network: update tunnel or vxlan with Local=dhcp4 and friends (#34957)

Fixes #24854.

src/network/netdev/netdev.c

@@ -413,6 +413,17 @@ int netdev_enter_ready(NetDev *netdev) {
         return 0;
 }
 
+bool netdev_needs_reconfigure(NetDev *netdev, NetDevLocalAddressType type) {
+        assert(netdev);
+        assert(type < _NETDEV_LOCAL_ADDRESS_TYPE_MAX);
+
+        if (type < 0)
+                return true;
+
+        return NETDEV_VTABLE(netdev)->needs_reconfigure &&
+                NETDEV_VTABLE(netdev)->needs_reconfigure(netdev, type);
+}
+
 /* callback for netdev's created without a backing Link */
 static int netdev_create_handler(sd_netlink *rtnl, sd_netlink_message *m, NetDev *netdev) {
         int r;

src/network/netdev/netdev.h

@@ -8,6 +8,7 @@
 #include "hash-funcs.h"
 #include "list.h"
 #include "log-link.h"
+#include "netdev-util.h"
 #include "networkd-link.h"
 #include "time-util.h"
 
@@ -186,6 +187,10 @@ typedef struct NetDevVTable {
         /* provides if MTU can be set. If this is not set, assumed to be yes. */
         bool (*can_set_mtu)(NetDev *netdev, uint32_t mtu);
 
+        /* provides if the netdev needs to be reconfigured when a specified type of address on the underlying
+         * interface is updated. */
+        bool (*needs_reconfigure)(NetDev *netdev, NetDevLocalAddressType type);
+
         /* expected iftype, e.g. ARPHRD_ETHER. */
         uint16_t iftype;
 
@@ -237,6 +242,7 @@ int netdev_set_ifindex(NetDev *netdev, sd_netlink_message *newlink);
 int netdev_generate_hw_addr(NetDev *netdev, Link *link, const char *name,
                             const struct hw_addr_data *hw_addr, struct hw_addr_data *ret);
 
+bool netdev_needs_reconfigure(NetDev *netdev, NetDevLocalAddressType type);
 int link_request_stacked_netdev(Link *link, NetDev *netdev);
 
 const char* netdev_kind_to_string(NetDevKind d) _const_;

src/network/netdev/tunnel.c

@@ -708,6 +708,14 @@ static int netdev_tunnel_verify(NetDev *netdev, const char *filename) {
         return 0;
 }
 
+static bool tunnel_needs_reconfigure(NetDev *netdev, NetDevLocalAddressType type) {
+        assert(type >= 0 && type < _NETDEV_LOCAL_ADDRESS_TYPE_MAX);
+
+        Tunnel *t = ASSERT_PTR(TUNNEL(netdev));
+
+        return t->local_type == type;
+}
+
 static int unset_local(Tunnel *t) {
         assert(t);
 
@@ -1119,6 +1127,7 @@ const NetDevVTable ipip_vtable = {
         .create_type = NETDEV_CREATE_STACKED,
         .is_ready_to_create = netdev_tunnel_is_ready_to_create,
         .config_verify = netdev_tunnel_verify,
+        .needs_reconfigure = tunnel_needs_reconfigure,
         .iftype = ARPHRD_TUNNEL,
 };
 
@@ -1130,6 +1139,7 @@ const NetDevVTable sit_vtable = {
         .create_type = NETDEV_CREATE_STACKED,
         .is_ready_to_create = netdev_tunnel_is_ready_to_create,
         .config_verify = netdev_tunnel_verify,
+        .needs_reconfigure = tunnel_needs_reconfigure,
         .iftype = ARPHRD_SIT,
 };
 
@@ -1141,6 +1151,7 @@ const NetDevVTable vti_vtable = {
         .create_type = NETDEV_CREATE_STACKED,
         .is_ready_to_create = netdev_tunnel_is_ready_to_create,
         .config_verify = netdev_tunnel_verify,
+        .needs_reconfigure = tunnel_needs_reconfigure,
         .iftype = ARPHRD_TUNNEL,
 };
 
@@ -1152,6 +1163,7 @@ const NetDevVTable vti6_vtable = {
         .create_type = NETDEV_CREATE_STACKED,
         .is_ready_to_create = netdev_tunnel_is_ready_to_create,
         .config_verify = netdev_tunnel_verify,
+        .needs_reconfigure = tunnel_needs_reconfigure,
         .iftype = ARPHRD_TUNNEL6,
 };
 
@@ -1163,6 +1175,7 @@ const NetDevVTable gre_vtable = {
         .create_type = NETDEV_CREATE_STACKED,
         .is_ready_to_create = netdev_tunnel_is_ready_to_create,
         .config_verify = netdev_tunnel_verify,
+        .needs_reconfigure = tunnel_needs_reconfigure,
         .iftype = ARPHRD_IPGRE,
 };
 
@@ -1174,6 +1187,7 @@ const NetDevVTable gretap_vtable = {
         .create_type = NETDEV_CREATE_STACKED,
         .is_ready_to_create = netdev_tunnel_is_ready_to_create,
         .config_verify = netdev_tunnel_verify,
+        .needs_reconfigure = tunnel_needs_reconfigure,
         .iftype = ARPHRD_ETHER,
         .generate_mac = true,
 };
@@ -1186,6 +1200,7 @@ const NetDevVTable ip6gre_vtable = {
         .create_type = NETDEV_CREATE_STACKED,
         .is_ready_to_create = netdev_tunnel_is_ready_to_create,
         .config_verify = netdev_tunnel_verify,
+        .needs_reconfigure = tunnel_needs_reconfigure,
         .iftype = ARPHRD_IP6GRE,
 };
 
@@ -1197,6 +1212,7 @@ const NetDevVTable ip6gretap_vtable = {
         .create_type = NETDEV_CREATE_STACKED,
         .is_ready_to_create = netdev_tunnel_is_ready_to_create,
         .config_verify = netdev_tunnel_verify,
+        .needs_reconfigure = tunnel_needs_reconfigure,
         .iftype = ARPHRD_ETHER,
         .generate_mac = true,
 };
@@ -1209,6 +1225,7 @@ const NetDevVTable ip6tnl_vtable = {
         .create_type = NETDEV_CREATE_STACKED,
         .is_ready_to_create = netdev_tunnel_is_ready_to_create,
         .config_verify = netdev_tunnel_verify,
+        .needs_reconfigure = tunnel_needs_reconfigure,
         .iftype = ARPHRD_TUNNEL6,
 };
 
@@ -1220,6 +1237,7 @@ const NetDevVTable erspan_vtable = {
         .create_type = NETDEV_CREATE_STACKED,
         .is_ready_to_create = netdev_tunnel_is_ready_to_create,
         .config_verify = netdev_tunnel_verify,
+        .needs_reconfigure = tunnel_needs_reconfigure,
         .iftype = ARPHRD_ETHER,
         .generate_mac = true,
 };

src/network/netdev/vxlan.c

@@ -415,6 +415,14 @@ static int netdev_vxlan_verify(NetDev *netdev, const char *filename) {
         return 0;
 }
 
+static bool vxlan_needs_reconfigure(NetDev *netdev, NetDevLocalAddressType type) {
+        assert(type >= 0 && type < _NETDEV_LOCAL_ADDRESS_TYPE_MAX);
+
+        VxLan *v = VXLAN(netdev);
+
+        return v->local_type == type;
+}
+
 static int netdev_vxlan_is_ready_to_create(NetDev *netdev, Link *link) {
         VxLan *v = VXLAN(netdev);
 
@@ -445,6 +453,7 @@ const NetDevVTable vxlan_vtable = {
         .is_ready_to_create = netdev_vxlan_is_ready_to_create,
         .config_verify = netdev_vxlan_verify,
         .can_set_mtu = vxlan_can_set_mtu,
+        .needs_reconfigure = vxlan_needs_reconfigure,
         .iftype = ARPHRD_ETHER,
         .generate_mac = true,
 };

src/network/networkd-dhcp4.c

@@ -326,6 +326,10 @@ int dhcp4_check_ready(Link *link) {
         if (r < 0)
                 return r;
 
+        r = link_request_stacked_netdevs(link, NETDEV_LOCAL_ADDRESS_DHCP4);
+        if (r < 0)
+                return r;
+
         r = sd_ipv4ll_stop(link->ipv4ll);
         if (r < 0)
                 return log_link_warning_errno(link, r, "Failed to drop IPv4 link-local address: %m");

src/network/networkd-dhcp6.c

@@ -122,6 +122,10 @@ int dhcp6_check_ready(Link *link) {
         if (r < 0)
                 return r;
 
+        r = link_request_stacked_netdevs(link, NETDEV_LOCAL_ADDRESS_DHCP6);
+        if (r < 0)
+                return r;
+
         link_check_ready(link);
         return 0;
 }

src/network/networkd-ipv4ll.c

@@ -109,6 +109,10 @@ static int ipv4ll_address_claimed(sd_ipv4ll *ll, Link *link) {
         log_link_debug(link, "IPv4 link-local claim "IPV4_ADDRESS_FMT_STR,
                        IPV4_ADDRESS_FMT_VAL(address->in_addr.in));
 
+        r = link_request_stacked_netdevs(link, NETDEV_LOCAL_ADDRESS_IPV4LL);
+        if (r < 0)
+                return r;
+
         return link_request_address(link, address, NULL, ipv4ll_address_handler, NULL);
 }
 

src/network/networkd-link.c

@@ -640,15 +640,23 @@ static int link_request_static_configs(Link *link) {
         return 0;
 }
 
-static int link_request_stacked_netdevs(Link *link) {
+int link_request_stacked_netdevs(Link *link, NetDevLocalAddressType type) {
         NetDev *netdev;
         int r;
 
         assert(link);
 
+        if (!IN_SET(link->state, LINK_STATE_CONFIGURING, LINK_STATE_CONFIGURED))
+                return 0;
+
+        assert(link->network);
+
         link->stacked_netdevs_created = false;
 
         HASHMAP_FOREACH(netdev, link->network->stacked_netdevs) {
+                if (!netdev_needs_reconfigure(netdev, type))
+                        continue;
+
                 r = link_request_stacked_netdev(link, netdev);
                 if (r < 0)
                         return r;
@@ -776,6 +784,10 @@ int link_ipv6ll_gained(Link *link) {
         if (r < 0)
                 return r;
 
+        r = link_request_stacked_netdevs(link, NETDEV_LOCAL_ADDRESS_IPV6LL);
+        if (r < 0)
+                return r;
+
         link_check_ready(link);
         return 0;
 }
@@ -1188,7 +1200,7 @@ static int link_configure(Link *link) {
         if (r < 0)
                 return r;
 
-        r = link_request_stacked_netdevs(link);
+        r = link_request_stacked_netdevs(link, _NETDEV_LOCAL_ADDRESS_TYPE_INVALID);
         if (r < 0)
                 return r;
 

src/network/networkd-link.h

@@ -19,6 +19,7 @@
 
 #include "ether-addr-util.h"
 #include "log-link.h"
+#include "netdev.h"
 #include "netif-util.h"
 #include "network-util.h"
 #include "networkd-bridge-vlan.h"
@@ -257,6 +258,8 @@ void link_free_engines(Link *link);
 const char* link_state_to_string(LinkState s) _const_;
 LinkState link_state_from_string(const char *s) _pure_;
 
+int link_request_stacked_netdevs(Link *link, NetDevLocalAddressType type);
+
 int link_reconfigure_impl(Link *link, bool force);
 int link_reconfigure(Link *link, bool force);
 int link_reconfigure_on_bus_method_reload(Link *link, sd_bus_message *message);

src/network/networkd-ndisc.c

@@ -2141,6 +2141,8 @@ static int ndisc_drop_outdated(Link *link, const struct in6_addr *router, usec_t
                 updated = true;
         }
 
+        RET_GATHER(ret, link_request_stacked_netdevs(link, NETDEV_LOCAL_ADDRESS_SLAAC));
+
         if (updated)
                 link_dirty(link);
 

test/test-network/conf/25-dhcp-client-ipv4-only.network

@@ -6,6 +6,7 @@ Name=veth99
 DHCP=ipv4
 IPv6AcceptRA=no
 Address=192.168.5.250/24
+Tunnel=sit-dhcp4
 
 [DHCPv4]
 RequestAddress=192.168.5.110

test/test-network/conf/25-sit-dhcp4.netdev

@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+[NetDev]
+Name=sit-dhcp4
+Kind=sit
+
+[Tunnel]
+Local=dhcp4
+Remote=any

test/test-network/conf/25-sit-dhcp4.network

@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+[Match]
+Name=sit-dhcp4
+Type=sit

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

@@ -6829,7 +6829,8 @@ class NetworkdDHCPClientTests(unittest.TestCase, Utilities):
 
     @expectedFailureIfKernelReturnsInvalidFlags()
     def test_dhcp_client_ipv4_only(self):
-        copy_network_unit('25-veth.netdev', '25-dhcp-server-veth-peer.network', '25-dhcp-client-ipv4-only.network')
+        copy_network_unit('25-veth.netdev', '25-dhcp-server-veth-peer.network', '25-dhcp-client-ipv4-only.network',
+                          '25-sit-dhcp4.netdev', '25-sit-dhcp4.network')
 
         self.setup_nftset('addr4', 'ipv4_addr')
         self.setup_nftset('network4', 'ipv4_addr', 'flags interval;')
@@ -6842,7 +6843,7 @@ class NetworkdDHCPClientTests(unittest.TestCase, Utilities):
                       '--dhcp-option=option:domain-search,example.com',
                       '--dhcp-alternate-port=67,5555',
                       ipv4_range='192.168.5.110,192.168.5.119')
-        self.wait_online('veth99:routable', 'veth-peer:routable')
+        self.wait_online('veth99:routable', 'veth-peer:routable', 'sit-dhcp4:carrier')
         self.wait_address('veth99', r'inet 192.168.5.11[0-9]*/24', ipv='-4')
 
         print('## ip address show dev veth99 scope global')
@@ -6915,6 +6916,11 @@ class NetworkdDHCPClientTests(unittest.TestCase, Utilities):
             a = socket.inet_ntop(socket.AF_INET, bytearray(i['ConfigProvider']))
             self.assertEqual('192.168.5.1', a)
 
+        print('## tunnel')
+        output = check_output('ip -d link show sit-dhcp4')
+        print(output)
+        self.assertRegex(output, fr'sit (ip6ip )?remote any local {address1} dev veth99')
+
         print('## dnsmasq log')
         output = read_dnsmasq_log_file()
         print(output)
@@ -7010,6 +7016,11 @@ class NetworkdDHCPClientTests(unittest.TestCase, Utilities):
             a = socket.inet_ntop(socket.AF_INET, bytearray(i['ConfigProvider']))
             self.assertEqual('192.168.5.1', a)
 
+        print('## tunnel')
+        output = check_output('ip -d link show sit-dhcp4')
+        print(output)
+        self.assertRegex(output, fr'sit (ip6ip )?remote any local {address2} dev veth99')
+
         print('## dnsmasq log')
         output = read_dnsmasq_log_file()
         print(output)