[lttng-tools.git] / liblttngctl / liblttngctl.c

/*
 * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#define _GNU_SOURCE
#include <errno.h>
#include <grp.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <lttng/lttng.h>

#include "liblttsessiondcomm.h"
#include "lttngerr.h"
#include "lttng-share.h"

/* Socket to session daemon for communication */
static int sessiond_socket;
static char sessiond_sock_path[PATH_MAX];

/* Communication structure to ltt-sessiond */
static struct lttcomm_session_msg lsm;
static struct lttcomm_lttng_msg llm;

/* Variables */
static char *tracing_group;
static int connected;

/*
 *  send_data_sessiond
 *
 *  Send lttcomm_session_msg to the session daemon.
 *
 *  On success, return 0
 *  On error, return error code
 */
static int send_data_sessiond(void)
{
	int ret;

	if (!connected) {
		ret = -ENOTCONN;
		goto end;
	}

	ret = lttcomm_send_unix_sock(sessiond_socket, &lsm, sizeof(lsm));

end:
	return ret;
}

/*
 *  recv_data_sessiond
 *
 *  Receive data from the sessiond socket.
 *
 *  On success, return 0
 *  On error, return recv() error code
 */
static int recv_data_sessiond(void *buf, size_t len)
{
	int ret;

	if (!connected) {
		ret = -ENOTCONN;
		goto end;
	}

	ret = lttcomm_recv_unix_sock(sessiond_socket, buf, len);

end:
	return ret;
}

/*
 *  Check if the specified group name exist.
 *
 *  If yes return 0, else return -1.
 */
static int check_tracing_group(const char *grp_name)
{
	struct group *grp_tracing;	/* no free(). See getgrnam(3) */
	gid_t *grp_list;
	int grp_list_size, grp_id, i;
	int ret = -1;

	/* Get GID of group 'tracing' */
	grp_tracing = getgrnam(grp_name);
	if (grp_tracing == NULL) {
		/* NULL means not found also. getgrnam(3) */
		if (errno != 0) {
			perror("getgrnam");
		}
		goto end;
	}

	/* Get number of supplementary group IDs */
	grp_list_size = getgroups(0, NULL);
	if (grp_list_size < 0) {
		perror("getgroups");
		goto end;
	}

	/* Alloc group list of the right size */
	grp_list = malloc(grp_list_size * sizeof(gid_t));
	grp_id = getgroups(grp_list_size, grp_list);
	if (grp_id < -1) {
		perror("getgroups");
		goto free_list;
	}

	for (i = 0; i < grp_list_size; i++) {
		if (grp_list[i] == grp_tracing->gr_gid) {
			ret = 0;
			break;
		}
	}

free_list:
	free(grp_list);

end:
	return ret;
}

/*
 *  Set sessiond socket path by putting it in the global sessiond_sock_path
 *  variable.
 */
static int set_session_daemon_path(void)
{
	int ret;

	/* Are we in the tracing group ? */
	ret = check_tracing_group(tracing_group);
	if (ret < 0 && getuid() != 0) {
		if (sprintf(sessiond_sock_path, DEFAULT_HOME_CLIENT_UNIX_SOCK,
					getenv("HOME")) < 0) {
			return -ENOMEM;
		}
	} else {
		strncpy(sessiond_sock_path, DEFAULT_GLOBAL_CLIENT_UNIX_SOCK,
				sizeof(DEFAULT_GLOBAL_CLIENT_UNIX_SOCK));
	}

	return 0;
}

/*
 *  Connect to the LTTng session daemon.
 *
 *  On success, return 0. On error, return -1.
 */
static int connect_sessiond(void)
{
	int ret;

	ret = set_session_daemon_path();
	if (ret < 0) {
		return ret;
	}

	/* Connect to the sesssion daemon */
	ret = lttcomm_connect_unix_sock(sessiond_sock_path);
	if (ret < 0) {
		return ret;
	}

	sessiond_socket = ret;
	connected = 1;

	return 0;
}

/*
 *  Clean disconnect the session daemon.
 */
static int disconnect_sessiond(void)
{
	int ret = 0;

	if (connected) {
		ret = lttcomm_close_unix_sock(sessiond_socket);
		sessiond_socket = 0;
		connected = 0;
	}

	return ret;
}

/*
 *  ask_sessiond
 *
 *  Ask the session daemon a specific command and put the data into buf.
 *
 *  Return size of data (only payload, not header).
 */
static int ask_sessiond(enum lttcomm_sessiond_command lct, void **buf)
{
	int ret;
	size_t size;
	void *data = NULL;

	ret = connect_sessiond();
	if (ret < 0) {
		goto end;
	}

	lsm.cmd_type = lct;

	/* Send command to session daemon */
	ret = send_data_sessiond();
	if (ret < 0) {
		goto end;
	}

	/* Get header from data transmission */
	ret = recv_data_sessiond(&llm, sizeof(llm));
	if (ret < 0) {
		goto end;
	}

	/* Check error code if OK */
	if (llm.ret_code != LTTCOMM_OK) {
		ret = -llm.ret_code;
		goto end;
	}

	size = llm.data_size;
	if (size == 0) {
		ret = 0;
		goto end;
	}

	data = (void*) malloc(size);

	/* Get payload data */
	ret = recv_data_sessiond(data, size);
	if (ret < 0) {
		free(data);
		goto end;
	}

	*buf = data;
	ret = size;

end:
	disconnect_sessiond();
	return ret;
}

/*
 *  Start tracing for all trace of the session.
 */
int lttng_start_tracing(char *session_name)
{
	strncpy(lsm.session_name, session_name, NAME_MAX);
	return ask_sessiond(LTTNG_START_TRACE, NULL);
}

/*
 *  Stop tracing for all trace of the session.
 */
int lttng_stop_tracing(char *session_name)
{
	strncpy(lsm.session_name, session_name, NAME_MAX);
	return ask_sessiond(LTTNG_STOP_TRACE, NULL);
}

/*
 *  lttng_add_context
 */
int lttng_add_context(struct lttng_domain *domain,
		struct lttng_event_context *ctx, char *event_name, char *channel_name)

{
	int ret;

	if (channel_name != NULL) {
		strncpy(lsm.u.context.channel_name, channel_name, NAME_MAX);
	}

	if (event_name != NULL) {
		strncpy(lsm.u.context.event_name, event_name, NAME_MAX);
	}

	memcpy(&lsm.u.context.ctx, ctx, sizeof(struct lttng_event_context));

	switch (domain->type) {
	case LTTNG_DOMAIN_KERNEL:
		ret = ask_sessiond(LTTNG_KERNEL_ADD_CONTEXT, NULL);
		break;
	case LTTNG_DOMAIN_UST:
		ret = LTTCOMM_NOT_IMPLEMENTED;
		break;
	default:
		ret = LTTCOMM_UNKNOWN_DOMAIN;
		break;
	};

	return ret;
}

/*
 *  lttng_enable_event
 */
int lttng_enable_event(struct lttng_domain *domain,
		struct lttng_event *ev, char *channel_name)
{
	int ret;

	if (channel_name == NULL) {
		strncpy(lsm.u.enable.channel_name, DEFAULT_CHANNEL_NAME, NAME_MAX);
	} else {
		strncpy(lsm.u.enable.channel_name, channel_name, NAME_MAX);
	}

	switch (domain->type) {
		case LTTNG_DOMAIN_KERNEL:
			if (ev == NULL) {
				ret = ask_sessiond(LTTNG_KERNEL_ENABLE_ALL_EVENT, NULL);
			} else {
				memcpy(&lsm.u.enable.event, ev, sizeof(struct lttng_event));
				ret = ask_sessiond(LTTNG_KERNEL_ENABLE_EVENT, NULL);
			}
			break;
		case LTTNG_DOMAIN_UST:
			ret = LTTCOMM_NOT_IMPLEMENTED;
			break;
		default:
			ret = LTTCOMM_UNKNOWN_DOMAIN;
			break;
	};

	return ret;
}

/*
 * Disable an event in the kernel tracer.
 */
int lttng_disable_event(struct lttng_domain *domain, char *name,
		char *channel_name)
{
	int ret;

	if (channel_name == NULL) {
		strncpy(lsm.u.disable.channel_name, DEFAULT_CHANNEL_NAME, NAME_MAX);
	} else {
		strncpy(lsm.u.disable.channel_name, channel_name, NAME_MAX);
	}

	switch (domain->type) {
		case LTTNG_DOMAIN_KERNEL:
			if (name == NULL) {
				ret = ask_sessiond(LTTNG_KERNEL_DISABLE_ALL_EVENT, NULL);
			} else {
				strncpy(lsm.u.disable.name, name, NAME_MAX);
				ret = ask_sessiond(LTTNG_KERNEL_DISABLE_EVENT, NULL);
			}
			break;
		case LTTNG_DOMAIN_UST:
			ret = LTTCOMM_NOT_IMPLEMENTED;
			break;
		default:
			ret = LTTCOMM_UNKNOWN_DOMAIN;
			break;
	};

	return ret;
}

/*
 * Enable recording for a channel for the kernel tracer.
 */
int lttng_enable_channel(struct lttng_domain *domain, struct lttng_channel *chan)
{
	int ret;

	memcpy(&lsm.u.channel.chan, chan, sizeof(struct lttng_channel));

	switch (domain->type) {
		case LTTNG_DOMAIN_KERNEL:
			ret = ask_sessiond(LTTNG_KERNEL_ENABLE_CHANNEL, NULL);
			break;
		case LTTNG_DOMAIN_UST:
			ret = LTTCOMM_NOT_IMPLEMENTED;
			break;
		default:
			ret = LTTCOMM_UNKNOWN_DOMAIN;
			break;
	};

	return ret;
}

/*
 * Disable recording for the channel for the kernel tracer.
 */
int lttng_disable_channel(struct lttng_domain *domain, char *name)
{
	int ret;

	strncpy(lsm.u.disable.channel_name, name, NAME_MAX);

	switch (domain->type) {
		case LTTNG_DOMAIN_KERNEL:
			ret = ask_sessiond(LTTNG_KERNEL_DISABLE_CHANNEL, NULL);
			break;
		case LTTNG_DOMAIN_UST:
			ret = LTTCOMM_NOT_IMPLEMENTED;
			break;
		default:
			ret = LTTCOMM_UNKNOWN_DOMAIN;
			break;
	};

	return ret;
}

/*
 * List all available events in the kernel.
 *
 * Return the size (bytes) of the list and set the event_list array.
 * On error, return negative value.
 */
int lttng_list_events(struct lttng_domain *domain, char **event_list)
{
	int ret;

	switch (domain->type) {
		case LTTNG_DOMAIN_KERNEL:
			ret = ask_sessiond(LTTNG_KERNEL_LIST_EVENTS, (void **) event_list);
			break;
		case LTTNG_DOMAIN_UST:
			ret = LTTCOMM_NOT_IMPLEMENTED;
			break;
		default:
			ret = LTTCOMM_UNKNOWN_DOMAIN;
			break;
	};

	return ret;
}

/*
 *  Return a human readable string of code
 */
const char *lttng_get_readable_code(int code)
{
	if (code > -LTTCOMM_OK) {
		return "Ended with errors";
	}

	return lttcomm_get_readable_code(code);
}

/*
 *  Create a brand new session using name.
 */
int lttng_create_session(char *name, char *path)
{
	strncpy(lsm.session_name, name, NAME_MAX);
	strncpy(lsm.path, path, PATH_MAX);
	return ask_sessiond(LTTNG_CREATE_SESSION, NULL);
}

/*
 *  Destroy session using name.
 */
int lttng_destroy_session(char *name)
{
	strncpy(lsm.session_name, name, NAME_MAX);
	return ask_sessiond(LTTNG_DESTROY_SESSION, NULL);
}

/*
 *  Ask the session daemon for all available sessions.
 *
 *  Return number of session.
 *  On error, return negative value.
 */
int lttng_list_sessions(struct lttng_session **sessions)
{
	int ret;

	ret = ask_sessiond(LTTNG_LIST_SESSIONS, (void**) sessions);
	if (ret < 0) {
		return ret;
	}

	return ret / sizeof(struct lttng_session);
}

/*
 * Set session name for the current lsm.
 */
void lttng_set_session_name(char *name)
{
	strncpy(lsm.session_name, name, NAME_MAX);
}

/*
 *  lttng_set_tracing_group
 *
 *  Set tracing group variable with name. This function
 *  allocate memory pointed by tracing_group.
 */
int lttng_set_tracing_group(const char *name)
{
	if (asprintf(&tracing_group, "%s", name) < 0) {
		return -ENOMEM;
	}

	return 0;
}

/*
 *  lttng_check_session_daemon
 *
 *  Yes, return 1
 *  No, return 0
 *  Error, return negative value
 */
int lttng_session_daemon_alive(void)
{
	int ret;

	ret = set_session_daemon_path();
	if (ret < 0) {
		/* Error */
		return ret;
	}

	/* If socket exist, we consider the daemon started */
	ret = access(sessiond_sock_path, F_OK);
	if (ret < 0) {
		/* Not alive */
		return 0;
	}

	/* Is alive */
	return 1;
}

/*
 * lib constructor
 */
static void __attribute__((constructor)) init()
{
	/* Set default session group */
	lttng_set_tracing_group(LTTNG_DEFAULT_TRACING_GROUP);
}
Commit	Line	Data
	1	/*
	2	* Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public License
	6	* as published by the Free Software Foundation; either version 2
	7	* of the License, or (at your option) any later version.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write to the Free Software
	16	* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	17	*/
	18
	19	#define _GNU_SOURCE
	20	#include <errno.h>
	21	#include <grp.h>
	22	#include <stdio.h>
	23	#include <stdlib.h>
	24	#include <string.h>
	25	#include <unistd.h>
	26
	27	#include <lttng/lttng.h>
	28
	29	#include "liblttsessiondcomm.h"
	30	#include "lttngerr.h"
	31	#include "lttng-share.h"
	32
	33	/* Socket to session daemon for communication */
	34	static int sessiond_socket;
	35	static char sessiond_sock_path[PATH_MAX];
	36
	37	/* Communication structure to ltt-sessiond */
	38	static struct lttcomm_session_msg lsm;
	39	static struct lttcomm_lttng_msg llm;
	40
	41	/* Variables */
	42	static char *tracing_group;
	43	static int connected;
	44
	45	/*
	46	* send_data_sessiond
	47	*
	48	* Send lttcomm_session_msg to the session daemon.
	49	*
	50	* On success, return 0
	51	* On error, return error code
	52	*/
	53	static int send_data_sessiond(void)
	54	{
	55	int ret;
	56
	57	if (!connected) {
	58	ret = -ENOTCONN;
	59	goto end;
	60	}
	61
	62	ret = lttcomm_send_unix_sock(sessiond_socket, &lsm, sizeof(lsm));
	63
	64	end:
	65	return ret;
	66	}
	67
	68	/*
	69	* recv_data_sessiond
	70	*
	71	* Receive data from the sessiond socket.
	72	*
	73	* On success, return 0
	74	* On error, return recv() error code
	75	*/
	76	static int recv_data_sessiond(void *buf, size_t len)
	77	{
	78	int ret;
	79
	80	if (!connected) {
	81	ret = -ENOTCONN;
	82	goto end;
	83	}
	84
	85	ret = lttcomm_recv_unix_sock(sessiond_socket, buf, len);
	86
	87	end:
	88	return ret;
	89	}
	90
	91	/*
	92	* Check if the specified group name exist.
	93	*
	94	* If yes return 0, else return -1.
	95	*/
	96	static int check_tracing_group(const char *grp_name)
	97	{
	98	struct group grp_tracing; / no free(). See getgrnam(3) */
	99	gid_t *grp_list;
	100	int grp_list_size, grp_id, i;
	101	int ret = -1;
	102
	103	/* Get GID of group 'tracing' */
	104	grp_tracing = getgrnam(grp_name);
	105	if (grp_tracing == NULL) {
	106	/* NULL means not found also. getgrnam(3) */
	107	if (errno != 0) {
	108	perror("getgrnam");
	109	}
	110	goto end;
	111	}
	112
	113	/* Get number of supplementary group IDs */
	114	grp_list_size = getgroups(0, NULL);
	115	if (grp_list_size < 0) {
	116	perror("getgroups");
	117	goto end;
	118	}
	119
	120	/* Alloc group list of the right size */
	121	grp_list = malloc(grp_list_size * sizeof(gid_t));
	122	grp_id = getgroups(grp_list_size, grp_list);
	123	if (grp_id < -1) {
	124	perror("getgroups");
	125	goto free_list;
	126	}
	127
	128	for (i = 0; i < grp_list_size; i++) {
	129	if (grp_list[i] == grp_tracing->gr_gid) {
	130	ret = 0;
	131	break;
	132	}
	133	}
	134
	135	free_list:
	136	free(grp_list);
	137
	138	end:
	139	return ret;
	140	}
	141
	142	/*
	143	* Set sessiond socket path by putting it in the global sessiond_sock_path
	144	* variable.
	145	*/
	146	static int set_session_daemon_path(void)
	147	{
	148	int ret;
	149
	150	/* Are we in the tracing group ? */
	151	ret = check_tracing_group(tracing_group);
	152	if (ret < 0 && getuid() != 0) {
	153	if (sprintf(sessiond_sock_path, DEFAULT_HOME_CLIENT_UNIX_SOCK,
	154	getenv("HOME")) < 0) {
	155	return -ENOMEM;
	156	}
	157	} else {
	158	strncpy(sessiond_sock_path, DEFAULT_GLOBAL_CLIENT_UNIX_SOCK,
	159	sizeof(DEFAULT_GLOBAL_CLIENT_UNIX_SOCK));
	160	}
	161
	162	return 0;
	163	}
	164
	165	/*
	166	* Connect to the LTTng session daemon.
	167	*
	168	* On success, return 0. On error, return -1.
	169	*/
	170	static int connect_sessiond(void)
	171	{
	172	int ret;
	173
	174	ret = set_session_daemon_path();
	175	if (ret < 0) {
	176	return ret;
	177	}
	178
	179	/* Connect to the sesssion daemon */
	180	ret = lttcomm_connect_unix_sock(sessiond_sock_path);
	181	if (ret < 0) {
	182	return ret;
	183	}
	184
	185	sessiond_socket = ret;
	186	connected = 1;
	187
	188	return 0;
	189	}
	190
	191	/*
	192	* Clean disconnect the session daemon.
	193	*/
	194	static int disconnect_sessiond(void)
	195	{
	196	int ret = 0;
	197
	198	if (connected) {
	199	ret = lttcomm_close_unix_sock(sessiond_socket);
	200	sessiond_socket = 0;
	201	connected = 0;
	202	}
	203
	204	return ret;
	205	}
	206
	207	/*
	208	* ask_sessiond
	209	*
	210	* Ask the session daemon a specific command and put the data into buf.
	211	*
	212	* Return size of data (only payload, not header).
	213	*/
	214	static int ask_sessiond(enum lttcomm_sessiond_command lct, void **buf)
	215	{
	216	int ret;
	217	size_t size;
	218	void *data = NULL;
	219
	220	ret = connect_sessiond();
	221	if (ret < 0) {
	222	goto end;
	223	}
	224
	225	lsm.cmd_type = lct;
	226
	227	/* Send command to session daemon */
	228	ret = send_data_sessiond();
	229	if (ret < 0) {
	230	goto end;
	231	}
	232
	233	/* Get header from data transmission */
	234	ret = recv_data_sessiond(&llm, sizeof(llm));
	235	if (ret < 0) {
	236	goto end;
	237	}
	238
	239	/* Check error code if OK */
	240	if (llm.ret_code != LTTCOMM_OK) {
	241	ret = -llm.ret_code;
	242	goto end;
	243	}
	244
	245	size = llm.data_size;
	246	if (size == 0) {
	247	ret = 0;
	248	goto end;
	249	}
	250
	251	data = (void*) malloc(size);
	252
	253	/* Get payload data */
	254	ret = recv_data_sessiond(data, size);
	255	if (ret < 0) {
	256	free(data);
	257	goto end;
	258	}
	259
	260	*buf = data;
	261	ret = size;
	262
	263	end:
	264	disconnect_sessiond();
	265	return ret;
	266	}
	267
	268	/*
	269	* Start tracing for all trace of the session.
	270	*/
	271	int lttng_start_tracing(char *session_name)
	272	{
	273	strncpy(lsm.session_name, session_name, NAME_MAX);
	274	return ask_sessiond(LTTNG_START_TRACE, NULL);
	275	}
	276
	277	/*
	278	* Stop tracing for all trace of the session.
	279	*/
	280	int lttng_stop_tracing(char *session_name)
	281	{
	282	strncpy(lsm.session_name, session_name, NAME_MAX);
	283	return ask_sessiond(LTTNG_STOP_TRACE, NULL);
	284	}
	285
	286	/*
	287	* lttng_add_context
	288	*/
	289	int lttng_add_context(struct lttng_domain *domain,
	290	struct lttng_event_context ctx, char event_name, char *channel_name)
	291
	292	{
	293	int ret;
	294
	295	if (channel_name != NULL) {
	296	strncpy(lsm.u.context.channel_name, channel_name, NAME_MAX);
	297	}
	298
	299	if (event_name != NULL) {
	300	strncpy(lsm.u.context.event_name, event_name, NAME_MAX);
	301	}
	302
	303	memcpy(&lsm.u.context.ctx, ctx, sizeof(struct lttng_event_context));
	304
	305	switch (domain->type) {
	306	case LTTNG_DOMAIN_KERNEL:
	307	ret = ask_sessiond(LTTNG_KERNEL_ADD_CONTEXT, NULL);
	308	break;
	309	case LTTNG_DOMAIN_UST:
	310	ret = LTTCOMM_NOT_IMPLEMENTED;
	311	break;
	312	default:
	313	ret = LTTCOMM_UNKNOWN_DOMAIN;
	314	break;
	315	};
	316
	317	return ret;
	318	}
	319
	320	/*
	321	* lttng_enable_event
	322	*/
	323	int lttng_enable_event(struct lttng_domain *domain,
	324	struct lttng_event ev, char channel_name)
	325	{
	326	int ret;
	327
	328	if (channel_name == NULL) {
	329	strncpy(lsm.u.enable.channel_name, DEFAULT_CHANNEL_NAME, NAME_MAX);
	330	} else {
	331	strncpy(lsm.u.enable.channel_name, channel_name, NAME_MAX);
	332	}
	333
	334	switch (domain->type) {
	335	case LTTNG_DOMAIN_KERNEL:
	336	if (ev == NULL) {
	337	ret = ask_sessiond(LTTNG_KERNEL_ENABLE_ALL_EVENT, NULL);
	338	} else {
	339	memcpy(&lsm.u.enable.event, ev, sizeof(struct lttng_event));
	340	ret = ask_sessiond(LTTNG_KERNEL_ENABLE_EVENT, NULL);
	341	}
	342	break;
	343	case LTTNG_DOMAIN_UST:
	344	ret = LTTCOMM_NOT_IMPLEMENTED;
	345	break;
	346	default:
	347	ret = LTTCOMM_UNKNOWN_DOMAIN;
	348	break;
	349	};
	350
	351	return ret;
	352	}
	353
	354	/*
	355	* Disable an event in the kernel tracer.
	356	*/
	357	int lttng_disable_event(struct lttng_domain domain, char name,
	358	char *channel_name)
	359	{
	360	int ret;
	361
	362	if (channel_name == NULL) {
	363	strncpy(lsm.u.disable.channel_name, DEFAULT_CHANNEL_NAME, NAME_MAX);
	364	} else {
	365	strncpy(lsm.u.disable.channel_name, channel_name, NAME_MAX);
	366	}
	367
	368	switch (domain->type) {
	369	case LTTNG_DOMAIN_KERNEL:
	370	if (name == NULL) {
	371	ret = ask_sessiond(LTTNG_KERNEL_DISABLE_ALL_EVENT, NULL);
	372	} else {
	373	strncpy(lsm.u.disable.name, name, NAME_MAX);
	374	ret = ask_sessiond(LTTNG_KERNEL_DISABLE_EVENT, NULL);
	375	}
	376	break;
	377	case LTTNG_DOMAIN_UST:
	378	ret = LTTCOMM_NOT_IMPLEMENTED;
	379	break;
	380	default:
	381	ret = LTTCOMM_UNKNOWN_DOMAIN;
	382	break;
	383	};
	384
	385	return ret;
	386	}
	387
	388	/*
	389	* Enable recording for a channel for the kernel tracer.
	390	*/
	391	int lttng_enable_channel(struct lttng_domain domain, struct lttng_channel chan)
	392	{
	393	int ret;
	394
	395	memcpy(&lsm.u.channel.chan, chan, sizeof(struct lttng_channel));
	396
	397	switch (domain->type) {
	398	case LTTNG_DOMAIN_KERNEL:
	399	ret = ask_sessiond(LTTNG_KERNEL_ENABLE_CHANNEL, NULL);
	400	break;
	401	case LTTNG_DOMAIN_UST:
	402	ret = LTTCOMM_NOT_IMPLEMENTED;
	403	break;
	404	default:
	405	ret = LTTCOMM_UNKNOWN_DOMAIN;
	406	break;
	407	};
	408
	409	return ret;
	410	}
	411
	412	/*
	413	* Disable recording for the channel for the kernel tracer.
	414	*/
	415	int lttng_disable_channel(struct lttng_domain domain, char name)
	416	{
	417	int ret;
	418
	419	strncpy(lsm.u.disable.channel_name, name, NAME_MAX);
	420
	421	switch (domain->type) {
	422	case LTTNG_DOMAIN_KERNEL:
	423	ret = ask_sessiond(LTTNG_KERNEL_DISABLE_CHANNEL, NULL);
	424	break;
	425	case LTTNG_DOMAIN_UST:
	426	ret = LTTCOMM_NOT_IMPLEMENTED;
	427	break;
	428	default:
	429	ret = LTTCOMM_UNKNOWN_DOMAIN;
	430	break;
	431	};
	432
	433	return ret;
	434	}
	435
	436	/*
	437	* List all available events in the kernel.
	438	*
	439	* Return the size (bytes) of the list and set the event_list array.
	440	* On error, return negative value.
	441	*/
	442	int lttng_list_events(struct lttng_domain domain, char *event_list)
	443	{
	444	int ret;
	445
	446	switch (domain->type) {
	447	case LTTNG_DOMAIN_KERNEL:
	448	ret = ask_sessiond(LTTNG_KERNEL_LIST_EVENTS, (void **) event_list);
	449	break;
	450	case LTTNG_DOMAIN_UST:
	451	ret = LTTCOMM_NOT_IMPLEMENTED;
	452	break;
	453	default:
	454	ret = LTTCOMM_UNKNOWN_DOMAIN;
	455	break;
	456	};
	457
	458	return ret;
	459	}
	460
	461	/*
	462	* Return a human readable string of code
	463	*/
	464	const char *lttng_get_readable_code(int code)
	465	{
	466	if (code > -LTTCOMM_OK) {
	467	return "Ended with errors";
	468	}
	469
	470	return lttcomm_get_readable_code(code);
	471	}
	472
	473	/*
	474	* Create a brand new session using name.
	475	*/
	476	int lttng_create_session(char name, char path)
	477	{
	478	strncpy(lsm.session_name, name, NAME_MAX);
	479	strncpy(lsm.path, path, PATH_MAX);
	480	return ask_sessiond(LTTNG_CREATE_SESSION, NULL);
	481	}
	482
	483	/*
	484	* Destroy session using name.
	485	*/
	486	int lttng_destroy_session(char *name)
	487	{
	488	strncpy(lsm.session_name, name, NAME_MAX);
	489	return ask_sessiond(LTTNG_DESTROY_SESSION, NULL);
	490	}
	491
	492	/*
	493	* Ask the session daemon for all available sessions.
	494	*
	495	* Return number of session.
	496	* On error, return negative value.
	497	*/
	498	int lttng_list_sessions(struct lttng_session **sessions)
	499	{
	500	int ret;
	501
	502	ret = ask_sessiond(LTTNG_LIST_SESSIONS, (void**) sessions);
	503	if (ret < 0) {
	504	return ret;
	505	}
	506
	507	return ret / sizeof(struct lttng_session);
	508	}
	509
	510	/*
	511	* Set session name for the current lsm.
	512	*/
	513	void lttng_set_session_name(char *name)
	514	{
	515	strncpy(lsm.session_name, name, NAME_MAX);
	516	}
	517
	518	/*
	519	* lttng_set_tracing_group
	520	*
	521	* Set tracing group variable with name. This function
	522	* allocate memory pointed by tracing_group.
	523	*/
	524	int lttng_set_tracing_group(const char *name)
	525	{
	526	if (asprintf(&tracing_group, "%s", name) < 0) {
	527	return -ENOMEM;
	528	}
	529
	530	return 0;
	531	}
	532
	533	/*
	534	* lttng_check_session_daemon
	535	*
	536	* Yes, return 1
	537	* No, return 0
	538	* Error, return negative value
	539	*/
	540	int lttng_session_daemon_alive(void)
	541	{
	542	int ret;
	543
	544	ret = set_session_daemon_path();
	545	if (ret < 0) {
	546	/* Error */
	547	return ret;
	548	}
	549
	550	/* If socket exist, we consider the daemon started */
	551	ret = access(sessiond_sock_path, F_OK);
	552	if (ret < 0) {
	553	/* Not alive */
	554	return 0;
	555	}
	556
	557	/* Is alive */
	558	return 1;
	559	}
	560
	561	/*
	562	* lib constructor
	563	*/
	564	static void __attribute__((constructor)) init()
	565	{
	566	/* Set default session group */
	567	lttng_set_tracing_group(LTTNG_DEFAULT_TRACING_GROUP);
	568	}