Re: [PATCH] net: ipv6: sysctl to specify IPv6 ND traffic class

[David Miller <davem@davemloft.net>]

From: Maciej Żenczykowski <zenczykowski@gmail.com>
Date: Tue,  7 Nov 2017 21:52:09 -0800

> From: Maciej Żenczykowski <maze@google.com>
> 
> Add a per-device sysctl to specify the default traffic class to use for
> kernel originated IPv6 Neighbour Discovery packets.
> 
> Currently this includes:
> 
>   - Router Solicitation (ICMPv6 type 133)
>     ndisc_send_rs() -> ndisc_send_skb() -> ip6_nd_hdr()
> 
>   - Neighbour Solicitation (ICMPv6 type 135)
>     ndisc_send_ns() -> ndisc_send_skb() -> ip6_nd_hdr()
> 
>   - Neighbour Advertisement (ICMPv6 type 136)
>     ndisc_send_na() -> ndisc_send_skb() -> ip6_nd_hdr()
> 
>   - Redirect (ICMPv6 type 137)
>     ndisc_send_redirect() -> ndisc_send_skb() -> ip6_nd_hdr()
> 
> and if the kernel ever gets around to generating RA's,
> it would presumably also include:
> 
>   - Router Advertisement (ICMPv6 type 134)
>     (radvd daemon could pick up on the kernel setting and use it)
> 
> Interface drivers may examine the Traffic Class value and translate
> the DiffServ Code Point into a link-layer appropriate traffic
> prioritization scheme.  An example of mapping IETF DSCP values to
> IEEE 802.11 User Priority values can be found here:
> 
>     https://tools.ietf.org/html/draft-ietf-tsvwg-ieee-802-11
> 
> The expected primary use case is to properly prioritize ND over wifi.
> 
> Testing:
 ...
> (based on original change written by Erik Kline, with minor changes)
> 
> v2: fix 'suspicious rcu_dereference_check() usage'
>     by explicitly grabbing the rcu_read_lock.
> 
> Cc: Lorenzo Colitti <lorenzo@google.com>
> Signed-off-by: Erik Kline <ek@google.com>
> Signed-off-by: Maciej Żenczykowski <maze@google.com>

Applied to net-next, thanks.