conf: refactor network deletion

I'm ashamed at how aweful my previous code was.

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

diff --git a/src/lxc/conf.c b/src/lxc/conf.c
index a3c19fbf722a2b75d461f5c0ca734f713e6d592f..722da8202c177fcdba4d6a7a9e5ee4ed612b95d5 100644 (file)
--- a/src/lxc/conf.c
+++ b/src/lxc/conf.c
@@ -3187,92 +3187,96 @@ int lxc_setup_networks_in_parent_namespaces(struct lxc_handler *handler)
 bool lxc_delete_network(struct lxc_handler *handler)
 {
        int ret;
-       struct lxc_list *network = &handler->conf->network;
        struct lxc_list *iterator;
-       struct lxc_netdev *netdev;
+       struct lxc_list *network = &handler->conf->network;
        bool deleted_all = true;
 
        lxc_list_for_each(iterator, network) {
-               netdev = iterator->elem;
+               char *hostveth = NULL;
+               struct lxc_netdev *netdev = iterator->elem;
 
-               if (netdev->ifindex != 0 && netdev->type == LXC_NET_PHYS) {
-                       if (lxc_netdev_rename_by_index(netdev->ifindex, netdev->link))
+               /* We can only delete devices whose ifindex we have. If we don't
+                * have the index it means that we didn't create it.
+                */
+               if (!netdev->ifindex)
+                       continue;
+
+               if (netdev->type == LXC_NET_PHYS) {
+                       ret = lxc_netdev_rename_by_index(netdev->ifindex, netdev->link);
+                       if (ret < 0)
                                WARN("Failed to rename interface with index %d "
-                                    "to its initial name \"%s\".",
+                                    "to its initial name \"%s\"",
                                     netdev->ifindex, netdev->link);
+                       else
+                               TRACE("Renamed interface with index %d to its "
+                                     "initial name \"%s\"",
+                                     netdev->ifindex, netdev->link);
                        continue;
                }
 
-               if (netdev_deconf[netdev->type](handler, netdev)) {
-                       WARN("Failed to destroy netdev");
-               }
+               ret = netdev_deconf[netdev->type](handler, netdev);
+               if (ret < 0)
+                       WARN("Failed to deconfigure network device");
 
                /* Recent kernel 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
                 */
-               if (netdev->ifindex != 0) {
-                       ret = lxc_netdev_delete_by_index(netdev->ifindex);
-                       if (-ret == ENODEV) {
-                               INFO("Interface \"%s\" with index %d already "
-                                    "deleted or existing in different network "
-                                    "namespace.",
-                                    netdev->name ? netdev->name : "(null)",
-                                    netdev->ifindex);
-                       } else if (ret < 0) {
-                               deleted_all = false;
-                               WARN("Failed to remove interface \"%s\" with "
-                                    "index %d: %s.",
-                                    netdev->name ? netdev->name : "(null)",
-                                    netdev->ifindex, strerror(-ret));
-                       } else {
-                               INFO("Removed interface \"%s\" with index %d.",
-                                    netdev->name ? netdev->name : "(null)",
-                                    netdev->ifindex);
-                       }
+               ret = lxc_netdev_delete_by_index(netdev->ifindex);
+               if (-ret == ENODEV) {
+                       INFO("Interface \"%s\" with index %d already deleted "
+                            "or existing in different network namespace",
+                            netdev->name ? netdev->name : "(null)", netdev->ifindex);
+               } else if (ret < 0) {
+                       deleted_all = false;
+                       WARN("Failed to remove interface \"%s\" with index %d: "
+                            "%s", netdev->name ? netdev->name : "(null)",
+                            netdev->ifindex, strerror(-ret));
+                       continue;
                }
+               INFO("Removed interface \"%s\" with index %d",
+                    netdev->name ? netdev->name : "(null)", netdev->ifindex);
+
+               if (netdev->type != LXC_NET_VETH)
+                       continue;
+
+               if (am_unpriv())
+                       continue;
 
                /* Explicitly delete host veth device to prevent lingering
                 * devices. We had issues in LXD around this.
                 */
-               if (netdev->ifindex != 0 && netdev->type == LXC_NET_VETH && !am_unpriv()) {
-                       char *hostveth;
-                       if (netdev->priv.veth_attr.pair) {
-                               hostveth = netdev->priv.veth_attr.pair;
-
-                               ret = lxc_netdev_delete_by_name(hostveth);
-                               if (ret < 0)
-                                       WARN("Failed to remove interface \"%s\" from host: %s.", hostveth, strerror(-ret));
-                               else
-                                       INFO("Removed interface \"%s\" from host.", hostveth);
-
-                               if (is_ovs_bridge(netdev->link)) {
-                                       ret = lxc_ovs_delete_port(netdev->link, hostveth);
-                                       if (ret < 0)
-                                               WARN("Failed to remove port \"%s\" from openvswitch bridge \"%s\"", hostveth, netdev->link);
-                                       else
-                                               INFO("Removed port \"%s\" from openvswitch bridge \"%s\"", hostveth, netdev->link);
-                               }
-                       } else if (strlen(netdev->priv.veth_attr.veth1) > 0) {
-                               hostveth = netdev->priv.veth_attr.veth1;
-                               ret = lxc_netdev_delete_by_name(hostveth);
-                               if (ret < 0) {
-                                       WARN("Failed to remove \"%s\" from host: %s.", hostveth, strerror(-ret));
-                               } else {
-                                       INFO("Removed interface \"%s\" from host.", hostveth);
-
-                                       if (is_ovs_bridge(netdev->link)) {
-                                               ret = lxc_ovs_delete_port(netdev->link, hostveth);
-                                               if (ret < 0) {
-                                                       WARN("Failed to remove port \"%s\" from openvswitch bridge \"%s\"", hostveth, netdev->link);
-                                               } else {
-                                                       INFO("Removed port \"%s\" from openvswitch bridge \"%s\"", hostveth, netdev->link);
-                                                       memset((void *)&netdev->priv.veth_attr.veth1, 0, sizeof(netdev->priv.veth_attr.veth1));
-                                               }
-                                       }
-                               }
-                       }
+               if (netdev->priv.veth_attr.pair)
+                       hostveth = netdev->priv.veth_attr.pair;
+               else
+                       hostveth = netdev->priv.veth_attr.veth1;
+               if (*hostveth == '\0')
+                       continue;
+
+               ret = lxc_netdev_delete_by_name(hostveth);
+               if (ret < 0) {
+                       deleted_all = false;
+                       WARN("Failed to remove interface \"%s\" from \"%s\": %s",
+                            hostveth, netdev->link, strerror(-ret));
+                       continue;
+               }
+               INFO("Removed interface \"%s\" from \"%s\"", hostveth, netdev->link);
+
+               if (!is_ovs_bridge(netdev->link)) {
+                       netdev->priv.veth_attr.veth1[0] = '\0';
+                       continue;
                }
+
+               /* Delete the openvswitch port. */
+               ret = lxc_ovs_delete_port(netdev->link, hostveth);
+               if (ret < 0)
+                       WARN("Failed to remove port \"%s\" from openvswitch "
+                            "bridge \"%s\"", hostveth, netdev->link);
+               else
+                       INFO("Removed port \"%s\" from openvswitch bridge \"%s\"",
+                            hostveth, netdev->link);
+
+               netdev->priv.veth_attr.veth1[0] = '\0';
        }
 
        return deleted_all;