X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Ftrigger.cpp;fp=src%2Fcommon%2Ftrigger.cpp;h=3782f49cad19c901d709d4531d7ca5e4db679d8a;hp=0000000000000000000000000000000000000000;hb=a6bc4ca9d659caf016ef932fcd944029737ac57c;hpb=97535efaa975ca52bf02c2d5e76351bfd2e3defa

diff --git a/src/common/trigger.cpp b/src/common/trigger.cpp
new file mode 100644
index 000000000..3782f49ca
--- /dev/null
+++ b/src/common/trigger.cpp
@@ -0,0 +1,1240 @@
+/*
+ * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ *
+ * SPDX-License-Identifier: LGPL-2.1-only
+ *
+ */
+
+#include <common/credentials.h>
+#include <common/dynamic-array.h>
+#include <common/error.h>
+#include <common/mi-lttng.h>
+#include <common/optional.h>
+#include <common/payload-view.h>
+#include <common/payload.h>
+#include <inttypes.h>
+#include <lttng/action/action-internal.h>
+#include <lttng/condition/buffer-usage.h>
+#include <lttng/condition/condition-internal.h>
+#include <lttng/condition/event-rule-matches-internal.h>
+#include <lttng/condition/event-rule-matches.h>
+#include <lttng/domain.h>
+#include <lttng/error-query-internal.h>
+#include <lttng/event-expr-internal.h>
+#include <lttng/event-rule/event-rule-internal.h>
+#include <lttng/trigger/trigger-internal.h>
+#include <pthread.h>
+
+bool lttng_trigger_validate(const struct lttng_trigger *trigger)
+{
+	bool valid;
+
+	if (!trigger) {
+		valid = false;
+		goto end;
+	}
+
+	if (!trigger->creds.uid.is_set) {
+		valid = false;
+		goto end;
+	}
+
+	valid = lttng_condition_validate(trigger->condition) &&
+			lttng_action_validate(trigger->action);
+end:
+	return valid;
+}
+
+struct lttng_trigger *lttng_trigger_create(
+		struct lttng_condition *condition,
+		struct lttng_action *action)
+{
+	struct lttng_trigger *trigger = NULL;
+
+	if (!condition || !action) {
+		goto end;
+	}
+
+	trigger = (lttng_trigger *) zmalloc(sizeof(struct lttng_trigger));
+	if (!trigger) {
+		goto end;
+	}
+
+	urcu_ref_init(&trigger->ref);
+
+	lttng_condition_get(condition);
+	trigger->condition = condition;
+
+	lttng_action_get(action);
+	trigger->action = action;
+
+	pthread_mutex_init(&trigger->lock, NULL);
+	trigger->registered = false;
+
+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);
+
+	LTTNG_ASSERT(action);
+	LTTNG_ASSERT(condition);
+
+	/* Release ownership. */
+	lttng_action_put(action);
+	lttng_condition_put(condition);
+
+	pthread_mutex_destroy(&trigger->lock);
+
+	free(trigger->name);
+	free(trigger);
+}
+
+void lttng_trigger_destroy(struct lttng_trigger *trigger)
+{
+	lttng_trigger_put(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, name_size = 0;
+	struct lttng_condition *condition = NULL;
+	struct lttng_action *action = NULL;
+	const struct lttng_trigger_comm *trigger_comm;
+	const char *name = NULL;
+	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) {
+		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 = (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);
+
+	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);
+	}
+
+	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);
+	}
+
+	if (action_size < 0) {
+		ret = action_size;
+		goto end;
+	}
+	offset += action_size;
+
+	/* Unexpected size of inner-elements; the buffer is corrupted. */
+	if ((ssize_t) trigger_comm->length != condition_size + action_size + name_size) {
+		ret = -1;
+		goto error;
+	}
+
+	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;
+		}
+	}
+
+	ret = offset;
+
+error:
+	lttng_condition_put(condition);
+	lttng_action_put(action);
+end:
+	if (ret >= 0) {
+		*_trigger = trigger;
+	} else {
+		lttng_trigger_put(trigger);
+	}
+
+	return ret;
+}
+
+/*
+ * Both elements are stored contiguously, see their "*_comm" structure
+ * for the detailed format.
+ */
+int lttng_trigger_serialize(const struct lttng_trigger *trigger,
+		struct lttng_payload *payload)
+{
+	int ret;
+	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);
+	LTTNG_ASSERT(creds);
+
+	trigger_comm.uid = LTTNG_OPTIONAL_GET(creds->uid);
+
+	if (trigger->name != NULL) {
+		size_name = strlen(trigger->name) + 1;
+	} else {
+		size_name = 0;
+	}
+
+	trigger_comm.name_length = size_name;
+
+	header_offset = payload->buffer.size;
+	ret = lttng_dynamic_buffer_append(&payload->buffer, &trigger_comm,
+			sizeof(trigger_comm));
+	if (ret) {
+		goto end;
+	}
+
+	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_condition_serialize(trigger->condition, payload);
+	if (ret) {
+		goto end;
+	}
+
+	ret = lttng_action_serialize(trigger->action, payload);
+	if (ret) {
+		goto end;
+	}
+
+	/* Update payload size. */
+	header = (typeof(header)) (payload->buffer.data + header_offset);
+	header->length = payload->buffer.size - size_before_payload;
+end:
+	return ret;
+}
+
+bool lttng_trigger_is_equal(
+		const struct lttng_trigger *a, const struct lttng_trigger *b)
+{
+	if (!!a->name != !!b->name) {
+		/* Both must be either anonymous or named. */
+		return false;
+	}
+
+	if (a->name && strcmp(a->name, b->name) != 0) {
+		return false;
+	}
+
+	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;
+	}
+
+	if (a->is_hidden != b->is_hidden) {
+		return false;
+	}
+
+	return true;
+}
+
+bool lttng_trigger_is_hidden(const struct lttng_trigger *trigger)
+{
+	return trigger->is_hidden;
+}
+
+void lttng_trigger_set_hidden(struct lttng_trigger *trigger)
+{
+	LTTNG_ASSERT(!trigger->is_hidden);
+	trigger->is_hidden = 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) {
+		status = LTTNG_TRIGGER_STATUS_INVALID;
+		goto end;
+	}
+
+	if (name) {
+		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;
+}
+
+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;
+}
+
+void lttng_trigger_set_tracer_token(struct lttng_trigger *trigger,
+		uint64_t token)
+{
+	LTTNG_ASSERT(trigger);
+	LTTNG_OPTIONAL_SET(&trigger->tracer_token, token);
+}
+
+uint64_t lttng_trigger_get_tracer_token(const struct lttng_trigger *trigger)
+{
+	LTTNG_ASSERT(trigger);
+
+	return LTTNG_OPTIONAL_GET(trigger->tracer_token);
+}
+
+int lttng_trigger_generate_name(struct lttng_trigger *trigger,
+		uint64_t unique_id)
+{
+	int ret = 0;
+	char *generated_name = NULL;
+
+	ret = asprintf(&generated_name, "trigger%" 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;
+}
+
+void lttng_trigger_get(struct lttng_trigger *trigger)
+{
+	urcu_ref_get(&trigger->ref);
+}
+
+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 = (lttng_trigger *) ptr;
+
+	lttng_trigger_put(trigger);
+}
+
+struct lttng_triggers *lttng_triggers_create(void)
+{
+	struct lttng_triggers *triggers = NULL;
+
+	triggers = (lttng_triggers *) zmalloc(sizeof(*triggers));
+	if (!triggers) {
+		goto end;
+	}
+
+	lttng_dynamic_pointer_array_init(&triggers->array, delete_trigger_array_element);
+
+end:
+	return triggers;
+}
+
+struct lttng_trigger *lttng_triggers_borrow_mutable_at_index(
+		const struct lttng_triggers *triggers, unsigned int index)
+{
+	struct lttng_trigger *trigger = NULL;
+
+	LTTNG_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;
+}
+
+int lttng_triggers_add(
+		struct lttng_triggers *triggers, struct lttng_trigger *trigger)
+{
+	int ret;
+
+	LTTNG_ASSERT(triggers);
+	LTTNG_ASSERT(trigger);
+
+	lttng_trigger_get(trigger);
+
+	ret = lttng_dynamic_pointer_array_add_pointer(&triggers->array, trigger);
+	if (ret) {
+		lttng_trigger_put(trigger);
+	}
+
+	return ret;
+}
+
+int lttng_triggers_remove_hidden_triggers(struct lttng_triggers *triggers)
+{
+	int ret;
+	unsigned int trigger_count, i = 0;
+	enum lttng_trigger_status trigger_status;
+
+	LTTNG_ASSERT(triggers);
+
+	trigger_status = lttng_triggers_get_count(triggers, &trigger_count);
+	LTTNG_ASSERT(trigger_status == LTTNG_TRIGGER_STATUS_OK);
+
+	while (i < trigger_count) {
+		const struct lttng_trigger *trigger =
+				lttng_triggers_get_at_index(triggers, i);
+
+		if (lttng_trigger_is_hidden(trigger)) {
+			ret = lttng_dynamic_pointer_array_remove_pointer(
+					&triggers->array, i);
+			if (ret) {
+				goto end;
+			}
+
+			trigger_count--;
+		} else {
+			i++;
+		}
+	}
+
+	ret = 0;
+end:
+	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);
+
+		LTTNG_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;
+}
+
+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;
+}
+
+const struct lttng_credentials *lttng_trigger_get_credentials(
+		const struct lttng_trigger *trigger)
+{
+	return &trigger->creds;
+}
+
+void lttng_trigger_set_credentials(struct lttng_trigger *trigger,
+		const struct lttng_credentials *creds)
+{
+	LTTNG_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 uid_t euid = geteuid();
+	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 (euid != 0 && euid != uid) {
+		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_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;
+
+	LTTNG_ASSERT(trigger);
+	LTTNG_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_MATCHES:
+		/* Return the domain of the event rule. */
+		c_status = lttng_condition_event_rule_matches_get_rule(
+				trigger->condition, &event_rule);
+		LTTNG_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);
+		LTTNG_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.
+ */
+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_MATCHES:
+	{
+		struct lttng_event_rule *event_rule;
+		const enum lttng_condition_status condition_status =
+				lttng_condition_event_rule_matches_borrow_rule_mutable(
+						condition, &event_rule);
+
+		LTTNG_ASSERT(condition_status == LTTNG_CONDITION_STATUS_OK);
+
+		/* Generate the filter bytecode. */
+		ret = lttng_event_rule_generate_filter_bytecode(
+				event_rule, creds);
+		if (ret != LTTNG_OK) {
+			goto end;
+		}
+
+		/* Generate the capture bytecode. */
+		ret = lttng_condition_event_rule_matches_generate_capture_descriptor_bytecode(
+				condition);
+		if (ret != LTTNG_OK) {
+			goto end;
+		}
+
+		ret = LTTNG_OK;
+		break;
+	}
+	default:
+		ret = LTTNG_OK;
+		break;
+	}
+end:
+	return ret;
+}
+
+struct lttng_trigger *lttng_trigger_copy(const struct lttng_trigger *trigger)
+{
+	int ret;
+	struct lttng_payload copy_buffer;
+	struct lttng_condition *condition_copy = NULL;
+	struct lttng_action *action_copy = NULL;
+	struct lttng_trigger *copy = NULL;
+	enum lttng_trigger_status trigger_status;
+	const char *trigger_name;
+	uid_t trigger_owner_uid;
+
+	lttng_payload_init(&copy_buffer);
+
+	ret = lttng_condition_serialize(trigger->condition, &copy_buffer);
+	if (ret < 0) {
+		goto end;
+	}
+
+	{
+		struct lttng_payload_view view =
+				lttng_payload_view_from_payload(
+						&copy_buffer, 0, -1);
+
+		ret = lttng_condition_create_from_payload(
+				&view, &condition_copy);
+		if (ret < 0) {
+			goto end;
+		}
+	}
+
+	lttng_payload_clear(&copy_buffer);
+
+	ret = lttng_action_serialize(trigger->action, &copy_buffer);
+	if (ret < 0) {
+		goto end;
+	}
+
+	{
+		struct lttng_payload_view view =
+				lttng_payload_view_from_payload(
+						&copy_buffer, 0, -1);
+
+		ret = lttng_action_create_from_payload(
+				&view, &action_copy);
+		if (ret < 0) {
+			goto end;
+		}
+	}
+
+	copy = lttng_trigger_create(condition_copy, action_copy);
+	if (!copy) {
+		ERR("Failed to allocate trigger during trigger copy");
+		goto end;
+	}
+
+	trigger_status = lttng_trigger_get_name(trigger, &trigger_name);
+	switch (trigger_status) {
+	case LTTNG_TRIGGER_STATUS_OK:
+		trigger_status = lttng_trigger_set_name(copy, trigger_name);
+		if (trigger_status != LTTNG_TRIGGER_STATUS_OK) {
+			ERR("Failed to set name of new trigger during copy");
+			goto error_cleanup_trigger;
+		}
+		break;
+	case LTTNG_TRIGGER_STATUS_UNSET:
+		break;
+	default:
+		ERR("Failed to get name of original trigger during copy");
+		goto error_cleanup_trigger;
+	}
+
+	trigger_status = lttng_trigger_get_owner_uid(
+			trigger, &trigger_owner_uid);
+	switch (trigger_status) {
+	case LTTNG_TRIGGER_STATUS_OK:
+		LTTNG_OPTIONAL_SET(&copy->creds.uid, trigger_owner_uid);
+		break;
+	case LTTNG_TRIGGER_STATUS_UNSET:
+		break;
+	default:
+		ERR("Failed to get owner uid of original trigger during copy");
+		goto error_cleanup_trigger;
+	}
+
+	copy->tracer_token = trigger->tracer_token;
+	copy->registered = trigger->registered;
+	copy->is_hidden = trigger->is_hidden;
+	goto end;
+
+error_cleanup_trigger:
+	lttng_trigger_destroy(copy);
+	copy = NULL;
+end:
+	lttng_condition_put(condition_copy);
+	lttng_action_put(action_copy);
+	lttng_payload_reset(&copy_buffer);
+	return copy;
+}
+
+bool lttng_trigger_needs_tracer_notifier(const struct lttng_trigger *trigger)
+{
+	bool needs_tracer_notifier = false;
+	const struct lttng_condition *condition =
+			lttng_trigger_get_const_condition(trigger);
+
+	switch (lttng_condition_get_type(condition)) {
+	case LTTNG_CONDITION_TYPE_EVENT_RULE_MATCHES:
+		needs_tracer_notifier = true;
+		goto end;
+	case LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE:
+	case LTTNG_CONDITION_TYPE_BUFFER_USAGE_HIGH:
+	case LTTNG_CONDITION_TYPE_BUFFER_USAGE_LOW:
+	case LTTNG_CONDITION_TYPE_SESSION_ROTATION_ONGOING:
+	case LTTNG_CONDITION_TYPE_SESSION_ROTATION_COMPLETED:
+		goto end;
+	case LTTNG_CONDITION_TYPE_UNKNOWN:
+	default:
+		abort();
+	}
+end:
+	return needs_tracer_notifier;
+}
+
+void lttng_trigger_set_as_registered(struct lttng_trigger *trigger)
+{
+	pthread_mutex_lock(&trigger->lock);
+	trigger->registered = true;
+	pthread_mutex_unlock(&trigger->lock);
+}
+
+void lttng_trigger_set_as_unregistered(struct lttng_trigger *trigger)
+{
+	pthread_mutex_lock(&trigger->lock);
+	trigger->registered = false;
+	pthread_mutex_unlock(&trigger->lock);
+}
+
+/*
+ * The trigger must be locked before calling lttng_trigger_registered.
+ * The lock is necessary since a trigger can be unregistered at anytime.
+ * Manipulations requiring that the trigger be registered must always acquire
+ * the trigger lock for the duration of the manipulation using
+ * `lttng_trigger_lock` and `lttng_trigger_unlock`.
+ */
+bool lttng_trigger_is_registered(struct lttng_trigger *trigger)
+{
+	ASSERT_LOCKED(trigger->lock);
+	return trigger->registered;
+}
+
+void lttng_trigger_lock(struct lttng_trigger *trigger)
+{
+	pthread_mutex_lock(&trigger->lock);
+}
+
+void lttng_trigger_unlock(struct lttng_trigger *trigger)
+{
+	pthread_mutex_unlock(&trigger->lock);
+}
+
+enum lttng_error_code lttng_trigger_mi_serialize(const struct lttng_trigger *trigger,
+		struct mi_writer *writer,
+		const struct mi_lttng_error_query_callbacks
+				*error_query_callbacks)
+{
+	int ret;
+	enum lttng_error_code ret_code;
+	enum lttng_trigger_status trigger_status;
+	const struct lttng_condition *condition = NULL;
+	const struct lttng_action *action = NULL;
+	struct lttng_dynamic_array action_path_indexes;
+	uid_t owner_uid;
+
+	LTTNG_ASSERT(trigger);
+	LTTNG_ASSERT(writer);
+
+	lttng_dynamic_array_init(&action_path_indexes, sizeof(uint64_t), NULL);
+
+	/* Open trigger element. */
+	ret = mi_lttng_writer_open_element(writer, mi_lttng_element_trigger);
+	if (ret) {
+		goto mi_error;
+	}
+
+	trigger_status = lttng_trigger_get_owner_uid(trigger, &owner_uid);
+	LTTNG_ASSERT(trigger_status == LTTNG_TRIGGER_STATUS_OK);
+
+	/* Name. */
+	ret = mi_lttng_writer_write_element_string(
+			writer, config_element_name, trigger->name);
+	if (ret) {
+		goto mi_error;
+	}
+
+	/* Owner uid. */
+	ret = mi_lttng_writer_write_element_signed_int(writer,
+			mi_lttng_element_trigger_owner_uid,
+			(int64_t) owner_uid);
+	if (ret) {
+		goto mi_error;
+	}
+
+	/* Condition. */
+	condition = lttng_trigger_get_const_condition(trigger);
+	LTTNG_ASSERT(condition);
+	ret_code = lttng_condition_mi_serialize(
+			trigger, condition, writer, error_query_callbacks);
+	if (ret_code != LTTNG_OK) {
+		goto end;
+	}
+
+	/* Action. */
+	action = lttng_trigger_get_const_action(trigger);
+	LTTNG_ASSERT(action);
+	ret_code = lttng_action_mi_serialize(trigger, action, writer,
+			error_query_callbacks, &action_path_indexes);
+	if (ret_code != LTTNG_OK) {
+		goto end;
+	}
+
+	if (error_query_callbacks && error_query_callbacks->trigger_cb) {
+		struct lttng_error_query_results *results = NULL;
+
+		ret_code = error_query_callbacks->trigger_cb(trigger, &results);
+		if (ret_code != LTTNG_OK) {
+			goto end;
+		}
+
+		ret_code = lttng_error_query_results_mi_serialize(
+				results, writer);
+		lttng_error_query_results_destroy(results);
+		if (ret_code != LTTNG_OK) {
+			goto end;
+		}
+	}
+
+	/* Close trigger 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:
+	lttng_dynamic_array_reset(&action_path_indexes);
+	return ret_code;
+}
+
+/* Used by qsort, which expects the semantics of strcmp(). */
+static int compare_triggers_by_name(const void *a, const void *b)
+{
+	const struct lttng_trigger *trigger_a =
+			*((const struct lttng_trigger **) a);
+	const struct lttng_trigger *trigger_b =
+			*((const struct lttng_trigger **) b);
+	const char *name_a, *name_b;
+	enum lttng_trigger_status trigger_status;
+
+	/* Anonymous triggers are not reachable here. */
+	trigger_status = lttng_trigger_get_name(trigger_a, &name_a);
+	LTTNG_ASSERT(trigger_status == LTTNG_TRIGGER_STATUS_OK);
+
+	trigger_status = lttng_trigger_get_name(trigger_b, &name_b);
+	LTTNG_ASSERT(trigger_status == LTTNG_TRIGGER_STATUS_OK);
+
+	return strcmp(name_a, name_b);
+}
+
+enum lttng_error_code lttng_triggers_mi_serialize(const struct lttng_triggers *triggers,
+		struct mi_writer *writer,
+		const struct mi_lttng_error_query_callbacks
+				*error_query_callbacks)
+{
+	int ret;
+	enum lttng_error_code ret_code;
+	enum lttng_trigger_status status;
+	unsigned int count, i;
+	struct lttng_dynamic_pointer_array sorted_triggers;
+
+	LTTNG_ASSERT(triggers);
+	LTTNG_ASSERT(writer);
+
+	/*
+	 * Sort trigger by name to ensure an order at the MI level and ignore
+	 * any anonymous trigger present.
+	 */
+	lttng_dynamic_pointer_array_init(&sorted_triggers, NULL);
+
+	status = lttng_triggers_get_count(triggers, &count);
+	LTTNG_ASSERT(status == LTTNG_TRIGGER_STATUS_OK);
+
+	for (i = 0; i < count; i++) {
+		int add_ret;
+		const char *unused_name;
+		const struct lttng_trigger *trigger =
+				lttng_triggers_get_at_index(triggers, i);
+
+		status = lttng_trigger_get_name(trigger, &unused_name);
+		switch (status) {
+		case LTTNG_TRIGGER_STATUS_OK:
+			break;
+		case LTTNG_TRIGGER_STATUS_UNSET:
+			/* Don't list anonymous triggers. */
+			continue;
+		default:
+			abort();
+		}
+
+		add_ret = lttng_dynamic_pointer_array_add_pointer(
+				&sorted_triggers, (void *) trigger);
+
+		if (add_ret) {
+			ERR("Failed to lttng_trigger to sorting array.");
+			ret_code = LTTNG_ERR_NOMEM;
+			goto error;
+		}
+	}
+
+	qsort(sorted_triggers.array.buffer.data, count,
+			sizeof(struct lttng_trigger *),
+			compare_triggers_by_name);
+
+	/* Open triggers element. */
+	ret = mi_lttng_writer_open_element(writer, mi_lttng_element_triggers);
+	if (ret) {
+		ret_code = LTTNG_ERR_MI_IO_FAIL;
+		goto error;
+	}
+
+	for (i = 0; i < lttng_dynamic_pointer_array_get_count(&sorted_triggers); i++) {
+		const struct lttng_trigger *trigger =
+				(const struct lttng_trigger *)
+				lttng_dynamic_pointer_array_get_pointer(
+						&sorted_triggers, i);
+
+		lttng_trigger_mi_serialize(trigger, writer, error_query_callbacks);
+	}
+
+	/* Close triggers element. */
+	ret = mi_lttng_writer_close_element(writer);
+	if (ret) {
+		ret_code = LTTNG_ERR_MI_IO_FAIL;
+		goto error;
+	}
+
+	ret_code = LTTNG_OK;
+
+error:
+	lttng_dynamic_pointer_array_reset(&sorted_triggers);
+	return ret_code;
+}