ospf6d: implement Type-7 default routes for NSSA areas

Add the "default-information-originate" option to the "area X nssa"
command. That option allows the origination of Type-7 default routes
on NSSA ABRs and ASBRs.

Signed-off-by: Renato Westphal <renato@opensourcerouting.org>

1 files changed, 44 insertions, 0 deletions

diff --git a/tests/topotests/ospf6_topo2/test_ospf6_topo2.py b/tests/topotests/ospf6_topo2/test_ospf6_topo2.py
index 997058f926..303bcd014d 100644
--- a/tests/topotests/ospf6_topo2/test_ospf6_topo2.py
+++ b/tests/topotests/ospf6_topo2/test_ospf6_topo2.py
@@ -431,6 +431,50 @@ def test_nssa_no_summary():
     assert result is None, assertmsg
 
 
+def test_nssa_default_originate():
+    """
+    Test the following:
+    * A type-7 default route should be originated into the NSSA area
+      when the default-information-originate option is configured;
+    * Once the default-information-originate option is unconfigured, the
+      previously originated Type-7 default route should be removed.
+    """
+    tgen = get_topogen()
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    #
+    # Configure r2 to announce a Type-7 default route.
+    #
+    config = """
+    configure terminal
+    router ospf6
+    no default-information originate
+    area 2 nssa default-information-originate
+    """
+    tgen.gears["r2"].vtysh_cmd(config)
+
+    logger.info("Expecting Type-7 default-route to be added")
+    routes = {"::/0": {}}
+    expect_ospfv3_routes("r4", routes, wait=30, type="external-2")
+
+    #
+    # Configure r2 to stop announcing a Type-7 default route.
+    #
+    config = """
+    configure terminal
+    router ospf6
+    area 2 nssa
+    """
+    tgen.gears["r2"].vtysh_cmd(config)
+
+    logger.info("Expecting Type-7 default route to be removed")
+    test_func = partial(dont_expect_route, "r4", "::/0", type="external-2")
+    _, result = topotest.run_and_expect(test_func, None, count=30, wait=1)
+    assertmsg = "r4's Type-7 default route still exists"
+    assert result is None, assertmsg
+
+
 def test_area_filters():
     """
     Test ABR import/export filters.