+ int ret = 0;
+ const char *c = name;
+ const char *event_name_end = c + LTTNG_SYMBOL_NAME_LEN;
+ bool null_terminated = false;
+
+ /*
+ * Make sure that unescaped wildcards are only used as the last
+ * character of the event name.
+ */
+ while (c < event_name_end) {
+ switch (*c) {
+ case '\0':
+ null_terminated = true;
+ goto end;
+ case '\\':
+ c++;
+ break;
+ case '*':
+ if ((c + 1) < event_name_end && *(c + 1)) {
+ /* Wildcard is not the last character */
+ ret = LTTNG_ERR_INVALID_EVENT_NAME;
+ goto end;
+ }
+ default:
+ break;
+ }
+ c++;
+ }
+end:
+ if (!ret && !null_terminated) {
+ ret = LTTNG_ERR_INVALID_EVENT_NAME;
+ }
+ return ret;
+}
+
+static inline bool name_starts_with(const char *name, const char *prefix)
+{
+ const size_t max_cmp_len = min(strlen(prefix), LTTNG_SYMBOL_NAME_LEN);
+
+ return !strncmp(name, prefix, max_cmp_len);
+}
+
+/* Perform userspace-specific event name validation */
+static int validate_ust_event_name(const char *name)
+{
+ int ret = 0;
+
+ if (!name) {
+ ret = -1;
+ goto end;
+ }
+
+ /*
+ * Check name against all internal UST event component namespaces used
+ * by the agents.
+ */
+ if (name_starts_with(name, DEFAULT_JUL_EVENT_COMPONENT) ||
+ name_starts_with(name, DEFAULT_LOG4J_EVENT_COMPONENT) ||
+ name_starts_with(name, DEFAULT_PYTHON_EVENT_COMPONENT)) {
+ ret = -1;
+ }
+
+end:
+ return ret;
+}
+
+static int cmd_enable_event_internal(struct ltt_session *session,
+ struct lttng_domain *domain,
+ char *channel_name, struct lttng_event *event,
+ char *filter_expression,
+ struct lttng_filter_bytecode *filter,
+ struct lttng_event_exclusion *exclusion,
+ int wpipe);
+
+/*
+ * Internal version of cmd_enable_event() with a supplemental
+ * "internal_event" flag which is used to enable internal events which should
+ * be hidden from clients. Such events are used in the agent implementation to
+ * enable the events through which all "agent" events are funeled.
+ */
+static int _cmd_enable_event(struct ltt_session *session,
+ struct lttng_domain *domain,
+ char *channel_name, struct lttng_event *event,
+ char *filter_expression,
+ struct lttng_filter_bytecode *filter,
+ struct lttng_event_exclusion *exclusion,
+ int wpipe, bool internal_event)
+{
+ int ret, channel_created = 0;