1.\" $OpenBSD: pflog.4,v 1.10 2007/05/31 19:19:51 jmc Exp $ 2.\" 3.\" Copyright (c) 2001 Tobias Weingartner 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25.\" 26.Dd December 10, 2001 27.Dt PFLOG 4 28.Os 29.Sh NAME 30.Nm pflog 31.Nd packet filter logging interface 32.Sh SYNOPSIS 33.Cd "device pflog" 34.Sh DESCRIPTION 35The 36.Nm 37interface is a pseudo-device which makes visible all packets logged by 38the packet filter, 39.Xr pf 4 . 40Logged packets can easily be monitored in real 41time by invoking 42.Xr tcpdump 1 43on the 44.Nm 45interface, or stored to disk using 46.Xr pflogd 8 . 47.Pp 48The pflog0 interface is created automatically at boot if both 49.Xr pf 4 50and 51.Xr pflogd 8 52are enabled; 53further instances can be created using 54.Xr ifconfig 8 . 55.Pp 56Each packet retrieved on this interface has a header associated 57with it of length 58.Dv PFLOG_HDRLEN . 59This header documents the address family, interface name, rule 60number, reason, action, and direction of the packet that was logged. 61This structure, defined in 62.In net/pf/if_pflog.h 63looks like 64.Bd -literal -offset indent 65struct pfloghdr { 66 u_int8_t length; 67 sa_family_t af; 68 u_int8_t action; 69 u_int8_t reason; 70 char ifname[IFNAMSIZ]; 71 char ruleset[PF_RULESET_NAME_SIZE]; 72 u_int32_t rulenr; 73 u_int32_t subrulenr; 74 uid_t uid; 75 pid_t pid; 76 uid_t rule_uid; 77 pid_t rule_pid; 78 u_int8_t dir; 79 u_int8_t pad[3]; 80}; 81.Ed 82.Sh EXAMPLES 83Create a 84.Nm 85interface 86and monitor all packets logged on it: 87.Bd -literal -offset indent 88# ifconfig pflog0 up 89# tcpdump -n -e -ttt -i pflog0 90.Ed 91.Sh SEE ALSO 92.Xr tcpdump 1 , 93.Xr inet 4 , 94.Xr inet6 4 , 95.Xr netintro 4 , 96.Xr pf 4 , 97.Xr ifconfig 8 , 98.Xr pflogd 8 99.Sh HISTORY 100The 101.Nm 102device first appeared in 103.Ox 3.0 104and was then integrated into 105.Dx 1.1 106by Devon H. O'Dell and Simon Schubert. 107.\" .Sh BUGS 108.\" Anything here? 109