usm, npm, classification: Fix a leak in connection_protocol

pkg/network/ebpf/c/protocols/classification/protocol-classification.h

@@ -60,12 +60,6 @@
 // file.  If, for example, application-layer is known, calling this helper multiple
 // times will result in traversing only the api and encryption-layer programs
 
-static __always_inline bool is_protocol_classification_supported() {
-    __u64 val = 0;
-    LOAD_CONSTANT("protocol_classification_enabled", val);
-    return val > 0;
-}
-
 // updates the the protocol stack and adds the current layer to the routing skip list
 static __always_inline void update_protocol_information(usm_context_t *usm_ctx, protocol_stack_t *stack, protocol_t proto) {
     set_protocol(stack, proto);

pkg/network/ebpf/c/protocols/classification/shared-tracer-maps.h

@@ -9,6 +9,12 @@
 // classification procedures on the same connection
 BPF_HASH_MAP(connection_protocol, conn_tuple_t, protocol_stack_wrapper_t, 0)
 
+static __always_inline bool is_protocol_classification_supported() {
+    __u64 val = 0;
+    LOAD_CONSTANT("protocol_classification_enabled", val);
+    return val > 0;
+}
+
 static __always_inline protocol_stack_t* __get_protocol_stack(conn_tuple_t* tuple) {
     protocol_stack_wrapper_t *wrapper = bpf_map_lookup_elem(&connection_protocol, tuple);
     if (!wrapper) {

pkg/network/ebpf/c/tracer/stats.h

@@ -148,7 +148,9 @@ static __always_inline void update_conn_stats(conn_tuple_t *t, size_t sent_bytes
         return;
     }
 
-    update_protocol_classification_information(t, val);
+    if (is_protocol_classification_supported()) {
+        update_protocol_classification_information(t, val);
+    }
 
     // If already in our map, increment size in-place
     update_conn_state(t, val, sent_bytes, recv_bytes);