From 0551c1cb8106bf3483433fd9da6e391b9c2c2712 Mon Sep 17 00:00:00 2001
From: Thomas Haller <thaller@redhat.com>
Date: Thu, 8 Oct 2015 11:11:42 +0200
Subject: [PATCH 1/1] device: fix race wrongly managing external-down device
 due to late udev signal

Executing:

  # brctl addbr lbr0
  # ip addr add 10.1.1.1/24 dev lbr0
  # ip link set lbr0 up

can result in a race so that NetworkManager would manage the device
(and clear the IP addresses).

It happens, when NetworkManager first receives platform signals that
the device is already up:

    signal: link changed: 11: lbr0 <UP,LOWER_UP;broadcast,multicast,up,running,lowerup> mtu 1500 arp 1 bridge* not-init addrgenmode eui64 addr D2:A1:B4:17:18:F2 driver bridge

Note that the device is still unknown via udev (not-init). The
unmanaged-state NM_UNMANAGED_EXTERNAL_DOWN gets cleared, but the
device still stays unmanaged.

Only afterwards the device is known in udev:

    signal: link changed: 11: lbr0 <UP,LOWER_UP;broadcast,multicast,up,running,lowerup> mtu 1500 arp 1 bridge* init addrgenmode eui64 addr D2:A1:B4:17:18:F2 driver bridge

At this point, we also clear NM_UNMANAGED_PLATFORM_INIT, making
the device managed with reason NM_DEVICE_STATE_REASON_NOW_MANAGED.
That results in managing the external device.

Fix that by only clearing NM_UNMANAGED_EXTERNAL_DOWN after the device
is no longer NM_UNMANAGED_PLATFORM_INIT.

https://bugzilla.redhat.com/show_bug.cgi?id=1269199

(cherry picked from commit e29ab54335c6a5ef1ce6bac525f1f18a8e81b96e)
(cherry picked from commit cde15dda2e513517433e6273ca62e8b8c2c35ccb)
---
 src/devices/nm-device.c | 44 ++++++++++++++++++++++++++------------------
 1 file changed, 26 insertions(+), 18 deletions(-)

diff --git a/src/devices/nm-device.c b/src/devices/nm-device.c
index 83cd6e9..7c49f3f 100644
--- a/src/devices/nm-device.c
+++ b/src/devices/nm-device.c
@@ -1375,6 +1375,8 @@ device_link_changed (NMDevice *self)
 	NMPlatformLink info;
 	const NMPlatformLink *pllink;
 	int ifindex;
+	gboolean emit_link_initialized = FALSE;
+	gboolean was_up;
 
 	priv->device_link_changed_id = 0;
 
@@ -1450,8 +1452,29 @@ device_link_changed (NMDevice *self)
 	if (ip_ifname_changed)
 		update_dynamic_ip_setup (self);
 
-	if (priv->up != NM_FLAGS_HAS (info.flags, IFF_UP)) {
-		priv->up = NM_FLAGS_HAS (info.flags, IFF_UP);
+	if (priv->ifindex > 0 && !priv->platform_link_initialized && info.initialized) {
+		priv->platform_link_initialized = TRUE;
+
+		if (nm_platform_link_get_unmanaged (NM_PLATFORM_GET, priv->ifindex, &platform_unmanaged)) {
+			nm_device_set_unmanaged (self,
+			                         NM_UNMANAGED_DEFAULT,
+			                         platform_unmanaged,
+			                         NM_DEVICE_STATE_REASON_USER_REQUESTED);
+		}
+
+		nm_device_set_unmanaged (self,
+		                         NM_UNMANAGED_PLATFORM_INIT,
+		                         FALSE,
+		                         NM_DEVICE_STATE_REASON_NOW_MANAGED);
+
+		emit_link_initialized = TRUE;
+	}
+
+	was_up = priv->up;
+	priv->up = NM_FLAGS_HAS (info.flags, IFF_UP);
+
+	if (   priv->platform_link_initialized
+	    && (emit_link_initialized || priv->up != was_up)) {
 
 		/* Manage externally-created software interfaces only when they are IFF_UP */
 		g_assert (priv->ifindex > 0);
@@ -1493,23 +1516,8 @@ device_link_changed (NMDevice *self)
 		}
 	}
 
-	if (priv->ifindex > 0 && !priv->platform_link_initialized && info.initialized) {
-		priv->platform_link_initialized = TRUE;
-
-		if (nm_platform_link_get_unmanaged (NM_PLATFORM_GET, priv->ifindex, &platform_unmanaged)) {
-			nm_device_set_unmanaged (self,
-			                         NM_UNMANAGED_DEFAULT,
-			                         platform_unmanaged,
-			                         NM_DEVICE_STATE_REASON_USER_REQUESTED);
-		}
-
-		nm_device_set_unmanaged (self,
-		                         NM_UNMANAGED_PLATFORM_INIT,
-		                         FALSE,
-		                         NM_DEVICE_STATE_REASON_NOW_MANAGED);
-
+	if (emit_link_initialized)
 		g_signal_emit (self, signals[LINK_INITIALIZED], 0);
-	}
 
 	return G_SOURCE_REMOVE;
 }
-- 
2.4.3