+ if (*ugid_lookupp == 0) { /* actively lookup and copy in cache */
+
+ /* returns null if any element of the chain up to file is null.
+ * if sk != NULL then we also have a reference
+ */
+ *ugid_lookupp = linux_lookup(proto,
+ src_ip.s_addr, htons(src_port),
+ dst_ip.s_addr, htons(dst_port),
+ skb, oif ? 1 : 0, ugp);