I am currently in the process of developing a DEXT for a USB based external mass storage device using the USBDriverKit framework. IOUSBHostInterface is used as the provider to communicate with the interface's endpoints and I am successful in it. As per the IOUSBHostInterface documentation, To use a host interface object, call Open to create a new session between the interface and your driver. After successfully opening your session, you can request information from the interface and set up pipes to communicate with the interface's endpoints. Remember to close the session you opened in the Stop method of your driver. However, calling Open gains exclusive access to the USB interface and does not allow other services to access the interface. Also, to let go of the exclusive access, Close method can be called but in the Stop method which is called only once during the lifecycle of the extension (when the DEXT is unloaded). As a result of this, Apple's mass storage related KEXTs (media and partition related specifically) do not match the interface and so the filesystem of the drive in question does not get mounted whenever the DEXT has matched the interface. Is this exclusive access a limitation of USBDriverkit or is there any way to get around this issue in this case?

I have developed a kernel extension (KEXT) for driving SCSI devices and I am able to successfully use it to send commands to the underlying device. The driver class overrides the newUserClient method which gets called whenever IOServiceOpen is called from the user space so that apps can make use of the driver. Is there any way to restrict access to this kernel extension such that only my app would be able to open a user client to access the driver and communicate with it using IOConnectCallMethod?