test: new test, verify dhcp option 3 (router)

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

test/case/infix_dhcp/all.yaml

@@ -1,2 +1,3 @@
 ---
 - case: dhcp_basic.py
+- case: dhcp_router.py

test/case/infix_dhcp/dhcp_router.py

@@ -0,0 +1,36 @@
+#!/usr/bin/env python3
+# Verify DHCP option 3 (router)
+
+import time
+import infamy, infamy.dhcp
+import infamy.iface as iface
+import infamy.route as route
+from infamy.util import until
+
+with infamy.Test() as test:
+    ROUTER  = '192.168.0.254'
+    with test.step("Initialize"):
+        env = infamy.Env(infamy.std_topology("1x2"))
+        target = env.attach("target", "mgmt")
+        _, host = env.ltop.xlate("host", "data")
+
+    with infamy.IsolatedMacVlan(host) as netns:
+        netns.addip("192.168.0.1")
+        with infamy.dhcp.Server(netns, router=ROUTER):
+            _, port = env.ltop.xlate("target", "data")
+            config = {
+                "dhcp-client": {
+                    "client-if": [{
+                        "if-name": f"{port}",
+                        "option": [
+                            { "name": "router" }
+                        ]
+                    }]
+                }
+            }
+            target.put_config_dict("infix-dhcp-client", config)
+
+            with test.step(f"Wait for client to set up default route via {ROUTER}"):
+                until(lambda: route.ipv4_route_exist(target, "0.0.0.0/0", ROUTER))
+
+    test.succeed()