Module: SafeImage::NativeHelper

Defined in:
lib/safe_image/native_helper.rb

Constant Summary collapse

DEFAULT_HELPER = 
File.expand_path("safe_image_vips_helper", __dir__).freeze
HELPER = 
ENV.fetch("SAFE_IMAGE_VIPS_HELPER", DEFAULT_HELPER).freeze
STDERR_TAIL_BYTES = 
2000

Class Method Summary collapse

Class Method Details

.append_helper_detail(message, _original_class, stderr_tail) ⇒ Object 



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# File 'lib/safe_image/native_helper.rb', line 261

def append_helper_detail(message, _original_class, stderr_tail)
  return message if stderr_tail.nil? || stderr_tail.empty?

  "#{message} (native vips helper stderr tail: #{stderr_tail})"
end

.available? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/safe_image/native_helper.rb', line 15

def available?
  verify!
  true
rescue Error, CommandError, LoadError
  false
end

.call!(command, sandbox: SafeImage.sandbox?, **options) ⇒ Object 



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# File 'lib/safe_image/native_helper.rb', line 111

def call!(command, sandbox: SafeImage.sandbox?, **options)
  ensure_available!

  Dir.mktmpdir("safe-image-vips-helper-") do |tmpdir|
    response = File.join(tmpdir, "response.json")
    argv = [HELPER, command, "--response", response]
    options.each do |key, value|
      next if value.nil?

      argv << "--#{key.to_s.tr("_", "-")}" << value.to_s
    end

    stdout = stderr = nil
    status = nil
    if sandbox
      begin
        stdout, stderr, status = run_sandboxed!(argv, tmpdir, options)
      rescue Sandbox.landlock_command_error => e
        stdout = e.stdout
        stderr = e.stderr
        status = e.status
        payload = read_response(response, stderr: stderr)
        raise_helper_error(payload, status, command, stderr: stderr, stdout: stdout)
      end
    else
      begin
        stdout, stderr, status = run_process!(argv, tmpdir)
      rescue CommandError => e
        stdout = e.stdout
        stderr = e.stderr
        status = e.status
        payload = read_response(response, stderr: stderr)
        raise_helper_error(payload, status, command, stderr: stderr, stdout: stdout)
      end
    end

    payload = read_response(response, stderr: stderr)
    helper_failed = status.respond_to?(:success?) ? !status.success? : false
    raise_helper_error(payload, status, command, stderr: stderr, stdout: stdout) if helper_failed || !payload[:ok]
    payload.reject { |key, _| key == :ok }
  end
rescue LoadError
  raise Error, "landlock sandbox requested but the landlock gem is unavailable"
end

.convert(input, output, format, quality, max_pixels) ⇒ Object 



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# File 'lib/safe_image/native_helper.rb', line 77

def convert(input, output, format, quality, max_pixels)
  call!("convert", input: input, output: output, format: format, quality: quality, max_pixels: max_pixels)
end

.crop_north(input, output, width, height, format, quality, max_pixels) ⇒ Object 



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# File 'lib/safe_image/native_helper.rb', line 64

def crop_north(input, output, width, height, format, quality, max_pixels)
  call!(
    "crop-north",
    input: input,
    output: output,
    width: width,
    height: height,
    format: format,
    quality: quality,
    max_pixels: max_pixels
  )
end

.dominant_color(path, max_pixels) ⇒ Object 



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# File 'lib/safe_image/native_helper.rb', line 99

def dominant_color(path, max_pixels)
  call!("dominant-color", input: path, max_pixels: max_pixels).fetch(:value)
end

.ensure_available! ⇒ Object

Raises:



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# File 'lib/safe_image/native_helper.rb', line 22

def ensure_available!
  return if File.executable?(HELPER)

  raise VipsUnavailableError, "compiled safe_image_vips_helper is missing or not executable: #{HELPER}"
end

.exit_status(status) ⇒ Object 



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# File 'lib/safe_image/native_helper.rb', line 257

def exit_status(status)
  status.respond_to?(:exitstatus) ? status.exitstatus : status
end

.helper_env(tmpdir) ⇒ Object 



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# File 'lib/safe_image/native_helper.rb', line 187

def helper_env(tmpdir)
  Runner.command_env(tmpdir).merge("SAFE_IMAGE_SANDBOX_CHILD" => "1")
end

.landlock_abi ⇒ Object 



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# File 'lib/safe_image/native_helper.rb', line 191

def landlock_abi
  @landlock_abi ||= Landlock.abi_version
end

.letter_avatar(output, size, red, green, blue, markup, font, fontfile) ⇒ Object 



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# File 'lib/safe_image/native_helper.rb', line 85

def letter_avatar(output, size, red, green, blue, markup, font, fontfile)
  call!(
    "letter-avatar",
    output: output,
    size: size,
    red: red,
    green: green,
    blue: blue,
    markup: markup,
    font: font,
    fontfile: fontfile
  )
end

.orientation(path, max_pixels) ⇒ Object 



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# File 'lib/safe_image/native_helper.rb', line 107

def orientation(path, max_pixels)
  call!("orientation", input: path, max_pixels: max_pixels).fetch(:value)
end

.pages(path, max_pixels) ⇒ Object 



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# File 'lib/safe_image/native_helper.rb', line 103

def pages(path, max_pixels)
  call!("pages", input: path, max_pixels: max_pixels).fetch(:value)
end

.png_from_rgba(raw_input, width, height, output) ⇒ Object 



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# File 'lib/safe_image/native_helper.rb', line 81

def png_from_rgba(raw_input, width, height, output)
  call!("png-from-rgba", raw_input: raw_input, width: width, height: height, output: output)
end

.probe(path, max_pixels) ⇒ Object 



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# File 'lib/safe_image/native_helper.rb', line 35

def probe(path, max_pixels)
  call!("probe", input: path, max_pixels: max_pixels)
end

.raise_helper_error(payload, status, command, stderr: nil, stdout: nil) ⇒ Object 



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# File 'lib/safe_image/native_helper.rb', line 220

def raise_helper_error(payload, status, command, stderr: nil, stdout: nil)
  message =
    (
      if payload[:message].to_s.empty?
        "native vips helper failed with status #{exit_status(status).inspect}"
      else
        payload[:message]
      end
    )
  original_class = payload[:error].to_s
  stderr_tail = payload[:stderr_tail] || tail(stderr)
  case original_class
  when "LimitError"
    raise LimitError.new(message, original_error_class: original_class, stderr_tail: stderr_tail)
  when "UnsupportedFormatError"
    raise UnsupportedFormatError.new(message, original_error_class: original_class, stderr_tail: stderr_tail)
  when "VipsUnavailableError"
    raise VipsUnavailableError.new(message, original_error_class: original_class, stderr_tail: stderr_tail)
  when "ArgumentError"
    raise ArgumentError, append_helper_detail(message, original_class, stderr_tail)
  when "InvalidImageError", ""
    raise InvalidImageError.new(message, original_error_class: original_class, stderr_tail: stderr_tail)
  else
    raise CommandError.new(
            "native vips helper downgraded unknown error class #{original_class.inspect}: #{message}",
            command: [HELPER, command],
            status: exit_status(status),
            stdout: stdout.to_s,
            stderr: stderr.to_s,
            category: :native_helper,
            operation: command,
            original_error_class: original_class,
            stderr_tail: stderr_tail
          )
  end
end

.read_paths(options) ⇒ Object 



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# File 'lib/safe_image/native_helper.rb', line 267

def read_paths(options)
  [options[:input], options[:raw_input], options[:fontfile]].compact.reject(&:empty?)
end

.read_response(path, stderr: nil) ⇒ Object 



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# File 'lib/safe_image/native_helper.rb', line 202

def read_response(path, stderr: nil)
  JSON.parse(File.read(path), symbolize_names: true)
rescue Errno::ENOENT
  {
    ok: false,
    error: "CommandError",
    message: "native vips helper did not write a response",
    stderr_tail: tail(stderr)
  }
rescue JSON::ParserError => e
  {
    ok: false,
    error: "CommandError",
    message: "native vips helper wrote invalid JSON: #{e.message}",
    stderr_tail: tail(stderr)
  }
end

.resize(input, output, scale, format, quality, max_pixels) ⇒ Object 



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# File 'lib/safe_image/native_helper.rb', line 52

def resize(input, output, scale, format, quality, max_pixels)
  call!(
    "resize",
    input: input,
    output: output,
    scale: scale,
    format: format,
    quality: quality,
    max_pixels: max_pixels
  )
end

.run_process!(argv, tmpdir) ⇒ Object 



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# File 'lib/safe_image/native_helper.rb', line 156

def run_process!(argv, tmpdir)
  stdout, stderr = Runner.run_process!(argv, helper_env(tmpdir), timeout: Runner::DEFAULT_TIMEOUT)
  [stdout, stderr, nil]
end

.run_sandboxed!(argv, tmpdir, options) ⇒ Object 



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# File 'lib/safe_image/native_helper.rb', line 161

def run_sandboxed!(argv, tmpdir, options)
  require "landlock"

  result =
    Sandbox.landlock_capture!(
      argv,
      read:
        Sandbox.existing_paths([*Sandbox.default_read_paths, *Sandbox.runtime_read_paths, *read_paths(options)]),
      write: Sandbox.existing_paths([tmpdir, *write_paths(options)]),
      execute: Sandbox.existing_paths([File.dirname(HELPER), *Sandbox.default_execute_paths]),
      env: helper_env(tmpdir),
      unsetenv_others: true,
      bind_tcp: landlock_abi >= 4 ? [1] : [],
      scope: landlock_abi >= 6 ? %i[abstract_unix_socket signal] : [],
      timeout: Runner::DEFAULT_TIMEOUT,
      rlimits: Sandbox::DEFAULT_RLIMITS,
      seccomp_deny_network: true,
      max_output_bytes: Runner::MAX_OUTPUT_BYTES,
      truncate_output: false
    )
  stdout = result.stdout if result.respond_to?(:stdout)
  stderr = result.stderr if result.respond_to?(:stderr)
  status = result.status if result.respond_to?(:status)
  [stdout, stderr, status]
end

.tail(value) ⇒ Object 



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# File 'lib/safe_image/native_helper.rb', line 195

def tail(value)
  text = value.to_s
  return nil if text.empty?

  text.bytesize > STDERR_TAIL_BYTES ? text.byteslice(-STDERR_TAIL_BYTES, STDERR_TAIL_BYTES) : text
end

.thumbnail(input, output, width, height, format, quality, max_pixels) ⇒ Object 



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# File 'lib/safe_image/native_helper.rb', line 39

def thumbnail(input, output, width, height, format, quality, max_pixels)
  call!(
    "thumbnail",
    input: input,
    output: output,
    width: width,
    height: height,
    format: format,
    quality: quality,
    max_pixels: max_pixels
  )
end

.verify! ⇒ Object 



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# File 'lib/safe_image/native_helper.rb', line 28

def verify!
  return true if @verified

  call!("version", sandbox: false)
  @verified = true
end

.write_paths(options) ⇒ Object 



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# File 'lib/safe_image/native_helper.rb', line 271

def write_paths(options)
  output = options[:output]
  return [] unless output

  expanded = File.expand_path(output)
  paths = [File.dirname(expanded)]
  paths << expanded if File.exist?(expanded)
  paths
end