qom: Check for wellformed id in user_creatable_add_type()

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>
Message-Id: <20210302171623.49709-1-kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/qom/object_interfaces.c b/qom/object_interfaces.c
index 1e9ad6f08a..7661270b98 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 != NULL && !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);