lacros: Provide synchronous version info for crosapi ash interfaces.

Ash now sends, at lacros startup, a map of all crosapi interfaces and
their versions to Lacros. Lacros can use this map to synchronously query
version info.

Bug: 1136652
Change-Id: I14be7f1c9c39709e342c6ab8045587f7d1245e74
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2454629
Commit-Queue: Erik Chen <erikchen@chromium.org>
Reviewed-by: James Cook <jamescook@chromium.org>
Reviewed-by: Greg Kerr <kerrnel@chromium.org>
Auto-Submit: Erik Chen <erikchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#816273}

chrome/browser/chromeos/crosapi/browser_util.cc

@@ -7,6 +7,7 @@
 #include <utility>
 
 #include "base/callback.h"
+#include "base/containers/flat_map.h"
 #include "base/files/file_path.h"
 #include "base/path_service.h"
 #include "base/process/process_handle.h"
@@ -58,6 +59,12 @@ bool IsUserTypeAllowed(const User* user) {
   }
 }
 
+using InterfaceVersions = base::flat_map<base::Token, uint32_t>;
+template <typename T>
+void AddVersion(InterfaceVersions* map) {
+  (*map)[T::Uuid_] = T::Version_;
+}
+
 mojom::LacrosInitParamsPtr GetLacrosInitParams(
     EnvironmentProvider* environment_provider) {
   auto params = mojom::LacrosInitParams::New();
@@ -69,6 +76,8 @@ mojom::LacrosInitParamsPtr GetLacrosInitParams(
 
   params->session_type = environment_provider->GetSessionType();
   params->device_mode = environment_provider->GetDeviceMode();
+  params->interface_versions = GetInterfaceVersions();
+
   return params;
 }
 
@@ -134,6 +143,23 @@ bool IsLacrosWindow(const aura::Window* window) {
   return base::StartsWith(*app_id, kLacrosAppIdPrefix);
 }
 
+base::flat_map<base::Token, uint32_t> GetInterfaceVersions() {
+  static_assert(
+      crosapi::mojom::AshChromeService::Version_ == 4,
+      "if you add a new crosapi, please add it to the version map here");
+  InterfaceVersions versions;
+  AddVersion<crosapi::mojom::AccountManager>(&versions);
+  AddVersion<crosapi::mojom::AshChromeService>(&versions);
+  AddVersion<crosapi::mojom::Feedback>(&versions);
+  AddVersion<crosapi::mojom::KeystoreService>(&versions);
+  AddVersion<crosapi::mojom::MessageCenter>(&versions);
+  AddVersion<crosapi::mojom::ScreenManager>(&versions);
+  AddVersion<crosapi::mojom::SnapshotCapturer>(&versions);
+  AddVersion<device::mojom::HidConnection>(&versions);
+  AddVersion<device::mojom::HidManager>(&versions);
+  return versions;
+}
+
 mojo::Remote<crosapi::mojom::LacrosChromeService>
 SendMojoInvitationToLacrosChrome(
     EnvironmentProvider* environment_provider,

chrome/browser/chromeos/crosapi/browser_util.h

@@ -6,6 +6,8 @@
 #define CHROME_BROWSER_CHROMEOS_CROSAPI_BROWSER_UTIL_H_
 
 #include "base/callback_forward.h"
+#include "base/containers/flat_map.h"
+#include "base/token.h"
 #include "chrome/browser/chromeos/crosapi/environment_provider.h"
 #include "chromeos/crosapi/mojom/crosapi.mojom.h"
 #include "mojo/public/cpp/bindings/pending_receiver.h"
@@ -53,6 +55,9 @@ bool IsLacrosAllowed(version_info::Channel channel);
 // browser.
 bool IsLacrosWindow(const aura::Window* window);
 
+// Returns the UUID and version for all tracked interfaces. Exposed for testing.
+base::flat_map<base::Token, uint32_t> GetInterfaceVersions();
+
 // Invite the lacros-chrome to the mojo universe.
 // Queue messages to establish the mojo connection, so that the passed IPC is
 // available already when lacros-chrome accepts the invitation.

chrome/browser/chromeos/crosapi/browser_util_unittest.cc

@@ -13,6 +13,7 @@
 #include "chrome/test/base/scoped_testing_local_state.h"
 #include "chrome/test/base/testing_browser_process.h"
 #include "chrome/test/base/testing_profile.h"
+#include "chromeos/crosapi/mojom/crosapi.mojom.h"
 #include "components/account_id/account_id.h"
 #include "components/user_manager/scoped_user_manager.h"
 #include "components/version_info/channel.h"
@@ -92,4 +93,18 @@ TEST_F(LacrosUtilTest, BlockedForChildUser) {
   EXPECT_FALSE(browser_util::IsLacrosAllowed(Channel::UNKNOWN));
 }
 
+TEST_F(LacrosUtilTest, GetInterfaceVersions) {
+  base::flat_map<base::Token, uint32_t> versions =
+      browser_util::GetInterfaceVersions();
+
+  // Check that a known interface with version > 0 is present and has non-zero
+  // version.
+  EXPECT_GT(versions[mojom::KeystoreService::Uuid_], 0);
+
+  // Check that the empty token is not present.
+  base::Token token;
+  auto it = versions.find(token);
+  EXPECT_EQ(it, versions.end());
+}
+
 }  // namespace crosapi

chromeos/crosapi/mojom/crosapi.mojom

@@ -10,6 +10,7 @@ import "chromeos/crosapi/mojom/keystore_service.mojom";
 import "chromeos/crosapi/mojom/message_center.mojom";
 import "chromeos/crosapi/mojom/screen_manager.mojom";
 import "chromeos/crosapi/mojom/select_file.mojom";
+import "mojo/public/mojom/base/token.mojom";
 import "services/device/public/mojom/hid.mojom";
 
 // LacrosInfo is a set of parameters passed to ash from lacros-chrome
@@ -143,6 +144,14 @@ struct LacrosInitParams {
   // user chooses to enroll the device).
   [MinVersion=4]
   DeviceMode device_mode@4;
+
+  // Ash sends all known crosapi interfaces and their versions at startup so
+  // that Lacros can synchronously query version info. Interfaces are identified
+  // by a UUID, which is manually generated and assigned via the UUID mojom
+  // qualifier.
+  // Added in M88.
+  [MinVersion=5]
+  map<mojo_base.mojom.Token, uint32>? interface_versions@5;
 };
 
 // LacrosChromeService defines the APIs that live in lacros-chrome and

chromeos/lacros/lacros_chrome_service_impl.cc

@@ -359,6 +359,20 @@ bool LacrosChromeServiceImpl::IsOnLacrosStartupAvailable() {
   return AshChromeServiceVersion() >= 3;
 }
 
+int LacrosChromeServiceImpl::GetInterfaceVersion(
+    base::Token interface_uuid) const {
+  if (g_disable_all_crosapi_for_tests)
+    return -1;
+  if (!init_params_->interface_versions)
+    return -1;
+  const base::flat_map<base::Token, uint32_t>& versions =
+      init_params_->interface_versions.value();
+  auto it = versions.find(interface_uuid);
+  if (it == versions.end())
+    return -1;
+  return it->second;
+}
+
 void LacrosChromeServiceImpl::BindScreenManagerReceiver(
     mojo::PendingReceiver<crosapi::mojom::ScreenManager> pending_receiver) {
   DCHECK(IsScreenManagerAvailable());

chromeos/lacros/lacros_chrome_service_impl.h

@@ -166,6 +166,12 @@ class COMPONENT_EXPORT(CHROMEOS_LACROS) LacrosChromeServiceImpl {
     return init_params_.get();
   }
 
+  // Returns the version for an ash interface with a given UUID. Returns -1 if
+  // the interface is not found. This is a synchronous version of
+  // mojo::Remote::QueryVersion. It relies on Ash M88. Features that need to
+  // work on M87 or older should not use this.
+  int GetInterfaceVersion(base::Token interface_uuid) const;
+
  private:
   // LacrosChromeServiceNeverBlockingState is an implementation detail of this
   // class.