From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/8749 Path: news.gmane.org!not-for-mail From: Jan Broer Newsgroups: gmane.linux.lib.musl.general Subject: Re: Re: Re: Would love to see reconsideration for domain and search Date: Fri, 23 Oct 2015 20:03:35 +0200 Message-ID: References: Reply-To: musl@lists.openwall.com NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary=001a113ed43c239a730522c96e32 X-Trace: ger.gmane.org 1445623444 32280 80.91.229.3 (23 Oct 2015 18:04:04 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 23 Oct 2015 18:04:04 +0000 (UTC) To: musl@lists.openwall.com Original-X-From: musl-return-8762-gllmg-musl=m.gmane.org@lists.openwall.com Fri Oct 23 20:03:59 2015 Return-path: Envelope-to: gllmg-musl@m.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by plane.gmane.org with smtp (Exim 4.69) (envelope-from ) id 1Zpggv-00021e-7h for gllmg-musl@m.gmane.org; Fri, 23 Oct 2015 20:03:49 +0200 Original-Received: (qmail 30224 invoked by uid 550); 23 Oct 2015 18:03:47 -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 30199 invoked from network); 23 Oct 2015 18:03:46 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=wXMYbVsTUIbDZBpCKJ8ZCgXDImfYmDSnzwzm49M8KD0=; b=1Fs7k+PUYYA5gqN/+ErqwxGctclXY2nfbpU5Of0RN2FFBR3B9pNVcoBN349RNZAjcN Ono/X90YkWaWJbDYRqf5hKXifGHA13Px6O94qm4839cgG8YUpwlyKG03FIENMDTOLcRl +6HVMEaHHCEuc4vXuAJkb2zcsZFy74X7ddqa60nnjzQ1gDtDI6RiNXnFMV+hkxhX+/I/ A3prROk9wEU1Jh32bc7spuPL31QHP5cvhKNrk2JPJRg8ASyMOpM54Brh3sWjtwPf+1Hm 7x7Mni082QRg1oVjoZPEEetqpslIs+O4d1lLkJtXyJ9rhw5BFYMTfTaBUPm+wL4EhO91 3h5w== X-Received: by 10.107.137.66 with SMTP id l63mr22918605iod.112.1445623415149; Fri, 23 Oct 2015 11:03:35 -0700 (PDT) In-Reply-To: Xref: news.gmane.org gmane.linux.lib.musl.general:8749 Archived-At: --001a113ed43c239a730522c96e32 Content-Type: text/plain; charset=UTF-8 > On Thu, Oct 22, 2015 at 10:37:53PM -0700, Tim Hockin wrote: > > I saw from a different thread that musl doesn't or didn't do TCP > > fallbacks - is that still the case? I know we need that for things > > like large multi-SRV sets (which I do not expect libc to support), and > > we have some people who have large A sets (which I do expect libc to > > support). >Indeed. The only way you can overflow the UDP size limit with the >records the stub resolver uses is with a max-length CNAME pointing to >a max or near-max length record with little or no overlap to allow for >compression. Most DNS servers are actually well able to send records greater than 512 bytes over UDP. This is part of the EDNS0 DNS extension. I think it's worth discussing to implement EDNS0 in the musl resolver. Codewise you just have to set the UDP receive buffer to the desired size and include an OPT RR in every query indicating the supported max UDP size. --001a113ed43c239a730522c96e32 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable 
> On Thu, Oct 22, 2015 at 10:37:53PM -0700, Tim Hockin wro=
te:
> > I saw from a different thread that musl doesn't or didn't=
 do TCP
> > fallbacks - is that still the case?  I know we need that for thin=
gs
> > like large multi-SRV sets (which I do not expect libc to support)=
, and
> > we have some people who have large A sets (which I do expect libc=
 to
> > support).

>Indeed. The only way you can overflow the UDP size limit with the
>records the stub resolver uses is with a max-length CNAME pointing to
>a max or near-max length record with little or no overlap to allow for
>compression.
Most DNS servers are actually well able to send records =
greater than 512 bytes over UDP. This is part of the EDNS0 DNS extension. I=
 think it's worth discussing to implement EDNS0 in the musl resolver. C=
odewise you just have to set the UDP receive buffer to the desired size and=
 include an OPT RR in every query indicating the supported max UDP size.
--001a113ed43c239a730522c96e32--