X-Git-Url: https://git.liburcu.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng-relayd%2Fhealth-relayd.cpp;fp=src%2Fbin%2Flttng-relayd%2Fhealth-relayd.cpp;h=2e532bde4eec832b13895372ddb2b314b7fae180;hb=ac497a37018f3c253d2e50397294f58d33f7f24f;hp=0000000000000000000000000000000000000000;hpb=7966af5763c4aaca39df9bbfa9277ff15715c720;p=lttng-tools.git

diff --git a/src/bin/lttng-relayd/health-relayd.cpp b/src/bin/lttng-relayd/health-relayd.cpp
new file mode 100644
index 000000000..2e532bde4
--- /dev/null
+++ b/src/bin/lttng-relayd/health-relayd.cpp
@@ -0,0 +1,498 @@
+/*
+ * 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;
+}