IP(3) User Contributed Perl Documentation IP(3)NAMENetAddr::IP - Manages IPv4 and IPv6 addresses and subnets
SYNOPSIS
use NetAddr::IP qw(
Compact
Coalesce
Zeros
Ones
V4mask
V4net
netlimit
:aton DEPRECATED
:lower
:upper
:old_storable
:old_nth
);
NOTE: NetAddr::IP::Util has a full complement of network address
utilites to convert back and from from binary to text.
inet_aton, inet_ntoa, ipv6_aton, ipv6_n2x, ipv6_n2d
inet_any2d, inet_n2dx, inet_n2ad, inetanyto6, ipv6to4
See NetAddr::IP::Util
my $ip = new NetAddr::IP::Lite '127.0.0.1';
or from a packed IPv4 address
my $ip = new_from_aton NetAddr::IP::Lite (inet_aton('127.0.0.1'));
or from an octal filtered IPv4 address
my $ip = new_no NetAddr::IP::Lite '127.012.0.0';
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 $ip...\n";
* The following four functions return ipV6 representations of:
:: = Zeros();
FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF = Ones();
FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:: = V4mask();
::FFFF:FFFF = V4net();
###### DEPRECATED, will be remove in version 5 ############
* To accept addresses in the format as returned by
inet_aton, invoke the module as:
use NetAddr::IP qw(:aton);
###### USE new_from_aton instead ##########################
* To enable usage of legacy data files containing NetAddr::IP objects
stored using the Storable module.
use NetAddr::IP qw(:old_storable);
* To compact many smaller subnets (see: "$me->com‐
pact($addr1,$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)
* By default NetAddr::IP functions and methods return string IPv6
addresses in uppercase. To change that to lowercase:
use NetAddr::IP qw(:lower);
* To ensure the current IPv6 string case behavior even if the default
changes:
use NetAddr::IP qw(:upper);
* To set a limit on the size of nets processed or returned by
NetAddr::IP. Set the maximum number of nets beyond which NetAddr::IP
will return and error as a power of 2 (default 16 or 65536 nets). Each
2**16 consumes approximately 4 megs of memory. A 2**20 consumes 64 megs
of memory, A 2**24 consumes 1 gigabyte of memory.
use NetAddr::IPqw(netlimit);
netlimit 20;
The maximum netlimit allowed is a 2**24. Attempts to set limits below
the default of 16 or above the maximum of 24 are ignored.
Returns true on success otherwise undef.
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 nota‐
tion. 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 NUMERIC cidr
portion of the masks are compared. This leads to the counterintu‐
itive result that
/24 > /16
Comparison should not be done on netaddr objects with different
CIDR as this may produce indeterminate - unexpected results, rather
the determination of which netblock is larger or smaller should be
done by comparing
$ip1->masklen <=> $ip2->masklen
Addition of a constant ("+")
Add a 32 bit signed constant to the address part of a NetAddr
object. This operation changes the address part to point so many
hosts above the current objects start address. For instance, this
code:
print NetAddr::IP::Lite->new('127.0.0.1') + 5;
will output 127.0.0.6/8. The address will wrap around at the broad‐
cast back to the network address. This code:
print NetAddr::IP::Lite->new('10.0.0.1/24') + 255;
outputs 10.0.0.0/24.
Returns the the unchanged object when the constant is missing or
out of range.
2147483647 <= constant >= -2147483648
Subtraction of a constant ("-")
The complement of the addition of a constant.
Difference ("-")
Returns the difference between the address parts of two
NetAddr::IP::Lite objects address parts as a 32 bit signed number.
Returns undef if the difference is out of range.
(See range restrictions on Addition above)
Auto-increment
Auto-incrementing a NetAddr::IP object causes the address part to
be adjusted to the next host address within the subnet. It will
wrap at the broadcast address and start again from the network
address.
Auto-decrement
Auto-decrementing a NetAddr::IP object performs exactly the oppo‐
site of auto-incrementing it, as you would expect.
Serializing and Deserializing
This module defines hooks to collaborate with Storable for serializing
"NetAddr::IP" objects, through compact and human readable strings. You
can revert to the old format by invoking this module as
use NetAddr::IP ':old_storable';
You must do this if you have legacy data files containing NetAddr::IP
objects stored using the Storable module.
Methods
"->new([$addr, [ $mask⎪IPv6 ]])"
"->new6([$addr, [ $mask]])"
"->new_no([$addr, [ $mask]])"
"->new_from_aton($netaddr)"
The first two methods create a new address with the supplied
address in $addr and an optional netmask $mask, which can be omit‐
ted to get a /32 or /128 netmask for IPv4 / IPv6 addresses respec‐
tively
new_from_aton takes a packed IPv4 address and assumes a /32 mask.
This function replaces the DEPRECATED :aton functionality which is
fundamentally broken.
The third method "new_no" is exclusively for IPv4 addresses and
filters improperly formatted dot quad strings for leading 0's that
would normally be interpreted as octal format by NetAddr per the
specifications for inet_aton.
"->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 con‐
tain the mask in CIDR notation.
prefix notation is understood, with the limitation that the range
specified by the prefix must match with a valid subnet.
Addresses in the same format returned by "inet_aton" or "gethostby‐
name" 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.
$addr can be any of the following and possibly more...
n.n
n.n/mm
n.n.n
n.n.n/mm
n.n.n.n
n.n.n.n/mm 32 bit cidr notation
n.n.n.n/m.m.m.m
loopback, localhost, broadcast, any, default
x.x.x.x/host
0xABCDEF, 0b111111000101011110, (a bcd number)
a netaddr as returned by 'inet_aton'
Any RFC1884 notation
::n.n.n.n
::n.n.n.n/mmm 128 bit cidr notation
::n.n.n.n/::m.m.m.m
::x:x
::x:x/mmm
x:x:x:x:x:x:x:x
x:x:x:x:x:x:x:x/mmm
x:x:x:x:x:x:x:x/m:m:m:m:m:m:m:m any RFC1884 notation
loopback, localhost, unspecified, any, default
::x:x/host
0xABCDEF, 0b111111000101011110 within the limits
of perl's number resolution
123456789012 a 'big' bcd number i.e. Math::BigInt
If called with no arguments, 'default' is assumed.
"->broadcast()"
Returns a new object referring to the broadcast address of a given
subnet. The broadcast address has all ones in all the bit positions
where the netmask has zero bits. This is normally used to address
all the hosts in a given subnet.
"->network()"
Returns a new object referring to the network address of a given
subnet. A network address has all zero bits where the bits of the
netmask are zero. Normally this is used to refer to a subnet.
"->addr()"
Returns a scalar with the address part of the object as an IPv4 or
IPv6 text string as appropriate. This is useful for printing or for
passing the address part of the NetAddr::IP object to other compo‐
nents that expect an IP address. If the object is an ipV6 address
or was created using ->new6($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 for‐
mat as the "inet_aton()" or "ipv6_aton" function respectively. If
the object was created using ->new6($ip), the address returned will
always be in ipV6 format, even for addresses in ipV4 address space.
"->range()"
Returns a scalar with the base address and the broadcast address
separated by a dash and spaces. This is called range notation.
"->prefix()"
Returns a scalar with the address and mask in ipV4 prefix represen‐
tation. This is useful for some programs, which expect its input to
be in this format. This method will include the broadcast address
in the encoding.
"->nprefix()"
Just as "->prefix()", but does not include the broadcast address.
"->numeric()"
When called in a scalar context, will return a numeric representa‐
tion of the address part of the IP address. When called in an array
contest, it returns a list of two elements. The first element is as
described, the second element is the numeric representation of the
netmask.
This method is essential for serializing the representation of a
subnet.
"->wildcard()"
When called in a scalar context, returns the wildcard bits corre‐
sponding to the mask, in dotted-quad or ipV6 format as applicable.
When called in an array context, returns a two-element array. The
first element, is the address part. The second element, is the
wildcard translation of the mask.
"->short()"
Returns the address part in a short or compact notation.
(ie, 127.0.0.1 becomes 127.1).
Works with both, V4 and V6.
"->full()"
Returns the address part in FULL notation for ipV4 and ipV6 respec‐
tively.
i.e. for ipV4
0000:0000:0000:0000:0000:0000:127.0.0.1
for ipV6
0000:0000:0000:0000:0000:0000:0000:0000
To force ipV4 addresses into full ipV6 format use:
"->full6()"
Returns the address part in FULL ipV6 notation
"$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 com‐
pletely contained within $other.
Note that $me and $other must be "NetAddr::IP" objects.
"->splitref($bits,[optional $bits1,$bits2,...])"
Returns a reference to 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.
ERROR conditions:
->splitref will DIE with the message 'netlimit exceeded'
if the number of return objects exceeds 'netlimit'.
See function 'netlimit' above (default 2**16 or 65536 nets).
->splitref returns undef when C<bits> or the (bits list)
will not fit within the original object.
->splitref returns undef if a supplied ipV4, ipV6, or NetAddr
mask in inappropriately formatted,
bits may be a CIDR mask, a dot quad or ipV6 string or a NetAddr::IP
object. If "bits" is missing, the object is split for into all
available addresses within the ipV4 or ipV6 object ( auto-mask of
CIDR 32, 128 respectively ).
With optional additional "bits" list, the original object is split
into parts sized based on the list. NOTE: a short list will repli‐
cate the last item. If the last item is too large to for what
remains of the object after splitting off the first parts of the
list, a "best fits" list of remaining objects will be returned
based on an increasing sort of the CIDR values of the "bits" list.
i.e. my $ip = new NetAddr::IP('192.168.0.0');
my $objptr = $ip->split(28, 29, 28, 29, 26);
has split plan 28 29 28 29 26 26 26 28
and returns this list of objects
192.168.0.0/28
192.168.0.16/29
192.168.0.24/28
192.168.0.40/29
192.168.0.48/26
192.168.0.112/26
192.168.0.176/26
192.168.0.240/28
NOTE: that /26 replicates twice beyond the original request and /28
fills the remaining return object requirement.
"->rsplitref($bits,[optional $bits1,$bits2,...])"
"->rsplitref" is the same as "->splitref" above except that the
split plan is applied to the original object in reverse order.
i.e. my $ip = new NetAddr::IP('192.168.0.0');
my @objects = $ip->split(28, 29, 28, 29, 26);
has split plan 28 26 26 26 29 28 29 28
and returns this list of objects
192.168.0.0/28
192.168.0.16/26
192.168.0.80/26
192.168.0.144/26
192.168.0.208/29
192.168.0.216/28
192.168.0.232/29
192.168.0.240/28
"->split($bits,[optional $bits1,$bits2,...])"
Similar to "->splitref" above but returns the list rather than a
list reference. You may not want to use this if a large number of
objects is expected.
"->rsplit($bits,[optional $bits1,$bits2,...])"
Similar to "->rsplitref" above but returns the list rather than a
list reference. You may not want to use this if a large number of
objects is expected.
"->hostenum()"
Returns the list of hosts within a subnet.
ERROR conditions:
->hostenum will DIE with the message 'netlimit exceeded'
if the number of return objects exceeds 'netlimit'.
See function 'netlimit' above (default 2**16 or 65536 nets).
"->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 sub‐
nets 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 documenta‐
tion 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($index)" and "->num()":
use NetAddr::IP::Lite qw(:old_nth);
"->num()"
Version 4.00 of NetAddr::IP and version 1.00 of NetAddr::IP::Lite
Returns the number of usable addresses IP addresses within the sub‐
net, not counting the broadcast or network address. Previous ver‐
sions returned th number of IP addresses not counting the broadcast
address.
To use the old behavior for "->nth($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
Zeros
Ones
V4mask
V4net
netlimit
NOTES / BUGS ... FEATURES
NetAddr::IP only runs in Pure Perl mode on Windows boxes because I
don't have the resources or know how to get the "configure" stuff work‐
ing in the Windows environment. Volunteers WELCOME to port the "C" por‐
tion of this module to Windows.
HISTORY
4.00
Dependence on Math::BigInt in earlier version is removed in this
release 4.00. NetAddr::IP now 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.
4.05
NetAddr::IP :aton DEPRECATED !
new method "new_from_aton"
THE FOLLOWING CHANGES MAY BREAK SOME CODE !
Inherited methods from Lite.pm updated as follows:
comparisons of the form <, >, <=, >=
10.0.0.0/24 {operator} 10.0.0.0/16
return now return the comparison of the cidr value
when the address portion is equal.
Thanks to Peter DeVries for spotting this bug.
... and leading us to discover that this next fix is required
comparisons of the form <=>, cmp
now return the correct value 1, or -1
when the address portion is equal and the CIDR value is not
i.e. where /16 is > /24, etc...
This is the OPPOSITE of the previous return values for
comparison of the CIDR portion of the address object
4.08
added method ->new_from_aton to supplement broken
:aton functionality which is now DEPRECATED and
will eventually go away.
4.13
added 'no octal' method ->new_no
4.17
add support for PTHREADS in the event that perl is
built with <pthreads.h>. This must be invoked at build
time with the switch --with-threads
WARNING: --with-threads is not tested in a threads
environment. Reports welcome and solicited.
update _compV6 which runs faster and produces more
compact ipV6 addresses.
....and
added minus (-) overloading to allow the subtraction
of two NetAddr::IP objects to get the difference between
the object->{addr}'s as a numeric value
Thanks to Rob Riepel <riepel@networking.Stanford.EDU> for
the _compV6 code and the inspiration for (-) overloading.
Extended the capability of 'splitref' to allow splitting of
objects into multiple pieces with differing CIDR masks.
Returned object list can be split from bottom to top
or from top to bottom depending on which routine is called
split, rsplit, splitref, rsplitref
Thanks to kashmish <kashmish@gmail.com> for the idea on
improving functionality of 'split'.
4.018
removed --with-threads, PTHREADS support, and all
the mutex locking - unlocking
updated Util.xs to be fully re-entrant and thus
fully thread safe.
4.020
Fixed core dump due to bug in perl 5.8.4 handling of
@_ in goto &sub operations. Unfortunately this version
of perl is standard on Solaris, 5.85 on RedHat and I'm
sure other distributions. -- all should be upgraded!
Similar behavior exists in perl versions 5.80 - 5.85
See perl bug [ 23429].
Included missing code to parse BCD numbers as argument
to sub new(bcdnum). Thanks to Carlos Vicente cvicente@cpan.org
for reporting this bug.
AUTHORS
Luis E. Muñoz <luismunoz@cpan.org>, Michael Robinton <michael@bizsys‐
tems.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. Muñoz, 1999 - 2007, and (c) Michael
Robinton, 2006 - 2008. It can be used under the terms of the Perl
artistic license provided that proper credit for the work of the
authors is preserved in the form of this copyright notice and license
for this module.
SEE ALSOperl(1),NetAddr::IP::Lite, NetAddr::IP::Util.
perl v5.8.8 2011-07-21 IP(3)
