test: new test, verify dhcp option 121 is preferred over option 3

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

test/case/infix_dhcp/all.yaml

@@ -1,3 +1,4 @@
 ---
 - case: dhcp_basic.py
 - case: dhcp_router.py
+- case: dhcp_routes.py

test/case/infix_dhcp/dhcp_routes.py

@@ -0,0 +1,42 @@
+#!/usr/bin/env python3
+# Verify DHCP option 121 (staticroutes) is used over option 3
+
+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:
+    PREFIX  = '10.0.0.0/24'
+    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, prefix=PREFIX, router=ROUTER):
+            _, port = env.ltop.xlate("target", "data")
+            config = {
+                "dhcp-client": {
+                    "client-if": [{
+                        "if-name": f"{port}",
+                        "option": [
+                            { "name": "router" },
+                            { "name": "staticroutes" }
+                        ]
+                    }]
+                }
+            }
+            target.put_config_dict("infix-dhcp-client", config)
+
+            with test.step(f"Verify client sets up correct route via {ROUTER}"):
+                # Wait for client to set the classless static route, option 121
+                until(lambda: route.ipv4_route_exist(target, PREFIX, ROUTER))
+                # Ensure client did *not* use option 3 (option 121 takes precedence)
+                if route.ipv4_route_exist(target, "0.0.0.0/0", ROUTER):
+                    test.fail()
+
+    test.succeed()

test/infamy/dhcp.py

@@ -7,10 +7,10 @@ class Server:
     config_file = '/tmp/udhcpd.conf'
     leases_file = '/tmp/udhcpd.leases'
 
-    def __init__(self, netns, start='192.168.0.100', end='192.168.0.110', netmask='255.255.255.0', ip=None, router=None):
+    def __init__(self, netns, start='192.168.0.100', end='192.168.0.110', netmask='255.255.255.0', ip=None, router=None, prefix=None):
         self.process = None
         self.netns = netns
-        self._create_files(start, end, netmask, ip, router)
+        self._create_files(start, end, netmask, ip, router, prefix)
 
     def __del__(self):
         print(self.config_file)
@@ -23,7 +23,7 @@ class Server:
     def __exit__(self, _, __, ___):
         self.stop()
 
-    def _create_files(self, start, end, netmask, ip, router):
+    def _create_files(self, start, end, netmask, ip, router, prefix):
         f = open(self.leases_file, "w")
         f.close()
 
@@ -42,6 +42,8 @@ option lease 864000
 ''')
             if router:
                 f.write(f"option router {router}\n")
+            if prefix and router:
+                f.write(f"option staticroutes {prefix} {router}\n")
 
     def get_pid(self):
         return self.process.pid