daemon: adjustments to support global configurable mtu values for node interfaces and bridges

daemon/core/emulator/data.py

@@ -142,6 +142,7 @@ class InterfaceData:
     ip4_mask: int = None
     ip6: str = None
     ip6_mask: int = None
+    mtu: int = None
 
     def get_ips(self) -> List[str]:
         """

daemon/core/emulator/distributed.py

@@ -187,6 +187,7 @@ class DistributedController:
 
         :return: nothing
         """
+        mtu = self.session.options.get_config_int("mtu")
         for node_id in self.session.nodes:
             node = self.session.nodes[node_id]
             if not isinstance(node, CoreNetwork):
@@ -195,17 +196,17 @@ class DistributedController:
                 continue
             for name in self.servers:
                 server = self.servers[name]
-                self.create_gre_tunnel(node, server)
+                self.create_gre_tunnel(node, server, mtu)
 
     def create_gre_tunnel(
-        self, node: CoreNetwork, server: DistributedServer
+        self, node: CoreNetwork, server: DistributedServer, mtu: int
     ) -> Tuple[GreTap, GreTap]:
         """
         Create gre tunnel using a pair of gre taps between the local and remote server.
 
         :param node: node to create gre tunnel for
-        :param server: server to create
-            tunnel for
+        :param server: server to create tunnel for
+        :param mtu: mtu for gre taps
         :return: local and remote gre taps created for tunnel
         """
         host = server.host
@@ -215,14 +216,14 @@ class DistributedController:
             return tunnel
         # local to server
         logger.info("local tunnel node(%s) to remote(%s) key(%s)", node.name, host, key)
-        local_tap = GreTap(session=self.session, remoteip=host, key=key)
+        local_tap = GreTap(session=self.session, remoteip=host, key=key, mtu=mtu)
         local_tap.net_client.set_iface_master(node.brname, local_tap.localname)
         # server to local
         logger.info(
             "remote tunnel node(%s) to local(%s) key(%s)", node.name, self.address, key
         )
         remote_tap = GreTap(
-            session=self.session, remoteip=self.address, key=key, server=server
+            session=self.session, remoteip=self.address, key=key, server=server, mtu=mtu
         )
         remote_tap.net_client.set_iface_master(node.brname, remote_tap.localname)
         # save tunnels for shutdown

daemon/core/emulator/session.py

@@ -46,7 +46,7 @@ from core.location.geo import GeoLocation
 from core.location.mobility import BasicRangeModel, MobilityManager
 from core.nodes.base import CoreNetworkBase, CoreNode, CoreNodeBase, NodeBase
 from core.nodes.docker import DockerNode
-from core.nodes.interface import CoreInterface
+from core.nodes.interface import DEFAULT_MTU, CoreInterface
 from core.nodes.lxd import LxcNode
 from core.nodes.network import (
     CtrlNet,
@@ -253,7 +253,12 @@ class Session:
         node2 = self.get_node(node2_id, NodeBase)
         iface1 = None
         iface2 = None
-
+        # set mtu
+        mtu = self.options.get_config_int("mtu") or DEFAULT_MTU
+        if iface1_data:
+            iface1_data.mtu = mtu
+        if iface2_data:
+            iface2_data.mtu = mtu
         # wireless link
         if link_type == LinkTypes.WIRELESS:
             if isinstance(node1, CoreNodeBase) and isinstance(node2, CoreNodeBase):
@@ -567,12 +572,18 @@ class Session:
                 service_class = self.service_manager.get_service(name)
                 node.add_config_service(service_class)
 
+        # set network mtu, if configured
+        mtu = self.options.get_config_int("mtu")
+        if isinstance(node, CoreNetworkBase) and mtu > 0:
+            node.mtu = mtu
+
         # ensure default emane configuration
         if isinstance(node, EmaneNet) and options.emane:
             model_class = self.emane.get_model(options.emane)
             node.model = model_class(self, node.id)
             if self.state == EventTypes.RUNTIME_STATE:
                 self.emane.add_node(node)
+
         # set default wlan config if needed
         if isinstance(node, WlanNode):
             self.mobility.set_model_config(_id, BasicRangeModel.name)

daemon/core/emulator/sessionconfig.py

@@ -40,6 +40,7 @@ class SessionConfig(ConfigurableManager, ConfigurableOptions):
             id="link_interval", default="1", label="EMANE Link Check Interval (sec)"
         ),
         ConfigInt(id="link_timeout", default="4", label="EMANE Link Timeout (sec)"),
+        ConfigInt(id="mtu", default="0", label="MTU for All Devices"),
     ]
     config_type: RegisterTlvs = RegisterTlvs.UTILITY