Re: [PATCH v2] openvswitch: supply a dummy err_handler of gre_cisco_protocol to prevent kernel crash

["wei zhang" <asuka.com@163.com>]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset=UTF-8, Size: 1976 bytes --]

At 2014-04-05 07:05:59,"Jesse Gross" <jesse@nicira.com> wrote:
>On Tue, Apr 1, 2014 at 5:23 PM, Wei Zhang <asuka.com@163.com> wrote:
>>
>> v2 -> v1: use the same logic of the gre_rcv() to distinguish which packet is
>> intended to us!
>
>As a tip on kernel process: if you put the version information after
>three dashes below the signed-off-by line then git will automatically
>remove it when the final patch is applied.

Thanks, should I modify it and send a v3 patch?

>
>> diff --git a/net/openvswitch/vport-gre.c b/net/openvswitch/vport-gre.c
>> index a3d6951..f391df1 100644
>> --- a/net/openvswitch/vport-gre.c
>> +++ b/net/openvswitch/vport-gre.c
>> @@ -110,6 +110,21 @@ static int gre_rcv(struct sk_buff *skb,
>>         return PACKET_RCVD;
>>  }
>>
>> +/* Called with rcu_read_lock and BH disabled. */
>> +static int gre_err(struct sk_buff *skb, u32 info,
>> +                  const struct tnl_ptk_info *tpi)
>> +{
>> +       struct ovs_net *ovs_net;
>> +       struct vport *vport;
>> +
>> +       ovs_net = net_generic(dev_net(skb->dev), ovs_net_id);
>> +       vport = rcu_dereference(ovs_net->vport_net.gre_vport);
>> +       if (unlikely(!vport))
>> +               return PACKET_REJECT;
>> +       else
>> +               return PACKET_RCVD;
>
>Sorry, I forgot to say this before - if we receive the packet then we
>should also call consume_skb() on it.

Maybe there is no need to call consume_skb()? The icmp_rcv() would
call kfree_skb() for us. I also checked the ipgre_err(), it return 
PACKET_RCVD without call consume_skb() too.

Regards,
Wei Zhangÿôèº{.nÇ+‰·Ÿ®‰­†+%ŠËÿ±éݶ\x17¥Šwÿº{.nÇ+‰·¥Š{±þG«éÿŠ{ayº\x1dʇڙë,j\a­¢f£¢·hšïêÿ‘êçz_è®\x03(­éšŽŠÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?™¨è­Ú&£ø§~á¶iO•æ¬z·švØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?–I¥