closes #3045, #3123 for tornado < version 3.0

related to facebook/tornado#593

I've verified that this fix works for tornado 2.1, 2.4, 2.4.1, and the
behavior it fixes does not trigger on tornado 3.0

IPython/frontend/html/notebook/notebookapp.py

@@ -522,6 +522,30 @@ class NotebookApp(BaseIPythonApplication):
             try:
                 self.http_server.listen(port, self.ip)
             except socket.error as e:
+                # XXX: remove the e.errno == -9 block when we require
+                # tornado >= 3.0
+                if e.errno == -9:
+                    # The flags passed to socket.getaddrinfo from
+                    # tornado.netutils.bind_sockets can cause "gaierror:
+                    # [Errno -9] Address family for hostname not supported"
+                    # when the interface is not associated, for example.
+                    # Changing the flags to exclude socket.AI_ADDRCONFIG does
+                    # not cause this error, but the only way to do this is to
+                    # monkeypatch socket to remove the AI_ADDRCONFIG attribute
+                    saved_AI_ADDRCONFIG = socket.AI_ADDRCONFIG
+                    self.log.info('Monkeypatching socket to fix tornado bug')
+                    del(socket.AI_ADDRCONFIG)
+                    try:
+                        # retry the tornado call without AI_ADDRCONFIG flags
+                        self.http_server.listen(port, self.ip)
+                    except socket.error as e2:
+                        e = e2
+                    else:
+                        self.port = port
+                        success = True
+                        break
+                    # restore the monekypatch
+                    socket.AI_ADDRCONFIG = saved_AI_ADDRCONFIG
                 if e.errno != errno.EADDRINUSE:
                     raise
                 self.log.info('The port %i is already in use, trying another random port.' % port)