+ /* TODO: what should be the value of cmd_result??? */
+ ERR("[notification-thread] Failed to add event source pipe fd to pollset");
+ goto end;
+ }
+
+end:
+ *_cmd_result = cmd_result;
+ return ret;
+}
+
+static
+int handle_notification_thread_command_remove_application(
+ struct notification_thread_handle *handle,
+ struct notification_thread_state *state,
+ int read_side_trigger_event_application_pipe,
+ enum lttng_error_code *_cmd_result)
+{
+ int ret = 0;
+ enum lttng_error_code cmd_result = LTTNG_OK;
+ /* Used for logging */
+ enum lttng_domain_type domain = LTTNG_DOMAIN_NONE;
+
+ /* TODO: missing a lock propably to revisit */
+ struct notification_event_trigger_source_element *source_element = NULL, *tmp;
+
+ cds_list_for_each_entry_safe(source_element, tmp,
+ &handle->event_trigger_sources.list, node) {
+ if (source_element->fd != read_side_trigger_event_application_pipe) {
+ continue;
+ }
+
+ cds_list_del(&source_element->node);
+ break;
+ }
+
+ /* It should always be found */
+ assert(source_element);
+
+ DBG3("[notification-thread] Removing application event source from fd: %d of domain: %s",
+ read_side_trigger_event_application_pipe,
+ lttng_domain_type_str(domain));
+ free(source_element);
+
+ /* Removing the read side pipe to the event poll */
+ ret = lttng_poll_del(&state->events,
+ read_side_trigger_event_application_pipe);
+ if (ret < 0) {
+ /* TODO: what should be the value of cmd_result??? */
+ ERR("[notification-thread] Failed to remove event source pipe fd from pollset");
+ goto end;
+ }
+
+end:
+ *_cmd_result = cmd_result;
+ return ret;
+}
+
+static int handle_notification_thread_command_get_tokens(
+ struct notification_thread_handle *handle,
+ struct notification_thread_state *state,
+ struct lttng_triggers **triggers,
+ enum lttng_error_code *_cmd_result)
+{
+ int ret = 0, i = 0;
+ enum lttng_error_code cmd_result = LTTNG_OK;
+ struct cds_lfht_iter iter;
+ struct notification_trigger_tokens_ht_element *element;
+ struct lttng_triggers *local_triggers = NULL;
+
+ local_triggers = lttng_triggers_create();
+ if (!local_triggers) {
+ cmd_result = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+
+ rcu_read_lock();
+ cds_lfht_for_each_entry (
+ state->trigger_tokens_ht, &iter, element, node) {
+ ret = lttng_triggers_add(local_triggers, element->trigger);
+ if (ret < 0) {
+ cmd_result = LTTNG_ERR_FATAL;
+ ret = -1;
+ goto end;
+ }
+
+ i++;
+ }
+
+ /* Passing ownership up */
+ *triggers = local_triggers;
+ local_triggers = NULL;
+
+end:
+ rcu_read_unlock();
+ lttng_triggers_destroy(local_triggers);
+ *_cmd_result = cmd_result;
+ return ret;
+}
+
+static
+int trigger_update_error_count(struct lttng_trigger *trigger)
+{
+ int ret = 0;
+ uint64_t error_count = 0;
+ enum trigger_error_accounting_status status;
+
+ status = trigger_error_accounting_get_count(trigger, &error_count);
+ if (status != TRIGGER_ERROR_ACCOUNTING_STATUS_OK) {
+ ERR("Error getting trigger error count");
+ }
+
+ lttng_trigger_set_error_count(trigger, error_count);
+ return ret;
+}
+
+static int handle_notification_thread_command_list_triggers(
+ struct notification_thread_handle *handle,
+ struct notification_thread_state *state,
+ uid_t uid,
+ struct lttng_triggers **triggers,
+ enum lttng_error_code *_cmd_result)
+{
+ int ret = 0, i = 0;
+ enum lttng_error_code cmd_result = LTTNG_OK;
+ struct cds_lfht_iter iter;
+ struct lttng_trigger_ht_element *trigger_ht_element;
+ struct lttng_triggers *local_triggers = NULL;
+ const struct lttng_credentials *creds;
+
+ long scb, sca;
+ unsigned long count;
+
+ rcu_read_lock();
+ cds_lfht_count_nodes(state->triggers_ht, &scb, &count, &sca);
+
+ local_triggers = lttng_triggers_create();
+ if (!local_triggers) {
+ cmd_result = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+
+ cds_lfht_for_each_entry (state->triggers_ht, &iter,
+ trigger_ht_element, node) {
+ /*
+ * Only return the trigger for which the requestion client have
+ * access.
+ * Root user have visibility over all triggers.
+ */
+ creds = lttng_trigger_get_credentials(trigger_ht_element->trigger);
+ if (uid != lttng_credentials_get_uid(creds) && uid != 0) {
+ continue;
+ }
+
+ ret = trigger_update_error_count(trigger_ht_element->trigger);
+ assert(!ret);
+
+ ret = lttng_triggers_add(local_triggers, trigger_ht_element->trigger);
+ if (ret < 0) {
+ ret = -1;
+ goto end;
+ }
+
+ i++;
+ }
+
+ /* Passing ownership up */
+ *triggers = local_triggers;
+ local_triggers = NULL;
+
+end:
+ rcu_read_unlock();
+ lttng_triggers_destroy(local_triggers);
+ *_cmd_result = cmd_result;
+ return ret;
+}
+
+static
+int condition_is_supported(struct lttng_condition *condition)
+{
+ int ret;
+
+ switch (lttng_condition_get_type(condition)) {
+ case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW:
+ case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH:
+ {
+ enum lttng_domain_type domain;
+
+ ret = lttng_condition_buffer_usage_get_domain_type(condition,
+ &domain);
+ if (ret) {
+ ret = -1;
+ goto end;
+ }
+
+ if (domain != LTTNG_DOMAIN_KERNEL) {
+ ret = 1;
+ goto end;
+ }
+
+ /*
+ * Older kernel tracers don't expose the API to monitor their
+ * buffers. Therefore, we reject triggers that require that
+ * mechanism to be available to be evaluated.
+ */
+ ret = kernel_supports_ring_buffer_snapshot_sample_positions();
+ break;
+ }
+ case LTTNG_CONDITION_TYPE_EVENT_RULE_HIT:
+ {
+ /* TODO:
+ * Check for kernel support.
+ * Check for ust support ??
+ */
+ ret = 1;
+ break;
+ }
+ default:
+ ret = 1;
+ }
+end:
+ return ret;
+}
+
+static
+int action_is_supported(struct lttng_action *action)
+{
+ int ret;
+
+ switch (lttng_action_get_type(action)) {
+ case LTTNG_ACTION_TYPE_NOTIFY:
+ case LTTNG_ACTION_TYPE_START_SESSION:
+ case LTTNG_ACTION_TYPE_STOP_SESSION:
+ case LTTNG_ACTION_TYPE_ROTATE_SESSION:
+ case LTTNG_ACTION_TYPE_SNAPSHOT_SESSION:
+ {
+ /* TODO validate that this is true for kernel in regards to
+ * rotation and snapshot. Start stop is not a problem notify
+ * either.
+ */
+ /* For now all type of actions are supported */
+ ret = 1;
+ break;
+ }
+ case LTTNG_ACTION_TYPE_GROUP:
+ {
+ /* TODO: Iterate over all internal actions and validate that
+ * they are supported
+ */
+ ret = 1;
+ break;
+
+ }
+ default:
+ ret = 1;
+ }
+
+ return ret;
+}
+
+/* Must be called with RCU read lock held. */
+static
+int bind_trigger_to_matching_session(struct lttng_trigger *trigger,
+ struct notification_thread_state *state)
+{
+ int ret = 0;
+ const struct lttng_condition *condition;
+ const char *session_name;
+ struct lttng_session_trigger_list *trigger_list;
+
+ condition = lttng_trigger_get_const_condition(trigger);
+ switch (lttng_condition_get_type(condition)) {
+ case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING:
+ case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED:
+ {
+ enum lttng_condition_status status;
+
+ status = lttng_condition_session_rotation_get_session_name(
+ condition, &session_name);
+ if (status != LTTNG_CONDITION_STATUS_OK) {
+ ERR("[notification-thread] Failed to bind trigger to session: unable to get 'session_rotation' condition's session name");
+ ret = -1;
+ goto end;
+ }
+ break;
+ }
+ default:
+ ret = -1;
+ goto end;
+ }
+
+ trigger_list = get_session_trigger_list(state, session_name);
+ if (!trigger_list) {
+ DBG("[notification-thread] Unable to bind trigger applying to session \"%s\" as it is not yet known to the notification system",
+ session_name);
+ goto end;
+
+ }
+
+ DBG("[notification-thread] Newly registered trigger bound to session \"%s\"",
+ session_name);
+ ret = lttng_session_trigger_list_add(trigger_list, trigger);
+end:
+ return ret;
+}
+
+/* Must be called with RCU read lock held. */
+static
+int bind_trigger_to_matching_channels(struct lttng_trigger *trigger,
+ struct notification_thread_state *state)
+{
+ int ret = 0;
+ struct cds_lfht_node *node;
+ struct cds_lfht_iter iter;
+ struct channel_info *channel;
+
+ cds_lfht_for_each_entry(state->channels_ht, &iter, channel,
+ channels_ht_node) {
+ struct lttng_trigger_list_element *trigger_list_element;
+ struct lttng_channel_trigger_list *trigger_list;
+ struct cds_lfht_iter lookup_iter;
+
+ if (!trigger_applies_to_channel(trigger, channel)) {
+ continue;
+ }
+
+ cds_lfht_lookup(state->channel_triggers_ht,
+ hash_channel_key(&channel->key),
+ match_channel_trigger_list,
+ &channel->key,
+ &lookup_iter);
+ node = cds_lfht_iter_get_node(&lookup_iter);
+ assert(node);
+ trigger_list = caa_container_of(node,
+ struct lttng_channel_trigger_list,
+ channel_triggers_ht_node);
+
+ trigger_list_element = zmalloc(sizeof(*trigger_list_element));
+ if (!trigger_list_element) {
+ ret = -1;
+ goto end;
+ }
+ CDS_INIT_LIST_HEAD(&trigger_list_element->node);
+ trigger_list_element->trigger = trigger;
+ cds_list_add(&trigger_list_element->node, &trigger_list->list);
+ DBG("[notification-thread] Newly registered trigger bound to channel \"%s\"",
+ channel->name);
+ }
+end:
+ return ret;
+}
+
+static
+bool is_trigger_action_notify(const struct lttng_trigger *trigger)
+{
+ bool is_notify = false;
+ unsigned int i, count;
+ enum lttng_action_status action_status;
+ const struct lttng_action *action =
+ lttng_trigger_get_const_action(trigger);
+ enum lttng_action_type action_type;
+
+ assert(action);
+ action_type = lttng_action_get_type(action);
+ if (action_type == LTTNG_ACTION_TYPE_NOTIFY) {
+ is_notify = true;
+ goto end;
+ } else if (action_type != LTTNG_ACTION_TYPE_GROUP) {
+ goto end;
+ }
+
+ action_status = lttng_action_group_get_count(action, &count);
+ assert(action_status == LTTNG_ACTION_STATUS_OK);
+
+ for (i = 0; i < count; i++) {
+ const struct lttng_action *inner_action =
+ lttng_action_group_get_at_index(
+ action, i);
+
+ action_type = lttng_action_get_type(inner_action);
+ if (action_type == LTTNG_ACTION_TYPE_NOTIFY) {
+ is_notify = true;
+ goto end;
+ }
+ }
+
+end:
+ return is_notify;
+}
+
+static bool trigger_name_taken(struct notification_thread_state *state,
+ const struct lttng_trigger *trigger)
+{
+ struct cds_lfht_node *triggers_by_name_uid_ht_node;
+ struct cds_lfht_iter iter;
+
+ /*
+ * No duplicata is allowed in the triggers_by_name_uid_ht.
+ * The match is done against the trigger name and uid.
+ */
+ cds_lfht_lookup(state->triggers_by_name_uid_ht,
+ hash_key_str(trigger->name, lttng_ht_seed),
+ match_name_uid,
+ trigger,
+ &iter);
+ triggers_by_name_uid_ht_node = cds_lfht_iter_get_node(&iter);
+ if (triggers_by_name_uid_ht_node) {
+ return true;
+ } else {
+ return false;
+ }
+}
+
+static
+void generate_trigger_name(struct notification_thread_state *state, struct lttng_trigger *trigger, const char **name)
+{
+ /*
+ * Here the offset criteria guarantee an end. This will be a nice
+ * bikeshedding conversation. I would simply generate uuid and use them
+ * as trigger name.
+ */
+ bool taken = false;
+ enum lttng_trigger_status status;
+ do {
+ lttng_trigger_generate_name(trigger, state->trigger_id.name_offset);
+
+ status = lttng_trigger_get_name(trigger, name);
+ assert(status == LTTNG_TRIGGER_STATUS_OK);
+
+ taken = trigger_name_taken(state, trigger);
+ if (taken) {
+ state->trigger_id.name_offset++;
+ }
+ } while (taken || state->trigger_id.name_offset == UINT32_MAX);
+}
+
+/*
+ * FIXME A client's credentials are not checked when registering a trigger.
+ *
+ * The effects of this are benign since:
+ * - The client will succeed in registering the trigger, as it is valid,
+ * - The trigger will, internally, be bound to the channel/session,
+ * - The notifications will not be sent since the client's credentials
+ * are checked against the channel at that moment.
+ *
+ * If this function returns a non-zero value, it means something is
+ * fundamentally broken and the whole subsystem/thread will be torn down.
+ *
+ * If a non-fatal error occurs, just set the cmd_result to the appropriate
+ * error code.
+ */
+static
+int handle_notification_thread_command_register_trigger(
+ struct notification_thread_state *state,
+ struct lttng_trigger *trigger,
+ enum lttng_error_code *cmd_result)
+{
+ int ret = 0;
+ int is_supported;
+ struct lttng_condition *condition;
+ struct lttng_action *action;
+ struct notification_client *client;
+ struct notification_client_list *client_list = NULL;
+ struct lttng_trigger_ht_element *trigger_ht_element = NULL;
+ struct notification_client_list_element *client_list_element;
+ struct notification_trigger_tokens_ht_element *trigger_tokens_ht_element = NULL;
+ struct cds_lfht_node *node;
+ struct cds_lfht_iter iter;
+ const char* trigger_name;
+ bool free_trigger = true;
+ struct lttng_evaluation *evaluation = NULL;
+ struct lttng_credentials object_creds;
+ uid_t object_uid;
+ gid_t object_gid;
+ enum action_executor_status executor_status;
+
+ rcu_read_lock();
+
+ /* Set the trigger's tracer token */
+ lttng_trigger_set_tracer_token(trigger, state->trigger_id.token_generator);
+
+ if (lttng_trigger_get_name(trigger, &trigger_name) ==
+ LTTNG_TRIGGER_STATUS_UNSET) {
+ generate_trigger_name(state, trigger, &trigger_name);
+ } else if (trigger_name_taken(state, trigger)) {
+ /* Not a fatal error */
+ *cmd_result = LTTNG_ERR_TRIGGER_EXISTS;
+ ret = 0;