Date: Wed, 13 Feb 2008 12:11:00 -0800 From: Xin LI <delphij@delphij.net> To: =?ISO-2022-JP?B?SklOTUVJIFRhdHV5YSAvIBskQj9ATEBDIzpIGyhC?= <Jinmei_Tatuya@isc.org> Cc: freebsd-net@freebsd.org, d@delphij.net, ume@FreeBSD.org Subject: [RESOLVED] Re: Strange resolver behavior Message-ID: <47B34ED4.6090302@delphij.net> In-Reply-To: <m2ejbgy81l.wl%Jinmei_Tatuya@isc.org> References: <47B2488D.70707@delphij.net> <m2ejbgy81l.wl%Jinmei_Tatuya@isc.org>
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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 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. Cheers, - -- Xin LI <delphij@delphij.net> http://www.delphij.net/ FreeBSD - The Power to Serve! -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4 (FreeBSD) iD8DBQFHs07Ui+vbBBjt66ARArTAAJ9bzw4f/tZ0LzH5QXQi9CM9nNr8egCdHprK fE6LNOaSyeGu/TadZqnF34w= =u82D -----END PGP SIGNATURE-----
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