freebsd-dev/share/man/man4/pflog.4
Kristof Provost 76c5eecc34 pf: Introduce ridentifier
Allow users to set a number on rules which will be exposed as part of
the pflog header.
The intent behind this is to allow users to correlate rules across
updates (remember that pf rules continue to exist and match existing
states, even if they're removed from the active ruleset) and pflog.

Obtained from:	pfSense
MFC after:	3 weeks
Sponsored by:	Rubicon Communications, LLC ("Netgate")
Differential Revision:	https://reviews.freebsd.org/D32750
2021-11-05 09:39:56 +01:00

118 lines
3.0 KiB
Groff

.\" $OpenBSD: pflog.4,v 1.10 2007/05/31 19:19:51 jmc Exp $
.\"
.\" Copyright (c) 2001 Tobias Weingartner
.\" All rights reserved.
.\"
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.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
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.\" $FreeBSD$
.\"
.Dd October 29, 2021
.Dt PFLOG 4
.Os
.Sh NAME
.Nm pflog
.Nd packet filter logging interface
.Sh SYNOPSIS
.Cd "device pflog"
.Sh DESCRIPTION
The
.Nm pflog
interface is a device which makes visible all packets logged by
the packet filter,
.Xr pf 4 .
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 when the
.Nm
module is loaded;
further instances can be created using
.Xr ifconfig 8 .
The
.Nm
module is loaded automatically if both
.Xr pf 4
and
.Xr pflogd 8
are enabled.
.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];
u_int32_t ridentifier;
};
.Ed
.Sh EXAMPLES
Create a
.Nm
interface
and monitor all packets logged on it:
.Bd -literal -offset indent
# ifconfig pflog create
pflog1
# ifconfig pflog1 up
# tcpdump -n -e -ttt -i pflog1
.Ed
.Sh SEE ALSO
.Xr tcpdump 1 ,
.Xr inet 4 ,
.Xr inet6 4 ,
.Xr netintro 4 ,
.Xr pf 4 ,
.Xr ifconfig 8 ,
.Xr pflogd 8
.Sh HISTORY
The
.Nm
device first appeared in
.Ox 3.0 .
.Sh BUGS
FreeBSD does not set a process id in the
.Fa pid
field in pfloghdr.