[lttng-tools.git] / src / bin / lttng-consumerd / health-consumerd.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
#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-consumerd.h"
#include "health-consumerd.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 setup_health_path(void)
{
	int is_root, ret = 0;
	enum lttng_consumer_type type;
	const char *home_path;

	type = lttng_consumer_get_type();
	is_root = !getuid();

	if (is_root) {
		if (strlen(health_unix_sock_path) != 0) {
			goto end;
		}
		switch (type) {
		case LTTNG_CONSUMER_KERNEL:
			snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
				DEFAULT_GLOBAL_KCONSUMER_HEALTH_UNIX_SOCK);
			break;
		case LTTNG_CONSUMER64_UST:
			snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
				DEFAULT_GLOBAL_USTCONSUMER64_HEALTH_UNIX_SOCK);
			break;
		case LTTNG_CONSUMER32_UST:
			snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
				DEFAULT_GLOBAL_USTCONSUMER32_HEALTH_UNIX_SOCK);
			break;
		default:
			ret = -EINVAL;
			goto end;
		}
	} else {
		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;
		}

		/* Set health check Unix path */
		if (strlen(health_unix_sock_path) != 0) {
			goto end;
		}
		switch (type) {
		case LTTNG_CONSUMER_KERNEL:
			snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
				DEFAULT_HOME_KCONSUMER_HEALTH_UNIX_SOCK, home_path);
			break;
		case LTTNG_CONSUMER64_UST:
			snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
				DEFAULT_HOME_USTCONSUMER64_HEALTH_UNIX_SOCK, home_path);
			break;
		case LTTNG_CONSUMER32_UST:
			snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
				DEFAULT_HOME_USTCONSUMER32_HEALTH_UNIX_SOCK, home_path);
			break;
		default:
			ret = -EINVAL;
			goto end;
		}
	}
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;

	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;
	}

	/* Perform prior memory accesses before decrementing ready */
	cmm_smp_mb__before_uatomic_dec();
	uatomic_dec(&lttng_consumer_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);

		reply.ret_code = 0;
		for (i = 0; i < NR_HEALTH_CONSUMERD_TYPES; i++) {
			/*
			 * health_check_state return 0 if thread is in
			 * error.
			 */
			if (!health_check_state(health_consumerd, 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");
		}
	}

	lttng_poll_clean(&events);

	rcu_unregister_thread();
	return NULL;
}
Commit	Line	Data
5c635c72 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
	19	#include <fcntl.h>
	20	#include <getopt.h>
	21	#include <grp.h>
	22	#include <limits.h>
	23	#include <pthread.h>
	24	#include <signal.h>
	25	#include <stdio.h>
	26	#include <stdlib.h>
	27	#include <string.h>
	28	#include <sys/ipc.h>
	29	#include <sys/resource.h>
	30	#include <sys/shm.h>
	31	#include <sys/socket.h>
	32	#include <sys/stat.h>
	33	#include <sys/types.h>
	34	#include <urcu/list.h>
	35	#include <poll.h>
	36	#include <unistd.h>
	37	#include <sys/mman.h>
	38	#include <assert.h>
	39	#include <config.h>
	40	#include <urcu/compiler.h>
	41	#include <ulimit.h>
6c71277b	42	#include <inttypes.h>
5c635c72 MD	43
	44	#include <common/defaults.h>
	45	#include <common/common.h>
	46	#include <common/consumer.h>
	47	#include <common/consumer-timer.h>
	48	#include <common/compat/poll.h>
	49	#include <common/sessiond-comm/sessiond-comm.h>
	50	#include <common/utils.h>
	51
	52	#include "lttng-consumerd.h"
	53	#include "health-consumerd.h"
	54
	55	/* Global health check unix path */
	56	static char health_unix_sock_path[PATH_MAX];
	57
	58	int health_quit_pipe[2];
	59
	60	/*
	61	* Check if the thread quit pipe was triggered.
	62	*
	63	* Return 1 if it was triggered else 0;
	64	*/
	65	static
	66	int check_health_quit_pipe(int fd, uint32_t events)
	67	{
	68	if (fd == health_quit_pipe[0] && (events & LPOLLIN)) {
	69	return 1;
	70	}
	71
	72	return 0;
	73	}
	74
	75	/*
	76	* Send data on a unix socket using the liblttsessiondcomm API.
	77	*
	78	* Return lttcomm error code.
	79	*/
	80	static int send_unix_sock(int sock, void *buf, size_t len)
	81	{
	82	/* Check valid length */
	83	if (len == 0) {
	84	return -1;
	85	}
	86
	87	return lttcomm_send_unix_sock(sock, buf, len);
	88	}
	89
	90	static
	91	int setup_health_path(void)
	92	{
	93	int is_root, ret = 0;
	94	enum lttng_consumer_type type;
	95	const char *home_path;
	96
	97	type = lttng_consumer_get_type();
	98	is_root = !getuid();
	99
	100	if (is_root) {
	101	if (strlen(health_unix_sock_path) != 0) {
	102	goto end;
	103	}
	104	switch (type) {
	105	case LTTNG_CONSUMER_KERNEL:
	106	snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
107	DEFAULT_GLOBAL_KCONSUMER_HEALTH_UNIX_SOCK);
108	break;
109	case LTTNG_CONSUMER64_UST:
110	snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
111	DEFAULT_GLOBAL_USTCONSUMER64_HEALTH_UNIX_SOCK);
112	break;
113	case LTTNG_CONSUMER32_UST:
114	snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
115	DEFAULT_GLOBAL_USTCONSUMER32_HEALTH_UNIX_SOCK);
116	break;
117	default:
118	ret = -EINVAL;
119	goto end;
120	}
121	} else {
5c635c72 MD	122	home_path = utils_get_home_dir();
	123	if (home_path == NULL) {
	124	/* TODO: Add --socket PATH option */
	125	ERR("Can't get HOME directory for sockets creation.");
	126	ret = -EPERM;
	127	goto end;
	128	}
	129
5c635c72 MD	130	/* Set health check Unix path */
	131	if (strlen(health_unix_sock_path) != 0) {
	132	goto end;
	133	}
	134	switch (type) {
	135	case LTTNG_CONSUMER_KERNEL:
	136	snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
dbc8403d	137	DEFAULT_HOME_KCONSUMER_HEALTH_UNIX_SOCK, home_path);
5c635c72 MD	138	break;
	139	case LTTNG_CONSUMER64_UST:
	140	snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
dbc8403d	141	DEFAULT_HOME_USTCONSUMER64_HEALTH_UNIX_SOCK, home_path);
5c635c72 MD	142	break;
	143	case LTTNG_CONSUMER32_UST:
	144	snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
dbc8403d	145	DEFAULT_HOME_USTCONSUMER32_HEALTH_UNIX_SOCK, home_path);
5c635c72 MD	146	break;
	147	default:
	148	ret = -EINVAL;
	149	goto end;
	150	}
	151	}
5c635c72 MD	152	end:
	153	return ret;
	154	}
	155
	156	/*
	157	* Thread managing health check socket.
	158	*/
	159	void thread_manage_health(void data)
	160	{
	161	int sock = -1, new_sock = -1, ret, i, pollfd, err = -1;
	162	uint32_t revents, nb_fd;
	163	struct lttng_poll_event events;
	164	struct health_comm_msg msg;
	165	struct health_comm_reply reply;
6c71277b	166	int is_root;
5c635c72 MD	167
	168	DBG("[thread] Manage health check started");
	169
	170	setup_health_path();
	171
	172	rcu_register_thread();
	173
	174	/* We might hit an error path before this is created. */
	175	lttng_poll_init(&events);
	176
	177	/* Create unix socket */
	178	sock = lttcomm_create_unix_sock(health_unix_sock_path);
	179	if (sock < 0) {
	180	ERR("Unable to create health check Unix socket");
	181	ret = -1;
	182	goto error;
	183	}
	184
6c71277b MD	185	is_root = !getuid();
	186	if (is_root) {
	187	/* lttng health client socket path permissions */
	188	ret = chown(health_unix_sock_path, 0,
	189	utils_get_group_id(tracing_group_name));
	190	if (ret < 0) {
	191	ERR("Unable to set group on %s", health_unix_sock_path);
	192	PERROR("chown");
	193	ret = -1;
	194	goto error;
	195	}
	196
	197	ret = chmod(health_unix_sock_path,
	198	S_IRUSR \| S_IWUSR \| S_IRGRP \| S_IWGRP);
	199	if (ret < 0) {
	200	ERR("Unable to set permissions on %s", health_unix_sock_path);
	201	PERROR("chmod");
	202	ret = -1;
	203	goto error;
	204	}
	205	}
	206
5c635c72 MD	207	/*
	208	* Set the CLOEXEC flag. Return code is useless because either way, the
	209	* show must go on.
	210	*/
	211	(void) utils_set_fd_cloexec(sock);
	212
	213	ret = lttcomm_listen_unix_sock(sock);
	214	if (ret < 0) {
	215	goto error;
	216	}
	217
	218	/* Size is set to 1 for the consumer_channel pipe */
	219	ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
	220	if (ret < 0) {
	221	ERR("Poll set creation failed");
	222	goto error;
	223	}
	224
	225	ret = lttng_poll_add(&events, health_quit_pipe[0], LPOLLIN);
	226	if (ret < 0) {
	227	goto error;
	228	}
	229
	230	/* Add the application registration socket */
	231	ret = lttng_poll_add(&events, sock, LPOLLIN \| LPOLLPRI);
	232	if (ret < 0) {
	233	goto error;
	234	}
	235
748b7b07 MD	236	/* Perform prior memory accesses before decrementing ready */
	237	cmm_smp_mb__before_uatomic_dec();
	238	uatomic_dec(&lttng_consumer_ready);
	239
5c635c72 MD	240	while (1) {
	241	DBG("Health check ready");
	242
	243	/* Inifinite blocking call, waiting for transmission */
	244	restart:
	245	ret = lttng_poll_wait(&events, -1);
	246	if (ret < 0) {
	247	/*
	248	* Restart interrupted system call.
	249	*/
	250	if (errno == EINTR) {
	251	goto restart;
	252	}
	253	goto error;
	254	}
	255
	256	nb_fd = ret;
	257
	258	for (i = 0; i < nb_fd; i++) {
	259	/* Fetch once the poll data */
	260	revents = LTTNG_POLL_GETEV(&events, i);
	261	pollfd = LTTNG_POLL_GETFD(&events, i);
	262
	263	/* Thread quit pipe has been closed. Killing thread. */
	264	ret = check_health_quit_pipe(pollfd, revents);
	265	if (ret) {
	266	err = 0;
	267	goto exit;
	268	}
	269
	270	/* Event on the registration socket */
	271	if (pollfd == sock) {
	272	if (revents & (LPOLLERR \| LPOLLHUP \| LPOLLRDHUP)) {
	273	ERR("Health socket poll error");
	274	goto error;
	275	}
	276	}
	277	}
	278
	279	new_sock = lttcomm_accept_unix_sock(sock);
	280	if (new_sock < 0) {
	281	goto error;
	282	}
	283
	284	/*
	285	* Set the CLOEXEC flag. Return code is useless because either way, the
	286	* show must go on.
	287	*/
	288	(void) utils_set_fd_cloexec(new_sock);
	289
	290	DBG("Receiving data from client for health...");
	291	ret = lttcomm_recv_unix_sock(new_sock, (void *)&msg, sizeof(msg));
	292	if (ret <= 0) {
	293	DBG("Nothing recv() from client... continuing");
	294	ret = close(new_sock);
	295	if (ret) {
	296	PERROR("close");
	297	}
	298	new_sock = -1;
	299	continue;
	300	}
	301
	302	rcu_thread_online();
	303
304	assert(msg.cmd == HEALTH_CMD_CHECK);
305
6c71277b MD	306	reply.ret_code = 0;
	307	for (i = 0; i < NR_HEALTH_CONSUMERD_TYPES; i++) {
	308	/*
	309	* health_check_state return 0 if thread is in
	310	* error.
	311	*/
	312	if (!health_check_state(health_consumerd, i)) {
	313	reply.ret_code \|= 1ULL << i;
	314	}
5c635c72 MD	315	}
5c635c72 MD	316
6c71277b	317	DBG2("Health check return value %" PRIx64, reply.ret_code);
5c635c72 MD	318
	319	ret = send_unix_sock(new_sock, (void *) &reply, sizeof(reply));
	320	if (ret < 0) {
	321	ERR("Failed to send health data back to client");
	322	}
	323
	324	/* End of transmission */
	325	ret = close(new_sock);
	326	if (ret) {
	327	PERROR("close");
	328	}
	329	new_sock = -1;
	330	}
	331
	332	exit:
	333	error:
	334	if (err) {
	335	ERR("Health error occurred in %s", __func__);
	336	}
	337	DBG("Health check thread dying");
	338	unlink(health_unix_sock_path);
	339	if (sock >= 0) {
	340	ret = close(sock);
	341	if (ret) {
	342	PERROR("close");
	343	}
	344	}
	345
	346	lttng_poll_clean(&events);
	347
	348	rcu_unregister_thread();
	349	return NULL;
	350	}