[nrf fromtree] net: if: Don't require native IP stack support for IPv6 lookups

IPv6 based interface lookups doesn't require native IP stack support,
hence reflect that in the API.

Signed-off-by: Robert Lubos <[email protected]>
(cherry picked from commit f4335d2)

Author: rlubos

include/zephyr/net/net_if.h

@@ -2038,7 +2038,7 @@ static inline uint32_t net_if_ipv6_get_retrans_timer(struct net_if *iface)
  * @return Pointer to IPv6 address to use, NULL if no IPv6 address
  * could be found.
  */
-#if defined(CONFIG_NET_NATIVE_IPV6)
+#if defined(CONFIG_NET_IPV6)
 const struct in6_addr *net_if_ipv6_select_src_addr(struct net_if *iface,
 						   const struct in6_addr *dst);
 #else
@@ -2065,7 +2065,7 @@ static inline const struct in6_addr *net_if_ipv6_select_src_addr(
  * @return Pointer to IPv6 address to use, NULL if no IPv6 address
  * could be found.
  */
-#if defined(CONFIG_NET_NATIVE_IPV6)
+#if defined(CONFIG_NET_IPV6)
 const struct in6_addr *net_if_ipv6_select_src_addr_hint(struct net_if *iface,
 							const struct in6_addr *dst,
 							int flags);
@@ -2090,7 +2090,7 @@ static inline const struct in6_addr *net_if_ipv6_select_src_addr_hint(
  * @return Pointer to network interface to use, NULL if no suitable interface
  * could be found.
  */
-#if defined(CONFIG_NET_NATIVE_IPV6)
+#if defined(CONFIG_NET_IPV6)
 struct net_if *net_if_ipv6_select_src_iface(const struct in6_addr *dst);
 #else
 static inline struct net_if *net_if_ipv6_select_src_iface(

subsys/net/ip/net_if.c

@@ -2983,6 +2983,8 @@ void net_if_ipv6_set_hop_limit(struct net_if *iface, uint8_t hop_limit)
 	net_if_unlock(iface);
 }
 
+#endif /* CONFIG_NET_NATIVE_IPV6 */
+
 static uint8_t get_diff_ipv6(const struct in6_addr *src,
 			  const struct in6_addr *dst)
 {
@@ -3208,6 +3210,8 @@ struct net_if *net_if_ipv6_select_src_iface(const struct in6_addr *dst)
 	return iface;
 }
 
+#if defined(CONFIG_NET_NATIVE_IPV6)
+
 uint32_t net_if_ipv6_calc_reachable_time(struct net_if_ipv6 *ipv6)
 {
 	uint32_t min_reachable, max_reachable;