NAME¶
Paranoid::Network - Network functions for paranoid programs
VERSION¶
$Id: Network.pm,v 0.68 2012/05/29 21:38:19 acorliss Exp $
SYNOPSIS¶
use Paranoid::Network;
$rv = ipInNetwork($ip, @networks);
$rv = hostInDomain($host, @domains);
@ips = extractIP($string1, $string2);
$rv = netIntersect( $cidr1, $cidr2 );
DESCRIPTION¶
This modules contains functions that may be useful for network operations. IPv6
is supported out of the box starting with Perl 5.14. Earlier versions of Perl
will require
Socket6(3) installed as well. If it is available this
module will use it automatically.
SUBROUTINES/METHODS¶
ipInNetwork¶
$rv = ipInNetwork($ip, @networks);
This function checks the passed IP against each of the networks or IPs in the
list and returns true if there's a match. The list of networks can be either
individual IP address or network addresses in CIDR notation or with full
netmasks:
@networks = qw(127.0.0.1
192.168.0.0/24
172.16.12.0/255.255.240.0);
IPv6 is supported if the
Socket6(3) module is installed or you're running
Perl 5.14 or higher. This routine will select the appropriate address family
based on the IP you're testing and filter out the opposing address family in
the list.
NOTE: IPv4 addresses encoded as IPv6 addresses, e.g.:
::ffff:192.168.0.5
are supported, however an IP address submitted in this format as the IP to test
for will be converted to a pure IPv4 address and compared only against the
IPv4 networks. This is meant as a convenience to the developer supporting
dual-stack systems to avoid having to list IPv4 networks in the array twice
like so:
::ffff:192.168.0.0/120, 192.168.0.0/24
Just list IPv4 as IPv4, IPv6 as IPv6, and this routine will convert IPv6-encoded
IPv4 addresses automatically. This would make the following test return a true
value:
ipInNetwork( '::ffff:192.168.0.5', '192.168.0.0/24' );
but
ipInNetwork( '::ffff:192.168.0.5', '::ffff:192.168.0.0/120' );
return a false value. This may seem counter intuitive, but it simplifies things
in (my alternate) reality.
Please note that this automatic conversion only applies to the
IP
argument, not to any member of the network array.
hostInDomain¶
$rv = hostInDomain($host, @domains);
This function checks the passed hostname (fully qualified) against each of the
domains in the list and returns true if there's a match. None of the domains
should have the preceding '.' (i.e., 'foo.com' rather than '.foo.com').
@ips = extractIP($string1, $string2);
This function extracts IP addresses from arbitrary text. If you have
Socket6(3) installed or running Perl 5.14 or higher it will extract
IPv6 addresses as well as IPv4 addresses. This extracts only IP addresses, not
network addresses in CIDR or dotted octet notation. In the case of the latter
the netmask will be extracted as an additional address.
NOTE: in the interest of performance this function does only rough regex
extraction of IP-looking candidates, then runs them through
inet_aton
(for IPv4) and
inet_pton (for IPv6) to see if they successfully
convert. Even with the overhead of
Paranoid (with debugging and
loadModule calls for Socket6 and what-not) it seems that this is an
order of a magnitude faster than doing a pure regex extraction &
validation of IPv6 addresses.
NOTE: Like the
ipInNetwork function we filter out IPv4 addresses
encoded as IPv6 addresses since that address is already returned as a pure
IPv4 address.
netIntersect¶
$rv = netIntersect( $cidr1, $cidr2 );
This function is an IPv4/IPv6 agnostic wrapper for the
ipv{4,6}NetIntersect functions provided by Paranoid::Network::IPv{4,6}
modules. The return value from which ever function called is passed on
directly. Passing this function non-IP or undefined values simply returns a
zero.
DEPENDENCIES¶
- o
- Paranoid
- o
- Paranoid::Network::Socket
- o
- Paranoid::Network::IPv4
- o
- Paranoid::Network::IPv6
BUGS AND LIMITATIONS¶
AUTHOR¶
Arthur Corliss (corliss@digitalmages.com)
LICENSE AND COPYRIGHT¶
This software is licensed under the same terms as Perl, itself. Please see
http://dev.perl.org/licenses/ for more information.
(c) 2005, Arthur Corliss (corliss@digitalmages.com)