IP(3) User Contributed Perl Documentation IP(3)NAMENetAddr::IP - Manages IPv4 and IPv6 addresses and subnets
SYNOPSIS
use NetAddr::IP qw(
Compact
Coalesce
Zero
Ones
V4mask
V4net
:aton
:old_storable
:old_nth
);
my $ip = new NetAddr::IP 'loopback';
print "The address is ", $ip->addr, " with mask ", $ip->mask, "\n" ;
if ($ip->within(new NetAddr::IP "127.0.0.0", "255.0.0.0")) {
print "Is a loopback address\n";
}
# This prints 127.0.0.1/32
print "You can also say $ip...\n";
* The following four functions return ipV6 representations of:
:: = Zeros();
FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF: = Ones();
FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:: = V4mask();
::FFFF:FFFF = V4net();
* To accept addresses in the format as returned by inet_aton, invoke
the module as:
use NetAddr::IP qw(:aton);
* To enable usage of legacy data files containing NetAddr::IP objects
stored using the Storable module.
use NetAddr::IP qw(:old_storable);
* To compact many smaller subnets (see: "$me->compact($addr1,
$addr2,...)"
@compacted_object_list = Compact(@object_list)
* Return a reference to list of "NetAddr::IP" subnets of $masklen mask
length, when $number or more addresses from @list_of_subnets are found
to be contained in said subnet.
$arrayref = Coalesce($masklen, $number, @list_of_subnets)
INSTALLATION
Un-tar the distribution in an appropriate directory and type:
perl Makefile.PL
make
make test
make install
NetAddr::IP depends on NetAddr::IP::Util which 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
This module provides an object-oriented abstraction on top of IP
addresses or IP subnets, that allows for easy manipulations. Version
4.xx of NetAdder::IP will will work older versions of Perl and does not
use Math::BigInt as in previous versions.
The internal representation of all IP objects is in 128 bit IPv6
notation. IPv4 and IPv6 objects may be freely mixed.
Overloaded Operators
Many operators have been overloaded, as described below:
Assignment ("=")
Has been optimized to copy one NetAddr::IP object to another very
quickly.
"->copy()"
The assignment ("=") operation is only put in to operation when the
copied object is further mutated by another overloaded operation.
See overload SPECIAL SYMBOLS FOR "use overload" for details.
"->copy()" actually creates a new object when called.
Stringification
An object can be used just as a string. For instance, the following
code
my $ip = new NetAddr::IP '192.168.1.123';
print "$ip\n";
Will print the string 192.168.1.123/32.
Equality
You can test for equality with either "eq" or "==". "eq" allows the
comparison with arbitrary strings as well as NetAddr::IP objects.
The following example:
if (NetAddr::IP->new('127.0.0.1','255.0.0.0') eq '127.0.0.1/8')
{ print "Yes\n"; }
Will print out "Yes".
Comparison with "==" requires both operands to be NetAddr::IP
objects.
In both cases, a true value is returned if the CIDR representation
of the operands is equal.
Comparison via >, <, >=, <=, <=> and "cmp"
Internally, all network objects are represented in 128 bit format.
The numeric representation of the network is compared through the
corresponding operation. Comparisons are tried first on the address
portion of the object and if that is equal then the cidr portion of
the masks are compared.
Addition of a constant
Adding a constant to a NetAddr::IP object changes its address part
to point to the one so many hosts above the start address. For
instance, this code:
print NetAddr::IP->new('127.0.0.1') + 5;
will output 127.0.0.6/8. The address will wrap around at the
broadcast back to the network address. This code:
print NetAddr::IP->new('10.0.0.1/24') + 255;
outputs 10.0.0.0/24.
Substraction of a constant
The complement of the addition of a constant.
Auto-increment
Auto-incrementing a NetAddr::IP object causes the address part to
be adjusted to the next host address within the subnet. It will
wrap at the broadcast address and start again from the network
address.
Auto-decrement
Auto-decrementing a NetAddr::IP object performs exactly the
opposite of auto-incrementing it, as you would expect.
Serializing and Deserializing
This module defines hooks to collaborate with Storable for serializing
"NetAddr::IP" objects, through compact and human readable strings. You
can revert to the old format by invoking this module as
use NetAddr::IP ':old_storable';
You must do this if you have legacy data files containing NetAddr::IP
objects stored using the Storable module.
Methods
"->new([$addr, [ $mask|IPv6 ]])"
"->new6([$addr, [ $mask]])"
These methods creates a new address with the supplied address in
$addr and an optional netmask $mask, which can be omitted to get a
/32 or /128 netmask for IPv4 / IPv6 addresses respectively
"->new6" marks the address as being in ipV6 address space even if
the format would suggest otherwise.
i.e. ->new6('1.2.3.4') will result in ::102:304
addresses submitted to ->new in ipV6 notation will
remain in that notation permanently. i.e.
->new('::1.2.3.4') will result in ::102:304
whereas new('1.2.3.4') would print out as 1.2.3.4
See "STRINGIFICATION" below.
$addr can be almost anything that can be resolved to an IP address
in all the notations I have seen over time. It can optionally
contain the mask in CIDR notation.
prefix notation is understood, with the limitation that the range
speficied by the prefix must match with a valid subnet.
Addresses in the same format returned by "inet_aton" or
"gethostbyname" can also be understood, although no mask can be
specified for them. The default is to not attempt to recognize this
format, as it seems to be seldom used.
To accept addresses in that format, invoke the module as in
use NetAddr::IP ':aton'
If called with no arguments, 'default' is assumed.
$addr can be any of the following and possibly more...
n.n
n.n/mm
n.n.n
n.n.n/mm
n.n.n.n
n.n.n.n/mm 32 bit cidr notation
n.n.n.n/m.m.m.m
loopback, localhost, broadcast, any, default
x.x.x.x/host
0xABCDEF, 0b111111000101011110, (a bcd number)
a netaddr as returned by 'inet_aton'
Any RFC1884 notation
::n.n.n.n
::n.n.n.n/mmm 128 bit cidr notation
::n.n.n.n/::m.m.m.m
::x:x
::x:x/mmm
x:x:x:x:x:x:x:x
x:x:x:x:x:x:x:x/mmm
x:x:x:x:x:x:x:x/m:m:m:m:m:m:m:m any RFC1884 notation
loopback, localhost, unspecified, any, default
::x:x/host
0xABCDEF, 0b111111000101011110 within the limits
of perl's number resolution
123456789012 a 'big' bcd number i.e. Math::BigInt
If called with no arguments, 'default' is assumed.
"->broadcast()"
Returns a new object refering to the broadcast address of a given
subnet. The broadcast address has all ones in all the bit positions
where the netmask has zero bits. This is normally used to address
all the hosts in a given subnet.
"->network()"
Returns a new object refering to the network address of a given
subnet. A network address has all zero bits where the bits of the
netmask are zero. Normally this is used to refer to a subnet.
"->addr()"
Returns a scalar with the address part of the object as an IPv4 or
IPv6 text string as appropriate. This is useful for printing or for
passing the address part of the NetAddr::IP object to other
components that expect an IP address. If the object is an ipV6
address or was created using ->new6($ip) it will be reported in
ipV6 hex format otherwise it will be reported in dot quad format
only if it resides in ipV4 address space.
"->mask()"
Returns a scalar with the mask as an IPv4 or IPv6 text string as
described above.
"->masklen()"
Returns a scalar the number of one bits in the mask.
"->bits()"
Returns the width of the address in bits. Normally 32 for v4 and
128 for v6.
"->version()"
Returns the version of the address or subnet. Currently this can be
either 4 or 6.
"->cidr()"
Returns a scalar with the address and mask in CIDR notation. A
NetAddr::IP object stringifies to the result of this function.
(see comments about ->new6() and ->addr() for output formats)
"->aton()"
Returns the address part of the NetAddr::IP object in the same
format as the "inet_aton()" or "ipv6_aton" function respectively.
If the object was created using ->new6($ip), the address returned
will always be in ipV6 format, even for addresses in ipV4 address
space.
"->range()"
Returns a scalar with the base address and the broadcast address
separated by a dash and spaces. This is called range notation.
"->prefix()"
Returns a scalar with the address and mask in ipV4 prefix
representation. This is useful for some programs, which expect its
input to be in this format. This method will include the broadcast
address in the encoding.
"->nprefix()"
Just as "->prefix()", but does not include the broadcast address.
"->numeric()"
When called in a scalar context, will return a numeric
representation of the address part of the IP address. When called
in an array contest, it returns a list of two elements. The first
element is as described, the second element is the numeric
representation of the netmask.
This method is essential for serializing the representation of a
subnet.
"->wildcard()"
When called in a scalar context, returns the wildcard bits
corresponding to the mask, in dotted-quad or ipV6 format as
applicable.
When called in an array context, returns a two-element array. The
first element, is the address part. The second element, is the
wildcard translation of the mask.
"->short()"
Returns the address part in a short or compact notation.
(ie, 127.0.0.1 becomes 127.1).
Works with both, V4 and V6.
"$me->contains($other)"
Returns true when $me completely contains $other. False is returned
otherwise and "undef" is returned if $me and $other are not both
"NetAddr::IP" objects.
"$me->within($other)"
The complement of "->contains()". Returns true when $me is
completely con tained within $other.
Note that $me and $other must be "NetAddr::IP" objects.
"->split($bits)"
Returns a list of objects, representing subnets of $bits mask
produced by splitting the original object, which is left unchanged.
Note that $bits must be longer than the original mask in order for
it to be splittable.
Note that $bits can be given as an integer (the length of the mask)
or as a dotted-quad. If omitted, a host mask is assumed.
"->splitref($bits)"
A (faster) version of "->split()" that returns a reference to a
list of objects instead of a real list. This is useful when large
numbers of objects are expected.
Return undef if the number of subnets > 2 ** 32
"->hostenum()"
Returns the list of hosts within a subnet.
"->hostenumref()"
Faster version of "->hostenum()", returning a reference to a list.
"$me->compact($addr1, $addr2, ...)"
"@compacted_object_list = Compact(@object_list)"
Given a list of objects (including $me), this method will compact
all the addresses and subnets into the largest (ie, least specific)
subnets possible that contain exactly all of the given objects.
Note that in versions prior to 3.02, if fed with the same IP
subnets multiple times, these subnets would be returned. From 3.02
on, a more "correct" approach has been adopted and only one address
would be returned.
Note that $me and all $addr's must be "NetAddr::IP" objects.
"$me->compactref(\@list)"
As usual, a faster version of =item "->compact()" that returns a
reference to a list. Note that this method takes a reference to a
list instead.
Note that $me must be a "NetAddr::IP" object.
"$me->coalesce($masklen, $number, @list_of_subnets)"
"$arrayref = Coalesce($masklen,$number,@list_of_subnets)"
Will return a reference to list of "NetAddr::IP" subnets of
$masklen mask length, when $number or more addresses from
@list_of_subnets are found to be contained in said subnet.
Subnets from @list_of_subnets with a mask shorter than $masklen are
passed "as is" to the return list.
Subnets from @list_of_subnets with a mask longer than $masklen will
be counted (actually, the number of IP addresses is counted)
towards $number.
Called as a method, the array will include $me.
WARNING: the list of subnet must be the same type. i.e ipV4 or ipV6
"->first()"
Returns a new object representing the first usable IP address
within the subnet (ie, the first host address).
"->last()"
Returns a new object representing the last usable IP address within
the subnet (ie, one less than the broadcast address).
"->nth($index)"
Returns a new object representing the n-th usable IP address within
the subnet (ie, the n-th host address). If no address is available
(for example, when the network is too small for $index hosts),
"undef" is returned.
Version 4.00 of NetAddr::IP and version 1.00 of NetAddr::IP::Lite
implements "->nth($index)" and "->num()" exactly as the
documentation states. Previous versions behaved slightly
differently and not in a consistent manner. See the README file for
details.
To use the old behavior for "->nth($index)" and "->num()":
use NetAddr::IP::Lite qw(:old_nth);
"->num()"
Version 4.00 of NetAddr::IP and version 1.00 of NetAddr::IP::Lite
Returns the number of usable addresses IP addresses within the
subnet, not counting the broadcast or network address. Previous
versions returned th number of IP addresses not counting the
broadcast address.
To use the old behavior for "->nth($index)" and "->num()":
use NetAddr::IP::Lite qw(:old_nth);
"->re()"
Returns a Perl regular expression that will match an IP address
within the given subnet. Defaults to ipV4 notation. Will return an
ipV6 regex if the address in not in ipV4 space.
"->re6()"
Returns a Perl regular expression that will match an IP address
within the given subnet. Always returns an ipV6 regex.
EXPORT_OK
Compact
Coalesce
Zero
Ones
V4mask
V4net
HISTORY
$Id: IP.pm,v 4.4 2006/08/17 01:00:54 lem Exp $
0.01
· original version; Basic testing and release to CPAN as
version 0.01. This is considered beta software.
0.02
· Multiple changes to fix endiannes issues. This code is now
moderately tested on Wintel and Sun/Solaris boxes.
0.03
· Added ->first and ->last methods. Version changed to 0.03.
1.00
· Implemented ->new_subnet. Version changed to 1.00.
· less croak()ing when improper input is fed to the module. A
more consistent 'undef' is returned now instead to allow the
user to better handle the error.
1.10
· As per Marnix A. Van Ammers [mav6@ns02.comp.pge.com]
suggestion, changed the syntax of the loop in host_enum to be
the same of the enum method.
· Fixed the MS-DOS ^M at the end-of-line problem. This should
make the module easier to use for *nix users.
1.20
· Implemented ->compact and ->expand methods.
· Applying for official name
1.21
· Added ->addr_number and ->mask_bits. Currently we return
normal numbers (not BigInts). Please test this in your
platform and report any problems!
2.00
· Released under the new *official* name of NetAddr::IP
2.10
· Added support for ->new($min, $max, $bits) form
· Added ->to_numeric. This helps serializing objects
2.20
· Chris Dowling reported that the sort method introduced in
v1.20 for ->expand and ->compact doesn't always return a
number under perl versions < 5.6.0. His fix was applied and
redistributed. Thanks Chris!
· This module is hopefully released with no CR-LF issues!
· Fixed a warning about uninitialized values during make test
2.21
· Dennis Boylan pointed out a bug under Linux and perhaps
other platforms as well causing the error "Sort subroutine
didn't return single value at
/usr/lib/perl5/site_perl/5.6.0/NetAddr/IP.pm line 299, <>
line 2." or similar. This was fixed.
2.22
· Some changes suggested by Jeroen Ruigrok and Anton Berezin
were included. Thanks guys!
2.23
· Bug fix for /XXX.XXX.XXX.XXX netmasks under v5.6.1 suggested by
Tim Wuyts. Thanks!
· Tested the module under MACHTYPE=hppa1.0-hp-hpux11.00. It is
now konwn to work under Linux (Intel/AMD), Digital Unix
(Alpha), Solaris (Sun), HP-UX11 (HP-PA-RISC), Windows
9x/NT/2K (using ActiveState on Intel).
2.24
· A spurious warning when expand()ing with "-w" under certain
circumstances was removed. This involved using /31s, /32s
and the same netmask as the input. Thanks to Elie Rosenblum
for pointing it out.
· Slight change in license terms to ease redistribution as a
Debian package.
3.00
This is a major rewrite, supposed to fix a number of issues
pointed out in earlier versions.
The goals for this version include getting rid of BigInts, speeding
up and also cleaning up the code, which is written in a modular
enough way so as to allow IPv6 functionality in the future,
taking benefit from most of the methods.
Note that no effort has been made to remain backwards compatible
with earlier versions. In particular, certain semantics of the
earlier versions have been removed in favor of faster performance.
This version was tested under Win98/2K (ActiveState
5.6.0/5.6.1), HP-UX11 on PA-RISC (5.6.0), RedHat Linux 6.2
(5.6.0), Digital Unix on Alpha (5.6.0), Solaris on Sparc (5.6.0)
and possibly others.
3.01
· Added "->numeric()".
· "->new()" called with no parameters creates a default
NetAddr::IP object.
3.02
· Fxed "->compact()" for cases of equal subnets or mutually-
contained IP addresses as pointed out by Peter Wirdemo. Note
that now only distinct IP addresses will be returned by this
method.
· Fixed the docs as suggested by Thomas Linden.
· Introduced overloading to ease certain common operations.
·
Fixed compatibility issue with C<-E<gt>num()> on 64-bit processors.
3.03
· Added more comparison operators.
· As per Peter Wirdemo's suggestion, added "->wildcard()" for
producing subnets in wildcard format.
· Added "++" and "+" to provide for efficient iteration
operations over all the hosts of a subnet without
"->expand()"ing it.
3.04
· Got rid of "croak()" when invalid input was fed to "->new()".
· As suggested by Andrew Gaskill, added support for prefix
notation. Thanks for the code of the initial "->prefix()"
function.
3.05
· Added support for range notation, where base and broadcast
addresses are given as arguments to "->new()".
3.06
· Andrew Ruthven pointed out a bug related to proper
interpretation of "compact" CIDR blocks. This was fixed.
Thanks!
3.07
· Sami Pohto pointed out a bug with "->last()". This was fixed.
· A small bug related to parsing of 'localhost' was fixed.
3.08
· By popular request, "->new()" now checks the sanity of the
netmasks it receives. If the netmask is invalid, "undef" will
be returned.
3.09
· Fixed typo that invalidated otherwise correct masks. This bug
appeared in 3.08.
3.10
· Fixed relops. Semantics where adjusted to remove the netmask
from the comparison. (ie, it does not make sense to say that
10.0.0.0/24 is > 10.0.0.0/16 or viceversa).
3.11
· Thanks to David D. Zuhn for contributing the "->nth()" method.
· tutorial.htm now included in the distribution. I hope this
helps some people to better understand what kind of stuff can
be done with this module.
· 'any' can be used as a synonim of 'default'. Also, 'host' is
now a valid (/32) netmask.
3.12
· Added CVS control files, though this is of no relevance to the
community.
· Thanks to Steve Snodgrass for pointing out a bug in the
processing of the special names such as default, any, etc. A
fix was produced and adequate tests were added to the code.
· First steps towards "regexp free" parsing.
· Documentation revisited and reorganized within the file, so
that it helps document the code.
· Added "->aton()" and support for this format in "->new()". This
makes the code helpful to interface with old-style socket code.
3.13
· Fixes a warning related to 'wrapping', introduced in 3.12 in
"pack()"/"unpack()" for the new support for "->aton()".
3.14
· "Socket::gethostbyaddr" in Solaris seems to behave a bit
different from other OSes. Reversed change in 3.13 and added
code around this difference.
3.14_1
This is an interim release just to incorporate the v6 patches
contributed. No extensive testing has been done with this support
yet. More tests are needed.
· Preliminary support for IPv6 contributed by Kadlecsik Jozsi
<kadlec at sunserv.kfki.hu>. Thanks a lot!
· IP.pm and other files are enconded in ISO-8859-1 (Latin1) so
that I can spell my name properly.
· Tested under Perl 5.8.0, no surprises found.
3.14_2
Minor development release.
· Added "->version" and "->bits", including testing.
· "Compact" can now be exported if the user so requests.
· Fixed a bug when octets in a dotted quad were > 256 (ie, were
not octets). Thanks to Anton Berezin for pointing this out.
3.14_3
Fixed a bug pointed out by Brent Imhoff related to the implicit
comparison that happens within "Compact()". The netmask was being
ignored in the comparison (ie, 10/8 was considered the same as
10.0/16). Since some people have requested that 10.0/16 was
considered larger than 10/8, I added this change, which makes the
bug go away. This will be the last '_' release, pending new bugs.
Regarding the comparison of subnets, I'm still open to debate so as
to wether 10.0/16 > 10/8. Certainly 255.255.0.0 > 255.0.0.0, but 2
** 24 are more hosts than 2 ** 16. I think we might use gt &
friends for this semantic and make everyone happy, but I won't do
anything else here without (significant) feedback.
3.14_4
As noted by Michael, 127/8 should be 127.0.0.0/8 and not
0.0.0.128/8. Also, improved docs on the usage of contains() and
friends.
3.15
Finally. Added POD tests (and fixed minor doc bug in IP.pm). As
reported by Anand Vijay, negative numbers are assumed to be signed
ints and converted accordingly to a v4 address. split() and nth()
now work with IPv6 addresses (Thanks to Venkata Pingali for
reporting). Tests were added for v6 base functionality and
splitting. Also tests for bitwise aritmethic with long integers has
been added. I'm afraid Math::BigInt is now required.
Note that IPv6 might not be as solid as I would like. Be careful...
3.16
Fixed a couple of (minor) bugs in shipped tests in the last
version. Also, fixed a small pod typo that caused code to show up
in the documentation.
3.17
Fixed IP.pm so that all test could pass in Solaris machines. Thanks
to all who reported this.
3.18
Fixed some bugs pointed out by David Lloyd, having to do with the
module packaging and version requirements. Thanks David!
3.19
Fixed a bug pointed out by Andrew D. Clark, regarding proper
parsing of IP ranges with non-contiguous masks. Thanks Andrew!
3.20
Suggestion by Reuland Olivier gave birth to "short()", which
provides for a compact representation of the IP address. Rewrote
"_compact" to find the longest sequence of zeros to compact.
Reuland also pointed out a flaw in contains() and within(), which
was fixed. Thanks Reuland!
Fixed rt bug #5478 in t/00-load.t.
3.21
Fixed minor v-string problem pointed out by Steve Snodgrass (Thanks
Steve!). NetAddr::IP can now collaborate with Storable to serialize
itself.
3.22
Fixed bug rt.cpan.org #7070 reported by Grover Browning
(auto-inc/dec on v6 fails). Thanks Grover. Ruben van Staveren
pointed out a bug in v6 canonicalization, as well as providing a
patch that was applied. Thanks Ruben.
3.23
Included support for Module::Signature. Added ->re() as contributed
by Laurent Facq (Thanks Laurent!). Added Coalesce() as suggested by
Perullo.
3.24
Version bump. Transfer of 3.23 to CPAN ended up in a truncated file
being uploaded.
3.25
Some IP specs resembling range notations but not depicting actual
CIDR ranges, were being erroneously recognized. Thanks to Steve
Snodgrass for reporting a bug with parsing IP addresses in 4-octet
binary format. Added optional Pod::Coverage tests. compact_addr has
been commented out, after a long time as deprecated. Improved speed
of ->new() for the case of a single host IPv4 address, which seems
to be the most common one.
4.00
Dependence on Math::BigInt removed, works with earlier versions of
Perl. The module was partitioned into three logical pieces as
follows:
Util.pm Math and logic operation on bit strings and number
that represent IP addresses and masks. Conversions
between various number formats. Implemented in
C_XS for speed and PURE PERL of transportability.
Lite.pm Operations, simple conversions and comparisons of
IP addresses, notations and formats.
IP.pm Complex operations and conversions of IP address
notation, nets, subnets, and ranges.
The internal representation of addresses was changed to 128 bit
binary strings as returned by inet_pton (ipv6_aton in this module).
Both ipV4 and ipV6 notations can be freely mixed and matched.
Additional methods added to force operations into ipV6 space even
when ipV4 notation is used.
AUTHORS
Luis E. Mun~oz <luismunoz@cpan.org>, Michael Robinton
<michael@bizsystems.com>
WARRANTY
This software comes with the same warranty as perl itself (ie, none),
so by using it you accept any and all the liability.
LICENSE
This software is (c) Luis E. Mun~oz, 1999 - 2005, and (c) Michael
Robinton, 2006. 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.
SEE ALSOperl(1)
L<NetAddr::IP::Lite>
L<NetAddr::IP::Util>
perl v5.10.0 2006-08-17 IP(3)
