Switch to using SRV records.

2 files changed, 18 insertions, 10 deletions

diff --git a/config.py.example b/config.py.example
index cff5ab0..7bdda5d 100644
--- a/config.py.example
+++ b/config.py.example
@@ -212,8 +212,11 @@ STATIC_BASE_URL = ""
 DYNAMIC_BASE_URL = ""
 
 # OPTION: CONNECTION_RESOLVER
-#         This specific object (if not None) will be used to resolve
-#         connections made to the IRC server.
+#         A list of (ip, port) tuples of resolvers to use for looking
+#         the SRV record(s) used for connecting to the name set in
+#         IRC_SERVER.
+#         The default value is None, and in this case qwebirc will use
+#         the system's default resolver(s).
 CONNECTION_RESOLVER = None
 
 # QUAKENET SPECIFIC VALUES
diff --git a/qwebirc/ircclient.py b/qwebirc/ircclient.py
index 7252669..efda3d4 100644
--- a/qwebirc/ircclient.py
+++ b/qwebirc/ircclient.py
@@ -1,12 +1,17 @@
 import twisted, sys, codecs, traceback
 from twisted.words.protocols import irc
-from twisted.internet import reactor, protocol
+from twisted.internet import reactor, protocol, abstract
 from twisted.web import resource, server
 from twisted.protocols import basic
-
-import hmac, time, config, qwebirc.config_options as config_options
+from twisted.names.client import Resolver
+import hmac, time, config, random, qwebirc.config_options as config_options
 from config import HMACTEMPORAL
 
+if config.get("CONNECTION_RESOLVER"):
+  CONNECTION_RESOLVER = Resolver(servers=config.get("CONNECTION_RESOLVER"))
+else:
+  CONNECTION_RESOLVER = None
+
 if hasattr(config, "WEBIRC_MODE") and config.WEBIRC_MODE == "hmac":
   HMACKEY = hmac.HMAC(key=config.HMACKEY)
 
@@ -140,18 +145,18 @@ class QWebIRCFactory(protocol.ClientFactory):
     self.publisher.disconnect()
 
 def createIRC(*args, **kwargs):
-  resolver = config.get("CONNECTION_RESOLVER")
   f = QWebIRCFactory(*args, **kwargs)
-  if resolver is None:
+  if CONNECTION_RESOLVER is None:
     reactor.connectTCP(config.IRCSERVER, config.IRCPORT, f)
     return f
 
-  def callback(addr):
-    reactor.connectTCP(addr, config.IRCPORT, f)
+  def callback(result):
+    name, port = random.choice(sorted((str(x.payload.target), x.payload.port) for x in result[0]))
+    reactor.connectTCP(name, port, f)
   def errback(err):
     f.clientConnectionFailed(None, err) # None?!
 
-  d = resolver.getHostByName(config.IRCSERVER, (1, 3, 11))
+  d = CONNECTION_RESOLVER.lookupService(config.IRCSERVER, (1, 3, 11))
   d.addCallbacks(callback, errback)
   return f