diff options
Diffstat (limited to 'util')
| -rw-r--r-- | util/ip.lua | 176 | ||||
| -rw-r--r-- | util/rfc3484.lua | 133 |
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}; |