Util(3)

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;

  NetAddr::IP::Util::lower();
  NetAddr::IP::Util::upper();

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     ^
                ~       compliment

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...

•   $dotquad = inet_ntoa($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

•   $netaddr = inet_aton($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

•   $ipv6addr = ipv6_aton($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

•   $hex_text = ipv6_n2x($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

•   $dec_text = ipv6_n2d($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

•   $ipv6naddr = inet_any2n($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

•   $rv = hasbits($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

•   $rv = isIPv4($bits128);

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

•   $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

•   $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

•   $ipv6naddr = ipv4to6($netaddr);

    Convert an ipv4 network address into an ipv6 network address.

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

•   $ipv6naddr = mask4to6($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

•   $ipv6naddr = ipanyto6($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

•   $ipv6naddr = maskanyto6($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

•   $netaddr = ipv6to4($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

•   $bitsXn = shiftleft($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

•   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)

•   add128($ipv6naddr1,$ipv6naddr2);

    Add two 128 bit string variables.

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

•   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

•   ($spurious,$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

•   $bcdtext = bin2bcd($bits128);

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

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

•   $bits128 = bcd2bin($bcdtxt);

    Convert a bcd text string to 128 bit string variable

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

•   $modetext = mode;

    Returns the operating mode of this module.

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

•   NetAddr::IP::Util::lower();

    Return IPv6 strings in lowercase.

•   NetAddr::IP::Util::upper();

    Return IPv6 strings in uppercase. This is the default.

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 boundaries
  # 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 <michael@bizsystems.com>

ACKNOWLEDGMENTS
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 - 2008, Michael Robinton <michael@bizsystems.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 <michael@bizsystems.com>