On Sun, 24 May 2009, Josua Dietze wrote:
> Some unusual usb devices from the maker "Option" are switched from storage to serial/modem mode by sending a SCSI REZERO command. In one case a fairly common vendor/device ID is affected which led to
> problems for users of other modems or phones which are not supposed to be switched.
> The patch adds a filter by reading the vendor name with the SCSI INQUIRY command, and skips the switching code for all unrecognized entries.
>
> Further changes are cleanups and corrections pointed out by Alan Stern.
>
> Tested with two devices with the IDs 05c6:1000, one from "Option" and switchable, and one from Samsung (cell phone).
>
> Patch is against 2.6.30-rc6
>
> ---------------
>
> Signed-off-by: Josua Dietze <digidietze@xxxxxxxxxxxxxxx>
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
> diff -upNr linux-2.6.30-rc6.orig/drivers/usb/storage/option_ms.c linux-2.6.30-rc6.new/drivers/usb/storage/option_ms.c
> --- linux-2.6.30-rc6.orig/drivers/usb/storage/option_ms.c 2009-05-16 06:12:57.000000000 +0200
> +++ linux-2.6.30-rc6.new/drivers/usb/storage/option_ms.c 2009-05-24 23:08:36.000000000 +0200
> @@ -37,7 +37,7 @@ MODULE_PARM_DESC(option_zero_cd, "ZeroCD
>
> #define RESPONSE_LEN 1024
>
> -static int option_rezero(struct us_data *us, int ep_in, int ep_out)
> +static int option_rezero(struct us_data *us)
> {
> const unsigned char rezero_msg[] = {
> 0x55, 0x53, 0x42, 0x43, 0x78, 0x56, 0x34, 0x12,
> @@ -54,10 +54,10 @@ static int option_rezero(struct us_data
> if (buffer == NULL)
> return USB_STOR_TRANSPORT_ERROR;
>
> - memcpy(buffer, rezero_msg, sizeof (rezero_msg));
> + memcpy(buffer, rezero_msg, sizeof(rezero_msg));
> result = usb_stor_bulk_transfer_buf(us,
> - usb_sndbulkpipe(us->pusb_dev, ep_out),
> - buffer, sizeof (rezero_msg), NULL);
> + us->send_bulk_pipe,
> + buffer, sizeof(rezero_msg), NULL);
> if (result != USB_STOR_XFER_GOOD) {
> result = USB_STOR_XFER_ERROR;
> goto out;
> @@ -66,9 +66,15 @@ static int option_rezero(struct us_data
> /* Some of the devices need to be asked for a response, but we don't
> * care what that response is.
> */
> - result = usb_stor_bulk_transfer_buf(us,
> - usb_sndbulkpipe(us->pusb_dev, ep_out),
> + usb_stor_bulk_transfer_buf(us,
> + us->recv_bulk_pipe,
> buffer, RESPONSE_LEN, NULL);
> +
> + /* Read the CSW */
> + usb_stor_bulk_transfer_buf(us,
> + us->recv_bulk_pipe,
> + buffer, 13, NULL);
> +
> result = USB_STOR_XFER_GOOD;
>
> out:
> @@ -76,63 +82,75 @@ out:
> return result;
> }
>
> -int option_ms_init(struct us_data *us)
> +static int option_inquiry(struct us_data *us)
> {
> - struct usb_device *udev;
> - struct usb_interface *intf;
> - struct usb_host_interface *iface_desc;
> - struct usb_endpoint_descriptor *endpoint = NULL;
> - u8 ep_in = 0, ep_out = 0;
> - int ep_in_size = 0, ep_out_size = 0;
> - int i, result;
> -
> - udev = us->pusb_dev;
> - intf = us->pusb_intf;
> + const unsigned char inquiry_msg[] = {
> + 0x55, 0x53, 0x42, 0x43, 0x12, 0x34, 0x56, 0x78,
> + 0x24, 0x00, 0x00, 0x00, 0x80, 0x00, 0x06, 0x12,
> + 0x00, 0x00, 0x00, 0x24, 0x00, 0x00, 0x00, 0x00,
> + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
> + };
> + char *buffer;
> + int result;
>
> - /* Ensure it's really a ZeroCD device; devices that are already
> - * in modem mode return 0xFF for class, subclass, and protocol.
> - */
> - if (udev->descriptor.bDeviceClass != 0 ||
> - udev->descriptor.bDeviceSubClass != 0 ||
> - udev->descriptor.bDeviceProtocol != 0)
> - return USB_STOR_TRANSPORT_GOOD;
> + US_DEBUGP("Option MS: %s", "device inquiry for vendor name\n");
>
> - US_DEBUGP("Option MS: option_ms_init called\n");
> + buffer = kzalloc(0x24, GFP_KERNEL);
> + if (buffer == NULL)
> + return USB_STOR_TRANSPORT_ERROR;
>
> - /* Find the right mass storage interface */
> - iface_desc = intf->cur_altsetting;
> - if (iface_desc->desc.bInterfaceClass != 0x8 ||
> - iface_desc->desc.bInterfaceSubClass != 0x6 ||
> - iface_desc->desc.bInterfaceProtocol != 0x50) {
> - US_DEBUGP("Option MS: mass storage interface not found, no action "
> - "required\n");
> - return USB_STOR_TRANSPORT_GOOD;
> + memcpy(buffer, inquiry_msg, sizeof(inquiry_msg));
> + result = usb_stor_bulk_transfer_buf(us,
> + us->send_bulk_pipe,
> + buffer, sizeof(inquiry_msg), NULL);
> + if (result != USB_STOR_XFER_GOOD) {
> + result = USB_STOR_XFER_ERROR;
> + goto out;
> }
>
> - /* Find the mass storage bulk endpoints */
> - for (i = 0; i < iface_desc->desc.bNumEndpoints && (!ep_in_size || !ep_out_size); ++i) {
> - endpoint = &iface_desc->endpoint[i].desc;
> -
> - if (usb_endpoint_is_bulk_in(endpoint)) {
> - ep_in = usb_endpoint_num(endpoint);
> - ep_in_size = le16_to_cpu(endpoint->wMaxPacketSize);
> - } else if (usb_endpoint_is_bulk_out(endpoint)) {
> - ep_out = usb_endpoint_num(endpoint);
> - ep_out_size = le16_to_cpu(endpoint->wMaxPacketSize);
> - }
> + result = usb_stor_bulk_transfer_buf(us,
> + us->recv_bulk_pipe,
> + buffer, 0x24, NULL);
> + if (result != USB_STOR_XFER_GOOD) {
> + result = USB_STOR_XFER_ERROR;
> + goto out;
> }
>
> - /* Can't find the mass storage endpoints */
> - if (!ep_in_size || !ep_out_size) {
> - US_DEBUGP("Option MS: mass storage endpoints not found, no action "
> - "required\n");
> - return USB_STOR_TRANSPORT_GOOD;
> - }
> + result = memcmp(buffer+8, "Option", 6);
> +
> + /* Read the CSW */
> + usb_stor_bulk_transfer_buf(us,
> + us->recv_bulk_pipe,
> + buffer, 13, NULL);
> +
> +out:
> + kfree(buffer);
> + return result;
> +}
> +
> +
> +int option_ms_init(struct us_data *us)
> +{
> + int result;
> +
> + US_DEBUGP("Option MS: option_ms_init called\n");
> +
> + /* Additional test for vendor information via INQUIRY,
> + * because some vendor/product IDs are ambiguous
> + */
> + result = option_inquiry(us);
> + if (result != 0) {
> + US_DEBUGP("Option MS: vendor is not Option or not determinable,"
> + " no action taken\n");
> + return 0;
> + } else
> + US_DEBUGP("Option MS: this is a genuine Option device,"
> + " proceeding\n");
>
> /* Force Modem mode */
> if (option_zero_cd == ZCD_FORCE_MODEM) {
> US_DEBUGP("Option MS: %s", "Forcing Modem Mode\n");
> - result = option_rezero(us, ep_in, ep_out);
> + result = option_rezero(us);
> if (result != USB_STOR_XFER_GOOD)
> US_DEBUGP("Option MS: Failed to switch to modem mode.\n");
> return -EIO;
> @@ -142,6 +160,5 @@ int option_ms_init(struct us_data *us)
> " requests it\n");
> }
>
> - return USB_STOR_TRANSPORT_GOOD;
> + return 0;
> }
> -
>
>
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