Re: [PATCH] enable usb control message with class specific request

From: Alan Stern
Date: Fri Sep 23 2011 - 14:31:42 EST


On Fri, 23 Sep 2011, Matthias Dellweg wrote:

> Am Fri, 23 Sep 2011 12:16:40 -0400 (EDT)
> schrieb Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>:
> > This is basically okay. But your mailer has mangled the whitespace.
> > [...]
> > Alan Stern
>
> OK, hoping that my mailer doesn't get wild again, this is the polished version
> following your suggestions.
> Thanks for your help!
> Matthias Dellweg
>
> From b7c4b6f5780296fd0d53d66e08d5bce0dc450b7f Mon Sep 17 00:00:00 2001
> From: Matthias Dellweg <2500@xxxxxx>
> Date: Fri, 23 Sep 2011 19:32:39 +0200
> Subject: [PATCH] drivers/usb/core/devio.c: Check for printer class specific
> request
>
> Signed-off-by: Matthias Dellweg <2500@xxxxxx>
> ---
> drivers/usb/core/devio.c | 20 +++++++++++++++++---
> 1 files changed, 17 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
> index 37518df..e4175cc 100644
> --- a/drivers/usb/core/devio.c
> +++ b/drivers/usb/core/devio.c
> @@ -607,9 +607,10 @@ 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
> @@ -618,6 +619,18 @@ 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)
> + */
> + 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 +783,8 @@ 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 */
> @@ -1100,7 +1114,7 @@ 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);
>

This looks fine to me. Greg may ask you for a non-empty patch
description when you submit it to him.

Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>

Alan Stern

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