Re: [quicwg/base-drafts] Invariant independent (#3684)

Jana Iyengar <notifications@github.com> Mon, 25 May 2020 22:06 UTC

Return-Path: <noreply@github.com>
X-Original-To: quic-issues@ietfa.amsl.com
Delivered-To: quic-issues@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id D7CB33A0A9B for <quic-issues@ietfa.amsl.com>; Mon, 25 May 2020 15:06:29 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.482
X-Spam-Level:
X-Spam-Status: No, score=-1.482 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, HTML_IMAGE_ONLY_24=1.618, HTML_MESSAGE=0.001, MAILING_LIST_MULTI=-1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=github.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 81ay7CR7j2mK for <quic-issues@ietfa.amsl.com>; Mon, 25 May 2020 15:06:27 -0700 (PDT)
Received: from out-16.smtp.github.com (out-16.smtp.github.com [192.30.254.199]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id A0AA13A0A92 for <quic-issues@ietf.org>; Mon, 25 May 2020 15:06:27 -0700 (PDT)
Received: from github-lowworker-c53a806.ac4-iad.github.net (github-lowworker-c53a806.ac4-iad.github.net [10.52.23.45]) by smtp.github.com (Postfix) with ESMTP id 7B898120350 for <quic-issues@ietf.org>; Mon, 25 May 2020 15:06:26 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=github.com; s=pf2014; t=1590444386; bh=L5iHbm2jBDVH1p6WsFw4T7twe2joqlyuqC5+p37wyE4=; h=Date:From:Reply-To:To:Cc:In-Reply-To:References:Subject:List-ID: List-Archive:List-Post:List-Unsubscribe:From; b=Q5eZE5audM9QKbPdtu0fmDaP0LPApWuLxVFq3Xq17eO+MBDV4RGqbvhrBRyZJJaI3 yIIhY3IbM5eqPvfWplIfn2Ds0RpJ/zUj7W+eOGmi/c3L2zg7AXUG8d85B+jWp9JVaT /PCEYzqg6HS54cS4ZZHx+JHrdjszWmtHaP1B6vMA=
Date: Mon, 25 May 2020 15:06:26 -0700
From: Jana Iyengar <notifications@github.com>
Reply-To: quicwg/base-drafts <reply+AFTOJK242UOMA7E7CB7VH5F43ARGFEVBNHHCKIHBQM@reply.github.com>
To: quicwg/base-drafts <base-drafts@noreply.github.com>
Cc: Subscribed <subscribed@noreply.github.com>
Message-ID: <quicwg/base-drafts/pull/3684/review/417887509@github.com>
In-Reply-To: <quicwg/base-drafts/pull/3684@github.com>
References: <quicwg/base-drafts/pull/3684@github.com>
Subject: Re: [quicwg/base-drafts] Invariant independent (#3684)
Mime-Version: 1.0
Content-Type: multipart/alternative; boundary="--==_mimepart_5ecc416235002_23193f96b00cd95c663884"; charset="UTF-8"
Content-Transfer-Encoding: 7bit
Precedence: list
X-GitHub-Sender: janaiyengar
X-GitHub-Recipient: quic-issues
X-GitHub-Reason: subscribed
X-Auto-Response-Suppress: All
X-GitHub-Recipient-Address: quic-issues@ietf.org
Archived-At: <https://mailarchive.ietf.org/arch/msg/quic-issues/9aCHml1eg-oefgKQnWFcc0S7u-E>
X-BeenThere: quic-issues@ietf.org
X-Mailman-Version: 2.1.29
List-Id: Notification list for GitHub issues related to the QUIC WG <quic-issues.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/quic-issues>, <mailto:quic-issues-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/quic-issues/>
List-Post: <mailto:quic-issues@ietf.org>
List-Help: <mailto:quic-issues-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/quic-issues>, <mailto:quic-issues-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 25 May 2020 22:06:30 -0000

@janaiyengar commented on this pull request.



>  # QUIC Packet Headers
 
-A QUIC packet is the content of the UDP datagrams exchanged by QUIC endpoints.
-This document describes the contents of those datagrams.
+QUIC endpoints exchange UDP datagrams that contain one or more QUIC packets.
+This section describes the invariant characteristics of a QUIC packet.  A
+version of QUIC could permit multiple QUIC packets in a single UDP datagram, but
+the invariant properties only describe the first packet in a datagram.

I think it's a design change. I think this allows for some freedom in the future on the part of endhost stack developers, so I like it, but I'm not sure I can simply justify it with that rationale.

That said, the way I read it, a new version of QUIC _could_ have a packet_len field, but the following packet within the same dgram is then not guaranteed to follow the invariants. This seems to deviate from the previous simple model about packets. Why can this not apply to all packets, even if it cannot be enforced?

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/quicwg/base-drafts/pull/3684#pullrequestreview-417887509