--- /dev/null
+/*
+ * Copyright (C) 2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ *
+ */
+
+#define _LGPL_SOURCE
+#include <fcntl.h>
+#include <getopt.h>
+#include <grp.h>
+#include <limits.h>
+#include <pthread.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ipc.h>
+#include <sys/resource.h>
+#include <sys/shm.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <urcu/list.h>
+#include <poll.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <urcu/compiler.h>
+#include <inttypes.h>
+
+#include <common/defaults.h>
+#include <common/common.h>
+#include <common/consumer/consumer.h>
+#include <common/consumer/consumer-timer.h>
+#include <common/compat/poll.h>
+#include <common/sessiond-comm/sessiond-comm.h>
+#include <common/utils.h>
+#include <common/compat/getenv.h>
+#include <common/fd-tracker/utils.h>
+
+#include "lttng-relayd.h"
+#include "health-relayd.h"
+
+/* Global health check unix path */
+static
+char health_unix_sock_path[PATH_MAX];
+
+int health_quit_pipe[2] = { -1, -1 };
+
+/*
+ * Check if the thread quit pipe was triggered.
+ *
+ * Return 1 if it was triggered else 0;
+ */
+static
+int check_health_quit_pipe(int fd, uint32_t events)
+{
+ if (fd == health_quit_pipe[0] && (events & LPOLLIN)) {
+ return 1;
+ }
+
+ return 0;
+}
+
+/*
+ * 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);
+}
+
+static int create_lttng_rundir_with_perm(const char *rundir)
+{
+ int ret;
+
+ DBG3("Creating LTTng run directory: %s", rundir);
+
+ ret = mkdir(rundir, S_IRWXU);
+ if (ret < 0) {
+ if (errno != EEXIST) {
+ ERR("Unable to create %s", rundir);
+ goto error;
+ } else {
+ ret = 0;
+ }
+ } else if (ret == 0) {
+ int is_root = !getuid();
+
+ if (is_root) {
+ gid_t gid;
+
+ ret = utils_get_group_id(tracing_group_name, true, &gid);
+ if (ret) {
+ /* Default to root group. */
+ gid = 0;
+ }
+
+ ret = chown(rundir, 0, gid);
+ if (ret < 0) {
+ ERR("Unable to set group on %s", rundir);
+ PERROR("chown");
+ ret = -1;
+ goto error;
+ }
+
+ ret = chmod(rundir,
+ S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH);
+ if (ret < 0) {
+ ERR("Unable to set permissions on %s", health_unix_sock_path);
+ PERROR("chmod");
+ ret = -1;
+ goto error;
+ }
+ }
+ }
+
+error:
+ return ret;
+}
+
+static
+int parse_health_env(void)
+{
+ const char *health_path;
+
+ health_path = lttng_secure_getenv(LTTNG_RELAYD_HEALTH_ENV);
+ if (health_path) {
+ strncpy(health_unix_sock_path, health_path,
+ PATH_MAX);
+ health_unix_sock_path[PATH_MAX - 1] = '\0';
+ }
+
+ return 0;
+}
+
+static
+int setup_health_path(void)
+{
+ int is_root, ret = 0;
+ const char *home_path = NULL;
+ char *rundir = NULL, *relayd_path = NULL;
+
+ ret = parse_health_env();
+ if (ret) {
+ return ret;
+ }
+
+ is_root = !getuid();
+
+ if (is_root) {
+ rundir = strdup(DEFAULT_LTTNG_RUNDIR);
+ if (!rundir) {
+ ret = -ENOMEM;
+ goto end;
+ }
+ } else {
+ /*
+ * Create rundir from home path. This will create something like
+ * $HOME/.lttng
+ */
+ home_path = utils_get_home_dir();
+
+ if (home_path == NULL) {
+ /* TODO: Add --socket PATH option */
+ ERR("Can't get HOME directory for sockets creation.");
+ ret = -EPERM;
+ goto end;
+ }
+
+ ret = asprintf(&rundir, DEFAULT_LTTNG_HOME_RUNDIR, home_path);
+ if (ret < 0) {
+ ret = -ENOMEM;
+ goto end;
+ }
+ }
+
+ ret = asprintf(&relayd_path, DEFAULT_RELAYD_PATH, rundir);
+ if (ret < 0) {
+ ret = -ENOMEM;
+ goto end;
+ }
+
+ ret = create_lttng_rundir_with_perm(rundir);
+ if (ret < 0) {
+ goto end;
+ }
+
+ ret = create_lttng_rundir_with_perm(relayd_path);
+ if (ret < 0) {
+ goto end;
+ }
+
+ if (is_root) {
+ if (strlen(health_unix_sock_path) != 0) {
+ goto end;
+ }
+ snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
+ DEFAULT_GLOBAL_RELAY_HEALTH_UNIX_SOCK,
+ (int) getpid());
+ } else {
+ /* Set health check Unix path */
+ if (strlen(health_unix_sock_path) != 0) {
+ goto end;
+ }
+
+ snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
+ DEFAULT_HOME_RELAY_HEALTH_UNIX_SOCK,
+ home_path, (int) getpid());
+ }
+
+end:
+ free(rundir);
+ free(relayd_path);
+ return ret;
+}
+
+static
+int accept_unix_socket(void *data, int *out_fd)
+{
+ int ret;
+ int accepting_sock = *((int *) data);
+
+ ret = lttcomm_accept_unix_sock(accepting_sock);
+ if (ret < 0) {
+ goto end;
+ }
+
+ *out_fd = ret;
+ ret = 0;
+end:
+ return ret;
+}
+
+static
+int open_unix_socket(void *data, int *out_fd)
+{
+ int ret;
+ const char *path = (const char *) data;
+
+ ret = lttcomm_create_unix_sock(path);
+ if (ret < 0) {
+ goto end;
+ }
+
+ *out_fd = ret;
+ ret = 0;
+end:
+ return ret;
+}
+
+/*
+ * Thread managing health check socket.
+ */
+void *thread_manage_health(void *data)
+{
+ 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;
+ int is_root;
+ char *sock_name;
+
+ DBG("[thread] Manage health check started");
+
+ setup_health_path();
+
+ rcu_register_thread();
+
+ /* We might hit an error path before this is created. */
+ lttng_poll_init(&events);
+
+ /* Create unix socket */
+ ret = asprintf(&sock_name, "Unix socket @ %s", health_unix_sock_path);
+ if (ret == -1) {
+ PERROR("Failed to allocate unix socket name");
+ err = -1;
+ goto error;
+ }
+ ret = fd_tracker_open_unsuspendable_fd(the_fd_tracker, &sock,
+ (const char **) &sock_name, 1, open_unix_socket,
+ health_unix_sock_path);
+ free(sock_name);
+ if (ret < 0) {
+ ERR("Unable to create health check Unix socket");
+ err = -1;
+ goto error;
+ }
+
+ is_root = !getuid();
+ if (is_root) {
+ /* lttng health client socket path permissions */
+ gid_t gid;
+
+ ret = utils_get_group_id(tracing_group_name, true, &gid);
+ if (ret) {
+ /* Default to root group. */
+ gid = 0;
+ }
+
+ ret = chown(health_unix_sock_path, 0, gid);
+ if (ret < 0) {
+ ERR("Unable to set group on %s", health_unix_sock_path);
+ PERROR("chown");
+ err = -1;
+ goto error;
+ }
+
+ ret = chmod(health_unix_sock_path,
+ S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
+ if (ret < 0) {
+ ERR("Unable to set permissions on %s", health_unix_sock_path);
+ PERROR("chmod");
+ err = -1;
+ 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;
+ }
+
+ /* Size is set to 2 for the unix socket and quit pipe. */
+ ret = fd_tracker_util_poll_create(the_fd_tracker,
+ "Health management thread epoll", &events, 2,
+ LTTNG_CLOEXEC);
+ if (ret < 0) {
+ ERR("Poll set creation failed");
+ goto error;
+ }
+
+ ret = lttng_poll_add(&events, health_quit_pipe[0], LPOLLIN);
+ if (ret < 0) {
+ goto error;
+ }
+
+ /* Add the application registration socket */
+ ret = lttng_poll_add(&events, sock, LPOLLIN | LPOLLPRI);
+ if (ret < 0) {
+ goto error;
+ }
+
+ lttng_relay_notify_ready();
+
+ while (1) {
+ char *accepted_socket_name;
+
+ DBG("Health check ready");
+
+ /* Inifinite 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);
+
+ /* Thread quit pipe has been closed. Killing thread. */
+ ret = check_health_quit_pipe(pollfd, revents);
+ if (ret) {
+ err = 0;
+ goto exit;
+ }
+
+ /* 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;
+ }
+ }
+ }
+
+ ret = asprintf(&accepted_socket_name, "Socket accepted from unix socket @ %s",
+ health_unix_sock_path);
+ if (ret == -1) {
+ PERROR("Failed to allocate name of accepted socket from unix socket @ %s",
+ health_unix_sock_path);
+ goto error;
+ }
+ ret = fd_tracker_open_unsuspendable_fd(the_fd_tracker, &new_sock,
+ (const char **) &accepted_socket_name, 1,
+ accept_unix_socket, &sock);
+ free(accepted_socket_name);
+ if (ret < 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 = fd_tracker_close_unsuspendable_fd(the_fd_tracker,
+ &new_sock, 1, fd_tracker_util_close_fd,
+ NULL);
+ if (ret) {
+ PERROR("close");
+ }
+ new_sock = -1;
+ continue;
+ }
+
+ rcu_thread_online();
+
+ LTTNG_ASSERT(msg.cmd == HEALTH_CMD_CHECK);
+
+ memset(&reply, 0, sizeof(reply));
+ for (i = 0; i < NR_HEALTH_RELAYD_TYPES; i++) {
+ /*
+ * health_check_state return 0 if thread is in
+ * error.
+ */
+ if (!health_check_state(health_relayd, i)) {
+ reply.ret_code |= 1ULL << i;
+ }
+ }
+
+ DBG2("Health check return value %" PRIx64, reply.ret_code);
+
+ ret = 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 = fd_tracker_close_unsuspendable_fd(the_fd_tracker,
+ &new_sock, 1, fd_tracker_util_close_fd,
+ NULL);
+ if (ret) {
+ PERROR("close");
+ }
+ new_sock = -1;
+ }
+
+error:
+ lttng_relay_stop_threads();
+exit:
+ if (err) {
+ ERR("Health error occurred in %s", __func__);
+ }
+ DBG("Health check thread dying");
+ unlink(health_unix_sock_path);
+ if (sock >= 0) {
+ ret = fd_tracker_close_unsuspendable_fd(the_fd_tracker, &sock,
+ 1, fd_tracker_util_close_fd, NULL);
+ if (ret) {
+ PERROR("close");
+ }
+ }
+
+ /*
+ * We do NOT rmdir rundir nor the relayd path because there are
+ * other processes using them.
+ */
+
+ (void) fd_tracker_util_poll_clean(the_fd_tracker, &events);
+
+ rcu_unregister_thread();
+ return NULL;
+}
projects / lttng-tools.git / blobdiff