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.\"	$apfw: pflog.4,v 1.3 2008/08/27 00:01:31 jhw Exp    $
.\"
.\"	$OpenBSD: pflog.4,v 1.9 2006/10/25 12:51:31 jmc Exp $
.\"
.\" Copyright (c) 2001 Tobias Weingartner
.\" All rights reserved.
.\"
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.Dd $Mdocdate: May 31 2007 $
.Dt PFLOG 4
.Os
.Sh NAME
.Nm pflog
.Nd packet filter logging interface
.Sh SYNOPSIS
.Cd "pseudo-device pflog"
.Sh DESCRIPTION
The
.Nm pflog
interface is a pseudo-device which makes visible all packets logged by
the packet filter.
Logged packets can easily be monitored in real
time by invoking
.Xr tcpdump 1
on the
.Nm
interface.
.\", or stored to disk using
.\".Xr pflogd 8 .
.\".Pp
.\"The pflog0 interface is created automatically at boot if both
.\"packet filter
.\"and
.\".Xr pflogd 8
.\"are enabled;
.\"further instances can be created using
.\".Xr ifconfig 8 .
.Pp
Instances of the
.Nm
interface can be created using
.Xr ifconfig 8 .
.\".Pp
.\"Each packet retrieved on this interface has a header associated
.\"with it of length
.\".Dv PFLOG_HDRLEN .
.\"This header documents the address family, interface name, rule
.\"number, reason, action, and direction of the packet that was logged.
.\"This structure, defined in
.\".Aq Pa net/if_pflog.h
.\"looks like
.\".Bd -literal -offset indent
.\"struct pfloghdr {
.\"	u_int8_t	length;
.\"	sa_family_t	af;
.\"	u_int8_t	action;
.\"	u_int8_t	reason;
.\"	char		ifname[IFNAMSIZ];
.\"	char		ruleset[PF_RULESET_NAME_SIZE];
.\"	u_int32_t	rulenr;
.\"	u_int32_t	subrulenr;
.\"	uid_t		uid;
.\"	pid_t		pid;
.\"	uid_t		rule_uid;
.\"	pid_t		rule_pid;
.\"	u_int8_t	dir;
.\"	u_int8_t	pad[3];
.\"};
.\".Ed
.Sh EXAMPLES
Create a
.Nm
interface
and monitor all packets logged on it:
.Bd -literal -offset indent
# ifconfig pflog1 create
# tcpdump -n -e -ttt -i pflog1
.Ed
.Sh SEE ALSO
.Xr inet 4 ,
.Xr inet6 4 ,
.Xr netintro 4 ,
.Xr pf 4 ,
.Xr ifconfig 8 ,
.\".Xr pflogd 8 ,
.Xr tcpdump 1
.Sh HISTORY
The
.Nm
device first appeared in
.Ox 3.0 .
.\" .Sh BUGS
.\" Anything here?