X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Ftrigger.c;h=55ab99729c338259d72476e1a8074d12b9e5f43f;hp=1de1b3b490328c05dc4d7e1f5bc2acc4d88ba692;hb=0de2479d5f5a287d31c69e34ea5202a69019f224;hpb=3647288fe42b25340f905046f3bd9aef21e12aaa

diff --git a/src/common/trigger.c b/src/common/trigger.c
index 1de1b3b49..55ab99729 100644
--- a/src/common/trigger.c
+++ b/src/common/trigger.c
@@ -1,25 +1,26 @@
 /*
- * Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
  *
- * This library is free software; you can redistribute it and/or modify it
- * under the terms of the GNU Lesser General Public License, version 2.1 only,
- * as published by the Free Software Foundation.
+ * SPDX-License-Identifier: LGPL-2.1-only
  *
- * This library 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 Lesser General Public License
- * for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with this library; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include <lttng/trigger/trigger-internal.h>
 #include <lttng/condition/condition-internal.h>
+#include <lttng/condition/event-rule.h>
+#include <lttng/condition/event-rule-internal.h>
+#include <lttng/condition/buffer-usage.h>
+#include <lttng/event-rule/event-rule-internal.h>
 #include <lttng/action/action-internal.h>
+#include <common/credentials.h>
+#include <common/payload.h>
+#include <common/payload-view.h>
+#include <lttng/domain.h>
 #include <common/error.h>
+#include <common/dynamic-array.h>
+#include <common/optional.h>
 #include <assert.h>
+#include <inttypes.h>
 
 LTTNG_HIDDEN
 bool lttng_trigger_validate(struct lttng_trigger *trigger)
@@ -31,6 +32,11 @@ bool lttng_trigger_validate(struct lttng_trigger *trigger)
 		goto end;
 	}
 
+	if (!trigger->creds.uid.is_set) {
+		valid = false;
+		goto end;
+	}
+
 	valid = lttng_condition_validate(trigger->condition) &&
 			lttng_action_validate(trigger->action);
 end:
@@ -52,68 +58,198 @@ struct lttng_trigger *lttng_trigger_create(
 		goto end;
 	}
 
+	urcu_ref_init(&trigger->ref);
+
+	trigger->firing_policy.type = LTTNG_TRIGGER_FIRING_POLICY_EVERY_N;
+	trigger->firing_policy.threshold = 1;
+
+	lttng_condition_get(condition);
 	trigger->condition = condition;
+
+	lttng_action_get(action);
 	trigger->action = action;
+
 end:
 	return trigger;
 }
 
+/*
+ * Note: the lack of reference counting 'get' on the condition object is normal.
+ * This API was exposed as such in 2.11. The client is not expected to call
+ * lttng_condition_destroy on the returned object.
+ */
 struct lttng_condition *lttng_trigger_get_condition(
 		struct lttng_trigger *trigger)
 {
 	return trigger ? trigger->condition : NULL;
 }
 
+const struct lttng_condition *lttng_trigger_get_const_condition(
+		const struct lttng_trigger *trigger)
+{
+	return trigger ? trigger->condition : NULL;
+}
+
+
+/*
+ * Note: the lack of reference counting 'get' on the action object is normal.
+ * This API was exposed as such in 2.11. The client is not expected to call
+ * lttng_action_destroy on the returned object.
+ */
 struct lttng_action *lttng_trigger_get_action(
 		struct lttng_trigger *trigger)
 {
 	return trigger ? trigger->action : NULL;
 }
 
+const struct lttng_action *lttng_trigger_get_const_action(
+		const struct lttng_trigger *trigger)
+{
+	return trigger ? trigger->action : NULL;
+}
+
+static void trigger_destroy_ref(struct urcu_ref *ref)
+{
+	struct lttng_trigger *trigger =
+			container_of(ref, struct lttng_trigger, ref);
+	struct lttng_action *action = lttng_trigger_get_action(trigger);
+	struct lttng_condition *condition =
+			lttng_trigger_get_condition(trigger);
+
+	assert(action);
+	assert(condition);
+
+	/* Release ownership. */
+	lttng_action_put(action);
+	lttng_condition_put(condition);
+
+	free(trigger->name);
+	free(trigger);
+}
+
 void lttng_trigger_destroy(struct lttng_trigger *trigger)
 {
-	if (!trigger) {
-		return;
+	lttng_trigger_put(trigger);
+}
+
+static bool is_firing_policy_valid(enum lttng_trigger_firing_policy policy)
+{
+	bool valid = false;
+
+	switch (policy) {
+	case LTTNG_TRIGGER_FIRING_POLICY_EVERY_N:
+	case LTTNG_TRIGGER_FIRING_POLICY_ONCE_AFTER_N:
+		valid = true;
+		break;
+	default:
+		valid = false;
+		break;
 	}
 
-	free(trigger);
+	return valid;
 }
 
 LTTNG_HIDDEN
-ssize_t lttng_trigger_create_from_buffer(
-		const struct lttng_buffer_view *src_view,
-		struct lttng_trigger **trigger)
+ssize_t lttng_trigger_create_from_payload(
+		struct lttng_payload_view *src_view,
+		struct lttng_trigger **_trigger)
 {
-	ssize_t ret, offset = 0, condition_size, action_size;
+	ssize_t ret, offset = 0, condition_size, action_size, name_size = 0;
 	struct lttng_condition *condition = NULL;
 	struct lttng_action *action = NULL;
 	const struct lttng_trigger_comm *trigger_comm;
-	struct lttng_buffer_view condition_view;
-	struct lttng_buffer_view action_view;
+	const char *name = NULL;
+	uint64_t firing_policy_threshold;
+	enum lttng_trigger_firing_policy firing_policy;
+	struct lttng_credentials creds = {
+		.uid = LTTNG_OPTIONAL_INIT_UNSET,
+		.gid = LTTNG_OPTIONAL_INIT_UNSET,
+	};
+	struct lttng_trigger *trigger = NULL;
+	const struct lttng_payload_view trigger_comm_view =
+			lttng_payload_view_from_view(
+					src_view, 0, sizeof(*trigger_comm));
 
-	if (!src_view || !trigger) {
+	if (!src_view || !_trigger) {
+		ret = -1;
+		goto end;
+	}
+
+	if (!lttng_payload_view_is_valid(&trigger_comm_view)) {
+		/* Payload not large enough to contain the header. */
 		ret = -1;
 		goto end;
 	}
 
 	/* lttng_trigger_comm header */
-	trigger_comm = (const struct lttng_trigger_comm *) src_view->data;
+	trigger_comm = (typeof(trigger_comm)) trigger_comm_view.buffer.data;
+
+	/* Set the trigger's creds. */
+	if (trigger_comm->uid > (uint64_t) ((uid_t) -1)) {
+		/* UID out of range for this platform. */
+		ret = -1;
+		goto end;
+	}
+
+	LTTNG_OPTIONAL_SET(&creds.uid, trigger_comm->uid);
+
 	offset += sizeof(*trigger_comm);
 
-	condition_view = lttng_buffer_view_from_view(src_view, offset, -1);
+	firing_policy = trigger_comm->firing_policy_type;
+	if (!is_firing_policy_valid(firing_policy)) {
+		ret =-1;
+		goto end;
+	}
+
+	firing_policy_threshold = trigger_comm->firing_policy_threshold;
+	if (trigger_comm->name_length != 0) {
+		/* Name. */
+		const struct lttng_payload_view name_view =
+				lttng_payload_view_from_view(
+						src_view, offset,
+						trigger_comm->name_length);
+
+		if (!lttng_payload_view_is_valid(&name_view)) {
+			ret = -1;
+			goto end;
+		}
+
+		name = name_view.buffer.data;
+		if (!lttng_buffer_view_contains_string(&name_view.buffer, name,
+				    trigger_comm->name_length)) {
+			ret = -1;
+			goto end;
+		}
+
+		offset += trigger_comm->name_length;
+		name_size = trigger_comm->name_length;
+	}
+
+	{
+		/* struct lttng_condition */
+		struct lttng_payload_view condition_view =
+				lttng_payload_view_from_view(
+						src_view, offset, -1);
+
+		condition_size = lttng_condition_create_from_payload(&condition_view,
+				&condition);
+	}
 
-	/* struct lttng_condition */
-	condition_size = lttng_condition_create_from_buffer(&condition_view,
-			&condition);
 	if (condition_size < 0) {
 		ret = condition_size;
 		goto end;
 	}
+
 	offset += condition_size;
+	{
+		/* struct lttng_action */
+		struct lttng_payload_view action_view =
+				lttng_payload_view_from_view(
+					src_view, offset, -1);
+
+		action_size = lttng_action_create_from_payload(&action_view, &action);
+	}
 
-	/* struct lttng_action */
-	action_view = lttng_buffer_view_from_view(src_view, offset, -1);
-	action_size = lttng_action_create_from_buffer(&action_view, &action);
 	if (action_size < 0) {
 		ret = action_size;
 		goto end;
@@ -121,22 +257,64 @@ ssize_t lttng_trigger_create_from_buffer(
 	offset += action_size;
 
 	/* Unexpected size of inner-elements; the buffer is corrupted. */
-	if ((ssize_t) trigger_comm->length != condition_size + action_size) {
+	if ((ssize_t) trigger_comm->length != condition_size + action_size + name_size) {
 		ret = -1;
 		goto error;
 	}
 
-	*trigger = lttng_trigger_create(condition, action);
-	if (!*trigger) {
+	trigger = lttng_trigger_create(condition, action);
+	if (!trigger) {
 		ret = -1;
 		goto error;
 	}
+
+	lttng_trigger_set_credentials(trigger, &creds);
+
+	/*
+	 * The trigger object owns references to the action and condition
+	 * objects.
+	 */
+	lttng_condition_put(condition);
+	condition = NULL;
+
+	lttng_action_put(action);
+	action = NULL;
+
+	if (name) {
+		const enum lttng_trigger_status status =
+				lttng_trigger_set_name(trigger, name);
+
+		if (status != LTTNG_TRIGGER_STATUS_OK) {
+			ret = -1;
+			goto end;
+		}
+	}
+
+	/* Set the policy. */
+	{
+		const enum lttng_trigger_status status =
+				lttng_trigger_set_firing_policy(trigger,
+						firing_policy,
+						firing_policy_threshold);
+
+		if (status != LTTNG_TRIGGER_STATUS_OK) {
+			ret = -1;
+			goto end;
+		}
+	}
+
 	ret = offset;
-end:
-	return ret;
+
 error:
-	lttng_condition_destroy(condition);
-	lttng_action_destroy(action);
+	lttng_condition_put(condition);
+	lttng_action_put(action);
+end:
+	if (ret >= 0) {
+		*_trigger = trigger;
+	} else {
+		lttng_trigger_put(trigger);
+	}
+
 	return ret;
 }
 
@@ -145,35 +323,651 @@ error:
  * for the detailed format.
  */
 LTTNG_HIDDEN
-int lttng_trigger_serialize(struct lttng_trigger *trigger,
-		struct lttng_dynamic_buffer *buf)
+int lttng_trigger_serialize(const struct lttng_trigger *trigger,
+		struct lttng_payload *payload)
 {
 	int ret;
-	size_t header_offset, size_before_payload;
-	struct lttng_trigger_comm trigger_comm = { 0 };
+	size_t header_offset, size_before_payload, size_name;
+	struct lttng_trigger_comm trigger_comm = {};
 	struct lttng_trigger_comm *header;
+	const struct lttng_credentials *creds = NULL;
+
+	creds = lttng_trigger_get_credentials(trigger);
+	assert(creds);
+
+	trigger_comm.uid = LTTNG_OPTIONAL_GET(creds->uid);
 
-	header_offset = buf->size;
-	ret = lttng_dynamic_buffer_append(buf, &trigger_comm,
+	if (trigger->name != NULL) {
+		size_name = strlen(trigger->name) + 1;
+	} else {
+		size_name = 0;
+	}
+
+	trigger_comm.name_length = size_name;
+	trigger_comm.firing_policy_type = (uint8_t) trigger->firing_policy.type;
+	trigger_comm.firing_policy_threshold = (uint64_t) trigger->firing_policy.threshold;
+
+	header_offset = payload->buffer.size;
+	ret = lttng_dynamic_buffer_append(&payload->buffer, &trigger_comm,
 			sizeof(trigger_comm));
 	if (ret) {
 		goto end;
 	}
 
-	size_before_payload = buf->size;
-	ret = lttng_condition_serialize(trigger->condition, buf);
+	size_before_payload = payload->buffer.size;
+
+	/* Trigger name. */
+	ret = lttng_dynamic_buffer_append(
+			&payload->buffer, trigger->name, size_name);
 	if (ret) {
 		goto end;
 	}
 
-	ret = lttng_action_serialize(trigger->action, buf);
+	ret = lttng_condition_serialize(trigger->condition, payload);
+	if (ret) {
+		goto end;
+	}
+
+	ret = lttng_action_serialize(trigger->action, payload);
 	if (ret) {
 		goto end;
 	}
 
 	/* Update payload size. */
-	header = (struct lttng_trigger_comm *) ((char *) buf->data + header_offset);
-	header->length = buf->size - size_before_payload;
+	header = (typeof(header)) (payload->buffer.data + header_offset);
+	header->length = payload->buffer.size - size_before_payload;
+end:
+	return ret;
+}
+
+LTTNG_HIDDEN
+bool lttng_trigger_is_equal(
+		const struct lttng_trigger *a, const struct lttng_trigger *b)
+{
+	if (a->firing_policy.type != b->firing_policy.type) {
+		return false;
+	}
+
+	if (a->firing_policy.threshold != b->firing_policy.threshold) {
+		return false;
+	}
+
+	/*
+	 * Name is not taken into account since it is cosmetic only.
+	 */
+	if (!lttng_condition_is_equal(a->condition, b->condition)) {
+		return false;
+	}
+
+	if (!lttng_action_is_equal(a->action, b->action)) {
+		return false;
+	}
+
+	if (!lttng_credentials_is_equal(lttng_trigger_get_credentials(a),
+			lttng_trigger_get_credentials(b))) {
+		return false;
+	}
+
+	return true;
+}
+
+enum lttng_trigger_status lttng_trigger_set_name(struct lttng_trigger *trigger,
+		const char* name)
+{
+	char *name_copy = NULL;
+	enum lttng_trigger_status status = LTTNG_TRIGGER_STATUS_OK;
+
+	if (!trigger || !name ||
+			strlen(name) == 0) {
+		status = LTTNG_TRIGGER_STATUS_INVALID;
+		goto end;
+	}
+
+	name_copy = strdup(name);
+	if (!name_copy) {
+		status = LTTNG_TRIGGER_STATUS_ERROR;
+		goto end;
+	}
+
+	free(trigger->name);
+
+	trigger->name = name_copy;
+	name_copy = NULL;
+end:
+	return status;
+}
+
+enum lttng_trigger_status lttng_trigger_get_name(
+		const struct lttng_trigger *trigger, const char **name)
+{
+	enum lttng_trigger_status status = LTTNG_TRIGGER_STATUS_OK;
+
+	if (!trigger || !name) {
+		status = LTTNG_TRIGGER_STATUS_INVALID;
+		goto end;
+	}
+
+	if (!trigger->name) {
+		status = LTTNG_TRIGGER_STATUS_UNSET;
+	}
+
+	*name = trigger->name;
+end:
+	return status;
+}
+
+LTTNG_HIDDEN
+int lttng_trigger_assign_name(struct lttng_trigger *dst,
+		const struct lttng_trigger *src)
+{
+	int ret = 0;
+	enum lttng_trigger_status status;
+
+	status = lttng_trigger_set_name(dst, src->name);
+	if (status != LTTNG_TRIGGER_STATUS_OK) {
+		ret = -1;
+		ERR("Failed to set name for trigger");
+		goto end;
+	}
+end:
+	return ret;
+}
+
+LTTNG_HIDDEN
+void lttng_trigger_set_tracer_token(struct lttng_trigger *trigger,
+		uint64_t token)
+{
+	assert(trigger);
+	LTTNG_OPTIONAL_SET(&trigger->tracer_token, token);
+}
+
+LTTNG_HIDDEN
+uint64_t lttng_trigger_get_tracer_token(const struct lttng_trigger *trigger)
+{
+	assert(trigger);
+
+	return LTTNG_OPTIONAL_GET(trigger->tracer_token);
+}
+
+LTTNG_HIDDEN
+int lttng_trigger_generate_name(struct lttng_trigger *trigger,
+		uint64_t unique_id)
+{
+	int ret = 0;
+	char *generated_name = NULL;
+
+	ret = asprintf(&generated_name, "T%" PRIu64 "", unique_id);
+	if (ret < 0) {
+		ERR("Failed to generate trigger name");
+		ret = -1;
+		goto end;
+	}
+
+	ret = 0;
+	free(trigger->name);
+	trigger->name = generated_name;
+end:
+	return ret;
+}
+
+LTTNG_HIDDEN
+void lttng_trigger_get(struct lttng_trigger *trigger)
+{
+	urcu_ref_get(&trigger->ref);
+}
+
+LTTNG_HIDDEN
+void lttng_trigger_put(struct lttng_trigger *trigger)
+{
+	if (!trigger) {
+		return;
+	}
+
+	urcu_ref_put(&trigger->ref , trigger_destroy_ref);
+}
+
+static void delete_trigger_array_element(void *ptr)
+{
+	struct lttng_trigger *trigger = ptr;
+
+	lttng_trigger_put(trigger);
+}
+
+LTTNG_HIDDEN
+struct lttng_triggers *lttng_triggers_create(void)
+{
+	struct lttng_triggers *triggers = NULL;
+
+	triggers = zmalloc(sizeof(*triggers));
+	if (!triggers) {
+		goto end;
+	}
+
+	lttng_dynamic_pointer_array_init(&triggers->array, delete_trigger_array_element);
+
+end:
+	return triggers;
+}
+
+LTTNG_HIDDEN
+struct lttng_trigger *lttng_triggers_borrow_mutable_at_index(
+		const struct lttng_triggers *triggers, unsigned int index)
+{
+	struct lttng_trigger *trigger = NULL;
+
+	assert(triggers);
+	if (index >= lttng_dynamic_pointer_array_get_count(&triggers->array)) {
+		goto end;
+	}
+
+	trigger = (struct lttng_trigger *)
+			lttng_dynamic_pointer_array_get_pointer(
+					&triggers->array, index);
+end:
+	return trigger;
+}
+
+LTTNG_HIDDEN
+int lttng_triggers_add(
+		struct lttng_triggers *triggers, struct lttng_trigger *trigger)
+{
+	int ret;
+
+	assert(triggers);
+	assert(trigger);
+
+	lttng_trigger_get(trigger);
+
+	ret = lttng_dynamic_pointer_array_add_pointer(&triggers->array, trigger);
+	if (ret) {
+		lttng_trigger_put(trigger);
+	}
+
+	return ret;
+}
+
+const struct lttng_trigger *lttng_triggers_get_at_index(
+		const struct lttng_triggers *triggers, unsigned int index)
+{
+	return lttng_triggers_borrow_mutable_at_index(triggers, index);
+}
+
+enum lttng_trigger_status lttng_triggers_get_count(const struct lttng_triggers *triggers, unsigned int *count)
+{
+	enum lttng_trigger_status status = LTTNG_TRIGGER_STATUS_OK;
+
+	if (!triggers || !count) {
+		status = LTTNG_TRIGGER_STATUS_INVALID;
+		goto end;
+	}
+
+	*count = lttng_dynamic_pointer_array_get_count(&triggers->array);
+end:
+	return status;
+}
+
+void lttng_triggers_destroy(struct lttng_triggers *triggers)
+{
+	if (!triggers) {
+		return;
+	}
+
+	lttng_dynamic_pointer_array_reset(&triggers->array);
+	free(triggers);
+}
+
+int lttng_triggers_serialize(const struct lttng_triggers *triggers,
+		struct lttng_payload *payload)
+{
+	int ret;
+	unsigned int i, count;
+	size_t size_before_payload;
+	struct lttng_triggers_comm triggers_comm = {};
+	struct lttng_triggers_comm *header;
+	enum lttng_trigger_status status;
+	const size_t header_offset = payload->buffer.size;
+
+	status = lttng_triggers_get_count(triggers, &count);
+	if (status != LTTNG_TRIGGER_STATUS_OK) {
+		ret = LTTNG_ERR_INVALID;
+		goto end;
+	}
+
+	triggers_comm.count = count;
+
+	/* Placeholder header; updated at the end. */
+	ret = lttng_dynamic_buffer_append(&payload->buffer, &triggers_comm,
+			sizeof(triggers_comm));
+	if (ret) {
+		goto end;
+	}
+
+	size_before_payload = payload->buffer.size;
+
+	for (i = 0; i < count; i++) {
+		const struct lttng_trigger *trigger =
+				lttng_triggers_get_at_index(triggers, i);
+
+		assert(trigger);
+
+		ret = lttng_trigger_serialize(trigger, payload);
+		if (ret) {
+			goto end;
+		}
+	}
+
+	/* Update payload size. */
+	header = (struct lttng_triggers_comm *) ((char *) payload->buffer.data + header_offset);
+	header->length = payload->buffer.size - size_before_payload;
+end:
+	return ret;
+}
+
+LTTNG_HIDDEN
+ssize_t lttng_triggers_create_from_payload(
+		struct lttng_payload_view *src_view,
+		struct lttng_triggers **triggers)
+{
+	ssize_t ret, offset = 0, triggers_size = 0;
+	unsigned int i;
+	const struct lttng_triggers_comm *triggers_comm;
+	struct lttng_triggers *local_triggers = NULL;
+
+	if (!src_view || !triggers) {
+		ret = -1;
+		goto error;
+	}
+
+	/* lttng_trigger_comms header */
+	triggers_comm = (const struct lttng_triggers_comm *) src_view->buffer.data;
+	offset += sizeof(*triggers_comm);
+
+	local_triggers = lttng_triggers_create();
+	if (!local_triggers) {
+		ret = -1;
+		goto error;
+	}
+
+	for (i = 0; i < triggers_comm->count; i++) {
+		struct lttng_trigger *trigger = NULL;
+		struct lttng_payload_view trigger_view =
+				lttng_payload_view_from_view(src_view, offset, -1);
+		ssize_t trigger_size;
+
+		trigger_size = lttng_trigger_create_from_payload(
+				&trigger_view, &trigger);
+		if (trigger_size < 0) {
+			ret = trigger_size;
+			goto error;
+		}
+
+		/* Transfer ownership of the trigger to the collection. */
+		ret = lttng_triggers_add(local_triggers, trigger);
+		lttng_trigger_put(trigger);
+		if (ret < 0) {
+			ret = -1;
+			goto error;
+		}
+
+		offset += trigger_size;
+		triggers_size += trigger_size;
+	}
+
+	/* Unexpected size of inner-elements; the buffer is corrupted. */
+	if ((ssize_t) triggers_comm->length != triggers_size) {
+		ret = -1;
+		goto error;
+	}
+
+	/* Pass ownership to caller. */
+	*triggers = local_triggers;
+	local_triggers = NULL;
+
+	ret = offset;
+error:
+
+	lttng_triggers_destroy(local_triggers);
+	return ret;
+}
+
+LTTNG_HIDDEN
+const struct lttng_credentials *lttng_trigger_get_credentials(
+		const struct lttng_trigger *trigger)
+{
+	return &trigger->creds;
+}
+
+LTTNG_HIDDEN
+void lttng_trigger_set_credentials(struct lttng_trigger *trigger,
+		const struct lttng_credentials *creds)
+{
+	assert(creds);
+	trigger->creds = *creds;
+}
+
+enum lttng_trigger_status lttng_trigger_set_owner_uid(
+		struct lttng_trigger *trigger, uid_t uid)
+{
+	enum lttng_trigger_status ret = LTTNG_TRIGGER_STATUS_OK;
+	const struct lttng_credentials creds = {
+		.uid = LTTNG_OPTIONAL_INIT_VALUE(uid),
+		.gid = LTTNG_OPTIONAL_INIT_UNSET,
+	};
+
+	if (!trigger) {
+		ret = LTTNG_TRIGGER_STATUS_INVALID;
+		goto end;
+	}
+
+	/* Client-side validation only to report a clearer error. */
+	if (geteuid() != 0) {
+		ret = LTTNG_TRIGGER_STATUS_PERMISSION_DENIED;
+		goto end;
+	}
+
+	lttng_trigger_set_credentials(trigger, &creds);
+
+end:
+	return ret;
+}
+
+enum lttng_trigger_status lttng_trigger_get_owner_uid(
+		const struct lttng_trigger *trigger, uid_t *uid)
+{
+	enum lttng_trigger_status ret = LTTNG_TRIGGER_STATUS_OK;
+	const struct lttng_credentials *creds = NULL;
+
+	if (!trigger || !uid ) {
+		ret = LTTNG_TRIGGER_STATUS_INVALID;
+		goto end;
+	}
+
+	if (!trigger->creds.uid.is_set ) {
+		ret = LTTNG_TRIGGER_STATUS_UNSET;
+		goto end;
+	}
+
+	creds = lttng_trigger_get_credentials(trigger);
+	*uid = lttng_credentials_get_uid(creds);
+
+end:
+	return ret;
+}
+
+enum lttng_trigger_status lttng_trigger_set_firing_policy(
+		struct lttng_trigger *trigger,
+		enum lttng_trigger_firing_policy policy_type,
+		uint64_t threshold)
+{
+	enum lttng_trigger_status ret = LTTNG_TRIGGER_STATUS_OK;
+	assert(trigger);
+
+	if (threshold < 1) {
+		ret = LTTNG_TRIGGER_STATUS_INVALID;
+		goto end;
+	}
+
+	trigger->firing_policy.type = policy_type;
+	trigger->firing_policy.threshold = threshold;
+
+end:
+	return ret;
+}
+
+enum lttng_trigger_status lttng_trigger_get_firing_policy(
+		const struct lttng_trigger *trigger,
+		enum lttng_trigger_firing_policy *policy_type,
+		uint64_t *threshold)
+{
+	enum lttng_trigger_status status = LTTNG_TRIGGER_STATUS_OK;
+
+	if (!trigger || !policy_type || !threshold) {
+		status = LTTNG_TRIGGER_STATUS_INVALID;
+		goto end;
+	}
+
+	*policy_type = trigger->firing_policy.type;
+	*threshold = trigger->firing_policy.threshold;
+
+end:
+	return status;
+}
+
+LTTNG_HIDDEN
+bool lttng_trigger_should_fire(const struct lttng_trigger *trigger)
+{
+	bool ready_to_fire = false;
+
+	assert(trigger);
+
+	switch (trigger->firing_policy.type) {
+	case LTTNG_TRIGGER_FIRING_POLICY_EVERY_N:
+		if (trigger->firing_policy.current_count < trigger->firing_policy.threshold) {
+			ready_to_fire = true;
+		}
+		break;
+	case LTTNG_TRIGGER_FIRING_POLICY_ONCE_AFTER_N:
+		if (trigger->firing_policy.current_count < trigger->firing_policy.threshold) {
+			ready_to_fire = true;
+		}
+		break;
+	default:
+		abort();
+	};
+
+	return ready_to_fire;
+}
+
+LTTNG_HIDDEN
+void lttng_trigger_fire(struct lttng_trigger *trigger)
+{
+	assert(trigger);
+
+	trigger->firing_policy.current_count++;
+
+	switch (trigger->firing_policy.type) {
+	case LTTNG_TRIGGER_FIRING_POLICY_EVERY_N:
+		if (trigger->firing_policy.current_count == trigger->firing_policy.threshold) {
+			trigger->firing_policy.current_count = 0;
+		}
+
+		break;
+	case LTTNG_TRIGGER_FIRING_POLICY_ONCE_AFTER_N:
+		/*
+		 * TODO:
+		 * As an optimisation, deactivate the trigger condition and
+		 * remove any checks in the traced application or kernel since
+		 * the trigger will never fire again.
+		 */
+		break;
+	default:
+		abort();
+	};
+}
+
+LTTNG_HIDDEN
+enum lttng_domain_type lttng_trigger_get_underlying_domain_type_restriction(
+		const struct lttng_trigger *trigger)
+{
+	enum lttng_domain_type type = LTTNG_DOMAIN_NONE;
+	const struct lttng_event_rule *event_rule;
+	enum lttng_condition_status c_status;
+	enum lttng_condition_type c_type;
+
+	assert(trigger);
+	assert(trigger->condition);
+
+	c_type = lttng_condition_get_type(trigger->condition);
+	assert (c_type != LTTNG_CONDITION_TYPE_UNKNOWN);
+
+	switch (c_type) {
+	case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE:
+	case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING:
+	case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED:
+		/* Apply to any domain. */
+		type = LTTNG_DOMAIN_NONE;
+		break;
+	case LTTNG_CONDITION_TYPE_EVENT_RULE_HIT:
+		/* Return the domain of the event rule. */
+		c_status = lttng_condition_event_rule_get_rule(
+				trigger->condition, &event_rule);
+		assert(c_status == LTTNG_CONDITION_STATUS_OK);
+		type = lttng_event_rule_get_domain_type(event_rule);
+		break;
+	case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH:
+	case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW:
+		/* Return the domain of the channel being monitored. */
+		c_status = lttng_condition_buffer_usage_get_domain_type(
+				trigger->condition, &type);
+		assert(c_status == LTTNG_CONDITION_STATUS_OK);
+		break;
+	default:
+		abort();
+	}
+
+	return type;
+}
+
+/*
+ * Generate bytecode related to the trigger.
+ * On success LTTNG_OK. On error, returns lttng_error code.
+ */
+LTTNG_HIDDEN
+enum lttng_error_code lttng_trigger_generate_bytecode(
+		struct lttng_trigger *trigger,
+		const struct lttng_credentials *creds)
+{
+	enum lttng_error_code ret;
+	struct lttng_condition *condition = NULL;
+
+	condition = lttng_trigger_get_condition(trigger);
+	if (!condition) {
+		ret = LTTNG_ERR_INVALID_TRIGGER;
+		goto end;
+	}
+
+	switch (lttng_condition_get_type(condition)) {
+	case LTTNG_CONDITION_TYPE_EVENT_RULE_HIT:
+	{
+		struct lttng_event_rule *event_rule;
+		const enum lttng_condition_status condition_status =
+				lttng_condition_event_rule_borrow_rule_mutable(
+					condition, &event_rule);
+
+		assert(condition_status == LTTNG_CONDITION_STATUS_OK);
+		ret = lttng_event_rule_generate_filter_bytecode(
+				event_rule, creds);
+		if (ret != LTTNG_OK) {
+			goto end;
+		}
+
+		ret = LTTNG_OK;
+		break;
+	}
+	default:
+		ret = LTTNG_OK;
+		break;
+	}
 end:
 	return ret;
 }