[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 <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", rundir);
				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_relayd(void *data __attribute__((unused)))
{
	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;
}
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
65931c8b MD	9	#include <fcntl.h>
	10	#include <getopt.h>
	11	#include <grp.h>
	12	#include <limits.h>
	13	#include <pthread.h>
	14	#include <signal.h>
	15	#include <stdio.h>
	16	#include <stdlib.h>
	17	#include <string.h>
	18	#include <sys/ipc.h>
	19	#include <sys/resource.h>
	20	#include <sys/shm.h>
	21	#include <sys/socket.h>
	22	#include <sys/stat.h>
	23	#include <sys/types.h>
	24	#include <urcu/list.h>
	25	#include <poll.h>
	26	#include <unistd.h>
	27	#include <sys/mman.h>
65931c8b	28	#include <urcu/compiler.h>
65931c8b MD	29	#include <inttypes.h>
	30
	31	#include <common/defaults.h>
	32	#include <common/common.h>
c8fea79c JR	33	#include <common/consumer/consumer.h>
c8fea79c JR	34	#include <common/consumer/consumer-timer.h>
65931c8b MD	35	#include <common/compat/poll.h>
	36	#include <common/sessiond-comm/sessiond-comm.h>
	37	#include <common/utils.h>
e8fa9fb0	38	#include <common/compat/getenv.h>
1c9bd75b	39	#include <common/fd-tracker/utils.h>
65931c8b MD	40
	41	#include "lttng-relayd.h"
	42	#include "health-relayd.h"
	43
	44	/* Global health check unix path */
094fe907 MD	45	static
094fe907 MD	46	char health_unix_sock_path[PATH_MAX];
65931c8b	47
794e2e5f	48	int health_quit_pipe[2] = { -1, -1 };
65931c8b MD	49
	50	/*
	51	* Check if the thread quit pipe was triggered.
	52	*
	53	* Return 1 if it was triggered else 0;
	54	*/
	55	static
	56	int check_health_quit_pipe(int fd, uint32_t events)
	57	{
	58	if (fd == health_quit_pipe[0] && (events & LPOLLIN)) {
	59	return 1;
	60	}
	61
	62	return 0;
	63	}
	64
	65	/*
	66	* Send data on a unix socket using the liblttsessiondcomm API.
	67	*
	68	* Return lttcomm error code.
	69	*/
	70	static int send_unix_sock(int sock, void *buf, size_t len)
	71	{
	72	/* Check valid length */
	73	if (len == 0) {
	74	return -1;
	75	}
	76
	77	return lttcomm_send_unix_sock(sock, buf, len);
	78	}
	79
	80	static int create_lttng_rundir_with_perm(const char *rundir)
	81	{
	82	int ret;
	83
	84	DBG3("Creating LTTng run directory: %s", rundir);
	85
	86	ret = mkdir(rundir, S_IRWXU);
	87	if (ret < 0) {
	88	if (errno != EEXIST) {
	89	ERR("Unable to create %s", rundir);
	90	goto error;
	91	} else {
	92	ret = 0;
	93	}
	94	} else if (ret == 0) {
	95	int is_root = !getuid();
	96
	97	if (is_root) {
28ab59d0 JR	98	gid_t gid;
	99
	100	ret = utils_get_group_id(tracing_group_name, true, &gid);
	101	if (ret) {
	102	/* Default to root group. */
	103	gid = 0;
	104	}
	105
	106	ret = chown(rundir, 0, gid);
65931c8b MD	107	if (ret < 0) {
	108	ERR("Unable to set group on %s", rundir);
	109	PERROR("chown");
	110	ret = -1;
	111	goto error;
	112	}
	113
	114	ret = chmod(rundir,
	115	S_IRUSR \| S_IWUSR \| S_IXUSR \| S_IRGRP \| S_IXGRP \| S_IROTH \| S_IXOTH);
	116	if (ret < 0) {
f7b09ec2	117	ERR("Unable to set permissions on %s", rundir);
65931c8b MD	118	PERROR("chmod");
	119	ret = -1;
	120	goto error;
	121	}
	122	}
	123	}
	124
	125	error:
	126	return ret;
	127	}
	128
094fe907 MD	129	static
	130	int parse_health_env(void)
	131	{
	132	const char *health_path;
	133
e8fa9fb0	134	health_path = lttng_secure_getenv(LTTNG_RELAYD_HEALTH_ENV);
094fe907 MD	135	if (health_path) {
	136	strncpy(health_unix_sock_path, health_path,
	137	PATH_MAX);
	138	health_unix_sock_path[PATH_MAX - 1] = '\0';
	139	}
	140
	141	return 0;
	142	}
	143
65931c8b MD	144	static
	145	int setup_health_path(void)
	146	{
	147	int is_root, ret = 0;
4f00620d JG	148	const char *home_path = NULL;
4f00620d JG	149	char rundir = NULL, relayd_path = NULL;
65931c8b	150
094fe907 MD	151	ret = parse_health_env();
	152	if (ret) {
	153	return ret;
	154	}
	155
65931c8b MD	156	is_root = !getuid();
	157
	158	if (is_root) {
c3844e39	159	rundir = strdup(DEFAULT_LTTNG_RUNDIR);
b6ab01aa MD	160	if (!rundir) {
	161	ret = -ENOMEM;
	162	goto end;
	163	}
65931c8b MD	164	} else {
	165	/*
	166	* Create rundir from home path. This will create something like
	167	* $HOME/.lttng
	168	*/
	169	home_path = utils_get_home_dir();
	170
	171	if (home_path == NULL) {
	172	/* TODO: Add --socket PATH option */
	173	ERR("Can't get HOME directory for sockets creation.");
	174	ret = -EPERM;
	175	goto end;
	176	}
	177
c3844e39	178	ret = asprintf(&rundir, DEFAULT_LTTNG_HOME_RUNDIR, home_path);
65931c8b MD	179	if (ret < 0) {
	180	ret = -ENOMEM;
	181	goto end;
	182	}
	183	}
	184
c3844e39	185	ret = asprintf(&relayd_path, DEFAULT_RELAYD_PATH, rundir);
65931c8b MD	186	if (ret < 0) {
	187	ret = -ENOMEM;
	188	goto end;
	189	}
	190
c3844e39	191	ret = create_lttng_rundir_with_perm(rundir);
65931c8b MD	192	if (ret < 0) {
	193	goto end;
	194	}
	195
	196	ret = create_lttng_rundir_with_perm(relayd_path);
	197	if (ret < 0) {
	198	goto end;
	199	}
	200
	201	if (is_root) {
	202	if (strlen(health_unix_sock_path) != 0) {
	203	goto end;
	204	}
	205	snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
	206	DEFAULT_GLOBAL_RELAY_HEALTH_UNIX_SOCK,
d1f721c5	207	(int) getpid());
65931c8b MD	208	} else {
	209	/* Set health check Unix path */
	210	if (strlen(health_unix_sock_path) != 0) {
	211	goto end;
	212	}
	213
	214	snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
	215	DEFAULT_HOME_RELAY_HEALTH_UNIX_SOCK,
d1f721c5	216	home_path, (int) getpid());
65931c8b MD	217	}
	218
	219	end:
c3844e39	220	free(rundir);
edd94901	221	free(relayd_path);
65931c8b MD	222	return ret;
	223	}
	224
1c9bd75b JG	225	static
	226	int accept_unix_socket(void data, int out_fd)
	227	{
	228	int ret;
	229	int accepting_sock = ((int ) data);
	230
	231	ret = lttcomm_accept_unix_sock(accepting_sock);
	232	if (ret < 0) {
	233	goto end;
	234	}
	235
	236	*out_fd = ret;
	237	ret = 0;
	238	end:
	239	return ret;
	240	}
	241
d7eddab9 JG	242	static
	243	int open_unix_socket(void data, int out_fd)
	244	{
	245	int ret;
ac497a37	246	const char path = (const char ) data;
d7eddab9 JG	247
	248	ret = lttcomm_create_unix_sock(path);
	249	if (ret < 0) {
	250	goto end;
	251	}
	252
	253	*out_fd = ret;
	254	ret = 0;
	255	end:
	256	return ret;
	257	}
	258
65931c8b MD	259	/*
	260	* Thread managing health check socket.
	261	*/
f46376a1	262	void thread_manage_health_relayd(void data __attribute__((unused)))
65931c8b MD	263	{
	264	int sock = -1, new_sock = -1, ret, i, pollfd, err = -1;
	265	uint32_t revents, nb_fd;
	266	struct lttng_poll_event events;
	267	struct health_comm_msg msg;
	268	struct health_comm_reply reply;
	269	int is_root;
d7eddab9	270	char *sock_name;
65931c8b MD	271
	272	DBG("[thread] Manage health check started");
	273
	274	setup_health_path();
	275
	276	rcu_register_thread();
	277
	278	/* We might hit an error path before this is created. */
	279	lttng_poll_init(&events);
	280
	281	/* Create unix socket */
d7eddab9 JG	282	ret = asprintf(&sock_name, "Unix socket @ %s", health_unix_sock_path);
	283	if (ret == -1) {
	284	PERROR("Failed to allocate unix socket name");
	285	err = -1;
	286	goto error;
	287	}
	288	ret = fd_tracker_open_unsuspendable_fd(the_fd_tracker, &sock,
	289	(const char **) &sock_name, 1, open_unix_socket,
	290	health_unix_sock_path);
	291	free(sock_name);
	292	if (ret < 0) {
65931c8b	293	ERR("Unable to create health check Unix socket");
7568ddbf	294	err = -1;
65931c8b MD	295	goto error;
	296	}
	297
	298	is_root = !getuid();
	299	if (is_root) {
	300	/* lttng health client socket path permissions */
28ab59d0 JR	301	gid_t gid;
	302
	303	ret = utils_get_group_id(tracing_group_name, true, &gid);
	304	if (ret) {
	305	/* Default to root group. */
	306	gid = 0;
	307	}
	308
	309	ret = chown(health_unix_sock_path, 0, gid);
65931c8b MD	310	if (ret < 0) {
	311	ERR("Unable to set group on %s", health_unix_sock_path);
	312	PERROR("chown");
7568ddbf	313	err = -1;
65931c8b MD	314	goto error;
	315	}
	316
	317	ret = chmod(health_unix_sock_path,
	318	S_IRUSR \| S_IWUSR \| S_IRGRP \| S_IWGRP);
	319	if (ret < 0) {
	320	ERR("Unable to set permissions on %s", health_unix_sock_path);
	321	PERROR("chmod");
7568ddbf	322	err = -1;
65931c8b MD	323	goto error;
	324	}
	325	}
	326
	327	/*
	328	* Set the CLOEXEC flag. Return code is useless because either way, the
	329	* show must go on.
	330	*/
	331	(void) utils_set_fd_cloexec(sock);
	332
	333	ret = lttcomm_listen_unix_sock(sock);
	334	if (ret < 0) {
	335	goto error;
	336	}
	337
aa91fbc5 JG	338	/* Size is set to 2 for the unix socket and quit pipe. */
	339	ret = fd_tracker_util_poll_create(the_fd_tracker,
	340	"Health management thread epoll", &events, 2,
	341	LTTNG_CLOEXEC);
65931c8b MD	342	if (ret < 0) {
	343	ERR("Poll set creation failed");
	344	goto error;
	345	}
	346
	347	ret = lttng_poll_add(&events, health_quit_pipe[0], LPOLLIN);
	348	if (ret < 0) {
	349	goto error;
	350	}
	351
	352	/* Add the application registration socket */
	353	ret = lttng_poll_add(&events, sock, LPOLLIN \| LPOLLPRI);
	354	if (ret < 0) {
	355	goto error;
	356	}
	357
3fd27398 MD	358	lttng_relay_notify_ready();
3fd27398 MD	359
65931c8b	360	while (1) {
1c9bd75b JG	361	char *accepted_socket_name;
1c9bd75b JG	362
65931c8b MD	363	DBG("Health check ready");
	364
	365	/* Inifinite blocking call, waiting for transmission */
	366	restart:
	367	ret = lttng_poll_wait(&events, -1);
	368	if (ret < 0) {
	369	/*
	370	* Restart interrupted system call.
	371	*/
	372	if (errno == EINTR) {
	373	goto restart;
	374	}
	375	goto error;
	376	}
	377
	378	nb_fd = ret;
	379
	380	for (i = 0; i < nb_fd; i++) {
	381	/* Fetch once the poll data */
	382	revents = LTTNG_POLL_GETEV(&events, i);
	383	pollfd = LTTNG_POLL_GETFD(&events, i);
	384
	385	/* Thread quit pipe has been closed. Killing thread. */
	386	ret = check_health_quit_pipe(pollfd, revents);
	387	if (ret) {
	388	err = 0;
	389	goto exit;
	390	}
	391
	392	/* Event on the registration socket */
	393	if (pollfd == sock) {
03e43155 MD	394	if (revents & LPOLLIN) {
	395	continue;
	396	} else if (revents & (LPOLLERR \| LPOLLHUP \| LPOLLRDHUP)) {
65931c8b MD	397	ERR("Health socket poll error");
65931c8b MD	398	goto error;
03e43155 MD	399	} else {
	400	ERR("Unexpected poll events %u for sock %d", revents, pollfd);
	401	goto error;
65931c8b MD	402	}
	403	}
	404	}
	405
1c9bd75b JG	406	ret = asprintf(&accepted_socket_name, "Socket accepted from unix socket @ %s",
	407	health_unix_sock_path);
	408	if (ret == -1) {
	409	PERROR("Failed to allocate name of accepted socket from unix socket @ %s",
	410	health_unix_sock_path);
	411	goto error;
	412	}
	413	ret = fd_tracker_open_unsuspendable_fd(the_fd_tracker, &new_sock,
	414	(const char **) &accepted_socket_name, 1,
	415	accept_unix_socket, &sock);
	416	free(accepted_socket_name);
	417	if (ret < 0) {
65931c8b MD	418	goto error;
	419	}
	420
	421	/*
	422	* Set the CLOEXEC flag. Return code is useless because either way, the
	423	* show must go on.
	424	*/
	425	(void) utils_set_fd_cloexec(new_sock);
	426
	427	DBG("Receiving data from client for health...");
	428	ret = lttcomm_recv_unix_sock(new_sock, (void *)&msg, sizeof(msg));
	429	if (ret <= 0) {
	430	DBG("Nothing recv() from client... continuing");
1c9bd75b JG	431	ret = fd_tracker_close_unsuspendable_fd(the_fd_tracker,
	432	&new_sock, 1, fd_tracker_util_close_fd,
	433	NULL);
65931c8b MD	434	if (ret) {
	435	PERROR("close");
	436	}
	437	new_sock = -1;
	438	continue;
	439	}
	440
	441	rcu_thread_online();
	442
a0377dfe	443	LTTNG_ASSERT(msg.cmd == HEALTH_CMD_CHECK);
65931c8b	444
53efb85a	445	memset(&reply, 0, sizeof(reply));
65931c8b MD	446	for (i = 0; i < NR_HEALTH_RELAYD_TYPES; i++) {
	447	/*
	448	* health_check_state return 0 if thread is in
	449	* error.
	450	*/
	451	if (!health_check_state(health_relayd, i)) {
	452	reply.ret_code \|= 1ULL << i;
	453	}
	454	}
	455
	456	DBG2("Health check return value %" PRIx64, reply.ret_code);
	457
	458	ret = send_unix_sock(new_sock, (void *) &reply, sizeof(reply));
	459	if (ret < 0) {
	460	ERR("Failed to send health data back to client");
	461	}
	462
	463	/* End of transmission */
1c9bd75b JG	464	ret = fd_tracker_close_unsuspendable_fd(the_fd_tracker,
	465	&new_sock, 1, fd_tracker_util_close_fd,
	466	NULL);
65931c8b MD	467	if (ret) {
	468	PERROR("close");
	469	}
	470	new_sock = -1;
	471	}
	472
65931c8b	473	error:
81714439 JG	474	lttng_relay_stop_threads();
81714439 JG	475	exit:
65931c8b MD	476	if (err) {
	477	ERR("Health error occurred in %s", __func__);
	478	}
	479	DBG("Health check thread dying");
	480	unlink(health_unix_sock_path);
	481	if (sock >= 0) {
d7eddab9 JG	482	ret = fd_tracker_close_unsuspendable_fd(the_fd_tracker, &sock,
d7eddab9 JG	483	1, fd_tracker_util_close_fd, NULL);
65931c8b MD	484	if (ret) {
	485	PERROR("close");
	486	}
	487	}
	488
dcbcae3e MD	489	/*
	490	* We do NOT rmdir rundir nor the relayd path because there are
	491	* other processes using them.
	492	*/
	493
aa91fbc5	494	(void) fd_tracker_util_poll_clean(the_fd_tracker, &events);
65931c8b MD	495
	496	rcu_unregister_thread();
	497	return NULL;
	498	}