// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
/*
* f_mass_storage.c -- Mass Storage USB Composite Function
*
* Copyright (C) 2003-2008 Alan Stern
* Copyright (C) 2009 Samsung Electronics
* Author: Michal Nazarewicz <mina86@mina86.com>
* All rights reserved.
*/
/*
* The Mass Storage Function acts as a USB Mass Storage device,
* appearing to the host as a disk drive or as a CD-ROM drive. In
* addition to providing an example of a genuinely useful composite
* function for a USB device, it also illustrates a technique of
* double-buffering for increased throughput.
*
* For more information about MSF and in particular its module
* parameters and sysfs interface read the
* <Documentation/usb/mass-storage.rst> file.
*/
/*
* MSF is configured by specifying a fsg_config structure. It has the
* following fields:
*
* nluns Number of LUNs function have (anywhere from 1
* to FSG_MAX_LUNS).
* luns An array of LUN configuration values. This
* should be filled for each LUN that
* function will include (ie. for "nluns"
* LUNs). Each element of the array has
* the following fields:
* ->filename The path to the backing file for the LUN.
* Required if LUN is not marked as
* removable.
* ->ro Flag specifying access to the LUN shall be
* read-only. This is implied if CD-ROM
* emulation is enabled as well as when
* it was impossible to open "filename"
* in R/W mode.
* ->removable Flag specifying that LUN shall be indicated as
* being removable.
* ->cdrom Flag specifying that LUN shall be reported as
* being a CD-ROM.
* ->nofua Flag specifying that FUA flag in SCSI WRITE(10,12)
* commands for this LUN shall be ignored.
*
* vendor_name
* product_name
* release Information used as a reply to INQUIRY
* request. To use default set to NULL,
* NULL, 0xffff respectively. The first
* field should be 8 and the second 16
* characters or less.
*
* can_stall Set to permit function to halt bulk endpoints.
* Disabled on some USB devices known not
* to work correctly. You should set it
* to true.
*
* If "removable" is not set for a LUN then a backing file must be
* specified. If it is set, then NULL filename means the LUN's medium
* is not loaded (an empty string as "filename" in the fsg_config
* structure causes error). The CD-ROM emulation includes a single
* data track and no audio tracks; hence there need be only one
* backing file per LUN.
*
* This function is heavily based on "File-backed Storage Gadget" by
* Alan Stern which in turn is heavily based on "Gadget Zero" by David
* Brownell. The driver's SCSI command interface was based on the
* "Information technology - Small Computer System Interface - 2"
* document from X3T9.2 Project 375D, Revision 10L, 7-SEP-93,
* available at <http://www.t10.org/ftp/t10/drafts/s2/s2-r10l.pdf>.
* The single exception is opcode 0x23 (READ FORMAT CAPACITIES), which
* was based on the "Universal Serial Bus Mass Storage Class UFI
* Command Specification" document, Revision 1.0, December 14, 1998,
* available at
* <http://www.usb.org/developers/devclass_docs/usbmass-ufi10.pdf>.
*/
/*
* Driver Design
*
* The MSF is fairly straightforward. There is a main kernel
* thread that handles most of the work. Interrupt routines field
* callbacks from the controller driver: bulk- and interrupt-request
* completion notifications, endpoint-0 events, and disconnect events.
* Completion events are passed to the main thread by wakeup calls. Many
* ep0 requests are handled at interrupt time, but SetInterface,
* SetConfiguration, and device reset requests are forwarded to the
* thread in the form of "exceptions" using SIGUSR1 signals (since they
* should interrupt any ongoing file I/O operations).
*
* The thread's main routine implements the standard command/data/status
* parts of a SCSI interaction. It and its subroutines are full of tests
* for pending signals/exceptions -- all this polling is necessary since
* the kernel has no setjmp/longjmp equivalents. (Maybe this is an
* indication that the driver really wants to be running in userspace.)
* An important point is that so long as the thread is alive it keeps an
* open reference to the backing file. This will prevent unmounting
* the backing file's underlying filesystem and could cause problems
* during system shutdown, for example. To prevent such problems, the
* thread catches INT, TERM, and KILL signals and converts them into
* an EXIT exception.
*
* In normal operation the main thread is started during the gadget's
* fsg_bind() callback and stopped during fsg_unbind(). But it can
* also exit when it receives a signal, and there's no point leaving
* the gadget running when the thread is dead. As of this moment, MSF
* provides no way to deregister the gadget when thread dies -- maybe
* a callback functions is needed.
*
* To provide maximum throughput, the driver uses a circular pipeline of
* buffer heads (struct fsg_buffhd). In principle the pipeline can be
* arbitrarily long; in practice the benefits don't justify having more
* than 2 stages (i.e., double buffering). But it helps to think of the
* pipeline as being a long one. Each buffer head contains a bulk-in and
* a bulk-out request pointer (since the buffer can be used for both
* output and input -- directions always are given from the host's
* point of view) as well as a pointer to the buffer and various state
* variables.
*
* Use of the pipeline follows a simple protocol. There is a variable
* (fsg->next_buffhd_to_fill) that points to the next buffer head to use.
* At any time that buffer head may still be in use from an earlier
* request, so each buffer head has a state variable indicating whether
* it is EMPTY, FULL, or BUSY. Typical use involves waiting for the
* buffer head to be EMPTY, filling the buffer either by file I/O or by
* USB I/O (during which the buffer head is BUSY), and marking the buffer
* head FULL when the I/O is complete. Then the buffer will be emptied
* (again possibly by USB I/O, during which it is marked BUSY) and
* finally marked EMPTY again (possibly by a completion routine).
*
* A module parameter tells the driver to avoid stalling the bulk
* endpoints wherever the transport specification allows. This is
* necessary for some UDCs like the SuperH, which cannot reliably clear a
* halt on a bulk endpoint. However, under certain circumstances the
* Bulk-only specification requires a stall. In such cases the driver
* will halt the endpoint and set a flag indicating that it should clear
* the halt in software during the next device reset. Hopefully this
* will permit everything to work correctly. Furthermore, although the
* specification allows the bulk-out endpoint to halt when the host sends
* too much data, implementing this would cause an unavoidable race.
* The driver will always use the "no-stall" approach for OUT transfers.
*
* One subtle point concerns sending status-stage responses for ep0
* requests. Some of these requests, such as device reset, can involve
* interrupting an ongoing file I/O operation, which might take an
* arbitrarily long time. During that delay the host might give up on
* the original ep0 request and issue a new one. When that happens the
* driver should not notify the host about completion of the original
* request, as the host will no longer be waiting for it. So the driver
* assigns to each ep0 request a unique tag, and it keeps track of the
* tag value of the request associated with a long-running exception
* (device-reset, interface-change, or configuration-change). When the
* exception handler is finished, the status-stage response is submitted
* only if the current ep0 request tag is equal to the exception request
* tag. Thus only the most recently received ep0 request will get a
* status-stage response.
*
* Warning: This driver source file is too long. It ought to be split up
* into a header file plus about 3 separate .c files, to handle the details
* of the Gadget, USB Mass Storage, and SCSI protocols.
*/
/* #define VERBOSE_DEBUG */
/* #define DUMP_MSGS */
#include <linux/blkdev.h>
#include <linux/completion.h>
#include <linux/dcache.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/fcntl.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/kstrtox.h>
#include <linux/kthread.h>
#include <linux/sched/signal.h>
#include <linux/limits.h>
#include <linux/pagemap.h>
#include <linux/rwsem.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/freezer.h>
#include <linux/module.h>
#include <linux/uaccess.h>
#include <linux/unaligned.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>
#include <linux/usb/composite.h>
#include <linux/nospec.h>
#include "configfs.h"
/*------------------------------------------------------------------------*/
#define FSG_DRIVER_DESC
"Mass Storage Function"
#define FSG_DRIVER_VERSION
"2009/09/11"
static const char fsg_string_interface[] =
"Mass Storage";
#include "storage_common.h"
#include "f_mass_storage.h"
/* Static strings, in UTF-8 (for simplicity we use only ASCII characters) */
static struct usb_string fsg_strings[] = {
{FSG_STRING_INTERFACE, fsg_string_interface},
{}
};
static struct usb_gadget_strings fsg_stringtab = {
.language = 0x0409,
/* en-us */
.strings = fsg_strings,
};
static struct usb_gadget_strings *fsg_strings_array[] = {
&fsg_stringtab,
NULL,
};
/*-------------------------------------------------------------------------*/
struct fsg_dev;
struct fsg_common;
/* Data shared by all the FSG instances. */
struct fsg_common {
struct usb_gadget *gadget;
struct usb_composite_dev *cdev;
struct fsg_dev *fsg;
wait_queue_head_t io_wait;
wait_queue_head_t fsg_wait;
/* filesem protects: backing files in use */
struct rw_semaphore filesem;
/* lock protects: state and thread_task */
spinlock_t lock;
struct usb_ep *ep0;
/* Copy of gadget->ep0 */
struct usb_request *ep0req;
/* Copy of cdev->req */
unsigned int ep0_req_tag;
struct fsg_buffhd *next_buffhd_to_fill;
struct fsg_buffhd *next_buffhd_to_drain;
struct fsg_buffhd *buffhds;
unsigned int fsg_num_buffers;
int cmnd_size;
u8 cmnd[MAX_COMMAND_SIZE];
unsigned int lun;
struct fsg_lun *luns[FSG_MAX_LUNS];
struct fsg_lun *curlun;
unsigned int bulk_out_maxpacket;
enum fsg_state state;
/* For exception handling */
unsigned int exception_req_tag;
void *exception_arg;
enum data_direction data_dir;
u32 data_size;
u32 data_size_from_cmnd;
u32 tag;
u32 residue;
u32 usb_amount_left;
unsigned int can_stall:1;
unsigned int free_storage_on_release:1;
unsigned int phase_error:1;
unsigned int short_packet_received:1;
unsigned int bad_lun_okay:1;
unsigned int running:1;
unsigned int sysfs:1;
struct completion thread_notifier;
struct task_struct *thread_task;
/* Gadget's private data. */
void *private_data;
char inquiry_string[INQUIRY_STRING_LEN];
};
struct fsg_dev {
struct usb_function function;
struct usb_gadget *gadget;
/* Copy of cdev->gadget */
struct fsg_common *common;
u16 interface_number;
unsigned int bulk_in_enabled:1;
unsigned int bulk_out_enabled:1;
unsigned long atomic_bitflags;
#define IGNORE_BULK_OUT 0
struct usb_ep *bulk_in;
struct usb_ep *bulk_out;
};
static inline int __fsg_is_set(
struct fsg_common *common,
const char *func,
unsigned line)
{
if (common->fsg)
return 1;
ERROR(common,
"common->fsg is NULL in %s at %u\n", func, line);
WARN_ON(1);
return 0;
}
#define fsg_is_set(common) likely(__fsg_is_set(common, __func__, __LINE__))
static inline struct fsg_dev *fsg_from_func(
struct usb_function *f)
{
return container_of(f,
struct fsg_dev, function);
}
static int exception_in_progress(
struct fsg_common *common)
{
return common->state > FSG_STATE_NORMAL;
}
/* Make bulk-out requests be divisible by the maxpacket size */
static void set_bulk_out_req_length(
struct fsg_common *common,
struct fsg_buffhd *bh,
unsigned int length)
{
unsigned int rem;
bh->bulk_out_intended_length = length;
rem = length % common->bulk_out_maxpacket;
if (rem > 0)
length += common->bulk_out_maxpacket - rem;
bh->outreq->length = length;
}
/*-------------------------------------------------------------------------*/
static int fsg_set_halt(
struct fsg_dev *fsg,
struct usb_ep *ep)
{
const char *name;
if (ep == fsg->bulk_in)
name =
"bulk-in";
else if (ep == fsg->bulk_out)
name =
"bulk-out";
else
name = ep->name;
DBG(fsg,
"%s set halt\n", name);
return usb_ep_set_halt(ep);
}
/*-------------------------------------------------------------------------*/
/* These routines may be called in process context or in_irq */
static void __raise_exception(
struct fsg_common *common,
enum fsg_state new_state,
void *arg)
{
unsigned long flags;
/*
* Do nothing if a higher-priority exception is already in progress.
* If a lower-or-equal priority exception is in progress, preempt it
* and notify the main thread by sending it a signal.
*/
spin_lock_irqsave(&common->lock, flags);
if (common->state <= new_state) {
common->exception_req_tag = common->ep0_req_tag;
common->state = new_state;
common->exception_arg = arg;
if (common->thread_task)
send_sig_info(SIGUSR1, SEND_SIG_PRIV,
common->thread_task);
}
spin_unlock_irqrestore(&common->lock, flags);
}
static void raise_exception(
struct fsg_common *common,
enum fsg_state new_state)
{
__raise_exception(common, new_state, NULL);
}
/*-------------------------------------------------------------------------*/
static int ep0_queue(
struct fsg_common *common)
{
int rc;
rc = usb_ep_queue(common->ep0, common->ep0req, GFP_ATOMIC);
common->ep0->driver_data = common;
if (rc != 0 && rc != -ESHUTDOWN) {
/* We can't do much more than wait for a reset */
WARNING(common,
"error in submission: %s --> %d\n",
common->ep0->name, rc);
}
return rc;
}
/*-------------------------------------------------------------------------*/
/* Completion handlers. These always run in_irq. */
static void bulk_in_complete(
struct usb_ep *ep,
struct usb_request *req)
{
struct fsg_common *common = ep->driver_data;
struct fsg_buffhd *bh = req->context;
if (req->status || req->actual != req->length)
DBG(common,
"%s --> %d, %u/%u\n", __func__,
req->status, req->actual, req->length);
if (req->status == -ECONNRESET)
/* Request was cancelled */
usb_ep_fifo_flush(ep);
/* Synchronize with the smp_load_acquire() in sleep_thread() */
smp_store_release(&bh->state, BUF_STATE_EMPTY);
wake_up(&common->io_wait);
}
static void bulk_out_complete(
struct usb_ep *ep,
struct usb_request *req)
{
struct fsg_common *common = ep->driver_data;
struct fsg_buffhd *bh = req->context;
dump_msg(common,
"bulk-out", req->buf, req->actual);
if (req->status || req->actual != bh->bulk_out_intended_length)
DBG(common,
"%s --> %d, %u/%u\n", __func__,
req->status, req->actual, bh->bulk_out_intended_length);
if (req->status == -ECONNRESET)
/* Request was cancelled */
usb_ep_fifo_flush(ep);
/* Synchronize with the smp_load_acquire() in sleep_thread() */
smp_store_release(&bh->state, BUF_STATE_FULL);
wake_up(&common->io_wait);
}
static int _fsg_common_get_max_lun(
struct fsg_common *common)
{
int i = ARRAY_SIZE(common->luns) - 1;
while (i >= 0 && !common->luns[i])
--i;
return i;
}
static int fsg_setup(
struct usb_function *f,
const struct usb_ctrlrequest *ctrl)
{
struct fsg_dev *fsg = fsg_from_func(f);
struct usb_request *req = fsg->common->ep0req;
u16 w_index = le16_to_cpu(ctrl->wIndex);
u16 w_value = le16_to_cpu(ctrl->wValue);
u16 w_length = le16_to_cpu(ctrl->wLength);
if (!fsg_is_set(fsg->common))
return -EOPNOTSUPP;
++fsg->common->ep0_req_tag;
/* Record arrival of a new request */
req->context = NULL;
req->length = 0;
dump_msg(fsg,
"ep0-setup", (u8 *) ctrl,
sizeof(*ctrl));
switch (ctrl->bRequest) {
case US_BULK_RESET_REQUEST:
if (ctrl->bRequestType !=
(USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
break;
if (w_index != fsg->interface_number || w_value != 0 ||
w_length != 0)
return -EDOM;
/*
* Raise an exception to stop the current operation
* and reinitialize our state.
*/
DBG(fsg,
"bulk reset request\n");
raise_exception(fsg->common, FSG_STATE_PROTOCOL_RESET);
return USB_GADGET_DELAYED_STATUS;
case US_BULK_GET_MAX_LUN:
if (ctrl->bRequestType !=
(USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE))
break;
if (w_index != fsg->interface_number || w_value != 0 ||
w_length != 1)
return -EDOM;
VDBG(fsg,
"get max LUN\n");
*(u8 *)req->buf = _fsg_common_get_max_lun(fsg->common);
/* Respond with data/status */
req->length = min_t(u16, 1, w_length);
return ep0_queue(fsg->common);
}
VDBG(fsg,
"unknown class-specific control req %02x.%02x v%04x i%04x l%u\n",
ctrl->bRequestType, ctrl->bRequest,
le16_to_cpu(ctrl->wValue), w_index, w_length);
return -EOPNOTSUPP;
}
/*-------------------------------------------------------------------------*/
/* All the following routines run in process context */
/* Use this for bulk or interrupt transfers, not ep0 */
static int start_transfer(
struct fsg_dev *fsg,
struct usb_ep *ep,
struct usb_request *req)
{
int rc;
if (ep == fsg->bulk_in)
dump_msg(fsg,
"bulk-in", req->buf, req->length);
rc = usb_ep_queue(ep, req, GFP_KERNEL);
if (rc) {
/* We can't do much more than wait for a reset */
req->status = rc;
/*
* Note: currently the net2280 driver fails zero-length
* submissions if DMA is enabled.
*/
if (rc != -ESHUTDOWN &&
!(rc == -EOPNOTSUPP && req->length == 0))
WARNING(fsg,
"error in submission: %s --> %d\n",
ep->name, rc);
}
return rc;
}
static bool start_in_transfer(
struct fsg_common *common,
struct fsg_buffhd *bh)
{
int rc;
if (!fsg_is_set(common))
return false;
bh->state = BUF_STATE_SENDING;
rc = start_transfer(common->fsg, common->fsg->bulk_in, bh->inreq);
if (rc) {
bh->state = BUF_STATE_EMPTY;
if (rc == -ESHUTDOWN) {
common->running = 0;
return false;
}
}
return true;
}
static bool start_out_transfer(
struct fsg_common *common,
struct fsg_buffhd *bh)
{
int rc;
if (!fsg_is_set(common))
return false;
bh->state = BUF_STATE_RECEIVING;
rc = start_transfer(common->fsg, common->fsg->bulk_out, bh->outreq);
if (rc) {
bh->state = BUF_STATE_FULL;
if (rc == -ESHUTDOWN) {
common->running = 0;
return false;
}
}
return true;
}
static int sleep_thread(
struct fsg_common *common,
bool can_freeze,
struct fsg_buffhd *bh)
{
int rc;
/* Wait until a signal arrives or bh is no longer busy */
if (can_freeze)
/*
* synchronize with the smp_store_release(&bh->state) in
* bulk_in_complete() or bulk_out_complete()
*/
rc = wait_event_freezable(common->io_wait,
bh && smp_load_acquire(&bh->state) >=
BUF_STATE_EMPTY);
else
rc = wait_event_interruptible(common->io_wait,
bh && smp_load_acquire(&bh->state) >=
BUF_STATE_EMPTY);
return rc ? -EINTR : 0;
}
/*-------------------------------------------------------------------------*/
static int do_read(
struct fsg_common *common)
{
struct fsg_lun *curlun = common->curlun;
u64 lba;
struct fsg_buffhd *bh;
int rc;
u32 amount_left;
loff_t file_offset, file_offset_tmp;
unsigned int amount;
ssize_t nread;
/*
* Get the starting Logical Block Address and check that it's
* not too big.
*/
if (common->cmnd[0] == READ_6)
lba = get_unaligned_be24(&common->cmnd[1]);
else {
if (common->cmnd[0] == READ_16)
lba = get_unaligned_be64(&common->cmnd[2]);
else /* READ_10 or READ_12 */
lba = get_unaligned_be32(&common->cmnd[2]);
/*
* We allow DPO (Disable Page Out = don't save data in the
* cache) and FUA (Force Unit Access = don't read from the
* cache), but we don't implement them.
*/
if ((common->cmnd[1] & ~0x18) != 0) {
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
}
if (lba >= curlun->num_sectors) {
curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
return -EINVAL;
}
file_offset = ((loff_t) lba) << curlun->blkbits;
/* Carry out the file reads */
amount_left = common->data_size_from_cmnd;
if (unlikely(amount_left == 0))
return -EIO;
/* No default reply */
for (;;) {
/*
* Figure out how much we need to read:
* Try to read the remaining amount.
* But don't read more than the buffer size.
* And don't try to read past the end of the file.
*/
amount = min(amount_left, FSG_BUFLEN);
amount = min_t(loff_t, amount,
curlun->file_length - file_offset);
/* Wait for the next buffer to become available */
bh = common->next_buffhd_to_fill;
rc = sleep_thread(common,
false, bh);
if (rc)
return rc;
/*
* If we were asked to read past the end of file,
* end with an empty buffer.
*/
if (amount == 0) {
curlun->sense_data =
SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
curlun->sense_data_info =
file_offset >> curlun->blkbits;
curlun->info_valid = 1;
bh->inreq->length = 0;
bh->state = BUF_STATE_FULL;
break;
}
/* Perform the read */
file_offset_tmp = file_offset;
nread = kernel_read(curlun->filp, bh->buf, amount,
&file_offset_tmp);
VLDBG(curlun,
"file read %u @ %llu -> %d\n", amount,
(
unsigned long long)file_offset, (
int)nread);
if (signal_pending(current))
return -EINTR;
if (nread < 0) {
LDBG(curlun,
"error in file read: %d\n", (
int)nread);
nread = 0;
}
else if (nread < amount) {
LDBG(curlun,
"partial file read: %d/%u\n",
(
int)nread, amount);
nread = round_down(nread, curlun->blksize);
}
file_offset += nread;
amount_left -= nread;
common->residue -= nread;
/*
* Except at the end of the transfer, nread will be
* equal to the buffer size, which is divisible by the
* bulk-in maxpacket size.
*/
bh->inreq->length = nread;
bh->state = BUF_STATE_FULL;
/* If an error occurred, report it and its position */
if (nread < amount) {
curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
curlun->sense_data_info =
file_offset >> curlun->blkbits;
curlun->info_valid = 1;
break;
}
if (amount_left == 0)
break;
/* No more left to read */
/* Send this buffer and go read some more */
bh->inreq->zero = 0;
if (!start_in_transfer(common, bh))
/* Don't know what to do if common->fsg is NULL */
return -EIO;
common->next_buffhd_to_fill = bh->next;
}
return -EIO;
/* No default reply */
}
/*-------------------------------------------------------------------------*/
static int do_write(
struct fsg_common *common)
{
struct fsg_lun *curlun = common->curlun;
u64 lba;
struct fsg_buffhd *bh;
int get_some_more;
u32 amount_left_to_req, amount_left_to_write;
loff_t usb_offset, file_offset, file_offset_tmp;
unsigned int amount;
ssize_t nwritten;
int rc;
if (curlun->ro) {
curlun->sense_data = SS_WRITE_PROTECTED;
return -EINVAL;
}
spin_lock(&curlun->filp->f_lock);
curlun->filp->f_flags &= ~O_SYNC;
/* Default is not to wait */
spin_unlock(&curlun->filp->f_lock);
/*
* Get the starting Logical Block Address and check that it's
* not too big
*/
if (common->cmnd[0] == WRITE_6)
lba = get_unaligned_be24(&common->cmnd[1]);
else {
if (common->cmnd[0] == WRITE_16)
lba = get_unaligned_be64(&common->cmnd[2]);
else /* WRITE_10 or WRITE_12 */
lba = get_unaligned_be32(&common->cmnd[2]);
/*
* We allow DPO (Disable Page Out = don't save data in the
* cache) and FUA (Force Unit Access = write directly to the
* medium). We don't implement DPO; we implement FUA by
* performing synchronous output.
*/
if (common->cmnd[1] & ~0x18) {
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
if (!curlun->nofua && (common->cmnd[1] & 0x08)) {
/* FUA */
spin_lock(&curlun->filp->f_lock);
curlun->filp->f_flags |= O_SYNC;
spin_unlock(&curlun->filp->f_lock);
}
}
if (lba >= curlun->num_sectors) {
curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
return -EINVAL;
}
/* Carry out the file writes */
get_some_more = 1;
file_offset = usb_offset = ((loff_t) lba) << curlun->blkbits;
amount_left_to_req = common->data_size_from_cmnd;
amount_left_to_write = common->data_size_from_cmnd;
while (amount_left_to_write > 0) {
/* Queue a request for more data from the host */
bh = common->next_buffhd_to_fill;
if (bh->state == BUF_STATE_EMPTY && get_some_more) {
/*
* Figure out how much we want to get:
* Try to get the remaining amount,
* but not more than the buffer size.
*/
amount = min(amount_left_to_req, FSG_BUFLEN);
/* Beyond the end of the backing file? */
if (usb_offset >= curlun->file_length) {
get_some_more = 0;
curlun->sense_data =
SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
curlun->sense_data_info =
usb_offset >> curlun->blkbits;
curlun->info_valid = 1;
continue;
}
/* Get the next buffer */
usb_offset += amount;
common->usb_amount_left -= amount;
amount_left_to_req -= amount;
if (amount_left_to_req == 0)
get_some_more = 0;
/*
* Except at the end of the transfer, amount will be
* equal to the buffer size, which is divisible by
* the bulk-out maxpacket size.
*/
set_bulk_out_req_length(common, bh, amount);
if (!start_out_transfer(common, bh))
/* Dunno what to do if common->fsg is NULL */
return -EIO;
common->next_buffhd_to_fill = bh->next;
continue;
}
/* Write the received data to the backing file */
bh = common->next_buffhd_to_drain;
if (bh->state == BUF_STATE_EMPTY && !get_some_more)
break;
/* We stopped early */
/* Wait for the data to be received */
rc = sleep_thread(common,
false, bh);
if (rc)
return rc;
common->next_buffhd_to_drain = bh->next;
bh->state = BUF_STATE_EMPTY;
/* Did something go wrong with the transfer? */
if (bh->outreq->status != 0) {
curlun->sense_data = SS_COMMUNICATION_FAILURE;
curlun->sense_data_info =
file_offset >> curlun->blkbits;
curlun->info_valid = 1;
break;
}
amount = bh->outreq->actual;
if (curlun->file_length - file_offset < amount) {
LERROR(curlun,
"write %u @ %llu beyond end %llu\n",
amount, (
unsigned long long)file_offset,
(
unsigned long long)curlun->file_length);
amount = curlun->file_length - file_offset;
}
/*
* Don't accept excess data. The spec doesn't say
* what to do in this case. We'll ignore the error.
*/
amount = min(amount, bh->bulk_out_intended_length);
/* Don't write a partial block */
amount = round_down(amount, curlun->blksize);
if (amount == 0)
goto empty_write;
/* Perform the write */
file_offset_tmp = file_offset;
nwritten = kernel_write(curlun->filp, bh->buf, amount,
&file_offset_tmp);
VLDBG(curlun,
"file write %u @ %llu -> %d\n", amount,
(
unsigned long long)file_offset, (
int)nwritten);
if (signal_pending(current))
return -EINTR;
/* Interrupted! */
if (nwritten < 0) {
LDBG(curlun,
"error in file write: %d\n",
(
int) nwritten);
nwritten = 0;
}
else if (nwritten < amount) {
LDBG(curlun,
"partial file write: %d/%u\n",
(
int) nwritten, amount);
nwritten = round_down(nwritten, curlun->blksize);
}
file_offset += nwritten;
amount_left_to_write -= nwritten;
common->residue -= nwritten;
/* If an error occurred, report it and its position */
if (nwritten < amount) {
curlun->sense_data = SS_WRITE_ERROR;
curlun->sense_data_info =
file_offset >> curlun->blkbits;
curlun->info_valid = 1;
break;
}
empty_write:
/* Did the host decide to stop early? */
if (bh->outreq->actual < bh->bulk_out_intended_length) {
common->short_packet_received = 1;
break;
}
}
return -EIO;
/* No default reply */
}
/*-------------------------------------------------------------------------*/
static int do_synchronize_cache(
struct fsg_common *common)
{
struct fsg_lun *curlun = common->curlun;
int rc;
/* We ignore the requested LBA and write out all file's
* dirty data buffers. */
rc = fsg_lun_fsync_sub(curlun);
if (rc)
curlun->sense_data = SS_WRITE_ERROR;
return 0;
}
/*-------------------------------------------------------------------------*/
static void invalidate_sub(
struct fsg_lun *curlun)
{
struct file *filp = curlun->filp;
struct inode *inode = file_inode(filp);
unsigned long __maybe_unused rc;
rc = invalidate_mapping_pages(inode->i_mapping, 0, -1);
VLDBG(curlun,
"invalidate_mapping_pages -> %ld\n", rc);
}
static int do_verify(
struct fsg_common *common)
{
struct fsg_lun *curlun = common->curlun;
u32 lba;
u32 verification_length;
struct fsg_buffhd *bh = common->next_buffhd_to_fill;
loff_t file_offset, file_offset_tmp;
u32 amount_left;
unsigned int amount;
ssize_t nread;
/*
* Get the starting Logical Block Address and check that it's
* not too big.
*/
lba = get_unaligned_be32(&common->cmnd[2]);
if (lba >= curlun->num_sectors) {
curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
return -EINVAL;
}
/*
* We allow DPO (Disable Page Out = don't save data in the
* cache) but we don't implement it.
*/
if (common->cmnd[1] & ~0x10) {
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
verification_length = get_unaligned_be16(&common->cmnd[7]);
if (unlikely(verification_length == 0))
return -EIO;
/* No default reply */
/* Prepare to carry out the file verify */
amount_left = verification_length << curlun->blkbits;
file_offset = ((loff_t) lba) << curlun->blkbits;
/* Write out all the dirty buffers before invalidating them */
fsg_lun_fsync_sub(curlun);
if (signal_pending(current))
return -EINTR;
invalidate_sub(curlun);
if (signal_pending(current))
return -EINTR;
/* Just try to read the requested blocks */
while (amount_left > 0) {
/*
* Figure out how much we need to read:
* Try to read the remaining amount, but not more than
* the buffer size.
* And don't try to read past the end of the file.
*/
amount = min(amount_left, FSG_BUFLEN);
amount = min_t(loff_t, amount,
curlun->file_length - file_offset);
if (amount == 0) {
curlun->sense_data =
SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
curlun->sense_data_info =
file_offset >> curlun->blkbits;
curlun->info_valid = 1;
break;
}
/* Perform the read */
file_offset_tmp = file_offset;
nread = kernel_read(curlun->filp, bh->buf, amount,
&file_offset_tmp);
VLDBG(curlun,
"file read %u @ %llu -> %d\n", amount,
(
unsigned long long) file_offset,
(
int) nread);
if (signal_pending(current))
return -EINTR;
if (nread < 0) {
LDBG(curlun,
"error in file verify: %d\n", (
int)nread);
nread = 0;
}
else if (nread < amount) {
LDBG(curlun,
"partial file verify: %d/%u\n",
(
int)nread, amount);
nread = round_down(nread, curlun->blksize);
}
if (nread == 0) {
curlun->sense_data = SS_UNRECOVERED_READ_ERROR;
curlun->sense_data_info =
file_offset >> curlun->blkbits;
curlun->info_valid = 1;
break;
}
file_offset += nread;
amount_left -= nread;
}
return 0;
}
/*-------------------------------------------------------------------------*/
static int do_inquiry(
struct fsg_common *common,
struct fsg_buffhd *bh)
{
struct fsg_lun *curlun = common->curlun;
u8 *buf = (u8 *) bh->buf;
if (!curlun) {
/* Unsupported LUNs are okay */
common->bad_lun_okay = 1;
memset(buf, 0, 36);
buf[0] = TYPE_NO_LUN;
/* Unsupported, no device-type */
buf[4] = 31;
/* Additional length */
return 36;
}
buf[0] = curlun->cdrom ? TYPE_ROM : TYPE_DISK;
buf[1] = curlun->removable ? 0x80 : 0;
buf[2] = 2;
/* ANSI SCSI level 2 */
buf[3] = 2;
/* SCSI-2 INQUIRY data format */
buf[4] = 31;
/* Additional length */
buf[5] = 0;
/* No special options */
buf[6] = 0;
buf[7] = 0;
if (curlun->inquiry_string[0])
memcpy(buf + 8, curlun->inquiry_string,
sizeof(curlun->inquiry_string));
else
memcpy(buf + 8, common->inquiry_string,
sizeof(common->inquiry_string));
return 36;
}
static int do_request_sense(
struct fsg_common *common,
struct fsg_buffhd *bh)
{
struct fsg_lun *curlun = common->curlun;
u8 *buf = (u8 *) bh->buf;
u32 sd, sdinfo;
int valid;
/*
* From the SCSI-2 spec., section 7.9 (Unit attention condition):
*
* If a REQUEST SENSE command is received from an initiator
* with a pending unit attention condition (before the target
* generates the contingent allegiance condition), then the
* target shall either:
* a) report any pending sense data and preserve the unit
* attention condition on the logical unit, or,
* b) report the unit attention condition, may discard any
* pending sense data, and clear the unit attention
* condition on the logical unit for that initiator.
*
* FSG normally uses option a); enable this code to use option b).
*/
#if 0
if (curlun && curlun->unit_attention_data != SS_NO_SENSE) {
curlun->sense_data = curlun->unit_attention_data;
curlun->unit_attention_data = SS_NO_SENSE;
}
#endif
if (!curlun) {
/* Unsupported LUNs are okay */
common->bad_lun_okay = 1;
sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
sdinfo = 0;
valid = 0;
}
else {
sd = curlun->sense_data;
sdinfo = curlun->sense_data_info;
valid = curlun->info_valid << 7;
curlun->sense_data = SS_NO_SENSE;
curlun->sense_data_info = 0;
curlun->info_valid = 0;
}
memset(buf, 0, 18);
buf[0] = valid | 0x70;
/* Valid, current error */
buf[2] = SK(sd);
put_unaligned_be32(sdinfo, &buf[3]);
/* Sense information */
buf[7] = 18 - 8;
/* Additional sense length */
buf[12] = ASC(sd);
buf[13] = ASCQ(sd);
return 18;
}
static int do_read_capacity(
struct fsg_common *common,
struct fsg_buffhd *bh)
{
struct fsg_lun *curlun = common->curlun;
u32 lba = get_unaligned_be32(&common->cmnd[2]);
int pmi = common->cmnd[8];
u8 *buf = (u8 *)bh->buf;
u32 max_lba;
/* Check the PMI and LBA fields */
if (pmi > 1 || (pmi == 0 && lba != 0)) {
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
if (curlun->num_sectors < 0x100000000ULL)
max_lba = curlun->num_sectors - 1;
else
max_lba = 0xffffffff;
put_unaligned_be32(max_lba, &buf[0]);
/* Max logical block */
put_unaligned_be32(curlun->blksize, &buf[4]);
/* Block length */
return 8;
}
static int do_read_capacity_16(
struct fsg_common *common,
struct fsg_buffhd *bh)
{
struct fsg_lun *curlun = common->curlun;
u64 lba = get_unaligned_be64(&common->cmnd[2]);
int pmi = common->cmnd[14];
u8 *buf = (u8 *)bh->buf;
/* Check the PMI and LBA fields */
if (pmi > 1 || (pmi == 0 && lba != 0)) {
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
put_unaligned_be64(curlun->num_sectors - 1, &buf[0]);
/* Max logical block */
put_unaligned_be32(curlun->blksize, &buf[8]);
/* Block length */
/* It is safe to keep other fields zeroed */
memset(&buf[12], 0, 32 - 12);
return 32;
}
static int do_read_header(
struct fsg_common *common,
struct fsg_buffhd *bh)
{
struct fsg_lun *curlun = common->curlun;
int msf = common->cmnd[1] & 0x02;
u32 lba = get_unaligned_be32(&common->cmnd[2]);
u8 *buf = (u8 *)bh->buf;
if (common->cmnd[1] & ~0x02) {
/* Mask away MSF */
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
if (lba >= curlun->num_sectors) {
curlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
return -EINVAL;
}
memset(buf, 0, 8);
buf[0] = 0x01;
/* 2048 bytes of user data, rest is EC */
store_cdrom_address(&buf[4], msf, lba);
return 8;
}
static int do_read_toc(
struct fsg_common *common,
struct fsg_buffhd *bh)
{
struct fsg_lun *curlun = common->curlun;
int msf = common->cmnd[1] & 0x02;
int start_track = common->cmnd[6];
u8 *buf = (u8 *)bh->buf;
u8 format;
int i, len;
format = common->cmnd[2] & 0xf;
if ((common->cmnd[1] & ~0x02) != 0 ||
/* Mask away MSF */
(start_track > 1 && format != 0x1)) {
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
/*
* Check if CDB is old style SFF-8020i
* i.e. format is in 2 MSBs of byte 9
* Mac OS-X host sends us this.
*/
if (format == 0)
format = (common->cmnd[9] >> 6) & 0x3;
switch (format) {
case 0:
/* Formatted TOC */
case 1:
/* Multi-session info */
len = 4 + 2*8;
/* 4 byte header + 2 descriptors */
memset(buf, 0, len);
buf[1] = len - 2;
/* TOC Length excludes length field */
buf[2] = 1;
/* First track number */
buf[3] = 1;
/* Last track number */
buf[5] = 0x16;
/* Data track, copying allowed */
buf[6] = 0x01;
/* Only track is number 1 */
store_cdrom_address(&buf[8], msf, 0);
buf[13] = 0x16;
/* Lead-out track is data */
buf[14] = 0xAA;
/* Lead-out track number */
store_cdrom_address(&buf[16], msf, curlun->num_sectors);
return len;
case 2:
/* Raw TOC */
len = 4 + 3*11;
/* 4 byte header + 3 descriptors */
memset(buf, 0, len);
/* Header + A0, A1 & A2 descriptors */
buf[1] = len - 2;
/* TOC Length excludes length field */
buf[2] = 1;
/* First complete session */
buf[3] = 1;
/* Last complete session */
buf += 4;
/* fill in A0, A1 and A2 points */
for (i = 0; i < 3; i++) {
buf[0] = 1;
/* Session number */
buf[1] = 0x16;
/* Data track, copying allowed */
/* 2 - Track number 0 -> TOC */
buf[3] = 0xA0 + i;
/* A0, A1, A2 point */
/* 4, 5, 6 - Min, sec, frame is zero */
buf[8] = 1;
/* Pmin: last track number */
buf += 11;
/* go to next track descriptor */
}
buf -= 11;
/* go back to A2 descriptor */
/* For A2, 7, 8, 9, 10 - zero, Pmin, Psec, Pframe of Lead out */
store_cdrom_address(&buf[7], msf, curlun->num_sectors);
return len;
default:
/* PMA, ATIP, CD-TEXT not supported/required */
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
}
static int do_mode_sense(
struct fsg_common *common,
struct fsg_buffhd *bh)
{
struct fsg_lun *curlun = common->curlun;
int mscmnd = common->cmnd[0];
u8 *buf = (u8 *) bh->buf;
u8 *buf0 = buf;
int pc, page_code;
int changeable_values, all_pages;
int valid_page = 0;
int len, limit;
if ((common->cmnd[1] & ~0x08) != 0) {
/* Mask away DBD */
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
pc = common->cmnd[2] >> 6;
page_code = common->cmnd[2] & 0x3f;
if (pc == 3) {
curlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
return -EINVAL;
}
changeable_values = (pc == 1);
all_pages = (page_code == 0x3f);
/*
* Write the mode parameter header. Fixed values are: default
* medium type, no cache control (DPOFUA), and no block descriptors.
* The only variable value is the WriteProtect bit. We will fill in
* the mode data length later.
*/
memset(buf, 0, 8);
if (mscmnd == MODE_SENSE) {
buf[2] = (curlun->ro ? 0x80 : 0x00);
/* WP, DPOFUA */
buf += 4;
limit = 255;
}
else {
/* MODE_SENSE_10 */
buf[3] = (curlun->ro ? 0x80 : 0x00);
/* WP, DPOFUA */
buf += 8;
limit = 65535;
/* Should really be FSG_BUFLEN */
}
/* No block descriptors */
/*
* The mode pages, in numerical order. The only page we support
* is the Caching page.
*/
if (page_code == 0x08 || all_pages) {
valid_page = 1;
buf[0] = 0x08;
/* Page code */
buf[1] = 10;
/* Page length */
memset(buf+2, 0, 10);
/* None of the fields are changeable */
if (!changeable_values) {
buf[2] = 0x04;
/* Write cache enable, */
/* Read cache not disabled */
/* No cache retention priorities */
put_unaligned_be16(0xffff, &buf[4]);
/* Don't disable prefetch */
/* Minimum prefetch = 0 */
put_unaligned_be16(0xffff, &buf[8]);
/* Maximum prefetch */
put_unaligned_be16(0xffff, &buf[10]);
/* Maximum prefetch ceiling */
}
buf += 12;
}
/*
* Check that a valid page was requested and the mode data length
* isn't too long.
*/
len = buf - buf0;
if (!valid_page || len > limit) {
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
/* Store the mode data length */
if (mscmnd == MODE_SENSE)
buf0[0] = len - 1;
else
put_unaligned_be16(len - 2, buf0);
return len;
}
static int do_start_stop(
struct fsg_common *common)
{
struct fsg_lun *curlun = common->curlun;
int loej, start;
if (!curlun) {
return -EINVAL;
}
else if (!curlun->removable) {
curlun->sense_data = SS_INVALID_COMMAND;
return -EINVAL;
}
else if ((common->cmnd[1] & ~0x01) != 0 ||
/* Mask away Immed */
(common->cmnd[4] & ~0x03) != 0) {
/* Mask LoEj, Start */
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
loej = common->cmnd[4] & 0x02;
start = common->cmnd[4] & 0x01;
/*
* Our emulation doesn't support mounting; the medium is
* available for use as soon as it is loaded.
*/
if (start) {
if (!fsg_lun_is_open(curlun)) {
curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
return -EINVAL;
}
return 0;
}
/* Are we allowed to unload the media? */
if (curlun->prevent_medium_removal) {
LDBG(curlun,
"unload attempt prevented\n");
curlun->sense_data = SS_MEDIUM_REMOVAL_PREVENTED;
return -EINVAL;
}
if (!loej)
return 0;
up_read(&common->filesem);
down_write(&common->filesem);
fsg_lun_close(curlun);
up_write(&common->filesem);
down_read(&common->filesem);
return 0;
}
static int do_prevent_allow(
struct fsg_common *common)
{
struct fsg_lun *curlun = common->curlun;
int prevent;
if (!common->curlun) {
return -EINVAL;
}
else if (!common->curlun->removable) {
common->curlun->sense_data = SS_INVALID_COMMAND;
return -EINVAL;
}
prevent = common->cmnd[4] & 0x01;
if ((common->cmnd[4] & ~0x01) != 0) {
/* Mask away Prevent */
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
if (curlun->prevent_medium_removal && !prevent)
fsg_lun_fsync_sub(curlun);
curlun->prevent_medium_removal = prevent;
return 0;
}
static int do_read_format_capacities(
struct fsg_common *common,
struct fsg_buffhd *bh)
{
struct fsg_lun *curlun = common->curlun;
u8 *buf = (u8 *) bh->buf;
buf[0] = buf[1] = buf[2] = 0;
buf[3] = 8;
/* Only the Current/Maximum Capacity Descriptor */
buf += 4;
put_unaligned_be32(curlun->num_sectors, &buf[0]);
/* Number of blocks */
put_unaligned_be32(curlun->blksize, &buf[4]);
/* Block length */
buf[4] = 0x02;
/* Current capacity */
return 12;
}
static int do_mode_select(
struct fsg_common *common,
struct fsg_buffhd *bh)
{
struct fsg_lun *curlun = common->curlun;
/* We don't support MODE SELECT */
if (curlun)
curlun->sense_data = SS_INVALID_COMMAND;
return -EINVAL;
}
/*-------------------------------------------------------------------------*/
static int halt_bulk_in_endpoint(
struct fsg_dev *fsg)
{
int rc;
rc = fsg_set_halt(fsg, fsg->bulk_in);
if (rc == -EAGAIN)
VDBG(fsg,
"delayed bulk-in endpoint halt\n");
while (rc != 0) {
if (rc != -EAGAIN) {
WARNING(fsg,
"usb_ep_set_halt -> %d\n", rc);
rc = 0;
break;
}
/* Wait for a short time and then try again */
if (msleep_interruptible(100) != 0)
return -EINTR;
rc = usb_ep_set_halt(fsg->bulk_in);
}
return rc;
}
static int wedge_bulk_in_endpoint(
struct fsg_dev *fsg)
{
int rc;
DBG(fsg,
"bulk-in set wedge\n");
rc = usb_ep_set_wedge(fsg->bulk_in);
if (rc == -EAGAIN)
VDBG(fsg,
"delayed bulk-in endpoint wedge\n");
while (rc != 0) {
if (rc != -EAGAIN) {
WARNING(fsg,
"usb_ep_set_wedge -> %d\n", rc);
rc = 0;
break;
}
/* Wait for a short time and then try again */
if (msleep_interruptible(100) != 0)
return -EINTR;
rc = usb_ep_set_wedge(fsg->bulk_in);
}
return rc;
}
static int throw_away_data(
struct fsg_common *common)
{
struct fsg_buffhd *bh, *bh2;
u32 amount;
int rc;
for (bh = common->next_buffhd_to_drain;
bh->state != BUF_STATE_EMPTY || common->usb_amount_left > 0;
bh = common->next_buffhd_to_drain) {
/* Try to submit another request if we need one */
bh2 = common->next_buffhd_to_fill;
if (bh2->state == BUF_STATE_EMPTY &&
common->usb_amount_left > 0) {
amount = min(common->usb_amount_left, FSG_BUFLEN);
/*
* Except at the end of the transfer, amount will be
* equal to the buffer size, which is divisible by
* the bulk-out maxpacket size.
*/
set_bulk_out_req_length(common, bh2, amount);
if (!start_out_transfer(common, bh2))
/* Dunno what to do if common->fsg is NULL */
return -EIO;
common->next_buffhd_to_fill = bh2->next;
common->usb_amount_left -= amount;
continue;
}
/* Wait for the data to be received */
rc = sleep_thread(common,
false, bh);
if (rc)
return rc;
/* Throw away the data in a filled buffer */
bh->state = BUF_STATE_EMPTY;
common->next_buffhd_to_drain = bh->next;
/* A short packet or an error ends everything */
if (bh->outreq->actual < bh->bulk_out_intended_length ||
bh->outreq->status != 0) {
raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
return -EINTR;
}
}
return 0;
}
static int finish_reply(
struct fsg_common *common)
{
struct fsg_buffhd *bh = common->next_buffhd_to_fill;
int rc = 0;
switch (common->data_dir) {
case DATA_DIR_NONE:
break;
/* Nothing to send */
/*
* If we don't know whether the host wants to read or write,
* this must be CB or CBI with an unknown command. We mustn't
* try to send or receive any data. So stall both bulk pipes
* if we can and wait for a reset.
*/
case DATA_DIR_UNKNOWN:
if (!common->can_stall) {
/* Nothing */
}
else if (fsg_is_set(common)) {
fsg_set_halt(common->fsg, common->fsg->bulk_out);
rc = halt_bulk_in_endpoint(common->fsg);
}
else {
/* Don't know what to do if common->fsg is NULL */
rc = -EIO;
}
break;
/* All but the last buffer of data must have already been sent */
case DATA_DIR_TO_HOST:
if (common->data_size == 0) {
/* Nothing to send */
/* Don't know what to do if common->fsg is NULL */
}
else if (!fsg_is_set(common)) {
rc = -EIO;
/* If there's no residue, simply send the last buffer */
}
else if (common->residue == 0) {
bh->inreq->zero = 0;
if (!start_in_transfer(common, bh))
return -EIO;
common->next_buffhd_to_fill = bh->next;
/*
* For Bulk-only, mark the end of the data with a short
* packet. If we are allowed to stall, halt the bulk-in
* endpoint. (Note: This violates the Bulk-Only Transport
* specification, which requires us to pad the data if we
* don't halt the endpoint. Presumably nobody will mind.)
*/
}
else {
bh->inreq->zero = 1;
if (!start_in_transfer(common, bh))
rc = -EIO;
common->next_buffhd_to_fill = bh->next;
if (common->can_stall)
rc = halt_bulk_in_endpoint(common->fsg);
}
break;
/*
* We have processed all we want from the data the host has sent.
* There may still be outstanding bulk-out requests.
*/
case DATA_DIR_FROM_HOST:
if (common->residue == 0) {
/* Nothing to receive */
/* Did the host stop sending unexpectedly early? */
}
else if (common->short_packet_received) {
raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
rc = -EINTR;
/*
* We haven't processed all the incoming data. Even though
* we may be allowed to stall, doing so would cause a race.
* The controller may already have ACK'ed all the remaining
* bulk-out packets, in which case the host wouldn't see a
* STALL. Not realizing the endpoint was halted, it wouldn't
* clear the halt -- leading to problems later on.
*/
#if 0
}
else if (common->can_stall) {
if (fsg_is_set(common))
fsg_set_halt(common->fsg,
common->fsg->bulk_out);
raise_exception(common, FSG_STATE_ABORT_BULK_OUT);
rc = -EINTR;
#endif
/*
* We can't stall. Read in the excess data and throw it
* all away.
*/
}
else {
rc = throw_away_data(common);
}
break;
}
return rc;
}
static void send_status(
struct fsg_common *common)
{
struct fsg_lun *curlun = common->curlun;
struct fsg_buffhd *bh;
struct bulk_cs_wrap *csw;
int rc;
u8 status = US_BULK_STAT_OK;
u32 sd, sdinfo = 0;
/* Wait for the next buffer to become available */
bh = common->next_buffhd_to_fill;
rc = sleep_thread(common,
false, bh);
if (rc)
return;
if (curlun) {
sd = curlun->sense_data;
sdinfo = curlun->sense_data_info;
}
else if (common->bad_lun_okay)
sd = SS_NO_SENSE;
else
sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
if (common->phase_error) {
DBG(common,
"sending phase-error status\n");
status = US_BULK_STAT_PHASE;
sd = SS_INVALID_COMMAND;
}
else if (sd != SS_NO_SENSE) {
DBG(common,
"sending command-failure status\n");
status = US_BULK_STAT_FAIL;
VDBG(common,
" sense data: SK x%02x, ASC x%02x, ASCQ x%02x;"
" info x%x\n",
SK(sd), ASC(sd), ASCQ(sd), sdinfo);
}
/* Store and send the Bulk-only CSW */
csw = (
void *)bh->buf;
csw->Signature = cpu_to_le32(US_BULK_CS_SIGN);
csw->Tag = common->tag;
csw->Residue = cpu_to_le32(common->residue);
csw->Status = status;
bh->inreq->length = US_BULK_CS_WRAP_LEN;
bh->inreq->zero = 0;
if (!start_in_transfer(common, bh))
/* Don't know what to do if common->fsg is NULL */
return;
common->next_buffhd_to_fill = bh->next;
return;
}
/*-------------------------------------------------------------------------*/
/*
* Check whether the command is properly formed and whether its data size
* and direction agree with the values we already have.
*/
static int check_command(
struct fsg_common *common,
int cmnd_size,
enum data_direction data_dir,
unsigned int mask,
int needs_medium,
const char *name)
{
int i;
unsigned int lun = common->cmnd[1] >> 5;
static const char dirletter[4] = {
'u',
'o',
'i',
'n'};
char hdlen[20];
struct fsg_lun *curlun;
hdlen[0] = 0;
if (common->data_dir != DATA_DIR_UNKNOWN)
sprintf(hdlen,
", H%c=%u", dirletter[(
int) common->data_dir],
common->data_size);
VDBG(common,
"SCSI command: %s; Dc=%d, D%c=%u; Hc=%d%s\n",
name, cmnd_size, dirletter[(
int) data_dir],
common->data_size_from_cmnd, common->cmnd_size, hdlen);
/*
* We can't reply at all until we know the correct data direction
* and size.
*/
if (common->data_size_from_cmnd == 0)
data_dir = DATA_DIR_NONE;
if (common->data_size < common->data_size_from_cmnd) {
/*
* Host data size < Device data size is a phase error.
* Carry out the command, but only transfer as much as
* we are allowed.
*/
common->data_size_from_cmnd = common->data_size;
common->phase_error = 1;
}
common->residue = common->data_size;
common->usb_amount_left = common->data_size;
/* Conflicting data directions is a phase error */
if (common->data_dir != data_dir && common->data_size_from_cmnd > 0) {
common->phase_error = 1;
return -EINVAL;
}
/* Verify the length of the command itself */
if (cmnd_size != common->cmnd_size) {
/*
* Special case workaround: There are plenty of buggy SCSI
* implementations. Many have issues with cbw->Length
* field passing a wrong command size. For those cases we
* always try to work around the problem by using the length
* sent by the host side provided it is at least as large
* as the correct command length.
* Examples of such cases would be MS-Windows, which issues
* REQUEST SENSE with cbw->Length == 12 where it should
* be 6, and xbox360 issuing INQUIRY, TEST UNIT READY and
* REQUEST SENSE with cbw->Length == 10 where it should
* be 6 as well.
*/
if (cmnd_size <= common->cmnd_size) {
DBG(common,
"%s is buggy! Expected length %d "
"but we got %d\n", name,
cmnd_size, common->cmnd_size);
cmnd_size = common->cmnd_size;
}
else {
common->phase_error = 1;
return -EINVAL;
}
}
/* Check that the LUN values are consistent */
if (common->lun != lun)
DBG(common,
"using LUN %u from CBW, not LUN %u from CDB\n",
common->lun, lun);
/* Check the LUN */
curlun = common->curlun;
if (curlun) {
if (common->cmnd[0] != REQUEST_SENSE) {
curlun->sense_data = SS_NO_SENSE;
curlun->sense_data_info = 0;
curlun->info_valid = 0;
}
}
else {
common->bad_lun_okay = 0;
/*
* INQUIRY and REQUEST SENSE commands are explicitly allowed
* to use unsupported LUNs; all others may not.
*/
if (common->cmnd[0] != INQUIRY &&
common->cmnd[0] != REQUEST_SENSE) {
DBG(common,
"unsupported LUN %u\n", common->lun);
return -EINVAL;
}
}
/*
* If a unit attention condition exists, only INQUIRY and
* REQUEST SENSE commands are allowed; anything else must fail.
*/
if (curlun && curlun->unit_attention_data != SS_NO_SENSE &&
common->cmnd[0] != INQUIRY &&
common->cmnd[0] != REQUEST_SENSE) {
curlun->sense_data = curlun->unit_attention_data;
curlun->unit_attention_data = SS_NO_SENSE;
return -EINVAL;
}
/* Check that only command bytes listed in the mask are non-zero */
common->cmnd[1] &= 0x1f;
/* Mask away the LUN */
for (i = 1; i < cmnd_size; ++i) {
if (common->cmnd[i] && !(mask & (1 << i))) {
if (curlun)
curlun->sense_data = SS_INVALID_FIELD_IN_CDB;
return -EINVAL;
}
}
/* If the medium isn't mounted and the command needs to access
* it, return an error. */
if (curlun && !fsg_lun_is_open(curlun) && needs_medium) {
curlun->sense_data = SS_MEDIUM_NOT_PRESENT;
return -EINVAL;
}
return 0;
}
/* wrapper of check_command for data size in blocks handling */
static int check_command_size_in_blocks(
struct fsg_common *common,
int cmnd_size,
enum data_direction data_dir,
unsigned int mask,
int needs_medium,
const char *name)
{
if (common->curlun)
common->data_size_from_cmnd <<= common->curlun->blkbits;
return check_command(common, cmnd_size, data_dir,
mask, needs_medium, name);
}
static int do_scsi_command(
struct fsg_common *common)
{
struct fsg_buffhd *bh;
int rc;
int reply = -EINVAL;
int i;
static char unknown[16];
dump_cdb(common);
/* Wait for the next buffer to become available for data or status */
bh = common->next_buffhd_to_fill;
common->next_buffhd_to_drain = bh;
rc = sleep_thread(common,
false, bh);
if (rc)
return rc;
common->phase_error = 0;
common->short_packet_received = 0;
down_read(&common->filesem);
/* We're using the backing file */
switch (common->cmnd[0]) {
case INQUIRY:
common->data_size_from_cmnd = common->cmnd[4];
reply = check_command(common, 6, DATA_DIR_TO_HOST,
(1<<4), 0,
"INQUIRY");
if (reply == 0)
reply = do_inquiry(common, bh);
break;
case MODE_SELECT:
common->data_size_from_cmnd = common->cmnd[4];
reply = check_command(common, 6, DATA_DIR_FROM_HOST,
(1<<1) | (1<<4), 0,
"MODE SELECT(6)");
if (reply == 0)
reply = do_mode_select(common, bh);
break;
case MODE_SELECT_10:
common->data_size_from_cmnd =
get_unaligned_be16(&common->cmnd[7]);
reply = check_command(common, 10, DATA_DIR_FROM_HOST,
(1<<1) | (3<<7), 0,
"MODE SELECT(10)");
if (reply == 0)
reply = do_mode_select(common, bh);
break;
case MODE_SENSE:
common->data_size_from_cmnd = common->cmnd[4];
reply = check_command(common, 6, DATA_DIR_TO_HOST,
(1<<1) | (1<<2) | (1<<4), 0,
"MODE SENSE(6)");
if (reply == 0)
reply = do_mode_sense(common, bh);
break;
case MODE_SENSE_10:
common->data_size_from_cmnd =
get_unaligned_be16(&common->cmnd[7]);
reply = check_command(common, 10, DATA_DIR_TO_HOST,
(1<<1) | (1<<2) | (3<<7), 0,
"MODE SENSE(10)");
if (reply == 0)
reply = do_mode_sense(common, bh);
break;
case ALLOW_MEDIUM_REMOVAL:
common->data_size_from_cmnd = 0;
reply = check_command(common, 6, DATA_DIR_NONE,
(1<<4), 0,
"PREVENT-ALLOW MEDIUM REMOVAL");
if (reply == 0)
reply = do_prevent_allow(common);
break;
case READ_6:
i = common->cmnd[4];
common->data_size_from_cmnd = (i == 0) ? 256 : i;
reply = check_command_size_in_blocks(common, 6,
DATA_DIR_TO_HOST,
(7<<1) | (1<<4), 1,
"READ(6)");
if (reply == 0)
reply = do_read(common);
break;
case READ_10:
common->data_size_from_cmnd =
get_unaligned_be16(&common->cmnd[7]);
reply = check_command_size_in_blocks(common, 10,
DATA_DIR_TO_HOST,
(1<<1) | (0xf<<2) | (3<<7), 1,
"READ(10)");
if (reply == 0)
reply = do_read(common);
break;
case READ_12:
common->data_size_from_cmnd =
get_unaligned_be32(&common->cmnd[6]);
reply = check_command_size_in_blocks(common, 12,
DATA_DIR_TO_HOST,
(1<<1) | (0xf<<2) | (0xf<<6), 1,
"READ(12)");
if (reply == 0)
reply = do_read(common);
break;
case READ_16:
common->data_size_from_cmnd =
get_unaligned_be32(&common->cmnd[10]);
reply = check_command_size_in_blocks(common, 16,
DATA_DIR_TO_HOST,
(1<<1) | (0xff<<2) | (0xf<<10), 1,
"READ(16)");
if (reply == 0)
reply = do_read(common);
break;
case READ_CAPACITY:
common->data_size_from_cmnd = 8;
reply = check_command(common, 10, DATA_DIR_TO_HOST,
(0xf<<2) | (1<<8), 1,
"READ CAPACITY");
if (reply == 0)
reply = do_read_capacity(common, bh);
break;
case READ_HEADER:
if (!common->curlun || !common->curlun->cdrom)
goto unknown_cmnd;
common->data_size_from_cmnd =
get_unaligned_be16(&common->cmnd[7]);
reply = check_command(common, 10, DATA_DIR_TO_HOST,
(3<<7) | (0x1f<<1), 1,
"READ HEADER");
if (reply == 0)
reply = do_read_header(common, bh);
break;
case READ_TOC:
if (!common->curlun || !common->curlun->cdrom)
goto unknown_cmnd;
common->data_size_from_cmnd =
get_unaligned_be16(&common->cmnd[7]);
reply = check_command(common, 10, DATA_DIR_TO_HOST,
(0xf<<6) | (3<<1), 1,
"READ TOC");
if (reply == 0)
reply = do_read_toc(common, bh);
break;
case READ_FORMAT_CAPACITIES:
common->data_size_from_cmnd =
get_unaligned_be16(&common->cmnd[7]);
reply = check_command(common, 10, DATA_DIR_TO_HOST,
(3<<7), 1,
"READ FORMAT CAPACITIES");
if (reply == 0)
reply = do_read_format_capacities(common, bh);
break;
case REQUEST_SENSE:
common->data_size_from_cmnd = common->cmnd[4];
reply = check_command(common, 6, DATA_DIR_TO_HOST,
(1<<4), 0,
"REQUEST SENSE");
if (reply == 0)
reply = do_request_sense(common, bh);
break;
case SERVICE_ACTION_IN_16:
switch (common->cmnd[1] & 0x1f) {
case SAI_READ_CAPACITY_16:
common->data_size_from_cmnd =
get_unaligned_be32(&common->cmnd[10]);
reply = check_command(common, 16, DATA_DIR_TO_HOST,
(1<<1) | (0xff<<2) | (0xf<<10) |
(1<<14), 1,
"READ CAPACITY(16)");
if (reply == 0)
reply = do_read_capacity_16(common, bh);
break;
default:
goto unknown_cmnd;
}
break;
case START_STOP:
common->data_size_from_cmnd = 0;
reply = check_command(common, 6, DATA_DIR_NONE,
(1<<1) | (1<<4), 0,
"START-STOP UNIT");
if (reply == 0)
reply = do_start_stop(common);
break;
case SYNCHRONIZE_CACHE:
common->data_size_from_cmnd = 0;
reply = check_command(common, 10, DATA_DIR_NONE,
(0xf<<2) | (3<<7), 1,
"SYNCHRONIZE CACHE");
if (reply == 0)
reply = do_synchronize_cache(common);
break;
case TEST_UNIT_READY:
common->data_size_from_cmnd = 0;
reply = check_command(common, 6, DATA_DIR_NONE,
0, 1,
"TEST UNIT READY");
break;
/*
* Although optional, this command is used by MS-Windows. We
* support a minimal version: BytChk must be 0.
*/
case VERIFY:
common->data_size_from_cmnd = 0;
reply = check_command(common, 10, DATA_DIR_NONE,
(1<<1) | (0xf<<2) | (3<<7), 1,
"VERIFY");
if (reply == 0)
reply = do_verify(common);
break;
case WRITE_6:
i = common->cmnd[4];
common->data_size_from_cmnd = (i == 0) ? 256 : i;
reply = check_command_size_in_blocks(common, 6,
DATA_DIR_FROM_HOST,
(7<<1) | (1<<4), 1,
"WRITE(6)");
if (reply == 0)
reply = do_write(common);
break;
case WRITE_10:
common->data_size_from_cmnd =
get_unaligned_be16(&common->cmnd[7]);
reply = check_command_size_in_blocks(common, 10,
DATA_DIR_FROM_HOST,
(1<<1) | (0xf<<2) | (3<<7), 1,
"WRITE(10)");
if (reply == 0)
reply = do_write(common);
break;
case WRITE_12:
common->data_size_from_cmnd =
get_unaligned_be32(&common->cmnd[6]);
reply = check_command_size_in_blocks(common, 12,
DATA_DIR_FROM_HOST,
(1<<1) | (0xf<<2) | (0xf<<6), 1,
"WRITE(12)");
if (reply == 0)
reply = do_write(common);
break;
case WRITE_16:
common->data_size_from_cmnd =
get_unaligned_be32(&common->cmnd[10]);
reply = check_command_size_in_blocks(common, 16,
DATA_DIR_FROM_HOST,
(1<<1) | (0xff<<2) | (0xf<<10), 1,
"WRITE(16)");
if (reply == 0)
reply = do_write(common);
break;
/*
* Some mandatory commands that we recognize but don't implement.
* They don't mean much in this setting. It's left as an exercise
* for anyone interested to implement RESERVE and RELEASE in terms
* of Posix locks.
*/
case FORMAT_UNIT:
case RELEASE_6:
case RESERVE_6:
case SEND_DIAGNOSTIC:
default:
unknown_cmnd:
common->data_size_from_cmnd = 0;
sprintf(unknown,
"Unknown x%02x", common->cmnd[0]);
reply = check_command(common, common->cmnd_size,
DATA_DIR_UNKNOWN, ~0, 0, unknown);
if (reply == 0) {
common->curlun->sense_data = SS_INVALID_COMMAND;
reply = -EINVAL;
}
break;
}
up_read(&common->filesem);
if (reply == -EINTR || signal_pending(current))
return -EINTR;
/* Set up the single reply buffer for finish_reply() */
if (reply == -EINVAL)
reply = 0;
/* Error reply length */
if (reply >= 0 && common->data_dir == DATA_DIR_TO_HOST) {
reply = min_t(u32, reply, common->data_size_from_cmnd);
bh->inreq->length = reply;
bh->state = BUF_STATE_FULL;
common->residue -= reply;
}
/* Otherwise it's already set */
return 0;
}
/*-------------------------------------------------------------------------*/
static int received_cbw(
struct fsg_dev *fsg,
struct fsg_buffhd *bh)
{
struct usb_request *req = bh->outreq;
struct bulk_cb_wrap *cbw = req->buf;
struct fsg_common *common = fsg->common;
/* Was this a real packet? Should it be ignored? */
if (req->status || test_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
return -EINVAL;
/* Is the CBW valid? */
if (req->actual != US_BULK_CB_WRAP_LEN ||
cbw->Signature != cpu_to_le32(
US_BULK_CB_SIGN)) {
DBG(fsg,
"invalid CBW: len %u sig 0x%x\n",
req->actual,
le32_to_cpu(cbw->Signature));
/*
* The Bulk-only spec says we MUST stall the IN endpoint
* (6.6.1), so it's unavoidable. It also says we must
* retain this state until the next reset, but there's
* no way to tell the controller driver it should ignore
* Clear-Feature(HALT) requests.
*
* We aren't required to halt the OUT endpoint; instead
* we can simply accept and discard any data received
* until the next reset.
*/
wedge_bulk_in_endpoint(fsg);
set_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
return -EINVAL;
}
/* Is the CBW meaningful? */
if (cbw->Lun >= ARRAY_SIZE(common->luns) ||
cbw->Flags & ~US_BULK_FLAG_IN || cbw->Length <= 0 ||
cbw->Length > MAX_COMMAND_SIZE) {
DBG(fsg,
"non-meaningful CBW: lun = %u, flags = 0x%x, "
"cmdlen %u\n",
cbw->Lun, cbw->Flags, cbw->Length);
/*
* We can do anything we want here, so let's stall the
* bulk pipes if we are allowed to.
*/
if (common->can_stall) {
fsg_set_halt(fsg, fsg->bulk_out);
halt_bulk_in_endpoint(fsg);
}
return -EINVAL;
}
/* Save the command for later */
common->cmnd_size = cbw->Length;
memcpy(common->cmnd, cbw->CDB, common->cmnd_size);
if (cbw->Flags & US_BULK_FLAG_IN)
common->data_dir = DATA_DIR_TO_HOST;
else
common->data_dir = DATA_DIR_FROM_HOST;
common->data_size = le32_to_cpu(cbw->DataTransferLength);
if (common->data_size == 0)
common->data_dir = DATA_DIR_NONE;
common->lun = cbw->Lun;
if (common->lun < ARRAY_SIZE(common->luns))
common->curlun = common->luns[common->lun];
else
common->curlun = NULL;
common->tag = cbw->Tag;
return 0;
}
static int get_next_command(
struct fsg_common *common)
{
struct fsg_buffhd *bh;
int rc = 0;
/* Wait for the next buffer to become available */
bh = common->next_buffhd_to_fill;
rc = sleep_thread(common,
true, bh);
if (rc)
return rc;
/* Queue a request to read a Bulk-only CBW */
set_bulk_out_req_length(common, bh, US_BULK_CB_WRAP_LEN);
if (!start_out_transfer(common, bh))
/* Don't know what to do if common->fsg is NULL */
return -EIO;
/*
* We will drain the buffer in software, which means we
* can reuse it for the next filling. No need to advance
* next_buffhd_to_fill.
*/
/* Wait for the CBW to arrive */
rc = sleep_thread(common,
true, bh);
if (rc)
return rc;
rc = fsg_is_set(common) ? received_cbw(common->fsg, bh) : -EIO;
bh->state = BUF_STATE_EMPTY;
return rc;
}
/*-------------------------------------------------------------------------*/
static int alloc_request(
struct fsg_common *common,
struct usb_ep *ep,
struct usb_request **preq)
{
--> --------------------
--> maximum size reached
--> --------------------
