device: wait DAD before starting dnsmasq in IPv4 shared mode

Currently, IPv4 shared mode fails to start when DAD is enabled because
dnsmasq tries to bind to an address that is not yet configured on the
interface. Delay the start of dnsmasq until the shared4 l3cd is ready.

Fixes: 58287cbcc0c8 ('core: rework IP configuration in NetworkManager using layer 3 configuration')

1 files changed, 22 insertions, 7 deletions

diff --git a/src/core/devices/nm-device.c b/src/core/devices/nm-device.c
index 6de0375324..53dbc9ac42 100644
--- a/src/core/devices/nm-device.c
+++ b/src/core/devices/nm-device.c
@@ -4284,7 +4284,6 @@ _dev_l3_cfg_notify_cb(NML3Cfg *l3cfg, const NML3ConfigNotifyData *notify_data, N
         if (priv->ipshared_data_4.state == NM_DEVICE_IP_STATE_PENDING
             && !priv->ipshared_data_4.v4.dnsmasq_manager && priv->ipshared_data_4.v4.l3cd) {
             _dev_ipshared4_spawn_dnsmasq(self);
-            nm_clear_l3cd(&priv->ipshared_data_4.v4.l3cd);
         }
         _dev_ip_state_check_async(self, AF_UNSPEC);
         _dev_ipmanual_check_ready(self);
@@ -12732,18 +12731,32 @@ out_fail:
 static void
 _dev_ipshared4_spawn_dnsmasq(NMDevice *self)
 {
-    NMDevicePrivate      *priv = NM_DEVICE_GET_PRIVATE(self);
-    const char           *ip_iface;
-    gs_free_error GError *error = NULL;
-    NMSettingConnection  *s_con;
-    gboolean              announce_android_metered;
-    NMConnection         *applied;
+    NMDevicePrivate       *priv = NM_DEVICE_GET_PRIVATE(self);
+    const char            *ip_iface;
+    gs_free_error GError  *error = NULL;
+    NMSettingConnection   *s_con;
+    gboolean               announce_android_metered;
+    NMConnection          *applied;
+    gs_unref_array GArray *conflicts = NULL;
+    gboolean               ready;
 
     nm_assert(priv->ipshared_data_4.v4.firewall_config);
     nm_assert(priv->ipshared_data_4.v4.dnsmasq_state_id == 0);
     nm_assert(!priv->ipshared_data_4.v4.dnsmasq_manager);
     nm_assert(priv->ipshared_data_4.v4.l3cd);
 
+    ready = nm_l3cfg_check_ready(priv->l3cfg,
+                                 priv->l3cds[L3_CONFIG_DATA_TYPE_SHARED_4].d,
+                                 AF_INET,
+                                 NM_L3CFG_CHECK_READY_FLAGS_IP4_ACD_READY,
+                                 &conflicts);
+    if (!ready) {
+        _LOGT_ipshared(AF_INET, "address not ready, wait");
+        return;
+    }
+    if (conflicts)
+        goto out_fail;
+
     ip_iface = nm_device_get_ip_iface(self);
     g_return_if_fail(ip_iface);
 
@@ -12788,9 +12801,11 @@ _dev_ipshared4_spawn_dnsmasq(NMDevice *self)
 
     _dev_ipsharedx_set_state(self, AF_INET, NM_DEVICE_IP_STATE_READY);
     _dev_ip_state_check_async(self, AF_INET);
+    nm_clear_l3cd(&priv->ipshared_data_4.v4.l3cd);
     return;
 
 out_fail:
+    nm_clear_l3cd(&priv->ipshared_data_4.v4.l3cd);
     _dev_ipsharedx_set_state(self, AF_INET, NM_DEVICE_IP_STATE_FAILED);
     _dev_ip_state_check_async(self, AF_INET);
 }