Module: Landlock::Runner::Fork

Defined in:
lib/landlock/runner/fork.rb

Class Method Summary collapse

Class Method Details

.call(argv, read:, write:, execute:, connect_tcp:, bind_tcp:, paths:, scope:, chdir:, env:, unsetenv_others:, close_others:, allow_all_known:, timeout:, stdin:, rlimits:, seccomp_deny_network:, max_output_bytes:, truncate_output:) ⇒ Object 



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# File 'lib/landlock/runner/fork.rb', line 54

def call(
  argv,
  read:,
  write:,
  execute:,
  connect_tcp:,
  bind_tcp:,
  paths:,
  scope:,
  chdir:,
  env:,
  unsetenv_others:,
  close_others:,
  allow_all_known:,
  timeout:,
  stdin:,
  rlimits:,
  seccomp_deny_network:,
  max_output_bytes:,
  truncate_output:
)
  stdout_reader, stdout_writer = IO.pipe
  stderr_reader, stderr_writer = IO.pipe
  stdin_reader, stdin_writer = IO.pipe

  pid =
    fork do
      begin
        stdout_reader.close
        stderr_reader.close
        stdin_writer.close
        ::Process.setpgrp
        STDIN.reopen(stdin_reader)
        STDOUT.reopen(stdout_writer)
        STDERR.reopen(stderr_writer)
        stdin_reader.close
        stdout_writer.close
        stderr_writer.close

        setup_child!(
          argv,
          read:,
          write:,
          execute:,
          connect_tcp:,
          bind_tcp:,
          paths:,
          scope:,
          chdir:,
          env:,
          unsetenv_others:,
          close_others:,
          allow_all_known:,
          rlimits:,
          seccomp_deny_network:
        )
      rescue Exception => error
        Runner.exit_child!(error)
      end
    end

  stdin_reader.close
  stdout_writer.close
  stderr_writer.close

  ProcessIO.complete_pipe_capture(
    pid,
    stdout_reader,
    stderr_reader,
    stdin_writer,
    stdin,
    timeout,
    max_output_bytes,
    truncate_output
  )
rescue OutputTooLargeError
  raise
rescue Exception
  if pid
    ProcessIO.terminate_process(pid)
    ProcessIO.wait_for_pid(pid)
  end
  raise
ensure
  [stdin_reader, stdin_writer, stdout_reader, stdout_writer, stderr_reader, stderr_writer].each do |io|
    io&.close unless io.closed?
  rescue IOError
  end
end

.setup_child!(argv, read:, write:, execute:, connect_tcp:, bind_tcp:, paths:, scope:, chdir:, env:, unsetenv_others:, close_others:, allow_all_known:, rlimits:, seccomp_deny_network:) ⇒ Object 



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# File 'lib/landlock/runner/fork.rb', line 144

def setup_child!(
  argv,
  read:,
  write:,
  execute:,
  connect_tcp:,
  bind_tcp:,
  paths:,
  scope:,
  chdir:,
  env:,
  unsetenv_others:,
  close_others:,
  allow_all_known:,
  rlimits:,
  seccomp_deny_network:
)
  Dir.chdir(chdir) if chdir # rubocop:disable Discourse/NoChdir
  if Policy.requested?(read:, write:, execute:, connect_tcp:, bind_tcp:, paths:, scope:, allow_all_known:)
    Landlock.restrict!(read:, write:, execute:, connect_tcp:, bind_tcp:, paths:, scope:, allow_all_known:)
  end
  Landlock::Native.seccomp_deny_network! if seccomp_deny_network
  Rlimits.apply!(rlimits)
  Kernel.exec(*Runner.kernel_exec_args(argv, env, unsetenv_others:, close_others:))
end

.spawn(argv, read:, write:, execute:, connect_tcp:, bind_tcp:, paths:, scope:, chdir:, env:, unsetenv_others:, close_others:, allow_all_known:) ⇒ Object 



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# File 'lib/landlock/runner/fork.rb', line 14

def spawn(
  argv,
  read:,
  write:,
  execute:,
  connect_tcp:,
  bind_tcp:,
  paths:,
  scope:,
  chdir:,
  env:,
  unsetenv_others:,
  close_others:,
  allow_all_known:
)
  fork do
    begin
      setup_child!(
        argv,
        read:,
        write:,
        execute:,
        connect_tcp:,
        bind_tcp:,
        paths:,
        scope:,
        chdir:,
        env:,
        unsetenv_others:,
        close_others:,
        allow_all_known:,
        rlimits: [],
        seccomp_deny_network: false
      )
    rescue Exception => error
      Runner.exit_child!(error)
    end
  end
end