[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 "thread.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);
	sem_destroy(&handle->ready);

	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;
	}

	sem_init(&handle->ready, 0, 0);

	event_pipe = lttng_pipe_open(FD_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(config.tracing_group_name.value));
		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->sessions_ht) {
		ret = cds_lfht_destroy(state->sessions_ht, NULL);
		assert(!ret);
	}
	/*
	 * Must be destroyed after all channels have been destroyed.
	 * See comment in struct lttng_session_trigger_list.
	 */
	if (state->session_triggers_ht) {
		ret = cds_lfht_destroy(state->session_triggers_ht, NULL);
		assert(!ret);
	}
	if (state->notification_channel_socket >= 0) {
		notification_channel_socket_destroy(
				state->notification_channel_socket);
	}
	lttng_poll_clean(&state->events);
}

static
void mark_thread_as_ready(struct notification_thread_handle *handle)
{
	DBG("Marking notification thread as ready");
	sem_post(&handle->ready);
}

static
void wait_until_thread_is_ready(struct notification_thread_handle *handle)
{
	DBG("Waiting for notification thread to be ready");
	sem_wait(&handle->ready);
	DBG("Notification thread is ready");
}

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->session_triggers_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
			CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
	if (!state->session_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->sessions_ht = cds_lfht_new(DEFAULT_HT_SIZE,
			1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
	if (!state->sessions_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;
	}
	mark_thread_as_ready(handle);
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.
 */
static
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;
	}

	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;
}

static
bool shutdown_notification_thread(void *thread_data)
{
	struct notification_thread_handle *handle = thread_data;

	notification_thread_command_quit(handle);
	return true;
}

bool launch_notification_thread(struct notification_thread_handle *handle)
{
	struct lttng_thread *thread;

	thread = lttng_thread_create("Notification",
			thread_notification,
			shutdown_notification_thread,
			NULL,
			handle);
	if (!thread) {
		goto error;
	}

	/*
	 * Wait for the thread to be marked as "ready" before returning
	 * as other subsystems depend on the notification subsystem
	 * (e.g. rotation thread).
	 */
	wait_until_thread_is_ready(handle);
	lttng_thread_put(thread);
	return true;
error:
	return false;
}
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"
c8a9de5a	40	#include "thread.h"
ab0ee2ca JG	41
	42	#include <urcu.h>
	43	#include <urcu/list.h>
	44	#include <urcu/rculfhash.h>
	45
ab0ee2ca JG	46	/*
	47	* Destroy the thread data previously created by the init function.
	48	*/
	49	void notification_thread_handle_destroy(
	50	struct notification_thread_handle *handle)
	51	{
	52	int ret;
ab0ee2ca JG	53
	54	if (!handle) {
	55	goto end;
	56	}
	57
8ada111f	58	assert(cds_list_empty(&handle->cmd_queue.list));
ab0ee2ca	59	pthread_mutex_destroy(&handle->cmd_queue.lock);
c8a9de5a	60	sem_destroy(&handle->ready);
ab0ee2ca	61
814b4934 JR	62	if (handle->cmd_queue.event_pipe) {
	63	lttng_pipe_destroy(handle->cmd_queue.event_pipe);
	64	}
ab0ee2ca JG	65	if (handle->channel_monitoring_pipes.ust32_consumer >= 0) {
	66	ret = close(handle->channel_monitoring_pipes.ust32_consumer);
	67	if (ret) {
	68	PERROR("close 32-bit consumer channel monitoring pipe");
	69	}
	70	}
	71	if (handle->channel_monitoring_pipes.ust64_consumer >= 0) {
	72	ret = close(handle->channel_monitoring_pipes.ust64_consumer);
	73	if (ret) {
	74	PERROR("close 64-bit consumer channel monitoring pipe");
	75	}
	76	}
	77	if (handle->channel_monitoring_pipes.kernel_consumer >= 0) {
	78	ret = close(handle->channel_monitoring_pipes.kernel_consumer);
	79	if (ret) {
	80	PERROR("close kernel consumer channel monitoring pipe");
	81	}
	82	}
	83	end:
	84	free(handle);
	85	}
	86
	87	struct notification_thread_handle *notification_thread_handle_create(
	88	struct lttng_pipe *ust32_channel_monitor_pipe,
	89	struct lttng_pipe *ust64_channel_monitor_pipe,
c8a9de5a	90	struct lttng_pipe *kernel_channel_monitor_pipe)
ab0ee2ca JG	91	{
	92	int ret;
	93	struct notification_thread_handle *handle;
814b4934	94	struct lttng_pipe *event_pipe = NULL;
ab0ee2ca JG	95
	96	handle = zmalloc(sizeof(*handle));
	97	if (!handle) {
	98	goto end;
	99	}
	100
c8a9de5a JG	101	sem_init(&handle->ready, 0, 0);
c8a9de5a JG	102
18d08850	103	event_pipe = lttng_pipe_open(FD_CLOEXEC);
814b4934 JR	104	if (!event_pipe) {
814b4934 JR	105	ERR("event_pipe creation");
ab0ee2ca JG	106	goto error;
ab0ee2ca JG	107	}
814b4934 JR	108
	109	handle->cmd_queue.event_pipe = event_pipe;
	110	event_pipe = NULL;
	111
ab0ee2ca JG	112	CDS_INIT_LIST_HEAD(&handle->cmd_queue.list);
	113	ret = pthread_mutex_init(&handle->cmd_queue.lock, NULL);
	114	if (ret) {
	115	goto error;
	116	}
	117
	118	if (ust32_channel_monitor_pipe) {
	119	handle->channel_monitoring_pipes.ust32_consumer =
	120	lttng_pipe_release_readfd(
	121	ust32_channel_monitor_pipe);
	122	if (handle->channel_monitoring_pipes.ust32_consumer < 0) {
	123	goto error;
	124	}
	125	} else {
	126	handle->channel_monitoring_pipes.ust32_consumer = -1;
	127	}
	128	if (ust64_channel_monitor_pipe) {
	129	handle->channel_monitoring_pipes.ust64_consumer =
	130	lttng_pipe_release_readfd(
	131	ust64_channel_monitor_pipe);
	132	if (handle->channel_monitoring_pipes.ust64_consumer < 0) {
	133	goto error;
	134	}
	135	} else {
	136	handle->channel_monitoring_pipes.ust64_consumer = -1;
	137	}
	138	if (kernel_channel_monitor_pipe) {
	139	handle->channel_monitoring_pipes.kernel_consumer =
	140	lttng_pipe_release_readfd(
	141	kernel_channel_monitor_pipe);
	142	if (handle->channel_monitoring_pipes.kernel_consumer < 0) {
	143	goto error;
	144	}
	145	} else {
	146	handle->channel_monitoring_pipes.kernel_consumer = -1;
	147	}
	148	end:
	149	return handle;
	150	error:
814b4934	151	lttng_pipe_destroy(event_pipe);
ab0ee2ca JG	152	notification_thread_handle_destroy(handle);
	153	return NULL;
	154	}
	155
	156	static
	157	char *get_notification_channel_sock_path(void)
	158	{
	159	int ret;
	160	bool is_root = !getuid();
	161	char *sock_path;
	162
	163	sock_path = zmalloc(LTTNG_PATH_MAX);
	164	if (!sock_path) {
	165	goto error;
	166	}
	167
	168	if (is_root) {
	169	ret = snprintf(sock_path, LTTNG_PATH_MAX,
	170	DEFAULT_GLOBAL_NOTIFICATION_CHANNEL_UNIX_SOCK);
	171	if (ret < 0) {
	172	goto error;
	173	}
	174	} else {
	175	char *home_path = utils_get_home_dir();
	176
	177	if (!home_path) {
	178	ERR("Can't get HOME directory for socket creation");
	179	goto error;
	180	}
	181
	182	ret = snprintf(sock_path, LTTNG_PATH_MAX,
	183	DEFAULT_HOME_NOTIFICATION_CHANNEL_UNIX_SOCK,
	184	home_path);
	185	if (ret < 0) {
	186	goto error;
	187	}
	188	}
	189
	190	return sock_path;
	191	error:
	192	free(sock_path);
	193	return NULL;
	194	}
	195
	196	static
	197	void notification_channel_socket_destroy(int fd)
	198	{
	199	int ret;
	200	char *sock_path = get_notification_channel_sock_path();
	201
	202	DBG("[notification-thread] Destroying notification channel socket");
	203
	204	if (sock_path) {
	205	ret = unlink(sock_path);
	206	free(sock_path);
	207	if (ret < 0) {
	208	PERROR("unlink notification channel socket");
	209	}
	210	}
	211
	212	ret = close(fd);
	213	if (ret) {
	214	PERROR("close notification channel socket");
	215	}
216	}
217
218	static
219	int notification_channel_socket_create(void)
220	{
221	int fd = -1, ret;
222	char *sock_path = get_notification_channel_sock_path();
223
224	DBG("[notification-thread] Creating notification channel UNIX socket at %s",
225	sock_path);
226
227	ret = lttcomm_create_unix_sock(sock_path);
228	if (ret < 0) {
229	ERR("[notification-thread] Failed to create notification socket");
230	goto error;
231	}
232	fd = ret;
233
234	ret = chmod(sock_path, S_IRUSR \| S_IWUSR \| S_IRGRP \| S_IWGRP);
235	if (ret < 0) {
236	ERR("Set file permissions failed: %s", sock_path);
237	PERROR("chmod notification channel socket");
238	goto error;
239	}
240
241	if (getuid() == 0) {
242	ret = chown(sock_path, 0,
e6142f2e	243	utils_get_group_id(config.tracing_group_name.value));
ab0ee2ca JG	244	if (ret) {
	245	ERR("Failed to set the notification channel socket's group");
	246	ret = -1;
	247	goto error;
	248	}
	249	}
	250
	251	DBG("[notification-thread] Notification channel UNIX socket created (fd = %i)",
	252	fd);
	253	free(sock_path);
	254	return fd;
	255	error:
	256	if (fd >= 0 && close(fd) < 0) {
	257	PERROR("close notification channel socket");
	258	}
	259	free(sock_path);
	260	return ret;
	261	}
	262
	263	static
	264	int init_poll_set(struct lttng_poll_event *poll_set,
	265	struct notification_thread_handle *handle,
	266	int notification_channel_socket)
	267	{
	268	int ret;
	269
	270	/*
	271	* Create pollset with size 5:
	272	* - notification channel socket (listen for new connections),
	273	* - command queue event fd (internal sessiond commands),
	274	* - consumerd (32-bit user space) channel monitor pipe,
	275	* - consumerd (64-bit user space) channel monitor pipe,
	276	* - consumerd (kernel) channel monitor pipe.
	277	*/
	278	ret = lttng_poll_create(poll_set, 5, LTTNG_CLOEXEC);
	279	if (ret < 0) {
	280	goto end;
	281	}
	282
	283	ret = lttng_poll_add(poll_set, notification_channel_socket,
	284	LPOLLIN \| LPOLLERR \| LPOLLHUP \| LPOLLRDHUP);
	285	if (ret < 0) {
	286	ERR("[notification-thread] Failed to add notification channel socket to pollset");
	287	goto error;
	288	}
814b4934	289	ret = lttng_poll_add(poll_set, lttng_pipe_get_readfd(handle->cmd_queue.event_pipe),
ab0ee2ca JG	290	LPOLLIN \| LPOLLERR);
	291	if (ret < 0) {
	292	ERR("[notification-thread] Failed to add notification command queue event fd to pollset");
	293	goto error;
	294	}
	295	ret = lttng_poll_add(poll_set,
	296	handle->channel_monitoring_pipes.ust32_consumer,
	297	LPOLLIN \| LPOLLERR);
	298	if (ret < 0) {
	299	ERR("[notification-thread] Failed to add ust-32 channel monitoring pipe fd to pollset");
	300	goto error;
	301	}
	302	ret = lttng_poll_add(poll_set,
	303	handle->channel_monitoring_pipes.ust64_consumer,
	304	LPOLLIN \| LPOLLERR);
	305	if (ret < 0) {
	306	ERR("[notification-thread] Failed to add ust-64 channel monitoring pipe fd to pollset");
	307	goto error;
	308	}
	309	if (handle->channel_monitoring_pipes.kernel_consumer < 0) {
	310	goto end;
	311	}
	312	ret = lttng_poll_add(poll_set,
	313	handle->channel_monitoring_pipes.kernel_consumer,
	314	LPOLLIN \| LPOLLERR);
	315	if (ret < 0) {
	316	ERR("[notification-thread] Failed to add kernel channel monitoring pipe fd to pollset");
	317	goto error;
	318	}
	319	end:
	320	return ret;
	321	error:
	322	lttng_poll_clean(poll_set);
	323	return ret;
	324	}
	325
	326	static
	327	void fini_thread_state(struct notification_thread_state *state)
	328	{
	329	int ret;
	330
	331	if (state->client_socket_ht) {
	332	ret = handle_notification_thread_client_disconnect_all(state);
	333	assert(!ret);
	334	ret = cds_lfht_destroy(state->client_socket_ht, NULL);
	335	assert(!ret);
	336	}
	337	if (state->triggers_ht) {
	338	ret = handle_notification_thread_trigger_unregister_all(state);
	339	assert(!ret);
	340	ret = cds_lfht_destroy(state->triggers_ht, NULL);
	341	assert(!ret);
	342	}
	343	if (state->channel_triggers_ht) {
	344	ret = cds_lfht_destroy(state->channel_triggers_ht, NULL);
	345	assert(!ret);
	346	}
	347	if (state->channel_state_ht) {
	348	ret = cds_lfht_destroy(state->channel_state_ht, NULL);
	349	assert(!ret);
	350	}
	351	if (state->notification_trigger_clients_ht) {
	352	ret = cds_lfht_destroy(state->notification_trigger_clients_ht,
	353	NULL);
354	assert(!ret);
355	}
356	if (state->channels_ht) {
8abe313a JG	357	ret = cds_lfht_destroy(state->channels_ht, NULL);
	358	assert(!ret);
	359	}
	360	if (state->sessions_ht) {
	361	ret = cds_lfht_destroy(state->sessions_ht, NULL);
ab0ee2ca JG	362	assert(!ret);
ab0ee2ca JG	363	}
ea9a44f0 JG	364	/*
	365	* Must be destroyed after all channels have been destroyed.
	366	* See comment in struct lttng_session_trigger_list.
	367	*/
	368	if (state->session_triggers_ht) {
	369	ret = cds_lfht_destroy(state->session_triggers_ht, NULL);
	370	assert(!ret);
	371	}
ab0ee2ca JG	372	if (state->notification_channel_socket >= 0) {
	373	notification_channel_socket_destroy(
	374	state->notification_channel_socket);
	375	}
	376	lttng_poll_clean(&state->events);
	377	}
	378
c8a9de5a JG	379	static
	380	void mark_thread_as_ready(struct notification_thread_handle *handle)
	381	{
	382	DBG("Marking notification thread as ready");
	383	sem_post(&handle->ready);
	384	}
	385
	386	static
	387	void wait_until_thread_is_ready(struct notification_thread_handle *handle)
	388	{
	389	DBG("Waiting for notification thread to be ready");
	390	sem_wait(&handle->ready);
	391	DBG("Notification thread is ready");
	392	}
	393
ab0ee2ca JG	394	static
	395	int init_thread_state(struct notification_thread_handle *handle,
	396	struct notification_thread_state *state)
	397	{
	398	int ret;
	399
	400	memset(state, 0, sizeof(*state));
	401	state->notification_channel_socket = -1;
	402	lttng_poll_init(&state->events);
	403
	404	ret = notification_channel_socket_create();
	405	if (ret < 0) {
	406	goto end;
	407	}
	408	state->notification_channel_socket = ret;
	409
	410	ret = init_poll_set(&state->events, handle,
	411	state->notification_channel_socket);
	412	if (ret) {
	413	goto end;
	414	}
	415
	416	DBG("[notification-thread] Listening on notification channel socket");
	417	ret = lttcomm_listen_unix_sock(state->notification_channel_socket);
	418	if (ret < 0) {
	419	ERR("[notification-thread] Listen failed on notification channel socket");
	420	goto error;
	421	}
	422
	423	state->client_socket_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
	424	CDS_LFHT_AUTO_RESIZE \| CDS_LFHT_ACCOUNTING, NULL);
	425	if (!state->client_socket_ht) {
	426	goto error;
	427	}
	428
	429	state->channel_triggers_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
	430	CDS_LFHT_AUTO_RESIZE \| CDS_LFHT_ACCOUNTING, NULL);
	431	if (!state->channel_triggers_ht) {
	432	goto error;
	433	}
	434
ea9a44f0 JG	435	state->session_triggers_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
	436	CDS_LFHT_AUTO_RESIZE \| CDS_LFHT_ACCOUNTING, NULL);
	437	if (!state->session_triggers_ht) {
	438	goto error;
	439	}
	440
ab0ee2ca JG	441	state->channel_state_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
	442	CDS_LFHT_AUTO_RESIZE \| CDS_LFHT_ACCOUNTING, NULL);
	443	if (!state->channel_state_ht) {
	444	goto error;
	445	}
	446
	447	state->notification_trigger_clients_ht = cds_lfht_new(DEFAULT_HT_SIZE,
	448	1, 0, CDS_LFHT_AUTO_RESIZE \| CDS_LFHT_ACCOUNTING, NULL);
	449	if (!state->notification_trigger_clients_ht) {
	450	goto error;
	451	}
	452
	453	state->channels_ht = cds_lfht_new(DEFAULT_HT_SIZE,
	454	1, 0, CDS_LFHT_AUTO_RESIZE \| CDS_LFHT_ACCOUNTING, NULL);
	455	if (!state->channels_ht) {
	456	goto error;
	457	}
8abe313a JG	458	state->sessions_ht = cds_lfht_new(DEFAULT_HT_SIZE,
	459	1, 0, CDS_LFHT_AUTO_RESIZE \| CDS_LFHT_ACCOUNTING, NULL);
	460	if (!state->sessions_ht) {
	461	goto error;
	462	}
ab0ee2ca JG	463	state->triggers_ht = cds_lfht_new(DEFAULT_HT_SIZE,
	464	1, 0, CDS_LFHT_AUTO_RESIZE \| CDS_LFHT_ACCOUNTING, NULL);
	465	if (!state->triggers_ht) {
	466	goto error;
	467	}
c8a9de5a	468	mark_thread_as_ready(handle);
ab0ee2ca JG	469	end:
	470	return 0;
	471	error:
	472	fini_thread_state(state);
	473	return -1;
	474	}
	475
	476	static
	477	int handle_channel_monitoring_pipe(int fd, uint32_t revents,
	478	struct notification_thread_handle *handle,
	479	struct notification_thread_state *state)
	480	{
	481	int ret = 0;
	482	enum lttng_domain_type domain;
	483
	484	if (fd == handle->channel_monitoring_pipes.ust32_consumer \|\|
	485	fd == handle->channel_monitoring_pipes.ust64_consumer) {
	486	domain = LTTNG_DOMAIN_UST;
	487	} else if (fd == handle->channel_monitoring_pipes.kernel_consumer) {
	488	domain = LTTNG_DOMAIN_KERNEL;
	489	} else {
	490	abort();
	491	}
	492
	493	if (revents & (LPOLLERR \| LPOLLHUP \| LPOLLRDHUP)) {
	494	ret = lttng_poll_del(&state->events, fd);
	495	if (ret) {
	496	ERR("[notification-thread] Failed to remove consumer monitoring pipe from poll set");
	497	}
	498	goto end;
	499	}
	500
	501	ret = handle_notification_thread_channel_sample(
	502	state, fd, domain);
	503	if (ret) {
4149ace8	504	ERR("[notification-thread] Consumer sample handling error occurred");
ab0ee2ca JG	505	ret = -1;
	506	goto end;
	507	}
	508	end:
	509	return ret;
	510	}
	511
	512	/*
	513	* This thread services notification channel clients and commands received
	514	* from various lttng-sessiond components over a command queue.
	515	*/
c8a9de5a	516	static
ab0ee2ca JG	517	void thread_notification(void data)
	518	{
	519	int ret;
	520	struct notification_thread_handle *handle = data;
	521	struct notification_thread_state state;
	522
	523	DBG("[notification-thread] Started notification thread");
	524
	525	if (!handle) {
	526	ERR("[notification-thread] Invalid thread context provided");
	527	goto end;
	528	}
	529
	530	rcu_register_thread();
	531	rcu_thread_online();
	532
	533	health_register(health_sessiond, HEALTH_SESSIOND_TYPE_NOTIFICATION);
	534	health_code_update();
	535
	536	ret = init_thread_state(handle, &state);
	537	if (ret) {
	538	goto end;
	539	}
	540
ab0ee2ca JG	541	while (true) {
	542	int fd_count, i;
	543
	544	health_poll_entry();
	545	DBG("[notification-thread] Entering poll wait");
	546	ret = lttng_poll_wait(&state.events, -1);
	547	DBG("[notification-thread] Poll wait returned (%i)", ret);
	548	health_poll_exit();
	549	if (ret < 0) {
	550	/*
	551	* Restart interrupted system call.
	552	*/
	553	if (errno == EINTR) {
	554	continue;
	555	}
	556	ERR("[notification-thread] Error encountered during lttng_poll_wait (%i)", ret);
	557	goto error;
	558	}
	559
	560	fd_count = ret;
	561	for (i = 0; i < fd_count; i++) {
	562	int fd = LTTNG_POLL_GETFD(&state.events, i);
	563	uint32_t revents = LTTNG_POLL_GETEV(&state.events, i);
	564
2d01d977 JG	565	if (!revents) {
	566	continue;
	567	}
ab0ee2ca JG	568	DBG("[notification-thread] Handling fd (%i) activity (%u)", fd, revents);
	569
	570	if (fd == state.notification_channel_socket) {
	571	if (revents & LPOLLIN) {
	572	ret = handle_notification_thread_client_connect(
	573	&state);
	574	if (ret < 0) {
	575	goto error;
	576	}
	577	} else if (revents &
	578	(LPOLLERR \| LPOLLHUP \| LPOLLRDHUP)) {
	579	ERR("[notification-thread] Notification socket poll error");
	580	goto error;
	581	} else {
	582	ERR("[notification-thread] Unexpected poll events %u for notification socket %i", revents, fd);
	583	goto error;
	584	}
814b4934	585	} else if (fd == lttng_pipe_get_readfd(handle->cmd_queue.event_pipe)) {
ab0ee2ca JG	586	ret = handle_notification_thread_command(handle,
	587	&state);
	588	if (ret < 0) {
	589	DBG("[notification-thread] Error encountered while servicing command queue");
	590	goto error;
	591	} else if (ret > 0) {
	592	goto exit;
	593	}
	594	} else if (fd == handle->channel_monitoring_pipes.ust32_consumer \|\|
	595	fd == handle->channel_monitoring_pipes.ust64_consumer \|\|
	596	fd == handle->channel_monitoring_pipes.kernel_consumer) {
	597	ret = handle_channel_monitoring_pipe(fd,
	598	revents, handle, &state);
	599	if (ret) {
	600	goto error;
	601	}
	602	} else {
	603	/* Activity on a client's socket. */
	604	if (revents & (LPOLLERR \| LPOLLHUP \| LPOLLRDHUP)) {
	605	/*
	606	* It doesn't matter if a command was
	607	* pending on the client socket at this
	608	* point since it now has no way to
	609	* receive the notifications to which
	610	* it was subscribing or unsubscribing.
	611	*/
	612	ret = handle_notification_thread_client_disconnect(
	613	fd, &state);
	614	if (ret) {
	615	goto error;
	616	}
	617	} else {
	618	if (revents & LPOLLIN) {
	619	ret = handle_notification_thread_client_in(
	620	&state, fd);
	621	if (ret) {
	622	goto error;
	623	}
	624	}
	625
	626	if (revents & LPOLLOUT) {
	627	ret = handle_notification_thread_client_out(
	628	&state, fd);
	629	if (ret) {
	630	goto error;
	631	}
	632	}
	633	}
	634	}
	635	}
	636	}
	637	exit:
	638	error:
	639	fini_thread_state(&state);
	640	health_unregister(health_sessiond);
	641	rcu_thread_offline();
	642	rcu_unregister_thread();
	643	end:
	644	return NULL;
	645	}
c8a9de5a JG	646
	647	static
	648	bool shutdown_notification_thread(void *thread_data)
	649	{
	650	struct notification_thread_handle *handle = thread_data;
	651
	652	notification_thread_command_quit(handle);
	653	return true;
	654	}
	655
	656	bool launch_notification_thread(struct notification_thread_handle *handle)
	657	{
	658	struct lttng_thread *thread;
	659
	660	thread = lttng_thread_create("Notification",
	661	thread_notification,
	662	shutdown_notification_thread,
	663	NULL,
	664	handle);
	665	if (!thread) {
	666	goto error;
	667	}
	668
	669	/*
	670	* Wait for the thread to be marked as "ready" before returning
	671	* as other subsystems depend on the notification subsystem
	672	* (e.g. rotation thread).
	673	*/
	674	wait_until_thread_is_ready(handle);
	675	lttng_thread_put(thread);
	676	return true;
	677	error:
	678	return false;
	679	}