platform: don't create udev client if udev isn't used

Inside container, where we don't use udev we don't receive
any events from udev client. Thus the client only returns
devices when iterating it initially, but no events for newly
added devices that appear later.

Thus, inside containers we don't want to create a udev client
at all.

5 files changed, 38 insertions, 52 deletions

diff --git a/src/platform/nm-linux-platform.c b/src/platform/nm-linux-platform.c
index 33e3ddf8e2..72ca62a71b 100644
--- a/src/platform/nm-linux-platform.c
+++ b/src/platform/nm-linux-platform.c
@@ -5937,15 +5937,21 @@ static void
 nm_linux_platform_init (NMLinuxPlatform *self)
 {
 	NMLinuxPlatformPrivate *priv = G_TYPE_INSTANCE_GET_PRIVATE (self, NM_TYPE_LINUX_PLATFORM, NMLinuxPlatformPrivate);
+	gboolean use_udev;
+
+	use_udev = access ("/sys", W_OK) == 0;
 
 	self->priv = priv;
 
 	priv->nlh_seq_next = 1;
-	priv->cache = nmp_cache_new ();
+	priv->cache = nmp_cache_new (use_udev);
 	priv->delayed_action.list_master_connected = g_ptr_array_new ();
 	priv->delayed_action.list_refresh_link = g_ptr_array_new ();
 	priv->delayed_action.list_wait_for_nl_response = g_array_new (FALSE, TRUE, sizeof (DelayedActionWaitForNlResponseData));
 	priv->wifi_data = g_hash_table_new_full (NULL, NULL, NULL, (GDestroyNotify) wifi_utils_deinit);
+
+	if (use_udev)
+		priv->udev_client = g_udev_client_new ((const char *[]) { "net", NULL });
 }
 
 static void
@@ -5953,14 +5959,12 @@ constructed (GObject *_object)
 {
 	NMPlatform *platform = NM_PLATFORM (_object);
 	NMLinuxPlatformPrivate *priv = NM_LINUX_PLATFORM_GET_PRIVATE (platform);
-	const char *udev_subsys[] = { "net", NULL };
 	int channel_flags;
 	gboolean status;
 	int nle;
-	GUdevEnumerator *enumerator;
-	GList *devices, *iter;
 
-	_LOGD ("create");
+	_LOGD ("create (%s udev)",
+	       nmp_cache_use_udev_get (priv->cache) ? "use" : "no");
 
 	priv->nlh = nl_socket_alloc ();
 	g_assert (priv->nlh);
@@ -5992,16 +5996,12 @@ constructed (GObject *_object)
 
 	channel_flags = g_io_channel_get_flags (priv->event_channel);
 	status = g_io_channel_set_flags (priv->event_channel,
-		channel_flags | G_IO_FLAG_NONBLOCK, NULL);
+	                                 channel_flags | G_IO_FLAG_NONBLOCK, NULL);
 	g_assert (status);
 	priv->event_id = g_io_add_watch (priv->event_channel,
 	                                (EVENT_CONDITIONS | ERROR_CONDITIONS | DISCONNECT_CONDITIONS),
 	                                 event_handler, platform);
 
-	/* Set up udev monitoring */
-	priv->udev_client = g_udev_client_new (udev_subsys);
-	g_signal_connect (priv->udev_client, "uevent", G_CALLBACK (handle_udev_event), platform);
-
 	/* complete construction of the GObject instance before populating the cache. */
 	G_OBJECT_CLASS (nm_linux_platform_parent_class)->constructed (_object);
 
@@ -6016,19 +6016,27 @@ constructed (GObject *_object)
 
 	delayed_action_handle_all (platform, FALSE);
 
-	/* And read initial device list */
-	enumerator = g_udev_enumerator_new (priv->udev_client);
-	g_udev_enumerator_add_match_subsystem (enumerator, "net");
+	/* Set up udev monitoring */
+	if (priv->udev_client) {
+		GUdevEnumerator *enumerator;
+		GList *devices, *iter;
+
+		g_signal_connect (priv->udev_client, "uevent", G_CALLBACK (handle_udev_event), platform);
+
+		/* And read initial device list */
+		enumerator = g_udev_enumerator_new (priv->udev_client);
+		g_udev_enumerator_add_match_subsystem (enumerator, "net");
 
-	g_udev_enumerator_add_match_is_initialized (enumerator);
+		g_udev_enumerator_add_match_is_initialized (enumerator);
 
-	devices = g_udev_enumerator_execute (enumerator);
-	for (iter = devices; iter; iter = g_list_next (iter)) {
-		udev_device_added (platform, G_UDEV_DEVICE (iter->data));
-		g_object_unref (G_UDEV_DEVICE (iter->data));
+		devices = g_udev_enumerator_execute (enumerator);
+		for (iter = devices; iter; iter = g_list_next (iter)) {
+			udev_device_added (platform, G_UDEV_DEVICE (iter->data));
+			g_object_unref (G_UDEV_DEVICE (iter->data));
+		}
+		g_list_free (devices);
+		g_object_unref (enumerator);
 	}
-	g_list_free (devices);
-	g_object_unref (enumerator);
 }
 
 static void
@@ -6047,6 +6055,11 @@ dispose (GObject *object)
 
 	g_clear_pointer (&priv->prune_candidates, g_hash_table_unref);
 
+	if (priv->udev_client) {
+		g_signal_handlers_disconnect_by_func (priv->udev_client, G_CALLBACK (handle_udev_event), platform);
+		g_clear_object (&priv->udev_client);
+	}
+
 	G_OBJECT_CLASS (nm_linux_platform_parent_class)->dispose (object);
 }
 
@@ -6066,7 +6079,6 @@ nm_linux_platform_finalize (GObject *object)
 	g_io_channel_unref (priv->event_channel);
 	nl_socket_free (priv->nlh);
 
-	g_object_unref (priv->udev_client);
 	g_hash_table_unref (priv->wifi_data);
 
 	if (priv->sysctl_get_prev_values) {
diff --git a/src/platform/nmp-object.c b/src/platform/nmp-object.c
index b7b04490c1..adeb3aabe3 100644
--- a/src/platform/nmp-object.c
+++ b/src/platform/nmp-object.c
@@ -174,10 +174,6 @@ _nmp_object_fixup_link_udev_fields (NMPObject *obj, gboolean use_udev)
 			 * nmp_cache_use_udev_get(). It is on purpose not to test
 			 * for a writable /sys on every call. A minor reason for that is
 			 * performance, but the real reason is reproducibility.
-			 *
-			 * If you want to support changing of whether udev is enabled,
-			 * reset the value via nmp_cache_use_udev_set() carefully -- and
-			 * possibly update the links in the cache accordingly.
 			 * */
 			initialized = TRUE;
 		}
@@ -1192,12 +1188,6 @@ _vt_cmd_obj_init_cache_id_ipx_route (const NMPObject *obj, NMPCacheIdType id_typ
 /******************************************************************/
 
 gboolean
-nmp_cache_use_udev_detect ()
-{
-	return access ("/sys", W_OK) == 0;
-}
-
-gboolean
 nmp_cache_use_udev_get (const NMPCache *cache)
 {
 	g_return_val_if_fail (cache, TRUE);
@@ -1205,19 +1195,6 @@ nmp_cache_use_udev_get (const NMPCache *cache)
 	return cache->use_udev;
 }
 
-gboolean
-nmp_cache_use_udev_set (NMPCache *cache, gboolean use_udev)
-{
-	g_return_val_if_fail (cache, FALSE);
-
-	use_udev = !!use_udev;
-	if (use_udev == cache->use_udev)
-		return FALSE;
-
-	cache->use_udev = use_udev;
-	return TRUE;
-}
-
 /******************************************************************/
 
 /**
@@ -1858,7 +1835,7 @@ nmp_cache_update_link_master_connected (NMPCache *cache, int ifindex, NMPObject
 /******************************************************************/
 
 NMPCache *
-nmp_cache_new ()
+nmp_cache_new (gboolean use_udev)
 {
 	NMPCache *cache = g_new (NMPCache, 1);
 
@@ -1870,7 +1847,7 @@ nmp_cache_new ()
 	                                       (NMMultiIndexFuncEqual) nmp_cache_id_equal,
 	                                       (NMMultiIndexFuncClone) nmp_cache_id_clone,
 	                                       (NMMultiIndexFuncDestroy) nmp_cache_id_destroy);
-	cache->use_udev = nmp_cache_use_udev_detect ();
+	cache->use_udev = !!use_udev;
 	return cache;
 }
 
diff --git a/src/platform/nmp-object.h b/src/platform/nmp-object.h
index 7758798f33..6d5b9627ce 100644
--- a/src/platform/nmp-object.h
+++ b/src/platform/nmp-object.h
@@ -399,9 +399,7 @@ GHashTable *nmp_cache_lookup_all_to_hash (const NMPCache *cache,
 gboolean nmp_cache_link_connected_needs_toggle (const NMPCache *cache, const NMPObject *master, const NMPObject *potential_slave, const NMPObject *ignore_slave);
 const NMPObject *nmp_cache_link_connected_needs_toggle_by_ifindex (const NMPCache *cache, int master_ifindex, const NMPObject *potential_slave, const NMPObject *ignore_slave);
 
-gboolean nmp_cache_use_udev_detect (void);
 gboolean nmp_cache_use_udev_get (const NMPCache *cache);
-gboolean nmp_cache_use_udev_set (NMPCache *cache, gboolean use_udev);
 
 void ASSERT_nmp_cache_is_consistent (const NMPCache *cache);
 
@@ -411,7 +409,7 @@ NMPCacheOpsType nmp_cache_update_netlink (NMPCache *cache, NMPObject *obj, NMPOb
 NMPCacheOpsType nmp_cache_update_link_udev (NMPCache *cache, int ifindex, GUdevDevice *udev_device, NMPObject **out_obj, gboolean *out_was_visible, NMPCachePreHook pre_hook, gpointer user_data);
 NMPCacheOpsType nmp_cache_update_link_master_connected (NMPCache *cache, int ifindex, NMPObject **out_obj, gboolean *out_was_visible, NMPCachePreHook pre_hook, gpointer user_data);
 
-NMPCache *nmp_cache_new (void);
+NMPCache *nmp_cache_new (gboolean use_udev);
 void nmp_cache_free (NMPCache *cache);
 
 #endif /* __NMP_OBJECT_H__ */
diff --git a/src/platform/tests/test-general.c b/src/platform/tests/test-general.c
index eb5adb9541..66f72fa570 100644
--- a/src/platform/tests/test-general.c
+++ b/src/platform/tests/test-general.c
@@ -22,6 +22,7 @@
 
 #include <linux/rtnetlink.h>
 
+#include "nm-platform-utils.h"
 #include "nm-linux-platform.h"
 
 #include "nm-test-utils.h"
diff --git a/src/platform/tests/test-nmp-object.c b/src/platform/tests/test-nmp-object.c
index 3b44abb8d6..d77170b364 100644
--- a/src/platform/tests/test-nmp-object.c
+++ b/src/platform/tests/test-nmp-object.c
@@ -223,9 +223,7 @@ test_cache_link (void)
 	GUdevDevice *udev_device_3 = g_list_nth_data (global.udev_devices, 0);
 	NMPCacheOpsType ops_type;
 
-	cache = nmp_cache_new ();
-
-	nmp_cache_use_udev_set (cache, g_rand_int_range (nmtst_get_rand (), 0, 2));
+	cache = nmp_cache_new (nmtst_get_rand_int () % 2);
 
 	/* if we have a link, and don't set is_in_netlink, adding it has no effect. */
 	obj1 = nmp_object_new (NMP_OBJECT_TYPE_LINK, (NMPlatformObject *) &pl_link_2);