Re: lib/42405: libc: getaddrinfo() should perform T_A lookups before T_AAAA lookups, was: Resolver problems

[Hajimu UMEMOTO <ume%mahoroba.org@localhost>]

Hi,

>>> Sat, 05 Dec 2009 02:56:01 +0900 の刻に「ume」、すなわち
>>> Hajimu UMEMOTO <ume%mahoroba.org@localhost> 氏曰く

ume> Hi,

>>>>> On Fri, 4 Dec 2009 17:26:54 +0000
>>>>> Matthias Scheler <tron%zhadum.org.uk@localhost> said:

tron> I'm sorry but I don't understand how would this help in this case? The
tron> problem was that the AAAA query resulted in a timeout because of the
tron> broken DNS server of the router. The FreeBSD solution would still be
tron> affected by that timeout because it does send an AAAA query after all.

ume> Ah, I might not understand the problem correctly.  You are correct.
ume> It helps for SERVFAIL against AAAA query in some case.  But, it
ume> doesn't help for the timeout against AAAA query.
ume> The KAME's getaddrinfo(3) has the workaround for this issue.  Query A
ume> 1st then query AAAA.  And, if got A, query AAAA with shorten timeout.
ume> AFAIK, Windows Vista does this manner as well.

Oops. s/SERVFAIL/NXDOMAIN/

Sincerely,

--
Hajimu UMEMOTO @ Internet Mutual Aid Society Yokohama, Japan
ume%mahoroba.org@localhost  ume@{,jp.}FreeBSD.org
http://www.imasy.org/~ume/