prosody
b1e49cc314cb
util/ip.lua

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util/ip.lua @ 4419:b1e49cc314cb

util.ip: New module containing IP related functions
author Florian Zeitz <florob@babelmonkeys.de>
date Sat, 22 Oct 2011 17:51:53 +0200
child 4432:cbc3224ed3c2
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4418:70b5e533325d 4419:b1e49cc314cb
1 -- Prosody IM
2 -- Copyright (C) 2008-2011 Florian Zeitz
3 --
4 -- This project is MIT/X11 licensed. Please see the
5 -- COPYING file in the source package for more information.
6 --
7
8 local ip_methods = {};
9 local ip_mt = { __index = function (ip, key) return (ip_methods[key])(ip); end,
10 __tostring = function (ip) return ip.addr; end,
11 __eq = function (ipA, ipB) return ipA.addr == ipB.addr; end};
12 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" };
13
14 local function new_ip(ipStr, proto)
15 if proto ~= "IPv4" and proto ~= "IPv6" then
16 return nil, "invalid protocol";
17 end
18
19 return setmetatable({ addr = ipStr, proto = proto }, ip_mt);
20 end
21
22 local function toBits(ip)
23 local result = "";
24 local fields = {};
25 if ip.proto == "IPv4" then
26 ip = ip.toV4mapped;
27 end
28 ip = (ip.addr):upper();
29 ip:gsub("([^:]*):?", function (c) fields[#fields + 1] = c end);
30 if not ip:match(":$") then fields[#fields] = nil; end
31 for i, field in ipairs(fields) do
32 if field:len() == 0 and i ~= 1 and i ~= #fields then
33 for i = 1, 16 * (9 - #fields) do
34 result = result .. "0";
35 end
36 else
37 for i = 1, 4 - field:len() do
38 result = result .. "0000";
39 end
40 for i = 1, field:len() do
41 result = result .. hex2bits[field:sub(i,i)];
42 end
43 end
44 end
45 return result;
46 end
47
48 local function commonPrefixLength(ipA, ipB)
49 ipA, ipB = toBits(ipA), toBits(ipB);
50 for i = 1, 128 do
51 if ipA:sub(i,i) ~= ipB:sub(i,i) then
52 return i-1;
53 end
54 end
55 return 128;
56 end
57
58 local function v4scope(ip)
59 local fields = {};
60 ip:gsub("([^.]*).?", function (c) fields[#fields + 1] = tonumber(c) end);
61 -- Loopback:
62 if fields[1] == 127 then
63 return 0x2;
64 -- Link-local unicast:
65 elseif fields[1] == 169 and fields[2] == 254 then
66 return 0x2;
67 -- Site-local unicast:
68 elseif (fields[1] == 10) or (fields[1] == 192 and fields[2] == 168) or (fields[1] == 172 and fields[2] > 16) then
69 return 0x5;
70 -- Global unicast:
71 else
72 return 0xE;
73 end
74 end
75
76 local function v6scope(ip)
77 -- Loopback:
78 if ip:match("^[0:]*1$") then
79 return 0x2;
80 -- Link-local unicast:
81 elseif ip:match("^[Ff][Ee][89ABab]") then
82 return 0x2;
83 -- Site-local unicast:
84 elseif ip:match("^[Ff][Ee][CcDdEeFf]") then
85 return 0x5;
86 -- Multicast:
87 elseif ip:match("^[Ff][Ff]") then
88 return tonumber("0x"..ip:sub(4,4));
89 -- Global unicast:
90 else
91 return 0xE;
92 end
93 end
94
95 local function label(ip)
96 if commonPrefixLength(ip, new_ip("::1", "IPv6")) == 128 then
97 return 0;
98 elseif commonPrefixLength(ip, new_ip("2002::", "IPv6")) >= 16 then
99 return 2;
100 elseif commonPrefixLength(ip, new_ip("::", "IPv6")) >= 96 then
101 return 3;
102 elseif commonPrefixLength(ip, new_ip("::ffff:0:0", "IPv6")) >= 96 then
103 return 4;
104 else
105 return 1;
106 end
107 end
108
109 local function precedence(ip)
110 if commonPrefixLength(ip, new_ip("::1", "IPv6")) == 128 then
111 return 50;
112 elseif commonPrefixLength(ip, new_ip("2002::", "IPv6")) >= 16 then
113 return 30;
114 elseif commonPrefixLength(ip, new_ip("::", "IPv6")) >= 96 then
115 return 20;
116 elseif commonPrefixLength(ip, new_ip("::ffff:0:0", "IPv6")) >= 96 then
117 return 10;
118 else
119 return 40;
120 end
121 end
122
123 local function toV4mapped(ip)
124 local fields = {};
125 local ret = "::ffff:";
126 ip:gsub("([^.]*).?", function (c) fields[#fields + 1] = tonumber(c) end);
127 ret = ret .. ("%02x"):format(fields[1]);
128 ret = ret .. ("%02x"):format(fields[2]);
129 ret = ret .. ":"
130 ret = ret .. ("%02x"):format(fields[3]);
131 ret = ret .. ("%02x"):format(fields[4]);
132 return new_ip(ret, "IPv6");
133 end
134
135 function ip_methods:toV4mapped()
136 if self.proto ~= "IPv4" then return nil, "No IPv4 address" end
137 local value = toV4mapped(self.addr);
138 self.toV4mapped = value;
139 return value;
140 end
141
142 function ip_methods:label()
143 local value;
144 if self.proto == "IPv4" then
145 value = label(self.toV4mapped);
146 else
147 value = label(self);
148 end
149 self.label = value;
150 return value;
151 end
152
153 function ip_methods:precedence()
154 local value;
155 if self.proto == "IPv4" then
156 value = precedence(self.toV4mapped);
157 else
158 value = precedence(self);
159 end
160 self.precedence = value;
161 return value;
162 end
163
164 function ip_methods:scope()
165 local value;
166 if self.proto == "IPv4" then
167 value = v4scope(self.addr);
168 else
169 value = v6scope(self.addr);
170 end
171 self.scope = value;
172 return value;
173 end
174
175 return {new_ip = new_ip,
176 commonPrefixLength = commonPrefixLength};