From 393cbb5151ecda9f9e14e3082d048dd27a1ff9f6 Mon Sep 17 00:00:00 2001 From: Matthias Dellweg <2500@gmx.de> Date: Sun, 25 Sep 2011 14:26:25 +0200 Subject: [PATCH] usb/core/devio.c: Check for printer class specific request 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 Signed-off-by: Matthias Dellweg <2500@gmx.de> Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/devio.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c index eea53ebe6706..0ca54e22d319 100644 --- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -609,9 +609,10 @@ static int findintfep(struct usb_device *dev, unsigned int ep) } 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 @@ -620,6 +621,19 @@ static int check_ctrlrecip(struct dev_state *ps, unsigned int requesttype, 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: @@ -772,7 +786,8 @@ static int proc_control(struct dev_state *ps, void __user *arg) 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 */ @@ -1102,7 +1117,7 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb, 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); -- 2.30.2