diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index 988c9f2..42ef6ab 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -320,6 +320,18 @@
 	return __ipv6_addr_src_scope(__ipv6_addr_type(addr));
 }
 
+static inline bool __ipv6_addr_needs_scope_id(int type)
+{
+	return type & IPV6_ADDR_LINKLOCAL ||
+	       (type & IPV6_ADDR_MULTICAST &&
+		(type & (IPV6_ADDR_LOOPBACK|IPV6_ADDR_LINKLOCAL)));
+}
+
+static inline __u32 ipv6_iface_scope_id(const struct in6_addr *addr, int iface)
+{
+	return __ipv6_addr_needs_scope_id(__ipv6_addr_type(addr)) ? iface : 0;
+}
+
 static inline int ipv6_addr_cmp(const struct in6_addr *a1, const struct in6_addr *a2)
 {
 	return memcmp(a1, a2, sizeof(struct in6_addr));