/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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/. */

#ifndef mozilla_SandboxInfo_h
#define mozilla_SandboxInfo_h

#include "mozilla/Types.h"

// Information on what parts of sandboxing are enabled in this build
// and/or supported by the system.

namespace mozilla {

class SandboxInfo {
 public:
  // No need to prevent copying; this is essentially just a const int.
  SandboxInfo(const SandboxInfo& aOther) = default;

  // Flags are checked at initializer time; this returns them.
  static const SandboxInfo& Get() { return sSingleton; }

  enum Flags {
    // System call filtering; kernel config option CONFIG_SECCOMP_FILTER.
    kHasSeccompBPF = 1 << 0,
    // Whether to use a sandbox for content processes; env var
    // MOZ_DISABLE_CONTENT_SANDBOX
    kEnabledForContent = 1 << 1,
    // Whether to use a sandbox for GMP processes; env var
    // MOZ_DISABLE_GMP_SANDBOX.
    kEnabledForMedia = 1 << 2,
    // Env var MOZ_SANDBOX_LOGGING.
    kVerbose = 1 << 3,
    // Kernel can atomically set system call filtering on entire thread group.
    kHasSeccompTSync = 1 << 4,
    // Can this process create user namespaces? (Man page user_namespaces(7).)
    kHasUserNamespaces = 1 << 5,
    // Could a more privileged process have user namespaces, even if we can't?
    kHasPrivilegedUserNamespaces = 1 << 6,
    // Env var MOZ_PERMISSIVE_CONTENT_SANDBOX
    kPermissive = 1 << 7,
    // (1 << 8) was kUnexpectedThreads
  };

  bool Test(Flags aFlag) const { return (mFlags & aFlag) == aFlag; }

  // Returns true if SetContentProcessSandbox may be called.
  bool CanSandboxContent() const {
    return !Test(kEnabledForContent) || Test(kHasSeccompBPF);
  }

  // Returns true if SetMediaPluginSandbox may be called.
  bool CanSandboxMedia() const {
    return !Test(kEnabledForMedia) || Test(kHasSeccompBPF);
  }

  // For telemetry / crash annotation uses.
  uint32_t AsInteger() const { return mFlags; }

 private:
  enum Flags mFlags;
  static const MOZ_EXPORT SandboxInfo sSingleton;
  SandboxInfo();
};

}  // namespace mozilla

#endif  // mozilla_SandboxInfo_h