+ int ret;
+
+ assert(session);
+
+ if (session->live_timer != 0) {
+ ret = LTTNG_ERR_LIVE_SESSION;
+ goto end;
+ }
+ if (!session->active) {
+ ret = LTTNG_ERR_SESSION_NOT_STARTED;
+ goto end;
+ }
+ if (session->ust_session) {
+ switch (session->ust_session->buffer_type) {
+ case LTTNG_BUFFER_PER_UID:
+ break;
+ case LTTNG_BUFFER_PER_PID:
+ ret = LTTNG_ERR_PER_PID_SESSION;
+ goto end;
+ default:
+ assert(0);
+ ret = LTTNG_ERR_UNK;
+ goto end;
+ }
+ }
+ if (session->consumer->type == CONSUMER_DST_NET &&
+ session->consumer->relay_minor_version < 8) {
+ ret = LTTNG_ERR_RELAYD_VERSION_FAIL;
+ goto end;
+ }
+ ret = 0;
+
+end:
+ return ret;
+}
+
+static
+int clear_metadata_file(int fd)
+{
+ int ret;
+ off_t lseek_ret;
+
+ lseek_ret = lseek(fd, 0, SEEK_SET);
+ if (lseek_ret < 0) {
+ PERROR("lseek");
+ ret = -1;
+ goto end;
+ }
+
+ ret = ftruncate(fd, 0);
+ if (ret < 0) {
+ PERROR("ftruncate");
+ goto end;
+ }
+
+end:
+ return ret;
+}
+
+static
+int ust_regenerate_metadata(struct ltt_ust_session *usess)
+{
+ int ret = 0;
+ struct buffer_reg_uid *uid_reg = NULL;
+ struct buffer_reg_session *session_reg = NULL;
+
+ rcu_read_lock();
+ cds_list_for_each_entry(uid_reg, &usess->buffer_reg_uid_list, lnode) {
+ struct ust_registry_session *registry;
+ struct ust_registry_channel *chan;
+ struct lttng_ht_iter iter_chan;
+
+ session_reg = uid_reg->registry;
+ registry = session_reg->reg.ust;
+
+ pthread_mutex_lock(®istry->lock);
+ registry->metadata_len_sent = 0;
+ memset(registry->metadata, 0, registry->metadata_alloc_len);
+ registry->metadata_len = 0;
+ registry->metadata_version++;
+ if (registry->metadata_fd > 0) {
+ /* Clear the metadata file's content. */
+ ret = clear_metadata_file(registry->metadata_fd);
+ if (ret) {
+ pthread_mutex_unlock(®istry->lock);
+ goto end;
+ }
+ }
+
+ ret = ust_metadata_session_statedump(registry, NULL,
+ registry->major, registry->minor);
+ if (ret) {
+ pthread_mutex_unlock(®istry->lock);
+ ERR("Failed to generate session metadata (err = %d)",
+ ret);
+ goto end;
+ }
+ cds_lfht_for_each_entry(registry->channels->ht, &iter_chan.iter,
+ chan, node.node) {
+ struct ust_registry_event *event;
+ struct lttng_ht_iter iter_event;
+
+ ret = ust_metadata_channel_statedump(registry, chan);
+ if (ret) {
+ pthread_mutex_unlock(®istry->lock);
+ ERR("Failed to generate channel metadata "
+ "(err = %d)", ret);
+ goto end;
+ }
+ cds_lfht_for_each_entry(chan->ht->ht, &iter_event.iter,
+ event, node.node) {
+ ret = ust_metadata_event_statedump(registry,
+ chan, event);
+ if (ret) {
+ pthread_mutex_unlock(®istry->lock);
+ ERR("Failed to generate event metadata "
+ "(err = %d)", ret);
+ goto end;
+ }
+ }
+ }
+ pthread_mutex_unlock(®istry->lock);
+ }
+
+end:
+ rcu_read_unlock();
+ return ret;
+}
+
+/*
+ * Command LTTNG_REGENERATE_METADATA from the lttng-ctl library.
+ *
+ * Ask the consumer to truncate the existing metadata file(s) and
+ * then regenerate the metadata. Live and per-pid sessions are not
+ * supported and return an error.
+ *
+ * Return 0 on success or else a LTTNG_ERR code.
+ */
+int cmd_regenerate_metadata(struct ltt_session *session)
+{
+ int ret;
+
+ assert(session);
+
+ ret = check_regenerate_metadata_support(session);
+ if (ret) {
+ goto end;
+ }
+
+ if (session->kernel_session) {
+ ret = kernctl_session_regenerate_metadata(
+ session->kernel_session->fd);
+ if (ret < 0) {
+ ERR("Failed to regenerate the kernel metadata");
+ goto end;
+ }
+ }
+
+ if (session->ust_session) {
+ ret = ust_regenerate_metadata(session->ust_session);
+ if (ret < 0) {
+ ERR("Failed to regenerate the UST metadata");
+ goto end;
+ }
+ }
+ DBG("Cmd metadata regenerate for session %s", session->name);
+ ret = LTTNG_OK;
+
+end:
+ return ret;
+}
+
+/*
+ * Command LTTNG_REGENERATE_STATEDUMP from the lttng-ctl library.
+ *
+ * Ask the tracer to regenerate a new statedump.
+ *
+ * Return 0 on success or else a LTTNG_ERR code.
+ */
+int cmd_regenerate_statedump(struct ltt_session *session)
+{
+ int ret;
+
+ assert(session);
+
+ if (!session->active) {
+ ret = LTTNG_ERR_SESSION_NOT_STARTED;
+ goto end;
+ }
+
+ if (session->kernel_session) {
+ ret = kernctl_session_regenerate_statedump(
+ session->kernel_session->fd);
+ /*
+ * Currently, the statedump in kernel can only fail if out
+ * of memory.
+ */
+ if (ret < 0) {
+ if (ret == -ENOMEM) {
+ ret = LTTNG_ERR_REGEN_STATEDUMP_NOMEM;
+ } else {
+ ret = LTTNG_ERR_REGEN_STATEDUMP_FAIL;
+ }
+ ERR("Failed to regenerate the kernel statedump");
+ goto end;
+ }
+ }
+
+ if (session->ust_session) {
+ ret = ust_app_regenerate_statedump_all(session->ust_session);
+ /*
+ * Currently, the statedump in UST always returns 0.
+ */
+ if (ret < 0) {
+ ret = LTTNG_ERR_REGEN_STATEDUMP_FAIL;
+ ERR("Failed to regenerate the UST statedump");
+ goto end;
+ }
+ }
+ DBG("Cmd regenerate statedump for session %s", session->name);
+ ret = LTTNG_OK;
+
+end:
+ return ret;
+}
+
+int cmd_register_trigger(struct command_ctx *cmd_ctx, int sock,
+ struct notification_thread_handle *notification_thread)
+{
+ int ret;
+ size_t trigger_len;
+ ssize_t sock_recv_len;
+ struct lttng_trigger *trigger = NULL;
+ struct lttng_buffer_view view;
+ struct lttng_dynamic_buffer trigger_buffer;
+
+ lttng_dynamic_buffer_init(&trigger_buffer);
+ trigger_len = (size_t) cmd_ctx->lsm->u.trigger.length;
+ ret = lttng_dynamic_buffer_set_size(&trigger_buffer, trigger_len);
+ if (ret) {
+ ret = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+
+ sock_recv_len = lttcomm_recv_unix_sock(sock, trigger_buffer.data,
+ trigger_len);
+ if (sock_recv_len < 0 || sock_recv_len != trigger_len) {
+ ERR("Failed to receive \"register trigger\" command payload");
+ /* TODO: should this be a new error enum ? */
+ ret = LTTNG_ERR_INVALID_TRIGGER;
+ goto end;
+ }
+
+ view = lttng_buffer_view_from_dynamic_buffer(&trigger_buffer, 0, -1);
+ if (lttng_trigger_create_from_buffer(&view, &trigger) !=
+ trigger_len) {
+ ERR("Invalid trigger payload received in \"register trigger\" command");
+ ret = LTTNG_ERR_INVALID_TRIGGER;
+ goto end;
+ }
+
+ ret = notification_thread_command_register_trigger(notification_thread,
+ trigger);
+ /* Ownership of trigger was transferred. */
+ trigger = NULL;
+end:
+ lttng_trigger_destroy(trigger);
+ lttng_dynamic_buffer_reset(&trigger_buffer);
+ return ret;
+}
+
+int cmd_unregister_trigger(struct command_ctx *cmd_ctx, int sock,
+ struct notification_thread_handle *notification_thread)
+{
+ int ret;
+ size_t trigger_len;
+ ssize_t sock_recv_len;
+ struct lttng_trigger *trigger = NULL;
+ struct lttng_buffer_view view;
+ struct lttng_dynamic_buffer trigger_buffer;
+
+ lttng_dynamic_buffer_init(&trigger_buffer);
+ trigger_len = (size_t) cmd_ctx->lsm->u.trigger.length;
+ ret = lttng_dynamic_buffer_set_size(&trigger_buffer, trigger_len);
+ if (ret) {
+ ret = LTTNG_ERR_NOMEM;
+ goto end;
+ }
+
+ sock_recv_len = lttcomm_recv_unix_sock(sock, trigger_buffer.data,
+ trigger_len);
+ if (sock_recv_len < 0 || sock_recv_len != trigger_len) {
+ ERR("Failed to receive \"unregister trigger\" command payload");
+ /* TODO: should this be a new error enum ? */
+ ret = LTTNG_ERR_INVALID_TRIGGER;
+ goto end;
+ }
+
+ view = lttng_buffer_view_from_dynamic_buffer(&trigger_buffer, 0, -1);
+ if (lttng_trigger_create_from_buffer(&view, &trigger) !=
+ trigger_len) {
+ ERR("Invalid trigger payload received in \"unregister trigger\" command");
+ ret = LTTNG_ERR_INVALID_TRIGGER;
+ goto end;
+ }
+
+ ret = notification_thread_command_unregister_trigger(notification_thread,
+ trigger);
+end:
+ lttng_trigger_destroy(trigger);
+ lttng_dynamic_buffer_reset(&trigger_buffer);
+ return ret;
+}
+
+/*
+ * Send relayd sockets from snapshot output to consumer. Ignore request if the
+ * snapshot output is *not* set with a remote destination.
+ *
+ * Return 0 on success or a LTTNG_ERR code.
+ */
+static int set_relayd_for_snapshot(struct consumer_output *consumer,
+ struct snapshot_output *snap_output, struct ltt_session *session)
+{
+ int ret = LTTNG_OK;