Class: Landlock::SafeExec

Inherits:
Object
  • Object
show all
Defined in:
lib/landlock/safe_exec.rb

Defined Under Namespace

Classes: CommandError, Result

Constant Summary collapse

Error = 
Class.new(StandardError)
OutputTooLargeError = 
Class.new(Error)
DEFAULT_READ_PATHS = 
%w[/bin /etc /lib /lib64 /usr].freeze
DEFAULT_EXECUTE_PATHS = 
%w[/bin /lib /lib64 /usr].freeze
READ_CHUNK_BYTES = 
16 * 1024

Class Method Summary collapse

Class Method Details

.capture(*command, **options) ⇒ Object 



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# File 'lib/landlock/safe_exec.rb', line 66

def capture(*command, **options)
  perform_capture(*command, raise_on_failure: false, **options)
end

.capture!(*command, **options) ⇒ Object 



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# File 'lib/landlock/safe_exec.rb', line 70

def capture!(*command, **options)
  perform_capture(*command, raise_on_failure: true, **options)
end

.default_execute_paths ⇒ Object 



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# File 'lib/landlock/safe_exec.rb', line 178

def default_execute_paths
  existing_paths(DEFAULT_EXECUTE_PATHS)
end

.default_read_paths ⇒ Object 



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# File 'lib/landlock/safe_exec.rb', line 174

def default_read_paths
  existing_paths(DEFAULT_READ_PATHS)
end

.existing_paths(paths) ⇒ Object 



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# File 'lib/landlock/safe_exec.rb', line 182

def existing_paths(paths)
  Array(paths).filter { |path| path.to_s != "" && File.exist?(path) }.uniq
end

.helper_path ⇒ Object 



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# File 'lib/landlock/safe_exec.rb', line 165

def helper_path
  candidates = [
    File.expand_path("landlock-safe-exec", __dir__),
    File.expand_path("../../tmp/#{RbConfig::CONFIG.fetch("arch")}/landlock/#{RUBY_VERSION}/landlock-safe-exec", __dir__),
    File.expand_path("../../ext/landlock/landlock-safe-exec", __dir__)
  ]
  candidates.find { |path| File.executable?(path) } || candidates.first
end

.perform_capture(*command, read: [], write: [], execute: [], timeout: nil, failure_message: "", success_status_codes: [0], env: {}, inherit_env: false, chdir: nil, stdin: nil, connect_tcp: nil, bind_tcp: [], rlimits: {}, seccomp_deny_network: false, max_output_bytes: nil, truncate_output: false, allow_all_known: true, raise_on_failure:) ⇒ Object 



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# File 'lib/landlock/safe_exec.rb', line 74

def perform_capture(
  *command,
  read: [],
  write: [],
  execute: [],
  timeout: nil,
  failure_message: "",
  success_status_codes: [0],
  env: {},
  inherit_env: false,
  chdir: nil,
  stdin: nil,
  connect_tcp: nil,
  bind_tcp: [],
  rlimits: {},
  seccomp_deny_network: false,
  max_output_bytes: nil,
  truncate_output: false,
  allow_all_known: true,
  raise_on_failure:
)
  validate_sandbox_option_values!(connect_tcp: connect_tcp, bind_tcp: bind_tcp)

  unsupported_options = unsupported_sandbox_options(
    read: read,
    write: write,
    execute: execute,
    connect_tcp: connect_tcp,
    bind_tcp: bind_tcp,
    seccomp_deny_network: seccomp_deny_network
  )
  use_helper = helper_available?
  warn_unsupported_platform_once(unsupported_options) if !use_helper && unsupported_options.any?

  stdout, stderr, status, output_truncated, timed_out = if use_helper
    max_output_bytes = validate_output_limit!(max_output_bytes)
    capture_process(
      command,
      read: read,
      write: write,
      execute: execute,
      timeout: timeout,
      env: env,
      inherit_env: inherit_env,
      chdir: chdir,
      stdin: stdin,
      connect_tcp: connect_tcp,
      bind_tcp: bind_tcp,
      rlimits: rlimits,
      seccomp_deny_network: seccomp_deny_network,
      max_output_bytes: max_output_bytes,
      truncate_output: truncate_output,
      allow_all_known: allow_all_known
    )
  else
    max_output_bytes = validate_output_limit!(max_output_bytes)
    capture_process_without_helper(
      command,
      timeout: timeout,
      env: env,
      inherit_env: inherit_env,
      chdir: chdir,
      stdin: stdin,
      rlimits: rlimits,
      max_output_bytes: max_output_bytes,
      truncate_output: truncate_output
    )
  end

  result = Result.new(stdout: stdout, stderr: stderr, status: status, output_truncated: output_truncated, timed_out: timed_out)

  if raise_on_failure && (!status.exited? || !success_status_codes.include?(status.exitstatus))
    message = [command.join(" "), failure_message, stderr].filter { |part| part.to_s != "" }.join("\n")
    raise CommandError.new(message, stdout: stdout, stderr: stderr, status: status, result: result)
  end

  result
rescue OutputTooLargeError => e
  message = [command.join(" "), failure_message, e.message].filter { |part| part.to_s != "" }.join("\n")
  raise CommandError.new(message)
end

.sandboxing? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/landlock/safe_exec.rb', line 161

def sandboxing?
  supported?
end

.supported? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/landlock/safe_exec.rb', line 157

def supported?
  helper_available? && Landlock.supported?
end