File

util/ip.lua @ 12471:a3b12eeedd4b

mod_smacks: Improve activation of smacks on outgoing s2s Using a timer was a hack to get around that stream features are not available at the right time and sendq stanzas were stored as strings so could not be counted properly. The later has now been fixed and the former is fixed by recording the relevant stream feature on the session so that the correct version of XEP-0198 can be activated once the connection has been authenticated and is ready to start.
author Kim Alvefur <zash@zash.se>
date Sun, 24 Apr 2022 16:17:32 +0200
parent 12355:a0ff5c438e9d
child 12931:bbae3acc6694
line wrap: on
line source

-- 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)
		local method = ip_methods[key];
		if not method then return nil; end
		local ret = method(ip);
		ip[key] = ret;
		return ret;
	end,
	__tostring = function (ip) return ip.addr; end,
};
ip_mt.__eq = function (ipA, ipB)
	if getmetatable(ipA) ~= ip_mt or getmetatable(ipB) ~= ip_mt then
		-- Lua 5.3+ calls this if both operands are tables, even if metatables differ
		return false;
	end
	return ipA.packed == ipB.packed;
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:normal()
	return net.ntop(self.packed);
end

function ip_methods.bits(ip)
	return hex.encode(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 match;

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

-- Instantiate once
local loopback = new_ip("::1");
local loopback4 = new_ip("127.0.0.0");
local sixtofour = new_ip("2002::");
local teredo = new_ip("2001::");
local linklocal = new_ip("fe80::");
local linklocal4 = new_ip("169.254.0.0");
local uniquelocal = new_ip("fc00::");
local sitelocal = new_ip("fec0::");
local sixbone = new_ip("3ffe::");
local defaultunicast = new_ip("::");
local multicast = new_ip("ff00::");
local ipv6mapped = new_ip("::ffff:0:0");

local function v4scope(ip)
	if match(ip, loopback4, 8) then
		return 0x2;
	elseif match(ip, linklocal4, 16) then
		return 0x2;
	else -- Global unicast
		return 0xE;
	end
end

local function v6scope(ip)
	if ip == loopback then
		return 0x2;
	elseif match(ip, linklocal, 10) then
		return 0x2;
	elseif match(ip, sitelocal, 10) then
		return 0x5;
	elseif match(ip, multicast, 10) then
		return ip.packed:byte(2) % 0x10;
	else -- Global unicast
		return 0xE;
	end
end

local function label(ip)
	if ip == loopback then
		return 0;
	elseif match(ip, sixtofour, 16) then
		return 2;
	elseif match(ip, teredo, 32) then
		return 5;
	elseif match(ip, uniquelocal, 7) then
		return 13;
	elseif match(ip, sitelocal, 10) then
		return 11;
	elseif match(ip, sixbone, 16) then
		return 12;
	elseif match(ip, defaultunicast, 96) then
		return 3;
	elseif match(ip, ipv6mapped, 96) then
		return 4;
	else
		return 1;
	end
end

local function precedence(ip)
	if ip == loopback then
		return 50;
	elseif match(ip, sixtofour, 16) then
		return 30;
	elseif match(ip, teredo, 32) then
		return 5;
	elseif match(ip, uniquelocal, 7) then
		return 3;
	elseif match(ip, sitelocal, 10) then
		return 1;
	elseif match(ip, sixbone, 16) then
		return 1;
	elseif match(ip, defaultunicast, 96) then
		return 1;
	elseif match(ip, ipv6mapped, 96) then
		return 35;
	else
		return 40;
	end
end

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

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

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

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

local rfc1918_8 = new_ip("10.0.0.0");
local rfc1918_12 = new_ip("172.16.0.0");
local rfc1918_16 = new_ip("192.168.0.0");
local rfc6598 = new_ip("100.64.0.0");

function ip_methods:private()
	local private = self.scope ~= 0xE;
	if not private and self.proto == "IPv4" then
		return match(self, rfc1918_8, 8) or match(self, rfc1918_12, 12) or match(self, rfc1918_16, 16) or match(self, rfc6598, 10);
	end
	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

function match(ipA, ipB, bits)
	if not bits or bits >= 128 or ipB.proto == "IPv4" and bits >= 32 then
		return ipA == ipB;
	elseif bits < 1 then
		return true;
	end
	if ipA.proto ~= ipB.proto then
		if ipA.proto == "IPv4" then
			ipA = ipA.toV4mapped;
		elseif ipB.proto == "IPv4" then
			ipB = ipB.toV4mapped;
			bits = bits + (128 - 32);
		end
	end
	return ipA.bits:sub(1, bits) == ipB.bits:sub(1, bits);
end

return {
	new_ip = new_ip,
	commonPrefixLength = commonPrefixLength,
	parse_cidr = parse_cidr,
	match = match,
};