+static inline int ipv6_addr_loopback(const struct in6_addr *a)
+{
+ return ((a->s6_addr32[0] | a->s6_addr32[1] |
+ a->s6_addr32[2] | (a->s6_addr32[3] ^ htonl(1))) == 0);
+}
+
+static inline int ipv6_addr_v4mapped(const struct in6_addr *a)
+{
+ return ((a->s6_addr32[0] | a->s6_addr32[1] |
+ (a->s6_addr32[2] ^ htonl(0x0000ffff))) == 0);
+}
+
+/*
+ * Check for a RFC 4843 ORCHID address
+ * (Overlay Routable Cryptographic Hash Identifiers)
+ */
+static inline int ipv6_addr_orchid(const struct in6_addr *a)
+{
+ return ((a->s6_addr32[0] & htonl(0xfffffff0))
+ == htonl(0x20010010));
+}
+
+static inline void ipv6_addr_set_v4mapped(const __be32 addr,
+ struct in6_addr *v4mapped)
+{
+ ipv6_addr_set(v4mapped,
+ 0, 0,
+ htonl(0x0000FFFF),
+ addr);
+}
+
+/*
+ * find the first different bit between two addresses
+ * length of address must be a multiple of 32bits
+ */
+static inline int __ipv6_addr_diff(const void *token1, const void *token2, int addrlen)
+{
+ const __be32 *a1 = token1, *a2 = token2;
+ int i;
+
+ addrlen >>= 2;
+
+ for (i = 0; i < addrlen; i++) {
+ __be32 xb = a1[i] ^ a2[i];
+ if (xb)
+ return i * 32 + 32 - fls(ntohl(xb));
+ }
+
+ /*
+ * we should *never* get to this point since that
+ * would mean the addrs are equal
+ *
+ * However, we do get to it 8) And exacly, when
+ * addresses are equal 8)
+ *
+ * ip route add 1111::/128 via ...
+ * ip route add 1111::/64 via ...
+ * and we are here.
+ *
+ * Ideally, this function should stop comparison
+ * at prefix length. It does not, but it is still OK,
+ * if returned value is greater than prefix length.
+ * --ANK (980803)
+ */
+ return (addrlen << 5);
+}
+
+static inline int ipv6_addr_diff(const struct in6_addr *a1, const struct in6_addr *a2)
+{
+ return __ipv6_addr_diff(a1, a2, sizeof(struct in6_addr));
+}
+