From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.11] helo=sc8-sf-mx1.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1AsO5V-00022y-KJ for user-mode-linux-devel@lists.sourceforge.net; Sun, 15 Feb 2004 07:21:41 -0800 Received: from mail.gmx.net ([213.165.64.20]) by sc8-sf-mx1.sourceforge.net with smtp (Exim 4.30) id 1AsO2Y-0003mm-31 for user-mode-linux-devel@lists.sourceforge.net; Sun, 15 Feb 2004 07:18:38 -0800 Message-ID: <163e01c3f3d7$c1762710$2000000a@schlepptopp> From: "roland" References: <20040122144020.GQ4203@erizo.shearer.org> <20040122162014.GA2895@ccure.user-mode-linux.org> Subject: Re: [uml-devel] Changes to port_user MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Sender: user-mode-linux-devel-admin@lists.sourceforge.net Errors-To: user-mode-linux-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: The user-mode Linux development list List-Post: List-Help: List-Subscribe: , List-Archive: Date: Sun, 15 Feb 2004 16:24:07 +0100 To: Jeff Dike , Dan Shearer Cc: user-mode-linux-devel@lists.sourceforge.net hi! > If you want to be able to telnet to the port, then you need something which > speaks telnet, hence you need telnetd. > > Now what I'm trying to do is replace in.telnetd with something else, for > > the moment netcat as a simple case, or something that gives the same > > effect. mhhh - as security oriented person i would like to admit: should such "new technology" like uml really "support" unencrypted remote logins and should it support exposing "non encrypted communication ports" to the outside world ? telnet is ancient and IMHO it should be replaced by something more secure like ssh. sshd is installed by default on all major distro`s and it has an "inetd" mode, too. maybe telnetd can easily be replaced sshd ? just my 10 eurocents.... regards roland ----- Original Message ----- From: "Jeff Dike" To: "Dan Shearer" Cc: Sent: Thursday, January 22, 2004 5:20 PM Subject: Re: [uml-devel] Changes to port_user > On Fri, Jan 23, 2004 at 01:10:20AM +1030, Dan Shearer wrote: > > I've done some minor work in drivers/port_user.c, including replacing > > the binding to INADDR_ANY with a gethostbyname(passed_ip), so you > > can specify which single IP to listen on. > > Cool, that's needed doing for a while. > > > Now what I'm trying to do is replace in.telnetd with something else, for > > the moment netcat as a simple case, or something that gives the same > > effect. > > If you want to be able to telnet to the port, then you need something which > speaks telnet, hence you need telnetd. > > If you can connect with something else and have terminal stuff continue > to work, and replace the telnetd dependency with something that works more > widely out of the box, then I'm all for it. > > > That involves understanding the significance of port_helper and > > kernel/helper.c, which I don't yet. > > What happens is that UML runs telnetd with the port helper as its "login" > program (problem - not every telnetd out there supports -L, even if it is > installed, which it often isn't). > > When there's a connection, UML gets a descriptor with the telnet on the > other end. It needs to get telnetd talking on that to do the telnet > protocol and another descriptor coming out of telnetd with actual characters > that the user typed. So, it does this as follows: > it execs telnetd with stdin, stderr, stdout duped from the portal > file descriptor > telnetd also gets a unix socket on descriptor 3 > port_helper gets the desired telnetd output descriptor on its > stdin/stdout > it passes this back to UML over the unix socket on descriptor 3 > which it inherited from telnetd > > Jeff > > > ------------------------------------------------------- > The SF.Net email is sponsored by EclipseCon 2004 > Premiere Conference on Open Tools Development and Integration > See the breadth of Eclipse activity. February 3-5 in Anaheim, CA. > http://www.eclipsecon.org/osdn > _______________________________________________ > User-mode-linux-devel mailing list > User-mode-linux-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel > ------------------------------------------------------- SF.Net is sponsored by: Speed Start Your Linux Apps Now. Build and deploy apps & Web services for Linux with a free DVD software kit from IBM. Click Now! http://ads.osdn.com/?ad_id=1356&alloc_id=3438&op=click _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel