[lttng-tools.git] / src / bin / lttng-relayd / health-relayd.cpp

/*
 * Copyright (C) 2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 */

#define _LGPL_SOURCE
#include "health-relayd.hpp"
#include "lttng-relayd.hpp"

#include <common/common.hpp>
#include <common/compat/getenv.hpp>
#include <common/compat/poll.hpp>
#include <common/consumer/consumer-timer.hpp>
#include <common/consumer/consumer.hpp>
#include <common/defaults.hpp>
#include <common/fd-tracker/utils.hpp>
#include <common/sessiond-comm/sessiond-comm.hpp>
#include <common/utils.hpp>

#include <fcntl.h>
#include <getopt.h>
#include <grp.h>
#include <inttypes.h>
#include <limits.h>
#include <poll.h>
#include <pthread.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ipc.h>
#include <sys/mman.h>
#include <sys/resource.h>
#include <sys/shm.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <urcu/compiler.h>
#include <urcu/list.h>

/* Global health check unix path */
static char health_unix_sock_path[PATH_MAX];

int health_quit_pipe[2] = { -1, -1 };

/*
 * 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", rundir);
				PERROR("chmod");
				ret = -1;
				goto error;
			}
		}
	}

error:
	return ret;
}

static int parse_health_env()
{
	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()
{
	int is_root, ret = 0;
	const char *home_path = nullptr;
	char *rundir = nullptr, *relayd_path = nullptr;

	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 == nullptr) {
			/* 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_relayd(void *data __attribute__((unused)))
{
	int sock = -1, new_sock = -1, ret, i, err = -1;
	uint32_t 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 (true) {
		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 */
			const auto revents = LTTNG_POLL_GETEV(&events, i);
			const auto pollfd = LTTNG_POLL_GETFD(&events, i);

			/* Activity on thread quit pipe, exiting. */
			if (pollfd == health_quit_pipe[0]) {
				DBG("Activity on thread quit pipe");
				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, nullptr);
			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, nullptr);
		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, nullptr);
		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 nullptr;
}
Commit	Line	Data
65931c8b	1	/*
ab5be9fa	2	* Copyright (C) 2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
65931c8b	3	*
ab5be9fa	4	* SPDX-License-Identifier: GPL-2.0-only
65931c8b	5	*
65931c8b MD	6	*/
65931c8b MD	7
6c1c0768	8	#define _LGPL_SOURCE
28ab034a JG	9	#include "health-relayd.hpp"
	10	#include "lttng-relayd.hpp"
	11
	12	#include <common/common.hpp>
	13	#include <common/compat/getenv.hpp>
	14	#include <common/compat/poll.hpp>
	15	#include <common/consumer/consumer-timer.hpp>
	16	#include <common/consumer/consumer.hpp>
	17	#include <common/defaults.hpp>
	18	#include <common/fd-tracker/utils.hpp>
	19	#include <common/sessiond-comm/sessiond-comm.hpp>
	20	#include <common/utils.hpp>
	21
65931c8b MD	22	#include <fcntl.h>
	23	#include <getopt.h>
	24	#include <grp.h>
28ab034a	25	#include <inttypes.h>
65931c8b	26	#include <limits.h>
28ab034a	27	#include <poll.h>
65931c8b MD	28	#include <pthread.h>
	29	#include <signal.h>
	30	#include <stdio.h>
	31	#include <stdlib.h>
	32	#include <string.h>
	33	#include <sys/ipc.h>
28ab034a	34	#include <sys/mman.h>
65931c8b MD	35	#include <sys/resource.h>
	36	#include <sys/shm.h>
	37	#include <sys/socket.h>
	38	#include <sys/stat.h>
	39	#include <sys/types.h>
65931c8b	40	#include <unistd.h>
65931c8b	41	#include <urcu/compiler.h>
28ab034a	42	#include <urcu/list.h>
65931c8b MD	43
65931c8b MD	44	/* Global health check unix path */
28ab034a	45	static char health_unix_sock_path[PATH_MAX];
65931c8b	46
794e2e5f	47	int health_quit_pipe[2] = { -1, -1 };
65931c8b	48
65931c8b MD	49	/*
	50	* Send data on a unix socket using the liblttsessiondcomm API.
	51	*
	52	* Return lttcomm error code.
	53	*/
	54	static int send_unix_sock(int sock, void *buf, size_t len)
	55	{
	56	/* Check valid length */
	57	if (len == 0) {
	58	return -1;
	59	}
	60
	61	return lttcomm_send_unix_sock(sock, buf, len);
	62	}
	63
	64	static int create_lttng_rundir_with_perm(const char *rundir)
	65	{
	66	int ret;
	67
	68	DBG3("Creating LTTng run directory: %s", rundir);
	69
	70	ret = mkdir(rundir, S_IRWXU);
	71	if (ret < 0) {
	72	if (errno != EEXIST) {
	73	ERR("Unable to create %s", rundir);
	74	goto error;
	75	} else {
	76	ret = 0;
	77	}
	78	} else if (ret == 0) {
	79	int is_root = !getuid();
	80
	81	if (is_root) {
28ab59d0 JR	82	gid_t gid;
	83
	84	ret = utils_get_group_id(tracing_group_name, true, &gid);
	85	if (ret) {
	86	/* Default to root group. */
	87	gid = 0;
	88	}
	89
	90	ret = chown(rundir, 0, gid);
65931c8b MD	91	if (ret < 0) {
	92	ERR("Unable to set group on %s", rundir);
	93	PERROR("chown");
	94	ret = -1;
	95	goto error;
	96	}
	97
	98	ret = chmod(rundir,
28ab034a JG	99	S_IRUSR \| S_IWUSR \| S_IXUSR \| S_IRGRP \| S_IXGRP \| S_IROTH \|
28ab034a JG	100	S_IXOTH);
65931c8b	101	if (ret < 0) {
f7b09ec2	102	ERR("Unable to set permissions on %s", rundir);
65931c8b MD	103	PERROR("chmod");
	104	ret = -1;
	105	goto error;
	106	}
	107	}
	108	}
	109
	110	error:
	111	return ret;
	112	}
	113
cd9adb8b	114	static int parse_health_env()
094fe907 MD	115	{
	116	const char *health_path;
	117
e8fa9fb0	118	health_path = lttng_secure_getenv(LTTNG_RELAYD_HEALTH_ENV);
094fe907	119	if (health_path) {
28ab034a	120	strncpy(health_unix_sock_path, health_path, PATH_MAX);
094fe907 MD	121	health_unix_sock_path[PATH_MAX - 1] = '\0';
	122	}
	123
	124	return 0;
	125	}
	126
cd9adb8b	127	static int setup_health_path()
65931c8b MD	128	{
65931c8b MD	129	int is_root, ret = 0;
cd9adb8b JG	130	const char *home_path = nullptr;
cd9adb8b JG	131	char rundir = nullptr, relayd_path = nullptr;
65931c8b	132
094fe907 MD	133	ret = parse_health_env();
	134	if (ret) {
	135	return ret;
	136	}
	137
65931c8b MD	138	is_root = !getuid();
	139
	140	if (is_root) {
c3844e39	141	rundir = strdup(DEFAULT_LTTNG_RUNDIR);
b6ab01aa MD	142	if (!rundir) {
	143	ret = -ENOMEM;
	144	goto end;
	145	}
65931c8b MD	146	} else {
	147	/*
	148	* Create rundir from home path. This will create something like
	149	* $HOME/.lttng
	150	*/
	151	home_path = utils_get_home_dir();
	152
cd9adb8b	153	if (home_path == nullptr) {
65931c8b MD	154	/* TODO: Add --socket PATH option */
	155	ERR("Can't get HOME directory for sockets creation.");
	156	ret = -EPERM;
	157	goto end;
	158	}
	159
c3844e39	160	ret = asprintf(&rundir, DEFAULT_LTTNG_HOME_RUNDIR, home_path);
65931c8b MD	161	if (ret < 0) {
	162	ret = -ENOMEM;
	163	goto end;
	164	}
	165	}
	166
c3844e39	167	ret = asprintf(&relayd_path, DEFAULT_RELAYD_PATH, rundir);
65931c8b MD	168	if (ret < 0) {
	169	ret = -ENOMEM;
	170	goto end;
	171	}
	172
c3844e39	173	ret = create_lttng_rundir_with_perm(rundir);
65931c8b MD	174	if (ret < 0) {
	175	goto end;
	176	}
	177
	178	ret = create_lttng_rundir_with_perm(relayd_path);
	179	if (ret < 0) {
	180	goto end;
	181	}
	182
	183	if (is_root) {
	184	if (strlen(health_unix_sock_path) != 0) {
	185	goto end;
	186	}
28ab034a JG	187	snprintf(health_unix_sock_path,
	188	sizeof(health_unix_sock_path),
	189	DEFAULT_GLOBAL_RELAY_HEALTH_UNIX_SOCK,
	190	(int) getpid());
65931c8b MD	191	} else {
	192	/* Set health check Unix path */
	193	if (strlen(health_unix_sock_path) != 0) {
	194	goto end;
	195	}
	196
28ab034a JG	197	snprintf(health_unix_sock_path,
	198	sizeof(health_unix_sock_path),
	199	DEFAULT_HOME_RELAY_HEALTH_UNIX_SOCK,
	200	home_path,
	201	(int) getpid());
65931c8b MD	202	}
	203
	204	end:
c3844e39	205	free(rundir);
edd94901	206	free(relayd_path);
65931c8b MD	207	return ret;
	208	}
	209
28ab034a	210	static int accept_unix_socket(void data, int out_fd)
1c9bd75b JG	211	{
	212	int ret;
	213	int accepting_sock = ((int ) data);
	214
	215	ret = lttcomm_accept_unix_sock(accepting_sock);
	216	if (ret < 0) {
	217	goto end;
	218	}
	219
	220	*out_fd = ret;
	221	ret = 0;
	222	end:
	223	return ret;
	224	}
	225
28ab034a	226	static int open_unix_socket(void data, int out_fd)
d7eddab9 JG	227	{
d7eddab9 JG	228	int ret;
ac497a37	229	const char path = (const char ) data;
d7eddab9 JG	230
	231	ret = lttcomm_create_unix_sock(path);
	232	if (ret < 0) {
	233	goto end;
	234	}
	235
	236	*out_fd = ret;
	237	ret = 0;
	238	end:
	239	return ret;
	240	}
	241
65931c8b MD	242	/*
	243	* Thread managing health check socket.
	244	*/
f46376a1	245	void thread_manage_health_relayd(void data __attribute__((unused)))
65931c8b	246	{
8a00688e MJ	247	int sock = -1, new_sock = -1, ret, i, err = -1;
8a00688e MJ	248	uint32_t nb_fd;
65931c8b MD	249	struct lttng_poll_event events;
	250	struct health_comm_msg msg;
	251	struct health_comm_reply reply;
	252	int is_root;
d7eddab9	253	char *sock_name;
65931c8b MD	254
	255	DBG("[thread] Manage health check started");
	256
	257	setup_health_path();
	258
	259	rcu_register_thread();
	260
	261	/* We might hit an error path before this is created. */
	262	lttng_poll_init(&events);
	263
	264	/* Create unix socket */
d7eddab9 JG	265	ret = asprintf(&sock_name, "Unix socket @ %s", health_unix_sock_path);
	266	if (ret == -1) {
	267	PERROR("Failed to allocate unix socket name");
	268	err = -1;
	269	goto error;
	270	}
28ab034a JG	271	ret = fd_tracker_open_unsuspendable_fd(the_fd_tracker,
	272	&sock,
	273	(const char **) &sock_name,
	274	1,
	275	open_unix_socket,
	276	health_unix_sock_path);
d7eddab9 JG	277	free(sock_name);
d7eddab9 JG	278	if (ret < 0) {
65931c8b	279	ERR("Unable to create health check Unix socket");
7568ddbf	280	err = -1;
65931c8b MD	281	goto error;
	282	}
	283
	284	is_root = !getuid();
	285	if (is_root) {
	286	/* lttng health client socket path permissions */
28ab59d0 JR	287	gid_t gid;
	288
	289	ret = utils_get_group_id(tracing_group_name, true, &gid);
	290	if (ret) {
	291	/* Default to root group. */
	292	gid = 0;
	293	}
	294
	295	ret = chown(health_unix_sock_path, 0, gid);
65931c8b MD	296	if (ret < 0) {
	297	ERR("Unable to set group on %s", health_unix_sock_path);
	298	PERROR("chown");
7568ddbf	299	err = -1;
65931c8b MD	300	goto error;
	301	}
	302
28ab034a	303	ret = chmod(health_unix_sock_path, S_IRUSR \| S_IWUSR \| S_IRGRP \| S_IWGRP);
65931c8b MD	304	if (ret < 0) {
	305	ERR("Unable to set permissions on %s", health_unix_sock_path);
	306	PERROR("chmod");
7568ddbf	307	err = -1;
65931c8b MD	308	goto error;
	309	}
	310	}
	311
	312	/*
	313	* Set the CLOEXEC flag. Return code is useless because either way, the
	314	* show must go on.
	315	*/
	316	(void) utils_set_fd_cloexec(sock);
	317
	318	ret = lttcomm_listen_unix_sock(sock);
	319	if (ret < 0) {
	320	goto error;
	321	}
	322
aa91fbc5	323	/* Size is set to 2 for the unix socket and quit pipe. */
28ab034a JG	324	ret = fd_tracker_util_poll_create(
28ab034a JG	325	the_fd_tracker, "Health management thread epoll", &events, 2, LTTNG_CLOEXEC);
65931c8b MD	326	if (ret < 0) {
	327	ERR("Poll set creation failed");
	328	goto error;
	329	}
	330
	331	ret = lttng_poll_add(&events, health_quit_pipe[0], LPOLLIN);
	332	if (ret < 0) {
	333	goto error;
	334	}
	335
	336	/* Add the application registration socket */
	337	ret = lttng_poll_add(&events, sock, LPOLLIN \| LPOLLPRI);
	338	if (ret < 0) {
	339	goto error;
	340	}
	341
3fd27398 MD	342	lttng_relay_notify_ready();
3fd27398 MD	343
cd9adb8b	344	while (true) {
1c9bd75b JG	345	char *accepted_socket_name;
1c9bd75b JG	346
65931c8b MD	347	DBG("Health check ready");
	348
	349	/* Inifinite blocking call, waiting for transmission */
28ab034a	350	restart:
65931c8b MD	351	ret = lttng_poll_wait(&events, -1);
	352	if (ret < 0) {
	353	/*
	354	* Restart interrupted system call.
	355	*/
	356	if (errno == EINTR) {
	357	goto restart;
	358	}
	359	goto error;
	360	}
	361
	362	nb_fd = ret;
	363
	364	for (i = 0; i < nb_fd; i++) {
	365	/* Fetch once the poll data */
8a00688e MJ	366	const auto revents = LTTNG_POLL_GETEV(&events, i);
8a00688e MJ	367	const auto pollfd = LTTNG_POLL_GETFD(&events, i);
65931c8b	368
8a00688e MJ	369	/* Activity on thread quit pipe, exiting. */
	370	if (pollfd == health_quit_pipe[0]) {
	371	DBG("Activity on thread quit pipe");
65931c8b MD	372	err = 0;
	373	goto exit;
	374	}
	375
	376	/* Event on the registration socket */
	377	if (pollfd == sock) {
03e43155 MD	378	if (revents & LPOLLIN) {
	379	continue;
	380	} else if (revents & (LPOLLERR \| LPOLLHUP \| LPOLLRDHUP)) {
65931c8b MD	381	ERR("Health socket poll error");
65931c8b MD	382	goto error;
03e43155	383	} else {
28ab034a JG	384	ERR("Unexpected poll events %u for sock %d",
	385	revents,
	386	pollfd);
03e43155	387	goto error;
65931c8b MD	388	}
	389	}
	390	}
	391
28ab034a JG	392	ret = asprintf(&accepted_socket_name,
	393	"Socket accepted from unix socket @ %s",
	394	health_unix_sock_path);
1c9bd75b JG	395	if (ret == -1) {
1c9bd75b JG	396	PERROR("Failed to allocate name of accepted socket from unix socket @ %s",
28ab034a	397	health_unix_sock_path);
1c9bd75b JG	398	goto error;
1c9bd75b JG	399	}
28ab034a JG	400	ret = fd_tracker_open_unsuspendable_fd(the_fd_tracker,
	401	&new_sock,
	402	(const char **) &accepted_socket_name,
	403	1,
	404	accept_unix_socket,
	405	&sock);
1c9bd75b JG	406	free(accepted_socket_name);
1c9bd75b JG	407	if (ret < 0) {
65931c8b MD	408	goto error;
	409	}
	410
	411	/*
	412	* Set the CLOEXEC flag. Return code is useless because either way, the
	413	* show must go on.
	414	*/
	415	(void) utils_set_fd_cloexec(new_sock);
	416
	417	DBG("Receiving data from client for health...");
28ab034a	418	ret = lttcomm_recv_unix_sock(new_sock, (void *) &msg, sizeof(msg));
65931c8b MD	419	if (ret <= 0) {
65931c8b MD	420	DBG("Nothing recv() from client... continuing");
28ab034a	421	ret = fd_tracker_close_unsuspendable_fd(
cd9adb8b	422	the_fd_tracker, &new_sock, 1, fd_tracker_util_close_fd, nullptr);
65931c8b MD	423	if (ret) {
	424	PERROR("close");
	425	}
	426	new_sock = -1;
	427	continue;
	428	}
	429
	430	rcu_thread_online();
	431
a0377dfe	432	LTTNG_ASSERT(msg.cmd == HEALTH_CMD_CHECK);
65931c8b	433
53efb85a	434	memset(&reply, 0, sizeof(reply));
65931c8b MD	435	for (i = 0; i < NR_HEALTH_RELAYD_TYPES; i++) {
	436	/*
	437	* health_check_state return 0 if thread is in
	438	* error.
	439	*/
	440	if (!health_check_state(health_relayd, i)) {
	441	reply.ret_code \|= 1ULL << i;
	442	}
	443	}
	444
	445	DBG2("Health check return value %" PRIx64, reply.ret_code);
	446
	447	ret = send_unix_sock(new_sock, (void *) &reply, sizeof(reply));
	448	if (ret < 0) {
	449	ERR("Failed to send health data back to client");
	450	}
	451
	452	/* End of transmission */
28ab034a	453	ret = fd_tracker_close_unsuspendable_fd(
cd9adb8b	454	the_fd_tracker, &new_sock, 1, fd_tracker_util_close_fd, nullptr);
65931c8b MD	455	if (ret) {
	456	PERROR("close");
	457	}
	458	new_sock = -1;
	459	}
	460
65931c8b	461	error:
81714439 JG	462	lttng_relay_stop_threads();
81714439 JG	463	exit:
65931c8b MD	464	if (err) {
	465	ERR("Health error occurred in %s", __func__);
	466	}
	467	DBG("Health check thread dying");
	468	unlink(health_unix_sock_path);
	469	if (sock >= 0) {
28ab034a	470	ret = fd_tracker_close_unsuspendable_fd(
cd9adb8b	471	the_fd_tracker, &sock, 1, fd_tracker_util_close_fd, nullptr);
65931c8b MD	472	if (ret) {
	473	PERROR("close");
	474	}
	475	}
	476
dcbcae3e MD	477	/*
	478	* We do NOT rmdir rundir nor the relayd path because there are
	479	* other processes using them.
	480	*/
	481
aa91fbc5	482	(void) fd_tracker_util_poll_clean(the_fd_tracker, &events);
65931c8b MD	483
65931c8b MD	484	rcu_unregister_thread();
cd9adb8b	485	return nullptr;
65931c8b	486	}