xref: /freebsd/usr.sbin/ipfwpcap/ipfwpcap.8 (revision 2008043f386721d58158e37e0d7e50df8095942d)
1.\" Copyright (c) 2006 Niclas Zeising <zeising@FreeBSD.org>
2.\"
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24.Dd May 22, 2006
25.Dt IPFWPCAP 8
26.Os
27.Sh NAME
28.Nm ipfwpcap
29.Nd "copy diverted packets to a file in tcpdump format"
30.Sh SYNOPSIS
31.Nm
32.Op Fl dr
33.Op Fl b Ar maxbytes
34.Op Fl p Ar maxpkts
35.Op Fl P Ar pidfile
36.Ar portnum
37.Ar dumpfile
38.Sh DESCRIPTION
39The
40.Nm
41utility is used to copy diverted packets to a file in
42.Xr tcpdump 1
43format.
44The interesting packets are diverted by
45.Xr ipfw 8
46to a port on which
47.Nm
48listens.
49The packets are then dropped unless
50.Fl r
51is used.
52.Pp
53The options are as follows:
54.Bl -tag -width indent
55.It Fl d
56Turns on extra debugging messages.
57.It Fl r
58Writes packets back to the
59.Xr divert 4
60socket.
61.It Fl rr
62Indicates that it is okay to quit if
63.Ar maxbytes
64or
65.Ar maxpkts
66are reached.
67Diverted packets will silently disappear if nothing is listening on the
68.Xr divert 4
69socket.
70.It Fl b Ar maxbytes
71Stop dumping after
72.Ar maxbytes
73bytes.
74.It Fl p Ar maxpkts
75Stop dumping after
76.Ar maxpkt
77packets.
78.It Fl P Ar pidfile
79File to store PID number in.
80Default is
81.Pa /var/run/ipwfpcap.portnr.pid .
82.El
83.Pp
84The
85.Ar portnum
86argument specifies which
87.Xr divert 4
88socket port to listen on.
89The
90.Ar dumpfile
91argument is the path to the file to write captured packets to.
92Specify
93.Sq Fl
94to write to stdout.
95.Sh EXIT STATUS
96.Ex -std
97.Sh EXAMPLES
98.Dl "ipfwpcap -r 8091 divt.log &"
99.Pp
100Starts
101.Nm
102as a background job listening to port 8091 and reflecting the packets
103back to the socket.
104.Pp
105.Dl "ipfw add 2864 divert 8091 ip from 192.0.2.101"
106.Pp
107Example
108.Xr ipfw 8
109rule to divert all packets from 192.0.2.101 to port 8091.
110See
111.Xr ipfw 8
112for details.
113.Sh SEE ALSO
114.Xr tcpdump 1 ,
115.Xr pcap 3 ,
116.Xr divert 4 ,
117.Xr ipfw 8
118.Sh HISTORY
119The
120.Nm
121utility first appeared in
122.Fx 7.0 .
123.Sh AUTHORS
124.An -nosplit
125.Nm
126was written by
127.An P. Kern Aq Mt pkern@cns.utoronto.ca .
128This manual page was written by
129.An Niclas Zeising Aq Mt zeising@FreeBSD.org .
130