1 files changed, 189 insertions, 0 deletions
diff --git a/dom/media/gmp/GMPLoader.cpp b/dom/media/gmp/GMPLoader.cpp
new file mode 100644
index 0000000000..6eedef903d
--- /dev/null
+++ b/dom/media/gmp/GMPLoader.cpp
@@ -0,0 +1,189 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 ts=4 et :
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "GMPLoader.h"
+#include <stdio.h>
+#include "mozilla/Attributes.h"
+#include "gmp-entrypoints.h"
+#include "prlink.h"
+#include "prenv.h"
+#if defined(XP_WIN) && defined(MOZ_SANDBOX)
+#  include "mozilla/sandboxTarget.h"
+#  include "mozilla/sandboxing/SandboxInitialization.h"
+#  include "mozilla/sandboxing/sandboxLogging.h"
+#endif
+#if defined(XP_LINUX) && defined(MOZ_SANDBOX)
+#  include "mozilla/Sandbox.h"
+#  include "mozilla/SandboxInfo.h"
+#endif
+
+#include <string>
+
+#ifdef XP_WIN
+#  include <windows.h>
+#endif
+
+namespace mozilla::gmp {
+class PassThroughGMPAdapter : public GMPAdapter {
+ public:
+  ~PassThroughGMPAdapter() override {
+    // Ensure we're always shutdown, even if caller forgets to call
+    // GMPShutdown().
+    GMPShutdown();
+  }
+
+  void SetAdaptee(PRLibrary* aLib) override { mLib = aLib; }
+
+  GMPErr GMPInit(const GMPPlatformAPI* aPlatformAPI) override {
+    if (!mLib) {
+      return GMPGenericErr;
+    }
+    GMPInitFunc initFunc =
+        reinterpret_cast<GMPInitFunc>(PR_FindFunctionSymbol(mLib, "GMPInit"));
+    if (!initFunc) {
+      return GMPNotImplementedErr;
+    }
+    return initFunc(aPlatformAPI);
+  }
+
+  GMPErr GMPGetAPI(const char* aAPIName, void* aHostAPI, void** aPluginAPI,
+                   const nsACString& /* aKeySystem */) override {
+    if (!mLib) {
+      return GMPGenericErr;
+    }
+    GMPGetAPIFunc getapiFunc = reinterpret_cast<GMPGetAPIFunc>(
+        PR_FindFunctionSymbol(mLib, "GMPGetAPI"));
+    if (!getapiFunc) {
+      return GMPNotImplementedErr;
+    }
+    return getapiFunc(aAPIName, aHostAPI, aPluginAPI);
+  }
+
+  void GMPShutdown() override {
+    if (mLib) {
+      GMPShutdownFunc shutdownFunc = reinterpret_cast<GMPShutdownFunc>(
+          PR_FindFunctionSymbol(mLib, "GMPShutdown"));
+      if (shutdownFunc) {
+        shutdownFunc();
+      }
+      PR_UnloadLibrary(mLib);
+      mLib = nullptr;
+    }
+  }
+
+ private:
+  PRLibrary* mLib = nullptr;
+};
+
+bool GMPLoader::Load(const char* aUTF8LibPath, uint32_t aUTF8LibPathLen,
+                     const GMPPlatformAPI* aPlatformAPI, GMPAdapter* aAdapter) {
+  if (!getenv("MOZ_DISABLE_GMP_SANDBOX") && mSandboxStarter &&
+      !mSandboxStarter->Start(aUTF8LibPath)) {
+    return false;
+  }
+
+  // Load the GMP.
+  PRLibSpec libSpec;
+#ifdef XP_WIN
+  int pathLen = MultiByteToWideChar(CP_UTF8, 0, aUTF8LibPath, -1, nullptr, 0);
+  if (pathLen == 0) {
+    return false;
+  }
+
+  auto widePath = MakeUnique<wchar_t[]>(pathLen);
+  if (MultiByteToWideChar(CP_UTF8, 0, aUTF8LibPath, -1, widePath.get(),
+                          pathLen) == 0) {
+    return false;
+  }
+
+  libSpec.value.pathname_u = widePath.get();
+  libSpec.type = PR_LibSpec_PathnameU;
+#else
+  libSpec.value.pathname = aUTF8LibPath;
+  libSpec.type = PR_LibSpec_Pathname;
+#endif
+  PRLibrary* lib = PR_LoadLibraryWithFlags(libSpec, 0);
+  if (!lib) {
+    return false;
+  }
+
+  mAdapter.reset((!aAdapter) ? new PassThroughGMPAdapter() : aAdapter);
+  mAdapter->SetAdaptee(lib);
+
+  if (mAdapter->GMPInit(aPlatformAPI) != GMPNoErr) {
+    return false;
+  }
+
+  return true;
+}
+
+GMPErr GMPLoader::GetAPI(const char* aAPIName, void* aHostAPI,
+                         void** aPluginAPI, const nsACString& aKeySystem) {
+  return mAdapter->GMPGetAPI(aAPIName, aHostAPI, aPluginAPI, aKeySystem);
+}
+
+void GMPLoader::Shutdown() {
+  if (mAdapter) {
+    mAdapter->GMPShutdown();
+  }
+}
+
+#if defined(XP_WIN) && defined(MOZ_SANDBOX)
+class WinSandboxStarter : public mozilla::gmp::SandboxStarter {
+ public:
+  bool Start(const char* aLibPath) override {
+    // Cause advapi32 to load before the sandbox is turned on, as
+    // Widevine version 970 and later require it and the sandbox
+    // blocks it on Win7.
+    unsigned int dummy_rand;
+    rand_s(&dummy_rand);
+
+    mozilla::SandboxTarget::Instance()->StartSandbox();
+    return true;
+  }
+};
+#endif
+
+#if defined(XP_LINUX) && defined(MOZ_SANDBOX)
+namespace {
+class LinuxSandboxStarter : public mozilla::gmp::SandboxStarter {
+ private:
+  LinuxSandboxStarter() = default;
+  friend mozilla::detail::UniqueSelector<LinuxSandboxStarter>::SingleObject
+  mozilla::MakeUnique<LinuxSandboxStarter>();
+
+ public:
+  static UniquePtr<SandboxStarter> Make() {
+    if (mozilla::SandboxInfo::Get().CanSandboxMedia()) {
+      return MakeUnique<LinuxSandboxStarter>();
+    }
+    // Sandboxing isn't possible, but the parent has already
+    // checked that this plugin doesn't require it.  (Bug 1074561)
+    return nullptr;
+  }
+  bool Start(const char* aLibPath) override {
+    mozilla::SetMediaPluginSandbox(aLibPath);
+    return true;
+  }
+};
+}  // anonymous namespace
+#endif  // XP_LINUX && MOZ_SANDBOX
+
+static UniquePtr<SandboxStarter> MakeSandboxStarter() {
+#if defined(XP_WIN) && defined(MOZ_SANDBOX)
+  return mozilla::MakeUnique<WinSandboxStarter>();
+#elif defined(XP_LINUX) && defined(MOZ_SANDBOX)
+  return LinuxSandboxStarter::Make();
+#else
+  return nullptr;
+#endif
+}
+
+GMPLoader::GMPLoader() : mSandboxStarter(MakeSandboxStarter()) {}
+
+bool GMPLoader::CanSandbox() const { return !!mSandboxStarter; }
+
+}  // namespace mozilla::gmp