test: ospf_bfd: Verify fast fail-over using BFD

test/case/ietf_routing/Readme.adoc

@@ -11,3 +11,5 @@ include::ospf_basic/Readme.adoc[]
 include::ospf_unnumbered_interface/Readme.adoc[]
 
 include::ospf_multiarea/Readme.adoc[]
+
+include::ospf_bfd/Readme.adoc[]

test/case/ietf_routing/ietf_routing.yaml

@@ -10,3 +10,6 @@
 
 - name: ospf_multiarea
   case: ospf_multiarea/test.py
+
+- name: ospf_bfd
+  case: ospf_bfd/test.py

test/case/ietf_routing/ospf_bfd/Readme.adoc

@@ -0,0 +1,35 @@
+=== OSPF BFD
+==== Description
+Verify that a router running OSPF, with Bidirectional Forwarding
+Detection (BFD) enabled, will detect link faults even when the
+physical layer is still operational.
+
+This can typically happen when one logical link, from OSPF's
+perspective, is made up of multiple physical links containing media
+converters without link fault forwarding.
+
+==== Topology
+ifdef::topdoc[]
+image::../../test/case/ietf_routing/ospf_bfd/topology.svg[OSPF BFD topology]
+endif::topdoc[]
+ifndef::topdoc[]
+ifdef::testgroup[]
+image::ospf_bfd/topology.svg[OSPF BFD topology]
+endif::testgroup[]
+ifndef::testgroup[]
+image::topology.svg[OSPF BFD topology]
+endif::testgroup[]
+endif::topdoc[]
+==== Test sequence
+. Set up topology and attach to target DUTs
+. Setup TPMR between R1fast and R2fast
+. Configure R1 and R2
+. Setup IP addresses and default routes on h1 and h2
+. Wait for R1 and R2 to peer
+. Verify connectivity from PC:src to PC:dst via fast link
+. Disable forwarding between R1fast and R2fast to trigger fail-over
+. Verify connectivity from PC:src to PC:dst via slow link
+
+
+<<<
+

test/case/ietf_routing/ospf_bfd/test.py

@@ -0,0 +1,183 @@
+#!/usr/bin/env python3
+
+"""
+OSPF BFD
+
+Verify that a router running OSPF, with Bidirectional Forwarding
+Detection (BFD) enabled, will detect link faults even when the
+physical layer is still operational.
+
+This can typically happen when one logical link, from OSPF's
+perspective, is made up of multiple physical links containing media
+converters without link fault forwarding.
+"""
+
+import time
+
+import infamy
+import infamy.route as route
+from infamy.netns import TPMR
+from infamy.util import until, parallel
+
+def config(target, params):
+    name = params["name"]
+    dif, fif, sif = \
+        params["link"]["data"], \
+        params["link"]["fast"], \
+        params["link"]["slow"]
+    rid, daddr, faddr, saddr = \
+        params["addr"]["rid"], \
+        params["addr"]["data"], \
+        params["addr"]["fast"], \
+        params["addr"]["slow"]
+
+    def ifconfig(name, addr, plen):
+        return {
+            "name": name,
+            "enabled": True,
+            "ipv4": {
+                "forwarding": True,
+                "address": [{
+                    "ip": addr,
+                    "prefix-length": plen,
+                }]}
+        }
+
+    target.put_config_dict("ietf-interfaces", {
+            "interfaces": {
+                "interface": [
+                    ifconfig("lo", rid, 32),
+
+                    ifconfig(dif, daddr, 24),
+                    ifconfig(fif, faddr, 30),
+                    ifconfig(sif, saddr, 30),
+                ]
+            }
+    })
+
+    target.put_config_dict("ietf-system", {
+        "system": {
+            "hostname": name,
+        }
+    })
+
+    target.put_config_dict("ietf-routing", {
+        "routing": {
+            "control-plane-protocols": {
+                "control-plane-protocol": [{
+                    "type": "infix-routing:ospfv2",
+                    "name": "default",
+                    "ospf": {
+                        "areas": {
+                            "area": [{
+                                "area-id": "0.0.0.0",
+                                "interfaces":
+                                {
+                                    "interface": [{
+                                        "bfd": {
+                                            "enabled": True
+                                        },
+                                        "name": fif,
+                                        "hello-interval": 1,
+                                        "dead-interval": 10,
+                                        "cost": 100,
+                                    },
+                                    {
+                                        "bfd": {
+                                            "enabled": True
+                                        },
+                                        "name": sif,
+                                        "hello-interval": 1,
+                                        "dead-interval": 10,
+                                        "cost": 200,
+                                    }, {
+                                        "name": dif,
+                                        "passive": True,
+                                    }]
+                                },
+                            }]
+                        }
+                    }
+                }]
+            }
+        }
+    })
+
+with infamy.Test() as test:
+    with test.step("Set up topology and attach to target DUTs"):
+        env = infamy.Env()
+        R1 = env.attach("R1", "mgmt")
+        R2 = env.attach("R2", "mgmt")
+
+    with test.step("Setup TPMR between R1fast and R2fast"):
+        breaker = TPMR(env.ltop.xlate("PC", "R1fast")[1],
+                       env.ltop.xlate("PC", "R2fast")[1]).start()
+
+    with test.step("Configure R1 and R2"):
+        r1cfg = {
+            "name": "R1",
+            "addr": {
+                "rid": "192.168.1.1",
+
+                "data": "192.168.10.1",
+                "fast": "192.168.100.1",
+                "slow": "192.168.200.1",
+            },
+            "link": {
+                "data": env.ltop.xlate("R1", "h1")[1],
+                "fast": env.ltop.xlate("R1", "fast")[1],
+                "slow": env.ltop.xlate("R1", "slow")[1],
+            }
+        }
+        r2cfg = {
+            "name": "R2",
+            "addr": {
+                "rid": "192.168.1.2",
+
+                "data": "192.168.20.1",
+                "fast": "192.168.100.2",
+                "slow": "192.168.200.2",
+            },
+            "link": {
+                "data": env.ltop.xlate("R2", "h2")[1],
+                "fast": env.ltop.xlate("R2", "fast")[1],
+                "slow": env.ltop.xlate("R2", "slow")[1],
+            }
+        }
+
+        parallel(config(R1, r1cfg), config(R2, r2cfg))
+
+    with test.step("Setup IP addresses and default routes on h1 and h2"):
+        _, h1 = env.ltop.xlate("PC", "h1")
+        _, h2 = env.ltop.xlate("PC", "h2")
+
+        h1net = infamy.IsolatedMacVlan(h1).start()
+        h1net.addip("192.168.10.2")
+        h1net.addroute("default", "192.168.10.1")
+
+        h2net = infamy.IsolatedMacVlan(h2).start()
+        h2net.addip("192.168.20.2")
+        h2net.addroute("default", "192.168.20.1")
+
+    with test.step("Wait for R1 and R2 to peer"):
+        print("Waiting for R1 and R2 to peer")
+        until(lambda: route.ipv4_route_exist(R1, "192.168.20.0/24", proto="ietf-ospf:ospfv2"), attempts=200)
+        until(lambda: route.ipv4_route_exist(R2, "192.168.10.0/24", proto="ietf-ospf:ospfv2"), attempts=200)
+
+    with test.step("Verify connectivity from PC:src to PC:dst via fast link"):
+        h1net.must_reach("192.168.20.2")
+        hops = [row[1] for row in h1net.traceroute("192.168.20.2")]
+        assert "192.168.100.2" in hops, f"Path to h2 ({repr(hops)}), does not use fast link"
+
+    with test.step("Disable forwarding between R1fast and R2fast to trigger fail-over"):
+        breaker.block()
+        print("Give BFD some time to detect the bad link, " +
+              "but not enough for the OSPF dead interval expire")
+        time.sleep(1)
+
+    with test.step("Verify connectivity from PC:src to PC:dst via slow link"):
+        h1net.must_reach("192.168.20.2")
+        hops = [row[1] for row in h1net.traceroute("192.168.20.2")]
+        assert "192.168.200.2" in hops, f"Path to h2 ({repr(hops)}), does not use slow link"
+
+    test.succeed()

test/case/ietf_routing/ospf_bfd/topology.dot

@@ -0,0 +1,39 @@
+graph "ospf-bfd" {
+	layout="neato";
+	overlap="false";
+	esep="+20";
+	size=10
+
+        node [shape=record, fontname="DejaVu Sans Mono, Book"];
+	edge [color="cornflowerblue", penwidth="2", fontname="DejaVu Serif, Book"];
+
+        R1 [
+	    label=" { { R1 | <slow> slow } | { <mgmt> mgmt | <h1> h1 | <fast> fast } }",
+	    pos="0,6!",
+
+	    kind="infix",
+	];
+	R2 [
+	    label="{ { <slow> slow | R2 } | { <fast> fast | <h2> h2 | <mgmt> mgmt  } }",
+	    pos="18,6!",
+
+	    kind="infix",
+	];
+
+	PC [
+	    label="{ { <R1mgmt> R1mgmt | <h1> h1 | <R1fast> R1fast | <R2fast> R2fast | <h2> h2 | <R2mgmt> R2mgmt } | PC }",
+	    pos="9,0!",
+	    kind="controller",
+	];
+
+	PC:R1mgmt -- R1:mgmt [kind=mgmt, color="lightgray"]
+        PC:R2mgmt -- R2:mgmt [kind=mgmt, color="lightgray"]
+
+	PC:h1 -- R1:h1
+	PC:h2 -- R2:h2
+
+	R1:fast -- PC:R1fast [color="lightgreen", taillabel="Cost: 100"]
+	R2:fast -- PC:R2fast [color="lightgreen"]
+
+	R1:slow -- R2:slow [color="crimson", taillabel="Cost: 200"]
+}