[lttng-tools.git] / src / common / event-rule / kernel-syscall.c

/*
 * Copyright (C) 2019 Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
 *
 * SPDX-License-Identifier: LGPL-2.1-only
 *
 */

#include <common/credentials.h>
#include <common/error.h>
#include <common/hashtable/hashtable.h>
#include <common/hashtable/utils.h>
#include <common/macros.h>
#include <common/mi-lttng.h>
#include <common/payload-view.h>
#include <common/payload.h>
#include <common/runas.h>
#include <common/string-utils/string-utils.h>
#include <lttng/event-rule/event-rule-internal.h>
#include <lttng/event-rule/kernel-syscall-internal.h>

#define IS_SYSCALL_EVENT_RULE(rule) \
	(lttng_event_rule_get_type(rule) == LTTNG_EVENT_RULE_TYPE_KERNEL_SYSCALL)

static void lttng_event_rule_kernel_syscall_destroy(struct lttng_event_rule *rule)
{
	struct lttng_event_rule_kernel_syscall *syscall;

	if (rule == NULL) {
		return;
	}

	syscall = container_of(rule, struct lttng_event_rule_kernel_syscall, parent);

	free(syscall->pattern);
	free(syscall->filter_expression);
	free(syscall->internal_filter.filter);
	free(syscall->internal_filter.bytecode);
	free(syscall);
}

static bool lttng_event_rule_kernel_syscall_validate(
		const struct lttng_event_rule *rule)
{
	bool valid = false;
	struct lttng_event_rule_kernel_syscall *syscall;

	if (!rule) {
		goto end;
	}

	syscall = container_of(rule, struct lttng_event_rule_kernel_syscall, parent);

	/* Required field. */
	if (!syscall->pattern) {
		ERR("Invalid syscall event rule: a pattern must be set.");
		goto end;
	}

	valid = true;
end:
	return valid;
}

static int lttng_event_rule_kernel_syscall_serialize(
		const struct lttng_event_rule *rule,
		struct lttng_payload *payload)
{
	int ret;
	size_t pattern_len, filter_expression_len;
	struct lttng_event_rule_kernel_syscall *syscall;
	struct lttng_event_rule_kernel_syscall_comm syscall_comm;

	if (!rule || !IS_SYSCALL_EVENT_RULE(rule)) {
		ret = -1;
		goto end;
	}

	DBG("Serializing syscall event rule");
	syscall = container_of(rule, struct lttng_event_rule_kernel_syscall, parent);

	pattern_len = strlen(syscall->pattern) + 1;

	if (syscall->filter_expression != NULL) {
		filter_expression_len = strlen(syscall->filter_expression) + 1;
	} else {
		filter_expression_len = 0;
	}

	syscall_comm.pattern_len = pattern_len;
	syscall_comm.filter_expression_len = filter_expression_len;
	syscall_comm.emission_site = syscall->emission_site;

	ret = lttng_dynamic_buffer_append(
			&payload->buffer, &syscall_comm, sizeof(syscall_comm));
	if (ret) {
		goto end;
	}

	ret = lttng_dynamic_buffer_append(
			&payload->buffer, syscall->pattern, pattern_len);
	if (ret) {
		goto end;
	}

	ret = lttng_dynamic_buffer_append(&payload->buffer,
			syscall->filter_expression, filter_expression_len);
end:
	return ret;
}

static bool lttng_event_rule_kernel_syscall_is_equal(const struct lttng_event_rule *_a,
		const struct lttng_event_rule *_b)
{
	bool is_equal = false;
	struct lttng_event_rule_kernel_syscall *a, *b;

	a = container_of(_a, struct lttng_event_rule_kernel_syscall, parent);
	b = container_of(_b, struct lttng_event_rule_kernel_syscall, parent);

	if (!!a->filter_expression != !!b->filter_expression) {
		goto end;
	}

	LTTNG_ASSERT(a->pattern);
	LTTNG_ASSERT(b->pattern);
	if (strcmp(a->pattern, b->pattern)) {
		goto end;
	}

	if (a->filter_expression && b->filter_expression) {
		if (strcmp(a->filter_expression, b->filter_expression)) {
			goto end;
		}
	} else if (!!a->filter_expression != !!b->filter_expression) {
		/* One is set and not the other. */
		goto end;
	}

	is_equal = true;
end:
	return is_equal;
}

static enum lttng_error_code lttng_event_rule_kernel_syscall_generate_filter_bytecode(
		struct lttng_event_rule *rule,
		const struct lttng_credentials *creds)
{
	int ret;
	enum lttng_error_code ret_code = LTTNG_OK;
	struct lttng_event_rule_kernel_syscall *syscall;
	enum lttng_event_rule_status status;
	const char *filter;
	struct lttng_bytecode *bytecode = NULL;

	LTTNG_ASSERT(rule);

	syscall = container_of(rule, struct lttng_event_rule_kernel_syscall, parent);

	/* Generate the filter bytecode. */
	status = lttng_event_rule_kernel_syscall_get_filter(rule, &filter);
	if (status == LTTNG_EVENT_RULE_STATUS_UNSET) {
		filter = NULL;
	} else if (status != LTTNG_EVENT_RULE_STATUS_OK) {
		ret_code = LTTNG_ERR_FILTER_INVAL;
		goto end;
	}

	if (filter && filter[0] == '\0') {
		ret_code = LTTNG_ERR_FILTER_INVAL;
		goto end;
	}

	if (filter == NULL) {
		/* Nothing to do. */
		ret = LTTNG_OK;
		goto end;
	}

	syscall->internal_filter.filter = strdup(filter);
	if (syscall->internal_filter.filter == NULL) {
		ret_code = LTTNG_ERR_NOMEM;
		goto end;
	}

	ret = run_as_generate_filter_bytecode(
			syscall->internal_filter.filter, creds, &bytecode);
	if (ret) {
		ret_code = LTTNG_ERR_FILTER_INVAL;
	}

	syscall->internal_filter.bytecode = bytecode;
	bytecode = NULL;

end:
	free(bytecode);
	return ret_code;
}

static const char *lttng_event_rule_kernel_syscall_get_internal_filter(
		const struct lttng_event_rule *rule)
{
	struct lttng_event_rule_kernel_syscall *syscall;

	LTTNG_ASSERT(rule);
	syscall = container_of(rule, struct lttng_event_rule_kernel_syscall, parent);

	return syscall->internal_filter.filter;
}

static const struct lttng_bytecode *
lttng_event_rule_kernel_syscall_get_internal_filter_bytecode(
		const struct lttng_event_rule *rule)
{
	struct lttng_event_rule_kernel_syscall *syscall;

	LTTNG_ASSERT(rule);
	syscall = container_of(rule, struct lttng_event_rule_kernel_syscall, parent);

	return syscall->internal_filter.bytecode;
}

static enum lttng_event_rule_generate_exclusions_status
lttng_event_rule_kernel_syscall_generate_exclusions(const struct lttng_event_rule *rule,
		struct lttng_event_exclusion **exclusions)
{
	/* Unsupported. */
	*exclusions = NULL;
	return LTTNG_EVENT_RULE_GENERATE_EXCLUSIONS_STATUS_NONE;
}

static unsigned long
lttng_event_rule_kernel_syscall_hash(
		const struct lttng_event_rule *rule)
{
	unsigned long hash;
	struct lttng_event_rule_kernel_syscall *syscall_rule =
			container_of(rule, typeof(*syscall_rule), parent);

	hash = hash_key_ulong((void *) LTTNG_EVENT_RULE_TYPE_KERNEL_SYSCALL,
			lttng_ht_seed);
	hash ^= hash_key_str(syscall_rule->pattern, lttng_ht_seed);
	if (syscall_rule->filter_expression) {
		hash ^= hash_key_str(syscall_rule->filter_expression,
				lttng_ht_seed);
	}

	return hash;
}

static enum lttng_error_code lttng_event_rule_kernel_syscall_mi_serialize(
		const struct lttng_event_rule *rule, struct mi_writer *writer)
{
	int ret;
	enum lttng_error_code ret_code;
	enum lttng_event_rule_status status;

	enum lttng_event_rule_kernel_syscall_emission_site site_type;
	const char *filter = NULL;
	const char *name_pattern = NULL;
	const char *site_type_str = NULL;

	LTTNG_ASSERT(rule);
	LTTNG_ASSERT(writer);
	LTTNG_ASSERT(IS_SYSCALL_EVENT_RULE(rule));

	status = lttng_event_rule_kernel_syscall_get_name_pattern(
			rule, &name_pattern);
	LTTNG_ASSERT(status == LTTNG_EVENT_RULE_STATUS_OK);
	LTTNG_ASSERT(name_pattern);

	status = lttng_event_rule_kernel_syscall_get_filter(rule, &filter);
	LTTNG_ASSERT(status == LTTNG_EVENT_RULE_STATUS_OK ||
			status == LTTNG_EVENT_RULE_STATUS_UNSET);

	site_type = lttng_event_rule_kernel_syscall_get_emission_site(rule);

	switch (site_type) {
	case LTTNG_EVENT_RULE_KERNEL_SYSCALL_EMISSION_SITE_ENTRY_EXIT:
		site_type_str = mi_lttng_event_rule_kernel_syscall_emission_site_entry_exit;
		break;
	case LTTNG_EVENT_RULE_KERNEL_SYSCALL_EMISSION_SITE_ENTRY:
		site_type_str = mi_lttng_event_rule_kernel_syscall_emission_site_entry;
		break;
	case LTTNG_EVENT_RULE_KERNEL_SYSCALL_EMISSION_SITE_EXIT:
		site_type_str = mi_lttng_event_rule_kernel_syscall_emission_site_exit;
		break;
	default:
		abort();
		break;
	}

	/* Open event rule kernel syscall element. */
	ret = mi_lttng_writer_open_element(
			writer, mi_lttng_element_event_rule_kernel_syscall);
	if (ret) {
		goto mi_error;
	}

	/* Emission site. */
	ret = mi_lttng_writer_write_element_string(writer,
			mi_lttng_element_event_rule_kernel_syscall_emission_site,
			site_type_str);
	if (ret) {
		goto mi_error;
	}

	/* Name pattern. */
	ret = mi_lttng_writer_write_element_string(writer,
			mi_lttng_element_event_rule_name_pattern, name_pattern);
	if (ret) {
		goto mi_error;
	}

	/* Filter. */
	if (filter != NULL) {
		ret = mi_lttng_writer_write_element_string(writer,
				mi_lttng_element_event_rule_filter_expression,
				filter);
		if (ret) {
			goto mi_error;
		}
	}

	/* Close event rule kernel syscall. */
	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_event_rule *lttng_event_rule_kernel_syscall_create(
		enum lttng_event_rule_kernel_syscall_emission_site
				emission_site)
{
	struct lttng_event_rule *rule = NULL;
	struct lttng_event_rule_kernel_syscall *syscall_rule;
	enum lttng_event_rule_status status;

	/* Validate the emission site type */
	switch (emission_site) {
	case LTTNG_EVENT_RULE_KERNEL_SYSCALL_EMISSION_SITE_ENTRY_EXIT:
	case LTTNG_EVENT_RULE_KERNEL_SYSCALL_EMISSION_SITE_ENTRY:
	case LTTNG_EVENT_RULE_KERNEL_SYSCALL_EMISSION_SITE_EXIT:
		break;
	default:
		/* Invalid emission type */
		goto end;
	}

	syscall_rule = zmalloc(sizeof(struct lttng_event_rule_kernel_syscall));
	if (!syscall_rule) {
		goto end;
	}

	rule = &syscall_rule->parent;
	lttng_event_rule_init(
			&syscall_rule->parent, LTTNG_EVENT_RULE_TYPE_KERNEL_SYSCALL);
	syscall_rule->parent.validate = lttng_event_rule_kernel_syscall_validate;
	syscall_rule->parent.serialize = lttng_event_rule_kernel_syscall_serialize;
	syscall_rule->parent.equal = lttng_event_rule_kernel_syscall_is_equal;
	syscall_rule->parent.destroy = lttng_event_rule_kernel_syscall_destroy;
	syscall_rule->parent.generate_filter_bytecode =
			lttng_event_rule_kernel_syscall_generate_filter_bytecode;
	syscall_rule->parent.get_filter =
			lttng_event_rule_kernel_syscall_get_internal_filter;
	syscall_rule->parent.get_filter_bytecode =
			lttng_event_rule_kernel_syscall_get_internal_filter_bytecode;
	syscall_rule->parent.generate_exclusions =
			lttng_event_rule_kernel_syscall_generate_exclusions;
	syscall_rule->parent.hash = lttng_event_rule_kernel_syscall_hash;
	syscall_rule->parent.mi_serialize = lttng_event_rule_kernel_syscall_mi_serialize;

	/* Default pattern is '*'. */
	status = lttng_event_rule_kernel_syscall_set_name_pattern(rule, "*");
	if (status != LTTNG_EVENT_RULE_STATUS_OK) {
		lttng_event_rule_destroy(rule);
		rule = NULL;
	}

	/* Emission site type */
	syscall_rule->emission_site = emission_site;

end:
	return rule;
}

LTTNG_HIDDEN
ssize_t lttng_event_rule_kernel_syscall_create_from_payload(
		struct lttng_payload_view *view,
		struct lttng_event_rule **_event_rule)
{
	ssize_t ret, offset = 0;
	enum lttng_event_rule_status status;
	const struct lttng_event_rule_kernel_syscall_comm *syscall_comm;
	const char *pattern;
	const char *filter_expression = NULL;
	struct lttng_buffer_view current_buffer_view;
	struct lttng_event_rule *rule = NULL;

	if (!_event_rule) {
		ret = -1;
		goto end;
	}

	if (view->buffer.size < sizeof(*syscall_comm)) {
		ERR("Failed to initialize from malformed event rule syscall: buffer too short to contain header");
		ret = -1;
		goto end;
	}

	current_buffer_view = lttng_buffer_view_from_view(
			&view->buffer, offset, sizeof(*syscall_comm));
	if (!lttng_buffer_view_is_valid(&current_buffer_view)) {
		ret = -1;
		goto end;
	}

	syscall_comm = (typeof(syscall_comm)) current_buffer_view.data;
	rule = lttng_event_rule_kernel_syscall_create(syscall_comm->emission_site);
	if (!rule) {
		ERR("Failed to create event rule syscall");
		ret = -1;
		goto end;
	}

	/* Skip to payload. */
	offset += current_buffer_view.size;

	/* Map the pattern. */
	current_buffer_view = lttng_buffer_view_from_view(
			&view->buffer, offset, syscall_comm->pattern_len);
	if (!lttng_buffer_view_is_valid(&current_buffer_view)) {
		ret = -1;
		goto end;
	}

	pattern = current_buffer_view.data;
	if (!lttng_buffer_view_contains_string(&current_buffer_view, pattern,
			syscall_comm->pattern_len)) {
		ret = -1;
		goto end;
	}

	/* Skip after the pattern. */
	offset += syscall_comm->pattern_len;

	if (!syscall_comm->filter_expression_len) {
		goto skip_filter_expression;
	}

	/* Map the filter_expression. */
	current_buffer_view = lttng_buffer_view_from_view(&view->buffer, offset,
			syscall_comm->filter_expression_len);
	if (!lttng_buffer_view_is_valid(&current_buffer_view)) {
		ret = -1;
		goto end;
	}

	filter_expression = current_buffer_view.data;
	if (!lttng_buffer_view_contains_string(&current_buffer_view,
				filter_expression,
				syscall_comm->filter_expression_len)) {
		ret = -1;
		goto end;
	}

	/* Skip after the pattern. */
	offset += syscall_comm->filter_expression_len;

skip_filter_expression:

	status = lttng_event_rule_kernel_syscall_set_name_pattern(rule, pattern);
	if (status != LTTNG_EVENT_RULE_STATUS_OK) {
		ERR("Failed to set event rule syscall pattern");
		ret = -1;
		goto end;
	}

	if (filter_expression) {
		status = lttng_event_rule_kernel_syscall_set_filter(
				rule, filter_expression);
		if (status != LTTNG_EVENT_RULE_STATUS_OK) {
			ERR("Failed to set event rule syscall pattern");
			ret = -1;
			goto end;
		}
	}

	*_event_rule = rule;
	rule = NULL;
	ret = offset;
end:
	lttng_event_rule_destroy(rule);
	return ret;
}

enum lttng_event_rule_status lttng_event_rule_kernel_syscall_set_name_pattern(
		struct lttng_event_rule *rule, const char *pattern)
{
	char *pattern_copy = NULL;
	struct lttng_event_rule_kernel_syscall *syscall;
	enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;

	if (!rule || !IS_SYSCALL_EVENT_RULE(rule) || !pattern ||
			strlen(pattern) == 0) {
		status = LTTNG_EVENT_RULE_STATUS_INVALID;
		goto end;
	}

	syscall = container_of(rule, struct lttng_event_rule_kernel_syscall, parent);
	pattern_copy = strdup(pattern);
	if (!pattern_copy) {
		status = LTTNG_EVENT_RULE_STATUS_ERROR;
		goto end;
	}

	strutils_normalize_star_glob_pattern(pattern_copy);

	free(syscall->pattern);

	syscall->pattern = pattern_copy;
	pattern_copy = NULL;
end:
	return status;
}

enum lttng_event_rule_status lttng_event_rule_kernel_syscall_get_name_pattern(
		const struct lttng_event_rule *rule, const char **pattern)
{
	struct lttng_event_rule_kernel_syscall *syscall;
	enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;

	if (!rule || !IS_SYSCALL_EVENT_RULE(rule) || !pattern) {
		status = LTTNG_EVENT_RULE_STATUS_INVALID;
		goto end;
	}

	syscall = container_of(rule, struct lttng_event_rule_kernel_syscall, parent);
	if (!syscall->pattern) {
		status = LTTNG_EVENT_RULE_STATUS_UNSET;
		goto end;
	}

	*pattern = syscall->pattern;
end:
	return status;
}

enum lttng_event_rule_status lttng_event_rule_kernel_syscall_set_filter(
		struct lttng_event_rule *rule, const char *expression)
{
	char *expression_copy = NULL;
	struct lttng_event_rule_kernel_syscall *syscall;
	enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;

	/* TODO: validate that the passed expression is valid. */

	if (!rule || !IS_SYSCALL_EVENT_RULE(rule) || !expression ||
			strlen(expression) == 0) {
		status = LTTNG_EVENT_RULE_STATUS_INVALID;
		goto end;
	}

	syscall = container_of(rule, struct lttng_event_rule_kernel_syscall, parent);
	expression_copy = strdup(expression);
	if (!expression_copy) {
		status = LTTNG_EVENT_RULE_STATUS_ERROR;
		goto end;
	}

	if (syscall->filter_expression) {
		free(syscall->filter_expression);
	}

	syscall->filter_expression = expression_copy;
	expression_copy = NULL;
end:
	return status;
}

enum lttng_event_rule_status lttng_event_rule_kernel_syscall_get_filter(
		const struct lttng_event_rule *rule, const char **expression)
{
	struct lttng_event_rule_kernel_syscall *syscall;
	enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;

	if (!rule || !IS_SYSCALL_EVENT_RULE(rule) || !expression) {
		status = LTTNG_EVENT_RULE_STATUS_INVALID;
		goto end;
	}

	syscall = container_of(rule, struct lttng_event_rule_kernel_syscall, parent);
	if (!syscall->filter_expression) {
		status = LTTNG_EVENT_RULE_STATUS_UNSET;
		goto end;
	}

	*expression = syscall->filter_expression;
end:
	return status;
}
extern enum lttng_event_rule_kernel_syscall_emission_site
lttng_event_rule_kernel_syscall_get_emission_site(
		const struct lttng_event_rule *rule)
{
	enum lttng_event_rule_kernel_syscall_emission_site emission_site =
		LTTNG_EVENT_RULE_KERNEL_SYSCALL_EMISSION_SITE_UNKNOWN;
	struct lttng_event_rule_kernel_syscall *syscall;

	if (!rule || !IS_SYSCALL_EVENT_RULE(rule)) {
		goto end;
	}

	syscall = container_of(rule, struct lttng_event_rule_kernel_syscall, parent);
	emission_site = syscall->emission_site;

end:
	return emission_site;
}

LTTNG_HIDDEN
const char *lttng_event_rule_kernel_syscall_emission_site_str(
		enum lttng_event_rule_kernel_syscall_emission_site emission_site)
{
	switch (emission_site) {
	case LTTNG_EVENT_RULE_KERNEL_SYSCALL_EMISSION_SITE_ENTRY:
		return "entry";
	case LTTNG_EVENT_RULE_KERNEL_SYSCALL_EMISSION_SITE_ENTRY_EXIT:
		return "entry+exit";
	case LTTNG_EVENT_RULE_KERNEL_SYSCALL_EMISSION_SITE_EXIT:
		return "exit";
	default:
		return "???";
	}
}
Commit	Line	Data
e6a39346 JR	1	/*
	2	* Copyright (C) 2019 Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
	3	*
	4	* SPDX-License-Identifier: LGPL-2.1-only
	5	*
	6	*/
	7
58daac01	8	#include <common/credentials.h>
e6a39346	9	#include <common/error.h>
6a751b95 JR	10	#include <common/hashtable/hashtable.h>
6a751b95 JR	11	#include <common/hashtable/utils.h>
e6a39346	12	#include <common/macros.h>
6a751b95	13	#include <common/mi-lttng.h>
e6a39346	14	#include <common/payload-view.h>
6a751b95	15	#include <common/payload.h>
e6a39346	16	#include <common/runas.h>
40fd2ccf	17	#include <common/string-utils/string-utils.h>
e6a39346	18	#include <lttng/event-rule/event-rule-internal.h>
4f7da553	19	#include <lttng/event-rule/kernel-syscall-internal.h>
e6a39346 JR	20
e6a39346 JR	21	#define IS_SYSCALL_EVENT_RULE(rule) \
4f7da553	22	(lttng_event_rule_get_type(rule) == LTTNG_EVENT_RULE_TYPE_KERNEL_SYSCALL)
e6a39346	23
4f7da553	24	static void lttng_event_rule_kernel_syscall_destroy(struct lttng_event_rule *rule)
e6a39346	25	{
4f7da553	26	struct lttng_event_rule_kernel_syscall *syscall;
e6a39346 JR	27
	28	if (rule == NULL) {
	29	return;
	30	}
	31
4f7da553	32	syscall = container_of(rule, struct lttng_event_rule_kernel_syscall, parent);
e6a39346 JR	33
	34	free(syscall->pattern);
	35	free(syscall->filter_expression);
	36	free(syscall->internal_filter.filter);
	37	free(syscall->internal_filter.bytecode);
	38	free(syscall);
	39	}
	40
4f7da553	41	static bool lttng_event_rule_kernel_syscall_validate(
e6a39346 JR	42	const struct lttng_event_rule *rule)
	43	{
	44	bool valid = false;
4f7da553	45	struct lttng_event_rule_kernel_syscall *syscall;
e6a39346 JR	46
	47	if (!rule) {
	48	goto end;
	49	}
	50
4f7da553	51	syscall = container_of(rule, struct lttng_event_rule_kernel_syscall, parent);
e6a39346 JR	52
	53	/* Required field. */
	54	if (!syscall->pattern) {
	55	ERR("Invalid syscall event rule: a pattern must be set.");
	56	goto end;
	57	}
	58
	59	valid = true;
	60	end:
	61	return valid;
	62	}
	63
4f7da553	64	static int lttng_event_rule_kernel_syscall_serialize(
e6a39346 JR	65	const struct lttng_event_rule *rule,
	66	struct lttng_payload *payload)
	67	{
	68	int ret;
	69	size_t pattern_len, filter_expression_len;
4f7da553 JR	70	struct lttng_event_rule_kernel_syscall *syscall;
4f7da553 JR	71	struct lttng_event_rule_kernel_syscall_comm syscall_comm;
e6a39346 JR	72
	73	if (!rule \|\| !IS_SYSCALL_EVENT_RULE(rule)) {
	74	ret = -1;
	75	goto end;
	76	}
	77
	78	DBG("Serializing syscall event rule");
4f7da553	79	syscall = container_of(rule, struct lttng_event_rule_kernel_syscall, parent);
e6a39346 JR	80
	81	pattern_len = strlen(syscall->pattern) + 1;
	82
	83	if (syscall->filter_expression != NULL) {
	84	filter_expression_len = strlen(syscall->filter_expression) + 1;
	85	} else {
	86	filter_expression_len = 0;
	87	}
	88
	89	syscall_comm.pattern_len = pattern_len;
	90	syscall_comm.filter_expression_len = filter_expression_len;
f6a5af19	91	syscall_comm.emission_site = syscall->emission_site;
e6a39346 JR	92
	93	ret = lttng_dynamic_buffer_append(
	94	&payload->buffer, &syscall_comm, sizeof(syscall_comm));
	95	if (ret) {
	96	goto end;
	97	}
	98
	99	ret = lttng_dynamic_buffer_append(
	100	&payload->buffer, syscall->pattern, pattern_len);
	101	if (ret) {
	102	goto end;
	103	}
	104
	105	ret = lttng_dynamic_buffer_append(&payload->buffer,
	106	syscall->filter_expression, filter_expression_len);
	107	end:
	108	return ret;
	109	}
	110
4f7da553	111	static bool lttng_event_rule_kernel_syscall_is_equal(const struct lttng_event_rule *_a,
e6a39346 JR	112	const struct lttng_event_rule *_b)
	113	{
	114	bool is_equal = false;
4f7da553	115	struct lttng_event_rule_kernel_syscall a, b;
e6a39346	116
4f7da553 JR	117	a = container_of(_a, struct lttng_event_rule_kernel_syscall, parent);
4f7da553 JR	118	b = container_of(_b, struct lttng_event_rule_kernel_syscall, parent);
e6a39346 JR	119
	120	if (!!a->filter_expression != !!b->filter_expression) {
	121	goto end;
	122	}
	123
a0377dfe FD	124	LTTNG_ASSERT(a->pattern);
a0377dfe FD	125	LTTNG_ASSERT(b->pattern);
e6a39346 JR	126	if (strcmp(a->pattern, b->pattern)) {
	127	goto end;
	128	}
	129
	130	if (a->filter_expression && b->filter_expression) {
	131	if (strcmp(a->filter_expression, b->filter_expression)) {
	132	goto end;
	133	}
	134	} else if (!!a->filter_expression != !!b->filter_expression) {
	135	/* One is set and not the other. */
	136	goto end;
	137	}
	138
	139	is_equal = true;
	140	end:
	141	return is_equal;
	142	}
	143
4f7da553	144	static enum lttng_error_code lttng_event_rule_kernel_syscall_generate_filter_bytecode(
58daac01 JR	145	struct lttng_event_rule *rule,
58daac01 JR	146	const struct lttng_credentials *creds)
e6a39346 JR	147	{
	148	int ret;
	149	enum lttng_error_code ret_code = LTTNG_OK;
4f7da553	150	struct lttng_event_rule_kernel_syscall *syscall;
e6a39346 JR	151	enum lttng_event_rule_status status;
e6a39346 JR	152	const char *filter;
2b00d462	153	struct lttng_bytecode *bytecode = NULL;
e6a39346	154
a0377dfe	155	LTTNG_ASSERT(rule);
e6a39346	156
4f7da553	157	syscall = container_of(rule, struct lttng_event_rule_kernel_syscall, parent);
e6a39346 JR	158
e6a39346 JR	159	/* Generate the filter bytecode. */
4f7da553	160	status = lttng_event_rule_kernel_syscall_get_filter(rule, &filter);
e6a39346 JR	161	if (status == LTTNG_EVENT_RULE_STATUS_UNSET) {
	162	filter = NULL;
	163	} else if (status != LTTNG_EVENT_RULE_STATUS_OK) {
	164	ret_code = LTTNG_ERR_FILTER_INVAL;
	165	goto end;
	166	}
	167
	168	if (filter && filter[0] == '\0') {
	169	ret_code = LTTNG_ERR_FILTER_INVAL;
	170	goto end;
	171	}
	172
	173	if (filter == NULL) {
	174	/* Nothing to do. */
	175	ret = LTTNG_OK;
	176	goto end;
	177	}
	178
	179	syscall->internal_filter.filter = strdup(filter);
	180	if (syscall->internal_filter.filter == NULL) {
	181	ret_code = LTTNG_ERR_NOMEM;
	182	goto end;
	183	}
	184
	185	ret = run_as_generate_filter_bytecode(
58daac01	186	syscall->internal_filter.filter, creds, &bytecode);
e6a39346 JR	187	if (ret) {
	188	ret_code = LTTNG_ERR_FILTER_INVAL;
	189	}
	190
	191	syscall->internal_filter.bytecode = bytecode;
	192	bytecode = NULL;
	193
	194	end:
	195	free(bytecode);
	196	return ret_code;
	197	}
	198
4f7da553	199	static const char *lttng_event_rule_kernel_syscall_get_internal_filter(
e6a39346 JR	200	const struct lttng_event_rule *rule)
e6a39346 JR	201	{
4f7da553	202	struct lttng_event_rule_kernel_syscall *syscall;
e6a39346	203
a0377dfe	204	LTTNG_ASSERT(rule);
4f7da553	205	syscall = container_of(rule, struct lttng_event_rule_kernel_syscall, parent);
e6a39346 JR	206
	207	return syscall->internal_filter.filter;
	208	}
	209
2b00d462	210	static const struct lttng_bytecode *
4f7da553	211	lttng_event_rule_kernel_syscall_get_internal_filter_bytecode(
e6a39346 JR	212	const struct lttng_event_rule *rule)
e6a39346 JR	213	{
4f7da553	214	struct lttng_event_rule_kernel_syscall *syscall;
e6a39346	215
a0377dfe	216	LTTNG_ASSERT(rule);
4f7da553	217	syscall = container_of(rule, struct lttng_event_rule_kernel_syscall, parent);
e6a39346 JR	218
	219	return syscall->internal_filter.bytecode;
	220	}
	221
993578ff	222	static enum lttng_event_rule_generate_exclusions_status
4f7da553	223	lttng_event_rule_kernel_syscall_generate_exclusions(const struct lttng_event_rule *rule,
993578ff	224	struct lttng_event_exclusion **exclusions)
e6a39346	225	{
993578ff JR	226	/* Unsupported. */
	227	*exclusions = NULL;
	228	return LTTNG_EVENT_RULE_GENERATE_EXCLUSIONS_STATUS_NONE;
e6a39346 JR	229	}
e6a39346 JR	230
959e3c66	231	static unsigned long
4f7da553	232	lttng_event_rule_kernel_syscall_hash(
959e3c66 JR	233	const struct lttng_event_rule *rule)
	234	{
	235	unsigned long hash;
4f7da553	236	struct lttng_event_rule_kernel_syscall *syscall_rule =
959e3c66 JR	237	container_of(rule, typeof(*syscall_rule), parent);
959e3c66 JR	238
4f7da553	239	hash = hash_key_ulong((void *) LTTNG_EVENT_RULE_TYPE_KERNEL_SYSCALL,
959e3c66 JR	240	lttng_ht_seed);
	241	hash ^= hash_key_str(syscall_rule->pattern, lttng_ht_seed);
	242	if (syscall_rule->filter_expression) {
	243	hash ^= hash_key_str(syscall_rule->filter_expression,
	244	lttng_ht_seed);
	245	}
	246
	247	return hash;
	248	}
	249
6a751b95 JR	250	static enum lttng_error_code lttng_event_rule_kernel_syscall_mi_serialize(
	251	const struct lttng_event_rule rule, struct mi_writer writer)
	252	{
	253	int ret;
	254	enum lttng_error_code ret_code;
	255	enum lttng_event_rule_status status;
	256
	257	enum lttng_event_rule_kernel_syscall_emission_site site_type;
	258	const char *filter = NULL;
	259	const char *name_pattern = NULL;
	260	const char *site_type_str = NULL;
	261
a0377dfe FD	262	LTTNG_ASSERT(rule);
	263	LTTNG_ASSERT(writer);
	264	LTTNG_ASSERT(IS_SYSCALL_EVENT_RULE(rule));
6a751b95 JR	265
	266	status = lttng_event_rule_kernel_syscall_get_name_pattern(
	267	rule, &name_pattern);
a0377dfe FD	268	LTTNG_ASSERT(status == LTTNG_EVENT_RULE_STATUS_OK);
a0377dfe FD	269	LTTNG_ASSERT(name_pattern);
6a751b95 JR	270
6a751b95 JR	271	status = lttng_event_rule_kernel_syscall_get_filter(rule, &filter);
a0377dfe	272	LTTNG_ASSERT(status == LTTNG_EVENT_RULE_STATUS_OK \|\|
6a751b95 JR	273	status == LTTNG_EVENT_RULE_STATUS_UNSET);
	274
	275	site_type = lttng_event_rule_kernel_syscall_get_emission_site(rule);
	276
	277	switch (site_type) {
	278	case LTTNG_EVENT_RULE_KERNEL_SYSCALL_EMISSION_SITE_ENTRY_EXIT:
	279	site_type_str = mi_lttng_event_rule_kernel_syscall_emission_site_entry_exit;
	280	break;
	281	case LTTNG_EVENT_RULE_KERNEL_SYSCALL_EMISSION_SITE_ENTRY:
	282	site_type_str = mi_lttng_event_rule_kernel_syscall_emission_site_entry;
	283	break;
	284	case LTTNG_EVENT_RULE_KERNEL_SYSCALL_EMISSION_SITE_EXIT:
	285	site_type_str = mi_lttng_event_rule_kernel_syscall_emission_site_exit;
	286	break;
	287	default:
	288	abort();
	289	break;
	290	}
	291
	292	/* Open event rule kernel syscall element. */
	293	ret = mi_lttng_writer_open_element(
	294	writer, mi_lttng_element_event_rule_kernel_syscall);
	295	if (ret) {
	296	goto mi_error;
	297	}
	298
	299	/* Emission site. */
	300	ret = mi_lttng_writer_write_element_string(writer,
	301	mi_lttng_element_event_rule_kernel_syscall_emission_site,
	302	site_type_str);
	303	if (ret) {
	304	goto mi_error;
	305	}
	306
	307	/* Name pattern. */
	308	ret = mi_lttng_writer_write_element_string(writer,
	309	mi_lttng_element_event_rule_name_pattern, name_pattern);
	310	if (ret) {
	311	goto mi_error;
	312	}
	313
	314	/* Filter. */
	315	if (filter != NULL) {
	316	ret = mi_lttng_writer_write_element_string(writer,
	317	mi_lttng_element_event_rule_filter_expression,
	318	filter);
	319	if (ret) {
	320	goto mi_error;
	321	}
	322	}
	323
	324	/* Close event rule kernel syscall. */
	325	ret = mi_lttng_writer_close_element(writer);
	326	if (ret) {
	327	goto mi_error;
	328	}
	329
	330	ret_code = LTTNG_OK;
	331	goto end;
	332
	333	mi_error:
	334	ret_code = LTTNG_ERR_MI_IO_FAIL;
	335	end:
	336	return ret_code;
337	}
338
4f7da553 JR	339	struct lttng_event_rule *lttng_event_rule_kernel_syscall_create(
4f7da553 JR	340	enum lttng_event_rule_kernel_syscall_emission_site
f6a5af19	341	emission_site)
e6a39346 JR	342	{
e6a39346 JR	343	struct lttng_event_rule *rule = NULL;
4f7da553	344	struct lttng_event_rule_kernel_syscall *syscall_rule;
67d38b93	345	enum lttng_event_rule_status status;
e6a39346	346
57739a6b	347	/* Validate the emission site type */
f6a5af19	348	switch (emission_site) {
4f7da553 JR	349	case LTTNG_EVENT_RULE_KERNEL_SYSCALL_EMISSION_SITE_ENTRY_EXIT:
	350	case LTTNG_EVENT_RULE_KERNEL_SYSCALL_EMISSION_SITE_ENTRY:
	351	case LTTNG_EVENT_RULE_KERNEL_SYSCALL_EMISSION_SITE_EXIT:
57739a6b JR	352	break;
	353	default:
	354	/* Invalid emission type */
	355	goto end;
	356	}
	357
4f7da553	358	syscall_rule = zmalloc(sizeof(struct lttng_event_rule_kernel_syscall));
e6a39346 JR	359	if (!syscall_rule) {
	360	goto end;
	361	}
	362
	363	rule = &syscall_rule->parent;
	364	lttng_event_rule_init(
4f7da553 JR	365	&syscall_rule->parent, LTTNG_EVENT_RULE_TYPE_KERNEL_SYSCALL);
	366	syscall_rule->parent.validate = lttng_event_rule_kernel_syscall_validate;
	367	syscall_rule->parent.serialize = lttng_event_rule_kernel_syscall_serialize;
	368	syscall_rule->parent.equal = lttng_event_rule_kernel_syscall_is_equal;
	369	syscall_rule->parent.destroy = lttng_event_rule_kernel_syscall_destroy;
e6a39346	370	syscall_rule->parent.generate_filter_bytecode =
4f7da553	371	lttng_event_rule_kernel_syscall_generate_filter_bytecode;
e6a39346	372	syscall_rule->parent.get_filter =
4f7da553	373	lttng_event_rule_kernel_syscall_get_internal_filter;
e6a39346	374	syscall_rule->parent.get_filter_bytecode =
4f7da553	375	lttng_event_rule_kernel_syscall_get_internal_filter_bytecode;
e6a39346	376	syscall_rule->parent.generate_exclusions =
4f7da553 JR	377	lttng_event_rule_kernel_syscall_generate_exclusions;
4f7da553 JR	378	syscall_rule->parent.hash = lttng_event_rule_kernel_syscall_hash;
6a751b95	379	syscall_rule->parent.mi_serialize = lttng_event_rule_kernel_syscall_mi_serialize;
67d38b93 JR	380
67d38b93 JR	381	/* Default pattern is ''. /
4f7da553	382	status = lttng_event_rule_kernel_syscall_set_name_pattern(rule, "*");
67d38b93 JR	383	if (status != LTTNG_EVENT_RULE_STATUS_OK) {
	384	lttng_event_rule_destroy(rule);
	385	rule = NULL;
	386	}
	387
57739a6b	388	/* Emission site type */
f6a5af19	389	syscall_rule->emission_site = emission_site;
57739a6b	390
e6a39346 JR	391	end:
	392	return rule;
	393	}
	394
	395	LTTNG_HIDDEN
4f7da553	396	ssize_t lttng_event_rule_kernel_syscall_create_from_payload(
e6a39346 JR	397	struct lttng_payload_view *view,
	398	struct lttng_event_rule **_event_rule)
	399	{
	400	ssize_t ret, offset = 0;
	401	enum lttng_event_rule_status status;
4f7da553	402	const struct lttng_event_rule_kernel_syscall_comm *syscall_comm;
e6a39346 JR	403	const char *pattern;
	404	const char *filter_expression = NULL;
	405	struct lttng_buffer_view current_buffer_view;
	406	struct lttng_event_rule *rule = NULL;
	407
	408	if (!_event_rule) {
	409	ret = -1;
	410	goto end;
	411	}
	412
	413	if (view->buffer.size < sizeof(*syscall_comm)) {
	414	ERR("Failed to initialize from malformed event rule syscall: buffer too short to contain header");
	415	ret = -1;
	416	goto end;
	417	}
	418
	419	current_buffer_view = lttng_buffer_view_from_view(
	420	&view->buffer, offset, sizeof(*syscall_comm));
3e6e0df2	421	if (!lttng_buffer_view_is_valid(&current_buffer_view)) {
e6a39346 JR	422	ret = -1;
	423	goto end;
	424	}
	425
3e6e0df2	426	syscall_comm = (typeof(syscall_comm)) current_buffer_view.data;
4f7da553	427	rule = lttng_event_rule_kernel_syscall_create(syscall_comm->emission_site);
e6a39346 JR	428	if (!rule) {
	429	ERR("Failed to create event rule syscall");
	430	ret = -1;
	431	goto end;
	432	}
	433
	434	/* Skip to payload. */
	435	offset += current_buffer_view.size;
	436
	437	/* Map the pattern. */
	438	current_buffer_view = lttng_buffer_view_from_view(
	439	&view->buffer, offset, syscall_comm->pattern_len);
3e6e0df2	440	if (!lttng_buffer_view_is_valid(&current_buffer_view)) {
e6a39346 JR	441	ret = -1;
	442	goto end;
	443	}
	444
3e6e0df2	445	pattern = current_buffer_view.data;
e6a39346 JR	446	if (!lttng_buffer_view_contains_string(&current_buffer_view, pattern,
	447	syscall_comm->pattern_len)) {
	448	ret = -1;
	449	goto end;
	450	}
	451
	452	/* Skip after the pattern. */
	453	offset += syscall_comm->pattern_len;
	454
	455	if (!syscall_comm->filter_expression_len) {
	456	goto skip_filter_expression;
	457	}
	458
	459	/* Map the filter_expression. */
	460	current_buffer_view = lttng_buffer_view_from_view(&view->buffer, offset,
	461	syscall_comm->filter_expression_len);
3e6e0df2	462	if (!lttng_buffer_view_is_valid(&current_buffer_view)) {
e6a39346 JR	463	ret = -1;
	464	goto end;
	465	}
	466
3e6e0df2	467	filter_expression = current_buffer_view.data;
e6a39346 JR	468	if (!lttng_buffer_view_contains_string(&current_buffer_view,
	469	filter_expression,
	470	syscall_comm->filter_expression_len)) {
	471	ret = -1;
	472	goto end;
	473	}
	474
	475	/* Skip after the pattern. */
	476	offset += syscall_comm->filter_expression_len;
	477
	478	skip_filter_expression:
	479
4f7da553	480	status = lttng_event_rule_kernel_syscall_set_name_pattern(rule, pattern);
e6a39346 JR	481	if (status != LTTNG_EVENT_RULE_STATUS_OK) {
	482	ERR("Failed to set event rule syscall pattern");
	483	ret = -1;
	484	goto end;
	485	}
	486
	487	if (filter_expression) {
4f7da553	488	status = lttng_event_rule_kernel_syscall_set_filter(
e6a39346 JR	489	rule, filter_expression);
	490	if (status != LTTNG_EVENT_RULE_STATUS_OK) {
	491	ERR("Failed to set event rule syscall pattern");
	492	ret = -1;
	493	goto end;
	494	}
	495	}
	496
	497	*_event_rule = rule;
	498	rule = NULL;
	499	ret = offset;
	500	end:
	501	lttng_event_rule_destroy(rule);
	502	return ret;
	503	}
	504
4f7da553	505	enum lttng_event_rule_status lttng_event_rule_kernel_syscall_set_name_pattern(
e6a39346 JR	506	struct lttng_event_rule rule, const char pattern)
	507	{
	508	char *pattern_copy = NULL;
4f7da553	509	struct lttng_event_rule_kernel_syscall *syscall;
e6a39346 JR	510	enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;
	511
	512	if (!rule \|\| !IS_SYSCALL_EVENT_RULE(rule) \|\| !pattern \|\|
	513	strlen(pattern) == 0) {
	514	status = LTTNG_EVENT_RULE_STATUS_INVALID;
	515	goto end;
	516	}
	517
4f7da553	518	syscall = container_of(rule, struct lttng_event_rule_kernel_syscall, parent);
e6a39346 JR	519	pattern_copy = strdup(pattern);
	520	if (!pattern_copy) {
	521	status = LTTNG_EVENT_RULE_STATUS_ERROR;
	522	goto end;
	523	}
	524
40fd2ccf JR	525	strutils_normalize_star_glob_pattern(pattern_copy);
	526
	527	free(syscall->pattern);
e6a39346 JR	528
	529	syscall->pattern = pattern_copy;
	530	pattern_copy = NULL;
	531	end:
	532	return status;
	533	}
	534
4f7da553	535	enum lttng_event_rule_status lttng_event_rule_kernel_syscall_get_name_pattern(
e6a39346 JR	536	const struct lttng_event_rule rule, const char *pattern)
e6a39346 JR	537	{
4f7da553	538	struct lttng_event_rule_kernel_syscall *syscall;
e6a39346 JR	539	enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;
	540
	541	if (!rule \|\| !IS_SYSCALL_EVENT_RULE(rule) \|\| !pattern) {
	542	status = LTTNG_EVENT_RULE_STATUS_INVALID;
	543	goto end;
	544	}
	545
4f7da553	546	syscall = container_of(rule, struct lttng_event_rule_kernel_syscall, parent);
e6a39346 JR	547	if (!syscall->pattern) {
	548	status = LTTNG_EVENT_RULE_STATUS_UNSET;
	549	goto end;
	550	}
	551
	552	*pattern = syscall->pattern;
	553	end:
	554	return status;
	555	}
	556
4f7da553	557	enum lttng_event_rule_status lttng_event_rule_kernel_syscall_set_filter(
e6a39346 JR	558	struct lttng_event_rule rule, const char expression)
	559	{
	560	char *expression_copy = NULL;
4f7da553	561	struct lttng_event_rule_kernel_syscall *syscall;
e6a39346 JR	562	enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;
	563
	564	/* TODO: validate that the passed expression is valid. */
	565
	566	if (!rule \|\| !IS_SYSCALL_EVENT_RULE(rule) \|\| !expression \|\|
	567	strlen(expression) == 0) {
	568	status = LTTNG_EVENT_RULE_STATUS_INVALID;
	569	goto end;
	570	}
	571
4f7da553	572	syscall = container_of(rule, struct lttng_event_rule_kernel_syscall, parent);
e6a39346 JR	573	expression_copy = strdup(expression);
	574	if (!expression_copy) {
	575	status = LTTNG_EVENT_RULE_STATUS_ERROR;
	576	goto end;
	577	}
	578
	579	if (syscall->filter_expression) {
	580	free(syscall->filter_expression);
	581	}
	582
	583	syscall->filter_expression = expression_copy;
	584	expression_copy = NULL;
	585	end:
	586	return status;
	587	}
	588
4f7da553	589	enum lttng_event_rule_status lttng_event_rule_kernel_syscall_get_filter(
e6a39346 JR	590	const struct lttng_event_rule rule, const char *expression)
e6a39346 JR	591	{
4f7da553	592	struct lttng_event_rule_kernel_syscall *syscall;
e6a39346 JR	593	enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK;
	594
	595	if (!rule \|\| !IS_SYSCALL_EVENT_RULE(rule) \|\| !expression) {
	596	status = LTTNG_EVENT_RULE_STATUS_INVALID;
	597	goto end;
	598	}
	599
4f7da553	600	syscall = container_of(rule, struct lttng_event_rule_kernel_syscall, parent);
e6a39346 JR	601	if (!syscall->filter_expression) {
	602	status = LTTNG_EVENT_RULE_STATUS_UNSET;
	603	goto end;
	604	}
	605
	606	*expression = syscall->filter_expression;
	607	end:
	608	return status;
	609	}
4f7da553 JR	610	extern enum lttng_event_rule_kernel_syscall_emission_site
4f7da553 JR	611	lttng_event_rule_kernel_syscall_get_emission_site(
57739a6b JR	612	const struct lttng_event_rule *rule)
57739a6b JR	613	{
4f7da553 JR	614	enum lttng_event_rule_kernel_syscall_emission_site emission_site =
	615	LTTNG_EVENT_RULE_KERNEL_SYSCALL_EMISSION_SITE_UNKNOWN;
	616	struct lttng_event_rule_kernel_syscall *syscall;
57739a6b JR	617
	618	if (!rule \|\| !IS_SYSCALL_EVENT_RULE(rule)) {
	619	goto end;
	620	}
	621
4f7da553	622	syscall = container_of(rule, struct lttng_event_rule_kernel_syscall, parent);
f6a5af19	623	emission_site = syscall->emission_site;
57739a6b JR	624
57739a6b JR	625	end:
f6a5af19	626	return emission_site;
57739a6b JR	627	}
	628
	629	LTTNG_HIDDEN
4f7da553 JR	630	const char *lttng_event_rule_kernel_syscall_emission_site_str(
4f7da553 JR	631	enum lttng_event_rule_kernel_syscall_emission_site emission_site)
57739a6b	632	{
f6a5af19	633	switch (emission_site) {
4f7da553	634	case LTTNG_EVENT_RULE_KERNEL_SYSCALL_EMISSION_SITE_ENTRY:
57739a6b	635	return "entry";
4f7da553	636	case LTTNG_EVENT_RULE_KERNEL_SYSCALL_EMISSION_SITE_ENTRY_EXIT:
57739a6b	637	return "entry+exit";
4f7da553	638	case LTTNG_EVENT_RULE_KERNEL_SYSCALL_EMISSION_SITE_EXIT:
57739a6b JR	639	return "exit";
	640	default:
	641	return "???";
	642	}
	643	}