Commit 83b496e9 authored May 22, 2007 by Patrick McHardy Committed by David S. Miller May 22, 2007

[RTNETLINK]: Allow changing of subsets of netdevice flags in rtnl_setlink

rtnl_setlink doesn't allow to change subsets of the flags, just to override
the set entirely by a new one. This means that for simply setting a device
up or down userspace first needs to query the current flags, change it and
send the changed flags back, which is racy and needlessly complicated.

Mask the flags using ifi_change since this is what it is intended for.
For backwards compatibility treat ifi_change == 0 as ~0 (even though it
seems quite unlikely that anyone has been using this so far).

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 1f8481d1

net/core/rtnetlink.c

+9 −2

Original line number	Diff line number	Diff line
		@@ -689,8 +689,15 @@ static int rtnl_setlink(struct sk_buff skb, struct nlmsghdr nlh, void *arg)
		}


		if (ifm->ifi_flags)
		dev_change_flags(dev, ifm->ifi_flags);
		if (ifm->ifi_flags \|\| ifm->ifi_change) {
		unsigned int flags = ifm->ifi_flags;

		/* bugwards compatibility: ifi_change == 0 is treated as ~0 */
		if (ifm->ifi_change)
		flags = (flags & ifm->ifi_change) \|
		(dev->flags & ~ifm->ifi_change);
		dev_change_flags(dev, flags);
		}

		if (tb[IFLA_TXQLEN])
		dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);

Admin message