NAME
ipmon - monitors /dev/ipl for logged packets
SYNOPSIS
ipmon [
-abBDFhnpstvxX ] [
-N <device> ] [
-L
<facility> ] [
-o [NSI] ] [
-O [NSI] ] [
-P
<pidfile> ] [
-S <device> ] [
-f <device>
] [
<filename> ]
DESCRIPTION
ipmon opens
/dev/ipl for reading and awaits data to be saved from
the packet filter. The binary data read from the device is reprinted in human
readable for, however, IP#'s are not mapped back to hostnames, nor are ports
mapped back to service names. The output goes to standard output by default or
a filename, if given on the command line. Should the
-s option be used,
output is instead sent to
syslogd(8). Messages sent via syslog have the
day, month and year removed from the message, but the time (including
microseconds), as recorded in the log, is still included.
Messages generated by ipmon consist of whitespace separated fields. Fields
common to all messages are:
1. The date of packet receipt. This is suppressed when the message is sent to
syslog.
2. The time of packet receipt. This is in the form HH:MM:SS.F, for hours,
minutes seconds, and fractions of a second (which can be several digits long).
3. The name of the interface the packet was processed on, e.g.,
we1.
4. The group and rule number of the rule, e.g.,
@0:17. These can be
viewed with
ipfstat -n.
5. The action:
p for passed,
b for blocked,
for a short
packet,
n did not match any rules or
L for a log rule.
6. The addresses. This is actually three fields: the source address and port
(separated by a comma), the
-> symbol, and the destination address
and port. E.g.:
209.53.17.22,80 -> 198.73.220.17,1722.
7.
PR followed by the protocol name or number, e.g.,
PR tcp.
8.
len followed by the header length and total length of the packet,
e.g.,
len 20 40.
If the packet is a TCP packet, there will be an additional field starting with a
hyphen followed by letters corresponding to any flags that were set. See the
ipf.conf manual page for a list of letters and their flags.
If the packet is an ICMP packet, there will be two fields at the end, the first
always being `icmp', and the next being the ICMP message and submessage type,
separated by a slash, e.g.,
icmp 3/3 for a port unreachable message.
In order for
ipmon to properly work, the kernel option
IPFILTER_LOG must be turned on in your kernel. Please see
options(4) for more details.
ipmon reopens its log file(s) and rereads its configuration file when it
receives a SIGHUP signal.
OPTIONS
- -a
- Open all of the device logfiles for reading log entries
from. All entries are displayed to the same output 'device' (stderr or
syslog).
- -b
- For rules which log the body of a packet, generate hex
output representing the packet contents after the headers.
- -B <binarylogfilename>
- Enable logging of the raw, unformatted binary data to the
specified <binarylogfilename> file. This can be read, later,
using ipmon with the -f option.
- -D
- Cause ipmon to turn itself into a daemon. Using subshells
or backgrounding of ipmon is not required to turn it into an orphan so it
can run indefinitely.
- -f <device>
- specify an alternative device/file from which to read the
log information for normal IP Filter log records.
- -F
- Flush the current packet log buffer. The number of bytes
flushed is displayed, even should the result be zero.
- -L <facility>
- Using this option allows you to change the default syslog
facility that ipmon uses for syslog messages. The default is local0.
- -n
- IP addresses and port numbers will be mapped, where
possible, back into hostnames and service names.
- -N <device>
- Set the logfile to be opened for reading NAT log records
from to <device>.
- -o
- Specify which log files to actually read data from. N - NAT
logfile, S - State logfile, I - normal IP Filter logfile. The -a
option is equivalent to using -o NSI.
- -O
- Specify which log files you do not wish to read from. This
is most sensibly used with the -a. Letters available as parameters
to this are the same as for -o.
- -p
- Cause the port number in log messages to always be printed
as a number and never attempt to look it up as from /etc/services,
etc.
- -P <pidfile>
- Write the pid of the ipmon process to a file. By default
this is //etc/opt/ipf/ipmon.pid (Solaris),
/var/run/ipmon.pid (44BSD or later) or /etc/ipmon.pid for
all others.
- -s
- Packet information read in will be sent through syslogd
rather than saved to a file. The default facility when compiled and
installed is local0. The following levels are used:
- LOG_INFO - packets logged using the "log"
keyword as the action rather than pass or block.
- LOG_NOTICE - packets logged which are also
passed
- LOG_WARNING - packets logged which are also
blocked
- LOG_ERR - packets which have been logged and which
can be considered "short".
- -S <device>
- Set the logfile to be opened for reading state log records
from to <device>.
- -t
- read the input file/device in a manner akin to
tail(1).
- -v
- show tcp window, ack and sequence fields.
- -x
- show the packet data in hex.
- -X
- show the log header record data in hex.
DIAGNOSTICS
ipmon expects data that it reads to be consistent with how it should be
saved and will abort if it fails an assertion which detects an anomaly in the
recorded data.
FILES
/dev/ipl
/dev/ipnat
/dev/ipstate
/etc/services
SEE ALSO
ipl(4), ipf(8), ipfstat(8), ipnat(8)
BUGS
If you find any, please send email to me at darrenr@pobox.com