> 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?
