AC_CHECK_MEMBER([struct in_pktinfo.ipi_spec_dst],
AC_DEFINE([HAVE_IPI_SPEC_DST], [], [struct in_pktinfo has ipi_spec_dst member]),
[],
AC_CHECK_MEMBER([struct in_pktinfo.ipi_spec_dst],
AC_DEFINE([HAVE_IPI_SPEC_DST], [], [struct in_pktinfo has ipi_spec_dst member]),
[],