#include <net/netfilter/nf_conntrack.h>
 #include <net/net_namespace.h>
 #include <net/checksum.h>
+#include <net/ip.h>
 
 #define CLUSTERIP_VERSION "0.8"
 
 {
        const struct iphdr *iph = ip_hdr(skb);
        unsigned long hashval;
-       u_int16_t sport, dport;
-       const u_int16_t *ports;
-
-       switch (iph->protocol) {
-       case IPPROTO_TCP:
-       case IPPROTO_UDP:
-       case IPPROTO_UDPLITE:
-       case IPPROTO_SCTP:
-       case IPPROTO_DCCP:
-       case IPPROTO_ICMP:
-               ports = (const void *)iph+iph->ihl*4;
-               sport = ports[0];
-               dport = ports[1];
-               break;
-       default:
+       u_int16_t sport = 0, dport = 0;
+       int poff;
+
+       poff = proto_ports_offset(iph->protocol);
+       if (poff >= 0) {
+               const u_int16_t *ports;
+               u16 _ports[2];
+
+               ports = skb_header_pointer(skb, iph->ihl * 4 + poff, 4, _ports);
+               if (ports) {
+                       sport = ports[0];
+                       dport = ports[1];
+               }
+       } else {
                if (net_ratelimit())
                        pr_info("unknown protocol %u\n", iph->protocol);
-               sport = dport = 0;
        }
 
        switch (config->hash_mode) {