From: Christian Brauner <christian.brauner@ubuntu.com>
Date: Thu, 9 Jan 2020 17:08:48 +0000 (+0100)
Subject: network: fix network device removal
X-Git-Tag: lxc-4.0.0~61^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0104c121a734f63d3304ee0210f7a7dc943ac173;p=thirdparty%2Flxc.git

network: fix network device removal

We can't delete by netdev->ifindex since that's the ifindex of the device in
the container, not on the host. The correct thing is done below.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
---

diff --git a/src/lxc/network.c b/src/lxc/network.c
index b3564e1a7..5618caea8 100644
--- a/src/lxc/network.c
+++ b/src/lxc/network.c
@@ -3323,6 +3323,12 @@ bool lxc_delete_network_priv(struct lxc_handler *handler)
 		if (!netdev->ifindex)
 			continue;
 
+		/*
+		 * If the network device has been moved back from the
+		 * containers network namespace, update the ifindex.
+		 */
+		netdev->ifindex = if_nametoindex(netdev->name);
+
 		/* Delete l2proxy entries if enabled and used with a link property */
 		if (netdev->l2proxy && netdev->link[0] != '\0') {
 			if (lxc_delete_l2proxy(netdev))
@@ -3361,26 +3367,6 @@ bool lxc_delete_network_priv(struct lxc_handler *handler)
 		if (ret < 0)
 			WARN("Failed to deconfigure network device");
 
-		/* Recent kernels remove the virtual interfaces when the network
-		 * namespace is destroyed but in case we did not move the
-		 * interface to the network namespace, we have to destroy it.
-		 */
-		ret = lxc_netdev_delete_by_index(netdev->ifindex);
-		if (ret < 0) {
-			if (errno != ENODEV) {
-				WARN("Failed to remove interface \"%s\" with index %d",
-				     netdev->name[0] != '\0' ? netdev->name : "(null)",
-				     netdev->ifindex);
-				goto clear_ifindices;
-			}
-			INFO("Interface \"%s\" with index %d already deleted or existing in different network namespace",
-			     netdev->name[0] != '\0' ? netdev->name : "(null)",
-			     netdev->ifindex);
-		}
-		INFO("Removed interface \"%s\" with index %d",
-		     netdev->name[0] != '\0' ? netdev->name : "(null)",
-		     netdev->ifindex);
-
 		if (netdev->type != LXC_NET_VETH)
 			goto clear_ifindices;