+ /* ICMPv4 and ICMPv6 have 8-bit "type" and "code" fields. struct flow uses
+ * the low 8 bits of the 16-bit tp_src and tp_dst members to represent
+ * these fields. The datapath interface, on the other hand, represents
+ * them with just 8 bits each. This means that if the high 8 bits of the
+ * masks for these fields somehow become set, then they will get chopped
+ * off by a round trip through the datapath, and revalidation will spot
+ * that as an inconsistency and delete the flow. Avoid the problem here by
+ * making sure that only the low 8 bits of either field can be unwildcarded
+ * for ICMP.
+ */
+ if (is_icmp) {
+ wc->masks.tp_src &= htons(UINT8_MAX);
+ wc->masks.tp_dst &= htons(UINT8_MAX);
+ }
+