Messages in this thread | | | Subject | Re: [PATCH v3 2/2] ip6_tunnel: fix ip6 tunnel lookup in collect_md mode | From | Alexei Starovoitov <> | Date | Tue, 5 Sep 2017 20:14:30 -0700 |
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On 9/4/17 1:36 AM, Haishuang Yan wrote: > In collect_md mode, if the tun dev is down, it still can call > __ip6_tnl_rcv to receive on packets, and the rx statistics increase > improperly. > > Fixes: 8d79266bc48c ("ip6_tunnel: add collect_md mode to IPv6 tunnels") > Cc: Alexei Starovoitov <ast@fb.com> > Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com> > > --- > Change since v3: > * Increment rx_dropped if tunnel device is not up, suggested by > Pravin B Shelar > * Fix wrong recipient address > --- > net/ipv6/ip6_tunnel.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c > index 10a693a..e91d3b6 100644 > --- a/net/ipv6/ip6_tunnel.c > +++ b/net/ipv6/ip6_tunnel.c > @@ -171,8 +171,11 @@ static struct net_device_stats *ip6_get_stats(struct net_device *dev) > } > > t = rcu_dereference(ip6n->collect_md_tun); > - if (t) > - return t; > + if (t) { > + if (t->dev->flags & IFF_UP) > + return t; > + t->dev->stats.rx_dropped++; > + }
Why increment the stats only for this drop case? There are plenty of other conditions where packet will be dropped in ip6 tunnel. I think it's important to present consistent behavior to the users, so I'd increment drop stats either for all drop cases or for none. And today it's none. The ! IFF_UP case should probably be return NULL too.
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