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').

   extractIPs
           @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)