feat(modbus-tcp):support backup ip

include/neuron/connection/neu_connection.h

@@ -301,4 +301,6 @@ int neu_conn_tcp_server_wait_msg(neu_conn_t *conn, int fd, void *context,
 int is_ipv4(const char *ip);
 int is_ipv6(const char *ip);
 
+bool neu_conn_is_connected(neu_conn_t *conn);
+
 #endif

plugins/modbus/modbus-tcp.json

@@ -257,5 +257,49 @@
 			"min": 1000,
 			"max": 65535
 		}
+	},
+	"backup": {
+		"name": "Enable Backup",
+		"name_zh": "启用主备切换",
+		"attribute": "required",
+		"type": "map",
+		"default": 0,
+		"valid": {
+			"map": [
+				{
+					"key": "False",
+					"value": 0
+				},
+				{
+					"key": "True",
+					"value": 1
+				}
+			]
+		}
+	},
+	"backup_host": {
+		"name": "Backup IP Address",
+		"name_zh": "备用 IP 地址",
+		"attribute": "required",
+		"type": "string",
+		"condition": {
+			"field": "backup",
+			"value": 1
+		}		
+	},
+	"backup_port": {
+		"name": "Backup Port",
+		"name_zh": "备用端口号",
+		"attribute": "required",
+		"type": "int",
+		"default": 502,
+		"valid": {
+			"min": 1,
+			"max": 65535
+		},
+		"condition": {
+			"field": "backup",
+			"value": 1
+		}	
 	}
 }

plugins/modbus/modbus_req.c

@@ -119,6 +119,23 @@ int modbus_send_msg(void *ctx, uint16_t n_byte, uint8_t *bytes)
         ret = neu_conn_tcp_server_send(plugin->conn, plugin->client_fd, bytes,
                                        n_byte);
     } else {
+        if (plugin->backup && neu_conn_is_connected(plugin->conn) == false) {
+            if (plugin->current_backup == false && plugin->first_attempt_done) {
+                plog_notice(plugin, "switch to backup ip:port %s:%hu",
+                            plugin->param_backup.params.tcp_client.ip,
+                            plugin->param_backup.params.tcp_client.port);
+                plugin->current_backup = true;
+                plugin->conn =
+                    neu_conn_reconfig(plugin->conn, &plugin->param_backup);
+            } else {
+                plog_notice(plugin, "switch to original ip:port %s:%hu",
+                            plugin->param.params.tcp_client.ip,
+                            plugin->param.params.tcp_client.port);
+                plugin->current_backup = false;
+                plugin->conn = neu_conn_reconfig(plugin->conn, &plugin->param);
+                plugin->first_attempt_done = true;
+            }
+        }
         ret = neu_conn_send(plugin->conn, bytes, n_byte);
     }
 

plugins/modbus/modbus_req.h

@@ -49,6 +49,12 @@ struct neu_plugin {
     bool     degradation;
     uint16_t degrade_cycle;
     uint16_t degrade_time;
+
+    bool             backup;
+    bool             current_backup;
+    bool             first_attempt_done;
+    neu_conn_param_t param;
+    neu_conn_param_t param_backup;
 };
 
 void modbus_conn_connected(void *data, int fd);

plugins/modbus/modbus_tcp.c

@@ -125,6 +125,13 @@ static int driver_uninit(neu_plugin_t *plugin)
         modbus_stack_destroy(plugin->stack);
     }
 
+    if (plugin->param.params.tcp_client.ip != NULL) {
+        free(plugin->param.params.tcp_client.ip);
+    }
+    if (plugin->param_backup.params.tcp_client.ip != NULL) {
+        free(plugin->param_backup.params.tcp_client.ip);
+    }
+
     neu_event_close(plugin->events);
 
     plog_notice(plugin, "%s uninit success", plugin->common.name);
@@ -175,6 +182,13 @@ static int driver_config(neu_plugin_t *plugin, const char *config)
     neu_json_elem_t address_base = { .name = "address_base",
                                      .t    = NEU_JSON_INT };
 
+    neu_json_elem_t  backup      = { .name = "backup", .t = NEU_JSON_INT };
+    neu_json_elem_t  backup_ip   = { .name      = "backup_host",
+                                  .t         = NEU_JSON_STR,
+                                  .v.val_str = NULL };
+    neu_json_elem_t  backup_port = { .name = "backup_port", .t = NEU_JSON_INT };
+    neu_conn_param_t param_backup = { 0 };
+
     ret = neu_parse_param((char *) config, &err_param, 5, &port, &host, &mode,
                           &timeout, &interval);
 
@@ -229,7 +243,18 @@ static int driver_config(neu_plugin_t *plugin, const char *config)
         address_base.v.val_int = base_1;
     }
 
+    ret = neu_parse_param((char *) config, &err_param, 3, &backup, &backup_ip,
+                          &backup_port);
+    if (ret != 0) {
+        free(err_param);
+        if (backup_ip.v.val_str != NULL) {
+            free(backup_ip.v.val_str);
+        }
+        backup.v.val_int = 0;
+    }
+
     param.log              = plugin->common.log;
+    param_backup.log       = plugin->common.log;
     plugin->interval       = interval.v.val_int;
     plugin->max_retries    = max_retries.v.val_int;
     plugin->retry_interval = retry_interval.v.val_int;
@@ -249,15 +274,27 @@ static int driver_config(neu_plugin_t *plugin, const char *config)
         param.params.tcp_server.timeout      = timeout.v.val_int;
         param.params.tcp_server.max_link     = 1;
         plugin->is_server                    = true;
+        backup.v.val_int                     = 0;
     }
     if (mode.v.val_int == 0) {
+        plugin->is_server               = false;
         param.type                      = NEU_CONN_TCP_CLIENT;
         param.params.tcp_client.ip      = host.v.val_str;
         param.params.tcp_client.port    = port.v.val_int;
         param.params.tcp_client.timeout = timeout.v.val_int;
-        plugin->is_server               = false;
+
+        param_backup.type = NEU_CONN_TCP_CLIENT;
+        if (backup_ip.v.val_str != NULL) {
+            param_backup.params.tcp_client.ip = backup_ip.v.val_str;
+        }
+        param_backup.params.tcp_client.port    = backup_port.v.val_int;
+        param_backup.params.tcp_client.timeout = timeout.v.val_int;
     }
 
+    plugin->backup       = backup.v.val_int;
+    plugin->param        = param;
+    plugin->param_backup = param_backup;
+
     plog_notice(plugin,
                 "config: host: %s, port: %" PRId64 ", mode: %" PRId64 "",
                 host.v.val_str, port.v.val_int, mode.v.val_int);
@@ -271,7 +308,6 @@ static int driver_config(neu_plugin_t *plugin, const char *config)
                          modbus_conn_disconnected);
     }
 
-    free(host.v.val_str);
     return 0;
 }
 

src/connection/connection.c

@@ -1425,4 +1425,9 @@ int is_ipv6(const char *ip)
 {
     struct sockaddr_in6 sa;
     return inet_pton(AF_INET6, ip, &(sa.sin6_addr)) != 0;
+}
+
+bool neu_conn_is_connected(neu_conn_t *conn)
+{
+    return conn->is_connected;
 }

tests/ft/driver/test_modbus.py

@@ -8,9 +8,11 @@
 import neuron.config as config
 from neuron.common import *
 
-tcp_port = random_port()
-rtu_port = random_port()
-otel_port = random_port()
+tcp_port        = random_port()
+rtu_port        = tcp_port + 1
+otel_port       = tcp_port + 2
+tcp_port_2      = tcp_port + 3
+backup_tcp_port = tcp_port + 4
 
 
 def start_socat():
@@ -1703,4 +1705,26 @@ def test_set_modbus_start_base(self, param):
         assert 1 == api.read_tag(
             node=param[0], group='group', tag=coil_bit_2[0]['name'])
         assert 0 == api.read_tag(
-            node=param[0], group='group', tag=coil_bit_3[0]['name'])
+            node=param[0], group='group', tag=coil_bit_3[0]['name'])
+
+    @description(given="configed modbus node with backup ip&port and start corresponding sinulators", 
+                 when="stop the original simulator",
+                 then="success to read tags from backup simulator")
+    def test_modbus_backup(self, param):        
+        if param[0] == 'modbus-tcp':
+            p_1 = process.start_simulator(['./modbus_simulator', 'tcp', f'{tcp_port_2}', 'ip_v4'])
+            p_2 = process.start_simulator(['./modbus_simulator', 'tcp', f'{backup_tcp_port}', 'ip_v4'])
+
+            api.modbus_tcp_node_setting(node=param[0], port=tcp_port_2)
+            time.sleep(0.3)
+            api.write_tag(node=param[0], group='group', tag=hold_int16[0]['name'], value=17)
+            time.sleep(0.3)
+            assert 17 == api.read_tag(node=param[0], group='group', tag=hold_int16[0]['name'])
+
+            api.modbus_tcp_node_setting_backup(node=param[0], port=tcp_port, backup_port=backup_tcp_port)
+            process.stop_simulator(p_1)
+            time.sleep(3)
+            assert 0 == api.read_tag(node=param[0], group='group', tag=hold_int16[0]['name'])
+            process.stop_simulator(p_2)
+        else:
+            pytest.skip()

tests/ft/neuron/api.py

@@ -378,6 +378,10 @@ def modbus_rtu_node_setting_base(node, port=502, connection_mode=0, transport_mo
                                     "max_retries": max_retries, "retry_interval": retry_interval, "link": link, "device": device, "stop": stop,
                                     "parity": parity, "baud": baud, "data": data, "address_base": base})
 
+def modbus_tcp_node_setting_backup(node, port, backup_port, connection_mode=0, transport_mode=0, interval=0, host='127.0.0.1', timeout=3000, max_retries=2, retry_interval=1):
+    return node_setting(node, json={"connection_mode": connection_mode, "transport_mode": transport_mode, "interval": interval,
+                                    "host": host, "port": port, "timeout": timeout, "max_retries": max_retries, "retry_interval": retry_interval, "backup": 1, "backup_host": "127.0.0.1", "backup_port": backup_port})
+
 
 def mqtt_node_setting(node, client_id="neuron_aBcDeF", host="broker.emqx.io", port=1883):
     return node_setting(node, json={"client-id": client_id, "qos": 0, "format": 0,

tests/ft/neuron/common.py

@@ -29,7 +29,7 @@ def wrapper(*args, **kwargs):
 
 
 def random_port():
-    return random.randint(30000, 65535)
+    return random.randint(30000, 65530)
 
 
 def compare_float(v1, v2, delta=0.001):