Module:IP: Difference between revisions

From the Croc Wiki, the Croc encyclopedia
Jump to navigationJump to search
Content added Content deleted
(Collection is good (I've always meant to fix it) but in case you don't have other plans, here is a change to make it work)
(some more style changes (it's still broken but I'll fix it later; also, sorry for the edit conflict))
Line 10: Line 10:
local V4 = 'IPv4'
local V4 = 'IPv4'
local V6 = 'IPv6'
local V6 = 'IPv6'

--------------------------------------------------------------------------------
-- Collection class
-- A table to hold items. Used internally.
--------------------------------------------------------------------------------

local Collection
do
local mt = {
__index = {
add = function (self, item)
self.n = self.n + 1
self[self.n] = item
end,
join = function (self, sep)
return table.concat(self, sep)
end,
}
}
Collection = function ()
return setmetatable({n = 0}, mt)
end
end


--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Line 45: Line 22:
RawIP.__index = RawIP
RawIP.__index = RawIP


do
function RawIP.newFromIPv4(ipStr)
-- Collection class.
-- If ipStr is a valid IPv4 string, return a collection of its parts.
-- This is a table used to hold items.
-- Otherwise, return nil.
local Collection
-- This representation is for compatibility with IPv6 addresses.
do
local octets = Collection()
local mt = {
local s = ipStr:match('^%s*(.-)%s*$') .. '.'
__index = {
for item in s:gmatch('(.-)%.') do
octets:add(item)
add = function (self, item)
self.n = self.n + 1
self[self.n] = item
end,
join = function (self, sep)
return table.concat(self, sep)
end,
}
}
Collection = function ()
return setmetatable({n = 0}, mt)
end
end
end

if octets.n == 4 then
-- Constructors
for i, s in ipairs(octets) do
function RawIP.newFromIPv4(ipStr)
if s:match('^%d+$') then
-- If ipStr is a valid IPv4 string, return a collection of its parts.
local num = tonumber(s)
-- Otherwise, return nil.
if 0 <= num and num <= 255 then
-- This representation is for compatibility with IPv6 addresses.
if num > 0 and s:match('^0') then
local octets = Collection()
-- A redundant leading zero is for an IP in octal.
local s = ipStr:match('^%s*(.-)%s*$') .. '.'
for item in s:gmatch('(.-)%.') do
octets:add(item)
end
if octets.n == 4 then
for i, s in ipairs(octets) do
if s:match('^%d+$') then
local num = tonumber(s)
if 0 <= num and num <= 255 then
if num > 0 and s:match('^0') then
-- A redundant leading zero is for an IP in octal.
return false
end
octets[i] = num
else
return false
return false
end
end
octets[i] = num
else
else
return false
return false
end
end
else
return false
end
end
local parts = Collection()
for i = 1, 3, 2 do
parts:add(octets[i] * 256 + octets[i+1])
end
return setmetatable(parts, RawIP)
end
return nil
end
function RawIP.newFromIPv6(ipStr)
-- If ipStr is a valid IPv6 string, return a collection of its parts.
-- Otherwise, return nil.
ipStr = ipStr:match('^%s*(.-)%s*$')
local _, n = ipStr:gsub(':', ':')
if n < 7 then
ipStr, n = ipStr:gsub('::', string.rep(':', 9 - n))
end
end
local parts = Collection()
local parts = Collection()
for i = 1, 3, 2 do
for item in (ipStr .. ':'):gmatch('(.-):') do
parts:add(octets[i] * 256 + octets[i+1])
parts:add(item)
end
end
return setmetatable(parts, RawIP)
if parts.n == 8 then
for i, s in ipairs(parts) do
end
if s == '' then
return nil
parts[i] = 0
end

function RawIP.newFromIPv6(ipStr)
-- If ipStr is a valid IPv6 string, return a collection of its parts.
-- Otherwise, return nil.
ipStr = ipStr:match('^%s*(.-)%s*$')
local _, n = ipStr:gsub(':', ':')
if n < 7 then
ipStr, n = ipStr:gsub('::', string.rep(':', 9 - n))
end
local parts = Collection()
for item in (ipStr .. ':'):gmatch('(.-):') do
parts:add(item)
end
if parts.n == 8 then
for i, s in ipairs(parts) do
if s == '' then
parts[i] = 0
else
local num = tonumber('0x' .. s)
if num and 0 <= num and num <= 65535 then
parts[i] = num
else
else
local num = tonumber('0x' .. s)
return false
if num and 0 <= num and num <= 65535 then
parts[i] = num
else
return false
end
end
end
end
end
return setmetatable(parts, RawIP)
end
end
return setmetatable(parts, RawIP)
return nil
end
end
return nil
function RawIP:getAdjacent(previous)
end
-- Return a RawIP object for an adjacent IP address. If previous is true

-- then the previous IP is returned; otherwise the next IP is returned.
function RawIP:copyChanged(down)
-- Will wraparound:
-- Return a copy of IPv4 or IPv6 parts, incremented or decremented.
-- next 255.255.255.255 → 0.0.0.0
-- Will wraparound:
-- ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff → ::
-- increment 255.255.255.255 → 0.0.0.0
-- previous 0.0.0.0 → 255.255.255.255
-- ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff → ::
-- :: → ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff
-- decrement 0.0.0.0 → 255.255.255.255
local result = Collection()
-- :: → ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff
local result = Collection()
result.n = self.n
local carry = down and 0xffff or 1
result.n = self.n
for i = self.n, 1, -1 do
local carry = down and 0xffff or 1
for i = self.n, 1, -1 do
local sum = self[i] + carry
local sum = self[i] + carry
if sum >= 0x10000 then
if sum >= 0x10000 then
carry = down and 0x10000 or 1
carry = down and 0x10000 or 1
sum = sum - 0x10000
else
sum = sum - 0x10000
carry = down and 0xffff or 0
else
end
carry = down and 0xffff or 0
result[i] = sum
end
end
return setmetatable(result, RawIP)
result[i] = sum
end
end
return setmetatable(result, RawIP)
end


-- Methods
function RawIP:copyPrefix(length)
function RawIP:getPrefix(length)
-- Return a copy of IPv4 or IPv6 parts, masked to length.
-- Return a copy of IPv4 or IPv6 parts, masked to length.
local result = Collection()
result.n = self.n
local result = Collection()
for i = 1, self.n do
result.n = self.n
if length > 0 then
for i = 1, self.n do
if length >= 16 then
if length > 0 then
result[i] = self[i]
if length >= 16 then
length = length - 16
result[i] = self[i]
length = length - 16
else
result[i] = bit32.band(self[i],
bit32.arshift(0xffff8000, length - 1))
length = 0
end
else
else
result[i] = bit32.band(self[i],
result[i] = 0
bit32.arshift(0xffff8000, length - 1))
length = 0
end
end
else
result[i] = 0
end
end
return setmetatable(result, RawIP)
end
end
return setmetatable(result, RawIP)
end


function RawIP:setHostBits(length)
function RawIP:setHostBits(length)
-- Return a copy of IPv4 or IPv6 parts, with the least-significant bits
-- Return a copy of IPv4 or IPv6 parts, with the least-significant bits
-- (host bits) set to 1.
-- (host bits) set to 1.
-- The most-significant length bits identify the network.
-- The most-significant length bits identify the network.
local bits = self.n * 16
local bits = self.n * 16
local width
local width
if length <= 0 then
if length <= 0 then
width = bits
width = bits
elseif length >= bits then
elseif length >= bits then
width = 0
width = 0
else
else
width = bits - length
width = bits - length
end
end
local result = Collection()
local result = Collection()
result.n = self.n
result.n = self.n
for i = self.n, 1, -1 do
for i = self.n, 1, -1 do
if width > 0 then
if width > 0 then
if width >= 16 then
if width >= 16 then
result[i] = 0xffff
result[i] = 0xffff
width = width - 16
width = width - 16
else
result[i] = bit32.replace(self[i], 0xffff, width - 1, width)
width = 0
end
else
else
result[i] = bit32.replace(self[i], 0xffff, width - 1, width)
result[i] = self[i]
width = 0
end
end
else
result[i] = self[i]
end
end
return setmetatable(result, rawIP)
end
end
return setmetatable(result, rawIP)
end


function RawIP:_makeIPv6String()
function RawIP:_makeIPv6String()
-- Return an IPv6 string representation of the object. Behavior is undefined
-- Return an IPv6 string representation of the object. Behavior is undefined
-- if the current object is IPv4.
-- if the current object is IPv4.
local z1, z2 -- indices of run of zeros to be displayed as "::"
local z1, z2 -- indices of run of zeros to be displayed as "::"
local zstart, zcount
local zstart, zcount
for i = 1, 9 do
for i = 1, 9 do
-- Find left-most occurrence of longest run of two or more zeros.
-- Find left-most occurrence of longest run of two or more zeros.
if i < 9 and self[i] == 0 then
if i < 9 and self[i] == 0 then
if zstart then
if zstart then
zcount = zcount + 1
zcount = zcount + 1
else
zstart = i
zcount = 1
end
else
else
if zcount and zcount > 1 then
zstart = i
zcount = 1
if not z1 or zcount > z2 - z1 + 1 then
z1 = zstart
end
z2 = zstart + zcount - 1
else
end
if zcount and zcount > 1 then
if not z1 or zcount > z2 - z1 + 1 then
z1 = zstart
z2 = zstart + zcount - 1
end
end
zstart = nil
zcount = nil
end
end
zstart = nil
zcount = nil
end
end
local parts = Collection()
end
for i = 1, 8 do
local parts = Collection()
if z1 and z1 <= i and i <= z2 then
for i = 1, 8 do
if z1 and z1 <= i and i <= z2 then
if i == z1 then
if i == z1 then
if z1 == 1 or z2 == 8 then
if z1 == 1 or z2 == 8 then
if z1 == 1 and z2 == 8 then
return '::'
if z1 == 1 and z2 == 8 then
return '::'
end
parts:add(':')
else
parts:add('')
end
end
parts:add(':')
else
parts:add('')
end
end
else
parts:add(string.format('%x', self[i]))
end
end
end
return parts:join(':')
end

function RawIP:_makeIPv4String()
-- Return an IPv4 string representation of the object. Behavior is undefined
-- if the current object is IPv6.
local parts = Collection()
for i = 1, 2 do
local w = self[i]
parts:add(math.floor(w / 256))
parts:add(w % 256)
end
return parts:join('.')
end

function RawIP:__tostring()
-- Return a string equivalent to given IP address (IPv4 or IPv6).
if self.n == 2 then
return self:_makeIPv4String()
else
else
return self:_makeIPv6String()
parts:add(string.format('%x', self[i]))
end
end
end
end
return parts:join(':')
end


function RawIP:_makeIPv4String()
function RawIP:__lt(obj)
if self.n == obj.n then
-- Return an IPv4 string representation of the object. Behavior is undefined
for i = 1, self.n do
-- if the current object is IPv6.
if self[i] ~= obj[i] then
local parts = Collection()
return self[i] < obj[i]
for i = 1, 2 do
end
local w = self[i]
end
parts:add(math.floor(w / 256))
return false
parts:add(w % 256)
end
return self.n < obj.n
end
end
return parts:join('.')
end


function RawIP:__tostring()
function RawIP:__eq(obj)
if self.n == obj.n then
-- Return a string equivalent to given IP address (IPv4 or IPv6).
for i = 1, self.n do
if self.n == 2 then
return self:_makeIPv4String()
if self[i] ~= obj[i] then
return false
else
end
return self:_makeIPv6String()
end
return true
end
return false
end
end
end
end
Line 258: Line 284:
local IPAddress = {}
local IPAddress = {}


local newIPFromRaw
-- newIPFromParts constructs a new IPAddress object from its parts. It needs to
-- be accessible from the Subnet object but it should not be public.
-- newIPFromRaw constructs a new IPAddress object from a rawIP object. It needs
-- to be accessible from the Subnet class but it should not be public.
local newIPFromParts


do
do
Line 267: Line 293:
-- Metamethods that don't need upvalues
-- Metamethods that don't need upvalues
local function ipEquals(ip1, ip2)
local function ipEquals(ip1, ip2)
local lhs = ip1[dataKey].parts
return ip1[dataKey].rawIP == ip2[dataKey].rawIP
local rhs = ip2[dataKey].parts
if lhs.n == rhs.n then
for i = 1, lhs.n do
if lhs[i] ~= rhs[i] then
return false
end
end
return true
end
return false
end
end


local function ipLessThan(ip1, ip2)
local function ipLessThan(ip1, ip2)
local lhs = ip1[dataKey].parts
return ip1[dataKey].rawIP < ip2[dataKey].rawIP
local rhs = ip2[dataKey].parts
if lhs.n == rhs.n then
for i = 1, lhs.n do
if lhs[i] ~= rhs[i] then
return lhs[i] < rhs[i]
end
end
return false
end
return lhs.n < rhs.n
end
end


local function concatIPs(ip1, ip2)
local function concatIPs(ip1, ip2)
return tostring(ip1) .. tostring(ip2)
return ip1:getIP() .. ip2:getIP()
end
end


local function ipToString(ip)
local function ipToString(ip)
return ipString(ip[dataKey].parts)
return ip:getIP()
end
end


-- Constructors
-- Constructors
newIPFromParts = function (parts)
newIPFromRaw = function (rawIP)
-- Constructs a new IPAddress object from its parts. This function is
-- Constructs a new IPAddress object from a rawIP object. This function
-- for internal use; it is called by IPAddress.new and can be called
-- is for internal use; it is called by IPAddress.new and from other
-- from the Subnet class, but it is not available to other modules.
-- IPAddress methods, and should be available to the Subnet class, but
-- should not be available to other modules.
assert(type(parts) == 'table', 'parts was type ' .. type(parts) .. '; expected type table')
assert(type(rawIP) == 'table', 'rawIP was type ' .. type(rawIP) .. '; expected type table')


-- Set up structure
-- Set up structure
local obj = {}
local obj = {}
local data = {
local data = {
parts = parts,
rawIP = rawIP,
version = parts.n == 2 and V4 or V6,
version = rawIP.n == 2 and V4 or V6,
}
}


-- Public methods
-- Public methods
function obj:getIP()
function obj:getIP()
return ipString(data.parts)
return tostring(data.rawIP)
end
end


Line 326: Line 333:


function obj:getHighestIP(bitLength)
function obj:getHighestIP(bitLength)
return newIPFromParts(setHostBits(data.parts, bitLength))
return newIPFromRaw(setHostBits(data.rawIP, bitLength))
end
end


function obj:getPrefix(bitLength)
function obj:getPrefix(bitLength)
return newIPFromParts(copyPrefix(data.parts, bitLength))
return newIPFromRaw(copyPrefix(data.rawIP, bitLength))
end
end


Line 352: Line 359:


function obj:getNextIP()
function obj:getNextIP()
return newIPFromParts(copyChanged(data.parts))
return newIPFromRaw(data.rawIP:getAdjacent())
end
end


function obj:getPreviousIP()
function obj:getPreviousIP()
return newIPFromParts(copyChanged(data.parts, true))
return newIPFromRaw(data.rawIP:getAdjacent(true))
end
end


Line 375: Line 382:
function IPAddress.new(ip)
function IPAddress.new(ip)
checkType('IPAddress.new', 1, ip, 'string')
checkType('IPAddress.new', 1, ip, 'string')
local parts = parseIPv4(ip) or parseIPv6(ip)
local rawIP = RawIP.newFromIPv4String(ip) or RawIP.newFromIPv6String(ip)
if not parts then
if not rawIP then
error('invalid IP', 2)
error('invalid IP', 2)
end
end
return newIPFromParts(parts)
return newIPFromRaw(rawIP)
end
end
end
end

Revision as of 03:50, July 19, 2016

Module:IP is a library for working with IP addresses and subnets. It can handle both IPv4 and IPv6. The library exports four classes, IPAddress, Subnet, IPv4Collection, and IPv6Collection.

Loading the library

local IP = require('Module:IP')
local IPAddress = IP.IPAddress
local Subnet = IP.Subnet

IPAddress

The IPAddress class is used to work with single IP addresses. To create a new IPAddress object: 

local ipAddress = IPAddress.new(ipString)

The ipString variable can be a valid IPv4 or IPv6 address.

Examples: 

local ipv4Address = IPAddress.new('1.2.3.4')
local ipv6Address = IPAddress.new('2001:db8::ff00:12:3456')

IPAddress objects can be compared with relational operators: 

-- Equality
IPAddress.new('1.2.3.4') == IPAddress.new('1.2.3.4') -- true
IPAddress.new('1.2.3.4') == IPAddress.new('1.2.3.5') -- false

-- Less than / greater than
IPAddress.new('1.2.3.4') < IPAddress.new('1.2.3.5')  -- true
IPAddress.new('1.2.3.4') > IPAddress.new('1.2.3.5')  -- false
IPAddress.new('1.2.3.4') <= IPAddress.new('1.2.3.5') -- true
IPAddress.new('1.2.3.4') <= IPAddress.new('1.2.3.4') -- true

You can use tostring on them (this is equivalent to using getIP): 

tostring(IPAddress.new('1.2.3.4'))                -- "1.2.3.4"
tostring(IPAddress.new('2001:db8::ff00:12:3456')) -- "2001:db8::ff00:12:3456"

-- Expanded IPv6 addresses are abbreviated:
tostring(IPAddress.new('2001:db8:0:0:0:0:0:0'))   -- "2001:db8::"

You can also concatenate them: 

IPAddress.new('1.2.3.4') .. ' foo'                   -- "1.2.3.4 foo"
IPAddress.new('1.2.3.4') .. IPAddress.new('5.6.7.8') -- "1.2.3.45.6.7.8"

IPAddress objects have several methods, outlined below.

getIP

ipAddress:getIP()

Returns a string representation of the IP address. IPv6 addresses are abbreviated if possible.

Examples: 

IPAddress.new('1.2.3.4'):getIP()                -- "1.2.3.4"
IPAddress.new('2001:db8::ff00:12:3456'):getIP() -- "2001:db8::ff00:12:3456"
IPAddress.new('2001:db8:0:0:0:0:0:0'):getIP()   -- "2001:db8::"

getVersion

ipAddress:getVersion()

Returns the version of the IP protocol being used. This is "IPv4" for IPv4 addresses, and "IPv6" for IPv6 addresses.

Examples: 

IPAddress.new('1.2.3.4'):getVersion()                -- "IPv4"
IPAddress.new('2001:db8::ff00:12:3456'):getVersion() -- "IPv6"

isIPv4

ipAddress:isIPv4()

Returns true if the IP address is an IPv4 address, and false otherwise.

Examples: 

IPAddress.new('1.2.3.4'):isIPv4()                -- true
IPAddress.new('2001:db8::ff00:12:3456'):isIPv4() -- false

isIPv6

ipAddress:isIPv6()

Returns true if the IP address is an IPv6 address, and false otherwise.

Examples: 

IPAddress.new('1.2.3.4'):isIPv6()                -- false
IPAddress.new('2001:db8::ff00:12:3456'):isIPv6() -- true

isInSubnet

ipAddress:isInSubnet(subnet)

Returns true if the IP address is in the subnet subnet, and false otherwise. subnet may be a Subnet object or a CIDR string.

Examples: 

IPAddress.new('1.2.3.4'):isInSubnet('1.2.3.0/24')                             -- true
IPAddress.new('1.2.3.4'):isInSubnet('1.2.4.0/24')                             -- false
IPAddress.new('1.2.3.4'):isInSubnet(Subnet.new('1.2.3.0/24'))                 -- true
IPAddress.new('2001:db8::ff00:12:3456'):isInSubnet('2001:db8::ff00:12:0/112') -- true

getSubnet

ipAddress:getSubnet(bitLength)

Returns a Subnet object for the subnet with a bit length of bitLength which contains the current IP. The bitLength parameter must be an integer between 0 and 32 for IPv4 addresses, or an integer between 0 and 128 for IPv6 addresses.

Examples: 

IPAddress.new('1.2.3.4'):getSubnet(24) -- Equivalent to Subnet.new('1.2.3.0/24')

getNextIP

ipAddress:getNextIP()

Returns a new IPAddress object equivalent to the current IP address incremented by one. The IPv4 address "255.255.255.255" rolls around to "0.0.0.0", and the IPv6 address "ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff" rolls around to "::".

Examples: 

IPAddress.new('1.2.3.4'):getNextIP()                -- Equivalent to IPAddress.new('1.2.3.5')
IPAddress.new('2001:db8::ff00:12:3456'):getNextIP() -- Equivalent to IPAddress.new('2001:db8::ff00:12:3457')
IPAddress.new('255.255.255.255'):getNextIP()        -- Equivalent to IPAddress.new('0.0.0.0')

getPreviousIP

ipAddress:getPreviousIP()

Returns a new IPAddress object equivalent to the current IP address decremented by one. The IPv4 address "0.0.0.0" rolls around to "255.255.255.255", and the IPv6 address "::" rolls around to "ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff".

Examples: 

IPAddress.new('1.2.3.4'):getPreviousIP()                -- Equivalent to IPAddress.new('1.2.3.3')
IPAddress.new('2001:db8::ff00:12:3456'):getPreviousIP() -- Equivalent to IPAddress.new('2001:db8::ff00:12:3455')
IPAddress.new('0.0.0.0'):getPreviousIP()                -- Equivalent to IPAddress.new('255.255.255.255')

Subnet

The Subnet class is used to work with subnetworks of IPv4 or IPv6 addresses. To create a new Subnet object: 

local subnet = Subnet.new(cidrString)

cidrString must be a valid IPv4 or IPv6 CIDR string.

Subnet objects can be compared for equality: 

Subnet.new('1.2.3.0/24') == Subnet.new('1.2.3.0/24')                           -- true
Subnet.new('1.2.3.0/24') == Subnet.new('1.2.3.0/25')                           -- false
Subnet.new('1.2.3.0/24') == Subnet.new('2001:db8::ff00:12:0/112')              -- false
Subnet.new('2001:db8::ff00:12:0/112') == Subnet.new('2001:db8::ff00:12:0/112') -- true
Subnet.new('2001:db8:0:0:0:0:0:0/112') == Subnet.new('2001:db8::/112')         -- true

You can use tostring on them (this is equivalent to getCIDR): 

tostring(Subnet.new('1.2.3.0/24'))               -- "1.2.3.0/24"
tostring(Subnet.new('2001:db8::ff00:12:0/112'))  -- "2001:db8::ff00:12:0/112"
tostring(Subnet.new('2001:db8:0:0:0:0:0:0/112')) -- "2001:db8::/112"

You can also concatenate them: 

Subnet.new('1.2.3.0/24') .. ' foo'                   -- "1.2.3.0/24 foo"
Subnet.new('1.2.3.0/24') .. Subnet.new('4.5.6.0/24') -- "1.2.3.0/244.5.6.0/24"

Subnet objects have several methods, outlined below.

getPrefix

subnet:getPrefix()

Returns an IPAddress object for the lowest IP address in the subnet.

Examples: 

Subnet.new('1.2.3.0/24'):getPrefix()              -- Equivalent to IPAddress.new('1.2.3.0')
Subnet.new('2001:db8::ff00:12:0/112'):getPrefix() -- Equivalent to IPAddress.new('2001:db8::ff00:12:0')

getHighestIP

subnet:getHighestIP()

Returns an IPAddress object for the highest IP address in the subnet.

Examples: 

Subnet.new('1.2.3.0/24'):getHighestIP()              -- Equivalent to IPAddress.new('1.2.3.255')
Subnet.new('2001:db8::ff00:12:0/112'):getHighestIP() -- Equivalent to IPAddress.new('2001:db8::ff00:12:ffff')

getBitLength

subnet:getBitLength()

Returns the bit length of the subnet. This is an integer between 0 and 32 for IPv4 addresses, or an integer between 0 and 128 for IPv6 addresses.

Examples: 

Subnet.new('1.2.3.0/24'):getBitLength()              -- 24
Subnet.new('2001:db8::ff00:12:0/112'):getBitLength() -- 112

getCIDR

subnet:getCIDR()

Returns a CIDR string representation of the subnet.

Examples: 

Subnet.new('1.2.3.0/24'):getCIDR()               -- "1.2.3.0/24"
Subnet.new('2001:db8::ff00:12:0/112'):getCIDR()  -- "2001:db8::ff00:12:0/112"
Subnet.new('2001:db8:0:0:0:0:0:0/112'):getCIDR() -- "2001:db8::/112"

getVersion

subnet:getVersion()

Returns the version of the IP protocol being used. This is "IPv4" for IPv4 addresses, and "IPv6" for IPv6 addresses.

Examples: 

Subnet.new('1.2.3.0/24'):getVersion()              -- "IPv4"
Subnet.new('2001:db8::ff00:12:0/112'):getVersion() -- "IPv6"

isIPv4

subnet:isIPv4()

Returns true if the subnet is using IPv4, and false otherwise.

Examples: 

Subnet.new('1.2.3.0/24'):isIPv4()              -- true
Subnet.new('2001:db8::ff00:12:0/112'):isIPv4() -- false

isIPv6

subnet:isIPv6()

Returns true if the subnet is using IPv6, and false otherwise.

Examples: 

Subnet.new('1.2.3.0/24'):isIPv6()              -- false
Subnet.new('2001:db8::ff00:12:0/112'):isIPv6() -- true

containsIP

subnet:containsIP(ip)

Returns true if the subnet contains the IP address ip, and false otherwise. ip can be an IP address string, or an IPAddress object.

Examples: 

Subnet.new('1.2.3.0/24'):containsIP('1.2.3.4')                             -- true
Subnet.new('1.2.3.0/24'):containsIP('1.2.4.4')                             -- false
Subnet.new('1.2.3.0/24'):containsIP(IPAddress.new('1.2.3.4'))              -- true
Subnet.new('2001:db8::ff00:12:0/112'):containsIP('2001:db8::ff00:12:3456') -- true

overlapsSubnet

subnet:overlapsSubnet(subnet)

Returns true if the current subnet overlaps with subnet, and false otherwise. subnet can be a CIDR string or a subnet object.

Examples: 

Subnet.new('1.2.3.0/24'):overlapsSubnet('1.2.0.0/16')                         -- true
Subnet.new('1.2.3.0/24'):overlapsSubnet('1.2.12.0/22')                        -- false
Subnet.new('1.2.3.0/24'):overlapsSubnet(Subnet.new('1.2.0.0/16'))             -- true
Subnet.new('2001:db8::ff00:12:0/112'):overlapsSubnet('2001:db8::ff00:0:0/96') -- true

walk

subnet:walk()

The walk method iterates over all of the IPAddress objects in the subnet.

Examples: 

for ipAddress in Subnet.new('192.168.0.0/30'):walk() do
	mw.log(tostring(ipAddress))
end
-- 192.168.0.0
-- 192.168.0.1
-- 192.168.0.2
-- 192.168.0.3

IPv4Collection

The IPv4Collection class is used to work with several different IPv4 addresses and IPv4 subnets. To create a new IPv4Collection object: 

local collection = IPv4Collection.new()

IPv4Collection objects have several methods, outlined below.

getVersion

collection:getVersion()

Returns the string "IPv4".

addIP

collection:addIP(ip)

Adds an IP to the collection. The IP can be either a string or an IPAddress object.

Examples: 

collection:addIP('1.2.3.4')
collection:addIP(IPAddress.new('1.2.3.4'))

This method is chainable: 

collection:addIP('1.2.3.4'):addIP('5.6.7.8')

addSubnet

collection:addSubnet(subnet)

Adds a subnet to the collection. The subnet can be either a CIDR string or a Subnet object.

Examples: 

collection:addSubnet('1.2.3.0/24')
collection:addSubnet(Subnet.new('1.2.3.0/24'))

This method is chainable: 

collection:addSubnet('1.2.0.0/24'):addSubnet('1.2.1.0/24')

addFromString

collection:addFromString(str)

Extracts any IPv4 addresses and IPv4 CIDR subnets from str and adds them to the collection. Any text that is not an IPv4 address or CIDR subnet is ignored.

Examples: 

collection:addFromString('Add some IPs and subnets: 1.2.3.4 1.2.3.5 2001:0::f foo 1.2.4.0/24')

This method is chainable: 

collection:addFromString('foo 1.2.3.4'):addFromString('bar 5.6.7.8')

containsIP

collection:containsIP(ip)

Returns true if the collection contains the specified IP; otherwise returns false. The ip parameter can be a string or an IPAddress object.

Examples: 

collection:containsIP('1.2.3.4')
collection:containsIP(IPAddress.new('1.2.3.4'))

getRanges

collection:getRanges()

Returns a sorted array of IP pairs equivalent to the collection. Each IP pair is an array representing a contiguous range of IP addresses from pair[1] to pair[2] inclusive. pair[1] and pair[2] are IPAddress objects.

Examples: 

collection:addSubnet('1.2.0.0/24')
collection:addSubnet('1.2.1.0/24')
collection:addSubnet('1.2.10.0/24')
mw.logObject(collection:getRanges())
-- Logs the following:
-- table#1 {
--   table#2 {
--     1.2.0.0,
--     1.2.1.255,
--   },
--   table#3 {
--     1.2.10.0,
--     1.2.10.255,
--   },
-- }

overlapsSubnet

collection:overlapsSubnet(subnet)

Returns true, obj if subnet overlaps this collection, where obj is the first IPAddress or Subnet object overlapping the subnet. Otherwise, returns false. subnet can be a CIDR string or a Subnet object.

Examples: 

collection:addIP('1.2.3.4')
collection:overlapsSubnet('1.2.3.0/24') -- true, IPAddress.new('1.2.3.4')
collection:overlapsSubnet('1.2.4.0/24') -- false

IPv6Collection

The IPv6Collection class is used to work with several different IPv6 addresses and IPv6 subnets. IPv6Collection objects are directly analogous to IPv4Collection objects: they contain the same methods and work the same way, but all IP addresses and subnets added to it must be IPv6, not IPv4.

To create a new IPv6Collection object: 

local collection = IPv6Collection.new()



-- IP library
-- This library contains classes for working with IP addresses and IP ranges.

-- Load modules
local bit32 = require('bit32')
local libraryUtil = require('libraryUtil')
local checkType = libraryUtil.checkType

-- Constants
local V4 = 'IPv4'
local V6 = 'IPv6'

--------------------------------------------------------------------------------
-- RawIP class
-- Numeric representation of an IPv4 or IPv6 address. Used internally.
-- A RawIP object is constructed by adding data to a Collection object and
-- then giving it a new metatable. This is to avoid the memory overhead of
-- copying the data to a new table.
--------------------------------------------------------------------------------

local RawIP = {}
RawIP.__index = RawIP

do
	-- Collection class.
	-- This is a table used to hold items.
	local Collection
	do
		local mt = {
			__index = {
				add = function (self, item)
					self.n = self.n + 1
					self[self.n] = item
				end,
				join = function (self, sep)
					return table.concat(self, sep)
				end,
			}
		}
		Collection = function ()
			return setmetatable({n = 0}, mt)
		end
	end

	-- Constructors
	function RawIP.newFromIPv4(ipStr)
		-- If ipStr is a valid IPv4 string, return a collection of its parts.
		-- Otherwise, return nil.
		-- This representation is for compatibility with IPv6 addresses.
		local octets = Collection()
		local s = ipStr:match('^%s*(.-)%s*$') .. '.'
		for item in s:gmatch('(.-)%.') do
			octets:add(item)
		end
		if octets.n == 4 then
			for i, s in ipairs(octets) do
				if s:match('^%d+$') then
					local num = tonumber(s)
					if 0 <= num and num <= 255 then
						if num > 0 and s:match('^0') then
							-- A redundant leading zero is for an IP in octal.
							return false
						end
						octets[i] = num
					else
						return false
					end
				else
					return false
				end
			end
			local parts = Collection()
			for i = 1, 3, 2 do
				parts:add(octets[i] * 256 + octets[i+1])
			end
			return setmetatable(parts, RawIP)
		end
		return nil
	end
	
	function RawIP.newFromIPv6(ipStr)
		-- If ipStr is a valid IPv6 string, return a collection of its parts.
		-- Otherwise, return nil.
		ipStr = ipStr:match('^%s*(.-)%s*$')
		local _, n = ipStr:gsub(':', ':')
		if n < 7 then
			ipStr, n = ipStr:gsub('::', string.rep(':', 9 - n))
		end
		local parts = Collection()
		for item in (ipStr .. ':'):gmatch('(.-):') do
			parts:add(item)
		end
		if parts.n == 8 then
			for i, s in ipairs(parts) do
				if s == '' then
					parts[i] = 0
				else
					local num = tonumber('0x' .. s)
					if num and 0 <= num and num <= 65535 then
						parts[i] = num
					else
						return false
					end
				end
			end
			return setmetatable(parts, RawIP)
		end
		return nil
	end
	
	function RawIP:getAdjacent(previous)
		-- Return a RawIP object for an adjacent IP address. If previous is true
		-- then the previous IP is returned; otherwise the next IP is returned.
		-- Will wraparound:
		--   next      255.255.255.255 → 0.0.0.0
		--             ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff → ::
		--   previous  0.0.0.0 → 255.255.255.255
		--             :: → ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff
		local result = Collection()
		result.n = self.n
		local carry = down and 0xffff or 1
		for i = self.n, 1, -1 do
			local sum = self[i] + carry
			if sum >= 0x10000 then
				carry = down and 0x10000 or 1
				sum = sum - 0x10000
			else
				carry = down and 0xffff or 0
			end
			result[i] = sum
		end
		return setmetatable(result, RawIP)
	end

	-- Methods
	function RawIP:getPrefix(length)
		-- Return a copy of IPv4 or IPv6 parts, masked to length.
		local result = Collection()
		result.n = self.n
		for i = 1, self.n do
			if length > 0 then
				if length >= 16 then
					result[i] = self[i]
					length = length - 16
				else
					result[i] = bit32.band(self[i],
						bit32.arshift(0xffff8000, length - 1))
					length = 0
				end
			else
				result[i] = 0
			end
		end
		return setmetatable(result, RawIP)
	end

	function RawIP:setHostBits(length)
		-- Return a copy of IPv4 or IPv6 parts, with the least-significant bits
		-- (host bits) set to 1.
		-- The most-significant length bits identify the network.
		local bits = self.n * 16
		local width
		if length <= 0 then
			width = bits
		elseif length >= bits then
			width = 0
		else
			width = bits - length
		end
		local result = Collection()
		result.n = self.n
		for i = self.n, 1, -1 do
			if width > 0 then
				if width >= 16 then
					result[i] = 0xffff
					width = width - 16
				else
					result[i] = bit32.replace(self[i], 0xffff, width - 1, width)
					width = 0
				end
			else
				result[i] = self[i]
			end
		end
		return setmetatable(result, rawIP)
	end

	function RawIP:_makeIPv6String()
		-- Return an IPv6 string representation of the object. Behavior is undefined
		-- if the current object is IPv4.
		local z1, z2  -- indices of run of zeros to be displayed as "::"
		local zstart, zcount
		for i = 1, 9 do
			-- Find left-most occurrence of longest run of two or more zeros.
			if i < 9 and self[i] == 0 then
				if zstart then
					zcount = zcount + 1
				else
					zstart = i
					zcount = 1
				end
			else
				if zcount and zcount > 1 then
					if not z1 or zcount > z2 - z1 + 1 then
						z1 = zstart
						z2 = zstart + zcount - 1
					end
				end
				zstart = nil
				zcount = nil
			end
		end
		local parts = Collection()
		for i = 1, 8 do
			if z1 and z1 <= i and i <= z2 then
				if i == z1 then
					if z1 == 1 or z2 == 8 then
						if z1 == 1 and z2 == 8 then
							return '::'
						end
						parts:add(':')
					else
						parts:add('')
					end
				end
			else
				parts:add(string.format('%x', self[i]))
			end
		end
		return parts:join(':')
	end

	function RawIP:_makeIPv4String()
		-- Return an IPv4 string representation of the object. Behavior is undefined
		-- if the current object is IPv6.
		local parts = Collection()
		for i = 1, 2 do
			local w = self[i]
			parts:add(math.floor(w / 256))
			parts:add(w % 256)
		end
		return parts:join('.')
	end

	function RawIP:__tostring()
		-- Return a string equivalent to given IP address (IPv4 or IPv6).
		if self.n == 2 then
			return self:_makeIPv4String()
		else
			return self:_makeIPv6String()
		end
	end

	function RawIP:__lt(obj)
		if self.n == obj.n then
			for i = 1, self.n do
				if self[i] ~= obj[i] then
					return self[i] < obj[i]
				end
			end
			return false
		end
		return self.n < obj.n
	end

	function RawIP:__eq(obj)
		if self.n == obj.n then
			for i = 1, self.n do
				if self[i] ~= obj[i] then
					return false
				end
			end
			return true
		end
		return false
	end
end

--------------------------------------------------------------------------------
-- IPAddress class
-- Represents a single IPv4 or IPv6 address.
--------------------------------------------------------------------------------

local IPAddress = {}

local newIPFromRaw
-- newIPFromRaw constructs a new IPAddress object from a rawIP object. It needs
-- to be accessible from the Subnet class but it should not be public.

do
	local dataKey = {} -- A unique key to access objects' internal data.

	-- Metamethods that don't need upvalues
	local function ipEquals(ip1, ip2)
		return ip1[dataKey].rawIP == ip2[dataKey].rawIP
	end

	local function ipLessThan(ip1, ip2)
		return ip1[dataKey].rawIP < ip2[dataKey].rawIP
	end

	local function concatIPs(ip1, ip2)
		return ip1:getIP() .. ip2:getIP()
	end

	local function ipToString(ip)
		return ip:getIP()
	end

	-- Constructors
	newIPFromRaw = function (rawIP)
		-- Constructs a new IPAddress object from a rawIP object. This function
		-- is for internal use; it is called by IPAddress.new and from other
		-- IPAddress methods, and should be available to the Subnet class, but
		-- should not be available to other modules.
		assert(type(rawIP) == 'table', 'rawIP was type ' .. type(rawIP) .. '; expected type table')

		-- Set up structure
		local obj = {}
		local data = {
			rawIP = rawIP,
			version = rawIP.n == 2 and V4 or V6,
		}

		-- Public methods
		function obj:getIP()
			return tostring(data.rawIP)
		end

		function obj:getVersion()
			return data.version
		end

		function obj:getHighestIP(bitLength)
			return newIPFromRaw(setHostBits(data.rawIP, bitLength))
		end

		function obj:getPrefix(bitLength)
			return newIPFromRaw(copyPrefix(data.rawIP, bitLength))
		end

		function obj:isIPv4()
			return data.version == V4
		end

		function obj:isIPv6()
			return data.version == V6
		end

		function obj:isInSubnet(subnet)
			-- TODO Consider alternative of checking:
			--   (ipFirst <= self and self <= ipLast)
			if self:getVersion() == subnet:getVersion() then
				local prefix = self:getPrefix(subnet:getBitLength())
				return prefix == subnet:getPrefix()
			end
			return false
		end

		function obj:getNextIP()
			return newIPFromRaw(data.rawIP:getAdjacent())
		end

		function obj:getPreviousIP()
			return newIPFromRaw(data.rawIP:getAdjacent(true))
		end

		-- Metamethods
		return setmetatable(obj, {
			__eq = ipEquals,
			__lt = ipLessThan,
			__concat = concatIPs,
			__tostring = ipToString,
			__index = function (self, key)
				if key == dataKey then
					return data
				end
			end,
		})
	end

	function IPAddress.new(ip)
		checkType('IPAddress.new', 1, ip, 'string')
		local rawIP = RawIP.newFromIPv4String(ip) or RawIP.newFromIPv6String(ip)
		if not rawIP then
			error('invalid IP', 2)
		end
		return newIPFromRaw(rawIP)
	end
end

local function makeSubnet(data, cidrStr)
	-- If cidrStr is a valid IPv4 or IPv6 CIDR specification, store its
	-- information in data and return its version. Otherwise, return nil.
	local lhs, rhs = cidrStr:match('^%s*(.-)/(%d+)%s*$')
	if lhs then
		local bits = lhs:find(':', 1, true) and 128 or 32
		local n = tonumber(rhs)
		if n and n <= bits then
			local base = IPAddress.new(lhs)
			local prefix = base:getPrefix(n)
			if base == prefix then
				data.bitLength = n
				data.prefix = prefix
				data.highestIP = base:getHighestIP(n)
				return bits == 32 and V4 or V6
			end
		end
	end
	return nil
end

--------------------------------------------------------------------------------
-- Subnet class
-- Represents a block of IPv4 or IPv6 addresses.
--------------------------------------------------------------------------------

local Subnet = {}

do
	-- Initialize metatable
	local mt = {}

	-- Constructor
	function Subnet.new(cidr)
		-- Set up structure
		local obj = setmetatable({}, mt)
		local data = {}

		-- Public methods
		function obj:getPrefix()
			return data.prefix
		end

		function obj:getHighestIP()
			return data.highestIP
		end

		function obj:getBitLength()
			return data.bitLength
		end

		function obj:getCIDR()
			return string.format('%s/%d', self:getPrefix(), self:getBitLength())
		end

		function obj:getVersion()
			return data.version
		end

		function obj:isIPv4()
			return data.version == V4
		end

		function obj:isIPv6()
			return data.version == V6
		end

		function obj:containsIP(ip)
			-- TODO See ip:isInSubnet(subnet); use this technique there?
			if self:getVersion() == ip:getVersion() then
				return self:getPrefix() <= ip and ip <= self:getHighestIP()
			end
			return false
		end

		function obj:overlapsSubnet(subnet)
			if self:getVersion() == subnet:getVersion() then
				return (
					subnet:getHighestIP() >= self:getPrefix() and
					subnet:getPrefix() <= self:getHighestIP()
				)
			end
			return false
		end

		-- Set initial values
		checkType('Subnet.new', 1, cidr, 'string')
		data.version = makeSubnet(data, cidr)
		if not data.version then
			error('invalid CIDR', 2)
		end

		return obj
	end

	-- Metamethods
	function mt:__eq(obj)
		return self:getCIDR() == obj:getCIDR()
	end

	function mt:__tostring()
		return self:getCIDR()
	end
end

return {
	IPAddress = IPAddress,
	Subnet = Subnet,
}
Retrieved from "https://crocwiki.com/wiki/Module:IP?oldid=30980"