feat(ns-plug): added custom MTU support (#1311)

Author: Tbaile

packages/ns-plug/README.md

@@ -53,6 +53,17 @@ uci commit rsyslog
 rm -f /usr/share/ns-plug/client.conf
 ```
 
+### MTU management
+
+In some cases the VPN connection may not work properly due to MTU issues.
+You can custom set the MTU values by:
+```
+uci set ns-plug.config.tun_mtu=<value>
+uci set ns-plug.config.mssfix=<value>
+uci commit ns-plug
+reload_config
+```
+
 ## Machine registration
 
 To register a machine:

packages/ns-plug/files/config

@@ -7,3 +7,5 @@ config main 'config'
     option backup_url 'https://backupd.nethesis.it'
     option repository_url 'https://updates.nethsecurity.nethserver.org'
     option channel ''
+    option tun_mtu ''
+    option mssfix ''

packages/ns-plug/files/ns-plug

@@ -136,6 +136,15 @@ auth-nocache
 verb 3
 EOF
 
+tun_mtu="$(uci -q get ${UCI_CONF}.config.tun_mtu)"
+mssfix="$(uci -q get ${UCI_CONF}.config.mssfix)"
+if [ -n "${tun_mtu}" ] && [ -n "${mssfix}" ]; then
+    echo "tun-mtu ${tun_mtu}" >> ${CONFIG_FILE}
+    echo "mssfix ${mssfix}" >> ${CONFIG_FILE}
+else
+    echo "mtu-test" >> ${CONFIG_FILE}
+fi
+
 # Configure rsyslog to send to promtail
 uci set rsyslog.promtail=forwarder
 uci set rsyslog.promtail.source=*.*

packages/ns-plug/files/ns-plug.init

@@ -32,3 +32,9 @@ service_triggers()
 {
 		procd_add_reload_trigger "ns-plug"
 }
+
+reload_service()
+{
+        stop
+        start
+}