+#ifdef CONFIG_IPV6_MIP6
+/**
+ * ipv6_rearrange_destopt - rearrange IPv6 destination options header
+ * @iph: IPv6 header
+ * @destopt: destionation options header
+ */
+static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt)
+{
+ u8 *opt = (u8 *)destopt;
+ int len = ipv6_optlen(destopt);
+ int off = 0;
+ int optlen = 0;
+
+ off += 2;
+ len -= 2;
+
+ while (len > 0) {
+
+ switch (opt[off]) {
+
+ case IPV6_TLV_PAD0:
+ optlen = 1;
+ break;
+ default:
+ if (len < 2)
+ goto bad;
+ optlen = opt[off+1]+2;
+ if (len < optlen)
+ goto bad;
+
+ /* Rearrange the source address in @iph and the
+ * addresses in home address option for final source.
+ * See 11.3.2 of RFC 3775 for details.
+ */
+ if (opt[off] == IPV6_TLV_HAO) {
+ struct in6_addr final_addr;
+ struct ipv6_destopt_hao *hao;
+
+ hao = (struct ipv6_destopt_hao *)&opt[off];
+ if (hao->length != sizeof(hao->addr)) {
+ if (net_ratelimit())
+ printk(KERN_WARNING "destopt hao: invalid header length: %u\n", hao->length);
+ goto bad;
+ }
+ ipv6_addr_copy(&final_addr, &hao->addr);
+ ipv6_addr_copy(&hao->addr, &iph->saddr);
+ ipv6_addr_copy(&iph->saddr, &final_addr);
+ }
+ break;
+ }
+
+ off += optlen;
+ len -= optlen;
+ }
+ /* Note: ok if len == 0 */
+bad:
+ return;
+}
+#endif
+