+ u8 next_label_is_entropy;
+ mpls_label_t ho_label;
+ u32 hash, value;
+
+ ho_label = clib_net_to_host_u32(hdr->label_exp_s_ttl);
+ hash = vnet_mpls_uc_get_label(ho_label);
+ next_label_is_entropy = 0;
+
+ while (MPLS_EOS != vnet_mpls_uc_get_s(ho_label))
+ {
+ hdr++;
+ ho_label = clib_net_to_host_u32(hdr->label_exp_s_ttl);
+ value = vnet_mpls_uc_get_label(ho_label);
+
+ if (1 == next_label_is_entropy)
+ {
+ /*
+ * The label is an entropy value, use it alone as the hash
+ */
+ return (ho_label);
+ }
+ if (MPLS_IETF_ENTROPY_LABEL == value)
+ {
+ /*
+ * we've met a label in the stack indicating that tha next
+ * label is an entropy value
+ */
+ next_label_is_entropy = 1;
+ }
+ else
+ {
+ /*
+ * XOR the label values in the stack together to
+ * build up the hash value
+ */
+ hash ^= value;
+ }
+ }
+
+ /*
+ * check the top nibble for v4 and v6
+ */
+ hdr++;
+
+ switch (((u8*)hdr)[0] >> 4)
+ {
+ case 4:
+ /* incorporate the v4 flow-hash */
+ hash ^= ip4_compute_flow_hash ((const ip4_header_t *)hdr,
+ IP_FLOW_HASH_DEFAULT);
+ break;
+ case 6:
+ /* incorporate the v6 flow-hash */
+ hash ^= ip6_compute_flow_hash ((const ip6_header_t *)hdr,
+ IP_FLOW_HASH_DEFAULT);
+ break;
+ default:
+ break;
+ }
+
+ return (hash);