- PERROR("close");
- }
-
-error_open:
- modprobe_remove_lttng_control();
-
-error:
- WARN("No kernel tracer available");
- kernel_tracer_fd = -1;
- if (!is_root) {
- return LTTNG_ERR_NEED_ROOT_SESSIOND;
- } else {
- return LTTNG_ERR_KERN_NA;
- }
-}
-
-
-/*
- * Copy consumer output from the tracing session to the domain session. The
- * function also applies the right modification on a per domain basis for the
- * trace files destination directory.
- */
-static int copy_session_consumer(int domain, struct ltt_session *session)
-{
- int ret;
- const char *dir_name;
- struct consumer_output *consumer;
-
- assert(session);
- assert(session->consumer);
-
- switch (domain) {
- case LTTNG_DOMAIN_KERNEL:
- DBG3("Copying tracing session consumer output in kernel session");
- session->kernel_session->consumer =
- consumer_copy_output(session->consumer);
- /* Ease our life a bit for the next part */
- consumer = session->kernel_session->consumer;
- dir_name = DEFAULT_KERNEL_TRACE_DIR;
- break;
- case LTTNG_DOMAIN_UST:
- DBG3("Copying tracing session consumer output in UST session");
- session->ust_session->consumer =
- consumer_copy_output(session->consumer);
- /* Ease our life a bit for the next part */
- consumer = session->ust_session->consumer;
- dir_name = DEFAULT_UST_TRACE_DIR;
- break;
- default:
- ret = LTTNG_ERR_UNKNOWN_DOMAIN;
- goto error;
- }
-
- /* Append correct directory to subdir */
- strncat(consumer->subdir, dir_name,
- sizeof(consumer->subdir) - strlen(consumer->subdir) - 1);
- DBG3("Copy session consumer subdir %s", consumer->subdir);
-
- ret = LTTNG_OK;
-
-error:
- return ret;
-}
-
-/*
- * Create an UST session and add it to the session ust list.
- */
-static int create_ust_session(struct ltt_session *session,
- struct lttng_domain *domain)
-{
- int ret;
- struct ltt_ust_session *lus = NULL;
-
- assert(session);
- assert(domain);
- assert(session->consumer);
-
- switch (domain->type) {
- case LTTNG_DOMAIN_UST:
- break;
- default:
- ERR("Unknown UST domain on create session %d", domain->type);
- ret = LTTNG_ERR_UNKNOWN_DOMAIN;
- goto error;
- }
-
- DBG("Creating UST session");
-
- lus = trace_ust_create_session(session->path, session->id, domain);
- if (lus == NULL) {
- ret = LTTNG_ERR_UST_SESS_FAIL;
- goto error;
- }
-
- lus->uid = session->uid;
- lus->gid = session->gid;
- session->ust_session = lus;
-
- /* Copy session output to the newly created UST session */
- ret = copy_session_consumer(domain->type, session);
- if (ret != LTTNG_OK) {
- goto error;
- }
-
- return LTTNG_OK;
-
-error:
- free(lus);
- session->ust_session = NULL;
- return ret;
-}
-
-/*
- * Create a kernel tracer session then create the default channel.
- */
-static int create_kernel_session(struct ltt_session *session)
-{
- int ret;
-
- DBG("Creating kernel session");
-
- ret = kernel_create_session(session, kernel_tracer_fd);
- if (ret < 0) {
- ret = LTTNG_ERR_KERN_SESS_FAIL;
- goto error;
- }
-
- /* Code flow safety */
- assert(session->kernel_session);
-
- /* Copy session output to the newly created Kernel session */
- ret = copy_session_consumer(LTTNG_DOMAIN_KERNEL, session);
- if (ret != LTTNG_OK) {
- goto error;
- }
-
- /* Create directory(ies) on local filesystem. */
- if (session->kernel_session->consumer->type == CONSUMER_DST_LOCAL &&
- strlen(session->kernel_session->consumer->dst.trace_path) > 0) {
- ret = run_as_mkdir_recursive(
- session->kernel_session->consumer->dst.trace_path,
- S_IRWXU | S_IRWXG, session->uid, session->gid);
- if (ret < 0) {
- if (ret != -EEXIST) {
- ERR("Trace directory creation error");
- goto error;
- }
- }
- }
-
- session->kernel_session->uid = session->uid;
- session->kernel_session->gid = session->gid;
-
- return LTTNG_OK;
-
-error:
- trace_kernel_destroy_session(session->kernel_session);
- session->kernel_session = NULL;
- return ret;
-}
-
-/*
- * Count number of session permitted by uid/gid.
- */
-static unsigned int lttng_sessions_count(uid_t uid, gid_t gid)
-{
- unsigned int i = 0;
- struct ltt_session *session;
-
- DBG("Counting number of available session for UID %d GID %d",
- uid, gid);
- cds_list_for_each_entry(session, &session_list_ptr->head, list) {
- /*
- * Only list the sessions the user can control.
- */
- if (!session_access_ok(session, uid, gid)) {
- continue;
- }
- i++;
- }
- return i;
-}
-
-/*
- * Process the command requested by the lttng client within the command
- * context structure. This function make sure that the return structure (llm)
- * is set and ready for transmission before returning.
- *
- * Return any error encountered or 0 for success.
- *
- * "sock" is only used for special-case var. len data.
- */
-static int process_client_msg(struct command_ctx *cmd_ctx, int sock,
- int *sock_error)
-{
- int ret = LTTNG_OK;
- int need_tracing_session = 1;
- int need_domain;
-
- DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
-
- *sock_error = 0;
-
- switch (cmd_ctx->lsm->cmd_type) {
- case LTTNG_CREATE_SESSION:
- case LTTNG_DESTROY_SESSION:
- case LTTNG_LIST_SESSIONS:
- case LTTNG_LIST_DOMAINS:
- case LTTNG_START_TRACE:
- case LTTNG_STOP_TRACE:
- need_domain = 0;
- break;
- default:
- need_domain = 1;
- }
-
- if (opt_no_kernel && need_domain
- && cmd_ctx->lsm->domain.type == LTTNG_DOMAIN_KERNEL) {
- if (!is_root) {
- ret = LTTNG_ERR_NEED_ROOT_SESSIOND;
- } else {
- ret = LTTNG_ERR_KERN_NA;
- }
- goto error;
- }
-
- /* Deny register consumer if we already have a spawned consumer. */
- if (cmd_ctx->lsm->cmd_type == LTTNG_REGISTER_CONSUMER) {
- pthread_mutex_lock(&kconsumer_data.pid_mutex);
- if (kconsumer_data.pid > 0) {
- ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
- pthread_mutex_unlock(&kconsumer_data.pid_mutex);
- goto error;
- }
- pthread_mutex_unlock(&kconsumer_data.pid_mutex);
- }
-
- /*
- * Check for command that don't needs to allocate a returned payload. We do
- * this here so we don't have to make the call for no payload at each
- * command.
- */
- switch(cmd_ctx->lsm->cmd_type) {
- case LTTNG_LIST_SESSIONS:
- case LTTNG_LIST_TRACEPOINTS:
- case LTTNG_LIST_TRACEPOINT_FIELDS:
- case LTTNG_LIST_DOMAINS:
- case LTTNG_LIST_CHANNELS:
- case LTTNG_LIST_EVENTS:
- break;
- default:
- /* Setup lttng message with no payload */
- ret = setup_lttng_msg(cmd_ctx, 0);
- if (ret < 0) {
- /* This label does not try to unlock the session */
- goto init_setup_error;
- }
- }
-
- /* Commands that DO NOT need a session. */
- switch (cmd_ctx->lsm->cmd_type) {
- case LTTNG_CREATE_SESSION:
- case LTTNG_CALIBRATE:
- case LTTNG_LIST_SESSIONS:
- case LTTNG_LIST_TRACEPOINTS:
- case LTTNG_LIST_TRACEPOINT_FIELDS:
- need_tracing_session = 0;
- break;
- default:
- DBG("Getting session %s by name", cmd_ctx->lsm->session.name);
- /*
- * We keep the session list lock across _all_ commands
- * for now, because the per-session lock does not
- * handle teardown properly.
- */
- session_lock_list();
- cmd_ctx->session = session_find_by_name(cmd_ctx->lsm->session.name);
- if (cmd_ctx->session == NULL) {
- if (cmd_ctx->lsm->session.name != NULL) {
- ret = LTTNG_ERR_SESS_NOT_FOUND;
- } else {
- /* If no session name specified */
- ret = LTTNG_ERR_SELECT_SESS;
- }
- goto error;
- } else {
- /* Acquire lock for the session */
- session_lock(cmd_ctx->session);
- }
- break;
- }
-
- if (!need_domain) {
- goto skip_domain;
- }
-
- /*
- * Check domain type for specific "pre-action".
- */
- switch (cmd_ctx->lsm->domain.type) {
- case LTTNG_DOMAIN_KERNEL:
- if (!is_root) {
- ret = LTTNG_ERR_NEED_ROOT_SESSIOND;
- goto error;
- }
-
- /* Kernel tracer check */
- if (kernel_tracer_fd == -1) {
- /* Basically, load kernel tracer modules */
- ret = init_kernel_tracer();
- if (ret != 0) {
- goto error;
- }
- }
-
- /* Consumer is in an ERROR state. Report back to client */
- if (uatomic_read(&kernel_consumerd_state) == CONSUMER_ERROR) {
- ret = LTTNG_ERR_NO_KERNCONSUMERD;
- goto error;
- }
-
- /* Need a session for kernel command */
- if (need_tracing_session) {
- if (cmd_ctx->session->kernel_session == NULL) {
- ret = create_kernel_session(cmd_ctx->session);
- if (ret < 0) {
- ret = LTTNG_ERR_KERN_SESS_FAIL;
- goto error;
- }
- }
-
- /* Start the kernel consumer daemon */
- pthread_mutex_lock(&kconsumer_data.pid_mutex);
- if (kconsumer_data.pid == 0 &&
- cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER &&
- cmd_ctx->session->start_consumer) {
- pthread_mutex_unlock(&kconsumer_data.pid_mutex);
- ret = start_consumerd(&kconsumer_data);
- if (ret < 0) {
- ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
- goto error;
- }
- uatomic_set(&kernel_consumerd_state, CONSUMER_STARTED);
- } else {
- pthread_mutex_unlock(&kconsumer_data.pid_mutex);
- }
-
- /*
- * The consumer was just spawned so we need to add the socket to
- * the consumer output of the session if exist.
- */
- ret = consumer_create_socket(&kconsumer_data,
- cmd_ctx->session->kernel_session->consumer);
- if (ret < 0) {
- goto error;
- }
- }
-
- break;
- case LTTNG_DOMAIN_UST:
- {
- /* Consumer is in an ERROR state. Report back to client */
- if (uatomic_read(&ust_consumerd_state) == CONSUMER_ERROR) {
- ret = LTTNG_ERR_NO_USTCONSUMERD;
- goto error;
- }
-
- if (need_tracing_session) {
- /* Create UST session if none exist. */
- if (cmd_ctx->session->ust_session == NULL) {
- ret = create_ust_session(cmd_ctx->session,
- &cmd_ctx->lsm->domain);
- if (ret != LTTNG_OK) {
- goto error;
- }
- }
-
- /* Start the UST consumer daemons */
- /* 64-bit */
- pthread_mutex_lock(&ustconsumer64_data.pid_mutex);
- if (consumerd64_bin[0] != '\0' &&
- ustconsumer64_data.pid == 0 &&
- cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER &&
- cmd_ctx->session->start_consumer) {
- pthread_mutex_unlock(&ustconsumer64_data.pid_mutex);
- ret = start_consumerd(&ustconsumer64_data);
- if (ret < 0) {
- ret = LTTNG_ERR_UST_CONSUMER64_FAIL;
- uatomic_set(&ust_consumerd64_fd, -EINVAL);
- goto error;
- }
-
- uatomic_set(&ust_consumerd64_fd, ustconsumer64_data.cmd_sock);
- uatomic_set(&ust_consumerd_state, CONSUMER_STARTED);
- } else {
- pthread_mutex_unlock(&ustconsumer64_data.pid_mutex);
- }
-
- /*
- * Setup socket for consumer 64 bit. No need for atomic access
- * since it was set above and can ONLY be set in this thread.
- */
- ret = consumer_create_socket(&ustconsumer64_data,
- cmd_ctx->session->ust_session->consumer);
- if (ret < 0) {
- goto error;
- }
-
- /* 32-bit */
- if (consumerd32_bin[0] != '\0' &&
- ustconsumer32_data.pid == 0 &&
- cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER &&
- cmd_ctx->session->start_consumer) {
- pthread_mutex_unlock(&ustconsumer32_data.pid_mutex);
- ret = start_consumerd(&ustconsumer32_data);
- if (ret < 0) {
- ret = LTTNG_ERR_UST_CONSUMER32_FAIL;
- uatomic_set(&ust_consumerd32_fd, -EINVAL);
- goto error;
- }
-
- uatomic_set(&ust_consumerd32_fd, ustconsumer32_data.cmd_sock);
- uatomic_set(&ust_consumerd_state, CONSUMER_STARTED);
- } else {
- pthread_mutex_unlock(&ustconsumer32_data.pid_mutex);
- }
-
- /*
- * Setup socket for consumer 64 bit. No need for atomic access
- * since it was set above and can ONLY be set in this thread.
- */
- ret = consumer_create_socket(&ustconsumer32_data,
- cmd_ctx->session->ust_session->consumer);
- if (ret < 0) {
- goto error;
- }
- }
- break;
- }
- default:
- break;
- }
-skip_domain:
-
- /* Validate consumer daemon state when start/stop trace command */
- if (cmd_ctx->lsm->cmd_type == LTTNG_START_TRACE ||
- cmd_ctx->lsm->cmd_type == LTTNG_STOP_TRACE) {
- switch (cmd_ctx->lsm->domain.type) {
- case LTTNG_DOMAIN_UST:
- if (uatomic_read(&ust_consumerd_state) != CONSUMER_STARTED) {
- ret = LTTNG_ERR_NO_USTCONSUMERD;
- goto error;
- }
- break;
- case LTTNG_DOMAIN_KERNEL:
- if (uatomic_read(&kernel_consumerd_state) != CONSUMER_STARTED) {
- ret = LTTNG_ERR_NO_KERNCONSUMERD;
- goto error;
- }
- break;
- }
- }
-
- /*
- * Check that the UID or GID match that of the tracing session.
- * The root user can interact with all sessions.
- */
- if (need_tracing_session) {
- if (!session_access_ok(cmd_ctx->session,
- LTTNG_SOCK_GET_UID_CRED(&cmd_ctx->creds),
- LTTNG_SOCK_GET_GID_CRED(&cmd_ctx->creds))) {
- ret = LTTNG_ERR_EPERM;
- goto error;
- }
- }
-
- /* Process by command type */
- switch (cmd_ctx->lsm->cmd_type) {
- case LTTNG_ADD_CONTEXT:
- {
- ret = cmd_add_context(cmd_ctx->session, cmd_ctx->lsm->domain.type,
- cmd_ctx->lsm->u.context.channel_name,
- cmd_ctx->lsm->u.context.event_name,
- &cmd_ctx->lsm->u.context.ctx);
- break;
- }
- case LTTNG_DISABLE_CHANNEL:
- {
- ret = cmd_disable_channel(cmd_ctx->session, cmd_ctx->lsm->domain.type,
- cmd_ctx->lsm->u.disable.channel_name);
- break;
- }
- case LTTNG_DISABLE_EVENT:
- {
- ret = cmd_disable_event(cmd_ctx->session, cmd_ctx->lsm->domain.type,
- cmd_ctx->lsm->u.disable.channel_name,
- cmd_ctx->lsm->u.disable.name);
- break;
- }
- case LTTNG_DISABLE_ALL_EVENT:
- {
- DBG("Disabling all events");
-
- ret = cmd_disable_event_all(cmd_ctx->session, cmd_ctx->lsm->domain.type,
- cmd_ctx->lsm->u.disable.channel_name);
- break;
- }
- case LTTNG_DISABLE_CONSUMER:
- {
- ret = cmd_disable_consumer(cmd_ctx->lsm->domain.type, cmd_ctx->session);
- break;
- }
- case LTTNG_ENABLE_CHANNEL:
- {
- ret = cmd_enable_channel(cmd_ctx->session, cmd_ctx->lsm->domain.type,
- &cmd_ctx->lsm->u.channel.chan, kernel_poll_pipe[1]);
- break;
- }
- case LTTNG_ENABLE_CONSUMER:
- {
- /*
- * XXX: 0 means that this URI should be applied on the session. Should
- * be a DOMAIN enuam.
- */
- ret = cmd_enable_consumer(cmd_ctx->lsm->domain.type, cmd_ctx->session);
- if (ret != LTTNG_OK) {
- goto error;
- }
-
- if (cmd_ctx->lsm->domain.type == 0) {
- /* Add the URI for the UST session if a consumer is present. */
- if (cmd_ctx->session->ust_session &&
- cmd_ctx->session->ust_session->consumer) {
- ret = cmd_enable_consumer(LTTNG_DOMAIN_UST, cmd_ctx->session);
- } else if (cmd_ctx->session->kernel_session &&
- cmd_ctx->session->kernel_session->consumer) {
- ret = cmd_enable_consumer(LTTNG_DOMAIN_KERNEL,
- cmd_ctx->session);
- }
- }
- break;
- }
- case LTTNG_ENABLE_EVENT:
- {
- ret = cmd_enable_event(cmd_ctx->session, cmd_ctx->lsm->domain.type,
- cmd_ctx->lsm->u.enable.channel_name,
- &cmd_ctx->lsm->u.enable.event, kernel_poll_pipe[1]);
- break;
- }
- case LTTNG_ENABLE_ALL_EVENT:
- {
- DBG("Enabling all events");
-
- ret = cmd_enable_event_all(cmd_ctx->session, cmd_ctx->lsm->domain.type,
- cmd_ctx->lsm->u.enable.channel_name,
- cmd_ctx->lsm->u.enable.event.type, kernel_poll_pipe[1]);
- break;
- }
- case LTTNG_LIST_TRACEPOINTS:
- {
- struct lttng_event *events;
- ssize_t nb_events;
-
- nb_events = cmd_list_tracepoints(cmd_ctx->lsm->domain.type, &events);
- if (nb_events < 0) {
- /* Return value is a negative lttng_error_code. */
- ret = -nb_events;
- goto error;
- }
-
- /*
- * Setup lttng message with payload size set to the event list size in
- * bytes and then copy list into the llm payload.
- */
- ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_event) * nb_events);
- if (ret < 0) {
- free(events);
- goto setup_error;
- }
-
- /* Copy event list into message payload */
- memcpy(cmd_ctx->llm->payload, events,
- sizeof(struct lttng_event) * nb_events);
-
- free(events);
-
- ret = LTTNG_OK;
- break;