Add a unit test for the IPV6_JOIN_ANYCAST hang.
Bug: 18902601
Change-Id: I67cff7954498b9bf2950a34b583be43fd21d6005
diff --git a/net/test/anycast_test.py b/net/test/anycast_test.py
new file mode 100755
index 0000000..4b03664
--- /dev/null
+++ b/net/test/anycast_test.py
@@ -0,0 +1,105 @@
+#!/usr/bin/python
+#
+# Copyright 2014 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import os
+from socket import * # pylint: disable=wildcard-import
+import threading
+import time
+import unittest
+
+import cstruct
+import multinetwork_base
+import net_test
+
+IPV6_JOIN_ANYCAST = 27
+IPV6_LEAVE_ANYCAST = 28
+
+# pylint: disable=invalid-name
+IPv6Mreq = cstruct.Struct("IPv6Mreq", "=16si", "multiaddr ifindex")
+
+
+_CLOSE_HUNG = False
+
+
+def CauseOops():
+ open("/proc/sysrq-trigger", "w").write("c")
+
+
+class CloseFileDescriptorThread(threading.Thread):
+
+ def __init__(self, fd):
+ super(CloseFileDescriptorThread, self).__init__()
+ self.daemon = True
+ self._fd = fd
+ self.finished = False
+
+ def run(self):
+ global _CLOSE_HUNG
+ _CLOSE_HUNG = True
+ self._fd.close()
+ _CLOSE_HUNG = False
+ self.finished = True
+
+
+class AnycastTest(multinetwork_base.MultiNetworkBaseTest):
+
+ _TEST_NETID = 123
+
+ def AnycastSetsockopt(self, s, is_add, netid, addr):
+ ifindex = self.ifindices[netid]
+ self.assertTrue(ifindex)
+ ipv6mreq = IPv6Mreq((addr, ifindex))
+ option = IPV6_JOIN_ANYCAST if is_add else IPV6_LEAVE_ANYCAST
+ s.setsockopt(IPPROTO_IPV6, option, ipv6mreq.Pack())
+
+ def testAnycastNetdeviceUnregister(self):
+ netid = self._TEST_NETID
+ self.assertNotIn(netid, self.tuns)
+ self.tuns[netid] = self.CreateTunInterface(netid)
+ self.SendRA(netid)
+ iface = self.GetInterfaceName(netid)
+ self.ifindices[netid] = net_test.GetInterfaceIndex(iface)
+
+ s = socket(AF_INET6, SOCK_DGRAM, 0)
+ addr = self.MyAddress(6, netid)
+ self.assertIsNotNone(addr)
+
+ addr = inet_pton(AF_INET6, addr)
+ addr = addr[:8] + os.urandom(8)
+ self.AnycastSetsockopt(s, True, netid, addr)
+
+ # Close the tun fd in the background.
+ # This will hang if the kernel has the bug.
+ thread = CloseFileDescriptorThread(self.tuns[netid])
+ thread.start()
+ time.sleep(0.1)
+
+ # Make teardown work.
+ del self.tuns[netid]
+ # Check that the interface is gone.
+ try:
+ self.assertIsNone(self.MyAddress(6, netid))
+ finally:
+ # This doesn't seem to help, but still.
+ self.AnycastSetsockopt(s, False, netid, addr)
+ self.assertTrue(thread.finished)
+
+
+if __name__ == "__main__":
+ unittest.main(exit=False)
+ if _CLOSE_HUNG:
+ time.sleep(3)
+ CauseOops()
