Delete the IPv6 link-local Neighbor when ipv6 link-local mode is disabled (sonic-net#1897)

AkhileshSamineni · preetham-singh · commit 311fbf122ff6 · 2022-08-05T23:03:37.000-07:00
* IPv6 link-local Neighbor deletion when ipv6 link-local mode is disabled.
Signed-off-by: Akhilesh Samineni &lt;akhilesh.samineni@broadcom.com&gt;
diff --git a/cfgmgr/intfmgr.cpp b/cfgmgr/intfmgr.cpp
@@ -40,6 +40,7 @@ IntfMgr::IntfMgr(DBConnector *cfgDb, DBConnector *appDb, DBConnector *stateDb, c
         m_stateVrfTable(stateDb, STATE_VRF_TABLE_NAME),
         m_stateIntfTable(stateDb, STATE_INTERFACE_TABLE_NAME),
         m_appIntfTableProducer(appDb, APP_INTF_TABLE_NAME),
+        m_neighTable(appDb, APP_NEIGH_TABLE_NAME),
         m_appLagTable(appDb, APP_LAG_TABLE_NAME)
 {
     auto subscriberStateTable = new swss::SubscriberStateTable(stateDb,
@@ -616,6 +617,35 @@ bool IntfMgr::isIntfStateOk(const string &alias)
     return false;
 }
 
+void IntfMgr::delIpv6LinkLocalNeigh(const string &alias)
+{
+    vector<string> neighEntries;
+
+    SWSS_LOG_INFO("Deleting ipv6 link local neighbors for %s", alias.c_str());
+
+    m_neighTable.getKeys(neighEntries);
+    for (auto neighKey : neighEntries)
+    {
+        if (!neighKey.compare(0, alias.size(), alias.c_str()))
+        {
+            vector<string> keys = tokenize(neighKey, ':', 1);
+            if (keys.size() == 2)
+            {
+                IpAddress ipAddress(keys[1]);
+                if (ipAddress.getAddrScope() == IpAddress::AddrScope::LINK_SCOPE)
+                {
+                    stringstream cmd;
+                    string res;
+
+                    cmd << IP_CMD << " neigh del dev " << keys[0] << " " << keys[1] ;
+                    swss::exec(cmd.str(), res);
+                    SWSS_LOG_INFO("Deleted ipv6 link local neighbor - %s", keys[1].c_str());
+                }
+            }
+        }
+    }
+}
+
 bool IntfMgr::doIntfGeneralTask(const vector<string>& keys,
         vector<FieldValueTuple> data,
         const string& op)
@@ -755,6 +785,17 @@ bool IntfMgr::doIntfGeneralTask(const vector<string>& keys,
             /* Set ipv6 mode */
             if (!ipv6_link_local_mode.empty())
             {
+                if ((ipv6_link_local_mode == "enable") && (m_ipv6LinkLocalModeList.find(alias) == m_ipv6LinkLocalModeList.end()))
+                {
+                    m_ipv6LinkLocalModeList.insert(alias);
+                    SWSS_LOG_INFO("Inserted ipv6 link local mode list for %s", alias.c_str());
+                }
+                else if ((ipv6_link_local_mode == "disable") && (m_ipv6LinkLocalModeList.find(alias) != m_ipv6LinkLocalModeList.end()))
+                {
+                    m_ipv6LinkLocalModeList.erase(alias);
+                    delIpv6LinkLocalNeigh(alias);
+                    SWSS_LOG_INFO("Erased ipv6 link local mode list for %s", alias.c_str());
+                }
                 FieldValueTuple fvTuple("ipv6_use_link_local_only", ipv6_link_local_mode);
                 data.push_back(fvTuple);
             }
@@ -910,6 +951,13 @@ bool IntfMgr::doIntfGeneralTask(const vector<string>& keys,
             removeSubIntfState(alias);
         }
 
+        if (m_ipv6LinkLocalModeList.find(alias) != m_ipv6LinkLocalModeList.end())
+        {
+            m_ipv6LinkLocalModeList.erase(alias);
+            delIpv6LinkLocalNeigh(alias);
+            SWSS_LOG_INFO("Erased ipv6 link local mode list for %s", alias.c_str());
+        }
+
         m_appIntfTableProducer.del(alias);
         m_stateIntfTable.del(alias);
     }
diff --git a/cfgmgr/intfmgr.h b/cfgmgr/intfmgr.h
@@ -31,10 +31,12 @@ class IntfMgr : public Orch
     ProducerStateTable m_appIntfTableProducer;
     Table m_cfgIntfTable, m_cfgVlanIntfTable, m_cfgLagIntfTable, m_cfgLoopbackIntfTable;
     Table m_statePortTable, m_stateLagTable, m_stateVlanTable, m_stateVrfTable, m_stateIntfTable, m_appLagTable;
+    Table m_neighTable;
 
     SubIntfMap m_subIntfList;
     std::set<std::string> m_loopbackIntfList;
     std::set<std::string> m_pendingReplayIntfList;
+    std::set<std::string> m_ipv6LinkLocalModeList;
 
     void setIntfIp(const std::string &alias, const std::string &opCmd, const IpPrefix &ipPrefix);
     void setIntfVrf(const std::string &alias, const std::string &vrfName);
@@ -65,6 +67,7 @@ class IntfMgr : public Orch
     void removeHostSubIntf(const std::string &subIntf);
     void setSubIntfStateOk(const std::string &alias);
     void removeSubIntfState(const std::string &alias);
+    void delIpv6LinkLocalNeigh(const std::string &alias);
 
     bool setIntfProxyArp(const std::string &alias, const std::string &proxy_arp);
     bool setIntfGratArp(const std::string &alias, const std::string &grat_arp);
diff --git a/neighsyncd/neighsync.cpp b/neighsyncd/neighsync.cpp
@@ -82,7 +82,7 @@ void NeighSync::onMsg(int nlmsg_type, struct nl_object *obj)
     /* Ignore IPv6 link-local addresses as neighbors, if ipv6 link local mode is disabled */
     if (family == IPV6_NAME && IN6_IS_ADDR_LINKLOCAL(nl_addr_get_binary_addr(rtnl_neigh_get_dst(neigh))))
     {
-        if (isLinkLocalEnabled(intfName) == false)
+        if ((isLinkLocalEnabled(intfName) == false) && (nlmsg_type != RTM_DELNEIGH))
         {
             return;
         }
diff --git a/tests/test_ipv6_link_local.py b/tests/test_ipv6_link_local.py
@@ -0,0 +1,112 @@
+import time
+import json
+import pytest
+
+from swsscommon import swsscommon
+
+class TestIPv6LinkLocal(object):
+    def setup_db(self, dvs):
+        self.pdb = dvs.get_app_db()
+        self.adb = dvs.get_asic_db()
+        self.cdb = dvs.get_config_db()
+
+    def set_admin_status(self, interface, status):
+        self.cdb.update_entry("PORT", interface, {"admin_status": status})
+
+    def add_ip_address(self, interface, ip):
+        self.cdb.create_entry("INTERFACE", interface + "|" + ip, {"NULL": "NULL"})
+        time.sleep(2)
+
+    def remove_ip_address(self, interface, ip):
+        self.cdb.delete_entry("INTERFACE", interface + "|" + ip)
+        time.sleep(2)
+
+    def create_ipv6_link_local_intf(self, interface):
+        self.cdb.create_entry("INTERFACE", interface, {"ipv6_use_link_local_only": "enable"})
+        time.sleep(2)
+
+    def remove_ipv6_link_local_intf(self, interface):
+        self.cdb.delete_entry("INTERFACE", interface)
+        time.sleep(2)
+
+    def test_NeighborAddRemoveIpv6LinkLocal(self, dvs, testlog):
+        self.setup_db(dvs)
+
+        # create ipv6 link local intf
+        self.create_ipv6_link_local_intf("Ethernet0")
+        self.create_ipv6_link_local_intf("Ethernet4")
+
+        # bring up interface
+        self.set_admin_status("Ethernet0", "up")
+        self.set_admin_status("Ethernet4", "up")
+
+        # set ip address
+        self.add_ip_address("Ethernet0", "2000::1/64")
+        self.add_ip_address("Ethernet4", "2001::1/64")
+        dvs.runcmd("sysctl -w net.ipv6.conf.all.forwarding=1")
+        dvs.runcmd("sysctl -w net.ipv6.conf.default.forwarding=1")
+
+        # set ip address and default route
+        dvs.servers[0].runcmd("ip -6 address add 2000::2/64 dev eth0")
+        dvs.servers[0].runcmd("ip -6 route add default via 2000::1")
+
+        dvs.servers[1].runcmd("ip -6 address add 2001::2/64 dev eth0")
+        dvs.servers[1].runcmd("ip -6 route add default via 2001::1")
+        time.sleep(2)
+
+        # get neighbor entry
+        dvs.servers[0].runcmd("ping -6 -c 1 2001::2")
+        time.sleep(2)
+
+        # Neigh entries should contain Ipv6-link-local neighbors, should be 4
+        neigh_entries = self.pdb.get_keys("NEIGH_TABLE")
+        assert (len(neigh_entries) == 4)
+
+        found_entry = False
+        for key in neigh_entries:
+            if (key.find("Ethernet4:2001::2") or key.find("Ethernet0:2000::2")):
+                found_entry = True
+
+        assert found_entry
+
+        # remove ip address
+        self.remove_ip_address("Ethernet0", "2000::1/64")
+        self.remove_ip_address("Ethernet4", "2001::1/64")
+
+        # remove ipv6 link local intf
+        self.remove_ipv6_link_local_intf("Ethernet0")
+        self.remove_ipv6_link_local_intf("Ethernet4")
+
+        # Neigh entries should not contain Ipv6-link-local neighbors, should be 2
+        neigh_after_entries = self.pdb.get_keys("NEIGH_TABLE")
+        print(neigh_after_entries)
+        assert (len(neigh_after_entries) == 2)
+
+        found_existing_entry = False
+        for key in neigh_entries:
+            if (key.find("Ethernet4:2001::2") or key.find("Ethernet0:2000::2")):
+                found_existing_entry = True
+
+        assert found_existing_entry
+
+        self.set_admin_status("Ethernet0", "down")
+        self.set_admin_status("Ethernet4", "down")
+
+        # remove ip address and default route
+        dvs.servers[0].runcmd("ip -6 route del default dev eth0")
+        dvs.servers[0].runcmd("ip -6 address del 2000::2/64 dev eth0")
+
+        dvs.servers[1].runcmd("ip -6 route del default dev eth0")
+        dvs.servers[1].runcmd("ip -6 address del 2001::2/64 dev eth0")
+
+        dvs.runcmd("sysctl -w net.ipv6.conf.all.forwarding=0")
+        dvs.runcmd("sysctl -w net.ipv6.conf.default.forwarding=0")
+
+        neigh_entries = self.pdb.get_keys("NEIGH_TABLE")
+        assert (len(neigh_entries) == 0)
+
+# Add Dummy always-pass test at end as workaroud
+# for issue when Flaky fail on final test it invokes module tear-down before retrying
+def test_nonflaky_dummy():
+    pass
+

Original file line number	Diff line number	Diff line change
`@@ -82,7 +82,7 @@ void NeighSync::onMsg(int nlmsg_type, struct nl_object *obj)`
`82`	`82`	`/* Ignore IPv6 link-local addresses as neighbors, if ipv6 link local mode is disabled */`
`83`	`83`	`if (family == IPV6_NAME && IN6_IS_ADDR_LINKLOCAL(nl_addr_get_binary_addr(rtnl_neigh_get_dst(neigh))))`
`84`	`84`	`{`
`85`		`- if (isLinkLocalEnabled(intfName) == false)`
	`85`	`+ if ((isLinkLocalEnabled(intfName) == false) && (nlmsg_type != RTM_DELNEIGH))`
`86`	`86`	`{`
`87`	`87`	`return;`
`88`	`88`	`}`