libsepol: split validation of datum array gaps and entries

Split the validation of array datums regarding their gaps and entries to
simplify further checking of common classes, booleans, levels and
categories.

Signed-off-by: Christian Göttsche <[email protected]>

Author: cgzones

libsepol/src/policydb_validate.c

@@ -6,11 +6,19 @@
 #include "debug.h"
 #include "policydb_validate.h"
 
+#define bool_xor(a, b) (!(a) != !(b))
+#define bool_xnor(a, b) !bool_xor(a, b)
+
 typedef struct validate {
 	uint32_t nprim;
 	ebitmap_t gaps;
 } validate_t;
 
+typedef struct map_arg {
+	validate_t *flavors;
+	sepol_handle_t *handle;
+	int mls;
+} map_arg_t;
 
 static int create_gap_ebitmap(char **val_to_name, uint32_t nprim, ebitmap_t *gaps)
 {
@@ -211,6 +219,13 @@ static int validate_class_datum(sepol_handle_t *handle, class_datum_t *class, va
 	return -1;
 }
 
+static int validate_class_datum_wrapper(__attribute__((unused)) hashtab_key_t k, hashtab_datum_t d, void *args)
+{
+	map_arg_t *margs = args;
+
+	return validate_class_datum(margs->handle, d, margs->flavors);
+}
+
 static int validate_role_datum(sepol_handle_t *handle, role_datum_t *role, validate_t flavors[])
 {
 	if (validate_value(role->s.value, &flavors[SYM_ROLES]))
@@ -231,6 +246,13 @@ static int validate_role_datum(sepol_handle_t *handle, role_datum_t *role, valid
 	return -1;
 }
 
+static int validate_role_datum_wrapper(__attribute__((unused)) hashtab_key_t k, hashtab_datum_t d, void *args)
+{
+	map_arg_t *margs = args;
+
+	return validate_role_datum(margs->handle, d, margs->flavors);
+}
+
 static int validate_type_datum(sepol_handle_t *handle, type_datum_t *type, validate_t flavors[])
 {
 	if (validate_value(type->s.value, &flavors[SYM_TYPES]))
@@ -247,6 +269,13 @@ static int validate_type_datum(sepol_handle_t *handle, type_datum_t *type, valid
 	return -1;
 }
 
+static int validate_type_datum_wrapper(__attribute__((unused)) hashtab_key_t k, hashtab_datum_t d, void *args)
+{
+	map_arg_t *margs = args;
+
+	return validate_type_datum(margs->handle, d, margs->flavors);
+}
+
 static int validate_mls_semantic_cat(mls_semantic_cat_t *cat, validate_t *cats)
 {
 	for (; cat; cat = cat->next) {
@@ -310,32 +339,25 @@ static int validate_user_datum(sepol_handle_t *handle, user_datum_t *user, valid
 	return -1;
 }
 
-static int validate_datum_arrays(sepol_handle_t *handle, policydb_t *p, validate_t flavors[])
+static int validate_user_datum_wrapper(__attribute__((unused)) hashtab_key_t k, hashtab_datum_t d, void *args)
+{
+	map_arg_t *margs = args;
+
+	return validate_user_datum(margs->handle, d, margs->flavors);
+}
+
+static int validate_datum_array_gaps(sepol_handle_t *handle, policydb_t *p, validate_t flavors[])
 {
 	unsigned int i;
 
 	for (i = 0; i < p->p_classes.nprim; i++) {
-		if (p->class_val_to_struct[i]) {
-			if (ebitmap_get_bit(&flavors[SYM_CLASSES].gaps, i))
-				goto bad;
-			if (validate_class_datum(handle, p->class_val_to_struct[i], flavors))
-				goto bad;
-		} else {
-			if (!ebitmap_get_bit(&flavors[SYM_CLASSES].gaps, i))
-				goto bad;
-		}
+		if (bool_xnor(p->class_val_to_struct[i], ebitmap_get_bit(&flavors[SYM_CLASSES].gaps, i)))
+			goto bad;
 	}
 
 	for (i = 0; i < p->p_roles.nprim; i++) {
-		if (p->role_val_to_struct[i]) {
-			if (ebitmap_get_bit(&flavors[SYM_ROLES].gaps, i))
-				goto bad;
-			if (validate_role_datum(handle, p->role_val_to_struct[i], flavors))
-				goto bad;
-		} else {
-			if (!ebitmap_get_bit(&flavors[SYM_ROLES].gaps, i))
-				goto bad;
-		}
+		if (bool_xnor(p->role_val_to_struct[i], ebitmap_get_bit(&flavors[SYM_ROLES].gaps, i)))
+			goto bad;
 	}
 
 	/*
@@ -344,34 +366,43 @@ static int validate_datum_arrays(sepol_handle_t *handle, policydb_t *p, validate
 	 */
 	if (p->policyvers < POLICYDB_VERSION_AVTAB || p->policyvers > POLICYDB_VERSION_PERMISSIVE) {
 		for (i = 0; i < p->p_types.nprim; i++) {
-			if (p->type_val_to_struct[i]) {
-				if (ebitmap_get_bit(&flavors[SYM_TYPES].gaps, i))
-					goto bad;
-				if (validate_type_datum(handle, p->type_val_to_struct[i], flavors))
-					goto bad;
-			} else {
-				if (!ebitmap_get_bit(&flavors[SYM_TYPES].gaps, i))
-					goto bad;
-			}
+			if (bool_xnor(p->type_val_to_struct[i], ebitmap_get_bit(&flavors[SYM_TYPES].gaps, i)))
+				goto bad;
 		}
 	}
 
 	for (i = 0; i < p->p_users.nprim; i++) {
-		if (p->user_val_to_struct[i]) {
-			if (ebitmap_get_bit(&flavors[SYM_USERS].gaps, i))
-				goto bad;
-			if (validate_user_datum(handle, p->user_val_to_struct[i], flavors))
-				goto bad;
-		} else {
-			if (!ebitmap_get_bit(&flavors[SYM_USERS].gaps, i))
-				goto bad;
-		}
+		if (bool_xnor(p->user_val_to_struct[i], ebitmap_get_bit(&flavors[SYM_USERS].gaps, i)))
+			goto bad;
 	}
 
 	return 0;
 
 bad:
-	ERR(handle, "Invalid datum arrays");
+	ERR(handle, "Invalid datum array gaps");
+	return -1;
+}
+
+static int validate_datum_array_entries(sepol_handle_t *handle, policydb_t *p, validate_t flavors[])
+{
+	map_arg_t margs = { flavors, handle, p->mls };
+
+	if (hashtab_map(p->p_classes.table, validate_class_datum_wrapper, &margs))
+		goto bad;
+
+	if (hashtab_map(p->p_roles.table, validate_role_datum_wrapper, &margs))
+		goto bad;
+
+	if (hashtab_map(p->p_types.table, validate_type_datum_wrapper, &margs))
+		goto bad;
+
+	if (hashtab_map(p->p_users.table, validate_user_datum_wrapper, &margs))
+		goto bad;
+
+	return 0;
+
+bad:
+	ERR(handle, "Invalid datum array entries");
 	return -1;
 }
 
@@ -762,7 +793,10 @@ int validate_policydb(sepol_handle_t *handle, policydb_t *p)
 	if (validate_scopes(handle, p->scope, p->global))
 		goto bad;
 
-	if (validate_datum_arrays(handle, p, flavors))
+	if (validate_datum_array_gaps(handle, p, flavors))
+		goto bad;
+
+	if (validate_datum_array_entries(handle, p, flavors))
 		goto bad;
 
 	validate_array_destroy(flavors);