ipmon(8)

NAME

ipmon - monitors /dev/ipl for logged packets

SYNOPSIS

ipmon  [ -abDFhnpstvxX ] [ -N <device> ] [ -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.

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.

-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.

-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 security. 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)

If you find any, please send email to me at darrenr@pobox.com

ipmon(8)