[RESOLVED] Re: Strange resolver behavior

[Stefan Lambrev]

Greetings,

Xin LI wrote:
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> JINMEI Tatuya / 神明達哉 wrote:
> [snip]
>
> At the beginning I was confused with host(1) and resolver library, they
> are different problems, sorry for the confusion.
>
> I think Hajimu-san's analysis was correct that it was caused by the
> check in resolver, here is a ktrace output from a system without patched
> libc:
>
> http://www.delphij.net/kdump.txt
>
> Note that, with a patched (with ume@'s patch) resolver, the program
> *does* worked as expected, also this will make firefox to be able to
> resolve the domain name.
>
> Test program can be downloaded from http://www.delphij.net/test.c .
> With patched libc you will get no output (expected), and with unpatched
> libc you will get "Unknown server error" and will be unable to get the A RR.
>
> It turns out that the baidu.com DNS administrator might be unaware of
> the potential violation of RFC 952 "ASSUMPTIONS" and RFC 1034 Section
> 3.5.  However, I am afraid that there are some DNS server
> implementations that does allow '_'s in domain names, so if there is no
> potential risks allowing it from the resolver side I think it might be a
> good idea to be more permissive for this case, because there are real
> uses of it, and other operating systems does allow it at the client side.
>   
Did you check http://tools.ietf.org/html/rfc2782 ?
It is "PROPOSED STANDARD" and MS DNS in Win2003 already uses it (if you 
have domain controller for example).

-- 

Best Wishes,
Stefan Lambrev
ICQ# 24134177