bin: compile lttng-consumerd as a C++
[lttng-tools.git] / src / bin / lttng-consumerd / health-consumerd.cpp
diff --git a/src/bin/lttng-consumerd/health-consumerd.cpp b/src/bin/lttng-consumerd/health-consumerd.cpp
new file mode 100644 (file)
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+/*
+ * 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 <ulimit.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 "lttng-consumerd.h"
+#include "health-consumerd.h"
+
+/* Global health check unix path */
+static char health_unix_sock_path[PATH_MAX];
+
+int health_quit_pipe[2];
+
+/*
+ * 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 setup_health_path(void)
+{
+       int is_root, ret = 0;
+       enum lttng_consumer_type type;
+       const char *home_path;
+
+       type = lttng_consumer_get_type();
+       is_root = !getuid();
+
+       if (is_root) {
+               if (strlen(health_unix_sock_path) != 0) {
+                       goto end;
+               }
+               switch (type) {
+               case LTTNG_CONSUMER_KERNEL:
+                       snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
+                               DEFAULT_GLOBAL_KCONSUMER_HEALTH_UNIX_SOCK);
+                       break;
+               case LTTNG_CONSUMER64_UST:
+                       snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
+                               DEFAULT_GLOBAL_USTCONSUMER64_HEALTH_UNIX_SOCK);
+                       break;
+               case LTTNG_CONSUMER32_UST:
+                       snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
+                               DEFAULT_GLOBAL_USTCONSUMER32_HEALTH_UNIX_SOCK);
+                       break;
+               default:
+                       ret = -EINVAL;
+                       goto end;
+               }
+       } else {
+               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;
+               }
+
+               /* Set health check Unix path */
+               if (strlen(health_unix_sock_path) != 0) {
+                       goto end;
+               }
+               switch (type) {
+               case LTTNG_CONSUMER_KERNEL:
+                       snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
+                               DEFAULT_HOME_KCONSUMER_HEALTH_UNIX_SOCK, home_path);
+                       break;
+               case LTTNG_CONSUMER64_UST:
+                       snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
+                               DEFAULT_HOME_USTCONSUMER64_HEALTH_UNIX_SOCK, home_path);
+                       break;
+               case LTTNG_CONSUMER32_UST:
+                       snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
+                               DEFAULT_HOME_USTCONSUMER32_HEALTH_UNIX_SOCK, home_path);
+                       break;
+               default:
+                       ret = -EINVAL;
+                       goto end;
+               }
+       }
+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;
+
+       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 */
+       sock = lttcomm_create_unix_sock(health_unix_sock_path);
+       if (sock < 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 1 for the consumer_channel pipe */
+       ret = lttng_poll_create(&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;
+       }
+
+       /* Perform prior memory accesses before decrementing ready */
+       cmm_smp_mb__before_uatomic_dec();
+       uatomic_dec(&lttng_consumer_ready);
+
+       while (1) {
+               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 & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)
+                                               && !(revents & LPOLLIN)) {
+                                       ERR("Health socket poll error");
+                                       goto error;
+                               }
+                       }
+               }
+
+               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");
+                       }
+                       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_CONSUMERD_TYPES; i++) {
+                       /*
+                        * health_check_state return 0 if thread is in
+                        * error.
+                        */
+                       if (!health_check_state(health_consumerd, i)) {
+                               reply.ret_code |= 1ULL << i;
+                       }
+               }
+
+               DBG("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 = close(new_sock);
+               if (ret) {
+                       PERROR("close");
+               }
+               new_sock = -1;
+       }
+
+exit:
+error:
+       if (err) {
+               ERR("Health error occurred in %s", __func__);
+       }
+       DBG("Health check thread dying");
+       unlink(health_unix_sock_path);
+       if (sock >= 0) {
+               ret = close(sock);
+               if (ret) {
+                       PERROR("close");
+               }
+       }
+
+       lttng_poll_clean(&events);
+
+       rcu_unregister_thread();
+       return NULL;
+}
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