[Pfx_len] Extend prefix length for routes and advertisement (#182)

IPv6 Prefix length to /48 (route) and /40 (advertised network)

IPv4 Prefix length fixed to /18 and above for both route prefixes and advertised prefixes.
However, for IPv6, its currently advertised prefix minimum length is /60. This has some limitations and extending it to accept /40 as the minimum for adv prefix and /48 as minimum for route prefixes.

Author: mssonicbld

go-server-server/go/default.go

@@ -1286,8 +1286,8 @@ func ConfigVrouterVrfIdRoutesPatch(w http.ResponseWriter, r *http.Request) {
                         continue                        
                     }
                 } else {
-                    if prefix_len < 64 {
-                        r.Error_msg = "Prefix length lesser than 64 is not supported"
+                    if prefix_len < 48 {
+                        r.Error_msg = "Prefix length lesser than 48 is not supported"
                         failed = append(failed, r)
                         continue                          
                     }
@@ -1483,8 +1483,8 @@ func ConfigVrouterVrfIdRoutesPatch(w http.ResponseWriter, r *http.Request) {
                             continue
                         }
                     } else {
-                        if prefix_len < 60 {
-                            r.Error_msg = "Adv Prefix length lesser than 60 is not supported"
+                        if prefix_len < 40 {
+                            r.Error_msg = "Adv Prefix length lesser than 40 is not supported"
                             failed = append(failed, r)
                             continue
                         }

test/test_restapi.py

@@ -2486,7 +2486,7 @@ def test_patch_update_routes_unsupported_ipprefix(sef, setup_restapi_client):
         r = restapi_client.patch_config_vrouter_vrf_id_routes("vnet-guid-1", [route])
         assert r.status_code == 207
         j = json.loads(r.text)
-        assert j['failed'][0]['error_msg'] == "Prefix length lesser than 64 is not supported"        
+        assert j['failed'][0]['error_msg'] == "Prefix length lesser than 48 is not supported"
 
     def test_patch_update_routes_with_optional_args(self, setup_restapi_client):
         db, _, _, restapi_client = setup_restapi_client
@@ -2535,7 +2535,7 @@ def test_patch_update_routes_with_optional_args(self, setup_restapi_client):
         r = restapi_client.patch_config_vrouter_vrf_id_routes("vnet-guid-1", [route])
         assert r.status_code == 207
         j = json.loads(r.text)
-        assert j['failed'][0]['error_msg'] == "Adv Prefix length lesser than 60 is not supported"
+        assert j['failed'][0]['error_msg'] == "Adv Prefix length lesser than 40 is not supported"
 
         # Append and remove
         route = {