X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Fevent-rule-syscall.c;fp=src%2Fcommon%2Fevent-rule-syscall.c;h=97f5f86b18d0444e1d9ca39d539b5c4d38d8e5b6;hp=0000000000000000000000000000000000000000;hb=1831ae68b70dece8e9b847081526495adbbf05e5;hpb=25357057de5ae4dd2a572e8f9b893c1b90cbd60a

diff --git a/src/common/event-rule-syscall.c b/src/common/event-rule-syscall.c
new file mode 100644
index 000000000..97f5f86b1
--- /dev/null
+++ b/src/common/event-rule-syscall.c
@@ -0,0 +1,492 @@
+/*
+ * Copyright (C) 2019 - Jonathan Rajotte-Julien <jonathan.rajotte-julien@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.
+ *
+ * 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/event-rule/event-rule-internal.h>
+#include <lttng/event-rule/syscall-internal.h>
+#include <common/macros.h>
+#include <common/error.h>
+#include <common/runas.h>
+#include <assert.h>
+
+#define IS_SYSCALL_EVENT_RULE(rule) ( \
+	lttng_event_rule_get_type(rule) == LTTNG_EVENT_RULE_TYPE_SYSCALL \
+	)
+
+static
+void lttng_event_rule_syscall_destroy(struct lttng_event_rule *rule)
+{
+	struct lttng_event_rule_syscall *syscall;
+
+	if (rule == NULL) {
+		return;
+	}
+
+	syscall = container_of(rule, struct lttng_event_rule_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_syscall_validate(
+		const struct lttng_event_rule *rule)
+{
+	bool valid = false;
+	struct lttng_event_rule_syscall *syscall;
+
+	if (!rule) {
+		goto end;
+	}
+
+	syscall = container_of(rule, struct lttng_event_rule_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_syscall_serialize(
+		const struct lttng_event_rule *rule,
+		struct lttng_dynamic_buffer *buf,
+		int *fd_to_send)
+{
+	int ret;
+	size_t pattern_len, filter_expression_len;
+	struct lttng_event_rule_syscall *syscall;
+	struct lttng_event_rule_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_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;
+
+	ret = lttng_dynamic_buffer_append(
+			buf, &syscall_comm, sizeof(syscall_comm));
+	if (ret) {
+		goto end;
+	}
+	ret = lttng_dynamic_buffer_append(buf, syscall->pattern, pattern_len);
+	if (ret) {
+		goto end;
+	}
+	ret = lttng_dynamic_buffer_append(
+			buf, syscall->filter_expression, filter_expression_len);
+	if (ret) {
+		goto end;
+	}
+
+	if (fd_to_send) {
+		/* Nothing to send */
+		*fd_to_send = -1;
+	}
+end:
+	return ret;
+}
+
+static
+bool lttng_event_rule_syscall_is_equal(const struct lttng_event_rule *_a,
+		const struct lttng_event_rule *_b)
+{
+	bool is_equal = false;
+	struct lttng_event_rule_syscall *a, *b;
+
+	a = container_of(_a, struct lttng_event_rule_syscall, parent);
+	b = container_of(_b, struct lttng_event_rule_syscall, parent);
+
+	if (!!a->filter_expression != !!b->filter_expression) {
+		goto end;
+	}
+
+	/* Long check */
+	/* syscall is invalid if this is not true */
+	assert(a->pattern);
+	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;
+		}
+	}
+
+	is_equal = true;
+end:
+	return is_equal;
+}
+
+static
+enum lttng_error_code lttng_event_rule_syscall_populate(struct lttng_event_rule *rule, uid_t uid, gid_t gid)
+{
+	int ret;
+	enum lttng_error_code ret_code = LTTNG_OK;
+	struct lttng_event_rule_syscall *syscall;
+	enum lttng_event_rule_status status;
+	const char *filter;
+	struct lttng_filter_bytecode *bytecode = NULL;
+
+	assert(rule);
+
+	syscall = container_of(rule, struct lttng_event_rule_syscall,
+			parent);
+
+	/* Generate the filter bytecode */
+	status = lttng_event_rule_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 error;
+	}
+
+	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, uid, gid, &bytecode);
+	if (ret) {
+		ret_code = LTTNG_ERR_FILTER_INVAL;
+	}
+
+	syscall->internal_filter.bytecode = bytecode;
+	bytecode = NULL;
+
+error:
+end:
+	free(bytecode);
+	return ret_code;
+}
+
+static const char *lttng_event_rule_syscall_get_internal_filter(
+		const struct lttng_event_rule *rule)
+{
+	struct lttng_event_rule_syscall *syscall;
+	assert(rule);
+
+	syscall = container_of(rule, struct lttng_event_rule_syscall, parent);
+	return syscall->internal_filter.filter;
+}
+
+static const struct lttng_filter_bytecode *
+lttng_event_rule_syscall_get_internal_filter_bytecode(
+		const struct lttng_event_rule *rule)
+{
+	struct lttng_event_rule_syscall *syscall;
+	assert(rule);
+
+	syscall = container_of(rule, struct lttng_event_rule_syscall, parent);
+	return syscall->internal_filter.bytecode;
+}
+
+static struct lttng_event_exclusion *
+lttng_event_rule_syscall_generate_exclusions(struct lttng_event_rule *rule)
+{
+	/* Not supported */
+	return NULL;
+}
+
+struct lttng_event_rule *lttng_event_rule_syscall_create()
+{
+	struct lttng_event_rule_syscall *rule;
+
+	rule = zmalloc(sizeof(struct lttng_event_rule_syscall));
+	if (!rule) {
+		return NULL;
+	}
+
+	lttng_event_rule_init(&rule->parent, LTTNG_EVENT_RULE_TYPE_SYSCALL);
+	rule->parent.validate = lttng_event_rule_syscall_validate;
+	rule->parent.serialize = lttng_event_rule_syscall_serialize;
+	rule->parent.equal = lttng_event_rule_syscall_is_equal;
+	rule->parent.destroy = lttng_event_rule_syscall_destroy;
+	rule->parent.populate = lttng_event_rule_syscall_populate;
+	rule->parent.get_filter = lttng_event_rule_syscall_get_internal_filter;
+	rule->parent.get_filter_bytecode =
+			lttng_event_rule_syscall_get_internal_filter_bytecode;
+	rule->parent.generate_exclusions =
+			lttng_event_rule_syscall_generate_exclusions;
+	return &rule->parent;
+}
+
+LTTNG_HIDDEN
+ssize_t lttng_event_rule_syscall_create_from_buffer(
+		const struct lttng_buffer_view *view,
+		struct lttng_event_rule **_event_rule)
+{
+	ssize_t ret, offset = 0;
+	enum lttng_event_rule_status status;
+	const struct lttng_event_rule_syscall_comm *syscall_comm;
+	const char *pattern;
+	const char *filter_expression = NULL;
+	struct lttng_buffer_view current_view;
+	struct lttng_event_rule *rule = NULL;
+
+	if (!_event_rule) {
+		ret = -1;
+		goto end;
+	}
+
+	if (view->size < sizeof(*syscall_comm)) {
+		ERR("Failed to initialize from malformed event rule syscall: buffer too short to contain header");
+		ret = -1;
+		goto end;
+	}
+
+	current_view = lttng_buffer_view_from_view(
+			view, offset, sizeof(*syscall_comm));
+	syscall_comm = (typeof(syscall_comm)) current_view.data;
+
+	if (!syscall_comm) {
+		ret = -1;
+		goto end;
+	}
+
+	rule = lttng_event_rule_syscall_create();
+	if (!rule) {
+		ERR("Failed to create event rule syscall");
+		ret = -1;
+		goto end;
+	}
+
+	/* Skip to payload */
+	offset += current_view.size;
+
+	/* Map the pattern */
+	current_view = lttng_buffer_view_from_view(
+			view, offset, syscall_comm->pattern_len);
+	pattern = current_view.data;
+	if (!pattern) {
+		ret = -1;
+		goto end;
+	}
+
+	if (syscall_comm->pattern_len == 1 ||
+			pattern[syscall_comm->pattern_len - 1] != '\0' ||
+			strlen(pattern) != syscall_comm->pattern_len - 1) {
+		/*
+		 * Check that the pattern is not NULL, is NULL-terminated, and
+		 * does not contain a NULL before the last byte.
+		 */
+		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_view = lttng_buffer_view_from_view(
+			view, offset, syscall_comm->filter_expression_len);
+	filter_expression = current_view.data;
+	if (!filter_expression) {
+		ret = -1;
+		goto end;
+	}
+
+	if (syscall_comm->filter_expression_len == 1 ||
+			filter_expression[syscall_comm->filter_expression_len -
+					  1] != '\0' ||
+			strlen(filter_expression) !=
+					syscall_comm->filter_expression_len -
+							1) {
+		/*
+		 * Check that the filter expression is not NULL, is
+		 * NULL-terminated, and does not contain a NULL before the last
+		 * byte.
+		 */
+		ret = -1;
+		goto end;
+	}
+
+	/* Skip after the pattern */
+	offset += syscall_comm->filter_expression_len;
+
+skip_filter_expression:
+
+	status = lttng_event_rule_syscall_set_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_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_syscall_set_pattern(
+		struct lttng_event_rule *rule, const char *pattern)
+{
+	char *pattern_copy = NULL;
+	struct lttng_event_rule_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_syscall, parent);
+	pattern_copy = strdup(pattern);
+	if (!pattern_copy) {
+		status = LTTNG_EVENT_RULE_STATUS_ERROR;
+		goto end;
+	}
+
+	if (syscall->pattern) {
+		free(syscall->pattern);
+	}
+
+	syscall->pattern = pattern_copy;
+	pattern_copy = NULL;
+end:
+	return status;
+}
+
+enum lttng_event_rule_status lttng_event_rule_syscall_get_pattern(
+		const struct lttng_event_rule *rule, const char **pattern)
+{
+	struct lttng_event_rule_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_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_syscall_set_filter(
+		struct lttng_event_rule *rule, const char *expression)
+{
+	char *expression_copy = NULL;
+	struct lttng_event_rule_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_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_syscall_get_filter(
+		const struct lttng_event_rule *rule, const char **expression)
+{
+	struct lttng_event_rule_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_syscall, parent);
+	if (!syscall->filter_expression) {
+		status = LTTNG_EVENT_RULE_STATUS_UNSET;
+		goto end;
+	}
+
+	*expression = syscall->filter_expression;
+end:
+	return status;
+}