[Dnsmasq-discuss] [PATCH] Re: RA-acquired address not marked as 'dynamic' with 2.82

[Iain Lane]

Hi Dominik,

On Sun, Sep 06, 2020 at 11:30:46PM +0200, Dominik wrote:
> > dnsmasq 2.81:
> >     inet6 fd42:d287:488a:d7e8:216:3eff:fecb:d41b/64 scope global dynamic mngtmpaddr noprefixroute 
> >
> > dnsmasq 2.82:
> >     inet6 fd42:d287:488a:d7e8:216:3eff:fecb:d41b/64 scope global mngtmpaddr noprefixroute 
> >
> > Was this intentional and is it actually a problem? i.e. I'm wondering if 
> > we should update the tests to not check for 'dynamic', or if a fix in 
> > dnsmasq is needed instead.
> 
> Hey Iain,
> 
> The only related difference I can see between v2.81 and v2.82 seem to be
> this one:
> http://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=commit;h=4d85e409cd2f4b0935d6ac5e8c72f6a151735d52
> 
> It's not clear to me when the kernel marks an address as "dynamic".
> Changing the flooring of the lease time may or not have an effect here.
> Would you be able to compile dnsmasq from source and check if this
> behavior you observed can be triggered by going to 4d85e40 and then back
> to its parent (2bd02d2)?

Yeah, thanks, I bisected just now and it is this change:

laney at groovy-vm:~/temp/dnsmasq$ git bisect log
git bisect start
# good: [7ddb99d251c3f5870c8c308a98bb8f283c831872] Debian changelog entry for CVE-2019-14834
git bisect good 7ddb99d251c3f5870c8c308a98bb8f283c831872
# bad: [f60fea1fb0a288011f57a25dfb653b8f6f8b46b9] CHANGELOG: Fix three typoes.
git bisect bad f60fea1fb0a288011f57a25dfb653b8f6f8b46b9
# good: [49bdf1ead9046c5c554c18ff62fe6e6a9e8a880c] Handle listening on duplicate addresses
git bisect good 49bdf1ead9046c5c554c18ff62fe6e6a9e8a880c
# good: [837e8f4eb550c688e8a83415c42a99c7bf9a4311] Remove runit support when building debs for Ubuntu.
git bisect good 837e8f4eb550c688e8a83415c42a99c7bf9a4311
# good: [7e194a0a7d483932eb3f416b8f26131ade588acc] Apply floor of 60s to TTL of DNSKEY and DS records in cache.
git bisect good 7e194a0a7d483932eb3f416b8f26131ade588acc
# bad: [4d85e409cd2f4b0935d6ac5e8c72f6a151735d52] Change default lease time for DHCPv6 to one day.
git bisect bad 4d85e409cd2f4b0935d6ac5e8c72f6a151735d52
# good: [2bd02d2f595f1d45a8598a5fce85cfc3d41dddd4] Backdated CHANGELOG update.
git bisect good 2bd02d2f595f1d45a8598a5fce85cfc3d41dddd4
# first bad commit: [4d85e409cd2f4b0935d6ac5e8c72f6a151735d52] Change default lease time for DHCPv6 to one day.

Good to know. Actually, I suppose that means in my pasted output I left 
out the real bug, which is:

    inet6 fd42:d287:488a:d7e8:216:3eff:fecb:d41b/64 scope global mngtmpaddr noprefixroute
       valid_lft forever preferred_lft forever

The lifetimes are *forever* now, but the intention of that commit is 
that they were supposed to be one day (86400 seconds). I think maybe the 
intention of the commit was this (attached)?

Cheers,

-- 
Iain Lane                                  [ iain at orangesquash.org.uk ]
Debian Developer                                   [ laney at debian.org ]
Ubuntu Developer                                   [ laney at ubuntu.com ]
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