--- /dev/null
+/*
+ * Copyright (C) 2019 Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
+ *
+ * SPDX-License-Identifier: LGPL-2.1-only
+ *
+ */
+
+#include <assert.h>
+#include <common/error.h>
+#include <common/macros.h>
+#include <common/runas.h>
+#include <lttng/event-rule/event-rule-internal.h>
+#include <lttng/event-rule/syscall-internal.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_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_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;
+}