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

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

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.

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

Sincerely,

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