xref: /dragonfly/sys/bus/u4b/storage/ustorage_fs.c (revision 8accc937)
1 /* $FreeBSD$ */
2 /*-
3  * Copyright (C) 2003-2005 Alan Stern
4  * Copyright (C) 2008 Hans Petter Selasky
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions, and the following disclaimer,
12  *    without modification.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. The names of the above-listed copyright holders may not be used
17  *    to endorse or promote products derived from this software without
18  *    specific prior written permission.
19  *
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
22  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
23  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
25  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
26  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
27  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
28  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
29  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
31  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 /*
35  * NOTE: Much of the SCSI statemachine handling code derives from the
36  * Linux USB gadget stack.
37  */
38 
39 #include <sys/stdint.h>
40 #include <sys/param.h>
41 #include <sys/queue.h>
42 #include <sys/types.h>
43 #include <sys/systm.h>
44 #include <sys/kernel.h>
45 #include <sys/bus.h>
46 #include <sys/module.h>
47 #include <sys/lock.h>
48 #include <sys/mutex.h>
49 #include <sys/condvar.h>
50 #include <sys/sysctl.h>
51 #include <sys/unistd.h>
52 #include <sys/callout.h>
53 #include <sys/malloc.h>
54 #include <sys/priv.h>
55 
56 #include <bus/u4b/usb.h>
57 #include <bus/u4b/usbdi.h>
58 #include <bus/u4b/usbdevs.h>
59 #include "usb_if.h"
60 
61 #define	USB_DEBUG_VAR ustorage_fs_debug
62 #include <bus/u4b/usb_debug.h>
63 
64 #ifdef USB_DEBUG
65 static int ustorage_fs_debug = 0;
66 
67 SYSCTL_NODE(_hw_usb, OID_AUTO, ustorage_fs, CTLFLAG_RW, 0, "USB ustorage_fs");
68 SYSCTL_INT(_hw_usb_ustorage_fs, OID_AUTO, debug, CTLFLAG_RW,
69     &ustorage_fs_debug, 0, "ustorage_fs debug level");
70 #endif
71 
72 /* Define some limits */
73 
74 #ifndef USTORAGE_FS_BULK_SIZE
75 #define	USTORAGE_FS_BULK_SIZE (1UL << 17)	/* bytes */
76 #endif
77 
78 #ifndef	USTORAGE_FS_MAX_LUN
79 #define	USTORAGE_FS_MAX_LUN	8	/* units */
80 #endif
81 
82 #ifndef USTORAGE_QDATA_MAX
83 #define	USTORAGE_QDATA_MAX	40	/* bytes */
84 #endif
85 
86 #define sc_cmd_data sc_cbw.CBWCDB
87 
88 /*
89  * The SCSI ID string must be exactly 28 characters long
90  * exluding the terminating zero.
91  */
92 #ifndef USTORAGE_FS_ID_STRING
93 #define	USTORAGE_FS_ID_STRING \
94 	"FreeBSD " /* 8 */ \
95 	"File-Stor Gadget" /* 16 */ \
96 	"0101" /* 4 */
97 #endif
98 
99 /*
100  * The following macro defines the number of
101  * sectors to be allocated for the RAM disk:
102  */
103 #ifndef USTORAGE_FS_RAM_SECT
104 #define	USTORAGE_FS_RAM_SECT (1UL << 13)
105 #endif
106 
107 static uint8_t *ustorage_fs_ramdisk;
108 
109 /* USB transfer definitions */
110 
111 #define	USTORAGE_FS_T_BBB_COMMAND     0
112 #define	USTORAGE_FS_T_BBB_DATA_DUMP   1
113 #define	USTORAGE_FS_T_BBB_DATA_READ   2
114 #define	USTORAGE_FS_T_BBB_DATA_WRITE  3
115 #define	USTORAGE_FS_T_BBB_STATUS      4
116 #define	USTORAGE_FS_T_BBB_MAX         5
117 
118 /* USB data stage direction */
119 
120 #define	DIR_NONE	0
121 #define	DIR_READ	1
122 #define	DIR_WRITE	2
123 
124 /* USB interface specific control request */
125 
126 #define	UR_BBB_RESET		0xff	/* Bulk-Only reset */
127 #define	UR_BBB_GET_MAX_LUN	0xfe	/* Get maximum lun */
128 
129 /* Command Block Wrapper */
130 typedef struct {
131 	uDWord	dCBWSignature;
132 #define	CBWSIGNATURE	0x43425355
133 	uDWord	dCBWTag;
134 	uDWord	dCBWDataTransferLength;
135 	uByte	bCBWFlags;
136 #define	CBWFLAGS_OUT	0x00
137 #define	CBWFLAGS_IN	0x80
138 	uByte	bCBWLUN;
139 	uByte	bCDBLength;
140 #define	CBWCDBLENGTH	16
141 	uByte	CBWCDB[CBWCDBLENGTH];
142 } __packed ustorage_fs_bbb_cbw_t;
143 
144 #define	USTORAGE_FS_BBB_CBW_SIZE	31
145 
146 /* Command Status Wrapper */
147 typedef struct {
148 	uDWord	dCSWSignature;
149 #define	CSWSIGNATURE	0x53425355
150 	uDWord	dCSWTag;
151 	uDWord	dCSWDataResidue;
152 	uByte	bCSWStatus;
153 #define	CSWSTATUS_GOOD	0x0
154 #define	CSWSTATUS_FAILED	0x1
155 #define	CSWSTATUS_PHASE	0x2
156 } __packed ustorage_fs_bbb_csw_t;
157 
158 #define	USTORAGE_FS_BBB_CSW_SIZE	13
159 
160 struct ustorage_fs_lun {
161 
162 	uint8_t	*memory_image;
163 
164 	uint32_t num_sectors;
165 	uint32_t sense_data;
166 	uint32_t sense_data_info;
167 	uint32_t unit_attention_data;
168 
169 	uint8_t	read_only:1;
170 	uint8_t	prevent_medium_removal:1;
171 	uint8_t	info_valid:1;
172 	uint8_t	removable:1;
173 };
174 
175 struct ustorage_fs_softc {
176 
177 	ustorage_fs_bbb_cbw_t sc_cbw;	/* Command Wrapper Block */
178 	ustorage_fs_bbb_csw_t sc_csw;	/* Command Status Block */
179 
180 	struct lock sc_lock;
181 
182 	struct ustorage_fs_lun sc_lun[USTORAGE_FS_MAX_LUN];
183 
184 	struct {
185 		uint8_t *data_ptr;
186 		struct ustorage_fs_lun *currlun;
187 
188 		uint32_t data_rem;	/* bytes, as reported by the command
189 					 * block wrapper */
190 		uint32_t offset;	/* bytes */
191 
192 		uint8_t	cbw_dir;
193 		uint8_t	cmd_dir;
194 		uint8_t	lun;
195 		uint8_t	cmd_len;
196 		uint8_t	data_short:1;
197 		uint8_t	data_error:1;
198 	}	sc_transfer;
199 
200 	device_t sc_dev;
201 	struct usb_device *sc_udev;
202 	struct usb_xfer *sc_xfer[USTORAGE_FS_T_BBB_MAX];
203 
204 	uint8_t	sc_iface_no;		/* interface number */
205 	uint8_t	sc_last_lun;
206 	uint8_t	sc_last_xfer_index;
207 	uint8_t	sc_qdata[USTORAGE_QDATA_MAX];
208 };
209 
210 /* prototypes */
211 
212 static device_probe_t ustorage_fs_probe;
213 static device_attach_t ustorage_fs_attach;
214 static device_detach_t ustorage_fs_detach;
215 static device_suspend_t ustorage_fs_suspend;
216 static device_resume_t ustorage_fs_resume;
217 static usb_handle_request_t ustorage_fs_handle_request;
218 
219 static usb_callback_t ustorage_fs_t_bbb_command_callback;
220 static usb_callback_t ustorage_fs_t_bbb_data_dump_callback;
221 static usb_callback_t ustorage_fs_t_bbb_data_read_callback;
222 static usb_callback_t ustorage_fs_t_bbb_data_write_callback;
223 static usb_callback_t ustorage_fs_t_bbb_status_callback;
224 
225 static void ustorage_fs_transfer_start(struct ustorage_fs_softc *sc, uint8_t xfer_index);
226 static void ustorage_fs_transfer_stop(struct ustorage_fs_softc *sc);
227 
228 static uint8_t ustorage_fs_verify(struct ustorage_fs_softc *sc);
229 static uint8_t ustorage_fs_inquiry(struct ustorage_fs_softc *sc);
230 static uint8_t ustorage_fs_request_sense(struct ustorage_fs_softc *sc);
231 static uint8_t ustorage_fs_read_capacity(struct ustorage_fs_softc *sc);
232 static uint8_t ustorage_fs_mode_sense(struct ustorage_fs_softc *sc);
233 static uint8_t ustorage_fs_start_stop(struct ustorage_fs_softc *sc);
234 static uint8_t ustorage_fs_prevent_allow(struct ustorage_fs_softc *sc);
235 static uint8_t ustorage_fs_read_format_capacities(struct ustorage_fs_softc *sc);
236 static uint8_t ustorage_fs_mode_select(struct ustorage_fs_softc *sc);
237 static uint8_t ustorage_fs_min_len(struct ustorage_fs_softc *sc, uint32_t len, uint32_t mask);
238 static uint8_t ustorage_fs_read(struct ustorage_fs_softc *sc);
239 static uint8_t ustorage_fs_write(struct ustorage_fs_softc *sc);
240 static uint8_t ustorage_fs_check_cmd(struct ustorage_fs_softc *sc, uint8_t cmd_size, uint16_t mask, uint8_t needs_medium);
241 static uint8_t ustorage_fs_do_cmd(struct ustorage_fs_softc *sc);
242 
243 static device_method_t ustorage_fs_methods[] = {
244 	/* USB interface */
245 	DEVMETHOD(usb_handle_request, ustorage_fs_handle_request),
246 
247 	/* Device interface */
248 	DEVMETHOD(device_probe, ustorage_fs_probe),
249 	DEVMETHOD(device_attach, ustorage_fs_attach),
250 	DEVMETHOD(device_detach, ustorage_fs_detach),
251 	DEVMETHOD(device_suspend, ustorage_fs_suspend),
252 	DEVMETHOD(device_resume, ustorage_fs_resume),
253 
254 	{0, 0}
255 };
256 
257 static driver_t ustorage_fs_driver = {
258 	.name = "ustorage_fs",
259 	.methods = ustorage_fs_methods,
260 	.size = sizeof(struct ustorage_fs_softc),
261 };
262 
263 static devclass_t ustorage_fs_devclass;
264 
265 DRIVER_MODULE(ustorage_fs, uhub, ustorage_fs_driver, ustorage_fs_devclass, NULL, NULL);
266 MODULE_VERSION(ustorage_fs, 0);
267 MODULE_DEPEND(ustorage_fs, usb, 1, 1, 1);
268 
269 static struct usb_config ustorage_fs_bbb_config[USTORAGE_FS_T_BBB_MAX] = {
270 
271 	[USTORAGE_FS_T_BBB_COMMAND] = {
272 		.type = UE_BULK,
273 		.endpoint = UE_ADDR_ANY,
274 		.direction = UE_DIR_OUT,
275 		.bufsize = sizeof(ustorage_fs_bbb_cbw_t),
276 		.flags = {.ext_buffer = 1,},
277 		.callback = &ustorage_fs_t_bbb_command_callback,
278 		.usb_mode = USB_MODE_DEVICE,
279 	},
280 
281 	[USTORAGE_FS_T_BBB_DATA_DUMP] = {
282 		.type = UE_BULK,
283 		.endpoint = UE_ADDR_ANY,
284 		.direction = UE_DIR_OUT,
285 		.bufsize = 0,	/* use wMaxPacketSize */
286 		.flags = {.proxy_buffer = 1,.short_xfer_ok = 1,},
287 		.callback = &ustorage_fs_t_bbb_data_dump_callback,
288 		.usb_mode = USB_MODE_DEVICE,
289 	},
290 
291 	[USTORAGE_FS_T_BBB_DATA_READ] = {
292 		.type = UE_BULK,
293 		.endpoint = UE_ADDR_ANY,
294 		.direction = UE_DIR_OUT,
295 		.bufsize = USTORAGE_FS_BULK_SIZE,
296 		.flags = {.proxy_buffer = 1,.short_xfer_ok = 1,.ext_buffer = 1},
297 		.callback = &ustorage_fs_t_bbb_data_read_callback,
298 		.usb_mode = USB_MODE_DEVICE,
299 	},
300 
301 	[USTORAGE_FS_T_BBB_DATA_WRITE] = {
302 		.type = UE_BULK,
303 		.endpoint = UE_ADDR_ANY,
304 		.direction = UE_DIR_IN,
305 		.bufsize = USTORAGE_FS_BULK_SIZE,
306 		.flags = {.proxy_buffer = 1,.short_xfer_ok = 1,.ext_buffer = 1},
307 		.callback = &ustorage_fs_t_bbb_data_write_callback,
308 		.usb_mode = USB_MODE_DEVICE,
309 	},
310 
311 	[USTORAGE_FS_T_BBB_STATUS] = {
312 		.type = UE_BULK,
313 		.endpoint = UE_ADDR_ANY,
314 		.direction = UE_DIR_IN,
315 		.bufsize = sizeof(ustorage_fs_bbb_csw_t),
316 		.flags = {.short_xfer_ok = 1,.ext_buffer = 1,},
317 		.callback = &ustorage_fs_t_bbb_status_callback,
318 		.usb_mode = USB_MODE_DEVICE,
319 	},
320 };
321 
322 /*
323  * USB device probe/attach/detach
324  */
325 
326 static int
327 ustorage_fs_probe(device_t dev)
328 {
329 	struct usb_attach_arg *uaa = device_get_ivars(dev);
330 	struct usb_interface_descriptor *id;
331 
332 	if (uaa->usb_mode != USB_MODE_DEVICE) {
333 		return (ENXIO);
334 	}
335 	/* Check for a standards compliant device */
336 	id = usbd_get_interface_descriptor(uaa->iface);
337 	if ((id == NULL) ||
338 	    (id->bInterfaceClass != UICLASS_MASS) ||
339 	    (id->bInterfaceSubClass != UISUBCLASS_SCSI) ||
340 	    (id->bInterfaceProtocol != UIPROTO_MASS_BBB)) {
341 		return (ENXIO);
342 	}
343 	return (BUS_PROBE_GENERIC);
344 }
345 
346 static int
347 ustorage_fs_attach(device_t dev)
348 {
349 	struct ustorage_fs_softc *sc = device_get_softc(dev);
350 	struct usb_attach_arg *uaa = device_get_ivars(dev);
351 	struct usb_interface_descriptor *id;
352 	int err;
353 	int unit;
354 
355 	/*
356 	 * NOTE: the softc struct is cleared in device_set_driver.
357 	 * We can safely call ustorage_fs_detach without specifically
358 	 * initializing the struct.
359 	 */
360 
361 	sc->sc_dev = dev;
362 	sc->sc_udev = uaa->device;
363 	unit = device_get_unit(dev);
364 
365 	/* enable power saving mode */
366 	usbd_set_power_mode(uaa->device, USB_POWER_MODE_SAVE);
367 
368 	if (unit == 0) {
369 		if (ustorage_fs_ramdisk == NULL) {
370 			/*
371 			 * allocate a memory image for our ramdisk until
372 			 * further
373 			 */
374 			ustorage_fs_ramdisk =
375 			    kmalloc(USTORAGE_FS_RAM_SECT << 9, M_USB,
376 			    M_ZERO | M_WAITOK);
377 
378 			if (ustorage_fs_ramdisk == NULL) {
379 				return (ENOMEM);
380 			}
381 		}
382 		sc->sc_lun[0].memory_image = ustorage_fs_ramdisk;
383 		sc->sc_lun[0].num_sectors = USTORAGE_FS_RAM_SECT;
384 		sc->sc_lun[0].removable = 1;
385 	}
386 
387 	device_set_usb_desc(dev);
388 
389 	lockinit(&sc->sc_lock, "USTORAGE_FS lock", 0, LK_CANRECURSE);
390 
391 	/* get interface index */
392 
393 	id = usbd_get_interface_descriptor(uaa->iface);
394 	if (id == NULL) {
395 		device_printf(dev, "failed to get "
396 		    "interface number\n");
397 		goto detach;
398 	}
399 	sc->sc_iface_no = id->bInterfaceNumber;
400 
401 	err = usbd_transfer_setup(uaa->device,
402 	    &uaa->info.bIfaceIndex, sc->sc_xfer, ustorage_fs_bbb_config,
403 	    USTORAGE_FS_T_BBB_MAX, sc, &sc->sc_lock);
404 	if (err) {
405 		device_printf(dev, "could not setup required "
406 		    "transfers, %s\n", usbd_errstr(err));
407 		goto detach;
408 	}
409 	/* start Mass Storage State Machine */
410 
411 	lockmgr(&sc->sc_lock, LK_EXCLUSIVE);
412 	ustorage_fs_transfer_start(sc, USTORAGE_FS_T_BBB_COMMAND);
413 	lockmgr(&sc->sc_lock, LK_RELEASE);
414 
415 	return (0);			/* success */
416 
417 detach:
418 	ustorage_fs_detach(dev);
419 	return (ENXIO);			/* failure */
420 }
421 
422 static int
423 ustorage_fs_detach(device_t dev)
424 {
425 	struct ustorage_fs_softc *sc = device_get_softc(dev);
426 
427 	/* teardown our statemachine */
428 
429 	usbd_transfer_unsetup(sc->sc_xfer, USTORAGE_FS_T_BBB_MAX);
430 
431 	lockuninit(&sc->sc_lock);
432 
433 	return (0);			/* success */
434 }
435 
436 static int
437 ustorage_fs_suspend(device_t dev)
438 {
439 	device_printf(dev, "suspending\n");
440 	return (0);			/* success */
441 }
442 
443 static int
444 ustorage_fs_resume(device_t dev)
445 {
446 	device_printf(dev, "resuming\n");
447 	return (0);			/* success */
448 }
449 
450 /*
451  * Generic functions to handle transfers
452  */
453 
454 static void
455 ustorage_fs_transfer_start(struct ustorage_fs_softc *sc, uint8_t xfer_index)
456 {
457 	if (sc->sc_xfer[xfer_index]) {
458 		sc->sc_last_xfer_index = xfer_index;
459 		usbd_transfer_start(sc->sc_xfer[xfer_index]);
460 	}
461 }
462 
463 static void
464 ustorage_fs_transfer_stop(struct ustorage_fs_softc *sc)
465 {
466 	usbd_transfer_stop(sc->sc_xfer[sc->sc_last_xfer_index]);
467 	lockmgr(&sc->sc_lock, LK_RELEASE);
468 	usbd_transfer_drain(sc->sc_xfer[sc->sc_last_xfer_index]);
469 	lockmgr(&sc->sc_lock, LK_EXCLUSIVE);
470 }
471 
472 static int
473 ustorage_fs_handle_request(device_t dev,
474     const void *preq, void **pptr, uint16_t *plen,
475     uint16_t offset, uint8_t *pstate)
476 {
477 	struct ustorage_fs_softc *sc = device_get_softc(dev);
478 	const struct usb_device_request *req = preq;
479 	uint8_t is_complete = *pstate;
480 
481 	if (!is_complete) {
482 		if ((req->bmRequestType == UT_WRITE_CLASS_INTERFACE) &&
483 		    (req->bRequest == UR_BBB_RESET)) {
484 			*plen = 0;
485 			lockmgr(&sc->sc_lock, LK_EXCLUSIVE);
486 			ustorage_fs_transfer_stop(sc);
487 			sc->sc_transfer.data_error = 1;
488 			ustorage_fs_transfer_start(sc,
489 			    USTORAGE_FS_T_BBB_COMMAND);
490 			lockmgr(&sc->sc_lock, LK_RELEASE);
491 			return (0);
492 		} else if ((req->bmRequestType == UT_READ_CLASS_INTERFACE) &&
493 			   (req->bRequest == UR_BBB_GET_MAX_LUN)) {
494 			if (offset == 0) {
495 				*plen = 1;
496 				*pptr = &sc->sc_last_lun;
497 			} else {
498 				*plen = 0;
499 			}
500 			return (0);
501 		}
502 	}
503 	return (ENXIO);			/* use builtin handler */
504 }
505 
506 static void
507 ustorage_fs_t_bbb_command_callback(struct usb_xfer *xfer, usb_error_t error)
508 {
509 	struct ustorage_fs_softc *sc = usbd_xfer_softc(xfer);
510 	uint32_t tag;
511 	uint8_t err = 0;
512 
513 	DPRINTF("\n");
514 
515 	switch (USB_GET_STATE(xfer)) {
516 	case USB_ST_TRANSFERRED:
517 
518 		tag = UGETDW(sc->sc_cbw.dCBWSignature);
519 
520 		if (tag != CBWSIGNATURE) {
521 			/* do nothing */
522 			DPRINTF("invalid signature 0x%08x\n", tag);
523 			break;
524 		}
525 		tag = UGETDW(sc->sc_cbw.dCBWTag);
526 
527 		/* echo back tag */
528 		USETDW(sc->sc_csw.dCSWTag, tag);
529 
530 		/* reset status */
531 		sc->sc_csw.bCSWStatus = 0;
532 
533 		/* reset data offset, data length and data remainder */
534 		sc->sc_transfer.offset = 0;
535 		sc->sc_transfer.data_rem =
536 		    UGETDW(sc->sc_cbw.dCBWDataTransferLength);
537 
538 		/* reset data flags */
539 		sc->sc_transfer.data_short = 0;
540 
541 		/* extract LUN */
542 		sc->sc_transfer.lun = sc->sc_cbw.bCBWLUN;
543 
544 		if (sc->sc_transfer.data_rem == 0) {
545 			sc->sc_transfer.cbw_dir = DIR_NONE;
546 		} else {
547 			if (sc->sc_cbw.bCBWFlags & CBWFLAGS_IN) {
548 				sc->sc_transfer.cbw_dir = DIR_WRITE;
549 			} else {
550 				sc->sc_transfer.cbw_dir = DIR_READ;
551 			}
552 		}
553 
554 		sc->sc_transfer.cmd_len = sc->sc_cbw.bCDBLength;
555 		if ((sc->sc_transfer.cmd_len > sizeof(sc->sc_cbw.CBWCDB)) ||
556 		    (sc->sc_transfer.cmd_len == 0)) {
557 			/* just halt - this is invalid */
558 			DPRINTF("invalid command length %d bytes\n",
559 			    sc->sc_transfer.cmd_len);
560 			break;
561 		}
562 
563 		err = ustorage_fs_do_cmd(sc);
564 		if (err) {
565 			/* got an error */
566 			DPRINTF("command failed\n");
567 			break;
568 		}
569 		if ((sc->sc_transfer.data_rem > 0) &&
570 		    (sc->sc_transfer.cbw_dir != sc->sc_transfer.cmd_dir)) {
571 			/* contradicting data transfer direction */
572 			err = 1;
573 			DPRINTF("data direction mismatch\n");
574 			break;
575 		}
576 		switch (sc->sc_transfer.cbw_dir) {
577 		case DIR_READ:
578 			ustorage_fs_transfer_start(sc, USTORAGE_FS_T_BBB_DATA_READ);
579 			break;
580 		case DIR_WRITE:
581 			ustorage_fs_transfer_start(sc, USTORAGE_FS_T_BBB_DATA_WRITE);
582 			break;
583 		default:
584 			ustorage_fs_transfer_start(sc,
585 			    USTORAGE_FS_T_BBB_STATUS);
586 			break;
587 		}
588 		break;
589 
590 	case USB_ST_SETUP:
591 tr_setup:
592 		if (sc->sc_transfer.data_error) {
593 			sc->sc_transfer.data_error = 0;
594 			usbd_xfer_set_stall(xfer);
595 			DPRINTF("stall pipe\n");
596 		}
597 
598 		usbd_xfer_set_frame_data(xfer, 0, &sc->sc_cbw,
599 		    sizeof(sc->sc_cbw));
600 		usbd_transfer_submit(xfer);
601 		break;
602 
603 	default:			/* Error */
604 		DPRINTF("error\n");
605 		if (error == USB_ERR_CANCELLED) {
606 			break;
607 		}
608 		/* If the pipe is already stalled, don't do another stall */
609 		if (!usbd_xfer_is_stalled(xfer))
610 			sc->sc_transfer.data_error = 1;
611 
612 		/* try again */
613 		goto tr_setup;
614 	}
615 	if (err) {
616 		if (sc->sc_csw.bCSWStatus == 0) {
617 			/* set some default error code */
618 			sc->sc_csw.bCSWStatus = CSWSTATUS_FAILED;
619 		}
620 		if (sc->sc_transfer.cbw_dir == DIR_READ) {
621 			/* dump all data */
622 			ustorage_fs_transfer_start(sc,
623 			    USTORAGE_FS_T_BBB_DATA_DUMP);
624 			return;
625 		}
626 		if (sc->sc_transfer.cbw_dir == DIR_WRITE) {
627 			/* need to stall before status */
628 			sc->sc_transfer.data_error = 1;
629 		}
630 		ustorage_fs_transfer_start(sc, USTORAGE_FS_T_BBB_STATUS);
631 	}
632 }
633 
634 static void
635 ustorage_fs_t_bbb_data_dump_callback(struct usb_xfer *xfer, usb_error_t error)
636 {
637 	struct ustorage_fs_softc *sc = usbd_xfer_softc(xfer);
638 	uint32_t max_bulk = usbd_xfer_max_len(xfer);
639 	int actlen, sumlen;
640 
641 	usbd_xfer_status(xfer, &actlen, &sumlen, NULL, NULL);
642 
643 	DPRINTF("\n");
644 
645 	switch (USB_GET_STATE(xfer)) {
646 	case USB_ST_TRANSFERRED:
647 		sc->sc_transfer.data_rem -= actlen;
648 		sc->sc_transfer.offset += actlen;
649 
650 		if (actlen != sumlen || sc->sc_transfer.data_rem == 0) {
651 			/* short transfer or end of data */
652 			ustorage_fs_transfer_start(sc,
653 			    USTORAGE_FS_T_BBB_STATUS);
654 			break;
655 		}
656 		/* Fallthrough */
657 
658 	case USB_ST_SETUP:
659 tr_setup:
660 		if (max_bulk > sc->sc_transfer.data_rem) {
661 			max_bulk = sc->sc_transfer.data_rem;
662 		}
663 		if (sc->sc_transfer.data_error) {
664 			sc->sc_transfer.data_error = 0;
665 			usbd_xfer_set_stall(xfer);
666 		}
667 		usbd_xfer_set_frame_len(xfer, 0, max_bulk);
668 		usbd_transfer_submit(xfer);
669 		break;
670 
671 	default:			/* Error */
672 		if (error == USB_ERR_CANCELLED) {
673 			break;
674 		}
675 		/*
676 		 * If the pipe is already stalled, don't do another stall:
677 		 */
678 		if (!usbd_xfer_is_stalled(xfer))
679 			sc->sc_transfer.data_error = 1;
680 
681 		/* try again */
682 		goto tr_setup;
683 	}
684 }
685 
686 static void
687 ustorage_fs_t_bbb_data_read_callback(struct usb_xfer *xfer, usb_error_t error)
688 {
689 	struct ustorage_fs_softc *sc = usbd_xfer_softc(xfer);
690 	uint32_t max_bulk = usbd_xfer_max_len(xfer);
691 	int actlen, sumlen;
692 
693 	usbd_xfer_status(xfer, &actlen, &sumlen, NULL, NULL);
694 
695 	DPRINTF("\n");
696 
697 	switch (USB_GET_STATE(xfer)) {
698 	case USB_ST_TRANSFERRED:
699 		sc->sc_transfer.data_rem -= actlen;
700 		sc->sc_transfer.data_ptr += actlen;
701 		sc->sc_transfer.offset += actlen;
702 
703 		if (actlen != sumlen || sc->sc_transfer.data_rem == 0) {
704 			/* short transfer or end of data */
705 			ustorage_fs_transfer_start(sc,
706 			    USTORAGE_FS_T_BBB_STATUS);
707 			break;
708 		}
709 		/* Fallthrough */
710 
711 	case USB_ST_SETUP:
712 tr_setup:
713 		if (max_bulk > sc->sc_transfer.data_rem) {
714 			max_bulk = sc->sc_transfer.data_rem;
715 		}
716 		if (sc->sc_transfer.data_error) {
717 			sc->sc_transfer.data_error = 0;
718 			usbd_xfer_set_stall(xfer);
719 		}
720 
721 		usbd_xfer_set_frame_data(xfer, 0, sc->sc_transfer.data_ptr,
722 		    max_bulk);
723 		usbd_transfer_submit(xfer);
724 		break;
725 
726 	default:			/* Error */
727 		if (error == USB_ERR_CANCELLED) {
728 			break;
729 		}
730 		/* If the pipe is already stalled, don't do another stall */
731 		if (!usbd_xfer_is_stalled(xfer))
732 			sc->sc_transfer.data_error = 1;
733 
734 		/* try again */
735 		goto tr_setup;
736 	}
737 }
738 
739 static void
740 ustorage_fs_t_bbb_data_write_callback(struct usb_xfer *xfer, usb_error_t error)
741 {
742 	struct ustorage_fs_softc *sc = usbd_xfer_softc(xfer);
743 	uint32_t max_bulk = usbd_xfer_max_len(xfer);
744 	int actlen, sumlen;
745 
746 	usbd_xfer_status(xfer, &actlen, &sumlen, NULL, NULL);
747 
748 	DPRINTF("\n");
749 
750 	switch (USB_GET_STATE(xfer)) {
751 	case USB_ST_TRANSFERRED:
752 		sc->sc_transfer.data_rem -= actlen;
753 		sc->sc_transfer.data_ptr += actlen;
754 		sc->sc_transfer.offset += actlen;
755 
756 		if (actlen != sumlen || sc->sc_transfer.data_rem == 0) {
757 			/* short transfer or end of data */
758 			ustorage_fs_transfer_start(sc,
759 			    USTORAGE_FS_T_BBB_STATUS);
760 			break;
761 		}
762 	case USB_ST_SETUP:
763 tr_setup:
764 		if (max_bulk >= sc->sc_transfer.data_rem) {
765 			max_bulk = sc->sc_transfer.data_rem;
766 			if (sc->sc_transfer.data_short)
767 				usbd_xfer_set_flag(xfer, USB_FORCE_SHORT_XFER);
768 			else
769 				usbd_xfer_clr_flag(xfer, USB_FORCE_SHORT_XFER);
770 		} else
771 			usbd_xfer_clr_flag(xfer, USB_FORCE_SHORT_XFER);
772 
773 		if (sc->sc_transfer.data_error) {
774 			sc->sc_transfer.data_error = 0;
775 			usbd_xfer_set_stall(xfer);
776 		}
777 
778 		usbd_xfer_set_frame_data(xfer, 0, sc->sc_transfer.data_ptr,
779 		    max_bulk);
780 		usbd_transfer_submit(xfer);
781 		break;
782 
783 	default:			/* Error */
784 		if (error == USB_ERR_CANCELLED) {
785 			break;
786 		}
787 		/*
788 		 * If the pipe is already stalled, don't do another
789 		 * stall
790 		 */
791 		if (!usbd_xfer_is_stalled(xfer))
792 			sc->sc_transfer.data_error = 1;
793 
794 		/* try again */
795 		goto tr_setup;
796 	}
797 }
798 
799 static void
800 ustorage_fs_t_bbb_status_callback(struct usb_xfer *xfer, usb_error_t error)
801 {
802 	struct ustorage_fs_softc *sc = usbd_xfer_softc(xfer);
803 
804 	DPRINTF("\n");
805 
806 	switch (USB_GET_STATE(xfer)) {
807 	case USB_ST_TRANSFERRED:
808 		ustorage_fs_transfer_start(sc, USTORAGE_FS_T_BBB_COMMAND);
809 		break;
810 
811 	case USB_ST_SETUP:
812 tr_setup:
813 		USETDW(sc->sc_csw.dCSWSignature, CSWSIGNATURE);
814 		USETDW(sc->sc_csw.dCSWDataResidue, sc->sc_transfer.data_rem);
815 
816 		if (sc->sc_transfer.data_error) {
817 			sc->sc_transfer.data_error = 0;
818 			usbd_xfer_set_stall(xfer);
819 		}
820 
821 		usbd_xfer_set_frame_data(xfer, 0, &sc->sc_csw,
822 		    sizeof(sc->sc_csw));
823 		usbd_transfer_submit(xfer);
824 		break;
825 
826 	default:
827 		if (error == USB_ERR_CANCELLED) {
828 			break;
829 		}
830 		/* If the pipe is already stalled, don't do another stall */
831 		if (!usbd_xfer_is_stalled(xfer))
832 			sc->sc_transfer.data_error = 1;
833 
834 		/* try again */
835 		goto tr_setup;
836 	}
837 }
838 
839 /* SCSI commands that we recognize */
840 #define	SC_FORMAT_UNIT			0x04
841 #define	SC_INQUIRY			0x12
842 #define	SC_MODE_SELECT_6		0x15
843 #define	SC_MODE_SELECT_10		0x55
844 #define	SC_MODE_SENSE_6			0x1a
845 #define	SC_MODE_SENSE_10		0x5a
846 #define	SC_PREVENT_ALLOW_MEDIUM_REMOVAL	0x1e
847 #define	SC_READ_6			0x08
848 #define	SC_READ_10			0x28
849 #define	SC_READ_12			0xa8
850 #define	SC_READ_CAPACITY		0x25
851 #define	SC_READ_FORMAT_CAPACITIES	0x23
852 #define	SC_RELEASE			0x17
853 #define	SC_REQUEST_SENSE		0x03
854 #define	SC_RESERVE			0x16
855 #define	SC_SEND_DIAGNOSTIC		0x1d
856 #define	SC_START_STOP_UNIT		0x1b
857 #define	SC_SYNCHRONIZE_CACHE		0x35
858 #define	SC_TEST_UNIT_READY		0x00
859 #define	SC_VERIFY			0x2f
860 #define	SC_WRITE_6			0x0a
861 #define	SC_WRITE_10			0x2a
862 #define	SC_WRITE_12			0xaa
863 
864 /* SCSI Sense Key/Additional Sense Code/ASC Qualifier values */
865 #define	SS_NO_SENSE				0
866 #define	SS_COMMUNICATION_FAILURE		0x040800
867 #define	SS_INVALID_COMMAND			0x052000
868 #define	SS_INVALID_FIELD_IN_CDB			0x052400
869 #define	SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE	0x052100
870 #define	SS_LOGICAL_UNIT_NOT_SUPPORTED		0x052500
871 #define	SS_MEDIUM_NOT_PRESENT			0x023a00
872 #define	SS_MEDIUM_REMOVAL_PREVENTED		0x055302
873 #define	SS_NOT_READY_TO_READY_TRANSITION	0x062800
874 #define	SS_RESET_OCCURRED			0x062900
875 #define	SS_SAVING_PARAMETERS_NOT_SUPPORTED	0x053900
876 #define	SS_UNRECOVERED_READ_ERROR		0x031100
877 #define	SS_WRITE_ERROR				0x030c02
878 #define	SS_WRITE_PROTECTED			0x072700
879 
880 #define	SK(x)		((uint8_t) ((x) >> 16))	/* Sense Key byte, etc. */
881 #define	ASC(x)		((uint8_t) ((x) >> 8))
882 #define	ASCQ(x)		((uint8_t) (x))
883 
884 /* Routines for unaligned data access */
885 
886 static uint16_t
887 get_be16(uint8_t *buf)
888 {
889 	return ((uint16_t)buf[0] << 8) | ((uint16_t)buf[1]);
890 }
891 
892 static uint32_t
893 get_be32(uint8_t *buf)
894 {
895 	return ((uint32_t)buf[0] << 24) | ((uint32_t)buf[1] << 16) |
896 	((uint32_t)buf[2] << 8) | ((uint32_t)buf[3]);
897 }
898 
899 static void
900 put_be16(uint8_t *buf, uint16_t val)
901 {
902 	buf[0] = val >> 8;
903 	buf[1] = val;
904 }
905 
906 static void
907 put_be32(uint8_t *buf, uint32_t val)
908 {
909 	buf[0] = val >> 24;
910 	buf[1] = val >> 16;
911 	buf[2] = val >> 8;
912 	buf[3] = val & 0xff;
913 }
914 
915 /*------------------------------------------------------------------------*
916  *	ustorage_fs_verify
917  *
918  * Returns:
919  *    0: Success
920  * Else: Failure
921  *------------------------------------------------------------------------*/
922 static uint8_t
923 ustorage_fs_verify(struct ustorage_fs_softc *sc)
924 {
925 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
926 	uint32_t lba;
927 	uint32_t vlen;
928 	uint64_t file_offset;
929 	uint64_t amount_left;
930 
931 	/*
932 	 * Get the starting Logical Block Address
933 	 */
934 	lba = get_be32(&sc->sc_cmd_data[2]);
935 
936 	/*
937 	 * We allow DPO (Disable Page Out = don't save data in the cache)
938 	 * but we don't implement it.
939 	 */
940 	if ((sc->sc_cmd_data[1] & ~0x10) != 0) {
941 		currlun->sense_data = SS_INVALID_FIELD_IN_CDB;
942 		return (1);
943 	}
944 	vlen = get_be16(&sc->sc_cmd_data[7]);
945 	if (vlen == 0) {
946 		goto done;
947 	}
948 	/* No default reply */
949 
950 	/* Prepare to carry out the file verify */
951 	amount_left = vlen;
952 	amount_left <<= 9;
953 	file_offset = lba;
954 	file_offset <<= 9;
955 
956 	/* Range check */
957 	vlen += lba;
958 
959 	if ((vlen < lba) ||
960 	    (vlen > currlun->num_sectors) ||
961 	    (lba >= currlun->num_sectors)) {
962 		currlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
963 		return (1);
964 	}
965 	/* XXX TODO: verify that data is readable */
966 done:
967 	return (ustorage_fs_min_len(sc, 0, 0 - 1));
968 }
969 
970 /*------------------------------------------------------------------------*
971  *	ustorage_fs_inquiry
972  *
973  * Returns:
974  *    0: Success
975  * Else: Failure
976  *------------------------------------------------------------------------*/
977 static uint8_t
978 ustorage_fs_inquiry(struct ustorage_fs_softc *sc)
979 {
980 	uint8_t *buf = sc->sc_transfer.data_ptr;
981 
982 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
983 
984 	if (!sc->sc_transfer.currlun) {
985 		/* Unsupported LUNs are okay */
986 		memset(buf, 0, 36);
987 		buf[0] = 0x7f;
988 		/* Unsupported, no device - type */
989 		return (ustorage_fs_min_len(sc, 36, 0 - 1));
990 	}
991 	memset(buf, 0, 8);
992 	/* Non - removable, direct - access device */
993 	if (currlun->removable)
994 		buf[1] = 0x80;
995 	buf[2] = 2;
996 	/* ANSI SCSI level 2 */
997 	buf[3] = 2;
998 	/* SCSI - 2 INQUIRY data format */
999 	buf[4] = 31;
1000 	/* Additional length */
1001 	/* No special options */
1002 	/* Copy in ID string */
1003 	memcpy(buf + 8, USTORAGE_FS_ID_STRING, 28);
1004 
1005 #if (USTORAGE_QDATA_MAX < 36)
1006 #error "(USTORAGE_QDATA_MAX < 36)"
1007 #endif
1008 	return (ustorage_fs_min_len(sc, 36, 0 - 1));
1009 }
1010 
1011 /*------------------------------------------------------------------------*
1012  *	ustorage_fs_request_sense
1013  *
1014  * Returns:
1015  *    0: Success
1016  * Else: Failure
1017  *------------------------------------------------------------------------*/
1018 static uint8_t
1019 ustorage_fs_request_sense(struct ustorage_fs_softc *sc)
1020 {
1021 	uint8_t *buf = sc->sc_transfer.data_ptr;
1022 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1023 	uint32_t sd;
1024 	uint32_t sdinfo;
1025 	uint8_t valid;
1026 
1027 	/*
1028 	 * From the SCSI-2 spec., section 7.9 (Unit attention condition):
1029 	 *
1030 	 * If a REQUEST SENSE command is received from an initiator
1031 	 * with a pending unit attention condition (before the target
1032 	 * generates the contingent allegiance condition), then the
1033 	 * target shall either:
1034 	 *   a) report any pending sense data and preserve the unit
1035 	 *	attention condition on the logical unit, or,
1036 	 *   b) report the unit attention condition, may discard any
1037 	 *	pending sense data, and clear the unit attention
1038 	 *	condition on the logical unit for that initiator.
1039 	 *
1040 	 * FSG normally uses option a); enable this code to use option b).
1041 	 */
1042 #if 0
1043 	if (currlun && currlun->unit_attention_data != SS_NO_SENSE) {
1044 		currlun->sense_data = currlun->unit_attention_data;
1045 		currlun->unit_attention_data = SS_NO_SENSE;
1046 	}
1047 #endif
1048 
1049 	if (!currlun) {
1050 		/* Unsupported LUNs are okay */
1051 		sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1052 		sdinfo = 0;
1053 		valid = 0;
1054 	} else {
1055 		sd = currlun->sense_data;
1056 		sdinfo = currlun->sense_data_info;
1057 		valid = currlun->info_valid << 7;
1058 		currlun->sense_data = SS_NO_SENSE;
1059 		currlun->sense_data_info = 0;
1060 		currlun->info_valid = 0;
1061 	}
1062 
1063 	memset(buf, 0, 18);
1064 	buf[0] = valid | 0x70;
1065 	/* Valid, current error */
1066 	buf[2] = SK(sd);
1067 	put_be32(&buf[3], sdinfo);
1068 	/* Sense information */
1069 	buf[7] = 18 - 8;
1070 	/* Additional sense length */
1071 	buf[12] = ASC(sd);
1072 	buf[13] = ASCQ(sd);
1073 
1074 #if (USTORAGE_QDATA_MAX < 18)
1075 #error "(USTORAGE_QDATA_MAX < 18)"
1076 #endif
1077 	return (ustorage_fs_min_len(sc, 18, 0 - 1));
1078 }
1079 
1080 /*------------------------------------------------------------------------*
1081  *	ustorage_fs_read_capacity
1082  *
1083  * Returns:
1084  *    0: Success
1085  * Else: Failure
1086  *------------------------------------------------------------------------*/
1087 static uint8_t
1088 ustorage_fs_read_capacity(struct ustorage_fs_softc *sc)
1089 {
1090 	uint8_t *buf = sc->sc_transfer.data_ptr;
1091 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1092 	uint32_t lba = get_be32(&sc->sc_cmd_data[2]);
1093 	uint8_t pmi = sc->sc_cmd_data[8];
1094 
1095 	/* Check the PMI and LBA fields */
1096 	if ((pmi > 1) || ((pmi == 0) && (lba != 0))) {
1097 		currlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1098 		return (1);
1099 	}
1100 	/* Max logical block */
1101 	put_be32(&buf[0], currlun->num_sectors - 1);
1102 	/* Block length */
1103 	put_be32(&buf[4], 512);
1104 
1105 #if (USTORAGE_QDATA_MAX < 8)
1106 #error "(USTORAGE_QDATA_MAX < 8)"
1107 #endif
1108 	return (ustorage_fs_min_len(sc, 8, 0 - 1));
1109 }
1110 
1111 /*------------------------------------------------------------------------*
1112  *	ustorage_fs_mode_sense
1113  *
1114  * Returns:
1115  *    0: Success
1116  * Else: Failure
1117  *------------------------------------------------------------------------*/
1118 static uint8_t
1119 ustorage_fs_mode_sense(struct ustorage_fs_softc *sc)
1120 {
1121 	uint8_t *buf = sc->sc_transfer.data_ptr;
1122 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1123 	uint8_t *buf0;
1124 	uint16_t len;
1125 	uint16_t limit;
1126 	uint8_t mscmnd = sc->sc_cmd_data[0];
1127 	uint8_t pc;
1128 	uint8_t page_code;
1129 	uint8_t changeable_values;
1130 	uint8_t all_pages;
1131 
1132 	buf0 = buf;
1133 
1134 	if ((sc->sc_cmd_data[1] & ~0x08) != 0) {
1135 		/* Mask away DBD */
1136 		currlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1137 		return (1);
1138 	}
1139 	pc = sc->sc_cmd_data[2] >> 6;
1140 	page_code = sc->sc_cmd_data[2] & 0x3f;
1141 	if (pc == 3) {
1142 		currlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
1143 		return (1);
1144 	}
1145 	changeable_values = (pc == 1);
1146 	all_pages = (page_code == 0x3f);
1147 
1148 	/*
1149 	 * Write the mode parameter header.  Fixed values are: default
1150 	 * medium type, no cache control (DPOFUA), and no block descriptors.
1151 	 * The only variable value is the WriteProtect bit.  We will fill in
1152 	 * the mode data length later.
1153 	 */
1154 	memset(buf, 0, 8);
1155 	if (mscmnd == SC_MODE_SENSE_6) {
1156 		buf[2] = (currlun->read_only ? 0x80 : 0x00);
1157 		/* WP, DPOFUA */
1158 		buf += 4;
1159 		limit = 255;
1160 	} else {
1161 		/* SC_MODE_SENSE_10 */
1162 		buf[3] = (currlun->read_only ? 0x80 : 0x00);
1163 		/* WP, DPOFUA */
1164 		buf += 8;
1165 		limit = 65535;
1166 		/* Should really be mod_data.buflen */
1167 	}
1168 
1169 	/* No block descriptors */
1170 
1171 	/*
1172 	 * The mode pages, in numerical order.
1173 	 */
1174 	if ((page_code == 0x08) || all_pages) {
1175 		buf[0] = 0x08;
1176 		/* Page code */
1177 		buf[1] = 10;
1178 		/* Page length */
1179 		memset(buf + 2, 0, 10);
1180 		/* None of the fields are changeable */
1181 
1182 		if (!changeable_values) {
1183 			buf[2] = 0x04;
1184 			/* Write cache enable, */
1185 			/* Read cache not disabled */
1186 			/* No cache retention priorities */
1187 			put_be16(&buf[4], 0xffff);
1188 			/* Don 't disable prefetch */
1189 			/* Minimum prefetch = 0 */
1190 			put_be16(&buf[8], 0xffff);
1191 			/* Maximum prefetch */
1192 			put_be16(&buf[10], 0xffff);
1193 			/* Maximum prefetch ceiling */
1194 		}
1195 		buf += 12;
1196 	}
1197 	/*
1198 	 * Check that a valid page was requested and the mode data length
1199 	 * isn't too long.
1200 	 */
1201 	len = buf - buf0;
1202 	if (len > limit) {
1203 		currlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1204 		return (1);
1205 	}
1206 	/* Store the mode data length */
1207 	if (mscmnd == SC_MODE_SENSE_6)
1208 		buf0[0] = len - 1;
1209 	else
1210 		put_be16(buf0, len - 2);
1211 
1212 #if (USTORAGE_QDATA_MAX < 24)
1213 #error "(USTORAGE_QDATA_MAX < 24)"
1214 #endif
1215 	return (ustorage_fs_min_len(sc, len, 0 - 1));
1216 }
1217 
1218 /*------------------------------------------------------------------------*
1219  *	ustorage_fs_start_stop
1220  *
1221  * Returns:
1222  *    0: Success
1223  * Else: Failure
1224  *------------------------------------------------------------------------*/
1225 static uint8_t
1226 ustorage_fs_start_stop(struct ustorage_fs_softc *sc)
1227 {
1228 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1229 	uint8_t loej;
1230 	uint8_t start;
1231 	uint8_t immed;
1232 
1233 	if (!currlun->removable) {
1234 		currlun->sense_data = SS_INVALID_COMMAND;
1235 		return (1);
1236 	}
1237 	immed = sc->sc_cmd_data[1] & 0x01;
1238 	loej = sc->sc_cmd_data[4] & 0x02;
1239 	start = sc->sc_cmd_data[4] & 0x01;
1240 
1241 	if (immed || loej || start) {
1242 		/* compile fix */
1243 	}
1244 	return (0);
1245 }
1246 
1247 /*------------------------------------------------------------------------*
1248  *	ustorage_fs_prevent_allow
1249  *
1250  * Returns:
1251  *    0: Success
1252  * Else: Failure
1253  *------------------------------------------------------------------------*/
1254 static uint8_t
1255 ustorage_fs_prevent_allow(struct ustorage_fs_softc *sc)
1256 {
1257 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1258 	uint8_t prevent;
1259 
1260 	if (!currlun->removable) {
1261 		currlun->sense_data = SS_INVALID_COMMAND;
1262 		return (1);
1263 	}
1264 	prevent = sc->sc_cmd_data[4] & 0x01;
1265 	if ((sc->sc_cmd_data[4] & ~0x01) != 0) {
1266 		/* Mask away Prevent */
1267 		currlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1268 		return (1);
1269 	}
1270 	if (currlun->prevent_medium_removal && !prevent) {
1271 		//fsync_sub(currlun);
1272 	}
1273 	currlun->prevent_medium_removal = prevent;
1274 	return (0);
1275 }
1276 
1277 /*------------------------------------------------------------------------*
1278  *	ustorage_fs_read_format_capacities
1279  *
1280  * Returns:
1281  *    0: Success
1282  * Else: Failure
1283  *------------------------------------------------------------------------*/
1284 static uint8_t
1285 ustorage_fs_read_format_capacities(struct ustorage_fs_softc *sc)
1286 {
1287 	uint8_t *buf = sc->sc_transfer.data_ptr;
1288 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1289 
1290 	buf[0] = buf[1] = buf[2] = 0;
1291 	buf[3] = 8;
1292 	/* Only the Current / Maximum Capacity Descriptor */
1293 	buf += 4;
1294 
1295 	/* Number of blocks */
1296 	put_be32(&buf[0], currlun->num_sectors);
1297 	/* Block length */
1298 	put_be32(&buf[4], 512);
1299 	/* Current capacity */
1300 	buf[4] = 0x02;
1301 
1302 #if (USTORAGE_QDATA_MAX < 12)
1303 #error "(USTORAGE_QDATA_MAX < 12)"
1304 #endif
1305 	return (ustorage_fs_min_len(sc, 12, 0 - 1));
1306 }
1307 
1308 /*------------------------------------------------------------------------*
1309  *	ustorage_fs_mode_select
1310  *
1311  * Return values:
1312  *    0: Success
1313  * Else: Failure
1314  *------------------------------------------------------------------------*/
1315 static uint8_t
1316 ustorage_fs_mode_select(struct ustorage_fs_softc *sc)
1317 {
1318 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1319 
1320 	/* We don't support MODE SELECT */
1321 	currlun->sense_data = SS_INVALID_COMMAND;
1322 	return (1);
1323 }
1324 
1325 /*------------------------------------------------------------------------*
1326  *	ustorage_fs_synchronize_cache
1327  *
1328  * Return values:
1329  *    0: Success
1330  * Else: Failure
1331  *------------------------------------------------------------------------*/
1332 static uint8_t
1333 ustorage_fs_synchronize_cache(struct ustorage_fs_softc *sc)
1334 {
1335 #if 0
1336 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1337 	uint8_t rc;
1338 
1339 	/*
1340 	 * We ignore the requested LBA and write out all dirty data buffers.
1341 	 */
1342 	rc = 0;
1343 	if (rc) {
1344 		currlun->sense_data = SS_WRITE_ERROR;
1345 	}
1346 #endif
1347 	return (0);
1348 }
1349 
1350 /*------------------------------------------------------------------------*
1351  *	ustorage_fs_read - read data from disk
1352  *
1353  * Return values:
1354  *    0: Success
1355  * Else: Failure
1356  *------------------------------------------------------------------------*/
1357 static uint8_t
1358 ustorage_fs_read(struct ustorage_fs_softc *sc)
1359 {
1360 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1361 	uint64_t file_offset;
1362 	uint32_t lba;
1363 	uint32_t len;
1364 
1365 	/*
1366 	 * Get the starting Logical Block Address and check that it's not
1367 	 * too big
1368 	 */
1369 	if (sc->sc_cmd_data[0] == SC_READ_6) {
1370 		lba = (((uint32_t)sc->sc_cmd_data[1]) << 16) |
1371 		    get_be16(&sc->sc_cmd_data[2]);
1372 	} else {
1373 		lba = get_be32(&sc->sc_cmd_data[2]);
1374 
1375 		/*
1376 		 * We allow DPO (Disable Page Out = don't save data in the
1377 		 * cache) and FUA (Force Unit Access = don't read from the
1378 		 * cache), but we don't implement them.
1379 		 */
1380 		if ((sc->sc_cmd_data[1] & ~0x18) != 0) {
1381 			currlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1382 			return (1);
1383 		}
1384 	}
1385 	len = sc->sc_transfer.data_rem >> 9;
1386 	len += lba;
1387 
1388 	if ((len < lba) ||
1389 	    (len > currlun->num_sectors) ||
1390 	    (lba >= currlun->num_sectors)) {
1391 		currlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1392 		return (1);
1393 	}
1394 	file_offset = lba;
1395 	file_offset <<= 9;
1396 
1397 	sc->sc_transfer.data_ptr = currlun->memory_image + file_offset;
1398 
1399 	return (0);
1400 }
1401 
1402 /*------------------------------------------------------------------------*
1403  *	ustorage_fs_write - write data to disk
1404  *
1405  * Return values:
1406  *    0: Success
1407  * Else: Failure
1408  *------------------------------------------------------------------------*/
1409 static uint8_t
1410 ustorage_fs_write(struct ustorage_fs_softc *sc)
1411 {
1412 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1413 	uint64_t file_offset;
1414 	uint32_t lba;
1415 	uint32_t len;
1416 
1417 	if (currlun->read_only) {
1418 		currlun->sense_data = SS_WRITE_PROTECTED;
1419 		return (1);
1420 	}
1421 	/* XXX clear SYNC */
1422 
1423 	/*
1424 	 * Get the starting Logical Block Address and check that it's not
1425 	 * too big.
1426 	 */
1427 	if (sc->sc_cmd_data[0] == SC_WRITE_6)
1428 		lba = (((uint32_t)sc->sc_cmd_data[1]) << 16) |
1429 		    get_be16(&sc->sc_cmd_data[2]);
1430 	else {
1431 		lba = get_be32(&sc->sc_cmd_data[2]);
1432 
1433 		/*
1434 		 * We allow DPO (Disable Page Out = don't save data in the
1435 		 * cache) and FUA (Force Unit Access = write directly to the
1436 		 * medium).  We don't implement DPO; we implement FUA by
1437 		 * performing synchronous output.
1438 		 */
1439 		if ((sc->sc_cmd_data[1] & ~0x18) != 0) {
1440 			currlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1441 			return (1);
1442 		}
1443 		if (sc->sc_cmd_data[1] & 0x08) {
1444 			/* FUA */
1445 			/* XXX set SYNC flag here */
1446 		}
1447 	}
1448 
1449 	len = sc->sc_transfer.data_rem >> 9;
1450 	len += lba;
1451 
1452 	if ((len < lba) ||
1453 	    (len > currlun->num_sectors) ||
1454 	    (lba >= currlun->num_sectors)) {
1455 		currlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1456 		return (1);
1457 	}
1458 	file_offset = lba;
1459 	file_offset <<= 9;
1460 
1461 	sc->sc_transfer.data_ptr = currlun->memory_image + file_offset;
1462 
1463 	return (0);
1464 }
1465 
1466 /*------------------------------------------------------------------------*
1467  *	ustorage_fs_min_len
1468  *
1469  * Return values:
1470  *    0: Success
1471  * Else: Failure
1472  *------------------------------------------------------------------------*/
1473 static uint8_t
1474 ustorage_fs_min_len(struct ustorage_fs_softc *sc, uint32_t len, uint32_t mask)
1475 {
1476 	if (len != sc->sc_transfer.data_rem) {
1477 
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_cmd_data[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_cmd_data[1] &= 0x1f;
1531 
1532 	/* Check if LUN is correct */
1533 	if (lun != sc->sc_transfer.lun) {
1534 
1535 	}
1536 	/* Check the LUN */
1537 	if (sc->sc_transfer.lun <= sc->sc_last_lun) {
1538 		sc->sc_transfer.currlun = currlun =
1539 		    sc->sc_lun + sc->sc_transfer.lun;
1540 		if (sc->sc_cmd_data[0] != SC_REQUEST_SENSE) {
1541 			currlun->sense_data = SS_NO_SENSE;
1542 			currlun->sense_data_info = 0;
1543 			currlun->info_valid = 0;
1544 		}
1545 		/*
1546 		 * If a unit attention condition exists, only INQUIRY
1547 		 * and REQUEST SENSE commands are allowed. Anything
1548 		 * else must fail!
1549 		 */
1550 		if ((currlun->unit_attention_data != SS_NO_SENSE) &&
1551 		    (sc->sc_cmd_data[0] != SC_INQUIRY) &&
1552 		    (sc->sc_cmd_data[0] != SC_REQUEST_SENSE)) {
1553 			currlun->sense_data = currlun->unit_attention_data;
1554 			currlun->unit_attention_data = SS_NO_SENSE;
1555 			return (1);
1556 		}
1557 	} else {
1558 		sc->sc_transfer.currlun = currlun = NULL;
1559 
1560 		/*
1561 		 * INQUIRY and REQUEST SENSE commands are explicitly allowed
1562 		 * to use unsupported LUNs; all others may not.
1563 		 */
1564 		if ((sc->sc_cmd_data[0] != SC_INQUIRY) &&
1565 		    (sc->sc_cmd_data[0] != SC_REQUEST_SENSE)) {
1566 			return (1);
1567 		}
1568 	}
1569 
1570 	/*
1571 	 * Check that only command bytes listed in the mask are
1572 	 * non-zero.
1573 	 */
1574 	for (i = 0; i != min_cmd_size; i++) {
1575 		if (sc->sc_cmd_data[i] && !(mask & (1UL << i))) {
1576 			if (currlun) {
1577 				currlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1578 			}
1579 			return (1);
1580 		}
1581 	}
1582 
1583 	/*
1584 	 * If the medium isn't mounted and the command needs to access
1585 	 * it, return an error.
1586 	 */
1587 	if (currlun && (!currlun->memory_image) && needs_medium) {
1588 		currlun->sense_data = SS_MEDIUM_NOT_PRESENT;
1589 		return (1);
1590 	}
1591 	return (0);
1592 }
1593 
1594 /*------------------------------------------------------------------------*
1595  *	ustorage_fs_do_cmd - do command
1596  *
1597  * Return values:
1598  *    0: Success
1599  * Else: Failure
1600  *------------------------------------------------------------------------*/
1601 static uint8_t
1602 ustorage_fs_do_cmd(struct ustorage_fs_softc *sc)
1603 {
1604 	uint8_t error = 1;
1605 	uint8_t i;
1606 	uint32_t temp;
1607 	const uint32_t mask9 = (0xFFFFFFFFUL >> 9) << 9;
1608 
1609 	/* set default data transfer pointer */
1610 	sc->sc_transfer.data_ptr = sc->sc_qdata;
1611 
1612 	DPRINTF("cmd_data[0]=0x%02x, data_rem=0x%08x\n",
1613 	    sc->sc_cmd_data[0], sc->sc_transfer.data_rem);
1614 
1615 	switch (sc->sc_cmd_data[0]) {
1616 	case SC_INQUIRY:
1617 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1618 		error = ustorage_fs_min_len(sc, sc->sc_cmd_data[4], 0 - 1);
1619 		if (error) {
1620 			break;
1621 		}
1622 		error = ustorage_fs_check_cmd(sc, 6,
1623 		    (1UL << 4) | 1, 0);
1624 		if (error) {
1625 			break;
1626 		}
1627 		error = ustorage_fs_inquiry(sc);
1628 
1629 		break;
1630 
1631 	case SC_MODE_SELECT_6:
1632 		sc->sc_transfer.cmd_dir = DIR_READ;
1633 		error = ustorage_fs_min_len(sc, sc->sc_cmd_data[4], 0 - 1);
1634 		if (error) {
1635 			break;
1636 		}
1637 		error = ustorage_fs_check_cmd(sc, 6,
1638 		    (1UL << 1) | (1UL << 4) | 1, 0);
1639 		if (error) {
1640 			break;
1641 		}
1642 		error = ustorage_fs_mode_select(sc);
1643 
1644 		break;
1645 
1646 	case SC_MODE_SELECT_10:
1647 		sc->sc_transfer.cmd_dir = DIR_READ;
1648 		error = ustorage_fs_min_len(sc,
1649 		    get_be16(&sc->sc_cmd_data[7]), 0 - 1);
1650 		if (error) {
1651 			break;
1652 		}
1653 		error = ustorage_fs_check_cmd(sc, 10,
1654 		    (1UL << 1) | (3UL << 7) | 1, 0);
1655 		if (error) {
1656 			break;
1657 		}
1658 		error = ustorage_fs_mode_select(sc);
1659 
1660 		break;
1661 
1662 	case SC_MODE_SENSE_6:
1663 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1664 		error = ustorage_fs_min_len(sc, sc->sc_cmd_data[4], 0 - 1);
1665 		if (error) {
1666 			break;
1667 		}
1668 		error = ustorage_fs_check_cmd(sc, 6,
1669 		    (1UL << 1) | (1UL << 2) | (1UL << 4) | 1, 0);
1670 		if (error) {
1671 			break;
1672 		}
1673 		error = ustorage_fs_mode_sense(sc);
1674 
1675 		break;
1676 
1677 	case SC_MODE_SENSE_10:
1678 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1679 		error = ustorage_fs_min_len(sc,
1680 		    get_be16(&sc->sc_cmd_data[7]), 0 - 1);
1681 		if (error) {
1682 			break;
1683 		}
1684 		error = ustorage_fs_check_cmd(sc, 10,
1685 		    (1UL << 1) | (1UL << 2) | (3UL << 7) | 1, 0);
1686 		if (error) {
1687 			break;
1688 		}
1689 		error = ustorage_fs_mode_sense(sc);
1690 
1691 		break;
1692 
1693 	case SC_PREVENT_ALLOW_MEDIUM_REMOVAL:
1694 		error = ustorage_fs_min_len(sc, 0, 0 - 1);
1695 		if (error) {
1696 			break;
1697 		}
1698 		error = ustorage_fs_check_cmd(sc, 6,
1699 		    (1UL << 4) | 1, 0);
1700 		if (error) {
1701 			break;
1702 		}
1703 		error = ustorage_fs_prevent_allow(sc);
1704 
1705 		break;
1706 
1707 	case SC_READ_6:
1708 		i = sc->sc_cmd_data[4];
1709 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1710 		temp = ((i == 0) ? 256UL : i);
1711 		error = ustorage_fs_min_len(sc, temp << 9, mask9);
1712 		if (error) {
1713 			break;
1714 		}
1715 		error = ustorage_fs_check_cmd(sc, 6,
1716 		    (7UL << 1) | (1UL << 4) | 1, 1);
1717 		if (error) {
1718 			break;
1719 		}
1720 		error = ustorage_fs_read(sc);
1721 
1722 		break;
1723 
1724 	case SC_READ_10:
1725 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1726 		temp = get_be16(&sc->sc_cmd_data[7]);
1727 		error = ustorage_fs_min_len(sc, temp << 9, mask9);
1728 		if (error) {
1729 			break;
1730 		}
1731 		error = ustorage_fs_check_cmd(sc, 10,
1732 		    (1UL << 1) | (0xfUL << 2) | (3UL << 7) | 1, 1);
1733 		if (error) {
1734 			break;
1735 		}
1736 		error = ustorage_fs_read(sc);
1737 
1738 		break;
1739 
1740 	case SC_READ_12:
1741 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1742 		temp = get_be32(&sc->sc_cmd_data[6]);
1743 		if (temp >= (1UL << (32 - 9))) {
1744 			/* numerical overflow */
1745 			sc->sc_csw.bCSWStatus = CSWSTATUS_FAILED;
1746 			error = 1;
1747 			break;
1748 		}
1749 		error = ustorage_fs_min_len(sc, temp << 9, mask9);
1750 		if (error) {
1751 			break;
1752 		}
1753 		error = ustorage_fs_check_cmd(sc, 12,
1754 		    (1UL << 1) | (0xfUL << 2) | (0xfUL << 6) | 1, 1);
1755 		if (error) {
1756 			break;
1757 		}
1758 		error = ustorage_fs_read(sc);
1759 
1760 		break;
1761 
1762 	case SC_READ_CAPACITY:
1763 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1764 		error = ustorage_fs_check_cmd(sc, 10,
1765 		    (0xfUL << 2) | (1UL << 8) | 1, 1);
1766 		if (error) {
1767 			break;
1768 		}
1769 		error = ustorage_fs_read_capacity(sc);
1770 
1771 		break;
1772 
1773 	case SC_READ_FORMAT_CAPACITIES:
1774 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1775 		error = ustorage_fs_min_len(sc,
1776 		    get_be16(&sc->sc_cmd_data[7]), 0 - 1);
1777 		if (error) {
1778 			break;
1779 		}
1780 		error = ustorage_fs_check_cmd(sc, 10,
1781 		    (3UL << 7) | 1, 1);
1782 		if (error) {
1783 			break;
1784 		}
1785 		error = ustorage_fs_read_format_capacities(sc);
1786 
1787 		break;
1788 
1789 	case SC_REQUEST_SENSE:
1790 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1791 		error = ustorage_fs_min_len(sc, sc->sc_cmd_data[4], 0 - 1);
1792 		if (error) {
1793 			break;
1794 		}
1795 		error = ustorage_fs_check_cmd(sc, 6,
1796 		    (1UL << 4) | 1, 0);
1797 		if (error) {
1798 			break;
1799 		}
1800 		error = ustorage_fs_request_sense(sc);
1801 
1802 		break;
1803 
1804 	case SC_START_STOP_UNIT:
1805 		error = ustorage_fs_min_len(sc, 0, 0 - 1);
1806 		if (error) {
1807 			break;
1808 		}
1809 		error = ustorage_fs_check_cmd(sc, 6,
1810 		    (1UL << 1) | (1UL << 4) | 1, 0);
1811 		if (error) {
1812 			break;
1813 		}
1814 		error = ustorage_fs_start_stop(sc);
1815 
1816 		break;
1817 
1818 	case SC_SYNCHRONIZE_CACHE:
1819 		error = ustorage_fs_min_len(sc, 0, 0 - 1);
1820 		if (error) {
1821 			break;
1822 		}
1823 		error = ustorage_fs_check_cmd(sc, 10,
1824 		    (0xfUL << 2) | (3UL << 7) | 1, 1);
1825 		if (error) {
1826 			break;
1827 		}
1828 		error = ustorage_fs_synchronize_cache(sc);
1829 
1830 		break;
1831 
1832 	case SC_TEST_UNIT_READY:
1833 		error = ustorage_fs_min_len(sc, 0, 0 - 1);
1834 		if (error) {
1835 			break;
1836 		}
1837 		error = ustorage_fs_check_cmd(sc, 6,
1838 		    0 | 1, 1);
1839 		break;
1840 
1841 		/*
1842 		 * Although optional, this command is used by MS-Windows.
1843 		 * We support a minimal version: BytChk must be 0.
1844 		 */
1845 	case SC_VERIFY:
1846 		error = ustorage_fs_min_len(sc, 0, 0 - 1);
1847 		if (error) {
1848 			break;
1849 		}
1850 		error = ustorage_fs_check_cmd(sc, 10,
1851 		    (1UL << 1) | (0xfUL << 2) | (3UL << 7) | 1, 1);
1852 		if (error) {
1853 			break;
1854 		}
1855 		error = ustorage_fs_verify(sc);
1856 
1857 		break;
1858 
1859 	case SC_WRITE_6:
1860 		i = sc->sc_cmd_data[4];
1861 		sc->sc_transfer.cmd_dir = DIR_READ;
1862 		temp = ((i == 0) ? 256UL : i);
1863 		error = ustorage_fs_min_len(sc, temp << 9, mask9);
1864 		if (error) {
1865 			break;
1866 		}
1867 		error = ustorage_fs_check_cmd(sc, 6,
1868 		    (7UL << 1) | (1UL << 4) | 1, 1);
1869 		if (error) {
1870 			break;
1871 		}
1872 		error = ustorage_fs_write(sc);
1873 
1874 		break;
1875 
1876 	case SC_WRITE_10:
1877 		sc->sc_transfer.cmd_dir = DIR_READ;
1878 		temp = get_be16(&sc->sc_cmd_data[7]);
1879 		error = ustorage_fs_min_len(sc, temp << 9, mask9);
1880 		if (error) {
1881 			break;
1882 		}
1883 		error = ustorage_fs_check_cmd(sc, 10,
1884 		    (1UL << 1) | (0xfUL << 2) | (3UL << 7) | 1, 1);
1885 		if (error) {
1886 			break;
1887 		}
1888 		error = ustorage_fs_write(sc);
1889 
1890 		break;
1891 
1892 	case SC_WRITE_12:
1893 		sc->sc_transfer.cmd_dir = DIR_READ;
1894 		temp = get_be32(&sc->sc_cmd_data[6]);
1895 		if (temp > (mask9 >> 9)) {
1896 			/* numerical overflow */
1897 			sc->sc_csw.bCSWStatus = CSWSTATUS_FAILED;
1898 			error = 1;
1899 			break;
1900 		}
1901 		error = ustorage_fs_min_len(sc, temp << 9, mask9);
1902 		if (error) {
1903 			break;
1904 		}
1905 		error = ustorage_fs_check_cmd(sc, 12,
1906 		    (1UL << 1) | (0xfUL << 2) | (0xfUL << 6) | 1, 1);
1907 		if (error) {
1908 			break;
1909 		}
1910 		error = ustorage_fs_write(sc);
1911 
1912 		break;
1913 
1914 		/*
1915 		 * Some mandatory commands that we recognize but don't
1916 		 * implement.  They don't mean much in this setting.
1917 		 * It's left as an exercise for anyone interested to
1918 		 * implement RESERVE and RELEASE in terms of Posix
1919 		 * locks.
1920 		 */
1921 	case SC_FORMAT_UNIT:
1922 	case SC_RELEASE:
1923 	case SC_RESERVE:
1924 	case SC_SEND_DIAGNOSTIC:
1925 		/* Fallthrough */
1926 
1927 	default:
1928 		error = ustorage_fs_min_len(sc, 0, 0 - 1);
1929 		if (error) {
1930 			break;
1931 		}
1932 		error = ustorage_fs_check_cmd(sc, sc->sc_transfer.cmd_len,
1933 		    0xff, 0);
1934 		if (error) {
1935 			break;
1936 		}
1937 		sc->sc_transfer.currlun->sense_data =
1938 		    SS_INVALID_COMMAND;
1939 		error = 1;
1940 
1941 		break;
1942 	}
1943 	return (error);
1944 }
1945