aboutsummaryrefslogtreecommitdiffstats
path: root/util/ip.lua
blob: ebeaf1c0156f4273687d092d466891563fc21fd1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
-- 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,
	__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:normal()
	return net.ntop(self.packed);
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 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) 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()
	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);
	else
		value = v6scope(self);
	end
	self.scope = value;
	return value;
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");

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

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,
};