Supports maximum keepalive limit

rmqtt.toml

@@ -79,12 +79,19 @@ listener.tcp.external.backlog = 1024
 listener.tcp.external.idle_timeout = "20s"
 #Whether anonymous login is allowed. Default: true
 listener.tcp.external.allow_anonymous = true
-#Minimum allowable keepalive value for mqtt connection,
-#less than this value will reject the connection, default: 0, unit: seconds
-listener.tcp.external.min_keepalive = 0
 #A value of zero indicates disabling the keep-alive feature, where the server
 #doesn't need to disconnect due to client inactivity, default: true
 listener.tcp.external.allow_zero_keepalive = true
+#Minimum allowable keepalive value for mqtt connection,
+#less than this value will reject the connection(MQTT V3),
+#less than this value will set keepalive to this value in CONNACK (MQTT V5),
+#default: 0, unit: seconds
+listener.tcp.external.min_keepalive = 0
+#Maximum allowable keepalive value for mqtt connection,
+#greater than this value will reject the connection(MQTT V3),
+#greater than this value will set keepalive to this value in CONNACK (MQTT V5),
+#default value: 65535, unit: seconds
+listener.tcp.external.max_keepalive = 65535
 # > 0.5, Keepalive * backoff * 2
 listener.tcp.external.keepalive_backoff = 0.75
 #Flight window size. The flight window is used to store the unanswered QoS 1 and QoS 2 messages

rmqtt/src/broker/default.rs

@@ -1187,13 +1187,14 @@ impl Fitter for DefaultFitter {
         if self.client.protocol() == MQTT_LEVEL_5 {
             if *keep_alive == 0 {
                 return if self.listen_cfg.allow_zero_keepalive {
-                    //*keep_alive = 10;
                     Ok(0)
                 } else {
                     Err(MqttError::from("Keepalive must be greater than 0"))
                 };
             } else if *keep_alive < self.listen_cfg.min_keepalive {
                 *keep_alive = self.listen_cfg.min_keepalive;
+            } else if *keep_alive > self.listen_cfg.max_keepalive {
+                *keep_alive = self.listen_cfg.max_keepalive;
             }
         } else if *keep_alive == 0 {
             return if self.listen_cfg.allow_zero_keepalive {
@@ -1203,9 +1204,14 @@ impl Fitter for DefaultFitter {
             };
         } else if *keep_alive < self.listen_cfg.min_keepalive {
             return Err(MqttError::from(format!(
-                "Keepalive is too small, cannot be less than {}",
+                "Keepalive is too small and cannot be less than {}",
                 self.listen_cfg.min_keepalive
             )));
+        } else if *keep_alive > self.listen_cfg.max_keepalive {
+            return Err(MqttError::from(format!(
+                "Keepalive is too large and cannot be greater than {}",
+                self.listen_cfg.max_keepalive
+            )));
         }
 
         if *keep_alive < 6 {

rmqtt/src/settings/listener.rs

@@ -164,11 +164,10 @@ pub struct ListenerInner {
     pub idle_timeout: Duration,
     #[serde(default = "ListenerInner::allow_anonymous_default")]
     pub allow_anonymous: bool,
-    #[serde(
-    default = "ListenerInner::min_keepalive_default",
-    //deserialize_with = "deserialize_duration"
-    )]
+    #[serde(default = "ListenerInner::min_keepalive_default")]
     pub min_keepalive: u16,
+    #[serde(default = "ListenerInner::max_keepalive_default")]
+    pub max_keepalive: u16,
     #[serde(default = "ListenerInner::allow_zero_keepalive_default")]
     pub allow_zero_keepalive: bool,
     #[serde(default = "ListenerInner::keepalive_backoff_default")]
@@ -251,6 +250,7 @@ impl Default for ListenerInner {
             idle_timeout: ListenerInner::idle_timeout_default(),
             allow_anonymous: ListenerInner::allow_anonymous_default(),
             min_keepalive: ListenerInner::min_keepalive_default(),
+            max_keepalive: ListenerInner::max_keepalive_default(),
             allow_zero_keepalive: ListenerInner::allow_zero_keepalive_default(),
             keepalive_backoff: ListenerInner::keepalive_backoff_default(),
             max_inflight: ListenerInner::max_inflight_default(),
@@ -324,6 +324,10 @@ impl ListenerInner {
         0
     }
     #[inline]
+    fn max_keepalive_default() -> u16 {
+        u16::MAX
+    }
+    #[inline]
     fn allow_zero_keepalive_default() -> bool {
         true
     }