1.\" $OpenBSD: pflogd.8,v 1.22 2003/06/03 13:16:08 jmc Exp $ 2.\" 3.\" Copyright (c) 2001 Can Erkin Acar. All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 3. The name of the author may not be used to endorse or promote products 14.\" derived from this software without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26.\" 27.Dd July 9, 2001 28.Dt PFLOGD 8 29.Os 30.Sh NAME 31.Nm pflogd 32.Nd packet filter logging daemon 33.Sh SYNOPSIS 34.Nm pflogd 35.Op Fl D 36.Op Fl d Ar delay 37.Op Fl f Ar filename 38.Op Fl s Ar snaplen 39.Op Ar expression 40.Sh DESCRIPTION 41.Nm 42is a background daemon which reads packets logged by 43.Xr pf 4 44to the packet logging interface 45.Pa pflog0 46and writes the packets to a logfile (normally 47.Pa /var/log/pflog ) 48in 49.Xr tcpdump 8 50binary format. 51These logs can be reviewed later using the 52.Fl r 53option of 54.Xr tcpdump 8 , 55hopefully offline in case there are bugs in the packet parsing code of 56.Xr tcpdump 8 . 57.Pp 58.Nm 59closes and then re-opens the log file when it receives 60.Va SIGHUP , 61permitting 62.Xr newsyslog 8 63to rotate logfiles automatically. 64.Va SIGALRM 65causes 66.Nm 67to flush the current logfile buffers to the disk, thus making the most 68recent logs available. 69The buffers are also flushed every 70.Ar delay 71seconds. 72.Pp 73If the log file contains data after a restart or a 74.Va SIGHUP , 75new logs are appended to the existing file. 76If the existing log file was created with a different snaplen, 77.Nm 78temporarily uses the old snaplen to keep the log file consistent. 79.Pp 80The options are as follows: 81.Bl -tag -width Ds 82.It Fl d Ar delay 83Time in seconds to delay between automatic flushes of the file. 84This may be specified with a value between 5 and 3600 seconds. 85If not specified, the default is 60 seconds. 86.It Fl D 87Debugging mode. 88.Nm 89does not disassociate from the controlling terminal. 90.It Fl f Ar filename 91Log output filename. 92Default is 93.Pa /var/log/pflog . 94.It Fl s Ar snaplen 95Analyze at most the first 96.Ar snaplen 97bytes of data from each packet rather than the default of 96. 98The default of 96 is adequate for IP, ICMP, TCP, and UDP headers but may 99truncate protocol information for other protocols. 100Other file parsers may desire a higher snaplen. 101.It Ar expression 102Selects which packets will be dumped, using the regular language of 103.Xr tcpdump 8 . 104.El 105.Sh FILES 106.Bl -tag -width /var/run/pflogd.pid -compact 107.It Pa /var/run/pflogd.pid 108Process ID of the currently running 109.Nm pflogd . 110.It Pa /var/log/pflog 111Default log file. 112.El 113.Sh EXAMPLES 114Log specific tcp packets to a different log file with a large snaplen 115(useful with a log-all rule to dump complete sessions) 116.Bd -literal -offset indent 117# pflogd -s 1600 -f suspicious.log port 80 and host evilhost 118.Ed 119.Pp 120Display binary logs: 121.Bd -literal -offset indent 122# tcpdump -n -e -ttt -r /var/log/pflog 123.Ed 124.Pp 125Display the logs in real time (this does not interfere with the 126operation of pflogd): 127.Bd -literal -offset indent 128# tcpdump -n -e -ttt -i pflog0 129.Ed 130.Pp 131Tcpdump has been extended to be able to filter on the pfloghdr 132structure defined in 133.Aq Ar net/if_pflog.h . 134Tcpdump can restrict the output 135to packets logged on a specified interface, a rule number, a reason, 136a direction, an ip family or an action. 137.Pp 138.Bl -tag -width "reason match " -compact 139.It ip 140Address family equals IPv4. 141.It ip6 142Address family equals IPv6. 143.It ifname kue0 144Interface name equals "kue0" 145.It on kue0 146Interface name equals "kue0" 147.It rulenum 10 148Rule number equals 10. 149.It reason match 150Reason equals match. 151Also accepts "bad-offset", "fragment", "short", "normalize" and "memory". 152.It action pass 153Action equals pass. 154Also accepts "block". 155.It inbound 156The direction was inbound. 157.It outbound 158The direction was outbound. 159.El 160.Pp 161Display the logs in real time of inbound packets that were blocked on 162the wi0 interface: 163.Bd -literal -offset indent 164# tcpdump -n -e -ttt -i pflog0 inbound and action block and on wi0 165.Ed 166.Sh SEE ALSO 167.Xr pcap 3 , 168.Xr pf 4 , 169.Xr pflog 4 , 170.Xr pf.conf 5 , 171.Xr newsyslog 8 , 172.Xr tcpdump 8 173.Sh HISTORY 174The 175.Nm 176command appeared in 177.Ox 3.0 . 178.Sh AUTHORS 179Can Erkin Acar 180