* luci/libs: add preliminary ip calculation library

1 files changed, 307 insertions, 0 deletions

diff --git a/libs/core/luasrc/ip.lua b/libs/core/luasrc/ip.lua
new file mode 100644
index 000000000..1edbf8ebe
--- /dev/null
+++ b/libs/core/luasrc/ip.lua
@@ -0,0 +1,307 @@
+--[[
+
+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
+
+$Id$
+
+]]--
+
+module( "luci.ip", package.seeall )
+
+require("bit")
+require("luci.util")
+
+LITTLE_ENDIAN = not luci.util.bigendian()
+BIG_ENDIAN    = not LITTLE_ENDIAN
+
+FAMILY_INET4  = 0x04
+FAMILY_INET6  = 0x06
+
+
+local function __bless(x)
+	return setmetatable( x, {
+		__index	= luci.ip.cidr,
+		__add   = luci.ip.cidr.add,
+		__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 __mask16(bits)
+	return bit.lshift(
+		bit.rshift( 0xFFFF, 16 - bits % 16 ),
+		16 - bits % 16
+	)
+end
+
+-- htons(), htonl(), ntohs(), ntohl()
+
+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
+
+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
+
+ntohs = htons
+ntohl = htonl
+
+
+function IPv4(address)
+	local data = {}
+	local prefix = address:match("/(.+)")
+
+	if prefix then
+		address = address:gsub("/.+","")
+		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
+	then
+		return __bless({
+			FAMILY_INET4,
+			{ b1 * 256 + b2, b3 * 256 + b4 },
+			prefix
+		})
+	end
+end
+
+function IPv6(address)
+	local data = {}
+	local prefix = address:match("/(.+)")
+
+	if prefix then
+		address = address:gsub("/.+","")
+		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
+
+	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 <= 65535 then
+			table.insert(data, 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 > 65535 then return nil end
+
+		table.insert(data, 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
+				table.insert(data, 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 then
+		return __bless({ FAMILY_INET6, data, prefix })
+	end
+end
+
+
+cidr = luci.util.class()
+
+function cidr.is4( self )
+	return self[1] == FAMILY_INET4
+end
+
+function cidr.is6( self )
+	return self[1] == FAMILY_INET6
+end
+
+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
+
+function cidr.lower( self, addr )
+	assert( self[1] == addr[1], "Can't compare IPv4 and IPv6 addresses" )
+	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
+
+function cidr.higher( self, addr )
+	assert( self[1] == addr[1], "Can't compare IPv4 and IPv6 addresses" )
+	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
+
+function cidr.equal( self, addr )
+	assert( self[1] == addr[1], "Can't compare IPv4 and IPv6 addresses" )
+	for i = 1, #self[2] do
+		if self[2][i] ~= addr[2][i] then
+			return false
+		end
+	end
+	return true
+end
+
+function cidr.prefix( self )
+	return self[3]
+end
+
+function cidr.network( self )
+	local data = { }
+
+	for i = 1, math.floor( self[3] / 16 ) do
+		table.insert( data, self[2][i] )
+	end
+
+	table.insert( data, bit.band( self[2][1+#data], __mask16(self[3]) ) )
+
+	for i = #data, #self[2] do
+		table.insert( data, 0 )
+	end
+
+	return __bless({ self[1], data, self:is4() and 32 or 128 })
+end
+
+function cidr.host( self )
+	return __bless({ self[1], data, self:is4() and 32 or 128 })
+end
+
+function cidr.mask( self, bits )
+	local data = { }
+	bits = bits or self[3]
+
+	for i = 1, math.floor( bits / 16 ) do
+		table.insert( data, 0xFFFF )
+	end
+
+	table.insert( data, __mask16(bits) )
+
+	for i = #data + 1, #self[2] do
+		table.insert( data, 0 )
+	end
+
+	return __bless({ self[1], data, self:is4() and 32 or 128 })
+end
+
+function cidr.contains( self, addr )
+	if self:mask() <= addr:mask() then
+		return self:mask(addr:prefix()) == addr:mask()
+	end
+
+	return false
+end
+
+function cidr.add( self, amount )
+	local shorts = { bit.rshift(amount, 16), bit.band(amount, 0xFFFF) }
+	local data   = { unpack(self[2]) }
+
+	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 > 2 then
+				data[pos-1] = data[pos-1] + ( add - data[pos] )
+			end
+		else
+			data[pos] = data[pos] + add
+		end
+	end
+
+	return __bless({ self[1], data, self:is4() and 32 and 128 })
+end