[ovs-dev] [PATCH 3/3] datapath: Do not fail to load on gre protocol conflict

Gregory Rose gvrose8192 at gmail.com
Mon Jun 25 16:00:49 UTC 2018


On 6/22/2018 5:36 PM, Yifeng Sun wrote:
> Hi Greg,
>
> I tried 4.4 and 4.16 both with ip_gre module loaded and didn't trigger 
> this error.
>
> I will try more, thanks!
>
> Yifeng

Try CentOS 7 or RHEL 7.  I think those systems will be the ones most 
likely to exhibit the problem.

Thanks,

- Greg

>
> On Fri, Jun 22, 2018 at 5:17 PM, Gregory Rose <gvrose8192 at gmail.com 
> <mailto:gvrose8192 at gmail.com>> wrote:
>
>
>
>     On 6/22/2018 4:40 PM, Yifeng Sun wrote:
>>     Hi Greg,
>>
>>     I am debugging a GRE related issue. Do you mind telling me which
>>     kernel version will lead to (err == -EEXIST) here?
>>
>>         else if (err == -EEXIST)
>>                     pr_warn("Cannot take GRE protocol entry - The
>>     ERSPAN feature may not be supported\n");
>>
>>     Thanks,
>>     Yifeng
>>
>
>     Yifeng,
>
>     I don't think it is kernel specific unless it is a very new kernel
>     (4.16 or newer).
>
>     The -EEXIST comes from ../datapath/linux/compat/gre.c in
>     rpl_gre_init()
>
>     int rpl_gre_init(void)
>     {
>             pr_info("GRE over IPv4 demultiplexor driver\n");
>
>             if (inet_add_protocol(&net_gre_protocol, IPPROTO_GRE) < 0) {
>                     pr_err("can't add protocol\n");
>                     return -EEXIST;
>             }
>             return 0;
>     }
>
>     Hope this helps,
>
>     - Greg
>
>
>>     On Tue, Jun 5, 2018 at 10:56 AM, Gregory Rose
>>     <gvrose8192 at gmail.com <mailto:gvrose8192 at gmail.com>> wrote:
>>
>>         On 6/5/2018 10:39 AM, Ben Pfaff wrote:
>>
>>             On Tue, Jun 05, 2018 at 09:34:10AM -0700, Gregory Rose wrote:
>>
>>                 On 6/5/2018 9:07 AM, William Tu wrote:
>>
>>                     On Mon, Jun 4, 2018 at 1:14 PM, Greg Rose
>>                     <gvrose8192 at gmail.com
>>                     <mailto:gvrose8192 at gmail.com>> wrote:
>>
>>                         The ERSPAN feature depends on the gre kernel
>>                         module so on systems where
>>                         the ERSPAN feature isn't supported the
>>                         openvswitch kernel module would
>>                         attempt to grab the ipv4 GRE protocol entry
>>                         point and would fail to load
>>                         if it could not.
>>
>>                         This patch modifies openvswitch to not fail
>>                         to load when the gre kernel
>>                         module is loaded and instead it will print a
>>                         warning message to the
>>                         kernel system log indicating that the ERSPAN
>>                         feature may not be
>>                         available.
>>
>>                         We need this patch because users are
>>                         experiencing failures due to the
>>                         conflicts and high priority bugs are resulting.
>>
>>                         Signed-off-by: Greg Rose
>>                         <gvrose8192 at gmail.com
>>                         <mailto:gvrose8192 at gmail.com>>
>>                         ---
>>
>>                     I read through the patch and look good to me.
>>                     Acked-by: William Tu <u9012063 at gmail.com
>>                     <mailto:u9012063 at gmail.com>>
>>
>>                 Thanks William.
>>
>>                 After loading the ip_gre and gre kernel modules you
>>                 can run a 'make
>>                 check-kmod' test with those modules
>>                 loaded and the results look good as well.
>>
>>             I applied this series to master.  I added a reference to
>>             the thread
>>             where Jiri nacked the previous solution.
>>
>>
>>         Thank you!
>>
>>         - Greg
>>
>>         _______________________________________________
>>         dev mailing list
>>         dev at openvswitch.org <mailto:dev at openvswitch.org>
>>         https://mail.openvswitch.org/mailman/listinfo/ovs-dev
>>         <https://mail.openvswitch.org/mailman/listinfo/ovs-dev>
>>
>>
>
>



More information about the dev mailing list