7 files changed, 62 insertions, 7 deletions
diff --git a/tools/net/sunrpc/xdrgen/generators/enum.py b/tools/net/sunrpc/xdrgen/generators/enum.py
index e62f715d3996..b4ed3ed6431e 100644
--- a/tools/net/sunrpc/xdrgen/generators/enum.py
+++ b/tools/net/sunrpc/xdrgen/generators/enum.py
@@ -5,6 +5,7 @@
 
 from generators import SourceGenerator, create_jinja2_environment
 from xdr_ast import _XdrEnum, public_apis, big_endian, get_header_name
+from xdr_parse import get_xdr_enum_validation
 
 
 class XdrEnumGenerator(SourceGenerator):
@@ -42,7 +43,13 @@ class XdrEnumGenerator(SourceGenerator):
             template = self.environment.get_template("decoder/enum_be.j2")
         else:
             template = self.environment.get_template("decoder/enum.j2")
-        print(template.render(name=node.name))
+        print(
+            template.render(
+                name=node.name,
+                enumerators=node.enumerators,
+                validate=get_xdr_enum_validation(),
+            )
+        )
 
     def emit_encoder(self, node: _XdrEnum) -> None:
         """Emit one encoder function for an XDR enum type"""
diff --git a/tools/net/sunrpc/xdrgen/subcmds/source.py b/tools/net/sunrpc/xdrgen/subcmds/source.py
index 08c883f547d7..6508563494fe 100644
--- a/tools/net/sunrpc/xdrgen/subcmds/source.py
+++ b/tools/net/sunrpc/xdrgen/subcmds/source.py
@@ -22,7 +22,7 @@ from xdr_ast import transform_parse_tree, _RpcProgram, Specification
 from xdr_ast import _XdrAst, _XdrEnum, _XdrPointer
 from xdr_ast import _XdrStruct, _XdrTypedef, _XdrUnion
 
-from xdr_parse import xdr_parser, set_xdr_annotate
+from xdr_parse import xdr_parser, set_xdr_annotate, set_xdr_enum_validation
 from xdr_parse import make_error_handler, XdrParseError
 from xdr_parse import handle_transform_error
 
@@ -98,6 +98,7 @@ def subcmd(args: Namespace) -> int:
     """Generate encoder and decoder functions"""
 
     set_xdr_annotate(args.annotate)
+    set_xdr_enum_validation(not args.no_enum_validation)
     parser = xdr_parser()
     with open(args.filename, encoding="utf-8") as f:
         source = f.read()
diff --git a/tools/net/sunrpc/xdrgen/templates/C/enum/decoder/enum.j2 b/tools/net/sunrpc/xdrgen/templates/C/enum/decoder/enum.j2
index 6482984f1cb7..735a34157fdf 100644
--- a/tools/net/sunrpc/xdrgen/templates/C/enum/decoder/enum.j2
+++ b/tools/net/sunrpc/xdrgen/templates/C/enum/decoder/enum.j2
@@ -14,6 +14,17 @@ xdrgen_decode_{{ name }}(struct xdr_stream *xdr, {{ name }} *ptr)
 
 	if (xdr_stream_decode_u32(xdr, &val) < 0)
 		return false;
+{% if validate and enumerators %}
+	/* Compiler may optimize to a range check for dense enums */
+	switch (val) {
+{% for e in enumerators %}
+	case {{ e.name }}:
+{% endfor %}
+		break;
+	default:
+		return false;
+	}
+{% endif %}
 	*ptr = val;
 	return true;
 }
diff --git a/tools/net/sunrpc/xdrgen/templates/C/enum/decoder/enum_be.j2 b/tools/net/sunrpc/xdrgen/templates/C/enum/decoder/enum_be.j2
index 44c391c10b42..82782a510d47 100644
--- a/tools/net/sunrpc/xdrgen/templates/C/enum/decoder/enum_be.j2
+++ b/tools/net/sunrpc/xdrgen/templates/C/enum/decoder/enum_be.j2
@@ -10,5 +10,25 @@ static bool __maybe_unused
 {% endif %}
 xdrgen_decode_{{ name }}(struct xdr_stream *xdr, {{ name }} *ptr)
 {
+{% if validate and enumerators %}
+	__be32 raw;
+	u32 val;
+
+	if (xdr_stream_decode_be32(xdr, &raw) < 0)
+		return false;
+	val = be32_to_cpu(raw);
+	/* Compiler may optimize to a range check for dense enums */
+	switch (val) {
+{% for e in enumerators %}
+	case {{ e.name }}:
+{% endfor %}
+		break;
+	default:
+		return false;
+	}
+	*ptr = raw;
+	return true;
+{% else %}
 	return xdr_stream_decode_be32(xdr, ptr) == 0;
+{% endif %}
 }
diff --git a/tools/net/sunrpc/xdrgen/xdr_ast.py b/tools/net/sunrpc/xdrgen/xdr_ast.py
index 2b5d160a0a60..dc2fa9fd8ec2 100644
--- a/tools/net/sunrpc/xdrgen/xdr_ast.py
+++ b/tools/net/sunrpc/xdrgen/xdr_ast.py
@@ -330,8 +330,6 @@ class _XdrEnum(_XdrAst):
     """An XDR enum definition"""
 
     name: str
-    minimum: int
-    maximum: int
     enumerators: List[_XdrEnumerator]
 
     def max_width(self) -> int:
@@ -572,8 +570,6 @@ class ParseToAst(Transformer):
         value = children[1].value
         return _XdrConstant(name, value)
 
-    # cel: Python can compute a min() and max() for the enumerator values
-    #      so that the generated code can perform proper range checking.
     def enum(self, children):
         """Instantiate one _XdrEnum object"""
         enum_name = children[0].symbol
@@ -587,7 +583,7 @@ class ParseToAst(Transformer):
             enumerators.append(_XdrEnumerator(name, value))
             i = i + 2
 
-        return _XdrEnum(enum_name, 0, 0, enumerators)
+        return _XdrEnum(enum_name, enumerators)
 
     def fixed_length_opaque(self, children):
         """Instantiate one _XdrFixedLengthOpaque declaration object"""
diff --git a/tools/net/sunrpc/xdrgen/xdr_parse.py b/tools/net/sunrpc/xdrgen/xdr_parse.py
index 38724ad5aea2..241e96c1fdd9 100644
--- a/tools/net/sunrpc/xdrgen/xdr_parse.py
+++ b/tools/net/sunrpc/xdrgen/xdr_parse.py
@@ -13,6 +13,9 @@ from lark.exceptions import UnexpectedInput, UnexpectedToken, VisitError
 # Set to True to emit annotation comments in generated source
 annotate = False
 
+# Set to True to emit enum value validation in decoders
+enum_validation = True
+
 # Map internal Lark token names to human-readable names
 TOKEN_NAMES = {
     "__ANON_0": "identifier",
@@ -49,6 +52,17 @@ def get_xdr_annotate() -> bool:
     return annotate
 
 
+def set_xdr_enum_validation(set_it: bool) -> None:
+    """Set 'enum_validation' based on command line options"""
+    global enum_validation
+    enum_validation = set_it
+
+
+def get_xdr_enum_validation() -> bool:
+    """Return True when enum validation is enabled for decoder generation"""
+    return enum_validation
+
+
 def make_error_handler(source: str, filename: str) -> Callable[[UnexpectedInput], bool]:
     """Create an error handler that reports the first parse error and aborts.
 
diff --git a/tools/net/sunrpc/xdrgen/xdrgen b/tools/net/sunrpc/xdrgen/xdrgen
index e22638f8324b..b2fb43f4a2ec 100755
--- a/tools/net/sunrpc/xdrgen/xdrgen
+++ b/tools/net/sunrpc/xdrgen/xdrgen
@@ -123,6 +123,12 @@ There is NO WARRANTY, to the extent permitted by law.""",
         help="Generate code for client or server side",
         type=str,
     )
+    source_parser.add_argument(
+        "--no-enum-validation",
+        action="store_true",
+        default=False,
+        help="Disable enum value validation in decoders",
+    )
     source_parser.add_argument("filename", help="File containing an XDR specification")
     source_parser.set_defaults(func=source.subcmd)