IP1_NXT_PROT_UDP_CHKSUM_OFF_MASK
val &= ~(IP1_NXT_PROT_UDP_CHKSUM_OFF_MASK |
#define IP1_NXT_PROT_UDP_CHKSUM_OFF(x) (((x) << 8) & IP1_NXT_PROT_UDP_CHKSUM_OFF_MASK)