From owner-cvs-src@FreeBSD.ORG Sun Oct 10 12:06:41 2004 Return-Path: Delivered-To: cvs-src@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 66A6A16A4CE; Sun, 10 Oct 2004 12:06:41 +0000 (GMT) Received: from cell.sick.ru (cell.sick.ru [217.72.144.68]) by mx1.FreeBSD.org (Postfix) with ESMTP id 9883C43D2D; Sun, 10 Oct 2004 12:06:40 +0000 (GMT) (envelope-from glebius@freebsd.org) Received: from cell.sick.ru (glebius@localhost [127.0.0.1]) by cell.sick.ru (8.12.11/8.12.8) with ESMTP id i9AC6bO5012477 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sun, 10 Oct 2004 16:06:38 +0400 (MSD) (envelope-from glebius@freebsd.org) Received: (from glebius@localhost) by cell.sick.ru (8.12.11/8.12.11/Submit) id i9AC6brn012476; Sun, 10 Oct 2004 16:06:37 +0400 (MSD) (envelope-from glebius@freebsd.org) X-Authentication-Warning: cell.sick.ru: glebius set sender to glebius@freebsd.org using -f Date: Sun, 10 Oct 2004 16:06:37 +0400 From: Gleb Smirnoff To: David Malone Message-ID: <20041010120637.GB12258@cell.sick.ru> References: <200410082115.i98LFLMU034965@repoman.freebsd.org> <20041009153916.GA2003@webcom.it> <20041009212952.GA8922@cell.sick.ru> <200410082115.i98LFLMU034965@repoman.freebsd.org> <20041009153916.GA2003@webcom.it> <20041009190714.GB1093@green.homeunix.org> <20041010072205.GA1617@webcom.it> <20041010101612.GB11523@cell.sick.ru> <20041010110842.GA16446@walton.maths.tcd.ie> Mime-Version: 1.0 Content-Type: text/plain; charset=koi8-r Content-Disposition: inline In-Reply-To: <20041010110842.GA16446@walton.maths.tcd.ie> User-Agent: Mutt/1.5.6i cc: Andrea Campi cc: Brian Fundakowski Feldman cc: src-committers@freebsd.org cc: cvs-all@freebsd.org cc: cvs-src@freebsd.org Subject: Re: cvs commit: src/lib/libc/gen syslog.c X-BeenThere: cvs-src@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 10 Oct 2004 12:06:41 -0000 On Sun, Oct 10, 2004 at 12:08:42PM +0100, David Malone wrote: D> > 1. Not forever. D> D> If syslogd has hung (as opposed to being busy), it will wait forever. D> Try "killall -STOP syslogd" and then logging a bundle of messages. D> With the old situation other services continue to run, with the new D> situation every program that calls syslog(3) end up stuck. Yes, after this change interface is less antifootshooting. But you shouldn't do "killall -STOP syslogd", as well as you shouldn't do "killall -STOP sshd". D> > 3. If /var/run/log is overflowed that means that your machine is already D> > slowed down by syslogd process and its IO. Your application is already D> > not doing its best. D> D> > Better have consistent logs later to investigate that DoS. An attacker D> > may trigger that DoS intentionally to hide some messages, which will D> > be logged if syslogd is not overflowed. D> D> This can happen in situations other than DoSs. Previously there D> have been situations where syslogd hangs if a serial console becomes D> confused or because of a coding error. This change makes it impossible D> to su and fix the problem. IMHO, this is worse than loosing syslog D> messages. Then we should correct these coding errors if they exist. D> (I guess if someone can log enough messages to the syslog socket D> to cause ENOBUFS, they can also log enough messages to fill up /var D> and have syslogd stop logging because the disk is full.) It is much easier to trigger ENOBUFS condition. And syslogd may write logs to multiple destinations, not only /var. If /var has enough free space to survive for 5 minutes, than newsyslog will save space on next run. -- Totus tuus, Glebius. GLEBIUS-RIPN GLEB-RIPE