usb: usbtest: support usb2 extension descriptor test

In Test 9 of usbtest module, it is used for performing chapter 9 tests N
times.

USB2.0 Extension descriptor is one of the generic device-level capbility
descriptors which added in section 9.6.2.1 of USB 3.0 spec.

This patch adds to support getting usb2.0 extension descriptor test
scenario for USB 3.0.

Signed-off-by: Huang Rui <ray.huang@amd.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 77 insertions, 0 deletions

diff --git a/drivers/usb/misc/usbtest.c b/drivers/usb/misc/usbtest.c
index e7235d5cce85..1c78e747f72b 100644
--- a/drivers/usb/misc/usbtest.c
+++ b/drivers/usb/misc/usbtest.c
@@ -606,6 +606,28 @@ static int is_good_config(struct usbtest_dev *tdev, int len)
         return 0;
 }
 
+static int is_good_ext(struct usbtest_dev *tdev, u8 *buf)
+{
+        struct usb_ext_cap_descriptor *ext;
+        u32 attr;
+
+        ext = (struct usb_ext_cap_descriptor *) buf;
+
+        if (ext->bLength != USB_DT_USB_EXT_CAP_SIZE) {
+                ERROR(tdev, "bogus usb 2.0 extension descriptor length\n");
+                return 0;
+        }
+
+        attr = le32_to_cpu(ext->bmAttributes);
+        /* bits[1:4] is used and others are reserved */
+        if (attr & ~0x1e) {     /* reserved == 0 */
+                ERROR(tdev, "reserved bits set\n");
+                return 0;
+        }
+
+        return 1;
+}
+
 /* sanity test for standard requests working with usb_control_mesg() and some
  * of the utility functions which use it.
  *
@@ -694,12 +716,67 @@ static int ch9_postconfig(struct usbtest_dev *dev)
          * 3.0 spec
          */
         if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0300) {
+                struct usb_bos_descriptor *bos = NULL;
+                struct usb_dev_cap_header *header = NULL;
+                unsigned total, num, length;
+                u8 *buf;
+
                 retval = usb_get_descriptor(udev, USB_DT_BOS, 0, dev->buf,
                                 sizeof(*udev->bos->desc));
                 if (retval != sizeof(*udev->bos->desc)) {
                         dev_err(&iface->dev, "bos descriptor --> %d\n", retval);
                         return (retval < 0) ? retval : -EDOM;
                 }
+
+                bos = (struct usb_bos_descriptor *)dev->buf;
+                total = le16_to_cpu(bos->wTotalLength);
+                num = bos->bNumDeviceCaps;
+
+                if (total > TBUF_SIZE)
+                        total = TBUF_SIZE;
+
+                /*
+                 * get generic device-level capability descriptors [9.6.2]
+                 * in USB 3.0 spec
+                 */
+                retval = usb_get_descriptor(udev, USB_DT_BOS, 0, dev->buf,
+                                total);
+                if (retval != total) {
+                        dev_err(&iface->dev, "bos descriptor set --> %d\n",
+                                        retval);
+                        return (retval < 0) ? retval : -EDOM;
+                }
+
+                length = sizeof(*udev->bos->desc);
+                buf = dev->buf;
+                for (i = 0; i < num; i++) {
+                        buf += length;
+                        if (buf + sizeof(struct usb_dev_cap_header) >
+                                        dev->buf + total)
+                                break;
+
+                        header = (struct usb_dev_cap_header *)buf;
+                        length = header->bLength;
+
+                        if (header->bDescriptorType !=
+                                        USB_DT_DEVICE_CAPABILITY) {
+                                dev_warn(&udev->dev, "not device capability descriptor, skip\n");
+                                continue;
+                        }
+
+                        switch (header->bDevCapabilityType) {
+                        case USB_CAP_TYPE_EXT:
+                                if (buf + USB_DT_USB_EXT_CAP_SIZE >
+                                                dev->buf + total ||
+                                                !is_good_ext(dev, buf)) {
+                                        dev_err(&iface->dev, "bogus usb 2.0 extension descriptor\n");
+                                        return -EDOM;
+                                }
+                                break;
+                        default:
+                                break;
+                        }
+                }
         }
 
         /* there's always [9.4.3] at least one config descriptor [9.6.3] */