From: Stephen Hemminger <stephen@networkplumber•org>
To: David Ahern <dsahern@gmail•com>
Cc: netdev@vger•kernel.org, yoshfuji@linux-ipv6•org,
idosch@mellanox•com, roopa@cumulusnetworks•com
Subject: Re: [PATCH v2 net-next] net/ipv6: Do not allow route add with a device that is down
Date: Wed, 24 Jan 2018 09:09:44 -0800 [thread overview]
Message-ID: <20180124090944.217c14b7@xeon-e3> (raw)
In-Reply-To: <20180124162924.6984-1-dsahern@gmail.com>
On Wed, 24 Jan 2018 08:29:24 -0800
David Ahern <dsahern@gmail•com> wrote:
> IPv6 allows routes to be installed when the device is not up (admin up).
> Worse, it does not mark it as LINKDOWN. IPv4 does not allow it and really
> there is no reason for IPv6 to allow it, so check the flags and deny if
> device is admin down.
>
> Signed-off-by: David Ahern <dsahern@gmail•com>
> ---
> v2
> - missed setting err to -ENETDOWN (thanks for catching that Roopa)
>
> net/ipv6/route.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/net/ipv6/route.c b/net/ipv6/route.c
> index f85da2f1e729..4e8fab766018 100644
> --- a/net/ipv6/route.c
> +++ b/net/ipv6/route.c
> @@ -2734,6 +2734,12 @@ static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg,
> if (!dev)
> goto out;
>
> + err = -ENETDOWN;
> + if (!(dev->flags & IFF_UP)) {
> + NL_SET_ERR_MSG(extack, "Nexthop device is not up");
> + goto out;
> + }
> +
> if (!ipv6_addr_any(&cfg->fc_prefsrc)) {
> if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) {
> NL_SET_ERR_MSG(extack, "Invalid source address");
This looks like a good idea.
There are two equal ways to check for admin up. Either the dev flags or
look at link state via netif_running(). Maybe the latter would
be better.
next prev parent reply other threads:[~2018-01-24 17:09 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-24 16:29 [PATCH v2 net-next] net/ipv6: Do not allow route add with a device that is down David Ahern
2018-01-24 17:09 ` Stephen Hemminger [this message]
2018-01-24 17:37 ` David Ahern
2018-01-24 17:23 ` Eric Dumazet
2018-01-24 17:29 ` David Ahern
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