xref: /freebsd/sys/dev/usb/storage/ustorage_fs.c (revision 7ef62cebc2f965b0f640263e179276928885e33d)
1 /* $FreeBSD$ */
2 /*-
3  * SPDX-License-Identifier: BSD-3-Clause
4  *
5  * Copyright (C) 2003-2005 Alan Stern
6  * Copyright (C) 2008 Hans Petter Selasky
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions, and the following disclaimer,
14  *    without modification.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. The names of the above-listed copyright holders may not be used
19  *    to endorse or promote products derived from this software without
20  *    specific prior written permission.
21  *
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
24  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
25  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
26  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
27  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
28  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
29  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 /*
37  * NOTE: Much of the SCSI statemachine handling code derives from the
38  * Linux USB gadget stack.
39  */
40 
41 #ifdef USB_GLOBAL_INCLUDE_FILE
42 #include USB_GLOBAL_INCLUDE_FILE
43 #else
44 #include <sys/stdint.h>
45 #include <sys/stddef.h>
46 #include <sys/param.h>
47 #include <sys/queue.h>
48 #include <sys/types.h>
49 #include <sys/systm.h>
50 #include <sys/kernel.h>
51 #include <sys/bus.h>
52 #include <sys/module.h>
53 #include <sys/lock.h>
54 #include <sys/mutex.h>
55 #include <sys/condvar.h>
56 #include <sys/sysctl.h>
57 #include <sys/sx.h>
58 #include <sys/unistd.h>
59 #include <sys/callout.h>
60 #include <sys/malloc.h>
61 #include <sys/priv.h>
62 
63 #include <dev/usb/usb.h>
64 #include <dev/usb/usbdi.h>
65 #include "usbdevs.h"
66 #include "usb_if.h"
67 
68 #define	USB_DEBUG_VAR ustorage_fs_debug
69 #include <dev/usb/usb_debug.h>
70 #endif			/* USB_GLOBAL_INCLUDE_FILE */
71 
72 #ifdef USB_DEBUG
73 static int ustorage_fs_debug = 0;
74 
75 SYSCTL_NODE(_hw_usb, OID_AUTO, ustorage_fs, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
76     "USB ustorage_fs");
77 SYSCTL_INT(_hw_usb_ustorage_fs, OID_AUTO, debug, CTLFLAG_RWTUN,
78     &ustorage_fs_debug, 0, "ustorage_fs debug level");
79 #endif
80 
81 /* Define some limits */
82 
83 #ifndef USTORAGE_FS_BULK_SIZE
84 #define	USTORAGE_FS_BULK_SIZE	(1U << 17)	/* bytes */
85 #endif
86 
87 #ifndef	USTORAGE_FS_MAX_LUN
88 #define	USTORAGE_FS_MAX_LUN	8	/* units */
89 #endif
90 
91 #ifndef USTORAGE_QDATA_MAX
92 #define	USTORAGE_QDATA_MAX	40	/* bytes */
93 #endif
94 
95 /*
96  * The SCSI ID string must be exactly 28 characters long
97  * exluding the terminating zero.
98  */
99 #ifndef USTORAGE_FS_ID_STRING
100 #define	USTORAGE_FS_ID_STRING \
101 	"FreeBSD " /* 8 */ \
102 	"File-Stor Gadget" /* 16 */ \
103 	"0101" /* 4 */
104 #endif
105 
106 /*
107  * The following macro defines the number of
108  * sectors to be allocated for the RAM disk:
109  */
110 #ifndef USTORAGE_FS_RAM_SECT
111 #define	USTORAGE_FS_RAM_SECT (1UL << 13)
112 #endif
113 
114 static uint8_t *ustorage_fs_ramdisk;
115 
116 /* USB transfer definitions */
117 
118 #define	USTORAGE_FS_T_BBB_COMMAND     0
119 #define	USTORAGE_FS_T_BBB_DATA_DUMP   1
120 #define	USTORAGE_FS_T_BBB_DATA_READ   2
121 #define	USTORAGE_FS_T_BBB_DATA_WRITE  3
122 #define	USTORAGE_FS_T_BBB_STATUS      4
123 #define	USTORAGE_FS_T_BBB_MAX         5
124 
125 /* USB data stage direction */
126 
127 #define	DIR_NONE	0
128 #define	DIR_READ	1
129 #define	DIR_WRITE	2
130 
131 /* USB interface specific control request */
132 
133 #define	UR_BBB_RESET		0xff	/* Bulk-Only reset */
134 #define	UR_BBB_GET_MAX_LUN	0xfe	/* Get maximum lun */
135 
136 /* Command Block Wrapper */
137 typedef struct {
138 	uDWord	dCBWSignature;
139 #define	CBWSIGNATURE	0x43425355
140 	uDWord	dCBWTag;
141 	uDWord	dCBWDataTransferLength;
142 	uByte	bCBWFlags;
143 #define	CBWFLAGS_OUT	0x00
144 #define	CBWFLAGS_IN	0x80
145 	uByte	bCBWLUN;
146 	uByte	bCDBLength;
147 #define	CBWCDBLENGTH	16
148 	uByte	CBWCDB[CBWCDBLENGTH];
149 } __packed ustorage_fs_bbb_cbw_t;
150 
151 #define	USTORAGE_FS_BBB_CBW_SIZE	31
152 
153 /* Command Status Wrapper */
154 typedef struct {
155 	uDWord	dCSWSignature;
156 #define	CSWSIGNATURE	0x53425355
157 	uDWord	dCSWTag;
158 	uDWord	dCSWDataResidue;
159 	uByte	bCSWStatus;
160 #define	CSWSTATUS_GOOD	0x0
161 #define	CSWSTATUS_FAILED	0x1
162 #define	CSWSTATUS_PHASE	0x2
163 } __packed ustorage_fs_bbb_csw_t;
164 
165 #define	USTORAGE_FS_BBB_CSW_SIZE	13
166 
167 struct ustorage_fs_lun {
168 	uint8_t	*memory_image;
169 
170 	uint32_t num_sectors;
171 	uint32_t sense_data;
172 	uint32_t sense_data_info;
173 	uint32_t unit_attention_data;
174 
175 	uint8_t	read_only:1;
176 	uint8_t	prevent_medium_removal:1;
177 	uint8_t	info_valid:1;
178 	uint8_t	removable:1;
179 };
180 
181 struct ustorage_fs_softc {
182 	ustorage_fs_bbb_cbw_t *sc_cbw;	/* Command Wrapper Block */
183 	ustorage_fs_bbb_csw_t *sc_csw;	/* Command Status Block */
184 	void *sc_dma_ptr;		/* Main data buffer */
185 
186 	struct mtx sc_mtx;
187 
188 	struct ustorage_fs_lun sc_lun[USTORAGE_FS_MAX_LUN];
189 
190 	struct {
191 		uint8_t *data_ptr;
192 		struct ustorage_fs_lun *currlun;
193 
194 		uint32_t data_rem;	/* bytes, as reported by the command
195 					 * block wrapper */
196 		uint32_t offset;	/* bytes */
197 
198 		uint8_t	cbw_dir;
199 		uint8_t	cmd_dir;
200 		uint8_t	lun;
201 		uint8_t	cmd_len;
202 		uint8_t	data_short:1;
203 		uint8_t	data_error:1;
204 	}	sc_transfer;
205 
206 	device_t sc_dev;
207 	struct usb_device *sc_udev;
208 	struct usb_xfer *sc_xfer[USTORAGE_FS_T_BBB_MAX];
209 
210 	uint8_t	sc_iface_no;		/* interface number */
211 	uint8_t	sc_last_lun;
212 	uint8_t	sc_last_xfer_index;
213 	uint8_t	sc_qdata[USTORAGE_QDATA_MAX];
214 };
215 
216 /* prototypes */
217 
218 static device_probe_t ustorage_fs_probe;
219 static device_attach_t ustorage_fs_attach;
220 static device_detach_t ustorage_fs_detach;
221 static device_suspend_t ustorage_fs_suspend;
222 static device_resume_t ustorage_fs_resume;
223 static usb_handle_request_t ustorage_fs_handle_request;
224 
225 static usb_callback_t ustorage_fs_t_bbb_command_callback;
226 static usb_callback_t ustorage_fs_t_bbb_data_dump_callback;
227 static usb_callback_t ustorage_fs_t_bbb_data_read_callback;
228 static usb_callback_t ustorage_fs_t_bbb_data_write_callback;
229 static usb_callback_t ustorage_fs_t_bbb_status_callback;
230 
231 static void ustorage_fs_transfer_start(struct ustorage_fs_softc *sc, uint8_t xfer_index);
232 static void ustorage_fs_transfer_stop(struct ustorage_fs_softc *sc);
233 
234 static uint8_t ustorage_fs_verify(struct ustorage_fs_softc *sc);
235 static uint8_t ustorage_fs_inquiry(struct ustorage_fs_softc *sc);
236 static uint8_t ustorage_fs_request_sense(struct ustorage_fs_softc *sc);
237 static uint8_t ustorage_fs_read_capacity(struct ustorage_fs_softc *sc);
238 static uint8_t ustorage_fs_mode_sense(struct ustorage_fs_softc *sc);
239 static uint8_t ustorage_fs_start_stop(struct ustorage_fs_softc *sc);
240 static uint8_t ustorage_fs_prevent_allow(struct ustorage_fs_softc *sc);
241 static uint8_t ustorage_fs_read_format_capacities(struct ustorage_fs_softc *sc);
242 static uint8_t ustorage_fs_mode_select(struct ustorage_fs_softc *sc);
243 static uint8_t ustorage_fs_min_len(struct ustorage_fs_softc *sc, uint32_t len, uint32_t mask);
244 static uint8_t ustorage_fs_read(struct ustorage_fs_softc *sc);
245 static uint8_t ustorage_fs_write(struct ustorage_fs_softc *sc);
246 static uint8_t ustorage_fs_check_cmd(struct ustorage_fs_softc *sc, uint8_t cmd_size, uint16_t mask, uint8_t needs_medium);
247 static uint8_t ustorage_fs_do_cmd(struct ustorage_fs_softc *sc);
248 
249 static device_method_t ustorage_fs_methods[] = {
250 	/* USB interface */
251 	DEVMETHOD(usb_handle_request, ustorage_fs_handle_request),
252 
253 	/* Device interface */
254 	DEVMETHOD(device_probe, ustorage_fs_probe),
255 	DEVMETHOD(device_attach, ustorage_fs_attach),
256 	DEVMETHOD(device_detach, ustorage_fs_detach),
257 	DEVMETHOD(device_suspend, ustorage_fs_suspend),
258 	DEVMETHOD(device_resume, ustorage_fs_resume),
259 
260 	DEVMETHOD_END
261 };
262 
263 static driver_t ustorage_fs_driver = {
264 	.name = "ustorage_fs",
265 	.methods = ustorage_fs_methods,
266 	.size = sizeof(struct ustorage_fs_softc),
267 };
268 
269 DRIVER_MODULE(ustorage_fs, uhub, ustorage_fs_driver, NULL, NULL);
270 MODULE_VERSION(ustorage_fs, 0);
271 MODULE_DEPEND(ustorage_fs, usb, 1, 1, 1);
272 
273 static struct usb_config ustorage_fs_bbb_config[USTORAGE_FS_T_BBB_MAX] = {
274 	[USTORAGE_FS_T_BBB_COMMAND] = {
275 		.type = UE_BULK,
276 		.endpoint = UE_ADDR_ANY,
277 		.direction = UE_DIR_OUT,
278 		.bufsize = sizeof(ustorage_fs_bbb_cbw_t),
279 		.callback = &ustorage_fs_t_bbb_command_callback,
280 		.usb_mode = USB_MODE_DEVICE,
281 	},
282 
283 	[USTORAGE_FS_T_BBB_DATA_DUMP] = {
284 		.type = UE_BULK,
285 		.endpoint = UE_ADDR_ANY,
286 		.direction = UE_DIR_OUT,
287 		.bufsize = 0,	/* use wMaxPacketSize */
288 		.flags = {.proxy_buffer = 1,.short_xfer_ok = 1,},
289 		.callback = &ustorage_fs_t_bbb_data_dump_callback,
290 		.usb_mode = USB_MODE_DEVICE,
291 	},
292 
293 	[USTORAGE_FS_T_BBB_DATA_READ] = {
294 		.type = UE_BULK,
295 		.endpoint = UE_ADDR_ANY,
296 		.direction = UE_DIR_OUT,
297 		.bufsize = USTORAGE_FS_BULK_SIZE,
298 		.flags = {.proxy_buffer = 1,.short_xfer_ok = 1},
299 		.callback = &ustorage_fs_t_bbb_data_read_callback,
300 		.usb_mode = USB_MODE_DEVICE,
301 	},
302 
303 	[USTORAGE_FS_T_BBB_DATA_WRITE] = {
304 		.type = UE_BULK,
305 		.endpoint = UE_ADDR_ANY,
306 		.direction = UE_DIR_IN,
307 		.bufsize = USTORAGE_FS_BULK_SIZE,
308 		.flags = {.proxy_buffer = 1,.short_xfer_ok = 1,.ext_buffer = 1},
309 		.callback = &ustorage_fs_t_bbb_data_write_callback,
310 		.usb_mode = USB_MODE_DEVICE,
311 	},
312 
313 	[USTORAGE_FS_T_BBB_STATUS] = {
314 		.type = UE_BULK,
315 		.endpoint = UE_ADDR_ANY,
316 		.direction = UE_DIR_IN,
317 		.bufsize = sizeof(ustorage_fs_bbb_csw_t),
318 		.flags = {.short_xfer_ok = 1},
319 		.callback = &ustorage_fs_t_bbb_status_callback,
320 		.usb_mode = USB_MODE_DEVICE,
321 	},
322 };
323 
324 /*
325  * USB device probe/attach/detach
326  */
327 
328 static int
329 ustorage_fs_probe(device_t dev)
330 {
331 	struct usb_attach_arg *uaa = device_get_ivars(dev);
332 	struct usb_interface_descriptor *id;
333 
334 	if (uaa->usb_mode != USB_MODE_DEVICE) {
335 		return (ENXIO);
336 	}
337 	/* Check for a standards compliant device */
338 	id = usbd_get_interface_descriptor(uaa->iface);
339 	if ((id == NULL) ||
340 	    (id->bInterfaceClass != UICLASS_MASS) ||
341 	    (id->bInterfaceSubClass != UISUBCLASS_SCSI) ||
342 	    (id->bInterfaceProtocol != UIPROTO_MASS_BBB)) {
343 		return (ENXIO);
344 	}
345 	return (BUS_PROBE_GENERIC);
346 }
347 
348 static int
349 ustorage_fs_attach(device_t dev)
350 {
351 	struct ustorage_fs_softc *sc = device_get_softc(dev);
352 	struct usb_attach_arg *uaa = device_get_ivars(dev);
353 	struct usb_interface_descriptor *id;
354 	int err;
355 	int unit;
356 
357 	/*
358 	 * NOTE: the softc struct is cleared in device_set_driver.
359 	 * We can safely call ustorage_fs_detach without specifically
360 	 * initializing the struct.
361 	 */
362 
363 	sc->sc_dev = dev;
364 	sc->sc_udev = uaa->device;
365 	unit = device_get_unit(dev);
366 
367 	/* enable power saving mode */
368 	usbd_set_power_mode(uaa->device, USB_POWER_MODE_SAVE);
369 
370 	if (unit == 0) {
371 		if (ustorage_fs_ramdisk == NULL) {
372 			/*
373 			 * allocate a memory image for our ramdisk until
374 			 * further
375 			 */
376 			ustorage_fs_ramdisk =
377 			    malloc(USTORAGE_FS_RAM_SECT << 9, M_USB,
378 			    M_ZERO | M_WAITOK);
379 		}
380 		sc->sc_lun[0].memory_image = ustorage_fs_ramdisk;
381 		sc->sc_lun[0].num_sectors = USTORAGE_FS_RAM_SECT;
382 		sc->sc_lun[0].removable = 1;
383 	}
384 
385 	device_set_usb_desc(dev);
386 
387 	mtx_init(&sc->sc_mtx, "USTORAGE_FS lock",
388 	    NULL, (MTX_DEF | MTX_RECURSE));
389 
390 	/* get interface index */
391 
392 	id = usbd_get_interface_descriptor(uaa->iface);
393 	if (id == NULL) {
394 		device_printf(dev, "failed to get "
395 		    "interface number\n");
396 		goto detach;
397 	}
398 	sc->sc_iface_no = id->bInterfaceNumber;
399 
400 	err = usbd_transfer_setup(uaa->device,
401 	    &uaa->info.bIfaceIndex, sc->sc_xfer, ustorage_fs_bbb_config,
402 	    USTORAGE_FS_T_BBB_MAX, sc, &sc->sc_mtx);
403 	if (err) {
404 		device_printf(dev, "could not setup required "
405 		    "transfers, %s\n", usbd_errstr(err));
406 		goto detach;
407 	}
408 
409 	sc->sc_cbw = usbd_xfer_get_frame_buffer(sc->sc_xfer[
410 	    USTORAGE_FS_T_BBB_COMMAND], 0);
411 	sc->sc_csw = usbd_xfer_get_frame_buffer(sc->sc_xfer[
412 	    USTORAGE_FS_T_BBB_STATUS], 0);
413  	sc->sc_dma_ptr = usbd_xfer_get_frame_buffer(sc->sc_xfer[
414 	    USTORAGE_FS_T_BBB_DATA_READ], 0);
415 
416 	/* start Mass Storage State Machine */
417 
418 	mtx_lock(&sc->sc_mtx);
419 	ustorage_fs_transfer_start(sc, USTORAGE_FS_T_BBB_COMMAND);
420 	mtx_unlock(&sc->sc_mtx);
421 
422 	return (0);			/* success */
423 
424 detach:
425 	ustorage_fs_detach(dev);
426 	return (ENXIO);			/* failure */
427 }
428 
429 static int
430 ustorage_fs_detach(device_t dev)
431 {
432 	struct ustorage_fs_softc *sc = device_get_softc(dev);
433 
434 	/* teardown our statemachine */
435 
436 	usbd_transfer_unsetup(sc->sc_xfer, USTORAGE_FS_T_BBB_MAX);
437 
438 	mtx_destroy(&sc->sc_mtx);
439 
440 	return (0);			/* success */
441 }
442 
443 static int
444 ustorage_fs_suspend(device_t dev)
445 {
446 	device_printf(dev, "suspending\n");
447 	return (0);			/* success */
448 }
449 
450 static int
451 ustorage_fs_resume(device_t dev)
452 {
453 	device_printf(dev, "resuming\n");
454 	return (0);			/* success */
455 }
456 
457 /*
458  * Generic functions to handle transfers
459  */
460 
461 static void
462 ustorage_fs_transfer_start(struct ustorage_fs_softc *sc, uint8_t xfer_index)
463 {
464 	if (sc->sc_xfer[xfer_index]) {
465 		sc->sc_last_xfer_index = xfer_index;
466 		usbd_transfer_start(sc->sc_xfer[xfer_index]);
467 	}
468 }
469 
470 static void
471 ustorage_fs_transfer_stop(struct ustorage_fs_softc *sc)
472 {
473 	usbd_transfer_stop(sc->sc_xfer[sc->sc_last_xfer_index]);
474 	mtx_unlock(&sc->sc_mtx);
475 	usbd_transfer_drain(sc->sc_xfer[sc->sc_last_xfer_index]);
476 	mtx_lock(&sc->sc_mtx);
477 }
478 
479 static int
480 ustorage_fs_handle_request(device_t dev,
481     const void *preq, void **pptr, uint16_t *plen,
482     uint16_t offset, uint8_t *pstate)
483 {
484 	struct ustorage_fs_softc *sc = device_get_softc(dev);
485 	const struct usb_device_request *req = preq;
486 	uint8_t is_complete = *pstate;
487 
488 	if (!is_complete) {
489 		if ((req->bmRequestType == UT_WRITE_CLASS_INTERFACE) &&
490 		    (req->bRequest == UR_BBB_RESET)) {
491 			*plen = 0;
492 			mtx_lock(&sc->sc_mtx);
493 			ustorage_fs_transfer_stop(sc);
494 			sc->sc_transfer.data_error = 1;
495 			ustorage_fs_transfer_start(sc,
496 			    USTORAGE_FS_T_BBB_COMMAND);
497 			mtx_unlock(&sc->sc_mtx);
498 			return (0);
499 		} else if ((req->bmRequestType == UT_READ_CLASS_INTERFACE) &&
500 			   (req->bRequest == UR_BBB_GET_MAX_LUN)) {
501 			if (offset == 0) {
502 				*plen = 1;
503 				*pptr = &sc->sc_last_lun;
504 			} else {
505 				*plen = 0;
506 			}
507 			return (0);
508 		}
509 	}
510 	return (ENXIO);			/* use builtin handler */
511 }
512 
513 static void
514 ustorage_fs_t_bbb_command_callback(struct usb_xfer *xfer, usb_error_t error)
515 {
516 	struct ustorage_fs_softc *sc = usbd_xfer_softc(xfer);
517 	uint32_t tag;
518 	uint8_t err = 0;
519 
520 	DPRINTF("\n");
521 
522 	switch (USB_GET_STATE(xfer)) {
523 	case USB_ST_TRANSFERRED:
524 
525 		tag = UGETDW(sc->sc_cbw->dCBWSignature);
526 
527 		if (tag != CBWSIGNATURE) {
528 			/* do nothing */
529 			DPRINTF("invalid signature 0x%08x\n", tag);
530 			break;
531 		}
532 		tag = UGETDW(sc->sc_cbw->dCBWTag);
533 
534 		/* echo back tag */
535 		USETDW(sc->sc_csw->dCSWTag, tag);
536 
537 		/* reset status */
538 		sc->sc_csw->bCSWStatus = 0;
539 
540 		/* reset data offset, data length and data remainder */
541 		sc->sc_transfer.offset = 0;
542 		sc->sc_transfer.data_rem =
543 		    UGETDW(sc->sc_cbw->dCBWDataTransferLength);
544 
545 		/* reset data flags */
546 		sc->sc_transfer.data_short = 0;
547 
548 		/* extract LUN */
549 		sc->sc_transfer.lun = sc->sc_cbw->bCBWLUN;
550 
551 		if (sc->sc_transfer.data_rem == 0) {
552 			sc->sc_transfer.cbw_dir = DIR_NONE;
553 		} else {
554 			if (sc->sc_cbw->bCBWFlags & CBWFLAGS_IN) {
555 				sc->sc_transfer.cbw_dir = DIR_WRITE;
556 			} else {
557 				sc->sc_transfer.cbw_dir = DIR_READ;
558 			}
559 		}
560 
561 		sc->sc_transfer.cmd_len = sc->sc_cbw->bCDBLength;
562 		if ((sc->sc_transfer.cmd_len > sizeof(sc->sc_cbw->CBWCDB)) ||
563 		    (sc->sc_transfer.cmd_len == 0)) {
564 			/* just halt - this is invalid */
565 			DPRINTF("invalid command length %d bytes\n",
566 			    sc->sc_transfer.cmd_len);
567 			break;
568 		}
569 
570 		err = ustorage_fs_do_cmd(sc);
571 		if (err) {
572 			/* got an error */
573 			DPRINTF("command failed\n");
574 			break;
575 		}
576 		if ((sc->sc_transfer.data_rem > 0) &&
577 		    (sc->sc_transfer.cbw_dir != sc->sc_transfer.cmd_dir)) {
578 			/* contradicting data transfer direction */
579 			err = 1;
580 			DPRINTF("data direction mismatch\n");
581 			break;
582 		}
583 		switch (sc->sc_transfer.cbw_dir) {
584 		case DIR_READ:
585 			ustorage_fs_transfer_start(sc, USTORAGE_FS_T_BBB_DATA_READ);
586 			break;
587 		case DIR_WRITE:
588 			ustorage_fs_transfer_start(sc, USTORAGE_FS_T_BBB_DATA_WRITE);
589 			break;
590 		default:
591 			ustorage_fs_transfer_start(sc,
592 			    USTORAGE_FS_T_BBB_STATUS);
593 			break;
594 		}
595 		break;
596 
597 	case USB_ST_SETUP:
598 tr_setup:
599 		if (sc->sc_transfer.data_error) {
600 			sc->sc_transfer.data_error = 0;
601 			usbd_xfer_set_stall(xfer);
602 			DPRINTF("stall pipe\n");
603 		}
604 		usbd_xfer_set_frame_len(xfer, 0,
605 		    sizeof(ustorage_fs_bbb_cbw_t));
606 		usbd_transfer_submit(xfer);
607 		break;
608 
609 	default:			/* Error */
610 		DPRINTF("error\n");
611 		if (error == USB_ERR_CANCELLED) {
612 			break;
613 		}
614 		/* If the pipe is already stalled, don't do another stall */
615 		if (!usbd_xfer_is_stalled(xfer))
616 			sc->sc_transfer.data_error = 1;
617 
618 		/* try again */
619 		goto tr_setup;
620 	}
621 	if (err) {
622 		if (sc->sc_csw->bCSWStatus == 0) {
623 			/* set some default error code */
624 			sc->sc_csw->bCSWStatus = CSWSTATUS_FAILED;
625 		}
626 		if (sc->sc_transfer.cbw_dir == DIR_READ) {
627 			/* dump all data */
628 			ustorage_fs_transfer_start(sc,
629 			    USTORAGE_FS_T_BBB_DATA_DUMP);
630 			return;
631 		}
632 		if (sc->sc_transfer.cbw_dir == DIR_WRITE) {
633 			/* need to stall before status */
634 			sc->sc_transfer.data_error = 1;
635 		}
636 		ustorage_fs_transfer_start(sc, USTORAGE_FS_T_BBB_STATUS);
637 	}
638 }
639 
640 static void
641 ustorage_fs_t_bbb_data_dump_callback(struct usb_xfer *xfer, usb_error_t error)
642 {
643 	struct ustorage_fs_softc *sc = usbd_xfer_softc(xfer);
644 	uint32_t max_bulk = usbd_xfer_max_len(xfer);
645 	int actlen, sumlen;
646 
647 	usbd_xfer_status(xfer, &actlen, &sumlen, NULL, NULL);
648 
649 	DPRINTF("\n");
650 
651 	switch (USB_GET_STATE(xfer)) {
652 	case USB_ST_TRANSFERRED:
653 		sc->sc_transfer.data_rem -= actlen;
654 		sc->sc_transfer.offset += actlen;
655 
656 		if (actlen != sumlen || sc->sc_transfer.data_rem == 0) {
657 			/* short transfer or end of data */
658 			ustorage_fs_transfer_start(sc,
659 			    USTORAGE_FS_T_BBB_STATUS);
660 			break;
661 		}
662 		/* Fallthrough */
663 
664 	case USB_ST_SETUP:
665 tr_setup:
666 		if (max_bulk > sc->sc_transfer.data_rem) {
667 			max_bulk = sc->sc_transfer.data_rem;
668 		}
669 		if (sc->sc_transfer.data_error) {
670 			sc->sc_transfer.data_error = 0;
671 			usbd_xfer_set_stall(xfer);
672 		}
673 		usbd_xfer_set_frame_len(xfer, 0, max_bulk);
674 		usbd_transfer_submit(xfer);
675 		break;
676 
677 	default:			/* Error */
678 		if (error == USB_ERR_CANCELLED) {
679 			break;
680 		}
681 		/*
682 		 * If the pipe is already stalled, don't do another stall:
683 		 */
684 		if (!usbd_xfer_is_stalled(xfer))
685 			sc->sc_transfer.data_error = 1;
686 
687 		/* try again */
688 		goto tr_setup;
689 	}
690 }
691 
692 static void
693 ustorage_fs_t_bbb_data_read_callback(struct usb_xfer *xfer, usb_error_t error)
694 {
695 	struct ustorage_fs_softc *sc = usbd_xfer_softc(xfer);
696 	uint32_t max_bulk = usbd_xfer_max_len(xfer);
697 	int actlen, sumlen;
698 
699 	usbd_xfer_status(xfer, &actlen, &sumlen, NULL, NULL);
700 
701 	DPRINTF("\n");
702 
703 	switch (USB_GET_STATE(xfer)) {
704 	case USB_ST_TRANSFERRED:
705 		/* XXX copy data from DMA buffer */
706 		memcpy(sc->sc_transfer.data_ptr, sc->sc_dma_ptr, actlen);
707 
708 		sc->sc_transfer.data_rem -= actlen;
709 		sc->sc_transfer.data_ptr += actlen;
710 		sc->sc_transfer.offset += actlen;
711 
712 		if (actlen != sumlen || sc->sc_transfer.data_rem == 0) {
713 			/* short transfer or end of data */
714 			ustorage_fs_transfer_start(sc,
715 			    USTORAGE_FS_T_BBB_STATUS);
716 			break;
717 		}
718 		/* Fallthrough */
719 
720 	case USB_ST_SETUP:
721 tr_setup:
722 		if (max_bulk > sc->sc_transfer.data_rem) {
723 			max_bulk = sc->sc_transfer.data_rem;
724 		}
725 		if (sc->sc_transfer.data_error) {
726 			sc->sc_transfer.data_error = 0;
727 			usbd_xfer_set_stall(xfer);
728 		}
729 
730 		usbd_xfer_set_frame_data(xfer, 0, sc->sc_dma_ptr, max_bulk);
731 		usbd_transfer_submit(xfer);
732 		break;
733 
734 	default:			/* Error */
735 		if (error == USB_ERR_CANCELLED) {
736 			break;
737 		}
738 		/* If the pipe is already stalled, don't do another stall */
739 		if (!usbd_xfer_is_stalled(xfer))
740 			sc->sc_transfer.data_error = 1;
741 
742 		/* try again */
743 		goto tr_setup;
744 	}
745 }
746 
747 static void
748 ustorage_fs_t_bbb_data_write_callback(struct usb_xfer *xfer, usb_error_t error)
749 {
750 	struct ustorage_fs_softc *sc = usbd_xfer_softc(xfer);
751 	uint32_t max_bulk = usbd_xfer_max_len(xfer);
752 	int actlen, sumlen;
753 
754 	usbd_xfer_status(xfer, &actlen, &sumlen, NULL, NULL);
755 
756 	DPRINTF("\n");
757 
758 	switch (USB_GET_STATE(xfer)) {
759 	case USB_ST_TRANSFERRED:
760 		sc->sc_transfer.data_rem -= actlen;
761 		sc->sc_transfer.data_ptr += actlen;
762 		sc->sc_transfer.offset += actlen;
763 
764 		if (actlen != sumlen || sc->sc_transfer.data_rem == 0) {
765 			/* short transfer or end of data */
766 			ustorage_fs_transfer_start(sc,
767 			    USTORAGE_FS_T_BBB_STATUS);
768 			break;
769 		}
770 	case USB_ST_SETUP:
771 tr_setup:
772 		if (max_bulk >= sc->sc_transfer.data_rem) {
773 			max_bulk = sc->sc_transfer.data_rem;
774 			if (sc->sc_transfer.data_short)
775 				usbd_xfer_set_flag(xfer, USB_FORCE_SHORT_XFER);
776 			else
777 				usbd_xfer_clr_flag(xfer, USB_FORCE_SHORT_XFER);
778 		} else
779 			usbd_xfer_clr_flag(xfer, USB_FORCE_SHORT_XFER);
780 
781 		if (sc->sc_transfer.data_error) {
782 			sc->sc_transfer.data_error = 0;
783 			usbd_xfer_set_stall(xfer);
784 		}
785 
786 		/* XXX copy data to DMA buffer */
787 		memcpy(sc->sc_dma_ptr, sc->sc_transfer.data_ptr, max_bulk);
788 
789 		usbd_xfer_set_frame_data(xfer, 0, sc->sc_dma_ptr, max_bulk);
790 		usbd_transfer_submit(xfer);
791 		break;
792 
793 	default:			/* Error */
794 		if (error == USB_ERR_CANCELLED) {
795 			break;
796 		}
797 		/*
798 		 * If the pipe is already stalled, don't do another
799 		 * stall
800 		 */
801 		if (!usbd_xfer_is_stalled(xfer))
802 			sc->sc_transfer.data_error = 1;
803 
804 		/* try again */
805 		goto tr_setup;
806 	}
807 }
808 
809 static void
810 ustorage_fs_t_bbb_status_callback(struct usb_xfer *xfer, usb_error_t error)
811 {
812 	struct ustorage_fs_softc *sc = usbd_xfer_softc(xfer);
813 
814 	DPRINTF("\n");
815 
816 	switch (USB_GET_STATE(xfer)) {
817 	case USB_ST_TRANSFERRED:
818 		ustorage_fs_transfer_start(sc, USTORAGE_FS_T_BBB_COMMAND);
819 		break;
820 
821 	case USB_ST_SETUP:
822 tr_setup:
823 		USETDW(sc->sc_csw->dCSWSignature, CSWSIGNATURE);
824 		USETDW(sc->sc_csw->dCSWDataResidue, sc->sc_transfer.data_rem);
825 
826 		if (sc->sc_transfer.data_error) {
827 			sc->sc_transfer.data_error = 0;
828 			usbd_xfer_set_stall(xfer);
829 		}
830 		usbd_xfer_set_frame_len(xfer, 0,
831 		    sizeof(ustorage_fs_bbb_csw_t));
832 		usbd_transfer_submit(xfer);
833 		break;
834 
835 	default:
836 		if (error == USB_ERR_CANCELLED) {
837 			break;
838 		}
839 		/* If the pipe is already stalled, don't do another stall */
840 		if (!usbd_xfer_is_stalled(xfer))
841 			sc->sc_transfer.data_error = 1;
842 
843 		/* try again */
844 		goto tr_setup;
845 	}
846 }
847 
848 /* SCSI commands that we recognize */
849 #define	SC_FORMAT_UNIT			0x04
850 #define	SC_INQUIRY			0x12
851 #define	SC_MODE_SELECT_6		0x15
852 #define	SC_MODE_SELECT_10		0x55
853 #define	SC_MODE_SENSE_6			0x1a
854 #define	SC_MODE_SENSE_10		0x5a
855 #define	SC_PREVENT_ALLOW_MEDIUM_REMOVAL	0x1e
856 #define	SC_READ_6			0x08
857 #define	SC_READ_10			0x28
858 #define	SC_READ_12			0xa8
859 #define	SC_READ_CAPACITY		0x25
860 #define	SC_READ_FORMAT_CAPACITIES	0x23
861 #define	SC_RELEASE			0x17
862 #define	SC_REQUEST_SENSE		0x03
863 #define	SC_RESERVE			0x16
864 #define	SC_SEND_DIAGNOSTIC		0x1d
865 #define	SC_START_STOP_UNIT		0x1b
866 #define	SC_SYNCHRONIZE_CACHE		0x35
867 #define	SC_TEST_UNIT_READY		0x00
868 #define	SC_VERIFY			0x2f
869 #define	SC_WRITE_6			0x0a
870 #define	SC_WRITE_10			0x2a
871 #define	SC_WRITE_12			0xaa
872 
873 /* SCSI Sense Key/Additional Sense Code/ASC Qualifier values */
874 #define	SS_NO_SENSE				0
875 #define	SS_COMMUNICATION_FAILURE		0x040800
876 #define	SS_INVALID_COMMAND			0x052000
877 #define	SS_INVALID_FIELD_IN_CDB			0x052400
878 #define	SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE	0x052100
879 #define	SS_LOGICAL_UNIT_NOT_SUPPORTED		0x052500
880 #define	SS_MEDIUM_NOT_PRESENT			0x023a00
881 #define	SS_MEDIUM_REMOVAL_PREVENTED		0x055302
882 #define	SS_NOT_READY_TO_READY_TRANSITION	0x062800
883 #define	SS_RESET_OCCURRED			0x062900
884 #define	SS_SAVING_PARAMETERS_NOT_SUPPORTED	0x053900
885 #define	SS_UNRECOVERED_READ_ERROR		0x031100
886 #define	SS_WRITE_ERROR				0x030c02
887 #define	SS_WRITE_PROTECTED			0x072700
888 
889 #define	SK(x)		((uint8_t) ((x) >> 16))	/* Sense Key byte, etc. */
890 #define	ASC(x)		((uint8_t) ((x) >> 8))
891 #define	ASCQ(x)		((uint8_t) (x))
892 
893 /* Routines for unaligned data access */
894 
895 static uint16_t
896 get_be16(uint8_t *buf)
897 {
898 	return ((uint16_t)buf[0] << 8) | ((uint16_t)buf[1]);
899 }
900 
901 static uint32_t
902 get_be32(uint8_t *buf)
903 {
904 	return ((uint32_t)buf[0] << 24) | ((uint32_t)buf[1] << 16) |
905 	((uint32_t)buf[2] << 8) | ((uint32_t)buf[3]);
906 }
907 
908 static void
909 put_be16(uint8_t *buf, uint16_t val)
910 {
911 	buf[0] = val >> 8;
912 	buf[1] = val;
913 }
914 
915 static void
916 put_be32(uint8_t *buf, uint32_t val)
917 {
918 	buf[0] = val >> 24;
919 	buf[1] = val >> 16;
920 	buf[2] = val >> 8;
921 	buf[3] = val & 0xff;
922 }
923 
924 /*------------------------------------------------------------------------*
925  *	ustorage_fs_verify
926  *
927  * Returns:
928  *    0: Success
929  * Else: Failure
930  *------------------------------------------------------------------------*/
931 static uint8_t
932 ustorage_fs_verify(struct ustorage_fs_softc *sc)
933 {
934 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
935 	uint32_t lba;
936 	uint32_t vlen;
937 
938 	/*
939 	 * Get the starting Logical Block Address
940 	 */
941 	lba = get_be32(&sc->sc_cbw->CBWCDB[2]);
942 
943 	/*
944 	 * We allow DPO (Disable Page Out = don't save data in the cache)
945 	 * but we don't implement it.
946 	 */
947 	if ((sc->sc_cbw->CBWCDB[1] & ~0x10) != 0) {
948 		currlun->sense_data = SS_INVALID_FIELD_IN_CDB;
949 		return (1);
950 	}
951 	vlen = get_be16(&sc->sc_cbw->CBWCDB[7]);
952 	if (vlen == 0) {
953 		goto done;
954 	}
955 	/* No default reply */
956 
957 	/* Range check */
958 	vlen += lba;
959 
960 	if ((vlen < lba) ||
961 	    (vlen > currlun->num_sectors) ||
962 	    (lba >= currlun->num_sectors)) {
963 		currlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
964 		return (1);
965 	}
966 	/* XXX TODO: verify that data is readable */
967 done:
968 	return (ustorage_fs_min_len(sc, 0, -1U));
969 }
970 
971 /*------------------------------------------------------------------------*
972  *	ustorage_fs_inquiry
973  *
974  * Returns:
975  *    0: Success
976  * Else: Failure
977  *------------------------------------------------------------------------*/
978 static uint8_t
979 ustorage_fs_inquiry(struct ustorage_fs_softc *sc)
980 {
981 	uint8_t *buf = sc->sc_transfer.data_ptr;
982 
983 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
984 
985 	if (!sc->sc_transfer.currlun) {
986 		/* Unsupported LUNs are okay */
987 		memset(buf, 0, 36);
988 		buf[0] = 0x7f;
989 		/* Unsupported, no device - type */
990 		return (ustorage_fs_min_len(sc, 36, -1U));
991 	}
992 	memset(buf, 0, 8);
993 	/* Non - removable, direct - access device */
994 	if (currlun->removable)
995 		buf[1] = 0x80;
996 	buf[2] = 2;
997 	/* ANSI SCSI level 2 */
998 	buf[3] = 2;
999 	/* SCSI - 2 INQUIRY data format */
1000 	buf[4] = 31;
1001 	/* Additional length */
1002 	/* No special options */
1003 	/* Copy in ID string */
1004 	memcpy(buf + 8, USTORAGE_FS_ID_STRING, 28);
1005 
1006 #if (USTORAGE_QDATA_MAX < 36)
1007 #error "(USTORAGE_QDATA_MAX < 36)"
1008 #endif
1009 	return (ustorage_fs_min_len(sc, 36, -1U));
1010 }
1011 
1012 /*------------------------------------------------------------------------*
1013  *	ustorage_fs_request_sense
1014  *
1015  * Returns:
1016  *    0: Success
1017  * Else: Failure
1018  *------------------------------------------------------------------------*/
1019 static uint8_t
1020 ustorage_fs_request_sense(struct ustorage_fs_softc *sc)
1021 {
1022 	uint8_t *buf = sc->sc_transfer.data_ptr;
1023 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1024 	uint32_t sd;
1025 	uint32_t sdinfo;
1026 	uint8_t valid;
1027 
1028 	/*
1029 	 * From the SCSI-2 spec., section 7.9 (Unit attention condition):
1030 	 *
1031 	 * If a REQUEST SENSE command is received from an initiator
1032 	 * with a pending unit attention condition (before the target
1033 	 * generates the contingent allegiance condition), then the
1034 	 * target shall either:
1035 	 *   a) report any pending sense data and preserve the unit
1036 	 *	attention condition on the logical unit, or,
1037 	 *   b) report the unit attention condition, may discard any
1038 	 *	pending sense data, and clear the unit attention
1039 	 *	condition on the logical unit for that initiator.
1040 	 *
1041 	 * FSG normally uses option a); enable this code to use option b).
1042 	 */
1043 #if 0
1044 	if (currlun && currlun->unit_attention_data != SS_NO_SENSE) {
1045 		currlun->sense_data = currlun->unit_attention_data;
1046 		currlun->unit_attention_data = SS_NO_SENSE;
1047 	}
1048 #endif
1049 
1050 	if (!currlun) {
1051 		/* Unsupported LUNs are okay */
1052 		sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1053 		sdinfo = 0;
1054 		valid = 0;
1055 	} else {
1056 		sd = currlun->sense_data;
1057 		sdinfo = currlun->sense_data_info;
1058 		valid = currlun->info_valid << 7;
1059 		currlun->sense_data = SS_NO_SENSE;
1060 		currlun->sense_data_info = 0;
1061 		currlun->info_valid = 0;
1062 	}
1063 
1064 	memset(buf, 0, 18);
1065 	buf[0] = valid | 0x70;
1066 	/* Valid, current error */
1067 	buf[2] = SK(sd);
1068 	put_be32(&buf[3], sdinfo);
1069 	/* Sense information */
1070 	buf[7] = 18 - 8;
1071 	/* Additional sense length */
1072 	buf[12] = ASC(sd);
1073 	buf[13] = ASCQ(sd);
1074 
1075 #if (USTORAGE_QDATA_MAX < 18)
1076 #error "(USTORAGE_QDATA_MAX < 18)"
1077 #endif
1078 	return (ustorage_fs_min_len(sc, 18, -1U));
1079 }
1080 
1081 /*------------------------------------------------------------------------*
1082  *	ustorage_fs_read_capacity
1083  *
1084  * Returns:
1085  *    0: Success
1086  * Else: Failure
1087  *------------------------------------------------------------------------*/
1088 static uint8_t
1089 ustorage_fs_read_capacity(struct ustorage_fs_softc *sc)
1090 {
1091 	uint8_t *buf = sc->sc_transfer.data_ptr;
1092 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1093 	uint32_t lba = get_be32(&sc->sc_cbw->CBWCDB[2]);
1094 	uint8_t pmi = sc->sc_cbw->CBWCDB[8];
1095 
1096 	/* Check the PMI and LBA fields */
1097 	if ((pmi > 1) || ((pmi == 0) && (lba != 0))) {
1098 		currlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1099 		return (1);
1100 	}
1101 	/* Max logical block */
1102 	put_be32(&buf[0], currlun->num_sectors - 1);
1103 	/* Block length */
1104 	put_be32(&buf[4], 512);
1105 
1106 #if (USTORAGE_QDATA_MAX < 8)
1107 #error "(USTORAGE_QDATA_MAX < 8)"
1108 #endif
1109 	return (ustorage_fs_min_len(sc, 8, -1U));
1110 }
1111 
1112 /*------------------------------------------------------------------------*
1113  *	ustorage_fs_mode_sense
1114  *
1115  * Returns:
1116  *    0: Success
1117  * Else: Failure
1118  *------------------------------------------------------------------------*/
1119 static uint8_t
1120 ustorage_fs_mode_sense(struct ustorage_fs_softc *sc)
1121 {
1122 	uint8_t *buf = sc->sc_transfer.data_ptr;
1123 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1124 	uint8_t *buf0;
1125 	uint16_t len;
1126 	uint16_t limit;
1127 	uint8_t mscmnd = sc->sc_cbw->CBWCDB[0];
1128 	uint8_t pc;
1129 	uint8_t page_code;
1130 	uint8_t changeable_values;
1131 	uint8_t all_pages;
1132 
1133 	buf0 = buf;
1134 
1135 	if ((sc->sc_cbw->CBWCDB[1] & ~0x08) != 0) {
1136 		/* Mask away DBD */
1137 		currlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1138 		return (1);
1139 	}
1140 	pc = sc->sc_cbw->CBWCDB[2] >> 6;
1141 	page_code = sc->sc_cbw->CBWCDB[2] & 0x3f;
1142 	if (pc == 3) {
1143 		currlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
1144 		return (1);
1145 	}
1146 	changeable_values = (pc == 1);
1147 	all_pages = (page_code == 0x3f);
1148 
1149 	/*
1150 	 * Write the mode parameter header.  Fixed values are: default
1151 	 * medium type, no cache control (DPOFUA), and no block descriptors.
1152 	 * The only variable value is the WriteProtect bit.  We will fill in
1153 	 * the mode data length later.
1154 	 */
1155 	memset(buf, 0, 8);
1156 	if (mscmnd == SC_MODE_SENSE_6) {
1157 		buf[2] = (currlun->read_only ? 0x80 : 0x00);
1158 		/* WP, DPOFUA */
1159 		buf += 4;
1160 		limit = 255;
1161 	} else {
1162 		/* SC_MODE_SENSE_10 */
1163 		buf[3] = (currlun->read_only ? 0x80 : 0x00);
1164 		/* WP, DPOFUA */
1165 		buf += 8;
1166 		limit = 65535;
1167 		/* Should really be mod_data.buflen */
1168 	}
1169 
1170 	/* No block descriptors */
1171 
1172 	/*
1173 	 * The mode pages, in numerical order.
1174 	 */
1175 	if ((page_code == 0x08) || all_pages) {
1176 		buf[0] = 0x08;
1177 		/* Page code */
1178 		buf[1] = 10;
1179 		/* Page length */
1180 		memset(buf + 2, 0, 10);
1181 		/* None of the fields are changeable */
1182 
1183 		if (!changeable_values) {
1184 			buf[2] = 0x04;
1185 			/* Write cache enable, */
1186 			/* Read cache not disabled */
1187 			/* No cache retention priorities */
1188 			put_be16(&buf[4], 0xffff);
1189 			/* Don 't disable prefetch */
1190 			/* Minimum prefetch = 0 */
1191 			put_be16(&buf[8], 0xffff);
1192 			/* Maximum prefetch */
1193 			put_be16(&buf[10], 0xffff);
1194 			/* Maximum prefetch ceiling */
1195 		}
1196 		buf += 12;
1197 	}
1198 	/*
1199 	 * Check that a valid page was requested and the mode data length
1200 	 * isn't too long.
1201 	 */
1202 	len = buf - buf0;
1203 	if (len > limit) {
1204 		currlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1205 		return (1);
1206 	}
1207 	/* Store the mode data length */
1208 	if (mscmnd == SC_MODE_SENSE_6)
1209 		buf0[0] = len - 1;
1210 	else
1211 		put_be16(buf0, len - 2);
1212 
1213 #if (USTORAGE_QDATA_MAX < 24)
1214 #error "(USTORAGE_QDATA_MAX < 24)"
1215 #endif
1216 	return (ustorage_fs_min_len(sc, len, -1U));
1217 }
1218 
1219 /*------------------------------------------------------------------------*
1220  *	ustorage_fs_start_stop
1221  *
1222  * Returns:
1223  *    0: Success
1224  * Else: Failure
1225  *------------------------------------------------------------------------*/
1226 static uint8_t
1227 ustorage_fs_start_stop(struct ustorage_fs_softc *sc)
1228 {
1229 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1230 	uint8_t loej;
1231 	uint8_t start;
1232 	uint8_t immed;
1233 
1234 	if (!currlun->removable) {
1235 		currlun->sense_data = SS_INVALID_COMMAND;
1236 		return (1);
1237 	}
1238 	immed = sc->sc_cbw->CBWCDB[1] & 0x01;
1239 	loej = sc->sc_cbw->CBWCDB[4] & 0x02;
1240 	start = sc->sc_cbw->CBWCDB[4] & 0x01;
1241 
1242 	if (immed || loej || start) {
1243 		/* compile fix */
1244 	}
1245 	return (0);
1246 }
1247 
1248 /*------------------------------------------------------------------------*
1249  *	ustorage_fs_prevent_allow
1250  *
1251  * Returns:
1252  *    0: Success
1253  * Else: Failure
1254  *------------------------------------------------------------------------*/
1255 static uint8_t
1256 ustorage_fs_prevent_allow(struct ustorage_fs_softc *sc)
1257 {
1258 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1259 	uint8_t prevent;
1260 
1261 	if (!currlun->removable) {
1262 		currlun->sense_data = SS_INVALID_COMMAND;
1263 		return (1);
1264 	}
1265 	prevent = sc->sc_cbw->CBWCDB[4] & 0x01;
1266 	if ((sc->sc_cbw->CBWCDB[4] & ~0x01) != 0) {
1267 		/* Mask away Prevent */
1268 		currlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1269 		return (1);
1270 	}
1271 	if (currlun->prevent_medium_removal && !prevent) {
1272 		//fsync_sub(currlun);
1273 	}
1274 	currlun->prevent_medium_removal = prevent;
1275 	return (0);
1276 }
1277 
1278 /*------------------------------------------------------------------------*
1279  *	ustorage_fs_read_format_capacities
1280  *
1281  * Returns:
1282  *    0: Success
1283  * Else: Failure
1284  *------------------------------------------------------------------------*/
1285 static uint8_t
1286 ustorage_fs_read_format_capacities(struct ustorage_fs_softc *sc)
1287 {
1288 	uint8_t *buf = sc->sc_transfer.data_ptr;
1289 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1290 
1291 	buf[0] = buf[1] = buf[2] = 0;
1292 	buf[3] = 8;
1293 	/* Only the Current / Maximum Capacity Descriptor */
1294 	buf += 4;
1295 
1296 	/* Number of blocks */
1297 	put_be32(&buf[0], currlun->num_sectors);
1298 	/* Block length */
1299 	put_be32(&buf[4], 512);
1300 	/* Current capacity */
1301 	buf[4] = 0x02;
1302 
1303 #if (USTORAGE_QDATA_MAX < 12)
1304 #error "(USTORAGE_QDATA_MAX < 12)"
1305 #endif
1306 	return (ustorage_fs_min_len(sc, 12, -1U));
1307 }
1308 
1309 /*------------------------------------------------------------------------*
1310  *	ustorage_fs_mode_select
1311  *
1312  * Return values:
1313  *    0: Success
1314  * Else: Failure
1315  *------------------------------------------------------------------------*/
1316 static uint8_t
1317 ustorage_fs_mode_select(struct ustorage_fs_softc *sc)
1318 {
1319 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1320 
1321 	/* We don't support MODE SELECT */
1322 	currlun->sense_data = SS_INVALID_COMMAND;
1323 	return (1);
1324 }
1325 
1326 /*------------------------------------------------------------------------*
1327  *	ustorage_fs_synchronize_cache
1328  *
1329  * Return values:
1330  *    0: Success
1331  * Else: Failure
1332  *------------------------------------------------------------------------*/
1333 static uint8_t
1334 ustorage_fs_synchronize_cache(struct ustorage_fs_softc *sc)
1335 {
1336 #if 0
1337 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1338 	uint8_t rc;
1339 
1340 	/*
1341 	 * We ignore the requested LBA and write out all dirty data buffers.
1342 	 */
1343 	rc = 0;
1344 	if (rc) {
1345 		currlun->sense_data = SS_WRITE_ERROR;
1346 	}
1347 #endif
1348 	return (0);
1349 }
1350 
1351 /*------------------------------------------------------------------------*
1352  *	ustorage_fs_read - read data from disk
1353  *
1354  * Return values:
1355  *    0: Success
1356  * Else: Failure
1357  *------------------------------------------------------------------------*/
1358 static uint8_t
1359 ustorage_fs_read(struct ustorage_fs_softc *sc)
1360 {
1361 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1362 	uint64_t file_offset;
1363 	uint32_t lba;
1364 	uint32_t len;
1365 
1366 	/*
1367 	 * Get the starting Logical Block Address and check that it's not
1368 	 * too big
1369 	 */
1370 	if (sc->sc_cbw->CBWCDB[0] == SC_READ_6) {
1371 		lba = (((uint32_t)sc->sc_cbw->CBWCDB[1]) << 16) |
1372 		    get_be16(&sc->sc_cbw->CBWCDB[2]);
1373 	} else {
1374 		lba = get_be32(&sc->sc_cbw->CBWCDB[2]);
1375 
1376 		/*
1377 		 * We allow DPO (Disable Page Out = don't save data in the
1378 		 * cache) and FUA (Force Unit Access = don't read from the
1379 		 * cache), but we don't implement them.
1380 		 */
1381 		if ((sc->sc_cbw->CBWCDB[1] & ~0x18) != 0) {
1382 			currlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1383 			return (1);
1384 		}
1385 	}
1386 	len = sc->sc_transfer.data_rem >> 9;
1387 	len += lba;
1388 
1389 	if ((len < lba) ||
1390 	    (len > currlun->num_sectors) ||
1391 	    (lba >= currlun->num_sectors)) {
1392 		currlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1393 		return (1);
1394 	}
1395 	file_offset = lba;
1396 	file_offset <<= 9;
1397 
1398 	sc->sc_transfer.data_ptr = currlun->memory_image + file_offset;
1399 
1400 	return (0);
1401 }
1402 
1403 /*------------------------------------------------------------------------*
1404  *	ustorage_fs_write - write data to disk
1405  *
1406  * Return values:
1407  *    0: Success
1408  * Else: Failure
1409  *------------------------------------------------------------------------*/
1410 static uint8_t
1411 ustorage_fs_write(struct ustorage_fs_softc *sc)
1412 {
1413 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1414 	uint64_t file_offset;
1415 	uint32_t lba;
1416 	uint32_t len;
1417 
1418 	if (currlun->read_only) {
1419 		currlun->sense_data = SS_WRITE_PROTECTED;
1420 		return (1);
1421 	}
1422 	/* XXX clear SYNC */
1423 
1424 	/*
1425 	 * Get the starting Logical Block Address and check that it's not
1426 	 * too big.
1427 	 */
1428 	if (sc->sc_cbw->CBWCDB[0] == SC_WRITE_6)
1429 		lba = (((uint32_t)sc->sc_cbw->CBWCDB[1]) << 16) |
1430 		    get_be16(&sc->sc_cbw->CBWCDB[2]);
1431 	else {
1432 		lba = get_be32(&sc->sc_cbw->CBWCDB[2]);
1433 
1434 		/*
1435 		 * We allow DPO (Disable Page Out = don't save data in the
1436 		 * cache) and FUA (Force Unit Access = write directly to the
1437 		 * medium).  We don't implement DPO; we implement FUA by
1438 		 * performing synchronous output.
1439 		 */
1440 		if ((sc->sc_cbw->CBWCDB[1] & ~0x18) != 0) {
1441 			currlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1442 			return (1);
1443 		}
1444 		if (sc->sc_cbw->CBWCDB[1] & 0x08) {
1445 			/* FUA */
1446 			/* XXX set SYNC flag here */
1447 		}
1448 	}
1449 
1450 	len = sc->sc_transfer.data_rem >> 9;
1451 	len += lba;
1452 
1453 	if ((len < lba) ||
1454 	    (len > currlun->num_sectors) ||
1455 	    (lba >= currlun->num_sectors)) {
1456 		currlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1457 		return (1);
1458 	}
1459 	file_offset = lba;
1460 	file_offset <<= 9;
1461 
1462 	sc->sc_transfer.data_ptr = currlun->memory_image + file_offset;
1463 
1464 	return (0);
1465 }
1466 
1467 /*------------------------------------------------------------------------*
1468  *	ustorage_fs_min_len
1469  *
1470  * Return values:
1471  *    0: Success
1472  * Else: Failure
1473  *------------------------------------------------------------------------*/
1474 static uint8_t
1475 ustorage_fs_min_len(struct ustorage_fs_softc *sc, uint32_t len, uint32_t mask)
1476 {
1477 	if (len != sc->sc_transfer.data_rem) {
1478 		if (sc->sc_transfer.cbw_dir == DIR_READ) {
1479 			/*
1480 			 * there must be something wrong about this SCSI
1481 			 * command
1482 			 */
1483 			sc->sc_csw->bCSWStatus = CSWSTATUS_PHASE;
1484 			return (1);
1485 		}
1486 		/* compute the minimum length */
1487 
1488 		if (sc->sc_transfer.data_rem > len) {
1489 			/* data ends prematurely */
1490 			sc->sc_transfer.data_rem = len;
1491 			sc->sc_transfer.data_short = 1;
1492 		}
1493 		/* check length alignment */
1494 
1495 		if (sc->sc_transfer.data_rem & ~mask) {
1496 			/* data ends prematurely */
1497 			sc->sc_transfer.data_rem &= mask;
1498 			sc->sc_transfer.data_short = 1;
1499 		}
1500 	}
1501 	return (0);
1502 }
1503 
1504 /*------------------------------------------------------------------------*
1505  *	ustorage_fs_check_cmd - check command routine
1506  *
1507  * Check whether the command is properly formed and whether its data
1508  * size and direction agree with the values we already have.
1509  *
1510  * Return values:
1511  *    0: Success
1512  * Else: Failure
1513  *------------------------------------------------------------------------*/
1514 static uint8_t
1515 ustorage_fs_check_cmd(struct ustorage_fs_softc *sc, uint8_t min_cmd_size,
1516     uint16_t mask, uint8_t needs_medium)
1517 {
1518 	struct ustorage_fs_lun *currlun;
1519 	uint8_t lun = (sc->sc_cbw->CBWCDB[1] >> 5);
1520 	uint8_t i;
1521 
1522 	/* Verify the length of the command itself */
1523 	if (min_cmd_size > sc->sc_transfer.cmd_len) {
1524 		DPRINTF("%u > %u\n",
1525 		    min_cmd_size, sc->sc_transfer.cmd_len);
1526 		sc->sc_csw->bCSWStatus = CSWSTATUS_PHASE;
1527 		return (1);
1528 	}
1529 	/* Mask away the LUN */
1530 	sc->sc_cbw->CBWCDB[1] &= 0x1f;
1531 
1532 	/* Check if LUN is correct */
1533 	if (lun != sc->sc_transfer.lun) {
1534 	}
1535 	/* Check the LUN */
1536 	if (sc->sc_transfer.lun <= sc->sc_last_lun) {
1537 		sc->sc_transfer.currlun = currlun =
1538 		    sc->sc_lun + sc->sc_transfer.lun;
1539 		if (sc->sc_cbw->CBWCDB[0] != SC_REQUEST_SENSE) {
1540 			currlun->sense_data = SS_NO_SENSE;
1541 			currlun->sense_data_info = 0;
1542 			currlun->info_valid = 0;
1543 		}
1544 		/*
1545 		 * If a unit attention condition exists, only INQUIRY
1546 		 * and REQUEST SENSE commands are allowed. Anything
1547 		 * else must fail!
1548 		 */
1549 		if ((currlun->unit_attention_data != SS_NO_SENSE) &&
1550 		    (sc->sc_cbw->CBWCDB[0] != SC_INQUIRY) &&
1551 		    (sc->sc_cbw->CBWCDB[0] != SC_REQUEST_SENSE)) {
1552 			currlun->sense_data = currlun->unit_attention_data;
1553 			currlun->unit_attention_data = SS_NO_SENSE;
1554 			return (1);
1555 		}
1556 	} else {
1557 		sc->sc_transfer.currlun = currlun = NULL;
1558 
1559 		/*
1560 		 * INQUIRY and REQUEST SENSE commands are explicitly allowed
1561 		 * to use unsupported LUNs; all others may not.
1562 		 */
1563 		if ((sc->sc_cbw->CBWCDB[0] != SC_INQUIRY) &&
1564 		    (sc->sc_cbw->CBWCDB[0] != SC_REQUEST_SENSE)) {
1565 			return (1);
1566 		}
1567 	}
1568 
1569 	/*
1570 	 * Check that only command bytes listed in the mask are
1571 	 * non-zero.
1572 	 */
1573 	for (i = 0; i != min_cmd_size; i++) {
1574 		if (sc->sc_cbw->CBWCDB[i] && !(mask & (1UL << i))) {
1575 			if (currlun) {
1576 				currlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1577 			}
1578 			return (1);
1579 		}
1580 	}
1581 
1582 	/*
1583 	 * If the medium isn't mounted and the command needs to access
1584 	 * it, return an error.
1585 	 */
1586 	if (currlun && (!currlun->memory_image) && needs_medium) {
1587 		currlun->sense_data = SS_MEDIUM_NOT_PRESENT;
1588 		return (1);
1589 	}
1590 	return (0);
1591 }
1592 
1593 /*------------------------------------------------------------------------*
1594  *	ustorage_fs_do_cmd - do command
1595  *
1596  * Return values:
1597  *    0: Success
1598  * Else: Failure
1599  *------------------------------------------------------------------------*/
1600 static uint8_t
1601 ustorage_fs_do_cmd(struct ustorage_fs_softc *sc)
1602 {
1603 	uint8_t error = 1;
1604 	uint8_t i;
1605 	uint32_t temp;
1606 	const uint32_t mask9 = (0xFFFFFFFFUL >> 9) << 9;
1607 
1608 	/* set default data transfer pointer */
1609 	sc->sc_transfer.data_ptr = sc->sc_qdata;
1610 
1611 	DPRINTF("cmd_data[0]=0x%02x, data_rem=0x%08x\n",
1612 	    sc->sc_cbw->CBWCDB[0], sc->sc_transfer.data_rem);
1613 
1614 	switch (sc->sc_cbw->CBWCDB[0]) {
1615 	case SC_INQUIRY:
1616 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1617 		error = ustorage_fs_min_len(sc, sc->sc_cbw->CBWCDB[4], -1U);
1618 		if (error) {
1619 			break;
1620 		}
1621 		error = ustorage_fs_check_cmd(sc, 6,
1622 		    (1UL << 4) | 1, 0);
1623 		if (error) {
1624 			break;
1625 		}
1626 		error = ustorage_fs_inquiry(sc);
1627 
1628 		break;
1629 
1630 	case SC_MODE_SELECT_6:
1631 		sc->sc_transfer.cmd_dir = DIR_READ;
1632 		error = ustorage_fs_min_len(sc, sc->sc_cbw->CBWCDB[4], -1U);
1633 		if (error) {
1634 			break;
1635 		}
1636 		error = ustorage_fs_check_cmd(sc, 6,
1637 		    (1UL << 1) | (1UL << 4) | 1, 0);
1638 		if (error) {
1639 			break;
1640 		}
1641 		error = ustorage_fs_mode_select(sc);
1642 
1643 		break;
1644 
1645 	case SC_MODE_SELECT_10:
1646 		sc->sc_transfer.cmd_dir = DIR_READ;
1647 		error = ustorage_fs_min_len(sc,
1648 		    get_be16(&sc->sc_cbw->CBWCDB[7]), -1U);
1649 		if (error) {
1650 			break;
1651 		}
1652 		error = ustorage_fs_check_cmd(sc, 10,
1653 		    (1UL << 1) | (3UL << 7) | 1, 0);
1654 		if (error) {
1655 			break;
1656 		}
1657 		error = ustorage_fs_mode_select(sc);
1658 
1659 		break;
1660 
1661 	case SC_MODE_SENSE_6:
1662 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1663 		error = ustorage_fs_min_len(sc, sc->sc_cbw->CBWCDB[4], -1U);
1664 		if (error) {
1665 			break;
1666 		}
1667 		error = ustorage_fs_check_cmd(sc, 6,
1668 		    (1UL << 1) | (1UL << 2) | (1UL << 4) | 1, 0);
1669 		if (error) {
1670 			break;
1671 		}
1672 		error = ustorage_fs_mode_sense(sc);
1673 
1674 		break;
1675 
1676 	case SC_MODE_SENSE_10:
1677 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1678 		error = ustorage_fs_min_len(sc,
1679 		    get_be16(&sc->sc_cbw->CBWCDB[7]), -1U);
1680 		if (error) {
1681 			break;
1682 		}
1683 		error = ustorage_fs_check_cmd(sc, 10,
1684 		    (1UL << 1) | (1UL << 2) | (3UL << 7) | 1, 0);
1685 		if (error) {
1686 			break;
1687 		}
1688 		error = ustorage_fs_mode_sense(sc);
1689 
1690 		break;
1691 
1692 	case SC_PREVENT_ALLOW_MEDIUM_REMOVAL:
1693 		error = ustorage_fs_min_len(sc, 0, -1U);
1694 		if (error) {
1695 			break;
1696 		}
1697 		error = ustorage_fs_check_cmd(sc, 6,
1698 		    (1UL << 4) | 1, 0);
1699 		if (error) {
1700 			break;
1701 		}
1702 		error = ustorage_fs_prevent_allow(sc);
1703 
1704 		break;
1705 
1706 	case SC_READ_6:
1707 		i = sc->sc_cbw->CBWCDB[4];
1708 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1709 		temp = ((i == 0) ? 256UL : i);
1710 		error = ustorage_fs_min_len(sc, temp << 9, mask9);
1711 		if (error) {
1712 			break;
1713 		}
1714 		error = ustorage_fs_check_cmd(sc, 6,
1715 		    (7UL << 1) | (1UL << 4) | 1, 1);
1716 		if (error) {
1717 			break;
1718 		}
1719 		error = ustorage_fs_read(sc);
1720 
1721 		break;
1722 
1723 	case SC_READ_10:
1724 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1725 		temp = get_be16(&sc->sc_cbw->CBWCDB[7]);
1726 		error = ustorage_fs_min_len(sc, temp << 9, mask9);
1727 		if (error) {
1728 			break;
1729 		}
1730 		error = ustorage_fs_check_cmd(sc, 10,
1731 		    (1UL << 1) | (0xfUL << 2) | (3UL << 7) | 1, 1);
1732 		if (error) {
1733 			break;
1734 		}
1735 		error = ustorage_fs_read(sc);
1736 
1737 		break;
1738 
1739 	case SC_READ_12:
1740 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1741 		temp = get_be32(&sc->sc_cbw->CBWCDB[6]);
1742 		if (temp >= (1UL << (32 - 9))) {
1743 			/* numerical overflow */
1744 			sc->sc_csw->bCSWStatus = CSWSTATUS_FAILED;
1745 			error = 1;
1746 			break;
1747 		}
1748 		error = ustorage_fs_min_len(sc, temp << 9, mask9);
1749 		if (error) {
1750 			break;
1751 		}
1752 		error = ustorage_fs_check_cmd(sc, 12,
1753 		    (1UL << 1) | (0xfUL << 2) | (0xfUL << 6) | 1, 1);
1754 		if (error) {
1755 			break;
1756 		}
1757 		error = ustorage_fs_read(sc);
1758 
1759 		break;
1760 
1761 	case SC_READ_CAPACITY:
1762 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1763 		error = ustorage_fs_check_cmd(sc, 10,
1764 		    (0xfUL << 2) | (1UL << 8) | 1, 1);
1765 		if (error) {
1766 			break;
1767 		}
1768 		error = ustorage_fs_read_capacity(sc);
1769 
1770 		break;
1771 
1772 	case SC_READ_FORMAT_CAPACITIES:
1773 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1774 		error = ustorage_fs_min_len(sc,
1775 		    get_be16(&sc->sc_cbw->CBWCDB[7]), -1U);
1776 		if (error) {
1777 			break;
1778 		}
1779 		error = ustorage_fs_check_cmd(sc, 10,
1780 		    (3UL << 7) | 1, 1);
1781 		if (error) {
1782 			break;
1783 		}
1784 		error = ustorage_fs_read_format_capacities(sc);
1785 
1786 		break;
1787 
1788 	case SC_REQUEST_SENSE:
1789 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1790 		error = ustorage_fs_min_len(sc, sc->sc_cbw->CBWCDB[4], -1U);
1791 		if (error) {
1792 			break;
1793 		}
1794 		error = ustorage_fs_check_cmd(sc, 6,
1795 		    (1UL << 4) | 1, 0);
1796 		if (error) {
1797 			break;
1798 		}
1799 		error = ustorage_fs_request_sense(sc);
1800 
1801 		break;
1802 
1803 	case SC_START_STOP_UNIT:
1804 		error = ustorage_fs_min_len(sc, 0, -1U);
1805 		if (error) {
1806 			break;
1807 		}
1808 		error = ustorage_fs_check_cmd(sc, 6,
1809 		    (1UL << 1) | (1UL << 4) | 1, 0);
1810 		if (error) {
1811 			break;
1812 		}
1813 		error = ustorage_fs_start_stop(sc);
1814 
1815 		break;
1816 
1817 	case SC_SYNCHRONIZE_CACHE:
1818 		error = ustorage_fs_min_len(sc, 0, -1U);
1819 		if (error) {
1820 			break;
1821 		}
1822 		error = ustorage_fs_check_cmd(sc, 10,
1823 		    (0xfUL << 2) | (3UL << 7) | 1, 1);
1824 		if (error) {
1825 			break;
1826 		}
1827 		error = ustorage_fs_synchronize_cache(sc);
1828 
1829 		break;
1830 
1831 	case SC_TEST_UNIT_READY:
1832 		error = ustorage_fs_min_len(sc, 0, -1U);
1833 		if (error) {
1834 			break;
1835 		}
1836 		error = ustorage_fs_check_cmd(sc, 6,
1837 		    0 | 1, 1);
1838 		break;
1839 
1840 		/*
1841 		 * Although optional, this command is used by MS-Windows.
1842 		 * We support a minimal version: BytChk must be 0.
1843 		 */
1844 	case SC_VERIFY:
1845 		error = ustorage_fs_min_len(sc, 0, -1U);
1846 		if (error) {
1847 			break;
1848 		}
1849 		error = ustorage_fs_check_cmd(sc, 10,
1850 		    (1UL << 1) | (0xfUL << 2) | (3UL << 7) | 1, 1);
1851 		if (error) {
1852 			break;
1853 		}
1854 		error = ustorage_fs_verify(sc);
1855 
1856 		break;
1857 
1858 	case SC_WRITE_6:
1859 		i = sc->sc_cbw->CBWCDB[4];
1860 		sc->sc_transfer.cmd_dir = DIR_READ;
1861 		temp = ((i == 0) ? 256UL : i);
1862 		error = ustorage_fs_min_len(sc, temp << 9, mask9);
1863 		if (error) {
1864 			break;
1865 		}
1866 		error = ustorage_fs_check_cmd(sc, 6,
1867 		    (7UL << 1) | (1UL << 4) | 1, 1);
1868 		if (error) {
1869 			break;
1870 		}
1871 		error = ustorage_fs_write(sc);
1872 
1873 		break;
1874 
1875 	case SC_WRITE_10:
1876 		sc->sc_transfer.cmd_dir = DIR_READ;
1877 		temp = get_be16(&sc->sc_cbw->CBWCDB[7]);
1878 		error = ustorage_fs_min_len(sc, temp << 9, mask9);
1879 		if (error) {
1880 			break;
1881 		}
1882 		error = ustorage_fs_check_cmd(sc, 10,
1883 		    (1UL << 1) | (0xfUL << 2) | (3UL << 7) | 1, 1);
1884 		if (error) {
1885 			break;
1886 		}
1887 		error = ustorage_fs_write(sc);
1888 
1889 		break;
1890 
1891 	case SC_WRITE_12:
1892 		sc->sc_transfer.cmd_dir = DIR_READ;
1893 		temp = get_be32(&sc->sc_cbw->CBWCDB[6]);
1894 		if (temp > (mask9 >> 9)) {
1895 			/* numerical overflow */
1896 			sc->sc_csw->bCSWStatus = CSWSTATUS_FAILED;
1897 			error = 1;
1898 			break;
1899 		}
1900 		error = ustorage_fs_min_len(sc, temp << 9, mask9);
1901 		if (error) {
1902 			break;
1903 		}
1904 		error = ustorage_fs_check_cmd(sc, 12,
1905 		    (1UL << 1) | (0xfUL << 2) | (0xfUL << 6) | 1, 1);
1906 		if (error) {
1907 			break;
1908 		}
1909 		error = ustorage_fs_write(sc);
1910 
1911 		break;
1912 
1913 		/*
1914 		 * Some mandatory commands that we recognize but don't
1915 		 * implement.  They don't mean much in this setting.
1916 		 * It's left as an exercise for anyone interested to
1917 		 * implement RESERVE and RELEASE in terms of Posix
1918 		 * locks.
1919 		 */
1920 	case SC_FORMAT_UNIT:
1921 	case SC_RELEASE:
1922 	case SC_RESERVE:
1923 	case SC_SEND_DIAGNOSTIC:
1924 		/* Fallthrough */
1925 
1926 	default:
1927 		error = ustorage_fs_min_len(sc, 0, -1U);
1928 		if (error) {
1929 			break;
1930 		}
1931 		error = ustorage_fs_check_cmd(sc, sc->sc_transfer.cmd_len,
1932 		    0xff, 0);
1933 		if (error) {
1934 			break;
1935 		}
1936 		sc->sc_transfer.currlun->sense_data =
1937 		    SS_INVALID_COMMAND;
1938 		error = 1;
1939 
1940 		break;
1941 	}
1942 	return (error);
1943 }
1944