start on transit relay client

src/wormhole/blocking/transit.py

@@ -57,13 +57,17 @@ TIMEOUT=15
 class BadHandshake(Exception):
     pass
 
+def force_ascii(s):
+    if isinstance(s, type(u"")):
+        return s.encode("ascii")
+    return s
+
 def connector(owner, hint, send_handshake, expected_handshake):
-    if isinstance(hint, type(u"")):
-        hint = hint.encode("ascii")
     addr,port = hint.split(",")
     skt = None
     try:
-        skt = socket.create_connection((addr,port)) # timeout here
+        skt = socket.create_connection((addr,port),
+                                       TIMEOUT) # timeout or ECONNREFUSED
         skt.settimeout(TIMEOUT)
         #print("socket(%s) connected" % (hint,))
         skt.send(send_handshake)
@@ -85,7 +89,7 @@ def connector(owner, hint, send_handshake, expected_handshake):
         # ignore socket errors, warn about coding errors
         if not isinstance(e, (socket.error, socket.timeout, BadHandshake)):
             raise
-        return
+        owner._connector_failed(hint)
     # owner is now responsible for the socket
     owner._negotiation_finished(skt) # note thread
 
@@ -169,9 +173,9 @@ class Common:
         return []
 
     def add_their_direct_hints(self, hints):
-        self._their_direct_hints = hints
+        self._their_direct_hints = [force_ascii(h) for h in hints]
     def add_their_relay_hints(self, hints):
-        self._their_relay_hints = hints # ignored
+        self._their_relay_hints = [force_ascii(h) for h in hints]
 
     def _send_this(self):
         if self.is_sender:
@@ -198,14 +202,23 @@ class Common:
         self._have_transit_key.release()
 
     def _start_outbound(self):
-        self.connectors = []
+        self._active_connectors = set(self._their_direct_hints)
         for hint in self._their_direct_hints:
-            t = threading.Thread(target=connector,
-                                 args=(self, hint,
-                                       self._send_this(),
-                                       self._expect_this()))
-            t.daemon = True
-            t.start()
+            self._start_connector(hint)
+        if not self._their_direct_hints:
+            self._start_relay_connectors()
+
+    def _start_connector(self, hint):
+        t = threading.Thread(target=connector,
+                             args=(self, hint,
+                                   self._send_this(),
+                                   self._expect_this()))
+        t.daemon = True
+        t.start()
+
+    def _start_relay_connectors(self):
+        for hint in self._their_relay_hints:
+            self._start_connector(hint)
 
     def establish_connection(self):
         self.winning_skt = None
@@ -223,6 +236,11 @@ class Common:
             return self.winning_skt
         raise TransitError
 
+    def _connector_failed(self, hint):
+        self._active_connectors.remove(hint)
+        if not self._active_connectors:
+            self._start_relay_connectors()
+
     def _negotiation_finished(self, skt):
         # inbound/outbound sockets call this when they finish negotiation.
         # The first one wins and gets a "go". Any subsequent ones lose and