From owner-freebsd-hackers Thu Oct 5 20:15:13 1995 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.6.12/8.6.6) id UAA06762 for hackers-outgoing; Thu, 5 Oct 1995 20:15:13 -0700 Received: from chemserv.umd.edu (chemserv.umd.edu [129.2.64.40]) by freefall.freebsd.org (8.6.12/8.6.6) with ESMTP id UAA06757 for ; Thu, 5 Oct 1995 20:15:10 -0700 Received: from espresso.eng.umd.edu (espresso.eng.umd.edu [129.2.98.13]) by chemserv.umd.edu (8.7/8.7) with ESMTP id XAA24050; Thu, 5 Oct 1995 23:14:59 -0400 (EDT) Received: (chuckr@localhost) by espresso.eng.umd.edu (8.7/8.6.4) id XAA13972; Thu, 5 Oct 1995 23:14:47 -0400 (EDT) Date: Thu, 5 Oct 1995 23:14:46 -0400 (EDT) From: Chuck Robey To: Terry Lambert cc: terry@lambert.org, j@uriah.heep.sax.de, freebsd-hackers@FreeBSD.ORG Subject: Re: Fiskars UPS support... In-Reply-To: <199510060146.SAA00522@phaeton.artisoft.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-hackers@FreeBSD.ORG Precedence: bulk On Thu, 5 Oct 1995, Terry Lambert wrote: > > I wanted to do a program myself like this, but I was hung up on one > > question. Many UPSs are going to be used to monitor more than one > > machine, so such a program (it seems to me) is going to have to have a > > local monitoring part, and a remote 'I take orders' part. This thing is > > going to be on the network, then, and have the ability to shut machines > > down, directly or indirectly. How then is security controlled? > > > > It's not too tough a problem on the machine that listens to the UPS port, > > but on the other machines, I don't see it clearly. The async port is two > > way, so only one machine at a time can talk to it. > > 1) Assume the host that monitors the thing is up if the thing > is up. > > 2) Make a TCP connection to a priveledged port on that host. > Retry at intervals if necessary. > > 3) It writes you on the connection you made when it wants to notify > you of some event. I don't find 'privileged ports' in my trusty O'Reillly TCP/IP book, could you give me a reference? I just don't see, right now, what would stop someone with a packet sniffer, finding how I communicate, then spoofing the remote. I know how to set up connections, I'm wondering about security, and how much is enough, when I'm talking about something that can shut down the machine. > > Fairly easy. > > > Terry Lambert > terry@lambert.org > --- > Any opinions in this posting are my own and not those of my present > or previous employers. > ----------------------------+----------------------------------------------- Chuck Robey | Interests include any kind of voice or data chuckr@eng.umd.edu | communications topic, C programming, and Unix. 9120 Edmonston Ct #302 | Greenbelt, MD 20770 | I run Journey2 and n3lxx, both FreeBSD (301) 220-2114 | version 2.2 current -- and great FUN! ----------------------------+-----------------------------------------------