NetAddr::IP::Util.3pm

Langue: en

Version: 2006-08-14 (openSuse - 09/10/07)

Section: 3 (Bibliothèques de fonctions)

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...



* $dotquad = inet_ntoa($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"



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 <michael@bizsystems.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 2003 - 2006, 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>