platform: add nm_platform_link_can_assume()

src/platform/nm-linux-platform.c

@@ -5128,6 +5128,49 @@ wifi_indicate_addressing_running (NMPlatform *platform, int ifindex, gboolean ru
 
 /******************************************************************/
 
+static gboolean
+link_can_assume (NMPlatform *platform, int ifindex)
+{
+	NMLinuxPlatformPrivate *priv = NM_LINUX_PLATFORM_GET_PRIVATE (platform);
+	NMPCacheId cache_id;
+	const NMPlatformObject *const *objs;
+	guint i, len;
+	const NMPObject *link;
+
+	if (ifindex <= 0)
+		return FALSE;
+
+	link = cache_lookup_link (platform, ifindex);
+	if (!link)
+		return FALSE;
+
+	if (!NM_FLAGS_HAS (link->link.n_ifi_flags, IFF_UP))
+		return FALSE;
+
+	if (link->link.master > 0)
+		return TRUE;
+
+	if (nmp_cache_lookup_multi (priv->cache,
+	                            nmp_cache_id_init_addrroute_visible_by_ifindex (&cache_id, NMP_OBJECT_TYPE_IP4_ADDRESS, ifindex),
+	                            NULL))
+		return TRUE;
+
+	objs = nmp_cache_lookup_multi (priv->cache,
+	                               nmp_cache_id_init_addrroute_visible_by_ifindex (&cache_id, NMP_OBJECT_TYPE_IP6_ADDRESS, ifindex),
+	                               &len);
+	if (objs) {
+		for (i = 0; i < len; i++) {
+			const NMPlatformIP6Address *a = (NMPlatformIP6Address *) objs[i];
+
+			if (!IN6_IS_ADDR_LINKLOCAL (&a->address))
+				return TRUE;
+		}
+	}
+	return FALSE;
+}
+
+/******************************************************************/
+
 static guint32
 mesh_get_channel (NMPlatform *platform, int ifindex)
 {
@@ -6218,6 +6261,8 @@ nm_linux_platform_class_init (NMLinuxPlatformClass *klass)
 	platform_class->link_enslave = link_enslave;
 	platform_class->link_release = link_release;
 
+	platform_class->link_can_assume = link_can_assume;
+
 	platform_class->vlan_add = vlan_add;
 	platform_class->link_vlan_change = link_vlan_change;
 	platform_class->link_vxlan_add = link_vxlan_add;

src/platform/nm-platform.c

@@ -1378,6 +1378,18 @@ nm_platform_link_get_master (NMPlatform *self, int slave)
 
 /*****************************************************************************/
 
+gboolean
+nm_platform_link_can_assume (NMPlatform *self, int ifindex)
+{
+	_CHECK_SELF (self, klass, FALSE);
+
+	if (klass->link_can_assume)
+		return klass->link_can_assume (self, ifindex);
+	g_return_val_if_reached (FALSE);
+}
+
+/*****************************************************************************/
+
 /**
  * nm_platform_link_get_lnk:
  * @self: the platform instance

src/platform/nm-platform.h

@@ -528,6 +528,8 @@ typedef struct {
 	gboolean (*link_enslave) (NMPlatform *, int master, int slave);
 	gboolean (*link_release) (NMPlatform *, int master, int slave);
 
+	gboolean (*link_can_assume) (NMPlatform *, int ifindex);
+
 	gboolean (*vlan_add) (NMPlatform *, const char *name, int parent, int vlanid, guint32 vlanflags, const NMPlatformLink **out_link);
 	gboolean (*link_vlan_change) (NMPlatform *self,
 	                              int ifindex,
@@ -717,6 +719,8 @@ gboolean nm_platform_link_get_user_ipv6ll_enabled (NMPlatform *self, int ifindex
 gconstpointer nm_platform_link_get_address (NMPlatform *self, int ifindex, size_t *length);
 int nm_platform_link_get_master (NMPlatform *self, int slave);
 
+gboolean nm_platform_link_can_assume (NMPlatform *self, int ifindex);
+
 gboolean nm_platform_link_get_unmanaged (NMPlatform *self, int ifindex, gboolean *unmanaged);
 gboolean nm_platform_link_supports_slaves (NMPlatform *self, int ifindex);
 const char *nm_platform_link_get_type_name (NMPlatform *self, int ifindex);