macvlan: don't touch promisc without passthrough

commit df8ef8f3aa
"macvlan: add FDB bridge ops and macvlan flags"
added a way to control NOPROMISC macvlan flag through netlink.

However, with a non passthrough device we never set promisc on open,
even if NOPROMISC is off.  As a result:

If userspace clears NOPROMISC on open, then does not clear it on a
netlink command, promisc counter is not decremented on stop and there
will be no way to clear it once macvlan is detached.

If userspace does not clear NOPROMISC on open, then sets NOPROMISC on a
netlink command, promisc counter will be decremented from 0 and overflow
to fffffffff with no way to clear promisc.

To fix, simply ignore NOPROMISC flag in a netlink command for
non-passthrough devices, same as we do at open/close.

Since we touch this code anyway - check dev_set_promiscuity return code
and pass it to users (though an error here is unlikely).

Cc: "David S. Miller" <davem@davemloft.net>
Reviewed-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Michael S. Tsirkin 2013-06-13 10:07:29 +03:00 committed by David S. Miller
parent 26e04462c8
commit 99ffc3e74f
1 changed files with 12 additions and 6 deletions

View File

@ -853,18 +853,24 @@ static int macvlan_changelink(struct net_device *dev,
struct nlattr *tb[], struct nlattr *data[])
{
struct macvlan_dev *vlan = netdev_priv(dev);
if (data && data[IFLA_MACVLAN_MODE])
vlan->mode = nla_get_u32(data[IFLA_MACVLAN_MODE]);
if (data && data[IFLA_MACVLAN_FLAGS]) {
__u16 flags = nla_get_u16(data[IFLA_MACVLAN_FLAGS]);
bool promisc = (flags ^ vlan->flags) & MACVLAN_FLAG_NOPROMISC;
if (vlan->port->passthru && promisc) {
int err;
if (promisc && (flags & MACVLAN_FLAG_NOPROMISC))
dev_set_promiscuity(vlan->lowerdev, -1);
else if (promisc && !(flags & MACVLAN_FLAG_NOPROMISC))
dev_set_promiscuity(vlan->lowerdev, 1);
if (flags & MACVLAN_FLAG_NOPROMISC)
err = dev_set_promiscuity(vlan->lowerdev, -1);
else
err = dev_set_promiscuity(vlan->lowerdev, 1);
if (err < 0)
return err;
}
vlan->flags = flags;
}
if (data && data[IFLA_MACVLAN_MODE])
vlan->mode = nla_get_u32(data[IFLA_MACVLAN_MODE]);
return 0;
}