Thank you Simon for the quick reply,
I did indeed miss `interface-name` when skimming through the manual page
and from the looks of it other users on this thread did too.
My suggestion is to have interface-name and dynamic-host mention each
other in the manual page and to modify the error message `warning: no
addresses found for interface dsl-provider` to something less cryptic.
The only reason I used dynamic-host is because it was first in the
manual page (I know it's not an excuse for not reading thoroughly, but
it seemed to do what I wanted and I didn't think that there was
something better).
Thanks again!
On 3/13/23 19:01, Simon Kelley wrote:
Thanks for the bug report, it's definitely not noise.
The history of line 363 is interesting.
When the dynamic-host option was added, it looked like
if (netmask.s_addr == 0xffff)
and stayed like that until October 2022 when it got changed to the
current version
if (netmask.s_addr == 0xffffffff)
That's what was released as part of 2.88
So that explains why it used to work for you, and no longer does in
2.88 and 2.89. If your PPoe interface had netmask 255.255.0.0 then it
would not have worked previously, but would work now.
The change was prompted by this email to the list.
https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2022q4/016607.html
and the explanation that it looks like the intention was to skip
interfaces with /32 prefixes looks pretty sensible, so the patch went
in without too much thought.
My dilemma is that I can't see the reason to do that and I have no
recollection of why I might done it in early 2021 when dynamic-host
was first implemented. Someone should invent a way to core-dump human
brain state to git for future reference.
The best I can come up with is that what you are trying to do is not
what I expected dynamic-host to be used for. I expected it to be used
to name hosts on an internal network whose prefix was supplied by the
ISP, typically in IPv6-land with prefix delegation. So the host is not
the one running dnsmasq but another host connected to the same network
as the interface but with a suffix. Clearly that can only exist when
the prefix length is smaller than 32(IPv4) or 128(IPv6).
Actually, it's reasonable not to have considered your "weird hack",
because dnsmasq has had an explicit mechanism to do what you want for
a long time, interface-name. You could just use.
interface-name=myip.my.local.domain,dsl-provider
So.
There's an easier way to do what you want to do.
Your "weird hack" used to work because the code that was supposed to
stop it used to be buggy and didn't.
The bug got fixed in 2.88 and now does stop your weird hack.
There's a very limited need for the once-buggy, now fixed code and I
can't really remember what it was for.
Going forward we have three options for line 363
1) revert the October 2022 change. That would be stupid.
2) leave as is and educate people to use interface-name for this and
not hack dynamic-host
3) remove it so that people skimming the man page who find
dynamic-host before they find interface-name and rediscover your
"weird hack" are not bewildered. This would also avoid people who
found and used the "weird hack" in pre-2.88 releases from suffering a
regression when they upgrade.
For that last reason alone, I propose option 3.
Comments?
Cheers,
Simon.
On 13/03/2023 00:31, 0zl wrote:
Well, it seems like dnsmasq just ignores addresses with /32s. I see
in src/network.c for some reason if an interface has 255.255.255.255
it just skips it (line 363)?
This might possibly the cause for the issue, I'm not sure if this is
intentional or some sort of bug.
Thanks again and sorry for the noise!
On 3/13/23 02:08, 0zl wrote:
Hi everyone,
Previously on Debian Stable, I was using dynamic-host as a weird
hack to get Dnsmasq to serve my PPPOE interface's IP address however
this no longer seems to work with the Dnsmasq supplied in Debian
Testing.
It was OK to just specify 0.0.0.0 as my ISP would allocate for me a
/32 and so this thankfully matched my interface address and worked
properly.
Now that this no longer works on 2.89, are there any alternatives I
could use?
(What no longer works is
`dynamic-host=myip.my.local.domain,0.0.0.0,dsl-provider` and Dnsmasq
fails with `warning: no addresses found for interface dsl-provider`)
TIA
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