Add routines to validate D-Bus signature in QtDBus

2 files changed, 97 insertions, 2 deletions

diff --git a/src/dbus/qdbusutil.cpp b/src/dbus/qdbusutil.cpp
index 844af9a..a4bd168 100644
--- a/src/dbus/qdbusutil.cpp
+++ b/src/dbus/qdbusutil.cpp
@@ -238,6 +238,68 @@ bool argToString(const QDBusArgument &busArg, QString &out)
     return true;
 }
 
+//------- D-Bus Types --------
+static const char oneLetterTypes[] = "vsogybnqiuxtdh";
+static const char basicTypes[] =      "sogybnqiuxtdh";
+static const char fixedTypes[] =         "ybnqiuxtdh";
+
+static bool isBasicType(int c)
+{
+    return c != DBUS_TYPE_INVALID && strchr(basicTypes, c) != NULL;
+}
+
+static bool isFixedType(int c)
+{
+    return c != DBUS_TYPE_INVALID && strchr(fixedTypes, c) != NULL;
+}
+
+// Returns a pointer to one-past-end of this type if it's valid;
+// returns NULL if it isn't valid.
+static const char *validateSingleType(const char *signature)
+{
+    register char c = *signature;
+    if (c == DBUS_TYPE_INVALID)
+        return false;
+
+    // is it one of the one-letter types?
+    if (strchr(oneLetterTypes, c) != NULL)
+        return signature + 1;
+
+    // is it an array?
+    if (c == DBUS_TYPE_ARRAY) {
+        // then it's valid if the next type is valid
+        // or if it's a dict-entry
+        c = *++signature;
+        if (c == DBUS_DICT_ENTRY_BEGIN_CHAR) {
+            // beginning of a dictionary entry
+            // a dictionary entry has a key which is of basic types
+            // and a free value
+            c = *++signature;
+            if (!isBasicType(c))
+                return 0;
+            signature = validateSingleType(signature + 1);
+            return signature && *signature == DBUS_DICT_ENTRY_END_CHAR ? signature + 1 : 0;
+        }
+
+        return validateSingleType(signature);
+    }
+
+    if (c == DBUS_STRUCT_BEGIN_CHAR) {
+        // beginning of a struct
+        ++signature;
+        while (true) {
+            signature = validateSingleType(signature);
+            if (!signature)
+                return 0;
+            if (*signature == DBUS_STRUCT_END_CHAR)
+                return signature + 1;
+        }
+    }
+
+    // invalid/unknown type
+    return 0;
+}
+
 /*!
     \namespace QDBusUtil
     \inmodule QtDBus
@@ -447,6 +509,25 @@ namespace QDBusUtil
     }
 
     /*!
+        \fn bool QDBusUtil::isValidBasicType(int type)
+        Returns true if \a c is a valid, basic D-Bus type.
+     */
+    bool isValidBasicType(int c)
+    {
+        return isBasicType(c);
+    }
+
+    /*!
+        \fn bool QDBusUtil::isValidFixedType(int type)
+        Returns true if \a c is a valid, fixed D-Bus type.
+     */
+    bool isValidFixedType(int c)
+    {
+        return isFixedType(c);
+    }
+
+
+    /*!
         \fn bool QDBusUtil::isValidSignature(const QString &signature)
         Returns true if \a signature is a valid D-Bus type signature for one or more types.
         This function returns true if it can all of \a signature into valid, individual types and no
@@ -456,7 +537,15 @@ namespace QDBusUtil
     */
     bool isValidSignature(const QString &signature)
     {
-        return q_dbus_signature_validate(signature.toUtf8(), 0);
+        QByteArray ba = signature.toLatin1();
+        const char *data = ba.constData();
+        while (true) {
+            data = validateSingleType(data);
+            if (!data)
+                return false;
+            if (*data == '\0')
+                return true;
+        }
     }
 
     /*!
@@ -467,7 +556,9 @@ namespace QDBusUtil
     */
     bool isValidSingleSignature(const QString &signature)
     {
-        return q_dbus_signature_validate_single(signature.toUtf8(), 0);
+        QByteArray ba = signature.toLatin1();
+        const char *data = validateSingleType(ba.constData());
+        return data && *data == '\0';
     }
 
 } // namespace QDBusUtil
diff --git a/src/dbus/qdbusutil_p.h b/src/dbus/qdbusutil_p.h
index 3721e98..24b5cea 100644
--- a/src/dbus/qdbusutil_p.h
+++ b/src/dbus/qdbusutil_p.h
@@ -81,6 +81,10 @@ namespace QDBusUtil
 
     Q_DBUS_EXPORT bool isValidObjectPath(const QString &path);
 
+    Q_DBUS_EXPORT bool isValidFixedType(int c);
+
+    Q_DBUS_EXPORT bool isValidBasicType(int c);
+
     Q_DBUS_EXPORT bool isValidSignature(const QString &signature);
 
     Q_DBUS_EXPORT bool isValidSingleSignature(const QString &signature);