xref: /freebsd/usr.sbin/ipfwpcap/ipfwpcap.8 (revision b3e7694832e81d7a904a10f525f8797b753bf0d3)
1.\" Copyright (c) 2006 Niclas Zeising <zeising@FreeBSD.org>
2.\"
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24.\" $FreeBSD$
25.\"
26.Dd May 22, 2006
27.Dt IPFWPCAP 8
28.Os
29.Sh NAME
30.Nm ipfwpcap
31.Nd "copy diverted packets to a file in tcpdump format"
32.Sh SYNOPSIS
33.Nm
34.Op Fl dr
35.Op Fl b Ar maxbytes
36.Op Fl p Ar maxpkts
37.Op Fl P Ar pidfile
38.Ar portnum
39.Ar dumpfile
40.Sh DESCRIPTION
41The
42.Nm
43utility is used to copy diverted packets to a file in
44.Xr tcpdump 1
45format.
46The interesting packets are diverted by
47.Xr ipfw 8
48to a port on which
49.Nm
50listens.
51The packets are then dropped unless
52.Fl r
53is used.
54.Pp
55The options are as follows:
56.Bl -tag -width indent
57.It Fl d
58Turns on extra debugging messages.
59.It Fl r
60Writes packets back to the
61.Xr divert 4
62socket.
63.It Fl rr
64Indicates that it is okay to quit if
65.Ar maxbytes
66or
67.Ar maxpkts
68are reached.
69Diverted packets will silently disappear if nothing is listening on the
70.Xr divert 4
71socket.
72.It Fl b Ar maxbytes
73Stop dumping after
74.Ar maxbytes
75bytes.
76.It Fl p Ar maxpkts
77Stop dumping after
78.Ar maxpkt
79packets.
80.It Fl P Ar pidfile
81File to store PID number in.
82Default is
83.Pa /var/run/ipwfpcap.portnr.pid .
84.El
85.Pp
86The
87.Ar portnum
88argument specifies which
89.Xr divert 4
90socket port to listen on.
91The
92.Ar dumpfile
93argument is the path to the file to write captured packets to.
94Specify
95.Sq Fl
96to write to stdout.
97.Sh EXIT STATUS
98.Ex -std
99.Sh EXAMPLES
100.Dl "ipfwpcap -r 8091 divt.log &"
101.Pp
102Starts
103.Nm
104as a background job listening to port 8091 and reflecting the packets
105back to the socket.
106.Pp
107.Dl "ipfw add 2864 divert 8091 ip from 192.0.2.101"
108.Pp
109Example
110.Xr ipfw 8
111rule to divert all packets from 192.0.2.101 to port 8091.
112See
113.Xr ipfw 8
114for details.
115.Sh SEE ALSO
116.Xr tcpdump 1 ,
117.Xr pcap 3 ,
118.Xr divert 4 ,
119.Xr ipfw 8
120.Sh HISTORY
121The
122.Nm
123utility first appeared in
124.Fx 7.0 .
125.Sh AUTHORS
126.An -nosplit
127.Nm
128was written by
129.An P. Kern Aq Mt pkern@cns.utoronto.ca .
130This manual page was written by
131.An Niclas Zeising Aq Mt zeising@FreeBSD.org .
132