diff --git a/shadowsocks/eventloop.py b/shadowsocks/eventloop.py
index 4b74825..89ffbcb 100644
--- a/shadowsocks/eventloop.py
+++ b/shadowsocks/eventloop.py
@@ -29,15 +29,15 @@ import select
 from collections import defaultdict
 
 
-__all__ = ['EventLoop', 'MODE_NULL', 'MODE_IN', 'MODE_OUT', 'MODE_ERR',
-           'MODE_HUP', 'MODE_NVAL']
+__all__ = ['EventLoop', 'POLL_NULL', 'POLL_IN', 'POLL_OUT', 'POLL_ERR',
+           'POLL_HUP', 'POLL_NVAL']
 
-MODE_NULL = 0x00
-MODE_IN = 0x01
-MODE_OUT = 0x04
-MODE_ERR = 0x08
-MODE_HUP = 0x10
-MODE_NVAL = 0x20
+POLL_NULL = 0x00
+POLL_IN = 0x01
+POLL_OUT = 0x04
+POLL_ERR = 0x08
+POLL_HUP = 0x10
+POLL_NVAL = 0x20
 
 
 class EpollLoop(object):
@@ -68,9 +68,9 @@ class KqueueLoop(object):
 
     def _control(self, fd, mode, flags):
         events = []
-        if mode & MODE_IN:
+        if mode & POLL_IN:
             events.append(select.kevent(fd, select.KQ_FILTER_READ, flags))
-        if mode & MODE_OUT:
+        if mode & POLL_OUT:
             events.append(select.kevent(fd, select.KQ_FILTER_WRITE, flags))
         for e in events:
             self._kqueue.control([e], 0)
@@ -79,13 +79,13 @@ class KqueueLoop(object):
         if timeout < 0:
             timeout = None  # kqueue behaviour
         events = self._kqueue.control(None, KqueueLoop.MAX_EVENTS, timeout)
-        results = defaultdict(lambda: MODE_NULL)
+        results = defaultdict(lambda: POLL_NULL)
         for e in events:
             fd = e.ident
             if e.filter == select.KQ_FILTER_READ:
-                results[fd] |= MODE_IN
+                results[fd] |= POLL_IN
             elif e.filter == select.KQ_FILTER_WRITE:
-                results[fd] |= MODE_OUT
+                results[fd] |= POLL_OUT
         return results.iteritems()
 
     def add_fd(self, fd, mode):
@@ -111,18 +111,18 @@ class SelectLoop(object):
     def poll(self, timeout):
         r, w, x = select.select(self._r_list, self._w_list, self._x_list,
                                 timeout)
-        results = defaultdict(lambda: MODE_NULL)
-        for p in [(r, MODE_IN), (w, MODE_OUT), (x, MODE_ERR)]:
+        results = defaultdict(lambda: POLL_NULL)
+        for p in [(r, POLL_IN), (w, POLL_OUT), (x, POLL_ERR)]:
             for fd in p[0]:
                 results[fd] |= p[1]
         return results.items()
 
     def add_fd(self, fd, mode):
-        if mode & MODE_IN:
+        if mode & POLL_IN:
             self._r_list.add(fd)
-        if mode & MODE_OUT:
+        if mode & POLL_OUT:
             self._w_list.add(fd)
-        if mode & MODE_ERR:
+        if mode & POLL_ERR:
             self._x_list.add(fd)
 
     def remove_fd(self, fd):
@@ -168,3 +168,22 @@ class EventLoop(object):
     def modify(self, f, mode):
         fd = f.fileno()
         self._impl.modify_fd(fd, mode)
+
+
+# from tornado
+def errno_from_exception(e):
+    """Provides the errno from an Exception object.
+
+    There are cases that the errno attribute was not set so we pull
+    the errno out of the args but if someone instatiates an Exception
+    without any args you will get a tuple error. So this function
+    abstracts all that behavior to give you a safe way to get the
+    errno.
+    """
+
+    if hasattr(e, 'errno'):
+        return e.errno
+    elif e.args:
+        return e.args[0]
+    else:
+        return None
diff --git a/shadowsocks/lru_cache.py b/shadowsocks/lru_cache.py
index 399c810..ce40d17 100644
--- a/shadowsocks/lru_cache.py
+++ b/shadowsocks/lru_cache.py
@@ -10,8 +10,9 @@ import time
 class LRUCache(collections.MutableMapping):
     """This class is not thread safe"""
 
-    def __init__(self, timeout=60, *args, **kwargs):
+    def __init__(self, timeout=60, close_callback=None, *args, **kwargs):
         self.timeout = timeout
+        self.close_callback = close_callback
         self.store = {}
         self.time_to_keys = collections.defaultdict(list)
         self.last_visits = []
@@ -53,8 +54,9 @@ class LRUCache(collections.MutableMapping):
                 heapq.heappop(self.last_visits)
                 if self.store.__contains__(key):
                     value = self.store[key]
-                    if hasattr(value, 'close'):
-                        value.close()
+                    if self.close_callback is not None:
+                        self.close_callback(value)
+
                     del self.store[key]
                     c += 1
             del self.time_to_keys[least]
diff --git a/shadowsocks/udprelay.py b/shadowsocks/udprelay.py
index eb5c677..1e72742 100644
--- a/shadowsocks/udprelay.py
+++ b/shadowsocks/udprelay.py
@@ -74,6 +74,7 @@ import struct
 import encrypt
 import eventloop
 import lru_cache
+import errno
 
 
 BUF_SIZE = 65536
@@ -137,6 +138,14 @@ class UDPRelay(object):
         self._cache = lru_cache.LRUCache(timeout=timeout)
         self._client_fd_to_server_addr = lru_cache.LRUCache(timeout=timeout)
 
+    def _close_client(self, client):
+        if hasattr(client, 'close'):
+            self._eventloop.remove(client)
+            client.close()
+        else:
+            # just an address
+            pass
+
     def _handle_server(self):
         server = self._server_socket
         data, r_addr = server.recvfrom(BUF_SIZE)
@@ -177,7 +186,7 @@ class UDPRelay(object):
             else:
                 # drop
                 return
-            self._eventloop.add(client, eventloop.MODE_IN)
+            self._eventloop.add(client, eventloop.POLL_IN)
 
             # prevent from recv other sources
             if self._is_local:
@@ -225,10 +234,18 @@ class UDPRelay(object):
 
     def _run(self):
         server_socket = self._server_socket
-        self._eventloop.add(server_socket, eventloop.MODE_IN)
+        self._eventloop.add(server_socket, eventloop.POLL_IN)
         last_time = time.time()
         while True:
-            events = self._eventloop.poll(10)
+            try:
+                events = self._eventloop.poll(10)
+            except (OSError, IOError) as e:
+                if eventloop.errno_from_exception(e) == errno.EPIPE:
+                    # Happens when the client closes the connection
+                    continue
+                else:
+                    logging.error(e)
+                    continue
             for sock, event in events:
                 if sock == self._server_socket:
                     self._handle_server()