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Util(3pm)             User Contributed Perl Documentation            Util(3pm)



NAME
       NetAddr::IP::Util -- IPv4/6 and 128 bit number utilities

SYNOPSIS
         use NetAddr::IP::Util qw(
               inet_aton
               inet_ntoa
               ipv6_aton
               ipv6_n2x
               ipv6_n2d
               inet_any2n
               hasbits
               isIPv4
               inet_n2dx
               inet_n2ad
               ipv4to6
               mask4to6
               ipanyto6
               maskanyto6
               ipv6to4
               shiftleft
               addconst
               add128
               sub128
               notcontiguous
               bin2bcd
               bcd2bin
               mode
         );

         use NetAddr::IP::Util qw(:all :inet :ipv4 :ipv6 :math)

         :inet   =>    inet_aton, inet_ntoa, ipv6_aton,
                       ipv6_n2x, ipv6_n2d, inet_any2n,
                       inet_n2dx, inet_n2ad, ipv4to6,
                       mask4to6, ipanyto6, maskanyto6,
                       ipv6to4

         :ipv4   =>    inet_aton, inet_ntoa

         :ipv6   =>    ipv6_aton, ipv6_n2x, ipv6_n2d,
                       inet_any2n, inet_n2dx, inet_n2ad
                       ipv4to6, mask4to6, ipanyto6,
                       maskanyto6, ipv6to4

         :math   =>    hasbits, isIPv4, addconst,
                       add128, sub128, notcontiguous,
                       bin2bcd, bcd2bin, shiftleft

         $dotquad = inet_ntoa($netaddr);
         $netaddr = inet_aton($dotquad);
         $ipv6naddr = ipv6_aton($ipv6_text);
         $hex_text = ipv6_n2x($ipv6naddr);
         $dec_text = ipv6_n2d($ipv6naddr);
         $ipv6naddr = inet_any2n($dotquad or $ipv6_text);
         $rv = hasbits($bits128);
         $rv = isIPv4($bits128);
         $dotquad or $hex_text = inet_n2dx($ipv6naddr);
         $dotquad or $dec_text = inet_n2ad($ipv6naddr);
         $ipv6naddr = ipv4to6($netaddr);
         $ipv6naddr = mask4to6($netaddr);
         $ipv6naddr = ipanyto6($netaddr);
         $ipv6naddr = maskanyto6($netaddr);
         $netaddr = ipv6to4($pv6naddr);
         $bitsX2 = shiftleft($bits128,$n);
         $carry = addconst($ipv6naddr,$signed_32con);
         ($carry,$ipv6naddr)=addconst($ipv6naddr,$signed_32con);
         $carry = add128($ipv6naddr1,$ipv6naddr2);
         ($carry,$ipv6naddr)=add128($ipv6naddr1,$ipv6naddr2);
         $carry = sub128($ipv6naddr1,$ipv6naddr2);
         ($carry,$ipv6naddr)=sub128($ipv6naddr1,$ipv6naddr2);
         ($spurious,$cidr) = notcontiguous($mask128);
         $bcdtext = bin2bcd($bits128);
         $bits128 = bcd2bin($bcdtxt);
         $modetext = mode;

INSTALLATION
       Un-tar the distribution in an appropriate directory and type:

               perl Makefile.PL
               make
               make test
               make install

       NetAddr::IP::Util installs by default with its primary functions
       compiled using Perl's XS extensions to build a 'C' library. If you do
       not have a 'C' complier available or would like the slower Pure Perl
       version for some other reason, then type:

               perl Makefile.PL -noxs
               make
               make test
               make install

DESCRIPTION
       NetAddr::IP::Util provides a suite of tools for manipulating and
       converting IPv4 and IPv6 addresses into 128 bit string context and back
       to text. The strings can be manipulated with Perl's logical operators:

               and     &
               or      |
               xor     ^

       in the same manner as 'vec' strings.

       The IPv6 functions support all rfc1884 formats.

         i.e.  x:x:x:x:x:x:x:x:x
               x:x:x:x:x:x:x:d.d.d.d
               ::x:x:x
               ::x:d.d.d.d
         and so on...

       o   $dotquad = inet_ntoa($netaddr);

           Convert a packed IPv4 network address to a dot-quad IP address.

             input:        packed network address
             returns:      IP address i.e. 10.4.12.123

       o   $netaddr = inet_aton($dotquad);

           Convert a dot-quad IP address into an IPv4 packed network address.

             input:        IP address i.e. 192.5.16.32
             returns:      packed network address

       o   $ipv6addr = ipv6_aton($ipv6_text);

           Takes an IPv6 address of the form described in rfc1884 and returns
           a 128 bit binary RDATA string.

             input:        ipv6 text
             returns:      128 bit RDATA string

       o   $hex_text = ipv6_n2x($ipv6addr);

           Takes an IPv6 RDATA string and returns an 8 segment IPv6 hex
           address

             input:        128 bit RDATA string
             returns:      x:x:x:x:x:x:x:x

       o   $dec_text = ipv6_n2d($ipv6addr);

           Takes an IPv6 RDATA string and returns a mixed hex - decimal IPv6
           address with the 6 uppermost chunks in hex and the lower 32 bits in
           dot-quad representation.

             input:        128 bit RDATA string
             returns:      x:x:x:x:x:x:d.d.d.d

       o   $ipv6naddr = inet_any2n($dotquad or $ipv6_text);

           This function converts a text IPv4 or IPv6 address in text format
           in any standard notation into a 128 bit IPv6 string address. It
           prefixes any dot-quad address (if found) with '::' and passes it to
           ipv6_aton.

             input:        dot-quad or rfc1844 address
             returns:      128 bit IPv6 string

       o   $rv = hasbits($bits128);

           This function returns true if there are one's present in the 128
           bit string and false if all the bits are zero.

             i.e.  if (hasbits($bits128)) {
                     &do_something;
                   }

             or    if (hasbits($bits128 & $mask128) {
                     &do_something;
                   }

           This allows the implementation of logical functions of the form of:

                   if ($bits128 & $mask128) {
                       ...

             input:        128 bit IPv6 string
             returns:      true if any bits are present

       o   $rv = isIPv4($bits128);

           This function returns true if there are no on bits present in the
           IPv6 portion of the 128 bit string and false otherwise.

       o   $dotquad or $hex_text = inet_n2dx($ipv6naddr);

           This function does the right thing and returns the text for either
           a dot-quad IPv4 or a hex notation IPv6 address.

             input:        128 bit IPv6 string
             returns:      ddd.ddd.ddd.ddd
                       or  x:x:x:x:x:x:x:x

       o   $dotquad or $dec_text = inet_n2ad($ipv6naddr);

           This function does the right thing and returns the text for either
           a dot-quad IPv4 or a hex::decimal notation IPv6 address.

             input:        128 bit IPv6 string
             returns:      ddd.ddd.ddd.ddd
                       or  x:x:x:x:x:x:ddd.ddd.ddd.dd

       o   $ipv6naddr = ipv4to6($netaddr);

           Convert an ipv4 network address into an ipv6 network address.

             input:        32 bit network address
             returns:      128 bit network address

       o   $ipv6naddr = mask4to6($netaddr);

           Convert an ipv4 network address/mask into an ipv6 network mask.

             input:        32 bit network/mask address
             returns:      128 bit network/mask address

           NOTE: returns the high 96 bits as one's

       o   $ipv6naddr = ipanyto6($netaddr);

           Similar to ipv4to6 except that this function takes either an IPv4
           or IPv6 input and always returns a 128 bit IPv6 network address.

             input:        32 or 128 bit network address
             returns:      128 bit network address

       o   $ipv6naddr = maskanyto6($netaddr);

           Similar to mask4to6 except that this function takes either an IPv4
           or IPv6 netmask and always returns a 128 bit IPv6 netmask.

             input:        32 or 128 bit network mask
             returns:      128 bit network mask

       o   $netaddr = ipv6to4($pv6naddr);

           Truncate the upper 96 bits of a 128 bit address and return the
           lower 32 bits. Returns an IPv4 address as returned by inet_aton.

             input:        128 bit network address
             returns:      32 bit inet_aton network address

       o   $bitsXn = shiftleft($bits128,$n);

             input:        128 bit string variable,
                           number of shifts [optional]
             returns:      bits X n shifts

             NOTE: a single shift is performed
                   if $n is not specified

       o   addconst($ipv6naddr,$signed_32con);

           Add a signed constant to a 128 bit string variable.

             input:        128 bit IPv6 string,
                           signed 32 bit integer
             returns:  scalar      carry
                       array       (carry, result)

       o   add128($ipv6naddr1,$ipv6naddr2);

           Add two 128 bit string variables.

             input:        128 bit string var1,
                           128 bit string var2
             returns:  scalar      carry
                       array       (carry, result)

       o   sub128($ipv6naddr1,$ipv6naddr2);

           Subtract two 128 bit string variables.

             input:        128 bit string var1,
                           128 bit string var2
             returns:  scalar      carry
                       array       (carry, result)

           Note: The carry from this operation is the result of adding the
           one's complement of ARG2 +1 to the ARG1. It is logically NOT
           borrow.

                   i.e.    if ARG1 >= ARG2 then carry = 1
                   or      if ARG1  < ARG2 then carry = 0

       o   ($spurious,$cidr) = notcontiguous($mask128);

           This function counts the bit positions remaining in the mask when
           the rightmost '0's are removed.

                   input:  128 bit netmask
                   returns true if there are spurious
                               zero bits remaining in the
                               mask, false if the mask is
                               contiguous one's,
                           128 bit cidr number

       o   $bcdtext = bin2bcd($bits128);

           Convert a 128 bit binary string into binary coded decimal text
           digits.

             input:        128 bit string variable
             returns:      string of bcd text digits

       o   $bits128 = bcd2bin($bcdtxt);

           Convert a bcd text string to 128 bit string variable

             input:        string of bcd text digits
             returns:      128 bit string variable

       o   $modetext = mode;

           Returns the operating mode of this module.

                   input:          none
                   returns:        "Pure Perl"
                              or   "CC XS"

EXAMPLES
         # convert any textual IP address into a 128 bit vector
         #
         sub text2vec {
           my($anyIP,$anyMask) = @_;

         # not IPv4 bit mask
           my $notiv4 = ipv6_aton('FFFF:FFFF:FFFF:FFFF:FFFF:FFFF::');

           my $vecip   = inet_any2n($anyIP);
           my $mask    = inet_any2n($anyMask);

         # extend mask bits for IPv4
           my $bits = 128;     # default
           unless (hasbits($mask & $notiv4)) {
             $mask |= $notiv4;
             $bits = 32;
           }
           return ($vecip, $mask, $bits);
         }

         ... alternate implementation, a little faster

         sub text2vec {
           my($anyIP,$anyMask) = @_;

         # not IPv4 bit mask
           my $notiv4 = ipv6_aton('FFFF:FFFF:FFFF:FFFF:FFFF:FFFF::');

           my $vecip   = inet_any2n($anyIP);
           my $mask    = inet_any2n($anyMask);

         # extend mask bits for IPv4
           my $bits = 128;     # default
           if (isIPv4($mask)) {
             $mask |= $notiv4;
             $bits = 32;
           }
           return ($vecip, $mask, $bits);
         }


         ... elsewhere
           $nip = {
               addr    => $vecip,
               mask    => $mask,
               bits    => $bits,
           };

         # return network and broadcast addresses from IP and Mask
         #
         sub netbroad {
           my($nip) = shift;
           my $notmask = ~ $nip->{mask};
           my $bcast   = $nip->{addr} | $notmask;
           my $network = $nip->{addr} & $nip->{mask};
           return ($network, $broadcast);
         }

         # check if address is within a network
         #
         sub within {
           my($nip,$net) = @_;
           my $addr = $nip->{addr}
           my($nw,$bc) = netbroad($net);
         # arg1 >= arg2, sub128 returns true
           return (sub128($addr,$nw) && sub128($bc,$addr))
               ? 1 : 0;
         }

         # add a constant, wrapping at netblock boundries
         # to subtract the constant, negate it before calling
         # 'addwrap' since 'addconst' will extend the sign bits
         #
         sub addwrap {
           my($nip,$const) = @_;
           my $mask    = $nip->{addr};
           my $bits    = $nip->{bits};
           my $notmask = ~ $mask;
           my $hibits  = $addr & $mask;
           my $addr = addconst($addr,$const);
           my $wraponly = $addr & $notmask;
           my $newip = {
               addr    => $hibits | $wraponly,
               mask    => $mask,
               bits    => $bits,
           };
           # bless $newip as appropriate
           return $newip;
         }

EXPORT_OK
               inet_aton
               inet_ntoa
               ipv6_aton
               ipv6_n2x
               ipv6_n2d
               inet_any2n
               hasbits
               isIPv4
               inet_n2dx
               inet_n2ad
               ipv4to6
               mask4to6
               ipanyto6
               maskanyto6
               ipv6to4
               shiftleft
               addconst
               add128
               sub128
               notcontiguous
               bin2bcd
               bcd2bin
               mode

AUTHOR
       Michael Robinton <michaelATbizsystems.com>

ACKNOWLEDGEMENTS
       The following functions are used in whole or in part as include files
       to Util.xs. The copyright is include in the file.

         file:              function:

         miniSocket.inc  inet_aton, inet_ntoa

       inet_aton, inet_ntoa are from the perl-5.8.0 release by Larry Wall,
       copyright 1989-2002. inet_aton, inet_ntoa code is current through
       perl-5.9.3 release.  Thank you Larry for making PERL possible for all
       of us.

COPYRIGHT
       Copyright 2003 - 2007, Michael Robinton <michaelATbizsystems.com>

       LICENSE AND WARRANTY

       This software is (c) Michael Robinton.  It can be used under the terms
       of the perl artistic license provided  that proper credit for the work
       of the  author is  preserved in  the form  of this  copyright  notice
       and license for this module.

       No warranty of any kind is  expressed or implied, by using it you
       accept any and all the liability.

AUTHOR
       Michael Robinton <michaelATbizsystems.com>



perl v5.10.0                      2007-06-07                         Util(3pm)