Module: BSD::Capsicum

Extended by:
Capsicum
Included in:
Capsicum
Defined in:
lib/bsd/capsicum.rb,
lib/bsd/capsicum/ffi.rb,
lib/bsd/capsicum/version.rb,
lib/bsd/capsicum/constants.rb

Defined Under Namespace

Modules: Constants

Constant Summary collapse

VERSION = 
"0.3.0"

Instance Method Summary collapse

Instance Method Details

#in_capability_mode? ⇒ Boolean Also known as: capability_mode?

Check if we’re in capability mode

Returns:

  • (Boolean) —

    Returns true when the current process is in capability mode

Raises:

  • (SystemCallError) —

    Might raise a subclass of SystemCallError

See Also:



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# File 'lib/bsd/capsicum.rb', line 19

def in_capability_mode?
  uintp = Fiddle::Pointer.malloc(Fiddle::SIZEOF_UINT)
  if FFI.cap_getmode(uintp).zero?
    uintp[0, Fiddle::SIZEOF_UINT].unpack("i") == [1]
  else
    raise SystemCallError.new("cap_getmode", Fiddle.last_error)
  end
ensure
  uintp.call_free
end

#enter! ⇒ Boolean Also known as: enter_capability_mode!

Enter a process into capability mode

Returns:

  • (Boolean) —

    Returns true when successful

Raises:

  • (SystemCallError) —

    Might raise a subclass of SystemCallError

See Also:



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# File 'lib/bsd/capsicum.rb', line 38

def enter!
  FFI.cap_enter.zero? ||
  raise(SystemCallError.new("cap_enter", Fiddle.last_error))
end

#limit!(io, allow:) ⇒ Boolean

Limit the capabilities of a file descriptor

Examples:

# Limit standard output operations to read and write
BSD::Capsicum.limit!(STDOUT, allow: %i[CAP_READ CAP_WRITE])
# Ditto
BSD::Capsicum.limit!(STDOUT, allow: %i[read write])

Parameters:

  • io (#to_i) —

    An IO object

  • allow (Array<Symbol, Integer>) —

    An allowed set of capabilities

Returns:

  • (Boolean) —

    Returns true when successful

Raises:

  • (SystemCallError) —

    Might raise a subclass of SystemCallError

See Also:



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# File 'lib/bsd/capsicum.rb', line 61

def limit!(io, allow:)
  rightsp = Fiddle::Pointer.malloc(Constants::SIZEOF_CAP_RIGHTS_T)
  FFI.cap_rights_init(rightsp, *allow)
  FFI.cap_rights_limit(io.to_i, rightsp).zero? ||
  raise(SystemCallError.new("cap_rights_limit", Fiddle.last_error))
ensure
  rightsp.call_free
end