RFC/WIP: Add basic check for naming style violations

README

@@ -157,6 +157,7 @@ CHECK IDS
 	C-005: Permissions in av rule or class declaration not ordered
 	C-006: Declarations in require block not ordered
 	C-007: Redudant type specification instead of self keyword
+	C-008: Violation of refpolicy style naming conventions
 
 	S-001: Require block used instead of interface call
 	S-002: File context file labels with type not declared in module

src/Makefile.am

@@ -13,7 +13,7 @@
 # limitations under the License.
 
 bin_PROGRAMS = selint
-selint_SOURCES = main.c lex.l parse.y tree.c tree.h selint_error.h parse_functions.c parse_functions.h maps.c maps.h runner.c runner.h parse_fc.c parse_fc.h template.c template.h file_list.c file_list.h check_hooks.c check_hooks.h fc_checks.c fc_checks.h util.c util.h if_checks.c if_checks.h selint_config.c selint_config.h string_list.c string_list.h startup.c startup.h te_checks.c te_checks.h ordering.c ordering.h color.c color.h perm_macro.c perm_macro.h
+selint_SOURCES = main.c lex.l parse.y tree.c tree.h selint_error.h parse_functions.c parse_functions.h maps.c maps.h runner.c runner.h parse_fc.c parse_fc.h template.c template.h file_list.c file_list.h check_hooks.c check_hooks.h fc_checks.c fc_checks.h util.c util.h if_checks.c if_checks.h selint_config.c selint_config.h string_list.c string_list.h startup.c startup.h te_checks.c te_checks.h ordering.c ordering.h color.c color.h perm_macro.c perm_macro.h naming.c naming.h
 BUILT_SOURCES = parse.h
 AM_YFLAGS = -d -Wno-yacc -Werror=conflicts-rr -Werror=conflicts-sr
 

src/check_hooks.h

@@ -27,6 +27,7 @@ enum convention_ids {
 	C_ID_UNORDERED_PERM = 5,
 	C_ID_UNORDERED_REQ  = 6,
 	C_ID_SELF           = 7,
+	C_ID_NAMING         = 8,
 	C_END
 };
 

src/naming.c

@@ -0,0 +1,235 @@
+/*
+* Copyright 2020 The SELint Contributors
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+*    http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+#include "naming.h"
+
+#include <ctype.h>
+#include <stddef.h>
+#include <string.h>
+
+static const char *const reason_invalid_char = "contains invalid character";
+static const char *const reason_start_underscore = "starts with an underscore";
+static const char *const reason_consecutive_underscores = "contains consecutive underscores";
+static const char *const reason_end_underscore = "ends with an underscore";
+static const char *const reason_type_postfix = "type does not end with type-specific postfix";
+static const char *const reason_role_postfix = "role does not end with role-specific postfix";
+static const char *const reason_user_postfix = "user does not end with user-specific postfix";
+static const char *const reason_if_no_mod_prefix = "interface has no module name prefix";
+static const char *const reason_if_no_postfix = "interface has no postfix";
+static const char *const reason_if_invalid_postfix = "interface has an invalid postfix";
+static const char *const reason_temp_no_mod_prefix = "template has no module name prefix";
+static const char *const reason_temp_no_postfix = "template has no postfix";
+static const char *const reason_temp_invalid_postfix = "template has an invalid postfix";
+
+
+static const char *generic_check(const char *name)
+{
+	const unsigned char *c = (const unsigned char *)name;
+
+	if (*c == '_') {
+		return reason_start_underscore;
+	}
+
+	unsigned short prev_is_underscore = 0;
+	while (*c != '\0') {
+		if (!islower(*c) && !isdigit(*c) && *c != '_') {
+			return reason_invalid_char;
+		}
+
+		if (*c == '_') {
+			if (prev_is_underscore) {
+				return reason_consecutive_underscores;
+			}
+
+			prev_is_underscore = 1;
+		} else {
+			prev_is_underscore = 0;
+		}
+
+		c++;
+	}
+
+	if (*(c-1) == '_') {
+		return reason_end_underscore;
+	}
+
+	return NULL;
+}
+
+static const char *type_check(const char *name)
+{
+	const size_t name_len = strlen(name);
+	if (name_len < 2 || name[name_len-2] != '_' || name[name_len-1] != 't') {
+		return reason_type_postfix;
+	}
+
+	return NULL;
+}
+
+static const char *role_check(const char *name)
+{
+	const size_t name_len = strlen(name);
+	if (name_len < 2 || name[name_len-2] != '_' || name[name_len-1] != 'r') {
+		return reason_role_postfix;
+	}
+
+	return NULL;
+}
+
+static const char *user_check(const char *name)
+{
+	const size_t name_len = strlen(name);
+	if (name_len < 2 || name[name_len-2] != '_' || name[name_len-1] != 'u') {
+		return reason_user_postfix;
+	}
+
+	return NULL;
+}
+
+const char *naming_decl_check(const char *name, enum decl_flavor flavor)
+{
+	// class and permission names are not in the scope of a policy writer
+	if (flavor == DECL_CLASS || flavor == DECL_PERM) {
+		return NULL;
+	}
+
+	const char *res = generic_check(name);
+	if (res) {
+		return res;
+	}
+
+	switch (flavor) {
+	case DECL_TYPE:
+		res = type_check(name);
+		break;
+	case DECL_ATTRIBUTE:
+		//TODO
+		break;
+	case DECL_ROLE:
+		res = role_check(name);
+		break;
+	case DECL_ATTRIBUTE_ROLE:
+		//TODO
+		break;
+	case DECL_USER:
+		res = user_check(name);
+		break;
+	case DECL_BOOL:
+		//TODO
+		break;
+	case DECL_CLASS:
+	case DECL_PERM:
+		break;
+	}
+
+	if (res) {
+		return res;
+	}
+
+	return NULL;
+}
+
+static int mod_prefix_check(const char *name, const char *mod_name)
+{
+	const size_t mod_name_len = strlen(mod_name);
+
+	if (0 == strncmp(name, mod_name, mod_name_len) && name[mod_name_len] == '_') {
+		return 0;
+	}
+
+	static const char *const exceptions[][2] = {
+		{ "fs"      , "filesystem"   },
+		{ "corecmd" , "corecommands" },
+		{ "seutil"  , "selinuxutil"  },
+		{ "libs"    , "libraries"    },
+		{ "dev"     , "devices"      },
+		{ "term"    , "terminal"     },
+		{ "corenet" , "corenetwork"  },
+		{ "auth"    , "authlogin"    },
+		{ "userdom" , "userdomain"   },
+		{ "sysnet"  , "sysnetwork"   },
+	};
+
+	const char *prefix = strchr(name, '_');
+	if (!prefix) {
+		return 1;
+	}
+
+	const size_t prefix_len = (size_t)(prefix - name);
+
+	size_t i;
+	for (i = 0; i < (sizeof exceptions / sizeof *exceptions); ++i) {
+		if (0 == strncmp(name, exceptions[i][0], prefix_len) &&
+		    0 == strcmp(mod_name, exceptions[i][1])) {
+			return 0;
+		}
+	}
+
+	return 1;
+}
+
+const char *naming_if_check(const char *name, const char *module_name)
+{
+	const char *res = generic_check(name);
+	if (res) {
+		return res;
+	}
+
+	if (mod_prefix_check(name, module_name)) {
+		return reason_if_no_mod_prefix;
+	}
+
+	const char *postfix = strrchr(name, '_');
+	if (!postfix) {
+		return reason_if_no_postfix;
+	}
+
+	static const char *const invalid_postfixes[] = {
+		"_pattern",
+	};
+	size_t i;
+	for (i = 0; i < (sizeof invalid_postfixes / sizeof *invalid_postfixes); ++i) {
+		if (0 == strcmp(postfix, invalid_postfixes[i])) {
+			return reason_if_invalid_postfix;
+		}
+	}
+
+	return NULL;
+}
+
+const char *naming_temp_check(const char *name, const char *module_name)
+{
+	const char *res = generic_check(name);
+	if (res) {
+		return res;
+	}
+
+	if (mod_prefix_check(name, module_name)) {
+		return reason_temp_no_mod_prefix;
+	}
+
+	const char *postfix = strrchr(name, '_');
+	if (!postfix) {
+		return reason_temp_no_postfix;
+	}
+
+	if (0 != strcmp(postfix, "_template") &&
+	    0 != strcmp(postfix, "_admin")) {
+		return reason_temp_invalid_postfix;
+	}
+
+	return NULL;
+}

src/naming.h

@@ -0,0 +1,49 @@
+/*
+* Copyright 2020 The SELint Contributors
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+*    http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+#ifndef NAMING_H
+#define NAMING_H
+
+#include "tree.h"
+
+/**********************************
+* Check the given name with the given kind of declaration for naming
+* convention violations.
+* name (in) - the name of the declaration
+* flavor (in) - the kind of declaration
+* Returns NULL if check passes, else a violation reason.
+**********************************/
+const char *naming_decl_check(const char *name, enum decl_flavor flavor);
+
+/**********************************
+* Check the given interface name for naming
+* convention violations.
+* name (in) - the name of the interface
+* module_name (in) - the name of the containing module
+* Returns NULL if check passes, else a violation reason.
+**********************************/
+const char *naming_if_check(const char *name, const char *module_name);
+
+/**********************************
+* Check the given template name for naming
+* convention violations.
+* name (in) - the name of the template
+* module_name (in) - the name of the containing module
+* Returns NULL if check passes, else a violation reason.
+**********************************/
+const char *naming_temp_check(const char *name, const char *module_name);
+
+#endif

src/runner.c

@@ -146,6 +146,14 @@ struct checks *register_checks(char level,
 			add_check(NODE_XAV_RULE, ck, "C-007",
 			          check_no_self);
 		}
+		if (CHECK_ENABLED("C-008")) {
+			add_check(NODE_DECL, ck, "C-008",
+			          check_naming);
+			add_check(NODE_TEMP_DEF, ck, "C-008",
+			          check_naming);
+			add_check(NODE_INTERFACE_DEF, ck, "C-008",
+			          check_naming);
+		}
 		// FALLTHRU
 	case 'S':
 		if (CHECK_ENABLED("S-001")) {

src/te_checks.c

@@ -24,6 +24,7 @@
 #include "ordering.h"
 #include "util.h"
 #include "perm_macro.h"
+#include "naming.h"
 
 struct check_result *check_te_order(const struct check_data *data,
                                     const struct policy_node *node)
@@ -167,7 +168,42 @@ struct check_result *check_no_self(__attribute__((unused)) const struct check_da
 
 	return make_check_result('C', C_ID_SELF,
 	                         "Recommend use of self keyword instead of redundant type");
+}
+
+struct check_result *check_naming(const struct check_data *data,
+                                  const struct policy_node *node)
+{
+	const char *reason;
+
+	switch (node->flavor) {
+	case NODE_DECL:
+		// check only declarations in te files
+		if (data->flavor != FILE_TE_FILE) {
+			return NULL;
+		}
+
+		reason = naming_decl_check(node->data.d_data->name, node->data.d_data->flavor);
+		break;
+
+	case NODE_INTERFACE_DEF:
+		reason = naming_if_check(node->data.str, data->mod_name);
+		break;
+
+	case NODE_TEMP_DEF:
+		reason = naming_temp_check(node->data.str, data->mod_name);
+		break;
+
+	default:
+		return alloc_internal_error("Invalid node type for `check_naming`");
+	}
+
+	if (!reason) {
+		return NULL;
+	}
 
+	return make_check_result('C', C_ID_NAMING,
+				 "Naming convention voliated: %s",
+				 reason);
 }
 
 struct check_result *check_require_block(const struct check_data *data,

src/te_checks.h

@@ -58,6 +58,16 @@ struct check_result *check_unordered_perms(const struct check_data *data,
 struct check_result *check_no_self(const struct check_data *data,
                                    const struct policy_node *node);
 
+/*********************************************
+* Check for  violations of refpolicy style naming conventions.
+* Called on NODE_DECL nodes.
+* data - metadata about the file currently being scanned
+* node - the node to check
+* returns NULL if passed or check_result for issue C-005
+*********************************************/
+struct check_result *check_naming(const struct check_data *data,
+                                  const struct policy_node *node);
+
 /*********************************************
 * Check for the presence of require blocks in TE files.
 * Interface calls are to be preferred.