Verify no NSes from optimistic addresses

- also, fixup tests to skip at more appropriate times.

Change-Id: Ib7df5a176a30a9e31e403883d52cd0d41b4475ae

1 files changed, 45 insertions, 4 deletions

diff --git a/tests/net_test/srcaddr_selection_test.py b/tests/net_test/srcaddr_selection_test.py
index 535a4779..6655bb7b 100755
--- a/tests/net_test/srcaddr_selection_test.py
+++ b/tests/net_test/srcaddr_selection_test.py
@@ -1,6 +1,7 @@
 #!/usr/bin/python
 
 import errno
+import os
 import random
 from socket import *  # pylint: disable=wildcard-import
 import time
@@ -18,6 +19,11 @@ IPV6_ADDR_PREFERENCES = 72
 IPV6_PREFER_SRC_PUBLIC = 0x0002
 
 
+USE_OPTIMISTIC_SYSCTL = "/proc/sys/net/ipv6/conf/default/use_optimistic"
+
+HAVE_USE_OPTIMISTIC = os.path.isfile(USE_OPTIMISTIC_SYSCTL)
+
+
 class IPv6SourceAddressSelectionTest(mark_test.MultiNetworkTest):
 
   def SetDAD(self, ifname, value):
@@ -63,11 +69,11 @@ class IPv6SourceAddressSelectionTest(mark_test.MultiNetworkTest):
     s = net_test.UDPSocket(AF_INET6)
     s.bind((address, 0, 0, 0))
 
-  def SendWithSourceAddress(self, address, netid):
+  def SendWithSourceAddress(self, address, netid, dest=net_test.IPV6_ADDR):
     pktinfo = mark_test.MakePktInfo(6, address, 0)
     cmsgs = [(net_test.SOL_IPV6, IPV6_PKTINFO, pktinfo)]
     s = self.BuildSocket(6, net_test.UDPSocket, netid, "mark")
-    return sendmsg.Sendmsg(s, (net_test.IPV6_ADDR, 53), "Hello", cmsgs, 0)
+    return sendmsg.Sendmsg(s, (dest, 53), "Hello", cmsgs, 0)
 
   def assertAddressUsable(self, address, netid):
     self.BindToAddress(address)
@@ -102,7 +108,8 @@ class MultiInterfaceSourceAddressSelectionTest(IPv6SourceAddressSelectionTest):
       self.SetDAD(self.GetInterfaceName(netid), 0)
       self.SetOptimisticDAD(self.GetInterfaceName(netid), 0)
       self.SetUseTempaddrs(self.GetInterfaceName(netid), 0)
-      self.SetUseOptimistic(self.GetInterfaceName(netid), 0)
+      if HAVE_USE_OPTIMISTIC:
+        self.SetUseOptimistic(self.GetInterfaceName(netid), 0)
 
     # [1]  Pick an interface on which to test.
     self.test_netid = random.choice(self.tuns.keys())
@@ -155,7 +162,7 @@ class OptimisticAddressTest(MultiInterfaceSourceAddressSelectionTest):
         self.test_ip, self.test_ifindex, iproute.IFA_F_OPTIMISTIC)
 
     # Optimistic addresses are usable but are not selected.
-    if mark_test.LinuxVersion() >= (3, 19, 0):
+    if mark_test.LinuxVersion() >= (3, 18, 0):
       # The version checked in to android kernels <= 3.10 requires the
       # use_optimistic sysctl to be turned on.
       self.assertAddressUsable(self.test_ip, self.test_netid)
@@ -172,6 +179,7 @@ class OptimisticAddressTest(MultiInterfaceSourceAddressSelectionTest):
 
 class OptimisticAddressOkayTest(MultiInterfaceSourceAddressSelectionTest):
 
+  @unittest.skipUnless(HAVE_USE_OPTIMISTIC, "use_optimistic not supported")
   def testModifiedRfc6724Behaviour(self):
     # [3]  Get an IPv6 address back, in optimistic DAD start-up.
     self.SetDAD(self.test_ifname, 1)  # Enable DAD
@@ -191,6 +199,7 @@ class OptimisticAddressOkayTest(MultiInterfaceSourceAddressSelectionTest):
 
 class ValidBeforeOptimisticTest(MultiInterfaceSourceAddressSelectionTest):
 
+  @unittest.skipUnless(HAVE_USE_OPTIMISTIC, "use_optimistic not supported")
   def testModifiedRfc6724Behaviour(self):
     # [3]  Add a valid IPv6 address to this interface and verify it is
     # selected as the source address.
@@ -219,6 +228,7 @@ class ValidBeforeOptimisticTest(MultiInterfaceSourceAddressSelectionTest):
 
 class DadFailureTest(MultiInterfaceSourceAddressSelectionTest):
 
+  @unittest.skipUnless(HAVE_USE_OPTIMISTIC, "use_optimistic not supported")
   def testDadFailure(self):
     # [3]  Get an IPv6 address back, in optimistic DAD start-up.
     self.SetDAD(self.test_ifname, 1)  # Enable DAD
@@ -248,6 +258,37 @@ class DadFailureTest(MultiInterfaceSourceAddressSelectionTest):
     # TODO(ek): verify that an RTM_DELADDR issued for the DAD-failed address.
 
 
+class NoNsFromOptimisticTest(MultiInterfaceSourceAddressSelectionTest):
+
+  @unittest.skipUnless(HAVE_USE_OPTIMISTIC, "use_optimistic not supported")
+  @unittest.skipUnless(mark_test.LinuxVersion() >= (3, 18, 0),
+                       "correct optimistic bind() not supported")
+  def testSendToOnlinkDestination(self):
+    # [3]  Get an IPv6 address back, in optimistic DAD start-up.
+    self.SetDAD(self.test_ifname, 1)  # Enable DAD
+    self.SetOptimisticDAD(self.test_ifname, 1)
+    self.SetUseOptimistic(self.test_ifname, 1)
+    # Send a RA to start SLAAC and subsequent DAD.
+    self.SendRA(self.test_netid, 0)
+    # Prove optimism and usability.
+    self.assertAddressHasExpectedAttributes(
+        self.test_ip, self.test_ifindex, iproute.IFA_F_OPTIMISTIC)
+    self.assertAddressUsable(self.test_ip, self.test_netid)
+    self.assertAddressSelected(self.test_ip, self.test_netid)
+
+    # [4]  Send to an on-link destination and observe a Neighbor Solicitation
+    # packet with a source address that is NOT the optimistic address.
+    # In this setup, the only usable address is the link-local address.
+    onlink_dest = self.GetRandomDestination(self.IPv6Prefix(self.test_netid))
+    self.SendWithSourceAddress(self.test_ip, self.test_netid, onlink_dest)
+
+    expected_ns = mark_test.Packets.NS(
+        net_test.GetLinkAddress(self.test_ifname, True),
+        onlink_dest,
+        self.MyMacAddress(self.test_netid))[1]
+    self.ExpectPacketOn(self.test_netid, "link-local NS", expected_ns)
+
+
 # TODO(ek): add tests listening for netlink events.