Merged PR 424: fix infini-ARP bug when pinging broadcast/network address

Related work items: #2661

src/primaite/simulator/system/services/arp/arp.py

@@ -138,6 +138,14 @@ class ARP(Service):
             target_ip_address
         )
         if outbound_network_interface:
+            # ensure we are not attempting to find the network address or broadcast address (not useable IPs)
+            if target_ip_address == outbound_network_interface.ip_network.network_address:
+                self.sys_log.info(f"Cannot send ARP request to a network address {str(target_ip_address)}")
+                return
+            if target_ip_address == outbound_network_interface.ip_network.broadcast_address:
+                self.sys_log.info(f"Cannot send ARP request to a broadcast address {str(target_ip_address)}")
+                return
+
             self.sys_log.info(f"Sending ARP request from NIC {outbound_network_interface} for ip {target_ip_address}")
             arp_packet = ARPPacket(
                 sender_ip_address=outbound_network_interface.ip_address,

tests/integration_tests/system/test_arp.py

@@ -0,0 +1,50 @@
+# © Crown-owned copyright 2024, Defence Science and Technology Laboratory UK
+from primaite.simulator.network.hardware.nodes.network.router import RouterARP
+from primaite.simulator.system.services.arp.arp import ARP
+from tests.integration_tests.network.test_routing import multi_hop_network
+
+
+def test_arp_from_host_to_default_gateway(multi_hop_network):
+    pc_a = multi_hop_network.get_node_by_hostname("pc_a")
+    router_1 = multi_hop_network.get_node_by_hostname("router_1")
+
+    pc_a_arp: ARP = pc_a.software_manager.arp
+
+    expected_result = router_1.network_interface[2].mac_address
+    actual_result = pc_a_arp.get_arp_cache_mac_address(router_1.network_interface[2].ip_address)
+
+    assert actual_result == expected_result
+
+
+def test_arp_from_router_to_router(multi_hop_network):
+    router_1 = multi_hop_network.get_node_by_hostname("router_1")
+    router_2 = multi_hop_network.get_node_by_hostname("router_2")
+
+    router_1_arp: RouterARP = router_1.software_manager.arp
+
+    expected_result = router_2.network_interface[1].mac_address
+    actual_result = router_1_arp.get_arp_cache_mac_address(router_2.network_interface[1].ip_address)
+
+    assert actual_result == expected_result
+
+
+def test_arp_fails_for_broadcast_address_between_routers(multi_hop_network):
+    router_1 = multi_hop_network.get_node_by_hostname("router_1")
+
+    router_1_arp: RouterARP = router_1.software_manager.arp
+
+    expected_result = None
+    actual_result = router_1_arp.get_arp_cache_mac_address(router_1.network_interface[1].ip_network.broadcast_address)
+
+    assert actual_result == expected_result
+
+
+def test_arp_fails_for_network_address_between_routers(multi_hop_network):
+    router_1 = multi_hop_network.get_node_by_hostname("router_1")
+
+    router_1_arp: RouterARP = router_1.software_manager.arp
+
+    expected_result = None
+    actual_result = router_1_arp.get_arp_cache_mac_address(router_1.network_interface[1].ip_network.network_address)
+
+    assert actual_result == expected_result