+/*
+ * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
+ * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; only version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#define _GNU_SOURCE
+#include <fcntl.h>
+#include <getopt.h>
+#include <grp.h>
+#include <limits.h>
+#include <pthread.h>
+#include <semaphore.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <sys/mount.h>
+#include <sys/resource.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <urcu/futex.h>
+#include <unistd.h>
+#include <config.h>
+
+#include <lttng-consumerd.h>
+#include <lttng-sessiond-comm.h>
+#include <lttng/lttng-consumer.h>
+
+#include <lttngerr.h>
+
+#include "channel.h"
+#include "compat/poll.h"
+#include "context.h"
+#include "event.h"
+#include "futex.h"
+#include "hashtable.h"
+#include "kernel-ctl.h"
+#include "lttng-sessiond.h"
+#include "shm.h"
+#include "ust-app.h"
+#include "ust-ctl.h"
+#include "utils.h"
+
+struct consumer_data {
+ enum lttng_consumer_type type;
+
+ pthread_t thread; /* Worker thread interacting with the consumer */
+ sem_t sem;
+
+ /* Mutex to control consumerd pid assignation */
+ pthread_mutex_t pid_mutex;
+ pid_t pid;
+
+ int err_sock;
+ int cmd_sock;
+
+ /* consumer error and command Unix socket path */
+ char err_unix_sock_path[PATH_MAX];
+ char cmd_unix_sock_path[PATH_MAX];
+};
+
+/* Const values */
+const char default_home_dir[] = DEFAULT_HOME_DIR;
+const char default_tracing_group[] = LTTNG_DEFAULT_TRACING_GROUP;
+const char default_ust_sock_dir[] = DEFAULT_UST_SOCK_DIR;
+const char default_global_apps_pipe[] = DEFAULT_GLOBAL_APPS_PIPE;
+
+/* Variables */
+int opt_verbose; /* Not static for lttngerr.h */
+int opt_verbose_consumer; /* Not static for lttngerr.h */
+int opt_quiet; /* Not static for lttngerr.h */
+
+const char *progname;
+const char *opt_tracing_group;
+static int opt_sig_parent;
+static int opt_daemon;
+static int is_root; /* Set to 1 if the daemon is running as root */
+static pid_t ppid; /* Parent PID for --sig-parent option */
+
+/* Consumer daemon specific control data */
+static struct consumer_data kconsumer_data = {
+ .type = LTTNG_CONSUMER_KERNEL,
+};
+static struct consumer_data ustconsumer_data = {
+ .type = LTTNG_CONSUMER_UST,
+};
+
+static int dispatch_thread_exit;
+
+/* Global application Unix socket path */
+static char apps_unix_sock_path[PATH_MAX];
+/* Global client Unix socket path */
+static char client_unix_sock_path[PATH_MAX];
+/* global wait shm path for UST */
+static char wait_shm_path[PATH_MAX];
+
+/* Sockets and FDs */
+static int client_sock;
+static int apps_sock;
+static int kernel_tracer_fd;
+static int kernel_poll_pipe[2];
+
+/*
+ * Quit pipe for all threads. This permits a single cancellation point
+ * for all threads when receiving an event on the pipe.
+ */
+static int thread_quit_pipe[2];
+
+/*
+ * This pipe is used to inform the thread managing application communication
+ * that a command is queued and ready to be processed.
+ */
+static int apps_cmd_pipe[2];
+
+/* Pthread, Mutexes and Semaphores */
+static pthread_t apps_thread;
+static pthread_t reg_apps_thread;
+static pthread_t client_thread;
+static pthread_t kernel_thread;
+static pthread_t dispatch_thread;
+
+
+/*
+ * UST registration command queue. This queue is tied with a futex and uses a N
+ * wakers / 1 waiter implemented and detailed in futex.c/.h
+ *
+ * The thread_manage_apps and thread_dispatch_ust_registration interact with
+ * this queue and the wait/wake scheme.
+ */
+static struct ust_cmd_queue ust_cmd_queue;
+
+/*
+ * Pointer initialized before thread creation.
+ *
+ * This points to the tracing session list containing the session count and a
+ * mutex lock. The lock MUST be taken if you iterate over the list. The lock
+ * MUST NOT be taken if you call a public function in session.c.
+ *
+ * The lock is nested inside the structure: session_list_ptr->lock. Please use
+ * session_lock_list and session_unlock_list for lock acquisition.
+ */
+static struct ltt_session_list *session_list_ptr;
+
+/*
+ * Create a poll set with O_CLOEXEC and add the thread quit pipe to the set.
+ */
+static int create_thread_poll_set(struct lttng_poll_event *events,
+ unsigned int size)
+{
+ int ret;
+
+ if (events == NULL || size == 0) {
+ ret = -1;
+ goto error;
+ }
+
+ ret = lttng_poll_create(events, size, LTTNG_CLOEXEC);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* Add quit pipe */
+ ret = lttng_poll_add(events, thread_quit_pipe[0], LPOLLIN);
+ if (ret < 0) {
+ goto error;
+ }
+
+ return 0;
+
+error:
+ return ret;
+}
+
+/*
+ * Check if the thread quit pipe was triggered.
+ *
+ * Return 1 if it was triggered else 0;
+ */
+static int check_thread_quit_pipe(int fd, uint32_t events)
+{
+ if (fd == thread_quit_pipe[0] && (events & LPOLLIN)) {
+ return 1;
+ }
+
+ return 0;
+}
+
+/*
+ * Remove modules in reverse load order.
+ */
+static int modprobe_remove_kernel_modules(void)
+{
+ int ret = 0, i;
+ char modprobe[256];
+
+ for (i = ARRAY_SIZE(kernel_modules_list) - 1; i >= 0; i--) {
+ ret = snprintf(modprobe, sizeof(modprobe),
+ "/sbin/modprobe -r -q %s",
+ kernel_modules_list[i].name);
+ if (ret < 0) {
+ perror("snprintf modprobe -r");
+ goto error;
+ }
+ modprobe[sizeof(modprobe) - 1] = '\0';
+ ret = system(modprobe);
+ if (ret == -1) {
+ ERR("Unable to launch modprobe -r for module %s",
+ kernel_modules_list[i].name);
+ } else if (kernel_modules_list[i].required
+ && WEXITSTATUS(ret) != 0) {
+ ERR("Unable to remove module %s",
+ kernel_modules_list[i].name);
+ } else {
+ DBG("Modprobe removal successful %s",
+ kernel_modules_list[i].name);
+ }
+ }
+
+error:
+ return ret;
+}
+
+/*
+ * Return group ID of the tracing group or -1 if not found.
+ */
+static gid_t allowed_group(void)
+{
+ struct group *grp;
+
+ if (opt_tracing_group) {
+ grp = getgrnam(opt_tracing_group);
+ } else {
+ grp = getgrnam(default_tracing_group);
+ }
+ if (!grp) {
+ return -1;
+ } else {
+ return grp->gr_gid;
+ }
+}
+
+/*
+ * Init thread quit pipe.
+ *
+ * Return -1 on error or 0 if all pipes are created.
+ */
+static int init_thread_quit_pipe(void)
+{
+ int ret;
+
+ ret = pipe2(thread_quit_pipe, O_CLOEXEC);
+ if (ret < 0) {
+ perror("thread quit pipe");
+ goto error;
+ }
+
+error:
+ return ret;
+}
+
+/*
+ * Complete teardown of a kernel session. This free all data structure related
+ * to a kernel session and update counter.
+ */
+static void teardown_kernel_session(struct ltt_session *session)
+{
+ if (session->kernel_session != NULL) {
+ DBG("Tearing down kernel session");
+
+ /*
+ * If a custom kernel consumer was registered, close the socket before
+ * tearing down the complete kernel session structure
+ */
+ if (session->kernel_session->consumer_fd != kconsumer_data.cmd_sock) {
+ lttcomm_close_unix_sock(session->kernel_session->consumer_fd);
+ }
+
+ trace_kernel_destroy_session(session->kernel_session);
+ /* Extra precaution */
+ session->kernel_session = NULL;
+ }
+}
+
+/*
+ * Complete teardown of all UST sessions. This will free everything on his path
+ * and destroy the core essence of all ust sessions :)
+ */
+static void teardown_ust_session(struct ltt_session *session)
+{
+ DBG("Tearing down UST session(s)");
+
+ trace_ust_destroy_session(session->ust_session);
+}
+
+/*
+ * Stop all threads by closing the thread quit pipe.
+ */
+static void stop_threads(void)
+{
+ int ret;
+
+ /* Stopping all threads */
+ DBG("Terminating all threads");
+ ret = notify_thread_pipe(thread_quit_pipe[1]);
+ if (ret < 0) {
+ ERR("write error on thread quit pipe");
+ }
+
+ /* Dispatch thread */
+ dispatch_thread_exit = 1;
+ futex_nto1_wake(&ust_cmd_queue.futex);
+}
+
+/*
+ * Cleanup the daemon
+ */
+static void cleanup(void)
+{
+ int ret;
+ char *cmd;
+ struct ltt_session *sess, *stmp;
+
+ DBG("Cleaning up");
+
+ /* <fun> */
+ MSG("%c[%d;%dm*** assert failed *** ==> %c[%dm%c[%d;%dm"
+ "Matthew, BEET driven development works!%c[%dm",
+ 27, 1, 31, 27, 0, 27, 1, 33, 27, 0);
+ /* </fun> */
+
+ if (is_root) {
+ DBG("Removing %s directory", LTTNG_RUNDIR);
+ ret = asprintf(&cmd, "rm -rf " LTTNG_RUNDIR);
+ if (ret < 0) {
+ ERR("asprintf failed. Something is really wrong!");
+ }
+
+ /* Remove lttng run directory */
+ ret = system(cmd);
+ if (ret < 0) {
+ ERR("Unable to clean " LTTNG_RUNDIR);
+ }
+ }
+
+ DBG("Cleaning up all session");
+
+ /* Destroy session list mutex */
+ if (session_list_ptr != NULL) {
+ pthread_mutex_destroy(&session_list_ptr->lock);
+
+ /* Cleanup ALL session */
+ cds_list_for_each_entry_safe(sess, stmp,
+ &session_list_ptr->head, list) {
+ teardown_kernel_session(sess);
+ teardown_ust_session(sess);
+ free(sess);
+ }
+ }
+
+ DBG("Closing all UST sockets");
+ ust_app_clean_list();
+
+ pthread_mutex_destroy(&kconsumer_data.pid_mutex);
+
+ DBG("Closing kernel fd");
+ close(kernel_tracer_fd);
+
+ if (is_root) {
+ DBG("Unloading kernel modules");
+ modprobe_remove_kernel_modules();
+ }
+
+ close(thread_quit_pipe[0]);
+ close(thread_quit_pipe[1]);
+}
+
+/*
+ * Send data on a unix socket using the liblttsessiondcomm API.
+ *
+ * Return lttcomm error code.
+ */
+static int send_unix_sock(int sock, void *buf, size_t len)
+{
+ /* Check valid length */
+ if (len <= 0) {
+ return -1;
+ }
+
+ return lttcomm_send_unix_sock(sock, buf, len);
+}
+
+/*
+ * Free memory of a command context structure.
+ */
+static void clean_command_ctx(struct command_ctx **cmd_ctx)
+{
+ DBG("Clean command context structure");
+ if (*cmd_ctx) {
+ if ((*cmd_ctx)->llm) {
+ free((*cmd_ctx)->llm);
+ }
+ if ((*cmd_ctx)->lsm) {
+ free((*cmd_ctx)->lsm);
+ }
+ free(*cmd_ctx);
+ *cmd_ctx = NULL;
+ }
+}
+
+/*
+ * Send all stream fds of kernel channel to the consumer.
+ */
+static int send_kconsumer_channel_streams(struct consumer_data *consumer_data,
+ int sock, struct ltt_kernel_channel *channel)
+{
+ int ret;
+ struct ltt_kernel_stream *stream;
+ struct lttcomm_consumer_msg lkm;
+
+ DBG("Sending streams of channel %s to kernel consumer",
+ channel->channel->name);
+
+ /* Send channel */
+ lkm.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
+ lkm.u.channel.channel_key = channel->fd;
+ lkm.u.channel.max_sb_size = channel->channel->attr.subbuf_size;
+ lkm.u.channel.mmap_len = 0; /* for kernel */
+ DBG("Sending channel %d to consumer", lkm.u.channel.channel_key);
+ ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
+ if (ret < 0) {
+ perror("send consumer channel");
+ goto error;
+ }
+
+ /* Send streams */
+ cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
+ if (!stream->fd) {
+ continue;
+ }
+ lkm.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
+ lkm.u.stream.channel_key = channel->fd;
+ lkm.u.stream.stream_key = stream->fd;
+ lkm.u.stream.state = stream->state;
+ lkm.u.stream.output = channel->channel->attr.output;
+ lkm.u.stream.mmap_len = 0; /* for kernel */
+ strncpy(lkm.u.stream.path_name, stream->pathname, PATH_MAX - 1);
+ lkm.u.stream.path_name[PATH_MAX - 1] = '\0';
+ DBG("Sending stream %d to consumer", lkm.u.stream.stream_key);
+ ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
+ if (ret < 0) {
+ perror("send consumer stream");
+ goto error;
+ }
+ ret = lttcomm_send_fds_unix_sock(sock, &stream->fd, 1);
+ if (ret < 0) {
+ perror("send consumer stream ancillary data");
+ goto error;
+ }
+ }
+
+ DBG("consumer channel streams sent");
+
+ return 0;
+
+error:
+ return ret;
+}
+
+/*
+ * Send all stream fds of the kernel session to the consumer.
+ */
+static int send_kconsumer_session_streams(struct consumer_data *consumer_data,
+ struct ltt_kernel_session *session)
+{
+ int ret;
+ struct ltt_kernel_channel *chan;
+ struct lttcomm_consumer_msg lkm;
+ int sock = session->consumer_fd;
+
+ DBG("Sending metadata stream fd");
+
+ /* Extra protection. It's NOT supposed to be set to 0 at this point */
+ if (session->consumer_fd == 0) {
+ session->consumer_fd = consumer_data->cmd_sock;
+ }
+
+ if (session->metadata_stream_fd != 0) {
+ /* Send metadata channel fd */
+ lkm.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
+ lkm.u.channel.channel_key = session->metadata->fd;
+ lkm.u.channel.max_sb_size = session->metadata->conf->attr.subbuf_size;
+ lkm.u.channel.mmap_len = 0; /* for kernel */
+ DBG("Sending metadata channel %d to consumer", lkm.u.stream.stream_key);
+ ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
+ if (ret < 0) {
+ perror("send consumer channel");
+ goto error;
+ }
+
+ /* Send metadata stream fd */
+ lkm.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
+ lkm.u.stream.channel_key = session->metadata->fd;
+ lkm.u.stream.stream_key = session->metadata_stream_fd;
+ lkm.u.stream.state = LTTNG_CONSUMER_ACTIVE_STREAM;
+ lkm.u.stream.output = DEFAULT_KERNEL_CHANNEL_OUTPUT;
+ lkm.u.stream.mmap_len = 0; /* for kernel */
+ strncpy(lkm.u.stream.path_name, session->metadata->pathname, PATH_MAX - 1);
+ lkm.u.stream.path_name[PATH_MAX - 1] = '\0';
+ DBG("Sending metadata stream %d to consumer", lkm.u.stream.stream_key);
+ ret = lttcomm_send_unix_sock(sock, &lkm, sizeof(lkm));
+ if (ret < 0) {
+ perror("send consumer stream");
+ goto error;
+ }
+ ret = lttcomm_send_fds_unix_sock(sock, &session->metadata_stream_fd, 1);
+ if (ret < 0) {
+ perror("send consumer stream");
+ goto error;
+ }
+ }
+
+ cds_list_for_each_entry(chan, &session->channel_list.head, list) {
+ ret = send_kconsumer_channel_streams(consumer_data, sock, chan);
+ if (ret < 0) {
+ goto error;
+ }
+ }
+
+ DBG("consumer fds (metadata and channel streams) sent");
+
+ return 0;
+
+error:
+ return ret;
+}
+
+/*
+ * Notify UST applications using the shm mmap futex.
+ */
+static int notify_ust_apps(int active)
+{
+ char *wait_shm_mmap;
+
+ DBG("Notifying applications of session daemon state: %d", active);
+
+ /* See shm.c for this call implying mmap, shm and futex calls */
+ wait_shm_mmap = shm_ust_get_mmap(wait_shm_path, is_root);
+ if (wait_shm_mmap == NULL) {
+ goto error;
+ }
+
+ /* Wake waiting process */
+ futex_wait_update((int32_t *) wait_shm_mmap, active);
+
+ /* Apps notified successfully */
+ return 0;
+
+error:
+ return -1;
+}
+
+/*
+ * Setup the outgoing data buffer for the response (llm) by allocating the
+ * right amount of memory and copying the original information from the lsm
+ * structure.
+ *
+ * Return total size of the buffer pointed by buf.
+ */
+static int setup_lttng_msg(struct command_ctx *cmd_ctx, size_t size)
+{
+ int ret, buf_size;
+
+ buf_size = size;
+
+ cmd_ctx->llm = malloc(sizeof(struct lttcomm_lttng_msg) + buf_size);
+ if (cmd_ctx->llm == NULL) {
+ perror("malloc");
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ /* Copy common data */
+ cmd_ctx->llm->cmd_type = cmd_ctx->lsm->cmd_type;
+ cmd_ctx->llm->pid = cmd_ctx->lsm->domain.attr.pid;
+
+ cmd_ctx->llm->data_size = size;
+ cmd_ctx->lttng_msg_size = sizeof(struct lttcomm_lttng_msg) + buf_size;
+
+ return buf_size;
+
+error:
+ return ret;
+}
+
+/*
+ * Update the kernel poll set of all channel fd available over all tracing
+ * session. Add the wakeup pipe at the end of the set.
+ */
+static int update_kernel_poll(struct lttng_poll_event *events)
+{
+ int ret;
+ struct ltt_session *session;
+ struct ltt_kernel_channel *channel;
+
+ DBG("Updating kernel poll set");
+
+ session_lock_list();
+ cds_list_for_each_entry(session, &session_list_ptr->head, list) {
+ session_lock(session);
+ if (session->kernel_session == NULL) {
+ session_unlock(session);
+ continue;
+ }
+
+ cds_list_for_each_entry(channel,
+ &session->kernel_session->channel_list.head, list) {
+ /* Add channel fd to the kernel poll set */
+ ret = lttng_poll_add(events, channel->fd, LPOLLIN | LPOLLRDNORM);
+ if (ret < 0) {
+ session_unlock(session);
+ goto error;
+ }
+ DBG("Channel fd %d added to kernel set", channel->fd);
+ }
+ session_unlock(session);
+ }
+ session_unlock_list();
+
+ return 0;
+
+error:
+ session_unlock_list();
+ return -1;
+}
+
+/*
+ * Find the channel fd from 'fd' over all tracing session. When found, check
+ * for new channel stream and send those stream fds to the kernel consumer.
+ *
+ * Useful for CPU hotplug feature.
+ */
+static int update_kernel_stream(struct consumer_data *consumer_data, int fd)
+{
+ int ret = 0;
+ struct ltt_session *session;
+ struct ltt_kernel_channel *channel;
+
+ DBG("Updating kernel streams for channel fd %d", fd);
+
+ session_lock_list();
+ cds_list_for_each_entry(session, &session_list_ptr->head, list) {
+ session_lock(session);
+ if (session->kernel_session == NULL) {
+ session_unlock(session);
+ continue;
+ }
+
+ /* This is not suppose to be 0 but this is an extra security check */
+ if (session->kernel_session->consumer_fd == 0) {
+ session->kernel_session->consumer_fd = consumer_data->cmd_sock;
+ }
+
+ cds_list_for_each_entry(channel,
+ &session->kernel_session->channel_list.head, list) {
+ if (channel->fd == fd) {
+ DBG("Channel found, updating kernel streams");
+ ret = kernel_open_channel_stream(channel);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /*
+ * Have we already sent fds to the consumer? If yes, it means
+ * that tracing is started so it is safe to send our updated
+ * stream fds.
+ */
+ if (session->kernel_session->consumer_fds_sent == 1) {
+ ret = send_kconsumer_channel_streams(consumer_data,
+ session->kernel_session->consumer_fd, channel);
+ if (ret < 0) {
+ goto error;
+ }
+ }
+ goto error;
+ }
+ }
+ session_unlock(session);
+ }
+ session_unlock_list();
+ return ret;
+
+error:
+ session_unlock(session);
+ session_unlock_list();
+ return ret;
+}
+
+/*
+ * This thread manage event coming from the kernel.
+ *
+ * Features supported in this thread:
+ * -) CPU Hotplug
+ */
+static void *thread_manage_kernel(void *data)
+{
+ int ret, i, pollfd, update_poll_flag = 1;
+ uint32_t revents, nb_fd;
+ char tmp;
+ struct lttng_poll_event events;
+
+ DBG("Thread manage kernel started");
+
+ ret = create_thread_poll_set(&events, 2);
+ if (ret < 0) {
+ goto error;
+ }
+
+ ret = lttng_poll_add(&events, kernel_poll_pipe[0], LPOLLIN);
+ if (ret < 0) {
+ goto error;
+ }
+
+ while (1) {
+ if (update_poll_flag == 1) {
+ /*
+ * Reset number of fd in the poll set. Always 2 since there is the thread
+ * quit pipe and the kernel pipe.
+ */
+ events.nb_fd = 2;
+
+ ret = update_kernel_poll(&events);
+ if (ret < 0) {
+ goto error;
+ }
+ update_poll_flag = 0;
+ }
+
+ nb_fd = LTTNG_POLL_GETNB(&events);
+
+ DBG("Thread kernel polling on %d fds", nb_fd);
+
+ /* Zeroed the poll events */
+ lttng_poll_reset(&events);
+
+ /* Poll infinite value of time */
+ ret = lttng_poll_wait(&events, -1);
+ if (ret < 0) {
+ goto error;
+ } else if (ret == 0) {
+ /* Should not happen since timeout is infinite */
+ ERR("Return value of poll is 0 with an infinite timeout.\n"
+ "This should not have happened! Continuing...");
+ continue;
+ }
+
+ for (i = 0; i < nb_fd; i++) {
+ /* Fetch once the poll data */
+ revents = LTTNG_POLL_GETEV(&events, i);
+ pollfd = LTTNG_POLL_GETFD(&events, i);
+
+ /* Thread quit pipe has been closed. Killing thread. */
+ ret = check_thread_quit_pipe(pollfd, revents);
+ if (ret) {
+ goto error;
+ }
+
+ /* Check for data on kernel pipe */
+ if (pollfd == kernel_poll_pipe[0] && (revents & LPOLLIN)) {
+ ret = read(kernel_poll_pipe[0], &tmp, 1);
+ update_poll_flag = 1;
+ continue;
+ } else {
+ /*
+ * New CPU detected by the kernel. Adding kernel stream to
+ * kernel session and updating the kernel consumer
+ */
+ if (revents & LPOLLIN) {
+ ret = update_kernel_stream(&kconsumer_data, pollfd);
+ if (ret < 0) {
+ continue;
+ }
+ break;
+ /*
+ * TODO: We might want to handle the LPOLLERR | LPOLLHUP
+ * and unregister kernel stream at this point.
+ */
+ }
+ }
+ }
+ }
+
+error:
+ DBG("Kernel thread dying");
+ close(kernel_poll_pipe[0]);
+ close(kernel_poll_pipe[1]);
+
+ lttng_poll_clean(&events);
+
+ return NULL;
+}
+
+/*
+ * This thread manage the consumer error sent back to the session daemon.
+ */
+static void *thread_manage_consumer(void *data)
+{
+ int sock = 0, i, ret, pollfd;
+ uint32_t revents, nb_fd;
+ enum lttcomm_return_code code;
+ struct lttng_poll_event events;
+ struct consumer_data *consumer_data = data;
+
+ DBG("[thread] Manage consumer started");
+
+ ret = lttcomm_listen_unix_sock(consumer_data->err_sock);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /*
+ * Pass 2 as size here for the thread quit pipe and kconsumerd_err_sock.
+ * Nothing more will be added to this poll set.
+ */
+ ret = create_thread_poll_set(&events, 2);
+ if (ret < 0) {
+ goto error;
+ }
+
+ ret = lttng_poll_add(&events, consumer_data->err_sock, LPOLLIN | LPOLLRDHUP);
+ if (ret < 0) {
+ goto error;
+ }
+
+ nb_fd = LTTNG_POLL_GETNB(&events);
+
+ /* Inifinite blocking call, waiting for transmission */
+ ret = lttng_poll_wait(&events, -1);
+ if (ret < 0) {
+ goto error;
+ }
+
+ for (i = 0; i < nb_fd; i++) {
+ /* Fetch once the poll data */
+ revents = LTTNG_POLL_GETEV(&events, i);
+ pollfd = LTTNG_POLL_GETFD(&events, i);
+
+ /* Thread quit pipe has been closed. Killing thread. */
+ ret = check_thread_quit_pipe(pollfd, revents);
+ if (ret) {
+ goto error;
+ }
+
+ /* Event on the registration socket */
+ if (pollfd == consumer_data->err_sock) {
+ if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+ ERR("consumer err socket poll error");
+ goto error;
+ }
+ }
+ }
+
+ sock = lttcomm_accept_unix_sock(consumer_data->err_sock);
+ if (sock < 0) {
+ goto error;
+ }
+
+ DBG2("Receiving code from consumer err_sock");
+
+ /* Getting status code from kconsumerd */
+ ret = lttcomm_recv_unix_sock(sock, &code,
+ sizeof(enum lttcomm_return_code));
+ if (ret <= 0) {
+ goto error;
+ }
+
+ if (code == CONSUMERD_COMMAND_SOCK_READY) {
+ consumer_data->cmd_sock =
+ lttcomm_connect_unix_sock(consumer_data->cmd_unix_sock_path);
+ if (consumer_data->cmd_sock < 0) {
+ sem_post(&consumer_data->sem);
+ PERROR("consumer connect");
+ goto error;
+ }
+ /* Signal condition to tell that the kconsumerd is ready */
+ sem_post(&consumer_data->sem);
+ DBG("consumer command socket ready");
+ } else {
+ ERR("consumer error when waiting for SOCK_READY : %s",
+ lttcomm_get_readable_code(-code));
+ goto error;
+ }
+
+ /* Remove the kconsumerd error sock since we've established a connexion */
+ ret = lttng_poll_del(&events, consumer_data->err_sock);
+ if (ret < 0) {
+ goto error;
+ }
+
+ ret = lttng_poll_add(&events, sock, LPOLLIN | LPOLLRDHUP);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* Update number of fd */
+ nb_fd = LTTNG_POLL_GETNB(&events);
+
+ /* Inifinite blocking call, waiting for transmission */
+ ret = lttng_poll_wait(&events, -1);
+ if (ret < 0) {
+ goto error;
+ }
+
+ for (i = 0; i < nb_fd; i++) {
+ /* Fetch once the poll data */
+ revents = LTTNG_POLL_GETEV(&events, i);
+ pollfd = LTTNG_POLL_GETFD(&events, i);
+
+ /* Thread quit pipe has been closed. Killing thread. */
+ ret = check_thread_quit_pipe(pollfd, revents);
+ if (ret) {
+ goto error;
+ }
+
+ /* Event on the kconsumerd socket */
+ if (pollfd == sock) {
+ if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+ ERR("consumer err socket second poll error");
+ goto error;
+ }
+ }
+ }
+
+ /* Wait for any kconsumerd error */
+ ret = lttcomm_recv_unix_sock(sock, &code,
+ sizeof(enum lttcomm_return_code));
+ if (ret <= 0) {
+ ERR("consumer closed the command socket");
+ goto error;
+ }
+
+ ERR("consumer return code : %s", lttcomm_get_readable_code(-code));
+
+error:
+ DBG("consumer thread dying");
+ close(consumer_data->err_sock);
+ close(consumer_data->cmd_sock);
+ close(sock);
+
+ unlink(consumer_data->err_unix_sock_path);
+ unlink(consumer_data->cmd_unix_sock_path);
+ consumer_data->pid = 0;
+
+ lttng_poll_clean(&events);
+
+ return NULL;
+}
+
+/*
+ * This thread manage application communication.
+ */
+static void *thread_manage_apps(void *data)
+{
+ int i, ret, pollfd;
+ uint32_t revents, nb_fd;
+ struct ust_command ust_cmd;
+ struct lttng_poll_event events;
+
+ DBG("[thread] Manage application started");
+
+ rcu_register_thread();
+ rcu_thread_online();
+
+ ret = create_thread_poll_set(&events, 2);
+ if (ret < 0) {
+ goto error;
+ }
+
+ ret = lttng_poll_add(&events, apps_cmd_pipe[0], LPOLLIN | LPOLLRDHUP);
+ if (ret < 0) {
+ goto error;
+ }
+
+ while (1) {
+ /* Zeroed the events structure */
+ lttng_poll_reset(&events);
+
+ nb_fd = LTTNG_POLL_GETNB(&events);
+
+ DBG("Apps thread polling on %d fds", nb_fd);
+
+ /* Inifinite blocking call, waiting for transmission */
+ ret = lttng_poll_wait(&events, -1);
+ if (ret < 0) {
+ goto error;
+ }
+
+ for (i = 0; i < nb_fd; i++) {
+ /* Fetch once the poll data */
+ revents = LTTNG_POLL_GETEV(&events, i);
+ pollfd = LTTNG_POLL_GETFD(&events, i);
+
+ /* Thread quit pipe has been closed. Killing thread. */
+ ret = check_thread_quit_pipe(pollfd, revents);
+ if (ret) {
+ goto error;
+ }
+
+ /* Inspect the apps cmd pipe */
+ if (pollfd == apps_cmd_pipe[0]) {
+ if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+ ERR("Apps command pipe error");
+ goto error;
+ } else if (revents & LPOLLIN) {
+ /* Empty pipe */
+ ret = read(apps_cmd_pipe[0], &ust_cmd, sizeof(ust_cmd));
+ if (ret < 0 || ret < sizeof(ust_cmd)) {
+ perror("read apps cmd pipe");
+ goto error;
+ }
+
+ /* Register applicaton to the session daemon */
+ ret = ust_app_register(&ust_cmd.reg_msg,
+ ust_cmd.sock);
+ if (ret < 0) {
+ /* Only critical ENOMEM error can be returned here */
+ goto error;
+ }
+
+ ret = ustctl_register_done(ust_cmd.sock);
+ if (ret < 0) {
+ /*
+ * If the registration is not possible, we simply
+ * unregister the apps and continue
+ */
+ ust_app_unregister(ust_cmd.sock);
+ } else {
+ /*
+ * We just need here to monitor the close of the UST
+ * socket and poll set monitor those by default.
+ */
+ ret = lttng_poll_add(&events, ust_cmd.sock, 0);
+ if (ret < 0) {
+ goto error;
+ }
+
+ DBG("Apps with sock %d added to poll set",
+ ust_cmd.sock);
+ }
+ break;
+ }
+ } else {
+ /*
+ * At this point, we know that a registered application made
+ * the event at poll_wait.
+ */
+ if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+ /* Removing from the poll set */
+ ret = lttng_poll_del(&events, pollfd);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* Socket closed */
+ ust_app_unregister(pollfd);
+ break;
+ }
+ }
+ }
+ }
+
+error:
+ DBG("Application communication apps dying");
+ close(apps_cmd_pipe[0]);
+ close(apps_cmd_pipe[1]);
+
+ lttng_poll_clean(&events);
+
+ rcu_thread_offline();
+ rcu_unregister_thread();
+ return NULL;
+}
+
+/*
+ * Dispatch request from the registration threads to the application
+ * communication thread.
+ */
+static void *thread_dispatch_ust_registration(void *data)
+{
+ int ret;
+ struct cds_wfq_node *node;
+ struct ust_command *ust_cmd = NULL;
+
+ DBG("[thread] Dispatch UST command started");
+
+ while (!dispatch_thread_exit) {
+ /* Atomically prepare the queue futex */
+ futex_nto1_prepare(&ust_cmd_queue.futex);
+
+ do {
+ /* Dequeue command for registration */
+ node = cds_wfq_dequeue_blocking(&ust_cmd_queue.queue);
+ if (node == NULL) {
+ DBG("Woken up but nothing in the UST command queue");
+ /* Continue thread execution */
+ break;
+ }
+
+ ust_cmd = caa_container_of(node, struct ust_command, node);
+
+ DBG("Dispatching UST registration pid:%d ppid:%d uid:%d"
+ " gid:%d sock:%d name:%s (version %d.%d)",
+ ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
+ ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
+ ust_cmd->sock, ust_cmd->reg_msg.name,
+ ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
+ /*
+ * Inform apps thread of the new application registration. This
+ * call is blocking so we can be assured that the data will be read
+ * at some point in time or wait to the end of the world :)
+ */
+ ret = write(apps_cmd_pipe[1], ust_cmd,
+ sizeof(struct ust_command));
+ if (ret < 0) {
+ perror("write apps cmd pipe");
+ if (errno == EBADF) {
+ /*
+ * We can't inform the application thread to process
+ * registration. We will exit or else application
+ * registration will not occur and tracing will never
+ * start.
+ */
+ goto error;
+ }
+ }
+ free(ust_cmd);
+ } while (node != NULL);
+
+ /* Futex wait on queue. Blocking call on futex() */
+ futex_nto1_wait(&ust_cmd_queue.futex);
+ }
+
+error:
+ DBG("Dispatch thread dying");
+ return NULL;
+}
+
+/*
+ * This thread manage application registration.
+ */
+static void *thread_registration_apps(void *data)
+{
+ int sock = 0, i, ret, pollfd;
+ uint32_t revents, nb_fd;
+ struct lttng_poll_event events;
+ /*
+ * Get allocated in this thread, enqueued to a global queue, dequeued and
+ * freed in the manage apps thread.
+ */
+ struct ust_command *ust_cmd = NULL;
+
+ DBG("[thread] Manage application registration started");
+
+ ret = lttcomm_listen_unix_sock(apps_sock);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /*
+ * Pass 2 as size here for the thread quit pipe and apps socket. Nothing
+ * more will be added to this poll set.
+ */
+ ret = create_thread_poll_set(&events, 2);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* Add the application registration socket */
+ ret = lttng_poll_add(&events, apps_sock, LPOLLIN | LPOLLRDHUP);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* Notify all applications to register */
+ ret = notify_ust_apps(1);
+ if (ret < 0) {
+ ERR("Failed to notify applications or create the wait shared memory.\n"
+ "Execution continues but there might be problem for already\n"
+ "running applications that wishes to register.");
+ }
+
+ while (1) {
+ DBG("Accepting application registration");
+
+ nb_fd = LTTNG_POLL_GETNB(&events);
+
+ /* Inifinite blocking call, waiting for transmission */
+ ret = lttng_poll_wait(&events, -1);
+ if (ret < 0) {
+ goto error;
+ }
+
+ for (i = 0; i < nb_fd; i++) {
+ /* Fetch once the poll data */
+ revents = LTTNG_POLL_GETEV(&events, i);
+ pollfd = LTTNG_POLL_GETFD(&events, i);
+
+ /* Thread quit pipe has been closed. Killing thread. */
+ ret = check_thread_quit_pipe(pollfd, revents);
+ if (ret) {
+ goto error;
+ }
+
+ /* Event on the registration socket */
+ if (pollfd == apps_sock) {
+ if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+ ERR("Register apps socket poll error");
+ goto error;
+ } else if (revents & LPOLLIN) {
+ sock = lttcomm_accept_unix_sock(apps_sock);
+ if (sock < 0) {
+ goto error;
+ }
+
+ /* Create UST registration command for enqueuing */
+ ust_cmd = malloc(sizeof(struct ust_command));
+ if (ust_cmd == NULL) {
+ perror("ust command malloc");
+ goto error;
+ }
+
+ /*
+ * Using message-based transmissions to ensure we don't
+ * have to deal with partially received messages.
+ */
+ ret = lttcomm_recv_unix_sock(sock, &ust_cmd->reg_msg,
+ sizeof(struct ust_register_msg));
+ if (ret < 0 || ret < sizeof(struct ust_register_msg)) {
+ if (ret < 0) {
+ perror("lttcomm_recv_unix_sock register apps");
+ } else {
+ ERR("Wrong size received on apps register");
+ }
+ free(ust_cmd);
+ close(sock);
+ continue;
+ }
+
+ ust_cmd->sock = sock;
+
+ DBG("UST registration received with pid:%d ppid:%d uid:%d"
+ " gid:%d sock:%d name:%s (version %d.%d)",
+ ust_cmd->reg_msg.pid, ust_cmd->reg_msg.ppid,
+ ust_cmd->reg_msg.uid, ust_cmd->reg_msg.gid,
+ ust_cmd->sock, ust_cmd->reg_msg.name,
+ ust_cmd->reg_msg.major, ust_cmd->reg_msg.minor);
+
+ /*
+ * Lock free enqueue the registration request. The red pill
+ * has been taken! This apps will be part of the *system*.
+ */
+ cds_wfq_enqueue(&ust_cmd_queue.queue, &ust_cmd->node);
+
+ /*
+ * Wake the registration queue futex. Implicit memory
+ * barrier with the exchange in cds_wfq_enqueue.
+ */
+ futex_nto1_wake(&ust_cmd_queue.futex);
+ }
+ }
+ }
+ }
+
+error:
+ DBG("UST Registration thread dying");
+
+ /* Notify that the registration thread is gone */
+ notify_ust_apps(0);
+
+ close(apps_sock);
+ close(sock);
+ unlink(apps_unix_sock_path);
+
+ lttng_poll_clean(&events);
+
+ return NULL;
+}
+
+/*
+ * Start the thread_manage_consumer. This must be done after a lttng-consumerd
+ * exec or it will fails.
+ */
+static int spawn_consumer_thread(struct consumer_data *consumer_data)
+{
+ int ret;
+ struct timespec timeout;
+
+ timeout.tv_sec = DEFAULT_SEM_WAIT_TIMEOUT;
+ timeout.tv_nsec = 0;
+
+ /* Setup semaphore */
+ ret = sem_init(&consumer_data->sem, 0, 0);
+ if (ret < 0) {
+ PERROR("sem_init consumer semaphore");
+ goto error;
+ }
+
+ ret = pthread_create(&consumer_data->thread, NULL,
+ thread_manage_consumer, consumer_data);
+ if (ret != 0) {
+ PERROR("pthread_create consumer");
+ ret = -1;
+ goto error;
+ }
+
+ /* Get time for sem_timedwait absolute timeout */
+ ret = clock_gettime(CLOCK_REALTIME, &timeout);
+ if (ret < 0) {
+ PERROR("clock_gettime spawn consumer");
+ /* Infinite wait for the kconsumerd thread to be ready */
+ ret = sem_wait(&consumer_data->sem);
+ } else {
+ /* Normal timeout if the gettime was successful */
+ timeout.tv_sec += DEFAULT_SEM_WAIT_TIMEOUT;
+ ret = sem_timedwait(&consumer_data->sem, &timeout);
+ }
+
+ if (ret < 0) {
+ if (errno == ETIMEDOUT) {
+ /*
+ * Call has timed out so we kill the kconsumerd_thread and return
+ * an error.
+ */
+ ERR("The consumer thread was never ready. Killing it");
+ ret = pthread_cancel(consumer_data->thread);
+ if (ret < 0) {
+ PERROR("pthread_cancel consumer thread");
+ }
+ } else {
+ PERROR("semaphore wait failed consumer thread");
+ }
+ goto error;
+ }
+
+ pthread_mutex_lock(&consumer_data->pid_mutex);
+ if (consumer_data->pid == 0) {
+ ERR("Kconsumerd did not start");
+ pthread_mutex_unlock(&consumer_data->pid_mutex);
+ goto error;
+ }
+ pthread_mutex_unlock(&consumer_data->pid_mutex);
+
+ return 0;
+
+error:
+ return ret;
+}
+
+/*
+ * Join consumer thread
+ */
+static int join_consumer_thread(struct consumer_data *consumer_data)
+{
+ void *status;
+ int ret;
+
+ if (consumer_data->pid != 0) {
+ ret = kill(consumer_data->pid, SIGTERM);
+ if (ret) {
+ ERR("Error killing consumer daemon");
+ return ret;
+ }
+ return pthread_join(consumer_data->thread, &status);
+ } else {
+ return 0;
+ }
+}
+
+/*
+ * Fork and exec a consumer daemon (consumerd).
+ *
+ * Return pid if successful else -1.
+ */
+static pid_t spawn_consumerd(struct consumer_data *consumer_data)
+{
+ int ret;
+ pid_t pid;
+ const char *verbosity;
+
+ DBG("Spawning consumerd");
+
+ pid = fork();
+ if (pid == 0) {
+ /*
+ * Exec consumerd.
+ */
+ if (opt_verbose > 1 || opt_verbose_consumer) {
+ verbosity = "--verbose";
+ } else {
+ verbosity = "--quiet";
+ }
+ switch (consumer_data->type) {
+ case LTTNG_CONSUMER_KERNEL:
+ execl(INSTALL_BIN_PATH "/lttng-consumerd",
+ "lttng-consumerd", verbosity, "-k", NULL);
+ break;
+ case LTTNG_CONSUMER_UST:
+ execl(INSTALL_BIN_PATH "/lttng-consumerd",
+ "lttng-consumerd", verbosity, "-u", NULL);
+ break;
+ default:
+ perror("unknown consumer type");
+ exit(EXIT_FAILURE);
+ }
+ if (errno != 0) {
+ perror("kernel start consumer exec");
+ }
+ exit(EXIT_FAILURE);
+ } else if (pid > 0) {
+ ret = pid;
+ } else {
+ perror("start consumer fork");
+ ret = -errno;
+ }
+ return ret;
+}
+
+/*
+ * Spawn the consumerd daemon and session daemon thread.
+ */
+static int start_consumerd(struct consumer_data *consumer_data)
+{
+ int ret;
+
+ pthread_mutex_lock(&consumer_data->pid_mutex);
+ if (consumer_data->pid != 0) {
+ pthread_mutex_unlock(&consumer_data->pid_mutex);
+ goto end;
+ }
+
+ ret = spawn_consumerd(consumer_data);
+ if (ret < 0) {
+ ERR("Spawning consumerd failed");
+ pthread_mutex_unlock(&consumer_data->pid_mutex);
+ goto error;
+ }
+
+ /* Setting up the consumer_data pid */
+ consumer_data->pid = ret;
+ DBG2("Consumer pid %d", consumer_data->pid);
+ pthread_mutex_unlock(&consumer_data->pid_mutex);
+
+ DBG2("Spawning consumer control thread");
+ ret = spawn_consumer_thread(consumer_data);
+ if (ret < 0) {
+ ERR("Fatal error spawning consumer control thread");
+ goto error;
+ }
+
+end:
+ return 0;
+
+error:
+ return ret;
+}
+
+/*
+ * modprobe_kernel_modules
+ */
+static int modprobe_kernel_modules(void)
+{
+ int ret = 0, i;
+ char modprobe[256];
+
+ for (i = 0; i < ARRAY_SIZE(kernel_modules_list); i++) {
+ ret = snprintf(modprobe, sizeof(modprobe),
+ "/sbin/modprobe %s%s",
+ kernel_modules_list[i].required ? "" : "-q ",
+ kernel_modules_list[i].name);
+ if (ret < 0) {
+ perror("snprintf modprobe");
+ goto error;
+ }
+ modprobe[sizeof(modprobe) - 1] = '\0';
+ ret = system(modprobe);
+ if (ret == -1) {
+ ERR("Unable to launch modprobe for module %s",
+ kernel_modules_list[i].name);
+ } else if (kernel_modules_list[i].required
+ && WEXITSTATUS(ret) != 0) {
+ ERR("Unable to load module %s",
+ kernel_modules_list[i].name);
+ } else {
+ DBG("Modprobe successfully %s",
+ kernel_modules_list[i].name);
+ }
+ }
+
+error:
+ return ret;
+}
+
+/*
+ * mount_debugfs
+ */
+static int mount_debugfs(char *path)
+{
+ int ret;
+ char *type = "debugfs";
+
+ ret = mkdir_recursive(path, S_IRWXU | S_IRWXG, geteuid(), getegid());
+ if (ret < 0) {
+ PERROR("Cannot create debugfs path");
+ goto error;
+ }
+
+ ret = mount(type, path, type, 0, NULL);
+ if (ret < 0) {
+ PERROR("Cannot mount debugfs");
+ goto error;
+ }
+
+ DBG("Mounted debugfs successfully at %s", path);
+
+error:
+ return ret;
+}
+
+/*
+ * Setup necessary data for kernel tracer action.
+ */
+static void init_kernel_tracer(void)
+{
+ int ret;
+ char *proc_mounts = "/proc/mounts";
+ char line[256];
+ char *debugfs_path = NULL, *lttng_path = NULL;
+ FILE *fp;
+
+ /* Detect debugfs */
+ fp = fopen(proc_mounts, "r");
+ if (fp == NULL) {
+ ERR("Unable to probe %s", proc_mounts);
+ goto error;
+ }
+
+ while (fgets(line, sizeof(line), fp) != NULL) {
+ if (strstr(line, "debugfs") != NULL) {
+ /* Remove first string */
+ strtok(line, " ");
+ /* Dup string here so we can reuse line later on */
+ debugfs_path = strdup(strtok(NULL, " "));
+ DBG("Got debugfs path : %s", debugfs_path);
+ break;
+ }
+ }
+
+ fclose(fp);
+
+ /* Mount debugfs if needded */
+ if (debugfs_path == NULL) {
+ ret = asprintf(&debugfs_path, "/mnt/debugfs");
+ if (ret < 0) {
+ perror("asprintf debugfs path");
+ goto error;
+ }
+ ret = mount_debugfs(debugfs_path);
+ if (ret < 0) {
+ perror("Cannot mount debugfs");
+ goto error;
+ }
+ }
+
+ /* Modprobe lttng kernel modules */
+ ret = modprobe_kernel_modules();
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* Setup lttng kernel path */
+ ret = asprintf(<tng_path, "%s/lttng", debugfs_path);
+ if (ret < 0) {
+ perror("asprintf lttng path");
+ goto error;
+ }
+
+ /* Open debugfs lttng */
+ kernel_tracer_fd = open(lttng_path, O_RDWR);
+ if (kernel_tracer_fd < 0) {
+ DBG("Failed to open %s", lttng_path);
+ goto error;
+ }
+
+ free(lttng_path);
+ free(debugfs_path);
+ DBG("Kernel tracer fd %d", kernel_tracer_fd);
+ return;
+
+error:
+ if (lttng_path) {
+ free(lttng_path);
+ }
+ if (debugfs_path) {
+ free(debugfs_path);
+ }
+ WARN("No kernel tracer available");
+ kernel_tracer_fd = 0;
+ return;
+}
+
+/*
+ * Init tracing by creating trace directory and sending fds kernel consumer.
+ */
+static int init_kernel_tracing(struct ltt_kernel_session *session)
+{
+ int ret = 0;
+
+ if (session->consumer_fds_sent == 0) {
+ /*
+ * Assign default kernel consumer socket if no consumer assigned to the
+ * kernel session. At this point, it's NOT suppose to be 0 but this is
+ * an extra security check.
+ */
+ if (session->consumer_fd == 0) {
+ session->consumer_fd = kconsumer_data.cmd_sock;
+ }
+
+ ret = send_kconsumer_session_streams(&kconsumer_data, session);
+ if (ret < 0) {
+ ret = LTTCOMM_KERN_CONSUMER_FAIL;
+ goto error;
+ }
+
+ session->consumer_fds_sent = 1;
+ }
+
+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;
+ unsigned int uid;
+ struct ltt_ust_session *lus = NULL;
+
+ switch (domain->type) {
+ case LTTNG_DOMAIN_UST:
+ break;
+ default:
+ ret = LTTCOMM_UNKNOWN_DOMAIN;
+ goto error;
+ }
+
+ DBG("Creating UST session");
+
+ session_lock_list();
+ uid = session_list_ptr->count;
+ session_unlock_list();
+
+ lus = trace_ust_create_session(session->path, uid, domain);
+ if (lus == NULL) {
+ ret = LTTCOMM_UST_SESS_FAIL;
+ goto error;
+ }
+
+ ret = mkdir_recursive(lus->pathname, S_IRWXU | S_IRWXG,
+ geteuid(), allowed_group());
+ if (ret < 0) {
+ if (ret != -EEXIST) {
+ ERR("Trace directory creation error");
+ ret = LTTCOMM_UST_SESS_FAIL;
+ goto error;
+ }
+ }
+
+ /* The domain type dictate different actions on session creation */
+ switch (domain->type) {
+ case LTTNG_DOMAIN_UST:
+ /* No ustctl for the global UST domain */
+ break;
+ default:
+ goto error;
+ }
+ session->ust_session = lus;
+
+ return LTTCOMM_OK;
+
+error:
+ free(lus);
+ 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 = LTTCOMM_KERN_SESS_FAIL;
+ goto error;
+ }
+
+ /* Set kernel consumer socket fd */
+ if (kconsumer_data.cmd_sock) {
+ session->kernel_session->consumer_fd = kconsumer_data.cmd_sock;
+ }
+
+ ret = mkdir_recursive(session->kernel_session->trace_path,
+ S_IRWXU | S_IRWXG, geteuid(), allowed_group());
+ if (ret < 0) {
+ if (ret != -EEXIST) {
+ ERR("Trace directory creation error");
+ goto error;
+ }
+ }
+
+error:
+ return ret;
+}
+
+/*
+ * Using the session list, filled a lttng_session array to send back to the
+ * client for session listing.
+ *
+ * The session list lock MUST be acquired before calling this function. Use
+ * session_lock_list() and session_unlock_list().
+ */
+static void list_lttng_sessions(struct lttng_session *sessions)
+{
+ int i = 0;
+ struct ltt_session *session;
+
+ DBG("Getting all available session");
+ /*
+ * Iterate over session list and append data after the control struct in
+ * the buffer.
+ */
+ cds_list_for_each_entry(session, &session_list_ptr->head, list) {
+ strncpy(sessions[i].path, session->path, PATH_MAX);
+ sessions[i].path[PATH_MAX - 1] = '\0';
+ strncpy(sessions[i].name, session->name, NAME_MAX);
+ sessions[i].name[NAME_MAX - 1] = '\0';
+ i++;
+ }
+}
+
+/*
+ * Fill lttng_channel array of all channels.
+ */
+static void list_lttng_channels(struct ltt_session *session,
+ struct lttng_channel *channels)
+{
+ int i = 0;
+ struct ltt_kernel_channel *kchan;
+
+ DBG("Listing channels for session %s", session->name);
+
+ /* Kernel channels */
+ if (session->kernel_session != NULL) {
+ cds_list_for_each_entry(kchan,
+ &session->kernel_session->channel_list.head, list) {
+ /* Copy lttng_channel struct to array */
+ memcpy(&channels[i], kchan->channel, sizeof(struct lttng_channel));
+ channels[i].enabled = kchan->enabled;
+ i++;
+ }
+ }
+
+ /* TODO: Missing UST listing */
+}
+
+/*
+ * Fill lttng_event array of all events in the channel.
+ */
+static void list_lttng_events(struct ltt_kernel_channel *kchan,
+ struct lttng_event *events)
+{
+ /*
+ * TODO: This is ONLY kernel. Need UST support.
+ */
+ int i = 0;
+ struct ltt_kernel_event *event;
+
+ DBG("Listing events for channel %s", kchan->channel->name);
+
+ /* Kernel channels */
+ cds_list_for_each_entry(event, &kchan->events_list.head , list) {
+ strncpy(events[i].name, event->event->name, LTTNG_SYMBOL_NAME_LEN);
+ events[i].name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
+ events[i].enabled = event->enabled;
+ switch (event->event->instrumentation) {
+ case LTTNG_KERNEL_TRACEPOINT:
+ events[i].type = LTTNG_EVENT_TRACEPOINT;
+ break;
+ case LTTNG_KERNEL_KPROBE:
+ case LTTNG_KERNEL_KRETPROBE:
+ events[i].type = LTTNG_EVENT_PROBE;
+ memcpy(&events[i].attr.probe, &event->event->u.kprobe,
+ sizeof(struct lttng_kernel_kprobe));
+ break;
+ case LTTNG_KERNEL_FUNCTION:
+ events[i].type = LTTNG_EVENT_FUNCTION;
+ memcpy(&events[i].attr.ftrace, &event->event->u.ftrace,
+ sizeof(struct lttng_kernel_function));
+ break;
+ case LTTNG_KERNEL_NOOP:
+ events[i].type = LTTNG_EVENT_NOOP;
+ break;
+ case LTTNG_KERNEL_SYSCALL:
+ events[i].type = LTTNG_EVENT_SYSCALL;
+ break;
+ case LTTNG_KERNEL_ALL:
+ assert(0);
+ break;
+ }
+ i++;
+ }
+}
+
+/*
+ * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
+ */
+static int cmd_disable_channel(struct ltt_session *session,
+ int domain, char *channel_name)
+{
+ int ret;
+
+ switch (domain) {
+ case LTTNG_DOMAIN_KERNEL:
+ ret = channel_kernel_disable(session->kernel_session,
+ channel_name);
+ if (ret != LTTCOMM_OK) {
+ goto error;
+ }
+
+ kernel_wait_quiescent(kernel_tracer_fd);
+ break;
+ case LTTNG_DOMAIN_UST_PID:
+ break;
+ default:
+ ret = LTTCOMM_UNKNOWN_DOMAIN;
+ goto error;
+ }
+
+ ret = LTTCOMM_OK;
+
+error:
+ return ret;
+}
+
+/*
+ * Copy channel from attributes and set it in the application channel list.
+ */
+/*
+static int copy_ust_channel_to_app(struct ltt_ust_session *usess,
+ struct lttng_channel *attr, struct ust_app *app)
+{
+ int ret;
+ struct ltt_ust_channel *uchan, *new_chan;
+
+ uchan = trace_ust_get_channel_by_key(usess->channels, attr->name);
+ if (uchan == NULL) {
+ ret = LTTCOMM_FATAL;
+ goto error;
+ }
+
+ new_chan = trace_ust_create_channel(attr, usess->path);
+ if (new_chan == NULL) {
+ PERROR("malloc ltt_ust_channel");
+ ret = LTTCOMM_FATAL;
+ goto error;
+ }
+
+ ret = channel_ust_copy(new_chan, uchan);
+ if (ret < 0) {
+ ret = LTTCOMM_FATAL;
+ goto error;
+ }
+
+error:
+ return ret;
+}
+*/
+
+/*
+ * Command LTTNG_ENABLE_CHANNEL processed by the client thread.
+ */
+static int cmd_enable_channel(struct ltt_session *session,
+ struct lttng_domain *domain, struct lttng_channel *attr)
+{
+ int ret;
+ struct ltt_ust_session *usess = session->ust_session;
+
+ DBG("Enabling channel %s for session %s", session->name, attr->name);
+
+ switch (domain->type) {
+ case LTTNG_DOMAIN_KERNEL:
+ {
+ struct ltt_kernel_channel *kchan;
+
+ kchan = trace_kernel_get_channel_by_name(attr->name,
+ session->kernel_session);
+ if (kchan == NULL) {
+ ret = channel_kernel_create(session->kernel_session,
+ attr, kernel_poll_pipe[1]);
+ } else {
+ ret = channel_kernel_enable(session->kernel_session, kchan);
+ }
+
+ if (ret != LTTCOMM_OK) {
+ goto error;
+ }
+
+ kernel_wait_quiescent(kernel_tracer_fd);
+ break;
+ }
+ case LTTNG_DOMAIN_UST:
+ {
+ struct ltt_ust_channel *uchan;
+
+ DBG2("Enabling channel for LTTNG_DOMAIN_UST");
+
+ /* Get channel in global UST domain HT */
+ uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
+ attr->name);
+ if (uchan == NULL) {
+ uchan = trace_ust_create_channel(attr, usess->pathname);
+ if (uchan == NULL) {
+ ret = LTTCOMM_UST_CHAN_FAIL;
+ goto error;
+ }
+ rcu_read_lock();
+ hashtable_add_unique(usess->domain_global.channels, &uchan->node);
+ rcu_read_unlock();
+ DBG2("UST channel %s added to global domain HT", attr->name);
+ } else {
+ ret = LTTCOMM_UST_CHAN_EXIST;
+ goto error;
+ }
+
+ ret = ust_app_add_channel(usess, uchan);
+ if (ret != LTTCOMM_OK) {
+ goto error;
+ }
+
+ break;
+ }
+ case LTTNG_DOMAIN_UST_PID:
+ {
+ /*
+ int sock;
+ struct ltt_ust_channel *uchan;
+ struct ltt_ust_session *usess;
+ struct ust_app *app;
+
+ usess = trace_ust_get_session_by_pid(&session->ust_session_list,
+ domain->attr.pid);
+ if (usess == NULL) {
+ ret = LTTCOMM_UST_CHAN_NOT_FOUND;
+ goto error;
+ }
+
+ app = ust_app_get_by_pid(domain->attr.pid);
+ if (app == NULL) {
+ ret = LTTCOMM_APP_NOT_FOUND;
+ goto error;
+ }
+ sock = app->sock;
+
+ uchan = trace_ust_get_channel_by_name(attr->name, usess);
+ if (uchan == NULL) {
+ ret = channel_ust_create(usess, attr, sock);
+ } else {
+ ret = channel_ust_enable(usess, uchan, sock);
+ }
+
+ if (ret != LTTCOMM_OK) {
+ goto error;
+ }
+
+ ret = copy_ust_channel_to_app(usess, attr, app);
+ if (ret != LTTCOMM_OK) {
+ goto error;
+ }
+
+ DBG("UST channel %s created for app sock %d with pid %d",
+ attr->name, app->sock, domain->attr.pid);
+ */
+ ret = LTTCOMM_NOT_IMPLEMENTED;
+ goto error;
+ }
+ default:
+ ret = LTTCOMM_UNKNOWN_DOMAIN;
+ goto error;
+ }
+
+ ret = LTTCOMM_OK;
+
+error:
+ return ret;
+}
+
+/*
+ * Command LTTNG_DISABLE_EVENT processed by the client thread.
+ */
+static int cmd_disable_event(struct ltt_session *session, int domain,
+ char *channel_name, char *event_name)
+{
+ int ret;
+
+ switch (domain) {
+ case LTTNG_DOMAIN_KERNEL:
+ {
+ struct ltt_kernel_channel *kchan;
+
+ kchan = trace_kernel_get_channel_by_name(channel_name,
+ session->kernel_session);
+ if (kchan == NULL) {
+ ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
+ goto error;
+ }
+
+ ret = event_kernel_disable_tracepoint(session->kernel_session, kchan, event_name);
+ if (ret != LTTCOMM_OK) {
+ goto error;
+ }
+
+ kernel_wait_quiescent(kernel_tracer_fd);
+ break;
+ }
+ case LTTNG_DOMAIN_UST:
+ case LTTNG_DOMAIN_UST_EXEC_NAME:
+ case LTTNG_DOMAIN_UST_PID:
+ case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
+ default:
+ /* TODO: Other UST domains */
+ ret = LTTCOMM_NOT_IMPLEMENTED;
+ goto error;
+ }
+
+ ret = LTTCOMM_OK;
+
+error:
+ return ret;
+}
+
+/*
+ * Command LTTNG_DISABLE_ALL_EVENT processed by the client thread.
+ */
+static int cmd_disable_event_all(struct ltt_session *session, int domain,
+ char *channel_name)
+{
+ int ret;
+ struct ltt_kernel_channel *kchan;
+
+ switch (domain) {
+ case LTTNG_DOMAIN_KERNEL:
+ kchan = trace_kernel_get_channel_by_name(channel_name,
+ session->kernel_session);
+ if (kchan == NULL) {
+ ret = LTTCOMM_KERN_CHAN_NOT_FOUND;
+ goto error;
+ }
+
+ ret = event_kernel_disable_all(session->kernel_session, kchan);
+ if (ret != LTTCOMM_OK) {
+ goto error;
+ }
+
+ kernel_wait_quiescent(kernel_tracer_fd);
+ break;
+ default:
+ /* TODO: Userspace tracing */
+ ret = LTTCOMM_NOT_IMPLEMENTED;
+ goto error;
+ }
+
+ ret = LTTCOMM_OK;
+
+error:
+ return ret;
+}
+
+/*
+ * Command LTTNG_ADD_CONTEXT processed by the client thread.
+ */
+static int cmd_add_context(struct ltt_session *session, int domain,
+ char *channel_name, char *event_name, struct lttng_event_context *ctx)
+{
+ int ret;
+
+ switch (domain) {
+ case LTTNG_DOMAIN_KERNEL:
+ /* Add kernel context to kernel tracer */
+ ret = context_kernel_add(session->kernel_session, ctx,
+ event_name, channel_name);
+ if (ret != LTTCOMM_OK) {
+ goto error;
+ }
+ break;
+ case LTTNG_DOMAIN_UST:
+ {
+ /*
+ struct ltt_ust_session *usess;
+
+ cds_list_for_each_entry(usess, &session->ust_session_list.head, list) {
+ ret = context_ust_add(usess, ctx,
+ event_name, channel_name, domain);
+ if (ret != LTTCOMM_OK) {
+ goto error;
+ }
+ }
+ break;
+ */
+ }
+ default:
+ /* TODO: UST other domains */
+ ret = LTTCOMM_NOT_IMPLEMENTED;
+ goto error;
+ }
+
+ ret = LTTCOMM_OK;
+
+error:
+ return ret;
+}
+
+/*
+ * Command LTTNG_ENABLE_EVENT processed by the client thread.
+ */
+static int cmd_enable_event(struct ltt_session *session, int domain,
+ char *channel_name, struct lttng_event *event)
+{
+ int ret;
+ struct lttng_channel *attr;
+ struct ltt_ust_session *usess = session->ust_session;
+
+ switch (domain) {
+ case LTTNG_DOMAIN_KERNEL:
+ {
+ struct ltt_kernel_channel *kchan;
+
+ kchan = trace_kernel_get_channel_by_name(channel_name,
+ session->kernel_session);
+ if (kchan == NULL) {
+ attr = channel_new_default_attr(domain);
+ if (attr == NULL) {
+ ret = LTTCOMM_FATAL;
+ goto error;
+ }
+ snprintf(attr->name, NAME_MAX, "%s", channel_name);
+
+ /* This call will notify the kernel thread */
+ ret = channel_kernel_create(session->kernel_session,
+ attr, kernel_poll_pipe[1]);
+ if (ret != LTTCOMM_OK) {
+ goto error;
+ }
+ }
+
+ /* Get the newly created kernel channel pointer */
+ kchan = trace_kernel_get_channel_by_name(channel_name,
+ session->kernel_session);
+ if (kchan == NULL) {
+ /* This sould not happen... */
+ ret = LTTCOMM_FATAL;
+ goto error;
+ }
+
+ ret = event_kernel_enable_tracepoint(session->kernel_session, kchan,
+ event);
+ if (ret != LTTCOMM_OK) {
+ goto error;
+ }
+
+ kernel_wait_quiescent(kernel_tracer_fd);
+ break;
+ }
+ case LTTNG_DOMAIN_UST:
+ {
+ struct ltt_ust_channel *uchan;
+ struct ltt_ust_event *uevent;
+
+ uchan = trace_ust_find_channel_by_name(usess->domain_global.channels,
+ channel_name);
+ if (uchan == NULL) {
+ /* TODO: Create default channel */
+ ret = LTTCOMM_UST_CHAN_NOT_FOUND;
+ goto error;
+ }
+
+ uevent = trace_ust_find_event_by_name(uchan->events, event->name);
+ if (uevent == NULL) {
+ uevent = trace_ust_create_event(event);
+ if (uevent == NULL) {
+ ret = LTTCOMM_FATAL;
+ goto error;
+ }
+ }
+
+ ret = ust_app_add_event(usess, uchan, uevent);
+ if (ret < 0) {
+ ret = LTTCOMM_UST_ENABLE_FAIL;
+ goto error;
+ }
+ break;
+ }
+ case LTTNG_DOMAIN_UST_EXEC_NAME:
+ case LTTNG_DOMAIN_UST_PID:
+ case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
+ default:
+ ret = LTTCOMM_NOT_IMPLEMENTED;
+ goto error;
+ }
+
+ ret = LTTCOMM_OK;
+
+error:
+ return ret;
+}
+
+/*
+ * Command LTTNG_ENABLE_ALL_EVENT processed by the client thread.
+ */
+static int cmd_enable_event_all(struct ltt_session *session, int domain,
+ char *channel_name, int event_type)
+{
+ int ret;
+ struct ltt_kernel_channel *kchan;
+
+ switch (domain) {
+ case LTTNG_DOMAIN_KERNEL:
+ kchan = trace_kernel_get_channel_by_name(channel_name,
+ session->kernel_session);
+ if (kchan == NULL) {
+ /* This call will notify the kernel thread */
+ ret = channel_kernel_create(session->kernel_session, NULL,
+ kernel_poll_pipe[1]);
+ if (ret != LTTCOMM_OK) {
+ goto error;
+ }
+ }
+
+ /* Get the newly created kernel channel pointer */
+ kchan = trace_kernel_get_channel_by_name(channel_name,
+ session->kernel_session);
+ if (kchan == NULL) {
+ /* This sould not happen... */
+ ret = LTTCOMM_FATAL;
+ goto error;
+ }
+
+ switch (event_type) {
+ case LTTNG_KERNEL_SYSCALL:
+ ret = event_kernel_enable_all_syscalls(session->kernel_session,
+ kchan, kernel_tracer_fd);
+ break;
+ case LTTNG_KERNEL_TRACEPOINT:
+ /*
+ * This call enables all LTTNG_KERNEL_TRACEPOINTS and
+ * events already registered to the channel.
+ */
+ ret = event_kernel_enable_all_tracepoints(session->kernel_session,
+ kchan, kernel_tracer_fd);
+ break;
+ case LTTNG_KERNEL_ALL:
+ /* Enable syscalls and tracepoints */
+ ret = event_kernel_enable_all(session->kernel_session,
+ kchan, kernel_tracer_fd);
+ break;
+ default:
+ ret = LTTCOMM_KERN_ENABLE_FAIL;
+ goto error;
+ }
+ if (ret != LTTCOMM_OK) {
+ goto error;
+ }
+
+ kernel_wait_quiescent(kernel_tracer_fd);
+ break;
+ default:
+ /* TODO: Userspace tracing */
+ ret = LTTCOMM_NOT_IMPLEMENTED;
+ goto error;
+ }
+
+ ret = LTTCOMM_OK;
+
+error:
+ return ret;
+}
+
+/*
+ * Command LTTNG_LIST_TRACEPOINTS processed by the client thread.
+ */
+static ssize_t cmd_list_tracepoints(int domain, struct lttng_event **events)
+{
+ int ret;
+ ssize_t nb_events = 0;
+
+ switch (domain) {
+ case LTTNG_DOMAIN_KERNEL:
+ nb_events = kernel_list_events(kernel_tracer_fd, events);
+ if (nb_events < 0) {
+ ret = LTTCOMM_KERN_LIST_FAIL;
+ goto error;
+ }
+ break;
+ default:
+ /* TODO: Userspace listing */
+ ret = LTTCOMM_NOT_IMPLEMENTED;
+ goto error;
+ }
+
+ return nb_events;
+
+error:
+ /* Return negative value to differentiate return code */
+ return -ret;
+}
+
+/*
+ * Command LTTNG_START_TRACE processed by the client thread.
+ */
+static int cmd_start_trace(struct ltt_session *session)
+{
+ int ret;
+ struct ltt_kernel_session *ksession;
+ struct ltt_ust_session *usess = session->ust_session;
+
+ /* Short cut */
+ ksession = session->kernel_session;
+
+ /* Kernel tracing */
+ if (ksession != NULL) {
+ struct ltt_kernel_channel *kchan;
+
+ /* Open kernel metadata */
+ if (ksession->metadata == NULL) {
+ ret = kernel_open_metadata(ksession, ksession->trace_path);
+ if (ret < 0) {
+ ret = LTTCOMM_KERN_META_FAIL;
+ goto error;
+ }
+ }
+
+ /* Open kernel metadata stream */
+ if (ksession->metadata_stream_fd == 0) {
+ ret = kernel_open_metadata_stream(ksession);
+ if (ret < 0) {
+ ERR("Kernel create metadata stream failed");
+ ret = LTTCOMM_KERN_STREAM_FAIL;
+ goto error;
+ }
+ }
+
+ /* For each channel */
+ cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
+ if (kchan->stream_count == 0) {
+ ret = kernel_open_channel_stream(kchan);
+ if (ret < 0) {
+ ret = LTTCOMM_KERN_STREAM_FAIL;
+ goto error;
+ }
+ /* Update the stream global counter */
+ ksession->stream_count_global += ret;
+ }
+ }
+
+ /* Setup kernel consumer socket and send fds to it */
+ ret = init_kernel_tracing(ksession);
+ if (ret < 0) {
+ ret = LTTCOMM_KERN_START_FAIL;
+ goto error;
+ }
+
+ /* This start the kernel tracing */
+ ret = kernel_start_session(ksession);
+ if (ret < 0) {
+ ret = LTTCOMM_KERN_START_FAIL;
+ goto error;
+ }
+
+ /* Quiescent wait after starting trace */
+ kernel_wait_quiescent(kernel_tracer_fd);
+ }
+
+ ret = ust_app_start_trace(usess);
+ if (ret < 0) {
+ ret = LTTCOMM_UST_START_FAIL;
+ goto error;
+ }
+
+ ret = LTTCOMM_OK;
+
+error:
+ return ret;
+}
+
+/*
+ * Command LTTNG_STOP_TRACE processed by the client thread.
+ */
+static int cmd_stop_trace(struct ltt_session *session)
+{
+ int ret;
+ struct ltt_kernel_channel *kchan;
+ struct ltt_kernel_session *ksession;
+ //struct ltt_ust_session *usess;
+ //struct ltt_ust_channel *ustchan;
+
+ /* Short cut */
+ ksession = session->kernel_session;
+
+ /* Kernel tracer */
+ if (ksession != NULL) {
+ DBG("Stop kernel tracing");
+
+ /* Flush all buffers before stopping */
+ ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
+ if (ret < 0) {
+ ERR("Kernel metadata flush failed");
+ }
+
+ cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
+ ret = kernel_flush_buffer(kchan);
+ if (ret < 0) {
+ ERR("Kernel flush buffer error");
+ }
+ }
+
+ ret = kernel_stop_session(ksession);
+ if (ret < 0) {
+ ret = LTTCOMM_KERN_STOP_FAIL;
+ goto error;
+ }
+
+ kernel_wait_quiescent(kernel_tracer_fd);
+ }
+
+#ifdef DISABLE
+ /* Stop each UST session */
+ DBG("Stop UST tracing");
+ cds_list_for_each_entry(usess, &session->ust_session_list.head, list) {
+ /* Flush all buffers before stopping */
+ ret = ustctl_flush_buffer(usess->sock, usess->metadata->obj);
+ if (ret < 0) {
+ ERR("UST metadata flush failed");
+ }
+
+ cds_list_for_each_entry(ustchan, &usess->channels.head, list) {
+ ret = ustctl_flush_buffer(usess->sock, ustchan->obj);
+ if (ret < 0) {
+ ERR("UST flush buffer error");
+ }
+ }
+
+ ret = ustctl_stop_session(usess->sock, usess->handle);
+ if (ret < 0) {
+ ret = LTTCOMM_KERN_STOP_FAIL;
+ goto error;
+ }
+
+ ustctl_wait_quiescent(usess->sock);
+ }
+#endif
+
+ ret = LTTCOMM_OK;
+
+error:
+ return ret;
+}
+
+/*
+ * Command LTTNG_CREATE_SESSION processed by the client thread.
+ */
+static int cmd_create_session(char *name, char *path)
+{
+ int ret;
+
+ ret = session_create(name, path);
+ if (ret != LTTCOMM_OK) {
+ goto error;
+ }
+
+ ret = LTTCOMM_OK;
+
+error:
+ return ret;
+}
+
+/*
+ * Command LTTNG_DESTROY_SESSION processed by the client thread.
+ */
+static int cmd_destroy_session(struct ltt_session *session, char *name)
+{
+ int ret;
+
+ /* Clean kernel session teardown */
+ teardown_kernel_session(session);
+
+ /*
+ * Must notify the kernel thread here to update it's poll setin order
+ * to remove the channel(s)' fd just destroyed.
+ */
+ ret = notify_thread_pipe(kernel_poll_pipe[1]);
+ if (ret < 0) {
+ perror("write kernel poll pipe");
+ }
+
+ ret = session_destroy(session);
+
+ return ret;
+}
+
+/*
+ * Command LTTNG_CALIBRATE processed by the client thread.
+ */
+static int cmd_calibrate(int domain, struct lttng_calibrate *calibrate)
+{
+ int ret;
+
+ switch (domain) {
+ case LTTNG_DOMAIN_KERNEL:
+ {
+ struct lttng_kernel_calibrate kcalibrate;
+
+ kcalibrate.type = calibrate->type;
+ ret = kernel_calibrate(kernel_tracer_fd, &kcalibrate);
+ if (ret < 0) {
+ ret = LTTCOMM_KERN_ENABLE_FAIL;
+ goto error;
+ }
+ break;
+ }
+ default:
+ /* TODO: Userspace tracing */
+ ret = LTTCOMM_NOT_IMPLEMENTED;
+ goto error;
+ }
+
+ ret = LTTCOMM_OK;
+
+error:
+ return ret;
+}
+
+/*
+ * Command LTTNG_REGISTER_CONSUMER processed by the client thread.
+ */
+static int cmd_register_consumer(struct ltt_session *session, int domain,
+ char *sock_path)
+{
+ int ret, sock;
+
+ switch (domain) {
+ case LTTNG_DOMAIN_KERNEL:
+ /* Can't register a consumer if there is already one */
+ if (session->kernel_session->consumer_fd != 0) {
+ ret = LTTCOMM_KERN_CONSUMER_FAIL;
+ goto error;
+ }
+
+ sock = lttcomm_connect_unix_sock(sock_path);
+ if (sock < 0) {
+ ret = LTTCOMM_CONNECT_FAIL;
+ goto error;
+ }
+
+ session->kernel_session->consumer_fd = sock;
+ break;
+ default:
+ /* TODO: Userspace tracing */
+ ret = LTTCOMM_NOT_IMPLEMENTED;
+ goto error;
+ }
+
+ ret = LTTCOMM_OK;
+
+error:
+ return ret;
+}
+
+/*
+ * Command LTTNG_LIST_DOMAINS processed by the client thread.
+ */
+static ssize_t cmd_list_domains(struct ltt_session *session,
+ struct lttng_domain **domains)
+{
+ int ret;
+ ssize_t nb_dom = 0;
+
+ if (session->kernel_session != NULL) {
+ nb_dom++;
+ }
+
+ /* TODO: User-space tracer domain support */
+
+ *domains = malloc(nb_dom * sizeof(struct lttng_domain));
+ if (*domains == NULL) {
+ ret = -LTTCOMM_FATAL;
+ goto error;
+ }
+
+ (*domains)[0].type = LTTNG_DOMAIN_KERNEL;
+
+ return nb_dom;
+
+error:
+ return ret;
+}
+
+/*
+ * Command LTTNG_LIST_CHANNELS processed by the client thread.
+ */
+static ssize_t cmd_list_channels(struct ltt_session *session,
+ struct lttng_channel **channels)
+{
+ int ret;
+ ssize_t nb_chan = 0;
+
+ if (session->kernel_session != NULL) {
+ nb_chan += session->kernel_session->channel_count;
+ }
+
+ *channels = malloc(nb_chan * sizeof(struct lttng_channel));
+ if (*channels == NULL) {
+ ret = -LTTCOMM_FATAL;
+ goto error;
+ }
+
+ list_lttng_channels(session, *channels);
+
+ /* TODO UST support */
+
+ return nb_chan;
+
+error:
+ return ret;
+}
+
+/*
+ * Command LTTNG_LIST_EVENTS processed by the client thread.
+ */
+static ssize_t cmd_list_events(struct ltt_session *session,
+ char *channel_name, struct lttng_event **events)
+{
+ int ret;
+ ssize_t nb_event = 0;
+ struct ltt_kernel_channel *kchan = NULL;
+
+ if (session->kernel_session != NULL) {
+ kchan = trace_kernel_get_channel_by_name(channel_name,
+ session->kernel_session);
+ if (kchan == NULL) {
+ ret = -LTTCOMM_KERN_CHAN_NOT_FOUND;
+ goto error;
+ }
+ nb_event += kchan->event_count;
+ }
+
+ *events = malloc(nb_event * sizeof(struct lttng_event));
+ if (*events == NULL) {
+ ret = -LTTCOMM_FATAL;
+ goto error;
+ }
+
+ list_lttng_events(kchan, *events);
+
+ /* TODO: User-space tracer support */
+
+ return nb_event;
+
+error:
+ return ret;
+}
+
+/*
+ * 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 = LTTCOMM_OK;
+ int need_tracing_session = 1;
+
+ DBG("Processing client command %d", cmd_ctx->lsm->cmd_type);
+
+ /*
+ * 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_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_CALIBRATE:
+ case LTTNG_CREATE_SESSION:
+ case LTTNG_LIST_SESSIONS:
+ case LTTNG_LIST_TRACEPOINTS:
+ need_tracing_session = 0;
+ break;
+ default:
+ DBG("Getting session %s by name", cmd_ctx->lsm->session.name);
+ session_lock_list();
+ cmd_ctx->session = session_find_by_name(cmd_ctx->lsm->session.name);
+ session_unlock_list();
+ if (cmd_ctx->session == NULL) {
+ if (cmd_ctx->lsm->session.name != NULL) {
+ ret = LTTCOMM_SESS_NOT_FOUND;
+ } else {
+ /* If no session name specified */
+ ret = LTTCOMM_SELECT_SESS;
+ }
+ goto error;
+ } else {
+ /* Acquire lock for the session */
+ session_lock(cmd_ctx->session);
+ }
+ break;
+ }
+
+ /*
+ * Check domain type for specific "pre-action".
+ */
+ switch (cmd_ctx->lsm->domain.type) {
+ case LTTNG_DOMAIN_KERNEL:
+ /* Kernel tracer check */
+ if (kernel_tracer_fd == 0) {
+ /* Basically, load kernel tracer modules */
+ init_kernel_tracer();
+ if (kernel_tracer_fd == 0) {
+ ret = LTTCOMM_KERN_NA;
+ 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 = LTTCOMM_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) {
+ pthread_mutex_unlock(&kconsumer_data.pid_mutex);
+ ret = start_consumerd(&kconsumer_data);
+ if (ret < 0) {
+ ret = LTTCOMM_KERN_CONSUMER_FAIL;
+ goto error;
+ }
+ }
+ pthread_mutex_unlock(&kconsumer_data.pid_mutex);
+ }
+ break;
+ case LTTNG_DOMAIN_UST:
+ {
+ if (need_tracing_session) {
+ if (cmd_ctx->session->ust_session == NULL) {
+ ret = create_ust_session(cmd_ctx->session,
+ &cmd_ctx->lsm->domain);
+ if (ret != LTTCOMM_OK) {
+ goto error;
+ }
+ }
+ /* Start the kernel consumer daemon */
+ pthread_mutex_lock(&ustconsumer_data.pid_mutex);
+ if (ustconsumer_data.pid == 0 &&
+ cmd_ctx->lsm->cmd_type != LTTNG_REGISTER_CONSUMER) {
+ pthread_mutex_unlock(&ustconsumer_data.pid_mutex);
+ ret = start_consumerd(&ustconsumer_data);
+ if (ret < 0) {
+ ret = LTTCOMM_KERN_CONSUMER_FAIL;
+ goto error;
+ }
+
+ cmd_ctx->session->ust_session->consumer_fd =
+ ustconsumer_data.cmd_sock;
+ }
+ pthread_mutex_unlock(&ustconsumer_data.pid_mutex);
+ }
+ break;
+ }
+ default:
+ break;
+ }
+
+ /* 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);
+ ret = LTTCOMM_OK;
+ 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_ENABLE_CHANNEL:
+ {
+ ret = cmd_enable_channel(cmd_ctx->session, &cmd_ctx->lsm->domain,
+ &cmd_ctx->lsm->u.channel.chan);
+ 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);
+ 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);
+ 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) {
+ 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 = LTTCOMM_OK;
+ break;
+ }
+ case LTTNG_START_TRACE:
+ {
+ ret = cmd_start_trace(cmd_ctx->session);
+ break;
+ }
+ case LTTNG_STOP_TRACE:
+ {
+ ret = cmd_stop_trace(cmd_ctx->session);
+ break;
+ }
+ case LTTNG_CREATE_SESSION:
+ {
+ ret = cmd_create_session(cmd_ctx->lsm->session.name,
+ cmd_ctx->lsm->session.path);
+ break;
+ }
+ case LTTNG_DESTROY_SESSION:
+ {
+ ret = cmd_destroy_session(cmd_ctx->session,
+ cmd_ctx->lsm->session.name);
+ break;
+ }
+ case LTTNG_LIST_DOMAINS:
+ {
+ ssize_t nb_dom;
+ struct lttng_domain *domains;
+
+ nb_dom = cmd_list_domains(cmd_ctx->session, &domains);
+ if (nb_dom < 0) {
+ ret = -nb_dom;
+ goto error;
+ }
+
+ ret = setup_lttng_msg(cmd_ctx, nb_dom * sizeof(struct lttng_domain));
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ /* Copy event list into message payload */
+ memcpy(cmd_ctx->llm->payload, domains,
+ nb_dom * sizeof(struct lttng_domain));
+
+ free(domains);
+
+ ret = LTTCOMM_OK;
+ break;
+ }
+ case LTTNG_LIST_CHANNELS:
+ {
+ size_t nb_chan;
+ struct lttng_channel *channels;
+
+ nb_chan = cmd_list_channels(cmd_ctx->session, &channels);
+ if (nb_chan < 0) {
+ ret = -nb_chan;
+ goto error;
+ }
+
+ ret = setup_lttng_msg(cmd_ctx, nb_chan * sizeof(struct lttng_channel));
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ /* Copy event list into message payload */
+ memcpy(cmd_ctx->llm->payload, channels,
+ nb_chan * sizeof(struct lttng_channel));
+
+ free(channels);
+
+ ret = LTTCOMM_OK;
+ break;
+ }
+ case LTTNG_LIST_EVENTS:
+ {
+ size_t nb_event;
+ struct lttng_event *events = NULL;
+
+ nb_event = cmd_list_events(cmd_ctx->session,
+ cmd_ctx->lsm->u.list.channel_name, &events);
+ if (nb_event < 0) {
+ ret = -nb_event;
+ goto error;
+ }
+
+ ret = setup_lttng_msg(cmd_ctx, nb_event * sizeof(struct lttng_event));
+ if (ret < 0) {
+ goto setup_error;
+ }
+
+ /* Copy event list into message payload */
+ memcpy(cmd_ctx->llm->payload, events,
+ nb_event * sizeof(struct lttng_event));
+
+ free(events);
+
+ ret = LTTCOMM_OK;
+ break;
+ }
+ case LTTNG_LIST_SESSIONS:
+ {
+ session_lock_list();
+
+ if (session_list_ptr->count == 0) {
+ ret = LTTCOMM_NO_SESSION;
+ session_unlock_list();
+ goto error;
+ }
+
+ ret = setup_lttng_msg(cmd_ctx, sizeof(struct lttng_session) *
+ session_list_ptr->count);
+ if (ret < 0) {
+ session_unlock_list();
+ goto setup_error;
+ }
+
+ /* Filled the session array */
+ list_lttng_sessions((struct lttng_session *)(cmd_ctx->llm->payload));
+
+ session_unlock_list();
+
+ ret = LTTCOMM_OK;
+ break;
+ }
+ case LTTNG_CALIBRATE:
+ {
+ ret = cmd_calibrate(cmd_ctx->lsm->domain.type,
+ &cmd_ctx->lsm->u.calibrate);
+ break;
+ }
+ case LTTNG_REGISTER_CONSUMER:
+ {
+ ret = cmd_register_consumer(cmd_ctx->session, cmd_ctx->lsm->domain.type,
+ cmd_ctx->lsm->u.reg.path);
+ break;
+ }
+ default:
+ ret = LTTCOMM_UND;
+ break;
+ }
+
+error:
+ if (cmd_ctx->llm == NULL) {
+ DBG("Missing llm structure. Allocating one.");
+ if (setup_lttng_msg(cmd_ctx, 0) < 0) {
+ goto setup_error;
+ }
+ }
+ /* Set return code */
+ cmd_ctx->llm->ret_code = ret;
+setup_error:
+ if (cmd_ctx->session) {
+ session_unlock(cmd_ctx->session);
+ }
+init_setup_error:
+ return ret;
+}
+
+/*
+ * This thread manage all clients request using the unix client socket for
+ * communication.
+ */
+static void *thread_manage_clients(void *data)
+{
+ int sock = 0, ret, i, pollfd;
+ uint32_t revents, nb_fd;
+ struct command_ctx *cmd_ctx = NULL;
+ struct lttng_poll_event events;
+
+ DBG("[thread] Manage client started");
+
+ rcu_register_thread();
+
+ ret = lttcomm_listen_unix_sock(client_sock);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /*
+ * Pass 2 as size here for the thread quit pipe and client_sock. Nothing
+ * more will be added to this poll set.
+ */
+ ret = create_thread_poll_set(&events, 2);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* Add the application registration socket */
+ ret = lttng_poll_add(&events, client_sock, LPOLLIN | LPOLLPRI);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /*
+ * Notify parent pid that we are ready to accept command for client side.
+ */
+ if (opt_sig_parent) {
+ kill(ppid, SIGCHLD);
+ }
+
+ while (1) {
+ DBG("Accepting client command ...");
+
+ nb_fd = LTTNG_POLL_GETNB(&events);
+
+ /* Inifinite blocking call, waiting for transmission */
+ ret = lttng_poll_wait(&events, -1);
+ if (ret < 0) {
+ goto error;
+ }
+
+ for (i = 0; i < nb_fd; i++) {
+ /* Fetch once the poll data */
+ revents = LTTNG_POLL_GETEV(&events, i);
+ pollfd = LTTNG_POLL_GETFD(&events, i);
+
+ /* Thread quit pipe has been closed. Killing thread. */
+ ret = check_thread_quit_pipe(pollfd, revents);
+ if (ret) {
+ goto error;
+ }
+
+ /* Event on the registration socket */
+ if (pollfd == client_sock) {
+ if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+ ERR("Client socket poll error");
+ goto error;
+ }
+ }
+ }
+
+ DBG("Wait for client response");
+
+ sock = lttcomm_accept_unix_sock(client_sock);
+ if (sock < 0) {
+ goto error;
+ }
+
+ /* Allocate context command to process the client request */
+ cmd_ctx = malloc(sizeof(struct command_ctx));
+ if (cmd_ctx == NULL) {
+ perror("malloc cmd_ctx");
+ goto error;
+ }
+
+ /* Allocate data buffer for reception */
+ cmd_ctx->lsm = malloc(sizeof(struct lttcomm_session_msg));
+ if (cmd_ctx->lsm == NULL) {
+ perror("malloc cmd_ctx->lsm");
+ goto error;
+ }
+
+ cmd_ctx->llm = NULL;
+ cmd_ctx->session = NULL;
+
+ /*
+ * Data is received from the lttng client. The struct
+ * lttcomm_session_msg (lsm) contains the command and data request of
+ * the client.
+ */
+ DBG("Receiving data from client ...");
+ ret = lttcomm_recv_unix_sock(sock, cmd_ctx->lsm,
+ sizeof(struct lttcomm_session_msg));
+ if (ret <= 0) {
+ DBG("Nothing recv() from client... continuing");
+ close(sock);
+ free(cmd_ctx);
+ continue;
+ }
+
+ // TODO: Validate cmd_ctx including sanity check for
+ // security purpose.
+
+ rcu_thread_online();
+ /*
+ * This function dispatch the work to the kernel or userspace tracer
+ * libs and fill the lttcomm_lttng_msg data structure of all the needed
+ * informations for the client. The command context struct contains
+ * everything this function may needs.
+ */
+ ret = process_client_msg(cmd_ctx);
+ rcu_thread_offline();
+ if (ret < 0) {
+ /*
+ * TODO: Inform client somehow of the fatal error. At
+ * this point, ret < 0 means that a malloc failed
+ * (ENOMEM). Error detected but still accept command.
+ */
+ clean_command_ctx(&cmd_ctx);
+ continue;
+ }
+
+ DBG("Sending response (size: %d, retcode: %s)",
+ cmd_ctx->lttng_msg_size,
+ lttng_strerror(-cmd_ctx->llm->ret_code));
+ ret = send_unix_sock(sock, cmd_ctx->llm, cmd_ctx->lttng_msg_size);
+ if (ret < 0) {
+ ERR("Failed to send data back to client");
+ }
+
+ clean_command_ctx(&cmd_ctx);
+
+ /* End of transmission */
+ close(sock);
+ }
+
+error:
+ DBG("Client thread dying");
+ unlink(client_unix_sock_path);
+ close(client_sock);
+ close(sock);
+
+ lttng_poll_clean(&events);
+ clean_command_ctx(&cmd_ctx);
+
+ rcu_unregister_thread();
+ return NULL;
+}
+
+
+/*
+ * usage function on stderr
+ */
+static void usage(void)
+{
+ fprintf(stderr, "Usage: %s OPTIONS\n\nOptions:\n", progname);
+ fprintf(stderr, " -h, --help Display this usage.\n");
+ fprintf(stderr, " -c, --client-sock PATH Specify path for the client unix socket\n");
+ fprintf(stderr, " -a, --apps-sock PATH Specify path for apps unix socket\n");
+ fprintf(stderr, " --kconsumerd-err-sock PATH Specify path for the kernel consumer error socket\n");
+ fprintf(stderr, " --kconsumerd-cmd-sock PATH Specify path for the kernel consumer command socket\n");
+ fprintf(stderr, " --ustconsumerd-err-sock PATH Specify path for the UST consumer error socket\n");
+ fprintf(stderr, " --ustconsumerd-cmd-sock PATH Specify path for the UST consumer command socket\n");
+ fprintf(stderr, " -d, --daemonize Start as a daemon.\n");
+ fprintf(stderr, " -g, --group NAME Specify the tracing group name. (default: tracing)\n");
+ fprintf(stderr, " -V, --version Show version number.\n");
+ fprintf(stderr, " -S, --sig-parent Send SIGCHLD to parent pid to notify readiness.\n");
+ fprintf(stderr, " -q, --quiet No output at all.\n");
+ fprintf(stderr, " -v, --verbose Verbose mode. Activate DBG() macro.\n");
+ fprintf(stderr, " --verbose-consumer Verbose mode for consumer. Activate DBG() macro.\n");
+}
+
+/*
+ * daemon argument parsing
+ */
+static int parse_args(int argc, char **argv)
+{
+ int c;
+
+ static struct option long_options[] = {
+ { "client-sock", 1, 0, 'c' },
+ { "apps-sock", 1, 0, 'a' },
+ { "kconsumerd-cmd-sock", 1, 0, 'C' },
+ { "kconsumerd-err-sock", 1, 0, 'E' },
+ { "ustconsumerd-cmd-sock", 1, 0, 'D' },
+ { "ustconsumerd-err-sock", 1, 0, 'F' },
+ { "daemonize", 0, 0, 'd' },
+ { "sig-parent", 0, 0, 'S' },
+ { "help", 0, 0, 'h' },
+ { "group", 1, 0, 'g' },
+ { "version", 0, 0, 'V' },
+ { "quiet", 0, 0, 'q' },
+ { "verbose", 0, 0, 'v' },
+ { "verbose-consumer", 0, 0, 'Z' },
+ { NULL, 0, 0, 0 }
+ };
+
+ while (1) {
+ int option_index = 0;
+ c = getopt_long(argc, argv, "dhqvVS" "a:c:g:s:C:E:D:F:Z",
+ long_options, &option_index);
+ if (c == -1) {
+ break;
+ }
+
+ switch (c) {
+ case 0:
+ fprintf(stderr, "option %s", long_options[option_index].name);
+ if (optarg) {
+ fprintf(stderr, " with arg %s\n", optarg);
+ }
+ break;
+ case 'c':
+ snprintf(client_unix_sock_path, PATH_MAX, "%s", optarg);
+ break;
+ case 'a':
+ snprintf(apps_unix_sock_path, PATH_MAX, "%s", optarg);
+ break;
+ case 'd':
+ opt_daemon = 1;
+ break;
+ case 'g':
+ opt_tracing_group = strdup(optarg);
+ break;
+ case 'h':
+ usage();
+ exit(EXIT_FAILURE);
+ case 'V':
+ fprintf(stdout, "%s\n", VERSION);
+ exit(EXIT_SUCCESS);
+ case 'S':
+ opt_sig_parent = 1;
+ break;
+ case 'E':
+ snprintf(kconsumer_data.err_unix_sock_path, PATH_MAX, "%s", optarg);
+ break;
+ case 'C':
+ snprintf(kconsumer_data.cmd_unix_sock_path, PATH_MAX, "%s", optarg);
+ break;
+ case 'F':
+ snprintf(ustconsumer_data.err_unix_sock_path, PATH_MAX, "%s", optarg);
+ break;
+ case 'D':
+ snprintf(ustconsumer_data.cmd_unix_sock_path, PATH_MAX, "%s", optarg);
+ break;
+ case 'q':
+ opt_quiet = 1;
+ break;
+ case 'v':
+ /* Verbose level can increase using multiple -v */
+ opt_verbose += 1;
+ break;
+ case 'Z':
+ opt_verbose_consumer += 1;
+ break;
+ default:
+ /* Unknown option or other error.
+ * Error is printed by getopt, just return */
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Creates the two needed socket by the daemon.
+ * apps_sock - The communication socket for all UST apps.
+ * client_sock - The communication of the cli tool (lttng).
+ */
+static int init_daemon_socket(void)
+{
+ int ret = 0;
+ mode_t old_umask;
+
+ old_umask = umask(0);
+
+ /* Create client tool unix socket */
+ client_sock = lttcomm_create_unix_sock(client_unix_sock_path);
+ if (client_sock < 0) {
+ ERR("Create unix sock failed: %s", client_unix_sock_path);
+ ret = -1;
+ goto end;
+ }
+
+ /* File permission MUST be 660 */
+ ret = chmod(client_unix_sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
+ if (ret < 0) {
+ ERR("Set file permissions failed: %s", client_unix_sock_path);
+ perror("chmod");
+ goto end;
+ }
+
+ /* Create the application unix socket */
+ apps_sock = lttcomm_create_unix_sock(apps_unix_sock_path);
+ if (apps_sock < 0) {
+ ERR("Create unix sock failed: %s", apps_unix_sock_path);
+ ret = -1;
+ goto end;
+ }
+
+ /* File permission MUST be 666 */
+ ret = chmod(apps_unix_sock_path,
+ S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
+ if (ret < 0) {
+ ERR("Set file permissions failed: %s", apps_unix_sock_path);
+ perror("chmod");
+ goto end;
+ }
+
+end:
+ umask(old_umask);
+ return ret;
+}
+
+/*
+ * Check if the global socket is available, and if a daemon is answering at the
+ * other side. If yes, error is returned.
+ */
+static int check_existing_daemon(void)
+{
+ if (access(client_unix_sock_path, F_OK) < 0 &&
+ access(apps_unix_sock_path, F_OK) < 0) {
+ return 0;
+ }
+
+ /* Is there anybody out there ? */
+ if (lttng_session_daemon_alive()) {
+ return -EEXIST;
+ } else {
+ return 0;
+ }
+}
+
+/*
+ * Set the tracing group gid onto the client socket.
+ *
+ * Race window between mkdir and chown is OK because we are going from more
+ * permissive (root.root) to les permissive (root.tracing).
+ */
+static int set_permissions(void)
+{
+ int ret;
+ gid_t gid;
+
+ gid = allowed_group();
+ if (gid < 0) {
+ if (is_root) {
+ WARN("No tracing group detected");
+ ret = 0;
+ } else {
+ ERR("Missing tracing group. Aborting execution.");
+ ret = -1;
+ }
+ goto end;
+ }
+
+ /* Set lttng run dir */
+ ret = chown(LTTNG_RUNDIR, 0, gid);
+ if (ret < 0) {
+ ERR("Unable to set group on " LTTNG_RUNDIR);
+ perror("chown");
+ }
+
+ /* lttng client socket path */
+ ret = chown(client_unix_sock_path, 0, gid);
+ if (ret < 0) {
+ ERR("Unable to set group on %s", client_unix_sock_path);
+ perror("chown");
+ }
+
+ /* kconsumer error socket path */
+ ret = chown(kconsumer_data.err_unix_sock_path, 0, gid);
+ if (ret < 0) {
+ ERR("Unable to set group on %s", kconsumer_data.err_unix_sock_path);
+ perror("chown");
+ }
+
+ /* ustconsumer error socket path */
+ ret = chown(ustconsumer_data.err_unix_sock_path, 0, gid);
+ if (ret < 0) {
+ ERR("Unable to set group on %s", ustconsumer_data.err_unix_sock_path);
+ perror("chown");
+ }
+
+ DBG("All permissions are set");
+
+end:
+ return ret;
+}
+
+/*
+ * Create the pipe used to wake up the kernel thread.
+ */
+static int create_kernel_poll_pipe(void)
+{
+ return pipe2(kernel_poll_pipe, O_CLOEXEC);
+}
+
+/*
+ * Create the application command pipe to wake thread_manage_apps.
+ */
+static int create_apps_cmd_pipe(void)
+{
+ return pipe2(apps_cmd_pipe, O_CLOEXEC);
+}
+
+/*
+ * Create the lttng run directory needed for all global sockets and pipe.
+ */
+static int create_lttng_rundir(void)
+{
+ int ret;
+
+ ret = mkdir(LTTNG_RUNDIR, S_IRWXU | S_IRWXG );
+ if (ret < 0) {
+ if (errno != EEXIST) {
+ ERR("Unable to create " LTTNG_RUNDIR);
+ goto error;
+ } else {
+ ret = 0;
+ }
+ }
+
+error:
+ return ret;
+}
+
+/*
+ * Setup sockets and directory needed by the kconsumerd communication with the
+ * session daemon.
+ */
+static int set_consumer_sockets(struct consumer_data *consumer_data)
+{
+ int ret;
+ const char *path = consumer_data->type == LTTNG_CONSUMER_KERNEL ?
+ KCONSUMERD_PATH : USTCONSUMERD_PATH;
+
+ if (strlen(consumer_data->err_unix_sock_path) == 0) {
+ snprintf(consumer_data->err_unix_sock_path, PATH_MAX,
+ consumer_data->type == LTTNG_CONSUMER_KERNEL ?
+ KCONSUMERD_ERR_SOCK_PATH :
+ USTCONSUMERD_ERR_SOCK_PATH);
+ }
+
+ if (strlen(consumer_data->cmd_unix_sock_path) == 0) {
+ snprintf(consumer_data->cmd_unix_sock_path, PATH_MAX,
+ consumer_data->type == LTTNG_CONSUMER_KERNEL ?
+ KCONSUMERD_CMD_SOCK_PATH :
+ USTCONSUMERD_CMD_SOCK_PATH);
+ }
+
+ ret = mkdir(path, S_IRWXU | S_IRWXG);
+ if (ret < 0) {
+ if (errno != EEXIST) {
+ ERR("Failed to create %s", path);
+ goto error;
+ }
+ ret = 0;
+ }
+
+ /* Create the kconsumerd error unix socket */
+ consumer_data->err_sock =
+ lttcomm_create_unix_sock(consumer_data->err_unix_sock_path);
+ if (consumer_data->err_sock < 0) {
+ ERR("Create unix sock failed: %s", consumer_data->err_unix_sock_path);
+ ret = -1;
+ goto error;
+ }
+
+ /* File permission MUST be 660 */
+ ret = chmod(consumer_data->err_unix_sock_path,
+ S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
+ if (ret < 0) {
+ ERR("Set file permissions failed: %s", consumer_data->err_unix_sock_path);
+ perror("chmod");
+ goto error;
+ }
+
+error:
+ return ret;
+}
+
+/*
+ * Signal handler for the daemon
+ *
+ * Simply stop all worker threads, leaving main() return gracefully after
+ * joining all threads and calling cleanup().
+ */
+static void sighandler(int sig)
+{
+ switch (sig) {
+ case SIGPIPE:
+ DBG("SIGPIPE catched");
+ return;
+ case SIGINT:
+ DBG("SIGINT catched");
+ stop_threads();
+ break;
+ case SIGTERM:
+ DBG("SIGTERM catched");
+ stop_threads();
+ break;
+ default:
+ break;
+ }
+}
+
+/*
+ * Setup signal handler for :
+ * SIGINT, SIGTERM, SIGPIPE
+ */
+static int set_signal_handler(void)
+{
+ int ret = 0;
+ struct sigaction sa;
+ sigset_t sigset;
+
+ if ((ret = sigemptyset(&sigset)) < 0) {
+ perror("sigemptyset");
+ return ret;
+ }
+
+ sa.sa_handler = sighandler;
+ sa.sa_mask = sigset;
+ sa.sa_flags = 0;
+ if ((ret = sigaction(SIGTERM, &sa, NULL)) < 0) {
+ perror("sigaction");
+ return ret;
+ }
+
+ if ((ret = sigaction(SIGINT, &sa, NULL)) < 0) {
+ perror("sigaction");
+ return ret;
+ }
+
+ if ((ret = sigaction(SIGPIPE, &sa, NULL)) < 0) {
+ perror("sigaction");
+ return ret;
+ }
+
+ DBG("Signal handler set for SIGTERM, SIGPIPE and SIGINT");
+
+ return ret;
+}
+
+/*
+ * Set open files limit to unlimited. This daemon can open a large number of
+ * file descriptors in order to consumer multiple kernel traces.
+ */
+static void set_ulimit(void)
+{
+ int ret;
+ struct rlimit lim;
+
+ /* The kernel does not allowed an infinite limit for open files */
+ lim.rlim_cur = 65535;
+ lim.rlim_max = 65535;
+
+ ret = setrlimit(RLIMIT_NOFILE, &lim);
+ if (ret < 0) {
+ perror("failed to set open files limit");
+ }
+}
+
+/*
+ * main
+ */
+int main(int argc, char **argv)
+{
+ int ret = 0;
+ void *status;
+ const char *home_path;
+
+ rcu_register_thread();
+
+ /* Create thread quit pipe */
+ if ((ret = init_thread_quit_pipe()) < 0) {
+ goto error;
+ }
+
+ /* Parse arguments */
+ progname = argv[0];
+ if ((ret = parse_args(argc, argv) < 0)) {
+ goto error;
+ }
+
+ /* Daemonize */
+ if (opt_daemon) {
+ ret = daemon(0, 0);
+ if (ret < 0) {
+ perror("daemon");
+ goto error;
+ }
+ }
+
+ /* Check if daemon is UID = 0 */
+ is_root = !getuid();
+
+ if (is_root) {
+ ret = create_lttng_rundir();
+ if (ret < 0) {
+ goto error;
+ }
+
+ if (strlen(apps_unix_sock_path) == 0) {
+ snprintf(apps_unix_sock_path, PATH_MAX,
+ DEFAULT_GLOBAL_APPS_UNIX_SOCK);
+ }
+
+ if (strlen(client_unix_sock_path) == 0) {
+ snprintf(client_unix_sock_path, PATH_MAX,
+ DEFAULT_GLOBAL_CLIENT_UNIX_SOCK);
+ }
+
+ /* Set global SHM for ust */
+ if (strlen(wait_shm_path) == 0) {
+ snprintf(wait_shm_path, PATH_MAX,
+ DEFAULT_GLOBAL_APPS_WAIT_SHM_PATH);
+ }
+ } else {
+ home_path = get_home_dir();
+ if (home_path == NULL) {
+ /* TODO: Add --socket PATH option */
+ ERR("Can't get HOME directory for sockets creation.");
+ ret = -EPERM;
+ goto error;
+ }
+
+ if (strlen(apps_unix_sock_path) == 0) {
+ snprintf(apps_unix_sock_path, PATH_MAX,
+ DEFAULT_HOME_APPS_UNIX_SOCK, home_path);
+ }
+
+ /* Set the cli tool unix socket path */
+ if (strlen(client_unix_sock_path) == 0) {
+ snprintf(client_unix_sock_path, PATH_MAX,
+ DEFAULT_HOME_CLIENT_UNIX_SOCK, home_path);
+ }
+
+ /* Set global SHM for ust */
+ if (strlen(wait_shm_path) == 0) {
+ snprintf(wait_shm_path, PATH_MAX,
+ DEFAULT_HOME_APPS_WAIT_SHM_PATH, geteuid());
+ }
+ }
+
+ DBG("Client socket path %s", client_unix_sock_path);
+ DBG("Application socket path %s", apps_unix_sock_path);
+
+ /*
+ * See if daemon already exist.
+ */
+ if ((ret = check_existing_daemon()) < 0) {
+ ERR("Already running daemon.\n");
+ /*
+ * We do not goto exit because we must not cleanup()
+ * because a daemon is already running.
+ */
+ goto error;
+ }
+
+ /* After this point, we can safely call cleanup() with "goto exit" */
+
+ /*
+ * These actions must be executed as root. We do that *after* setting up
+ * the sockets path because we MUST make the check for another daemon using
+ * those paths *before* trying to set the kernel consumer sockets and init
+ * kernel tracer.
+ */
+ if (is_root) {
+ ret = set_consumer_sockets(&kconsumer_data);
+ if (ret < 0) {
+ goto exit;
+ }
+
+ ret = set_consumer_sockets(&ustconsumer_data);
+ if (ret < 0) {
+ goto exit;
+ }
+ /* Setup kernel tracer */
+ init_kernel_tracer();
+
+ /* Set ulimit for open files */
+ set_ulimit();
+ }
+
+ if ((ret = set_signal_handler()) < 0) {
+ goto exit;
+ }
+
+ /* Setup the needed unix socket */
+ if ((ret = init_daemon_socket()) < 0) {
+ goto exit;
+ }
+
+ /* Set credentials to socket */
+ if (is_root && ((ret = set_permissions()) < 0)) {
+ goto exit;
+ }
+
+ /* Get parent pid if -S, --sig-parent is specified. */
+ if (opt_sig_parent) {
+ ppid = getppid();
+ }
+
+ /* Setup the kernel pipe for waking up the kernel thread */
+ if ((ret = create_kernel_poll_pipe()) < 0) {
+ goto exit;
+ }
+
+ /* Setup the thread apps communication pipe. */
+ if ((ret = create_apps_cmd_pipe()) < 0) {
+ goto exit;
+ }
+
+ /* Init UST command queue. */
+ cds_wfq_init(&ust_cmd_queue.queue);
+
+ /* Init UST app hash table */
+ ust_app_ht_alloc();
+
+ /*
+ * Get session list pointer. This pointer MUST NOT be free(). This list is
+ * statically declared in session.c
+ */
+ session_list_ptr = session_get_list();
+
+ /* Set up max poll set size */
+ lttng_poll_set_max_size();
+
+ /* Create thread to manage the client socket */
+ ret = pthread_create(&client_thread, NULL,
+ thread_manage_clients, (void *) NULL);
+ if (ret != 0) {
+ perror("pthread_create clients");
+ goto exit_client;
+ }
+
+ /* Create thread to dispatch registration */
+ ret = pthread_create(&dispatch_thread, NULL,
+ thread_dispatch_ust_registration, (void *) NULL);
+ if (ret != 0) {
+ perror("pthread_create dispatch");
+ goto exit_dispatch;
+ }
+
+ /* Create thread to manage application registration. */
+ ret = pthread_create(®_apps_thread, NULL,
+ thread_registration_apps, (void *) NULL);
+ if (ret != 0) {
+ perror("pthread_create registration");
+ goto exit_reg_apps;
+ }
+
+ /* Create thread to manage application socket */
+ ret = pthread_create(&apps_thread, NULL,
+ thread_manage_apps, (void *) NULL);
+ if (ret != 0) {
+ perror("pthread_create apps");
+ goto exit_apps;
+ }
+
+ /* Create kernel thread to manage kernel event */
+ ret = pthread_create(&kernel_thread, NULL,
+ thread_manage_kernel, (void *) NULL);
+ if (ret != 0) {
+ perror("pthread_create kernel");
+ goto exit_kernel;
+ }
+
+ ret = pthread_join(kernel_thread, &status);
+ if (ret != 0) {
+ perror("pthread_join");
+ goto error; /* join error, exit without cleanup */
+ }
+
+exit_kernel:
+ ret = pthread_join(apps_thread, &status);
+ if (ret != 0) {
+ perror("pthread_join");
+ goto error; /* join error, exit without cleanup */
+ }
+
+exit_apps:
+ ret = pthread_join(reg_apps_thread, &status);
+ if (ret != 0) {
+ perror("pthread_join");
+ goto error; /* join error, exit without cleanup */
+ }
+
+exit_reg_apps:
+ ret = pthread_join(dispatch_thread, &status);
+ if (ret != 0) {
+ perror("pthread_join");
+ goto error; /* join error, exit without cleanup */
+ }
+
+exit_dispatch:
+ ret = pthread_join(client_thread, &status);
+ if (ret != 0) {
+ perror("pthread_join");
+ goto error; /* join error, exit without cleanup */
+ }
+
+ ret = join_consumer_thread(&kconsumer_data);
+ if (ret != 0) {
+ perror("join_consumer");
+ goto error; /* join error, exit without cleanup */
+ }
+
+exit_client:
+exit:
+ /*
+ * cleanup() is called when no other thread is running.
+ */
+ rcu_thread_online();
+ cleanup();
+ rcu_thread_offline();
+ rcu_unregister_thread();
+ if (!ret)
+ exit(EXIT_SUCCESS);
+error:
+ exit(EXIT_FAILURE);
+}
projects / lttng-tools.git / commitdiff
