Refactoring to support DHCP

Cargo.lock

@@ -427,7 +427,7 @@ dependencies = [
 [[package]]
 name = "minimq"
 version = "0.2.0"
-source = "git+https://github.com/quartiq/minimq.git?branch=rs/issue-40/copyable-properties#c95c758b620ee98752852bb643df8557a7200f3f"
+source = "git+https://github.com/quartiq/minimq.git?rev=b3f364d#b3f364d55dea35da6572f78ddb91c87bfbb453bf"
 dependencies = [
  "bit_field",
  "embedded-nal",
@@ -690,7 +690,7 @@ dependencies = [
 [[package]]
 name = "serde-json-core"
 version = "0.2.0"
-source = "git+https://github.com/quartiq/serde-json-core.git?branch=feature/dependency-update#a304506a1efb4a90a6ef3faf71ec3ef5f8433fb4"
+source = "git+https://github.com/rust-embedded-community/serde-json-core.git?rev=da460d1#da460d123e217f0e822a3977eb2170ed5d279d5e"
 dependencies = [
  "heapless 0.6.1",
  "ryu",

Cargo.toml

@@ -64,11 +64,11 @@ rev = "8468f11"
 
 [dependencies.minimq]
 git = "https://github.com/quartiq/minimq.git"
-branch = "rs/issue-40/copyable-properties"
+rev = "b3f364d"
 
 [patch.crates-io.serde-json-core]
-git = "https://github.com/quartiq/serde-json-core.git"
-branch = "feature/dependency-update"
+git = "https://github.com/rust-embedded-community/serde-json-core.git"
+rev = "da460d1"
 
 [features]
 semihosting = ["panic-semihosting", "cortex-m-log/semihosting"]

src/net/mqtt_interface.rs

@@ -22,7 +22,7 @@ where
     phy: EthernetPhy,
     network_was_reset: bool,
     subscribed: bool,
-    id: String<consts::U32>,
+    id: String<consts::U64>,
 }
 
 impl<S> MqttInterface<S>
@@ -99,9 +99,24 @@ where
             self.network_was_reset = false;
         }
 
+        let mqtt_connected = match self.mqtt.borrow_mut().is_connected() {
+            Ok(connected) => connected,
+            Err(minimq::Error::Network(
+                smoltcp_nal::NetworkError::NoIpAddress,
+            )) => false,
+            Err(minimq::Error::Network(error)) => {
+                log::info!("Unexpected network error: {:?}", error);
+                false
+            }
+            Err(error) => {
+                log::warn!("Unexpected MQTT error: {:?}", error);
+                false
+            }
+        };
+
         // If we're no longer subscribed to the settings topic, but we are connected to the broker,
         // resubscribe.
-        if !self.subscribed && self.mqtt.borrow_mut().is_connected().unwrap() {
+        if !self.subscribed && mqtt_connected {
             let mut settings_topic: String<consts::U128> = String::new();
             write!(&mut settings_topic, "{}/settings/#", self.id.as_str())
                 .unwrap();