+static const struct nla_policy devconf_ipv4_policy[NETCONFA_MAX+1] = {
+ [NETCONFA_IFINDEX] = { .len = sizeof(int) },
+ [NETCONFA_FORWARDING] = { .len = sizeof(int) },
+};
+
+static int inet_netconf_get_devconf(struct sk_buff *in_skb,
+ struct nlmsghdr *nlh,
+ void *arg)
+{
+ struct net *net = sock_net(in_skb->sk);
+ struct nlattr *tb[NETCONFA_MAX+1];
+ struct netconfmsg *ncm;
+ struct sk_buff *skb;
+ struct ipv4_devconf *devconf;
+ struct in_device *in_dev;
+ struct net_device *dev;
+ int ifindex;
+ int err;
+
+ err = nlmsg_parse(nlh, sizeof(*ncm), tb, NETCONFA_MAX,
+ devconf_ipv4_policy);
+ if (err < 0)
+ goto errout;
+
+ err = EINVAL;
+ if (!tb[NETCONFA_IFINDEX])
+ goto errout;
+
+ ifindex = nla_get_s32(tb[NETCONFA_IFINDEX]);
+ switch (ifindex) {
+ case NETCONFA_IFINDEX_ALL:
+ devconf = net->ipv4.devconf_all;
+ break;
+ case NETCONFA_IFINDEX_DEFAULT:
+ devconf = net->ipv4.devconf_dflt;
+ break;
+ default:
+ dev = __dev_get_by_index(net, ifindex);
+ if (dev == NULL)
+ goto errout;
+ in_dev = __in_dev_get_rtnl(dev);
+ if (in_dev == NULL)
+ goto errout;
+ devconf = &in_dev->cnf;
+ break;
+ }
+
+ err = -ENOBUFS;
+ skb = nlmsg_new(inet_netconf_msgsize_devconf(-1), GFP_ATOMIC);
+ if (skb == NULL)
+ goto errout;
+
+ err = inet_netconf_fill_devconf(skb, ifindex, devconf,
+ NETLINK_CB(in_skb).portid,
+ nlh->nlmsg_seq, RTM_NEWNETCONF, 0,
+ -1);
+ if (err < 0) {
+ /* -EMSGSIZE implies BUG in inet_netconf_msgsize_devconf() */
+ WARN_ON(err == -EMSGSIZE);
+ kfree_skb(skb);
+ goto errout;
+ }
+ err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
+errout:
+ return err;
+}
+