+
+error:
+ return ret;
+}
+
+/*
+ * Send channel to sessiond.
+ *
+ * Return 0 on success or else a negative value.
+ */
+static int send_sessiond_channel(int sock,
+ struct lttng_consumer_channel *channel,
+ struct lttng_consumer_local_data *ctx, int *relayd_error)
+{
+ int ret, ret_code = LTTCOMM_CONSUMERD_SUCCESS;
+ struct lttng_consumer_stream *stream;
+ uint64_t net_seq_idx = -1ULL;
+
+ assert(channel);
+ assert(ctx);
+ assert(sock >= 0);
+
+ DBG("UST consumer sending channel %s to sessiond", channel->name);
+
+ if (channel->relayd_id != (uint64_t) -1ULL) {
+ cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
+
+ health_code_update();
+
+ /* Try to send the stream to the relayd if one is available. */
+ ret = consumer_send_relayd_stream(stream, stream->chan->pathname);
+ if (ret < 0) {
+ /*
+ * Flag that the relayd was the problem here probably due to a
+ * communicaton error on the socket.
+ */
+ if (relayd_error) {
+ *relayd_error = 1;
+ }
+ ret_code = LTTCOMM_CONSUMERD_RELAYD_FAIL;
+ }
+ if (net_seq_idx == -1ULL) {
+ net_seq_idx = stream->net_seq_idx;
+ }
+ }
+ }
+
+ /* Inform sessiond that we are about to send channel and streams. */
+ ret = consumer_send_status_msg(sock, ret_code);
+ if (ret < 0 || ret_code != LTTCOMM_CONSUMERD_SUCCESS) {
+ /*
+ * Either the session daemon is not responding or the relayd died so we
+ * stop now.
+ */
+ goto error;
+ }
+
+ /* Send channel to sessiond. */
+ ret = ustctl_send_channel_to_sessiond(sock, channel->uchan);
+ if (ret < 0) {
+ goto error;
+ }
+
+ ret = ustctl_channel_close_wakeup_fd(channel->uchan);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* The channel was sent successfully to the sessiond at this point. */
+ cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
+
+ health_code_update();
+
+ /* Send stream to session daemon. */
+ ret = send_sessiond_stream(sock, stream);
+ if (ret < 0) {
+ goto error;
+ }
+ }
+
+ /* Tell sessiond there is no more stream. */
+ ret = ustctl_send_stream_to_sessiond(sock, NULL);
+ if (ret < 0) {
+ goto error;
+ }
+
+ DBG("UST consumer NULL stream sent to sessiond");
+
+ return 0;
+
+error:
+ if (ret_code != LTTCOMM_CONSUMERD_SUCCESS) {
+ ret = -1;
+ }
+ return ret;
+}
+
+/*
+ * Creates a channel and streams and add the channel it to the channel internal
+ * state. The created stream must ONLY be sent once the GET_CHANNEL command is
+ * received.
+ *
+ * Return 0 on success or else, a negative value is returned and the channel
+ * MUST be destroyed by consumer_del_channel().
+ */
+static int ask_channel(struct lttng_consumer_local_data *ctx, int sock,
+ struct lttng_consumer_channel *channel,
+ struct ustctl_consumer_channel_attr *attr)
+{
+ int ret;
+
+ assert(ctx);
+ assert(channel);
+ assert(attr);
+
+ /*
+ * This value is still used by the kernel consumer since for the kernel,
+ * the stream ownership is not IN the consumer so we need to have the
+ * number of left stream that needs to be initialized so we can know when
+ * to delete the channel (see consumer.c).
+ *
+ * As for the user space tracer now, the consumer creates and sends the
+ * stream to the session daemon which only sends them to the application
+ * once every stream of a channel is received making this value useless
+ * because we they will be added to the poll thread before the application
+ * receives them. This ensures that a stream can not hang up during
+ * initilization of a channel.
+ */
+ channel->nb_init_stream_left = 0;
+
+ /* The reply msg status is handled in the following call. */
+ ret = create_ust_channel(channel, attr, &channel->uchan);
+ if (ret < 0) {
+ goto end;
+ }
+
+ channel->wait_fd = ustctl_channel_get_wait_fd(channel->uchan);
+
+ /*
+ * For the snapshots (no monitor), we create the metadata streams
+ * on demand, not during the channel creation.
+ */
+ if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA && !channel->monitor) {
+ ret = 0;
+ goto end;
+ }
+
+ /* Open all streams for this channel. */
+ ret = create_ust_streams(channel, ctx);
+ if (ret < 0) {
+ goto end;
+ }
+
+end:
+ return ret;
+}
+
+/*
+ * Send all stream of a channel to the right thread handling it.
+ *
+ * On error, return a negative value else 0 on success.
+ */
+static int send_streams_to_thread(struct lttng_consumer_channel *channel,
+ struct lttng_consumer_local_data *ctx)
+{
+ int ret = 0;
+ struct lttng_consumer_stream *stream, *stmp;
+
+ assert(channel);
+ assert(ctx);
+
+ /* Send streams to the corresponding thread. */
+ cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head,
+ send_node) {
+
+ health_code_update();
+
+ /* Sending the stream to the thread. */
+ ret = send_stream_to_thread(stream, ctx);
+ if (ret < 0) {
+ /*
+ * If we are unable to send the stream to the thread, there is
+ * a big problem so just stop everything.
+ */
+ /* Remove node from the channel stream list. */
+ cds_list_del(&stream->send_node);
+ goto error;
+ }
+
+ /* Remove node from the channel stream list. */
+ cds_list_del(&stream->send_node);
+
+ }
+
+error:
+ return ret;
+}
+
+/*
+ * Flush channel's streams using the given key to retrieve the channel.
+ *
+ * Return 0 on success else an LTTng error code.
+ */
+static int flush_channel(uint64_t chan_key)
+{
+ int ret = 0;
+ struct lttng_consumer_channel *channel;
+ struct lttng_consumer_stream *stream;
+ struct lttng_ht *ht;
+ struct lttng_ht_iter iter;
+
+ DBG("UST consumer flush channel key %" PRIu64, chan_key);
+
+ rcu_read_lock();
+ channel = consumer_find_channel(chan_key);
+ if (!channel) {
+ ERR("UST consumer flush channel %" PRIu64 " not found", chan_key);
+ ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
+ goto error;
+ }
+
+ ht = consumer_data.stream_per_chan_id_ht;
+
+ /* For each stream of the channel id, flush it. */
+ cds_lfht_for_each_entry_duplicate(ht->ht,
+ ht->hash_fct(&channel->key, lttng_ht_seed), ht->match_fct,
+ &channel->key, &iter.iter, stream, node_channel_id.node) {
+
+ health_code_update();
+
+ ustctl_flush_buffer(stream->ustream, 1);
+ }
+error:
+ rcu_read_unlock();
+ return ret;
+}
+
+/*
+ * Close metadata stream wakeup_fd using the given key to retrieve the channel.
+ * RCU read side lock MUST be acquired before calling this function.
+ *
+ * Return 0 on success else an LTTng error code.
+ */
+static int close_metadata(uint64_t chan_key)
+{
+ int ret = 0;
+ struct lttng_consumer_channel *channel;
+
+ DBG("UST consumer close metadata key %" PRIu64, chan_key);
+
+ channel = consumer_find_channel(chan_key);
+ if (!channel) {
+ /*
+ * This is possible if the metadata thread has issue a delete because
+ * the endpoint point of the stream hung up. There is no way the
+ * session daemon can know about it thus use a DBG instead of an actual
+ * error.
+ */
+ DBG("UST consumer close metadata %" PRIu64 " not found", chan_key);
+ ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
+ goto error;
+ }
+
+ pthread_mutex_lock(&consumer_data.lock);
+ pthread_mutex_lock(&channel->lock);
+
+ if (cds_lfht_is_node_deleted(&channel->node.node)) {
+ goto error_unlock;
+ }
+
+ lttng_ustconsumer_close_metadata(channel);
+
+error_unlock:
+ pthread_mutex_unlock(&channel->lock);
+ pthread_mutex_unlock(&consumer_data.lock);
+error:
+ return ret;
+}
+
+/*
+ * RCU read side lock MUST be acquired before calling this function.
+ *
+ * Return 0 on success else an LTTng error code.
+ */
+static int setup_metadata(struct lttng_consumer_local_data *ctx, uint64_t key)
+{
+ int ret;
+ struct lttng_consumer_channel *metadata;
+
+ DBG("UST consumer setup metadata key %" PRIu64, key);
+
+ metadata = consumer_find_channel(key);
+ if (!metadata) {
+ ERR("UST consumer push metadata %" PRIu64 " not found", key);
+ ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
+ goto end;
+ }
+
+ /*
+ * In no monitor mode, the metadata channel has no stream(s) so skip the
+ * ownership transfer to the metadata thread.
+ */
+ if (!metadata->monitor) {
+ DBG("Metadata channel in no monitor");
+ ret = 0;
+ goto end;
+ }
+
+ /*
+ * Send metadata stream to relayd if one available. Availability is
+ * known if the stream is still in the list of the channel.
+ */
+ if (cds_list_empty(&metadata->streams.head)) {
+ ERR("Metadata channel key %" PRIu64 ", no stream available.", key);
+ ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
+ goto error_no_stream;
+ }
+
+ /* Send metadata stream to relayd if needed. */
+ if (metadata->metadata_stream->net_seq_idx != (uint64_t) -1ULL) {
+ ret = consumer_send_relayd_stream(metadata->metadata_stream,
+ metadata->pathname);
+ if (ret < 0) {
+ ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
+ goto error;
+ }
+ ret = consumer_send_relayd_streams_sent(
+ metadata->metadata_stream->net_seq_idx);
+ if (ret < 0) {
+ ret = LTTCOMM_CONSUMERD_RELAYD_FAIL;
+ goto error;
+ }
+ }
+
+ ret = send_streams_to_thread(metadata, ctx);
+ if (ret < 0) {
+ /*
+ * If we are unable to send the stream to the thread, there is
+ * a big problem so just stop everything.
+ */
+ ret = LTTCOMM_CONSUMERD_FATAL;
+ goto error;
+ }
+ /* List MUST be empty after or else it could be reused. */
+ assert(cds_list_empty(&metadata->streams.head));
+
+ ret = 0;
+ goto end;
+
+error:
+ /*
+ * Delete metadata channel on error. At this point, the metadata stream can
+ * NOT be monitored by the metadata thread thus having the guarantee that
+ * the stream is still in the local stream list of the channel. This call
+ * will make sure to clean that list.
+ */
+ consumer_stream_destroy(metadata->metadata_stream, NULL);
+ cds_list_del(&metadata->metadata_stream->send_node);
+ metadata->metadata_stream = NULL;
+error_no_stream:
+end:
+ return ret;
+}
+
+/*
+ * Snapshot the whole metadata.
+ *
+ * Returns 0 on success, < 0 on error
+ */
+static int snapshot_metadata(uint64_t key, char *path, uint64_t relayd_id,
+ struct lttng_consumer_local_data *ctx)
+{
+ int ret = 0;
+ struct lttng_consumer_channel *metadata_channel;
+ struct lttng_consumer_stream *metadata_stream;
+
+ assert(path);
+ assert(ctx);
+
+ DBG("UST consumer snapshot metadata with key %" PRIu64 " at path %s",
+ key, path);
+
+ rcu_read_lock();
+
+ metadata_channel = consumer_find_channel(key);
+ if (!metadata_channel) {
+ ERR("UST snapshot metadata channel not found for key %" PRIu64,
+ key);
+ ret = -1;
+ goto error;
+ }
+ assert(!metadata_channel->monitor);
+
+ health_code_update();
+
+ /*
+ * Ask the sessiond if we have new metadata waiting and update the
+ * consumer metadata cache.
+ */
+ ret = lttng_ustconsumer_request_metadata(ctx, metadata_channel, 0, 1);
+ if (ret < 0) {
+ goto error;
+ }
+
+ health_code_update();
+
+ /*
+ * The metadata stream is NOT created in no monitor mode when the channel
+ * is created on a sessiond ask channel command.
+ */
+ ret = create_ust_streams(metadata_channel, ctx);
+ if (ret < 0) {
+ goto error;
+ }
+
+ metadata_stream = metadata_channel->metadata_stream;
+ assert(metadata_stream);
+
+ if (relayd_id != (uint64_t) -1ULL) {
+ metadata_stream->net_seq_idx = relayd_id;
+ ret = consumer_send_relayd_stream(metadata_stream, path);
+ if (ret < 0) {
+ goto error_stream;
+ }
+ } else {
+ ret = utils_create_stream_file(path, metadata_stream->name,
+ metadata_stream->chan->tracefile_size,
+ metadata_stream->tracefile_count_current,
+ metadata_stream->uid, metadata_stream->gid, NULL);
+ if (ret < 0) {
+ goto error_stream;
+ }
+ metadata_stream->out_fd = ret;
+ metadata_stream->tracefile_size_current = 0;
+ }
+
+ do {
+ health_code_update();
+
+ ret = lttng_consumer_read_subbuffer(metadata_stream, ctx);
+ if (ret < 0) {
+ goto error_stream;
+ }
+ } while (ret > 0);
+
+error_stream:
+ /*
+ * Clean up the stream completly because the next snapshot will use a new
+ * metadata stream.
+ */
+ consumer_stream_destroy(metadata_stream, NULL);
+ cds_list_del(&metadata_stream->send_node);
+ metadata_channel->metadata_stream = NULL;
+
+error:
+ rcu_read_unlock();
+ return ret;
+}
+
+/*
+ * Take a snapshot of all the stream of a channel.
+ *
+ * Returns 0 on success, < 0 on error
+ */
+static int snapshot_channel(uint64_t key, char *path, uint64_t relayd_id,
+ uint64_t nb_packets_per_stream, struct lttng_consumer_local_data *ctx)
+{
+ int ret;
+ unsigned use_relayd = 0;
+ unsigned long consumed_pos, produced_pos;
+ struct lttng_consumer_channel *channel;
+ struct lttng_consumer_stream *stream;
+
+ assert(path);
+ assert(ctx);
+
+ rcu_read_lock();
+
+ if (relayd_id != (uint64_t) -1ULL) {
+ use_relayd = 1;
+ }
+
+ channel = consumer_find_channel(key);
+ if (!channel) {
+ ERR("UST snapshot channel not found for key %" PRIu64, key);
+ ret = -1;
+ goto error;
+ }
+ assert(!channel->monitor);
+ DBG("UST consumer snapshot channel %" PRIu64, key);
+
+ cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
+
+ health_code_update();
+
+ /* Lock stream because we are about to change its state. */
+ pthread_mutex_lock(&stream->lock);
+ stream->net_seq_idx = relayd_id;
+
+ if (use_relayd) {
+ ret = consumer_send_relayd_stream(stream, path);
+ if (ret < 0) {
+ goto error_unlock;
+ }
+ } else {
+ ret = utils_create_stream_file(path, stream->name,
+ stream->chan->tracefile_size,
+ stream->tracefile_count_current,
+ stream->uid, stream->gid, NULL);
+ if (ret < 0) {
+ goto error_unlock;
+ }
+ stream->out_fd = ret;
+ stream->tracefile_size_current = 0;
+
+ DBG("UST consumer snapshot stream %s/%s (%" PRIu64 ")", path,
+ stream->name, stream->key);
+ }
+ if (relayd_id != -1ULL) {
+ ret = consumer_send_relayd_streams_sent(relayd_id);
+ if (ret < 0) {
+ goto error_unlock;
+ }
+ }
+
+ ustctl_flush_buffer(stream->ustream, 1);
+
+ ret = lttng_ustconsumer_take_snapshot(stream);
+ if (ret < 0) {
+ ERR("Taking UST snapshot");
+ goto error_unlock;
+ }
+
+ ret = lttng_ustconsumer_get_produced_snapshot(stream, &produced_pos);
+ if (ret < 0) {
+ ERR("Produced UST snapshot position");
+ goto error_unlock;
+ }
+
+ ret = lttng_ustconsumer_get_consumed_snapshot(stream, &consumed_pos);
+ if (ret < 0) {
+ ERR("Consumerd UST snapshot position");
+ goto error_unlock;
+ }
+
+ /*
+ * The original value is sent back if max stream size is larger than
+ * the possible size of the snapshot. Also, we assume that the session
+ * daemon should never send a maximum stream size that is lower than
+ * subbuffer size.
+ */
+ consumed_pos = consumer_get_consume_start_pos(consumed_pos,
+ produced_pos, nb_packets_per_stream,
+ stream->max_sb_size);
+
+ while (consumed_pos < produced_pos) {
+ ssize_t read_len;
+ unsigned long len, padded_len;
+
+ health_code_update();
+
+ DBG("UST consumer taking snapshot at pos %lu", consumed_pos);
+
+ ret = ustctl_get_subbuf(stream->ustream, &consumed_pos);
+ if (ret < 0) {
+ if (ret != -EAGAIN) {
+ PERROR("ustctl_get_subbuf snapshot");
+ goto error_close_stream;
+ }
+ DBG("UST consumer get subbuf failed. Skipping it.");
+ consumed_pos += stream->max_sb_size;
+ continue;
+ }
+
+ ret = ustctl_get_subbuf_size(stream->ustream, &len);
+ if (ret < 0) {
+ ERR("Snapshot ustctl_get_subbuf_size");
+ goto error_put_subbuf;
+ }
+
+ ret = ustctl_get_padded_subbuf_size(stream->ustream, &padded_len);
+ if (ret < 0) {
+ ERR("Snapshot ustctl_get_padded_subbuf_size");
+ goto error_put_subbuf;
+ }
+
+ read_len = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len,
+ padded_len - len, NULL);
+ if (use_relayd) {
+ if (read_len != len) {
+ ret = -EPERM;
+ goto error_put_subbuf;
+ }
+ } else {
+ if (read_len != padded_len) {
+ ret = -EPERM;
+ goto error_put_subbuf;
+ }
+ }
+
+ ret = ustctl_put_subbuf(stream->ustream);
+ if (ret < 0) {
+ ERR("Snapshot ustctl_put_subbuf");
+ goto error_close_stream;
+ }
+ consumed_pos += stream->max_sb_size;
+ }
+
+ /* Simply close the stream so we can use it on the next snapshot. */
+ consumer_stream_close(stream);
+ pthread_mutex_unlock(&stream->lock);
+ }
+
+ rcu_read_unlock();
+ return 0;
+
+error_put_subbuf:
+ if (ustctl_put_subbuf(stream->ustream) < 0) {
+ ERR("Snapshot ustctl_put_subbuf");
+ }
+error_close_stream:
+ consumer_stream_close(stream);
+error_unlock:
+ pthread_mutex_unlock(&stream->lock);
+error:
+ rcu_read_unlock();
+ return ret;
+}
+
+/*
+ * Receive the metadata updates from the sessiond. Supports receiving
+ * overlapping metadata, but is needs to always belong to a contiguous
+ * range starting from 0.
+ * Be careful about the locks held when calling this function: it needs
+ * the metadata cache flush to concurrently progress in order to
+ * complete.
+ */
+int lttng_ustconsumer_recv_metadata(int sock, uint64_t key, uint64_t offset,
+ uint64_t len, struct lttng_consumer_channel *channel,
+ int timer, int wait)
+{
+ int ret, ret_code = LTTCOMM_CONSUMERD_SUCCESS;
+ char *metadata_str;
+
+ DBG("UST consumer push metadata key %" PRIu64 " of len %" PRIu64, key, len);
+
+ metadata_str = zmalloc(len * sizeof(char));
+ if (!metadata_str) {
+ PERROR("zmalloc metadata string");
+ ret_code = LTTCOMM_CONSUMERD_ENOMEM;
+ goto end;
+ }
+
+ health_code_update();
+
+ /* Receive metadata string. */
+ ret = lttcomm_recv_unix_sock(sock, metadata_str, len);
+ if (ret < 0) {
+ /* Session daemon is dead so return gracefully. */
+ ret_code = ret;
+ goto end_free;
+ }
+
+ health_code_update();
+
+ pthread_mutex_lock(&channel->metadata_cache->lock);
+ ret = consumer_metadata_cache_write(channel, offset, len, metadata_str);
+ if (ret < 0) {
+ /* Unable to handle metadata. Notify session daemon. */
+ ret_code = LTTCOMM_CONSUMERD_ERROR_METADATA;
+ /*
+ * Skip metadata flush on write error since the offset and len might
+ * not have been updated which could create an infinite loop below when
+ * waiting for the metadata cache to be flushed.
+ */
+ pthread_mutex_unlock(&channel->metadata_cache->lock);
+ goto end_free;
+ }
+ pthread_mutex_unlock(&channel->metadata_cache->lock);
+
+ if (!wait) {
+ goto end_free;
+ }
+ while (consumer_metadata_cache_flushed(channel, offset + len, timer)) {
+ DBG("Waiting for metadata to be flushed");
+
+ health_code_update();
+
+ usleep(DEFAULT_METADATA_AVAILABILITY_WAIT_TIME);
+ }
+
+end_free:
+ free(metadata_str);
+end:
+ return ret_code;
+}
+
+/*
+ * Receive command from session daemon and process it.
+ *
+ * Return 1 on success else a negative value or 0.
+ */
+int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
+ int sock, struct pollfd *consumer_sockpoll)
+{
+ ssize_t ret;
+ enum lttcomm_return_code ret_code = LTTCOMM_CONSUMERD_SUCCESS;
+ struct lttcomm_consumer_msg msg;
+ struct lttng_consumer_channel *channel = NULL;
+
+ health_code_update();
+
+ ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg));
+ if (ret != sizeof(msg)) {
+ DBG("Consumer received unexpected message size %zd (expects %zu)",
+ ret, sizeof(msg));
+ /*
+ * The ret value might 0 meaning an orderly shutdown but this is ok
+ * since the caller handles this.
+ */
+ if (ret > 0) {
+ lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD);
+ ret = -1;
+ }
+ return ret;
+ }
+
+ health_code_update();
+
+ /* deprecated */
+ assert(msg.cmd_type != LTTNG_CONSUMER_STOP);
+
+ health_code_update();
+
+ /* relayd needs RCU read-side lock */
+ rcu_read_lock();
+
+ switch (msg.cmd_type) {
+ case LTTNG_CONSUMER_ADD_RELAYD_SOCKET:
+ {
+ /* Session daemon status message are handled in the following call. */
+ ret = consumer_add_relayd_socket(msg.u.relayd_sock.net_index,
+ msg.u.relayd_sock.type, ctx, sock, consumer_sockpoll,
+ &msg.u.relayd_sock.sock, msg.u.relayd_sock.session_id,
+ msg.u.relayd_sock.relayd_session_id);
+ goto end_nosignal;
+ }
+ case LTTNG_CONSUMER_DESTROY_RELAYD:
+ {
+ uint64_t index = msg.u.destroy_relayd.net_seq_idx;
+ struct consumer_relayd_sock_pair *relayd;
+
+ DBG("UST consumer destroying relayd %" PRIu64, index);
+
+ /* Get relayd reference if exists. */
+ relayd = consumer_find_relayd(index);
+ if (relayd == NULL) {
+ DBG("Unable to find relayd %" PRIu64, index);
+ ret_code = LTTCOMM_CONSUMERD_RELAYD_FAIL;
+ }
+
+ /*
+ * Each relayd socket pair has a refcount of stream attached to it
+ * which tells if the relayd is still active or not depending on the
+ * refcount value.
+ *
+ * This will set the destroy flag of the relayd object and destroy it
+ * if the refcount reaches zero when called.
+ *
+ * The destroy can happen either here or when a stream fd hangs up.
+ */
+ if (relayd) {
+ consumer_flag_relayd_for_destroy(relayd);
+ }
+
+ goto end_msg_sessiond;
+ }
+ case LTTNG_CONSUMER_UPDATE_STREAM:
+ {
+ rcu_read_unlock();
+ return -ENOSYS;
+ }
+ case LTTNG_CONSUMER_DATA_PENDING:
+ {
+ int ret, is_data_pending;
+ uint64_t id = msg.u.data_pending.session_id;
+
+ DBG("UST consumer data pending command for id %" PRIu64, id);
+
+ is_data_pending = consumer_data_pending(id);
+
+ /* Send back returned value to session daemon */
+ ret = lttcomm_send_unix_sock(sock, &is_data_pending,
+ sizeof(is_data_pending));
+ if (ret < 0) {
+ DBG("Error when sending the data pending ret code: %d", ret);
+ goto error_fatal;
+ }
+
+ /*
+ * No need to send back a status message since the data pending
+ * returned value is the response.
+ */
+ break;
+ }
+ case LTTNG_CONSUMER_ASK_CHANNEL_CREATION:
+ {
+ int ret;
+ struct ustctl_consumer_channel_attr attr;
+
+ /* Create a plain object and reserve a channel key. */
+ channel = allocate_channel(msg.u.ask_channel.session_id,
+ msg.u.ask_channel.pathname, msg.u.ask_channel.name,
+ msg.u.ask_channel.uid, msg.u.ask_channel.gid,
+ msg.u.ask_channel.relayd_id, msg.u.ask_channel.key,
+ (enum lttng_event_output) msg.u.ask_channel.output,
+ msg.u.ask_channel.tracefile_size,
+ msg.u.ask_channel.tracefile_count,
+ msg.u.ask_channel.session_id_per_pid,
+ msg.u.ask_channel.monitor,
+ msg.u.ask_channel.live_timer_interval,
+ msg.u.ask_channel.root_shm_path,
+ msg.u.ask_channel.shm_path);
+ if (!channel) {
+ goto end_channel_error;
+ }
+
+ /*
+ * Assign UST application UID to the channel. This value is ignored for
+ * per PID buffers. This is specific to UST thus setting this after the
+ * allocation.
+ */
+ channel->ust_app_uid = msg.u.ask_channel.ust_app_uid;
+
+ /* Build channel attributes from received message. */
+ attr.subbuf_size = msg.u.ask_channel.subbuf_size;
+ attr.num_subbuf = msg.u.ask_channel.num_subbuf;
+ attr.overwrite = msg.u.ask_channel.overwrite;
+ attr.switch_timer_interval = msg.u.ask_channel.switch_timer_interval;
+ attr.read_timer_interval = msg.u.ask_channel.read_timer_interval;
+ attr.chan_id = msg.u.ask_channel.chan_id;
+ memcpy(attr.uuid, msg.u.ask_channel.uuid, sizeof(attr.uuid));
+
+ /* Match channel buffer type to the UST abi. */
+ switch (msg.u.ask_channel.output) {
+ case LTTNG_EVENT_MMAP:
+ default:
+ attr.output = LTTNG_UST_MMAP;
+ break;
+ }
+
+ /* Translate and save channel type. */
+ switch (msg.u.ask_channel.type) {
+ case LTTNG_UST_CHAN_PER_CPU:
+ channel->type = CONSUMER_CHANNEL_TYPE_DATA;
+ attr.type = LTTNG_UST_CHAN_PER_CPU;
+ /*
+ * Set refcount to 1 for owner. Below, we will
+ * pass ownership to the
+ * consumer_thread_channel_poll() thread.
+ */
+ channel->refcount = 1;
+ break;
+ case LTTNG_UST_CHAN_METADATA:
+ channel->type = CONSUMER_CHANNEL_TYPE_METADATA;
+ attr.type = LTTNG_UST_CHAN_METADATA;
+ break;
+ default:
+ assert(0);
+ goto error_fatal;
+ };
+
+ health_code_update();
+
+ ret = ask_channel(ctx, sock, channel, &attr);
+ if (ret < 0) {
+ goto end_channel_error;
+ }
+
+ if (msg.u.ask_channel.type == LTTNG_UST_CHAN_METADATA) {
+ ret = consumer_metadata_cache_allocate(channel);
+ if (ret < 0) {
+ ERR("Allocating metadata cache");
+ goto end_channel_error;
+ }
+ consumer_timer_switch_start(channel, attr.switch_timer_interval);
+ attr.switch_timer_interval = 0;
+ } else {
+ consumer_timer_live_start(channel,
+ msg.u.ask_channel.live_timer_interval);
+ }
+
+ health_code_update();
+
+ /*
+ * Add the channel to the internal state AFTER all streams were created
+ * and successfully sent to session daemon. This way, all streams must
+ * be ready before this channel is visible to the threads.
+ * If add_channel succeeds, ownership of the channel is
+ * passed to consumer_thread_channel_poll().
+ */
+ ret = add_channel(channel, ctx);
+ if (ret < 0) {
+ if (msg.u.ask_channel.type == LTTNG_UST_CHAN_METADATA) {
+ if (channel->switch_timer_enabled == 1) {
+ consumer_timer_switch_stop(channel);
+ }
+ consumer_metadata_cache_destroy(channel);
+ }
+ if (channel->live_timer_enabled == 1) {
+ consumer_timer_live_stop(channel);
+ }
+ goto end_channel_error;
+ }
+
+ health_code_update();
+
+ /*
+ * Channel and streams are now created. Inform the session daemon that
+ * everything went well and should wait to receive the channel and
+ * streams with ustctl API.
+ */
+ ret = consumer_send_status_channel(sock, channel);
+ if (ret < 0) {
+ /*
+ * There is probably a problem on the socket.
+ */
+ goto error_fatal;
+ }
+
+ break;
+ }
+ case LTTNG_CONSUMER_GET_CHANNEL:
+ {
+ int ret, relayd_err = 0;
+ uint64_t key = msg.u.get_channel.key;
+ struct lttng_consumer_channel *channel;
+
+ channel = consumer_find_channel(key);
+ if (!channel) {
+ ERR("UST consumer get channel key %" PRIu64 " not found", key);
+ ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND;
+ goto end_msg_sessiond;
+ }
+
+ health_code_update();
+
+ /* Send everything to sessiond. */
+ ret = send_sessiond_channel(sock, channel, ctx, &relayd_err);
+ if (ret < 0) {
+ if (relayd_err) {
+ /*
+ * We were unable to send to the relayd the stream so avoid
+ * sending back a fatal error to the thread since this is OK
+ * and the consumer can continue its work. The above call
+ * has sent the error status message to the sessiond.
+ */
+ goto end_nosignal;
+ }
+ /*
+ * The communicaton was broken hence there is a bad state between
+ * the consumer and sessiond so stop everything.
+ */
+ goto error_fatal;
+ }
+
+ health_code_update();
+
+ /*
+ * In no monitor mode, the streams ownership is kept inside the channel
+ * so don't send them to the data thread.
+ */
+ if (!channel->monitor) {
+ goto end_msg_sessiond;
+ }
+
+ ret = send_streams_to_thread(channel, ctx);
+ if (ret < 0) {
+ /*
+ * If we are unable to send the stream to the thread, there is
+ * a big problem so just stop everything.
+ */
+ goto error_fatal;
+ }
+ /* List MUST be empty after or else it could be reused. */
+ assert(cds_list_empty(&channel->streams.head));
+ goto end_msg_sessiond;
+ }
+ case LTTNG_CONSUMER_DESTROY_CHANNEL:
+ {
+ uint64_t key = msg.u.destroy_channel.key;
+
+ /*
+ * Only called if streams have not been sent to stream
+ * manager thread. However, channel has been sent to
+ * channel manager thread.
+ */
+ notify_thread_del_channel(ctx, key);
+ goto end_msg_sessiond;
+ }
+ case LTTNG_CONSUMER_CLOSE_METADATA:
+ {
+ int ret;
+
+ ret = close_metadata(msg.u.close_metadata.key);
+ if (ret != 0) {
+ ret_code = ret;
+ }
+
+ goto end_msg_sessiond;
+ }
+ case LTTNG_CONSUMER_FLUSH_CHANNEL:
+ {
+ int ret;
+
+ ret = flush_channel(msg.u.flush_channel.key);
+ if (ret != 0) {
+ ret_code = ret;
+ }
+
+ goto end_msg_sessiond;
+ }
+ case LTTNG_CONSUMER_PUSH_METADATA:
+ {
+ int ret;
+ uint64_t len = msg.u.push_metadata.len;
+ uint64_t key = msg.u.push_metadata.key;
+ uint64_t offset = msg.u.push_metadata.target_offset;
+ struct lttng_consumer_channel *channel;
+
+ DBG("UST consumer push metadata key %" PRIu64 " of len %" PRIu64, key,
+ len);
+
+ channel = consumer_find_channel(key);
+ if (!channel) {
+ /*
+ * This is possible if the metadata creation on the consumer side
+ * is in flight vis-a-vis a concurrent push metadata from the
+ * session daemon. Simply return that the channel failed and the
+ * session daemon will handle that message correctly considering
+ * that this race is acceptable thus the DBG() statement here.
+ */
+ DBG("UST consumer push metadata %" PRIu64 " not found", key);
+ ret_code = LTTCOMM_CONSUMERD_CHANNEL_FAIL;
+ goto end_msg_sessiond;
+ }
+
+ health_code_update();
+
+ if (!len) {
+ /*
+ * There is nothing to receive. We have simply
+ * checked whether the channel can be found.
+ */
+ ret_code = LTTCOMM_CONSUMERD_SUCCESS;
+ goto end_msg_sessiond;
+ }
+
+ /* Tell session daemon we are ready to receive the metadata. */
+ ret = consumer_send_status_msg(sock, LTTCOMM_CONSUMERD_SUCCESS);
+ if (ret < 0) {
+ /* Somehow, the session daemon is not responding anymore. */
+ goto error_fatal;
+ }
+
+ health_code_update();
+
+ /* Wait for more data. */
+ health_poll_entry();
+ ret = lttng_consumer_poll_socket(consumer_sockpoll);
+ health_poll_exit();
+ if (ret) {
+ goto error_fatal;
+ }
+
+ health_code_update();
+
+ ret = lttng_ustconsumer_recv_metadata(sock, key, offset,
+ len, channel, 0, 1);
+ if (ret < 0) {
+ /* error receiving from sessiond */
+ goto error_fatal;
+ } else {
+ ret_code = ret;
+ goto end_msg_sessiond;
+ }
+ }
+ case LTTNG_CONSUMER_SETUP_METADATA:
+ {
+ int ret;
+
+ ret = setup_metadata(ctx, msg.u.setup_metadata.key);
+ if (ret) {
+ ret_code = ret;
+ }
+ goto end_msg_sessiond;
+ }
+ case LTTNG_CONSUMER_SNAPSHOT_CHANNEL:
+ {
+ if (msg.u.snapshot_channel.metadata) {
+ ret = snapshot_metadata(msg.u.snapshot_channel.key,
+ msg.u.snapshot_channel.pathname,
+ msg.u.snapshot_channel.relayd_id,
+ ctx);
+ if (ret < 0) {
+ ERR("Snapshot metadata failed");
+ ret_code = LTTCOMM_CONSUMERD_ERROR_METADATA;
+ }
+ } else {
+ ret = snapshot_channel(msg.u.snapshot_channel.key,
+ msg.u.snapshot_channel.pathname,
+ msg.u.snapshot_channel.relayd_id,
+ msg.u.snapshot_channel.nb_packets_per_stream,
+ ctx);
+ if (ret < 0) {
+ ERR("Snapshot channel failed");
+ ret_code = LTTCOMM_CONSUMERD_CHANNEL_FAIL;
+ }
+ }
+
+ health_code_update();
+ ret = consumer_send_status_msg(sock, ret_code);
+ if (ret < 0) {
+ /* Somehow, the session daemon is not responding anymore. */
+ goto end_nosignal;
+ }
+ health_code_update();
+ break;
+ }
+ default:
+ break;
+ }
+
+end_nosignal:
+ rcu_read_unlock();
+
+ health_code_update();
+
+ /*
+ * Return 1 to indicate success since the 0 value can be a socket
+ * shutdown during the recv() or send() call.
+ */
+ return 1;
+
+end_msg_sessiond:
+ /*
+ * The returned value here is not useful since either way we'll return 1 to
+ * the caller because the session daemon socket management is done
+ * elsewhere. Returning a negative code or 0 will shutdown the consumer.
+ */
+ ret = consumer_send_status_msg(sock, ret_code);
+ if (ret < 0) {
+ goto error_fatal;
+ }
+ rcu_read_unlock();
+
+ health_code_update();
+
+ return 1;
+end_channel_error:
+ if (channel) {
+ /*
+ * Free channel here since no one has a reference to it. We don't
+ * free after that because a stream can store this pointer.
+ */
+ destroy_channel(channel);
+ }
+ /* We have to send a status channel message indicating an error. */
+ ret = consumer_send_status_channel(sock, NULL);
+ if (ret < 0) {
+ /* Stop everything if session daemon can not be notified. */
+ goto error_fatal;
+ }
+ rcu_read_unlock();
+
+ health_code_update();
+
+ return 1;
+error_fatal:
+ rcu_read_unlock();
+ /* This will issue a consumer stop. */
+ return -1;
+}
+
+/*
+ * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
+ * compiled out, we isolate it in this library.
+ */
+int lttng_ustctl_get_mmap_read_offset(struct lttng_consumer_stream *stream,
+ unsigned long *off)
+{
+ assert(stream);
+ assert(stream->ustream);
+
+ return ustctl_get_mmap_read_offset(stream->ustream, off);
+}
+
+/*
+ * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
+ * compiled out, we isolate it in this library.
+ */
+void *lttng_ustctl_get_mmap_base(struct lttng_consumer_stream *stream)
+{
+ assert(stream);
+ assert(stream->ustream);
+
+ return ustctl_get_mmap_base(stream->ustream);
+}
+
+/*
+ * Take a snapshot for a specific fd
+ *
+ * Returns 0 on success, < 0 on error
+ */
+int lttng_ustconsumer_take_snapshot(struct lttng_consumer_stream *stream)
+{
+ assert(stream);
+ assert(stream->ustream);
+
+ return ustctl_snapshot(stream->ustream);
+}
+
+/*
+ * Get the produced position
+ *
+ * Returns 0 on success, < 0 on error
+ */
+int lttng_ustconsumer_get_produced_snapshot(
+ struct lttng_consumer_stream *stream, unsigned long *pos)
+{
+ assert(stream);
+ assert(stream->ustream);
+ assert(pos);
+
+ return ustctl_snapshot_get_produced(stream->ustream, pos);
+}
+
+/*
+ * Get the consumed position
+ *
+ * Returns 0 on success, < 0 on error
+ */
+int lttng_ustconsumer_get_consumed_snapshot(
+ struct lttng_consumer_stream *stream, unsigned long *pos)
+{
+ assert(stream);
+ assert(stream->ustream);
+ assert(pos);
+
+ return ustctl_snapshot_get_consumed(stream->ustream, pos);
+}
+
+void lttng_ustconsumer_flush_buffer(struct lttng_consumer_stream *stream,
+ int producer)
+{
+ assert(stream);
+ assert(stream->ustream);
+
+ ustctl_flush_buffer(stream->ustream, producer);
+}
+
+int lttng_ustconsumer_get_current_timestamp(
+ struct lttng_consumer_stream *stream, uint64_t *ts)
+{
+ assert(stream);
+ assert(stream->ustream);
+ assert(ts);
+
+ return ustctl_get_current_timestamp(stream->ustream, ts);
+}
+
+/*
+ * Called when the stream signal the consumer that it has hang up.
+ */
+void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream)
+{
+ assert(stream);
+ assert(stream->ustream);
+
+ ustctl_flush_buffer(stream->ustream, 0);
+ stream->hangup_flush_done = 1;
+}
+
+void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan)
+{
+ int i;
+
+ assert(chan);
+ assert(chan->uchan);
+
+ if (chan->switch_timer_enabled == 1) {
+ consumer_timer_switch_stop(chan);
+ }
+ for (i = 0; i < chan->nr_stream_fds; i++) {
+ int ret;
+
+ ret = close(chan->stream_fds[i]);
+ if (ret) {
+ PERROR("close");
+ }
+ if (chan->shm_path[0]) {
+ char shm_path[PATH_MAX];
+
+ ret = get_stream_shm_path(shm_path, chan->shm_path, i);
+ if (ret) {
+ ERR("Cannot get stream shm path");
+ }
+ ret = run_as_unlink(shm_path, chan->uid, chan->gid);
+ if (ret) {
+ PERROR("unlink %s", shm_path);
+ }
+ }
+ }
+ /* Try to rmdir all directories under shm_path root. */
+ if (chan->root_shm_path[0]) {
+ (void) run_as_recursive_rmdir(chan->root_shm_path,
+ chan->uid, chan->gid);
+ }
+}
+
+void lttng_ustconsumer_free_channel(struct lttng_consumer_channel *chan)
+{
+ assert(chan);
+ assert(chan->uchan);
+
+ consumer_metadata_cache_destroy(chan);
+ ustctl_destroy_channel(chan->uchan);
+ free(chan->stream_fds);
+}
+
+void lttng_ustconsumer_del_stream(struct lttng_consumer_stream *stream)
+{
+ assert(stream);
+ assert(stream->ustream);
+
+ if (stream->chan->switch_timer_enabled == 1) {
+ consumer_timer_switch_stop(stream->chan);
+ }
+ ustctl_destroy_stream(stream->ustream);
+}
+
+int lttng_ustconsumer_get_wakeup_fd(struct lttng_consumer_stream *stream)
+{
+ assert(stream);
+ assert(stream->ustream);
+
+ return ustctl_stream_get_wakeup_fd(stream->ustream);
+}
+
+int lttng_ustconsumer_close_wakeup_fd(struct lttng_consumer_stream *stream)
+{
+ assert(stream);
+ assert(stream->ustream);
+
+ return ustctl_stream_close_wakeup_fd(stream->ustream);
+}
+
+/*
+ * Populate index values of a UST stream. Values are set in big endian order.
+ *
+ * Return 0 on success or else a negative value.
+ */
+static int get_index_values(struct ctf_packet_index *index,
+ struct ustctl_consumer_stream *ustream)
+{
+ int ret;
+
+ ret = ustctl_get_timestamp_begin(ustream, &index->timestamp_begin);
+ if (ret < 0) {
+ PERROR("ustctl_get_timestamp_begin");
+ goto error;
+ }
+ index->timestamp_begin = htobe64(index->timestamp_begin);
+
+ ret = ustctl_get_timestamp_end(ustream, &index->timestamp_end);
+ if (ret < 0) {
+ PERROR("ustctl_get_timestamp_end");
+ goto error;
+ }
+ index->timestamp_end = htobe64(index->timestamp_end);
+
+ ret = ustctl_get_events_discarded(ustream, &index->events_discarded);
+ if (ret < 0) {
+ PERROR("ustctl_get_events_discarded");
+ goto error;
+ }
+ index->events_discarded = htobe64(index->events_discarded);
+
+ ret = ustctl_get_content_size(ustream, &index->content_size);
+ if (ret < 0) {
+ PERROR("ustctl_get_content_size");
+ goto error;
+ }
+ index->content_size = htobe64(index->content_size);
+
+ ret = ustctl_get_packet_size(ustream, &index->packet_size);
+ if (ret < 0) {
+ PERROR("ustctl_get_packet_size");
+ goto error;