net: ipv6: add function checking if given address is ULA

This patch adds a helper function to verify if given IPv6 address is
a unique local address.

Signed-off-by: Hubert Miś <[email protected]>

Author: Hubert Miś

include/net/net_ip.h

@@ -763,6 +763,18 @@ static inline bool net_ipv6_is_ll_addr(const struct in6_addr *addr)
 	return UNALIGNED_GET(&addr->s6_addr16[0]) == htons(0xFE80);
 }
 
+/**
+ * @brief Check if the given IPv6 address is a unique local address.
+ *
+ * @param addr A valid pointer on an IPv6 address
+ *
+ * @return True if it is, false otherwise.
+ */
+static inline bool net_ipv6_is_ula_addr(const struct in6_addr *addr)
+{
+	return addr->s6_addr[0] == 0xFD;
+}
+
 /**
  * @brief Return pointer to any (all bits zeros) IPv6 address.
  *