lib/facter/resolvers/freebsd/ffi/ffi_helper.rb
# frozen_string_literal: true
require 'ffi'
module Facter
module Freebsd
module FfiHelper
module Libc
extend FFI::Library
KENV_GET = 0
KENV_MVALLEN = 128
ffi_lib 'c'
attach_function :kenv, %i[int string pointer int], :int
attach_function :sysctlbyname, %i[string pointer pointer pointer size_t], :int
end
def self.kenv(action, name, value = nil)
case action
when :get
len = Libc::KENV_MVALLEN + 1
value = FFI::MemoryPointer.new(:char, len)
res = Libc.kenv(Libc::KENV_GET, name, value, len)
return nil if res.negative?
value.read_string(res).chomp("\0")
else
raise "Action #{action} not supported"
end
end
def self.sysctl_by_name(type, name)
oldp = FFI::Pointer::NULL
oldlenp = FFI::MemoryPointer.new(:size_t)
newp = FFI::Pointer::NULL
newlenp = 0
if type == :string
res = Libc.sysctlbyname(name, oldp, oldlenp, newp, newlenp)
return nil if res.negative?
else
oldlenp.write(:size_t, FFI.type_size(type))
end
oldp = FFI::MemoryPointer.new(:uint8_t, oldlenp.read(:size_t))
res = Libc.sysctlbyname(name, oldp, oldlenp, newp, newlenp)
return nil if res.negative?
case type
when :string
oldp.read_string
else
oldp.read(type)
end
end
end
end
end