Add timer support

src/config_interface.cpp

@@ -116,8 +116,6 @@ void processRelayNotification(std::deque<swss::KeyOpFieldsValuesTuple> &entries,
     std::vector<std::string> servers;
     bool option_79_default = true;
     bool interface_id_default = false;
-    const int wait_timeout = 120;
-    int current_wait = 0;
 
     if (dual_tor_sock) {
         interface_id_default = true;
@@ -128,7 +126,6 @@ void processRelayNotification(std::deque<swss::KeyOpFieldsValuesTuple> &entries,
         std::string operation = kfvOp(entry);
         std::vector<swss::FieldValueTuple> fieldValues = kfvFieldsValues(entry);
         bool has_ipv6_address = false;
-        bool is_lla_ready = false;
 
         const std::string match_pattern = "VLAN_INTERFACE|" + vlan + "|*";
         auto keys = config_db->keys(match_pattern);
@@ -149,37 +146,13 @@ void processRelayNotification(std::deque<swss::KeyOpFieldsValuesTuple> &entries,
             continue;
         }
 
-        // Checke whether link local address is ready for Vlan, wait total 120s for all Vlans
-        do {
-            const std::string cmd = "ip -6 addr show " + vlan + " scope link 2> /dev/null";
-            std::array<char, 256> buffer;
-            std::string result;
-            std::unique_ptr<FILE, decltype(&pclose)> pipe(popen(cmd.c_str(), "r"), pclose);
-            if (pipe) {
-                while (fgets(buffer.data(), buffer.size(), pipe.get()) != nullptr) {
-                    result += buffer.data();
-                }
-                if (!result.empty()) {
-                    is_lla_ready = true;
-                    break;
-                }
-            }
-            syslog(LOG_WARNING, "Cannot get link local address for %s, wait 5s", vlan.c_str());
-            sleep(5);
-            current_wait += 5;
-        } while (current_wait <= wait_timeout);
-
-        if (!is_lla_ready) {
-            syslog(LOG_WARNING, "%s doesn't have IPv6 link local address, skip it", vlan.c_str());
-            continue;
-        }
-
         relay_config intf;
         intf.is_option_79 = option_79_default;
         intf.is_interface_id = interface_id_default;
         intf.interface = vlan;
         intf.mux_key = "";
         intf.state_db = nullptr;
+        intf.is_lla_ready = false;
         for (auto &fieldValue: fieldValues) {
             std::string f = fvField(fieldValue);
             std::string v = fvValue(fieldValue);
@@ -208,3 +181,28 @@ void processRelayNotification(std::deque<swss::KeyOpFieldsValuesTuple> &entries,
         vlans[vlan] = intf;
     }
 }
+
+/**
+ * @code                    bool check_is_lla_ready(std::string vlan)
+ * 
+ * @brief                   Check whether link local address appear in vlan interface
+ *
+ * @param vlan              string of vlan name
+ *
+ * @return                  bool value indicates whether lla ready
+ */
+bool check_is_lla_ready(std::string vlan) {
+    const std::string cmd = "ip -6 addr show " + vlan + " scope link 2> /dev/null";
+    std::array<char, 256> buffer;
+    std::string result;
+    std::unique_ptr<FILE, decltype(&pclose)> pipe(popen(cmd.c_str(), "r"), pclose);
+    if (pipe) {
+        while (fgets(buffer.data(), buffer.size(), pipe.get()) != nullptr) {
+            result += buffer.data();
+        }
+        if (!result.empty()) {
+            return true;
+        }
+    }
+    return false;
+}

src/config_interface.h

@@ -70,3 +70,14 @@ void handleRelayNotification(swss::SubscriberStateTable &ipHelpersTable, std::un
  */
 void processRelayNotification(std::deque<swss::KeyOpFieldsValuesTuple> &entries, std::unordered_map<std::string, relay_config> &vlans,
                               std::shared_ptr<swss::DBConnector> config_db);
+
+/**
+ * @code                    bool check_is_lla_ready(std::string vlan)
+ * 
+ * @brief                   Check whether link local address appear in vlan interface
+ *
+ * @param vlan              string of vlan name
+ *
+ * @return                  bool value indicates whether lla ready
+ */
+bool check_is_lla_ready(std::string vlan);

src/relay.cpp

@@ -1087,6 +1087,10 @@ void server_callback_dualtor(evutil_socket_t fd, short event, void *arg) {
             syslog(LOG_WARNING, "Invalid DHCPv6 header content on loopback socket, packet will be dropped\n");
             continue;
         }
+        if (!config->is_lla_ready) {
+            syslog(LOG_WARNING, "Link local address for %s is not ready, packet will be dropped\n", config->interface.c_str());
+            continue;
+        }
         auto loopback_str = std::string(loopback);
         increase_counter(config->state_db, loopback_str, msg_type);
         relay_relay_reply(server_recv_buffer, buffer_sz, config);
@@ -1278,7 +1282,87 @@ void loop_relay(std::unordered_map<std::string, relay_config> &vlans) {
         }
     }
 
+    struct event *timer_event;
+    struct timeval tv;
+    auto timer_args = new std::tuple<
+        std::unordered_map<std::string, struct relay_config> &,
+        std::shared_ptr<swss::DBConnector>,
+        std::shared_ptr<swss::DBConnector>,
+        std::shared_ptr<swss::Table>,
+        std::vector<int>,
+        int,
+        int,
+        struct event *
+    >(vlans, config_db, state_db, mStateDbMuxTablePtr, sockets, lo_sock, lo_sock, nullptr);
+    timer_event = event_new(base, -1, EV_PERSIST, lla_check_callback, timer_args);
+    std::get<7>(*timer_args) = timer_event;
+    evutil_timerclear(&tv);
+    tv.tv_sec = 5;
+    event_add(timer_event, &tv);
+
+    if(signal_init() == 0 && signal_start() == 0) {
+        shutdown_relay();
+        for(std::size_t i = 0; i < sockets.size(); i++) {
+            close(sockets.at(i));
+        }
+    }
+}
+
+/**
+ * @code shutdown_relay();
+ *
+ * @brief free signals and terminate threads
+ */
+void shutdown_relay() {
+    event_del(ev_sigint);
+    event_del(ev_sigterm);
+    event_free(ev_sigint);
+    event_free(ev_sigterm);
+    event_base_free(base);
+    deinitialize_swss();
+}
+
+/**
+ * @code                void lla_check_callback(evutil_socket_t fd, short event, void *arg);
+ * 
+ * @brief               callback for libevent timer to check whether lla is ready for vlan
+ *
+ * @param fd            libevent socket
+ * @param event         libevent triggered event  
+ * @param arg           callback argument provided by user
+ *
+ * @return              none
+ */
+void lla_check_callback(evutil_socket_t fd, short event, void *arg) {
+    syslog(LOG_WARNING, "Timer event");
+    auto args = reinterpret_cast<std::tuple<
+        std::unordered_map<std::string, struct relay_config> &,
+        std::shared_ptr<swss::DBConnector>,
+        std::shared_ptr<swss::DBConnector>,
+        std::shared_ptr<swss::Table>,
+        std::vector<int>,
+        int,
+        int,
+        struct event *
+    > *>(arg);
+    auto vlans = std::get<0>(*args);
+    auto config_db = std::get<1>(*args);
+    auto state_db = std::get<2>(*args);
+    auto mStateDbMuxTablePtr = std::get<3>(*args);
+    auto sockets = std::get<4>(*args);
+    auto lo_sock = std::get<5>(*args);
+    auto filter = std::get<6>(*args);
+    auto timer_event = std::get<7>(*args);
+
     for(auto &vlan : vlans) {
+        if (vlan.second.is_lla_ready) {
+            continue;
+        }
+        if (!check_is_lla_ready(vlan.first)) {
+            syslog(LOG_WARNING, "Link local address for %s is not ready\n", vlan.first.c_str());
+            continue;
+        }
+        vlan.second.is_lla_ready = true;
         int gua_sock = 0;
         int lla_sock = 0;
         vlan.second.config_db = config_db;
@@ -1312,25 +1396,5 @@ void loop_relay(std::unordered_map<std::string, relay_config> &vlans) {
             exit(EXIT_FAILURE);
         }
     }
-
-    if(signal_init() == 0 && signal_start() == 0) {
-        shutdown_relay();
-        for(std::size_t i = 0; i < sockets.size(); i++) {
-            close(sockets.at(i));
-        }
-    }
 }
 
-/**
- * @code shutdown_relay();
- *
- * @brief free signals and terminate threads
- */
-void shutdown_relay() {
-    event_del(ev_sigint);
-    event_del(ev_sigterm);
-    event_free(ev_sigint);
-    event_free(ev_sigterm);
-    event_base_free(base);
-    deinitialize_swss();
-}

src/relay.h

@@ -76,6 +76,7 @@ struct relay_config {
     bool is_interface_id;
     std::shared_ptr<swss::Table> mux_table;
     std::shared_ptr<swss::DBConnector> config_db;
+    bool is_lla_ready;
 };
 
 /* DHCPv6 messages and options */
@@ -474,3 +475,15 @@ void client_packet_handler(uint8_t *buffer, ssize_t length, struct relay_config
  */
 void server_callback(evutil_socket_t fd, short event, void *arg);
 
+/**
+ * @code                void lla_check_callback(evutil_socket_t fd, short event, void *arg);
+ * 
+ * @brief               callback for libevent timer to check whether lla is ready for vlan
+ *
+ * @param fd            libevent socket
+ * @param event         libevent triggered event  
+ * @param arg           callback argument provided by user
+ *
+ * @return              none
+ */
+void lla_check_callback(evutil_socket_t fd, short event, void *arg);

test/mock_config_interface.cpp

@@ -2,6 +2,7 @@
 
 using namespace ::testing;
 
+MOCK_GLOBAL_FUNC0(get_dhcp, void(void));
 TEST(configInterface, initialize_swss) {
   std::shared_ptr<swss::DBConnector> config_db = std::make_shared<swss::DBConnector> ("CONFIG_DB", 0);
   config_db->hset("DHCP_RELAY|Vlan1000", "dhcpv6_servers@", "fc02:2000::1,fc02:2000::2,fc02:2000::3,fc02:2000::4");