Return-Path: X-Original-To: apps-discuss@ietfa.amsl.com Delivered-To: apps-discuss@ietfa.amsl.com Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 3FAE112D0A7 for ; Sun, 28 Aug 2016 16:22:17 -0700 (PDT) X-Virus-Scanned: amavisd-new at amsl.com X-Spam-Flag: NO X-Spam-Score: -2.347 X-Spam-Level: X-Spam-Status: No, score=-2.347 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FORGED_FROMDOMAIN=0.001, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.001, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_LOW=-0.7, SPF_PASS=-0.001] autolearn=ham autolearn_force=no Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id qtxWtmjlQTuD for ; Sun, 28 Aug 2016 16:22:15 -0700 (PDT) Received: from mail-it0-x232.google.com (mail-it0-x232.google.com [IPv6:2607:f8b0:4001:c0b::232]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 4F57012B01A for ; Sun, 28 Aug 2016 16:22:15 -0700 (PDT) Received: by mail-it0-x232.google.com with SMTP id x131so77722234ite.0 for ; Sun, 28 Aug 2016 16:22:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc; bh=afub5+z49J8FqQJzYfhkxeoNqV6uJBK9e6xGQVU2W7A=; b=YUINBQ0XarwZAkscTcfRKPkfAiypBTUCdxQspS+c4wDva6Hiyh8iI8NqNFWUOM7mbA bO4rgzc2kplnRqxncrenIZoqjE3g/M/XA82mLQ2zD48Xc5ZPHrXrJEzc8DfeSW5W3C1w eWYvQq9/agg6N1wmt84vmJTfbcdzQZyliUAau3qTLR12KKOiB4QHWP6jXSwe4TRbn5EB S16+yAmnoOZyw4Ns2DwfM093jR3v8tAS8n0Km5McACNr/zSa925SKIq/n8dyNicsXfin LlvZJUqVb7OvD9vT2qq1bTPFmYzaSLzOcLBRqmI42DLTlgW04mo/kbbc5YTo3WZRjFjm 7D9A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:cc; bh=afub5+z49J8FqQJzYfhkxeoNqV6uJBK9e6xGQVU2W7A=; b=Jrz1SagL7ChosHQQ0a7rEqYMnVDN9RTK5ofXbw4K4PdxC1HN0hLYgY6CANxDGD0Qxt k5QRP1tF4dJuuT/5Z1ohaZ0ZceENBRLRnUJQ0hJtfQnRGhABSuLGLOGK+mWmZGRSQC12 fQo+n2PHeSjaqU+0v3BOFwxH2Z7WJ9kWVZiNVyIRgAGAPKLAy8vkwoqB1GoD5xfV3lij eyWsyRq4v2XiZGGu7bdh5bFnW3xQz4cMlxy/2th6LSR/VQ3CoeAvRd+0HVUGrOQAGnFD ELWZThGrrrdhQNlNz7uB4xYYGOJnn+kpUWXr2coRRVxKb3w5Y921iMHzS4Ie/qF4i3XJ p57Q== X-Gm-Message-State: AE9vXwNASyq43xvQ6ymPRBDAiChMNchcvBLP9PW2+jnEavdUcHEIpGMw5CCNyP+iU2hqPAR3fDtgiEbSobVS6w== X-Received: by 10.36.102.194 with SMTP id k185mr11577683itc.45.1472426534619; Sun, 28 Aug 2016 16:22:14 -0700 (PDT) MIME-Version: 1.0 Sender: phluid61@gmail.com Received: by 10.107.158.207 with HTTP; Sun, 28 Aug 2016 16:22:13 -0700 (PDT) In-Reply-To: <399542882.4083761472419322679.JavaMail.httpd@webmail-56.iol.local> References: <399542882.4083761472419322679.JavaMail.httpd@webmail-56.iol.local> From: Matthew Kerwin Date: Mon, 29 Aug 2016 09:22:13 +1000 X-Google-Sender-Auth: nVmcymj1nZE2327TP4D4xrcB6zE Message-ID: To: "luigipinca@libero.it" Content-Type: multipart/alternative; boundary=001a1147ab448dd1f8053b2a047e Archived-At: Cc: Julian Reschke , IETF Apps Discuss Subject: Re: [apps-discuss] R: Re: Question about RFC 7239 X-BeenThere: apps-discuss@ietf.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: General discussion of application-layer protocols List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 28 Aug 2016 23:22:17 -0000 --001a1147ab448dd1f8053b2a047e Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 29 August 2016 at 07:22, luigipinca@libero.it wrote: > Thank you Julian but I still don't fully get it. > According to the #rule extension as shown in your link, > > "foo , ,bar," > > is a valid value, so I assume that in our case > > "; , ," > > is also a valid value as forwarded-element is defined like this > > forwarded-element =3D [ forwarded-pair ] *( ";" [ forwarded-pair ] ) > > =E2=80=8BThe words in RFC 7230 say a lot more than the ABNF does. If you're concerned about the parser you should accept "a reasonable number of empty list elements"; but if you're generating headers you "MUST NOT generate empty list elements." The question, then, is whether ";" is a valid forwarded-element. I believe the intention was to make Forwarded be a list of lists, where the outer list (joined by commas) is as defined in RFC 7230, and the inner list (joined by semicolons) has the same semantics for ignoring a reasonable number of empty elements. To that end, within a single forwarded-element, this might be acceptable: " ;for=3D1.2.3.4;;proto=3Dhttp;" (Although I think you probably shouldn't generate such a value.) That said, that's only my reading. If it's the case, I suspect maybe it wasn't made clear enough in RFC 7239. > My main concern is actually on this definition. Why is forwarded-pair > optional? > > Regards, > > Luigi > =E2=80=8BCheers=E2=80=8B --=20 Matthew Kerwin http://matthew.kerwin.net.au/ --001a1147ab448dd1f8053b2a047e Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable


On 29 August 2016 at 07:22, luigipinca@libero.it <luigipinca@libero.it> wrote:
Thank you Ju= lian but I still don't fully get it.
According to the #rule extension as shown in your link,

"foo , ,bar,"

is a valid value, so I assume that in our case

"; , ,"

is also a valid value as forwarded-element is defined like this

forwarded-element =3D [ forwarded-pair ] *( ";" [ forwarded-pair = ] )


=E2=80=8BThe wor= ds in RFC 7230 say a lot more than the ABNF does. If you're concerned a= bout the parser you should accept "a reasonable number of empty list e= lements"; but if you're generating headers you "MUST NOT gene= rate empty list elements." The question, then, is whether ";" is a valid <= font style=3D"color:rgb(7,55,99)" face=3D"monospace, monospace">forwarded-e= lement.

I believe the intention was to make = Forwarded be a list of lists, where the outer list (joined by commas) is as= defined in RFC 7230, and the inner list (joined by semicolons) has the sam= e semantics for ignoring a reasonable number of empty elements.

To that end, within a single forwarded-element,= this might be acceptable: ";for=3D1.2.3.4;;proto=3Dhttp;" (Although I think you probabl= y shouldn't generate such a value.)

That said, that's only my reading. If it's the case, I suspect= maybe it wasn't made clear enough in RFC 7239.

=C2= =A0
My main concern is actually on this definition. Why is forwarded-pai= r
optional?

Regards,

Luigi

=E2=80=8BCheers=E2= =80=8B
--
=C2=A0 Matthew Kerwin
=C2=A0 http://matthew.kerwin.net= .au/
--001a1147ab448dd1f8053b2a047e--