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-rw-r--r--util/ip.lua176
-rw-r--r--util/rfc3484.lua133
2 files changed, 309 insertions, 0 deletions
diff --git a/util/ip.lua b/util/ip.lua
new file mode 100644
index 00000000..5e2f46bb
--- /dev/null
+++ b/util/ip.lua
@@ -0,0 +1,176 @@
+-- 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 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(":$") then fields[#fields] = nil; end
+ for i, field in ipairs(fields) do
+ if field:len() == 0 and i ~= 1 and i ~= #fields then
+ for i = 1, 16 * (9 - #fields) do
+ result = result .. "0";
+ end
+ else
+ for i = 1, 4 - field:len() do
+ result = result .. "0000";
+ end
+ for i = 1, field:len() do
+ result = result .. hex2bits[field:sub(i,i)];
+ end
+ end
+ end
+ return result;
+end
+
+local function commonPrefixLength(ipA, ipB)
+ ipA, ipB = toBits(ipA), toBits(ipB);
+ for i = 1, 128 do
+ if ipA:sub(i,i) ~= ipB:sub(i,i) then
+ return i-1;
+ end
+ end
+ return 128;
+end
+
+local function v4scope(ip)
+ local fields = {};
+ ip:gsub("([^.]*).?", function (c) fields[#fields + 1] = tonumber(c) end);
+ -- Loopback:
+ if fields[1] == 127 then
+ return 0x2;
+ -- Link-local unicast:
+ elseif fields[1] == 169 and fields[2] == 254 then
+ return 0x2;
+ -- Site-local unicast:
+ elseif (fields[1] == 10) or (fields[1] == 192 and fields[2] == 168) or (fields[1] == 172 and fields[2] > 16) then
+ return 0x5;
+ -- Global unicast:
+ else
+ return 0xE;
+ end
+end
+
+local function v6scope(ip)
+ -- Loopback:
+ if ip:match("^[0:]*1$") 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("::", "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("::", "IPv6")) >= 96 then
+ return 20;
+ elseif commonPrefixLength(ip, new_ip("::ffff:0:0", "IPv6")) >= 96 then
+ return 10;
+ 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};
diff --git a/util/rfc3484.lua b/util/rfc3484.lua
new file mode 100644
index 00000000..dd855a84
--- /dev/null
+++ b/util/rfc3484.lua
@@ -0,0 +1,133 @@
+-- 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 commonPrefixLength = require"util.ip".commonPrefixLength
+local new_ip = require"util.ip".new_ip;
+
+local function t_sort(t, comp)
+ for i = 1, (#t - 1) do
+ for j = (i + 1), #t do
+ local a, b = t[i], t[j];
+ if not comp(a,b) then
+ t[i], t[j] = b, a;
+ end
+ end
+ end
+end
+
+function source(dest, candidates)
+ local function comp(ipA, ipB)
+ -- Rule 1: Prefer same address
+ if dest == ipA then
+ return true;
+ elseif dest == ipB then
+ return false;
+ end
+
+ -- Rule 2: Prefer appropriate scope
+ if ipA.scope < ipB.scope then
+ if ipA.scope < dest.scope then
+ return false;
+ else
+ return true;
+ end
+ elseif ipA.scope > ipB.scope then
+ if ipB.scope < dest.scope then
+ return true;
+ else
+ return false;
+ end
+ end
+
+ -- Rule 3: Avoid deprecated addresses
+ -- XXX: No way to determine this
+ -- Rule 4: Prefer home addresses
+ -- XXX: Mobility Address related, no way to determine this
+ -- Rule 5: Prefer outgoing interface
+ -- XXX: Interface to address relation. No way to determine this
+ -- Rule 6: Prefer matching label
+ if ipA.label == dest.label and ipB.label ~= dest.label then
+ return true;
+ elseif ipB.label == dest.label and ipA.label ~= dest.label then
+ return false;
+ end
+
+ -- Rule 7: Prefer public addresses (over temporary ones)
+ -- XXX: No way to determine this
+ -- Rule 8: Use longest matching prefix
+ if commonPrefixLength(ipA, dest) > commonPrefixLength(ipB, dest) then
+ return true;
+ else
+ return false;
+ end
+ end
+
+ t_sort(candidates, comp);
+ return candidates[1];
+end
+
+function destination(candidates, sources)
+ local sourceAddrs = {};
+ local function comp(ipA, ipB)
+ local ipAsource = sourceAddrs[ipA];
+ local ipBsource = sourceAddrs[ipB];
+ -- Rule 1: Avoid unusable destinations
+ -- XXX: No such information
+ -- Rule 2: Prefer matching scope
+ if ipA.scope == ipAsource.scope and ipB.scope ~= ipBsource.scope then
+ return true;
+ elseif ipA.scope ~= ipAsource.scope and ipB.scope == ipBsource.scope then
+ return false;
+ end
+
+ -- Rule 3: Avoid deprecated addresses
+ -- XXX: No way to determine this
+ -- Rule 4: Prefer home addresses
+ -- XXX: Mobility Address related, no way to determine this
+ -- Rule 5: Prefer matching label
+ if ipAsource.label == ipA.label and ipBsource.label ~= ipB.label then
+ return true;
+ elseif ipBsource.label == ipB.label and ipAsource.label ~= ipA.label then
+ return false;
+ end
+
+ -- Rule 6: Prefer higher precedence
+ if ipA.precedence > ipB.precedence then
+ return true;
+ elseif ipA.precedence < ipB.precedence then
+ return false;
+ end
+
+ -- Rule 7: Prefer native transport
+ -- XXX: No way to determine this
+ -- Rule 8: Prefer smaller scope
+ if ipA.scope < ipB.scope then
+ return true;
+ elseif ipA.scope > ipB.scope then
+ return false;
+ end
+
+ -- Rule 9: Use longest matching prefix
+ if commonPrefixLength(ipA, ipAsource) > commonPrefixLength(ipB, ipBsource) then
+ return true;
+ elseif commonPrefixLength(ipA, ipAsource) < commonPrefixLength(ipB, ipBsource) then
+ return false;
+ end
+
+ -- Rule 10: Otherwise, leave order unchanged
+ return true;
+ end
+ for _, ip in ipairs(candidates) do
+ sourceAddrs[ip] = source(ip, sources);
+ end
+
+ t_sort(candidates, comp);
+ return candidates;
+end
+
+return {source = source,
+ destination = destination};