Re: WGLC: p2 MUSTs

"Roy T. Fielding" <fielding@gbiv.com> Sun, 04 August 2013 01:50 UTC

Return-Path: <ietf-http-wg-request@listhub.w3.org>
X-Original-To: ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com
Delivered-To: ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 248BC21F995B for <ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com>; Sat, 3 Aug 2013 18:50:44 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -10.349
X-Spam-Level:
X-Spam-Status: No, score=-10.349 tagged_above=-999 required=5 tests=[AWL=0.250, BAYES_00=-2.599, RCVD_IN_DNSWL_HI=-8]
Received: from mail.ietf.org ([12.22.58.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id o0OpUuuT0OHg for <ietfarch-httpbisa-archive-bis2Juki@ietfa.amsl.com>; Sat, 3 Aug 2013 18:50:32 -0700 (PDT)
Received: from frink.w3.org (frink.w3.org [128.30.52.56]) by ietfa.amsl.com (Postfix) with ESMTP id 4E30021E8084 for <httpbisa-archive-bis2Juki@lists.ietf.org>; Sat, 3 Aug 2013 18:50:31 -0700 (PDT)
Received: from lists by frink.w3.org with local (Exim 4.72) (envelope-from <ietf-http-wg-request@listhub.w3.org>) id 1V5nRM-0002ha-NP for ietf-http-wg-dist@listhub.w3.org; Sun, 04 Aug 2013 01:49:00 +0000
Resent-Date: Sun, 04 Aug 2013 01:49:00 +0000
Resent-Message-Id: <E1V5nRM-0002ha-NP@frink.w3.org>
Received: from lisa.w3.org ([128.30.52.41]) by frink.w3.org with esmtp (Exim 4.72) (envelope-from <fielding@gbiv.com>) id 1V5nR9-0002gj-42 for ietf-http-wg@listhub.w3.org; Sun, 04 Aug 2013 01:48:47 +0000
Received: from caiajhbdcagg.dreamhost.com ([208.97.132.66] helo=homiemail-a71.g.dreamhost.com) by lisa.w3.org with esmtp (Exim 4.72) (envelope-from <fielding@gbiv.com>) id 1V5nR7-0002iV-LQ for ietf-http-wg@w3.org; Sun, 04 Aug 2013 01:48:46 +0000
Received: from homiemail-a71.g.dreamhost.com (localhost [127.0.0.1]) by homiemail-a71.g.dreamhost.com (Postfix) with ESMTP id 10E48428076; Sat, 3 Aug 2013 18:48:24 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=gbiv.com; h=subject :mime-version:content-type:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; s=gbiv.com; bh=DNvN/4UWsQBT1zy2f6sqHmbK+N8=; b=5liipSZp7rkn1nk7GZw0pA3ylncQ YZ2fj1wa7Tn3CV5cCVPhrIXDB7nQXvZK7KVa5qBgU8esIsdo0fcAKCEjudYT9Yy0 Gr+HBJAgZQSw1Gig/eS4OBqU7zA9yYV5MXv5fBE+RClOS04RiW7SIXyCNpINSnwB Ysf+GHCP3Blxwrg=
Received: from [192.168.1.84] (99-21-208-82.lightspeed.irvnca.sbcglobal.net [99.21.208.82]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) (Authenticated sender: fielding@gbiv.com) by homiemail-a71.g.dreamhost.com (Postfix) with ESMTPSA id CDD44428075; Sat, 3 Aug 2013 18:48:23 -0700 (PDT)
Mime-Version: 1.0 (Apple Message framework v1283)
Content-Type: text/plain; charset=windows-1252
From: "Roy T. Fielding" <fielding@gbiv.com>
In-Reply-To: <51802D89.6000001@measurement-factory.com>
Date: Sat, 3 Aug 2013 18:48:22 -0700
Cc: IETF HTTP WG <ietf-http-wg@w3.org>
Content-Transfer-Encoding: quoted-printable
Message-Id: <6DAAF751-4C18-4A71-AD54-B8338B9B1B47@gbiv.com>
References: <D69329FD-7456-46C5-BE24-6E7EE7E48C39@mnot.net> <51802D89.6000001@measurement-factory.com>
To: Alex Rousskov <rousskov@measurement-factory.com>
X-Mailer: Apple Mail (2.1283)
Received-SPF: none client-ip=208.97.132.66; envelope-from=fielding@gbiv.com; helo=homiemail-a71.g.dreamhost.com
X-W3C-Hub-Spam-Status: No, score=-0.1
X-W3C-Hub-Spam-Report: DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_NONE=-0.0001
X-W3C-Scan-Sig: lisa.w3.org 1V5nR7-0002iV-LQ 763740c5cbd8b35497fb8eda96489e41
X-Original-To: ietf-http-wg@w3.org
Subject: Re: WGLC: p2 MUSTs
Archived-At: <http://www.w3.org/mid/6DAAF751-4C18-4A71-AD54-B8338B9B1B47@gbiv.com>
Resent-From: ietf-http-wg@w3.org
X-Mailing-List: <ietf-http-wg@w3.org> archive/latest/19050
X-Loop: ietf-http-wg@w3.org
Resent-Sender: ietf-http-wg-request@w3.org
Precedence: list
List-Id: <ietf-http-wg.w3.org>
List-Help: <http://www.w3.org/Mail/>
List-Post: <mailto:ietf-http-wg@w3.org>
List-Unsubscribe: <mailto:ietf-http-wg-request@w3.org?subject=unsubscribe>

On Apr 30, 2013, at 1:46 PM, Alex Rousskov wrote:

>> The CONNECT method requests that the recipient establish a tunnel to
>> the destination origin server [...], until the connection is closed.
> 
> The "until the connection is closed" part is misleading and inaccurate.
> 
> There are two connections in a CONNECT tunnel: (a) between a CONNECT
> sender and CONNECT recipient and (2) between CONNECT recipient the the
> next HTTP hop. The tunnel termination condition is rather complex and is
> detailed later in the same section. It may be a good idea to drop the
> "until..." part. At least I cannot suggest a way to describe it
> correctly as an ending of an already long sentence :-).

Changed to "until the tunnel is closed".

>> When a tunnel intermediary detects that either side has closed its
>> connection, any outstanding data that came from that side will first
>> be sent to the other side and then the intermediary will close both
>> connections. If there is outstanding data left undelivered, that data
>> will be discarded.
> 
> These "will"s should be rephrased as intermediary MUSTs IMO. I also
> suggest moving them higher, before the informal risk discussion.

Moved, fixed, and rephrased to "A tunnel is closed when ..."

>> A client MUST NOT send header fields in a TRACE request containing
>> sensitive data
> 
> The above rule seems too onerous to proxies. Replace "MUST NOT send"
> with "MUST NOT generate"?

Fixed.

>> 5.1.1.1 Use of the 100 (Continue) Status
>> Requirements for HTTP/1.1 clients:
>> ...
>> Requirements for HTTP/1.1 proxies:
> 
> Should we explicitly exclude proxies from the first group of
> requirements by saying "Requirements for user agents" instead of
> "Requirements for clients"?

No, the first set applies to proxies that want to use 100-continue
for their own reasons.

>> MUST contain an updated Max-Forwards field with a value decremented by one (1).
> 
> A lot of proxies violate this MUST because they cannot grok and, hence,
> cannot decrement large integer values. Interoperability problems might
> happen when a client generates Max-Forwards with a maximum value it can
> store (e.g., to count the number of hops to the origin server) but the
> proxy cannot store such a large value (e.g., 64bit vs 32bit).
> 
> Perhaps we can relax this rule by allowing proxies to decrement by "at
> least one", so that a huge value can be replaced with the maximum value
> the proxy can represent?

Changed to

  If the received Max-Forwards value is greater than zero,
  the intermediary MUST generate an updated Max-Forwards field
  in the forwarded message with a field-value that is the lesser of:
  a) the received value decremented by one (1), or
  b) the recipient's maximum supported value for Max-Forwards.

>> A client MUST be prepared to accept one or more 1xx
> 
> Drop "be prepared" to demand acceptance rather than preparedness?

Fixed in prior commit.

>> Proxies MUST forward 1xx responses, unless the connection between the
>> proxy and its client has been closed,
> 
> This "unless" clause should be dropped as implied. Otherwise, we would
> have to add it to every "MUST forward" requirement! :-)

Fixed.

>> A sender MUST generate the IMF-fixdate format when sending an
>> HTTP-date value in a header field.
> 
> Please polish to remove the implication that proxies must fix dates when
> forwarding HTTP-date values. For example: "A sender MUST use the
> IMF-fixdate format when generating a header field containing an
> HTTP-date value".
> 
> Or perhaps simply: "A sender MUST generate HTTP-date values in the
> IMF-fixdate format".

Fixed.

> And here is a list of requirements that are missing an explicit actor on
> which the requirement is placed. Most of these should be easy to
> rephrase to place the requirement on the intended actor (e.g., "A proxy
> MUST" instead of "header field MUST":
> 
>> the content codings MUST be listed in the order in which they were applied

Fixed.

>> then the resource MUST disable or disallow that action

resource owner

>> The Expect header field MUST be forwarded

Fixed.

>> the forwarded message MUST contain an updated Max-Forwards field

Fixed above.

>> The Max-Forwards header field MAY be ignored for all other request methods. 

Fixed.

>> a response with an unrecognized status code MUST NOT be cached.

Fixed.

Committed in
  http://trac.tools.ietf.org/wg/httpbis/trac/changeset/2342

....Roy