From owner-freebsd-bugs Sun Dec 1 15:31:49 1996 Return-Path: owner-bugs Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id PAA05929 for bugs-outgoing; Sun, 1 Dec 1996 15:31:49 -0800 (PST) Received: from tuminfo2.informatik.tu-muenchen.de (root@tuminfo2.informatik.tu-muenchen.de [131.159.0.81]) by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id PAA05922 for ; Sun, 1 Dec 1996 15:31:46 -0800 (PST) Received: from hphalle0.informatik.tu-muenchen.de ([131.159.4.1]) by tuminfo2.informatik.tu-muenchen.de with ESMTP id <52955-269>; Mon, 2 Dec 1996 00:31:18 +0100 Received: from schmidts ([172.16.0.35]) by hphalle0.informatik.tu-muenchen.de with SMTP id <410459-221>; Mon, 2 Dec 1996 00:31:03 +0100 Message-ID: <32A2159B.41C67EA6@informatik.tu-muenchen.de> Date: Mon, 02 Dec 1996 00:32:44 +0100 From: Stefan Schmidt Organization: Munich University Of Technology X-Mailer: Mozilla 3.01 (X11; I; FreeBSD 2.1.5-RELEASE i386) MIME-Version: 1.0 To: bugs@freebsd.org Subject: lp0 problems Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-bugs@freebsd.org X-Loop: FreeBSD.org Precedence: bulk Hi, I recently connected a laptop (2.2-961014-SNAP) and a pc (2.1.5-RELEASE) through lp0 w/ laplink cable. The following problems occured: (1) the 2.2-961014-SNAP machine spontaneously freezes/panics/reboots when sending/receiving over lp0. as I tried to spot this bug: (2) tcpdump on lp0 didn't work after looking at /sys/i386/isa/lpt.c and searching the mailing-lists, it seems that a suggested fix from Bill Fenner hasn't been applied yet. (from Mon, 22 Jan 1996 12:34:20 PST) the problem is a off-by-2 error when sending data to bpf. another problem is: in lpoutput(), the to-be-sent mbuf is manipulated during output to lpt. therefore the following call to bpf_mtap() handles a corrupted mbuf to bpf. (tcpdump may segfault) after applying some quick&dirty patches to lpt.c (fixing the off-by-2 errors and calling bpf_mtap before the mbufs are corrupted) tcpdump an lp0 works. stefan