[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
#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 setup_health_path(void)
{
	int is_root, ret = 0;
	char *home_path = NULL, *rundir = NULL, *relayd_path;

	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;
	}

	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_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
	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>
	42	#include <inttypes.h>
	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-relayd.h"
	53	#include "health-relayd.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 int create_lttng_rundir_with_perm(const char *rundir)
91	{
92	int ret;
93
94	DBG3("Creating LTTng run directory: %s", rundir);
95
96	ret = mkdir(rundir, S_IRWXU);
97	if (ret < 0) {
98	if (errno != EEXIST) {
99	ERR("Unable to create %s", rundir);
100	goto error;
101	} else {
102	ret = 0;
103	}
104	} else if (ret == 0) {
105	int is_root = !getuid();
106
107	if (is_root) {
108	ret = chown(rundir, 0,
109	utils_get_group_id(tracing_group_name));
110	if (ret < 0) {
111	ERR("Unable to set group on %s", rundir);
112	PERROR("chown");
113	ret = -1;
114	goto error;
115	}
116
117	ret = chmod(rundir,
118	S_IRUSR \| S_IWUSR \| S_IXUSR \| S_IRGRP \| S_IXGRP \| S_IROTH \| S_IXOTH);
119	if (ret < 0) {
120	ERR("Unable to set permissions on %s", health_unix_sock_path);
121	PERROR("chmod");
122	ret = -1;
123	goto error;
124	}
125	}
126	}
127
128	error:
129	return ret;
130	}
131
132	static
133	int setup_health_path(void)
134	{
135	int is_root, ret = 0;
c3844e39	136	char home_path = NULL, rundir = NULL, *relayd_path;
65931c8b MD	137
	138	is_root = !getuid();
	139
	140	if (is_root) {
c3844e39	141	rundir = strdup(DEFAULT_LTTNG_RUNDIR);
65931c8b MD	142	} else {
	143	/*
	144	* Create rundir from home path. This will create something like
	145	* $HOME/.lttng
	146	*/
	147	home_path = utils_get_home_dir();
	148
	149	if (home_path == NULL) {
	150	/* TODO: Add --socket PATH option */
	151	ERR("Can't get HOME directory for sockets creation.");
	152	ret = -EPERM;
	153	goto end;
	154	}
	155
c3844e39	156	ret = asprintf(&rundir, DEFAULT_LTTNG_HOME_RUNDIR, home_path);
65931c8b MD	157	if (ret < 0) {
	158	ret = -ENOMEM;
	159	goto end;
	160	}
	161	}
	162
c3844e39	163	ret = asprintf(&relayd_path, DEFAULT_RELAYD_PATH, rundir);
65931c8b MD	164	if (ret < 0) {
	165	ret = -ENOMEM;
	166	goto end;
	167	}
	168
c3844e39	169	ret = create_lttng_rundir_with_perm(rundir);
65931c8b MD	170	if (ret < 0) {
	171	goto end;
	172	}
	173
	174	ret = create_lttng_rundir_with_perm(relayd_path);
	175	if (ret < 0) {
	176	goto end;
	177	}
	178
	179	if (is_root) {
	180	if (strlen(health_unix_sock_path) != 0) {
	181	goto end;
	182	}
	183	snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
	184	DEFAULT_GLOBAL_RELAY_HEALTH_UNIX_SOCK,
	185	getpid());
	186	} else {
	187	/* Set health check Unix path */
	188	if (strlen(health_unix_sock_path) != 0) {
	189	goto end;
	190	}
	191
	192	snprintf(health_unix_sock_path, sizeof(health_unix_sock_path),
	193	DEFAULT_HOME_RELAY_HEALTH_UNIX_SOCK,
	194	home_path, getpid());
	195	}
	196
	197	end:
c3844e39	198	free(rundir);
65931c8b MD	199	return ret;
	200	}
	201
	202	/*
	203	* Thread managing health check socket.
	204	*/
	205	void thread_manage_health(void data)
	206	{
	207	int sock = -1, new_sock = -1, ret, i, pollfd, err = -1;
	208	uint32_t revents, nb_fd;
	209	struct lttng_poll_event events;
	210	struct health_comm_msg msg;
	211	struct health_comm_reply reply;
	212	int is_root;
	213
	214	DBG("[thread] Manage health check started");
	215
	216	setup_health_path();
	217
	218	rcu_register_thread();
	219
	220	/* We might hit an error path before this is created. */
	221	lttng_poll_init(&events);
	222
	223	/* Create unix socket */
	224	sock = lttcomm_create_unix_sock(health_unix_sock_path);
	225	if (sock < 0) {
	226	ERR("Unable to create health check Unix socket");
	227	ret = -1;
	228	goto error;
	229	}
	230
	231	is_root = !getuid();
	232	if (is_root) {
	233	/* lttng health client socket path permissions */
	234	ret = chown(health_unix_sock_path, 0,
	235	utils_get_group_id(tracing_group_name));
	236	if (ret < 0) {
	237	ERR("Unable to set group on %s", health_unix_sock_path);
	238	PERROR("chown");
	239	ret = -1;
	240	goto error;
	241	}
	242
	243	ret = chmod(health_unix_sock_path,
	244	S_IRUSR \| S_IWUSR \| S_IRGRP \| S_IWGRP);
	245	if (ret < 0) {
	246	ERR("Unable to set permissions on %s", health_unix_sock_path);
	247	PERROR("chmod");
	248	ret = -1;
	249	goto error;
	250	}
	251	}
	252
	253	/*
	254	* Set the CLOEXEC flag. Return code is useless because either way, the
	255	* show must go on.
	256	*/
	257	(void) utils_set_fd_cloexec(sock);
	258
	259	ret = lttcomm_listen_unix_sock(sock);
	260	if (ret < 0) {
	261	goto error;
	262	}
263
264	/* Size is set to 1 for the consumer_channel pipe */
265	ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
266	if (ret < 0) {
267	ERR("Poll set creation failed");
268	goto error;
269	}
270
271	ret = lttng_poll_add(&events, health_quit_pipe[0], LPOLLIN);
272	if (ret < 0) {
273	goto error;
274	}
275
276	/* Add the application registration socket */
277	ret = lttng_poll_add(&events, sock, LPOLLIN \| LPOLLPRI);
278	if (ret < 0) {
279	goto error;
280	}
281
282	while (1) {
283	DBG("Health check ready");
284
285	/* Inifinite blocking call, waiting for transmission */
286	restart:
287	ret = lttng_poll_wait(&events, -1);
288	if (ret < 0) {
289	/*
290	* Restart interrupted system call.
291	*/
292	if (errno == EINTR) {
293	goto restart;
294	}
295	goto error;
296	}
297
298	nb_fd = ret;
299
300	for (i = 0; i < nb_fd; i++) {
301	/* Fetch once the poll data */
302	revents = LTTNG_POLL_GETEV(&events, i);
303	pollfd = LTTNG_POLL_GETFD(&events, i);
304
305	/* Thread quit pipe has been closed. Killing thread. */
306	ret = check_health_quit_pipe(pollfd, revents);
307	if (ret) {
308	err = 0;
309	goto exit;
310	}
311
312	/* Event on the registration socket */
313	if (pollfd == sock) {
314	if (revents & (LPOLLERR \| LPOLLHUP \| LPOLLRDHUP)) {
315	ERR("Health socket poll error");
316	goto error;
317	}
318	}
319	}
320
321	new_sock = lttcomm_accept_unix_sock(sock);
322	if (new_sock < 0) {
323	goto error;
324	}
325
326	/*
327	* Set the CLOEXEC flag. Return code is useless because either way, the
328	* show must go on.
329	*/
330	(void) utils_set_fd_cloexec(new_sock);
331
332	DBG("Receiving data from client for health...");
333	ret = lttcomm_recv_unix_sock(new_sock, (void *)&msg, sizeof(msg));
334	if (ret <= 0) {
335	DBG("Nothing recv() from client... continuing");
336	ret = close(new_sock);
337	if (ret) {
338	PERROR("close");
339	}
340	new_sock = -1;
341	continue;
342	}
343
344	rcu_thread_online();
345
346	assert(msg.cmd == HEALTH_CMD_CHECK);
347
348	reply.ret_code = 0;
349	for (i = 0; i < NR_HEALTH_RELAYD_TYPES; i++) {
350	/*
351	* health_check_state return 0 if thread is in
352	* error.
353	*/
354	if (!health_check_state(health_relayd, i)) {
355	reply.ret_code \|= 1ULL << i;
356	}
357	}
358
359	DBG2("Health check return value %" PRIx64, reply.ret_code);
360
361	ret = send_unix_sock(new_sock, (void *) &reply, sizeof(reply));
362	if (ret < 0) {
363	ERR("Failed to send health data back to client");
364	}
365
366	/* End of transmission */
367	ret = close(new_sock);
368	if (ret) {
369	PERROR("close");
370	}
371	new_sock = -1;
372	}
373
374	exit:
375	error:
376	if (err) {
377	ERR("Health error occurred in %s", __func__);
378	}
379	DBG("Health check thread dying");
380	unlink(health_unix_sock_path);
381	if (sock >= 0) {
382	ret = close(sock);
383	if (ret) {
384	PERROR("close");
385	}
386	}
387
dcbcae3e MD	388	/*
	389	* We do NOT rmdir rundir nor the relayd path because there are
	390	* other processes using them.
	391	*/
	392
65931c8b MD	393	lttng_poll_clean(&events);
	394
	395	rcu_unregister_thread();
	396	return NULL;
	397	}