single nexthop flags bug

Justin Mayfield jmayfield at cradlepoint.com
Thu Aug 16 21:03:48 EDT 2012


Well that's embarrassing. Here is just the libnl change.


On 08/16/2012 06:47 PM, Justin Mayfield wrote:
> Hi Everyone,
>
> I ran into a bug today related to how Linux handles a route's nexthop 
> flags when there is just one nexthop.  Namely Linux expects the flags 
> to be OR'd into the rtm_flags field when there is only one nexthop and 
> so rtnl_route_build_msg needs to check the number of nexthops and 
> store the nexthops flags into this field prior to calling 
> nlmsg_append(...&rtmsg).
>
> Conversely the rtnl_route_parse function needs to pull these lower 
> 0xff bits when a single nexthop is detected.
>
> Attached is my patch.  I don't like the slight duplication of doing 
> the rtnl_route_get_nnexthops check twice but it seemed to be the least 
> turmoil of any solution I thought of.
>
> Cheers!
> Justin Mayfield
> !SIG:502d94f9190323796110542! 

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