a/platform/base/ip_address_unittest.cc b/platform/base/ip_address_unittest.cc
index c012cc89..b18e8de0 100644
--- a/platform/base/ip_address_unittest.cc
+++ b/platform/base/ip_address_unittest.cc
@@ -257,4 +257,26 @@ TEST(IPAddressTest, V6ParseThreeDigitValue) {
                                        0x01, 0x23}));
 }
 
+TEST(IPAddressTest, IPEndpointBoolOperator) {
+  IPEndpoint endpoint;
+  if (endpoint) {
+    FAIL();
+  }
+
+  endpoint = IPEndpoint{{192, 168, 0, 1}, 80};
+  if (!endpoint) {
+    FAIL();
+  }
+
+  endpoint = IPEndpoint{{192, 168, 0, 1}, 0};
+  if (!endpoint) {
+    FAIL();
+  }
+
+  endpoint = IPEndpoint{{}, 80};
+  if (!endpoint) {
+    FAIL();
+  }
+}
+
 }  // namespace openscreen