[PATCH] qom: Check for wellformed id in user_creatable_add_type()

[Kevin Wolf <kwolf@redhat.com>]

Most code paths for creating a user creatable object go through
QemuOpts, which ensures that the provided 'id' option is actually a
valid identifier.

However, there are some code paths that don't go through QemuOpts:
qemu-storage-daemon --object (since commit 8db1efd3) and QMP object-add
(since it was first introduced in commit cff8b2c6). We need to have the
same validity check for those, too.

This adds the check and makes it print the same error message as
QemuOpts on failure.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
This makes sense even without the -object QAPIfication, so no reason to
wait for v3 of that series to get this fixed.

 qom/object_interfaces.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/qom/object_interfaces.c b/qom/object_interfaces.c
index 1e9ad6f08a..515ca4557e 100644
--- a/qom/object_interfaces.c
+++ b/qom/object_interfaces.c
@@ -8,6 +8,7 @@
 #include "qapi/qobject-input-visitor.h"
 #include "qom/object_interfaces.h"
 #include "qemu/help_option.h"
+#include "qemu/id.h"
 #include "qemu/module.h"
 #include "qemu/option.h"
 #include "qapi/opts-visitor.h"
@@ -41,11 +42,19 @@ Object *user_creatable_add_type(const char *type, const char *id,
                                 const QDict *qdict,
                                 Visitor *v, Error **errp)
 {
+    ERRP_GUARD();
     Object *obj;
     ObjectClass *klass;
     const QDictEntry *e;
     Error *local_err = NULL;
 
+    if (!id_wellformed(id)) {
+        error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "id", "an identifier");
+        error_append_hint(errp, "Identifiers consist of letters, digits, "
+                          "'-', '.', '_', starting with a letter.\n");
+        return NULL;
+    }
+
     klass = object_class_by_name(type);
     if (!klass) {
         error_setg(errp, "invalid object type: %s", type);
-- 
2.29.2