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-rw-r--r--core/s2smanager.lua168
-rw-r--r--net/dns.lua1
-rw-r--r--net/xmppserver_listener.lua2
-rw-r--r--tests/test.lua1
-rw-r--r--tests/test_util_rfc3484.lua51
-rw-r--r--util/ip.lua176
-rw-r--r--util/rfc3484.lua133
7 files changed, 494 insertions, 38 deletions
diff --git a/core/s2smanager.lua b/core/s2smanager.lua
index 974b2f4f..b930ceab 100644
--- a/core/s2smanager.lua
+++ b/core/s2smanager.lua
@@ -16,8 +16,8 @@ local socket = require "socket";
local format = string.format;
local t_insert, t_sort = table.insert, table.sort;
local get_traceback = debug.traceback;
-local tostring, pairs, ipairs, getmetatable, newproxy, error, tonumber, setmetatable
- = tostring, pairs, ipairs, getmetatable, newproxy, error, tonumber, setmetatable;
+local tostring, pairs, ipairs, getmetatable, newproxy, next, error, tonumber, setmetatable
+ = tostring, pairs, ipairs, getmetatable, newproxy, next, error, tonumber, setmetatable;
local idna_to_ascii = require "util.encodings".idna.to_ascii;
local connlisteners_get = require "net.connlisteners".get;
@@ -28,6 +28,8 @@ local st = require "stanza";
local stanza = st.stanza;
local nameprep = require "util.encodings".stringprep.nameprep;
local cert_verify_identity = require "util.x509".verify_identity;
+local new_ip = require "util.ip".new_ip;
+local rfc3484_dest = require "util.rfc3484".destination;
local fire_event = prosody.events.fire_event;
local uuid_gen = require "util.uuid".generate;
@@ -43,6 +45,7 @@ local config = require "core.configmanager";
local connect_timeout = config.get("*", "core", "s2s_timeout") or 60;
local dns_timeout = config.get("*", "core", "dns_timeout") or 15;
local max_dns_depth = config.get("*", "core", "dns_max_depth") or 3;
+local sources;
dns.settimeout(dns_timeout);
@@ -243,6 +246,11 @@ function attempt_connection(host_session, err)
for _, record in ipairs(answer) do
t_insert(srv_hosts, record.srv);
end
+ if #srv_hosts == 1 and srv_hosts[1].target == "." then
+ log("debug", to_host.." does not provide a XMPP service");
+ destroy_session(host_session, err); -- Nothing to see here
+ return;
+ end
t_sort(srv_hosts, compare_srv_priorities);
local srv_choice = srv_hosts[1];
@@ -265,6 +273,8 @@ function attempt_connection(host_session, err)
end, "_xmpp-server._tcp."..connect_host..".", "SRV");
return true; -- Attempt in progress
+ elseif host_session.ip_hosts then
+ return try_connect(host_session, connect_host, connect_port, err);
elseif host_session.srv_hosts and #host_session.srv_hosts > host_session.srv_choice then -- Not our first attempt, and we also have SRV
host_session.srv_choice = host_session.srv_choice + 1;
local srv_choice = host_session.srv_hosts[host_session.srv_choice];
@@ -285,54 +295,138 @@ function attempt_connection(host_session, err)
return try_connect(host_session, connect_host, connect_port);
end
-function try_connect(host_session, connect_host, connect_port)
+function try_next_ip(host_session, connect_port)
+ host_session.connecting = nil;
+ host_session.ip_choice = host_session.ip_choice + 1;
+ local ip = host_session.ip_hosts[host_session.ip_choice];
+ local ok, err= make_connect(host_session, ip, connect_port);
+ if not ok then
+ if not attempt_connection(host_session, err or "closed") then
+ err = err and (": "..err) or "";
+ destroy_session(host_session, "Connection failed"..err);
+ end
+ end
+end
+
+function try_connect(host_session, connect_host, connect_port, err)
host_session.connecting = true;
- local handle;
- handle = adns.lookup(function (reply, err)
- handle = nil;
- host_session.connecting = nil;
-
- -- COMPAT: This is a compromise for all you CNAME-(ab)users :)
- if not (reply and reply[#reply] and reply[#reply].a) then
- local count = max_dns_depth;
- reply = dns.peek(connect_host, "CNAME", "IN");
- while count > 0 and reply and reply[#reply] and not reply[#reply].a and reply[#reply].cname do
- log("debug", "Looking up %s (DNS depth is %d)", tostring(reply[#reply].cname), count);
- reply = dns.peek(reply[#reply].cname, "A", "IN") or dns.peek(reply[#reply].cname, "CNAME", "IN");
- count = count - 1;
+
+ if not err then
+ local IPs = {};
+ host_session.ip_hosts = IPs;
+ local handle4, handle6;
+ local has_other = false;
+
+ if not sources then
+ sources = {};
+ local cfg_sources = connlisteners_get("xmppserver").default_interface or config.get("*", "core", "interface");
+ for i, source in ipairs(cfg_sources) do
+ if source == "*" then
+ sources[i] = new_ip("0.0.0.0", "IPv4");
+ else
+ sources[i] = new_ip(source, (source:find(":") and "IPv6") or "IPv4");
+ end
end
end
- -- end of CNAME resolving
-
- if reply and reply[#reply] and reply[#reply].a then
- log("debug", "DNS reply for %s gives us %s", connect_host, reply[#reply].a);
- local ok, err = make_connect(host_session, reply[#reply].a, connect_port);
- if not ok then
- if not attempt_connection(host_session, err or "closed") then
- err = err and (": "..err) or "";
- destroy_session(host_session, "Connection failed"..err);
+
+ handle4 = adns.lookup(function (reply, err)
+ handle4 = nil;
+
+ -- COMPAT: This is a compromise for all you CNAME-(ab)users :)
+ if not (reply and reply[#reply] and reply[#reply].a) then
+ local count = max_dns_depth;
+ reply = dns.peek(connect_host, "CNAME", "IN");
+ while count > 0 and reply and reply[#reply] and not reply[#reply].a and reply[#reply].cname do
+ log("debug", "Looking up %s (DNS depth is %d)", tostring(reply[#reply].cname), count);
+ reply = dns.peek(reply[#reply].cname, "A", "IN") or dns.peek(reply[#reply].cname, "CNAME", "IN");
+ count = count - 1;
end
end
- else
- log("debug", "DNS lookup failed to get a response for %s", connect_host);
- if not attempt_connection(host_session, "name resolution failed") then -- Retry if we can
- log("debug", "No other records to try for %s - destroying", host_session.to_host);
- err = err and (": "..err) or "";
- destroy_session(host_session, "DNS resolution failed"..err); -- End of the line, we can't
+ -- end of CNAME resolving
+
+ if reply and reply[#reply] and reply[#reply].a then
+ for _, ip in ipairs(reply) do
+ log("debug", "DNS reply for %s gives us %s", connect_host, ip.a);
+ IPs[#IPs+1] = new_ip(ip.a, "IPv4");
+ end
end
+
+ if has_other then
+ if #IPs > 0 then
+ rfc3484_dest(host_session.ip_hosts, sources);
+ host_session.ip_choice = 0;
+ try_next_ip(host_session, connect_port);
+ else
+ log("debug", "DNS lookup failed to get a response for %s", connect_host);
+ host_session.ip_hosts = nil;
+ if not attempt_connection(host_session, "name resolution failed") then -- Retry if we can
+ log("debug", "No other records to try for %s - destroying", host_session.to_host);
+ err = err and (": "..err) or "";
+ destroy_session(host_session, "DNS resolution failed"..err); -- End of the line, we can't
+ end
+ end
+ else
+ has_other = true;
+ end
+ end, connect_host, "A", "IN");
+
+ handle6 = adns.lookup(function (reply, err)
+ handle6 = nil;
+
+ if reply and reply[#reply] and reply[#reply].aaaa then
+ for _, ip in ipairs(reply) do
+ log("debug", "DNS reply for %s gives us %s", connect_host, ip.aaaa);
+ IPs[#IPs+1] = new_ip(ip.aaaa, "IPv6");
+ end
+ end
+
+ if has_other then
+ if #IPs > 0 then
+ rfc3484_dest(host_session.ip_hosts, sources);
+ host_session.ip_choice = 0;
+ try_next_ip(host_session, connect_port);
+ else
+ log("debug", "DNS lookup failed to get a response for %s", connect_host);
+ host_session.ip_hosts = nil;
+ if not attempt_connection(host_session, "name resolution failed") then -- Retry if we can
+ log("debug", "No other records to try for %s - destroying", host_session.to_host);
+ err = err and (": "..err) or "";
+ destroy_session(host_session, "DNS resolution failed"..err); -- End of the line, we can't
+ end
+ end
+ else
+ has_other = true;
+ end
+ end, connect_host, "AAAA", "IN");
+
+ return true;
+ elseif host_session.ip_hosts and #host_session.ip_hosts > host_session.ip_choice then -- Not our first attempt, and we also have IPs left to try
+ try_next_ip(host_session, connect_port);
+ else
+ host_session.ip_hosts = nil;
+ if not attempt_connection(host_session, "out of IP addresses") then -- Retry if we can
+ log("debug", "No other records to try for %s - destroying", host_session.to_host);
+ err = err and (": "..err) or "";
+ destroy_session(host_session, "Connecting failed"..err); -- End of the line, we can't
+ return false;
end
- end, connect_host, "A", "IN");
+ end
return true;
end
function make_connect(host_session, connect_host, connect_port)
- (host_session.log or log)("info", "Beginning new connection attempt to %s (%s:%d)", host_session.to_host, connect_host, connect_port);
+ (host_session.log or log)("info", "Beginning new connection attempt to %s ([%s]:%d)", host_session.to_host, connect_host.addr, connect_port);
-- Ok, we're going to try to connect
local from_host, to_host = host_session.from_host, host_session.to_host;
- local conn, handler = socket.tcp();
+ local conn, handler;
+ if connect_host.proto == "IPv4" then
+ conn, handler = socket.tcp();
+ else
+ conn, handler = socket.tcp6();
+ end
if not conn then
log("warn", "Failed to create outgoing connection, system error: %s", handler);
@@ -340,14 +434,14 @@ function make_connect(host_session, connect_host, connect_port)
end
conn:settimeout(0);
- local success, err = conn:connect(connect_host, connect_port);
+ local success, err = conn:connect(connect_host.addr, connect_port);
if not success and err ~= "timeout" then
- log("warn", "s2s connect() to %s (%s:%d) failed: %s", host_session.to_host, connect_host, connect_port, err);
+ log("warn", "s2s connect() to %s (%s:%d) failed: %s", host_session.to_host, connect_host.addr, connect_port, err);
return false, err;
end
local cl = connlisteners_get("xmppserver");
- conn = wrapclient(conn, connect_host, connect_port, cl, cl.default_mode or 1 );
+ conn = wrapclient(conn, connect_host.addr, connect_port, cl, cl.default_mode or 1 );
host_session.conn = conn;
local filter = initialize_filters(host_session);
diff --git a/net/dns.lua b/net/dns.lua
index 8f428476..5b32a56c 100644
--- a/net/dns.lua
+++ b/net/dns.lua
@@ -358,6 +358,7 @@ function resolver:name() -- - - - - - - - - - - - - - - - - - - - - - name
local remember, pointers = nil, 0;
local len = self:byte();
local n = {};
+ if len == 0 then return "." end -- Root label
while len > 0 do
if len >= 0xc0 then -- name is "compressed"
pointers = pointers + 1;
diff --git a/net/xmppserver_listener.lua b/net/xmppserver_listener.lua
index 3af0b962..fe661033 100644
--- a/net/xmppserver_listener.lua
+++ b/net/xmppserver_listener.lua
@@ -178,7 +178,7 @@ end
function xmppserver.ondisconnect(conn, err)
local session = sessions[conn];
if session then
- if err and err ~= "closed" and session.srv_hosts then
+ if err and err ~= "closed" then
(session.log or log)("debug", "s2s connection attempt failed: %s", err);
if s2s_attempt_connect(session, err) then
(session.log or log)("debug", "...so we're going to try another target");
diff --git a/tests/test.lua b/tests/test.lua
index 000c3ee9..db727ce1 100644
--- a/tests/test.lua
+++ b/tests/test.lua
@@ -12,6 +12,7 @@ function run_all_tests()
package.loaded["net.connlisteners"] = { get = function () return {} end };
dotest "util.jid"
dotest "util.multitable"
+ dotest "util.rfc3484"
dotest "net.http"
dotest "core.modulemanager"
dotest "core.stanza_router"
diff --git a/tests/test_util_rfc3484.lua b/tests/test_util_rfc3484.lua
new file mode 100644
index 00000000..18ae310e
--- /dev/null
+++ b/tests/test_util_rfc3484.lua
@@ -0,0 +1,51 @@
+-- Prosody IM
+-- Copyright (C) 2011 Florian Zeitz
+--
+-- This project is MIT/X11 licensed. Please see the
+-- COPYING file in the source package for more information.
+--
+
+function source(source)
+ local new_ip = require"util.ip".new_ip;
+ assert_equal(source(new_ip("2001::1", "IPv6"), {new_ip("3ffe::1", "IPv6"), new_ip("fe80::1", "IPv6")}).addr, "3ffe::1", "prefer appropriate scope");
+ assert_equal(source(new_ip("2001::1", "IPv6"), {new_ip("fe80::1", "IPv6"), new_ip("fec0::1", "IPv6")}).addr, "fec0::1", "prefer appropriate scope");
+ assert_equal(source(new_ip("fec0::1", "IPv6"), {new_ip("fe80::1", "IPv6"), new_ip("2001::1", "IPv6")}).addr, "2001::1", "prefer appropriate scope");
+ assert_equal(source(new_ip("ff05::1", "IPv6"), {new_ip("fe80::1", "IPv6"), new_ip("fec0::1", "IPv6"), new_ip("2001::1", "IPv6")}).addr, "fec0::1", "prefer appropriate scope");
+ assert_equal(source(new_ip("2001::1", "IPv6"), {new_ip("2001::1", "IPv6"), new_ip("2002::1", "IPv6")}).addr, "2001::1", "prefer same address");
+ assert_equal(source(new_ip("fec0::1", "IPv6"), {new_ip("fec0::2", "IPv6"), new_ip("2001::1", "IPv6")}).addr, "fec0::2", "prefer appropriate scope");
+ assert_equal(source(new_ip("2001::1", "IPv6"), {new_ip("2001::2", "IPv6"), new_ip("3ffe::2", "IPv6")}).addr, "2001::2", "longest matching prefix");
+ assert_equal(source(new_ip("2002:836b:2179::1", "IPv6"), {new_ip("2002:836b:2179::d5e3:7953:13eb:22e8", "IPv6"), new_ip("2001::2", "IPv6")}).addr, "2002:836b:2179::d5e3:7953:13eb:22e8", "prefer matching label");
+end
+
+function destination(dest)
+ local order;
+ local new_ip = require"util.ip".new_ip;
+ order = dest({new_ip("2001::1", "IPv6"), new_ip("131.107.65.121", "IPv4")}, {new_ip("2001::2", "IPv6"), new_ip("fe80::1", "IPv6"), new_ip("169.254.13.78", "IPv4")})
+ assert_equal(order[1].addr, "2001::1", "prefer matching scope");
+ assert_equal(order[2].addr, "131.107.65.121", "prefer matching scope")
+
+ order = dest({new_ip("2001::1", "IPv6"), new_ip("131.107.65.121", "IPv4")}, {new_ip("fe80::1", "IPv6"), new_ip("131.107.65.117", "IPv4")})
+ assert_equal(order[1].addr, "131.107.65.121", "prefer matching scope")
+ assert_equal(order[2].addr, "2001::1", "prefer matching scope")
+
+ order = dest({new_ip("2001::1", "IPv6"), new_ip("10.1.2.3", "IPv4")}, {new_ip("2001::2", "IPv6"), new_ip("fe80::1", "IPv6"), new_ip("10.1.2.4", "IPv4")})
+ assert_equal(order[1].addr, "2001::1", "prefer higher precedence");
+ assert_equal(order[2].addr, "10.1.2.3", "prefer higher precedence");
+
+ order = dest({new_ip("2001::1", "IPv6"), new_ip("fec0::1", "IPv6"), new_ip("fe80::1", "IPv6")}, {new_ip("2001::2", "IPv6"), new_ip("fec0::1", "IPv6"), new_ip("fe80::2", "IPv6")})
+ assert_equal(order[1].addr, "fe80::1", "prefer smaller scope");
+ assert_equal(order[2].addr, "fec0::1", "prefer smaller scope");
+ assert_equal(order[3].addr, "2001::1", "prefer smaller scope");
+
+ order = dest({new_ip("2001::1", "IPv6"), new_ip("3ffe::1", "IPv6")}, {new_ip("2001::2", "IPv6"), new_ip("3f44::2", "IPv6"), new_ip("fe80::2", "IPv6")})
+ assert_equal(order[1].addr, "2001::1", "longest matching prefix");
+ assert_equal(order[2].addr, "3ffe::1", "longest matching prefix");
+
+ order = dest({new_ip("2002:836b:4179::1", "IPv6"), new_ip("2001::1", "IPv6")}, {new_ip("2002:836b:4179::2", "IPv6"), new_ip("fe80::2", "IPv6")})
+ assert_equal(order[1].addr, "2002:836b:4179::1", "prefer matching label");
+ assert_equal(order[2].addr, "2001::1", "prefer matching label");
+
+ order = dest({new_ip("2002:836b:4179::1", "IPv6"), new_ip("2001::1", "IPv6")}, {new_ip("2002:836b:4179::2", "IPv6"), new_ip("2001::2", "IPv6"), new_ip("fe80::2", "IPv6")})
+ assert_equal(order[1].addr, "2001::1", "prefer higher precedence");
+ assert_equal(order[2].addr, "2002:836b:4179::1", "prefer higher precedence");
+end
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};