X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Fust-consumer%2Fust-consumer.cpp;fp=src%2Fcommon%2Fust-consumer%2Fust-consumer.cpp;h=c9ec3c5576f5cef04e5c3411d247b61b7ed9d510;hp=0000000000000000000000000000000000000000;hb=97535efaa975ca52bf02c2d5e76351bfd2e3defa;hpb=7fe0498a9173fca00dcd45a41847e629b70cd941 diff --git a/src/common/ust-consumer/ust-consumer.cpp b/src/common/ust-consumer/ust-consumer.cpp new file mode 100644 index 000000000..c9ec3c557 --- /dev/null +++ b/src/common/ust-consumer/ust-consumer.cpp @@ -0,0 +1,3439 @@ +/* + * Copyright (C) 2011 Julien Desfossez + * Copyright (C) 2011 Mathieu Desnoyers + * Copyright (C) 2017 Jérémie Galarneau + * + * SPDX-License-Identifier: GPL-2.0-only + * + */ + +#define _LGPL_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "ust-consumer.h" + +#define INT_MAX_STR_LEN 12 /* includes \0 */ + +extern struct lttng_consumer_global_data the_consumer_data; +extern int consumer_poll_timeout; + +LTTNG_EXPORT DEFINE_LTTNG_UST_SIGBUS_STATE(); + +/* + * Free channel object and all streams associated with it. This MUST be used + * only and only if the channel has _NEVER_ been added to the global channel + * hash table. + */ +static void destroy_channel(struct lttng_consumer_channel *channel) +{ + struct lttng_consumer_stream *stream, *stmp; + + LTTNG_ASSERT(channel); + + DBG("UST consumer cleaning stream list"); + + cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head, + send_node) { + + health_code_update(); + + cds_list_del(&stream->send_node); + lttng_ust_ctl_destroy_stream(stream->ustream); + lttng_trace_chunk_put(stream->trace_chunk); + free(stream); + } + + /* + * If a channel is available meaning that was created before the streams + * were, delete it. + */ + if (channel->uchan) { + lttng_ustconsumer_del_channel(channel); + lttng_ustconsumer_free_channel(channel); + } + + if (channel->trace_chunk) { + lttng_trace_chunk_put(channel->trace_chunk); + } + + free(channel); +} + +/* + * Add channel to internal consumer state. + * + * Returns 0 on success or else a negative value. + */ +static int add_channel(struct lttng_consumer_channel *channel, + struct lttng_consumer_local_data *ctx) +{ + int ret = 0; + + LTTNG_ASSERT(channel); + LTTNG_ASSERT(ctx); + + if (ctx->on_recv_channel != NULL) { + ret = ctx->on_recv_channel(channel); + if (ret == 0) { + ret = consumer_add_channel(channel, ctx); + } else if (ret < 0) { + /* Most likely an ENOMEM. */ + lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR); + goto error; + } + } else { + ret = consumer_add_channel(channel, ctx); + } + + DBG("UST consumer channel added (key: %" PRIu64 ")", channel->key); + +error: + return ret; +} + +/* + * Allocate and return a consumer stream object. If _alloc_ret is not NULL, the + * error value if applicable is set in it else it is kept untouched. + * + * Return NULL on error else the newly allocated stream object. + */ +static struct lttng_consumer_stream *allocate_stream(int cpu, int key, + struct lttng_consumer_channel *channel, + struct lttng_consumer_local_data *ctx, int *_alloc_ret) +{ + int alloc_ret; + struct lttng_consumer_stream *stream = NULL; + + LTTNG_ASSERT(channel); + LTTNG_ASSERT(ctx); + + stream = consumer_stream_create( + channel, + channel->key, + key, + channel->name, + channel->relayd_id, + channel->session_id, + channel->trace_chunk, + cpu, + &alloc_ret, + channel->type, + channel->monitor); + if (stream == NULL) { + switch (alloc_ret) { + case -ENOENT: + /* + * We could not find the channel. Can happen if cpu hotplug + * happens while tearing down. + */ + DBG3("Could not find channel"); + break; + case -ENOMEM: + case -EINVAL: + default: + lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR); + break; + } + goto error; + } + + consumer_stream_update_channel_attributes(stream, channel); + +error: + if (_alloc_ret) { + *_alloc_ret = alloc_ret; + } + return stream; +} + +/* + * Send the given stream pointer to the corresponding thread. + * + * Returns 0 on success else a negative value. + */ +static int send_stream_to_thread(struct lttng_consumer_stream *stream, + struct lttng_consumer_local_data *ctx) +{ + int ret; + struct lttng_pipe *stream_pipe; + + /* Get the right pipe where the stream will be sent. */ + if (stream->metadata_flag) { + consumer_add_metadata_stream(stream); + stream_pipe = ctx->consumer_metadata_pipe; + } else { + consumer_add_data_stream(stream); + stream_pipe = ctx->consumer_data_pipe; + } + + /* + * From this point on, the stream's ownership has been moved away from + * the channel and it becomes globally visible. Hence, remove it from + * the local stream list to prevent the stream from being both local and + * global. + */ + stream->globally_visible = 1; + cds_list_del(&stream->send_node); + + ret = lttng_pipe_write(stream_pipe, &stream, sizeof(stream)); + if (ret < 0) { + ERR("Consumer write %s stream to pipe %d", + stream->metadata_flag ? "metadata" : "data", + lttng_pipe_get_writefd(stream_pipe)); + if (stream->metadata_flag) { + consumer_del_stream_for_metadata(stream); + } else { + consumer_del_stream_for_data(stream); + } + goto error; + } + +error: + return ret; +} + +static +int get_stream_shm_path(char *stream_shm_path, const char *shm_path, int cpu) +{ + char cpu_nr[INT_MAX_STR_LEN]; /* int max len */ + int ret; + + strncpy(stream_shm_path, shm_path, PATH_MAX); + stream_shm_path[PATH_MAX - 1] = '\0'; + ret = snprintf(cpu_nr, INT_MAX_STR_LEN, "%i", cpu); + if (ret < 0) { + PERROR("snprintf"); + goto end; + } + strncat(stream_shm_path, cpu_nr, + PATH_MAX - strlen(stream_shm_path) - 1); + ret = 0; +end: + return ret; +} + +/* + * Create streams for the given channel using liblttng-ust-ctl. + * The channel lock must be acquired by the caller. + * + * Return 0 on success else a negative value. + */ +static int create_ust_streams(struct lttng_consumer_channel *channel, + struct lttng_consumer_local_data *ctx) +{ + int ret, cpu = 0; + struct lttng_ust_ctl_consumer_stream *ustream; + struct lttng_consumer_stream *stream; + pthread_mutex_t *current_stream_lock = NULL; + + LTTNG_ASSERT(channel); + LTTNG_ASSERT(ctx); + + /* + * While a stream is available from ustctl. When NULL is returned, we've + * reached the end of the possible stream for the channel. + */ + while ((ustream = lttng_ust_ctl_create_stream(channel->uchan, cpu))) { + int wait_fd; + int ust_metadata_pipe[2]; + + health_code_update(); + + if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA && channel->monitor) { + ret = utils_create_pipe_cloexec_nonblock(ust_metadata_pipe); + if (ret < 0) { + ERR("Create ust metadata poll pipe"); + goto error; + } + wait_fd = ust_metadata_pipe[0]; + } else { + wait_fd = lttng_ust_ctl_stream_get_wait_fd(ustream); + } + + /* Allocate consumer stream object. */ + stream = allocate_stream(cpu, wait_fd, channel, ctx, &ret); + if (!stream) { + goto error_alloc; + } + stream->ustream = ustream; + /* + * Store it so we can save multiple function calls afterwards since + * this value is used heavily in the stream threads. This is UST + * specific so this is why it's done after allocation. + */ + stream->wait_fd = wait_fd; + + /* + * Increment channel refcount since the channel reference has now been + * assigned in the allocation process above. + */ + if (stream->chan->monitor) { + uatomic_inc(&stream->chan->refcount); + } + + pthread_mutex_lock(&stream->lock); + current_stream_lock = &stream->lock; + /* + * Order is important this is why a list is used. On error, the caller + * should clean this list. + */ + cds_list_add_tail(&stream->send_node, &channel->streams.head); + + ret = lttng_ust_ctl_get_max_subbuf_size(stream->ustream, + &stream->max_sb_size); + if (ret < 0) { + ERR("lttng_ust_ctl_get_max_subbuf_size failed for stream %s", + stream->name); + goto error; + } + + /* Do actions once stream has been received. */ + if (ctx->on_recv_stream) { + ret = ctx->on_recv_stream(stream); + if (ret < 0) { + goto error; + } + } + + DBG("UST consumer add stream %s (key: %" PRIu64 ") with relayd id %" PRIu64, + stream->name, stream->key, stream->relayd_stream_id); + + /* Set next CPU stream. */ + channel->streams.count = ++cpu; + + /* Keep stream reference when creating metadata. */ + if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA) { + channel->metadata_stream = stream; + if (channel->monitor) { + /* Set metadata poll pipe if we created one */ + memcpy(stream->ust_metadata_poll_pipe, + ust_metadata_pipe, + sizeof(ust_metadata_pipe)); + } + } + pthread_mutex_unlock(&stream->lock); + current_stream_lock = NULL; + } + + return 0; + +error: +error_alloc: + if (current_stream_lock) { + pthread_mutex_unlock(current_stream_lock); + } + return ret; +} + +static int open_ust_stream_fd(struct lttng_consumer_channel *channel, int cpu, + const struct lttng_credentials *session_credentials) +{ + char shm_path[PATH_MAX]; + int ret; + + if (!channel->shm_path[0]) { + return shm_create_anonymous("ust-consumer"); + } + ret = get_stream_shm_path(shm_path, channel->shm_path, cpu); + if (ret) { + goto error_shm_path; + } + return run_as_open(shm_path, + O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR, + lttng_credentials_get_uid(session_credentials), + lttng_credentials_get_gid(session_credentials)); + +error_shm_path: + return -1; +} + +/* + * Create an UST channel with the given attributes and send it to the session + * daemon using the ust ctl API. + * + * Return 0 on success or else a negative value. + */ +static int create_ust_channel(struct lttng_consumer_channel *channel, + struct lttng_ust_ctl_consumer_channel_attr *attr, + struct lttng_ust_ctl_consumer_channel **ust_chanp) +{ + int ret, nr_stream_fds, i, j; + int *stream_fds; + struct lttng_ust_ctl_consumer_channel *ust_channel; + + LTTNG_ASSERT(channel); + LTTNG_ASSERT(attr); + LTTNG_ASSERT(ust_chanp); + LTTNG_ASSERT(channel->buffer_credentials.is_set); + + DBG3("Creating channel to ustctl with attr: [overwrite: %d, " + "subbuf_size: %" PRIu64 ", num_subbuf: %" PRIu64 ", " + "switch_timer_interval: %u, read_timer_interval: %u, " + "output: %d, type: %d", attr->overwrite, attr->subbuf_size, + attr->num_subbuf, attr->switch_timer_interval, + attr->read_timer_interval, attr->output, attr->type); + + if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA) + nr_stream_fds = 1; + else + nr_stream_fds = lttng_ust_ctl_get_nr_stream_per_channel(); + stream_fds = (int *) zmalloc(nr_stream_fds * sizeof(*stream_fds)); + if (!stream_fds) { + ret = -1; + goto error_alloc; + } + for (i = 0; i < nr_stream_fds; i++) { + stream_fds[i] = open_ust_stream_fd(channel, i, + &channel->buffer_credentials.value); + if (stream_fds[i] < 0) { + ret = -1; + goto error_open; + } + } + ust_channel = lttng_ust_ctl_create_channel(attr, stream_fds, nr_stream_fds); + if (!ust_channel) { + ret = -1; + goto error_create; + } + channel->nr_stream_fds = nr_stream_fds; + channel->stream_fds = stream_fds; + *ust_chanp = ust_channel; + + return 0; + +error_create: +error_open: + for (j = i - 1; j >= 0; j--) { + int closeret; + + closeret = close(stream_fds[j]); + if (closeret) { + PERROR("close"); + } + if (channel->shm_path[0]) { + char shm_path[PATH_MAX]; + + closeret = get_stream_shm_path(shm_path, + channel->shm_path, j); + if (closeret) { + ERR("Cannot get stream shm path"); + } + closeret = run_as_unlink(shm_path, + lttng_credentials_get_uid(LTTNG_OPTIONAL_GET_PTR( + channel->buffer_credentials)), + lttng_credentials_get_gid(LTTNG_OPTIONAL_GET_PTR( + channel->buffer_credentials))); + if (closeret) { + PERROR("unlink %s", shm_path); + } + } + } + /* Try to rmdir all directories under shm_path root. */ + if (channel->root_shm_path[0]) { + (void) run_as_rmdir_recursive(channel->root_shm_path, + lttng_credentials_get_uid(LTTNG_OPTIONAL_GET_PTR( + channel->buffer_credentials)), + lttng_credentials_get_gid(LTTNG_OPTIONAL_GET_PTR( + channel->buffer_credentials)), + LTTNG_DIRECTORY_HANDLE_SKIP_NON_EMPTY_FLAG); + } + free(stream_fds); +error_alloc: + return ret; +} + +/* + * Send a single given stream to the session daemon using the sock. + * + * Return 0 on success else a negative value. + */ +static int send_sessiond_stream(int sock, struct lttng_consumer_stream *stream) +{ + int ret; + + LTTNG_ASSERT(stream); + LTTNG_ASSERT(sock >= 0); + + DBG("UST consumer sending stream %" PRIu64 " to sessiond", stream->key); + + /* Send stream to session daemon. */ + ret = lttng_ust_ctl_send_stream_to_sessiond(sock, stream->ustream); + if (ret < 0) { + goto error; + } + +error: + return ret; +} + +/* + * Send channel to sessiond and relayd if applicable. + * + * Return 0 on success or else a negative value. + */ +static int send_channel_to_sessiond_and_relayd(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; + + LTTNG_ASSERT(channel); + LTTNG_ASSERT(ctx); + LTTNG_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. */ + DBG("Sending stream %" PRIu64 " of channel \"%s\" to relayd", + stream->key, channel->name); + 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 = lttng_ust_ctl_send_channel_to_sessiond(sock, channel->uchan); + if (ret < 0) { + goto error; + } + + ret = lttng_ust_ctl_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 = lttng_ust_ctl_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, + struct lttng_consumer_channel *channel, + struct lttng_ust_ctl_consumer_channel_attr *attr) +{ + int ret; + + LTTNG_ASSERT(ctx); + LTTNG_ASSERT(channel); + LTTNG_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 = lttng_ust_ctl_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. */ + pthread_mutex_lock(&channel->lock); + ret = create_ust_streams(channel, ctx); + pthread_mutex_unlock(&channel->lock); + 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; + + LTTNG_ASSERT(channel); + LTTNG_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. + */ + goto error; + } + } + +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 = the_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(); + + pthread_mutex_lock(&stream->lock); + + /* + * Protect against concurrent teardown of a stream. + */ + if (cds_lfht_is_node_deleted(&stream->node.node)) { + goto next; + } + + if (!stream->quiescent) { + ret = lttng_ust_ctl_flush_buffer(stream->ustream, 0); + if (ret) { + ERR("Failed to flush buffer while flushing channel: channel key = %" PRIu64 ", channel name = '%s'", + chan_key, channel->name); + ret = LTTNG_ERR_BUFFER_FLUSH_FAILED; + pthread_mutex_unlock(&stream->lock); + goto error; + } + stream->quiescent = true; + } +next: + pthread_mutex_unlock(&stream->lock); + } +error: + rcu_read_unlock(); + return ret; +} + +/* + * Clear quiescent state from channel's streams using the given key to + * retrieve the channel. + * + * Return 0 on success else an LTTng error code. + */ +static int clear_quiescent_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 clear quiescent channel key %" PRIu64, chan_key); + + rcu_read_lock(); + channel = consumer_find_channel(chan_key); + if (!channel) { + ERR("UST consumer clear quiescent channel %" PRIu64 " not found", chan_key); + ret = LTTNG_ERR_UST_CHAN_NOT_FOUND; + goto error; + } + + ht = the_consumer_data.stream_per_chan_id_ht; + + /* For each stream of the channel id, clear quiescent state. */ + 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(); + + pthread_mutex_lock(&stream->lock); + stream->quiescent = false; + pthread_mutex_unlock(&stream->lock); + } +error: + rcu_read_unlock(); + return ret; +} + +/* + * Close metadata stream wakeup_fd using the given key to retrieve the channel. + * + * 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; + unsigned int channel_monitor; + + 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(&the_consumer_data.lock); + pthread_mutex_lock(&channel->lock); + channel_monitor = channel->monitor; + if (cds_lfht_is_node_deleted(&channel->node.node)) { + goto error_unlock; + } + + lttng_ustconsumer_close_metadata(channel); + pthread_mutex_unlock(&channel->lock); + pthread_mutex_unlock(&the_consumer_data.lock); + + /* + * The ownership of a metadata channel depends on the type of + * session to which it belongs. In effect, the monitor flag is checked + * to determine if this metadata channel is in "snapshot" mode or not. + * + * In the non-snapshot case, the metadata channel is created along with + * a single stream which will remain present until the metadata channel + * is destroyed (on the destruction of its session). In this case, the + * metadata stream in "monitored" by the metadata poll thread and holds + * the ownership of its channel. + * + * Closing the metadata will cause the metadata stream's "metadata poll + * pipe" to be closed. Closing this pipe will wake-up the metadata poll + * thread which will teardown the metadata stream which, in return, + * deletes the metadata channel. + * + * In the snapshot case, the metadata stream is created and destroyed + * on every snapshot record. Since the channel doesn't have an owner + * other than the session daemon, it is safe to destroy it immediately + * on reception of the CLOSE_METADATA command. + */ + if (!channel_monitor) { + /* + * The channel and consumer_data locks must be + * released before this call since consumer_del_channel + * re-acquires the channel and consumer_data locks to teardown + * the channel and queue its reclamation by the "call_rcu" + * worker thread. + */ + consumer_del_channel(channel); + } + + return ret; +error_unlock: + pthread_mutex_unlock(&channel->lock); + pthread_mutex_unlock(&the_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; + } + } + + /* + * Ownership of metadata stream is passed along. Freeing is handled by + * the callee. + */ + 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 send_streams_error; + } + /* List MUST be empty after or else it could be reused. */ + LTTNG_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; +send_streams_error: +error_no_stream: +end: + return ret; +} + +/* + * Snapshot the whole metadata. + * RCU read-side lock must be held by the caller. + * + * Returns 0 on success, < 0 on error + */ +static int snapshot_metadata(struct lttng_consumer_channel *metadata_channel, + uint64_t key, char *path, uint64_t relayd_id, + struct lttng_consumer_local_data *ctx) +{ + int ret = 0; + struct lttng_consumer_stream *metadata_stream; + + LTTNG_ASSERT(path); + LTTNG_ASSERT(ctx); + + DBG("UST consumer snapshot metadata with key %" PRIu64 " at path %s", + key, path); + + rcu_read_lock(); + + LTTNG_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; + LTTNG_ASSERT(metadata_stream); + + pthread_mutex_lock(&metadata_stream->lock); + if (relayd_id != (uint64_t) -1ULL) { + metadata_stream->net_seq_idx = relayd_id; + ret = consumer_send_relayd_stream(metadata_stream, path); + } else { + ret = consumer_stream_create_output_files(metadata_stream, + false); + } + pthread_mutex_unlock(&metadata_stream->lock); + if (ret < 0) { + goto error_stream; + } + + do { + health_code_update(); + + ret = lttng_consumer_read_subbuffer(metadata_stream, ctx, true); + 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; +} + +static +int get_current_subbuf_addr(struct lttng_consumer_stream *stream, + const char **addr) +{ + int ret; + unsigned long mmap_offset; + const char *mmap_base; + + mmap_base = (const char *) lttng_ust_ctl_get_mmap_base(stream->ustream); + if (!mmap_base) { + ERR("Failed to get mmap base for stream `%s`", + stream->name); + ret = -EPERM; + goto error; + } + + ret = lttng_ust_ctl_get_mmap_read_offset(stream->ustream, &mmap_offset); + if (ret != 0) { + ERR("Failed to get mmap offset for stream `%s`", stream->name); + ret = -EINVAL; + goto error; + } + + *addr = mmap_base + mmap_offset; +error: + return ret; + +} + +/* + * Take a snapshot of all the stream of a channel. + * RCU read-side lock and the channel lock must be held by the caller. + * + * Returns 0 on success, < 0 on error + */ +static int snapshot_channel(struct lttng_consumer_channel *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_stream *stream; + + LTTNG_ASSERT(path); + LTTNG_ASSERT(ctx); + + rcu_read_lock(); + + if (relayd_id != (uint64_t) -1ULL) { + use_relayd = 1; + } + + LTTNG_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); + LTTNG_ASSERT(channel->trace_chunk); + if (!lttng_trace_chunk_get(channel->trace_chunk)) { + /* + * Can't happen barring an internal error as the channel + * holds a reference to the trace chunk. + */ + ERR("Failed to acquire reference to channel's trace chunk"); + ret = -1; + goto error_unlock; + } + LTTNG_ASSERT(!stream->trace_chunk); + stream->trace_chunk = channel->trace_chunk; + + stream->net_seq_idx = relayd_id; + + if (use_relayd) { + ret = consumer_send_relayd_stream(stream, path); + if (ret < 0) { + goto error_unlock; + } + } else { + ret = consumer_stream_create_output_files(stream, + false); + if (ret < 0) { + goto error_unlock; + } + DBG("UST consumer snapshot stream (%" PRIu64 ")", + stream->key); + } + + /* + * If tracing is active, we want to perform a "full" buffer flush. + * Else, if quiescent, it has already been done by the prior stop. + */ + if (!stream->quiescent) { + ret = lttng_ust_ctl_flush_buffer(stream->ustream, 0); + if (ret < 0) { + ERR("Failed to flush buffer during snapshot of channel: channel key = %" PRIu64 ", channel name = '%s'", + channel->key, channel->name); + goto error_unlock; + } + } + + 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 ((long) (consumed_pos - produced_pos) < 0) { + ssize_t read_len; + unsigned long len, padded_len; + const char *subbuf_addr; + struct lttng_buffer_view subbuf_view; + + health_code_update(); + + DBG("UST consumer taking snapshot at pos %lu", consumed_pos); + + ret = lttng_ust_ctl_get_subbuf(stream->ustream, &consumed_pos); + if (ret < 0) { + if (ret != -EAGAIN) { + PERROR("lttng_ust_ctl_get_subbuf snapshot"); + goto error_close_stream; + } + DBG("UST consumer get subbuf failed. Skipping it."); + consumed_pos += stream->max_sb_size; + stream->chan->lost_packets++; + continue; + } + + ret = lttng_ust_ctl_get_subbuf_size(stream->ustream, &len); + if (ret < 0) { + ERR("Snapshot lttng_ust_ctl_get_subbuf_size"); + goto error_put_subbuf; + } + + ret = lttng_ust_ctl_get_padded_subbuf_size(stream->ustream, &padded_len); + if (ret < 0) { + ERR("Snapshot lttng_ust_ctl_get_padded_subbuf_size"); + goto error_put_subbuf; + } + + ret = get_current_subbuf_addr(stream, &subbuf_addr); + if (ret) { + goto error_put_subbuf; + } + + subbuf_view = lttng_buffer_view_init( + subbuf_addr, 0, padded_len); + read_len = lttng_consumer_on_read_subbuffer_mmap( + stream, &subbuf_view, padded_len - len); + 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 = lttng_ust_ctl_put_subbuf(stream->ustream); + if (ret < 0) { + ERR("Snapshot lttng_ust_ctl_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 (lttng_ust_ctl_put_subbuf(stream->ustream) < 0) { + ERR("Snapshot lttng_ust_ctl_put_subbuf"); + } +error_close_stream: + consumer_stream_close(stream); +error_unlock: + pthread_mutex_unlock(&stream->lock); + rcu_read_unlock(); + return ret; +} + +static +void metadata_stream_reset_cache_consumed_position( + struct lttng_consumer_stream *stream) +{ + ASSERT_LOCKED(stream->lock); + + DBG("Reset metadata cache of session %" PRIu64, + stream->chan->session_id); + stream->ust_metadata_pushed = 0; +} + +/* + * 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, uint64_t version, + struct lttng_consumer_channel *channel, int timer, int wait) +{ + int ret, ret_code = LTTCOMM_CONSUMERD_SUCCESS; + char *metadata_str; + enum consumer_metadata_cache_write_status cache_write_status; + + DBG("UST consumer push metadata key %" PRIu64 " of len %" PRIu64, key, len); + + metadata_str = (char *) 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); + cache_write_status = consumer_metadata_cache_write( + channel->metadata_cache, offset, len, version, + metadata_str); + pthread_mutex_unlock(&channel->metadata_cache->lock); + switch (cache_write_status) { + case CONSUMER_METADATA_CACHE_WRITE_STATUS_NO_CHANGE: + /* + * The write entirely overlapped with existing contents of the + * same metadata version (same content); there is nothing to do. + */ + break; + case CONSUMER_METADATA_CACHE_WRITE_STATUS_INVALIDATED: + /* + * The metadata cache was invalidated (previously pushed + * content has been overwritten). Reset the stream's consumed + * metadata position to ensure the metadata poll thread consumes + * the whole cache. + */ + pthread_mutex_lock(&channel->metadata_stream->lock); + metadata_stream_reset_cache_consumed_position( + channel->metadata_stream); + pthread_mutex_unlock(&channel->metadata_stream->lock); + /* Fall-through. */ + case CONSUMER_METADATA_CACHE_WRITE_STATUS_APPENDED_CONTENT: + /* + * In both cases, the metadata poll thread has new data to + * consume. + */ + ret = consumer_metadata_wakeup_pipe(channel); + if (ret) { + ret_code = LTTCOMM_CONSUMERD_ERROR_METADATA; + goto end_free; + } + break; + case CONSUMER_METADATA_CACHE_WRITE_STATUS_ERROR: + /* 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. + */ + goto end_free; + default: + abort(); + } + + 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) +{ + int ret_func; + enum lttcomm_return_code ret_code = LTTCOMM_CONSUMERD_SUCCESS; + struct lttcomm_consumer_msg msg; + struct lttng_consumer_channel *channel = NULL; + + health_code_update(); + + { + ssize_t ret_recv; + + ret_recv = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg)); + if (ret_recv != sizeof(msg)) { + DBG("Consumer received unexpected message size %zd (expects %zu)", + ret_recv, sizeof(msg)); + /* + * The ret value might 0 meaning an orderly shutdown but this is ok + * since the caller handles this. + */ + if (ret_recv > 0) { + lttng_consumer_send_error(ctx, + LTTCOMM_CONSUMERD_ERROR_RECV_CMD); + ret_recv = -1; + } + return ret_recv; + } + } + + health_code_update(); + + /* deprecated */ + LTTNG_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. */ + 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 is_data_pending; + ssize_t ret_send; + 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_send = lttcomm_send_unix_sock(sock, &is_data_pending, + sizeof(is_data_pending)); + if (ret_send < 0) { + DBG("Error when sending the data pending ret code: %zd", + ret_send); + 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_ask_channel, ret_add_channel, ret_send; + struct lttng_ust_ctl_consumer_channel_attr attr; + const uint64_t chunk_id = msg.u.ask_channel.chunk_id.value; + const struct lttng_credentials buffer_credentials = { + .uid = LTTNG_OPTIONAL_INIT_VALUE(msg.u.ask_channel.buffer_credentials.uid), + .gid = LTTNG_OPTIONAL_INIT_VALUE(msg.u.ask_channel.buffer_credentials.gid), + }; + + /* Create a plain object and reserve a channel key. */ + channel = consumer_allocate_channel( + msg.u.ask_channel.key, + msg.u.ask_channel.session_id, + msg.u.ask_channel.chunk_id.is_set ? + &chunk_id : NULL, + msg.u.ask_channel.pathname, + msg.u.ask_channel.name, + msg.u.ask_channel.relayd_id, + (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.is_live, + msg.u.ask_channel.root_shm_path, + msg.u.ask_channel.shm_path); + if (!channel) { + goto end_channel_error; + } + + LTTNG_OPTIONAL_SET(&channel->buffer_credentials, + buffer_credentials); + + /* + * 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)); + attr.blocking_timeout= msg.u.ask_channel.blocking_timeout; + + /* Match channel buffer type to the UST abi. */ + switch (msg.u.ask_channel.output) { + case LTTNG_EVENT_MMAP: + default: + attr.output = LTTNG_UST_ABI_MMAP; + break; + } + + /* Translate and save channel type. */ + switch (msg.u.ask_channel.type) { + case LTTNG_UST_ABI_CHAN_PER_CPU: + channel->type = CONSUMER_CHANNEL_TYPE_DATA; + attr.type = LTTNG_UST_ABI_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_ABI_CHAN_METADATA: + channel->type = CONSUMER_CHANNEL_TYPE_METADATA; + attr.type = LTTNG_UST_ABI_CHAN_METADATA; + break; + default: + abort(); + goto error_fatal; + }; + + health_code_update(); + + ret_ask_channel = ask_channel(ctx, channel, &attr); + if (ret_ask_channel < 0) { + goto end_channel_error; + } + + if (msg.u.ask_channel.type == LTTNG_UST_ABI_CHAN_METADATA) { + int ret_allocate; + + ret_allocate = consumer_metadata_cache_allocate( + channel); + if (ret_allocate < 0) { + ERR("Allocating metadata cache"); + goto end_channel_error; + } + consumer_timer_switch_start(channel, attr.switch_timer_interval); + attr.switch_timer_interval = 0; + } else { + int monitor_start_ret; + + consumer_timer_live_start(channel, + msg.u.ask_channel.live_timer_interval); + monitor_start_ret = consumer_timer_monitor_start( + channel, + msg.u.ask_channel.monitor_timer_interval); + if (monitor_start_ret < 0) { + ERR("Starting channel monitoring timer failed"); + goto end_channel_error; + } + } + + 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 = add_channel(channel, ctx); + if (ret_add_channel < 0) { + if (msg.u.ask_channel.type == LTTNG_UST_ABI_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); + } + if (channel->monitor_timer_enabled == 1) { + consumer_timer_monitor_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_send = consumer_send_status_channel(sock, channel); + if (ret_send < 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 *found_channel; + + found_channel = consumer_find_channel(key); + if (!found_channel) { + ERR("UST consumer get channel key %" PRIu64 " not found", key); + ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND; + goto end_get_channel; + } + + health_code_update(); + + /* Send the channel to sessiond (and relayd, if applicable). */ + ret = send_channel_to_sessiond_and_relayd( + sock, found_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_get_channel_nosignal; + } + /* + * The communicaton was broken hence there is a bad state between + * the consumer and sessiond so stop everything. + */ + goto error_get_channel_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 (!found_channel->monitor) { + goto end_get_channel; + } + + ret = send_streams_to_thread(found_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_get_channel_fatal; + } + /* List MUST be empty after or else it could be reused. */ + LTTNG_ASSERT(cds_list_empty(&found_channel->streams.head)); +end_get_channel: + goto end_msg_sessiond; +error_get_channel_fatal: + goto error_fatal; +end_get_channel_nosignal: + goto end_nosignal; + } + 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 = (lttcomm_return_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 = (lttcomm_return_code) ret; + } + + goto end_msg_sessiond; + } + case LTTNG_CONSUMER_CLEAR_QUIESCENT_CHANNEL: + { + int ret; + + ret = clear_quiescent_channel( + msg.u.clear_quiescent_channel.key); + if (ret != 0) { + ret_code = (lttcomm_return_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; + uint64_t version = msg.u.push_metadata.version; + struct lttng_consumer_channel *found_channel; + + DBG("UST consumer push metadata key %" PRIu64 " of len %" PRIu64, key, + len); + + found_channel = consumer_find_channel(key); + if (!found_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_push_metadata_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_push_metadata_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_push_metadata_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_push_metadata_fatal; + } + + health_code_update(); + + ret = lttng_ustconsumer_recv_metadata(sock, key, offset, len, + version, found_channel, 0, 1); + if (ret < 0) { + /* error receiving from sessiond */ + goto error_push_metadata_fatal; + } else { + ret_code = (lttcomm_return_code) ret; + goto end_push_metadata_msg_sessiond; + } +end_push_metadata_msg_sessiond: + goto end_msg_sessiond; +error_push_metadata_fatal: + goto error_fatal; + } + case LTTNG_CONSUMER_SETUP_METADATA: + { + int ret; + + ret = setup_metadata(ctx, msg.u.setup_metadata.key); + if (ret) { + ret_code = (lttcomm_return_code) ret; + } + goto end_msg_sessiond; + } + case LTTNG_CONSUMER_SNAPSHOT_CHANNEL: + { + struct lttng_consumer_channel *found_channel; + uint64_t key = msg.u.snapshot_channel.key; + int ret_send; + + found_channel = consumer_find_channel(key); + if (!found_channel) { + DBG("UST snapshot channel not found for key %" PRIu64, key); + ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND; + } else { + if (msg.u.snapshot_channel.metadata) { + int ret_snapshot; + + ret_snapshot = snapshot_metadata(found_channel, + key, + msg.u.snapshot_channel.pathname, + msg.u.snapshot_channel.relayd_id, + ctx); + if (ret_snapshot < 0) { + ERR("Snapshot metadata failed"); + ret_code = LTTCOMM_CONSUMERD_SNAPSHOT_FAILED; + } + } else { + int ret_snapshot; + + ret_snapshot = snapshot_channel(found_channel, + key, + msg.u.snapshot_channel.pathname, + msg.u.snapshot_channel.relayd_id, + msg.u.snapshot_channel + .nb_packets_per_stream, + ctx); + if (ret_snapshot < 0) { + ERR("Snapshot channel failed"); + ret_code = LTTCOMM_CONSUMERD_SNAPSHOT_FAILED; + } + } + } + health_code_update(); + ret_send = consumer_send_status_msg(sock, ret_code); + if (ret_send < 0) { + /* Somehow, the session daemon is not responding anymore. */ + goto end_nosignal; + } + health_code_update(); + break; + } + case LTTNG_CONSUMER_DISCARDED_EVENTS: + { + int ret = 0; + uint64_t discarded_events; + struct lttng_ht_iter iter; + struct lttng_ht *ht; + struct lttng_consumer_stream *stream; + uint64_t id = msg.u.discarded_events.session_id; + uint64_t key = msg.u.discarded_events.channel_key; + + DBG("UST consumer discarded events command for session id %" + PRIu64, id); + rcu_read_lock(); + pthread_mutex_lock(&the_consumer_data.lock); + + ht = the_consumer_data.stream_list_ht; + + /* + * We only need a reference to the channel, but they are not + * directly indexed, so we just use the first matching stream + * to extract the information we need, we default to 0 if not + * found (no events are dropped if the channel is not yet in + * use). + */ + discarded_events = 0; + cds_lfht_for_each_entry_duplicate(ht->ht, + ht->hash_fct(&id, lttng_ht_seed), + ht->match_fct, &id, + &iter.iter, stream, node_session_id.node) { + if (stream->chan->key == key) { + discarded_events = stream->chan->discarded_events; + break; + } + } + pthread_mutex_unlock(&the_consumer_data.lock); + rcu_read_unlock(); + + DBG("UST consumer discarded events command for session id %" + PRIu64 ", channel key %" PRIu64, id, key); + + health_code_update(); + + /* Send back returned value to session daemon */ + ret = lttcomm_send_unix_sock(sock, &discarded_events, sizeof(discarded_events)); + if (ret < 0) { + PERROR("send discarded events"); + goto error_fatal; + } + + break; + } + case LTTNG_CONSUMER_LOST_PACKETS: + { + int ret; + uint64_t lost_packets; + struct lttng_ht_iter iter; + struct lttng_ht *ht; + struct lttng_consumer_stream *stream; + uint64_t id = msg.u.lost_packets.session_id; + uint64_t key = msg.u.lost_packets.channel_key; + + DBG("UST consumer lost packets command for session id %" + PRIu64, id); + rcu_read_lock(); + pthread_mutex_lock(&the_consumer_data.lock); + + ht = the_consumer_data.stream_list_ht; + + /* + * We only need a reference to the channel, but they are not + * directly indexed, so we just use the first matching stream + * to extract the information we need, we default to 0 if not + * found (no packets lost if the channel is not yet in use). + */ + lost_packets = 0; + cds_lfht_for_each_entry_duplicate(ht->ht, + ht->hash_fct(&id, lttng_ht_seed), + ht->match_fct, &id, + &iter.iter, stream, node_session_id.node) { + if (stream->chan->key == key) { + lost_packets = stream->chan->lost_packets; + break; + } + } + pthread_mutex_unlock(&the_consumer_data.lock); + rcu_read_unlock(); + + DBG("UST consumer lost packets command for session id %" + PRIu64 ", channel key %" PRIu64, id, key); + + health_code_update(); + + /* Send back returned value to session daemon */ + ret = lttcomm_send_unix_sock(sock, &lost_packets, + sizeof(lost_packets)); + if (ret < 0) { + PERROR("send lost packets"); + goto error_fatal; + } + + break; + } + case LTTNG_CONSUMER_SET_CHANNEL_MONITOR_PIPE: + { + int channel_monitor_pipe, ret_send, + ret_set_channel_monitor_pipe; + ssize_t ret_recv; + + ret_code = LTTCOMM_CONSUMERD_SUCCESS; + /* Successfully received the command's type. */ + ret_send = consumer_send_status_msg(sock, ret_code); + if (ret_send < 0) { + goto error_fatal; + } + + ret_recv = lttcomm_recv_fds_unix_sock( + sock, &channel_monitor_pipe, 1); + if (ret_recv != sizeof(channel_monitor_pipe)) { + ERR("Failed to receive channel monitor pipe"); + goto error_fatal; + } + + DBG("Received channel monitor pipe (%d)", channel_monitor_pipe); + ret_set_channel_monitor_pipe = + consumer_timer_thread_set_channel_monitor_pipe( + channel_monitor_pipe); + if (!ret_set_channel_monitor_pipe) { + int flags; + int ret_fcntl; + + ret_code = LTTCOMM_CONSUMERD_SUCCESS; + /* Set the pipe as non-blocking. */ + ret_fcntl = fcntl(channel_monitor_pipe, F_GETFL, 0); + if (ret_fcntl == -1) { + PERROR("fcntl get flags of the channel monitoring pipe"); + goto error_fatal; + } + flags = ret_fcntl; + + ret_fcntl = fcntl(channel_monitor_pipe, F_SETFL, + flags | O_NONBLOCK); + if (ret_fcntl == -1) { + PERROR("fcntl set O_NONBLOCK flag of the channel monitoring pipe"); + goto error_fatal; + } + DBG("Channel monitor pipe set as non-blocking"); + } else { + ret_code = LTTCOMM_CONSUMERD_ALREADY_SET; + } + goto end_msg_sessiond; + } + case LTTNG_CONSUMER_ROTATE_CHANNEL: + { + struct lttng_consumer_channel *found_channel; + uint64_t key = msg.u.rotate_channel.key; + int ret_send_status; + + found_channel = consumer_find_channel(key); + if (!found_channel) { + DBG("Channel %" PRIu64 " not found", key); + ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND; + } else { + int rotate_channel; + + /* + * Sample the rotate position of all the streams in + * this channel. + */ + rotate_channel = lttng_consumer_rotate_channel( + found_channel, key, + msg.u.rotate_channel.relayd_id, + msg.u.rotate_channel.metadata, ctx); + if (rotate_channel < 0) { + ERR("Rotate channel failed"); + ret_code = LTTCOMM_CONSUMERD_ROTATION_FAIL; + } + + health_code_update(); + } + + ret_send_status = consumer_send_status_msg(sock, ret_code); + if (ret_send_status < 0) { + /* Somehow, the session daemon is not responding anymore. */ + goto end_rotate_channel_nosignal; + } + + /* + * Rotate the streams that are ready right now. + * FIXME: this is a second consecutive iteration over the + * streams in a channel, there is probably a better way to + * handle this, but it needs to be after the + * consumer_send_status_msg() call. + */ + if (found_channel) { + int ret_rotate_read_streams; + + ret_rotate_read_streams = + lttng_consumer_rotate_ready_streams( + found_channel, key, + ctx); + if (ret_rotate_read_streams < 0) { + ERR("Rotate channel failed"); + } + } + break; +end_rotate_channel_nosignal: + goto end_nosignal; + } + case LTTNG_CONSUMER_CLEAR_CHANNEL: + { + struct lttng_consumer_channel *found_channel; + uint64_t key = msg.u.clear_channel.key; + int ret_send_status; + + found_channel = consumer_find_channel(key); + if (!found_channel) { + DBG("Channel %" PRIu64 " not found", key); + ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND; + } else { + int ret_clear_channel; + + ret_clear_channel = lttng_consumer_clear_channel( + found_channel); + if (ret_clear_channel) { + ERR("Clear channel failed key %" PRIu64, key); + ret_code = (lttcomm_return_code) ret_clear_channel; + } + + health_code_update(); + } + ret_send_status = consumer_send_status_msg(sock, ret_code); + if (ret_send_status < 0) { + /* Somehow, the session daemon is not responding anymore. */ + goto end_nosignal; + } + break; + } + case LTTNG_CONSUMER_INIT: + { + int ret_send_status; + + ret_code = lttng_consumer_init_command(ctx, + msg.u.init.sessiond_uuid); + health_code_update(); + ret_send_status = consumer_send_status_msg(sock, ret_code); + if (ret_send_status < 0) { + /* Somehow, the session daemon is not responding anymore. */ + goto end_nosignal; + } + break; + } + case LTTNG_CONSUMER_CREATE_TRACE_CHUNK: + { + const struct lttng_credentials credentials = { + .uid = LTTNG_OPTIONAL_INIT_VALUE(msg.u.create_trace_chunk.credentials.value.uid), + .gid = LTTNG_OPTIONAL_INIT_VALUE(msg.u.create_trace_chunk.credentials.value.gid), + }; + const bool is_local_trace = + !msg.u.create_trace_chunk.relayd_id.is_set; + const uint64_t relayd_id = + msg.u.create_trace_chunk.relayd_id.value; + const char *chunk_override_name = + *msg.u.create_trace_chunk.override_name ? + msg.u.create_trace_chunk.override_name : + NULL; + struct lttng_directory_handle *chunk_directory_handle = NULL; + + /* + * The session daemon will only provide a chunk directory file + * descriptor for local traces. + */ + if (is_local_trace) { + int chunk_dirfd; + int ret_send_status; + ssize_t ret_recv; + + /* Acnowledge the reception of the command. */ + ret_send_status = consumer_send_status_msg( + sock, LTTCOMM_CONSUMERD_SUCCESS); + if (ret_send_status < 0) { + /* Somehow, the session daemon is not responding anymore. */ + goto end_nosignal; + } + + /* + * Receive trace chunk domain dirfd. + */ + ret_recv = lttcomm_recv_fds_unix_sock( + sock, &chunk_dirfd, 1); + if (ret_recv != sizeof(chunk_dirfd)) { + ERR("Failed to receive trace chunk domain directory file descriptor"); + goto error_fatal; + } + + DBG("Received trace chunk domain directory fd (%d)", + chunk_dirfd); + chunk_directory_handle = lttng_directory_handle_create_from_dirfd( + chunk_dirfd); + if (!chunk_directory_handle) { + ERR("Failed to initialize chunk domain directory handle from directory file descriptor"); + if (close(chunk_dirfd)) { + PERROR("Failed to close chunk directory file descriptor"); + } + goto error_fatal; + } + } + + ret_code = lttng_consumer_create_trace_chunk( + !is_local_trace ? &relayd_id : NULL, + msg.u.create_trace_chunk.session_id, + msg.u.create_trace_chunk.chunk_id, + (time_t) msg.u.create_trace_chunk + .creation_timestamp, + chunk_override_name, + msg.u.create_trace_chunk.credentials.is_set ? + &credentials : + NULL, + chunk_directory_handle); + lttng_directory_handle_put(chunk_directory_handle); + goto end_msg_sessiond; + } + case LTTNG_CONSUMER_CLOSE_TRACE_CHUNK: + { + enum lttng_trace_chunk_command_type close_command = + (lttng_trace_chunk_command_type) + msg.u.close_trace_chunk.close_command.value; + const uint64_t relayd_id = + msg.u.close_trace_chunk.relayd_id.value; + struct lttcomm_consumer_close_trace_chunk_reply reply; + char closed_trace_chunk_path[LTTNG_PATH_MAX] = {}; + int ret; + + ret_code = lttng_consumer_close_trace_chunk( + msg.u.close_trace_chunk.relayd_id.is_set ? + &relayd_id : + NULL, + msg.u.close_trace_chunk.session_id, + msg.u.close_trace_chunk.chunk_id, + (time_t) msg.u.close_trace_chunk.close_timestamp, + msg.u.close_trace_chunk.close_command.is_set ? + &close_command : + NULL, closed_trace_chunk_path); + reply.ret_code = ret_code; + reply.path_length = strlen(closed_trace_chunk_path) + 1; + ret = lttcomm_send_unix_sock(sock, &reply, sizeof(reply)); + if (ret != sizeof(reply)) { + goto error_fatal; + } + ret = lttcomm_send_unix_sock(sock, closed_trace_chunk_path, + reply.path_length); + if (ret != reply.path_length) { + goto error_fatal; + } + goto end_nosignal; + } + case LTTNG_CONSUMER_TRACE_CHUNK_EXISTS: + { + const uint64_t relayd_id = + msg.u.trace_chunk_exists.relayd_id.value; + + ret_code = lttng_consumer_trace_chunk_exists( + msg.u.trace_chunk_exists.relayd_id.is_set ? + &relayd_id : NULL, + msg.u.trace_chunk_exists.session_id, + msg.u.trace_chunk_exists.chunk_id); + goto end_msg_sessiond; + } + case LTTNG_CONSUMER_OPEN_CHANNEL_PACKETS: + { + const uint64_t key = msg.u.open_channel_packets.key; + struct lttng_consumer_channel *found_channel = + consumer_find_channel(key); + + if (found_channel) { + pthread_mutex_lock(&found_channel->lock); + ret_code = lttng_consumer_open_channel_packets( + found_channel); + pthread_mutex_unlock(&found_channel->lock); + } else { + /* + * The channel could have disappeared in per-pid + * buffering mode. + */ + DBG("Channel %" PRIu64 " not found", key); + ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND; + } + + health_code_update(); + goto end_msg_sessiond; + } + default: + break; + } + +end_nosignal: + /* + * Return 1 to indicate success since the 0 value can be a socket + * shutdown during the recv() or send() call. + */ + ret_func = 1; + goto end; + +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. + */ + { + int ret_send_status; + + ret_send_status = consumer_send_status_msg(sock, ret_code); + if (ret_send_status < 0) { + goto error_fatal; + } + } + + ret_func = 1; + goto end; + +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. */ + { + int ret_send_status; + + ret_send_status = consumer_send_status_channel(sock, NULL); + if (ret_send_status < 0) { + /* Stop everything if session daemon can not be notified. */ + goto error_fatal; + } + } + + ret_func = 1; + goto end; + +error_fatal: + /* This will issue a consumer stop. */ + ret_func = -1; + goto end; + +end: + rcu_read_unlock(); + health_code_update(); + return ret_func; +} + +int lttng_ust_flush_buffer(struct lttng_consumer_stream *stream, + int producer_active) +{ + LTTNG_ASSERT(stream); + LTTNG_ASSERT(stream->ustream); + + return lttng_ust_ctl_flush_buffer(stream->ustream, producer_active); +} + +/* + * Take a snapshot for a specific stream. + * + * Returns 0 on success, < 0 on error + */ +int lttng_ustconsumer_take_snapshot(struct lttng_consumer_stream *stream) +{ + LTTNG_ASSERT(stream); + LTTNG_ASSERT(stream->ustream); + + return lttng_ust_ctl_snapshot(stream->ustream); +} + +/* + * Sample consumed and produced positions for a specific stream. + * + * Returns 0 on success, < 0 on error. + */ +int lttng_ustconsumer_sample_snapshot_positions( + struct lttng_consumer_stream *stream) +{ + LTTNG_ASSERT(stream); + LTTNG_ASSERT(stream->ustream); + + return lttng_ust_ctl_snapshot_sample_positions(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) +{ + LTTNG_ASSERT(stream); + LTTNG_ASSERT(stream->ustream); + LTTNG_ASSERT(pos); + + return lttng_ust_ctl_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) +{ + LTTNG_ASSERT(stream); + LTTNG_ASSERT(stream->ustream); + LTTNG_ASSERT(pos); + + return lttng_ust_ctl_snapshot_get_consumed(stream->ustream, pos); +} + +int lttng_ustconsumer_flush_buffer(struct lttng_consumer_stream *stream, + int producer) +{ + LTTNG_ASSERT(stream); + LTTNG_ASSERT(stream->ustream); + + return lttng_ust_ctl_flush_buffer(stream->ustream, producer); +} + +int lttng_ustconsumer_clear_buffer(struct lttng_consumer_stream *stream) +{ + LTTNG_ASSERT(stream); + LTTNG_ASSERT(stream->ustream); + + return lttng_ust_ctl_clear_buffer(stream->ustream); +} + +int lttng_ustconsumer_get_current_timestamp( + struct lttng_consumer_stream *stream, uint64_t *ts) +{ + LTTNG_ASSERT(stream); + LTTNG_ASSERT(stream->ustream); + LTTNG_ASSERT(ts); + + return lttng_ust_ctl_get_current_timestamp(stream->ustream, ts); +} + +int lttng_ustconsumer_get_sequence_number( + struct lttng_consumer_stream *stream, uint64_t *seq) +{ + LTTNG_ASSERT(stream); + LTTNG_ASSERT(stream->ustream); + LTTNG_ASSERT(seq); + + return lttng_ust_ctl_get_sequence_number(stream->ustream, seq); +} + +/* + * Called when the stream signals the consumer that it has hung up. + */ +void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream) +{ + LTTNG_ASSERT(stream); + LTTNG_ASSERT(stream->ustream); + + pthread_mutex_lock(&stream->lock); + if (!stream->quiescent) { + if (lttng_ust_ctl_flush_buffer(stream->ustream, 0) < 0) { + ERR("Failed to flush buffer on stream hang-up"); + } else { + stream->quiescent = true; + } + } + pthread_mutex_unlock(&stream->lock); + stream->hangup_flush_done = 1; +} + +void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan) +{ + int i; + + LTTNG_ASSERT(chan); + LTTNG_ASSERT(chan->uchan); + LTTNG_ASSERT(chan->buffer_credentials.is_set); + + 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, + lttng_credentials_get_uid(LTTNG_OPTIONAL_GET_PTR( + chan->buffer_credentials)), + lttng_credentials_get_gid(LTTNG_OPTIONAL_GET_PTR( + chan->buffer_credentials))); + if (ret) { + PERROR("unlink %s", shm_path); + } + } + } +} + +void lttng_ustconsumer_free_channel(struct lttng_consumer_channel *chan) +{ + LTTNG_ASSERT(chan); + LTTNG_ASSERT(chan->uchan); + LTTNG_ASSERT(chan->buffer_credentials.is_set); + + consumer_metadata_cache_destroy(chan); + lttng_ust_ctl_destroy_channel(chan->uchan); + /* Try to rmdir all directories under shm_path root. */ + if (chan->root_shm_path[0]) { + (void) run_as_rmdir_recursive(chan->root_shm_path, + lttng_credentials_get_uid(LTTNG_OPTIONAL_GET_PTR( + chan->buffer_credentials)), + lttng_credentials_get_gid(LTTNG_OPTIONAL_GET_PTR( + chan->buffer_credentials)), + LTTNG_DIRECTORY_HANDLE_SKIP_NON_EMPTY_FLAG); + } + free(chan->stream_fds); +} + +void lttng_ustconsumer_del_stream(struct lttng_consumer_stream *stream) +{ + LTTNG_ASSERT(stream); + LTTNG_ASSERT(stream->ustream); + + if (stream->chan->switch_timer_enabled == 1) { + consumer_timer_switch_stop(stream->chan); + } + lttng_ust_ctl_destroy_stream(stream->ustream); +} + +int lttng_ustconsumer_get_wakeup_fd(struct lttng_consumer_stream *stream) +{ + LTTNG_ASSERT(stream); + LTTNG_ASSERT(stream->ustream); + + return lttng_ust_ctl_stream_get_wakeup_fd(stream->ustream); +} + +int lttng_ustconsumer_close_wakeup_fd(struct lttng_consumer_stream *stream) +{ + LTTNG_ASSERT(stream); + LTTNG_ASSERT(stream->ustream); + + return lttng_ust_ctl_stream_close_wakeup_fd(stream->ustream); +} + +/* + * Write up to one packet from the metadata cache to the channel. + * + * Returns the number of bytes pushed from the cache into the ring buffer, or a + * negative value on error. + */ +static +int commit_one_metadata_packet(struct lttng_consumer_stream *stream) +{ + ssize_t write_len; + int ret; + + pthread_mutex_lock(&stream->chan->metadata_cache->lock); + if (stream->chan->metadata_cache->contents.size == + stream->ust_metadata_pushed) { + /* + * In the context of a user space metadata channel, a + * change in version can be detected in two ways: + * 1) During the pre-consume of the `read_subbuffer` loop, + * 2) When populating the metadata ring buffer (i.e. here). + * + * This function is invoked when there is no metadata + * available in the ring-buffer. If all data was consumed + * up to the size of the metadata cache, there is no metadata + * to insert in the ring-buffer. + * + * However, the metadata version could still have changed (a + * regeneration without any new data will yield the same cache + * size). + * + * The cache's version is checked for a version change and the + * consumed position is reset if one occurred. + * + * This check is only necessary for the user space domain as + * it has to manage the cache explicitly. If this reset was not + * performed, no metadata would be consumed (and no reset would + * occur as part of the pre-consume) until the metadata size + * exceeded the cache size. + */ + if (stream->metadata_version != + stream->chan->metadata_cache->version) { + metadata_stream_reset_cache_consumed_position(stream); + consumer_stream_metadata_set_version(stream, + stream->chan->metadata_cache->version); + } else { + ret = 0; + goto end; + } + } + + write_len = lttng_ust_ctl_write_one_packet_to_channel(stream->chan->uchan, + &stream->chan->metadata_cache->contents.data[stream->ust_metadata_pushed], + stream->chan->metadata_cache->contents.size - + stream->ust_metadata_pushed); + LTTNG_ASSERT(write_len != 0); + if (write_len < 0) { + ERR("Writing one metadata packet"); + ret = write_len; + goto end; + } + stream->ust_metadata_pushed += write_len; + + LTTNG_ASSERT(stream->chan->metadata_cache->contents.size >= + stream->ust_metadata_pushed); + ret = write_len; + + /* + * Switch packet (but don't open the next one) on every commit of + * a metadata packet. Since the subbuffer is fully filled (with padding, + * if needed), the stream is "quiescent" after this commit. + */ + if (lttng_ust_ctl_flush_buffer(stream->ustream, 1)) { + ERR("Failed to flush buffer while commiting one metadata packet"); + ret = -EIO; + } else { + stream->quiescent = true; + } +end: + pthread_mutex_unlock(&stream->chan->metadata_cache->lock); + return ret; +} + + +/* + * Sync metadata meaning request them to the session daemon and snapshot to the + * metadata thread can consumer them. + * + * Metadata stream lock is held here, but we need to release it when + * interacting with sessiond, else we cause a deadlock with live + * awaiting on metadata to be pushed out. + * + * The RCU read side lock must be held by the caller. + */ +enum sync_metadata_status lttng_ustconsumer_sync_metadata( + struct lttng_consumer_local_data *ctx, + struct lttng_consumer_stream *metadata_stream) +{ + int ret; + enum sync_metadata_status status; + struct lttng_consumer_channel *metadata_channel; + + LTTNG_ASSERT(ctx); + LTTNG_ASSERT(metadata_stream); + + metadata_channel = metadata_stream->chan; + pthread_mutex_unlock(&metadata_stream->lock); + /* + * Request metadata from the sessiond, but don't wait for the flush + * because we locked the metadata thread. + */ + ret = lttng_ustconsumer_request_metadata(ctx, metadata_channel, 0, 0); + pthread_mutex_lock(&metadata_stream->lock); + if (ret < 0) { + status = SYNC_METADATA_STATUS_ERROR; + goto end; + } + + /* + * The metadata stream and channel can be deleted while the + * metadata stream lock was released. The streamed is checked + * for deletion before we use it further. + * + * Note that it is safe to access a logically-deleted stream since its + * existence is still guaranteed by the RCU read side lock. However, + * it should no longer be used. The close/deletion of the metadata + * channel and stream already guarantees that all metadata has been + * consumed. Therefore, there is nothing left to do in this function. + */ + if (consumer_stream_is_deleted(metadata_stream)) { + DBG("Metadata stream %" PRIu64 " was deleted during the metadata synchronization", + metadata_stream->key); + status = SYNC_METADATA_STATUS_NO_DATA; + goto end; + } + + ret = commit_one_metadata_packet(metadata_stream); + if (ret < 0) { + status = SYNC_METADATA_STATUS_ERROR; + goto end; + } else if (ret > 0) { + status = SYNC_METADATA_STATUS_NEW_DATA; + } else /* ret == 0 */ { + status = SYNC_METADATA_STATUS_NO_DATA; + goto end; + } + + ret = lttng_ust_ctl_snapshot(metadata_stream->ustream); + if (ret < 0) { + ERR("Failed to take a snapshot of the metadata ring-buffer positions, ret = %d", ret); + status = SYNC_METADATA_STATUS_ERROR; + goto end; + } + +end: + return status; +} + +/* + * Return 0 on success else a negative value. + */ +static int notify_if_more_data(struct lttng_consumer_stream *stream, + struct lttng_consumer_local_data *ctx) +{ + int ret; + struct lttng_ust_ctl_consumer_stream *ustream; + + LTTNG_ASSERT(stream); + LTTNG_ASSERT(ctx); + + ustream = stream->ustream; + + /* + * First, we are going to check if there is a new subbuffer available + * before reading the stream wait_fd. + */ + /* Get the next subbuffer */ + ret = lttng_ust_ctl_get_next_subbuf(ustream); + if (ret) { + /* No more data found, flag the stream. */ + stream->has_data = 0; + ret = 0; + goto end; + } + + ret = lttng_ust_ctl_put_subbuf(ustream); + LTTNG_ASSERT(!ret); + + /* This stream still has data. Flag it and wake up the data thread. */ + stream->has_data = 1; + + if (stream->monitor && !stream->hangup_flush_done && !ctx->has_wakeup) { + ssize_t writelen; + + writelen = lttng_pipe_write(ctx->consumer_wakeup_pipe, "!", 1); + if (writelen < 0 && errno != EAGAIN && errno != EWOULDBLOCK) { + ret = writelen; + goto end; + } + + /* The wake up pipe has been notified. */ + ctx->has_wakeup = 1; + } + ret = 0; + +end: + return ret; +} + +static int consumer_stream_ust_on_wake_up(struct lttng_consumer_stream *stream) +{ + int ret = 0; + + /* + * We can consume the 1 byte written into the wait_fd by + * UST. Don't trigger error if we cannot read this one byte + * (read returns 0), or if the error is EAGAIN or EWOULDBLOCK. + * + * This is only done when the stream is monitored by a thread, + * before the flush is done after a hangup and if the stream + * is not flagged with data since there might be nothing to + * consume in the wait fd but still have data available + * flagged by the consumer wake up pipe. + */ + if (stream->monitor && !stream->hangup_flush_done && !stream->has_data) { + char dummy; + ssize_t readlen; + + readlen = lttng_read(stream->wait_fd, &dummy, 1); + if (readlen < 0 && errno != EAGAIN && errno != EWOULDBLOCK) { + ret = readlen; + } + } + + return ret; +} + +static int extract_common_subbuffer_info(struct lttng_consumer_stream *stream, + struct stream_subbuffer *subbuf) +{ + int ret; + + ret = lttng_ust_ctl_get_subbuf_size( + stream->ustream, &subbuf->info.data.subbuf_size); + if (ret) { + goto end; + } + + ret = lttng_ust_ctl_get_padded_subbuf_size( + stream->ustream, &subbuf->info.data.padded_subbuf_size); + if (ret) { + goto end; + } + +end: + return ret; +} + +static int extract_metadata_subbuffer_info(struct lttng_consumer_stream *stream, + struct stream_subbuffer *subbuf) +{ + int ret; + + ret = extract_common_subbuffer_info(stream, subbuf); + if (ret) { + goto end; + } + + subbuf->info.metadata.version = stream->metadata_version; + +end: + return ret; +} + +static int extract_data_subbuffer_info(struct lttng_consumer_stream *stream, + struct stream_subbuffer *subbuf) +{ + int ret; + + ret = extract_common_subbuffer_info(stream, subbuf); + if (ret) { + goto end; + } + + ret = lttng_ust_ctl_get_packet_size( + stream->ustream, &subbuf->info.data.packet_size); + if (ret < 0) { + PERROR("Failed to get sub-buffer packet size"); + goto end; + } + + ret = lttng_ust_ctl_get_content_size( + stream->ustream, &subbuf->info.data.content_size); + if (ret < 0) { + PERROR("Failed to get sub-buffer content size"); + goto end; + } + + ret = lttng_ust_ctl_get_timestamp_begin( + stream->ustream, &subbuf->info.data.timestamp_begin); + if (ret < 0) { + PERROR("Failed to get sub-buffer begin timestamp"); + goto end; + } + + ret = lttng_ust_ctl_get_timestamp_end( + stream->ustream, &subbuf->info.data.timestamp_end); + if (ret < 0) { + PERROR("Failed to get sub-buffer end timestamp"); + goto end; + } + + ret = lttng_ust_ctl_get_events_discarded( + stream->ustream, &subbuf->info.data.events_discarded); + if (ret) { + PERROR("Failed to get sub-buffer events discarded count"); + goto end; + } + + ret = lttng_ust_ctl_get_sequence_number(stream->ustream, + &subbuf->info.data.sequence_number.value); + if (ret) { + /* May not be supported by older LTTng-modules. */ + if (ret != -ENOTTY) { + PERROR("Failed to get sub-buffer sequence number"); + goto end; + } + } else { + subbuf->info.data.sequence_number.is_set = true; + } + + ret = lttng_ust_ctl_get_stream_id( + stream->ustream, &subbuf->info.data.stream_id); + if (ret < 0) { + PERROR("Failed to get stream id"); + goto end; + } + + ret = lttng_ust_ctl_get_instance_id(stream->ustream, + &subbuf->info.data.stream_instance_id.value); + if (ret) { + /* May not be supported by older LTTng-modules. */ + if (ret != -ENOTTY) { + PERROR("Failed to get stream instance id"); + goto end; + } + } else { + subbuf->info.data.stream_instance_id.is_set = true; + } +end: + return ret; +} + +static int get_next_subbuffer_common(struct lttng_consumer_stream *stream, + struct stream_subbuffer *subbuffer) +{ + int ret; + const char *addr; + + ret = stream->read_subbuffer_ops.extract_subbuffer_info( + stream, subbuffer); + if (ret) { + goto end; + } + + ret = get_current_subbuf_addr(stream, &addr); + if (ret) { + goto end; + } + + subbuffer->buffer.buffer = lttng_buffer_view_init( + addr, 0, subbuffer->info.data.padded_subbuf_size); + LTTNG_ASSERT(subbuffer->buffer.buffer.data != NULL); +end: + return ret; +} + +static enum get_next_subbuffer_status get_next_subbuffer( + struct lttng_consumer_stream *stream, + struct stream_subbuffer *subbuffer) +{ + int ret; + enum get_next_subbuffer_status status; + + ret = lttng_ust_ctl_get_next_subbuf(stream->ustream); + switch (ret) { + case 0: + status = GET_NEXT_SUBBUFFER_STATUS_OK; + break; + case -ENODATA: + case -EAGAIN: + /* + * The caller only expects -ENODATA when there is no data to + * read, but the kernel tracer returns -EAGAIN when there is + * currently no data for a non-finalized stream, and -ENODATA + * when there is no data for a finalized stream. Those can be + * combined into a -ENODATA return value. + */ + status = GET_NEXT_SUBBUFFER_STATUS_NO_DATA; + goto end; + default: + status = GET_NEXT_SUBBUFFER_STATUS_ERROR; + goto end; + } + + ret = get_next_subbuffer_common(stream, subbuffer); + if (ret) { + status = GET_NEXT_SUBBUFFER_STATUS_ERROR; + goto end; + } +end: + return status; +} + +static enum get_next_subbuffer_status get_next_subbuffer_metadata( + struct lttng_consumer_stream *stream, + struct stream_subbuffer *subbuffer) +{ + int ret; + bool cache_empty; + bool got_subbuffer; + bool coherent; + bool buffer_empty; + unsigned long consumed_pos, produced_pos; + enum get_next_subbuffer_status status; + + do { + ret = lttng_ust_ctl_get_next_subbuf(stream->ustream); + if (ret == 0) { + got_subbuffer = true; + } else { + got_subbuffer = false; + if (ret != -EAGAIN) { + /* Fatal error. */ + status = GET_NEXT_SUBBUFFER_STATUS_ERROR; + goto end; + } + } + + /* + * Determine if the cache is empty and ensure that a sub-buffer + * is made available if the cache is not empty. + */ + if (!got_subbuffer) { + ret = commit_one_metadata_packet(stream); + if (ret < 0 && ret != -ENOBUFS) { + status = GET_NEXT_SUBBUFFER_STATUS_ERROR; + goto end; + } else if (ret == 0) { + /* Not an error, the cache is empty. */ + cache_empty = true; + status = GET_NEXT_SUBBUFFER_STATUS_NO_DATA; + goto end; + } else { + cache_empty = false; + } + } else { + pthread_mutex_lock(&stream->chan->metadata_cache->lock); + cache_empty = stream->chan->metadata_cache->contents.size == + stream->ust_metadata_pushed; + pthread_mutex_unlock(&stream->chan->metadata_cache->lock); + } + } while (!got_subbuffer); + + /* Populate sub-buffer infos and view. */ + ret = get_next_subbuffer_common(stream, subbuffer); + if (ret) { + status = GET_NEXT_SUBBUFFER_STATUS_ERROR; + goto end; + } + + ret = lttng_ustconsumer_sample_snapshot_positions(stream); + if (ret < 0) { + /* + * -EAGAIN is not expected since we got a sub-buffer and haven't + * pushed the consumption position yet (on put_next). + */ + PERROR("Failed to take a snapshot of metadata buffer positions"); + status = GET_NEXT_SUBBUFFER_STATUS_ERROR; + goto end; + } + + ret = lttng_ustconsumer_get_consumed_snapshot(stream, &consumed_pos); + if (ret) { + PERROR("Failed to get metadata consumed position"); + status = GET_NEXT_SUBBUFFER_STATUS_ERROR; + goto end; + } + + ret = lttng_ustconsumer_get_produced_snapshot(stream, &produced_pos); + if (ret) { + PERROR("Failed to get metadata produced position"); + status = GET_NEXT_SUBBUFFER_STATUS_ERROR; + goto end; + } + + /* Last sub-buffer of the ring buffer ? */ + buffer_empty = (consumed_pos + stream->max_sb_size) == produced_pos; + + /* + * The sessiond registry lock ensures that coherent units of metadata + * are pushed to the consumer daemon at once. Hence, if a sub-buffer is + * acquired, the cache is empty, and it is the only available sub-buffer + * available, it is safe to assume that it is "coherent". + */ + coherent = got_subbuffer && cache_empty && buffer_empty; + + LTTNG_OPTIONAL_SET(&subbuffer->info.metadata.coherent, coherent); + status = GET_NEXT_SUBBUFFER_STATUS_OK; +end: + return status; +} + +static int put_next_subbuffer(struct lttng_consumer_stream *stream, + struct stream_subbuffer *subbuffer) +{ + const int ret = lttng_ust_ctl_put_next_subbuf(stream->ustream); + + LTTNG_ASSERT(ret == 0); + return ret; +} + +static int signal_metadata(struct lttng_consumer_stream *stream, + struct lttng_consumer_local_data *ctx) +{ + ASSERT_LOCKED(stream->metadata_rdv_lock); + return pthread_cond_broadcast(&stream->metadata_rdv) ? -errno : 0; +} + +static int lttng_ustconsumer_set_stream_ops( + struct lttng_consumer_stream *stream) +{ + int ret = 0; + + stream->read_subbuffer_ops.on_wake_up = consumer_stream_ust_on_wake_up; + if (stream->metadata_flag) { + stream->read_subbuffer_ops.get_next_subbuffer = + get_next_subbuffer_metadata; + stream->read_subbuffer_ops.extract_subbuffer_info = + extract_metadata_subbuffer_info; + stream->read_subbuffer_ops.reset_metadata = + metadata_stream_reset_cache_consumed_position; + if (stream->chan->is_live) { + stream->read_subbuffer_ops.on_sleep = signal_metadata; + ret = consumer_stream_enable_metadata_bucketization( + stream); + if (ret) { + goto end; + } + } + } else { + stream->read_subbuffer_ops.get_next_subbuffer = + get_next_subbuffer; + stream->read_subbuffer_ops.extract_subbuffer_info = + extract_data_subbuffer_info; + stream->read_subbuffer_ops.on_sleep = notify_if_more_data; + if (stream->chan->is_live) { + stream->read_subbuffer_ops.send_live_beacon = + consumer_flush_ust_index; + } + } + + stream->read_subbuffer_ops.put_next_subbuffer = put_next_subbuffer; +end: + return ret; +} + +/* + * Called when a stream is created. + * + * Return 0 on success or else a negative value. + */ +int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream *stream) +{ + int ret; + + LTTNG_ASSERT(stream); + + /* + * Don't create anything if this is set for streaming or if there is + * no current trace chunk on the parent channel. + */ + if (stream->net_seq_idx == (uint64_t) -1ULL && stream->chan->monitor && + stream->chan->trace_chunk) { + ret = consumer_stream_create_output_files(stream, true); + if (ret) { + goto error; + } + } + + lttng_ustconsumer_set_stream_ops(stream); + ret = 0; + +error: + return ret; +} + +/* + * Check if data is still being extracted from the buffers for a specific + * stream. Consumer data lock MUST be acquired before calling this function + * and the stream lock. + * + * Return 1 if the traced data are still getting read else 0 meaning that the + * data is available for trace viewer reading. + */ +int lttng_ustconsumer_data_pending(struct lttng_consumer_stream *stream) +{ + int ret; + + LTTNG_ASSERT(stream); + LTTNG_ASSERT(stream->ustream); + ASSERT_LOCKED(stream->lock); + + DBG("UST consumer checking data pending"); + + if (stream->endpoint_status != CONSUMER_ENDPOINT_ACTIVE) { + ret = 0; + goto end; + } + + if (stream->chan->type == CONSUMER_CHANNEL_TYPE_METADATA) { + uint64_t contiguous, pushed; + + /* Ease our life a bit. */ + pthread_mutex_lock(&stream->chan->metadata_cache->lock); + contiguous = stream->chan->metadata_cache->contents.size; + pthread_mutex_unlock(&stream->chan->metadata_cache->lock); + pushed = stream->ust_metadata_pushed; + + /* + * We can simply check whether all contiguously available data + * has been pushed to the ring buffer, since the push operation + * is performed within get_next_subbuf(), and because both + * get_next_subbuf() and put_next_subbuf() are issued atomically + * thanks to the stream lock within + * lttng_ustconsumer_read_subbuffer(). This basically means that + * whetnever ust_metadata_pushed is incremented, the associated + * metadata has been consumed from the metadata stream. + */ + DBG("UST consumer metadata pending check: contiguous %" PRIu64 " vs pushed %" PRIu64, + contiguous, pushed); + LTTNG_ASSERT(((int64_t) (contiguous - pushed)) >= 0); + if ((contiguous != pushed) || + (((int64_t) contiguous - pushed) > 0 || contiguous == 0)) { + ret = 1; /* Data is pending */ + goto end; + } + } else { + ret = lttng_ust_ctl_get_next_subbuf(stream->ustream); + if (ret == 0) { + /* + * There is still data so let's put back this + * subbuffer. + */ + ret = lttng_ust_ctl_put_subbuf(stream->ustream); + LTTNG_ASSERT(ret == 0); + ret = 1; /* Data is pending */ + goto end; + } + } + + /* Data is NOT pending so ready to be read. */ + ret = 0; + +end: + return ret; +} + +/* + * Stop a given metadata channel timer if enabled and close the wait fd which + * is the poll pipe of the metadata stream. + * + * This MUST be called with the metadata channel lock acquired. + */ +void lttng_ustconsumer_close_metadata(struct lttng_consumer_channel *metadata) +{ + int ret; + + LTTNG_ASSERT(metadata); + LTTNG_ASSERT(metadata->type == CONSUMER_CHANNEL_TYPE_METADATA); + + DBG("Closing metadata channel key %" PRIu64, metadata->key); + + if (metadata->switch_timer_enabled == 1) { + consumer_timer_switch_stop(metadata); + } + + if (!metadata->metadata_stream) { + goto end; + } + + /* + * Closing write side so the thread monitoring the stream wakes up if any + * and clean the metadata stream. + */ + if (metadata->metadata_stream->ust_metadata_poll_pipe[1] >= 0) { + ret = close(metadata->metadata_stream->ust_metadata_poll_pipe[1]); + if (ret < 0) { + PERROR("closing metadata pipe write side"); + } + metadata->metadata_stream->ust_metadata_poll_pipe[1] = -1; + } + +end: + return; +} + +/* + * Close every metadata stream wait fd of the metadata hash table. This + * function MUST be used very carefully so not to run into a race between the + * metadata thread handling streams and this function closing their wait fd. + * + * For UST, this is used when the session daemon hangs up. Its the metadata + * producer so calling this is safe because we are assured that no state change + * can occur in the metadata thread for the streams in the hash table. + */ +void lttng_ustconsumer_close_all_metadata(struct lttng_ht *metadata_ht) +{ + struct lttng_ht_iter iter; + struct lttng_consumer_stream *stream; + + LTTNG_ASSERT(metadata_ht); + LTTNG_ASSERT(metadata_ht->ht); + + DBG("UST consumer closing all metadata streams"); + + rcu_read_lock(); + cds_lfht_for_each_entry(metadata_ht->ht, &iter.iter, stream, + node.node) { + + health_code_update(); + + pthread_mutex_lock(&stream->chan->lock); + lttng_ustconsumer_close_metadata(stream->chan); + pthread_mutex_unlock(&stream->chan->lock); + + } + rcu_read_unlock(); +} + +void lttng_ustconsumer_close_stream_wakeup(struct lttng_consumer_stream *stream) +{ + int ret; + + ret = lttng_ust_ctl_stream_close_wakeup_fd(stream->ustream); + if (ret < 0) { + ERR("Unable to close wakeup fd"); + } +} + +/* + * Please refer to consumer-timer.c before adding any lock within this + * function or any of its callees. Timers have a very strict locking + * semantic with respect to teardown. Failure to respect this semantic + * introduces deadlocks. + * + * DON'T hold the metadata lock when calling this function, else this + * can cause deadlock involving consumer awaiting for metadata to be + * pushed out due to concurrent interaction with the session daemon. + */ +int lttng_ustconsumer_request_metadata(struct lttng_consumer_local_data *ctx, + struct lttng_consumer_channel *channel, int timer, int wait) +{ + struct lttcomm_metadata_request_msg request; + struct lttcomm_consumer_msg msg; + enum lttcomm_return_code ret_code = LTTCOMM_CONSUMERD_SUCCESS; + uint64_t len, key, offset, version; + int ret; + + LTTNG_ASSERT(channel); + LTTNG_ASSERT(channel->metadata_cache); + + memset(&request, 0, sizeof(request)); + + /* send the metadata request to sessiond */ + switch (the_consumer_data.type) { + case LTTNG_CONSUMER64_UST: + request.bits_per_long = 64; + break; + case LTTNG_CONSUMER32_UST: + request.bits_per_long = 32; + break; + default: + request.bits_per_long = 0; + break; + } + + request.session_id = channel->session_id; + request.session_id_per_pid = channel->session_id_per_pid; + /* + * Request the application UID here so the metadata of that application can + * be sent back. The channel UID corresponds to the user UID of the session + * used for the rights on the stream file(s). + */ + request.uid = channel->ust_app_uid; + request.key = channel->key; + + DBG("Sending metadata request to sessiond, session id %" PRIu64 + ", per-pid %" PRIu64 ", app UID %u and channel key %" PRIu64, + request.session_id, request.session_id_per_pid, request.uid, + request.key); + + pthread_mutex_lock(&ctx->metadata_socket_lock); + + health_code_update(); + + ret = lttcomm_send_unix_sock(ctx->consumer_metadata_socket, &request, + sizeof(request)); + if (ret < 0) { + ERR("Asking metadata to sessiond"); + goto end; + } + + health_code_update(); + + /* Receive the metadata from sessiond */ + ret = lttcomm_recv_unix_sock(ctx->consumer_metadata_socket, &msg, + sizeof(msg)); + if (ret != sizeof(msg)) { + DBG("Consumer received unexpected message size %d (expects %zu)", + ret, sizeof(msg)); + lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD); + /* + * The ret value might 0 meaning an orderly shutdown but this is ok + * since the caller handles this. + */ + goto end; + } + + health_code_update(); + + if (msg.cmd_type == LTTNG_ERR_UND) { + /* No registry found */ + (void) consumer_send_status_msg(ctx->consumer_metadata_socket, + ret_code); + ret = 0; + goto end; + } else if (msg.cmd_type != LTTNG_CONSUMER_PUSH_METADATA) { + ERR("Unexpected cmd_type received %d", msg.cmd_type); + ret = -1; + goto end; + } + + len = msg.u.push_metadata.len; + key = msg.u.push_metadata.key; + offset = msg.u.push_metadata.target_offset; + version = msg.u.push_metadata.version; + + LTTNG_ASSERT(key == channel->key); + if (len == 0) { + DBG("No new metadata to receive for key %" PRIu64, key); + } + + health_code_update(); + + /* Tell session daemon we are ready to receive the metadata. */ + ret = consumer_send_status_msg(ctx->consumer_metadata_socket, + LTTCOMM_CONSUMERD_SUCCESS); + if (ret < 0 || len == 0) { + /* + * Somehow, the session daemon is not responding anymore or there is + * nothing to receive. + */ + goto end; + } + + health_code_update(); + + ret = lttng_ustconsumer_recv_metadata(ctx->consumer_metadata_socket, + key, offset, len, version, channel, timer, wait); + if (ret >= 0) { + /* + * Only send the status msg if the sessiond is alive meaning a positive + * ret code. + */ + (void) consumer_send_status_msg(ctx->consumer_metadata_socket, ret); + } + ret = 0; + +end: + health_code_update(); + + pthread_mutex_unlock(&ctx->metadata_socket_lock); + return ret; +} + +/* + * Return the ustctl call for the get stream id. + */ +int lttng_ustconsumer_get_stream_id(struct lttng_consumer_stream *stream, + uint64_t *stream_id) +{ + LTTNG_ASSERT(stream); + LTTNG_ASSERT(stream_id); + + return lttng_ust_ctl_get_stream_id(stream->ustream, stream_id); +} + +void lttng_ustconsumer_sigbus_handle(void *addr) +{ + lttng_ust_ctl_sigbus_handle(addr); +}