/* * f_mass_storage.c -- Mass Storage USB Composite Function * * Copyright (C) 2003-2008 Alan Stern * Copyright (C) 2009 Samsung Electronics * Author: Michal Nazarewicz * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions, and the following disclaimer, * without modification. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The names of the above-listed copyright holders may not be used * to endorse or promote products derived from this software without * specific prior written permission. * * ALTERNATIVELY, this software may be distributed under the terms of the * GNU General Public License ("GPL") as published by the Free Software * Foundation, either version 2 of that License or (at your option) any * later version. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /* * 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. * * Function supports multiple logical units (LUNs). Backing storage * for each LUN is provided by a regular file or a block device. * Access for each LUN can be limited to read-only. Moreover, the * function can indicate that LUN is removable and/or CD-ROM. (The * later implies read-only access.) * * 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 which is 8). * 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. * * lun_name_format A printf-like format for names of the LUN * devices. This determines how the * directory in sysfs will be named. * Unless you are using several MSFs in * a single gadget (as opposed to single * MSF in many configurations) you may * leave it as NULL (in which case * "lun%d" will be used). In the format * you can use "%d" to index LUNs for * MSF's with more than one LUN. (Beware * that there is only one integer given * as an argument for the format and * specifying invalid format may cause * unspecified behaviour.) * thread_name Name of the kernel thread process used by the * MSF. You can safely set it to NULL * (in which case default "file-storage" * will be used). * * 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. * * * MSF includes support for module parameters. If gadget using it * decides to use it, the following module parameters will be * available: * * file=filename[,filename...] * Names of the files or block devices used for * backing storage. * ro=b[,b...] Default false, boolean for read-only access. * removable=b[,b...] * Default true, boolean for removable media. * cdrom=b[,b...] Default false, boolean for whether to emulate * a CD-ROM drive. * nofua=b[,b...] Default false, booleans for ignore FUA flag * in SCSI WRITE(10,12) commands * luns=N Default N = number of filenames, number of * LUNs to support. * stall Default determined according to the type of * USB device controller (usually true), * boolean to permit the driver to halt * bulk endpoints. * * The module parameters may be prefixed with some string. You need * to consult gadget's documentation or source to verify whether it is * using those module parameters and if it does what are the prefixes * (look for FSG_MODULE_PARAMETERS() macro usage, what's inside it is * the prefix). * * * Requirements are modest; only a bulk-in and a bulk-out endpoint are * needed. The memory requirement amounts to two 16K buffers, size * configurable by a parameter. Support is included for both * full-speed and high-speed operation. * * Note that the driver is slightly non-portable in that it assumes a * single memory/DMA buffer will be useable for bulk-in, bulk-out, and * interrupt-in endpoints. With most device controllers this isn't an * issue, but there may be some with hardware restrictions that prevent * a buffer from being used by more than one endpoint. * * * The pathnames of the backing files and the ro settings are * available in the attribute files "file" and "ro" in the lun (or * to be more precise in a directory which name comes from * "lun_name_format" option!) subdirectory of the gadget's sysfs * directory. If the "removable" option is set, writing to these * files will simulate ejecting/loading the medium (writing an empty * line means eject) and adjusting a write-enable tab. Changes to the * ro setting are not allowed when the medium is loaded or if CD-ROM * emulation is being used. * * When a LUN receive an "eject" SCSI request (Start/Stop Unit), * if the LUN is removable, the backing file is released to simulate * ejection. * * * 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 . * 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 * . */ /* * 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. At 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "gadget_chips.h" /*------------------------------------------------------------------------*/ #define FSG_DRIVER_DESC "Mass Storage Function" #define FSG_DRIVER_VERSION "2009/09/11" static const char fsg_string_interface[] = "Mass Storage"; #define FSG_NO_DEVICE_STRINGS 1 #define FSG_NO_OTG 1 #define FSG_NO_INTR_EP 1 #include "storage_common.c" /*-------------------------------------------------------------------------*/ struct fsg_dev; struct fsg_common; /* FSF callback functions */ struct fsg_operations { /* * Callback function to call when thread exits. If no * callback is set or it returns value lower then zero MSF * will force eject all LUNs it operates on (including those * marked as non-removable or with prevent_medium_removal flag * set). */ int (*thread_exits)(struct fsg_common *common); /* * Called prior to ejection. Negative return means error, * zero means to continue with ejection, positive means not to * eject. */ int (*pre_eject)(struct fsg_common *common, struct fsg_lun *lun, int num); /* * Called after ejection. Negative return means error, zero * or positive is just a success. */ int (*post_eject)(struct fsg_common *common, struct fsg_lun *lun, int num); }; /* Data shared by all the FSG instances. */ struct fsg_common { struct usb_gadget *gadget; struct usb_composite_dev *cdev; struct fsg_dev *fsg, *new_fsg; wait_queue_head_t fsg_wait; /* filesem protects: backing files in use */ struct rw_semaphore filesem; /* lock protects: state, all the req_busy's */ 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; int cmnd_size; u8 cmnd[MAX_COMMAND_SIZE]; unsigned int nluns; unsigned int lun; struct fsg_lun *luns; struct fsg_lun *curlun; unsigned int bulk_out_maxpacket; enum fsg_state state; /* For exception handling */ unsigned int exception_req_tag; 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; int thread_wakeup_needed; struct completion thread_notifier; struct task_struct *thread_task; /* Callback functions. */ const struct fsg_operations *ops; /* Gadget's private data. */ void *private_data; /* * Vendor (8 chars), product (16 chars), release (4 * hexadecimal digits) and NUL byte */ char inquiry_string[8 + 16 + 4 + 1]; struct kref ref; }; struct fsg_config { unsigned nluns; struct fsg_lun_config { const char *filename; char ro; char removable; char cdrom; char nofua; } luns[FSG_MAX_LUNS]; const char *lun_name_format; const char *thread_name; /* Callback functions. */ const struct fsg_operations *ops; /* Gadget's private data. */ void *private_data; const char *vendor_name; /* 8 characters or less */ const char *product_name; /* 16 characters or less */ u16 release; char can_stall; }; 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); } typedef void (*fsg_routine_t)(struct fsg_dev *); static int exception_in_progress(struct fsg_common *common) { return common->state > FSG_STATE_IDLE; } /* 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 */ /* Caller must hold fsg->lock */ static void wakeup_thread(struct fsg_common *common) { /* Tell the main thread that something has happened */ common->thread_wakeup_needed = 1; if (common->thread_task) wake_up_process(common->thread_task); } static void raise_exception(struct fsg_common *common, enum fsg_state new_state) { 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; if (common->thread_task) send_sig_info(SIGUSR1, SEND_SIG_FORCED, common->thread_task); } spin_unlock_irqrestore(&common->lock, flags); } /*-------------------------------------------------------------------------*/ 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); /* Hold the lock while we update the request and buffer states */ smp_wmb(); spin_lock(&common->lock); bh->inreq_busy = 0; bh->state = BUF_STATE_EMPTY; wakeup_thread(common); spin_unlock(&common->lock); } 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); /* Hold the lock while we update the request and buffer states */ smp_wmb(); spin_lock(&common->lock); bh->outreq_busy = 0; bh->state = BUF_STATE_FULL; wakeup_thread(common); spin_unlock(&common->lock); } 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_RESET); return 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->nluns - 1; /* Respond with data/status */ req->length = min((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 void start_transfer(struct fsg_dev *fsg, struct usb_ep *ep, struct usb_request *req, int *pbusy, enum fsg_buffer_state *state) { int rc; if (ep == fsg->bulk_in) dump_msg(fsg, "bulk-in", req->buf, req->length); spin_lock_irq(&fsg->common->lock); *pbusy = 1; *state = BUF_STATE_BUSY; spin_unlock_irq(&fsg->common->lock); rc = usb_ep_queue(ep, req, GFP_KERNEL); if (rc != 0) { *pbusy = 0; *state = BUF_STATE_EMPTY; /* We can't do much more than wait for a reset */ /* * 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); } } static bool start_in_transfer(struct fsg_common *common, struct fsg_buffhd *bh) { if (!fsg_is_set(common)) return false; start_transfer(common->fsg, common->fsg->bulk_in, bh->inreq, &bh->inreq_busy, &bh->state); return true; } static bool start_out_transfer(struct fsg_common *common, struct fsg_buffhd *bh) { if (!fsg_is_set(common)) return false; start_transfer(common->fsg, common->fsg->bulk_out, bh->outreq, &bh->outreq_busy, &bh->state); return true; } static int sleep_thread(struct fsg_common *common) { int rc = 0; /* Wait until a signal arrives or we are woken up */ for (;;) { try_to_freeze(); set_current_state(TASK_INTERRUPTIBLE); if (signal_pending(current)) { rc = -EINTR; break; } if (common->thread_wakeup_needed) break; schedule(); } __set_current_state(TASK_RUNNING); common->thread_wakeup_needed = 0; return rc; } /*-------------------------------------------------------------------------*/ static int do_read(struct fsg_common *common) { struct fsg_lun *curlun = common->curlun; u32 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 { 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((loff_t)amount, curlun->file_length - file_offset); /* Wait for the next buffer to become available */ bh = common->next_buffhd_to_fill; while (bh->state != BUF_STATE_EMPTY) { rc = sleep_thread(common); 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 = vfs_read(curlun->filp, (char __user *)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; u32 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 { 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 */ if (bh->state == BUF_STATE_FULL) { smp_rmb(); 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 = vfs_write(curlun->filp, (char __user *)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; } continue; } /* Wait for something to happen */ rc = sleep_thread(common); if (rc) return rc; } 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 = filp->f_path.dentry->d_inode; unsigned long 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((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 = vfs_read(curlun->filp, (char __user *) 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] = 0x7f; /* 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; 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; /* 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_be32(curlun->num_sectors - 1, &buf[0]); /* Max logical block */ put_unaligned_be32(curlun->blksize, &buf[4]);/* Block length */ return 8; } 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; if ((common->cmnd[1] & ~0x02) != 0 || /* Mask away MSF */ start_track > 1) { curlun->sense_data = SS_INVALID_FIELD_IN_CDB; return -EINVAL; } memset(buf, 0, 20); buf[1] = (20-2); /* TOC data length */ 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 20; } 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; /* Simulate an unload/eject */ if (common->ops && common->ops->pre_eject) { int r = common->ops->pre_eject(common, curlun, curlun - common->luns); if (unlikely(r < 0)) return r; else if (r) return 0; } up_read(&common->filesem); down_write(&common->filesem); fsg_lun_close(curlun); up_write(&common->filesem); down_read(&common->filesem); return common->ops && common->ops->post_eject ? min(0, common->ops->post_eject(common, curlun, curlun - common->luns)) : 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; 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) { /* Throw away the data in a filled buffer */ if (bh->state == BUF_STATE_FULL) { smp_rmb(); 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; } continue; } /* Try to submit another request if we need one */ bh = common->next_buffhd_to_fill; if (bh->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, 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; common->usb_amount_left -= amount; continue; } /* Otherwise wait for something to happen */ rc = sleep_thread(common); if (rc) return rc; } 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 int 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; while (bh->state != BUF_STATE_EMPTY) { rc = sleep_thread(common); if (rc) return rc; } 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 -EIO; common->next_buffhd_to_fill = bh->next; return 0; } /*-------------------------------------------------------------------------*/ /* * 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; 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 %d from CBW, not LUN %d 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 %d\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; while (bh->state != BUF_STATE_EMPTY) { rc = sleep_thread(common); 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_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, (7<<6) | (1<<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 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; /* * 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: case RESERVE: case SEND_DIAGNOSTIC: /* Fall through */ 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((u32)reply, common->data_size_fro