Class: Sandbox Private

Inherits:
Object show all
Extended by:
Utils::Output::Mixin
Includes:
OS::Linux::Sandbox, OS::Mac::Sandbox, Utils::Output::Mixin
Defined in:
sandbox.rb,
extend/os/linux/sandbox/backend.rb,
extend/os/linux/sandbox/landlock.rb

Overview

This class is part of a private API. This class may only be used in the Homebrew/brew repository. Third parties should avoid using this class if possible, as it may be removed or changed without warning.

Helper class for running a sub-process inside of a sandboxed environment.

Defined Under Namespace

Classes: Landlock, LinuxBackend

Constant Summary collapse

PRIVILEGED_GROUPS =

This constant is part of a private API. This constant may only be used in the Homebrew/brew repository. Third parties should avoid using this constant if possible, as it may be removed or changed without warning.

Privileged groups that are expected to be able to use a working sandbox.

%w[admin staff root wheel].freeze
INHERITANCE_FD =

This constant is part of a private API. This constant may only be used in the Homebrew/brew repository. Third parties should avoid using this constant if possible, as it may be removed or changed without warning.

A read-only descriptor identifies Homebrew's sandbox across exec, without trusting ENV.

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Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Utils::Output::Mixin

issue_reporting_message, odebug, odeprecated, odie, odisabled, ofail, oh1, oh1_title, ohai, ohai_title, onoe, opoo, opoo_once, opoo_outside_github_actions, opoo_without_github_actions_annotation, pretty_cannot_install, pretty_deprecated, pretty_disabled, pretty_duration, pretty_install_status, pretty_installed, pretty_uninstalled, pretty_unmarked, pretty_upgradable, pretty_warning

Constructor Details

#initialize ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning. 



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# File 'sandbox.rb', line 375

def initialize
  @profile = T.let(SandboxProfile.new, SandboxProfile)
  @failed = T.let(false, T::Boolean)
  @logfile = T.let(nil, T.nilable(T.any(String, Pathname)))
  @start = T.let(nil, T.nilable(Time))
end

Instance Attribute Details

#profile ⇒ SandboxProfile (readonly)

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Returns:

  • (SandboxProfile) 


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# File 'sandbox.rb', line 860

def profile
  @profile
end

Class Method Details

.available? ⇒ Boolean

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Returns:

  • (Boolean) 


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# File 'sandbox.rb', line 88

def self.available?
  false
end

.avoid_nested_sandboxing? ⇒ Boolean

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Skip Homebrew's own sandbox when it is opted into via $HOMEBREW_AVOID_NESTED_SANDBOXING and already running inside another sandbox. The skip is only supported for an unprivileged user in a custom prefix; error out explaining why rather than silently sandboxing (and hanging) when either is not the case.

Returns:

  • (Boolean) 


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# File 'sandbox.rb', line 107

def self.avoid_nested_sandboxing?
  return false unless Homebrew::EnvConfig.avoid_nested_sandboxing?
  return false unless nested_sandbox?

  if Homebrew.default_prefix?
    odie "Refusing to skip the sandbox: `$HOMEBREW_AVOID_NESTED_SANDBOXING` is set " \
         "inside another sandbox but Homebrew is using its default prefix " \
         "(#{HOMEBREW_PREFIX}); this is only supported in a custom prefix."
  end

  privileged_group = PRIVILEGED_GROUPS.find do |name|
    group = Etc.getgrnam(name)
    group && Process.groups.include?(group.gid)
  rescue ArgumentError
    false
  end
  if privileged_group
    odie "Refusing to skip the sandbox: `$HOMEBREW_AVOID_NESTED_SANDBOXING` is set " \
         "inside another sandbox but you are in the privileged `#{privileged_group}` " \
         "group; this is only supported for an unprivileged user."
  end

  true
end

.capture(executable, args: [], read_paths: [], write_paths: [], env: {}, input: [], must_succeed: true, print_stdout: false, print_stderr: true, chdir: nil) ⇒ SystemCommand::Result

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Parameters:

Returns:



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# File 'sandbox.rb', line 238

def self.capture(executable, args: [], read_paths: [], write_paths: [], env: {}, input: [],
                 must_succeed: true, print_stdout: false, print_stderr: true, chdir: nil)
  if isolate_operation?
    for_operation(read_paths:, write_paths:).capture(executable, args:, env:, input:, must_succeed:,
                                                    print_stdout:, print_stderr:, chdir:)
  else
    SystemCommand.run(executable, args:, env:, input:, must_succeed:, print_stdout:, print_stderr:, chdir:)
  end
end

.ensure_sandbox_available! ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.



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# File 'sandbox.rb', line 279

def self.ensure_sandbox_available!
  return if available?

  raise failure_reason || "The sandbox is not available."
end

.executable ⇒ Pathname?

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Returns:



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# File 'sandbox.rb', line 333

def self.executable
  executable_candidate_paths.each do |path|
    begin
      candidate = Pathname.new(File.expand_path(executable_name, path))
    rescue ArgumentError
      next
    end

    next if !candidate.file? || !candidate.executable?
    next unless executable_usable?(candidate)

    return candidate
  end

  nil
end

.executable! ⇒ Pathname

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Returns:



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# File 'sandbox.rb', line 351

def self.executable!
  executable || raise("#{executable_name} is required to use the sandbox.")
end

.executable_candidate_paths ⇒ ::PATH

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Returns:



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# File 'sandbox.rb', line 325

def self.executable_candidate_paths
  executable_path = Pathname.new(executable_name)
  return PATH.new(executable_path.dirname) if executable_path.absolute?

  PATH.new(ORIGINAL_PATHS, ENV.fetch("PATH"), HOMEBREW_BREW_FILE.dirname)
end

.executable_name ⇒ String

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Returns:

Raises:

  • (NotImplementedError) 


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# File 'sandbox.rb', line 320

def self.executable_name
  raise NotImplementedError, "Sandbox is not implemented for this OS."
end

.executable_usable?(_candidate) ⇒ Boolean

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Parameters:

Returns:

  • (Boolean) 


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# File 'sandbox.rb', line 356

def self.executable_usable?(_candidate)
  true
end

.failure_reason ⇒ String?

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Returns:



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# File 'sandbox.rb', line 291

def self.failure_reason
  return if state == :available

  "The sandbox is not available."
end

.for_operation(read_paths: [], write_paths: [], network_access: false, home_read_exception: nil) ⇒ Sandbox

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Parameters:

  • read_paths (Array<Pathname>) (defaults to: [])
  • write_paths (Array<Pathname>) (defaults to: [])
  • network_access (Boolean) (defaults to: false)
  • home_read_exception (Symbol, nil) (defaults to: nil)

Returns:



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# File 'sandbox.rb', line 219

def self.for_operation(read_paths: [], write_paths: [], network_access: false, home_read_exception: nil)
  new.tap do |sandbox|
    sandbox.deny_read_home(except: home_read_exception)
    sandbox.deny_all_network unless network_access
    (read_paths | write_paths).each { |path| sandbox.allow_read(path:, type: :subpath) }
    write_paths.each { |path| sandbox.allow_write_path(path) }
    sandbox.deny_write_homebrew_repository
  end
end

.full_write_isolation? ⇒ Boolean

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Returns:

  • (Boolean) 


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# File 'sandbox.rb', line 93

def self.full_write_isolation? = true

.inherited_sandbox? ⇒ Boolean

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Only the sandbox launcher passes this descriptor to its child.

Returns:

  • (Boolean) 


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# File 'sandbox.rb', line 174

def self.inherited_sandbox?
  return false unless File.identical?(IO.new(INHERITANCE_FD, autoclose: false), __FILE__)

  # Ordinary file permissions cannot establish sandbox confinement.
  # When they already deny writes, rely on the inherited descriptor instead.
  return true unless File.stat(HOMEBREW_BREW_FILE).writable?

  # Probe without creating, truncating or modifying the executable.
  File.open(HOMEBREW_BREW_FILE, File::WRONLY) do
    raise "Inherited sandbox permits writes to #{HOMEBREW_BREW_FILE}"
  end
rescue Errno::EBADF
  false
rescue Errno::EACCES, Errno::EPERM, Errno::EROFS
  true
end

.isolate_operation? ⇒ Boolean

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Returns:

  • (Boolean) 


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# File 'sandbox.rb', line 170

def self.isolate_operation? = use_for?("processing downloaded files")

.nested_sandbox? ⇒ Boolean

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Whether Homebrew is itself running inside another sandbox, which would make its own nested sandbox hang (macOS) or fail to start (Linux). Overridden per-OS.

Returns:

  • (Boolean) 


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# File 'sandbox.rb', line 99

def self.nested_sandbox? = false

.operation(action, payload, read_paths: [], write_paths: [], temporary_directory: HOMEBREW_TEMP) ⇒ String

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

The child accepts structured arguments and returns JSON, never Ruby objects.

Parameters:

Returns:



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# File 'sandbox.rb', line 196

def self.operation(action, payload, read_paths: [], write_paths: [], temporary_directory: HOMEBREW_TEMP)
  sandbox = for_operation(read_paths:, write_paths:)
  command = ruby_command("sandbox_operation.rb", action)
  sandbox.capture(
    command.fetch(0),
    args:                command.drop(1),
    input:               payload,
    env:                 { "HOMEBREW_NO_BOOTSNAP" => "1" },
    temporary_directory:,
  ).stdout
end

.reset_state! ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.



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# File 'sandbox.rb', line 298

def self.reset_state!; end

.ruby_command(file, *args) ⇒ Array<String, Pathname>

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Launch Homebrew's worker scripts with the same Ruby and library paths.

Parameters:

Returns:



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# File 'sandbox.rb', line 210

def self.ruby_command(file, *args)
  [*HOMEBREW_RUBY_EXEC_ARGS, "-I", $LOAD_PATH.join(File::PATH_SEPARATOR),
   "--", HOMEBREW_LIBRARY_PATH/file, *args]
end

.run_command(*command, writable_path:, deny_network: false) ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.

Parameters:



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# File 'sandbox.rb', line 301

def self.run_command(*command, writable_path:, deny_network: false)
  ensure_sandbox_available!

  writable_path = Pathname(writable_path).expand_path
  if !writable_path.directory? || !writable_path.writable?
    raise UsageError,
          "`#{writable_path}` is not a writable directory."
  end

  writable_path = writable_path.realpath
  sandbox = new
  sandbox.allow_write_temp_and_cache
  sandbox.allow_write_path writable_path
  sandbox.deny_read_home
  sandbox.deny_all_network if deny_network
  sandbox.run "/bin/sh", "-c", "cd \"$1\" && shift && exec \"$@\"", "brew-sandbox-exec", writable_path, *command
end

.run_or_fork(*args, step:, warn_without_sandbox: true, retain_tmp: false, debug: false, &_block) ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.

Parameters:

  • args (String, Pathname)
  • step (String)
  • warn_without_sandbox (Boolean) (defaults to: true)
  • retain_tmp (Boolean) (defaults to: false)
  • debug (Boolean) (defaults to: false)
  • _block (T.proc.params(sandbox: Sandbox).void) 


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# File 'sandbox.rb', line 159

def self.run_or_fork(*args, step:, warn_without_sandbox: true, retain_tmp: false, debug: false, &_block)
  if use_for?(step, warn_without_sandbox:)
    sandbox = new
    yield sandbox
    sandbox.run(*args, retain_tmp:, debug:)
  else
    Utils.safe_fork { exec(*args) }
  end
end

.state ⇒ Symbol

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Returns:



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# File 'sandbox.rb', line 286

def self.state
  available? ? :available : :unavailable
end

.terminal_ioctl_request ⇒ Integer

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Returns:

Raises:

  • (NotImplementedError) 


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# File 'sandbox.rb', line 361

def self.terminal_ioctl_request
  raise NotImplementedError, "Sandbox is not implemented for this OS."
end

.tty_state ⇒ String?

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

The terminal state to restore after a PTY passthrough. It cannot change in the background while brew runs (each passthrough restores it), so capture it once per process. nil when it cannot be captured.

Returns:



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# File 'sandbox.rb', line 369

def self.tty_state
  @tty_state ||= T.let(Utils.popen_read("stty", "-g", in: :in).chomp, T.nilable(String))
  @tty_state.presence
end

.use_for?(step, warn_without_sandbox: true) ⇒ Boolean

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Parameters:

  • step (String)
  • warn_without_sandbox (Boolean) (defaults to: true)

Returns:

  • (Boolean) 


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# File 'sandbox.rb', line 133

def self.use_for?(step, warn_without_sandbox: true)
  return false if inherited_sandbox?

  unless available?
    opoo_once "Sandbox unavailable: #{step} without sandboxing!" if warn_without_sandbox
    return false
  end

  if avoid_nested_sandboxing?
    opoo_once "#{step.capitalize} without Homebrew's sandbox; relying on the outer sandbox." if warn_without_sandbox
    return false
  end

  true
end

.with_preserved_brew_file(&block) ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.

Landlock cannot protect bin/brew while allowing writes to bin, so a sandboxed install hook could replace brew to persist into later commands.

Parameters:

  • block (T.proc.void) 


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# File 'sandbox.rb', line 251

def self.with_preserved_brew_file(&block)
  return yield if full_write_isolation?

  brew_file = HOMEBREW_PREFIX/"bin/brew"
  File.open(brew_file.dirname) do |brew_directory|
    brew_directory_mode = brew_directory.stat.mode & 07777
    symlink = brew_file.symlink?
    contents = symlink ? brew_file.readlink.to_s : brew_file.binread
    brew_file_mode = brew_file.lstat.mode & 07777

    begin
      yield
    ensure
      brew_directory.chmod brew_directory_mode
      if symlink && (!brew_file.symlink? || brew_file.readlink.to_s != contents)
        FileUtils.rm_rf brew_file
        brew_file.make_symlink contents
      elsif !symlink && (brew_file.symlink? || !brew_file.file? || brew_file.binread != contents ||
                         (brew_file.lstat.mode & 07777) != brew_file_mode)
        FileUtils.rm_rf brew_file
        brew_file.atomic_write contents
        brew_file.chmod brew_file_mode
      end
    end
  end
end

Instance Method Details

#add_install_hook_rules(network_access_allowed:) ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.

Parameters:

  • network_access_allowed (Boolean) 


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# File 'sandbox.rb', line 602

def add_install_hook_rules(network_access_allowed:)
  allow_write_temp_and_cache
  deny_write_homebrew_repository
  deny_read_home
  deny_all_network unless network_access_allowed
end

#add_rule(allow:, operation:, filter: nil, modifier: nil) ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.

Parameters:

  • allow (Boolean)
  • operation (String)
  • filter (SandboxPathFilter, nil) (defaults to: nil)
  • modifier (String, nil) (defaults to: nil) 


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# File 'sandbox.rb', line 391

def add_rule(allow:, operation:, filter: nil, modifier: nil)
  rule = SandboxRule.new(allow:, operation:, filter:, modifier:)
  @profile.add_rule(rule)
end

#allow_cvs ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.



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# File 'sandbox.rb', line 610

def allow_cvs
  allow_write_path "#{Dir.home(ENV.fetch("USER"))}/.cvspass"
end

#allow_fossil ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.



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# File 'sandbox.rb', line 615

def allow_fossil
  allow_write_path "#{Dir.home(ENV.fetch("USER"))}/.fossil"
  allow_write_path "#{Dir.home(ENV.fetch("USER"))}/.fossil-journal"
end

#allow_network(path:, type: :literal) ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.

Parameters:



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# File 'sandbox.rb', line 656

def allow_network(path:, type: :literal)
  add_rule allow: true, operation: "network*", filter: path_filter(path, type)
end

#allow_process_exec(path, no_sandbox: false) ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.

Parameters:



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# File 'sandbox.rb', line 402

def allow_process_exec(path, no_sandbox: false)
  modifier = "no-sandbox" if no_sandbox
  add_rule allow: true, operation: "process-exec", filter: path_filter(path, :literal), modifier:
end

#allow_read(path:, type: :literal) ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.

Parameters:



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# File 'sandbox.rb', line 397

def allow_read(path:, type: :literal)
  add_rule allow: true, operation: "file-read*", filter: path_filter(path, type)
end

#allow_read_if_exists(path:, type: :literal) ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.

Parameters:



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# File 'sandbox.rb', line 553

def allow_read_if_exists(path:, type: :literal)
  return unless path
  return unless File.exist?(path)

  allow_read path:, type:
end

#allow_write(path:, type: :literal) ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.

Parameters:



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# File 'sandbox.rb', line 561

def allow_write(path:, type: :literal)
  add_rule allow: true, operation: "file-write*", filter: path_filter(path, type)
  add_rule allow: true, operation: "file-write-setugid", filter: path_filter(path, type)
  add_rule allow: true, operation: "file-write-mode", filter: path_filter(path, type)
end

#allow_write_cellar(formula) ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.

Parameters:



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# File 'sandbox.rb', line 621

def allow_write_cellar(formula)
  allow_write_path formula.rack
  allow_write_path formula.etc
  allow_write_path formula.var
end

#allow_write_log(formula) ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.

Parameters:



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# File 'sandbox.rb', line 640

def allow_write_log(formula)
  allow_write_path formula.logs
end

#allow_write_path(path) ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.

Parameters:



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# File 'sandbox.rb', line 573

def allow_write_path(path)
  allow_write path:, type: :subpath
end

#allow_write_path_if_exists(path) ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.

Parameters:



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# File 'sandbox.rb', line 578

def allow_write_path_if_exists(path)
  return unless path
  return unless File.exist?(path)

  allow_write_path path
end

#allow_write_system_temp ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.



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# File 'sandbox.rb', line 591

def allow_write_system_temp
  allow_write_path HOMEBREW_TEMP
end

#allow_write_temp_and_cache ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.



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# File 'sandbox.rb', line 596

def allow_write_temp_and_cache
  allow_write_system_temp
  allow_write_path HOMEBREW_CACHE
end

#allow_write_xcode ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.



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# File 'sandbox.rb', line 637

def allow_write_xcode; end

#apply! ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.

Only called in a forked child immediately before exec on Linux.



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# File 'sandbox.rb', line 701

def apply!; end

#apply_before_exec? ⇒ Boolean

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Returns:

  • (Boolean) 


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# File 'sandbox.rb', line 704

def apply_before_exec? = false

#capture(executable, args: [], env: {}, input: [], must_succeed: true, print_stdout: false, print_stderr: true, debug: nil, verbose: nil, secrets: [], chdir: nil, timeout: nil, temporary_directory: HOMEBREW_TEMP) ⇒ SystemCommand::Result

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Capture a non-interactive command without a PTY or process-wide signal handlers.

Parameters:

Returns:



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# File 'sandbox.rb', line 676

def capture(executable, args: [], env: {}, input: [], must_succeed: true, print_stdout: false, print_stderr: true,
            debug: nil, verbose: nil, secrets: [], chdir: nil, timeout: nil, temporary_directory: HOMEBREW_TEMP)
  require "extend/ENV"

  Dir.mktmpdir("homebrew-sandbox", temporary_directory) do |tmpdir|
    env = ENV.sensitive_environment.transform_values { nil }.merge("HOME" => tmpdir)
             .merge(env).merge(sandbox_environment(tmpdir))
    sandbox_executable, *sandbox_args = sandbox_command([executable, *args.map(&:to_s)], tmpdir)
    raise "Missing sandbox command" unless sandbox_executable

    command = SystemCommand.new(sandbox_executable, args: sandbox_args, env:, input:, must_succeed:,
                                print_stdout:, print_stderr:,
                                debug:, verbose:, secrets:, chdir: chdir || tmpdir, timeout:)
    command.sandbox = self if apply_before_exec?
    File.open(__FILE__) do |inheritance|
      command.sandbox_inheritance = inheritance
      command.run!
    end
  end
ensure
  cleanup_sandbox
end

#cleanup_sandbox ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.



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# File 'sandbox.rb', line 707

def cleanup_sandbox; end

#copy_pty_output(controller) ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.

Parameters:

  • controller (IO) 


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# File 'sandbox.rb', line 863

def copy_pty_output(controller)
  controller.each_char { |c| print(c) }
rescue Errno::EIO
  # Linux marks a PTY as an I/O error when its peer closes, so treat this as EOF:
  # https://github.com/torvalds/linux/blob/master/drivers/tty/pty.c
end

#deny_all_network ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.



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# File 'sandbox.rb', line 661

def deny_all_network
  add_rule allow: false, operation: "network*"
end

#deny_read(path:, type: :literal) ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.

Parameters:



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# File 'sandbox.rb', line 408

def deny_read(path:, type: :literal)
  add_rule allow: false, operation: "file-read*", filter: path_filter(path, type)
end

#deny_read_home(except: nil) ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.

Parameters:

  • except (Symbol, nil) (defaults to: nil) 


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# File 'sandbox.rb', line 418

def deny_read_home(except: nil)
  if !except.nil? && except != :git
    raise ArgumentError, "Unknown home credential exception: #{except.inspect}"
  end

  require "trust"

  home = Pathname(Dir.home(ENV.fetch("USER"))).realpath
  readable_paths = [
    HOMEBREW_PREFIX,
    HOMEBREW_REPOSITORY,
    HOMEBREW_CACHE,
    HOMEBREW_LOGS,
    HOMEBREW_TEMP,
    ENV.fetch("GITHUB_WORKSPACE", nil),
    ENV.fetch("RUNNER_WORKSPACE", nil),
    ENV.fetch("RUNNER_TEMP", nil),
    Homebrew::Trust.trust_file,
    *home_write_paths.select { |path| File.exist?(path) },
  ].compact.flat_map do |path|
    path = Pathname(path)
    [path.expand_path, (path.realpath if path.exist?)].compact
  end
  if except == :git || readable_paths.any? { |path| path.ascend.include?(home) }
    # When credentials, Homebrew or CI need `$HOME` paths to stay readable, deny only
    # well-known credential and personal-data paths instead of enumerating all
    # of `$HOME`.
    [
      *GIT_CREDENTIAL_PATHS,
      ".aws",
      ".azure",
      ".boto",
      ".docker",
      ".config/fish",
      ".config/gcloud",
      ".config/huggingface",
      ".config/pip",
      ".config/pypoetry",
      ".config/rclone",
      ".config/containers/auth.json",
      ".config/composer/auth.json",
      ".config/sops/age/keys.txt",
      ".gnupg",
      ".gsutil",
      ".kube",
      ".npmrc",
      ".yarnrc",
      ".yarnrc.yml",
      ".pnpmrc",
      ".bunfig.toml",
      ".pypirc",
      ".pip",
      ".poetry",
      ".local/share/pypoetry",
      ".gem/credentials",
      ".bundle/config",
      ".cargo/credentials",
      ".cargo/credentials.toml",
      ".composer/auth.json",
      ".condarc",
      ".m2/settings.xml",
      ".gradle/gradle.properties",
      ".sbt/1.0/credentials.sbt",
      ".terraform.d/credentials.tfrc.json",
      ".pulumi/credentials.json",
      ".oci/config",
      ".huggingface/token",
      ".cache/huggingface/token",
      ".claude",
      ".claude.json",
      ".kiro",
      ".bash_login",
      ".bash_logout",
      ".bash_profile",
      ".bashrc",
      ".bash_history",
      ".profile",
      ".zlogin",
      ".zlogout",
      ".zprofile",
      ".zshenv",
      ".zshrc",
      ".zsh_history",
      ".python_history",
      ".mysql_history",
      ".psql_history",
      ".env",
      ".env.local",
      "Documents",
      "Movies",
      "Music",
      "Pictures",
      "Library/Keychains",
      "Library/Mobile Documents",
      "Library/CloudStorage",
      "Dropbox",
      "Google Drive",
      "OneDrive",
    ].each do |path|
      next if except == :git && GIT_CREDENTIAL_PATHS.include?(path)

      path = home/path
      next unless path.exist?

      path = path.realpath
      next unless path.ascend.include?(home)

      if (readable_path = readable_paths.find { |required_path| required_path.ascend.include?(path) })
        opoo <<~EOS
          The sandbox cannot prevent formulae from reading:
            #{path}
          because this required path is inside it:
            #{readable_path}
          Formulae may access personal data in this directory.
        EOS
        next
      end

      deny_read_path path
    rescue Errno::ENOENT
      nil
    end
    if except == :git
      GIT_CREDENTIAL_PATHS.each do |path|
        path = home/path
        allow_read(path:) if path.symlink? && path.file?
      end
    end
    return
  end

  deny_read_path home
end

#deny_read_path(path) ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.

Parameters:



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# File 'sandbox.rb', line 413

def deny_read_path(path)
  deny_read path:, type: :subpath
end

#deny_write(path:, type: :literal) ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.

Parameters:



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# File 'sandbox.rb', line 568

def deny_write(path:, type: :literal)
  add_rule allow: false, operation: "file-write*", filter: path_filter(path, type)
end

#deny_write_homebrew_repository ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.



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# File 'sandbox.rb', line 645

def deny_write_homebrew_repository
  deny_write path: HOMEBREW_BREW_FILE
  if expand_realpath(HOMEBREW_PREFIX).ascend.include?(expand_realpath(HOMEBREW_REPOSITORY))
    deny_write_path HOMEBREW_LIBRARY
    deny_write_path HOMEBREW_REPOSITORY/".git"
  else
    deny_write_path HOMEBREW_REPOSITORY
  end
end

#deny_write_path(path) ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.

Parameters:



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# File 'sandbox.rb', line 586

def deny_write_path(path)
  deny_write path:, type: :subpath
end

#deny_write_temp_cellar ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.

Deny writes to the download queue's temporary Cellar so sandboxed steps cannot plant kegs or markers that pour would move into the Cellar. Call this after allow_write_cellar: the temporary Cellar is inside the granted var tree and macOS applies the last matching rule.



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# File 'sandbox.rb', line 632

def deny_write_temp_cellar
  deny_write_path HOMEBREW_TEMP_CELLAR
end

#path_filter(path, type) ⇒ SandboxPathFilter

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

Parameters:

Returns:

  • (SandboxPathFilter) 


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# File 'sandbox.rb', line 844

def path_filter(path, type)
  # Any character is allowed: the OS-specific renderer quotes paths safely
  # (the seatbelt renderer escapes the `"` and `\` string delimiters; the
  # Linux sandbox passes each path as a separate argument), so even paths
  # with spaces, parentheses, quotes, backslashes or newlines are expressible.
  filter_path = case type
  when :regex   then path.to_s
  when :subpath, :literal
    expand_realpath(Pathname.new(path)).to_s
  else raise ArgumentError, "Invalid path filter type: #{type}"
  end

  SandboxPathFilter.new(path: filter_path, type:)
end

#record_log(file) ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.

Parameters:



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# File 'sandbox.rb', line 383

def record_log(file)
  @logfile = file
end

#run(*args, passthrough_stdin: true, child_message_handler: nil, retain_tmp: false, debug: false) ⇒ void

This method is part of a private API. This method may only be used in the Homebrew/brew repository. Third parties should avoid using this method if possible, as it may be removed or changed without warning.

This method returns an undefined value.

Parameters:

  • args (String, Pathname)
  • passthrough_stdin (Boolean) (defaults to: true)
  • child_message_handler (T.proc.params(message: String).returns(T.nilable(String)), nil) (defaults to: nil)
  • retain_tmp (Boolean) (defaults to: false)
  • debug (Boolean) (defaults to: false) 


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# File 'sandbox.rb', line 718

def run(*args, passthrough_stdin: true, child_message_handler: nil, retain_tmp: false, debug: false)
  Mktemp.new("sandbox", retain: retain_tmp, compact: true).run(chdir: false) do |staging|
    temporary = staging.tmpdir
    raise "Sandbox temporary directory is unexpectedly unset." if temporary.nil?

    tmpdir = temporary.to_s
    env = sandbox_environment(tmpdir)
    @start = T.let(Time.now, T.nilable(Time))

    begin
      command = sandbox_command(args, tmpdir)
      # Start sandbox in a pseudoterminal to prevent access of the parent terminal.
      PTY.open do |controller, worker|
        # Set the PTY's window size to match the parent terminal.
        # Some formula tests are sensitive to the terminal size and fail if this is not set.
        winch = proc do |_sig|
          controller.winsize = if $stdout.tty?
            # We can only use IO#winsize if the IO object is a TTY.
            $stdout.winsize
          else
            # Otherwise, default to tput, if available.
            # This relies on ncurses rather than the system's ioctl.
            [Utils.popen_read("tput", "lines").to_i, Utils.popen_read("tput", "cols").to_i]
          end
        end

        write_to_pty = proc do
          # Don't hang if stdin is not able to be used - throw EIO instead.
          old_ttin = trap(:TTIN, "IGNORE")

          # Update the window size whenever the parent terminal's window size changes.
          old_winch = trap(:WINCH, &winch)
          winch.call(nil)

          if passthrough_stdin
            stdin_thread = Thread.new do
              IO.copy_stream($stdin, controller)
            rescue Errno::EIO
              # stdin is unavailable - move on.
            end
          end

          stdout_thread = Thread.new do
            copy_pty_output(controller)
          end

          Utils.safe_fork(directory: tmpdir, yield_parent: true, child_message_handler:) do |error_pipe|
            if error_pipe
              # Child side
              Process.setsid
              controller.close
              worker.ioctl(self.class.terminal_ioctl_request, 0) # Make this the controlling terminal.

              ensure_child_tty_available

              # Move into a non-denied directory before `exec` so subsequent
              # `getcwd(3)` calls (which walk every parent) never cross a
              # `deny_read_home` path inherited from the caller's CWD.
              Dir.chdir(tmpdir)

              worker.close_on_exec = true
              apply!
              # Map the terminal and inheritance descriptor into the sandboxed child.
              File.open(__FILE__) do |inheritance|
                exec(env, *command, INHERITANCE_FD => inheritance, in: worker, out: worker, err: worker)
              end
            else
              # Parent side
              worker.close
            end
          end
        rescue ChildProcessError => e
          raise ErrorDuringExecution.new(command, status: e.status)
        ensure
          stdin_thread&.kill
          stdout_thread&.kill
          trap(:TTIN, old_ttin)
          trap(:WINCH, old_winch)
        end

        if $stdin.tty? && passthrough_stdin
          # If stdin is a TTY, set it to a raw, passthrough mode while we
          # copy the input/output of the process spawned in the PTY, then
          # restore its original state afterwards. Keep `opost` set, unlike
          # `IO#raw`: clearing it stops LF -> CRLF translation for the whole
          # terminal, so anything written outside the PTY meanwhile (e.g.
          # our own `$stdout` when piped) renders staircased — and set the
          # mode in one `stty` call so there is no window where `opost` is
          # clear.
          begin
            # Ignore SIGTTOU as setting raw mode will hang if the process is in the background.
            old_ttou = trap(:TTOU, "IGNORE")
            if (tty_state = Sandbox.tty_state)
              begin
                # `-echo` matches `IO#raw`; `stty raw` alone leaves echo on.
                Utils.popen_read("stty", "raw", "-echo", "opost", in: :in)
                write_to_pty.call
              ensure
                Utils.popen_read("stty", tty_state, in: :in)
              end
            else
              # Cannot get the terminal state, so don't change it either.
              write_to_pty.call
            end
          ensure
            trap(:TTOU, old_ttou)
          end
        else
          write_to_pty.call
        end
      end
    # Preserve temporary files for debugging, including interrupted commands.
    rescue StandardError, SignalException
      staging.retain! if debug
      @failed = true
      raise
    ensure
      record_sandbox_log
    end
  end
ensure
  cleanup_sandbox
end