Clarifying that wildcard hostname matching is suffix matching

apis/v1alpha2/gateway_types.go

@@ -172,6 +172,10 @@ type Listener struct {
 	// accepted. For more information, refer to the Route specific Hostnames
 	// documentation.
 	//
+	// Hostnames that are prefixed with a wildcard label (`*.`) are interpreted
+	// as a suffix match. That means that a match for `*.example.com` would match
+	// both `test.example.com`, and `foo.test.example.com`, but not `example.com`.
+	//
 	// Support: Core
 	//
 	// +optional

apis/v1alpha2/httproute_types.go

@@ -74,8 +74,13 @@ type HTTPRouteSpec struct {
 	// * A Listener with `*.example.com` as the hostname matches HTTPRoutes
 	//   that have either not specified any hostnames or have specified at least
 	//   one hostname that matches the Listener hostname. For example,
-	//   `test.example.com` and `*.example.com` would both match. On the other
-	//   hand, `example.com` and `test.example.net` would not match.
+	//   `*.example.com`, `test.example.com`, and `foo.test.example.com` would
+	//   all match. On the other hand, `example.com` and `test.example.net` would
+	//   not match.
+	//
+	// Hostnames that are prefixed with a wildcard label (`*.`) are interpreted
+	// as a suffix match. That means that a match for `*.example.com` would match
+	// both `test.example.com`, and `foo.test.example.com`, but not `example.com`.
 	//
 	// If both the Listener and HTTPRoute have specified hostnames, any
 	// HTTPRoute hostnames that do not match the Listener hostname MUST be

conformance/tests/httproute-listener-hostname-matching.go

@@ -66,8 +66,9 @@ var HTTPRouteListenerHostnameMatching = suite.ConformanceTest{
 			Backend:   "infra-backend-v3",
 			Namespace: ns,
 		}, {
-			Request:    http.ExpectedRequest{Host: "too.many.prefixes.bar.com", Path: "/"},
-			StatusCode: 404,
+			Request:   http.ExpectedRequest{Host: "multiple.prefixes.bar.com", Path: "/"},
+			Backend:   "infra-backend-v3",
+			Namespace: ns,
 		}, {
 			Request:    http.ExpectedRequest{Host: "no.matching.host", Path: "/"},
 			StatusCode: 404,