off by one for delta checksums

3 years ago · 0b7f0347d4
1 changed files with 11 additions and 1 deletions
--- a/p4src/checksum_diff.p4
+++ b/p4src/checksum_diff.p4
@ -197,14 +197,24 @@ control MyIngress(inout headers hdr,
                    v4sum();
                    v6sum();
                    bit<16> diff = meta.v6sum - meta.v4sum;
-                    hdr.udp.checksum = hdr.udp.checksum + ~diff;
+                    hdr.udp.checksum = hdr.udp.checksum + ~diff +1;
+//                    hdr.udp.checksum = ~diff;

                    #else
                    meta.chk_udp_v6 = 1;
                    #endif
                }
                if(hdr.tcp.isValid()) {
+                    #ifdef USE_NICO_DELTA_CHECKSUM
+                    v4sum();
+                    v6sum();
+                    bit<16> diff = meta.v6sum - meta.v4sum;
+                    hdr.tcp.checksum = hdr.tcp.checksum + ~diff;
+
+                    #else
+
                    meta.chk_tcp_v6 = 1;
+                    #endif
                }

                v6_networks.apply();