net: Add device index to tcp_md5sig

Add support for userspace to specify a device index to limit the scope
of an entry via the TCP_MD5SIG_EXT setsockopt. The existing __tcpm_pad
is renamed to tcpm_ifindex and the new field is only checked if the new
TCP_MD5SIG_FLAG_IFINDEX is set in tcpm_flags. For now, the device index
must point to an L3 master device (e.g., VRF). The API and error
handling are setup to allow the constraint to be relaxed in the future
to any device index.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David Ahern
2019-12-30 14:14:29 -08:00
committed by David S. Miller
parent dea53bb80e
commit 6b102db50c
3 changed files with 40 additions and 3 deletions

View File

@@ -1196,6 +1196,24 @@ static int tcp_v4_parse_md5_keys(struct sock *sk, int optname,
return -EINVAL;
}
if (optname == TCP_MD5SIG_EXT &&
cmd.tcpm_flags & TCP_MD5SIG_FLAG_IFINDEX) {
struct net_device *dev;
rcu_read_lock();
dev = dev_get_by_index_rcu(sock_net(sk), cmd.tcpm_ifindex);
if (dev && netif_is_l3_master(dev))
l3index = dev->ifindex;
rcu_read_unlock();
/* ok to reference set/not set outside of rcu;
* right now device MUST be an L3 master
*/
if (!dev || !l3index)
return -EINVAL;
}
addr = (union tcp_md5_addr *)&sin->sin_addr.s_addr;
if (!cmd.tcpm_keylen)