From 5e3ebdedd46817464682fad129802cb6a396e76f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=8D=C3=B1igo=20Huguet?= <ihuguet@redhat.com>
Date: Tue, 31 Oct 2023 13:23:22 +0100
Subject: [PATCH] auto-default: check NM_AUTO_DEFAULT_LINK_LOCAL_ONLY from
 nm-device

When creating default connections automatically, we check if udev has
set the NM_AUTO_DEFAULT_LINK_LOCAL_ONLY variable, and if so, we create
the connection with method=link-local. It was checked only for ethernet
connection type, which works fine because it's the only device type that
we create connections automatically for.

However, link-local connections are not specific to Ethernet, and if we
add auto-default connections for more devices in the future we should
honor this configuration too. Do it from nm-device, but only if the
device class has defined a "new_default_connection" method so the
behaviour is identical as the current one, but will be used by future
implementors of this method too.
---
 src/core/devices/nm-device-ethernet.c | 26 -------------------
 src/core/devices/nm-device.c          | 36 +++++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 26 deletions(-)

diff --git a/src/core/devices/nm-device-ethernet.c b/src/core/devices/nm-device-ethernet.c
index aedacc248b..5d58b69d67 100644
--- a/src/core/devices/nm-device-ethernet.c
+++ b/src/core/devices/nm-device-ethernet.c
@@ -1711,10 +1711,8 @@ new_default_connection(NMDevice *self)
     NMSettingsConnection *const   *connections;
     NMSetting                     *setting;
     gs_unref_hashtable GHashTable *existing_ids = NULL;
-    struct udev_device            *dev;
     const char                    *perm_hw_addr;
     const char                    *iface;
-    const char                    *uprop   = "0";
     gs_free char                  *defname = NULL;
     gs_free char                  *uuid    = NULL;
     guint                          i, n_connections;
@@ -1760,30 +1758,6 @@ new_default_connection(NMDevice *self)
                  iface,
                  NULL);
 
-    /* Check if we should create a Link-Local only connection */
-    dev = nm_platform_link_get_udev_device(nm_device_get_platform(NM_DEVICE(self)),
-                                           nm_device_get_ip_ifindex(self));
-    if (dev)
-        uprop = udev_device_get_property_value(dev, "NM_AUTO_DEFAULT_LINK_LOCAL_ONLY");
-
-    if (_nm_utils_ascii_str_to_bool(uprop, FALSE)) {
-        setting = nm_setting_ip4_config_new();
-        g_object_set(setting,
-                     NM_SETTING_IP_CONFIG_METHOD,
-                     NM_SETTING_IP4_CONFIG_METHOD_LINK_LOCAL,
-                     NULL);
-        nm_connection_add_setting(connection, setting);
-
-        setting = nm_setting_ip6_config_new();
-        g_object_set(setting,
-                     NM_SETTING_IP_CONFIG_METHOD,
-                     NM_SETTING_IP6_CONFIG_METHOD_LINK_LOCAL,
-                     NM_SETTING_IP_CONFIG_MAY_FAIL,
-                     TRUE,
-                     NULL);
-        nm_connection_add_setting(connection, setting);
-    }
-
     return connection;
 }
 
diff --git a/src/core/devices/nm-device.c b/src/core/devices/nm-device.c
index 71b597fb34..c3886b7db0 100644
--- a/src/core/devices/nm-device.c
+++ b/src/core/devices/nm-device.c
@@ -22,6 +22,7 @@
 #include <linux/rtnetlink.h>
 #include <linux/if_ether.h>
 #include <linux/if_infiniband.h>
+#include <libudev.h>
 
 #include "libnm-std-aux/unaligned.h"
 #include "libnm-glib-aux/nm-uuid.h"
@@ -8098,6 +8099,39 @@ nm_device_owns_iface(NMDevice *self, const char *iface)
     return FALSE;
 }
 
+static void
+apply_udev_auto_default_configs(NMDevice *self, NMConnection *connection)
+{
+    struct udev_device *dev;
+    const char         *uprop;
+    NMSetting          *setting;
+
+    dev = nm_platform_link_get_udev_device(nm_device_get_platform(NM_DEVICE(self)),
+                                           nm_device_get_ip_ifindex(self));
+    if (!dev)
+        return;
+
+    uprop = udev_device_get_property_value(dev, "NM_AUTO_DEFAULT_LINK_LOCAL_ONLY");
+
+    if (_nm_utils_ascii_str_to_bool(uprop, FALSE)) {
+        setting = nm_setting_ip4_config_new();
+        g_object_set(setting,
+                     NM_SETTING_IP_CONFIG_METHOD,
+                     NM_SETTING_IP4_CONFIG_METHOD_LINK_LOCAL,
+                     NULL);
+        nm_connection_add_setting(connection, setting);
+
+        setting = nm_setting_ip6_config_new();
+        g_object_set(setting,
+                     NM_SETTING_IP_CONFIG_METHOD,
+                     NM_SETTING_IP6_CONFIG_METHOD_LINK_LOCAL,
+                     NM_SETTING_IP_CONFIG_MAY_FAIL,
+                     TRUE,
+                     NULL);
+        nm_connection_add_setting(connection, setting);
+    }
+}
+
 NMConnection *
 nm_device_new_default_connection(NMDevice *self)
 {
@@ -8111,6 +8145,8 @@ nm_device_new_default_connection(NMDevice *self)
     if (!connection)
         return NULL;
 
+    apply_udev_auto_default_configs(self, connection);
+
     if (!nm_connection_normalize(connection, NULL, NULL, &error)) {
         _LOGD(LOGD_DEVICE, "device generated an invalid default connection: %s", error->message);
         g_error_free(error);