+static int rtnl_bridge_dellink(struct sk_buff *skb, struct nlmsghdr *nlh,
+ void *arg)
+{
+ struct net *net = sock_net(skb->sk);
+ struct ifinfomsg *ifm;
+ struct net_device *dev;
+ struct nlattr *br_spec, *attr = NULL;
+ int rem, err = -EOPNOTSUPP;
+ u16 oflags, flags = 0;
+ bool have_flags = false;
+
+ if (nlmsg_len(nlh) < sizeof(*ifm))
+ return -EINVAL;
+
+ ifm = nlmsg_data(nlh);
+ if (ifm->ifi_family != AF_BRIDGE)
+ return -EPFNOSUPPORT;
+
+ dev = __dev_get_by_index(net, ifm->ifi_index);
+ if (!dev) {
+ pr_info("PF_BRIDGE: RTM_SETLINK with unknown ifindex\n");
+ return -ENODEV;
+ }
+
+ br_spec = nlmsg_find_attr(nlh, sizeof(struct ifinfomsg), IFLA_AF_SPEC);
+ if (br_spec) {
+ nla_for_each_nested(attr, br_spec, rem) {
+ if (nla_type(attr) == IFLA_BRIDGE_FLAGS) {
+ have_flags = true;
+ flags = nla_get_u16(attr);
+ break;
+ }
+ }
+ }
+
+ oflags = flags;
+
+ if (!flags || (flags & BRIDGE_FLAGS_MASTER)) {
+ struct net_device *br_dev = netdev_master_upper_dev_get(dev);
+
+ if (!br_dev || !br_dev->netdev_ops->ndo_bridge_dellink) {
+ err = -EOPNOTSUPP;
+ goto out;
+ }
+
+ err = br_dev->netdev_ops->ndo_bridge_dellink(dev, nlh);
+ if (err)
+ goto out;
+
+ flags &= ~BRIDGE_FLAGS_MASTER;
+ }
+
+ if ((flags & BRIDGE_FLAGS_SELF)) {
+ if (!dev->netdev_ops->ndo_bridge_dellink)
+ err = -EOPNOTSUPP;
+ else
+ err = dev->netdev_ops->ndo_bridge_dellink(dev, nlh);
+
+ if (!err)
+ flags &= ~BRIDGE_FLAGS_SELF;
+ }
+
+ if (have_flags)
+ memcpy(nla_data(attr), &flags, sizeof(flags));
+ /* Generate event to notify upper layer of bridge change */
+ if (!err)
+ err = rtnl_bridge_notify(dev, oflags);
+out:
+ return err;
+}
+