xref: /freebsd/sys/dev/usb/storage/ustorage_fs.c (revision b2d48be1bc7df45ddd13b143a160d0acb5a383c5)
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 #ifdef USB_GLOBAL_INCLUDE_FILE
40 #include USB_GLOBAL_INCLUDE_FILE
41 #else
42 #include <sys/stdint.h>
43 #include <sys/stddef.h>
44 #include <sys/param.h>
45 #include <sys/queue.h>
46 #include <sys/types.h>
47 #include <sys/systm.h>
48 #include <sys/kernel.h>
49 #include <sys/bus.h>
50 #include <sys/module.h>
51 #include <sys/lock.h>
52 #include <sys/mutex.h>
53 #include <sys/condvar.h>
54 #include <sys/sysctl.h>
55 #include <sys/sx.h>
56 #include <sys/unistd.h>
57 #include <sys/callout.h>
58 #include <sys/malloc.h>
59 #include <sys/priv.h>
60 
61 #include <dev/usb/usb.h>
62 #include <dev/usb/usbdi.h>
63 #include "usbdevs.h"
64 #include "usb_if.h"
65 
66 #define	USB_DEBUG_VAR ustorage_fs_debug
67 #include <dev/usb/usb_debug.h>
68 #endif			/* USB_GLOBAL_INCLUDE_FILE */
69 
70 #ifdef USB_DEBUG
71 static int ustorage_fs_debug = 0;
72 
73 SYSCTL_NODE(_hw_usb, OID_AUTO, ustorage_fs, CTLFLAG_RW, 0, "USB ustorage_fs");
74 SYSCTL_INT(_hw_usb_ustorage_fs, OID_AUTO, debug, CTLFLAG_RWTUN,
75     &ustorage_fs_debug, 0, "ustorage_fs debug level");
76 #endif
77 
78 /* Define some limits */
79 
80 #ifndef USTORAGE_FS_BULK_SIZE
81 #define	USTORAGE_FS_BULK_SIZE	(1U << 17)	/* bytes */
82 #endif
83 
84 #ifndef	USTORAGE_FS_MAX_LUN
85 #define	USTORAGE_FS_MAX_LUN	8	/* units */
86 #endif
87 
88 #ifndef USTORAGE_QDATA_MAX
89 #define	USTORAGE_QDATA_MAX	40	/* bytes */
90 #endif
91 
92 /*
93  * The SCSI ID string must be exactly 28 characters long
94  * exluding the terminating zero.
95  */
96 #ifndef USTORAGE_FS_ID_STRING
97 #define	USTORAGE_FS_ID_STRING \
98 	"FreeBSD " /* 8 */ \
99 	"File-Stor Gadget" /* 16 */ \
100 	"0101" /* 4 */
101 #endif
102 
103 /*
104  * The following macro defines the number of
105  * sectors to be allocated for the RAM disk:
106  */
107 #ifndef USTORAGE_FS_RAM_SECT
108 #define	USTORAGE_FS_RAM_SECT (1UL << 13)
109 #endif
110 
111 static uint8_t *ustorage_fs_ramdisk;
112 
113 /* USB transfer definitions */
114 
115 #define	USTORAGE_FS_T_BBB_COMMAND     0
116 #define	USTORAGE_FS_T_BBB_DATA_DUMP   1
117 #define	USTORAGE_FS_T_BBB_DATA_READ   2
118 #define	USTORAGE_FS_T_BBB_DATA_WRITE  3
119 #define	USTORAGE_FS_T_BBB_STATUS      4
120 #define	USTORAGE_FS_T_BBB_MAX         5
121 
122 /* USB data stage direction */
123 
124 #define	DIR_NONE	0
125 #define	DIR_READ	1
126 #define	DIR_WRITE	2
127 
128 /* USB interface specific control request */
129 
130 #define	UR_BBB_RESET		0xff	/* Bulk-Only reset */
131 #define	UR_BBB_GET_MAX_LUN	0xfe	/* Get maximum lun */
132 
133 /* Command Block Wrapper */
134 typedef struct {
135 	uDWord	dCBWSignature;
136 #define	CBWSIGNATURE	0x43425355
137 	uDWord	dCBWTag;
138 	uDWord	dCBWDataTransferLength;
139 	uByte	bCBWFlags;
140 #define	CBWFLAGS_OUT	0x00
141 #define	CBWFLAGS_IN	0x80
142 	uByte	bCBWLUN;
143 	uByte	bCDBLength;
144 #define	CBWCDBLENGTH	16
145 	uByte	CBWCDB[CBWCDBLENGTH];
146 } __packed ustorage_fs_bbb_cbw_t;
147 
148 #define	USTORAGE_FS_BBB_CBW_SIZE	31
149 
150 /* Command Status Wrapper */
151 typedef struct {
152 	uDWord	dCSWSignature;
153 #define	CSWSIGNATURE	0x53425355
154 	uDWord	dCSWTag;
155 	uDWord	dCSWDataResidue;
156 	uByte	bCSWStatus;
157 #define	CSWSTATUS_GOOD	0x0
158 #define	CSWSTATUS_FAILED	0x1
159 #define	CSWSTATUS_PHASE	0x2
160 } __packed ustorage_fs_bbb_csw_t;
161 
162 #define	USTORAGE_FS_BBB_CSW_SIZE	13
163 
164 struct ustorage_fs_lun {
165 
166 	uint8_t	*memory_image;
167 
168 	uint32_t num_sectors;
169 	uint32_t sense_data;
170 	uint32_t sense_data_info;
171 	uint32_t unit_attention_data;
172 
173 	uint8_t	read_only:1;
174 	uint8_t	prevent_medium_removal:1;
175 	uint8_t	info_valid:1;
176 	uint8_t	removable:1;
177 };
178 
179 struct ustorage_fs_softc {
180 
181 	ustorage_fs_bbb_cbw_t *sc_cbw;	/* Command Wrapper Block */
182 	ustorage_fs_bbb_csw_t *sc_csw;	/* Command Status Block */
183 	void *sc_dma_ptr;		/* Main data buffer */
184 
185 	struct mtx sc_mtx;
186 
187 	struct ustorage_fs_lun sc_lun[USTORAGE_FS_MAX_LUN];
188 
189 	struct {
190 		uint8_t *data_ptr;
191 		struct ustorage_fs_lun *currlun;
192 
193 		uint32_t data_rem;	/* bytes, as reported by the command
194 					 * block wrapper */
195 		uint32_t offset;	/* bytes */
196 
197 		uint8_t	cbw_dir;
198 		uint8_t	cmd_dir;
199 		uint8_t	lun;
200 		uint8_t	cmd_len;
201 		uint8_t	data_short:1;
202 		uint8_t	data_error:1;
203 	}	sc_transfer;
204 
205 	device_t sc_dev;
206 	struct usb_device *sc_udev;
207 	struct usb_xfer *sc_xfer[USTORAGE_FS_T_BBB_MAX];
208 
209 	uint8_t	sc_iface_no;		/* interface number */
210 	uint8_t	sc_last_lun;
211 	uint8_t	sc_last_xfer_index;
212 	uint8_t	sc_qdata[USTORAGE_QDATA_MAX];
213 };
214 
215 /* prototypes */
216 
217 static device_probe_t ustorage_fs_probe;
218 static device_attach_t ustorage_fs_attach;
219 static device_detach_t ustorage_fs_detach;
220 static device_suspend_t ustorage_fs_suspend;
221 static device_resume_t ustorage_fs_resume;
222 static usb_handle_request_t ustorage_fs_handle_request;
223 
224 static usb_callback_t ustorage_fs_t_bbb_command_callback;
225 static usb_callback_t ustorage_fs_t_bbb_data_dump_callback;
226 static usb_callback_t ustorage_fs_t_bbb_data_read_callback;
227 static usb_callback_t ustorage_fs_t_bbb_data_write_callback;
228 static usb_callback_t ustorage_fs_t_bbb_status_callback;
229 
230 static void ustorage_fs_transfer_start(struct ustorage_fs_softc *sc, uint8_t xfer_index);
231 static void ustorage_fs_transfer_stop(struct ustorage_fs_softc *sc);
232 
233 static uint8_t ustorage_fs_verify(struct ustorage_fs_softc *sc);
234 static uint8_t ustorage_fs_inquiry(struct ustorage_fs_softc *sc);
235 static uint8_t ustorage_fs_request_sense(struct ustorage_fs_softc *sc);
236 static uint8_t ustorage_fs_read_capacity(struct ustorage_fs_softc *sc);
237 static uint8_t ustorage_fs_mode_sense(struct ustorage_fs_softc *sc);
238 static uint8_t ustorage_fs_start_stop(struct ustorage_fs_softc *sc);
239 static uint8_t ustorage_fs_prevent_allow(struct ustorage_fs_softc *sc);
240 static uint8_t ustorage_fs_read_format_capacities(struct ustorage_fs_softc *sc);
241 static uint8_t ustorage_fs_mode_select(struct ustorage_fs_softc *sc);
242 static uint8_t ustorage_fs_min_len(struct ustorage_fs_softc *sc, uint32_t len, uint32_t mask);
243 static uint8_t ustorage_fs_read(struct ustorage_fs_softc *sc);
244 static uint8_t ustorage_fs_write(struct ustorage_fs_softc *sc);
245 static uint8_t ustorage_fs_check_cmd(struct ustorage_fs_softc *sc, uint8_t cmd_size, uint16_t mask, uint8_t needs_medium);
246 static uint8_t ustorage_fs_do_cmd(struct ustorage_fs_softc *sc);
247 
248 static device_method_t ustorage_fs_methods[] = {
249 	/* USB interface */
250 	DEVMETHOD(usb_handle_request, ustorage_fs_handle_request),
251 
252 	/* Device interface */
253 	DEVMETHOD(device_probe, ustorage_fs_probe),
254 	DEVMETHOD(device_attach, ustorage_fs_attach),
255 	DEVMETHOD(device_detach, ustorage_fs_detach),
256 	DEVMETHOD(device_suspend, ustorage_fs_suspend),
257 	DEVMETHOD(device_resume, ustorage_fs_resume),
258 
259 	DEVMETHOD_END
260 };
261 
262 static driver_t ustorage_fs_driver = {
263 	.name = "ustorage_fs",
264 	.methods = ustorage_fs_methods,
265 	.size = sizeof(struct ustorage_fs_softc),
266 };
267 
268 static devclass_t ustorage_fs_devclass;
269 
270 DRIVER_MODULE(ustorage_fs, uhub, ustorage_fs_driver, ustorage_fs_devclass, NULL, 0);
271 MODULE_VERSION(ustorage_fs, 0);
272 MODULE_DEPEND(ustorage_fs, usb, 1, 1, 1);
273 
274 static struct usb_config ustorage_fs_bbb_config[USTORAGE_FS_T_BBB_MAX] = {
275 
276 	[USTORAGE_FS_T_BBB_COMMAND] = {
277 		.type = UE_BULK,
278 		.endpoint = UE_ADDR_ANY,
279 		.direction = UE_DIR_OUT,
280 		.bufsize = sizeof(ustorage_fs_bbb_cbw_t),
281 		.callback = &ustorage_fs_t_bbb_command_callback,
282 		.usb_mode = USB_MODE_DEVICE,
283 	},
284 
285 	[USTORAGE_FS_T_BBB_DATA_DUMP] = {
286 		.type = UE_BULK,
287 		.endpoint = UE_ADDR_ANY,
288 		.direction = UE_DIR_OUT,
289 		.bufsize = 0,	/* use wMaxPacketSize */
290 		.flags = {.proxy_buffer = 1,.short_xfer_ok = 1,},
291 		.callback = &ustorage_fs_t_bbb_data_dump_callback,
292 		.usb_mode = USB_MODE_DEVICE,
293 	},
294 
295 	[USTORAGE_FS_T_BBB_DATA_READ] = {
296 		.type = UE_BULK,
297 		.endpoint = UE_ADDR_ANY,
298 		.direction = UE_DIR_OUT,
299 		.bufsize = USTORAGE_FS_BULK_SIZE,
300 		.flags = {.proxy_buffer = 1,.short_xfer_ok = 1},
301 		.callback = &ustorage_fs_t_bbb_data_read_callback,
302 		.usb_mode = USB_MODE_DEVICE,
303 	},
304 
305 	[USTORAGE_FS_T_BBB_DATA_WRITE] = {
306 		.type = UE_BULK,
307 		.endpoint = UE_ADDR_ANY,
308 		.direction = UE_DIR_IN,
309 		.bufsize = USTORAGE_FS_BULK_SIZE,
310 		.flags = {.proxy_buffer = 1,.short_xfer_ok = 1,.ext_buffer = 1},
311 		.callback = &ustorage_fs_t_bbb_data_write_callback,
312 		.usb_mode = USB_MODE_DEVICE,
313 	},
314 
315 	[USTORAGE_FS_T_BBB_STATUS] = {
316 		.type = UE_BULK,
317 		.endpoint = UE_ADDR_ANY,
318 		.direction = UE_DIR_IN,
319 		.bufsize = sizeof(ustorage_fs_bbb_csw_t),
320 		.flags = {.short_xfer_ok = 1},
321 		.callback = &ustorage_fs_t_bbb_status_callback,
322 		.usb_mode = USB_MODE_DEVICE,
323 	},
324 };
325 
326 /*
327  * USB device probe/attach/detach
328  */
329 
330 static int
331 ustorage_fs_probe(device_t dev)
332 {
333 	struct usb_attach_arg *uaa = device_get_ivars(dev);
334 	struct usb_interface_descriptor *id;
335 
336 	if (uaa->usb_mode != USB_MODE_DEVICE) {
337 		return (ENXIO);
338 	}
339 	/* Check for a standards compliant device */
340 	id = usbd_get_interface_descriptor(uaa->iface);
341 	if ((id == NULL) ||
342 	    (id->bInterfaceClass != UICLASS_MASS) ||
343 	    (id->bInterfaceSubClass != UISUBCLASS_SCSI) ||
344 	    (id->bInterfaceProtocol != UIPROTO_MASS_BBB)) {
345 		return (ENXIO);
346 	}
347 	return (BUS_PROBE_GENERIC);
348 }
349 
350 static int
351 ustorage_fs_attach(device_t dev)
352 {
353 	struct ustorage_fs_softc *sc = device_get_softc(dev);
354 	struct usb_attach_arg *uaa = device_get_ivars(dev);
355 	struct usb_interface_descriptor *id;
356 	int err;
357 	int unit;
358 
359 	/*
360 	 * NOTE: the softc struct is cleared in device_set_driver.
361 	 * We can safely call ustorage_fs_detach without specifically
362 	 * initializing the struct.
363 	 */
364 
365 	sc->sc_dev = dev;
366 	sc->sc_udev = uaa->device;
367 	unit = device_get_unit(dev);
368 
369 	/* enable power saving mode */
370 	usbd_set_power_mode(uaa->device, USB_POWER_MODE_SAVE);
371 
372 	if (unit == 0) {
373 		if (ustorage_fs_ramdisk == NULL) {
374 			/*
375 			 * allocate a memory image for our ramdisk until
376 			 * further
377 			 */
378 			ustorage_fs_ramdisk =
379 			    malloc(USTORAGE_FS_RAM_SECT << 9, M_USB,
380 			    M_ZERO | M_WAITOK);
381 
382 			if (ustorage_fs_ramdisk == NULL) {
383 				return (ENOMEM);
384 			}
385 		}
386 		sc->sc_lun[0].memory_image = ustorage_fs_ramdisk;
387 		sc->sc_lun[0].num_sectors = USTORAGE_FS_RAM_SECT;
388 		sc->sc_lun[0].removable = 1;
389 	}
390 
391 	device_set_usb_desc(dev);
392 
393 	mtx_init(&sc->sc_mtx, "USTORAGE_FS lock",
394 	    NULL, (MTX_DEF | MTX_RECURSE));
395 
396 	/* get interface index */
397 
398 	id = usbd_get_interface_descriptor(uaa->iface);
399 	if (id == NULL) {
400 		device_printf(dev, "failed to get "
401 		    "interface number\n");
402 		goto detach;
403 	}
404 	sc->sc_iface_no = id->bInterfaceNumber;
405 
406 	err = usbd_transfer_setup(uaa->device,
407 	    &uaa->info.bIfaceIndex, sc->sc_xfer, ustorage_fs_bbb_config,
408 	    USTORAGE_FS_T_BBB_MAX, sc, &sc->sc_mtx);
409 	if (err) {
410 		device_printf(dev, "could not setup required "
411 		    "transfers, %s\n", usbd_errstr(err));
412 		goto detach;
413 	}
414 
415 	sc->sc_cbw = usbd_xfer_get_frame_buffer(sc->sc_xfer[
416 	    USTORAGE_FS_T_BBB_COMMAND], 0);
417 	sc->sc_csw = usbd_xfer_get_frame_buffer(sc->sc_xfer[
418 	    USTORAGE_FS_T_BBB_STATUS], 0);
419  	sc->sc_dma_ptr = usbd_xfer_get_frame_buffer(sc->sc_xfer[
420 	    USTORAGE_FS_T_BBB_DATA_READ], 0);
421 
422 	/* start Mass Storage State Machine */
423 
424 	mtx_lock(&sc->sc_mtx);
425 	ustorage_fs_transfer_start(sc, USTORAGE_FS_T_BBB_COMMAND);
426 	mtx_unlock(&sc->sc_mtx);
427 
428 	return (0);			/* success */
429 
430 detach:
431 	ustorage_fs_detach(dev);
432 	return (ENXIO);			/* failure */
433 }
434 
435 static int
436 ustorage_fs_detach(device_t dev)
437 {
438 	struct ustorage_fs_softc *sc = device_get_softc(dev);
439 
440 	/* teardown our statemachine */
441 
442 	usbd_transfer_unsetup(sc->sc_xfer, USTORAGE_FS_T_BBB_MAX);
443 
444 	mtx_destroy(&sc->sc_mtx);
445 
446 	return (0);			/* success */
447 }
448 
449 static int
450 ustorage_fs_suspend(device_t dev)
451 {
452 	device_printf(dev, "suspending\n");
453 	return (0);			/* success */
454 }
455 
456 static int
457 ustorage_fs_resume(device_t dev)
458 {
459 	device_printf(dev, "resuming\n");
460 	return (0);			/* success */
461 }
462 
463 /*
464  * Generic functions to handle transfers
465  */
466 
467 static void
468 ustorage_fs_transfer_start(struct ustorage_fs_softc *sc, uint8_t xfer_index)
469 {
470 	if (sc->sc_xfer[xfer_index]) {
471 		sc->sc_last_xfer_index = xfer_index;
472 		usbd_transfer_start(sc->sc_xfer[xfer_index]);
473 	}
474 }
475 
476 static void
477 ustorage_fs_transfer_stop(struct ustorage_fs_softc *sc)
478 {
479 	usbd_transfer_stop(sc->sc_xfer[sc->sc_last_xfer_index]);
480 	mtx_unlock(&sc->sc_mtx);
481 	usbd_transfer_drain(sc->sc_xfer[sc->sc_last_xfer_index]);
482 	mtx_lock(&sc->sc_mtx);
483 }
484 
485 static int
486 ustorage_fs_handle_request(device_t dev,
487     const void *preq, void **pptr, uint16_t *plen,
488     uint16_t offset, uint8_t *pstate)
489 {
490 	struct ustorage_fs_softc *sc = device_get_softc(dev);
491 	const struct usb_device_request *req = preq;
492 	uint8_t is_complete = *pstate;
493 
494 	if (!is_complete) {
495 		if ((req->bmRequestType == UT_WRITE_CLASS_INTERFACE) &&
496 		    (req->bRequest == UR_BBB_RESET)) {
497 			*plen = 0;
498 			mtx_lock(&sc->sc_mtx);
499 			ustorage_fs_transfer_stop(sc);
500 			sc->sc_transfer.data_error = 1;
501 			ustorage_fs_transfer_start(sc,
502 			    USTORAGE_FS_T_BBB_COMMAND);
503 			mtx_unlock(&sc->sc_mtx);
504 			return (0);
505 		} else if ((req->bmRequestType == UT_READ_CLASS_INTERFACE) &&
506 			   (req->bRequest == UR_BBB_GET_MAX_LUN)) {
507 			if (offset == 0) {
508 				*plen = 1;
509 				*pptr = &sc->sc_last_lun;
510 			} else {
511 				*plen = 0;
512 			}
513 			return (0);
514 		}
515 	}
516 	return (ENXIO);			/* use builtin handler */
517 }
518 
519 static void
520 ustorage_fs_t_bbb_command_callback(struct usb_xfer *xfer, usb_error_t error)
521 {
522 	struct ustorage_fs_softc *sc = usbd_xfer_softc(xfer);
523 	uint32_t tag;
524 	uint8_t err = 0;
525 
526 	DPRINTF("\n");
527 
528 	switch (USB_GET_STATE(xfer)) {
529 	case USB_ST_TRANSFERRED:
530 
531 		tag = UGETDW(sc->sc_cbw->dCBWSignature);
532 
533 		if (tag != CBWSIGNATURE) {
534 			/* do nothing */
535 			DPRINTF("invalid signature 0x%08x\n", tag);
536 			break;
537 		}
538 		tag = UGETDW(sc->sc_cbw->dCBWTag);
539 
540 		/* echo back tag */
541 		USETDW(sc->sc_csw->dCSWTag, tag);
542 
543 		/* reset status */
544 		sc->sc_csw->bCSWStatus = 0;
545 
546 		/* reset data offset, data length and data remainder */
547 		sc->sc_transfer.offset = 0;
548 		sc->sc_transfer.data_rem =
549 		    UGETDW(sc->sc_cbw->dCBWDataTransferLength);
550 
551 		/* reset data flags */
552 		sc->sc_transfer.data_short = 0;
553 
554 		/* extract LUN */
555 		sc->sc_transfer.lun = sc->sc_cbw->bCBWLUN;
556 
557 		if (sc->sc_transfer.data_rem == 0) {
558 			sc->sc_transfer.cbw_dir = DIR_NONE;
559 		} else {
560 			if (sc->sc_cbw->bCBWFlags & CBWFLAGS_IN) {
561 				sc->sc_transfer.cbw_dir = DIR_WRITE;
562 			} else {
563 				sc->sc_transfer.cbw_dir = DIR_READ;
564 			}
565 		}
566 
567 		sc->sc_transfer.cmd_len = sc->sc_cbw->bCDBLength;
568 		if ((sc->sc_transfer.cmd_len > sizeof(sc->sc_cbw->CBWCDB)) ||
569 		    (sc->sc_transfer.cmd_len == 0)) {
570 			/* just halt - this is invalid */
571 			DPRINTF("invalid command length %d bytes\n",
572 			    sc->sc_transfer.cmd_len);
573 			break;
574 		}
575 
576 		err = ustorage_fs_do_cmd(sc);
577 		if (err) {
578 			/* got an error */
579 			DPRINTF("command failed\n");
580 			break;
581 		}
582 		if ((sc->sc_transfer.data_rem > 0) &&
583 		    (sc->sc_transfer.cbw_dir != sc->sc_transfer.cmd_dir)) {
584 			/* contradicting data transfer direction */
585 			err = 1;
586 			DPRINTF("data direction mismatch\n");
587 			break;
588 		}
589 		switch (sc->sc_transfer.cbw_dir) {
590 		case DIR_READ:
591 			ustorage_fs_transfer_start(sc, USTORAGE_FS_T_BBB_DATA_READ);
592 			break;
593 		case DIR_WRITE:
594 			ustorage_fs_transfer_start(sc, USTORAGE_FS_T_BBB_DATA_WRITE);
595 			break;
596 		default:
597 			ustorage_fs_transfer_start(sc,
598 			    USTORAGE_FS_T_BBB_STATUS);
599 			break;
600 		}
601 		break;
602 
603 	case USB_ST_SETUP:
604 tr_setup:
605 		if (sc->sc_transfer.data_error) {
606 			sc->sc_transfer.data_error = 0;
607 			usbd_xfer_set_stall(xfer);
608 			DPRINTF("stall pipe\n");
609 		}
610 		usbd_xfer_set_frame_len(xfer, 0,
611 		    sizeof(ustorage_fs_bbb_cbw_t));
612 		usbd_transfer_submit(xfer);
613 		break;
614 
615 	default:			/* Error */
616 		DPRINTF("error\n");
617 		if (error == USB_ERR_CANCELLED) {
618 			break;
619 		}
620 		/* If the pipe is already stalled, don't do another stall */
621 		if (!usbd_xfer_is_stalled(xfer))
622 			sc->sc_transfer.data_error = 1;
623 
624 		/* try again */
625 		goto tr_setup;
626 	}
627 	if (err) {
628 		if (sc->sc_csw->bCSWStatus == 0) {
629 			/* set some default error code */
630 			sc->sc_csw->bCSWStatus = CSWSTATUS_FAILED;
631 		}
632 		if (sc->sc_transfer.cbw_dir == DIR_READ) {
633 			/* dump all data */
634 			ustorage_fs_transfer_start(sc,
635 			    USTORAGE_FS_T_BBB_DATA_DUMP);
636 			return;
637 		}
638 		if (sc->sc_transfer.cbw_dir == DIR_WRITE) {
639 			/* need to stall before status */
640 			sc->sc_transfer.data_error = 1;
641 		}
642 		ustorage_fs_transfer_start(sc, USTORAGE_FS_T_BBB_STATUS);
643 	}
644 }
645 
646 static void
647 ustorage_fs_t_bbb_data_dump_callback(struct usb_xfer *xfer, usb_error_t error)
648 {
649 	struct ustorage_fs_softc *sc = usbd_xfer_softc(xfer);
650 	uint32_t max_bulk = usbd_xfer_max_len(xfer);
651 	int actlen, sumlen;
652 
653 	usbd_xfer_status(xfer, &actlen, &sumlen, NULL, NULL);
654 
655 	DPRINTF("\n");
656 
657 	switch (USB_GET_STATE(xfer)) {
658 	case USB_ST_TRANSFERRED:
659 		sc->sc_transfer.data_rem -= actlen;
660 		sc->sc_transfer.offset += actlen;
661 
662 		if (actlen != sumlen || sc->sc_transfer.data_rem == 0) {
663 			/* short transfer or end of data */
664 			ustorage_fs_transfer_start(sc,
665 			    USTORAGE_FS_T_BBB_STATUS);
666 			break;
667 		}
668 		/* Fallthrough */
669 
670 	case USB_ST_SETUP:
671 tr_setup:
672 		if (max_bulk > sc->sc_transfer.data_rem) {
673 			max_bulk = sc->sc_transfer.data_rem;
674 		}
675 		if (sc->sc_transfer.data_error) {
676 			sc->sc_transfer.data_error = 0;
677 			usbd_xfer_set_stall(xfer);
678 		}
679 		usbd_xfer_set_frame_len(xfer, 0, max_bulk);
680 		usbd_transfer_submit(xfer);
681 		break;
682 
683 	default:			/* Error */
684 		if (error == USB_ERR_CANCELLED) {
685 			break;
686 		}
687 		/*
688 		 * If the pipe is already stalled, don't do another stall:
689 		 */
690 		if (!usbd_xfer_is_stalled(xfer))
691 			sc->sc_transfer.data_error = 1;
692 
693 		/* try again */
694 		goto tr_setup;
695 	}
696 }
697 
698 static void
699 ustorage_fs_t_bbb_data_read_callback(struct usb_xfer *xfer, usb_error_t error)
700 {
701 	struct ustorage_fs_softc *sc = usbd_xfer_softc(xfer);
702 	uint32_t max_bulk = usbd_xfer_max_len(xfer);
703 	int actlen, sumlen;
704 
705 	usbd_xfer_status(xfer, &actlen, &sumlen, NULL, NULL);
706 
707 	DPRINTF("\n");
708 
709 	switch (USB_GET_STATE(xfer)) {
710 	case USB_ST_TRANSFERRED:
711 		/* XXX copy data from DMA buffer */
712 		memcpy(sc->sc_transfer.data_ptr, sc->sc_dma_ptr, actlen);
713 
714 		sc->sc_transfer.data_rem -= actlen;
715 		sc->sc_transfer.data_ptr += actlen;
716 		sc->sc_transfer.offset += actlen;
717 
718 		if (actlen != sumlen || sc->sc_transfer.data_rem == 0) {
719 			/* short transfer or end of data */
720 			ustorage_fs_transfer_start(sc,
721 			    USTORAGE_FS_T_BBB_STATUS);
722 			break;
723 		}
724 		/* Fallthrough */
725 
726 	case USB_ST_SETUP:
727 tr_setup:
728 		if (max_bulk > sc->sc_transfer.data_rem) {
729 			max_bulk = sc->sc_transfer.data_rem;
730 		}
731 		if (sc->sc_transfer.data_error) {
732 			sc->sc_transfer.data_error = 0;
733 			usbd_xfer_set_stall(xfer);
734 		}
735 
736 		usbd_xfer_set_frame_data(xfer, 0, sc->sc_dma_ptr, max_bulk);
737 		usbd_transfer_submit(xfer);
738 		break;
739 
740 	default:			/* Error */
741 		if (error == USB_ERR_CANCELLED) {
742 			break;
743 		}
744 		/* If the pipe is already stalled, don't do another stall */
745 		if (!usbd_xfer_is_stalled(xfer))
746 			sc->sc_transfer.data_error = 1;
747 
748 		/* try again */
749 		goto tr_setup;
750 	}
751 }
752 
753 static void
754 ustorage_fs_t_bbb_data_write_callback(struct usb_xfer *xfer, usb_error_t error)
755 {
756 	struct ustorage_fs_softc *sc = usbd_xfer_softc(xfer);
757 	uint32_t max_bulk = usbd_xfer_max_len(xfer);
758 	int actlen, sumlen;
759 
760 	usbd_xfer_status(xfer, &actlen, &sumlen, NULL, NULL);
761 
762 	DPRINTF("\n");
763 
764 	switch (USB_GET_STATE(xfer)) {
765 	case USB_ST_TRANSFERRED:
766 		sc->sc_transfer.data_rem -= actlen;
767 		sc->sc_transfer.data_ptr += actlen;
768 		sc->sc_transfer.offset += actlen;
769 
770 		if (actlen != sumlen || sc->sc_transfer.data_rem == 0) {
771 			/* short transfer or end of data */
772 			ustorage_fs_transfer_start(sc,
773 			    USTORAGE_FS_T_BBB_STATUS);
774 			break;
775 		}
776 	case USB_ST_SETUP:
777 tr_setup:
778 		if (max_bulk >= sc->sc_transfer.data_rem) {
779 			max_bulk = sc->sc_transfer.data_rem;
780 			if (sc->sc_transfer.data_short)
781 				usbd_xfer_set_flag(xfer, USB_FORCE_SHORT_XFER);
782 			else
783 				usbd_xfer_clr_flag(xfer, USB_FORCE_SHORT_XFER);
784 		} else
785 			usbd_xfer_clr_flag(xfer, USB_FORCE_SHORT_XFER);
786 
787 		if (sc->sc_transfer.data_error) {
788 			sc->sc_transfer.data_error = 0;
789 			usbd_xfer_set_stall(xfer);
790 		}
791 
792 		/* XXX copy data to DMA buffer */
793 		memcpy(sc->sc_dma_ptr, sc->sc_transfer.data_ptr, max_bulk);
794 
795 		usbd_xfer_set_frame_data(xfer, 0, sc->sc_dma_ptr, max_bulk);
796 		usbd_transfer_submit(xfer);
797 		break;
798 
799 	default:			/* Error */
800 		if (error == USB_ERR_CANCELLED) {
801 			break;
802 		}
803 		/*
804 		 * If the pipe is already stalled, don't do another
805 		 * stall
806 		 */
807 		if (!usbd_xfer_is_stalled(xfer))
808 			sc->sc_transfer.data_error = 1;
809 
810 		/* try again */
811 		goto tr_setup;
812 	}
813 }
814 
815 static void
816 ustorage_fs_t_bbb_status_callback(struct usb_xfer *xfer, usb_error_t error)
817 {
818 	struct ustorage_fs_softc *sc = usbd_xfer_softc(xfer);
819 
820 	DPRINTF("\n");
821 
822 	switch (USB_GET_STATE(xfer)) {
823 	case USB_ST_TRANSFERRED:
824 		ustorage_fs_transfer_start(sc, USTORAGE_FS_T_BBB_COMMAND);
825 		break;
826 
827 	case USB_ST_SETUP:
828 tr_setup:
829 		USETDW(sc->sc_csw->dCSWSignature, CSWSIGNATURE);
830 		USETDW(sc->sc_csw->dCSWDataResidue, sc->sc_transfer.data_rem);
831 
832 		if (sc->sc_transfer.data_error) {
833 			sc->sc_transfer.data_error = 0;
834 			usbd_xfer_set_stall(xfer);
835 		}
836 		usbd_xfer_set_frame_len(xfer, 0,
837 		    sizeof(ustorage_fs_bbb_csw_t));
838 		usbd_transfer_submit(xfer);
839 		break;
840 
841 	default:
842 		if (error == USB_ERR_CANCELLED) {
843 			break;
844 		}
845 		/* If the pipe is already stalled, don't do another stall */
846 		if (!usbd_xfer_is_stalled(xfer))
847 			sc->sc_transfer.data_error = 1;
848 
849 		/* try again */
850 		goto tr_setup;
851 	}
852 }
853 
854 /* SCSI commands that we recognize */
855 #define	SC_FORMAT_UNIT			0x04
856 #define	SC_INQUIRY			0x12
857 #define	SC_MODE_SELECT_6		0x15
858 #define	SC_MODE_SELECT_10		0x55
859 #define	SC_MODE_SENSE_6			0x1a
860 #define	SC_MODE_SENSE_10		0x5a
861 #define	SC_PREVENT_ALLOW_MEDIUM_REMOVAL	0x1e
862 #define	SC_READ_6			0x08
863 #define	SC_READ_10			0x28
864 #define	SC_READ_12			0xa8
865 #define	SC_READ_CAPACITY		0x25
866 #define	SC_READ_FORMAT_CAPACITIES	0x23
867 #define	SC_RELEASE			0x17
868 #define	SC_REQUEST_SENSE		0x03
869 #define	SC_RESERVE			0x16
870 #define	SC_SEND_DIAGNOSTIC		0x1d
871 #define	SC_START_STOP_UNIT		0x1b
872 #define	SC_SYNCHRONIZE_CACHE		0x35
873 #define	SC_TEST_UNIT_READY		0x00
874 #define	SC_VERIFY			0x2f
875 #define	SC_WRITE_6			0x0a
876 #define	SC_WRITE_10			0x2a
877 #define	SC_WRITE_12			0xaa
878 
879 /* SCSI Sense Key/Additional Sense Code/ASC Qualifier values */
880 #define	SS_NO_SENSE				0
881 #define	SS_COMMUNICATION_FAILURE		0x040800
882 #define	SS_INVALID_COMMAND			0x052000
883 #define	SS_INVALID_FIELD_IN_CDB			0x052400
884 #define	SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE	0x052100
885 #define	SS_LOGICAL_UNIT_NOT_SUPPORTED		0x052500
886 #define	SS_MEDIUM_NOT_PRESENT			0x023a00
887 #define	SS_MEDIUM_REMOVAL_PREVENTED		0x055302
888 #define	SS_NOT_READY_TO_READY_TRANSITION	0x062800
889 #define	SS_RESET_OCCURRED			0x062900
890 #define	SS_SAVING_PARAMETERS_NOT_SUPPORTED	0x053900
891 #define	SS_UNRECOVERED_READ_ERROR		0x031100
892 #define	SS_WRITE_ERROR				0x030c02
893 #define	SS_WRITE_PROTECTED			0x072700
894 
895 #define	SK(x)		((uint8_t) ((x) >> 16))	/* Sense Key byte, etc. */
896 #define	ASC(x)		((uint8_t) ((x) >> 8))
897 #define	ASCQ(x)		((uint8_t) (x))
898 
899 /* Routines for unaligned data access */
900 
901 static uint16_t
902 get_be16(uint8_t *buf)
903 {
904 	return ((uint16_t)buf[0] << 8) | ((uint16_t)buf[1]);
905 }
906 
907 static uint32_t
908 get_be32(uint8_t *buf)
909 {
910 	return ((uint32_t)buf[0] << 24) | ((uint32_t)buf[1] << 16) |
911 	((uint32_t)buf[2] << 8) | ((uint32_t)buf[3]);
912 }
913 
914 static void
915 put_be16(uint8_t *buf, uint16_t val)
916 {
917 	buf[0] = val >> 8;
918 	buf[1] = val;
919 }
920 
921 static void
922 put_be32(uint8_t *buf, uint32_t val)
923 {
924 	buf[0] = val >> 24;
925 	buf[1] = val >> 16;
926 	buf[2] = val >> 8;
927 	buf[3] = val & 0xff;
928 }
929 
930 /*------------------------------------------------------------------------*
931  *	ustorage_fs_verify
932  *
933  * Returns:
934  *    0: Success
935  * Else: Failure
936  *------------------------------------------------------------------------*/
937 static uint8_t
938 ustorage_fs_verify(struct ustorage_fs_softc *sc)
939 {
940 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
941 	uint32_t lba;
942 	uint32_t vlen;
943 	uint64_t file_offset;
944 	uint64_t amount_left;
945 
946 	/*
947 	 * Get the starting Logical Block Address
948 	 */
949 	lba = get_be32(&sc->sc_cbw->CBWCDB[2]);
950 
951 	/*
952 	 * We allow DPO (Disable Page Out = don't save data in the cache)
953 	 * but we don't implement it.
954 	 */
955 	if ((sc->sc_cbw->CBWCDB[1] & ~0x10) != 0) {
956 		currlun->sense_data = SS_INVALID_FIELD_IN_CDB;
957 		return (1);
958 	}
959 	vlen = get_be16(&sc->sc_cbw->CBWCDB[7]);
960 	if (vlen == 0) {
961 		goto done;
962 	}
963 	/* No default reply */
964 
965 	/* Prepare to carry out the file verify */
966 	amount_left = vlen;
967 	amount_left <<= 9;
968 	file_offset = lba;
969 	file_offset <<= 9;
970 
971 	/* Range check */
972 	vlen += lba;
973 
974 	if ((vlen < lba) ||
975 	    (vlen > currlun->num_sectors) ||
976 	    (lba >= currlun->num_sectors)) {
977 		currlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
978 		return (1);
979 	}
980 	/* XXX TODO: verify that data is readable */
981 done:
982 	return (ustorage_fs_min_len(sc, 0, -1U));
983 }
984 
985 /*------------------------------------------------------------------------*
986  *	ustorage_fs_inquiry
987  *
988  * Returns:
989  *    0: Success
990  * Else: Failure
991  *------------------------------------------------------------------------*/
992 static uint8_t
993 ustorage_fs_inquiry(struct ustorage_fs_softc *sc)
994 {
995 	uint8_t *buf = sc->sc_transfer.data_ptr;
996 
997 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
998 
999 	if (!sc->sc_transfer.currlun) {
1000 		/* Unsupported LUNs are okay */
1001 		memset(buf, 0, 36);
1002 		buf[0] = 0x7f;
1003 		/* Unsupported, no device - type */
1004 		return (ustorage_fs_min_len(sc, 36, -1U));
1005 	}
1006 	memset(buf, 0, 8);
1007 	/* Non - removable, direct - access device */
1008 	if (currlun->removable)
1009 		buf[1] = 0x80;
1010 	buf[2] = 2;
1011 	/* ANSI SCSI level 2 */
1012 	buf[3] = 2;
1013 	/* SCSI - 2 INQUIRY data format */
1014 	buf[4] = 31;
1015 	/* Additional length */
1016 	/* No special options */
1017 	/* Copy in ID string */
1018 	memcpy(buf + 8, USTORAGE_FS_ID_STRING, 28);
1019 
1020 #if (USTORAGE_QDATA_MAX < 36)
1021 #error "(USTORAGE_QDATA_MAX < 36)"
1022 #endif
1023 	return (ustorage_fs_min_len(sc, 36, -1U));
1024 }
1025 
1026 /*------------------------------------------------------------------------*
1027  *	ustorage_fs_request_sense
1028  *
1029  * Returns:
1030  *    0: Success
1031  * Else: Failure
1032  *------------------------------------------------------------------------*/
1033 static uint8_t
1034 ustorage_fs_request_sense(struct ustorage_fs_softc *sc)
1035 {
1036 	uint8_t *buf = sc->sc_transfer.data_ptr;
1037 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1038 	uint32_t sd;
1039 	uint32_t sdinfo;
1040 	uint8_t valid;
1041 
1042 	/*
1043 	 * From the SCSI-2 spec., section 7.9 (Unit attention condition):
1044 	 *
1045 	 * If a REQUEST SENSE command is received from an initiator
1046 	 * with a pending unit attention condition (before the target
1047 	 * generates the contingent allegiance condition), then the
1048 	 * target shall either:
1049 	 *   a) report any pending sense data and preserve the unit
1050 	 *	attention condition on the logical unit, or,
1051 	 *   b) report the unit attention condition, may discard any
1052 	 *	pending sense data, and clear the unit attention
1053 	 *	condition on the logical unit for that initiator.
1054 	 *
1055 	 * FSG normally uses option a); enable this code to use option b).
1056 	 */
1057 #if 0
1058 	if (currlun && currlun->unit_attention_data != SS_NO_SENSE) {
1059 		currlun->sense_data = currlun->unit_attention_data;
1060 		currlun->unit_attention_data = SS_NO_SENSE;
1061 	}
1062 #endif
1063 
1064 	if (!currlun) {
1065 		/* Unsupported LUNs are okay */
1066 		sd = SS_LOGICAL_UNIT_NOT_SUPPORTED;
1067 		sdinfo = 0;
1068 		valid = 0;
1069 	} else {
1070 		sd = currlun->sense_data;
1071 		sdinfo = currlun->sense_data_info;
1072 		valid = currlun->info_valid << 7;
1073 		currlun->sense_data = SS_NO_SENSE;
1074 		currlun->sense_data_info = 0;
1075 		currlun->info_valid = 0;
1076 	}
1077 
1078 	memset(buf, 0, 18);
1079 	buf[0] = valid | 0x70;
1080 	/* Valid, current error */
1081 	buf[2] = SK(sd);
1082 	put_be32(&buf[3], sdinfo);
1083 	/* Sense information */
1084 	buf[7] = 18 - 8;
1085 	/* Additional sense length */
1086 	buf[12] = ASC(sd);
1087 	buf[13] = ASCQ(sd);
1088 
1089 #if (USTORAGE_QDATA_MAX < 18)
1090 #error "(USTORAGE_QDATA_MAX < 18)"
1091 #endif
1092 	return (ustorage_fs_min_len(sc, 18, -1U));
1093 }
1094 
1095 /*------------------------------------------------------------------------*
1096  *	ustorage_fs_read_capacity
1097  *
1098  * Returns:
1099  *    0: Success
1100  * Else: Failure
1101  *------------------------------------------------------------------------*/
1102 static uint8_t
1103 ustorage_fs_read_capacity(struct ustorage_fs_softc *sc)
1104 {
1105 	uint8_t *buf = sc->sc_transfer.data_ptr;
1106 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1107 	uint32_t lba = get_be32(&sc->sc_cbw->CBWCDB[2]);
1108 	uint8_t pmi = sc->sc_cbw->CBWCDB[8];
1109 
1110 	/* Check the PMI and LBA fields */
1111 	if ((pmi > 1) || ((pmi == 0) && (lba != 0))) {
1112 		currlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1113 		return (1);
1114 	}
1115 	/* Max logical block */
1116 	put_be32(&buf[0], currlun->num_sectors - 1);
1117 	/* Block length */
1118 	put_be32(&buf[4], 512);
1119 
1120 #if (USTORAGE_QDATA_MAX < 8)
1121 #error "(USTORAGE_QDATA_MAX < 8)"
1122 #endif
1123 	return (ustorage_fs_min_len(sc, 8, -1U));
1124 }
1125 
1126 /*------------------------------------------------------------------------*
1127  *	ustorage_fs_mode_sense
1128  *
1129  * Returns:
1130  *    0: Success
1131  * Else: Failure
1132  *------------------------------------------------------------------------*/
1133 static uint8_t
1134 ustorage_fs_mode_sense(struct ustorage_fs_softc *sc)
1135 {
1136 	uint8_t *buf = sc->sc_transfer.data_ptr;
1137 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1138 	uint8_t *buf0;
1139 	uint16_t len;
1140 	uint16_t limit;
1141 	uint8_t mscmnd = sc->sc_cbw->CBWCDB[0];
1142 	uint8_t pc;
1143 	uint8_t page_code;
1144 	uint8_t changeable_values;
1145 	uint8_t all_pages;
1146 
1147 	buf0 = buf;
1148 
1149 	if ((sc->sc_cbw->CBWCDB[1] & ~0x08) != 0) {
1150 		/* Mask away DBD */
1151 		currlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1152 		return (1);
1153 	}
1154 	pc = sc->sc_cbw->CBWCDB[2] >> 6;
1155 	page_code = sc->sc_cbw->CBWCDB[2] & 0x3f;
1156 	if (pc == 3) {
1157 		currlun->sense_data = SS_SAVING_PARAMETERS_NOT_SUPPORTED;
1158 		return (1);
1159 	}
1160 	changeable_values = (pc == 1);
1161 	all_pages = (page_code == 0x3f);
1162 
1163 	/*
1164 	 * Write the mode parameter header.  Fixed values are: default
1165 	 * medium type, no cache control (DPOFUA), and no block descriptors.
1166 	 * The only variable value is the WriteProtect bit.  We will fill in
1167 	 * the mode data length later.
1168 	 */
1169 	memset(buf, 0, 8);
1170 	if (mscmnd == SC_MODE_SENSE_6) {
1171 		buf[2] = (currlun->read_only ? 0x80 : 0x00);
1172 		/* WP, DPOFUA */
1173 		buf += 4;
1174 		limit = 255;
1175 	} else {
1176 		/* SC_MODE_SENSE_10 */
1177 		buf[3] = (currlun->read_only ? 0x80 : 0x00);
1178 		/* WP, DPOFUA */
1179 		buf += 8;
1180 		limit = 65535;
1181 		/* Should really be mod_data.buflen */
1182 	}
1183 
1184 	/* No block descriptors */
1185 
1186 	/*
1187 	 * The mode pages, in numerical order.
1188 	 */
1189 	if ((page_code == 0x08) || all_pages) {
1190 		buf[0] = 0x08;
1191 		/* Page code */
1192 		buf[1] = 10;
1193 		/* Page length */
1194 		memset(buf + 2, 0, 10);
1195 		/* None of the fields are changeable */
1196 
1197 		if (!changeable_values) {
1198 			buf[2] = 0x04;
1199 			/* Write cache enable, */
1200 			/* Read cache not disabled */
1201 			/* No cache retention priorities */
1202 			put_be16(&buf[4], 0xffff);
1203 			/* Don 't disable prefetch */
1204 			/* Minimum prefetch = 0 */
1205 			put_be16(&buf[8], 0xffff);
1206 			/* Maximum prefetch */
1207 			put_be16(&buf[10], 0xffff);
1208 			/* Maximum prefetch ceiling */
1209 		}
1210 		buf += 12;
1211 	}
1212 	/*
1213 	 * Check that a valid page was requested and the mode data length
1214 	 * isn't too long.
1215 	 */
1216 	len = buf - buf0;
1217 	if (len > limit) {
1218 		currlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1219 		return (1);
1220 	}
1221 	/* Store the mode data length */
1222 	if (mscmnd == SC_MODE_SENSE_6)
1223 		buf0[0] = len - 1;
1224 	else
1225 		put_be16(buf0, len - 2);
1226 
1227 #if (USTORAGE_QDATA_MAX < 24)
1228 #error "(USTORAGE_QDATA_MAX < 24)"
1229 #endif
1230 	return (ustorage_fs_min_len(sc, len, -1U));
1231 }
1232 
1233 /*------------------------------------------------------------------------*
1234  *	ustorage_fs_start_stop
1235  *
1236  * Returns:
1237  *    0: Success
1238  * Else: Failure
1239  *------------------------------------------------------------------------*/
1240 static uint8_t
1241 ustorage_fs_start_stop(struct ustorage_fs_softc *sc)
1242 {
1243 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1244 	uint8_t loej;
1245 	uint8_t start;
1246 	uint8_t immed;
1247 
1248 	if (!currlun->removable) {
1249 		currlun->sense_data = SS_INVALID_COMMAND;
1250 		return (1);
1251 	}
1252 	immed = sc->sc_cbw->CBWCDB[1] & 0x01;
1253 	loej = sc->sc_cbw->CBWCDB[4] & 0x02;
1254 	start = sc->sc_cbw->CBWCDB[4] & 0x01;
1255 
1256 	if (immed || loej || start) {
1257 		/* compile fix */
1258 	}
1259 	return (0);
1260 }
1261 
1262 /*------------------------------------------------------------------------*
1263  *	ustorage_fs_prevent_allow
1264  *
1265  * Returns:
1266  *    0: Success
1267  * Else: Failure
1268  *------------------------------------------------------------------------*/
1269 static uint8_t
1270 ustorage_fs_prevent_allow(struct ustorage_fs_softc *sc)
1271 {
1272 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1273 	uint8_t prevent;
1274 
1275 	if (!currlun->removable) {
1276 		currlun->sense_data = SS_INVALID_COMMAND;
1277 		return (1);
1278 	}
1279 	prevent = sc->sc_cbw->CBWCDB[4] & 0x01;
1280 	if ((sc->sc_cbw->CBWCDB[4] & ~0x01) != 0) {
1281 		/* Mask away Prevent */
1282 		currlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1283 		return (1);
1284 	}
1285 	if (currlun->prevent_medium_removal && !prevent) {
1286 		//fsync_sub(currlun);
1287 	}
1288 	currlun->prevent_medium_removal = prevent;
1289 	return (0);
1290 }
1291 
1292 /*------------------------------------------------------------------------*
1293  *	ustorage_fs_read_format_capacities
1294  *
1295  * Returns:
1296  *    0: Success
1297  * Else: Failure
1298  *------------------------------------------------------------------------*/
1299 static uint8_t
1300 ustorage_fs_read_format_capacities(struct ustorage_fs_softc *sc)
1301 {
1302 	uint8_t *buf = sc->sc_transfer.data_ptr;
1303 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1304 
1305 	buf[0] = buf[1] = buf[2] = 0;
1306 	buf[3] = 8;
1307 	/* Only the Current / Maximum Capacity Descriptor */
1308 	buf += 4;
1309 
1310 	/* Number of blocks */
1311 	put_be32(&buf[0], currlun->num_sectors);
1312 	/* Block length */
1313 	put_be32(&buf[4], 512);
1314 	/* Current capacity */
1315 	buf[4] = 0x02;
1316 
1317 #if (USTORAGE_QDATA_MAX < 12)
1318 #error "(USTORAGE_QDATA_MAX < 12)"
1319 #endif
1320 	return (ustorage_fs_min_len(sc, 12, -1U));
1321 }
1322 
1323 /*------------------------------------------------------------------------*
1324  *	ustorage_fs_mode_select
1325  *
1326  * Return values:
1327  *    0: Success
1328  * Else: Failure
1329  *------------------------------------------------------------------------*/
1330 static uint8_t
1331 ustorage_fs_mode_select(struct ustorage_fs_softc *sc)
1332 {
1333 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1334 
1335 	/* We don't support MODE SELECT */
1336 	currlun->sense_data = SS_INVALID_COMMAND;
1337 	return (1);
1338 }
1339 
1340 /*------------------------------------------------------------------------*
1341  *	ustorage_fs_synchronize_cache
1342  *
1343  * Return values:
1344  *    0: Success
1345  * Else: Failure
1346  *------------------------------------------------------------------------*/
1347 static uint8_t
1348 ustorage_fs_synchronize_cache(struct ustorage_fs_softc *sc)
1349 {
1350 #if 0
1351 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1352 	uint8_t rc;
1353 
1354 	/*
1355 	 * We ignore the requested LBA and write out all dirty data buffers.
1356 	 */
1357 	rc = 0;
1358 	if (rc) {
1359 		currlun->sense_data = SS_WRITE_ERROR;
1360 	}
1361 #endif
1362 	return (0);
1363 }
1364 
1365 /*------------------------------------------------------------------------*
1366  *	ustorage_fs_read - read data from disk
1367  *
1368  * Return values:
1369  *    0: Success
1370  * Else: Failure
1371  *------------------------------------------------------------------------*/
1372 static uint8_t
1373 ustorage_fs_read(struct ustorage_fs_softc *sc)
1374 {
1375 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1376 	uint64_t file_offset;
1377 	uint32_t lba;
1378 	uint32_t len;
1379 
1380 	/*
1381 	 * Get the starting Logical Block Address and check that it's not
1382 	 * too big
1383 	 */
1384 	if (sc->sc_cbw->CBWCDB[0] == SC_READ_6) {
1385 		lba = (((uint32_t)sc->sc_cbw->CBWCDB[1]) << 16) |
1386 		    get_be16(&sc->sc_cbw->CBWCDB[2]);
1387 	} else {
1388 		lba = get_be32(&sc->sc_cbw->CBWCDB[2]);
1389 
1390 		/*
1391 		 * We allow DPO (Disable Page Out = don't save data in the
1392 		 * cache) and FUA (Force Unit Access = don't read from the
1393 		 * cache), but we don't implement them.
1394 		 */
1395 		if ((sc->sc_cbw->CBWCDB[1] & ~0x18) != 0) {
1396 			currlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1397 			return (1);
1398 		}
1399 	}
1400 	len = sc->sc_transfer.data_rem >> 9;
1401 	len += lba;
1402 
1403 	if ((len < lba) ||
1404 	    (len > currlun->num_sectors) ||
1405 	    (lba >= currlun->num_sectors)) {
1406 		currlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1407 		return (1);
1408 	}
1409 	file_offset = lba;
1410 	file_offset <<= 9;
1411 
1412 	sc->sc_transfer.data_ptr = currlun->memory_image + file_offset;
1413 
1414 	return (0);
1415 }
1416 
1417 /*------------------------------------------------------------------------*
1418  *	ustorage_fs_write - write data to disk
1419  *
1420  * Return values:
1421  *    0: Success
1422  * Else: Failure
1423  *------------------------------------------------------------------------*/
1424 static uint8_t
1425 ustorage_fs_write(struct ustorage_fs_softc *sc)
1426 {
1427 	struct ustorage_fs_lun *currlun = sc->sc_transfer.currlun;
1428 	uint64_t file_offset;
1429 	uint32_t lba;
1430 	uint32_t len;
1431 
1432 	if (currlun->read_only) {
1433 		currlun->sense_data = SS_WRITE_PROTECTED;
1434 		return (1);
1435 	}
1436 	/* XXX clear SYNC */
1437 
1438 	/*
1439 	 * Get the starting Logical Block Address and check that it's not
1440 	 * too big.
1441 	 */
1442 	if (sc->sc_cbw->CBWCDB[0] == SC_WRITE_6)
1443 		lba = (((uint32_t)sc->sc_cbw->CBWCDB[1]) << 16) |
1444 		    get_be16(&sc->sc_cbw->CBWCDB[2]);
1445 	else {
1446 		lba = get_be32(&sc->sc_cbw->CBWCDB[2]);
1447 
1448 		/*
1449 		 * We allow DPO (Disable Page Out = don't save data in the
1450 		 * cache) and FUA (Force Unit Access = write directly to the
1451 		 * medium).  We don't implement DPO; we implement FUA by
1452 		 * performing synchronous output.
1453 		 */
1454 		if ((sc->sc_cbw->CBWCDB[1] & ~0x18) != 0) {
1455 			currlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1456 			return (1);
1457 		}
1458 		if (sc->sc_cbw->CBWCDB[1] & 0x08) {
1459 			/* FUA */
1460 			/* XXX set SYNC flag here */
1461 		}
1462 	}
1463 
1464 	len = sc->sc_transfer.data_rem >> 9;
1465 	len += lba;
1466 
1467 	if ((len < lba) ||
1468 	    (len > currlun->num_sectors) ||
1469 	    (lba >= currlun->num_sectors)) {
1470 		currlun->sense_data = SS_LOGICAL_BLOCK_ADDRESS_OUT_OF_RANGE;
1471 		return (1);
1472 	}
1473 	file_offset = lba;
1474 	file_offset <<= 9;
1475 
1476 	sc->sc_transfer.data_ptr = currlun->memory_image + file_offset;
1477 
1478 	return (0);
1479 }
1480 
1481 /*------------------------------------------------------------------------*
1482  *	ustorage_fs_min_len
1483  *
1484  * Return values:
1485  *    0: Success
1486  * Else: Failure
1487  *------------------------------------------------------------------------*/
1488 static uint8_t
1489 ustorage_fs_min_len(struct ustorage_fs_softc *sc, uint32_t len, uint32_t mask)
1490 {
1491 	if (len != sc->sc_transfer.data_rem) {
1492 
1493 		if (sc->sc_transfer.cbw_dir == DIR_READ) {
1494 			/*
1495 			 * there must be something wrong about this SCSI
1496 			 * command
1497 			 */
1498 			sc->sc_csw->bCSWStatus = CSWSTATUS_PHASE;
1499 			return (1);
1500 		}
1501 		/* compute the minimum length */
1502 
1503 		if (sc->sc_transfer.data_rem > len) {
1504 			/* data ends prematurely */
1505 			sc->sc_transfer.data_rem = len;
1506 			sc->sc_transfer.data_short = 1;
1507 		}
1508 		/* check length alignment */
1509 
1510 		if (sc->sc_transfer.data_rem & ~mask) {
1511 			/* data ends prematurely */
1512 			sc->sc_transfer.data_rem &= mask;
1513 			sc->sc_transfer.data_short = 1;
1514 		}
1515 	}
1516 	return (0);
1517 }
1518 
1519 /*------------------------------------------------------------------------*
1520  *	ustorage_fs_check_cmd - check command routine
1521  *
1522  * Check whether the command is properly formed and whether its data
1523  * size and direction agree with the values we already have.
1524  *
1525  * Return values:
1526  *    0: Success
1527  * Else: Failure
1528  *------------------------------------------------------------------------*/
1529 static uint8_t
1530 ustorage_fs_check_cmd(struct ustorage_fs_softc *sc, uint8_t min_cmd_size,
1531     uint16_t mask, uint8_t needs_medium)
1532 {
1533 	struct ustorage_fs_lun *currlun;
1534 	uint8_t lun = (sc->sc_cbw->CBWCDB[1] >> 5);
1535 	uint8_t i;
1536 
1537 	/* Verify the length of the command itself */
1538 	if (min_cmd_size > sc->sc_transfer.cmd_len) {
1539 		DPRINTF("%u > %u\n",
1540 		    min_cmd_size, sc->sc_transfer.cmd_len);
1541 		sc->sc_csw->bCSWStatus = CSWSTATUS_PHASE;
1542 		return (1);
1543 	}
1544 	/* Mask away the LUN */
1545 	sc->sc_cbw->CBWCDB[1] &= 0x1f;
1546 
1547 	/* Check if LUN is correct */
1548 	if (lun != sc->sc_transfer.lun) {
1549 
1550 	}
1551 	/* Check the LUN */
1552 	if (sc->sc_transfer.lun <= sc->sc_last_lun) {
1553 		sc->sc_transfer.currlun = currlun =
1554 		    sc->sc_lun + sc->sc_transfer.lun;
1555 		if (sc->sc_cbw->CBWCDB[0] != SC_REQUEST_SENSE) {
1556 			currlun->sense_data = SS_NO_SENSE;
1557 			currlun->sense_data_info = 0;
1558 			currlun->info_valid = 0;
1559 		}
1560 		/*
1561 		 * If a unit attention condition exists, only INQUIRY
1562 		 * and REQUEST SENSE commands are allowed. Anything
1563 		 * else must fail!
1564 		 */
1565 		if ((currlun->unit_attention_data != SS_NO_SENSE) &&
1566 		    (sc->sc_cbw->CBWCDB[0] != SC_INQUIRY) &&
1567 		    (sc->sc_cbw->CBWCDB[0] != SC_REQUEST_SENSE)) {
1568 			currlun->sense_data = currlun->unit_attention_data;
1569 			currlun->unit_attention_data = SS_NO_SENSE;
1570 			return (1);
1571 		}
1572 	} else {
1573 		sc->sc_transfer.currlun = currlun = NULL;
1574 
1575 		/*
1576 		 * INQUIRY and REQUEST SENSE commands are explicitly allowed
1577 		 * to use unsupported LUNs; all others may not.
1578 		 */
1579 		if ((sc->sc_cbw->CBWCDB[0] != SC_INQUIRY) &&
1580 		    (sc->sc_cbw->CBWCDB[0] != SC_REQUEST_SENSE)) {
1581 			return (1);
1582 		}
1583 	}
1584 
1585 	/*
1586 	 * Check that only command bytes listed in the mask are
1587 	 * non-zero.
1588 	 */
1589 	for (i = 0; i != min_cmd_size; i++) {
1590 		if (sc->sc_cbw->CBWCDB[i] && !(mask & (1UL << i))) {
1591 			if (currlun) {
1592 				currlun->sense_data = SS_INVALID_FIELD_IN_CDB;
1593 			}
1594 			return (1);
1595 		}
1596 	}
1597 
1598 	/*
1599 	 * If the medium isn't mounted and the command needs to access
1600 	 * it, return an error.
1601 	 */
1602 	if (currlun && (!currlun->memory_image) && needs_medium) {
1603 		currlun->sense_data = SS_MEDIUM_NOT_PRESENT;
1604 		return (1);
1605 	}
1606 	return (0);
1607 }
1608 
1609 /*------------------------------------------------------------------------*
1610  *	ustorage_fs_do_cmd - do command
1611  *
1612  * Return values:
1613  *    0: Success
1614  * Else: Failure
1615  *------------------------------------------------------------------------*/
1616 static uint8_t
1617 ustorage_fs_do_cmd(struct ustorage_fs_softc *sc)
1618 {
1619 	uint8_t error = 1;
1620 	uint8_t i;
1621 	uint32_t temp;
1622 	const uint32_t mask9 = (0xFFFFFFFFUL >> 9) << 9;
1623 
1624 	/* set default data transfer pointer */
1625 	sc->sc_transfer.data_ptr = sc->sc_qdata;
1626 
1627 	DPRINTF("cmd_data[0]=0x%02x, data_rem=0x%08x\n",
1628 	    sc->sc_cbw->CBWCDB[0], sc->sc_transfer.data_rem);
1629 
1630 	switch (sc->sc_cbw->CBWCDB[0]) {
1631 	case SC_INQUIRY:
1632 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1633 		error = ustorage_fs_min_len(sc, sc->sc_cbw->CBWCDB[4], -1U);
1634 		if (error) {
1635 			break;
1636 		}
1637 		error = ustorage_fs_check_cmd(sc, 6,
1638 		    (1UL << 4) | 1, 0);
1639 		if (error) {
1640 			break;
1641 		}
1642 		error = ustorage_fs_inquiry(sc);
1643 
1644 		break;
1645 
1646 	case SC_MODE_SELECT_6:
1647 		sc->sc_transfer.cmd_dir = DIR_READ;
1648 		error = ustorage_fs_min_len(sc, sc->sc_cbw->CBWCDB[4], -1U);
1649 		if (error) {
1650 			break;
1651 		}
1652 		error = ustorage_fs_check_cmd(sc, 6,
1653 		    (1UL << 1) | (1UL << 4) | 1, 0);
1654 		if (error) {
1655 			break;
1656 		}
1657 		error = ustorage_fs_mode_select(sc);
1658 
1659 		break;
1660 
1661 	case SC_MODE_SELECT_10:
1662 		sc->sc_transfer.cmd_dir = DIR_READ;
1663 		error = ustorage_fs_min_len(sc,
1664 		    get_be16(&sc->sc_cbw->CBWCDB[7]), -1U);
1665 		if (error) {
1666 			break;
1667 		}
1668 		error = ustorage_fs_check_cmd(sc, 10,
1669 		    (1UL << 1) | (3UL << 7) | 1, 0);
1670 		if (error) {
1671 			break;
1672 		}
1673 		error = ustorage_fs_mode_select(sc);
1674 
1675 		break;
1676 
1677 	case SC_MODE_SENSE_6:
1678 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1679 		error = ustorage_fs_min_len(sc, sc->sc_cbw->CBWCDB[4], -1U);
1680 		if (error) {
1681 			break;
1682 		}
1683 		error = ustorage_fs_check_cmd(sc, 6,
1684 		    (1UL << 1) | (1UL << 2) | (1UL << 4) | 1, 0);
1685 		if (error) {
1686 			break;
1687 		}
1688 		error = ustorage_fs_mode_sense(sc);
1689 
1690 		break;
1691 
1692 	case SC_MODE_SENSE_10:
1693 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1694 		error = ustorage_fs_min_len(sc,
1695 		    get_be16(&sc->sc_cbw->CBWCDB[7]), -1U);
1696 		if (error) {
1697 			break;
1698 		}
1699 		error = ustorage_fs_check_cmd(sc, 10,
1700 		    (1UL << 1) | (1UL << 2) | (3UL << 7) | 1, 0);
1701 		if (error) {
1702 			break;
1703 		}
1704 		error = ustorage_fs_mode_sense(sc);
1705 
1706 		break;
1707 
1708 	case SC_PREVENT_ALLOW_MEDIUM_REMOVAL:
1709 		error = ustorage_fs_min_len(sc, 0, -1U);
1710 		if (error) {
1711 			break;
1712 		}
1713 		error = ustorage_fs_check_cmd(sc, 6,
1714 		    (1UL << 4) | 1, 0);
1715 		if (error) {
1716 			break;
1717 		}
1718 		error = ustorage_fs_prevent_allow(sc);
1719 
1720 		break;
1721 
1722 	case SC_READ_6:
1723 		i = sc->sc_cbw->CBWCDB[4];
1724 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1725 		temp = ((i == 0) ? 256UL : i);
1726 		error = ustorage_fs_min_len(sc, temp << 9, mask9);
1727 		if (error) {
1728 			break;
1729 		}
1730 		error = ustorage_fs_check_cmd(sc, 6,
1731 		    (7UL << 1) | (1UL << 4) | 1, 1);
1732 		if (error) {
1733 			break;
1734 		}
1735 		error = ustorage_fs_read(sc);
1736 
1737 		break;
1738 
1739 	case SC_READ_10:
1740 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1741 		temp = get_be16(&sc->sc_cbw->CBWCDB[7]);
1742 		error = ustorage_fs_min_len(sc, temp << 9, mask9);
1743 		if (error) {
1744 			break;
1745 		}
1746 		error = ustorage_fs_check_cmd(sc, 10,
1747 		    (1UL << 1) | (0xfUL << 2) | (3UL << 7) | 1, 1);
1748 		if (error) {
1749 			break;
1750 		}
1751 		error = ustorage_fs_read(sc);
1752 
1753 		break;
1754 
1755 	case SC_READ_12:
1756 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1757 		temp = get_be32(&sc->sc_cbw->CBWCDB[6]);
1758 		if (temp >= (1UL << (32 - 9))) {
1759 			/* numerical overflow */
1760 			sc->sc_csw->bCSWStatus = CSWSTATUS_FAILED;
1761 			error = 1;
1762 			break;
1763 		}
1764 		error = ustorage_fs_min_len(sc, temp << 9, mask9);
1765 		if (error) {
1766 			break;
1767 		}
1768 		error = ustorage_fs_check_cmd(sc, 12,
1769 		    (1UL << 1) | (0xfUL << 2) | (0xfUL << 6) | 1, 1);
1770 		if (error) {
1771 			break;
1772 		}
1773 		error = ustorage_fs_read(sc);
1774 
1775 		break;
1776 
1777 	case SC_READ_CAPACITY:
1778 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1779 		error = ustorage_fs_check_cmd(sc, 10,
1780 		    (0xfUL << 2) | (1UL << 8) | 1, 1);
1781 		if (error) {
1782 			break;
1783 		}
1784 		error = ustorage_fs_read_capacity(sc);
1785 
1786 		break;
1787 
1788 	case SC_READ_FORMAT_CAPACITIES:
1789 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1790 		error = ustorage_fs_min_len(sc,
1791 		    get_be16(&sc->sc_cbw->CBWCDB[7]), -1U);
1792 		if (error) {
1793 			break;
1794 		}
1795 		error = ustorage_fs_check_cmd(sc, 10,
1796 		    (3UL << 7) | 1, 1);
1797 		if (error) {
1798 			break;
1799 		}
1800 		error = ustorage_fs_read_format_capacities(sc);
1801 
1802 		break;
1803 
1804 	case SC_REQUEST_SENSE:
1805 		sc->sc_transfer.cmd_dir = DIR_WRITE;
1806 		error = ustorage_fs_min_len(sc, sc->sc_cbw->CBWCDB[4], -1U);
1807 		if (error) {
1808 			break;
1809 		}
1810 		error = ustorage_fs_check_cmd(sc, 6,
1811 		    (1UL << 4) | 1, 0);
1812 		if (error) {
1813 			break;
1814 		}
1815 		error = ustorage_fs_request_sense(sc);
1816 
1817 		break;
1818 
1819 	case SC_START_STOP_UNIT:
1820 		error = ustorage_fs_min_len(sc, 0, -1U);
1821 		if (error) {
1822 			break;
1823 		}
1824 		error = ustorage_fs_check_cmd(sc, 6,
1825 		    (1UL << 1) | (1UL << 4) | 1, 0);
1826 		if (error) {
1827 			break;
1828 		}
1829 		error = ustorage_fs_start_stop(sc);
1830 
1831 		break;
1832 
1833 	case SC_SYNCHRONIZE_CACHE:
1834 		error = ustorage_fs_min_len(sc, 0, -1U);
1835 		if (error) {
1836 			break;
1837 		}
1838 		error = ustorage_fs_check_cmd(sc, 10,
1839 		    (0xfUL << 2) | (3UL << 7) | 1, 1);
1840 		if (error) {
1841 			break;
1842 		}
1843 		error = ustorage_fs_synchronize_cache(sc);
1844 
1845 		break;
1846 
1847 	case SC_TEST_UNIT_READY:
1848 		error = ustorage_fs_min_len(sc, 0, -1U);
1849 		if (error) {
1850 			break;
1851 		}
1852 		error = ustorage_fs_check_cmd(sc, 6,
1853 		    0 | 1, 1);
1854 		break;
1855 
1856 		/*
1857 		 * Although optional, this command is used by MS-Windows.
1858 		 * We support a minimal version: BytChk must be 0.
1859 		 */
1860 	case SC_VERIFY:
1861 		error = ustorage_fs_min_len(sc, 0, -1U);
1862 		if (error) {
1863 			break;
1864 		}
1865 		error = ustorage_fs_check_cmd(sc, 10,
1866 		    (1UL << 1) | (0xfUL << 2) | (3UL << 7) | 1, 1);
1867 		if (error) {
1868 			break;
1869 		}
1870 		error = ustorage_fs_verify(sc);
1871 
1872 		break;
1873 
1874 	case SC_WRITE_6:
1875 		i = sc->sc_cbw->CBWCDB[4];
1876 		sc->sc_transfer.cmd_dir = DIR_READ;
1877 		temp = ((i == 0) ? 256UL : i);
1878 		error = ustorage_fs_min_len(sc, temp << 9, mask9);
1879 		if (error) {
1880 			break;
1881 		}
1882 		error = ustorage_fs_check_cmd(sc, 6,
1883 		    (7UL << 1) | (1UL << 4) | 1, 1);
1884 		if (error) {
1885 			break;
1886 		}
1887 		error = ustorage_fs_write(sc);
1888 
1889 		break;
1890 
1891 	case SC_WRITE_10:
1892 		sc->sc_transfer.cmd_dir = DIR_READ;
1893 		temp = get_be16(&sc->sc_cbw->CBWCDB[7]);
1894 		error = ustorage_fs_min_len(sc, temp << 9, mask9);
1895 		if (error) {
1896 			break;
1897 		}
1898 		error = ustorage_fs_check_cmd(sc, 10,
1899 		    (1UL << 1) | (0xfUL << 2) | (3UL << 7) | 1, 1);
1900 		if (error) {
1901 			break;
1902 		}
1903 		error = ustorage_fs_write(sc);
1904 
1905 		break;
1906 
1907 	case SC_WRITE_12:
1908 		sc->sc_transfer.cmd_dir = DIR_READ;
1909 		temp = get_be32(&sc->sc_cbw->CBWCDB[6]);
1910 		if (temp > (mask9 >> 9)) {
1911 			/* numerical overflow */
1912 			sc->sc_csw->bCSWStatus = CSWSTATUS_FAILED;
1913 			error = 1;
1914 			break;
1915 		}
1916 		error = ustorage_fs_min_len(sc, temp << 9, mask9);
1917 		if (error) {
1918 			break;
1919 		}
1920 		error = ustorage_fs_check_cmd(sc, 12,
1921 		    (1UL << 1) | (0xfUL << 2) | (0xfUL << 6) | 1, 1);
1922 		if (error) {
1923 			break;
1924 		}
1925 		error = ustorage_fs_write(sc);
1926 
1927 		break;
1928 
1929 		/*
1930 		 * Some mandatory commands that we recognize but don't
1931 		 * implement.  They don't mean much in this setting.
1932 		 * It's left as an exercise for anyone interested to
1933 		 * implement RESERVE and RELEASE in terms of Posix
1934 		 * locks.
1935 		 */
1936 	case SC_FORMAT_UNIT:
1937 	case SC_RELEASE:
1938 	case SC_RESERVE:
1939 	case SC_SEND_DIAGNOSTIC:
1940 		/* Fallthrough */
1941 
1942 	default:
1943 		error = ustorage_fs_min_len(sc, 0, -1U);
1944 		if (error) {
1945 			break;
1946 		}
1947 		error = ustorage_fs_check_cmd(sc, sc->sc_transfer.cmd_len,
1948 		    0xff, 0);
1949 		if (error) {
1950 			break;
1951 		}
1952 		sc->sc_transfer.currlun->sense_data =
1953 		    SS_INVALID_COMMAND;
1954 		error = 1;
1955 
1956 		break;
1957 	}
1958 	return (error);
1959 }
1960