[dua] handle AddressError (#5516)

This commit enhances DUA feature to handle Address Error by increasing
the DAD counter and generating new DUA address if a DUA conflict is
detected.

src/core/thread/address_resolver.cpp

@@ -704,7 +704,16 @@ void AddressResolver::HandleAddressError(Coap::Message &aMessage, const Ip6::Mes
         if (address->GetAddress() == target && Get<Mle::MleRouter>().GetMeshLocal64().GetIid() != meshLocalIid)
         {
             // Target EID matches address and Mesh Local EID differs
-            Get<ThreadNetif>().RemoveUnicastAddress(*address);
+#if OPENTHREAD_CONFIG_DUA_ENABLE
+            if (Get<BackboneRouter::Leader>().IsDomainUnicast(address->GetAddress()))
+            {
+                Get<DuaManager>().NotifyDuplicateDomainUnicastAddress();
+            }
+            else
+#endif
+            {
+                Get<ThreadNetif>().RemoveUnicastAddress(*address);
+            }
             ExitNow();
         }
     }

src/core/thread/dua_manager.cpp

@@ -258,7 +258,18 @@ void DuaManager::UpdateRegistrationDelay(uint8_t aDelay)
         UpdateTimeTickerRegistration();
     }
 }
-#endif
+
+void DuaManager::NotifyDuplicateDomainUnicastAddress(void)
+{
+    RemoveDomainUnicastAddress();
+    mDadCounter++;
+
+    if (GenerateDomainUnicastAddressIid() == OT_ERROR_NONE)
+    {
+        AddDomainUnicastAddress();
+    }
+}
+#endif // OPENTHREAD_CONFIG_DUA_ENABLE
 
 void DuaManager::UpdateReregistrationDelay(void)
 {
@@ -584,14 +595,7 @@ otError DuaManager::ProcessDuaResponse(Coap::Message &aMessage)
             RemoveDomainUnicastAddress();
             break;
         case ThreadStatusTlv::kDuaDuplicate:
-            RemoveDomainUnicastAddress();
-            mDadCounter++;
-
-            if (GenerateDomainUnicastAddressIid() == OT_ERROR_NONE)
-            {
-                AddDomainUnicastAddress();
-            }
-
+            NotifyDuplicateDomainUnicastAddress();
             break;
         case ThreadStatusTlv::kDuaNoResources:
         case ThreadStatusTlv::kDuaNotPrimary:

src/core/thread/dua_manager.hpp

@@ -153,6 +153,12 @@ public:
      *
      */
     void Restore(void);
+
+    /**
+     * This method notifies duplicated Domain Unicast Address.
+     *
+     */
+    void NotifyDuplicateDomainUnicastAddress(void);
 #endif
 
 #if OPENTHREAD_CONFIG_TMF_PROXY_DUA_ENABLE

tests/scripts/thread-cert/config.py

@@ -127,6 +127,7 @@ AQ_TIMEOUT = 3
 ADDRESS_QUERY_INITIAL_RETRY_DELAY = 15
 DEFAULT_CHILD_TIMEOUT = 6
 VIRTUAL_TIME = int(os.getenv('VIRTUAL_TIME', 0))
+PARENT_AGGREGATIOIN_DELAY = 5
 
 LEADER_NOTIFY_SED_BY_CHILD_UPDATE_REQUEST = True
 

tests/scripts/thread-cert/node.py

@@ -959,6 +959,16 @@ class NodeImpl:
         self.send_command('routerdowngradethreshold')
         return int(self._expect_result(r'\d+'))
 
+    def set_router_eligible(self, enable: bool):
+        cmd = f'routereligible {"enable" if enable else "disable"}'
+        self.send_command(cmd)
+        self._expect('Done')
+
+    def get_router_eligible(self) -> bool:
+        states = [r'Disabled', r'Enabled']
+        self.send_command('routereligible')
+        return self._expect_result(states) == 'Enabled'
+
     def prefer_router_id(self, router_id):
         cmd = 'preferrouterid %d' % router_id
         self.send_command(cmd)
@@ -1007,6 +1017,11 @@ class NodeImpl:
         self.send_command(cmd)
         self._expect('Done')
 
+    def del_ipaddr(self, ipaddr):
+        cmd = 'ipaddr del %s' % ipaddr
+        self.send_command(cmd)
+        self._expect('Done')
+
     def add_ipmaddr(self, ipmaddr):
         cmd = 'ipmaddr add %s' % ipmaddr
         self.send_command(cmd)

tests/scripts/thread-cert/thread_cert.py

@@ -174,6 +174,8 @@ class TestCase(NcpSupportMixin, unittest.TestCase):
                 self.nodes[i].set_router_upgrade_threshold(params['router_upgrade_threshold'])
             if 'router_downgrade_threshold' in params:
                 self.nodes[i].set_router_downgrade_threshold(params['router_downgrade_threshold'])
+            if 'router_eligible' in params:
+                self.nodes[i].set_router_eligible(params['router_eligible'])
 
             if 'timeout' in params:
                 self.nodes[i].set_timeout(params['timeout'])

tests/scripts/thread-cert/v1_2_test_dua_handle_address_error.py

@@ -0,0 +1,151 @@
+#!/usr/bin/env python3
+#
+#  Copyright (c) 2020, The OpenThread Authors.
+#  All rights reserved.
+#
+#  Redistribution and use in source and binary forms, with or without
+#  modification, are permitted provided that the following conditions are met:
+#  1. Redistributions of source code must retain the above copyright
+#     notice, this list of conditions and the following disclaimer.
+#  2. Redistributions in binary form must reproduce the above copyright
+#     notice, this list of conditions and the following disclaimer in the
+#     documentation and/or other materials provided with the distribution.
+#  3. Neither the name of the copyright holder nor the
+#     names of its contributors may be used to endorse or promote products
+#     derived from this software without specific prior written permission.
+#
+#  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 'AS IS'
+#  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+#  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+#  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+#  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+#  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+#  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+#  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+#  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+#  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+#  POSSIBILITY OF SUCH DAMAGE.
+#
+# This script tests how node would handle duplicated Domain Unicast Address.
+#
+
+import unittest
+
+import config
+import thread_cert
+
+BBR_1 = 1  # Collapsed with Leader Role
+ROUTER = 2
+FED = 3
+MED = 4
+
+WAIT_ATTACH = 5
+WAIT_REDUNDANCE = 3
+ROUTER_SELECTION_JITTER = 1
+BBR_REGISTRATION_JITTER = 5
+SED_POLL_PERIOD = 2000  # 2s
+MED_TIMEOUT = 20  # 20s
+"""
+ Topology
+
+  BBR_1 (Leader)
+     |
+  ROUTER_1---FED
+     |
+    MED
+"""
+
+WAIT_REDUNDANCE = 3
+REG_DELAY = 5
+
+
+class TestDomainUnicastAddress(thread_cert.TestCase):
+    TOPOLOGY = {
+        BBR_1: {
+            'version': '1.2',
+            'allowlist': [ROUTER],
+            'router_selection_jitter': ROUTER_SELECTION_JITTER,
+            'is_bbr': True
+        },
+        ROUTER: {
+            'version': '1.2',
+            'allowlist': [BBR_1, FED, MED],
+            'router_selection_jitter': ROUTER_SELECTION_JITTER,
+        },
+        FED: {
+            'version': '1.2',
+            'allowlist': [ROUTER],
+            'router_eligible': False,
+            'mode': 'rsdn',
+        },
+        MED: {
+            'version': '1.2',
+            'allowlist': [ROUTER],
+            'mode': 'rsn',
+        },
+    }
+
+    def test(self):
+        self.simulator.set_lowpan_context(1, config.DOMAIN_PREFIX)
+
+        # 1) Bring up BBR_1, BBR_1 becomes Leader and Primary Backbone Router, with Domain
+        #    Prefix without `P_slaac`.
+        self.nodes[BBR_1].set_bbr_registration_jitter(BBR_REGISTRATION_JITTER)
+        self.nodes[BBR_1].set_backbone_router(seqno=1, reg_delay=REG_DELAY)
+        self.nodes[BBR_1].start()
+
+        self.simulator.go(WAIT_ATTACH + ROUTER_SELECTION_JITTER)
+        self.assertEqual(self.nodes[BBR_1].get_state(), 'leader')
+        self.nodes[BBR_1].enable_backbone_router()
+        self.simulator.go(BBR_REGISTRATION_JITTER + WAIT_REDUNDANCE)
+        self.assertEqual(self.nodes[BBR_1].get_backbone_router_state(), 'Primary')
+
+        self.nodes[BBR_1].set_domain_prefix(config.DOMAIN_PREFIX, 'prosD')
+        self.simulator.go(WAIT_REDUNDANCE)
+        assert self.nodes[BBR_1].has_ipmaddr(config.ALL_DOMAIN_BBRS_ADDRESS)
+
+        # 2) Bring up ROUTER_1
+        self.nodes[ROUTER].start()
+        self.simulator.go(WAIT_ATTACH + REG_DELAY + WAIT_REDUNDANCE)
+        self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
+
+        # Bring up FED
+        self.nodes[FED].start()
+        self.simulator.go(WAIT_ATTACH + REG_DELAY + WAIT_REDUNDANCE)
+        self.assertEqual(self.nodes[FED].get_state(), 'child')
+
+        # Bring up MED
+        self.nodes[MED].start()
+        self.simulator.go(WAIT_ATTACH + config.PARENT_AGGREGATIOIN_DELAY + REG_DELAY + WAIT_REDUNDANCE)
+        self.assertEqual(self.nodes[MED].get_state(), 'child')
+
+        self._verify_dua_handle_address_error(ROUTER)
+        self._verify_dua_handle_address_error(FED)
+        self._verify_dua_handle_address_error(MED, is_med=True)
+
+    def _verify_dua_handle_address_error(self, nodeid, is_med=False):
+        dua = self.nodes[nodeid].get_addr(config.DOMAIN_PREFIX)
+        self.assertIsNotNone(dua)
+
+        # Ping the DUA to verify reachability, and also fill the EID cache on BBR_1
+        self.assertTrue(self.nodes[BBR_1].ping(dua))
+
+        self.simulator.go(WAIT_REDUNDANCE)
+
+        # Send fake /a/an from ROUTER to BBR_1 for the node's DUA
+        pbbr_rloc = self.nodes[BBR_1].get_ip6_address(config.ADDRESS_TYPE.RLOC)
+        self.nodes[ROUTER].send_address_notification(pbbr_rloc, dua, f'000000000000{nodeid:04x}')
+
+        self.simulator.go(config.PARENT_AGGREGATIOIN_DELAY * is_med + REG_DELAY + WAIT_REDUNDANCE + 50)
+
+        # Make sure device handles /a/ae correctly by generating new DUA
+        new_dua = self.nodes[nodeid].get_addr(config.DOMAIN_PREFIX)
+        self.assertNotEqual(dua, new_dua)
+        self.assertTrue(self.nodes[BBR_1].ping(new_dua))
+        self.assertFalse(self.nodes[BBR_1].ping(dua))
+
+        self.simulator.go(3)
+
+
+if __name__ == '__main__':
+    unittest.main()