NAME¶
tcpspy.rules - configuration file for tcpspy
DESCRIPTION¶
This file, by default
/etc/tcpspy.rules, is read by the
/etc/init.d/tcpspy script at init time in order to configure tcpspy
(see
tcpspy(8)) logger filtering rules.
It might look like:
-
# /etc/tcpspt.rules example
user "joedoe" and rport 22 and raddr 192.168.1.10
user 1003
lport 22 or lport 21
(lport 23 and user "joedoe") or raddr 192.168.1.20
This rules file specifies that tcpspy logs tcp connections according to 4 rules
(line 1 to line 4 - one per each line) using the boolean logic (see below) to
evaluate each rule.
This particular example logs conections:
- line 1 - for user "joedoe" connecting to
192.168.1.10:22 (remote)
- line 2 - for user whose UID is 1003
- line 3 - to localhost:22 or localhost:21
- line 4 - for user "joedoe" to localhost:23 or to
192.168.1.20 (remote)
Everything from an "#" signal and the end of the line will not be
evaluated.
A rule may be specified with the following comparison operators:
- user uid
- True if the local user initiating or accepting the
connection has the effective user id uid.
- user "username"
- Same as above, but using a username instead of a user
id.
- lport port
- True if the local end of the connection has port number
port.
- lport [low] - [high]
- True if the local end of the connection has a port number
greater than or equal to low and less than or equal to high.
If the form low- is used, high is assumed to be 65535. If the form
-high is used, low is assumed to be 0. It is an error to omit both
low and high.
- lport "service"
- Same as above, but using a service name from
/etc/services instead of a port number.
- rport
- Same as lport but compares the port number of the
remote end of the connection.
- laddr n.n.n.n[/m.m.m.m]
- Interpreted as a "net/mask" expression; true if
"net" is equal to the bitwise AND of the local address of the
connection and "mask". If no mask is specified, a default mask
with all bits set (255.255.255.255) is used.
- raddr
- Same as laddr but compares the remote address.
- exe "pattern"
- True if the full filename (including directory) of the
executable that created/accepted the connection matches pattern, a
glob(7)-style wildcard pattern.
- The pattern "" (an empty string) matches
connections created/accepted by processes whose executable filename is
unknown.
- If the -p option is not specified, a warning message
will be printed, and the result of this comparison will always be
true.
Expressions (including the comparisons listed above) may be joined together with
the following logical operations:
- expr1 or expr2
- True if either of expr1 or expr2 are true
(logical OR).
- expr1 and expr2
- True if both expr1 and expr2 are true
(logical AND).
- not expr
- True if expr is false (logical NOT).
Rules are evaluated from left to right. Whitespace (space, tab and newline)
characters are ignored between "words". Rules consisting of only
whitespace match no connections, but do not cause an error. Parentheses, '('
and ')' may be placed around expressions to affect the order of evaluation.
Examples¶
- These are some sample rules which further demonstrate how
they are constructed:
-
user "joe" and rport "ssh"
-
Log connections made by user "joe" for the service
"ssh".
-
not raddr 10.0.0.0/255.0.0.0 and rport 25 and (user "bob" or user "joe")
-
Log connections made by users "bob" and "joe" to remote
port 25 on machines not on a fictional "intranet".
AUTHOR¶
Tim J. Robbins (tcpspy), Pablo Lorenzzoni (this manpage)
SEE ALSO¶
glob(7),
proc(5),
services(5),
signal(7),
syslog(3),
tcpspy(8)
