[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);
	} 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);

			/* 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);
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,
	207	getpid());
	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,
	216	home_path, getpid());
	217	}
	218
	219	end:
c3844e39	220	free(rundir);
65931c8b MD	221	return ret;
	222	}
	223
	224	/*
	225	* Thread managing health check socket.
	226	*/
	227	void thread_manage_health(void data)
	228	{
	229	int sock = -1, new_sock = -1, ret, i, pollfd, err = -1;
	230	uint32_t revents, nb_fd;
	231	struct lttng_poll_event events;
	232	struct health_comm_msg msg;
	233	struct health_comm_reply reply;
	234	int is_root;
	235
	236	DBG("[thread] Manage health check started");
	237
	238	setup_health_path();
	239
	240	rcu_register_thread();
	241
	242	/* We might hit an error path before this is created. */
	243	lttng_poll_init(&events);
	244
	245	/* Create unix socket */
	246	sock = lttcomm_create_unix_sock(health_unix_sock_path);
	247	if (sock < 0) {
	248	ERR("Unable to create health check Unix socket");
	249	ret = -1;
	250	goto error;
	251	}
	252
	253	is_root = !getuid();
	254	if (is_root) {
	255	/* lttng health client socket path permissions */
	256	ret = chown(health_unix_sock_path, 0,
	257	utils_get_group_id(tracing_group_name));
	258	if (ret < 0) {
	259	ERR("Unable to set group on %s", health_unix_sock_path);
	260	PERROR("chown");
	261	ret = -1;
	262	goto error;
	263	}
	264
	265	ret = chmod(health_unix_sock_path,
	266	S_IRUSR \| S_IWUSR \| S_IRGRP \| S_IWGRP);
	267	if (ret < 0) {
	268	ERR("Unable to set permissions on %s", health_unix_sock_path);
	269	PERROR("chmod");
	270	ret = -1;
	271	goto error;
	272	}
	273	}
	274
	275	/*
	276	* Set the CLOEXEC flag. Return code is useless because either way, the
	277	* show must go on.
	278	*/
	279	(void) utils_set_fd_cloexec(sock);
	280
	281	ret = lttcomm_listen_unix_sock(sock);
	282	if (ret < 0) {
	283	goto error;
	284	}
285
286	/* Size is set to 1 for the consumer_channel pipe */
287	ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
288	if (ret < 0) {
289	ERR("Poll set creation failed");
290	goto error;
291	}
292
293	ret = lttng_poll_add(&events, health_quit_pipe[0], LPOLLIN);
294	if (ret < 0) {
295	goto error;
296	}
297
298	/* Add the application registration socket */
299	ret = lttng_poll_add(&events, sock, LPOLLIN \| LPOLLPRI);
300	if (ret < 0) {
301	goto error;
302	}
303
3fd27398 MD	304	lttng_relay_notify_ready();
3fd27398 MD	305
65931c8b MD	306	while (1) {
	307	DBG("Health check ready");
	308
	309	/* Inifinite blocking call, waiting for transmission */
	310	restart:
	311	ret = lttng_poll_wait(&events, -1);
	312	if (ret < 0) {
	313	/*
	314	* Restart interrupted system call.
	315	*/
	316	if (errno == EINTR) {
	317	goto restart;
	318	}
	319	goto error;
	320	}
	321
	322	nb_fd = ret;
	323
	324	for (i = 0; i < nb_fd; i++) {
	325	/* Fetch once the poll data */
	326	revents = LTTNG_POLL_GETEV(&events, i);
	327	pollfd = LTTNG_POLL_GETFD(&events, i);
	328
	329	/* Thread quit pipe has been closed. Killing thread. */
	330	ret = check_health_quit_pipe(pollfd, revents);
	331	if (ret) {
	332	err = 0;
	333	goto exit;
	334	}
	335
	336	/* Event on the registration socket */
	337	if (pollfd == sock) {
	338	if (revents & (LPOLLERR \| LPOLLHUP \| LPOLLRDHUP)) {
	339	ERR("Health socket poll error");
	340	goto error;
	341	}
	342	}
	343	}
	344
	345	new_sock = lttcomm_accept_unix_sock(sock);
	346	if (new_sock < 0) {
	347	goto error;
	348	}
	349
	350	/*
	351	* Set the CLOEXEC flag. Return code is useless because either way, the
	352	* show must go on.
	353	*/
	354	(void) utils_set_fd_cloexec(new_sock);
	355
	356	DBG("Receiving data from client for health...");
	357	ret = lttcomm_recv_unix_sock(new_sock, (void *)&msg, sizeof(msg));
	358	if (ret <= 0) {
	359	DBG("Nothing recv() from client... continuing");
	360	ret = close(new_sock);
	361	if (ret) {
	362	PERROR("close");
	363	}
	364	new_sock = -1;
	365	continue;
	366	}
	367
	368	rcu_thread_online();
	369
370	assert(msg.cmd == HEALTH_CMD_CHECK);
371
53efb85a	372	memset(&reply, 0, sizeof(reply));
65931c8b MD	373	for (i = 0; i < NR_HEALTH_RELAYD_TYPES; i++) {
	374	/*
	375	* health_check_state return 0 if thread is in
	376	* error.
	377	*/
	378	if (!health_check_state(health_relayd, i)) {
	379	reply.ret_code \|= 1ULL << i;
	380	}
	381	}
	382
	383	DBG2("Health check return value %" PRIx64, reply.ret_code);
	384
	385	ret = send_unix_sock(new_sock, (void *) &reply, sizeof(reply));
	386	if (ret < 0) {
	387	ERR("Failed to send health data back to client");
	388	}
	389
	390	/* End of transmission */
	391	ret = close(new_sock);
	392	if (ret) {
	393	PERROR("close");
	394	}
	395	new_sock = -1;
	396	}
	397
	398	exit:
	399	error:
	400	if (err) {
	401	ERR("Health error occurred in %s", __func__);
	402	}
	403	DBG("Health check thread dying");
	404	unlink(health_unix_sock_path);
	405	if (sock >= 0) {
	406	ret = close(sock);
	407	if (ret) {
	408	PERROR("close");
	409	}
	410	}
	411
dcbcae3e MD	412	/*
	413	* We do NOT rmdir rundir nor the relayd path because there are
	414	* other processes using them.
	415	*/
	416
65931c8b MD	417	lttng_poll_clean(&events);
	418
	419	rcu_unregister_thread();
	420	return NULL;
	421	}