device: add nm_match_spec_device_data_init_from_device() helper

Will be used later.

src/core/NetworkManagerUtils.c

@@ -30,6 +30,7 @@
 #include "libnm-platform/nm-linux-platform.h"
 #include "libnm-platform/nm-platform-utils.h"
 #include "nm-auth-utils.h"
+#include "devices/nm-device.h"
 
 /*****************************************************************************/
 
@@ -900,6 +901,47 @@ nm_utils_match_connection(NMConnection *const   *connections,
 
 /*****************************************************************************/
 
+const struct _NMMatchSpecDeviceData *
+nm_match_spec_device_data_init_from_device(struct _NMMatchSpecDeviceData *out_data,
+                                           NMDevice                      *device)
+{
+    const char *hw_address;
+    gboolean    is_fake;
+
+    nm_assert(out_data);
+
+    if (!device) {
+        *out_data = (NMMatchSpecDeviceData){};
+        return out_data;
+    }
+
+    nm_assert(NM_IS_DEVICE(device));
+
+    hw_address = nm_device_get_permanent_hw_address_full(
+        device,
+        !nm_device_get_unmanaged_flags(device, NM_UNMANAGED_PLATFORM_INIT),
+        &is_fake);
+
+    /* Note that here we access various getters on @device, without cloning
+     * or taking ownership and return it to the caller.
+     *
+     * The returned data is only valid, until NMDevice gets modified again. */
+
+    *out_data = (NMMatchSpecDeviceData){
+        .interface_name   = nm_device_get_iface(device),
+        .device_type      = nm_device_get_type_description(device),
+        .driver           = nm_device_get_driver(device),
+        .driver_version   = nm_device_get_driver_version(device),
+        .hwaddr           = is_fake ? NULL : hw_address,
+        .s390_subchannels = nm_device_get_s390_subchannels(device),
+        .dhcp_plugin      = nm_dhcp_manager_get_config(nm_dhcp_manager_get()),
+    };
+
+    return out_data;
+}
+
+/*****************************************************************************/
+
 int
 nm_match_spec_device_by_pllink(const NMPlatformLink *pllink,
                                const char           *match_device_type,

src/core/NetworkManagerUtils.h

@@ -91,6 +91,12 @@ NMConnection *nm_utils_match_connection(NMConnection *const   *connections,
 
 /*****************************************************************************/
 
+struct _NMMatchSpecDeviceData;
+
+const struct _NMMatchSpecDeviceData *
+nm_match_spec_device_data_init_from_device(struct _NMMatchSpecDeviceData *out_data,
+                                           NMDevice                      *device);
+
 int nm_match_spec_device_by_pllink(const NMPlatformLink *pllink,
                                    const char           *match_device_type,
                                    const char           *match_dhcp_plugin,

src/core/devices/nm-device.c

@@ -17293,32 +17293,10 @@ nm_device_spec_match_list(NMDevice *self, const GSList *specs)
 int
 nm_device_spec_match_list_full(NMDevice *self, const GSList *specs, int no_match_value)
 {
-    NMDeviceClass       *klass;
+    NMMatchSpecDeviceData data;
-    NMMatchSpecMatchType m;
+    NMMatchSpecMatchType  m;
-    const char          *hw_address = NULL;
-    gboolean             is_fake;
-
-    g_return_val_if_fail(NM_IS_DEVICE(self), FALSE);
-
-    klass      = NM_DEVICE_GET_CLASS(self);
-    hw_address = nm_device_get_permanent_hw_address_full(
-        self,
-        !nm_device_get_unmanaged_flags(self, NM_UNMANAGED_PLATFORM_INIT),
-        &is_fake);
-
-    m = nm_match_spec_device(
-        specs,
-        &((const NMMatchSpecDeviceData){
-            .interface_name = nm_device_get_iface(self),
-            .device_type    = nm_device_get_type_description(self),
-            .driver         = nm_device_get_driver(self),
-            .driver_version = nm_device_get_driver_version(self),
-            .hwaddr         = is_fake ? NULL : hw_address,
-            .s390_subchannels =
-                klass->get_s390_subchannels ? klass->get_s390_subchannels(self) : NULL,
-            .dhcp_plugin = nm_dhcp_manager_get_config(nm_dhcp_manager_get()),
-        }));
 
+    m = nm_match_spec_device(specs, nm_match_spec_device_data_init_from_device(&data, self));
     return nm_match_spec_match_type_to_bool(m, no_match_value);
 }