netlink: add support for NIC driver ioctls

By returning -ENOIOCTLCMD, sock_do_ioctl() falls back to calling
dev_ioctl(), which provides support for NIC driver ioctls, which
includes ethtool support. This is similar to the way ioctls are handled
in udp.c or tcp.c.

This removes the requirement that ethtool for example be tied to the
support of a specific L3 protocol (ethtool uses an AF_INET socket
today).

Signed-off-by: David Decotigny <decot@googlers.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index c8416792cce0bed9bedcd18f15aa7c2278afa3de..215fc08c02ab5508374b08ba9dcefc44e8d0875b 100644 (file)
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1033,6 +1033,14 @@ static int netlink_getname(struct socket *sock, struct sockaddr *addr,
        return 0;
 }
 
+static int netlink_ioctl(struct socket *sock, unsigned int cmd,
+                        unsigned long arg)
+{
+       /* try to hand this ioctl down to the NIC drivers.
+        */
+       return -ENOIOCTLCMD;
+}
+
 static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid)
 {
        struct sock *sock;
@@ -2494,7 +2502,7 @@ static const struct proto_ops netlink_ops = {
        .accept =       sock_no_accept,
        .getname =      netlink_getname,
        .poll =         datagram_poll,
-       .ioctl =        sock_no_ioctl,
+       .ioctl =        netlink_ioctl,
        .listen =       sock_no_listen,
        .shutdown =     sock_no_shutdown,
        .setsockopt =   netlink_setsockopt,