Expand checks about requirements to userspace classes

Refpolicy findings:

    unconfined.te:       63: (W): No explicit declaration for userspace class system.  You should access it via interface call or use a require block. (W-001)
    systemd.te:        1170: (W): No explicit declaration for userspace class dbus.  You should access it via interface call or use a require block. (W-001)
    systemd.te:        1282: (W): No explicit declaration for userspace class dbus.  You should access it via interface call or use a require block. (W-001)
    init.te:            261: (W): No explicit declaration for userspace class system.  You should access it via interface call or use a require block. (W-001)
    init.te:            302: (W): No explicit declaration for userspace class service.  You should access it via interface call or use a require block. (W-001)
    init.te:           1094: (W): No explicit declaration for userspace class system.  You should access it via interface call or use a require block. (W-001)
    init.te:           1102: (W): No explicit declaration for userspace class service.  You should access it via interface call or use a require block. (W-001)
    init.te:           1110: (W): No explicit declaration for userspace class service.  You should access it via interface call or use a require block. (W-001)
    init.te:           1114: (W): No explicit declaration for userspace class service.  You should access it via interface call or use a require block. (W-001)
    init.te:           1115: (W): No explicit declaration for userspace class service.  You should access it via interface call or use a require block. (W-001)
    devicekit.te:        56: (W): No explicit declaration for userspace class dbus.  You should access it via interface call or use a require block. (W-001)
    devicekit.te:       157: (W): No explicit declaration for userspace class dbus.  You should access it via interface call or use a require block. (W-001)
    devicekit.te:       297: (W): No explicit declaration for userspace class dbus.  You should access it via interface call or use a require block. (W-001)
    kernel.te:          558: (W): No explicit declaration for userspace class system.  You should access it via interface call or use a require block. (W-001)
    chromium.if:        139: (W): Class dbus is listed in require block but not used in interface (W-003)
    init.if:           1200: (W): Class system is used in interface but not required (W-002)
    init.if:           1218: (W): Class system is used in interface but not required (W-002)
    init.if:           1236: (W): Class system is used in interface but not required (W-002)
    init.if:           1254: (W): Class system is used in interface but not required (W-002)
    init.if:           1272: (W): Class system is used in interface but not required (W-002)
    init.if:           1290: (W): Class system is used in interface but not required (W-002)
    init.if:           1308: (W): Class system is used in interface but not required (W-002)
    init.if:           1326: (W): Class system is used in interface but not required (W-002)
    init.if:           1401: (W): Class bpf is listed in require block but is not a userspace class (W-003)
    systemd.if:         148: (W): Class system is used in interface but not required (W-002)
    systemd.if:         158: (W): Class service is used in interface but not required (W-002)
    systemd.if:         159: (W): Class service is used in interface but not required (W-002)
    systemd.if:         391: (W): Class system is used in interface but not required (W-002)
    systemd.if:         415: (W): Class system is used in interface but not required (W-002)
    systemd.if:         439: (W): Class system is used in interface but not required (W-002)
    unconfined.if:       34: (W): Class service is listed in require block but not used in interface (W-003)
    xserver.if:         353: (W): Class x_property is listed in require block but not used in interface (W-003)
    postgresql.if:       31: (W): Class db_database is listed in require block but not used in interface (W-003)
    postgresql.if:       37: (W): Class db_language is listed in require block but not used in interface (W-003)
    postgresql.if:      465: (W): Class db_database is listed in require block but not used in interface (W-003)
    postgresql.if:      471: (W): Class db_language is listed in require block but not used in interface (W-003)
    Found the following issue counts:
    W-001: 14
    W-002: 14
    W-003: 8

README

@@ -175,9 +175,9 @@ CHECK IDS
 	S-009: Permission macro suffix does not match class name
 	S-010: Permission macro usage suggested
 
-	W-001: Type or attribute referenced without explicit declaration
-	W-002: Type, attribute or role used but not listed in require block in interface
-	W-003: Unused type, attribute or role listed in require block
+	W-001: Type, attribute or userspace class referenced without explicit declaration
+	W-002: Type, attribute, role or userspace class used but not listed in require block in interface
+	W-003: Unused type, attribute, role or userspace class listed in require block
 	W-004: Potentially unescaped regex character in file contexts paths
 	W-005: Interface call from module not in optional_policy block
 	W-006: Interface call with empty argument

src/if_checks.c

@@ -330,6 +330,13 @@ struct check_result *check_name_used_but_not_required_in_if(const struct
 				flavor = "Role Attribute";
 			} else if (name_is_role(ndata) && look_up_in_decl_map(ndata->name, DECL_ROLE)) {
 				flavor = "Role";
+			} else if (name_is_class(ndata) && look_up_in_decl_map(ndata->name, DECL_CLASS)) {
+				/* Ignore kernel classes */
+				if (!is_userspace_class(ndata->name, ndata->traits)) {
+					name_node = name_node->next;
+					continue;
+				}
+				flavor = "Class";
 			} else {
 				// This is a string we don't recognize.  Other checks and/or
 				// the compiler catch invalid bare words
@@ -374,6 +381,14 @@ struct check_result *check_name_required_but_not_used_in_if(const struct
 		flavor = "Role Attribute";
 	} else if (dd->flavor == DECL_ROLE) {
 		flavor = "Role";
+	} else if (dd->flavor == DECL_CLASS) {
+		flavor = "Class";
+		if (!is_userspace_class(dd->name, dd->attrs)) {
+			return make_check_result('W',
+			                         W_ID_UNUSED_REQ,
+			                         "Class %s is listed in require block but is not a userspace class",
+			                         dd->name);
+		}
 	} else {
 		return NULL;
 	}
@@ -400,7 +415,12 @@ struct check_result *check_name_required_but_not_used_in_if(const struct
 		return NULL;
 	}
 
-	struct name_list *names_to_check = get_names_in_node(node);
+	struct name_list *names_to_check;
+	if (dd->flavor == DECL_CLASS) {
+		names_to_check = name_list_create(dd->name, NAME_CLASS);
+	} else {
+		names_to_check = get_names_in_node(node);
+	}
 	if (!names_to_check) {
 		// This should never happen
 		return alloc_internal_error(

src/main.c

@@ -411,6 +411,7 @@ int main(int argc, char **argv)
 	char *obj_perm_sets_path = NULL;
 	char *access_vector_path = NULL;
 	struct string_list *global_cond_files = NULL;
+	char *security_classes_path = NULL;
 
 	while (file) {
 		const char *suffix = (file->fts_pathlen > 3) ? (file->fts_path + file->fts_pathlen - 3) : NULL;
@@ -447,6 +448,10 @@ int main(int argc, char **argv)
 		           && (!strcmp(file->fts_name, "global_booleans") || !strcmp(file->fts_name, "global_tunables"))) {
 			// TODO: Make names configurable
 			global_cond_files = concat_string_lists(global_cond_files, sl_from_str(file->fts_path));
+		} else if (source_flag
+			   && !strcmp(file->fts_name, "security_classes")) {
+			// TODO: Make access_vectors name configurable
+			security_classes_path = strdup(file->fts_path);
 		} else {
 			// Directories might get traversed twice: preorder and final visit.
 			// Print only the final visit
@@ -518,6 +523,10 @@ int main(int argc, char **argv)
 			           && !str_in_sl(file->fts_path, global_cond_files)
 			           && (0 == strcmp(file->fts_name, "global_booleans") || 0 == strcmp(file->fts_name, "global_tunables"))) {
 				global_cond_files = concat_string_lists(global_cond_files, sl_from_str(file->fts_path));
+			} else if (source_flag
+			           && !security_classes_path
+			           && 0 == strcmp(file->fts_name, "security_classes")) {
+				security_classes_path = strdup(file->fts_path);
 			}
 			file = fts_read(ftsp);
 		}
@@ -542,6 +551,17 @@ int main(int argc, char **argv)
 			printf("%sWarning%s: Failed to locate access_vectors file.\n", color_warning(), color_reset());
 		}
 
+		if (security_classes_path) {
+			enum selint_error res = load_security_classes_source(security_classes_path);
+			if (res != SELINT_SUCCESS) {
+				printf("%sWarning%s: Failed to parse security_classes from %s: %d\n", color_warning(), color_reset(), security_classes_path, res);
+			} else {
+				print_if_verbose("Loaded security classes from %s\n", security_classes_path);
+			}
+		} else {
+			printf("%sWarning%s: Failed to locate security_classes file.\n", color_warning(), color_reset());
+		}
+
 		if (modules_conf_path) {
 			enum selint_error res =
 				load_modules_source(modules_conf_path);
@@ -615,13 +635,15 @@ int main(int argc, char **argv)
 		free_file_list(context_if_files);
 		free(obj_perm_sets_path);
 		free(access_vector_path);
+		free(security_classes_path);
 		free(modules_conf_path);
 		free_string_list(global_cond_files);
 		return EX_CONFIG;
 	}
 
 	free(obj_perm_sets_path);
 	free(access_vector_path);
+	free(security_classes_path);
 	free(modules_conf_path);
 	free_string_list(global_cond_files);
 

src/maps.c

@@ -38,6 +38,7 @@ static struct hash_elem *perm_map = NULL;
 static struct hash_elem *mods_map = NULL;
 static struct hash_elem *mod_layers_map = NULL;
 static struct if_hash_elem *interfaces_map = NULL;
+static struct bool_hash_elem *userspace_class_map = NULL;
 static struct sl_hash_elem *permmacros_map = NULL;
 static struct template_hash_elem *template_map = NULL;
 
@@ -273,6 +274,56 @@ unsigned int decl_map_count(enum decl_flavor flavor)
 	}
 }
 
+no_sanitize_unsigned_integer_
+void mark_userspace_class(const char *class_name)
+{
+	struct bool_hash_elem *userspace_class;
+
+	HASH_FIND(hh_userspace_class, userspace_class_map, class_name, strlen(class_name), userspace_class);
+
+	if (!userspace_class) {
+		userspace_class = malloc(sizeof(struct bool_hash_elem));
+		userspace_class->key = strdup(class_name);
+		userspace_class->val = 1;
+		HASH_ADD_KEYPTR(hh_userspace_class, userspace_class_map, userspace_class->key,
+				strlen(userspace_class->key), userspace_class);
+	} else {
+		userspace_class->val = 1;
+	}
+}
+
+no_sanitize_unsigned_integer_
+int is_userspace_class(const char *class_name, const struct string_list *permissions)
+{
+	struct bool_hash_elem *userspace_class;
+	HASH_FIND(hh_userspace_class, userspace_class_map, class_name, strlen(class_name), userspace_class);
+	if (userspace_class && userspace_class->val == 1) {
+		return 1;
+	}
+
+	// the system class might be used by systemd depending on the permission
+	if (0 != strcmp(class_name, "system")) {
+		return 0;
+	}
+
+	for (const struct string_list *p = permissions; p; p = p->next) {
+		// if permission is not one of the kernel ones
+		// treat system as userspace class
+		if (0 != strcmp(p->string, "ipc_info") &&
+		    0 != strcmp(p->string, "syslog_read") &&
+		    0 != strcmp(p->string, "syslog_mod") &&
+		    0 != strcmp(p->string, "syslog_console") &&
+		    0 != strcmp(p->string, "module_request") &&
+		    0 != strcmp(p->string, "module_load") &&
+		    0 != strcmp(p->string, "*") &&
+		    0 != strcmp(p->string, "~")) {
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
 no_sanitize_unsigned_integer_
 void mark_transform_if(const char *if_name)
 {
@@ -583,6 +634,12 @@ unsigned int permmacros_map_count(void)
 		free(cur_decl); \
 } \
 
+#define FREE_BOOL_MAP(mn) HASH_ITER(hh_ ## mn, mn ## _map, cur_bool, tmp_bool) { \
+		HASH_DELETE(hh_ ## mn, mn ## _map, cur_bool); \
+		free(cur_bool->key); \
+		free(cur_bool); \
+} \
+
 #define FREE_IF_MAP(mn) HASH_ITER(hh_ ## mn, mn ## _map, cur_if, tmp_if) { \
 		HASH_DELETE(hh_ ## mn, mn ## _map, cur_if); \
 		free(cur_if->name); \
@@ -619,6 +676,10 @@ void free_all_maps(void)
 
 	FREE_IF_MAP(interfaces);
 
+	struct bool_hash_elem *cur_bool, *tmp_bool;
+
+	FREE_BOOL_MAP(userspace_class);
+
 	struct sl_hash_elem *cur_sl, *tmp_sl;
 
 	HASH_ITER(hh_permmacros, permmacros_map, cur_sl, tmp_sl) {

src/maps.h

@@ -29,6 +29,12 @@ struct hash_elem {
 	               hh_class, hh_perm, hh_mods, hh_mod_layers;
 };
 
+struct bool_hash_elem {
+	char *key;
+	int val;
+	UT_hash_handle hh_userspace_class;
+};
+
 struct sl_hash_elem {
 	char *key;
 	struct string_list *val;
@@ -71,6 +77,10 @@ void insert_into_ifs_map(const char *if_name, const char *mod_name);
 
 const char *look_up_in_ifs_map(const char *if_name);
 
+void mark_userspace_class(const char *class_name);
+
+int is_userspace_class(const char *class_name, const struct string_list *permissions);
+
 void mark_transform_if(const char *if_name);
 
 int is_transform_if(const char *if_name);

src/startup.c

@@ -14,6 +14,7 @@
 * limitations under the License.
 */
 
+#include <ctype.h>
 #include <errno.h>
 #include <fts.h>
 #include <stdio.h>
@@ -93,6 +94,75 @@ enum selint_error load_access_vectors_source(const char *av_path)
 	return SELINT_SUCCESS;
 }
 
+enum selint_error load_security_classes_source(const char *sec_class_path)
+{
+	FILE *fd = fopen(sec_class_path, "r");
+
+	if (!fd) {
+		return SELINT_IO_ERROR;
+	}
+
+	enum selint_error ret = SELINT_SUCCESS;
+
+	char *line = NULL;
+	ssize_t len_read = 0;
+	size_t buf_len = 0;
+	while ((len_read = getline(&line, &buf_len, fd)) != -1) {
+		if (len_read <= 1 || line[0] == '#') {
+			continue;
+		}
+
+		const char *pos = line;
+		if (0 != strncmp(pos, "class", strlen("class"))) {
+			ret = SELINT_PARSE_ERROR;
+			break;
+		}
+		pos += strlen("class");
+
+		if (*pos != ' ' && *pos != '\t') {
+			ret = SELINT_PARSE_ERROR;
+			break;
+		}
+
+		while (*pos == ' ' || *pos == '\t') {
+			pos++;
+		}
+
+		if (!islower((unsigned char)*pos)) {
+			ret = SELINT_PARSE_ERROR;
+			break;
+		}
+
+		const char *name_start = pos;
+
+		while (*pos == '_' || islower((unsigned char)*pos) || isdigit((unsigned char)*pos)) {
+			pos++;
+		}
+
+		const char *name_end = pos;
+
+		while (isspace((unsigned char)*pos)) {
+			pos++;
+		}
+
+		if (*pos != '\0' && *pos != '#') {
+			ret = SELINT_PARSE_ERROR;
+			break;
+		}
+
+		if (*pos == '#' && NULL != strstr(pos, "userspace")) {
+			char *name = strndup(name_start, (size_t)(name_end - name_start));
+			mark_userspace_class(name);
+			free(name);
+		}
+	}
+
+	free(line);
+	fclose(fd);
+
+	return ret;
+}
+
 void load_modules_normal(void)
 {
 

src/startup.h

@@ -25,6 +25,8 @@ enum selint_error load_access_vectors_kernel(const char *av_path);
 
 enum selint_error load_access_vectors_source(const char *av_path);
 
+enum selint_error load_security_classes_source(const char *sec_class_path);
+
 void load_modules_normal(void);
 
 enum selint_error load_modules_source(const char *modules_conf_path);

src/te_checks.c

@@ -531,20 +531,34 @@ struct check_result *check_no_explicit_declaration(const struct check_data *data
 			flavor = DECL_ATTRIBUTE;
 		} else if (name_is_roleattr(ndata) && (mod_name = look_up_in_decl_map(ndata->name, DECL_ATTRIBUTE_ROLE))) {
 			flavor = DECL_ATTRIBUTE_ROLE;
+		} else if (name_is_class(ndata) && look_up_in_decl_map(name->data->name, DECL_CLASS)) {
+			// Ignore kernel classes
+			if (!is_userspace_class(name->data->name, name->data->traits)) {
+				continue;
+			}
+			flavor = DECL_CLASS;
+			mod_name = NULL;
 		// Do not check for roles: in refpolicy they are defined in the kernel module
 		// and used in role modules (like unprivuser)
 		} else {
 			//Not a known name
 			continue;
 		}
 
-		if (0 != strcmp(data->mod_name, mod_name)) {
+		if (!mod_name || 0 != strcmp(data->mod_name, mod_name)) {
 			// It may be required
 			if (!has_require(node, ndata->name, flavor)) {
 				// We didn't find a require block with this name
-				struct check_result *to_ret = make_check_result('W', W_ID_NO_EXPLICIT_DECL,
-										"No explicit declaration for %s from module %s.  You should access it via interface call or use a require block.",
-										ndata->name, mod_name);
+				struct check_result *to_ret;
+				if (flavor == DECL_CLASS) {
+					to_ret = make_check_result('W', W_ID_NO_EXPLICIT_DECL,
+					                           "No explicit declaration for userspace class %s.  You should access it via interface call or use a require block.",
+					                           ndata->name);
+				} else {
+					to_ret = make_check_result('W', W_ID_NO_EXPLICIT_DECL,
+					                           "No explicit declaration for %s from module %s.  You should access it via interface call or use a require block.",
+					                           ndata->name, mod_name);
+				}
 				free_name_list(names);
 				return to_ret;
 			}

tests/Makefile.am

@@ -148,6 +148,7 @@ FUNCTIONAL_TEST_FILES=functional/end-to-end.bats \
 			functional/policies/check_triggers/e10.warn.te \
 			functional/policies/check_triggers/modules.conf \
 			functional/policies/check_triggers/obj_perm_sets.spt \
+			functional/policies/check_triggers/security_classes \
 			functional/policies/check_triggers/s01.te \
 			functional/policies/check_triggers/s02.fc \
 			functional/policies/check_triggers/s02_other.te \
@@ -166,7 +167,11 @@ FUNCTIONAL_TEST_FILES=functional/end-to-end.bats \
 			functional/policies/check_triggers/w02_role.te \
 			functional/policies/check_triggers/w02.te \
 			functional/policies/check_triggers/w02.bad_if.if \
+			functional/policies/check_triggers/w02_system_nowarn.if \
+			functional/policies/check_triggers/w02_system_warn.if \
 			functional/policies/check_triggers/w03_alias.if \
+			functional/policies/check_triggers/w03_system_nowarn.if \
+			functional/policies/check_triggers/w03_system_warn.if \
 			functional/policies/check_triggers/w03.if \
 			functional/policies/check_triggers/w03_role.if \
 			functional/policies/check_triggers/w03_stub.if \