> On 20 Jun 2017, at 2:08 AM, Pravin Shelar <pshe...@ovn.org> wrote: > > On Mon, Jun 19, 2017 at 6:13 AM, 严海双 <yanhaishu...@cmss.chinamobile.com> > wrote: >> >> >>> On 19 Jun 2017, at 1:43 PM, Pravin Shelar <pshe...@ovn.org> wrote: >>> >>> On Fri, Jun 16, 2017 at 8:27 PM, Haishuang Yan >>> <yanhaishu...@cmss.chinamobile.com> wrote: >>>> In collect_md mode, if the tun dev is down, it still can call >>>> ip_tunnel_rcv to receive on packets, and the rx statistics increase >>>> improperly. >>>> >>>> Fixes: 2e15ea390e6f ("ip_gre: Add support to collect tunnel metadata.") >>>> Cc: Pravin B Shelar <pshe...@nicira.com> >>>> Signed-off-by: Haishuang Yan <yanhaishu...@cmss.chinamobile.com> >>>> >>>> --- >>>> Change since v2: >>>> * Fix wrong recipient addresss >>>> --- >>>> net/ipv4/ip_tunnel.c | 2 +- >>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>> >>>> diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c >>>> index 0f1d876..a3caba1 100644 >>>> --- a/net/ipv4/ip_tunnel.c >>>> +++ b/net/ipv4/ip_tunnel.c >>>> @@ -176,7 +176,7 @@ struct ip_tunnel *ip_tunnel_lookup(struct >>>> ip_tunnel_net *itn, >>>> return cand; >>>> >>>> t = rcu_dereference(itn->collect_md_tun); >>>> - if (t) >>>> + if (t && (t->dev->flags & IFF_UP)) >>>> return t; >>>> >>> It would be nice if we could increment drop count if tunnel device is not >>> up. >>> >> Hi Pravin >> >> I think it’s not necessary, for example as gre tunnel, if ipgre_rcv fails, >> it would trigger send an icmp unreachable >> message: >> >> if (ipgre_rcv(skb, &tpi, hdr_len) == PACKET_RCVD) >> return 0; >> >> icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); >> >> Since the tunnel device didn’t touch the packets, so increase drop >> statistics is not necessary. >> > icmp err packets are not reliable on all networks. device stats are > much more convenient during debugging connectivity issues. >
Okay, if the tunnel device is not up, packets will transfer to fallback tunnel, and if the fallback device is up, the RX drops will be increased as expected: gre0: flags=193<UP,RUNNING,NOARP> mtu 1476 inet 172.16.20.1 netmask 255.255.255.0 unspec 00-00-00-00-00-00-F0-00-00-00-00-00-00-00-00-00 txqueuelen 1000 (UNSPEC) RX packets 105 bytes 4522 (4.4 KiB) RX errors 0 dropped 105 overruns 0 frame 0 TX packets 0 bytes 0 (0.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 My question is whether we should increase the drops of original tunnel device instead of fallback device?