Re: [ftpext] End byte of transfer in FTP

Daniel Stenberg <daniel@haxx.se> Wed, 01 December 2010 19:01 UTC

Return-Path: <daniel@haxx.se>
X-Original-To: ftpext@core3.amsl.com
Delivered-To: ftpext@core3.amsl.com
Received: from localhost (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id 57A713A6C29 for <ftpext@core3.amsl.com>; Wed, 1 Dec 2010 11:01:38 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.282
X-Spam-Level:
X-Spam-Status: No, score=-2.282 tagged_above=-999 required=5 tests=[AWL=-0.633, BAYES_00=-2.599, HELO_EQ_SE=0.35, J_CHICKENPOX_101=0.6]
Received: from mail.ietf.org ([64.170.98.32]) by localhost (core3.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id o0Zm941Y5dxx for <ftpext@core3.amsl.com>; Wed, 1 Dec 2010 11:01:37 -0800 (PST)
Received: from giant.haxx.se (giant.haxx.se [80.67.6.50]) by core3.amsl.com (Postfix) with ESMTP id 343553A6C20 for <ftpext@ietf.org>; Wed, 1 Dec 2010 11:01:35 -0800 (PST)
Received: from giant.haxx.se (giant.haxx.se [80.67.6.50]) by giant.haxx.se (8.14.3/8.14.3/Debian-9.1) with ESMTP id oB1J2ocF027327; Wed, 1 Dec 2010 20:02:50 +0100
Date: Wed, 01 Dec 2010 20:02:50 +0100
From: Daniel Stenberg <daniel@haxx.se>
X-X-Sender: dast@giant.haxx.se
To: Tatsuhiro Tsujikawa <tatsuhiro.t@gmail.com>
In-Reply-To: <AANLkTi=_OsGPMsC=BHtOyHzTTM5vJ1=yW9fYk_Tp1xm7@mail.gmail.com>
Message-ID: <alpine.DEB.2.00.1012011959520.21860@tvnag.unkk.fr>
References: <AANLkTi=_OsGPMsC=BHtOyHzTTM5vJ1=yW9fYk_Tp1xm7@mail.gmail.com>
User-Agent: Alpine 2.00 (DEB 1167 2008-08-23)
X-fromdanielhimself: yes
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset="US-ASCII"; format="flowed"
X-Greylist: Default is to whitelist mail, not delayed by milter-greylist-4.3.5 (giant.haxx.se [80.67.6.50]); Wed, 01 Dec 2010 20:02:50 +0100 (CET)
Cc: ftpext@ietf.org
Subject: Re: [ftpext] End byte of transfer in FTP
X-BeenThere: ftpext@ietf.org
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: <ftpext.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/listinfo/ftpext>, <mailto:ftpext-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/ftpext>
List-Post: <mailto:ftpext@ietf.org>
List-Help: <mailto:ftpext-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ftpext>, <mailto:ftpext-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 01 Dec 2010 19:01:38 -0000

On Mon, 29 Nov 2010, Tatsuhiro Tsujikawa wrote:

> Issuing ABOR command is workaround but sometimes it does not stop 
> immediately and unused bytes are transfered. Another possible workaround is 
> that just closing data connection and wait for reply from control 
> connection(I've not tested this yet).

curl does FTP range requests that way. It used to just close the transfer at 
the desired end point, and it even works fine with "most" servers while the 
remaining servers we've found requires an ABOR for the server to notice that 
the transfer was indeed closed. And after an ABOR like that, it really is hard 
to re-use the control connection safely, so this kind of "range" request 
certainly has its limitations.

-- 

  / daniel.haxx.se