From owner-freebsd-current@FreeBSD.ORG Tue Sep 26 17:33:31 2006 Return-Path: X-Original-To: current@freebsd.org Delivered-To: freebsd-current@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 285D616A416 for ; Tue, 26 Sep 2006 17:33:31 +0000 (UTC) (envelope-from allbery@ece.cmu.edu) Received: from bache.ece.cmu.edu (BACHE.ECE.CMU.EDU [128.2.129.23]) by mx1.FreeBSD.org (Postfix) with ESMTP id 81D0D43D46 for ; Tue, 26 Sep 2006 17:33:30 +0000 (GMT) (envelope-from allbery@ece.cmu.edu) Received: by bache.ece.cmu.edu (Postfix, from userid 953) id DC080A5; Tue, 26 Sep 2006 13:33:29 -0400 (EDT) X-Spam-Checker-Version: SpamAssassin 3.1.4 (2006-07-25) on filt1.ece.cmu.edu X-Spam-Level: X-Spam-Status: No, score=0.0 required=6.0 tests=BAYES_50 autolearn=no version=3.1.4 Received: from [10.9.204.128] (dsl093-061-215.pit1.dsl.speakeasy.net [66.93.61.215]) by bache.ece.cmu.edu (Postfix) with ESMTP id 4E5E49E; Tue, 26 Sep 2006 13:33:27 -0400 (EDT) In-Reply-To: <4f674ca50609261029s76432971yfc15171a3e89cb72@mail.google.com> References: <20060926111452.J91466@godot.imp.ch> <0C4B0125-11AA-4BDB-A4E3-163A6194AB68@alumni.cwru.edu> <98FD6058-7220-48DB-AC24-F989FCB2AE11@ece.cmu.edu> <4f674ca50609261029s76432971yfc15171a3e89cb72@mail.google.com> Mime-Version: 1.0 (Apple Message framework v752.2) Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Message-Id: <8EECEF0C-8C94-4A7C-862A-633F67D3D229@ece.cmu.edu> Content-Transfer-Encoding: 7bit From: "Brandon S. Allbery KF8NH" Date: Tue, 26 Sep 2006 13:33:24 -0400 To: "Magnus Ringman" X-Mailer: Apple Mail (2.752.2) Cc: current@freebsd.org, Justin Hibbits Subject: Re: What do you think ?: How should pseundo terminals behave ... X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 26 Sep 2006 17:33:31 -0000 On Sep 26, 2006, at 13:29 , Magnus Ringman wrote: > On 9/26/06, Brandon S. Allbery KF8NH wrote: >> >> 3a) Hangup all processes attached to the client and switch them to >> some kind of "dead" inode (which could be a fixed entity since all >> operations on it except close() fail). (Don't real ttys do this?) > > -1. > Yes and no. ttys do that on an actual hangup (when a hardware hangup > happens), however PTYs are intended to allow emulating the full > terminal line semantics, including hangup. Imo the case of "pty > master side disappearing" is equivalent to "backing device (hardware) > no longer exists", not "remote end hung up". I think that in many circumstances (and, as you note, implemented in other OSes), the correct behavior *is* to treat hangup as "backing device no longer exists" --- an older session should not leak into a newer one, it is a potential security hole and certainly a potential source of confusion. And if hardware ttys do it, I should think virtual ones should also do so for consistency. -- brandon s. allbery [linux,solaris,freebsd,perl] allbery@kf8nh.com system administrator [openafs,heimdal,too many hats] allbery@ece.cmu.edu electrical and computer engineering, carnegie mellon university KF8NH