From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/4314 Path: news.gmane.org!not-for-mail From: Rob Newsgroups: gmane.linux.lib.musl.general Subject: Re: IPv4 and IPv6 addresses in resolv.conf Date: Sat, 30 Nov 2013 17:33:35 +0000 (GMT) Message-ID: References: <20131129174410.GD24286@brightrain.aerifal.cx> <20131130003704.GL24286@brightrain.aerifal.cx> <20131130031744.GM24286@brightrain.aerifal.cx> <20131130035116.GO24286@brightrain.aerifal.cx> <20131130035912.GP24286@brightrain.aerifal.cx> <20131130170112.GR24286@brightrain.aerifal.cx> <20131130173026.GS24286@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; format=flowed X-Trace: ger.gmane.org 1385832987 28492 80.91.229.3 (30 Nov 2013 17:36:27 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 30 Nov 2013 17:36:27 +0000 (UTC) To: musl@lists.openwall.com Original-X-From: musl-return-4318-gllmg-musl=m.gmane.org@lists.openwall.com Sat Nov 30 18:36:30 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 1VmoSx-00037T-EV for gllmg-musl@plane.gmane.org; Sat, 30 Nov 2013 18:36:27 +0100 Original-Received: (qmail 20330 invoked by uid 550); 30 Nov 2013 17:36:26 -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 20322 invoked from network); 30 Nov 2013 17:36:26 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=date:from:to:subject:in-reply-to:message-id:references:user-agent :mime-version:content-type; bh=Ny7wUFvkWu020//eCzteNWtViTPluh7fVJYi1699RO0=; b=KkM/tDMNyQHmtECmCeToouhdP4TmAdBflQ0Jkn2PT+qLJPXM9LgiBlhkuT0bv2/A+9 ZUP7cKQy7gFt5ZEVPzDyGfFMyMub33YQFDxVSKt/e3umblfPtX6QchURmzS4nGcU688S 8eW+JrAtIEDDr2J2eA+Nq2chZ8qAXOSz5cIX3UXmvyehb71JKeVV4sOBOGcSamNrL2m9 Ppaq+Msuxu2jDKQLXi/fhvo1chtRw96NUewvpIhfiC0wlUbwFDE1ndpqkdwqeJRDB9OT hhCjSTxNXEfAadWwbL9Q/iWdPlTX/Wak4zD8/X0k7DtQtZ76MejlA8csxIQk6J6B3KOt XiQw== X-Received: by 10.180.36.105 with SMTP id p9mr11332926wij.58.1385832975059; Sat, 30 Nov 2013 09:36:15 -0800 (PST) In-Reply-To: <20131130173026.GS24286@brightrain.aerifal.cx> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) Xref: news.gmane.org gmane.linux.lib.musl.general:4314 Archived-At: Rich Felker, Sat, 30 Nov 2013: >> >> It is EAFNOSUPPORT if no kernel support at all. >> >> Actually I don't think there can be any cases where sending to the >> v4-mapped address (ie ::ffff:1.2.3.4) can fail where an ipv4 socket >> will succeed because those are basically ipv4 sockets with just ipv6 >> notation, those addresses can't be routed by the ipv6 stack. So it > > One thing I'm confused about is the addresses on the actual packets. > If we've already called bind for address :: and gotten assigned port > N, does this also reserve port N on 0.0.0.0, which will be needed when > sending from (and receiving back) IPv4 packets? Also, is there some > kernel option we might need to worry about that prevents :: from > receiving packets sent to IPv4 addresses, or does that only apply to > TCP, not UDP? I've been seeing this output consistently from mpd at startup: listen: bind to '0.0.0.0:6600' failed: Address already in use (continuing anyway, because binding to '[::]:6600' succeeded) mpd is the only program on my machine that binds to 6600 so it would appear that :: port bindings reserve the ipv4 port too. Could be a kernel configuration option though... Rob