ppp: rename the interface only when necessary

Previously when the interface created by pppd was already the one we
expected, we would rename it to itself and remove the device from the
manager. Don't do it.

Fixes: 6c3195931e94cab70208ce97f3b834f5d9f5ff62

3 files changed, 28 insertions, 15 deletions

diff --git a/src/devices/nm-device-ppp.c b/src/devices/nm-device-ppp.c
index 7c034f5f85..d786a62e22 100644
--- a/src/devices/nm-device-ppp.c
+++ b/src/devices/nm-device-ppp.c
@@ -105,17 +105,20 @@ ppp_ip4_config (NMPPPManager *ppp_manager,
 	NMDevice *device = NM_DEVICE (user_data);
 	NMDevicePpp *self = NM_DEVICE_PPP (device);
 	NMDevicePppPrivate *priv = NM_DEVICE_PPP_GET_PRIVATE (self);
+	gboolean renamed;
 
 	_LOGT (LOGD_DEVICE | LOGD_PPP, "received IPv4 config from pppd");
 
 	if (nm_device_get_state (device) == NM_DEVICE_STATE_IP_CONFIG) {
 		if (nm_device_activate_ip4_state_in_conf (device)) {
-			if (!nm_device_take_over_link (device, iface)) {
+			if (!nm_device_take_over_link (device, iface, &renamed)) {
 				nm_device_state_changed (device, NM_DEVICE_STATE_FAILED,
 				                         NM_DEVICE_STATE_REASON_IP_CONFIG_UNAVAILABLE);
 				return;
 			}
-			nm_manager_remove_device (nm_manager_get (), iface);
+			if (renamed)
+				nm_manager_remove_device (nm_manager_get (), iface);
+
 			nm_device_activate_schedule_ip4_config_result (device, config);
 			return;
 		}
@@ -178,11 +181,13 @@ act_stage3_ip4_config_start (NMDevice *device,
 {
 	NMDevicePpp *self = NM_DEVICE_PPP (device);
 	NMDevicePppPrivate *priv = NM_DEVICE_PPP_GET_PRIVATE (self);
+	gboolean renamed;
 
 	if (priv->pending_ip4_config) {
-		if  (!nm_device_take_over_link (device, priv->pending_ifname))
+		if  (!nm_device_take_over_link (device, priv->pending_ifname, &renamed))
 			return NM_ACT_STAGE_RETURN_FAILURE;
-		nm_manager_remove_device (nm_manager_get (), priv->pending_ifname);
+		if (renamed)
+			nm_manager_remove_device (nm_manager_get (), priv->pending_ifname);
 		if (out_config)
 			*out_config = g_steal_pointer (&priv->pending_ip4_config);
 		else
diff --git a/src/devices/nm-device-private.h b/src/devices/nm-device-private.h
index a02cab3159..a884faa2bf 100644
--- a/src/devices/nm-device-private.h
+++ b/src/devices/nm-device-private.h
@@ -57,7 +57,7 @@ gboolean nm_device_bring_up (NMDevice *self, gboolean wait, gboolean *no_firmwar
 
 void nm_device_take_down (NMDevice *self, gboolean block);
 
-gboolean nm_device_take_over_link (NMDevice *self, const char *ifname);
+gboolean nm_device_take_over_link (NMDevice *self, const char *ifname, gboolean *renamed);
 
 gboolean nm_device_hw_addr_set (NMDevice *device,
                                 const char *addr,
diff --git a/src/devices/nm-device.c b/src/devices/nm-device.c
index aadd2cd6cf..9cb29cf27f 100644
--- a/src/devices/nm-device.c
+++ b/src/devices/nm-device.c
@@ -1007,15 +1007,18 @@ nm_device_get_iface (NMDevice *self)
 }
 
 gboolean
-nm_device_take_over_link (NMDevice *self, const char *ifname)
+nm_device_take_over_link (NMDevice *self, const char *ifname, gboolean *renamed)
 {
 	NMDevicePrivate *priv = NM_DEVICE_GET_PRIVATE (self);
 	const NMPlatformLink *plink;
 	NMPlatform *platform;
-	gboolean up, success;
+	gboolean up, success = TRUE;
 	int ifindex;
 
 	g_return_val_if_fail (priv->ifindex <= 0, FALSE);
+	g_return_val_if_fail (ifname, FALSE);
+
+	NM_SET_OUT (renamed, FALSE);
 
 	platform = nm_device_get_platform (self);
 	plink = nm_platform_link_get_by_ifname (platform, ifname);
@@ -1023,14 +1026,19 @@ nm_device_take_over_link (NMDevice *self, const char *ifname)
 		return FALSE;
 
 	ifindex = plink->ifindex;
-	up = NM_FLAGS_HAS (plink->n_ifi_flags, IFF_UP);
-
-	/* Rename the link to the device ifname */
-	if (up)
-		nm_platform_link_set_down (platform, ifindex);
-	success = nm_platform_link_set_name (platform, ifindex, nm_device_get_iface (self));
-	if (up)
-		nm_platform_link_set_up (platform, ifindex, NULL);
+
+	if (!nm_streq (ifname, nm_device_get_iface (self))) {
+		up = NM_FLAGS_HAS (plink->n_ifi_flags, IFF_UP);
+
+		/* Rename the link to the device ifname */
+		if (up)
+			nm_platform_link_set_down (platform, ifindex);
+		success = nm_platform_link_set_name (platform, ifindex, nm_device_get_iface (self));
+		if (up)
+			nm_platform_link_set_up (platform, ifindex, NULL);
+
+		NM_SET_OUT (renamed, success);
+	}
 
 	if (success) {
 		priv->ifindex = ifindex;