From: Christian Brauner <christian.brauner@ubuntu.com>
Date: Thu, 31 Aug 2017 20:58:30 +0000 (+0200)
Subject: network: retrieve the host's veth device ifindex
X-Git-Tag: lxc-2.0.9~48^2~29
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=59574a77e34c5646cc0fe74f4996a3e11a3d1f94;p=thirdparty%2Flxc.git

network: retrieve the host's veth device ifindex

- Retrieve the host's veth device ifindex in the host's network namespace.
- Add a note why we retrieve the container's veth device ifindex in the host's
  network namespace.

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

diff --git a/src/lxc/network.c b/src/lxc/network.c
index 8d565ed53..6a3c36dcc 100644
--- a/src/lxc/network.c
+++ b/src/lxc/network.c
@@ -140,6 +140,18 @@ static int instantiate_veth(struct lxc_handler *handler, struct lxc_netdev *netd
 		goto out_delete;
 	}
 
+	/* Retrieve ifindex of the host's veth device. */
+	netdev->priv.veth_attr.ifindex = if_nametoindex(veth1);
+	if (!netdev->priv.veth_attr.ifindex) {
+		ERROR("Failed to retrieve ifindex for \"%s\"", veth1);
+		goto out_delete;
+	}
+
+	/* Note that we're retrieving the container's ifindex in the host's
+	 * network namespace because we need it to move the device from the
+	 * host's network namespace to the container's network namespace later
+	 * on.
+	 */
 	netdev->ifindex = if_nametoindex(veth2);
 	if (!netdev->ifindex) {
 		ERROR("Failed to retrieve ifindex for \"%s\"", veth2);