+ /* Getting status code from kconsumerd */
+ ret = lttcomm_recv_unix_sock(sock, &code, sizeof(enum lttcomm_return_code));
+ if (ret <= 0) {
+ goto error;
+ }
+
+ if (code == KCONSUMERD_COMMAND_SOCK_READY) {
+ kconsumerd_cmd_sock = lttcomm_connect_unix_sock(kconsumerd_cmd_unix_sock_path);
+ if (kconsumerd_cmd_sock < 0) {
+ sem_post(&kconsumerd_sem);
+ perror("kconsumerd connect");
+ goto error;
+ }
+ /* Signal condition to tell that the kconsumerd is ready */
+ sem_post(&kconsumerd_sem);
+ DBG("Kconsumerd command socket ready");
+ } else {
+ DBG("Kconsumerd error when waiting for SOCK_READY : %s",
+ lttcomm_get_readable_code(-code));
+ goto error;
+ }
+
+ /* Wait for any kconsumerd error */
+ ret = lttcomm_recv_unix_sock(sock, &code, sizeof(enum lttcomm_return_code));
+ if (ret <= 0) {
+ ERR("Kconsumerd closed the command socket");
+ goto error;
+ }
+
+ ERR("Kconsumerd return code : %s", lttcomm_get_readable_code(-code));
+
+error:
+ kconsumerd_pid = 0;
+ DBG("Kconsumerd thread dying");
+ return NULL;
+}
+
+/*
+ * thread_manage_apps
+ *
+ * This thread manage the application socket communication
+ */
+static void *thread_manage_apps(void *data)
+{
+ int sock, ret;
+
+ /* TODO: Something more elegant is needed but fine for now */
+ /* FIXME: change all types to either uint8_t, uint32_t, uint64_t
+ * for 32-bit vs 64-bit compat processes. */
+ /* replicate in ust with version number */
+ struct {
+ int reg; /* 1:register, 0:unregister */
+ pid_t pid;
+ uid_t uid;
+ } reg_msg;
+
+ DBG("[thread] Manage apps started");
+
+ ret = lttcomm_listen_unix_sock(apps_sock);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* Notify all applications to register */
+ notify_apps(default_global_apps_pipe);
+
+ while (1) {
+ DBG("Accepting application registration");
+ /* Blocking call, waiting for transmission */
+ sock = lttcomm_accept_unix_sock(apps_sock);
+ if (sock < 0) {
+ goto error;
+ }
+
+ /* Basic recv here to handle the very simple data
+ * that the libust send to register (reg_msg).
+ */
+ ret = recv(sock, ®_msg, sizeof(reg_msg), 0);
+ if (ret < 0) {
+ perror("recv");
+ continue;
+ }
+
+ /* Add application to the global traceable list */
+ if (reg_msg.reg == 1) {
+ /* Registering */
+ ret = register_traceable_app(reg_msg.pid, reg_msg.uid);
+ if (ret < 0) {
+ /* register_traceable_app only return an error with
+ * ENOMEM. At this point, we better stop everything.
+ */
+ goto error;
+ }
+ } else {
+ /* Unregistering */
+ unregister_traceable_app(reg_msg.pid);
+ }
+ }
+
+error:
+
+ return NULL;
+}
+
+/*
+ * spawn_kconsumerd_thread
+ *
+ * Start the thread_manage_kconsumerd. This must be done after a kconsumerd
+ * exec or it will fails.
+ */
+static int spawn_kconsumerd_thread(void)
+{
+ int ret;
+
+ /* Setup semaphore */
+ sem_init(&kconsumerd_sem, 0, 0);
+
+ ret = pthread_create(&kconsumerd_thread, NULL, thread_manage_kconsumerd, (void *) NULL);
+ if (ret != 0) {
+ perror("pthread_create kconsumerd");
+ goto error;
+ }
+
+ /* Wait for the kconsumerd thread to be ready */
+ sem_wait(&kconsumerd_sem);
+
+ if (kconsumerd_pid == 0) {
+ ERR("Kconsumerd did not start");
+ goto error;
+ }
+
+ return 0;
+
+error:
+ ret = LTTCOMM_KERN_CONSUMER_FAIL;
+ return ret;
+}
+
+/*
+ * spawn_kconsumerd
+ *
+ * Fork and exec a kernel consumer daemon (kconsumerd).
+ *
+ * NOTE: It is very important to fork a kconsumerd BEFORE opening any kernel
+ * file descriptor using the libkernelctl or kernel-ctl functions. So, a
+ * kernel consumer MUST only be spawned before creating a kernel session.
+ *
+ * Return pid if successful else -1.
+ */
+static pid_t spawn_kconsumerd(void)
+{
+ int ret;
+ pid_t pid;
+
+ DBG("Spawning kconsumerd");
+
+ pid = fork();
+ if (pid == 0) {
+ /*
+ * Exec kconsumerd.
+ */
+ execlp("kconsumerd", "kconsumerd", "--verbose", NULL);
+ if (errno != 0) {
+ perror("kernel start consumer exec");
+ }
+ exit(EXIT_FAILURE);
+ } else if (pid > 0) {
+ ret = pid;
+ goto error;
+ } else {
+ perror("kernel start consumer fork");
+ ret = -errno;
+ goto error;
+ }
+
+error:
+ return ret;
+}
+
+/*
+ * start_kconsumerd
+ *
+ * Spawn the kconsumerd daemon and session daemon thread.
+ */
+static int start_kconsumerd(void)
+{
+ int ret;
+
+ pthread_mutex_lock(&kconsumerd_pid_mutex);
+ if (kconsumerd_pid != 0) {
+ goto end;
+ }
+
+ ret = spawn_kconsumerd();
+ if (ret < 0) {
+ ERR("Spawning kconsumerd failed");
+ ret = LTTCOMM_KERN_CONSUMER_FAIL;
+ pthread_mutex_unlock(&kconsumerd_pid_mutex);
+ goto error;
+ }
+
+ /* Setting up the global kconsumerd_pid */
+ kconsumerd_pid = ret;
+ pthread_mutex_unlock(&kconsumerd_pid_mutex);
+
+ DBG("Kconsumerd pid %d", ret);
+
+ DBG("Spawning kconsumerd thread");
+ ret = spawn_kconsumerd_thread();
+ if (ret < 0) {
+ ERR("Fatal error spawning kconsumerd thread");
+ goto error;
+ }
+
+end:
+ pthread_mutex_unlock(&kconsumerd_pid_mutex);
+ return 0;
+
+error:
+ return ret;
+}
+
+/*
+ * init_kernel_tracer
+ *
+ * Setup necessary data for kernel tracer action.
+ */
+static void init_kernel_tracer(void)
+{
+ /* Set the global kernel tracer fd */
+ kernel_tracer_fd = open(DEFAULT_KERNEL_TRACER_PATH, O_RDWR);
+ if (kernel_tracer_fd < 0) {
+ WARN("No kernel tracer available");
+ kernel_tracer_fd = 0;
+ }
+
+ DBG("Kernel tracer fd %d", kernel_tracer_fd);
+}
+
+/*
+ * start_kernel_trace
+ *
+ * Start tracing by creating trace directory and sending FDs to the kernel
+ * consumer.
+ */
+static int start_kernel_trace(struct ltt_kernel_session *session)
+{
+ int ret;
+
+ /* Create trace directory */
+ ret = create_trace_dir(session);
+ if (ret < 0) {
+ if (ret == -EEXIST) {
+ ret = LTTCOMM_KERN_DIR_EXIST;
+ } else {
+ ret = LTTCOMM_KERN_DIR_FAIL;
+ goto error;
+ }
+ }
+
+ if (session->kconsumer_fds_sent == 0) {
+ ret = send_kconsumerd_fds(kconsumerd_cmd_sock, session);
+ if (ret < 0) {
+ ERR("Send kconsumerd fds failed");
+ ret = LTTCOMM_KERN_CONSUMER_FAIL;
+ goto error;
+ }
+
+ session->kconsumer_fds_sent = 1;
+ }
+
+error:
+ return ret;
+}
+
+/*
+ * init_default_channel
+ *
+ * Allocate a channel structure and fill it.
+ */
+static struct lttng_channel *init_default_channel(void)
+{
+ struct lttng_channel *chan;
+
+ chan = malloc(sizeof(struct lttng_channel));
+ if (chan == NULL) {
+ perror("init channel malloc");
+ goto error;
+ }
+
+ if (snprintf(chan->name, NAME_MAX, DEFAULT_CHANNEL_NAME) < 0) {
+ perror("snprintf defautl channel name");
+ return NULL;
+ }
+
+ chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE;
+ chan->attr.subbuf_size = DEFAULT_CHANNEL_SUBBUF_SIZE;
+ chan->attr.num_subbuf = DEFAULT_CHANNEL_SUBBUF_NUM;
+ chan->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER;
+ chan->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER;
+
+error:
+ return chan;
+}
+
+/*
+ * create_kernel_session
+ *
+ * Create a kernel tracer session then create the default channel.
+ */
+static int create_kernel_session(struct ltt_session *session)
+{
+ int ret;
+ struct lttng_channel *chan;
+
+ DBG("Creating kernel session");
+
+ ret = kernel_create_session(session, kernel_tracer_fd);
+ if (ret < 0) {
+ ret = LTTCOMM_KERN_SESS_FAIL;
+ goto error;
+ }
+
+ chan = init_default_channel();
+ if (chan == NULL) {
+ ret = LTTCOMM_FATAL;
+ goto error;
+ }
+
+ DBG("Creating default kernel channel %s", DEFAULT_CHANNEL_NAME);
+
+ ret = kernel_create_channel(session->kernel_session, chan);
+ if (ret < 0) {
+ ret = LTTCOMM_KERN_CHAN_FAIL;
+ goto error;
+ }
+
+error:
+ return ret;
+}
+
+/*
+ * process_client_msg
+ *
+ * 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.
+ */
+static int process_client_msg(struct command_ctx *cmd_ctx)
+{
+ int ret;
+
+ DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
+
+ /* Listing commands don't need a session */
+ switch (cmd_ctx->lsm->cmd_type) {
+ case LTTNG_CREATE_SESSION:
+ case LTTNG_LIST_SESSIONS:
+ case LTTNG_LIST_EVENTS:
+ case LTTNG_KERNEL_LIST_EVENTS:
+ case LTTNG_LIST_TRACEABLE_APPS:
+ break;
+ default:
+ DBG("Getting session %s by name", cmd_ctx->lsm->session_name);
+ cmd_ctx->session = find_session_by_name(cmd_ctx->lsm->session_name);
+ if (cmd_ctx->session == NULL) {
+ /* If session name not found */
+ if (cmd_ctx->lsm->session_name != NULL) {
+ ret = LTTCOMM_SESS_NOT_FOUND;
+ } else { /* If no session name specified */
+ ret = LTTCOMM_SELECT_SESS;
+ }
+ goto error;
+ }
+ break;
+ }
+
+ /*
+ * Check kernel command for kernel session.
+ */
+ switch (cmd_ctx->lsm->cmd_type) {
+ case LTTNG_KERNEL_CREATE_CHANNEL:
+ case LTTNG_KERNEL_DISABLE_ALL_EVENT:
+ case LTTNG_KERNEL_DISABLE_CHANNEL:
+ case LTTNG_KERNEL_DISABLE_EVENT:
+ case LTTNG_KERNEL_ENABLE_ALL_EVENT:
+ case LTTNG_KERNEL_ENABLE_CHANNEL:
+ case LTTNG_KERNEL_ENABLE_EVENT:
+ case LTTNG_KERNEL_LIST_EVENTS:
+ /* Kernel tracer check */
+ if (kernel_tracer_fd == 0) {
+ init_kernel_tracer();
+ if (kernel_tracer_fd == 0) {
+ ret = LTTCOMM_KERN_NA;
+ goto error;
+ }
+ }
+
+ /* Need a session for kernel command */
+ if (cmd_ctx->lsm->cmd_type != LTTNG_KERNEL_LIST_EVENTS &&
+ cmd_ctx->session->kernel_session == NULL) {
+
+ ret = create_kernel_session(cmd_ctx->session);
+ if (ret < 0) {
+ ret = LTTCOMM_KERN_SESS_FAIL;
+ goto error;
+ }
+
+ /* Start the kernel consumer daemon */
+ if (kconsumerd_pid == 0) {
+ ret = start_kconsumerd();
+ if (ret < 0) {
+ goto error;
+ }
+ }
+ }
+ }
+
+ /* Connect to ust apps if available pid */
+ if (cmd_ctx->lsm->pid > 0) {
+ /* Connect to app using ustctl API */
+ cmd_ctx->ust_sock = ust_connect_app(cmd_ctx->lsm->pid);
+ if (cmd_ctx->ust_sock < 0) {
+ ret = LTTCOMM_NO_TRACEABLE;
+ goto error;
+ }
+ }
+
+ /* Process by command type */
+ switch (cmd_ctx->lsm->cmd_type) {
+ case LTTNG_KERNEL_CREATE_CHANNEL:
+ {
+ /* Setup lttng message with no payload */
+ ret = setup_lttng_msg(cmd_ctx, 0);
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ /* Kernel tracer */
+ DBG("Creating kernel channel");
+
+ ret = kernel_create_channel(cmd_ctx->session->kernel_session,
+ &cmd_ctx->lsm->u.channel.chan);
+ if (ret < 0) {
+ ret = LTTCOMM_KERN_CHAN_FAIL;
+ goto error;
+ }
+
+ ret = LTTCOMM_OK;
+ break;
+ }
+ case LTTNG_KERNEL_ENABLE_EVENT:
+ {
+ int found = 0;
+ struct ltt_kernel_channel *chan;
+
+ /* Setup lttng message with no payload */
+ ret = setup_lttng_msg(cmd_ctx, 0);
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ /* Get channel by name and create event for that channel */
+ cds_list_for_each_entry(chan, &cmd_ctx->session->kernel_session->channel_list.head, list) {
+ if (strcmp(cmd_ctx->lsm->u.enable.channel_name, chan->channel->name) == 0) {
+ DBG("Creating kernel event %s for channel %s.",
+ cmd_ctx->lsm->u.enable.event.name, cmd_ctx->lsm->u.enable.channel_name);
+
+ ret = kernel_create_event(chan, &cmd_ctx->lsm->u.enable.event);
+ if (ret < 0) {
+ ret = LTTCOMM_KERN_ENABLE_FAIL;
+ goto error;
+ }
+ found = 1;
+ break;
+ }
+ }
+
+ if (!found) {
+ ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
+ } else {
+ kernel_wait_quiescent(kernel_tracer_fd);
+ ret = LTTCOMM_OK;
+ }
+ break;
+ }
+ case LTTNG_KERNEL_ENABLE_ALL_EVENT:
+ {
+ int pos, size, found;
+ char *event_list, *event, *ptr;
+ struct ltt_kernel_channel *chan;
+ struct lttng_event ev;
+
+ /* Setup lttng message with no payload */
+ ret = setup_lttng_msg(cmd_ctx, 0);
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ DBG("Enabling all kernel event");
+
+ size = kernel_list_events(kernel_tracer_fd, &event_list);
+ if (size < 0) {
+ ret = LTTCOMM_KERN_LIST_FAIL;
+ goto error;
+ }
+
+ /* Get channel by name and create event for that channel */
+ cds_list_for_each_entry(chan, &cmd_ctx->session->kernel_session->channel_list.head, list) {
+ if (strcmp(cmd_ctx->lsm->u.enable.channel_name, chan->channel->name) == 0) {
+ found = 1;
+ break;
+ }
+ }
+
+ if (!found) {
+ ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
+ goto error;
+ }
+
+ ptr = event_list;
+ while ((size = sscanf(ptr, "event { name = %m[^;]; };%n\n", &event, &pos)) == 1) {
+ strncpy(ev.name, event, LTTNG_SYM_NAME_LEN);
+ /* Default event type for enable all */
+ ev.type = LTTNG_EVENT_TRACEPOINTS;
+ /* Enable each single tracepoint event */
+ ret = kernel_create_event(chan, &ev);
+ if (ret < 0) {
+ ret = LTTCOMM_KERN_ENABLE_FAIL;
+ goto error;
+ }
+ /* Move pointer to the next line */
+ ptr += pos + 1;
+ free(event);
+ }
+
+ free(event_list);
+
+ /* Quiescent wait after event enable */
+ kernel_wait_quiescent(kernel_tracer_fd);
+ ret = LTTCOMM_OK;
+ break;
+ }
+ case LTTNG_KERNEL_LIST_EVENTS:
+ {
+ char *event_list;
+ ssize_t size = 0;
+
+ DBG("Listing kernel events");
+
+ size = kernel_list_events(kernel_tracer_fd, &event_list);
+ if (size < 0) {
+ ret = LTTCOMM_KERN_LIST_FAIL;
+ 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, size);
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ /* Copy event list into message payload */
+ memcpy(cmd_ctx->llm->payload, event_list, size);
+
+ free(event_list);
+
+ ret = LTTCOMM_OK;
+ break;
+ }
+ case LTTNG_START_TRACE:
+ {
+ struct ltt_kernel_channel *chan;
+
+ /* Setup lttng message with no payload */
+ ret = setup_lttng_msg(cmd_ctx, 0);
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ /* Kernel tracing */
+ if (cmd_ctx->session->kernel_session != NULL) {
+ if (cmd_ctx->session->kernel_session->metadata == NULL) {
+ DBG("Open kernel metadata");
+ ret = kernel_open_metadata(cmd_ctx->session->kernel_session);
+ if (ret < 0) {
+ ret = LTTCOMM_KERN_META_FAIL;
+ goto error;
+ }
+ }
+
+ if (cmd_ctx->session->kernel_session->metadata_stream_fd == 0) {
+ DBG("Opening kernel metadata stream");
+ if (cmd_ctx->session->kernel_session->metadata_stream_fd == 0) {
+ ret = kernel_open_metadata_stream(cmd_ctx->session->kernel_session);
+ if (ret < 0) {
+ ERR("Kernel create metadata stream failed");
+ ret = LTTCOMM_KERN_STREAM_FAIL;
+ goto error;
+ }
+ }
+ }
+
+ /* For each channel */
+ cds_list_for_each_entry(chan, &cmd_ctx->session->kernel_session->channel_list.head, list) {
+ if (chan->stream_count == 0) {
+ ret = kernel_open_channel_stream(chan);
+ if (ret < 0) {
+ ERR("Kernel create channel stream failed");
+ ret = LTTCOMM_KERN_STREAM_FAIL;
+ goto error;
+ }
+ /* Update the stream global counter */
+ cmd_ctx->session->kernel_session->stream_count_global += ret;
+ }
+ }
+
+ DBG("Start kernel tracing");
+ ret = kernel_start_session(cmd_ctx->session->kernel_session);
+ if (ret < 0) {
+ ERR("Kernel start session failed");
+ ret = LTTCOMM_KERN_START_FAIL;
+ goto error;
+ }
+
+ ret = start_kernel_trace(cmd_ctx->session->kernel_session);
+ if (ret < 0) {
+ ret = LTTCOMM_KERN_START_FAIL;
+ goto error;
+ }
+
+ /* Quiescent wait after starting trace */
+ kernel_wait_quiescent(kernel_tracer_fd);
+ }
+
+ /* TODO: Start all UST traces */
+
+ ret = LTTCOMM_OK;
+ break;
+ }
+ case LTTNG_STOP_TRACE:
+ {
+ struct ltt_kernel_channel *chan;
+ /* Setup lttng message with no payload */
+ ret = setup_lttng_msg(cmd_ctx, 0);
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ /* Kernel tracer */
+ if (cmd_ctx->session->kernel_session != NULL) {
+ DBG("Stop kernel tracing");
+
+ ret = kernel_metadata_flush_buffer(cmd_ctx->session->kernel_session->metadata_stream_fd);
+ if (ret < 0) {
+ ERR("Kernel metadata flush failed");
+ }
+
+ cds_list_for_each_entry(chan, &cmd_ctx->session->kernel_session->channel_list.head, list) {
+ ret = kernel_flush_buffer(chan);
+ if (ret < 0) {
+ ERR("Kernel flush buffer error");
+ }
+ }
+
+ ret = kernel_stop_session(cmd_ctx->session->kernel_session);
+ if (ret < 0) {
+ ERR("Kernel stop session failed");
+ ret = LTTCOMM_KERN_STOP_FAIL;
+ goto error;
+ }
+
+ /* Quiescent wait after stopping trace */
+ kernel_wait_quiescent(kernel_tracer_fd);
+ }
+
+ /* TODO : User-space tracer */
+
+ ret = LTTCOMM_OK;
+ break;
+ }
+ case LTTNG_CREATE_SESSION:
+ {
+ /* Setup lttng message with no payload */
+ ret = setup_lttng_msg(cmd_ctx, 0);
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ ret = create_session(cmd_ctx->lsm->session_name, cmd_ctx->lsm->path);
+ if (ret < 0) {
+ if (ret == -EEXIST) {
+ ret = LTTCOMM_EXIST_SESS;
+ } else {
+ ret = LTTCOMM_FATAL;
+ }
+ goto error;
+ }
+
+ ret = LTTCOMM_OK;
+ break;
+ }
+ case LTTNG_DESTROY_SESSION:
+ {
+ /* Setup lttng message with no payload */
+ ret = setup_lttng_msg(cmd_ctx, 0);
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ /* Clean kernel session teardown */
+ teardown_kernel_session(cmd_ctx->session);
+
+ ret = destroy_session(cmd_ctx->lsm->session_name);
+ if (ret < 0) {
+ ret = LTTCOMM_FATAL;
+ goto error;
+ }
+
+ ret = LTTCOMM_OK;
+ break;
+ }
+ /*
+ case LTTNG_LIST_TRACES:
+ {
+ unsigned int trace_count;
+
+ trace_count = get_trace_count_per_session(cmd_ctx->session);
+ if (trace_count == 0) {
+ ret = LTTCOMM_NO_TRACE;
+ goto error;
+ }
+
+ ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_trace) * trace_count);
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ get_traces_per_session(cmd_ctx->session,
+ (struct lttng_trace *)(cmd_ctx->llm->payload));
+
+ ret = LTTCOMM_OK;
+ break;
+ }
+ */
+ /*
+ case UST_CREATE_TRACE:
+ {
+ ret = setup_lttng_msg(cmd_ctx, 0);
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ ret = ust_create_trace(cmd_ctx);
+ if (ret < 0) {
+ goto error;
+ }
+ break;
+ }
+ */
+ case LTTNG_LIST_TRACEABLE_APPS:
+ {
+ unsigned int app_count;
+
+ app_count = get_app_count();
+ DBG("Traceable application count : %d", app_count);
+ if (app_count == 0) {
+ ret = LTTCOMM_NO_APPS;
+ goto error;
+ }
+
+ ret = setup_lttng_msg(cmd_ctx, sizeof(pid_t) * app_count);
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ get_app_list_pids((pid_t *)(cmd_ctx->llm->payload));
+
+ ret = LTTCOMM_OK;
+ break;