File: tcllib_ip.n

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'\"
'\" Generated from file 'tcllib_ip\&.man' by tcllib/doctools with format 'nroff'
'\" Copyright (c) 2004, Pat Thoyts
'\" Copyright (c) 2005 Aamer Akhter <aakhter@cisco\&.com>
'\"
.TH "tcllib_ip" n 1\&.4 tcllib "Domain Name Service"
.\" The -*- nroff -*- definitions below are for supplemental macros used
.\" in Tcl/Tk manual entries.
.\"
.\" .AP type name in/out ?indent?
.\"	Start paragraph describing an argument to a library procedure.
.\"	type is type of argument (int, etc.), in/out is either "in", "out",
.\"	or "in/out" to describe whether procedure reads or modifies arg,
.\"	and indent is equivalent to second arg of .IP (shouldn't ever be
.\"	needed;  use .AS below instead)
.\"
.\" .AS ?type? ?name?
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.\"	name are examples of largest possible arguments that will be passed
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.\"
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.\" .SO ?manpage?
.\"	Start of list of standard options for a Tk widget. The manpage
.\"	argument defines where to look up the standard options; if
.\"	omitted, defaults to "options". The options follow on successive
.\"	lines, in three columns separated by tabs.
.\"
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.\"
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.\"	option's name as specified in the class command, dbName gives
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.\"	(for trailing punctuation) and then a closing parenthesis.
.\"
.\"	# Set up traps and other miscellaneous stuff for Tcl/Tk man pages.
.if t .wh -1.3i ^B
.nr ^l \n(.l
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.LP
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.LP
See the \\*(So manual entry for details on the standard options.
..
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Command-Line Name:	\\fB\\$1\\fR
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.\"	# MT - "empty" string
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.QW ""
..
.BS
.SH NAME
tcllib_ip \- IPv4 and IPv6 address manipulation
.SH SYNOPSIS
package require \fBTcl  8\&.2\fR
.sp
package require \fBip  ?1\&.4?\fR
.sp
\fB::ip::version\fR \fIaddress\fR
.sp
\fB::ip::is\fR \fIclass\fR \fIaddress\fR
.sp
\fB::ip::equal\fR \fIaddress\fR \fIaddress\fR
.sp
\fB::ip::normalize\fR \fIaddress\fR
.sp
\fB::ip::contract\fR \fIaddress\fR
.sp
\fB::ip::distance\fR \fIipaddr1\fR \fIipaddr2\fR
.sp
\fB::ip::nextIp\fR \fIipaddr\fR ?\fIoffset\fR?
.sp
\fB::ip::prefix\fR \fIaddress\fR
.sp
\fB::ip::type\fR \fIaddress\fR
.sp
\fB::ip::mask\fR \fIaddress\fR
.sp
\fB::ip::prefixToNative\fR \fIprefix\fR
.sp
\fB::ip::nativeToPrefix\fR \fInativeList\fR|\fInative\fR ?\fB-ipv4\fR?
.sp
\fB::ip::intToString\fR \fInumber\fR ?\fB-ipv4\fR?
.sp
\fB::ip::toInteger\fR \fIipaddr\fR
.sp
\fB::ip::toHex\fR \fIipaddr\fR
.sp
\fB::ip::maskToInt\fR \fIipmask\fR
.sp
\fB::ip::broadcastAddress\fR \fIprefix\fR ?\fB-ipv4\fR?
.sp
\fB::ip::maskToLength\fR \fIdottedMask\fR|\fIintegerMask\fR|\fIhexMask\fR ?\fB-ipv4\fR?
.sp
\fB::ip::lengthToMask\fR \fImaskLength\fR ?\fB-ipv4\fR?
.sp
\fB::ip::nextNet\fR \fIipaddr\fR \fIipmask\fR ?\fIcount\fR? ?\fB-ipv4\fR?
.sp
\fB::ip::isOverlap\fR \fIprefix\fR \fIprefix\fR\&.\&.\&.
.sp
\fB::ip::isOverlapNative\fR ?\fB-all\fR? ?\fB-inline\fR? ?\fB-ipv4\fR? \fIhexipaddr\fR \fIhexipmask\fR \fIhexiplist\fR
.sp
\fB::ip::ipToLayer2Multicast\fR \fIipaddr\fR
.sp
\fB::ip::ipHostFromPrefix\fR \fIprefix\fR ?\fB-exclude\fR \fIprefixExcludeList\fR?
.sp
\fB::ip::reduceToAggregates\fR \fIprefixlist\fR
.sp
\fB::ip::longestPrefixMatch\fR \fIipaddr\fR \fIprefixlist\fR ?\fB-ipv4\fR?
.sp
\fB::ip::collapse\fR \fIprefixlist\fR
.sp
\fB::ip::subtract\fR \fIprefixlist\fR
.sp
.BE
.SH DESCRIPTION
.PP
This package provides a set of commands to help in parsing, displaying
and comparing internet addresses\&. The package can handle both IPv4 (1)
and IPv6 (2) address types\&.
.SH COMMANDS
.TP
\fB::ip::version\fR \fIaddress\fR
Returns the protocol version of the address (\fB4\fR or \fB6\fR),
or \fB-1\fR if the address is neither IPv4 or IPv6\&.
.TP
\fB::ip::is\fR \fIclass\fR \fIaddress\fR
Returns true if the address is a member of the given protocol
class\&. The class parameter may be either \fBipv4\fR or \fBipv6\fR
This is effectively a boolean equivalent of the \fBversion\fR
command\&. The \fIclass\fR argument may be shortened to \fB4\fR or
\fB6\fR\&.
.TP
\fB::ip::equal\fR \fIaddress\fR \fIaddress\fR
Compare two address specifications for equivalence\&. The arguments are
normalized and the address prefix determined (if a mask is
supplied)\&. The normalized addresses are then compared bit-by-bit and
the procedure returns true if they match\&.
.TP
\fB::ip::normalize\fR \fIaddress\fR
Convert an IPv4 or IPv6 address into a fully expanded version\&. There
are various shorthand ways to write internet addresses, missing out
redundant parts or digits\&. This procedure is the opposite of
\fBcontract\fR\&.
.TP
\fB::ip::contract\fR \fIaddress\fR
Convert a \fBnormalize\fRd internet address into a more compact form
suitable for displaying to users\&.
.TP
\fB::ip::distance\fR \fIipaddr1\fR \fIipaddr2\fR
This command computes the (integer) distance from IPv4 address
\fIipaddr1\fR to IPv4 address \fIipaddr2\fR, i\&.e\&. "ipaddr2 - ipaddr1"
.sp
.CS


   % ::ip::distance 1\&.1\&.1\&.1  1\&.1\&.1\&.5
   4

.CE
.TP
\fB::ip::nextIp\fR \fIipaddr\fR ?\fIoffset\fR?
This command adds the integer \fIoffset\fR to the IPv4 address \fIipaddr\fR
and returns the new IPv4 address\&.
.sp
.CS


   % ::ip::distance 1\&.1\&.1\&.1  4
   1\&.1\&.1\&.5

.CE
.TP
\fB::ip::prefix\fR \fIaddress\fR
Returns the address prefix generated by masking the address part with
the mask if provided\&. If there is no mask then it is equivalent to
calling \fBnormalize\fR
.TP
\fB::ip::type\fR \fIaddress\fR
.TP
\fB::ip::mask\fR \fIaddress\fR
If the address supplied includes a mask then this is returned
otherwise returns an empty string\&.
.TP
\fB::ip::prefixToNative\fR \fIprefix\fR
This command converts the string \fIprefix\fR from dotted form
(<ipaddr>/<mask> format) to native (hex) form\&. Returns a list
containing two elements, ipaddress and mask, in this order, in
hexadecimal notation\&.
.sp
.CS


   % ip::prefixToNative 1\&.1\&.1\&.0/24
   0x01010100 0xffffff00

.CE
.TP
\fB::ip::nativeToPrefix\fR \fInativeList\fR|\fInative\fR ?\fB-ipv4\fR?
This command converts from native (hex) form to dotted form\&.
It is the complement of \fB::ip::prefixToNative\fR\&.
.sp
.RS
.TP
list \fInativeList\fR (in)
List of several ip addresses in native form\&. The native form is a list
as returned by \fB::ip::prefixToNative\fR\&.
.TP
list \fInative\fR (in)
A list as returned by \fB::ip::prefixToNative\fR\&.
.RE
.sp
The command returns a list of addresses in dotted form if it was
called with a list of addresses\&. Otherwise a single address in dotted
form is returned\&.
.sp
.CS


   % ip::nativeToPrefix {0x01010100 0xffffff00} -ipv4
   1\&.1\&.1\&.0/24

.CE
.TP
\fB::ip::intToString\fR \fInumber\fR ?\fB-ipv4\fR?
This command converts from an ip address specified as integer number
to dotted form\&.
.sp
.CS


       ip::intToString 4294967295
       255\&.255\&.255\&.255

.CE
.TP
\fB::ip::toInteger\fR \fIipaddr\fR
This command converts a dotted form ip into an integer number\&.
.sp
.CS


   % ::ip::toInteger 1\&.1\&.1\&.0
   16843008

.CE
.TP
\fB::ip::toHex\fR \fIipaddr\fR
This command converts dotted form ip into a hexadecimal number\&.
.sp
.CS


   % ::ip::toHex 1\&.1\&.1\&.0
   0x01010100

.CE
.TP
\fB::ip::maskToInt\fR \fIipmask\fR
This command convert an ipmask in either dotted (255\&.255\&.255\&.0) form
or mask length form (24) into an integer number\&.
.sp
.CS


   ::ip::maskToInt 24
   4294967040

.CE
.TP
\fB::ip::broadcastAddress\fR \fIprefix\fR ?\fB-ipv4\fR?
This commands returns a broadcast address in dotted form for the given
route \fIprefix\fR, either in the form "addr/mask", or in native
form\&. The result is in dotted form\&.
.sp
.CS


   ::ip::broadcastAddress 1\&.1\&.1\&.0/24
   1\&.1\&.1\&.255

   ::ip::broadcastAddress {0x01010100 0xffffff00}
   0x010101ff

.CE
.TP
\fB::ip::maskToLength\fR \fIdottedMask\fR|\fIintegerMask\fR|\fIhexMask\fR ?\fB-ipv4\fR?
This command converts the dotted or integer form of an ipmask to
the mask length form\&.
.sp
.CS


   ::ip::maskToLength 0xffffff00 -ipv4
   24

   % ::ip::maskToLength 255\&.255\&.255\&.0
   24

.CE
.TP
\fB::ip::lengthToMask\fR \fImaskLength\fR ?\fB-ipv4\fR?
This command converts an ipmask in mask length form to its dotted
form\&.
.sp
.CS


   ::ip::lengthToMask 24
   255\&.255\&.255\&.0

.CE
.TP
\fB::ip::nextNet\fR \fIipaddr\fR \fIipmask\fR ?\fIcount\fR? ?\fB-ipv4\fR?
This command returns an ipaddress in the same position in the
\fIcount\fR next network\&. The default value for \fIcount\fR is
\fB1\fR\&.
.sp
The address can be specified as either integer number or in dotted
form\&. The mask can be specified as either integer number, dotted form,
or mask length form\&.
.sp
The result is in hex form\&.
.TP
\fB::ip::isOverlap\fR \fIprefix\fR \fIprefix\fR\&.\&.\&.
This command checks if the given ip prefixes overlap\&.  All arguments
are in dotted "addr/mask" form\&. All arguments after the first prefix
are compared against the first prefix\&. The result is a boolean
value\&. It is true if an overlap was found for any of the prefixes\&.
.sp
.CS


  % ::ip::isOverlap 1\&.1\&.1\&.0/24 2\&.1\&.0\&.1/32
  0

  ::ip::isOverlap 1\&.1\&.1\&.0/24 2\&.1\&.0\&.1/32 1\&.1\&.1\&.1/32
  1

.CE
.TP
\fB::ip::isOverlapNative\fR ?\fB-all\fR? ?\fB-inline\fR? ?\fB-ipv4\fR? \fIhexipaddr\fR \fIhexipmask\fR \fIhexiplist\fR
This command is similar to \fB::ip::isOverlap\fR, however the
arguments are in the native form, and the form of the result is under
greater control of the caller\&.
If the option \fB-all\fR is specified it checks all addresses for
overlap, not only until the first one is found\&.
If the option \fB-inline\fR is specified the command returns the
overlapping prefix instead of index values\&.
.sp
The result of the command is, depending on the specified options,
.RS
.TP
no options
The index of the first overlap found, or 0 if there is none\&.
.TP
-all
A list containing the indices of all overlaps found, or an empty list
if there are none\&.
.TP
-inline
The first overlapping prefix, or an empoty string if there is none\&.
.TP
-all -inline
A list containing the prefixes of all overlaps found, or an empty list
if there are none\&.
.RE
.sp
.CS


  % ::ip::isOverlapNative 0x01010100 0xffffff00 {{0x02010001 0xffffffff}}
  0

  % ::ip::isOverlapNative 0x01010100 0xffffff00 {{0x02010001 0xffffffff} {0x01010101 0xffffffff}}
  2

.CE
.TP
\fB::ip::ipToLayer2Multicast\fR \fIipaddr\fR
This command an converts ipv4 address in dotted form into a layer 2
multicast address, also in dotted form\&.
.sp
.CS


  % ::ip::ipToLayer2Multicast 224\&.0\&.0\&.2
  01\&.00\&.5e\&.00\&.00\&.02

.CE
.TP
\fB::ip::ipHostFromPrefix\fR \fIprefix\fR ?\fB-exclude\fR \fIprefixExcludeList\fR?
This command returns a host address from a prefix in the form
"ipaddr/masklen", also making sure that the result is not an address
found in the \fIprefixExcludeList\fR\&.
The result is an ip address in dotted form\&.
.sp
.CS


  %::ip::ipHostFromPrefix  1\&.1\&.1\&.5/24
  1\&.1\&.1\&.1

  %::ip::ipHostFromPrefix  1\&.1\&.1\&.1/32
  1\&.1\&.1\&.1

.CE
.TP
\fB::ip::reduceToAggregates\fR \fIprefixlist\fR
This command finds nets that overlap and filters out the more specific
nets\&. The prefixes are in either addr/mask form or in native format\&.
The result is a list containing the non-overlapping ip prefixes from
the input\&.
.sp
.CS


  % ::ip::reduceToAggregates {1\&.1\&.1\&.0/24 1\&.1\&.0\&.0/8  2\&.1\&.1\&.0/24 1\&.1\&.1\&.1/32 }
  1\&.0\&.0\&.0/8 2\&.1\&.1\&.0/24

.CE
.TP
\fB::ip::longestPrefixMatch\fR \fIipaddr\fR \fIprefixlist\fR ?\fB-ipv4\fR?
This command finds longest prefix match from set of prefixes, given a
specific host address\&. The prefixes in the list are in either native
or dotted form, whereas the host address is in either ipprefix format,
dotted form, or integer form\&.
The result is the prefix which is the most specific match to the host
address\&.
.sp
.CS


  % ::ip::longestPrefixMatch 1\&.1\&.1\&.1 {1\&.1\&.1\&.0/24 1\&.0\&.0\&.0/8  2\&.1\&.1\&.0/24 1\&.1\&.1\&.0/28 }
  1\&.1\&.1\&.0/28

.CE
.TP
\fB::ip::collapse\fR \fIprefixlist\fR
This commands takes a list of prefixes and returns a list prefixes
with the largest possible subnet masks covering the input, in this
manner collapsing adjacent prefixes into larger ranges\&.
.sp
This is different from \fB::ip::reduceToAggregates\fR in that
the latter only removes specific nets from a list when they are
covered by other elements of the input whereas this command actively
merges nets into larger ranges when they are adjacent to each other\&.
.sp
.CS


% ::ip::collapse {1\&.2\&.2\&.0/24 1\&.2\&.3\&.0/24}
1\&.2\&.2\&.0/23

.CE
.TP
\fB::ip::subtract\fR \fIprefixlist\fR
This command takes a list of prefixes, some of which are prefixed by a
dash\&. These latter \fInegative\fR prefixes are used to punch holes
into the ranges described by the other, \fIpositive\fR,
prefixes\&. I\&.e\&. the negative prefixes are subtracted frrom the positive
ones, resulting in a larger list of describes describing the covered
ranges only as positives\&.
.PP
.SH EXAMPLES
.PP
.CS


% ip::version ::1
6
% ip::version 127\&.0\&.0\&.1
4

.CE
.CS


% ip::normalize 127/8
127\&.0\&.0\&.0/8
% ip::contract 192\&.168\&.0\&.0
192\&.168
%
% ip::normalize fec0::1
fec0:0000:0000:0000:0000:0000:0000:0001
% ip::contract fec0:0000:0000:0000:0000:0000:0000:0001
fec0::1

.CE
.CS


% ip::equal 192\&.168\&.0\&.4/16 192\&.168\&.0\&.0/16
1
% ip::equal fec0::1/10 fec0::fe01/10
1

.CE
.SH REFERENCES
.IP [1]
Postel, J\&. "Internet Protocol\&." RFC 791,  September 1981,
(\fIhttp://www\&.ietf\&.org/rfc/rfc791\&.txt\fR)
.IP [2]
Hinden, R\&. and Deering, S\&.,
"Internet Protocol Version 6 (IPv6) Addressing Architecture",
RFC 3513, April 2003
(\fIhttp://www\&.ietf\&.org/rfc/rfc3513\&.txt\fR)
.PP
.SH AUTHORS
Pat Thoyts
.SH "BUGS, IDEAS, FEEDBACK"
This document, and the package it describes, will undoubtedly contain
bugs and other problems\&.
Please report such in the category \fIdns\fR of the
\fITcllib Trackers\fR [http://core\&.tcl\&.tk/tcllib/reportlist]\&.
Please also report any ideas for enhancements you may have for either
package and/or documentation\&.
.PP
When proposing code changes, please provide \fIunified diffs\fR,
i\&.e the output of \fBdiff -u\fR\&.
.PP
Note further that \fIattachments\fR are strongly preferred over
inlined patches\&. Attachments can be made by going to the \fBEdit\fR
form of the ticket immediately after its creation, and then using the
left-most button in the secondary navigation bar\&.
.SH "SEE ALSO"
inet(3), ip(7), ipv6(7)
.SH KEYWORDS
internet address, ip, ipv4, ipv6, rfc 3513
.SH CATEGORY
Networking
.SH COPYRIGHT
.nf
Copyright (c) 2004, Pat Thoyts
Copyright (c) 2005 Aamer Akhter <aakhter@cisco\&.com>

.fi