X-Recipient: archive-cygwin@delorie.com
X-Original-To: cygwin@cygwin.com
Delivered-To: cygwin@cygwin.com
DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org E98753858CDB
Authentication-Results: sourceware.org;
 dmarc=none (p=none dis=none) header.from=dinwoodie.org
Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=dinwoodie.org
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
 d=dinwoodie.org; s=google;
 h=content-transfer-encoding:to:subject:message-id:date:from
 :in-reply-to:references:mime-version:from:to:cc:subject:date
 :message-id:reply-to;
 bh=0SdeXwIt9sQwzOxRtHEO2vAnH4peuLxLvPByXbfZlsg=;
 b=gZvZvgL/zX9Q04IdKaqe+L8WRjlDKGkPvECh2eIAxWl+SfwV5BD7uCFH5ZjngTybWn
 bMhTzOhhKK0xMkXVZIB4ATAy4DvuUJPaRsLWmTXPbUc1O+n2ZWPhf/n5+kVkDlV6pEp0
 05wgQDl+iZbxbkPJQKFoU3I8KcAEYwz9MqKQg=
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
 d=1e100.net; s=20210112;
 h=content-transfer-encoding:to:subject:message-id:date:from
 :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc
 :subject:date:message-id:reply-to;
 bh=0SdeXwIt9sQwzOxRtHEO2vAnH4peuLxLvPByXbfZlsg=;
 b=FRDpNZs582ec62kd/ta/mM0jUxBw+TKErwnUzbmftXR+KjRkYqDg3KiUSZxdNYIQeV
 LAhGGxXCmcQsmz837eXBKLpDgyco4WxJDQ7n+K+/HTwWBW290HGwv/WAGR3k1a856Prx
 4AhvwSdw/fHiHPqz/gkfYWrsmGZMeIo9c3gjdubL5uLhorXzwuTqdScvVOfBAXC4CuOz
 pZ/WxgURlDL+5jE4P7QoX5VEZ60W77CLPxjJeiKqZSCyOCsvFn924d0jrf3PaknUsaiC
 r/aW2RfAetR2RsN9yqVRP/1sRSGg32XdKlEvZLvD+j8SQGvLhx2yLdBLHm4hb2dM6ih2
 DiKg==
X-Gm-Message-State: ACrzQf3A56CG89v686QVtX7AfftjGFgV08rK8LaeGwpV9X9NS8enPAj/
 rqyZAma9jEFtYFIQfpwXzydffUUKjLjAgcfhhJnPUb/fmEw=
X-Google-Smtp-Source: AMsMyM5YAKxJMx4xz/pZNkoQgQvhF4jVughNEsv7AdhdcT16N5zQLiCW0kN0xmdc0pQ4O5B/tZLafTeZbdjed34gVDw=
X-Received: by 2002:a05:6870:c391:b0:10c:a937:aaf1 with SMTP id
 g17-20020a056870c39100b0010ca937aaf1mr5071344oao.272.1665235215207; Sat, 08
 Oct 2022 06:20:15 -0700 (PDT)
MIME-Version: 1.0
References: <BY5PR10MB418011A882FE4A6C4433BCD2FF5C9@BY5PR10MB4180.namprd10.prod.outlook.com>
In-Reply-To: <BY5PR10MB418011A882FE4A6C4433BCD2FF5C9@BY5PR10MB4180.namprd10.prod.outlook.com>
From: Adam Dinwoodie <adam@dinwoodie.org>
Date: Sat, 8 Oct 2022 14:19:41 +0100
Message-ID: <CA+kUOamq5aidTFqeA2N=y72486_JZZdfmPaUytQcKR25UK80FA@mail.gmail.com>
Subject: Re: Feature request: File descriptor support by sockets.
To: "cygwin@cygwin.com" <cygwin@cygwin.com>
X-Spam-Status: No, score=-0.2 required=5.0 tests=BAYES_00, DKIM_SIGNED,
 DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,
 SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
 server2.sourceware.org
X-BeenThere: cygwin@cygwin.com
X-Mailman-Version: 2.1.29
List-Id: General Cygwin discussions and problem reports <cygwin.cygwin.com>
List-Archive: <https://cygwin.com/pipermail/cygwin/>
List-Post: <mailto:cygwin@cygwin.com>
List-Help: <mailto:cygwin-request@cygwin.com?subject=help>
List-Subscribe: <https://cygwin.com/mailman/listinfo/cygwin>,
 <mailto:cygwin-request@cygwin.com?subject=subscribe>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Sender: "Cygwin" <cygwin-bounces+archive-cygwin=delorie.com@cygwin.com>

On Thu, 6 Oct 2022 at 18:37, Darren Whobrey wrote:
>
> Hi, I'm using the latest version of Cygwin (3.3.6) and the Cygwin OpenSSH (OpenSSH_9.0p1, OpenSSL 1.1.1q  5 Jul 2022) version of ssh to talk to hosts using ControlMaster connection sharing. This uses sockets behind the scenes. When ControlMaster is set to no, the connection is successful.
>
> Ssh connections are failing at the point where IO starts to be forwarded to the host.
>
> Here's a snippet of log output from "ssh -vvv some-host":
>
> <snip>
>
> When successful connections are made from an OL7 client (with older version of OpenSSH, but mux commands are similar), comparative logs are:
>
> <snip>
>
> According to this web posting, it suggests the bug lies with "file descriptors over unix sockets do not work in Cygwin":
> https://exchangetuts.com/is-ssh-controlmaster-with-cygwin-on-windows-actually-possible-1639696447917488
>
> Is this something that can be fixed?

I'm very confident it *can* be fixed! But this gap has existed since
at least 2009 (see
https://cygwin.com/pipermail/cygwin/2012-February/199995.html and
https://sourceware.org/legacy-ml/cygwin/2009-10/msg00397.html) so I
suspect that, unless you're proposing to do the work or pay someone to
do it on your behalf, it's unlikely to happen any time soon.

-- 
Problem reports:      https://cygwin.com/problems.html
FAQ:                  https://cygwin.com/faq/
Documentation:        https://cygwin.com/docs.html
Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple