--- /dev/null
+/*
+ * Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License, version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * 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., 51
+ * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#define _LGPL_SOURCE
+#include <lttng/trigger/trigger.h>
+#include <common/error.h>
+#include <common/config/session-config.h>
+#include <common/defaults.h>
+#include <common/utils.h>
+#include <sys/eventfd.h>
+#include <sys/stat.h>
+
+#include "notification-thread.h"
+#include "lttng-sessiond.h"
+#include "health-sessiond.h"
+
+/*
+ * Destroy the thread data previously created by the init function.
+ */
+void notification_destroy_data(struct notification_thread_data *data)
+{
+ int ret;
+
+ if (!data) {
+ goto end;
+ }
+
+ if (data->cmd_queue.event_fd < 0) {
+ goto end;
+ }
+ ret = close(data->cmd_queue.event_fd);
+ if (ret < 0) {
+ PERROR("close notification command queue event_fd");
+ }
+
+ /* TODO: purge queue and mark commands as cancelled. */
+end:
+ free(data);
+}
+
+/*
+ * Initialize the thread's data. This MUST be called before the notification
+ * thread is started.
+ */
+struct notification_thread_data *notification_init_data(void)
+{
+ struct notification_thread_data *data;
+
+ data = zmalloc(sizeof(*data));
+ if (!data) {
+ goto end;
+ }
+
+ data->cmd_queue.event_fd = eventfd(0, EFD_CLOEXEC);
+ if (data->cmd_queue.event_fd < 0) {
+ PERROR("eventfd notification command queue");
+ goto error;
+ }
+ cds_wfcq_init(&data->cmd_queue.head, &data->cmd_queue.tail);
+end:
+ return data;
+error:
+ notification_destroy_data(data);
+ return NULL;
+}
+
+static
+char *get_notification_channel_sock_path(void)
+{
+ int ret;
+ bool is_root = !getuid();
+ char *sock_path;
+
+ sock_path = zmalloc(LTTNG_PATH_MAX);
+ if (!sock_path) {
+ goto error;
+ }
+
+ if (is_root) {
+ ret = snprintf(sock_path, LTTNG_PATH_MAX,
+ DEFAULT_GLOBAL_NOTIFICATION_CHANNEL_UNIX_SOCK);
+ if (ret < 0) {
+ goto error;
+ }
+ } else {
+ char *home_path = utils_get_home_dir();
+
+ if (!home_path) {
+ ERR("Can't get HOME directory for socket creation");
+ goto error;
+ }
+ puts(home_path);
+
+ ret = snprintf(sock_path, LTTNG_PATH_MAX,
+ DEFAULT_HOME_NOTIFICATION_CHANNEL_UNIX_SOCK,
+ home_path);
+ if (ret < 0) {
+ goto error;
+ }
+ }
+
+ return sock_path;
+error:
+ free(sock_path);
+ return NULL;
+}
+
+static
+void notification_channel_socket_destroy(int fd)
+{
+ int ret;
+ char *sock_path = get_notification_channel_sock_path();
+
+ DBG("[notification-thread] Destroying notification channel socket");
+
+ if (sock_path) {
+ ret = unlink(sock_path);
+ free(sock_path);
+ if (ret < 0) {
+ PERROR("unlink notification channel socket");
+ }
+ }
+
+ ret = close(fd);
+ if (ret) {
+ PERROR("close notification channel socket");
+ }
+}
+
+static
+int notification_channel_socket_create(void)
+{
+ int fd = -1, ret;
+ char *sock_path = get_notification_channel_sock_path();
+
+ DBG("[notification-thread] Creating notification channel UNIX socket at %s",
+ sock_path);
+
+ ret = lttcomm_create_unix_sock(sock_path);
+ if (ret < 0) {
+ ERR("[notification-thread] Failed to create notification socket");
+ goto error;
+ }
+ fd = ret;
+
+ ret = chmod(sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
+ if (ret < 0) {
+ ERR("Set file permissions failed: %s", sock_path);
+ PERROR("chmod notification channel socket");
+ goto error;
+ }
+
+ DBG("[notification-thread] Notification channel UNIX socket created (fd = %i)",
+ fd);
+ free(sock_path);
+ return fd;
+error:
+ if (fd >= 0 && close(fd) < 0) {
+ PERROR("close notification channel socket");
+ }
+ free(sock_path);
+ return ret;
+}
+
+/*
+ * This thread services notification channel clients and received notifications
+ * from various lttng-sessiond components over a command queue.
+ */
+void *thread_notification(void *data)
+{
+ int ret;
+ struct lttng_poll_event events;
+ int notification_channel_socket;
+ struct notification_thread_data *ctx = data;
+
+ DBG("[notification-thread] Started notification thread");
+
+ if (!ctx) {
+ ERR("[notification-thread] Invalid thread context provided");
+ goto end;
+ }
+
+ rcu_register_thread();
+ rcu_thread_online();
+
+ health_register(health_sessiond, HEALTH_SESSIOND_TYPE_NOTIFICATION);
+ health_code_update();
+
+ notification_channel_socket = notification_channel_socket_create();
+
+ /*
+ * Create pollset with size 2, quit pipe and notification channel
+ * socket, and the command queue event fd.
+ */
+ ret = sessiond_set_thread_pollset(&events, 3);
+ if (ret < 0) {
+ goto error_poll_create;
+ }
+
+ /* Add notification channel socket to poll set. */
+ ret = lttng_poll_add(&events, notification_channel_socket,
+ LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP);
+ if (ret < 0) {
+ ERR("[notification-thread] Failed to add notification channel socket to pollset");
+ goto error;
+ }
+
+ ret = lttng_poll_add(&events, ctx->cmd_queue.event_fd,
+ LPOLLIN | LPOLLERR);
+ if (ret < 0) {
+ ERR("[notification-thread] Failed to add notification command queue event fd to pollset");
+ goto error;
+ }
+
+ DBG("[notification-thread] Listening on notification channel socket");
+ ret = lttcomm_listen_unix_sock(notification_channel_socket);
+ if (ret < 0) {
+ ERR("[notification-thread] Listen failed on notification channel socket");
+ goto error;
+ }
+
+ while (true) {
+ int fd_count, i;
+
+ health_poll_entry();
+ DBG("[notification-thread] Entering poll wait");
+ ret = lttng_poll_wait(&events, -1);
+ DBG("[notification-thread] Poll wait returned (%i)", ret);
+ health_poll_exit();
+ if (ret < 0) {
+ /*
+ * Restart interrupted system call.
+ */
+ if (errno == EINTR) {
+ continue;
+ }
+ ERR("[notification-thread] Error encountered during lttng_poll_wait (%i)", ret);
+ goto error;
+ }
+
+ fd_count = ret;
+ for (i = 0; i < fd_count; i++) {
+ int fd = LTTNG_POLL_GETFD(&events, i);
+ uint32_t revents = LTTNG_POLL_GETEV(&events, i);
+
+ /* Thread quit pipe has been closed. Killing thread. */
+ if (sessiond_check_thread_quit_pipe(fd, revents)) {
+ DBG("[notification-thread] Quit pipe signaled, exiting.");
+ goto exit;
+ }
+ }
+ }
+exit:
+
+error:
+ lttng_poll_clean(&events);
+error_poll_create:
+ notification_channel_socket_destroy(notification_channel_socket);
+ health_unregister(health_sessiond);
+ rcu_thread_offline();
+ rcu_unregister_thread();
+end:
+ return NULL;
+}
projects / lttng-tools.git / blobdiff