Re: [PATCH net] ipv4: lock mtu in fnhe when received PMTU < net.ipv4.route.min_pmtu

From: Sabrina Dubroca <sd@queasysnail.net>
Date: Mon, 12 Mar 2018 17:05:28 +0100

2018-03-09, 16:06:19 -0500, David Miller wrote:

quoted

From: Sabrina Dubroca <sd@queasysnail.net>
Date: Fri,  9 Mar 2018 17:43:21 +0100

I think if you just choose an unused RTCF_* bit (f.e. 0x02000000) for
the state, you can use that because values propagate into the
rtable->rt_flags, and do not propagate out.  So you should be able to
use it in this way privately inside the kernel.

What about a bitfield?

-	u32			rt_pmtu;
+	u32			rt_mtu_locked:1,
+				rt_pmtu:31;

I guess that's fine.