From owner-freebsd-virtualization@freebsd.org Fri May 25 08:05:16 2018 Return-Path: Delivered-To: freebsd-virtualization@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 7FD7EF759AF for ; Fri, 25 May 2018 08:05:16 +0000 (UTC) (envelope-from danny@cs.huji.ac.il) Received: from kabab.cs.huji.ac.il (kabab.cs.huji.ac.il [132.65.116.210]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 0410A774F9 for ; Fri, 25 May 2018 08:05:15 +0000 (UTC) (envelope-from danny@cs.huji.ac.il) Received: from bach.cs.huji.ac.il ([132.65.80.20]) by kabab.cs.huji.ac.il with esmtp id 1fM7io-000KIm-7L; Fri, 25 May 2018 11:05:10 +0300 Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 11.3 \(3445.6.18\)) Subject: Re: bhyve client: who is hosting me? From: Daniel Braniss In-Reply-To: Date: Fri, 25 May 2018 11:05:09 +0300 Cc: freebsd-virtualization@freebsd.org Content-Transfer-Encoding: quoted-printable Message-Id: <8B1DEC42-1B40-4957-AEB6-2D9BA019287F@cs.huji.ac.il> References: <49FCEBE6-5551-42C1-8A9F-5F84ECAD0581@cs.huji.ac.il> To: Darius Mihai X-Mailer: Apple Mail (2.3445.6.18) X-BeenThere: freebsd-virtualization@freebsd.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: "Discussion of various virtualization techniques FreeBSD supports." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 25 May 2018 08:05:16 -0000 > On 25 May 2018, at 10:02, Darius Mihai wrote: >=20 > On Fri, May 25, 2018 at 9:08 AM Daniel Braniss = wrote: >=20 >> Hi, >> I=E2=80=99m trying out bhyve with different setups, but mailny = FreeBSD (11.2 and > 12), and >> was wondering if there is any way for the client to know who is = hosting > it? >=20 >> thanks, >> danny >=20 > Hi, >=20 > What do you mean 'knowing who is hosting it?' > If you mean obtaining information such as IP address or hostname of = the > host from inside the guest operating system, it should not be possible = and > is likely a security flaw if it were allowed by default. ok, so not by default, but is there a way? i don=E2=80=99t know why this is a security flaw - maybe security by = obscurity? in any case since the client knows that it=E2=80=99s running as a bhive client, = (hw.hv_vendor), again, if this is also a security flaw, it could be set/reset when the client is = being configured? thanks, danny =20 >=20 > Operating systems should ideally be unable to determine even that the > system is a virtual machine instead of a hardware based host; however = since > bhyve uses VirtIO devices and other virtualization mechanisms due to > performance issues you are indeed able to determine that the OS is = running > in a virtual machine. More specific information should be impossible = to > obtain if not injected by the host (e.g., running a web server on the = host > with some information, adding a virtual block device with a = configuration > file, and so on). >=20 > Darius >=20 >> _______________________________________________ >> freebsd-virtualization@freebsd.org mailing list >> https://lists.freebsd.org/mailman/listinfo/freebsd-virtualization >> To unsubscribe, send any mail to " > freebsd-virtualization-unsubscribe@freebsd.org"