- else if (udp0->checksum)
- {
- sum0 = udp0->checksum;
- sum0 = ip_csum_update (sum0, old_addr0, new_addr0, ip4_header_t,
- dst_address);
- sum0 = ip_csum_update (sum0, old_port0, new_port0, ip4_header_t,
- length);
- if (PREDICT_FALSE (is_twice_nat_session (s0)))
- {
- sum0 = ip_csum_update (sum0, ip0->src_address.as_u32,
- s0->ext_host_nat_addr.as_u32,
- ip4_header_t, dst_address);
- sum0 = ip_csum_update (sum0, udp0->src_port,
- s0->ext_host_nat_port, ip4_header_t,
- length);
- udp0->src_port = s0->ext_host_nat_port;
- ip0->src_address.as_u32 = s0->ext_host_nat_addr.as_u32;
- }
- udp0->checksum = ip_csum_fold (sum0);
- udp_packets++;
- }