+/*
+ * Enable event(s) for a channel, possibly with exclusions and a filter.
+ * If no event name is specified, all events are enabled.
+ * If no channel name is specified, the default name is used.
+ * If filter expression is not NULL, the filter is set for the event.
+ * If exclusion count is not zero, the exclusions are set for the event.
+ * Returns size of returned session payload data or a negative error code.
+ */
+int lttng_enable_event_with_exclusions(struct lttng_handle *handle,
+ struct lttng_event *ev, const char *channel_name,
+ const char *original_filter_expression,
+ int exclusion_count, char **exclusion_list)
+{
+ struct lttcomm_session_msg lsm;
+ char *varlen_data;
+ int ret = 0;
+ unsigned int free_filter_expression = 0;
+ struct filter_parser_ctx *ctx = NULL;
+ /*
+ * Cast as non-const since we may replace the filter expression
+ * by a dynamically allocated string. Otherwise, the original
+ * string is not modified.
+ */
+ char *filter_expression = (char *) original_filter_expression;
+
+ if (handle == NULL || ev == NULL) {
+ ret = -LTTNG_ERR_INVALID;
+ goto error;
+ }
+
+ /* Empty filter string will always be rejected by the parser
+ * anyway, so treat this corner-case early to eliminate
+ * lttng_fmemopen error for 0-byte allocation.
+ */
+ if (filter_expression && filter_expression[0] == '\0') {
+ ret = -LTTNG_ERR_INVALID;
+ goto error;
+ }
+
+ memset(&lsm, 0, sizeof(lsm));
+
+ /* If no channel name, send empty string. */
+ if (channel_name == NULL) {
+ lttng_ctl_copy_string(lsm.u.enable.channel_name, "",
+ sizeof(lsm.u.enable.channel_name));
+ } else {
+ lttng_ctl_copy_string(lsm.u.enable.channel_name, channel_name,
+ sizeof(lsm.u.enable.channel_name));
+ }
+
+ if (ev->name[0] != '\0') {
+ lsm.cmd_type = LTTNG_ENABLE_EVENT;
+ } else {
+ lsm.cmd_type = LTTNG_ENABLE_ALL_EVENT;
+ }