uas: Add uas_find_endpoints() helper function

This is a preparation patch for adding better descriptor validation.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>

diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c
index e817e72d86732faf490033d6af67371ecbbfd4e9..1ac66f290fbf7db62e49c61be96c6016638deb95 100644 (file)
--- a/drivers/usb/storage/uas.c
+++ b/drivers/usb/storage/uas.c
@@ -898,16 +898,11 @@ static int uas_switch_interface(struct usb_device *udev,
                        intf->altsetting[0].desc.bInterfaceNumber, alt);
 }
 
-static void uas_configure_endpoints(struct uas_dev_info *devinfo)
+static int uas_find_endpoints(struct usb_host_interface *alt,
+                             struct usb_host_endpoint *eps[])
 {
-       struct usb_host_endpoint *eps[4] = { };
-       struct usb_interface *intf = devinfo->intf;
-       struct usb_device *udev = devinfo->udev;
-       struct usb_host_endpoint *endpoint = intf->cur_altsetting->endpoint;
-       unsigned i, n_endpoints = intf->cur_altsetting->desc.bNumEndpoints;
-
-       devinfo->uas_sense_old = 0;
-       devinfo->cmnd = NULL;
+       struct usb_host_endpoint *endpoint = alt->endpoint;
+       unsigned i, n_endpoints = alt->desc.bNumEndpoints;
 
        for (i = 0; i < n_endpoints; i++) {
                unsigned char *extra = endpoint[i].extra;
@@ -924,12 +919,29 @@ static void uas_configure_endpoints(struct uas_dev_info *devinfo)
                }
        }
 
+       if (!eps[0] || !eps[1] || !eps[2] || !eps[3])
+               return -ENODEV;
+
+       return 0;
+}
+
+static void uas_configure_endpoints(struct uas_dev_info *devinfo)
+{
+       struct usb_host_endpoint *eps[4] = { };
+       struct usb_device *udev = devinfo->udev;
+       int r;
+
+       devinfo->uas_sense_old = 0;
+       devinfo->cmnd = NULL;
+
+       r = uas_find_endpoints(devinfo->intf->cur_altsetting, eps);
+
        /*
-        * Assume that if we didn't find a control pipe descriptor, we're
+        * Assume that if we didn't find a proper set of descriptors, we're
         * using a device with old firmware that happens to be set up like
         * this.
         */
-       if (!eps[0]) {
+       if (r != 0) {
                devinfo->cmd_pipe = usb_sndbulkpipe(udev, 1);
                devinfo->status_pipe = usb_rcvbulkpipe(udev, 1);
                devinfo->data_in_pipe = usb_rcvbulkpipe(udev, 2);