bsdcapsicum.rb/lib/capsicum.rb
2024-06-24 22:57:01 -03:00

79 lines
1.6 KiB
Ruby

# frozen_string_literal: true
require "capsicum/version"
require "fiddle"
module Capsicum
# @api private
module LibC
module_function
##
# Provides a Ruby interface for cap_enter(2)
# @return [Integer]
def cap_enter
Fiddle::Function.new(
libc["cap_enter"],
[],
Fiddle::Types::INT
).call
end
##
# Provides a Ruby interface for cap_getmode(2)
# @param [Fiddle::Pointer] uintp
# @return [Integer]
def cap_getmode(uintp)
Fiddle::Function.new(
libc["cap_getmode"],
[Fiddle::Types::INTPTR_T],
Fiddle::Types::INT
).call(uintp)
end
##
# @api private
def libc
@libc ||= Fiddle.dlopen Dir["/lib/libc.*"].first
end
end
module_function
##
# Check if we're in capability mode.
#
# @see cap_getmode(2)
# @raise [SystemCallError]
# Might raise a subclass of SystemCallError
# @return [Boolean]
# Returns true if the current process is in capability mode
def in_capability_mode?
uintp = Fiddle::Pointer.malloc(Fiddle::SIZEOF_UINT)
ret = LibC.cap_getmode(uintp)
if ret == 0
uintp[0, Fiddle::SIZEOF_UINT].unpack("i") == [1]
else
raise SystemCallError.new("cap_getmode", Fiddle.last_error)
end
ensure
uintp.call_free
end
##
# Enter capability mode
#
# @see cap_enter(2)
# @raise [SystemCallError]
# Might raise a subclass of SystemCallError
# @return [Boolean]
# Returns true when the current process is in capability mode
def enter!
if LibC.cap_enter == 0
true
else
raise SystemCallError.new("cap_enter", Fiddle.last_error)
end
end
end