From mboxrd@z Thu Jan  1 00:00:00 1970
From: Michael Tremer <michael.tremer@ipfire.org>
To: ddns@lists.ipfire.org
Subject: Re: Passing key algo to nsupdate
Date: Mon, 04 Apr 2022 10:11:59 +0100
Message-ID: <C0A1284F-F41D-4BEF-ABC6-9307C5AD958A@ipfire.org>
In-Reply-To: <1985172.IPymiuymL7@haiash>
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Hello Adrian,

Thank you for looking into this. We really would like some help to improve dd=
ns.

> On 3 Apr 2022, at 13:15, Adrian Zaugg <ipfire.org(a)mailgurgler.com> wrote:
>=20
> Hi there
>=20
> After some digging in the code I found some Problems with the ddns componen=
t=20
> of IPFire and especially with the nsupdate provider. The main thing which=20
> renders the nsupdate provider unusable, I reported under Bug #12837 [1]. It=
=20
> seems to me there are more problems, but since I don't use IPFire, I do not=
=20
> feel to get involved to much.

Generally, the UI does not have good support for nsupdate, since we did not w=
ant to add any extra fields. This method is not very popular and since we wan=
ted to release ddns, we skipped changing the UI and never revisited this.

However, it should work if you write the correct configuration by hand.

> It seems to me that the scriptlet the nsupdate provider produces is missing=
=20
> the "update" commands. It connects, authenticates and saves, but does not p=
ass=20
> any information to the server. A generated scriptlet for nsupdate should lo=
ok=20
> like this:
>=20
> 	server $SERVER
> 	zone $ZONE
> 	update delete $HOSTNAME $RR
> 	update add $HOSTNAME $TTL $RR $IP
> 	send
>=20
> ...where:=20
> $SERVER is the name server to send the record update/ deletion
> $ZONE is the domain in which to update the host record
> $HOSTNAME is the dynamic host's FQDN
> $TTL is the time to live value for the record
> $IP is the numerical IP address of the dynamic host
> $RR is the record type, "A" for an IPv4, "AAAA" for an IPv6 host address
>=20
> If I watch the debug output of ddns I do not see the update command being=20
> sent. I did not check this good enough to report a bug.

This scriptlet looks good and in theory is what ddns generates and sends to n=
supdate:

https://git.ipfire.org/?p=3Dddns.git;a=3Dblob;f=3Dsrc/ddns/providers.py;h=3D5=
b2a82d1b727172c2011574277988977b8013db0;hb=3DHEAD#l507

It can happen that no update line is generated if the system cannot find its =
own IP address.

So the problem is not in support for nsupdate, it is that this function is no=
t returning a valid result:

https://git.ipfire.org/?p=3Dddns.git;a=3Dblob;f=3Dsrc/ddns/system.py;h=3D73a2=
7a5cd0b56484feda70006b3ba4065e11e0c8;hb=3DHEAD#l281

This will cause other methods that cannot detect your IP address automaticall=
y to fail, too.

What do you get when you run this command:

  ddns guess-ip-addresses

> The whole provider does not work at all and the code in the ddns seems half=
=20
> baken to me. I started to report bugs, but I gave up, when I saw, that it=20
> nsupdate doesn't work at all. So if some one corrects the code and tests it=
=20
> (who actually knows to code in Python unlike me), those deficiencies should=
=20
> get discovered anyway. I hope I could help with some bug reports against th=
e=20
> ddns core and the hint in this mail here.
>=20
> Best regards, Adrian.
>=20
> [1] https://bugzilla.ipfire.org/show_bug.cgi?id=3D12837
> _______________________________________________
> ddns mailing list
> ddns(a)lists.ipfire.org
> https://lists.ipfire.org/mailman/listinfo/ddns


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