--- /dev/null
+/*
+ * Copyright (C) 2012 David Goulet <dgoulet@efficios.com>
+ * Copyright (C) 2018 Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ *
+ */
+
+#include "lttng-sessiond.h"
+#include "health-sessiond.h"
+#include <common/macros.h>
+#include <common/error.h>
+#include <common/utils.h>
+#include <common/pipe.h>
+#include <inttypes.h>
+#include <sys/stat.h>
+#include "utils.h"
+#include "thread.h"
+
+struct thread_notifiers {
+ struct lttng_pipe *quit_pipe;
+ sem_t ready;
+};
+
+static
+void mark_thread_as_ready(struct thread_notifiers *notifiers)
+{
+ DBG("Marking health management thread as ready");
+ sem_post(¬ifiers->ready);
+}
+
+static
+void wait_until_thread_is_ready(struct thread_notifiers *notifiers)
+{
+ DBG("Waiting for health management thread to be ready");
+ sem_wait(¬ifiers->ready);
+ DBG("Health management thread is ready");
+}
+
+static void cleanup_health_management_thread(void *data)
+{
+ struct thread_notifiers *notifiers = (thread_notifiers *) data;
+
+ lttng_pipe_destroy(notifiers->quit_pipe);
+ sem_destroy(¬ifiers->ready);
+ free(notifiers);
+}
+
+/*
+ * Thread managing health check socket.
+ */
+static void *thread_manage_health(void *data)
+{
+ const bool is_root = (getuid() == 0);
+ int sock = -1, new_sock = -1, ret, i, pollfd, err = -1;
+ uint32_t revents, nb_fd;
+ struct lttng_poll_event events;
+ struct health_comm_msg msg;
+ struct health_comm_reply reply;
+ /* Thread-specific quit pipe. */
+ struct thread_notifiers *notifiers = (thread_notifiers *) data;
+ const int quit_pipe_read_fd = lttng_pipe_get_readfd(
+ notifiers->quit_pipe);
+
+ DBG("[thread] Manage health check started");
+
+ rcu_register_thread();
+
+ /*
+ * Created with a size of two for:
+ * - client socket
+ * - thread quit pipe
+ */
+ ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* Create unix socket */
+ sock = lttcomm_create_unix_sock(the_config.health_unix_sock_path.value);
+ if (sock < 0) {
+ ERR("Unable to create health check Unix socket");
+ goto error;
+ }
+
+ if (is_root) {
+ /* lttng health client socket path permissions */
+ gid_t gid;
+
+ ret = utils_get_group_id(the_config.tracing_group_name.value, true, &gid);
+ if (ret) {
+ /* Default to root group. */
+ gid = 0;
+ }
+
+ ret = chown(the_config.health_unix_sock_path.value, 0, gid);
+ if (ret < 0) {
+ ERR("Unable to set group on %s", the_config.health_unix_sock_path.value);
+ PERROR("chown");
+ goto error;
+ }
+
+ ret = chmod(the_config.health_unix_sock_path.value,
+ S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
+ if (ret < 0) {
+ ERR("Unable to set permissions on %s", the_config.health_unix_sock_path.value);
+ PERROR("chmod");
+ goto error;
+ }
+ }
+
+ /*
+ * Set the CLOEXEC flag. Return code is useless because either way, the
+ * show must go on.
+ */
+ (void) utils_set_fd_cloexec(sock);
+
+ ret = lttcomm_listen_unix_sock(sock);
+ if (ret < 0) {
+ goto error;
+ }
+
+ ret = lttng_poll_add(&events, quit_pipe_read_fd, LPOLLIN | LPOLLERR);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* Add the application registration socket */
+ ret = lttng_poll_add(&events, sock, LPOLLIN | LPOLLPRI);
+ if (ret < 0) {
+ goto error;
+ }
+
+ mark_thread_as_ready(notifiers);
+ while (1) {
+ DBG("Health check ready");
+
+ /* Infinite blocking call, waiting for transmission */
+restart:
+ ret = lttng_poll_wait(&events, -1);
+ if (ret < 0) {
+ /*
+ * Restart interrupted system call.
+ */
+ if (errno == EINTR) {
+ goto restart;
+ }
+ goto error;
+ }
+
+ nb_fd = ret;
+
+ for (i = 0; i < nb_fd; i++) {
+ /* Fetch once the poll data */
+ revents = LTTNG_POLL_GETEV(&events, i);
+ pollfd = LTTNG_POLL_GETFD(&events, i);
+
+ /* Event on the registration socket */
+ if (pollfd == sock) {
+ if (revents & LPOLLIN) {
+ continue;
+ } else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+ ERR("Health socket poll error");
+ goto error;
+ } else {
+ ERR("Unexpected poll events %u for sock %d", revents, pollfd);
+ goto error;
+ }
+ } else {
+ /* Event on the thread's quit pipe. */
+ err = 0;
+ goto exit;
+ }
+ }
+
+ new_sock = lttcomm_accept_unix_sock(sock);
+ if (new_sock < 0) {
+ goto error;
+ }
+
+ /*
+ * Set the CLOEXEC flag. Return code is useless because either way, the
+ * show must go on.
+ */
+ (void) utils_set_fd_cloexec(new_sock);
+
+ DBG("Receiving data from client for health...");
+ ret = lttcomm_recv_unix_sock(new_sock, (void *)&msg, sizeof(msg));
+ if (ret <= 0) {
+ DBG("Nothing recv() from client... continuing");
+ ret = close(new_sock);
+ if (ret) {
+ PERROR("close");
+ }
+ continue;
+ }
+
+ rcu_thread_online();
+
+ memset(&reply, 0, sizeof(reply));
+ for (i = 0; i < NR_HEALTH_SESSIOND_TYPES; i++) {
+ /*
+ * health_check_state returns 0 if health is
+ * bad.
+ */
+ if (!health_check_state(the_health_sessiond, i)) {
+ reply.ret_code |= 1ULL << i;
+ }
+ }
+
+ DBG2("Health check return value %" PRIx64, reply.ret_code);
+
+ ret = lttcomm_send_unix_sock(new_sock, (void *) &reply,
+ sizeof(reply));
+ if (ret < 0) {
+ ERR("Failed to send health data back to client");
+ }
+
+ /* End of transmission */
+ ret = close(new_sock);
+ if (ret) {
+ PERROR("close");
+ }
+ }
+
+exit:
+error:
+ if (err) {
+ ERR("Health error occurred in %s", __func__);
+ }
+ DBG("Health check thread dying");
+ unlink(the_config.health_unix_sock_path.value);
+ if (sock >= 0) {
+ ret = close(sock);
+ if (ret) {
+ PERROR("close");
+ }
+ }
+
+ lttng_poll_clean(&events);
+ rcu_unregister_thread();
+ return NULL;
+}
+
+static bool shutdown_health_management_thread(void *data)
+{
+ struct thread_notifiers *notifiers = ( thread_notifiers *) data;
+ const int write_fd = lttng_pipe_get_writefd(notifiers->quit_pipe);
+
+ return notify_thread_pipe(write_fd) == 1;
+}
+
+bool launch_health_management_thread(void)
+{
+ struct thread_notifiers *notifiers;
+ struct lttng_thread *thread;
+
+ notifiers = (thread_notifiers *) zmalloc(sizeof(*notifiers));
+ if (!notifiers) {
+ goto error_alloc;
+ }
+
+ sem_init(¬ifiers->ready, 0, 0);
+ notifiers->quit_pipe = lttng_pipe_open(FD_CLOEXEC);
+ if (!notifiers->quit_pipe) {
+ goto error;
+ }
+ thread = lttng_thread_create("Health management",
+ thread_manage_health,
+ shutdown_health_management_thread,
+ cleanup_health_management_thread,
+ notifiers);
+ if (!thread) {
+ goto error;
+ }
+
+ wait_until_thread_is_ready(notifiers);
+ lttng_thread_put(thread);
+ return true;
+error:
+ cleanup_health_management_thread(notifiers);
+error_alloc:
+ return false;
+}
projects / lttng-tools.git / blobdiff