[lttng-tools.git] / src / common / actions / snapshot-session.cpp

/*
 * Copyright (C) 2019 Simon Marchi <simon.marchi@efficios.com>
 *
 * SPDX-License-Identifier: LGPL-2.1-only
 *
 */

#include <common/error.h>
#include <common/macros.h>
#include <common/mi-lttng.h>
#include <common/payload-view.h>
#include <common/payload.h>
#include <common/snapshot.h>
#include <inttypes.h>
#include <lttng/action/action-internal.h>
#include <lttng/action/rate-policy-internal.h>
#include <lttng/action/rate-policy.h>
#include <lttng/action/snapshot-session-internal.h>
#include <lttng/action/snapshot-session.h>
#include <lttng/snapshot-internal.h>
#include <lttng/snapshot.h>

#define IS_SNAPSHOT_SESSION_ACTION(action) \
	(lttng_action_get_type(action) == LTTNG_ACTION_TYPE_SNAPSHOT_SESSION)

struct lttng_action_snapshot_session {
	struct lttng_action parent;

	/* Owned by this. */
	char *session_name;

	/*
	 * When non-NULL, use this custom output when taking the snapshot,
	 * rather than the session's registered snapshot output.
	 *
	 * Owned by this.
	 */
	struct lttng_snapshot_output *output;
	struct lttng_rate_policy *policy;
};

struct lttng_action_snapshot_session_comm {
	/* All string lengths include the trailing \0. */
	uint32_t session_name_len;
	uint32_t snapshot_output_len;
	uint32_t rate_policy_len;

	/*
	 * Variable data (all strings are null-terminated):
	 *
	 *  - session name string
	 *  - snapshot output object
	 *  - policy object
	 */
	char data[];
} LTTNG_PACKED;

static const struct lttng_rate_policy *
lttng_action_snapshot_session_internal_get_rate_policy(
		const struct lttng_action *action);

static struct lttng_action_snapshot_session *
action_snapshot_session_from_action(struct lttng_action *action)
{
	LTTNG_ASSERT(action);

	return container_of(
			action, struct lttng_action_snapshot_session, parent);
}

static const struct lttng_action_snapshot_session *
action_snapshot_session_from_action_const(const struct lttng_action *action)
{
	LTTNG_ASSERT(action);

	return container_of(
			action, struct lttng_action_snapshot_session, parent);
}

static bool lttng_action_snapshot_session_validate(struct lttng_action *action)
{
	bool valid = false;
	struct lttng_action_snapshot_session *action_snapshot_session;

	if (!action) {
		goto end;
	}

	action_snapshot_session = action_snapshot_session_from_action(action);

	/* A non-empty session name is mandatory. */
	if (!action_snapshot_session->session_name ||
			strlen(action_snapshot_session->session_name) == 0) {
		goto end;
	}

	if (action_snapshot_session->output &&
			!lttng_snapshot_output_validate(action_snapshot_session->output)) {
		goto end;
	}

	valid = true;
end:
	return valid;
}

static bool lttng_action_snapshot_session_is_equal(
		const struct lttng_action *_a, const struct lttng_action *_b)
{
	bool is_equal = false;
	const struct lttng_action_snapshot_session *a, *b;

	a = action_snapshot_session_from_action_const(_a);
	b = action_snapshot_session_from_action_const(_b);

	/* Action is not valid if this is not true. */
	LTTNG_ASSERT(a->session_name);
	LTTNG_ASSERT(b->session_name);
	if (strcmp(a->session_name, b->session_name)) {
		goto end;
	}

	if (a->output && b->output &&
			!lttng_snapshot_output_is_equal(a->output, b->output)) {
		goto end;
	} else if (!!a->output != !!b->output) {
		goto end;
	}

	is_equal = lttng_rate_policy_is_equal(a->policy, b->policy);
end:
	return is_equal;
}

static size_t serialize_strlen(const char *str)
{
	return str ? strlen(str) + 1 : 0;
}

static int lttng_action_snapshot_session_serialize(
		struct lttng_action *action, struct lttng_payload *payload)
{
	struct lttng_action_snapshot_session *action_snapshot_session;
	struct lttng_action_snapshot_session_comm comm = {};
	int ret;
	size_t size_before_comm;

	LTTNG_ASSERT(action);
	LTTNG_ASSERT(payload);

	size_before_comm = payload->buffer.size;

	action_snapshot_session = action_snapshot_session_from_action(action);
	comm.session_name_len =
		serialize_strlen(action_snapshot_session->session_name);

	/* Add header. */
	ret = lttng_dynamic_buffer_append(
			&payload->buffer, &comm, sizeof(comm));
	if (ret) {
		goto end;
	}

	LTTNG_ASSERT(action_snapshot_session->session_name);
	DBG("Serializing snapshot session action: session-name: %s",
			action_snapshot_session->session_name);

	/* Add session name. */
	ret = lttng_dynamic_buffer_append(&payload->buffer,
			action_snapshot_session->session_name,
			comm.session_name_len);
	if (ret) {
		goto end;
	}

	/* Serialize the snapshot output object, if any. */
	if (action_snapshot_session->output) {
		const size_t size_before_output = payload->buffer.size;
		struct lttng_action_snapshot_session_comm *comm_in_payload;

		ret = lttng_snapshot_output_serialize(
				action_snapshot_session->output,
				payload);
		if (ret) {
			goto end;
		}

		comm_in_payload = (typeof(comm_in_payload))(
				payload->buffer.data + size_before_comm);
		/* Adjust action length in header. */
		comm_in_payload->snapshot_output_len =
				payload->buffer.size - size_before_output;
	}

	/* Serialize the rate policy. */
	{
		const size_t size_before_output = payload->buffer.size;
		struct lttng_action_snapshot_session_comm *comm_in_payload;

		ret = lttng_rate_policy_serialize(
				action_snapshot_session->policy, payload);
		if (ret) {
			ret = -1;
			goto end;
		}

		comm_in_payload = (typeof(comm_in_payload))(
				payload->buffer.data + size_before_comm);
		/* Adjust rate policy length in header. */
		comm_in_payload->rate_policy_len =
				payload->buffer.size - size_before_output;
	}

end:
	return ret;
}

static void lttng_action_snapshot_session_destroy(struct lttng_action *action)
{
	struct lttng_action_snapshot_session *action_snapshot_session;

	if (!action) {
		goto end;
	}

	action_snapshot_session = action_snapshot_session_from_action(action);

	free(action_snapshot_session->session_name);
	lttng_snapshot_output_destroy(action_snapshot_session->output);
	lttng_rate_policy_destroy(action_snapshot_session->policy);
	free(action_snapshot_session);

end:
	return;
}

ssize_t lttng_action_snapshot_session_create_from_payload(
		struct lttng_payload_view *view,
		struct lttng_action **p_action)
{
	ssize_t consumed_len;
	const char *variable_data;
	struct lttng_action *action;
	enum lttng_action_status status;
	struct lttng_snapshot_output *snapshot_output = NULL;
	struct lttng_rate_policy *policy = NULL;
	const struct lttng_action_snapshot_session_comm *comm;
	const struct lttng_payload_view snapshot_session_comm_view =
			lttng_payload_view_from_view(
				view, 0, sizeof(*comm));

	action = lttng_action_snapshot_session_create();
	if (!action) {
		goto error;
	}

	if (!lttng_payload_view_is_valid(&snapshot_session_comm_view)) {
		/* Payload not large enough to contain the header. */
		goto error;
	}

	comm = (typeof(comm)) snapshot_session_comm_view.buffer.data;
	variable_data = (const char *) &comm->data;

	consumed_len = sizeof(struct lttng_action_snapshot_session_comm);

	if (!lttng_buffer_view_contains_string(
			&view->buffer, variable_data, comm->session_name_len)) {
		goto error;
	}

	status = lttng_action_snapshot_session_set_session_name(
			action, variable_data);
	if (status != LTTNG_ACTION_STATUS_OK) {
		goto error;
	}

	variable_data += comm->session_name_len;
	consumed_len += comm->session_name_len;

	/* If there is a snapshot output object, deserialize it. */
	if (comm->snapshot_output_len > 0) {
		ssize_t snapshot_output_consumed_len;
		enum lttng_action_status action_status;
		struct lttng_payload_view snapshot_output_buffer_view =
			lttng_payload_view_from_view(view, consumed_len,
				comm->snapshot_output_len);

		if (!lttng_payload_view_is_valid(&snapshot_output_buffer_view)) {
			ERR("Failed to create buffer view for snapshot output.");
			goto error;
		}

		snapshot_output_consumed_len =
				lttng_snapshot_output_create_from_payload(
						&snapshot_output_buffer_view,
						&snapshot_output);
		if (snapshot_output_consumed_len != comm->snapshot_output_len) {
			ERR("Failed to deserialize snapshot output object: "
					"consumed-len: %zd, expected-len: %" PRIu32,
					snapshot_output_consumed_len,
					comm->snapshot_output_len);
			goto error;
		}

		action_status = lttng_action_snapshot_session_set_output(
			action, snapshot_output);
		if (action_status != LTTNG_ACTION_STATUS_OK) {
			goto error;
		}

		/* Ownership has been transferred to the action. */
		snapshot_output = NULL;
	}

	variable_data += comm->snapshot_output_len;
	consumed_len += comm->snapshot_output_len;

	/* Rate policy. */
	if (comm->rate_policy_len <= 0) {
		ERR("Rate policy should be present.");
		goto error;
	}
	{
		ssize_t rate_policy_consumed_len;
		struct lttng_payload_view policy_view =
				lttng_payload_view_from_view(view, consumed_len,
						comm->rate_policy_len);

		if (!lttng_payload_view_is_valid(&policy_view)) {
			ERR("Failed to create buffer view for rate policy.");
			goto error;
		}

		rate_policy_consumed_len =
				lttng_rate_policy_create_from_payload(
						&policy_view, &policy);
		if (rate_policy_consumed_len < 0) {
			goto error;
		}

		if (rate_policy_consumed_len != comm->rate_policy_len) {
			ERR("Failed to deserialize rate policy object: "
			    "consumed-len: %zd, expected-len: %" PRIu32,
					rate_policy_consumed_len,
					comm->rate_policy_len);
			goto error;
		}

		status = lttng_action_snapshot_session_set_rate_policy(
				action, policy);
		if (status != LTTNG_ACTION_STATUS_OK) {
			goto error;
		}
	}

	variable_data += comm->rate_policy_len;
	consumed_len += comm->rate_policy_len;

	*p_action = action;
	action = NULL;

	goto end;

error:
	consumed_len = -1;

end:
	lttng_rate_policy_destroy(policy);
	lttng_action_snapshot_session_destroy(action);
	lttng_snapshot_output_destroy(snapshot_output);

	return consumed_len;
}

static enum lttng_error_code lttng_action_snapshot_session_mi_serialize(
		const struct lttng_action *action, struct mi_writer *writer)
{
	int ret;
	enum lttng_error_code ret_code;
	enum lttng_action_status status;
	const char *session_name = NULL;
	const struct lttng_snapshot_output *output = NULL;
	const struct lttng_rate_policy *policy = NULL;

	LTTNG_ASSERT(action);
	LTTNG_ASSERT(IS_SNAPSHOT_SESSION_ACTION(action));

	status = lttng_action_snapshot_session_get_session_name(
			action, &session_name);
	LTTNG_ASSERT(status == LTTNG_ACTION_STATUS_OK);
	LTTNG_ASSERT(session_name != NULL);

	status = lttng_action_snapshot_session_get_rate_policy(action, &policy);
	LTTNG_ASSERT(status == LTTNG_ACTION_STATUS_OK);
	LTTNG_ASSERT(policy != NULL);

	/* Open action snapshot session element. */
	ret = mi_lttng_writer_open_element(
			writer, mi_lttng_element_action_snapshot_session);
	if (ret) {
		goto mi_error;
	}

	/* Session name. */
	ret = mi_lttng_writer_write_element_string(
			writer, mi_lttng_element_session_name, session_name);
	if (ret) {
		goto mi_error;
	}

	/* Output if any. */
	status = lttng_action_snapshot_session_get_output(action, &output);
	if (status == LTTNG_ACTION_STATUS_OK) {
		LTTNG_ASSERT(output != NULL);
		ret_code = lttng_snapshot_output_mi_serialize(output, writer);
		if (ret_code != LTTNG_OK) {
			goto end;
		}
	} else if (status != LTTNG_ACTION_STATUS_UNSET) {
		/* This should not happen at this point. */
		abort();
	}

	/* Rate policy. */
	ret_code = lttng_rate_policy_mi_serialize(policy, writer);
	if (ret_code != LTTNG_OK) {
		goto end;
	}

	/* Close action_snapshot_session element. */
	ret = mi_lttng_writer_close_element(writer);
	if (ret) {
		goto mi_error;
	}

	ret_code = LTTNG_OK;
	goto end;

mi_error:
	ret_code = LTTNG_ERR_MI_IO_FAIL;
end:
	return ret_code;
}

struct lttng_action *lttng_action_snapshot_session_create(void)
{
	struct lttng_action *action = NULL;
	struct lttng_rate_policy *policy = NULL;
	enum lttng_action_status status;

	/* Create a every N = 1 rate policy. */
	policy = lttng_rate_policy_every_n_create(1);
	if (!policy) {
		goto end;
	}

	action = (lttng_action *) zmalloc(sizeof(struct lttng_action_snapshot_session));
	if (!action) {
		goto end;
	}

	lttng_action_init(action, LTTNG_ACTION_TYPE_SNAPSHOT_SESSION,
			lttng_action_snapshot_session_validate,
			lttng_action_snapshot_session_serialize,
			lttng_action_snapshot_session_is_equal,
			lttng_action_snapshot_session_destroy,
			lttng_action_snapshot_session_internal_get_rate_policy,
			lttng_action_generic_add_error_query_results,
			lttng_action_snapshot_session_mi_serialize);

	status = lttng_action_snapshot_session_set_rate_policy(action, policy);
	if (status != LTTNG_ACTION_STATUS_OK) {
		free(action);
		action = NULL;
		goto end;
	}

end:
	lttng_rate_policy_destroy(policy);
	return action;
}

enum lttng_action_status lttng_action_snapshot_session_set_session_name(
		struct lttng_action *action, const char *session_name)
{
	struct lttng_action_snapshot_session *action_snapshot_session;
	enum lttng_action_status status;

	if (!action || !IS_SNAPSHOT_SESSION_ACTION(action) || !session_name ||
			strlen(session_name) == 0) {
		status = LTTNG_ACTION_STATUS_INVALID;
		goto end;
	}

	action_snapshot_session = action_snapshot_session_from_action(action);

	free(action_snapshot_session->session_name);

	action_snapshot_session->session_name = strdup(session_name);
	if (!action_snapshot_session->session_name) {
		status = LTTNG_ACTION_STATUS_ERROR;
		goto end;
	}

	status = LTTNG_ACTION_STATUS_OK;
end:
	return status;
}

enum lttng_action_status lttng_action_snapshot_session_get_session_name(
		const struct lttng_action *action, const char **session_name)
{
	const struct lttng_action_snapshot_session *action_snapshot_session;
	enum lttng_action_status status;

	if (!action || !IS_SNAPSHOT_SESSION_ACTION(action) || !session_name) {
		status = LTTNG_ACTION_STATUS_INVALID;
		goto end;
	}

	action_snapshot_session = action_snapshot_session_from_action_const(action);

	if (action_snapshot_session->session_name) {
		*session_name = action_snapshot_session->session_name;
		status = LTTNG_ACTION_STATUS_OK;
	} else {
		status = LTTNG_ACTION_STATUS_UNSET;
	}

end:

	return status;
}

enum lttng_action_status lttng_action_snapshot_session_set_output(
		struct lttng_action *action,
		struct lttng_snapshot_output *output)
{
	struct lttng_action_snapshot_session *action_snapshot_session;
	enum lttng_action_status status;

	if (!action || !IS_SNAPSHOT_SESSION_ACTION(action) || !output) {
		status = LTTNG_ACTION_STATUS_INVALID;
		goto end;
	}

	action_snapshot_session = action_snapshot_session_from_action(action);

	lttng_snapshot_output_destroy(action_snapshot_session->output);
	action_snapshot_session->output = output;

	status = LTTNG_ACTION_STATUS_OK;

end:
	return status;
}

enum lttng_action_status lttng_action_snapshot_session_get_output(
		const struct lttng_action *action,
		const struct lttng_snapshot_output **output)
{
	const struct lttng_action_snapshot_session *action_snapshot_session;
	enum lttng_action_status status;

	if (!action || !IS_SNAPSHOT_SESSION_ACTION(action)|| !output) {
		status = LTTNG_ACTION_STATUS_INVALID;
		goto end;
	}

	action_snapshot_session = action_snapshot_session_from_action_const(action);

	if (action_snapshot_session->output) {
		*output = action_snapshot_session->output;
		status = LTTNG_ACTION_STATUS_OK;
	} else {
		status = LTTNG_ACTION_STATUS_UNSET;
	}

end:
	return status;
}

enum lttng_action_status lttng_action_snapshot_session_set_rate_policy(
		struct lttng_action *action,
		const struct lttng_rate_policy *policy)
{
	enum lttng_action_status status;
	struct lttng_action_snapshot_session *snapshot_session_action;
	struct lttng_rate_policy *copy = NULL;

	if (!action || !policy || !IS_SNAPSHOT_SESSION_ACTION(action)) {
		status = LTTNG_ACTION_STATUS_INVALID;
		goto end;
	}

	copy = lttng_rate_policy_copy(policy);
	if (!copy) {
		status = LTTNG_ACTION_STATUS_ERROR;
		goto end;
	}

	snapshot_session_action = action_snapshot_session_from_action(action);

	/* Free the previous rate policy .*/
	lttng_rate_policy_destroy(snapshot_session_action->policy);

	/* Assign the policy. */
	snapshot_session_action->policy = copy;
	status = LTTNG_ACTION_STATUS_OK;
	copy = NULL;

end:
	lttng_rate_policy_destroy(copy);
	return status;
}

enum lttng_action_status lttng_action_snapshot_session_get_rate_policy(
		const struct lttng_action *action,
		const struct lttng_rate_policy **policy)
{
	enum lttng_action_status status;
	const struct lttng_action_snapshot_session *snapshot_session_action;

	if (!action || !policy || !IS_SNAPSHOT_SESSION_ACTION(action)) {
		status = LTTNG_ACTION_STATUS_INVALID;
		goto end;
	}

	snapshot_session_action =
			action_snapshot_session_from_action_const(action);

	*policy = snapshot_session_action->policy;
	status = LTTNG_ACTION_STATUS_OK;
end:
	return status;
}

static const struct lttng_rate_policy *
lttng_action_snapshot_session_internal_get_rate_policy(
		const struct lttng_action *action)
{
	const struct lttng_action_snapshot_session *_action;
	_action = action_snapshot_session_from_action_const(action);

	return _action->policy;
}
Commit	Line	Data
757c48a2 SM	1	/*
	2	* Copyright (C) 2019 Simon Marchi <simon.marchi@efficios.com>
	3	*
	4	* SPDX-License-Identifier: LGPL-2.1-only
	5	*
	6	*/
	7
757c48a2 SM	8	#include <common/error.h>
757c48a2 SM	9	#include <common/macros.h>
6a751b95	10	#include <common/mi-lttng.h>
9e620ea7	11	#include <common/payload-view.h>
d35c7a38 JR	12	#include <common/payload.h>
	13	#include <common/snapshot.h>
	14	#include <inttypes.h>
757c48a2	15	#include <lttng/action/action-internal.h>
7f4d5b07 JR	16	#include <lttng/action/rate-policy-internal.h>
7f4d5b07 JR	17	#include <lttng/action/rate-policy.h>
757c48a2 SM	18	#include <lttng/action/snapshot-session-internal.h>
757c48a2 SM	19	#include <lttng/action/snapshot-session.h>
757c48a2	20	#include <lttng/snapshot-internal.h>
d35c7a38	21	#include <lttng/snapshot.h>
757c48a2 SM	22
757c48a2 SM	23	#define IS_SNAPSHOT_SESSION_ACTION(action) \
17182cfd	24	(lttng_action_get_type(action) == LTTNG_ACTION_TYPE_SNAPSHOT_SESSION)
757c48a2 SM	25
	26	struct lttng_action_snapshot_session {
	27	struct lttng_action parent;
	28
	29	/* Owned by this. */
	30	char *session_name;
	31
	32	/*
	33	* When non-NULL, use this custom output when taking the snapshot,
	34	* rather than the session's registered snapshot output.
	35	*
	36	* Owned by this.
	37	*/
	38	struct lttng_snapshot_output *output;
7f4d5b07	39	struct lttng_rate_policy *policy;
757c48a2 SM	40	};
	41
	42	struct lttng_action_snapshot_session_comm {
	43	/* All string lengths include the trailing \0. */
	44	uint32_t session_name_len;
	45	uint32_t snapshot_output_len;
7f4d5b07	46	uint32_t rate_policy_len;
757c48a2 SM	47
	48	/*
	49	* Variable data (all strings are null-terminated):
	50	*
	51	* - session name string
	52	* - snapshot output object
d35c7a38	53	* - policy object
757c48a2 SM	54	*/
	55	char data[];
	56	} LTTNG_PACKED;
	57
7f4d5b07 JR	58	static const struct lttng_rate_policy *
7f4d5b07 JR	59	lttng_action_snapshot_session_internal_get_rate_policy(
2d57482c JR	60	const struct lttng_action *action);
2d57482c JR	61
757c48a2 SM	62	static struct lttng_action_snapshot_session *
	63	action_snapshot_session_from_action(struct lttng_action *action)
	64	{
a0377dfe	65	LTTNG_ASSERT(action);
757c48a2 SM	66
	67	return container_of(
	68	action, struct lttng_action_snapshot_session, parent);
	69	}
	70
	71	static const struct lttng_action_snapshot_session *
	72	action_snapshot_session_from_action_const(const struct lttng_action *action)
	73	{
a0377dfe	74	LTTNG_ASSERT(action);
757c48a2 SM	75
	76	return container_of(
	77	action, struct lttng_action_snapshot_session, parent);
	78	}
	79
	80	static bool lttng_action_snapshot_session_validate(struct lttng_action *action)
	81	{
	82	bool valid = false;
	83	struct lttng_action_snapshot_session *action_snapshot_session;
	84
	85	if (!action) {
	86	goto end;
	87	}
	88
	89	action_snapshot_session = action_snapshot_session_from_action(action);
	90
	91	/* A non-empty session name is mandatory. */
	92	if (!action_snapshot_session->session_name \|\|
	93	strlen(action_snapshot_session->session_name) == 0) {
	94	goto end;
	95	}
	96
	97	if (action_snapshot_session->output &&
	98	!lttng_snapshot_output_validate(action_snapshot_session->output)) {
	99	goto end;
	100	}
	101
	102	valid = true;
	103	end:
	104	return valid;
	105	}
	106
	107	static bool lttng_action_snapshot_session_is_equal(
	108	const struct lttng_action _a, const struct lttng_action _b)
	109	{
	110	bool is_equal = false;
	111	const struct lttng_action_snapshot_session a, b;
	112
	113	a = action_snapshot_session_from_action_const(_a);
	114	b = action_snapshot_session_from_action_const(_b);
	115
	116	/* Action is not valid if this is not true. */
a0377dfe FD	117	LTTNG_ASSERT(a->session_name);
a0377dfe FD	118	LTTNG_ASSERT(b->session_name);
757c48a2 SM	119	if (strcmp(a->session_name, b->session_name)) {
	120	goto end;
	121	}
	122
	123	if (a->output && b->output &&
	124	!lttng_snapshot_output_is_equal(a->output, b->output)) {
	125	goto end;
	126	} else if (!!a->output != !!b->output) {
	127	goto end;
	128	}
	129
7f4d5b07	130	is_equal = lttng_rate_policy_is_equal(a->policy, b->policy);
757c48a2 SM	131	end:
	132	return is_equal;
	133	}
	134
0c51e8f3	135	static size_t serialize_strlen(const char *str)
757c48a2	136	{
0c51e8f3	137	return str ? strlen(str) + 1 : 0;
757c48a2 SM	138	}
	139
	140	static int lttng_action_snapshot_session_serialize(
	141	struct lttng_action action, struct lttng_payload payload)
	142	{
	143	struct lttng_action_snapshot_session *action_snapshot_session;
	144	struct lttng_action_snapshot_session_comm comm = {};
	145	int ret;
	146	size_t size_before_comm;
	147
a0377dfe FD	148	LTTNG_ASSERT(action);
a0377dfe FD	149	LTTNG_ASSERT(payload);
757c48a2 SM	150
757c48a2 SM	151	size_before_comm = payload->buffer.size;
757c48a2 SM	152
	153	action_snapshot_session = action_snapshot_session_from_action(action);
	154	comm.session_name_len =
	155	serialize_strlen(action_snapshot_session->session_name);
	156
	157	/* Add header. */
	158	ret = lttng_dynamic_buffer_append(
	159	&payload->buffer, &comm, sizeof(comm));
	160	if (ret) {
	161	goto end;
	162	}
	163
a0377dfe	164	LTTNG_ASSERT(action_snapshot_session->session_name);
757c48a2 SM	165	DBG("Serializing snapshot session action: session-name: %s",
	166	action_snapshot_session->session_name);
	167
	168	/* Add session name. */
	169	ret = lttng_dynamic_buffer_append(&payload->buffer,
	170	action_snapshot_session->session_name,
	171	comm.session_name_len);
	172	if (ret) {
	173	goto end;
	174	}
	175
	176	/* Serialize the snapshot output object, if any. */
	177	if (action_snapshot_session->output) {
	178	const size_t size_before_output = payload->buffer.size;
	179	struct lttng_action_snapshot_session_comm *comm_in_payload;
	180
	181	ret = lttng_snapshot_output_serialize(
	182	action_snapshot_session->output,
	183	payload);
	184	if (ret) {
	185	goto end;
	186	}
	187
757c48a2 SM	188	comm_in_payload = (typeof(comm_in_payload))(
757c48a2 SM	189	payload->buffer.data + size_before_comm);
d35c7a38	190	/* Adjust action length in header. */
757c48a2 SM	191	comm_in_payload->snapshot_output_len =
	192	payload->buffer.size - size_before_output;
	193	}
	194
7f4d5b07	195	/* Serialize the rate policy. */
d35c7a38 JR	196	{
	197	const size_t size_before_output = payload->buffer.size;
	198	struct lttng_action_snapshot_session_comm *comm_in_payload;
	199
7f4d5b07	200	ret = lttng_rate_policy_serialize(
d35c7a38 JR	201	action_snapshot_session->policy, payload);
	202	if (ret) {
	203	ret = -1;
	204	goto end;
	205	}
	206
	207	comm_in_payload = (typeof(comm_in_payload))(
	208	payload->buffer.data + size_before_comm);
7f4d5b07 JR	209	/* Adjust rate policy length in header. */
7f4d5b07 JR	210	comm_in_payload->rate_policy_len =
d35c7a38 JR	211	payload->buffer.size - size_before_output;
	212	}
	213
757c48a2 SM	214	end:
	215	return ret;
	216	}
	217
	218	static void lttng_action_snapshot_session_destroy(struct lttng_action *action)
	219	{
	220	struct lttng_action_snapshot_session *action_snapshot_session;
	221
	222	if (!action) {
	223	goto end;
	224	}
	225
	226	action_snapshot_session = action_snapshot_session_from_action(action);
	227
	228	free(action_snapshot_session->session_name);
	229	lttng_snapshot_output_destroy(action_snapshot_session->output);
7f4d5b07	230	lttng_rate_policy_destroy(action_snapshot_session->policy);
757c48a2 SM	231	free(action_snapshot_session);
	232
	233	end:
	234	return;
	235	}
	236
	237	ssize_t lttng_action_snapshot_session_create_from_payload(
	238	struct lttng_payload_view *view,
	239	struct lttng_action **p_action)
	240	{
	241	ssize_t consumed_len;
757c48a2 SM	242	const char *variable_data;
	243	struct lttng_action *action;
	244	enum lttng_action_status status;
	245	struct lttng_snapshot_output *snapshot_output = NULL;
7f4d5b07	246	struct lttng_rate_policy *policy = NULL;
3e6e0df2 JG	247	const struct lttng_action_snapshot_session_comm *comm;
	248	const struct lttng_payload_view snapshot_session_comm_view =
	249	lttng_payload_view_from_view(
	250	view, 0, sizeof(*comm));
757c48a2 SM	251
	252	action = lttng_action_snapshot_session_create();
	253	if (!action) {
	254	goto error;
	255	}
	256
3e6e0df2 JG	257	if (!lttng_payload_view_is_valid(&snapshot_session_comm_view)) {
	258	/* Payload not large enough to contain the header. */
	259	goto error;
	260	}
	261
	262	comm = (typeof(comm)) snapshot_session_comm_view.buffer.data;
757c48a2 SM	263	variable_data = (const char *) &comm->data;
	264
	265	consumed_len = sizeof(struct lttng_action_snapshot_session_comm);
	266
	267	if (!lttng_buffer_view_contains_string(
	268	&view->buffer, variable_data, comm->session_name_len)) {
	269	goto error;
	270	}
	271
	272	status = lttng_action_snapshot_session_set_session_name(
	273	action, variable_data);
	274	if (status != LTTNG_ACTION_STATUS_OK) {
	275	goto error;
	276	}
	277
	278	variable_data += comm->session_name_len;
	279	consumed_len += comm->session_name_len;
	280
	281	/* If there is a snapshot output object, deserialize it. */
	282	if (comm->snapshot_output_len > 0) {
	283	ssize_t snapshot_output_consumed_len;
	284	enum lttng_action_status action_status;
	285	struct lttng_payload_view snapshot_output_buffer_view =
	286	lttng_payload_view_from_view(view, consumed_len,
	287	comm->snapshot_output_len);
	288
3e6e0df2	289	if (!lttng_payload_view_is_valid(&snapshot_output_buffer_view)) {
0c51e8f3	290	ERR("Failed to create buffer view for snapshot output.");
757c48a2 SM	291	goto error;
	292	}
	293
	294	snapshot_output_consumed_len =
	295	lttng_snapshot_output_create_from_payload(
	296	&snapshot_output_buffer_view,
	297	&snapshot_output);
	298	if (snapshot_output_consumed_len != comm->snapshot_output_len) {
0c51e8f3	299	ERR("Failed to deserialize snapshot output object: "
757c48a2 SM	300	"consumed-len: %zd, expected-len: %" PRIu32,
	301	snapshot_output_consumed_len,
	302	comm->snapshot_output_len);
	303	goto error;
	304	}
	305
	306	action_status = lttng_action_snapshot_session_set_output(
	307	action, snapshot_output);
	308	if (action_status != LTTNG_ACTION_STATUS_OK) {
	309	goto error;
	310	}
	311
	312	/* Ownership has been transferred to the action. */
	313	snapshot_output = NULL;
	314	}
	315
	316	variable_data += comm->snapshot_output_len;
	317	consumed_len += comm->snapshot_output_len;
d35c7a38	318
7f4d5b07 JR	319	/* Rate policy. */
	320	if (comm->rate_policy_len <= 0) {
	321	ERR("Rate policy should be present.");
d35c7a38 JR	322	goto error;
	323	}
	324	{
7f4d5b07	325	ssize_t rate_policy_consumed_len;
d35c7a38 JR	326	struct lttng_payload_view policy_view =
d35c7a38 JR	327	lttng_payload_view_from_view(view, consumed_len,
7f4d5b07	328	comm->rate_policy_len);
d35c7a38 JR	329
d35c7a38 JR	330	if (!lttng_payload_view_is_valid(&policy_view)) {
7f4d5b07	331	ERR("Failed to create buffer view for rate policy.");
d35c7a38 JR	332	goto error;
	333	}
	334
7f4d5b07 JR	335	rate_policy_consumed_len =
7f4d5b07 JR	336	lttng_rate_policy_create_from_payload(
d35c7a38	337	&policy_view, &policy);
7f4d5b07	338	if (rate_policy_consumed_len < 0) {
d35c7a38 JR	339	goto error;
	340	}
	341
7f4d5b07 JR	342	if (rate_policy_consumed_len != comm->rate_policy_len) {
7f4d5b07 JR	343	ERR("Failed to deserialize rate policy object: "
d35c7a38	344	"consumed-len: %zd, expected-len: %" PRIu32,
7f4d5b07 JR	345	rate_policy_consumed_len,
7f4d5b07 JR	346	comm->rate_policy_len);
d35c7a38 JR	347	goto error;
	348	}
	349
7f4d5b07	350	status = lttng_action_snapshot_session_set_rate_policy(
d35c7a38 JR	351	action, policy);
	352	if (status != LTTNG_ACTION_STATUS_OK) {
	353	goto error;
	354	}
	355	}
	356
7f4d5b07 JR	357	variable_data += comm->rate_policy_len;
7f4d5b07 JR	358	consumed_len += comm->rate_policy_len;
d35c7a38	359
757c48a2 SM	360	*p_action = action;
	361	action = NULL;
	362
	363	goto end;
	364
	365	error:
	366	consumed_len = -1;
	367
	368	end:
7f4d5b07	369	lttng_rate_policy_destroy(policy);
757c48a2 SM	370	lttng_action_snapshot_session_destroy(action);
	371	lttng_snapshot_output_destroy(snapshot_output);
	372
	373	return consumed_len;
	374	}
	375
6a751b95 JR	376	static enum lttng_error_code lttng_action_snapshot_session_mi_serialize(
	377	const struct lttng_action action, struct mi_writer writer)
	378	{
	379	int ret;
	380	enum lttng_error_code ret_code;
	381	enum lttng_action_status status;
	382	const char *session_name = NULL;
	383	const struct lttng_snapshot_output *output = NULL;
	384	const struct lttng_rate_policy *policy = NULL;
	385
a0377dfe FD	386	LTTNG_ASSERT(action);
a0377dfe FD	387	LTTNG_ASSERT(IS_SNAPSHOT_SESSION_ACTION(action));
6a751b95 JR	388
	389	status = lttng_action_snapshot_session_get_session_name(
	390	action, &session_name);
a0377dfe FD	391	LTTNG_ASSERT(status == LTTNG_ACTION_STATUS_OK);
a0377dfe FD	392	LTTNG_ASSERT(session_name != NULL);
6a751b95 JR	393
6a751b95 JR	394	status = lttng_action_snapshot_session_get_rate_policy(action, &policy);
a0377dfe FD	395	LTTNG_ASSERT(status == LTTNG_ACTION_STATUS_OK);
a0377dfe FD	396	LTTNG_ASSERT(policy != NULL);
6a751b95 JR	397
	398	/* Open action snapshot session element. */
	399	ret = mi_lttng_writer_open_element(
	400	writer, mi_lttng_element_action_snapshot_session);
	401	if (ret) {
	402	goto mi_error;
	403	}
	404
	405	/* Session name. */
	406	ret = mi_lttng_writer_write_element_string(
	407	writer, mi_lttng_element_session_name, session_name);
	408	if (ret) {
	409	goto mi_error;
	410	}
	411
	412	/* Output if any. */
	413	status = lttng_action_snapshot_session_get_output(action, &output);
	414	if (status == LTTNG_ACTION_STATUS_OK) {
a0377dfe	415	LTTNG_ASSERT(output != NULL);
6a751b95 JR	416	ret_code = lttng_snapshot_output_mi_serialize(output, writer);
	417	if (ret_code != LTTNG_OK) {
	418	goto end;
	419	}
	420	} else if (status != LTTNG_ACTION_STATUS_UNSET) {
	421	/* This should not happen at this point. */
	422	abort();
	423	}
	424
	425	/* Rate policy. */
	426	ret_code = lttng_rate_policy_mi_serialize(policy, writer);
	427	if (ret_code != LTTNG_OK) {
	428	goto end;
	429	}
	430
	431	/* Close action_snapshot_session element. */
	432	ret = mi_lttng_writer_close_element(writer);
	433	if (ret) {
	434	goto mi_error;
	435	}
	436
	437	ret_code = LTTNG_OK;
	438	goto end;
	439
	440	mi_error:
	441	ret_code = LTTNG_ERR_MI_IO_FAIL;
	442	end:
	443	return ret_code;
	444	}
	445
757c48a2 SM	446	struct lttng_action *lttng_action_snapshot_session_create(void)
757c48a2 SM	447	{
d35c7a38	448	struct lttng_action *action = NULL;
7f4d5b07	449	struct lttng_rate_policy *policy = NULL;
d35c7a38 JR	450	enum lttng_action_status status;
d35c7a38 JR	451
7f4d5b07 JR	452	/* Create a every N = 1 rate policy. */
7f4d5b07 JR	453	policy = lttng_rate_policy_every_n_create(1);
d35c7a38 JR	454	if (!policy) {
	455	goto end;
	456	}
757c48a2	457
a6bc4ca9	458	action = (lttng_action *) zmalloc(sizeof(struct lttng_action_snapshot_session));
757c48a2 SM	459	if (!action) {
	460	goto end;
	461	}
	462
	463	lttng_action_init(action, LTTNG_ACTION_TYPE_SNAPSHOT_SESSION,
	464	lttng_action_snapshot_session_validate,
	465	lttng_action_snapshot_session_serialize,
	466	lttng_action_snapshot_session_is_equal,
2d57482c	467	lttng_action_snapshot_session_destroy,
588c4b0d	468	lttng_action_snapshot_session_internal_get_rate_policy,
6a751b95 JR	469	lttng_action_generic_add_error_query_results,
6a751b95 JR	470	lttng_action_snapshot_session_mi_serialize);
757c48a2	471
7f4d5b07	472	status = lttng_action_snapshot_session_set_rate_policy(action, policy);
d35c7a38 JR	473	if (status != LTTNG_ACTION_STATUS_OK) {
	474	free(action);
	475	action = NULL;
	476	goto end;
	477	}
	478
757c48a2	479	end:
7f4d5b07	480	lttng_rate_policy_destroy(policy);
757c48a2 SM	481	return action;
	482	}
	483
	484	enum lttng_action_status lttng_action_snapshot_session_set_session_name(
	485	struct lttng_action action, const char session_name)
	486	{
	487	struct lttng_action_snapshot_session *action_snapshot_session;
	488	enum lttng_action_status status;
	489
	490	if (!action \|\| !IS_SNAPSHOT_SESSION_ACTION(action) \|\| !session_name \|\|
	491	strlen(session_name) == 0) {
	492	status = LTTNG_ACTION_STATUS_INVALID;
	493	goto end;
	494	}
	495
	496	action_snapshot_session = action_snapshot_session_from_action(action);
	497
	498	free(action_snapshot_session->session_name);
	499
	500	action_snapshot_session->session_name = strdup(session_name);
	501	if (!action_snapshot_session->session_name) {
	502	status = LTTNG_ACTION_STATUS_ERROR;
	503	goto end;
	504	}
	505
	506	status = LTTNG_ACTION_STATUS_OK;
	507	end:
	508	return status;
	509	}
	510
	511	enum lttng_action_status lttng_action_snapshot_session_get_session_name(
	512	const struct lttng_action action, const char *session_name)
	513	{
	514	const struct lttng_action_snapshot_session *action_snapshot_session;
	515	enum lttng_action_status status;
	516
	517	if (!action \|\| !IS_SNAPSHOT_SESSION_ACTION(action) \|\| !session_name) {
	518	status = LTTNG_ACTION_STATUS_INVALID;
	519	goto end;
	520	}
	521
	522	action_snapshot_session = action_snapshot_session_from_action_const(action);
	523
	524	if (action_snapshot_session->session_name) {
	525	*session_name = action_snapshot_session->session_name;
	526	status = LTTNG_ACTION_STATUS_OK;
	527	} else {
	528	status = LTTNG_ACTION_STATUS_UNSET;
	529	}
	530
	531	end:
	532
	533	return status;
	534	}
	535
	536	enum lttng_action_status lttng_action_snapshot_session_set_output(
	537	struct lttng_action *action,
	538	struct lttng_snapshot_output *output)
	539	{
	540	struct lttng_action_snapshot_session *action_snapshot_session;
	541	enum lttng_action_status status;
	542
	543	if (!action \|\| !IS_SNAPSHOT_SESSION_ACTION(action) \|\| !output) {
	544	status = LTTNG_ACTION_STATUS_INVALID;
545	goto end;
546	}
547
548	action_snapshot_session = action_snapshot_session_from_action(action);
549
550	lttng_snapshot_output_destroy(action_snapshot_session->output);
551	action_snapshot_session->output = output;
552
553	status = LTTNG_ACTION_STATUS_OK;
554
555	end:
556	return status;
557	}
558
559	enum lttng_action_status lttng_action_snapshot_session_get_output(
560	const struct lttng_action *action,
561	const struct lttng_snapshot_output **output)
562	{
563	const struct lttng_action_snapshot_session *action_snapshot_session;
564	enum lttng_action_status status;
565
566	if (!action \|\| !IS_SNAPSHOT_SESSION_ACTION(action)\|\| !output) {
567	status = LTTNG_ACTION_STATUS_INVALID;
568	goto end;
569	}
570
571	action_snapshot_session = action_snapshot_session_from_action_const(action);
572
573	if (action_snapshot_session->output) {
574	*output = action_snapshot_session->output;
575	status = LTTNG_ACTION_STATUS_OK;
576	} else {
577	status = LTTNG_ACTION_STATUS_UNSET;
578	}
579
580	end:
581	return status;
582	}
d35c7a38	583
7f4d5b07	584	enum lttng_action_status lttng_action_snapshot_session_set_rate_policy(
d35c7a38	585	struct lttng_action *action,
7f4d5b07	586	const struct lttng_rate_policy *policy)
d35c7a38 JR	587	{
	588	enum lttng_action_status status;
	589	struct lttng_action_snapshot_session *snapshot_session_action;
7f4d5b07	590	struct lttng_rate_policy *copy = NULL;
d35c7a38 JR	591
	592	if (!action \|\| !policy \|\| !IS_SNAPSHOT_SESSION_ACTION(action)) {
	593	status = LTTNG_ACTION_STATUS_INVALID;
	594	goto end;
	595	}
	596
7f4d5b07	597	copy = lttng_rate_policy_copy(policy);
d35c7a38 JR	598	if (!copy) {
	599	status = LTTNG_ACTION_STATUS_ERROR;
	600	goto end;
	601	}
	602
	603	snapshot_session_action = action_snapshot_session_from_action(action);
	604
7f4d5b07 JR	605	/* Free the previous rate policy .*/
7f4d5b07 JR	606	lttng_rate_policy_destroy(snapshot_session_action->policy);
d35c7a38 JR	607
	608	/* Assign the policy. */
	609	snapshot_session_action->policy = copy;
	610	status = LTTNG_ACTION_STATUS_OK;
	611	copy = NULL;
	612
	613	end:
7f4d5b07	614	lttng_rate_policy_destroy(copy);
d35c7a38 JR	615	return status;
	616	}
	617
7f4d5b07	618	enum lttng_action_status lttng_action_snapshot_session_get_rate_policy(
d35c7a38	619	const struct lttng_action *action,
7f4d5b07	620	const struct lttng_rate_policy **policy)
d35c7a38 JR	621	{
	622	enum lttng_action_status status;
	623	const struct lttng_action_snapshot_session *snapshot_session_action;
	624
	625	if (!action \|\| !policy \|\| !IS_SNAPSHOT_SESSION_ACTION(action)) {
	626	status = LTTNG_ACTION_STATUS_INVALID;
	627	goto end;
	628	}
	629
	630	snapshot_session_action =
	631	action_snapshot_session_from_action_const(action);
	632
	633	*policy = snapshot_session_action->policy;
	634	status = LTTNG_ACTION_STATUS_OK;
	635	end:
	636	return status;
	637	}
2d57482c	638
7f4d5b07 JR	639	static const struct lttng_rate_policy *
7f4d5b07 JR	640	lttng_action_snapshot_session_internal_get_rate_policy(
2d57482c JR	641	const struct lttng_action *action)
	642	{
	643	const struct lttng_action_snapshot_session *_action;
	644	_action = action_snapshot_session_from_action_const(action);
	645
	646	return _action->policy;
	647	}