Make dbus_type_is_valid into public API

This is just as useful for bindings as dbus_signature_validate, and I
think it's a good design principle to say that anything checked in a
_dbus_return_if_fail should be something the caller could check
for themselves.

Bug: https://bugs.freedesktop.org/show_bug.cgi?id=20496
Reviewed-by: Will Thompson <will.thompson@collabora.co.uk>

1 files changed, 47 insertions, 6 deletions

diff --git a/dbus/dbus-signature.c b/dbus/dbus-signature.c
index 9c13ff43..c130de5b 100644
--- a/dbus/dbus-signature.c
+++ b/dbus/dbus-signature.c
@@ -284,7 +284,8 @@ dbus_signature_validate_single (const char       *signature,
  * container types. #DBUS_TYPE_INVALID is not a container type.
  *
  * It is an error to pass an invalid type-code, other than DBUS_TYPE_INVALID,
- * to this function. The valid type-codes are defined by dbus-protocol.h.
+ * to this function. The valid type-codes are defined by dbus-protocol.h
+ * and can be checked with dbus_type_is_valid().
  *
  * @param typecode either a valid type-code or DBUS_TYPE_INVALID
  * @returns #TRUE if type is a container
@@ -293,7 +294,7 @@ dbus_bool_t
 dbus_type_is_container (int typecode)
 {
   /* only reasonable (non-line-noise) typecodes are allowed */
-  _dbus_return_val_if_fail (_dbus_type_is_valid (typecode) || typecode == DBUS_TYPE_INVALID,
+  _dbus_return_val_if_fail (dbus_type_is_valid (typecode) || typecode == DBUS_TYPE_INVALID,
 			    FALSE);
   return TYPE_IS_CONTAINER (typecode);
 }
@@ -307,7 +308,8 @@ dbus_type_is_container (int typecode)
  * type.
  *
  * It is an error to pass an invalid type-code, other than DBUS_TYPE_INVALID,
- * to this function. The valid type-codes are defined by dbus-protocol.h.
+ * to this function. The valid type-codes are defined by dbus-protocol.h
+ * and can be checked with dbus_type_is_valid().
  *
  * @param typecode either a valid type-code or DBUS_TYPE_INVALID
  * @returns #TRUE if type is basic
@@ -316,7 +318,7 @@ dbus_bool_t
 dbus_type_is_basic (int typecode)
 {
   /* only reasonable (non-line-noise) typecodes are allowed */
-  _dbus_return_val_if_fail (_dbus_type_is_valid (typecode) || typecode == DBUS_TYPE_INVALID,
+  _dbus_return_val_if_fail (dbus_type_is_valid (typecode) || typecode == DBUS_TYPE_INVALID,
 			    FALSE);
 
   /* everything that isn't invalid or a container */
@@ -337,7 +339,8 @@ dbus_type_is_basic (int typecode)
  * function.
  *
  * It is an error to pass an invalid type-code, other than DBUS_TYPE_INVALID,
- * to this function. The valid type-codes are defined by dbus-protocol.h.
+ * to this function. The valid type-codes are defined by dbus-protocol.h
+ * and can be checked with dbus_type_is_valid().
  *
  * @param typecode either a valid type-code or DBUS_TYPE_INVALID
  * @returns #FALSE if the type can occupy different lengths
@@ -346,7 +349,7 @@ dbus_bool_t
 dbus_type_is_fixed (int typecode)
 {
   /* only reasonable (non-line-noise) typecodes are allowed */
-  _dbus_return_val_if_fail (_dbus_type_is_valid (typecode) || typecode == DBUS_TYPE_INVALID,
+  _dbus_return_val_if_fail (dbus_type_is_valid (typecode) || typecode == DBUS_TYPE_INVALID,
 			    FALSE);
   
   switch (typecode)
@@ -367,6 +370,44 @@ dbus_type_is_fixed (int typecode)
     }
 }
 
+/**
+ * Return #TRUE if the argument is a valid typecode.
+ * #DBUS_TYPE_INVALID surprisingly enough is not considered valid, and
+ * random unknown bytes aren't either. This function is safe with
+ * untrusted data.
+ *
+ * @param typecode a potential type-code
+ * @returns #TRUE if valid
+ */
+dbus_bool_t
+dbus_type_is_valid (int typecode)
+{
+  switch (typecode)
+    {
+    case DBUS_TYPE_BYTE:
+    case DBUS_TYPE_BOOLEAN:
+    case DBUS_TYPE_INT16:
+    case DBUS_TYPE_UINT16:
+    case DBUS_TYPE_INT32:
+    case DBUS_TYPE_UINT32:
+    case DBUS_TYPE_INT64:
+    case DBUS_TYPE_UINT64:
+    case DBUS_TYPE_DOUBLE:
+    case DBUS_TYPE_STRING:
+    case DBUS_TYPE_OBJECT_PATH:
+    case DBUS_TYPE_SIGNATURE:
+    case DBUS_TYPE_ARRAY:
+    case DBUS_TYPE_STRUCT:
+    case DBUS_TYPE_DICT_ENTRY:
+    case DBUS_TYPE_VARIANT:
+    case DBUS_TYPE_UNIX_FD:
+      return TRUE;
+
+    default:
+      return FALSE;
+    }
+}
+
 /** @} */ /* end of DBusSignature group */
 
 #ifdef DBUS_BUILD_TESTS