Restrict VR HWC access to services with RESTRICTED_VR_ACCESS permission

#include "vr_composer.h"

#include <binder/IPCThreadState.h>

#include <binder/PermissionCache.h>

namespace android {

namespace dvr {

namespace {

bool CheckPermission() {

  const android::IPCThreadState* ipc = android::IPCThreadState::self();

  const pid_t pid = ipc->getCallingPid();

  const uid_t uid = ipc->getCallingUid();

  const bool permission = PermissionCache::checkPermission(

      String16("android.permission.RESTRICTED_VR_ACCESS"), pid, uid);

  if (!permission)

    ALOGE("permission denied to pid=%d uid=%u", pid, uid);

  return permission;

}

}  // namespace

VrComposer::VrComposer() {}

    const sp<IVrComposerCallback>& callback) {

  std::lock_guard<std::mutex> guard(mutex_);

  if (!CheckPermission())

    return binder::Status::fromStatusT(PERMISSION_DENIED);

  if (callback_.get()) {

    ALOGE("Failed to register callback, already registered");

    return binder::Status::fromStatusT(ALREADY_EXISTS);