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.TH "firehol-iptrap" "5" "Built 30 Mar 2024" "FireHOL Reference" "3.1.7"
.hy
.SH NAME
.PP
firehol-iptrap - dynamically put IP addresses in an ipset
.SH SYNOPSIS
.PP
{ iptrap | iptrap4 | iptrap6 } \f[I]ipset\f[R] \f[I]type\f[R]
\f[I]seconds\f[R] [ timeout | counters ] [ method \f[B]method\f[R] ]
[\f[I]rule-params\f[R]] [ except [\f[I]rule-params\f[R]] ]\&...
.PP
{ ipuntrap | ipuntrap4 | ipuntrap6 } \f[I]ipset\f[R] \f[I]type\f[R] [
timeout | counters ] [ method \f[B]method\f[R] ] [\f[I]rule-params\f[R]]
[ except [\f[I]rule-params\f[R]] ]\&...
.SH DESCRIPTION
.PP
\f[V]iptrap\f[R] adds the IP addresses of the matching packets to
\f[V]ipset\f[R].
.PP
\f[V]ipuntrap\f[R] deletes the IP addresses of the matching packets from
\f[V]ipset\f[R].
.PP
Both helpers do not affect the flow of traffic.
They do not \f[V]ACCEPT\f[R], \f[V]REJECT\f[R], \f[V]DROP\f[R] packets
or affect the firewall in any way.
.PP
\f[V]ipset\f[R] is the name of the ipset to use.
.PP
\f[V]type\f[R] selects which of the IP addresses of the matching packets
will be used (added or removed from the ipset).
\f[V]type\f[R] can be \f[V]src\f[R], \f[V]dst\f[R], \f[V]src,dst\f[R],
\f[V]dst,src\f[R], etc.
If type is a pair, then the ipset must be an ipset of pairs too.
.PP
\f[V]seconds\f[R] is required by \f[V]iptrap\f[R] and gives the duration
in seconds of the lifetime of each IP address that is added to
\f[V]ipset\f[R].
Every matching packet will refresh this duration for the IP address in
the ipset.
The Linux kernel will automatically remove the IP from the ipset when
this time expires.
The user may monitor the remaining time for each IP, by running
\f[V]ipset list NAME\f[R] (where \f[V]NAME\f[R] is the \f[V]ipset\f[R]
parameter given in the \f[V]iptrap\f[R] command).
.PP
The seconds value \f[V]default\f[R] will not set any seconds.
The ipset default will be used.
.PP
A seconds of \f[V]0\f[R] (zero), writes to the ipset permanently (this
is a feature of the ipset command, not the ipset FireHOL helper).
.PP
The keywords \f[V]timeout\f[R] and \f[V]counters\f[R] are mutually
exclusive.
\f[V]timeout\f[R] is the default and means that each IP address every
time is matched its timeout will be refreshed, while \f[V]counters\f[R]
means that its packets and bytes counters will be refreshed.
Unfortunately the kernel either re-add the IP in the ipset with the new
timeout - but its counters will be lost, or just the counters will be
updated, but the timeout will not be refreshed.
.PP
\f[V]method\f[R] is defines the storage method of the underlying ipset.
It accepts all the types the ipset commands accepts.
.PP
\f[V]method\f[R] and \f[V]type\f[R] should match.
For example if method is \f[V]hash:ip\f[R] then method should be either
\f[V]src\f[R] or \f[V]dst\f[R].
If method is \f[V]hash:ip,ip\f[R] then method should be either
\f[V]src,dst\f[R] or \f[V]dst,src\f[R].
If method is \f[V]hash:ip,port,ip\f[R] method should be
\f[V]src,src,dst\f[R] or \f[V]src,dst,dst\f[R] or \f[V]dst,src,src\f[R]
or \f[V]dst,dst,src\f[R].
For more information check the manual page of the ipset command.
.PP
The \f[I]rule-params\f[R] define a set of rule parameters to restrict
the traffic that is matched to this helper.
See firehol-params(5) for more details.
.PP
\f[V]except\f[R] \f[I]rule-params\f[R] are used to exclude traffic,
i.e.\ traffic that normally is matched by the first set of
\f[I]rule-params\f[R], will be excluded if matched by the second.
.PP
\f[V]iptrap\f[R] and \f[V]ipuntrap\f[R] are hooked on PREROUTING so it
is only useful for incoming traffic.
.PP
\f[V]iptrap\f[R] and \f[V]ipuntrap\f[R] cannot setup both IPv4 and IPv6
traps with one call.
The reason is that the \f[V]ipset\f[R] can either be IPv4 or IPv6.
.PP
Both helpers will create the \f[V]ipset\f[R] specified, if that ipset is
not already created by other statements.
When the ipset is created by the \f[V]iptrap\f[R] helper, the ipset will
not be reset (emptied) when the firewall is restarted.
.PP
The ipset options used when these helpers create ipsets can be
controlled with the variable IPTRAP_DEFAULT_IPSET_OPTIONS.
.SH EXAMPLES
.IP
.nf
\f[C]
 # Example: mini-IDS
 # add to the ipset \[ga]trap\[ga] for an hour (3600 seconds) all IPs from all packets
 # coming from eth0 and going to tcp/3306 (mysql).
 iptrap4 src trap 3600 inface eth0 proto tcp dport 3306 log \[dq]TRAPPED HTTP\[dq]
 # block them
 blacklist4 full inface eth0 log \[dq]BLOCKED\[dq] src ipset:trap except src ipset:whitelist

 # Example: ipuntrap
 ipuntrap4 src trap inface eth0 src ipset:trap proto tcp dport 80 log \[dq]UNTRAPPED HTTP\[dq]

 # Example: a knock
 # The user will be able to knock at tcp/12345
 iptrap4 src knock1 30 inface eth0 proto tcp dport 12345 log \[dq]KNOCK STEP 1\[dq]
 # in 30 seconds knock at tcp/23456
 iptrap4 src knock2 60 inface eth0 proto tcp dport 23456 src ipset:knock1 log \[dq]KNOCK STEP 2\[dq]
 # in 60 seconds knock at tcp/34566
 iptrap4 src knock3 90 inface eth0 proto tcp dport 34567 src ipset:knock2 log \[dq]KNOCK STEP 3\[dq]
 #
 # and in 90 seconds ssh
 interface ...
     server ssh accept src ipset:knock3
\f[R]
.fi
.SH SEE ALSO
.IP \[bu] 2
firehol(1) - FireHOL program
.IP \[bu] 2
firehol.conf(5) - FireHOL configuration
.IP \[bu] 2
FireHOL Website (http://firehol.org/)
.IP \[bu] 2
FireHOL Online PDF Manual (http://firehol.org/firehol-manual.pdf)
.IP \[bu] 2
FireHOL Online Documentation (http://firehol.org/documentation/)
.SH AUTHORS
FireHOL Team.