Subject: Re: PR15662, why was it backed out?
To: None <tech-kern@netbsd.org>
From: Christos Zoulas <christos@zoulas.com>
List: tech-kern
Date: 01/06/2003 14:16:47
In article <20030106135504.GB213274670@qnx.com>,
Sean Boudreau <seanb@qnx.com> wrote:

Ask Itojun I guess...

christos

>
>FWIW, 1.72 was only around for about half an hour.  1.73
>should have the fix without the bug.
>
>-seanb
>
>On Fri, Jan 03, 2003 at 03:52:53PM -0800, Tad Hunt wrote:
>> 
>> I'm running into the same problem described in PR15662, though I
>> can reproduce the behavior with a simpler setup.  I believe that
>> the code Christos committed to fix this problem should be fixed,
>> not backed out.
>
><snip>
>
>> 
>> According to the commit message from itojun when the code was backed
>> out:
>> 
>> 	> CVS log for src/sys/netinet/in.c  Revision 1.76
>> 	>
>> 	> backout 1.72.  it is not correct for the kernel to remove routes
>> 	> by itself, and the code was buggy (dereferenced null pointer when
>> 	> IFAFREE removes the route).
>> 
>> Other than backing it out because it was buggy, I am not clear on
>> why the kernel is not *required* to remove routes which no longer
>> make any sense.
>> 
>> When an interface address is removed or changed, I don't think that
>> any more packets should exit the box stamped with that source
>> address.  This problem is clearly in the domain of the kernel to
>> rectify.  Those routes no longer make sense, and userland apparently
>> has no knowledge of which source address the kernel is going to
>> stamp into the outgoing packet.
>> 
>> -Tad