[PATCH] net-ipv6-ndisc: add support for 'PREF64' dns64 prefix identifier

[PATCH] net-ipv6-ndisc: add support for 'PREF64' dns64 prefix identifier

[Maciej Żenczykowski]

From: Maciej Żenczykowski <maze@google.com>

This is trivial since we already have support for the entirely
identical (from the kernel's point of view) RDNSS, DNSSL, etc. that
also contain opaque data that needs to be passed down to userspace
for further processing.

As specified in draft-ietf-6man-ra-pref64-09 (while it is still a draft,
it is purely waiting on the RFC Editor for cleanups and publishing):
  PREF64 option contains lifetime and a (up to) 96-bit IPv6 prefix.

The 8-bit identifier of the option type as assigned by the IANA is 38.

Since we lack DNS64/NAT64/CLAT support in kernel at the moment,
thus this option should also be passed on to userland.

See:
  https://tools.ietf.org/html/draft-ietf-6man-ra-pref64-09
  https://www.iana.org/assignments/icmpv6-parameters/icmpv6-parameters.xhtml#icmpv6-parameters-5

Cc: Erik Kline <ek@google.com>
Cc: Jen Linkova <furry@google.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Cc: Michael Haro <mharo@google.com>
Signed-off-by: Maciej Żenczykowski <maze@google.com>
---
 include/net/ndisc.h | 1 +
 net/ipv6/ndisc.c    | 1 +
 2 files changed, 2 insertions(+)

diff --git a/include/net/ndisc.h b/include/net/ndisc.h
index 1c61aeb3a1c0..7d107113f988 100644
--- a/include/net/ndisc.h
+++ b/include/net/ndisc.h
@@ -41,6 +41,7 @@ enum {
 	ND_OPT_DNSSL = 31,		/* RFC6106 */
 	ND_OPT_6CO = 34,		/* RFC6775 */
 	ND_OPT_CAPTIVE_PORTAL = 37,	/* RFC7710 */
+	ND_OPT_PREF64 = 38,		/* RFC-ietf-6man-ra-pref64-09 */
 	__ND_OPT_MAX
 };
 
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 4a3feccd5b10..6ffa153e5166 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -197,6 +197,7 @@ static inline int ndisc_is_useropt(const struct net_device *dev,
 	return opt->nd_opt_type == ND_OPT_RDNSS ||
 		opt->nd_opt_type == ND_OPT_DNSSL ||
 		opt->nd_opt_type == ND_OPT_CAPTIVE_PORTAL ||
+		opt->nd_opt_type == ND_OPT_PREF64 ||
 		ndisc_ops_is_useropt(dev, opt->nd_opt_type);
 }
 
-- 
2.25.1.696.g5e7596f4ac-goog

Re: [PATCH] net-ipv6-ndisc: add support for 'PREF64' dns64 prefix identifier

[Lorenzo Colitti]

On Tue, Mar 24, 2020 at 10:10 AM Maciej Żenczykowski
<zenczykowski@gmail.com> wrote:
> As specified in draft-ietf-6man-ra-pref64-09 (while it is still a draft,
> it is purely waiting on the RFC Editor for cleanups and publishing):
>   PREF64 option contains lifetime and a (up to) 96-bit IPv6 prefix.

Right. The number is assigned by IANA and the draft is in the RFC
editor queue, so this number will not change.

> diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
> index 4a3feccd5b10..6ffa153e5166 100644
> --- a/net/ipv6/ndisc.c
> +++ b/net/ipv6/ndisc.c
> @@ -197,6 +197,7 @@ static inline int ndisc_is_useropt(const struct net_device *dev,
>         return opt->nd_opt_type == ND_OPT_RDNSS ||
>                 opt->nd_opt_type == ND_OPT_DNSSL ||
>                 opt->nd_opt_type == ND_OPT_CAPTIVE_PORTAL ||
> +               opt->nd_opt_type == ND_OPT_PREF64 ||
>                 ndisc_ops_is_useropt(dev, opt->nd_opt_type);
>  }

Acked-By: Lorenzo Colitti <lorenzo@google.com>

Re: [PATCH] net-ipv6-ndisc: add support for 'PREF64' dns64 prefix identifier

[David Miller]

From: Maciej Żenczykowski <zenczykowski@gmail.com>
Date: Mon, 23 Mar 2020 18:10:19 -0700

> From: Maciej Żenczykowski <maze@google.com>
> 
> This is trivial since we already have support for the entirely
> identical (from the kernel's point of view) RDNSS, DNSSL, etc. that
> also contain opaque data that needs to be passed down to userspace
> for further processing.
> 
> As specified in draft-ietf-6man-ra-pref64-09 (while it is still a draft,
> it is purely waiting on the RFC Editor for cleanups and publishing):
>   PREF64 option contains lifetime and a (up to) 96-bit IPv6 prefix.
> 
> The 8-bit identifier of the option type as assigned by the IANA is 38.
> 
> Since we lack DNS64/NAT64/CLAT support in kernel at the moment,
> thus this option should also be passed on to userland.
> 
> See:
>   https://tools.ietf.org/html/draft-ietf-6man-ra-pref64-09
>   https://www.iana.org/assignments/icmpv6-parameters/icmpv6-parameters.xhtml#icmpv6-parameters-5
> 
> Cc: Erik Kline <ek@google.com>
> Cc: Jen Linkova <furry@google.com>
> Cc: Lorenzo Colitti <lorenzo@google.com>
> Cc: Michael Haro <mharo@google.com>
> Signed-off-by: Maciej Żenczykowski <maze@google.com>

Applied to net-next.