network: Introduce method to generate EUI-64 addresses

2 files changed, 20 insertions, 0 deletions

diff --git a/src/network/networkd-address.c b/src/network/networkd-address.c
index 6244f75201..1567bd7ee9 100644
--- a/src/network/networkd-address.c
+++ b/src/network/networkd-address.c
@@ -20,6 +20,24 @@
 #define ADDRESSES_PER_LINK_MAX 2048U
 #define STATIC_ADDRESSES_PER_NETWORK_MAX 1024U
 
+int generate_ipv6_eui_64_address(Link *link, struct in6_addr *ret) {
+        assert(link);
+        assert(ret);
+
+        /* see RFC4291 section 2.5.1 */
+        ret->s6_addr[8]  = link->mac.ether_addr_octet[0];
+        ret->s6_addr[8] ^= 1 << 1;
+        ret->s6_addr[9]  = link->mac.ether_addr_octet[1];
+        ret->s6_addr[10] = link->mac.ether_addr_octet[2];
+        ret->s6_addr[11] = 0xff;
+        ret->s6_addr[12] = 0xfe;
+        ret->s6_addr[13] = link->mac.ether_addr_octet[3];
+        ret->s6_addr[14] = link->mac.ether_addr_octet[4];
+        ret->s6_addr[15] = link->mac.ether_addr_octet[5];
+
+        return 0;
+}
+
 int address_new(Address **ret) {
         _cleanup_(address_freep) Address *address = NULL;
 
diff --git a/src/network/networkd-address.h b/src/network/networkd-address.h
index ad2412c75a..bd0485e0ab 100644
--- a/src/network/networkd-address.h
+++ b/src/network/networkd-address.h
@@ -66,6 +66,8 @@ bool address_is_ready(const Address *a);
 int address_section_verify(Address *a);
 int configure_ipv4_duplicate_address_detection(Link *link, Address *address);
 
+int generate_ipv6_eui_64_address(Link *link, struct in6_addr *ret);
+
 DEFINE_NETWORK_SECTION_FUNCTIONS(Address, address_free);
 
 extern const struct hash_ops address_hash_ops;