X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fhealth.c;fp=src%2Fbin%2Flttng-sessiond%2Fhealth.c;h=e2b8cc5a3e1b3794b75299737f064e9ac3fff220;hp=0000000000000000000000000000000000000000;hb=173fca4fb73279d919e1738b61e007231f43d519;hpb=a3707772aa2b063a321dd6d7dfb2ea369bc02c43 diff --git a/src/bin/lttng-sessiond/health.c b/src/bin/lttng-sessiond/health.c new file mode 100644 index 000000000..e2b8cc5a3 --- /dev/null +++ b/src/bin/lttng-sessiond/health.c @@ -0,0 +1,271 @@ +/* + * Copyright (C) 2012 - David Goulet + * Copyright (C) 2018 - Jérémie Galarneau + * + * 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. + */ + +#include "lttng-sessiond.h" +#include "health-sessiond.h" +#include +#include +#include +#include +#include +#include +#include "utils.h" +#include "thread.h" + +static void cleanup_health_management_thread(void *thread_data) +{ + struct lttng_pipe *quit_pipe = thread_data; + + lttng_pipe_destroy(quit_pipe); +} + +/* + * Thread managing health check socket. + */ +static void *thread_manage_health(void *thread_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 lttng_pipe *quit_pipe = thread_data; + const int quit_pipe_read_fd = lttng_pipe_get_readfd(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(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 */ + ret = chown(config.health_unix_sock_path.value, 0, + utils_get_group_id(config.tracing_group_name.value)); + if (ret < 0) { + ERR("Unable to set group on %s", config.health_unix_sock_path.value); + PERROR("chown"); + goto error; + } + + ret = chmod(config.health_unix_sock_path.value, + S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP); + if (ret < 0) { + ERR("Unable to set permissions on %s", 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; + } + + sessiond_notify_ready(); + + 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); + + if (!revents) { + /* No activity for this FD (poll implementation). */ + continue; + } + + /* 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(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(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 *thread_data) +{ + int ret; + int pipe_write_fd; + struct lttng_pipe *health_quit_pipe = thread_data; + + pipe_write_fd = lttng_pipe_get_writefd(health_quit_pipe); + ret = notify_thread_pipe(pipe_write_fd); + if (ret < 0) { + ERR("Failed to notify Health management thread's quit pipe"); + goto error; + } + return true; +error: + return false; +} + +bool launch_health_management_thread(void) +{ + struct lttng_thread *thread; + struct lttng_pipe *health_quit_pipe = NULL; + + health_quit_pipe = lttng_pipe_open(FD_CLOEXEC); + if (!health_quit_pipe) { + goto error; + } + + thread = lttng_thread_create("Health management", + thread_manage_health, + shutdown_health_management_thread, + cleanup_health_management_thread, + health_quit_pipe); + if (!thread) { + goto error; + } + lttng_thread_put(thread); + return true; +error: + cleanup_health_management_thread(health_quit_pipe); + return false; +}