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

/*
 * Copyright (C) 2013 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#define _GNU_SOURCE
#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 <assert.h>
#include <config.h>
#include <urcu/compiler.h>
#include <ulimit.h>
#include <inttypes.h>

#include <common/defaults.h>
#include <common/common.h>
#include <common/consumer.h>
#include <common/consumer-timer.h>
#include <common/compat/poll.h>
#include <common/sessiond-comm/sessiond-comm.h>
#include <common/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];

/*
 * 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) {
			ret = chown(rundir, 0,
					utils_get_group_id(tracing_group_name));
			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 = 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;
	char *home_path = NULL, *rundir = NULL, *relayd_path;

	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,
			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, getpid());
	}

end:
	free(rundir);
	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");
		ret = -1;
		goto error;
	}

	is_root = !getuid();
	if (is_root) {
		/* lttng health client socket path permissions */
		ret = chown(health_unix_sock_path, 0,
				utils_get_group_id(tracing_group_name));
		if (ret < 0) {
			ERR("Unable to set group on %s", health_unix_sock_path);
			PERROR("chown");
			ret = -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");
			ret = -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;
	}

	lttng_relay_notify_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);

			if (!revents) {
				/* No activity for this FD (poll implementation). */
				continue;
			}

			/* 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)) {
					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();

		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 = 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");
		}
	}

	/*
	 * We do NOT rmdir rundir nor the relayd path because there are
	 * other processes using them.
	 */

	lttng_poll_clean(&events);

	rcu_unregister_thread();
	return NULL;
}
Commit	Line	Data
65931c8b MD	1	/*
	2	* Copyright (C) 2013 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License, version 2 only,
	6	* as published by the Free Software Foundation.
	7	*
	8	* This program is distributed in the hope that it will be useful,
	9	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	11	* GNU General Public License for more details.
	12	*
	13	* You should have received a copy of the GNU General Public License along
	14	* with this program; if not, write to the Free Software Foundation, Inc.,
	15	* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
	16	*/
	17
	18	#define _GNU_SOURCE
6c1c0768	19	#define _LGPL_SOURCE
65931c8b MD	20	#include <fcntl.h>
	21	#include <getopt.h>
	22	#include <grp.h>
	23	#include <limits.h>
	24	#include <pthread.h>
	25	#include <signal.h>
	26	#include <stdio.h>
	27	#include <stdlib.h>
	28	#include <string.h>
	29	#include <sys/ipc.h>
	30	#include <sys/resource.h>
	31	#include <sys/shm.h>
	32	#include <sys/socket.h>
	33	#include <sys/stat.h>
	34	#include <sys/types.h>
	35	#include <urcu/list.h>
	36	#include <poll.h>
	37	#include <unistd.h>
	38	#include <sys/mman.h>
	39	#include <assert.h>
	40	#include <config.h>
	41	#include <urcu/compiler.h>
	42	#include <ulimit.h>
	43	#include <inttypes.h>
	44
	45	#include <common/defaults.h>
	46	#include <common/common.h>
	47	#include <common/consumer.h>
	48	#include <common/consumer-timer.h>
	49	#include <common/compat/poll.h>
	50	#include <common/sessiond-comm/sessiond-comm.h>
	51	#include <common/utils.h>
	52
	53	#include "lttng-relayd.h"
	54	#include "health-relayd.h"
	55
	56	/* Global health check unix path */
094fe907 MD	57	static
094fe907 MD	58	char health_unix_sock_path[PATH_MAX];
65931c8b MD	59
	60	int health_quit_pipe[2];
	61
	62	/*
	63	* Check if the thread quit pipe was triggered.
	64	*
	65	* Return 1 if it was triggered else 0;
	66	*/
	67	static
	68	int check_health_quit_pipe(int fd, uint32_t events)
	69	{
	70	if (fd == health_quit_pipe[0] && (events & LPOLLIN)) {
	71	return 1;
	72	}
	73
	74	return 0;
	75	}
	76
	77	/*
	78	* Send data on a unix socket using the liblttsessiondcomm API.
	79	*
	80	* Return lttcomm error code.
	81	*/
	82	static int send_unix_sock(int sock, void *buf, size_t len)
	83	{
	84	/* Check valid length */
	85	if (len == 0) {
	86	return -1;
	87	}
	88
	89	return lttcomm_send_unix_sock(sock, buf, len);
	90	}
	91
	92	static int create_lttng_rundir_with_perm(const char *rundir)
	93	{
	94	int ret;
	95
	96	DBG3("Creating LTTng run directory: %s", rundir);
	97
	98	ret = mkdir(rundir, S_IRWXU);
	99	if (ret < 0) {
	100	if (errno != EEXIST) {
	101	ERR("Unable to create %s", rundir);
	102	goto error;
	103	} else {
	104	ret = 0;
	105	}
	106	} else if (ret == 0) {
	107	int is_root = !getuid();
	108
	109	if (is_root) {
	110	ret = chown(rundir, 0,
	111	utils_get_group_id(tracing_group_name));
	112	if (ret < 0) {
	113	ERR("Unable to set group on %s", rundir);
	114	PERROR("chown");
	115	ret = -1;
	116	goto error;
	117	}
	118
	119	ret = chmod(rundir,
	120	S_IRUSR \| S_IWUSR \| S_IXUSR \| S_IRGRP \| S_IXGRP \| S_IROTH \| S_IXOTH);
	121	if (ret < 0) {
	122	ERR("Unable to set permissions on %s", health_unix_sock_path);
123	PERROR("chmod");
124	ret = -1;
125	goto error;
126	}
127	}
128	}
129
130	error:
131	return ret;
132	}
133
094fe907 MD	134	static
	135	int parse_health_env(void)
	136	{
	137	const char *health_path;
	138
	139	health_path = getenv(LTTNG_RELAYD_HEALTH_ENV);
	140	if (health_path) {
	141	strncpy(health_unix_sock_path, health_path,
	142	PATH_MAX);
	143	health_unix_sock_path[PATH_MAX - 1] = '\0';
	144	}
	145
	146	return 0;
	147	}
	148
65931c8b MD	149	static
	150	int setup_health_path(void)
	151	{
	152	int is_root, ret = 0;
c3844e39	153	char home_path = NULL, rundir = NULL, *relayd_path;
65931c8b	154
094fe907 MD	155	ret = parse_health_env();
	156	if (ret) {
	157	return ret;
	158	}
	159
65931c8b MD	160	is_root = !getuid();
	161
	162	if (is_root) {
c3844e39	163	rundir = strdup(DEFAULT_LTTNG_RUNDIR);
b6ab01aa MD	164	if (!rundir) {
	165	ret = -ENOMEM;
	166	goto end;
	167	}
65931c8b MD	168	} else {
	169	/*
	170	* Create rundir from home path. This will create something like
	171	* $HOME/.lttng
	172	*/
	173	home_path = utils_get_home_dir();
	174
	175	if (home_path == NULL) {
	176	/* TODO: Add --socket PATH option */
	177	ERR("Can't get HOME directory for sockets creation.");
	178	ret = -EPERM;
	179	goto end;
	180	}
	181
c3844e39	182	ret = asprintf(&rundir, DEFAULT_LTTNG_HOME_RUNDIR, home_path);
65931c8b MD	183	if (ret < 0) {
	184	ret = -ENOMEM;
	185	goto end;
	186	}
	187	}
	188
c3844e39	189	ret = asprintf(&relayd_path, DEFAULT_RELAYD_PATH, rundir);
65931c8b MD	190	if (ret < 0) {
	191	ret = -ENOMEM;
	192	goto end;
	193	}
	194
c3844e39	195	ret = create_lttng_rundir_with_perm(rundir);
65931c8b MD	196	if (ret < 0) {
	197	goto end;
	198	}
	199
	200	ret = create_lttng_rundir_with_perm(relayd_path);
	201	if (ret < 0) {
	202	goto end;
	203	}
	204
	205	if (is_root) {
	206	if (strlen(health_unix_sock_path) != 0) {
	207	goto end;
	208	}
	209	snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
	210	DEFAULT_GLOBAL_RELAY_HEALTH_UNIX_SOCK,
	211	getpid());
	212	} else {
	213	/* Set health check Unix path */
	214	if (strlen(health_unix_sock_path) != 0) {
	215	goto end;
	216	}
	217
	218	snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
	219	DEFAULT_HOME_RELAY_HEALTH_UNIX_SOCK,
	220	home_path, getpid());
	221	}
	222
	223	end:
c3844e39	224	free(rundir);
65931c8b MD	225	return ret;
	226	}
	227
	228	/*
	229	* Thread managing health check socket.
	230	*/
	231	void thread_manage_health(void data)
	232	{
	233	int sock = -1, new_sock = -1, ret, i, pollfd, err = -1;
	234	uint32_t revents, nb_fd;
	235	struct lttng_poll_event events;
	236	struct health_comm_msg msg;
	237	struct health_comm_reply reply;
	238	int is_root;
	239
	240	DBG("[thread] Manage health check started");
	241
	242	setup_health_path();
	243
	244	rcu_register_thread();
	245
	246	/* We might hit an error path before this is created. */
	247	lttng_poll_init(&events);
	248
	249	/* Create unix socket */
	250	sock = lttcomm_create_unix_sock(health_unix_sock_path);
	251	if (sock < 0) {
	252	ERR("Unable to create health check Unix socket");
	253	ret = -1;
	254	goto error;
	255	}
	256
	257	is_root = !getuid();
	258	if (is_root) {
	259	/* lttng health client socket path permissions */
	260	ret = chown(health_unix_sock_path, 0,
	261	utils_get_group_id(tracing_group_name));
	262	if (ret < 0) {
	263	ERR("Unable to set group on %s", health_unix_sock_path);
	264	PERROR("chown");
	265	ret = -1;
	266	goto error;
	267	}
	268
	269	ret = chmod(health_unix_sock_path,
	270	S_IRUSR \| S_IWUSR \| S_IRGRP \| S_IWGRP);
	271	if (ret < 0) {
	272	ERR("Unable to set permissions on %s", health_unix_sock_path);
	273	PERROR("chmod");
	274	ret = -1;
	275	goto error;
	276	}
	277	}
	278
	279	/*
	280	* Set the CLOEXEC flag. Return code is useless because either way, the
	281	* show must go on.
	282	*/
	283	(void) utils_set_fd_cloexec(sock);
	284
	285	ret = lttcomm_listen_unix_sock(sock);
	286	if (ret < 0) {
	287	goto error;
	288	}
289
290	/* Size is set to 1 for the consumer_channel pipe */
291	ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
292	if (ret < 0) {
293	ERR("Poll set creation failed");
294	goto error;
295	}
296
297	ret = lttng_poll_add(&events, health_quit_pipe[0], LPOLLIN);
298	if (ret < 0) {
299	goto error;
300	}
301
302	/* Add the application registration socket */
303	ret = lttng_poll_add(&events, sock, LPOLLIN \| LPOLLPRI);
304	if (ret < 0) {
305	goto error;
306	}
307
3fd27398 MD	308	lttng_relay_notify_ready();
3fd27398 MD	309
65931c8b MD	310	while (1) {
	311	DBG("Health check ready");
	312
	313	/* Inifinite blocking call, waiting for transmission */
	314	restart:
	315	ret = lttng_poll_wait(&events, -1);
	316	if (ret < 0) {
	317	/*
	318	* Restart interrupted system call.
	319	*/
	320	if (errno == EINTR) {
	321	goto restart;
	322	}
	323	goto error;
	324	}
	325
	326	nb_fd = ret;
	327
	328	for (i = 0; i < nb_fd; i++) {
	329	/* Fetch once the poll data */
	330	revents = LTTNG_POLL_GETEV(&events, i);
	331	pollfd = LTTNG_POLL_GETFD(&events, i);
	332
fd20dac9 MD	333	if (!revents) {
	334	/* No activity for this FD (poll implementation). */
	335	continue;
	336	}
	337
65931c8b MD	338	/* Thread quit pipe has been closed. Killing thread. */
	339	ret = check_health_quit_pipe(pollfd, revents);
	340	if (ret) {
	341	err = 0;
	342	goto exit;
	343	}
	344
	345	/* Event on the registration socket */
	346	if (pollfd == sock) {
	347	if (revents & (LPOLLERR \| LPOLLHUP \| LPOLLRDHUP)) {
	348	ERR("Health socket poll error");
	349	goto error;
	350	}
	351	}
	352	}
	353
	354	new_sock = lttcomm_accept_unix_sock(sock);
	355	if (new_sock < 0) {
	356	goto error;
	357	}
	358
	359	/*
	360	* Set the CLOEXEC flag. Return code is useless because either way, the
	361	* show must go on.
	362	*/
	363	(void) utils_set_fd_cloexec(new_sock);
	364
	365	DBG("Receiving data from client for health...");
	366	ret = lttcomm_recv_unix_sock(new_sock, (void *)&msg, sizeof(msg));
	367	if (ret <= 0) {
	368	DBG("Nothing recv() from client... continuing");
	369	ret = close(new_sock);
	370	if (ret) {
	371	PERROR("close");
	372	}
	373	new_sock = -1;
	374	continue;
	375	}
	376
	377	rcu_thread_online();
	378
	379	assert(msg.cmd == HEALTH_CMD_CHECK);
	380
53efb85a	381	memset(&reply, 0, sizeof(reply));
65931c8b MD	382	for (i = 0; i < NR_HEALTH_RELAYD_TYPES; i++) {
	383	/*
	384	* health_check_state return 0 if thread is in
	385	* error.
	386	*/
	387	if (!health_check_state(health_relayd, i)) {
	388	reply.ret_code \|= 1ULL << i;
	389	}
	390	}
	391
	392	DBG2("Health check return value %" PRIx64, reply.ret_code);
	393
	394	ret = send_unix_sock(new_sock, (void *) &reply, sizeof(reply));
	395	if (ret < 0) {
	396	ERR("Failed to send health data back to client");
	397	}
	398
	399	/* End of transmission */
	400	ret = close(new_sock);
	401	if (ret) {
	402	PERROR("close");
	403	}
	404	new_sock = -1;
	405	}
	406
	407	exit:
	408	error:
	409	if (err) {
	410	ERR("Health error occurred in %s", __func__);
	411	}
	412	DBG("Health check thread dying");
	413	unlink(health_unix_sock_path);
	414	if (sock >= 0) {
	415	ret = close(sock);
	416	if (ret) {
	417	PERROR("close");
	418	}
	419	}
	420
dcbcae3e MD	421	/*
	422	* We do NOT rmdir rundir nor the relayd path because there are
	423	* other processes using them.
	424	*/
	425
65931c8b MD	426	lttng_poll_clean(&events);
	427
	428	rcu_unregister_thread();
	429	return NULL;
	430	}