From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/4305 Path: news.gmane.org!not-for-mail From: Rich Felker Newsgroups: gmane.linux.lib.musl.general Subject: Re: IPv4 and IPv6 addresses in resolv.conf Date: Fri, 29 Nov 2013 22:59:13 -0500 Message-ID: <20131130035912.GP24286@brightrain.aerifal.cx> References: <761df492-c2ee-41d5-84f8-faef313164bf@email.android.com> <20131129174410.GD24286@brightrain.aerifal.cx> <20131130003704.GL24286@brightrain.aerifal.cx> <20131130031744.GM24286@brightrain.aerifal.cx> <20131130035116.GO24286@brightrain.aerifal.cx> Reply-To: musl@lists.openwall.com NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1385783959 25068 80.91.229.3 (30 Nov 2013 03:59:19 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 30 Nov 2013 03:59:19 +0000 (UTC) To: musl@lists.openwall.com Original-X-From: musl-return-4309-gllmg-musl=m.gmane.org@lists.openwall.com Sat Nov 30 04:59:25 2013 Return-path: Envelope-to: gllmg-musl@plane.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by plane.gmane.org with smtp (Exim 4.69) (envelope-from ) id 1VmbiH-0006NO-Kr for gllmg-musl@plane.gmane.org; Sat, 30 Nov 2013 04:59:25 +0100 Original-Received: (qmail 13975 invoked by uid 550); 30 Nov 2013 03:59:25 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: Original-Received: (qmail 13964 invoked from network); 30 Nov 2013 03:59:24 -0000 Content-Disposition: inline In-Reply-To: <20131130035116.GO24286@brightrain.aerifal.cx> User-Agent: Mutt/1.5.21 (2010-09-15) Xref: news.gmane.org gmane.linux.lib.musl.general:4305 Archived-At: On Fri, Nov 29, 2013 at 10:51:16PM -0500, Rich Felker wrote: > On Fri, Nov 29, 2013 at 10:45:26PM -0500, Strake wrote: > > On 29/11/2013, Rich Felker wrote: > > > But that would mean complete unconditional DNS failure on systems > > > lacking IPv6. > > > > We could do so iff system has IPv6. Switching on whether system has > > IPv6 rather than whether resolv.conf has any IPv6 nameservers means > > * no check whether resolv.conf includes v6 server > > * that adding a v6 server to resolv.conf can not break DNS even on > > systems lacking v6 > > which seems saner. > > OK, so how do we detect if the system "has IPv6"? I don't think it's BTW, short of an answer to this question, I think the approach I already suggested is rather safe. I can't imagine how an IPv6 nameserver address would end up in resolv.conf on a system completely lacking IPv6 support at the kernel level. Rich