Re: kern/57037: unncessary and unwarranted RTM_NEWADDR for IPv6 routing messages

[Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>]

Hi,

On 2022/10/12 18:35, Frank Kardel wrote:
> The following reply was made to PR kern/57037; it has been noted by GNATS.
>
> From: Frank Kardel <kardel%netbsd.org@localhost>
> To: gnats-bugs%netbsd.org@localhost
> Cc:
> Subject: Re: kern/57037: unncessary and unwarranted RTM_NEWADDR for IPv6
>   routing messages
> Date: Wed, 12 Oct 2022 11:33:53 +0200
>
>   Hi,
>   
>   yes. It follows the principle of least astonishment. So that is now fine.
>   
>   I was wondering whether parameter changes should be announced via
>   
>   #define RTM_CHGADDR     0x18    /* address properties changed */
>   
>   but I currently have no idea how widely the interface is defined/used
>   and what the
>   breakage would be.
>   RTM_CHGADDR sounds in the comment the this could be right for parameter
>   changes, but
>   I am no up to date on the semantics of that. Maybe someone (tm) could
>   shed more light on that.

I have considered about RTM_CHGADDR idea, however I cannot come up with
a good design.  So, I change net.inet6.ip6.param_rt_msg value type from
bool to int for future expandability, and the values are consisted of
    - 0 : don't send parameter changing routing message
    - 1(default) : send parameter changing routing message by RTM_NEWADDR
                   (same as before)
Maybe someone (tm) will implement
    - 2 : send parameter changing routing message by RTM_CHGADDR (or better way?)

Here is the updated patch
    https://www.netbsd.org/~knakahara/20221017-param-rt-msg.patch

If there is no objection, I will commit this patch.


Thanks,

>   Best regards,
>      Frank
>   
>   On 10/11/22 09:40, Kengo NAKAHARA wrote:
>   > The following reply was made to PR kern/57037; it has been noted by GNATS.
>   >
>   > From: Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>
>   > To: Frank Kardel <kardel%netbsd.org@localhost>, gnats-bugs <gnats-bugs%NetBSD.org@localhost>
>   > Cc:
>   > Subject: Re: kern/57037: unncessary and unwarranted RTM_NEWADDR for IPv6
>   >   routing messages
>   > Date: Tue, 11 Oct 2022 16:05:54 +0900
>   >
>   >   Hi,
>   >
>   >   Thank you for your fixing!
>   >
>   >   Is the behavior is  what you want?
>   >
>   >
>   >   Thanks,
>   >
>   >   On 2022/10/07 23:19, Frank Kardel wrote:
>   >   > Hi,
>   >   >
>   >   > I debugged the patch and the issue was the the comparison was with dst6 and dst addrs. Instead the actual addresses needed to be compared.
>   >   >
>   >   > The corrected patch is attached.
>   >   >
>   >   > Best regards,
>   >   >
>   >   >  Â  Frank
>   >   >
>   >   >
>   >   > On 10/06/22 08:46, Kengo NAKAHARA wrote:
>   >   >> Hi,
>   >   >>
>   >   >> Thank you for your testing!
>   >   >>
>   >   >> Sorry I can't help you.  Hmm, the patch may be old, I will review
>   >   >> and test it again.
>   >   >>
>   >   >>
>   >   >> Thanks,
>   >   >>
>   >   >> On 2022/10/06 15:34, Frank Kardel wrote:
>   >   >>> Hi!
>   >   >>>
>   >   >>> Thanks for the patch.
>   >   >>>
>   >   >>> Unfortunately I still see RTM_NEWADDRs after setting net.inet6.ip6.param_rt_msg=0
>   >   >>>
>   >   >>> This needs a bit more debugging - maybe I get to that after may $DAYJOB.
>   >   >>>
>   >   >>> Best regards,
>   >   >>>
>   >   >>> Â Â  Frank
>   >   >>>
>   >   >>>
>   >   >>> On 10/06/22 01:51, Kengo NAKAHARA wrote:
>   >   >>>> sysctl -w net.inet6.ip6.param_rt_msg=0
>   >   >>>
>   >   >>
>   >   >
>   >
>   >   --
>   >   //////////////////////////////////////////////////////////////////////
>   >   Internet Initiative Japan Inc.
>   >
>   >   Device Engineering Section,
>   >   Product Division,
>   >   Technology Unit
>   >
>   >   Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>
>   >
>   >
>   

--
//////////////////////////////////////////////////////////////////////
Internet Initiative Japan Inc.

Device Engineering Section,
Product Division,
Technology Unit

Kengo NAKAHARA <k-nakahara%iij.ad.jp@localhost>