[lttng-tools.git] / src / bin / lttng-sessiond / notification-thread.c

/*
 * Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@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 _LGPL_SOURCE
#include <lttng/trigger/trigger.h>
#include <lttng/notification/channel-internal.h>
#include <lttng/notification/notification-internal.h>
#include <lttng/condition/condition-internal.h>
#include <lttng/condition/buffer-usage-internal.h>
#include <common/error.h>
#include <common/config/session-config.h>
#include <common/defaults.h>
#include <common/utils.h>
#include <common/align.h>
#include <common/time.h>
#include <sys/eventfd.h>
#include <sys/stat.h>
#include <time.h>
#include <signal.h>

#include "notification-thread.h"
#include "notification-thread-events.h"
#include "notification-thread-commands.h"
#include "lttng-sessiond.h"
#include "health-sessiond.h"

#include <urcu.h>
#include <urcu/list.h>
#include <urcu/rculfhash.h>

/*
 * Destroy the thread data previously created by the init function.
 */
void notification_thread_handle_destroy(
		struct notification_thread_handle *handle)
{
	int ret;

	if (!handle) {
		goto end;
	}

	assert(cds_list_empty(&handle->cmd_queue.list));
	pthread_mutex_destroy(&handle->cmd_queue.lock);

	if (handle->cmd_queue.event_pipe) {
		lttng_pipe_destroy(handle->cmd_queue.event_pipe);
	}
	if (handle->channel_monitoring_pipes.ust32_consumer >= 0) {
		ret = close(handle->channel_monitoring_pipes.ust32_consumer);
		if (ret) {
			PERROR("close 32-bit consumer channel monitoring pipe");
		}
	}
	if (handle->channel_monitoring_pipes.ust64_consumer >= 0) {
		ret = close(handle->channel_monitoring_pipes.ust64_consumer);
		if (ret) {
			PERROR("close 64-bit consumer channel monitoring pipe");
		}
	}
	if (handle->channel_monitoring_pipes.kernel_consumer >= 0) {
		ret = close(handle->channel_monitoring_pipes.kernel_consumer);
		if (ret) {
			PERROR("close kernel consumer channel monitoring pipe");
		}
	}
end:
	free(handle);
}

struct notification_thread_handle *notification_thread_handle_create(
		struct lttng_pipe *ust32_channel_monitor_pipe,
		struct lttng_pipe *ust64_channel_monitor_pipe,
		struct lttng_pipe *kernel_channel_monitor_pipe)
{
	int ret;
	struct notification_thread_handle *handle;
	struct lttng_pipe *event_pipe = NULL;

	handle = zmalloc(sizeof(*handle));
	if (!handle) {
		goto end;
	}

	event_pipe = lttng_pipe_open(O_CLOEXEC);
	if (!event_pipe) {
		ERR("event_pipe creation");
		goto error;
	}

	handle->cmd_queue.event_pipe = event_pipe;
	event_pipe = NULL;

	CDS_INIT_LIST_HEAD(&handle->cmd_queue.list);
	ret = pthread_mutex_init(&handle->cmd_queue.lock, NULL);
	if (ret) {
		goto error;
	}

	if (ust32_channel_monitor_pipe) {
		handle->channel_monitoring_pipes.ust32_consumer =
				lttng_pipe_release_readfd(
					ust32_channel_monitor_pipe);
		if (handle->channel_monitoring_pipes.ust32_consumer < 0) {
			goto error;
		}
	} else {
		handle->channel_monitoring_pipes.ust32_consumer = -1;
	}
	if (ust64_channel_monitor_pipe) {
		handle->channel_monitoring_pipes.ust64_consumer =
				lttng_pipe_release_readfd(
					ust64_channel_monitor_pipe);
		if (handle->channel_monitoring_pipes.ust64_consumer < 0) {
			goto error;
		}
	} else {
		handle->channel_monitoring_pipes.ust64_consumer = -1;
	}
	if (kernel_channel_monitor_pipe) {
		handle->channel_monitoring_pipes.kernel_consumer =
				lttng_pipe_release_readfd(
					kernel_channel_monitor_pipe);
		if (handle->channel_monitoring_pipes.kernel_consumer < 0) {
			goto error;
		}
	} else {
		handle->channel_monitoring_pipes.kernel_consumer = -1;
	}
end:
	return handle;
error:
	lttng_pipe_destroy(event_pipe);
	notification_thread_handle_destroy(handle);
	return NULL;
}

static
char *get_notification_channel_sock_path(void)
{
	int ret;
	bool is_root = !getuid();
	char *sock_path;

	sock_path = zmalloc(LTTNG_PATH_MAX);
	if (!sock_path) {
		goto error;
	}

	if (is_root) {
		ret = snprintf(sock_path, LTTNG_PATH_MAX,
				DEFAULT_GLOBAL_NOTIFICATION_CHANNEL_UNIX_SOCK);
		if (ret < 0) {
			goto error;
		}
	} else {
		char *home_path = utils_get_home_dir();

		if (!home_path) {
			ERR("Can't get HOME directory for socket creation");
			goto error;
		}

		ret = snprintf(sock_path, LTTNG_PATH_MAX,
				DEFAULT_HOME_NOTIFICATION_CHANNEL_UNIX_SOCK,
				home_path);
		if (ret < 0) {
			goto error;
		}
	}

	return sock_path;
error:
	free(sock_path);
	return NULL;
}

static
void notification_channel_socket_destroy(int fd)
{
	int ret;
	char *sock_path = get_notification_channel_sock_path();

	DBG("[notification-thread] Destroying notification channel socket");

	if (sock_path) {
		ret = unlink(sock_path);
		free(sock_path);
		if (ret < 0) {
			PERROR("unlink notification channel socket");
		}
	}

	ret = close(fd);
	if (ret) {
		PERROR("close notification channel socket");
	}
}

static
int notification_channel_socket_create(void)
{
	int fd = -1, ret;
	char *sock_path = get_notification_channel_sock_path();

	DBG("[notification-thread] Creating notification channel UNIX socket at %s",
			sock_path);

	ret = lttcomm_create_unix_sock(sock_path);
	if (ret < 0) {
		ERR("[notification-thread] Failed to create notification socket");
		goto error;
	}
	fd = ret;

	ret = chmod(sock_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
	if (ret < 0) {
		ERR("Set file permissions failed: %s", sock_path);
		PERROR("chmod notification channel socket");
		goto error;
	}

	if (getuid() == 0) {
		ret = chown(sock_path, 0,
				utils_get_group_id(tracing_group_name));
		if (ret) {
			ERR("Failed to set the notification channel socket's group");
			ret = -1;
			goto error;
		}
	}

	DBG("[notification-thread] Notification channel UNIX socket created (fd = %i)",
			fd);
	free(sock_path);
	return fd;
error:
	if (fd >= 0 && close(fd) < 0) {
		PERROR("close notification channel socket");
	}
	free(sock_path);
	return ret;
}

static
int init_poll_set(struct lttng_poll_event *poll_set,
		struct notification_thread_handle *handle,
		int notification_channel_socket)
{
	int ret;

	/*
	 * Create pollset with size 5:
	 *	- notification channel socket (listen for new connections),
	 *	- command queue event fd (internal sessiond commands),
	 *	- consumerd (32-bit user space) channel monitor pipe,
	 *	- consumerd (64-bit user space) channel monitor pipe,
	 *	- consumerd (kernel) channel monitor pipe.
	 */
	ret = lttng_poll_create(poll_set, 5, LTTNG_CLOEXEC);
	if (ret < 0) {
		goto end;
	}

	ret = lttng_poll_add(poll_set, notification_channel_socket,
			LPOLLIN | LPOLLERR | LPOLLHUP | LPOLLRDHUP);
	if (ret < 0) {
		ERR("[notification-thread] Failed to add notification channel socket to pollset");
		goto error;
	}
	ret = lttng_poll_add(poll_set, lttng_pipe_get_readfd(handle->cmd_queue.event_pipe),
			LPOLLIN | LPOLLERR);
	if (ret < 0) {
		ERR("[notification-thread] Failed to add notification command queue event fd to pollset");
		goto error;
	}
	ret = lttng_poll_add(poll_set,
			handle->channel_monitoring_pipes.ust32_consumer,
			LPOLLIN | LPOLLERR);
	if (ret < 0) {
		ERR("[notification-thread] Failed to add ust-32 channel monitoring pipe fd to pollset");
		goto error;
	}
	ret = lttng_poll_add(poll_set,
			handle->channel_monitoring_pipes.ust64_consumer,
			LPOLLIN | LPOLLERR);
	if (ret < 0) {
		ERR("[notification-thread] Failed to add ust-64 channel monitoring pipe fd to pollset");
		goto error;
	}
	if (handle->channel_monitoring_pipes.kernel_consumer < 0) {
		goto end;
	}
	ret = lttng_poll_add(poll_set,
			handle->channel_monitoring_pipes.kernel_consumer,
			LPOLLIN | LPOLLERR);
	if (ret < 0) {
		ERR("[notification-thread] Failed to add kernel channel monitoring pipe fd to pollset");
		goto error;
	}
end:
	return ret;
error:
	lttng_poll_clean(poll_set);
	return ret;
}

static
void fini_thread_state(struct notification_thread_state *state)
{
	int ret;

	if (state->client_socket_ht) {
		ret = handle_notification_thread_client_disconnect_all(state);
		assert(!ret);
		ret = cds_lfht_destroy(state->client_socket_ht, NULL);
		assert(!ret);
	}
	if (state->triggers_ht) {
		ret = handle_notification_thread_trigger_unregister_all(state);
		assert(!ret);
		ret = cds_lfht_destroy(state->triggers_ht, NULL);
		assert(!ret);
	}
	if (state->channel_triggers_ht) {
		ret = cds_lfht_destroy(state->channel_triggers_ht, NULL);
		assert(!ret);
	}
	if (state->channel_state_ht) {
		ret = cds_lfht_destroy(state->channel_state_ht, NULL);
		assert(!ret);
	}
	if (state->notification_trigger_clients_ht) {
		ret = cds_lfht_destroy(state->notification_trigger_clients_ht,
				NULL);
		assert(!ret);
	}
	if (state->channels_ht) {
		ret = cds_lfht_destroy(state->channels_ht,
				NULL);
		assert(!ret);
	}

	if (state->notification_channel_socket >= 0) {
		notification_channel_socket_destroy(
				state->notification_channel_socket);
	}
	lttng_poll_clean(&state->events);
}

static
int init_thread_state(struct notification_thread_handle *handle,
		struct notification_thread_state *state)
{
	int ret;

	memset(state, 0, sizeof(*state));
	state->notification_channel_socket = -1;
	lttng_poll_init(&state->events);

	ret = notification_channel_socket_create();
	if (ret < 0) {
		goto end;
	}
	state->notification_channel_socket = ret;

	ret = init_poll_set(&state->events, handle,
			state->notification_channel_socket);
	if (ret) {
		goto end;
	}

	DBG("[notification-thread] Listening on notification channel socket");
	ret = lttcomm_listen_unix_sock(state->notification_channel_socket);
	if (ret < 0) {
		ERR("[notification-thread] Listen failed on notification channel socket");
		goto error;
	}

	state->client_socket_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
			CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
	if (!state->client_socket_ht) {
		goto error;
	}

	state->channel_triggers_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
			CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
	if (!state->channel_triggers_ht) {
		goto error;
	}

	state->channel_state_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
			CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
	if (!state->channel_state_ht) {
		goto error;
	}

	state->notification_trigger_clients_ht = cds_lfht_new(DEFAULT_HT_SIZE,
			1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
	if (!state->notification_trigger_clients_ht) {
		goto error;
	}

	state->channels_ht = cds_lfht_new(DEFAULT_HT_SIZE,
			1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
	if (!state->channels_ht) {
		goto error;
	}

	state->triggers_ht = cds_lfht_new(DEFAULT_HT_SIZE,
			1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
	if (!state->triggers_ht) {
		goto error;
	}
end:
	return 0;
error:
	fini_thread_state(state);
	return -1;
}

static
int handle_channel_monitoring_pipe(int fd, uint32_t revents,
		struct notification_thread_handle *handle,
		struct notification_thread_state *state)
{
	int ret = 0;
	enum lttng_domain_type domain;

	if (fd == handle->channel_monitoring_pipes.ust32_consumer ||
			fd == handle->channel_monitoring_pipes.ust64_consumer) {
		domain = LTTNG_DOMAIN_UST;
	} else if (fd == handle->channel_monitoring_pipes.kernel_consumer) {
		domain = LTTNG_DOMAIN_KERNEL;
	} else {
		abort();
	}

	if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
		ret = lttng_poll_del(&state->events, fd);
		if (ret) {
			ERR("[notification-thread] Failed to remove consumer monitoring pipe from poll set");
		}
		goto end;
	}

	ret = handle_notification_thread_channel_sample(
			state, fd, domain);
	if (ret) {
		ERR("[notification-thread] Consumer sample handling error occurred");
		ret = -1;
		goto end;
	}
end:
	return ret;
}

/*
 * This thread services notification channel clients and commands received
 * from various lttng-sessiond components over a command queue.
 */
void *thread_notification(void *data)
{
	int ret;
	struct notification_thread_handle *handle = data;
	struct notification_thread_state state;

	DBG("[notification-thread] Started notification thread");

	if (!handle) {
		ERR("[notification-thread] Invalid thread context provided");
		goto end;
	}

	rcu_register_thread();
	rcu_thread_online();

	health_register(health_sessiond, HEALTH_SESSIOND_TYPE_NOTIFICATION);
	health_code_update();

	ret = init_thread_state(handle, &state);
	if (ret) {
		goto end;
	}

	/* Ready to handle client connections. */
	sessiond_notify_ready();

	while (true) {
		int fd_count, i;

		health_poll_entry();
		DBG("[notification-thread] Entering poll wait");
		ret = lttng_poll_wait(&state.events, -1);
		DBG("[notification-thread] Poll wait returned (%i)", ret);
		health_poll_exit();
		if (ret < 0) {
			/*
			 * Restart interrupted system call.
			 */
			if (errno == EINTR) {
				continue;
			}
			ERR("[notification-thread] Error encountered during lttng_poll_wait (%i)", ret);
			goto error;
		}

		fd_count = ret;
		for (i = 0; i < fd_count; i++) {
			int fd = LTTNG_POLL_GETFD(&state.events, i);
			uint32_t revents = LTTNG_POLL_GETEV(&state.events, i);

			if (!revents) {
				continue;
			}
			DBG("[notification-thread] Handling fd (%i) activity (%u)", fd, revents);

			if (fd == state.notification_channel_socket) {
				if (revents & LPOLLIN) {
					ret = handle_notification_thread_client_connect(
							&state);
					if (ret < 0) {
						goto error;
					}
				} else if (revents &
						(LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
					ERR("[notification-thread] Notification socket poll error");
					goto error;
				} else {
					ERR("[notification-thread] Unexpected poll events %u for notification socket %i", revents, fd);
					goto error;
				}
			} else if (fd == lttng_pipe_get_readfd(handle->cmd_queue.event_pipe)) {
				ret = handle_notification_thread_command(handle,
						&state);
				if (ret < 0) {
					DBG("[notification-thread] Error encountered while servicing command queue");
					goto error;
				} else if (ret > 0) {
					goto exit;
				}
			} else if (fd == handle->channel_monitoring_pipes.ust32_consumer ||
					fd == handle->channel_monitoring_pipes.ust64_consumer ||
					fd == handle->channel_monitoring_pipes.kernel_consumer) {
				ret = handle_channel_monitoring_pipe(fd,
						revents, handle, &state);
				if (ret) {
					goto error;
				}
			} else {
				/* Activity on a client's socket. */
				if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
					/*
					 * It doesn't matter if a command was
					 * pending on the client socket at this
					 * point since it now has no way to
					 * receive the notifications to which
					 * it was subscribing or unsubscribing.
					 */
					ret = handle_notification_thread_client_disconnect(
							fd, &state);
					if (ret) {
						goto error;
					}
				} else {
					if (revents & LPOLLIN) {
						ret = handle_notification_thread_client_in(
							&state, fd);
						if (ret) {
							goto error;
						}
					}

					if (revents & LPOLLOUT) {
						ret = handle_notification_thread_client_out(
							&state, fd);
						if (ret) {
							goto error;
						}
					}
				}
			}
		}
	}
exit:
error:
	fini_thread_state(&state);
	health_unregister(health_sessiond);
	rcu_thread_offline();
	rcu_unregister_thread();
end:
	return NULL;
}
Commit	Line	Data
ab0ee2ca JG	1	/*
	2	* Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
	3	*
	4	* This program is free software; you can redistribute it and/or modify it
	5	* under the terms of the GNU General Public License, version 2 only, as
	6	* published by the Free Software Foundation.
	7	*
	8	* This program is distributed in the hope that it will be useful, but WITHOUT
	9	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	10	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	11	* more details.
	12	*
	13	* You should have received a copy of the GNU General Public License along with
	14	* this program; if not, write to the Free Software Foundation, Inc., 51
	15	* Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
	16	*/
	17
	18	#define _LGPL_SOURCE
	19	#include <lttng/trigger/trigger.h>
	20	#include <lttng/notification/channel-internal.h>
	21	#include <lttng/notification/notification-internal.h>
	22	#include <lttng/condition/condition-internal.h>
	23	#include <lttng/condition/buffer-usage-internal.h>
	24	#include <common/error.h>
	25	#include <common/config/session-config.h>
	26	#include <common/defaults.h>
	27	#include <common/utils.h>
ab0ee2ca JG	28	#include <common/align.h>
	29	#include <common/time.h>
	30	#include <sys/eventfd.h>
	31	#include <sys/stat.h>
	32	#include <time.h>
	33	#include <signal.h>
	34
	35	#include "notification-thread.h"
	36	#include "notification-thread-events.h"
	37	#include "notification-thread-commands.h"
	38	#include "lttng-sessiond.h"
	39	#include "health-sessiond.h"
	40
	41	#include <urcu.h>
	42	#include <urcu/list.h>
	43	#include <urcu/rculfhash.h>
	44
ab0ee2ca JG	45	/*
	46	* Destroy the thread data previously created by the init function.
	47	*/
	48	void notification_thread_handle_destroy(
	49	struct notification_thread_handle *handle)
	50	{
	51	int ret;
ab0ee2ca JG	52
	53	if (!handle) {
	54	goto end;
	55	}
	56
8ada111f	57	assert(cds_list_empty(&handle->cmd_queue.list));
ab0ee2ca JG	58	pthread_mutex_destroy(&handle->cmd_queue.lock);
ab0ee2ca JG	59
814b4934 JR	60	if (handle->cmd_queue.event_pipe) {
	61	lttng_pipe_destroy(handle->cmd_queue.event_pipe);
	62	}
ab0ee2ca JG	63	if (handle->channel_monitoring_pipes.ust32_consumer >= 0) {
	64	ret = close(handle->channel_monitoring_pipes.ust32_consumer);
	65	if (ret) {
	66	PERROR("close 32-bit consumer channel monitoring pipe");
	67	}
	68	}
	69	if (handle->channel_monitoring_pipes.ust64_consumer >= 0) {
	70	ret = close(handle->channel_monitoring_pipes.ust64_consumer);
	71	if (ret) {
	72	PERROR("close 64-bit consumer channel monitoring pipe");
	73	}
	74	}
	75	if (handle->channel_monitoring_pipes.kernel_consumer >= 0) {
	76	ret = close(handle->channel_monitoring_pipes.kernel_consumer);
	77	if (ret) {
	78	PERROR("close kernel consumer channel monitoring pipe");
	79	}
	80	}
	81	end:
	82	free(handle);
	83	}
	84
	85	struct notification_thread_handle *notification_thread_handle_create(
	86	struct lttng_pipe *ust32_channel_monitor_pipe,
	87	struct lttng_pipe *ust64_channel_monitor_pipe,
	88	struct lttng_pipe *kernel_channel_monitor_pipe)
	89	{
	90	int ret;
	91	struct notification_thread_handle *handle;
814b4934	92	struct lttng_pipe *event_pipe = NULL;
ab0ee2ca JG	93
	94	handle = zmalloc(sizeof(*handle));
	95	if (!handle) {
	96	goto end;
	97	}
	98
814b4934 JR	99	event_pipe = lttng_pipe_open(O_CLOEXEC);
	100	if (!event_pipe) {
	101	ERR("event_pipe creation");
ab0ee2ca JG	102	goto error;
ab0ee2ca JG	103	}
814b4934 JR	104
	105	handle->cmd_queue.event_pipe = event_pipe;
	106	event_pipe = NULL;
	107
ab0ee2ca JG	108	CDS_INIT_LIST_HEAD(&handle->cmd_queue.list);
	109	ret = pthread_mutex_init(&handle->cmd_queue.lock, NULL);
	110	if (ret) {
	111	goto error;
	112	}
	113
	114	if (ust32_channel_monitor_pipe) {
	115	handle->channel_monitoring_pipes.ust32_consumer =
	116	lttng_pipe_release_readfd(
	117	ust32_channel_monitor_pipe);
	118	if (handle->channel_monitoring_pipes.ust32_consumer < 0) {
	119	goto error;
	120	}
	121	} else {
	122	handle->channel_monitoring_pipes.ust32_consumer = -1;
	123	}
	124	if (ust64_channel_monitor_pipe) {
	125	handle->channel_monitoring_pipes.ust64_consumer =
	126	lttng_pipe_release_readfd(
	127	ust64_channel_monitor_pipe);
	128	if (handle->channel_monitoring_pipes.ust64_consumer < 0) {
	129	goto error;
	130	}
	131	} else {
	132	handle->channel_monitoring_pipes.ust64_consumer = -1;
	133	}
	134	if (kernel_channel_monitor_pipe) {
	135	handle->channel_monitoring_pipes.kernel_consumer =
	136	lttng_pipe_release_readfd(
	137	kernel_channel_monitor_pipe);
	138	if (handle->channel_monitoring_pipes.kernel_consumer < 0) {
	139	goto error;
	140	}
	141	} else {
	142	handle->channel_monitoring_pipes.kernel_consumer = -1;
	143	}
	144	end:
	145	return handle;
	146	error:
814b4934	147	lttng_pipe_destroy(event_pipe);
ab0ee2ca JG	148	notification_thread_handle_destroy(handle);
	149	return NULL;
	150	}
	151
	152	static
	153	char *get_notification_channel_sock_path(void)
	154	{
	155	int ret;
	156	bool is_root = !getuid();
	157	char *sock_path;
	158
	159	sock_path = zmalloc(LTTNG_PATH_MAX);
	160	if (!sock_path) {
	161	goto error;
	162	}
	163
	164	if (is_root) {
	165	ret = snprintf(sock_path, LTTNG_PATH_MAX,
	166	DEFAULT_GLOBAL_NOTIFICATION_CHANNEL_UNIX_SOCK);
	167	if (ret < 0) {
	168	goto error;
	169	}
	170	} else {
	171	char *home_path = utils_get_home_dir();
	172
	173	if (!home_path) {
	174	ERR("Can't get HOME directory for socket creation");
	175	goto error;
	176	}
	177
	178	ret = snprintf(sock_path, LTTNG_PATH_MAX,
	179	DEFAULT_HOME_NOTIFICATION_CHANNEL_UNIX_SOCK,
	180	home_path);
	181	if (ret < 0) {
	182	goto error;
	183	}
	184	}
	185
	186	return sock_path;
	187	error:
	188	free(sock_path);
	189	return NULL;
	190	}
	191
	192	static
	193	void notification_channel_socket_destroy(int fd)
	194	{
	195	int ret;
	196	char *sock_path = get_notification_channel_sock_path();
	197
	198	DBG("[notification-thread] Destroying notification channel socket");
	199
	200	if (sock_path) {
	201	ret = unlink(sock_path);
	202	free(sock_path);
	203	if (ret < 0) {
	204	PERROR("unlink notification channel socket");
	205	}
	206	}
	207
	208	ret = close(fd);
	209	if (ret) {
	210	PERROR("close notification channel socket");
	211	}
212	}
213
214	static
215	int notification_channel_socket_create(void)
216	{
217	int fd = -1, ret;
218	char *sock_path = get_notification_channel_sock_path();
219
220	DBG("[notification-thread] Creating notification channel UNIX socket at %s",
221	sock_path);
222
223	ret = lttcomm_create_unix_sock(sock_path);
224	if (ret < 0) {
225	ERR("[notification-thread] Failed to create notification socket");
226	goto error;
227	}
228	fd = ret;
229
230	ret = chmod(sock_path, S_IRUSR \| S_IWUSR \| S_IRGRP \| S_IWGRP);
231	if (ret < 0) {
232	ERR("Set file permissions failed: %s", sock_path);
233	PERROR("chmod notification channel socket");
234	goto error;
235	}
236
237	if (getuid() == 0) {
238	ret = chown(sock_path, 0,
239	utils_get_group_id(tracing_group_name));
240	if (ret) {
241	ERR("Failed to set the notification channel socket's group");
242	ret = -1;
243	goto error;
244	}
245	}
246
247	DBG("[notification-thread] Notification channel UNIX socket created (fd = %i)",
248	fd);
249	free(sock_path);
250	return fd;
251	error:
252	if (fd >= 0 && close(fd) < 0) {
253	PERROR("close notification channel socket");
254	}
255	free(sock_path);
256	return ret;
257	}
258
259	static
260	int init_poll_set(struct lttng_poll_event *poll_set,
261	struct notification_thread_handle *handle,
262	int notification_channel_socket)
263	{
264	int ret;
265
266	/*
267	* Create pollset with size 5:
268	* - notification channel socket (listen for new connections),
269	* - command queue event fd (internal sessiond commands),
270	* - consumerd (32-bit user space) channel monitor pipe,
271	* - consumerd (64-bit user space) channel monitor pipe,
272	* - consumerd (kernel) channel monitor pipe.
273	*/
274	ret = lttng_poll_create(poll_set, 5, LTTNG_CLOEXEC);
275	if (ret < 0) {
276	goto end;
277	}
278
279	ret = lttng_poll_add(poll_set, notification_channel_socket,
280	LPOLLIN \| LPOLLERR \| LPOLLHUP \| LPOLLRDHUP);
281	if (ret < 0) {
282	ERR("[notification-thread] Failed to add notification channel socket to pollset");
283	goto error;
284	}
814b4934	285	ret = lttng_poll_add(poll_set, lttng_pipe_get_readfd(handle->cmd_queue.event_pipe),
ab0ee2ca JG	286	LPOLLIN \| LPOLLERR);
	287	if (ret < 0) {
	288	ERR("[notification-thread] Failed to add notification command queue event fd to pollset");
	289	goto error;
	290	}
	291	ret = lttng_poll_add(poll_set,
	292	handle->channel_monitoring_pipes.ust32_consumer,
	293	LPOLLIN \| LPOLLERR);
	294	if (ret < 0) {
	295	ERR("[notification-thread] Failed to add ust-32 channel monitoring pipe fd to pollset");
	296	goto error;
	297	}
	298	ret = lttng_poll_add(poll_set,
	299	handle->channel_monitoring_pipes.ust64_consumer,
	300	LPOLLIN \| LPOLLERR);
	301	if (ret < 0) {
	302	ERR("[notification-thread] Failed to add ust-64 channel monitoring pipe fd to pollset");
	303	goto error;
	304	}
	305	if (handle->channel_monitoring_pipes.kernel_consumer < 0) {
	306	goto end;
	307	}
	308	ret = lttng_poll_add(poll_set,
	309	handle->channel_monitoring_pipes.kernel_consumer,
	310	LPOLLIN \| LPOLLERR);
	311	if (ret < 0) {
	312	ERR("[notification-thread] Failed to add kernel channel monitoring pipe fd to pollset");
	313	goto error;
	314	}
	315	end:
	316	return ret;
	317	error:
	318	lttng_poll_clean(poll_set);
	319	return ret;
	320	}
	321
	322	static
	323	void fini_thread_state(struct notification_thread_state *state)
	324	{
	325	int ret;
	326
	327	if (state->client_socket_ht) {
	328	ret = handle_notification_thread_client_disconnect_all(state);
	329	assert(!ret);
	330	ret = cds_lfht_destroy(state->client_socket_ht, NULL);
	331	assert(!ret);
	332	}
	333	if (state->triggers_ht) {
	334	ret = handle_notification_thread_trigger_unregister_all(state);
	335	assert(!ret);
	336	ret = cds_lfht_destroy(state->triggers_ht, NULL);
	337	assert(!ret);
	338	}
	339	if (state->channel_triggers_ht) {
	340	ret = cds_lfht_destroy(state->channel_triggers_ht, NULL);
	341	assert(!ret);
	342	}
	343	if (state->channel_state_ht) {
	344	ret = cds_lfht_destroy(state->channel_state_ht, NULL);
	345	assert(!ret);
	346	}
	347	if (state->notification_trigger_clients_ht) {
	348	ret = cds_lfht_destroy(state->notification_trigger_clients_ht,
	349	NULL);
350	assert(!ret);
351	}
352	if (state->channels_ht) {
353	ret = cds_lfht_destroy(state->channels_ht,
354	NULL);
355	assert(!ret);
356	}
357
358	if (state->notification_channel_socket >= 0) {
359	notification_channel_socket_destroy(
360	state->notification_channel_socket);
361	}
362	lttng_poll_clean(&state->events);
363	}
364
365	static
366	int init_thread_state(struct notification_thread_handle *handle,
367	struct notification_thread_state *state)
368	{
369	int ret;
370
371	memset(state, 0, sizeof(*state));
372	state->notification_channel_socket = -1;
373	lttng_poll_init(&state->events);
374
375	ret = notification_channel_socket_create();
376	if (ret < 0) {
377	goto end;
378	}
379	state->notification_channel_socket = ret;
380
381	ret = init_poll_set(&state->events, handle,
382	state->notification_channel_socket);
383	if (ret) {
384	goto end;
385	}
386
387	DBG("[notification-thread] Listening on notification channel socket");
388	ret = lttcomm_listen_unix_sock(state->notification_channel_socket);
389	if (ret < 0) {
390	ERR("[notification-thread] Listen failed on notification channel socket");
391	goto error;
392	}
393
394	state->client_socket_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
395	CDS_LFHT_AUTO_RESIZE \| CDS_LFHT_ACCOUNTING, NULL);
396	if (!state->client_socket_ht) {
397	goto error;
398	}
399
400	state->channel_triggers_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
401	CDS_LFHT_AUTO_RESIZE \| CDS_LFHT_ACCOUNTING, NULL);
402	if (!state->channel_triggers_ht) {
403	goto error;
404	}
405
406	state->channel_state_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
407	CDS_LFHT_AUTO_RESIZE \| CDS_LFHT_ACCOUNTING, NULL);
408	if (!state->channel_state_ht) {
409	goto error;
410	}
411
412	state->notification_trigger_clients_ht = cds_lfht_new(DEFAULT_HT_SIZE,
413	1, 0, CDS_LFHT_AUTO_RESIZE \| CDS_LFHT_ACCOUNTING, NULL);
414	if (!state->notification_trigger_clients_ht) {
415	goto error;
416	}
417
418	state->channels_ht = cds_lfht_new(DEFAULT_HT_SIZE,
419	1, 0, CDS_LFHT_AUTO_RESIZE \| CDS_LFHT_ACCOUNTING, NULL);
420	if (!state->channels_ht) {
421	goto error;
422	}
423
424	state->triggers_ht = cds_lfht_new(DEFAULT_HT_SIZE,
425	1, 0, CDS_LFHT_AUTO_RESIZE \| CDS_LFHT_ACCOUNTING, NULL);
426	if (!state->triggers_ht) {
427	goto error;
428	}
429	end:
430	return 0;
431	error:
432	fini_thread_state(state);
433	return -1;
434	}
435
436	static
437	int handle_channel_monitoring_pipe(int fd, uint32_t revents,
438	struct notification_thread_handle *handle,
439	struct notification_thread_state *state)
440	{
441	int ret = 0;
442	enum lttng_domain_type domain;
443
444	if (fd == handle->channel_monitoring_pipes.ust32_consumer \|\|
445	fd == handle->channel_monitoring_pipes.ust64_consumer) {
446	domain = LTTNG_DOMAIN_UST;
447	} else if (fd == handle->channel_monitoring_pipes.kernel_consumer) {
448	domain = LTTNG_DOMAIN_KERNEL;
449	} else {
450	abort();
451	}
452
453	if (revents & (LPOLLERR \| LPOLLHUP \| LPOLLRDHUP)) {
454	ret = lttng_poll_del(&state->events, fd);
455	if (ret) {
456	ERR("[notification-thread] Failed to remove consumer monitoring pipe from poll set");
457	}
458	goto end;
459	}
460
461	ret = handle_notification_thread_channel_sample(
462	state, fd, domain);
463	if (ret) {
4149ace8	464	ERR("[notification-thread] Consumer sample handling error occurred");
ab0ee2ca JG	465	ret = -1;
	466	goto end;
	467	}
	468	end:
	469	return ret;
	470	}
	471
	472	/*
	473	* This thread services notification channel clients and commands received
	474	* from various lttng-sessiond components over a command queue.
	475	*/
	476	void thread_notification(void data)
	477	{
	478	int ret;
	479	struct notification_thread_handle *handle = data;
	480	struct notification_thread_state state;
	481
	482	DBG("[notification-thread] Started notification thread");
	483
	484	if (!handle) {
	485	ERR("[notification-thread] Invalid thread context provided");
	486	goto end;
	487	}
	488
	489	rcu_register_thread();
	490	rcu_thread_online();
	491
	492	health_register(health_sessiond, HEALTH_SESSIOND_TYPE_NOTIFICATION);
	493	health_code_update();
	494
	495	ret = init_thread_state(handle, &state);
	496	if (ret) {
	497	goto end;
	498	}
	499
	500	/* Ready to handle client connections. */
	501	sessiond_notify_ready();
	502
	503	while (true) {
	504	int fd_count, i;
	505
	506	health_poll_entry();
	507	DBG("[notification-thread] Entering poll wait");
	508	ret = lttng_poll_wait(&state.events, -1);
	509	DBG("[notification-thread] Poll wait returned (%i)", ret);
	510	health_poll_exit();
	511	if (ret < 0) {
	512	/*
	513	* Restart interrupted system call.
	514	*/
	515	if (errno == EINTR) {
	516	continue;
	517	}
	518	ERR("[notification-thread] Error encountered during lttng_poll_wait (%i)", ret);
	519	goto error;
	520	}
	521
	522	fd_count = ret;
	523	for (i = 0; i < fd_count; i++) {
	524	int fd = LTTNG_POLL_GETFD(&state.events, i);
	525	uint32_t revents = LTTNG_POLL_GETEV(&state.events, i);
	526
2d01d977 JG	527	if (!revents) {
	528	continue;
	529	}
ab0ee2ca JG	530	DBG("[notification-thread] Handling fd (%i) activity (%u)", fd, revents);
	531
	532	if (fd == state.notification_channel_socket) {
	533	if (revents & LPOLLIN) {
	534	ret = handle_notification_thread_client_connect(
	535	&state);
	536	if (ret < 0) {
	537	goto error;
	538	}
	539	} else if (revents &
	540	(LPOLLERR \| LPOLLHUP \| LPOLLRDHUP)) {
	541	ERR("[notification-thread] Notification socket poll error");
	542	goto error;
	543	} else {
	544	ERR("[notification-thread] Unexpected poll events %u for notification socket %i", revents, fd);
	545	goto error;
	546	}
814b4934	547	} else if (fd == lttng_pipe_get_readfd(handle->cmd_queue.event_pipe)) {
ab0ee2ca JG	548	ret = handle_notification_thread_command(handle,
	549	&state);
	550	if (ret < 0) {
	551	DBG("[notification-thread] Error encountered while servicing command queue");
	552	goto error;
	553	} else if (ret > 0) {
	554	goto exit;
	555	}
	556	} else if (fd == handle->channel_monitoring_pipes.ust32_consumer \|\|
	557	fd == handle->channel_monitoring_pipes.ust64_consumer \|\|
	558	fd == handle->channel_monitoring_pipes.kernel_consumer) {
	559	ret = handle_channel_monitoring_pipe(fd,
	560	revents, handle, &state);
	561	if (ret) {
	562	goto error;
	563	}
	564	} else {
	565	/* Activity on a client's socket. */
	566	if (revents & (LPOLLERR \| LPOLLHUP \| LPOLLRDHUP)) {
	567	/*
	568	* It doesn't matter if a command was
	569	* pending on the client socket at this
	570	* point since it now has no way to
	571	* receive the notifications to which
	572	* it was subscribing or unsubscribing.
	573	*/
	574	ret = handle_notification_thread_client_disconnect(
	575	fd, &state);
	576	if (ret) {
	577	goto error;
	578	}
	579	} else {
	580	if (revents & LPOLLIN) {
	581	ret = handle_notification_thread_client_in(
	582	&state, fd);
	583	if (ret) {
	584	goto error;
	585	}
	586	}
	587
	588	if (revents & LPOLLOUT) {
	589	ret = handle_notification_thread_client_out(
	590	&state, fd);
	591	if (ret) {
	592	goto error;
	593	}
	594	}
	595	}
	596	}
	597	}
	598	}
	599	exit:
	600	error:
	601	fini_thread_state(&state);
	602	health_unregister(health_sessiond);
	603	rcu_thread_offline();
	604	rcu_unregister_thread();
	605	end:
	606	return NULL;
	607	}