Merge pull request #24174 from yuwata/network-link-local-address

network: fix link local address handling

src/network/networkd-address.c

@@ -802,7 +802,7 @@ int link_drop_ipv6ll_addresses(Link *link) {
         /* IPv6LL address may be in the tentative state, and in that case networkd has not received it.
          * So, we need to dump all IPv6 addresses. */
 
-        if (link_may_have_ipv6ll(link))
+        if (link_may_have_ipv6ll(link, /* check_multicast = */ false))
                 return 0;
 
         r = sd_rtnl_message_new_addr(link->manager->rtnl, &req, RTM_GETADDR, link->ifindex, AF_INET6);

src/network/networkd-ipv4acd.c

@@ -1,14 +1,44 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+#include <linux/if_arp.h>
+
 #include "sd-dhcp-client.h"
 #include "sd-ipv4acd.h"
 
+#include "ipvlan.h"
 #include "networkd-address.h"
 #include "networkd-dhcp4.h"
 #include "networkd-ipv4acd.h"
 #include "networkd-link.h"
 #include "networkd-manager.h"
 
+bool link_ipv4acd_supported(Link *link) {
+        assert(link);
+
+        if (link->flags & IFF_LOOPBACK)
+                return false;
+
+        /* ARPHRD_INFINIBAND seems to potentially support IPv4ACD.
+         * But currently sd-ipv4acd only supports ARPHRD_ETHER. */
+        if (link->iftype != ARPHRD_ETHER)
+                return false;
+
+        if (link->hw_addr.length != ETH_ALEN)
+                return false;
+
+        if (ether_addr_is_null(&link->hw_addr.ether))
+                return false;
+
+        if (streq_ptr(link->kind, "vrf"))
+                return false;
+
+        /* L3 or L3S mode do not support ARP. */
+        if (IN_SET(link_get_ipvlan_mode(link), NETDEV_IPVLAN_MODE_L3, NETDEV_IPVLAN_MODE_L3S))
+                return false;
+
+        return true;
+}
+
 static int static_ipv4acd_address_remove(Link *link, Address *address, bool on_conflict) {
         int r;
 
@@ -141,7 +171,7 @@ int ipv4acd_configure(Address *address) {
         if (!FLAGS_SET(address->duplicate_address_detection, ADDRESS_FAMILY_IPV4))
                 return 0;
 
-        if (link->hw_addr.length != ETH_ALEN || hw_addr_is_null(&link->hw_addr))
+        if (!link_ipv4acd_supported(link))
                 return 0;
 
         /* Currently, only static and DHCP4 addresses are supported. */

src/network/networkd-ipv4acd.h

@@ -4,6 +4,7 @@
 typedef struct Address Address;
 typedef struct Link Link;
 
+bool link_ipv4acd_supported(Link *link);
 int ipv4acd_configure(Address *address);
 int ipv4acd_update_mac(Link *link);
 int ipv4acd_start(Link *link);

src/network/networkd-ipv4ll.c

@@ -5,12 +5,28 @@
 
 #include "netif-util.h"
 #include "networkd-address.h"
+#include "networkd-ipv4acd.h"
 #include "networkd-ipv4ll.h"
 #include "networkd-link.h"
 #include "networkd-manager.h"
 #include "networkd-queue.h"
 #include "parse-util.h"
 
+bool link_ipv4ll_enabled(Link *link) {
+        assert(link);
+
+        if (!link_ipv4acd_supported(link))
+                return false;
+
+        if (!link->network)
+                return false;
+
+        if (link->network->bond)
+                return false;
+
+        return link->network->link_local & ADDRESS_FAMILY_IPV4;
+}
+
 static int address_new_from_ipv4ll(Link *link, Address **ret) {
         _cleanup_(address_freep) Address *address = NULL;
         struct in_addr addr;

src/network/networkd-ipv4ll.h

@@ -7,6 +7,8 @@
 
 typedef struct Link Link;
 
+bool link_ipv4ll_enabled(Link *link);
+
 int ipv4ll_configure(Link *link);
 int ipv4ll_update_mac(Link *link);
 

src/network/networkd-ipv6ll.c

@@ -38,7 +38,7 @@ bool link_ipv6ll_enabled(Link *link) {
         return link->network->link_local & ADDRESS_FAMILY_IPV6;
 }
 
-bool link_may_have_ipv6ll(Link *link) {
+bool link_may_have_ipv6ll(Link *link, bool check_multicast) {
         assert(link);
 
         /*
@@ -62,6 +62,9 @@ bool link_may_have_ipv6ll(Link *link) {
                 if (!link->network)
                         return false;
 
+                if (check_multicast && !FLAGS_SET(link->flags, IFF_MULTICAST) && link->network->multicast <= 0)
+                        return false;
+
                 ORDERED_HASHMAP_FOREACH(a, link->network->addresses_by_section) {
                         if (a->family != AF_INET6)
                                 continue;

src/network/networkd-ipv6ll.h

@@ -22,7 +22,7 @@ typedef enum IPv6LinkLocalAddressGenMode {
 } IPv6LinkLocalAddressGenMode;
 
 bool link_ipv6ll_enabled(Link *link);
-bool link_may_have_ipv6ll(Link *link);
+bool link_may_have_ipv6ll(Link *link, bool check_multicast);
 
 IPv6LinkLocalAddressGenMode link_get_ipv6ll_addrgen_mode(Link *link);
 int ipv6ll_addrgen_mode_fill_message(sd_netlink_message *message, IPv6LinkLocalAddressGenMode mode);

src/network/networkd-link.c

@@ -27,7 +27,6 @@
 #include "format-util.h"
 #include "fs-util.h"
 #include "glyph-util.h"
-#include "ipvlan.h"
 #include "missing_network.h"
 #include "netlink-util.h"
 #include "network-internal.h"
@@ -69,56 +68,22 @@
 #include "util.h"
 #include "vrf.h"
 
-bool link_ipv4ll_enabled(Link *link) {
-        assert(link);
-
-        if (link->flags & IFF_LOOPBACK)
-                return false;
-
-        if (!link->network)
-                return false;
-
-        if (link->iftype == ARPHRD_CAN)
-                return false;
-
-        if (link->hw_addr.length != ETH_ALEN)
-                return false;
-
-        if (ether_addr_is_null(&link->hw_addr.ether))
-                return false;
-
-        /* ARPHRD_INFINIBAND seems to potentially support IPv4LL.
-         * But currently sd-ipv4ll and sd-ipv4acd only support ARPHRD_ETHER. */
-        if (link->iftype != ARPHRD_ETHER)
-                return false;
-
-        if (streq_ptr(link->kind, "vrf"))
-                return false;
-
-        /* L3 or L3S mode do not support ARP. */
-        if (IN_SET(link_get_ipvlan_mode(link), NETDEV_IPVLAN_MODE_L3, NETDEV_IPVLAN_MODE_L3S))
-                return false;
-
-        if (link->network->bond)
-                return false;
-
-        return link->network->link_local & ADDRESS_FAMILY_IPV4;
-}
-
 bool link_ipv6_enabled(Link *link) {
         assert(link);
 
         if (!socket_ipv6_is_supported())
                 return false;
 
-        if (link->network->bond)
-                return false;
-
         if (link->iftype == ARPHRD_CAN)
                 return false;
 
-        /* DHCPv6 client will not be started if no IPv6 link-local address is configured. */
-        if (link_ipv6ll_enabled(link))
+        if (!link->network)
+                return false;
+
+        if (link->network->bond)
+                return false;
+
+        if (link_may_have_ipv6ll(link, /* check_multicast = */ false))
                 return true;
 
         if (network_has_static_ipv6_configurations(link->network))

src/network/networkd-link.h

@@ -225,8 +225,6 @@ static inline bool link_has_carrier(Link *link) {
 bool link_ipv6_enabled(Link *link);
 int link_ipv6ll_gained(Link *link);
 
-bool link_ipv4ll_enabled(Link *link);
-
 int link_stop_engines(Link *link, bool may_keep_dhcp);
 
 const char* link_state_to_string(LinkState s) _const_;

src/network/networkd-ndisc.c

@@ -41,7 +41,7 @@ bool link_ipv6_accept_ra_enabled(Link *link) {
         if (!link->network)
                 return false;
 
-        if (!link_may_have_ipv6ll(link))
+        if (!link_may_have_ipv6ll(link, /* check_multicast = */ true))
                 return false;
 
         assert(link->network->ipv6_accept_ra >= 0);

src/network/networkd-radv.c

@@ -54,7 +54,7 @@ void network_adjust_radv(Network *network) {
 bool link_radv_enabled(Link *link) {
         assert(link);
 
-        if (!link_may_have_ipv6ll(link))
+        if (!link_may_have_ipv6ll(link, /* check_multicast = */ true))
                 return false;
 
         if (link->hw_addr.length != ETH_ALEN)

test/test-network/conf/25-wireguard.network

@@ -4,4 +4,6 @@ Name=wg99
 
 [Network]
 Address=192.168.124.1/24
+Address=fe80::1/64
+Address=169.254.11.1/24
 IPv6AcceptRA=no

test/test-network/systemd-networkd-tests.py

@@ -1416,6 +1416,14 @@ class NetworkdNetDevTests(unittest.TestCase, Utilities):
         print(output)
         self.assertIn('inet 192.168.124.1/24 scope global wg99', output)
 
+        output = check_output('ip -4 address show dev wg99')
+        print(output)
+        self.assertIn('inet 169.254.11.1/24 scope link wg99', output)
+
+        output = check_output('ip -6 address show dev wg99')
+        print(output)
+        self.assertIn('inet6 fe80::1/64 scope link', output)
+
         output = check_output('ip -4 address show dev wg98')
         print(output)
         self.assertIn('inet 192.168.123.123/24 scope global wg98', output)