Hi,
I've done my homework the best i can, so here it is.
This patch add a serial number parameter to the g_file_storage
module. There's validity checks against the string passed to comply
with the specs.
It's against a linux-next git clone.
A remaining question about the serial number :
The fallback serial may not be ok if DRIVER_VERSION isn't long enough, and it is
in fact hardcoded. What if 2 devices are used, as they should have unique serial ?
Should it be randomized ?
I also note a kernel oops after inserting/removing the module several times (even
with the vanilla code). Does it need to be investigated ?
BTW : Thanks to Michal for his coding lesson :)
Signed-off-by: Yann Cantin <yann.cantin@xxxxxxxxxxx>
---
drivers/usb/gadget/file_storage.c | 71 ++++++++++++++++++++++++++++++------
1 files changed, 59 insertions(+), 12 deletions(-)
diff --git a/drivers/usb/gadget/file_storage.c b/drivers/usb/gadget/file_storage.c
index b49d86e..9e18cc2 100644
--- a/drivers/usb/gadget/file_storage.c
+++ b/drivers/usb/gadget/file_storage.c
@@ -56,7 +56,7 @@
* following protocols: RBC (0x01), ATAPI or SFF-8020i (0x02), QIC-157 (0c03),
* UFI (0x04), SFF-8070i (0x05), and transparent SCSI (0x06), selected by
* the optional "protocol" module parameter. In addition, the default
- * Vendor ID, Product ID, and release number can be overridden.
+ * Vendor ID, Product ID, release number and serial number can be overridden.
*
* There is support for multiple logical units (LUNs), each of which has
* its own backing file. The number of LUNs can be set using the optional
@@ -106,6 +106,7 @@
* vendor=0xVVVV Default 0x0525 (NetChip), USB Vendor ID
* product=0xPPPP Default 0xa4a5 (FSG), USB Product ID
* release=0xRRRR Override the USB release number (bcdDevice)
+ * serial=HHHH... Override serial number (string of hex chars)
* buflen=N Default N=16384, buffer size used (will be
* rounded down to a multiple of
* PAGE_CACHE_SIZE)
@@ -274,7 +275,7 @@
static char fsg_string_manufacturer[64];
static const char fsg_string_product[] = DRIVER_DESC;
-static char fsg_string_serial[13];
+static char fsg_string_serial[25];
static const char fsg_string_config[] = "Self-powered";
static const char fsg_string_interface[] = "Mass Storage";
@@ -314,6 +315,7 @@ static struct {
unsigned short vendor;
unsigned short product;
unsigned short release;
+ char *serial_parm;
unsigned int buflen;
int transport_type;
@@ -330,6 +332,7 @@ static struct {
.vendor = FSG_VENDOR_ID,
.product = FSG_PRODUCT_ID,
.release = 0xffff, // Use controller chip type
+ .serial_parm = NULL,
.buflen = 16384,
};
@@ -374,6 +377,9 @@ MODULE_PARM_DESC(product, "USB Product ID");
module_param_named(release, mod_data.release, ushort, S_IRUGO);
MODULE_PARM_DESC(release, "USB release number");
+module_param_named(serial, mod_data.serial_parm, charp, S_IRUGO);
+MODULE_PARM_DESC(serial, "USB serial number");
+
module_param_named(buflen, mod_data.buflen, uint, S_IRUGO);
MODULE_PARM_DESC(buflen, "I/O buffer size");
@@ -3197,6 +3203,7 @@ static int __init check_parameters(struct fsg_dev *fsg)
{
int prot;
int gcnum;
+ int i;
/* Store the default values */
mod_data.transport_type = USB_PR_BULK;
@@ -3272,6 +3279,56 @@ static int __init check_parameters(struct fsg_dev *fsg)
ERROR(fsg, "invalid buflen\n");
return -ETOOSMALL;
}
+
+ /* Serial string handling.
+ * On a real device, fsg_string_serial[] would be loaded
+ * from permanent storage. */
+ memset(&fsg_string_serial, 0, sizeof fsg_string_serial);
+ if (mod_data.serial_parm) {
+ const char *ch;
+ unsigned len = 0;
+
+ /* Sanity check :
+ * The CB[I] specification limits the serial string to
+ * 12 uppercase hexadecimal characters.
+ * BBB need *at least* 12 uppercase hexadecimal characters.
+ * (Usb sticks use 24 uppercase hexadecimal characters). */
+ len = strlen(mod_data.serial_parm);
+ if (len >= sizeof fsg_string_serial ||
+ (mod_data.transport_type == USB_PR_BULK && len < 12) ||
+ (mod_data.transport_type != USB_PR_BULK && len > 12)) {
+ WARNING(fsg,
+ "Invalid serial string length; "
+ "Failing back to default\n");
+ goto fill_serial;
+ }
+ len = 0;
+ for (ch = mod_data.serial_parm; *ch; ++ch) {
+ ++len;
+ if ((*ch < '0' || *ch > '9') &&
+ (*ch < 'A' || *ch > 'F')) { /* not uppercase hex */
+ WARNING(fsg,
+ "Invalid serial string character: %c; "
+ "Failing back to default\n",
+ *ch);
+ goto fill_serial;
+ }
+ }
+ memcpy(fsg_string_serial, mod_data.serial_parm, len + 1);
+ } else {
+fill_serial:
+ /* Serial number not specified or invalid, make our own.
+ * We just encode it from the driver version string,
+ * 12 characters long to comply both CB[I] and BBB spec. */
+ for (i = 0; i < 12; i += 2) {
+ unsigned char c = DRIVER_VERSION[i / 2];
+
+ if (!c)
+ break;
+ sprintf(&fsg_string_serial[i], "%02X", c);
+ }
+ }
+
#endif /* CONFIG_USB_FILE_STORAGE_TEST */
return 0;
@@ -3447,16 +3504,6 @@ static int __init fsg_bind(struct usb_gadget *gadget)
init_utsname()->sysname, init_utsname()->release,
gadget->name);
- /* On a real device, serial[] would be loaded from permanent
- * storage. We just encode it from the driver version string. */
- for (i = 0; i < sizeof fsg_string_serial - 2; i += 2) {
- unsigned char c = DRIVER_VERSION[i / 2];
-
- if (!c)
- break;
- sprintf(&fsg_string_serial[i], "%02X", c);
- }
-
fsg->thread_task = kthread_create(fsg_main_thread, fsg,
"file-storage-gadget");
if (IS_ERR(fsg->thread_task)) {
--
1.6.4.4
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