NAME

ippool, ippool.conf - IP Pool file format

DESCRIPTION

The format for files accepted by ippool is described by the following grammar:

line ::= table | groupmap .
table ::= "table" role tabletype .
groupmap ::= "group-map" inout role number ipfgroup
tabletype ::= ipftree | ipfhash .
role ::= "role" "=" "ipf" .
inout ::= "in" | "out" .
ipftree ::= "type" "=" "tree" number "{" addrlist "}" .
ipfhash ::= "type" "=" "hash" number hashopts "{" hashlist "}" .
ipfgroup ::= setgroup hashopts "{" grouplist "}" |
             hashopts "{" setgrouplist "}" .
setgroup ::= "group" "=" groupname .
hashopts ::= size [ seed ] | seed .
size ::= "size" number .
seed ::= "seed" number .
addrlist ::= [ "!" ] addrmask ";" [ addrlist ] .
grouplist ::= groupentry ";" [ grouplist ] | addrmask ";" [ grouplist ] .
setgrouplist ::= groupentry ";" [ setgrouplist ] .
groupentry ::= addrmask "," setgroup .
hashlist ::= hashentry ";" [ hashlist ] .
hashentry ::= addrmask .
addrmask ::= ipaddr | ipaddr "/" mask .
mask ::= number | ipaddr .
groupname ::= number | name .
number ::= digit { digit } .
ipaddr  = host-num "." host-num "." host-num "." host-num .
host-num = digit [ digit [ digit ] ] .
digit ::= "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9" .
name ::= letter { letter | digit } .

The IP pool configuration file is used for defining a single object that contains a reference to multiple IP address/netmask pairs. A pool may consist of a mixture of netmask sizes, from 0 to 32.

At this point in time, only IPv4 addressing is supported.

OVERVIEW

The IP pool configuration file provides for defining two different mechanisms for improving speed in matching IP addresses with rules. The first, table , defines a lookup table to provide a single reference in a filter rule to multiple targets and the second, group-map , provides a mechanism to target multiple groups from a single filter line.

The group-map command can only be used with filter rules that use the call command to invoke either fr_srcgrpmap or fr_dstgrpmap , to use the source or destination address, respectively, for determining which filter group to jump to next for continuation of filter packet processing.

POOL TYPES

Two storage formats are provided: hash tables and tree structure. The hash table is intended for use with objects all containing the same netmask or a few different sized netmasks of non-overlapping address space and the tree is designed for being able to support exceptions to a covering mask, in addition to normal searching as you would do with a table. It is not possible to use the tree data storage type with group-map configuration entries.

POOL ROLES

When a pool is defined in the configruation file, it must have an associated role. At present the only supported role is ipf. Future development will see futher expansion of their use by other sections of IPFilter code.

EXAMPLES

The following examples show how the pool configuration file is used with the ipf configuration file to enhance the ability for the ipf configuration file to be succinct in meaning.

1

The first example shows how a filter rule makes reference to a specific pool for matching of the source address.

pass in from pool/100 to any

The pool configuration, which matches IP addresses 1.1.1.1 and any in 2.2.0.0/16, except for those in 2.2.2.0/24.

table role = ipf type = tree number = 100
        { 1.1.1.1/32; 2.2.0.0/16; !2.2.2.0/24 };

2

The following ipf.conf extract uses the fr_srcgrpmap/fr_dstgrpmap lookups to use the group-map facility to lookup the next group to use for filter processing, providing the call filter rule is matched.

call now fr_srcgrpmap/1010 in all
call now fr_dstgrpmap/2010 out all
pass in all group 1020
block in all group 1030
pass out all group 2020
block out all group 2040

A ippool configuration to work with the above ipf.conf file might look like this:

group-map in role = ipf number = 1010
	{ 1.1.1.1/32, group = 1020; 3.3.0.0/16, group = 1030; };
group-map out role = ipf number = 2010 group = 2020
	{ 2.2.2.2/32; 4.4.0.0/16; 5.0.0.0/8, group = 2040; };

FILES

/dev/iplookup
/etc/ippool.conf
/etc/hosts