[lttng-tools.git] / src / bin / lttng-sessiond / tracker.cpp

/*
 * Copyright (C) 2018 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 * Copyright (C) 2020 Jérémie Galarneau <jeremie.galarneau@efficios.com>
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 */

#include "lttng/tracker.h"
#include "common/dynamic-array.hpp"
#include "common/macros.hpp"
#define _LGPL_SOURCE
#include <grp.h>
#include <pwd.h>
#include <sys/types.h>
#include <unistd.h>
#include <urcu.h>
#include <urcu/list.h>
#include <urcu/rculfhash.h>

#include "tracker.hpp"
#include <common/defaults.hpp>
#include <common/error.hpp>
#include <common/hashtable/hashtable.hpp>
#include <common/hashtable/utils.hpp>
#include <common/tracker.hpp>
#include <lttng/lttng-error.h>

struct process_attr_tracker {
	enum lttng_tracking_policy policy;
	struct cds_lfht *inclusion_set_ht;
};

namespace {
struct process_attr_tracker_value_node {
	struct process_attr_value *value;
	struct cds_lfht_node inclusion_set_ht_node;
	struct rcu_head rcu_head;
};
} /* namespace */

static void process_attr_tracker_value_node_rcu_free(struct rcu_head *rcu_head)
{
	struct process_attr_tracker_value_node *node =
			container_of(rcu_head, typeof(*node), rcu_head);

	free(node);
}

struct process_attr_tracker *process_attr_tracker_create(void)
{
	struct process_attr_tracker *tracker;

	tracker = zmalloc<process_attr_tracker>();
	if (!tracker) {
		return NULL;
	}

	(void) process_attr_tracker_set_tracking_policy(
			tracker, LTTNG_TRACKING_POLICY_INCLUDE_ALL);

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

	return tracker;
error:
	process_attr_tracker_destroy(tracker);
	return NULL;
}

static void process_attr_tracker_remove_value_node(
		struct process_attr_tracker *tracker,
		struct process_attr_tracker_value_node *value_node)
{
	cds_lfht_del(tracker->inclusion_set_ht,
			&value_node->inclusion_set_ht_node);
	process_attr_value_destroy(value_node->value);
	call_rcu(&value_node->rcu_head,
			process_attr_tracker_value_node_rcu_free);
}

static void process_attr_tracker_clear_inclusion_set(
		struct process_attr_tracker *tracker)
{
	int ret;
	struct lttng_ht_iter iter;
	struct process_attr_tracker_value_node *value_node;

	if (!tracker->inclusion_set_ht) {
		return;
	}

	rcu_read_lock();
	cds_lfht_for_each_entry (tracker->inclusion_set_ht, &iter.iter,
			value_node, inclusion_set_ht_node) {
		process_attr_tracker_remove_value_node(tracker, value_node);
	}
	rcu_read_unlock();
	ret = cds_lfht_destroy(tracker->inclusion_set_ht, NULL);
	LTTNG_ASSERT(ret == 0);
	tracker->inclusion_set_ht = NULL;
}

static int process_attr_tracker_create_inclusion_set(
		struct process_attr_tracker *tracker)
{
	LTTNG_ASSERT(!tracker->inclusion_set_ht);
	tracker->inclusion_set_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
			CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
	return tracker->inclusion_set_ht ? 0 : -1;
}

void process_attr_tracker_destroy(struct process_attr_tracker *tracker)
{
	if (!tracker) {
		return;
	}

	process_attr_tracker_clear_inclusion_set(tracker);
	free(tracker);
}

enum lttng_tracking_policy process_attr_tracker_get_tracking_policy(
		const struct process_attr_tracker *tracker)
{
	return tracker->policy;
}

int process_attr_tracker_set_tracking_policy(
		struct process_attr_tracker *tracker,
		enum lttng_tracking_policy tracking_policy)
{
	int ret = 0;

	if (tracker->policy == tracking_policy) {
		goto end;
	}

	process_attr_tracker_clear_inclusion_set(tracker);
	ret = process_attr_tracker_create_inclusion_set(tracker);
	if (ret) {
		goto end;
	}
	tracker->policy = tracking_policy;
end:
	return ret;
}

static int match_inclusion_set_value(
		struct cds_lfht_node *node, const void *key)
{
	const struct process_attr_value *value_key = (process_attr_value *) key;
	const struct process_attr_tracker_value_node *value_node =
			caa_container_of(node,
					struct process_attr_tracker_value_node,
					inclusion_set_ht_node);

	return process_attr_tracker_value_equal(value_node->value, value_key);
}

static struct process_attr_tracker_value_node *process_attr_tracker_lookup(
		const struct process_attr_tracker *tracker,
		const struct process_attr_value *value)
{
	struct cds_lfht_iter iter;
	struct cds_lfht_node *node;

	LTTNG_ASSERT(tracker->policy == LTTNG_TRACKING_POLICY_INCLUDE_SET);

	rcu_read_lock();
	cds_lfht_lookup(tracker->inclusion_set_ht,
			process_attr_value_hash(value),
			match_inclusion_set_value, value, &iter);
	node = cds_lfht_iter_get_node(&iter);
	rcu_read_unlock();

	return node ? container_of(node, struct process_attr_tracker_value_node,
				      inclusion_set_ht_node) :
		      NULL;
}

/* Protected by session mutex held by caller. */
enum process_attr_tracker_status process_attr_tracker_inclusion_set_add_value(
		struct process_attr_tracker *tracker,
		const struct process_attr_value *value)
{
	enum process_attr_tracker_status status =
			PROCESS_ATTR_TRACKER_STATUS_OK;
	struct process_attr_value *value_copy = NULL;
	struct process_attr_tracker_value_node *value_node = NULL;

	rcu_read_lock();
	if (tracker->policy != LTTNG_TRACKING_POLICY_INCLUDE_SET) {
		status = PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY;
		goto end;
	}

	if (process_attr_tracker_lookup(tracker, value)) {
		status = PROCESS_ATTR_TRACKER_STATUS_EXISTS;
		goto end;
	}

	value_node = zmalloc<process_attr_tracker_value_node>();
	if (!value_node) {
		status = PROCESS_ATTR_TRACKER_STATUS_ERROR;
		goto end;
	}

	value_copy = process_attr_value_copy(value);
	if (!value_copy) {
		status = PROCESS_ATTR_TRACKER_STATUS_ERROR;
		goto end;
	}

	value_node->value = value_copy;
	cds_lfht_add(tracker->inclusion_set_ht,
			process_attr_value_hash(value_copy),
			&value_node->inclusion_set_ht_node);
	value_copy = NULL;
	value_node = NULL;
end:
	if (value_copy) {
		process_attr_value_destroy(value_copy);
	}
	if (value_node) {
		free(value_node);
	}
	rcu_read_unlock();
	return status;
}

/* Protected by session mutex held by caller. */
enum process_attr_tracker_status
process_attr_tracker_inclusion_set_remove_value(
		struct process_attr_tracker *tracker,
		const struct process_attr_value *value)
{
	struct process_attr_tracker_value_node *value_node;
	enum process_attr_tracker_status status =
			PROCESS_ATTR_TRACKER_STATUS_OK;

	rcu_read_lock();
	if (tracker->policy != LTTNG_TRACKING_POLICY_INCLUDE_SET) {
		status = PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY;
		goto end;
	}

	value_node = process_attr_tracker_lookup(tracker, value);
	if (!value_node) {
		status = PROCESS_ATTR_TRACKER_STATUS_MISSING;
		goto end;
	}

	process_attr_tracker_remove_value_node(tracker, value_node);
end:
	rcu_read_unlock();
	return status;
}

enum process_attr_tracker_status process_attr_tracker_get_inclusion_set(
		const struct process_attr_tracker *tracker,
		struct lttng_process_attr_values **_values)
{
	struct lttng_ht_iter iter;
	struct process_attr_tracker_value_node *value_node;
	enum process_attr_tracker_status status =
			PROCESS_ATTR_TRACKER_STATUS_OK;
	struct lttng_process_attr_values *values;
	struct process_attr_value *new_value = NULL;

	values = lttng_process_attr_values_create();
	if (!values) {
		status = PROCESS_ATTR_TRACKER_STATUS_ERROR;
		goto error;
	}

	if (tracker->policy != LTTNG_TRACKING_POLICY_INCLUDE_SET) {
		status = PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY;
		goto error;
	}

	rcu_read_lock();
	cds_lfht_for_each_entry (tracker->inclusion_set_ht, &iter.iter,
			value_node, inclusion_set_ht_node) {
		int ret;

		new_value = process_attr_value_copy(value_node->value);
		if (!new_value) {
			status = PROCESS_ATTR_TRACKER_STATUS_ERROR;
			goto error_unlock;
		}

		ret = lttng_dynamic_pointer_array_add_pointer(
				&values->array, new_value);
		if (ret) {
			status = PROCESS_ATTR_TRACKER_STATUS_ERROR;
			goto error_unlock;
		}

		new_value = NULL;
	}
	rcu_read_unlock();
	*_values = values;
	return status;
error_unlock:
	rcu_read_unlock();
error:
	lttng_process_attr_values_destroy(values);
	process_attr_value_destroy(new_value);
	return status;
}
Commit	Line	Data
	1	/*
	2	* Copyright (C) 2018 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	3	* Copyright (C) 2020 Jérémie Galarneau <jeremie.galarneau@efficios.com>
	4	*
	5	* SPDX-License-Identifier: GPL-2.0-only
	6	*
	7	*/
	8
	9	#include "lttng/tracker.h"
	10	#include "common/dynamic-array.hpp"
	11	#include "common/macros.hpp"
	12	#define _LGPL_SOURCE
	13	#include <grp.h>
	14	#include <pwd.h>
	15	#include <sys/types.h>
	16	#include <unistd.h>
	17	#include <urcu.h>
	18	#include <urcu/list.h>
	19	#include <urcu/rculfhash.h>
	20
	21	#include "tracker.hpp"
	22	#include <common/defaults.hpp>
	23	#include <common/error.hpp>
	24	#include <common/hashtable/hashtable.hpp>
	25	#include <common/hashtable/utils.hpp>
	26	#include <common/tracker.hpp>
	27	#include <lttng/lttng-error.h>
	28
	29	struct process_attr_tracker {
	30	enum lttng_tracking_policy policy;
	31	struct cds_lfht *inclusion_set_ht;
	32	};
	33
	34	namespace {
	35	struct process_attr_tracker_value_node {
	36	struct process_attr_value *value;
	37	struct cds_lfht_node inclusion_set_ht_node;
	38	struct rcu_head rcu_head;
	39	};
	40	} /* namespace */
	41
	42	static void process_attr_tracker_value_node_rcu_free(struct rcu_head *rcu_head)
	43	{
	44	struct process_attr_tracker_value_node *node =
	45	container_of(rcu_head, typeof(*node), rcu_head);
	46
	47	free(node);
	48	}
	49
	50	struct process_attr_tracker *process_attr_tracker_create(void)
	51	{
	52	struct process_attr_tracker *tracker;
	53
	54	tracker = zmalloc<process_attr_tracker>();
	55	if (!tracker) {
	56	return NULL;
	57	}
	58
	59	(void) process_attr_tracker_set_tracking_policy(
	60	tracker, LTTNG_TRACKING_POLICY_INCLUDE_ALL);
	61
	62	tracker->inclusion_set_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
	63	CDS_LFHT_AUTO_RESIZE \| CDS_LFHT_ACCOUNTING, NULL);
	64	if (!tracker->inclusion_set_ht) {
	65	goto error;
	66	}
	67
	68	return tracker;
	69	error:
	70	process_attr_tracker_destroy(tracker);
	71	return NULL;
	72	}
	73
	74	static void process_attr_tracker_remove_value_node(
	75	struct process_attr_tracker *tracker,
	76	struct process_attr_tracker_value_node *value_node)
	77	{
	78	cds_lfht_del(tracker->inclusion_set_ht,
	79	&value_node->inclusion_set_ht_node);
	80	process_attr_value_destroy(value_node->value);
	81	call_rcu(&value_node->rcu_head,
	82	process_attr_tracker_value_node_rcu_free);
	83	}
	84
	85	static void process_attr_tracker_clear_inclusion_set(
	86	struct process_attr_tracker *tracker)
	87	{
	88	int ret;
	89	struct lttng_ht_iter iter;
	90	struct process_attr_tracker_value_node *value_node;
	91
	92	if (!tracker->inclusion_set_ht) {
	93	return;
	94	}
	95
	96	rcu_read_lock();
	97	cds_lfht_for_each_entry (tracker->inclusion_set_ht, &iter.iter,
	98	value_node, inclusion_set_ht_node) {
	99	process_attr_tracker_remove_value_node(tracker, value_node);
	100	}
	101	rcu_read_unlock();
	102	ret = cds_lfht_destroy(tracker->inclusion_set_ht, NULL);
	103	LTTNG_ASSERT(ret == 0);
	104	tracker->inclusion_set_ht = NULL;
	105	}
	106
	107	static int process_attr_tracker_create_inclusion_set(
	108	struct process_attr_tracker *tracker)
	109	{
	110	LTTNG_ASSERT(!tracker->inclusion_set_ht);
	111	tracker->inclusion_set_ht = cds_lfht_new(DEFAULT_HT_SIZE, 1, 0,
	112	CDS_LFHT_AUTO_RESIZE \| CDS_LFHT_ACCOUNTING, NULL);
	113	return tracker->inclusion_set_ht ? 0 : -1;
	114	}
	115
	116	void process_attr_tracker_destroy(struct process_attr_tracker *tracker)
	117	{
	118	if (!tracker) {
	119	return;
	120	}
	121
	122	process_attr_tracker_clear_inclusion_set(tracker);
	123	free(tracker);
	124	}
	125
	126	enum lttng_tracking_policy process_attr_tracker_get_tracking_policy(
	127	const struct process_attr_tracker *tracker)
	128	{
	129	return tracker->policy;
	130	}
	131
	132	int process_attr_tracker_set_tracking_policy(
	133	struct process_attr_tracker *tracker,
	134	enum lttng_tracking_policy tracking_policy)
	135	{
	136	int ret = 0;
	137
	138	if (tracker->policy == tracking_policy) {
	139	goto end;
	140	}
	141
	142	process_attr_tracker_clear_inclusion_set(tracker);
	143	ret = process_attr_tracker_create_inclusion_set(tracker);
	144	if (ret) {
	145	goto end;
	146	}
	147	tracker->policy = tracking_policy;
	148	end:
	149	return ret;
	150	}
	151
	152	static int match_inclusion_set_value(
	153	struct cds_lfht_node node, const void key)
	154	{
	155	const struct process_attr_value value_key = (process_attr_value ) key;
	156	const struct process_attr_tracker_value_node *value_node =
	157	caa_container_of(node,
	158	struct process_attr_tracker_value_node,
	159	inclusion_set_ht_node);
	160
	161	return process_attr_tracker_value_equal(value_node->value, value_key);
	162	}
	163
	164	static struct process_attr_tracker_value_node *process_attr_tracker_lookup(
	165	const struct process_attr_tracker *tracker,
	166	const struct process_attr_value *value)
	167	{
	168	struct cds_lfht_iter iter;
	169	struct cds_lfht_node *node;
	170
	171	LTTNG_ASSERT(tracker->policy == LTTNG_TRACKING_POLICY_INCLUDE_SET);
	172
	173	rcu_read_lock();
	174	cds_lfht_lookup(tracker->inclusion_set_ht,
	175	process_attr_value_hash(value),
	176	match_inclusion_set_value, value, &iter);
	177	node = cds_lfht_iter_get_node(&iter);
	178	rcu_read_unlock();
	179
	180	return node ? container_of(node, struct process_attr_tracker_value_node,
	181	inclusion_set_ht_node) :
	182	NULL;
	183	}
	184
	185	/* Protected by session mutex held by caller. */
	186	enum process_attr_tracker_status process_attr_tracker_inclusion_set_add_value(
	187	struct process_attr_tracker *tracker,
	188	const struct process_attr_value *value)
	189	{
	190	enum process_attr_tracker_status status =
	191	PROCESS_ATTR_TRACKER_STATUS_OK;
	192	struct process_attr_value *value_copy = NULL;
	193	struct process_attr_tracker_value_node *value_node = NULL;
	194
	195	rcu_read_lock();
	196	if (tracker->policy != LTTNG_TRACKING_POLICY_INCLUDE_SET) {
	197	status = PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY;
	198	goto end;
	199	}
	200
	201	if (process_attr_tracker_lookup(tracker, value)) {
	202	status = PROCESS_ATTR_TRACKER_STATUS_EXISTS;
	203	goto end;
	204	}
	205
	206	value_node = zmalloc<process_attr_tracker_value_node>();
	207	if (!value_node) {
	208	status = PROCESS_ATTR_TRACKER_STATUS_ERROR;
	209	goto end;
	210	}
	211
	212	value_copy = process_attr_value_copy(value);
	213	if (!value_copy) {
	214	status = PROCESS_ATTR_TRACKER_STATUS_ERROR;
	215	goto end;
	216	}
	217
	218	value_node->value = value_copy;
	219	cds_lfht_add(tracker->inclusion_set_ht,
	220	process_attr_value_hash(value_copy),
	221	&value_node->inclusion_set_ht_node);
	222	value_copy = NULL;
	223	value_node = NULL;
	224	end:
	225	if (value_copy) {
	226	process_attr_value_destroy(value_copy);
	227	}
	228	if (value_node) {
	229	free(value_node);
	230	}
	231	rcu_read_unlock();
	232	return status;
	233	}
	234
	235	/* Protected by session mutex held by caller. */
	236	enum process_attr_tracker_status
	237	process_attr_tracker_inclusion_set_remove_value(
	238	struct process_attr_tracker *tracker,
	239	const struct process_attr_value *value)
	240	{
	241	struct process_attr_tracker_value_node *value_node;
	242	enum process_attr_tracker_status status =
	243	PROCESS_ATTR_TRACKER_STATUS_OK;
	244
	245	rcu_read_lock();
	246	if (tracker->policy != LTTNG_TRACKING_POLICY_INCLUDE_SET) {
	247	status = PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY;
	248	goto end;
	249	}
	250
	251	value_node = process_attr_tracker_lookup(tracker, value);
	252	if (!value_node) {
	253	status = PROCESS_ATTR_TRACKER_STATUS_MISSING;
	254	goto end;
	255	}
	256
	257	process_attr_tracker_remove_value_node(tracker, value_node);
	258	end:
	259	rcu_read_unlock();
	260	return status;
	261	}
	262
	263	enum process_attr_tracker_status process_attr_tracker_get_inclusion_set(
	264	const struct process_attr_tracker *tracker,
	265	struct lttng_process_attr_values **_values)
	266	{
	267	struct lttng_ht_iter iter;
	268	struct process_attr_tracker_value_node *value_node;
	269	enum process_attr_tracker_status status =
	270	PROCESS_ATTR_TRACKER_STATUS_OK;
	271	struct lttng_process_attr_values *values;
	272	struct process_attr_value *new_value = NULL;
	273
	274	values = lttng_process_attr_values_create();
	275	if (!values) {
	276	status = PROCESS_ATTR_TRACKER_STATUS_ERROR;
	277	goto error;
	278	}
	279
	280	if (tracker->policy != LTTNG_TRACKING_POLICY_INCLUDE_SET) {
	281	status = PROCESS_ATTR_TRACKER_STATUS_INVALID_TRACKING_POLICY;
	282	goto error;
	283	}
	284
	285	rcu_read_lock();
	286	cds_lfht_for_each_entry (tracker->inclusion_set_ht, &iter.iter,
	287	value_node, inclusion_set_ht_node) {
	288	int ret;
	289
	290	new_value = process_attr_value_copy(value_node->value);
	291	if (!new_value) {
	292	status = PROCESS_ATTR_TRACKER_STATUS_ERROR;
	293	goto error_unlock;
	294	}
	295
	296	ret = lttng_dynamic_pointer_array_add_pointer(
	297	&values->array, new_value);
	298	if (ret) {
	299	status = PROCESS_ATTR_TRACKER_STATUS_ERROR;
	300	goto error_unlock;
	301	}
	302
	303	new_value = NULL;
	304	}
	305	rcu_read_unlock();
	306	*_values = values;
	307	return status;
	308	error_unlock:
	309	rcu_read_unlock();
	310	error:
	311	lttng_process_attr_values_destroy(values);
	312	process_attr_value_destroy(new_value);
	313	return status;
	314	}