// 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 * 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 * 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 . * 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. 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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((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; 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; 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; 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 */ /* 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((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; /* 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; 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_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: 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_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) { *preq = usb_ep_alloc_request(ep, GFP_ATOMIC); if (*preq) return 0; ERROR(common, "can't allocate request for %s\n", ep->name); return -ENOMEM; } /* Reset interface setting and re-init endpoint state (toggle etc). */ static int do_set_interface(struct fsg_common *common, struct fsg_dev *new_fsg) { struct fsg_dev *fsg; int i, rc = 0; if (common->running) DBG(common, "reset interface\n"); reset: /* Deallocate the requests */ if (common->fsg) { fsg = common->fsg; for (i = 0; i < common->fsg_num_buffers; ++i) { struct fsg_buffhd *bh = &common->buffhds[i]; if (bh->inreq) { usb_ep_free_request(fsg->bulk_in, bh->inreq); bh->inreq = NULL; } if (bh->outreq) { usb_ep_free_request(fsg->bulk_out, bh->outreq); bh->outreq = NULL; } } /* Disable the endpoints */ if (fsg->bulk_in_enabled) { usb_ep_disable(fsg->bulk_in); fsg->bulk_in_enabled = 0; } if (fsg->bulk_out_enabled) { usb_ep_disable(fsg->bulk_out); fsg->bulk_out_enabled = 0; } common->fsg = NULL; wake_up(&common->fsg_wait); } common->running = 0; if (!new_fsg || rc) return rc; common->fsg = new_fsg; fsg = common->fsg; /* Enable the endpoints */ rc = config_ep_by_speed(common->gadget, &(fsg->function), fsg->bulk_in); if (rc) goto reset; rc = usb_ep_enable(fsg->bulk_in); if (rc) goto reset; fsg->bulk_in->driver_data = common; fsg->bulk_in_enabled = 1; rc = config_ep_by_speed(common->gadget, &(fsg->function), fsg->bulk_out); if (rc) goto reset; rc = usb_ep_enable(fsg->bulk_out); if (rc) goto reset; fsg->bulk_out->driver_data = common; fsg->bulk_out_enabled = 1; common->bulk_out_maxpacket = usb_endpoint_maxp(fsg->bulk_out->desc); clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags); /* Allocate the requests */ for (i = 0; i < common->fsg_num_buffers; ++i) { struct fsg_buffhd *bh = &common->buffhds[i]; rc = alloc_request(common, fsg->bulk_in, &bh->inreq); if (rc) goto reset; rc = alloc_request(common, fsg->bulk_out, &bh->outreq); if (rc) goto reset; bh->inreq->buf = bh->outreq->buf = bh->buf; bh->inreq->context = bh->outreq->context = bh; bh->inreq->complete = bulk_in_complete; bh->outreq->complete = bulk_out_complete; } common->running = 1; for (i = 0; i < ARRAY_SIZE(common->luns); ++i) if (common->luns[i]) common->luns[i]->unit_attention_data = SS_RESET_OCCURRED; return rc; } /****************************** ALT CONFIGS ******************************/ static int fsg_set_alt(struct usb_function *f, unsigned intf, unsigned alt) { struct fsg_dev *fsg = fsg_from_func(f); __raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE, fsg); return USB_GADGET_DELAYED_STATUS; } static void fsg_disable(struct usb_function *f) { struct fsg_dev *fsg = fsg_from_func(f); __raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE, NULL); } /*-------------------------------------------------------------------------*/ static void handle_exception(struct fsg_common *common) { int i; struct fsg_buffhd *bh; enum fsg_state old_state; struct fsg_lun *curlun; unsigned int exception_req_tag; struct fsg_dev *new_fsg; /* * Clear the existing signals. Anything but SIGUSR1 is converted * into a high-priority EXIT exception. */ for (;;) { int sig = kernel_dequeue_signal(); if (!sig) break; if (sig != SIGUSR1) { spin_lock_irq(&common->lock); if (common->state < FSG_STATE_EXIT) DBG(common, "Main thread exiting on signal\n"); common->state = FSG_STATE_EXIT; spin_unlock_irq(&common->lock); } } /* Cancel all the pending transfers */ if (likely(common->fsg)) { for (i = 0; i < common->fsg_num_buffers; ++i) { bh = &common->buffhds[i]; if (bh->state == BUF_STATE_SENDING) usb_ep_dequeue(common->fsg->bulk_in, bh->inreq); if (bh->state == BUF_STATE_RECEIVING) usb_ep_dequeue(common->fsg->bulk_out, bh->outreq); /* Wait for a transfer to become idle */ if (sleep_thread(common, false, bh)) return; } /* Clear out the controller's fifos */ if (common->fsg->bulk_in_enabled) usb_ep_fifo_flush(common->fsg->bulk_in); if (common->fsg->bulk_out_enabled) usb_ep_fifo_flush(common->fsg->bulk_out); } /* * Reset the I/O buffer states and pointers, the SCSI * state, and the exception. Then invoke the handler. */ spin_lock_irq(&common->lock); for (i = 0; i < common->fsg_num_buffers; ++i) { bh = &common->buffhds[i]; bh->state = BUF_STATE_EMPTY; } common->next_buffhd_to_fill = &common->buffhds[0]; common->next_buffhd_to_drain = &common->buffhds[0]; exception_req_tag = common->exception_req_tag; new_fsg = common->exception_arg; old_state = common->state; common->state = FSG_STATE_NORMAL; if (old_state != FSG_STATE_ABORT_BULK_OUT) { for (i = 0; i < ARRAY_SIZE(common->luns); ++i) { curlun = common->luns[i]; if (!curlun) continue; curlun->prevent_medium_removal = 0; curlun->sense_data = SS_NO_SENSE; curlun->unit_attention_data = SS_NO_SENSE; curlun->sense_data_info = 0; curlun->info_valid = 0; } } spin_unlock_irq(&common->lock); /* Carry out any extra actions required for the exception */ switch (old_state) { case FSG_STATE_NORMAL: break; case FSG_STATE_ABORT_BULK_OUT: send_status(common); break; case FSG_STATE_PROTOCOL_RESET: /* * In case we were forced against our will to halt a * bulk endpoint, clear the halt now. (The SuperH UDC * requires this.) */ if (!fsg_is_set(common)) break; if (test_and_clear_bit(IGNORE_BULK_OUT, &common->fsg->atomic_bitflags)) usb_ep_clear_halt(common->fsg->bulk_in); if (common->ep0_req_tag == exception_req_tag) ep0_queue(common); /* Complete the status stage */ /* * Technically this should go here, but it would only be * a waste of time. Ditto for the INTERFACE_CHANGE and * CONFIG_CHANGE cases. */ /* for (i = 0; i < common->ARRAY_SIZE(common->luns); ++i) */ /* if (common->luns[i]) */ /* common->luns[i]->unit_attention_data = */ /* SS_RESET_OCCURRED; */ break; case FSG_STATE_CONFIG_CHANGE: do_set_interface(common, new_fsg); if (new_fsg) usb_composite_setup_continue(common->cdev); break; case FSG_STATE_EXIT: do_set_interface(common, NULL); /* Free resources */ spin_lock_irq(&common->lock); common->state = FSG_STATE_TERMINATED; /* Stop the thread */ spin_unlock_irq(&common->lock); break; case FSG_STATE_TERMINATED: break; } } /*-------------------------------------------------------------------------*/ static int fsg_main_thread(void *common_) { struct fsg_common *common = common_; int i; /* * Allow the thread to be killed by a signal, but set the signal mask * to block everything but INT, TERM, KILL, and USR1. */ allow_signal(SIGINT); allow_signal(SIGTERM); allow_signal(SIGKILL); allow_signal(SIGUSR1); /* Allow the thread to be frozen */ set_freezable(); /* The main loop */ while (common->state != FSG_STATE_TERMINATED) { if (exception_in_progress(common) || signal_pending(current)) { handle_exception(common); continue; } if (!common->running) { sleep_thread(common, true, NULL); continue; } if (get_next_command(common) || exception_in_progress(common)) continue; if (do_scsi_command(common) || exception_in_progress(common)) continue; if (finish_reply(common) || exception_in_progress(common)) continue; send_status(common); } spin_lock_irq(&common->lock); common->thread_task = NULL; spin_unlock_irq(&common->lock); /* Eject media from all LUNs */ down_write(&common->filesem); for (i = 0; i < ARRAY_SIZE(common->luns); i++) { struct fsg_lun *curlun = common->luns[i]; if (curlun && fsg_lun_is_open(curlun)) fsg_lun_close(curlun); } up_write(&common->filesem); /* Let fsg_unbind() know the thread has exited */ complete_and_exit(&common->thread_notifier, 0); } /*************************** DEVICE ATTRIBUTES ***************************/ static ssize_t ro_show(struct device *dev, struct device_attribute *attr, char *buf) { struct fsg_lun *curlun = fsg_lun_from_dev(dev); return fsg_show_ro(curlun, buf); } static ssize_t nofua_show(struct device *dev, struct device_attribute *attr, char *buf) { struct fsg_lun *curlun = fsg_lun_from_dev(dev); return fsg_show_nofua(curlun, buf); } static ssize_t file_show(struct device *dev, struct device_attribute *attr, char *buf) { struct fsg_lun *curlun = fsg_lun_from_dev(dev); struct rw_semaphore *filesem = dev_get_drvdata(dev); return fsg_show_file(curlun, filesem, buf); } static ssize_t ro_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct fsg_lun *curlun = fsg_lun_from_dev(dev); struct rw_semaphore *filesem = dev_get_drvdata(dev); return fsg_store_ro(curlun, filesem, buf, count); } static ssize_t nofua_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct fsg_lun *curlun = fsg_lun_from_dev(dev); return fsg_store_nofua(curlun, buf, count); } static ssize_t file_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct fsg_lun *curlun = fsg_lun_from_dev(dev); struct rw_semaphore *filesem = dev_get_drvdata(dev); return fsg_store_file(curlun, filesem, buf, count); } static DEVICE_ATTR_RW(nofua); /* mode wil be set in fsg_lun_attr_is_visible() */ static DEVICE_ATTR(ro, 0, ro_show, ro_store); static DEVICE_ATTR(file, 0, file_show, file_store); /****************************** FSG COMMON ******************************/ static void fsg_lun_release(struct device *dev) { /* Nothing needs to be done */ } static struct fsg_common *fsg_common_setup(struct fsg_common *common) { if (!common) { common = kzalloc(sizeof(*common), GFP_KERNEL); if (!common) return ERR_PTR(-ENOMEM); common->free_storage_on_release = 1; } else { common->free_storage_on_release = 0; } init_rwsem(&common->filesem); spin_lock_init(&common->lock); init_completion(&common->thread_notifier); init_waitqueue_head(&common->io_wait); init_waitqueue_head(&common->fsg_wait); common->state = FSG_STATE_TERMINATED; memset(common->luns, 0, sizeof(common->luns)); return common; } void fsg_common_set_sysfs(struct fsg_common *common, bool sysfs) { common->sysfs = sysfs; } EXPORT_SYMBOL_GPL(fsg_common_set_sysfs); static void _fsg_common_free_buffers(struct fsg_buffhd *buffhds, unsigned n) { if (buffhds) { struct fsg_buffhd *bh = buffhds; while (n--) { kfree(bh->buf); ++bh; } kfree(buffhds); } } int fsg_common_set_num_buffers(struct fsg_common *common, unsigned int n) { struct fsg_buffhd *bh, *buffhds; int i; buffhds = kcalloc(n, sizeof(*buffhds), GFP_KERNEL); if (!buffhds) return -ENOMEM; /* Data buffers cyclic list */ bh = buffhds; i = n; goto buffhds_first_it; do { bh->next = bh + 1; ++bh; buffhds_first_it: bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL); if (unlikely(!bh->buf)) goto error_release; } while (--i); bh->next = buffhds; _fsg_common_free_buffers(common->buffhds, common->fsg_num_buffers); common->fsg_num_buffers = n; common->buffhds = buffhds; return 0; error_release: /* * "buf"s pointed to by heads after n - i are NULL * so releasing them won't hurt */ _fsg_common_free_buffers(buffhds, n); return -ENOMEM; } EXPORT_SYMBOL_GPL(fsg_common_set_num_buffers); void fsg_common_remove_lun(struct fsg_lun *lun) { if (device_is_registered(&lun->dev)) device_unregister(&lun->dev); fsg_lun_close(lun); kfree(lun); } EXPORT_SYMBOL_GPL(fsg_common_remove_lun); static void _fsg_common_remove_luns(struct fsg_common *common, int n) { int i; for (i = 0; i < n; ++i) if (common->luns[i]) { fsg_common_remove_lun(common->luns[i]); common->luns[i] = NULL; } } void fsg_common_remove_luns(struct fsg_common *common) { _fsg_common_remove_luns(common, ARRAY_SIZE(common->luns)); } EXPORT_SYMBOL_GPL(fsg_common_remove_luns); void fsg_common_free_buffers(struct fsg_common *common) { _fsg_common_free_buffers(common->buffhds, common->fsg_num_buffers); common->buffhds = NULL; } EXPORT_SYMBOL_GPL(fsg_common_free_buffers); int fsg_common_set_cdev(struct fsg_common *common, struct usb_composite_dev *cdev, bool can_stall) { struct usb_string *us; common->gadget = cdev->gadget; common->ep0 = cdev->gadget->ep0; common->ep0req = cdev->req; common->cdev = cdev; us = usb_gstrings_attach(cdev, fsg_strings_array, ARRAY_SIZE(fsg_strings)); if (IS_ERR(us)) return PTR_ERR(us); fsg_intf_desc.iInterface = us[FSG_STRING_INTERFACE].id; /* * Some peripheral controllers are known not to be able to * halt bulk endpoints correctly. If one of them is present, * disable stalls. */ common->can_stall = can_stall && gadget_is_stall_supported(common->gadget); return 0; } EXPORT_SYMBOL_GPL(fsg_common_set_cdev); static struct attribute *fsg_lun_dev_attrs[] = { &dev_attr_ro.attr, &dev_attr_file.attr, &dev_attr_nofua.attr, NULL }; static umode_t fsg_lun_dev_is_visible(struct kobject *kobj, struct attribute *attr, int idx) { struct device *dev = kobj_to_dev(kobj); struct fsg_lun *lun = fsg_lun_from_dev(dev); if (attr == &dev_attr_ro.attr) return lun->cdrom ? S_IRUGO : (S_IWUSR | S_IRUGO); if (attr == &dev_attr_file.attr) return lun->removable ? (S_IWUSR | S_IRUGO) : S_IRUGO; return attr->mode; } static const struct attribute_group fsg_lun_dev_group = { .attrs = fsg_lun_dev_attrs, .is_visible = fsg_lun_dev_is_visible, }; static const struct attribute_group *fsg_lun_dev_groups[] = { &fsg_lun_dev_group, NULL }; int fsg_common_create_lun(struct fsg_common *common, struct fsg_lun_config *cfg, unsigned int id, const char *name, const char **name_pfx) { struct fsg_lun *lun; char *pathbuf, *p; int rc = -ENOMEM; if (id >= ARRAY_SIZE(common->luns)) return -ENODEV; if (common->luns[id]) return -EBUSY; if (!cfg->filename && !cfg->removable) { pr_err("no file given for LUN%d\n", id); return -EINVAL; } lun = kzalloc(sizeof(*lun), GFP_KERNEL); if (!lun) return -ENOMEM; lun->name_pfx = name_pfx; lun->cdrom = !!cfg->cdrom; lun->ro = cfg->cdrom || cfg->ro; lun->initially_ro = lun->ro; lun->removable = !!cfg->removable; if (!common->sysfs) { /* we DON'T own the name!*/ lun->name = name; } else { lun->dev.release = fsg_lun_release; lun->dev.parent = &common->gadget->dev; lun->dev.groups = fsg_lun_dev_groups; dev_set_drvdata(&lun->dev, &common->filesem); dev_set_name(&lun->dev, "%s", name); lun->name = dev_name(&lun->dev); rc = device_register(&lun->dev); if (rc) { pr_info("failed to register LUN%d: %d\n", id, rc); put_device(&lun->dev); goto error_sysfs; } } common->luns[id] = lun; if (cfg->filename) { rc = fsg_lun_open(lun, cfg->filename); if (rc) goto error_lun; } pathbuf = kmalloc(PATH_MAX, GFP_KERNEL); p = "(no medium)"; if (fsg_lun_is_open(lun)) { p = "(error)"; if (pathbuf) { p = file_path(lun->filp, pathbuf, PATH_MAX); if (IS_ERR(p)) p = "(error)"; } } pr_info("LUN: %s%s%sfile: %s\n", lun->removable ? "removable " : "", lun->ro ? "read only " : "", lun->cdrom ? "CD-ROM " : "", p); kfree(pathbuf); return 0; error_lun: if (device_is_registered(&lun->dev)) device_unregister(&lun->dev); fsg_lun_close(lun); common->luns[id] = NULL; error_sysfs: kfree(lun); return rc; } EXPORT_SYMBOL_GPL(fsg_common_create_lun); int fsg_common_create_luns(struct fsg_common *common, struct fsg_config *cfg) { char buf[8]; /* enough for 100000000 different numbers, decimal */ int i, rc; fsg_common_remove_luns(common); for (i = 0; i < cfg->nluns; ++i) { snprintf(buf, sizeof(buf), "lun%d", i); rc = fsg_common_create_lun(common, &cfg->luns[i], i, buf, NULL); if (rc) goto fail; } pr_info("Number of LUNs=%d\n", cfg->nluns); return 0; fail: _fsg_common_remove_luns(common, i); return rc; } EXPORT_SYMBOL_GPL(fsg_common_create_luns); void fsg_common_set_inquiry_string(struct fsg_common *common, const char *vn, const char *pn) { int i; /* Prepare inquiryString */ i = get_default_bcdDevice(); snprintf(common->inquiry_string, sizeof(common->inquiry_string), "%-8s%-16s%04x", vn ?: "Linux", /* Assume product name dependent on the first LUN */ pn ?: ((*common->luns)->cdrom ? "File-CD Gadget" : "File-Stor Gadget"), i); } EXPORT_SYMBOL_GPL(fsg_common_set_inquiry_string); static void fsg_common_release(struct fsg_common *common) { int i; /* If the thread isn't already dead, tell it to exit now */ if (common->state != FSG_STATE_TERMINATED) { raise_exception(common, FSG_STATE_EXIT); wait_for_completion(&common->thread_notifier); } for (i = 0; i < ARRAY_SIZE(common->luns); ++i) { struct fsg_lun *lun = common->luns[i]; if (!lun) continue; fsg_lun_close(lun); if (device_is_registered(&lun->dev)) device_unregister(&lun->dev); kfree(lun); } _fsg_common_free_buffers(common->buffhds, common->fsg_num_buffers); if (common->free_storage_on_release) kfree(common); } /*-------------------------------------------------------------------------*/ static int fsg_bind(struct usb_configuration *c, struct usb_function *f) { struct fsg_dev *fsg = fsg_from_func(f); struct fsg_common *common = fsg->common; struct usb_gadget *gadget = c->cdev->gadget; int i; struct usb_ep *ep; unsigned max_burst; int ret; struct fsg_opts *opts; /* Don't allow to bind if we don't have at least one LUN */ ret = _fsg_common_get_max_lun(common); if (ret < 0) { pr_err("There should be at least one LUN.\n"); return -EINVAL; } opts = fsg_opts_from_func_inst(f->fi); if (!opts->no_configfs) { ret = fsg_common_set_cdev(fsg->common, c->cdev, fsg->common->can_stall); if (ret) return ret; fsg_common_set_inquiry_string(fsg->common, NULL, NULL); } if (!common->thread_task) { common->state = FSG_STATE_NORMAL; common->thread_task = kthread_create(fsg_main_thread, common, "file-storage"); if (IS_ERR(common->thread_task)) { ret = PTR_ERR(common->thread_task); common->thread_task = NULL; common->state = FSG_STATE_TERMINATED; return ret; } DBG(common, "I/O thread pid: %d\n", task_pid_nr(common->thread_task)); wake_up_process(common->thread_task); } fsg->gadget = gadget; /* New interface */ i = usb_interface_id(c, f); if (i < 0) goto fail; fsg_intf_desc.bInterfaceNumber = i; fsg->interface_number = i; /* Find all the endpoints we will use */ ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_in_desc); if (!ep) goto autoconf_fail; fsg->bulk_in = ep; ep = usb_ep_autoconfig(gadget, &fsg_fs_bulk_out_desc); if (!ep) goto autoconf_fail; fsg->bulk_out = ep; /* Assume endpoint addresses are the same for both speeds */ fsg_hs_bulk_in_desc.bEndpointAddress = fsg_fs_bulk_in_desc.bEndpointAddress; fsg_hs_bulk_out_desc.bEndpointAddress = fsg_fs_bulk_out_desc.bEndpointAddress; /* Calculate bMaxBurst, we know packet size is 1024 */ max_burst = min_t(unsigned, FSG_BUFLEN / 1024, 15); fsg_ss_bulk_in_desc.bEndpointAddress = fsg_fs_bulk_in_desc.bEndpointAddress; fsg_ss_bulk_in_comp_desc.bMaxBurst = max_burst; fsg_ss_bulk_out_desc.bEndpointAddress = fsg_fs_bulk_out_desc.bEndpointAddress; fsg_ss_bulk_out_comp_desc.bMaxBurst = max_burst; ret = usb_assign_descriptors(f, fsg_fs_function, fsg_hs_function, fsg_ss_function, fsg_ss_function); if (ret) goto autoconf_fail; return 0; autoconf_fail: ERROR(fsg, "unable to autoconfigure all endpoints\n"); i = -ENOTSUPP; fail: /* terminate the thread */ if (fsg->common->state != FSG_STATE_TERMINATED) { raise_exception(fsg->common, FSG_STATE_EXIT); wait_for_completion(&fsg->common->thread_notifier); } return i; } /****************************** ALLOCATE FUNCTION *************************/ static void fsg_unbind(struct usb_configuration *c, struct usb_function *f) { struct fsg_dev *fsg = fsg_from_func(f); struct fsg_common *common = fsg->common; DBG(fsg, "unbind\n"); if (fsg->common->fsg == fsg) { __raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE, NULL); /* FIXME: make interruptible or killable somehow? */ wait_event(common->fsg_wait, common->fsg != fsg); } usb_free_all_descriptors(&fsg->function); } static inline struct fsg_lun_opts *to_fsg_lun_opts(struct config_item *item) { return container_of(to_config_group(item), struct fsg_lun_opts, group); } static inline struct fsg_opts *to_fsg_opts(struct config_item *item) { return container_of(to_config_group(item), struct fsg_opts, func_inst.group); } static void fsg_lun_attr_release(struct config_item *item) { struct fsg_lun_opts *lun_opts; lun_opts = to_fsg_lun_opts(item); kfree(lun_opts); } static struct configfs_item_operations fsg_lun_item_ops = { .release = fsg_lun_attr_release, }; static ssize_t fsg_lun_opts_file_show(struct config_item *item, char *page) { struct fsg_lun_opts *opts = to_fsg_lun_opts(item); struct fsg_opts *fsg_opts = to_fsg_opts(opts->group.cg_item.ci_parent); return fsg_show_file(opts->lun, &fsg_opts->common->filesem, page); } static ssize_t fsg_lun_opts_file_store(struct config_item *item, const char *page, size_t len) { struct fsg_lun_opts *opts = to_fsg_lun_opts(item); struct fsg_opts *fsg_opts = to_fsg_opts(opts->group.cg_item.ci_parent); return fsg_store_file(opts->lun, &fsg_opts->common->filesem, page, len); } CONFIGFS_ATTR(fsg_lun_opts_, file); static ssize_t fsg_lun_opts_ro_show(struct config_item *item, char *page) { return fsg_show_ro(to_fsg_lun_opts(item)->lun, page); } static ssize_t fsg_lun_opts_ro_store(struct config_item *item, const char *page, size_t len) { struct fsg_lun_opts *opts = to_fsg_lun_opts(item); struct fsg_opts *fsg_opts = to_fsg_opts(opts->group.cg_item.ci_parent); return fsg_store_ro(opts->lun, &fsg_opts->common->filesem, page, len); } CONFIGFS_ATTR(fsg_lun_opts_, ro); static ssize_t fsg_lun_opts_removable_show(struct config_item *item, char *page) { return fsg_show_removable(to_fsg_lun_opts(item)->lun, page); } static ssize_t fsg_lun_opts_removable_store(struct config_item *item, const char *page, size_t len) { return fsg_store_removable(to_fsg_lun_opts(item)->lun, page, len); } CONFIGFS_ATTR(fsg_lun_opts_, removable); static ssize_t fsg_lun_opts_cdrom_show(struct config_item *item, char *page) { return fsg_show_cdrom(to_fsg_lun_opts(item)->lun, page); } static ssize_t fsg_lun_opts_cdrom_store(struct config_item *item, const char *page, size_t len) { struct fsg_lun_opts *opts = to_fsg_lun_opts(item); struct fsg_opts *fsg_opts = to_fsg_opts(opts->group.cg_item.ci_parent); return fsg_store_cdrom(opts->lun, &fsg_opts->common->filesem, page, len); } CONFIGFS_ATTR(fsg_lun_opts_, cdrom); static ssize_t fsg_lun_opts_nofua_show(struct config_item *item, char *page) { return fsg_show_nofua(to_fsg_lun_opts(item)->lun, page); } static ssize_t fsg_lun_opts_nofua_store(struct config_item *item, const char *page, size_t len) { return fsg_store_nofua(to_fsg_lun_opts(item)->lun, page, len); } CONFIGFS_ATTR(fsg_lun_opts_, nofua); static ssize_t fsg_lun_opts_inquiry_string_show(struct config_item *item, char *page) { return fsg_show_inquiry_string(to_fsg_lun_opts(item)->lun, page); } static ssize_t fsg_lun_opts_inquiry_string_store(struct config_item *item, const char *page, size_t len) { return fsg_store_inquiry_string(to_fsg_lun_opts(item)->lun, page, len); } CONFIGFS_ATTR(fsg_lun_opts_, inquiry_string); static struct configfs_attribute *fsg_lun_attrs[] = { &fsg_lun_opts_attr_file, &fsg_lun_opts_attr_ro, &fsg_lun_opts_attr_removable, &fsg_lun_opts_attr_cdrom, &fsg_lun_opts_attr_nofua, &fsg_lun_opts_attr_inquiry_string, NULL, }; static const struct config_item_type fsg_lun_type = { .ct_item_ops = &fsg_lun_item_ops, .ct_attrs = fsg_lun_attrs, .ct_owner = THIS_MODULE, }; static struct config_group *fsg_lun_make(struct config_group *group, const char *name) { struct fsg_lun_opts *opts; struct fsg_opts *fsg_opts; struct fsg_lun_config config; char *num_str; u8 num; int ret; num_str = strchr(name, '.'); if (!num_str) { pr_err("Unable to locate . in LUN.NUMBER\n"); return ERR_PTR(-EINVAL); } num_str++; ret = kstrtou8(num_str, 0, &num); if (ret) return ERR_PTR(ret); fsg_opts = to_fsg_opts(&group->cg_item); if (num >= FSG_MAX_LUNS) return ERR_PTR(-ERANGE); num = array_index_nospec(num, FSG_MAX_LUNS); mutex_lock(&fsg_opts->lock); if (fsg_opts->refcnt || fsg_opts->common->luns[num]) { ret = -EBUSY; goto out; } opts = kzalloc(sizeof(*opts), GFP_KERNEL); if (!opts) { ret = -ENOMEM; goto out; } memset(&config, 0, sizeof(config)); config.removable = true; ret = fsg_common_create_lun(fsg_opts->common, &config, num, name, (const char **)&group->cg_item.ci_name); if (ret) { kfree(opts); goto out; } opts->lun = fsg_opts->common->luns[num]; opts->lun_id = num; mutex_unlock(&fsg_opts->lock); config_group_init_type_name(&opts->group, name, &fsg_lun_type); return &opts->group; out: mutex_unlock(&fsg_opts->lock); return ERR_PTR(ret); } static void fsg_lun_drop(struct config_group *group, struct config_item *item) { struct fsg_lun_opts *lun_opts; struct fsg_opts *fsg_opts; lun_opts = to_fsg_lun_opts(item); fsg_opts = to_fsg_opts(&group->cg_item); mutex_lock(&fsg_opts->lock); if (fsg_opts->refcnt) { struct config_item *gadget; gadget = group->cg_item.ci_parent->ci_parent; unregister_gadget_item(gadget); } fsg_common_remove_lun(lun_opts->lun); fsg_opts->common->luns[lun_opts->lun_id] = NULL; lun_opts->lun_id = 0; mutex_unlock(&fsg_opts->lock); config_item_put(item); } static void fsg_attr_release(struct config_item *item) { struct fsg_opts *opts = to_fsg_opts(item); usb_put_function_instance(&opts->func_inst); } static struct configfs_item_operations fsg_item_ops = { .release = fsg_attr_release, }; static ssize_t fsg_opts_stall_show(struct config_item *item, char *page) { struct fsg_opts *opts = to_fsg_opts(item); int result; mutex_lock(&opts->lock); result = sprintf(page, "%d", opts->common->can_stall); mutex_unlock(&opts->lock); return result; } static ssize_t fsg_opts_stall_store(struct config_item *item, const char *page, size_t len) { struct fsg_opts *opts = to_fsg_opts(item); int ret; bool stall; mutex_lock(&opts->lock); if (opts->refcnt) { mutex_unlock(&opts->lock); return -EBUSY; } ret = strtobool(page, &stall); if (!ret) { opts->common->can_stall = stall; ret = len; } mutex_unlock(&opts->lock); return ret; } CONFIGFS_ATTR(fsg_opts_, stall); #ifdef CONFIG_USB_GADGET_DEBUG_FILES static ssize_t fsg_opts_num_buffers_show(struct config_item *item, char *page) { struct fsg_opts *opts = to_fsg_opts(item); int result; mutex_lock(&opts->lock); result = sprintf(page, "%d", opts->common->fsg_num_buffers); mutex_unlock(&opts->lock); return result; } static ssize_t fsg_opts_num_buffers_store(struct config_item *item, const char *page, size_t len) { struct fsg_opts *opts = to_fsg_opts(item); int ret; u8 num; mutex_lock(&opts->lock); if (opts->refcnt) { ret = -EBUSY; goto end; } ret = kstrtou8(page, 0, &num); if (ret) goto end; ret = fsg_common_set_num_buffers(opts->common, num); if (ret) goto end; ret = len; end: mutex_unlock(&opts->lock); return ret; } CONFIGFS_ATTR(fsg_opts_, num_buffers); #endif static struct configfs_attribute *fsg_attrs[] = { &fsg_opts_attr_stall, #ifdef CONFIG_USB_GADGET_DEBUG_FILES &fsg_opts_attr_num_buffers, #endif NULL, }; static struct configfs_group_operations fsg_group_ops = { .make_group = fsg_lun_make, .drop_item = fsg_lun_drop, }; static const struct config_item_type fsg_func_type = { .ct_item_ops = &fsg_item_ops, .ct_group_ops = &fsg_group_ops, .ct_attrs = fsg_attrs, .ct_owner = THIS_MODULE, }; static void fsg_free_inst(struct usb_function_instance *fi) { struct fsg_opts *opts; opts = fsg_opts_from_func_inst(fi); fsg_common_release(opts->common); kfree(opts); } static struct usb_function_instance *fsg_alloc_inst(void) { struct fsg_opts *opts; struct fsg_lun_config config; int rc; opts = kzalloc(sizeof(*opts), GFP_KERNEL); if (!opts) return ERR_PTR(-ENOMEM); mutex_init(&opts->lock); opts->func_inst.free_func_inst = fsg_free_inst; opts->common = fsg_common_setup(opts->common); if (IS_ERR(opts->common)) { rc = PTR_ERR(opts->common); goto release_opts; } rc = fsg_common_set_num_buffers(opts->common, CONFIG_USB_GADGET_STORAGE_NUM_BUFFERS); if (rc) goto release_common; pr_info(FSG_DRIVER_DESC ", version: " FSG_DRIVER_VERSION "\n"); memset(&config, 0, sizeof(config)); config.removable = true; rc = fsg_common_create_lun(opts->common, &config, 0, "lun.0", (const char **)&opts->func_inst.group.cg_item.ci_name); if (rc) goto release_buffers; opts->lun0.lun = opts->common->luns[0]; opts->lun0.lun_id = 0; config_group_init_type_name(&opts->func_inst.group, "", &fsg_func_type); config_group_init_type_name(&opts->lun0.group, "lun.0", &fsg_lun_type); configfs_add_default_group(&opts->lun0.group, &opts->func_inst.group); return &opts->func_inst; release_buffers: fsg_common_free_buffers(opts->common); release_common: kfree(opts->common); release_opts: kfree(opts); return ERR_PTR(rc); } static void fsg_free(struct usb_function *f) { struct fsg_dev *fsg; struct fsg_opts *opts; fsg = container_of(f, struct fsg_dev, function); opts = container_of(f->fi, struct fsg_opts, func_inst); mutex_lock(&opts->lock); opts->refcnt--; mutex_unlock(&opts->lock); kfree(fsg); } static struct usb_function *fsg_alloc(struct usb_function_instance *fi) { struct fsg_opts *opts = fsg_opts_from_func_inst(fi); struct fsg_common *common = opts->common; struct fsg_dev *fsg; fsg = kzalloc(sizeof(*fsg), GFP_KERNEL); if (unlikely(!fsg)) return ERR_PTR(-ENOMEM); mutex_lock(&opts->lock); opts->refcnt++; mutex_unlock(&opts->lock); fsg->function.name = FSG_DRIVER_DESC; fsg->function.bind = fsg_bind; fsg->function.unbind = fsg_unbind; fsg->function.setup = fsg_setup; fsg->function.set_alt = fsg_set_alt; fsg->function.disable = fsg_disable; fsg->function.free_func = fsg_free; fsg->common = common; return &fsg->function; } DECLARE_USB_FUNCTION_INIT(mass_storage, fsg_alloc_inst, fsg_alloc); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Michal Nazarewicz"); /************************* Module parameters *************************/ void fsg_config_from_params(struct fsg_config *cfg, const struct fsg_module_parameters *params, unsigned int fsg_num_buffers) { struct fsg_lun_config *lun; unsigned i; /* Configure LUNs */ cfg->nluns = min(params->luns ?: (params->file_count ?: 1u), (unsigned)FSG_MAX_LUNS); for (i = 0, lun = cfg->luns; i < cfg->nluns; ++i, ++lun) { lun->ro = !!params->ro[i]; lun->cdrom = !!params->cdrom[i]; lun->removable = !!params->removable[i]; lun->filename = params->file_count > i && params->file[i][0] ? params->file[i] : NULL; } /* Let MSF use defaults */ cfg->vendor_name = NULL; cfg->product_name = NULL; cfg->ops = NULL; cfg->private_data = NULL; /* Finalise */ cfg->can_stall = params->stall; cfg->fsg_num_buffers = fsg_num_buffers; } EXPORT_SYMBOL_GPL(fsg_config_from_params);