tests: Add test case to verify SRv6 SID modify

This commit adds a test case that modifies a SID and verifies that the
RIB is as expected.

Signed-off-by: Carmine Scarpitta <cscarpit@cisco.com>
(cherry picked from commit 23403e01a3ece0b206bc8acf36c08b4bb538cb79)

3 files changed, 242 insertions, 0 deletions

diff --git a/tests/topotests/static_srv6_sids/expected_srv6_sids_sid_modify.json b/tests/topotests/static_srv6_sids/expected_srv6_sids_sid_modify.json
new file mode 100644
index 0000000000..070b7ade20
--- /dev/null
+++ b/tests/topotests/static_srv6_sids/expected_srv6_sids_sid_modify.json
@@ -0,0 +1,201 @@
+{
+	"fcbb:bbbb:1::/48": [
+		{
+			"prefix": "fcbb:bbbb:1::/48",
+			"prefixLen": 48,
+			"protocol": "static",
+			"vrfId": 0,
+			"vrfName": "default",
+			"selected": true,
+			"destSelected": true,
+			"distance": 1,
+			"metric": 0,
+			"installed": true,
+			"table": 254,
+			"internalStatus": 16,
+			"internalFlags": 9,
+			"internalNextHopNum": 1,
+			"internalNextHopActiveNum": 1,
+			"nexthops": [
+				{
+					"flags": 3,
+					"fib": true,
+					"directlyConnected": true,
+					"interfaceName": "sr0",
+					"active": true,
+					"weight": 1,
+					"seg6local": {
+						"action": "End",
+						"sidStructure": {
+							"blockLen": 32,
+							"nodeLen": 16,
+							"funcLen": 0,
+							"argLen": 0
+						}
+					},
+					"seg6localContext": {
+
+					}
+				}
+			]
+		}
+	],
+	"fcbb:bbbb:1:fe10::/64": [
+		{
+			"prefix": "fcbb:bbbb:1:fe10::/64",
+			"prefixLen": 64,
+			"protocol": "static",
+			"vrfId": 0,
+			"vrfName": "default",
+			"selected": true,
+			"destSelected": true,
+			"distance": 1,
+			"metric": 0,
+			"installed": true,
+			"table": 254,
+			"internalStatus": 16,
+			"internalFlags": 9,
+			"internalNextHopNum": 1,
+			"internalNextHopActiveNum": 1,
+			"nexthops": [
+				{
+					"flags": 3,
+					"fib": true,
+					"directlyConnected": true,
+					"interfaceName": "Vrf10",
+					"active": true,
+					"weight": 1,
+					"seg6local": {
+						"action": "End.DT4",
+						"sidStructure": {
+							"blockLen": 32,
+							"nodeLen": 16,
+							"funcLen": 16,
+							"argLen": 0
+						}
+					},
+					"seg6localContext": {
+						"table": 10
+					}
+				}
+			]
+		}
+	],
+	"fcbb:bbbb:1:fe20::/64": [
+		{
+			"prefix": "fcbb:bbbb:1:fe20::/64",
+			"prefixLen": 64,
+			"protocol": "static",
+			"vrfId": 0,
+			"vrfName": "default",
+			"selected": true,
+			"destSelected": true,
+			"distance": 1,
+			"metric": 0,
+			"installed": true,
+			"table": 254,
+			"internalStatus": 16,
+			"internalFlags": 9,
+			"internalNextHopNum": 1,
+			"internalNextHopActiveNum": 1,
+			"nexthops": [
+				{
+					"flags": 3,
+					"fib": true,
+					"directlyConnected": true,
+					"interfaceName": "Vrf40",
+					"active": true,
+					"weight": 1,
+					"seg6local": {
+						"action": "End.DT46",
+						"sidStructure": {
+							"blockLen": 32,
+							"nodeLen": 16,
+							"funcLen": 16,
+							"argLen": 0
+						}
+					},
+					"seg6localContext": {
+						"table": 40
+					}
+				}
+			]
+		}
+	],
+	"fcbb:bbbb:1:fe30::/64": [
+		{
+			"prefix": "fcbb:bbbb:1:fe30::/64",
+			"prefixLen": 64,
+			"protocol": "static",
+			"vrfId": 0,
+			"vrfName": "default",
+			"selected": true,
+			"destSelected": true,
+			"distance": 1,
+			"metric": 0,
+			"installed": true,
+			"table": 254,
+			"internalStatus": 16,
+			"internalFlags": 9,
+			"internalNextHopNum": 1,
+			"internalNextHopActiveNum": 1,
+			"nexthops": [
+				{
+					"flags": 3,
+					"fib": true,
+					"directlyConnected": true,
+					"interfaceName": "Vrf30",
+					"active": true,
+					"weight": 1,
+					"seg6local": {
+						"action": "End.DT46",
+						"sidStructure": {
+							"blockLen": 32,
+							"nodeLen": 16,
+							"funcLen": 16,
+							"argLen": 0
+						}
+					},
+					"seg6localContext": {
+						"table": 30
+					}
+				}
+			]
+		}
+	],
+	"fcbb:bbbb:1:fe40::/64": [
+		{
+			"prefix": "fcbb:bbbb:1:fe40::/64",
+			"prefixLen": 64,
+			"protocol": "static",
+			"vrfId": 0,
+			"vrfName": "default",
+			"selected": true,
+			"destSelected": true,
+			"distance": 1,
+			"metric": 0,
+			"installed": true,
+			"table": 254,
+			"internalStatus": 16,
+			"internalFlags": 9,
+			"internalNextHopNum": 1,
+			"internalNextHopActiveNum": 1,
+			"nexthops": [
+				{
+					"flags": 3,
+					"fib": true,
+					"directlyConnected": true,
+					"interfaceName": "sr0",
+					"active": true,
+					"weight": 1,
+					"seg6local": {
+						"action": "End.X"
+					},
+					"seg6localContext": {
+						"nh6": "2001::2"
+					}
+				}
+			]
+		}
+	]
+}
\ No newline at end of file
diff --git a/tests/topotests/static_srv6_sids/r1/setup.sh b/tests/topotests/static_srv6_sids/r1/setup.sh
index 040be73914..99cbdee280 100644
--- a/tests/topotests/static_srv6_sids/r1/setup.sh
+++ b/tests/topotests/static_srv6_sids/r1/setup.sh
@@ -10,4 +10,7 @@ ip link set Vrf20 up
 ip link add Vrf30 type vrf table 30
 ip link set Vrf30 up
 
+ip link add Vrf40 type vrf table 40
+ip link set Vrf40 up
+
 sysctl -w net.vrf.strict_mode=1
diff --git a/tests/topotests/static_srv6_sids/test_static_srv6_sids.py b/tests/topotests/static_srv6_sids/test_static_srv6_sids.py
index 565b38f625..1ea94c8c07 100755
--- a/tests/topotests/static_srv6_sids/test_static_srv6_sids.py
+++ b/tests/topotests/static_srv6_sids/test_static_srv6_sids.py
@@ -172,6 +172,44 @@ def test_srv6_static_sids_sid_readd():
     check_srv6_static_sids(router, "expected_srv6_sids.json")
 
 
+def test_srv6_static_sids_sid_modify():
+    """
+    Modify the static SIDs and verify the routing table
+    """
+    tgen = get_topogen()
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+    router = tgen.gears["r1"]
+
+    def _check_srv6_static_sids(router, expected_route_file):
+        logger.info("checking zebra srv6 static sids")
+        output = json.loads(router.vtysh_cmd("show ipv6 route static json"))
+        expected = open_json_file("{}/{}".format(CWD, expected_route_file))
+        return topotest.json_cmp(output, expected)
+
+    def check_srv6_static_sids(router, expected_file):
+        func = functools.partial(_check_srv6_static_sids, router, expected_file)
+        _, result = topotest.run_and_expect(func, None, count=15, wait=1)
+        assert result is None, "Failed"
+
+    router.vtysh_cmd(
+        """
+        configure terminal
+         segment-routing
+          srv6
+           static-sids
+            sid fcbb:bbbb:1:fe20::/64 locator MAIN behavior uDT46 vrf Vrf40
+        """
+    )
+
+    # FOR DEVELOPER:
+    # If you want to stop some specific line and start interactive shell,
+    # please use tgen.mininet_cli() to start it.
+
+    logger.info("Test for srv6 sids configuration")
+    check_srv6_static_sids(router, "expected_srv6_sids_sid_modify.json")
+
+
 def test_srv6_static_sids_sid_delete_all():
     """
     Remove all static SIDs and verify they get removed