network: move ipv6ll related functions to networkd-ipv6ll.[ch]

1 files changed, 89 insertions, 0 deletions

diff --git a/src/network/networkd-ipv6ll.c b/src/network/networkd-ipv6ll.c
new file mode 100644
index 0000000000..016df4a1b0
--- /dev/null
+++ b/src/network/networkd-ipv6ll.c
@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <linux/if.h>
+#include <linux/if_arp.h>
+
+#include "in-addr-util.h"
+#include "networkd-address.h"
+#include "networkd-ipv6ll.h"
+#include "networkd-link.h"
+#include "networkd-network.h"
+#include "networkd-util.h"
+#include "socket-util.h"
+#include "string-table.h"
+#include "strv.h"
+
+bool link_ipv6ll_enabled(Link *link) {
+        assert(link);
+
+        if (!socket_ipv6_is_supported())
+                return false;
+
+        if (link->flags & IFF_LOOPBACK)
+                return false;
+
+        if (!link->network)
+                return false;
+
+        if (link->iftype == ARPHRD_CAN)
+                return false;
+
+        if (STRPTR_IN_SET(link->kind, "vrf", "wireguard", "ipip", "gre", "sit", "vti", "nlmon"))
+                return false;
+
+        if (link->network->bond)
+                return false;
+
+        return link->network->link_local & ADDRESS_FAMILY_IPV6;
+}
+
+bool link_may_have_ipv6ll(Link *link) {
+        assert(link);
+
+        /*
+         * This is equivalent to link_ipv6ll_enabled() for non-WireGuard interfaces.
+         *
+         * For WireGuard interface, the kernel does not assign any IPv6LL addresses, but we can assign
+         * it manually. It is necessary to set an IPv6LL address manually to run NDisc or RADV on
+         * WireGuard interface. Note, also Multicast=yes must be set. See #17380.
+         *
+         * TODO: May be better to introduce GenerateIPv6LinkLocalAddress= setting, and use algorithms
+         *       used in networkd-address-generation.c
+         */
+
+        if (link_ipv6ll_enabled(link))
+                return true;
+
+        /* IPv6LL address can be manually assigned on WireGuard interface. */
+        if (streq_ptr(link->kind, "wireguard")) {
+                Address *a;
+
+                if (!link->network)
+                        return false;
+
+                ORDERED_HASHMAP_FOREACH(a, link->network->addresses_by_section) {
+                        if (a->family != AF_INET6)
+                                continue;
+                        if (in6_addr_is_set(&a->in_addr_peer.in6))
+                                continue;
+                        if (in6_addr_is_link_local(&a->in_addr.in6))
+                                return true;
+                }
+        }
+
+        return false;
+}
+
+static const char* const ipv6_link_local_address_gen_mode_table[_IPV6_LINK_LOCAL_ADDRESS_GEN_MODE_MAX] = {
+        [IPV6_LINK_LOCAL_ADDRESSS_GEN_MODE_EUI64]          = "eui64",
+        [IPV6_LINK_LOCAL_ADDRESSS_GEN_MODE_NONE]           = "none",
+        [IPV6_LINK_LOCAL_ADDRESSS_GEN_MODE_STABLE_PRIVACY] = "stable-privacy",
+        [IPV6_LINK_LOCAL_ADDRESSS_GEN_MODE_RANDOM]         = "random",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(ipv6_link_local_address_gen_mode, IPv6LinkLocalAddressGenMode);
+DEFINE_CONFIG_PARSE_ENUM(
+        config_parse_ipv6_link_local_address_gen_mode,
+        ipv6_link_local_address_gen_mode,
+        IPv6LinkLocalAddressGenMode,
+        "Failed to parse IPv6 link local address generation mode");