Re: CVS commit: src/sys/netinet

[Ryota Ozaki <ozaki-r%netbsd.org@localhost>]

On Fri, Nov 6, 2015 at 6:09 PM, Roy Marples <roy%marples.name@localhost> wrote:
> On 06/11/2015 08:38, Ryota Ozaki wrote:
>> Module Name:  src
>> Committed By: ozaki-r
>> Date:         Fri Nov  6 08:38:43 UTC 2015
>>
>> Modified Files:
>>       src/sys/netinet: if_arp.c
>>
>> Log Message:
>> Fix inappropriate rt_flags check
>>
>> It depended on either RTF_CLONED or RTF_CLONING must be set, however,
>> the assumption didn't meet for userland problems that create a route
>> via RTM_ADD.
>
> Userland can set RTF_CLONING on any route.
>
>>
>> This fixes an issue that running rarpd causes the following kernel panic
>> reported by nonaka@:
>>   panic: kernel diagnostic assertion "(la->la_flags & LLE_STATIC) == 0"
>>   failed: file "/usr/src/sys/netinet/if_arp.c", line 1339
>
> While I agree that the panic should be fixed, should rarpd be fixed too
> add the RTF_CLONING flag if indeed it is a subnet route on the attached
> network or should userland never care about this flag and all added
> routes should be considered as attached (keep in mind we want similar
> semantics for IPv6 routes).

I prefer the latter because allowing userland programs freely setting
flags (and other parameters) easily breaks consistency in the kernel
(IOW that makes keeping consistency hard). Do we need some policies on
manipulating routes from userland? Let me know if there is already.

  ozaki-r