Bug 1846848 - part5 : display MFCDM capabilites in `about:support`. r=fluent-reviewers,gerard-majax,jolin,niklas

This patch implements retrieving the capabilities from MFCDMs. I will
add non-MFCDM support in following patches, eg. Widevine L3, and
ClearKey.

Differential Revision: https://phabricator.services.mozilla.com/D194837

dom/base/ChromeUtils.cpp

@@ -52,6 +52,8 @@
 #include "mozilla/ipc/UtilityProcessManager.h"
 #include "mozilla/ipc/UtilityProcessHost.h"
 #include "mozilla/net/UrlClassifierFeatureFactory.h"
+#include "mozilla/RemoteDecoderManagerChild.h"
+#include "mozilla/KeySystemConfig.h"
 #include "mozilla/WheelHandlingHelper.h"
 #include "IOActivityMonitor.h"
 #include "nsNativeTheme.h"
@@ -74,6 +76,10 @@
 #  endif
 #endif
 
+#ifdef MOZ_WMF_CDM
+#  include "mozilla/MFCDMParent.h"
+#endif
+
 namespace mozilla::dom {
 
 /* static */
@@ -1922,4 +1928,20 @@ void ChromeUtils::NotifyDevToolsClosed(GlobalObject& aGlobal) {
   ChromeUtils::sDevToolsOpenedCount--;
 }
 
+#ifdef MOZ_WMF_CDM
+/* static */
+already_AddRefed<Promise> ChromeUtils::GetWMFContentDecryptionModuleInformation(
+    GlobalObject& aGlobal, ErrorResult& aRv) {
+  nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(aGlobal.GetAsSupports());
+  MOZ_ASSERT(global);
+  RefPtr<Promise> domPromise = Promise::Create(global, aRv);
+  if (NS_WARN_IF(aRv.Failed())) {
+    return nullptr;
+  }
+  MOZ_ASSERT(domPromise);
+  MFCDMCapabilities::GetAllKeySystemsCapabilities(domPromise);
+  return domPromise.forget();
+}
+#endif
+
 }  // namespace mozilla::dom

dom/base/ChromeUtils.h

@@ -308,6 +308,11 @@ class ChromeUtils {
       GlobalObject& aGlobal, JSRFPTarget aTarget,
       const Nullable<uint64_t>& aOverriddenFingerprintingSettings);
 
+#ifdef MOZ_WMF_CDM
+  static already_AddRefed<Promise> GetWMFContentDecryptionModuleInformation(
+      GlobalObject& aGlobal, ErrorResult& aRv);
+#endif
+
  private:
   // Number of DevTools session debugging the current process
   static std::atomic<uint32_t> sDevToolsOpenedCount;

dom/chrome-webidl/ChromeUtils.webidl

@@ -297,6 +297,15 @@ namespace ChromeUtils {
   LibcConstants getLibcConstants();
 #endif
 
+#ifdef MOZ_WMF_CDM
+  /**
+   * Returns the information about all Media Foundation based content decryption
+   * modules, which would include key system names and their capabilities.
+   */
+  [NewObject]
+  Promise<sequence<CDMInformation>> getWMFContentDecryptionModuleInformation();
+#endif
+
   /**
    * IF YOU ADD NEW METHODS HERE, MAKE SURE THEY ARE THREAD-SAFE.
    */
@@ -1079,3 +1088,8 @@ dictionary LibcConstants {
 #endif
 };
 #endif
+
+dictionary CDMInformation {
+  required DOMString keySystemName;
+  required DOMString capabilities;
+};

dom/media/eme/EMEUtils.cpp

@@ -12,6 +12,11 @@
 #include "mozilla/dom/KeySystemNames.h"
 #include "mozilla/dom/UnionTypes.h"
 
+#ifdef MOZ_WMF_CDM
+#  include "mozilla/PMFCDM.h"
+#  include "KeySystemConfig.h"
+#endif
+
 namespace mozilla {
 
 LogModule* GetEMELog() {
@@ -140,4 +145,45 @@ const char* EncryptionSchemeStr(const CryptoScheme& aScheme) {
   }
 }
 
+#ifdef MOZ_WMF_CDM
+void MFCDMCapabilitiesIPDLToKeySystemConfig(
+    const MFCDMCapabilitiesIPDL& aCDMConfig,
+    KeySystemConfig& aKeySystemConfig) {
+  aKeySystemConfig.mKeySystem = aCDMConfig.keySystem();
+
+  for (const auto& type : aCDMConfig.initDataTypes()) {
+    aKeySystemConfig.mInitDataTypes.AppendElement(type);
+  }
+
+  for (const auto& type : aCDMConfig.sessionTypes()) {
+    aKeySystemConfig.mSessionTypes.AppendElement(type);
+  }
+
+  for (const auto& c : aCDMConfig.videoCapabilities()) {
+    if (!c.robustness().IsEmpty() &&
+        !aKeySystemConfig.mVideoRobustness.Contains(c.robustness())) {
+      aKeySystemConfig.mVideoRobustness.AppendElement(c.robustness());
+    }
+    aKeySystemConfig.mMP4.SetCanDecryptAndDecode(
+        NS_ConvertUTF16toUTF8(c.contentType()));
+  }
+  for (const auto& c : aCDMConfig.audioCapabilities()) {
+    if (!c.robustness().IsEmpty() &&
+        !aKeySystemConfig.mAudioRobustness.Contains(c.robustness())) {
+      aKeySystemConfig.mAudioRobustness.AppendElement(c.robustness());
+    }
+    aKeySystemConfig.mMP4.SetCanDecryptAndDecode(
+        NS_ConvertUTF16toUTF8(c.contentType()));
+  }
+  aKeySystemConfig.mPersistentState = aCDMConfig.persistentState();
+  aKeySystemConfig.mDistinctiveIdentifier = aCDMConfig.distinctiveID();
+  for (const auto& scheme : aCDMConfig.encryptionSchemes()) {
+    aKeySystemConfig.mEncryptionSchemes.AppendElement(
+        NS_ConvertUTF8toUTF16(EncryptionSchemeStr(scheme)));
+  }
+  EME_LOG("New Capabilities=%s",
+          NS_ConvertUTF16toUTF8(aKeySystemConfig.GetDebugInfo()).get());
+}
+#endif
+
 }  // namespace mozilla

dom/media/eme/EMEUtils.h

@@ -16,6 +16,10 @@
 namespace mozilla {
 
 enum class CryptoScheme : uint8_t;
+#ifdef MOZ_WMF_CDM
+class MFCDMCapabilitiesIPDL;
+#endif
+struct KeySystemConfig;
 
 namespace dom {
 class ArrayBufferViewOrArrayBuffer;
@@ -82,6 +86,11 @@ bool IsHardwareDecryptionSupported(
 
 const char* EncryptionSchemeStr(const CryptoScheme& aScheme);
 
+#ifdef MOZ_WMF_CDM
+void MFCDMCapabilitiesIPDLToKeySystemConfig(
+    const MFCDMCapabilitiesIPDL& aCDMConfig, KeySystemConfig& aKeySystemConfig);
+#endif
+
 }  // namespace mozilla
 
 #endif  // EME_LOG_H_

dom/media/eme/mediafoundation/WMFCDMImpl.cpp

@@ -29,47 +29,6 @@ bool WMFCDMImpl::Supports(const nsAString& aKeySystem) {
   return s;
 }
 
-static void MFCDMCapabilitiesIPDLToKeySystemConfig(
-    const MFCDMCapabilitiesIPDL& aCDMConfig,
-    KeySystemConfig& aKeySystemConfig) {
-  aKeySystemConfig.mKeySystem = aCDMConfig.keySystem();
-
-  for (const auto& type : aCDMConfig.initDataTypes()) {
-    aKeySystemConfig.mInitDataTypes.AppendElement(type);
-  }
-
-  for (const auto& type : aCDMConfig.sessionTypes()) {
-    aKeySystemConfig.mSessionTypes.AppendElement(type);
-  }
-
-  for (const auto& c : aCDMConfig.videoCapabilities()) {
-    if (!c.robustness().IsEmpty() &&
-        !aKeySystemConfig.mVideoRobustness.Contains(c.robustness())) {
-      aKeySystemConfig.mVideoRobustness.AppendElement(c.robustness());
-    }
-    aKeySystemConfig.mMP4.SetCanDecryptAndDecode(
-        NS_ConvertUTF16toUTF8(c.contentType()));
-  }
-  for (const auto& c : aCDMConfig.audioCapabilities()) {
-    if (!c.robustness().IsEmpty() &&
-        !aKeySystemConfig.mAudioRobustness.Contains(c.robustness())) {
-      aKeySystemConfig.mAudioRobustness.AppendElement(c.robustness());
-    }
-    aKeySystemConfig.mMP4.SetCanDecryptAndDecode(
-        NS_ConvertUTF16toUTF8(c.contentType()));
-  }
-  aKeySystemConfig.mPersistentState = aCDMConfig.persistentState();
-  aKeySystemConfig.mDistinctiveIdentifier = aCDMConfig.distinctiveID();
-
-  for (const auto& scheme : aCDMConfig.encryptionSchemes()) {
-    aKeySystemConfig.mEncryptionSchemes.AppendElement(
-        NS_ConvertUTF8toUTF16(CryptoSchemeToString(scheme)));
-  }
-
-  EME_LOG("New Capabilities=%s",
-          NS_ConvertUTF16toUTF8(aKeySystemConfig.GetDebugInfo()).get());
-}
-
 bool WMFCDMImpl::GetCapabilities(nsTArray<KeySystemConfig>& aOutConfigs) {
   nsCOMPtr<nsISerialEventTarget> backgroundTaskQueue;
   NS_CreateBackgroundTaskQueue(__func__, getter_AddRefs(backgroundTaskQueue));

dom/media/ipc/MFCDMParent.cpp

@@ -10,7 +10,11 @@
 #include <propkeydef.h>   // For DEFINE_PROPERTYKEY() definition
 #include <propvarutil.h>  // For InitPropVariantFrom*()
 
+#include "mozilla/dom/Promise.h"
 #include "mozilla/dom/KeySystemNames.h"
+#include "mozilla/ipc/UtilityAudioDecoderChild.h"
+#include "mozilla/ipc/UtilityProcessManager.h"
+#include "mozilla/ipc/UtilityProcessParent.h"
 #include "mozilla/EMEUtils.h"
 #include "mozilla/StaticMutex.h"
 #include "mozilla/StaticPrefs_media.h"
@@ -1067,6 +1071,76 @@ already_AddRefed<MFCDMProxy> MFCDMParent::GetMFCDMProxy() {
   return proxy.forget();
 }
 
+/* static */
+void MFCDMCapabilities::GetAllKeySystemsCapabilities(dom::Promise* aPromise) {
+  const static auto kSandboxKind = ipc::SandboxingKind::MF_MEDIA_ENGINE_CDM;
+  LaunchMFCDMProcessIfNeeded(kSandboxKind)
+      ->Then(
+          GetMainThreadSerialEventTarget(), __func__,
+          [promise = RefPtr(aPromise)]() {
+            RefPtr<ipc::UtilityAudioDecoderChild> uadc =
+                ipc::UtilityAudioDecoderChild::GetSingleton(kSandboxKind);
+            if (NS_WARN_IF(!uadc)) {
+              promise->MaybeReject(NS_ERROR_FAILURE);
+              return;
+            }
+            uadc->GetKeySystemCapabilities(promise);
+          },
+          [promise = RefPtr(aPromise)](nsresult aError) {
+            promise->MaybeReject(NS_ERROR_FAILURE);
+          });
+}
+
+/* static */
+RefPtr<GenericNonExclusivePromise>
+MFCDMCapabilities::LaunchMFCDMProcessIfNeeded(ipc::SandboxingKind aSandbox) {
+  MOZ_ASSERT(aSandbox == ipc::SandboxingKind::MF_MEDIA_ENGINE_CDM);
+  RefPtr<ipc::UtilityProcessManager> utilityProc =
+      ipc::UtilityProcessManager::GetSingleton();
+  if (NS_WARN_IF(!utilityProc)) {
+    NS_WARNING("Failed to get UtilityProcessManager");
+    return GenericNonExclusivePromise::CreateAndReject(NS_ERROR_FAILURE,
+                                                       __func__);
+  }
+
+  // Check if the MFCDM process exists or not. If not, launch it.
+  if (utilityProc->Process(aSandbox)) {
+    return GenericNonExclusivePromise::CreateAndResolve(true, __func__);
+  }
+
+  RefPtr<ipc::UtilityAudioDecoderChild> uadc =
+      ipc::UtilityAudioDecoderChild::GetSingleton(aSandbox);
+  if (NS_WARN_IF(!uadc)) {
+    NS_WARNING("Failed to get UtilityAudioDecoderChild");
+    return GenericNonExclusivePromise::CreateAndReject(NS_ERROR_FAILURE,
+                                                       __func__);
+  }
+  return utilityProc->StartUtility(uadc, aSandbox)
+      ->Then(
+          GetMainThreadSerialEventTarget(), __func__,
+          [uadc, utilityProc, aSandbox]() {
+            RefPtr<ipc::UtilityProcessParent> parent =
+                utilityProc->GetProcessParent(aSandbox);
+            if (!parent) {
+              NS_WARNING("UtilityAudioDecoderParent lost in the middle");
+              return GenericNonExclusivePromise::CreateAndReject(
+                  NS_ERROR_FAILURE, __func__);
+            }
+
+            if (!uadc->CanSend()) {
+              NS_WARNING("UtilityAudioDecoderChild lost in the middle");
+              return GenericNonExclusivePromise::CreateAndReject(
+                  NS_ERROR_FAILURE, __func__);
+            }
+            return GenericNonExclusivePromise::CreateAndResolve(true, __func__);
+          },
+          [](nsresult aError) {
+            NS_WARNING("Failed to start the MFCDM process!");
+            return GenericNonExclusivePromise::CreateAndReject(NS_ERROR_FAILURE,
+                                                               __func__);
+          });
+}
+
 #undef MFCDM_REJECT_IF_FAILED
 #undef MFCDM_REJECT_IF
 #undef MFCDM_RETURN_IF_FAILED

dom/media/ipc/MFCDMParent.h

@@ -140,6 +140,16 @@ class MFCDMParent final : public PMFCDMParent {
   MediaEventListener mExpirationListener;
 };
 
+// A helper class to display CDM capabilites in `about:support`.
+class MFCDMCapabilities {
+ public:
+  static void GetAllKeySystemsCapabilities(dom::Promise* aPromise);
+
+ private:
+  static RefPtr<GenericNonExclusivePromise> LaunchMFCDMProcessIfNeeded(
+      ipc::SandboxingKind aSandbox);
+};
+
 }  // namespace mozilla
 
 #endif  // DOM_MEDIA_IPC_MFCDMPARENT_H_

ipc/glue/UtilityAudioDecoderChild.cpp

@@ -20,6 +20,7 @@
 #endif
 
 #ifdef MOZ_WMF_CDM
+#  include "mozilla/dom/Promise.h"
 #  include "mozilla/EMEUtils.h"
 #  include "mozilla/PMFCDM.h"
 #endif
@@ -179,11 +180,14 @@ bool UtilityAudioDecoderChild::CreateVideoBridge() {
 #endif
 
 #ifdef MOZ_WMF_CDM
-void UtilityAudioDecoderChild::GetKeySystemCapabilities() {
+void UtilityAudioDecoderChild::GetKeySystemCapabilities(
+    dom::Promise* aPromise) {
   EME_LOG("Ask capabilities for all supported CDMs");
   SendGetKeySystemCapabilities()->Then(
       NS_GetCurrentThread(), __func__,
-      [](CopyableTArray<MFCDMCapabilitiesIPDL>&& result) {
+      [promise = RefPtr<dom::Promise>(aPromise)](
+          CopyableTArray<MFCDMCapabilitiesIPDL>&& result) {
+        FallibleTArray<dom::CDMInformation> cdmInfo;
         for (const auto& capabilities : result) {
           EME_LOG("Received capabilities for %s",
                   NS_ConvertUTF16toUTF8(capabilities.keySystem()).get());
@@ -199,7 +203,18 @@ void UtilityAudioDecoderChild::GetKeySystemCapabilities() {
             EME_LOG("  capabilities: encryptionScheme=%s",
                     EncryptionSchemeStr(e));
           }
+          auto* info = cdmInfo.AppendElement(fallible);
+          if (!info) {
+            promise->MaybeReject(NS_ERROR_OUT_OF_MEMORY);
+            return;
+          }
+          info->mKeySystemName = capabilities.keySystem();
+
+          KeySystemConfig config;
+          MFCDMCapabilitiesIPDLToKeySystemConfig(capabilities, config);
+          info->mCapabilities = config.GetDebugInfo();
         }
+        promise->MaybeResolve(cdmInfo);
       },
       [](const mozilla::ipc::ResponseRejectReason& aReason) {
         EME_LOG("IPC failure for GetKeySystemCapabilities!");

ipc/glue/UtilityAudioDecoderChild.h

@@ -108,7 +108,7 @@ class UtilityAudioDecoderChild final : public PUtilityAudioDecoderChild
 #endif
 
 #ifdef MOZ_WMF_CDM
-  void GetKeySystemCapabilities();
+  void GetKeySystemCapabilities(dom::Promise* aPromise);
 #endif
 
  private:

toolkit/content/aboutSupport.js

@@ -1105,6 +1105,94 @@ var snapshotFormatters = {
         .catch(e => {});
     }
 
+    function createCDMInfoRow(cdmInfo) {
+      function findElementInArray(array, name) {
+        const rv = array.find(element => element.includes(name));
+        return rv ? rv.split("=")[1] : "Unknown";
+      }
+
+      function getAudioRobustness(array) {
+        return findElementInArray(array, "audio-robustness");
+      }
+
+      function getVideoRobustness(array) {
+        return findElementInArray(array, "video-robustness");
+      }
+
+      function getSupportedCodecs(array) {
+        const mp4Content = findElementInArray(array, "MP4");
+        const webContent = findElementInArray(array, "WEBM");
+
+        const mp4DecodingAndDecryptingCodecs = mp4Content
+          .match(/decoding-and-decrypting:\[([^\]]*)\]/)[1]
+          .split(",");
+        const webmDecodingAndDecryptingCodecs = webContent
+          .match(/decoding-and-decrypting:\[([^\]]*)\]/)[1]
+          .split(",");
+
+        const mp4DecryptingOnlyCodecs = mp4Content
+          .match(/decrypting-only:\[([^\]]*)\]/)[1]
+          .split(",");
+        const webmDecryptingOnlyCodecs = webContent
+          .match(/decrypting-only:\[([^\]]*)\]/)[1]
+          .split(",");
+
+        // Combine and get unique codecs for decoding-and-decrypting (always)
+        // and decrypting-only (only set when it's not empty)
+        let rv = {};
+        rv.decodingAndDecrypting = [
+          ...new Set(
+            [
+              ...mp4DecodingAndDecryptingCodecs,
+              ...webmDecodingAndDecryptingCodecs,
+            ].filter(Boolean)
+          ),
+        ];
+        let temp = [
+          ...new Set(
+            [...mp4DecryptingOnlyCodecs, ...webmDecryptingOnlyCodecs].filter(
+              Boolean
+            )
+          ),
+        ];
+        if (temp.length) {
+          rv.decryptingOnly = temp;
+        }
+        return rv;
+      }
+
+      function getCapabilities(array) {
+        let capabilities = {};
+        capabilities.persistent = findElementInArray(array, "persistent");
+        capabilities.distinctive = findElementInArray(array, "distinctive");
+        capabilities.sessionType = findElementInArray(array, "sessionType");
+        capabilities.scheme = findElementInArray(array, "scheme");
+        capabilities.codec = getSupportedCodecs(array);
+        return JSON.stringify(capabilities);
+      }
+
+      const rvArray = cdmInfo.capabilities.split(" ");
+      return $.new("tr", [
+        $.new("td", cdmInfo.keySystemName),
+        $.new("td", getVideoRobustness(rvArray)),
+        $.new("td", getAudioRobustness(rvArray)),
+        $.new("td", getCapabilities(rvArray)),
+      ]);
+    }
+
+    async function insertContentDecryptionModuleInfo() {
+      let rows = [];
+      // Retrieve information from WMFCDM, only works when MOZ_WMF_CDM is true
+      if (ChromeUtils.getWMFContentDecryptionModuleInformation !== undefined) {
+        const cdmInfo =
+          await ChromeUtils.getWMFContentDecryptionModuleInformation();
+        for (let info of cdmInfo) {
+          rows.push(createCDMInfoRow(info));
+        }
+      }
+      $.append($("media-content-decryption-modules-tbody"), rows);
+    }
+
     // Basic information
     insertBasicInfo("audio-backend", data.currentAudioBackend);
     insertBasicInfo("max-audio-channels", data.currentMaxAudioChannels);
@@ -1258,6 +1346,9 @@ var snapshotFormatters = {
     if (["win", "macosx", "linux", "android"].includes(AppConstants.platform)) {
       insertBasicInfo("media-codec-support-info", supportInfo);
     }
+
+    // CDM info
+    insertContentDecryptionModuleInfo();
   },
 
   remoteAgent(data) {

toolkit/content/aboutSupport.xhtml

@@ -565,6 +565,18 @@
           </tr>
         </tbody>
 
+        <tbody id="media-content-decryption-modules-tbody">
+          <tr>
+            <th colspan="4" class="title-column" data-l10n-id="media-content-decryption-modules-title"/>
+          </tr>
+          <tr>
+            <th data-l10n-id="media-key-system-name"/>
+            <th data-l10n-id="media-video-robustness"/>
+            <th data-l10n-id="media-audio-robustness"/>
+            <th data-l10n-id="media-cdm-capabilities"/>
+          </tr>
+        </tbody>
+
       </table>
 
       <!-- - - - - - - - - - - - - - - - - - - - - -->

toolkit/locales/en-US/toolkit/about/aboutSupport.ftl

@@ -192,6 +192,16 @@ media-codec-support-unsupported = Unsupported
 media-codec-support-error = Codec support information unavailable. Try again after playing back a media file.
 media-codec-support-lack-of-extension = Install extension
 
+## Media Content Decryption Modules (CDM)
+## See EME Spec for more explanation for following technical terms
+## https://w3c.github.io/encrypted-media/
+
+media-content-decryption-modules-title = Content Decryption Modules Information
+media-key-system-name = Key System Name
+media-video-robustness = Video Robustness
+media-audio-robustness = Audio Robustness
+media-cdm-capabilities = Capabilities
+
 ##
 
 intl-title = Internationalization & Localization