From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0EDC2C433E1 for ; Fri, 29 May 2020 14:25:37 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D21AC20776 for ; Fri, 29 May 2020 14:25:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="avBuiXIv" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D21AC20776 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:35386 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jefx1-0003eq-Vo for qemu-devel@archiver.kernel.org; Fri, 29 May 2020 10:25:36 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:52528) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jefWa-00020d-26 for qemu-devel@nongnu.org; Fri, 29 May 2020 09:58:17 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:28457 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jefWZ-0006BJ-5t for qemu-devel@nongnu.org; Fri, 29 May 2020 09:58:15 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1590760693; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=T/x9tO4BQ7uwPwEwbV192uAZ4YFpLY/ahrULk+3N5Bw=; b=avBuiXIvNRbT8bX/eVdakc93kPwn0rnYchVrCHGZnAW6yONANh6hPGjhkJ5Uv+DI2l1ENl Ler/NWE/Bww+MRFLAE1sNopX6oJru5Uism9w4QYQy61W8gM0VqAjwsiDDI/oEXU+j+Qg54 iw/ot36IgyR39vXKxn9F/M6tsz28G7A= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-418-Edg8FJTbPtKek37W0wA_TA-1; Fri, 29 May 2020 09:58:12 -0400 X-MC-Unique: Edg8FJTbPtKek37W0wA_TA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0B705EC1A8; Fri, 29 May 2020 13:58:11 +0000 (UTC) Received: from [10.3.112.88] (ovpn-112-88.phx2.redhat.com [10.3.112.88]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 646D65D9D5; Fri, 29 May 2020 13:58:07 +0000 (UTC) Subject: Re: [Libguestfs] Provide NBD via Browser over Websockets To: =?UTF-8?Q?Daniel_P=2e_Berrang=c3=a9?= References: <20200528090443.GN7304@redhat.com> <20200529093744.GS3888@redhat.com> <13571029-5bf4-2dfa-6879-0ad2642afb3f@redhat.com> <20200529135042.GJ2755532@redhat.com> From: Eric Blake Organization: Red Hat, Inc. Message-ID: Date: Fri, 29 May 2020 08:58:06 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <20200529135042.GJ2755532@redhat.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=205.139.110.61; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/29 03:05:19 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) 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, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Eric Wheeler , QEMU , "Richard W.M. Jones" , Nir Soffer , nbd@other.debian.org, libguestfs Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 5/29/20 8:50 AM, Daniel P. Berrangé wrote: >>> (2) You need to persuade qemu's NBD client to read from a WebSocket. >>> I didn't really know anything about WebSockets until today but it >>> seems as if they are a full-duplex protocol layered on top of HTTP [a]. >>> Is there a WebSocket proxy that turns WS into plain TCP (a bit like >>> stunnel)? Google suggests [b]. >>> >>> [a] https://en.wikipedia.org/wiki/WebSocket#Protocol_handshake >>> [b] https://github.com/novnc/websockify >> >> qemu already knows how to connect as a client to websockets; Dan Berrange >> knows more about that setup. I suspect it would not be too difficult to >> teach the qemu NBD client code to use a WebSocket instead of a Unix or TCP >> socket as its data source. > > Actually the inverse. The QIOChannelWebsocket impl is only the server > side of the problem, as used by QEMU's VNC server. We've never implemented > the client side. There is nothing especially stopping us doing that - just > needs someone motivated with time to work on it. In the meantime, you may still be able to set up something like: local machine: iso -> NBD server -> Unix socket -> websockify -> WebSocket remote machine: WebSocket -> websockify -> Unix socket -> qemu NBD client Adding websocket client support into qemu would reduce the length of the chain slightly (for less data copying) by getting rid of a websockify proxy middleman, but would not necessarily improve performance (it's hard to say where the latency bottlenecks will be in the chain). -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org