File

util/ip.lua @ 5915:e6fed1d80116

Back out 1b0ac7950129, as SSLv3 appears to still be in moderate use on the network. Also, although obsolete, SSLv3 isn't documented to have any weaknesses that TLS 1.0 (the most common version used today) doesn't also have. Get your act together clients!
author Matthew Wild <mwild1@gmail.com>
date Tue, 12 Nov 2013 02:13:01 +0000
parent 5597:6fe09707c73b
child 5599:34e9f237b915
child 7052:306aabf2d57d
line wrap: on
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-- Prosody IM
-- Copyright (C) 2008-2011 Florian Zeitz
--
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--

local ip_methods = {};
local ip_mt = { __index = function (ip, key) return (ip_methods[key])(ip); end,
		__tostring = function (ip) return ip.addr; end,
		__eq = function (ipA, ipB) return ipA.addr == ipB.addr; end};
local hex2bits = { ["0"] = "0000", ["1"] = "0001", ["2"] = "0010", ["3"] = "0011", ["4"] = "0100", ["5"] = "0101", ["6"] = "0110", ["7"] = "0111", ["8"] = "1000", ["9"] = "1001", ["A"] = "1010", ["B"] = "1011", ["C"] = "1100", ["D"] = "1101", ["E"] = "1110", ["F"] = "1111" };

local function new_ip(ipStr, proto)
	if proto ~= "IPv4" and proto ~= "IPv6" then
		return nil, "invalid protocol";
	end
	if proto == "IPv6" and ipStr:find('.', 1, true) then
		local changed;
		ipStr, changed = ipStr:gsub(":(%d+)%.(%d+)%.(%d+)%.(%d+)$", function(a,b,c,d)
			return (":%04X:%04X"):format(a*256+b,c*256+d);
		end);
		if changed ~= 1 then return nil, "invalid-address"; end
	end

	return setmetatable({ addr = ipStr, proto = proto }, ip_mt);
end

local function toBits(ip)
	local result = "";
	local fields = {};
	if ip.proto == "IPv4" then
		ip = ip.toV4mapped;
	end
	ip = (ip.addr):upper();
	ip:gsub("([^:]*):?", function (c) fields[#fields + 1] = c end);
	if not ip:match(":$") then fields[#fields] = nil; end
	for i, field in ipairs(fields) do
		if field:len() == 0 and i ~= 1 and i ~= #fields then
			for i = 1, 16 * (9 - #fields) do
				result = result .. "0";
			end
		else
			for i = 1, 4 - field:len() do
				result = result .. "0000";
			end
			for i = 1, field:len() do
				result = result .. hex2bits[field:sub(i,i)];
			end
		end
	end
	return result;
end

local function commonPrefixLength(ipA, ipB)
	ipA, ipB = toBits(ipA), toBits(ipB);
	for i = 1, 128 do
		if ipA:sub(i,i) ~= ipB:sub(i,i) then
			return i-1;
		end
	end
	return 128;
end

local function v4scope(ip)
	local fields = {};
	ip:gsub("([^.]*).?", function (c) fields[#fields + 1] = tonumber(c) end);
	-- Loopback:
	if fields[1] == 127 then
		return 0x2;
	-- Link-local unicast:
	elseif fields[1] == 169 and fields[2] == 254 then
		return 0x2;
	-- Global unicast:
	else
		return 0xE;
	end
end

local function v6scope(ip)
	-- Loopback:
	if ip:match("^[0:]*1$") then
		return 0x2;
	-- Link-local unicast:
	elseif ip:match("^[Ff][Ee][89ABab]") then 
		return 0x2;
	-- Site-local unicast:
	elseif ip:match("^[Ff][Ee][CcDdEeFf]") then
		return 0x5;
	-- Multicast:
	elseif ip:match("^[Ff][Ff]") then
		return tonumber("0x"..ip:sub(4,4));
	-- Global unicast:
	else
		return 0xE;
	end
end

local function label(ip)
	if commonPrefixLength(ip, new_ip("::1", "IPv6")) == 128 then
		return 0;
	elseif commonPrefixLength(ip, new_ip("2002::", "IPv6")) >= 16 then
		return 2;
	elseif commonPrefixLength(ip, new_ip("2001::", "IPv6")) >= 32 then
		return 5;
	elseif commonPrefixLength(ip, new_ip("fc00::", "IPv6")) >= 7 then
		return 13;
	elseif commonPrefixLength(ip, new_ip("fec0::", "IPv6")) >= 10 then
		return 11;
	elseif commonPrefixLength(ip, new_ip("3ffe::", "IPv6")) >= 16 then
		return 12;
	elseif commonPrefixLength(ip, new_ip("::", "IPv6")) >= 96 then
		return 3;
	elseif commonPrefixLength(ip, new_ip("::ffff:0:0", "IPv6")) >= 96 then
		return 4;
	else
		return 1;
	end
end

local function precedence(ip)
	if commonPrefixLength(ip, new_ip("::1", "IPv6")) == 128 then
		return 50;
	elseif commonPrefixLength(ip, new_ip("2002::", "IPv6")) >= 16 then
		return 30;
	elseif commonPrefixLength(ip, new_ip("2001::", "IPv6")) >= 32 then
		return 5;
	elseif commonPrefixLength(ip, new_ip("fc00::", "IPv6")) >= 7 then
		return 3;
	elseif commonPrefixLength(ip, new_ip("fec0::", "IPv6")) >= 10 then
		return 1;
	elseif commonPrefixLength(ip, new_ip("3ffe::", "IPv6")) >= 16 then
		return 1;
	elseif commonPrefixLength(ip, new_ip("::", "IPv6")) >= 96 then
		return 1;
	elseif commonPrefixLength(ip, new_ip("::ffff:0:0", "IPv6")) >= 96 then
		return 35;
	else
		return 40;
	end
end

local function toV4mapped(ip)
	local fields = {};
	local ret = "::ffff:";
	ip:gsub("([^.]*).?", function (c) fields[#fields + 1] = tonumber(c) end);
	ret = ret .. ("%02x"):format(fields[1]);
	ret = ret .. ("%02x"):format(fields[2]);
	ret = ret .. ":"
	ret = ret .. ("%02x"):format(fields[3]);
	ret = ret .. ("%02x"):format(fields[4]);
	return new_ip(ret, "IPv6");
end

function ip_methods:toV4mapped()
	if self.proto ~= "IPv4" then return nil, "No IPv4 address" end
	local value = toV4mapped(self.addr);
	self.toV4mapped = value;
	return value;
end

function ip_methods:label()
	local value;
	if self.proto == "IPv4" then
		value = label(self.toV4mapped);
	else
		value = label(self);
	end
	self.label = value;
	return value;
end

function ip_methods:precedence()
	local value;
	if self.proto == "IPv4" then
		value = precedence(self.toV4mapped);
	else
		value = precedence(self);
	end
	self.precedence = value;
	return value;
end

function ip_methods:scope()
	local value;
	if self.proto == "IPv4" then
		value = v4scope(self.addr);
	else
		value = v6scope(self.addr);
	end
	self.scope = value;
	return value;
end

return {new_ip = new_ip,
	commonPrefixLength = commonPrefixLength};