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util/ip.lua @ 8432:da807f4f706c
util.ip: Simplify bitstring method
author | Kim Alvefur <zash@zash.se> |
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date | Fri, 01 Dec 2017 04:32:20 +0100 |
parent | 8431:a5a03d40a20c |
child | 8433:ca7f8e60410a |
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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 net = require "util.net"; local hex = require "util.hex"; 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) local zone; if (not proto or proto == "IPv6") and ipStr:find('%', 1, true) then ipStr, zone = ipStr:match("^(.-)%%(.*)"); end local packed, err = net.pton(ipStr); if not packed then return packed, err end if proto == "IPv6" and #packed ~= 16 then return nil, "invalid-ipv6"; elseif proto == "IPv4" and #packed ~= 4 then return nil, "invalid-ipv4"; elseif not proto then if #packed == 16 then proto = "IPv6"; elseif #packed == 4 then proto = "IPv4"; else return nil, "unknown protocol"; end elseif proto ~= "IPv6" and proto ~= "IPv4" then return nil, "invalid protocol"; end return setmetatable({ addr = ipStr, packed = packed, proto = proto, zone = zone }, ip_mt); end function ip_methods.bits(ip) return hex.to(ip.packed):upper():gsub(".", hex2bits); end function ip_methods.bits_full(ip) if ip.proto == "IPv4" then ip = ip.toV4mapped; end return ip.bits; end local function commonPrefixLength(ipA, ipB) ipA, ipB = ipA.bits_full, ipB.bits_full; 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 function ip_methods:private() local private = self.scope ~= 0xE; if not private and self.proto == "IPv4" then local ip = self.addr; local fields = {}; ip:gsub("([^.]*).?", function (c) fields[#fields + 1] = tonumber(c) end); if fields[1] == 127 or fields[1] == 10 or (fields[1] == 192 and fields[2] == 168) or (fields[1] == 172 and (fields[2] >= 16 or fields[2] <= 32)) then private = true; end end self.private = private; return private; end local function parse_cidr(cidr) local bits; local ip_len = cidr:find("/", 1, true); if ip_len then bits = tonumber(cidr:sub(ip_len+1, -1)); cidr = cidr:sub(1, ip_len-1); end return new_ip(cidr), bits; end local function match(ipA, ipB, bits) local common_bits = commonPrefixLength(ipA, ipB); if bits and ipB.proto == "IPv4" then common_bits = common_bits - 96; -- v6 mapped addresses always share these bits end return common_bits >= (bits or 128); end return { new_ip = new_ip, commonPrefixLength = commonPrefixLength, parse_cidr = parse_cidr, match = match, };