usb/core/devio.c: Check for printer class specific request
commit 393cbb5151ecda9f9e14e3082d048dd27a1ff9f6 upstream.
In the usb printer class specific request get_device_id the value of
wIndex is (interface << 8 | altsetting) instead of just interface.
This enables the detection of some printers with libusb.
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Matthias Dellweg <2500@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index 37518df..1d73709 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -607,9 +607,10 @@
}
static int check_ctrlrecip(struct dev_state *ps, unsigned int requesttype,
- unsigned int index)
+ unsigned int request, unsigned int index)
{
int ret = 0;
+ struct usb_host_interface *alt_setting;
if (ps->dev->state != USB_STATE_UNAUTHENTICATED
&& ps->dev->state != USB_STATE_ADDRESS
@@ -618,6 +619,19 @@
if (USB_TYPE_VENDOR == (USB_TYPE_MASK & requesttype))
return 0;
+ /*
+ * check for the special corner case 'get_device_id' in the printer
+ * class specification, where wIndex is (interface << 8 | altsetting)
+ * instead of just interface
+ */
+ if (requesttype == 0xa1 && request == 0) {
+ alt_setting = usb_find_alt_setting(ps->dev->actconfig,
+ index >> 8, index & 0xff);
+ if (alt_setting
+ && alt_setting->desc.bInterfaceClass == USB_CLASS_PRINTER)
+ index >>= 8;
+ }
+
index &= 0xff;
switch (requesttype & USB_RECIP_MASK) {
case USB_RECIP_ENDPOINT:
@@ -770,7 +784,8 @@
if (copy_from_user(&ctrl, arg, sizeof(ctrl)))
return -EFAULT;
- ret = check_ctrlrecip(ps, ctrl.bRequestType, ctrl.wIndex);
+ ret = check_ctrlrecip(ps, ctrl.bRequestType, ctrl.bRequest,
+ ctrl.wIndex);
if (ret)
return ret;
wLength = ctrl.wLength; /* To suppress 64k PAGE_SIZE warning */
@@ -1100,7 +1115,7 @@
kfree(dr);
return -EINVAL;
}
- ret = check_ctrlrecip(ps, dr->bRequestType,
+ ret = check_ctrlrecip(ps, dr->bRequestType, dr->bRequest,
le16_to_cpup(&dr->wIndex));
if (ret) {
kfree(dr);