Add offloading again (#3062)

microk8s-resources/wrappers/apiservice-kicker

@@ -24,11 +24,30 @@ fi
 restart_attempt=0
 installed_registry_help=0
 nic_name="vxlan.calico"
+# This flag is used so we do not perform the offload check every time.
+# This check is shown to cause issues on rpi, see
+# https://bugs.launchpad.net/ubuntu/+source/linux-raspi/+bug/1955174
+installed_offloading=0
 
 is_nic_available() {
   ip a show dev $nic_name > /dev/null 2>&1
 }
 
+deactivate_offloading() {
+  ethtool --offload $nic_name rx off tx off
+}
+
+check_offloading() {
+  # Return an error if at least one offload is enabled (rx or tx)
+  if ethtool --show-offload $nic_name 2>&1 | grep -E '^.x-checksumming:' | grep -q  ': on'; then
+    return 1
+  else
+    # if offloading is already disabled update the respective flag.
+    installed_offloading=1
+    return 0
+  fi
+}
+
 while true
 do
     if [ $restart_attempt -ge 5 ]
@@ -121,6 +140,22 @@ do
       fi
     fi
 
+    if ! [ -e "${SNAP_DATA}/var/lock/skip-offloading" ] &&
+      [ $installed_offloading -eq 0 ] &&
+      [ -e "${SNAP_DATA}/var/lock/cni-loaded" ] &&
+      is_nic_available &&
+      ! check_offloading
+    then
+      echo "Network interface $nic_name found! Disabling offloading on it..."
+      deactivate_offloading
+      sleep 2
+      if check_offloading; then
+        echo "Offloading successfully disabled on interface $nic_name"
+      else
+        echo "Offloading has not been disabled correctly on interface $nic_name. Please check what happened"
+      fi
+    fi
+
     # If no local-registry-hosting documentation has been installed,
     # install a help guide that points to the microk8s registry docs.
     #