aboutsummaryrefslogtreecommitdiffstats
path: root/util/ip.lua
blob: 9e668d1b5c47464ae9aa31825e5c65909e48b6c1 (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
-- 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 not proto then
		local sep = ipStr:match("^%x+(.)");
		if sep == ":" then proto = "IPv6"
		elseif sep == "." then proto = "IPv4"
		end
		if not proto then
			return nil, "invalid address";
		end
	elseif proto ~= "IPv4" and proto ~= "IPv6" then
		return nil, "invalid protocol";
	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};