connectivity: add per-device check-connectivity setting

Adds a new `check-connectivity` setting to the `device` section which can be
used to disable the connectivity check for a particular device.

NEWS

@@ -12,6 +12,8 @@ USE AT YOUR OWN RISK.  NOT RECOMMENDED FOR PRODUCTION USE!
   same link. If the link has no DNS servers, the connectivity check will
   use any servers available in the system.
 * Install the systemd units in the initramfs using a systemd generator.
+* A new "check-connectivity" configuration option is available to disable the
+  connectivity check for selected interfaces.
 
 =============================================
 NetworkManager-1.56

man/NetworkManager.conf.xml

@@ -1329,6 +1329,20 @@ managed=1
             </para>
           </listitem>
         </varlistentry>
+        <varlistentry id="check-connectivity">
+          <term><varname>check-connectivity</varname></term>
+          <listitem>
+            <para>
+              A boolean value specifying whether NetworkManager will perform a connectivity check
+              for this device. Defaults to <literal>yes</literal>.
+            </para>
+            <para>
+              This setting does nothing if the connectivity check has been
+              disabled globally using the
+              <literal>connectivity.enabled</literal> setting.
+            </para>
+          </listitem>
+        </varlistentry>
         <varlistentry id="keep-configuration">
           <term><varname>keep-configuration</varname></term>
           <listitem>

src/core/devices/nm-device.c

@@ -6331,6 +6331,14 @@ concheck_is_possible(NMDevice *self)
     if (priv->state == NM_DEVICE_STATE_UNKNOWN)
         return FALSE;
 
+    if (!nm_config_data_get_device_config_boolean_by_device(
+            NM_CONFIG_GET_DATA,
+            NM_CONFIG_KEYFILE_KEY_DEVICE_CHECK_CONNECTIVITY,
+            self,
+            TRUE,
+            TRUE))
+        return FALSE;
+
     return TRUE;
 }
 
@@ -6351,8 +6359,10 @@ concheck_periodic_schedule_do(NMDevice *self, int addr_family, gint64 now_ns)
         goto out;
     }
 
-    if (!concheck_is_possible(self))
+    if (!concheck_is_possible(self)) {
+        concheck_update_state(self, addr_family, NM_CONNECTIVITY_UNKNOWN, FALSE);
         goto out;
+    }
 
     nm_assert(now_ns > 0);
     nm_assert(priv->concheck_x[IS_IPv4].p_cur_interval > 0);
@@ -6575,7 +6585,11 @@ concheck_update_interval(NMDevice *self, int addr_family, gboolean check_now)
         concheck_periodic_schedule_do(self, addr_family, 0);
 
         /* also update the fake connectivity state. */
+        if (concheck_is_possible(self))
             concheck_update_state(self, addr_family, NM_CONNECTIVITY_FAKE, TRUE);
+        else
+            concheck_update_state(self, addr_family, NM_CONNECTIVITY_UNKNOWN, FALSE);
+
         return;
     }
 
@@ -6604,6 +6618,7 @@ concheck_update_state(NMDevice           *self,
     /* @state is a result of the connectivity check. We only expect a precise
      * number of possible values. */
     nm_assert(NM_IN_SET(state,
+                        NM_CONNECTIVITY_UNKNOWN,
                         NM_CONNECTIVITY_LIMITED,
                         NM_CONNECTIVITY_PORTAL,
                         NM_CONNECTIVITY_FULL,
@@ -6927,8 +6942,11 @@ nm_device_check_connectivity(NMDevice                    *self,
                              NMDeviceConnectivityCallback callback,
                              gpointer                     user_data)
 {
-    if (!concheck_is_possible(self))
+    if (!concheck_is_possible(self)) {
+        concheck_update_state(self, AF_INET, NM_CONNECTIVITY_UNKNOWN, FALSE);
+        concheck_update_state(self, AF_INET6, NM_CONNECTIVITY_UNKNOWN, FALSE);
         return NULL;
+    }
 
     concheck_periodic_schedule_set(self, addr_family, CONCHECK_SCHEDULE_CHECK_EXTERNAL);
     return concheck_start(self, addr_family, callback, user_data, FALSE);
@@ -8316,6 +8334,17 @@ config_changed(NMConfig           *config,
             && !nm_device_get_applied_setting(self, NM_TYPE_SETTING_SRIOV))
             device_init_static_sriov_num_vfs(self);
     }
+
+    if (NM_FLAGS_HAS(changes, NM_CONFIG_CHANGE_VALUES) && concheck_is_possible(self)) {
+        /* restart (periodic) connectivity checks if they were previously disabled */
+        if (!nm_config_data_get_device_config_boolean_by_device(
+                old_data,
+                NM_CONFIG_KEYFILE_KEY_DEVICE_CHECK_CONNECTIVITY,
+                self,
+                TRUE,
+                TRUE))
+            nm_device_check_connectivity_update_interval(self);
+    }
 }
 
 static void

src/core/nm-config.c

@@ -892,6 +892,7 @@ static const ConfigGroup config_groups[] = {
         .is_prefix = TRUE,
         .keys      = NM_MAKE_STRV(NM_CONFIG_KEYFILE_KEY_DEVICE_CARRIER_WAIT_TIMEOUT,
                              NM_CONFIG_KEYFILE_KEY_DEVICE_IGNORE_CARRIER,
+                             NM_CONFIG_KEYFILE_KEY_DEVICE_CHECK_CONNECTIVITY,
                              NM_CONFIG_KEYFILE_KEY_DEVICE_MANAGED,
                              NM_CONFIG_KEYFILE_KEY_DEVICE_SRIOV_NUM_VFS,
                              NM_CONFIG_KEYFILE_KEY_DEVICE_KEEP_CONFIGURATION,

src/libnm-base/nm-config-base.h

@@ -65,6 +65,7 @@
 
 #define NM_CONFIG_KEYFILE_KEY_DEVICE_MANAGED                    "managed"
 #define NM_CONFIG_KEYFILE_KEY_DEVICE_IGNORE_CARRIER             "ignore-carrier"
+#define NM_CONFIG_KEYFILE_KEY_DEVICE_CHECK_CONNECTIVITY         "check-connectivity"
 #define NM_CONFIG_KEYFILE_KEY_DEVICE_SRIOV_NUM_VFS              "sriov-num-vfs"
 #define NM_CONFIG_KEYFILE_KEY_DEVICE_KEEP_CONFIGURATION         "keep-configuration"
 #define NM_CONFIG_KEYFILE_KEY_DEVICE_ALLOWED_CONNECTIONS        "allowed-connections"