Make 'any' a reserved name for prefixlists

docs/config-guide.md

@@ -363,7 +363,7 @@ interfaces:
 
 This construct allows to enumerate a list of IPv4 or IPv6 host addresses and/or networks. Each
 prefixlist has a name which consists of anywhere between 1 and 56 characters, and it must start
-with a letter. The syntax is straight forward:
+with a letter. The prefixlist name `any` is reserved. The syntax is straight forward:
 
 *   ***description***: A string, no longer than 64 characters, and excluding the single quote '
     and double quote ". This string is currently not used anywhere, and serves for enduser

vppcfg/config/prefixlist.py

@@ -113,6 +113,12 @@ def validate_prefixlists(yaml):
 
     for plname, pl in yaml["prefixlists"].items():
         logger.debug(f"prefixlist {plname}: {pl}")
+        if plname in ["any"]:
+            ## Note: ACL 'source' and 'destination', when they are empty, will resolve
+            ## to 'any', and can thus never refer to a prefixlist called 'any'.
+            msgs.append(f"prefixlist {plname} is a reserved name")
+            result = False
+
         members = 0
         for pl_member in pl["members"]:
             members += 1

vppcfg/unittest/yaml/error-prefixlist1.yaml

@@ -0,0 +1,18 @@
+test:
+  description: "Some prefixlist names are reserved"
+  errors:
+    expected:
+      - "prefixlist any is a reserved name"
+    count: 1
+---
+prefixlists:
+  any:
+    description: "any is a reserved name"
+    members:
+     - 192.0.2.1
+     - 192.0.2.0/24
+  v6only:
+    members:
+     - 2001:db8::1
+     - 2001:db8::/64
+     - 2001:db8::/48