OVS_GREP_IFELSE([$KSRC26/include/linux/types.h], [__wsum],
[OVS_DEFINE([HAVE_CSUM_TYPES])])
+ OVS_GREP_IFELSE([$KSRC26/include/net/checksum.h], [csum_replace4])
OVS_GREP_IFELSE([$KSRC26/include/net/checksum.h], [csum_unfold])
OVS_GREP_IFELSE([$KSRC26/include/net/netlink.h], [NLA_NUL_STRING])