Re: [PATCH net-next] ipv4: accept u8 in IP_TOS ancillary data

[David Miller <davem@davemloft.net>]

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Wed, 07 Sep 2016 21:52:56 -0700

> From: Eric Dumazet <edumazet@google.com>
> 
> In commit f02db315b8d8 ("ipv4: IP_TOS and IP_TTL can be specified as
> ancillary data") Francesco added IP_TOS values specified as integer.
> 
> However, kernel sends to userspace (at recvmsg() time) an IP_TOS value
> in a single byte, when IP_RECVTOS is set on the socket.
> 
> It can be very useful to reflect all ancillary options as given by the
> kernel in a subsequent sendmsg(), instead of aborting the sendmsg() with
> EINVAL after Francesco patch.
> 
> So this patch extends IP_TOS ancillary to accept an u8, so that an UDP
> server can simply reuse same ancillary block without having to mangle
> it.
> 
> Jesper can then augment
> https://github.com/netoptimizer/network-testing/blob/master/src/udp_example02.c
> to add TOS reflection ;)
> 
> Fixes: f02db315b8d8 ("ipv4: IP_TOS and IP_TTL can be specified as ancillary data")
> Signed-off-by: Eric Dumazet <edumazet@google.com>

Applied, thanks Eric.