--- /dev/null
+--[[
+
+LuCI ip calculation libarary
+(c) 2008 Jo-Philipp Wich <xm@leipzig.freifunk.net>
+(c) 2008 Steven Barth <steven@midlink.org>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+$Id$
+
+]]--
+
+--- LuCI IP calculation library.
+module( "luci.ip", package.seeall )
+
+require "nixio"
+local bit = nixio.bit
+local util = require "luci.util"
+
+--- Boolean; true if system is little endian
+LITTLE_ENDIAN = not util.bigendian()
+
+--- Boolean; true if system is big endian
+BIG_ENDIAN = not LITTLE_ENDIAN
+
+--- Specifier for IPv4 address family
+FAMILY_INET4 = 0x04
+
+--- Specifier for IPv6 address family
+FAMILY_INET6 = 0x06
+
+
+local function __bless(x)
+ return setmetatable( x, {
+ __index = luci.ip.cidr,
+ __add = luci.ip.cidr.add,
+ __sub = luci.ip.cidr.sub,
+ __lt = luci.ip.cidr.lower,
+ __eq = luci.ip.cidr.equal,
+ __le =
+ function(...)
+ return luci.ip.cidr.equal(...) or luci.ip.cidr.lower(...)
+ end
+ } )
+end
+
+local function __array16( x, family )
+ local list
+
+ if type(x) == "number" then
+ list = { bit.rshift(x, 16), bit.band(x, 0xFFFF) }
+
+ elseif type(x) == "string" then
+ if x:find(":") then x = IPv6(x) else x = IPv4(x) end
+ if x then
+ assert( x[1] == family, "Can't mix IPv4 and IPv6 addresses" )
+ list = { unpack(x[2]) }
+ end
+
+ elseif type(x) == "table" and type(x[2]) == "table" then
+ assert( x[1] == family, "Can't mix IPv4 and IPv6 addresses" )
+ list = { unpack(x[2]) }
+
+ elseif type(x) == "table" then
+ list = { unpack(x) }
+ end
+
+ assert( list, "Invalid operand" )
+
+ return list
+end
+
+local function __mask16(bits)
+ return bit.lshift( bit.rshift( 0xFFFF, 16 - bits % 16 ), 16 - bits % 16 )
+end
+
+local function __not16(bits)
+ return bit.band( bit.bnot( __mask16(bits) ), 0xFFFF )
+end
+
+local function __maxlen(family)
+ return ( family == FAMILY_INET4 ) and 32 or 128
+end
+
+local function __sublen(family)
+ return ( family == FAMILY_INET4 ) and 30 or 127
+end
+
+
+--- Convert given short value to network byte order on little endian hosts
+-- @param x Unsigned integer value between 0x0000 and 0xFFFF
+-- @return Byte-swapped value
+-- @see htonl
+-- @see ntohs
+function htons(x)
+ if LITTLE_ENDIAN then
+ return bit.bor(
+ bit.rshift( x, 8 ),
+ bit.band( bit.lshift( x, 8 ), 0xFF00 )
+ )
+ else
+ return x
+ end
+end
+
+--- Convert given long value to network byte order on little endian hosts
+-- @param x Unsigned integer value between 0x00000000 and 0xFFFFFFFF
+-- @return Byte-swapped value
+-- @see htons
+-- @see ntohl
+function htonl(x)
+ if LITTLE_ENDIAN then
+ return bit.bor(
+ bit.lshift( htons( bit.band( x, 0xFFFF ) ), 16 ),
+ htons( bit.rshift( x, 16 ) )
+ )
+ else
+ return x
+ end
+end
+
+--- Convert given short value to host byte order on little endian hosts
+-- @class function
+-- @name ntohs
+-- @param x Unsigned integer value between 0x0000 and 0xFFFF
+-- @return Byte-swapped value
+-- @see htonl
+-- @see ntohs
+ntohs = htons
+
+--- Convert given short value to host byte order on little endian hosts
+-- @class function
+-- @name ntohl
+-- @param x Unsigned integer value between 0x00000000 and 0xFFFFFFFF
+-- @return Byte-swapped value
+-- @see htons
+-- @see ntohl
+ntohl = htonl
+
+
+--- Parse given IPv4 address in dotted quad or CIDR notation. If an optional
+-- netmask is given as second argument and the IP address is encoded in CIDR
+-- notation then the netmask parameter takes precedence. If neither a CIDR
+-- encoded prefix nor a netmask parameter is given, then a prefix length of
+-- 32 bit is assumed.
+-- @param address IPv4 address in dotted quad or CIDR notation
+-- @param netmask IPv4 netmask in dotted quad notation (optional)
+-- @return luci.ip.cidr instance or nil if given address was invalid
+-- @see IPv6
+-- @see Hex
+function IPv4(address, netmask)
+ address = address or "0.0.0.0/0"
+
+ local obj = __bless({ FAMILY_INET4 })
+
+ local data = {}
+ local prefix = address:match("/(.+)")
+ address = address:gsub("/.+","")
+ address = address:gsub("^%[(.*)%]$", "%1"):upper():gsub("^::FFFF:", "")
+
+ if netmask then
+ prefix = obj:prefix(netmask)
+ elseif prefix then
+ prefix = tonumber(prefix)
+ if not prefix or prefix < 0 or prefix > 32 then return nil end
+ else
+ prefix = 32
+ end
+
+ local b1, b2, b3, b4 = address:match("^(%d+)%.(%d+)%.(%d+)%.(%d+)$")
+
+ b1 = tonumber(b1)
+ b2 = tonumber(b2)
+ b3 = tonumber(b3)
+ b4 = tonumber(b4)
+
+ if b1 and b1 <= 255 and
+ b2 and b2 <= 255 and
+ b3 and b3 <= 255 and
+ b4 and b4 <= 255 and
+ prefix
+ then
+ table.insert(obj, { b1 * 256 + b2, b3 * 256 + b4 })
+ table.insert(obj, prefix)
+ return obj
+ end
+end
+
+--- Parse given IPv6 address in full, compressed, mixed or CIDR notation.
+-- If an optional netmask is given as second argument and the IP address is
+-- encoded in CIDR notation then the netmask parameter takes precedence.
+-- If neither a CIDR encoded prefix nor a netmask parameter is given, then a
+-- prefix length of 128 bit is assumed.
+-- @param address IPv6 address in full/compressed/mixed or CIDR notation
+-- @param netmask IPv6 netmask in full/compressed/mixed notation (optional)
+-- @return luci.ip.cidr instance or nil if given address was invalid
+-- @see IPv4
+-- @see Hex
+function IPv6(address, netmask)
+ address = address or "::/0"
+
+ local obj = __bless({ FAMILY_INET6 })
+
+ local data = {}
+ local prefix = address:match("/(.+)")
+ address = address:gsub("/.+","")
+ address = address:gsub("^%[(.*)%]$", "%1")
+
+ if netmask then
+ prefix = obj:prefix(netmask)
+ elseif prefix then
+ prefix = tonumber(prefix)
+ if not prefix or prefix < 0 or prefix > 128 then return nil end
+ else
+ prefix = 128
+ end
+
+ local borderl = address:sub(1, 1) == ":" and 2 or 1
+ local borderh, zeroh, chunk, block, i
+
+ if #address > 45 then return nil end
+
+ repeat
+ borderh = address:find(":", borderl, true)
+ if not borderh then break end
+
+ block = tonumber(address:sub(borderl, borderh - 1), 16)
+ if block and block <= 0xFFFF then
+ data[#data+1] = block
+ else
+ if zeroh or borderh - borderl > 1 then return nil end
+ zeroh = #data + 1
+ end
+
+ borderl = borderh + 1
+ until #data == 7
+
+ chunk = address:sub(borderl)
+ if #chunk > 0 and #chunk <= 4 then
+ block = tonumber(chunk, 16)
+ if not block or block > 0xFFFF then return nil end
+
+ data[#data+1] = block
+ elseif #chunk > 4 then
+ if #data == 7 or #chunk > 15 then return nil end
+ borderl = 1
+ for i=1, 4 do
+ borderh = chunk:find(".", borderl, true)
+ if not borderh and i < 4 then return nil end
+ borderh = borderh and borderh - 1
+
+ block = tonumber(chunk:sub(borderl, borderh))
+ if not block or block > 255 then return nil end
+
+ if i == 1 or i == 3 then
+ data[#data+1] = block * 256
+ else
+ data[#data] = data[#data] + block
+ end
+
+ borderl = borderh and borderh + 2
+ end
+ end
+
+ if zeroh then
+ if #data == 8 then return nil end
+ while #data < 8 do
+ table.insert(data, zeroh, 0)
+ end
+ end
+
+ if #data == 8 and prefix then
+ table.insert(obj, data)
+ table.insert(obj, prefix)
+ return obj
+ end
+end
+
+--- Transform given hex-encoded value to luci.ip.cidr instance of specified
+-- address family.
+-- @param hex String containing hex encoded value
+-- @param prefix Prefix length of CIDR instance (optional, default is 32/128)
+-- @param family Address family, either luci.ip.FAMILY_INET4 or FAMILY_INET6
+-- @param swap Bool indicating whether to swap byteorder on low endian host
+-- @return luci.ip.cidr instance or nil if given value was invalid
+-- @see IPv4
+-- @see IPv6
+function Hex( hex, prefix, family, swap )
+ family = ( family ~= nil ) and family or FAMILY_INET4
+ swap = ( swap == nil ) and true or swap
+ prefix = prefix or __maxlen(family)
+
+ local len = __maxlen(family)
+ local tmp = ""
+ local data = { }
+ local i
+
+ for i = 1, (len/4) - #hex do tmp = tmp .. '0' end
+
+ if swap and LITTLE_ENDIAN then
+ for i = #hex, 1, -2 do tmp = tmp .. hex:sub( i - 1, i ) end
+ else
+ tmp = tmp .. hex
+ end
+
+ hex = tmp
+
+ for i = 1, ( len / 4 ), 4 do
+ local n = tonumber( hex:sub( i, i+3 ), 16 )
+ if n then
+ data[#data+1] = n
+ else
+ return nil
+ end
+ end
+
+ return __bless({ family, data, prefix })
+end
+
+
+--- LuCI IP Library / CIDR instances
+-- @class module
+-- @cstyle instance
+-- @name luci.ip.cidr
+cidr = util.class()
+
+--- Test whether the instance is a IPv4 address.
+-- @return Boolean indicating a IPv4 address type
+-- @see cidr.is6
+function cidr.is4( self )
+ return self[1] == FAMILY_INET4
+end
+
+--- Test whether this instance is an IPv4 RFC1918 private address
+-- @return Boolean indicating whether this instance is an RFC1918 address
+function cidr.is4rfc1918( self )
+ if self[1] == FAMILY_INET4 then
+ return ((self[2][1] >= 0x0A00) and (self[2][1] <= 0x0AFF)) or
+ ((self[2][1] >= 0xAC10) and (self[2][1] <= 0xAC1F)) or
+ (self[2][1] == 0xC0A8)
+ end
+ return false
+end
+
+--- Test whether this instance is an IPv4 link-local address (Zeroconf)
+-- @return Boolean indicating whether this instance is IPv4 link-local
+function cidr.is4linklocal( self )
+ if self[1] == FAMILY_INET4 then
+ return (self[2][1] == 0xA9FE)
+ end
+ return false
+end
+
+--- Test whether the instance is a IPv6 address.
+-- @return Boolean indicating a IPv6 address type
+-- @see cidr.is4
+function cidr.is6( self )
+ return self[1] == FAMILY_INET6
+end
+
+--- Test whether this instance is an IPv6 link-local address
+-- @return Boolean indicating whether this instance is IPv6 link-local
+function cidr.is6linklocal( self )
+ if self[1] == FAMILY_INET6 then
+ return (self[2][1] >= 0xFE80) and (self[2][1] <= 0xFEBF)
+ end
+ return false
+end
+
+--- Return a corresponding string representation of the instance.
+-- If the prefix length is lower then the maximum possible prefix length for the
+-- corresponding address type then the address is returned in CIDR notation,
+-- otherwise the prefix will be left out.
+function cidr.string( self )
+ local str
+ if self:is4() then
+ str = string.format(
+ "%d.%d.%d.%d",
+ bit.rshift(self[2][1], 8), bit.band(self[2][1], 0xFF),
+ bit.rshift(self[2][2], 8), bit.band(self[2][2], 0xFF)
+ )
+ if self[3] < 32 then
+ str = str .. "/" .. self[3]
+ end
+ elseif self:is6() then
+ str = string.format( "%X:%X:%X:%X:%X:%X:%X:%X", unpack(self[2]) )
+ if self[3] < 128 then
+ str = str .. "/" .. self[3]
+ end
+ end
+ return str
+end
+
+--- Test whether the value of the instance is lower then the given address.
+-- This function will throw an exception if the given address has a different
+-- family than this instance.
+-- @param addr A luci.ip.cidr instance to compare against
+-- @return Boolean indicating whether this instance is lower
+-- @see cidr.higher
+-- @see cidr.equal
+function cidr.lower( self, addr )
+ assert( self[1] == addr[1], "Can't compare IPv4 and IPv6 addresses" )
+ local i
+ for i = 1, #self[2] do
+ if self[2][i] ~= addr[2][i] then
+ return self[2][i] < addr[2][i]
+ end
+ end
+ return false
+end
+
+--- Test whether the value of the instance is higher then the given address.
+-- This function will throw an exception if the given address has a different
+-- family than this instance.
+-- @param addr A luci.ip.cidr instance to compare against
+-- @return Boolean indicating whether this instance is higher
+-- @see cidr.lower
+-- @see cidr.equal
+function cidr.higher( self, addr )
+ assert( self[1] == addr[1], "Can't compare IPv4 and IPv6 addresses" )
+ local i
+ for i = 1, #self[2] do
+ if self[2][i] ~= addr[2][i] then
+ return self[2][i] > addr[2][i]
+ end
+ end
+ return false
+end
+
+--- Test whether the value of the instance is equal to the given address.
+-- This function will throw an exception if the given address is a different
+-- family than this instance.
+-- @param addr A luci.ip.cidr instance to compare against
+-- @return Boolean indicating whether this instance is equal
+-- @see cidr.lower
+-- @see cidr.higher
+function cidr.equal( self, addr )
+ assert( self[1] == addr[1], "Can't compare IPv4 and IPv6 addresses" )
+ local i
+ for i = 1, #self[2] do
+ if self[2][i] ~= addr[2][i] then
+ return false
+ end
+ end
+ return true
+end
+
+--- Return the prefix length of this CIDR instance.
+-- @param mask Override instance prefix with given netmask (optional)
+-- @return Prefix length in bit
+function cidr.prefix( self, mask )
+ local prefix = self[3]
+
+ if mask then
+ prefix = 0
+
+ local stop = false
+ local obj = type(mask) ~= "table"
+ and ( self:is4() and IPv4(mask) or IPv6(mask) ) or mask
+
+ if not obj then return nil end
+
+ local _, word
+ for _, word in ipairs(obj[2]) do
+ if word == 0xFFFF then
+ prefix = prefix + 16
+ else
+ local bitmask = bit.lshift(1, 15)
+ while bit.band(word, bitmask) == bitmask do
+ prefix = prefix + 1
+ bitmask = bit.lshift(1, 15 - (prefix % 16))
+ end
+
+ break
+ end
+ end
+ end
+
+ return prefix
+end
+
+--- Return a corresponding CIDR representing the network address of this
+-- instance.
+-- @param bits Override prefix length of this instance (optional)
+-- @return CIDR instance containing the network address
+-- @see cidr.host
+-- @see cidr.broadcast
+-- @see cidr.mask
+function cidr.network( self, bits )
+ local data = { }
+ bits = bits or self[3]
+
+ local i
+ for i = 1, math.floor( bits / 16 ) do
+ data[#data+1] = self[2][i]
+ end
+
+ if #data < #self[2] then
+ data[#data+1] = bit.band( self[2][1+#data], __mask16(bits) )
+
+ for i = #data + 1, #self[2] do
+ data[#data+1] = 0
+ end
+ end
+
+ return __bless({ self[1], data, __maxlen(self[1]) })
+end
+
+--- Return a corresponding CIDR representing the host address of this
+-- instance. This is intended to extract the host address from larger subnet.
+-- @return CIDR instance containing the network address
+-- @see cidr.network
+-- @see cidr.broadcast
+-- @see cidr.mask
+function cidr.host( self )
+ return __bless({ self[1], self[2], __maxlen(self[1]) })
+end
+
+--- Return a corresponding CIDR representing the netmask of this instance.
+-- @param bits Override prefix length of this instance (optional)
+-- @return CIDR instance containing the netmask
+-- @see cidr.network
+-- @see cidr.host
+-- @see cidr.broadcast
+function cidr.mask( self, bits )
+ local data = { }
+ bits = bits or self[3]
+
+ for i = 1, math.floor( bits / 16 ) do
+ data[#data+1] = 0xFFFF
+ end
+
+ if #data < #self[2] then
+ data[#data+1] = __mask16(bits)
+
+ for i = #data + 1, #self[2] do
+ data[#data+1] = 0
+ end
+ end
+
+ return __bless({ self[1], data, __maxlen(self[1]) })
+end
+
+--- Return CIDR containing the broadcast address of this instance.
+-- @return CIDR instance containing the netmask, always nil for IPv6
+-- @see cidr.network
+-- @see cidr.host
+-- @see cidr.mask
+function cidr.broadcast( self )
+ -- IPv6 has no broadcast addresses (XXX: assert() instead?)
+ if self[1] == FAMILY_INET4 then
+ local data = { unpack(self[2]) }
+ local offset = math.floor( self[3] / 16 ) + 1
+
+ if offset <= #data then
+ data[offset] = bit.bor( data[offset], __not16(self[3]) )
+ for i = offset + 1, #data do data[i] = 0xFFFF end
+
+ return __bless({ self[1], data, __maxlen(self[1]) })
+ end
+ end
+end
+
+--- Test whether this instance fully contains the given CIDR instance.
+-- @param addr CIDR instance to test against
+-- @return Boolean indicating whether this instance contains the given CIDR
+function cidr.contains( self, addr )
+ assert( self[1] == addr[1], "Can't compare IPv4 and IPv6 addresses" )
+
+ if self:prefix() <= addr:prefix() then
+ return self:network() == addr:network(self:prefix())
+ end
+
+ return false
+end
+
+--- Add specified amount of hosts to this instance.
+-- @param amount Number of hosts to add to this instance
+-- @param inplace Boolen indicating whether to alter values inplace (optional)
+-- @return CIDR representing the new address or nil on overflow error
+-- @see cidr.sub
+function cidr.add( self, amount, inplace )
+ local pos
+ local data = { unpack(self[2]) }
+ local shorts = __array16( amount, self[1] )
+
+ for pos = #data, 1, -1 do
+ local add = ( #shorts > 0 ) and table.remove( shorts, #shorts ) or 0
+ if ( data[pos] + add ) > 0xFFFF then
+ data[pos] = ( data[pos] + add ) % 0xFFFF
+ if pos > 1 then
+ data[pos-1] = data[pos-1] + ( add - data[pos] )
+ else
+ return nil
+ end
+ else
+ data[pos] = data[pos] + add
+ end
+ end
+
+ if inplace then
+ self[2] = data
+ return self
+ else
+ return __bless({ self[1], data, self[3] })
+ end
+end
+
+--- Substract specified amount of hosts from this instance.
+-- @param amount Number of hosts to substract from this instance
+-- @param inplace Boolen indicating whether to alter values inplace (optional)
+-- @return CIDR representing the new address or nil on underflow error
+-- @see cidr.add
+function cidr.sub( self, amount, inplace )
+ local pos
+ local data = { unpack(self[2]) }
+ local shorts = __array16( amount, self[1] )
+
+ for pos = #data, 1, -1 do
+ local sub = ( #shorts > 0 ) and table.remove( shorts, #shorts ) or 0
+ if ( data[pos] - sub ) < 0 then
+ data[pos] = ( sub - data[pos] ) % 0xFFFF
+ if pos > 1 then
+ data[pos-1] = data[pos-1] - ( sub + data[pos] )
+ else
+ return nil
+ end
+ else
+ data[pos] = data[pos] - sub
+ end
+ end
+
+ if inplace then
+ self[2] = data
+ return self
+ else
+ return __bless({ self[1], data, self[3] })
+ end
+end
+
+--- Return CIDR containing the lowest available host address within this subnet.
+-- @return CIDR containing the host address, nil if subnet is too small
+-- @see cidr.maxhost
+function cidr.minhost( self )
+ if self[3] <= __sublen(self[1]) then
+ -- 1st is Network Address in IPv4 and Subnet-Router Anycast Adresse in IPv6
+ return self:network():add(1, true)
+ end
+end
+
+--- Return CIDR containing the highest available host address within the subnet.
+-- @return CIDR containing the host address, nil if subnet is too small
+-- @see cidr.minhost
+function cidr.maxhost( self )
+ if self[3] <= __sublen(self[1]) then
+ local i
+ local data = { unpack(self[2]) }
+ local offset = math.floor( self[3] / 16 ) + 1
+
+ data[offset] = bit.bor( data[offset], __not16(self[3]) )
+ for i = offset + 1, #data do data[i] = 0xFFFF end
+ data = __bless({ self[1], data, __maxlen(self[1]) })
+
+ -- Last address in reserved for Broadcast Address in IPv4
+ if data[1] == FAMILY_INET4 then data:sub(1, true) end
+
+ return data
+ end
+end
projects / project / luci.git / blobdiff