xref: /freebsd/sys/cam/scsi/scsi_target.c (revision c37420b0d5b3b6ef875fbf0b84a13f6f09be56d6)
1 /*
2  * Generic SCSI Target Kernel Mode Driver
3  *
4  * Copyright (c) 2002 Nate Lawson.
5  * Copyright (c) 1998, 1999, 2001, 2002 Justin T. Gibbs.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions, and the following disclaimer,
13  *    without modification, immediately at the beginning of the file.
14  * 2. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
21  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/kernel.h>
36 #include <sys/conf.h>
37 #include <sys/malloc.h>
38 #include <sys/poll.h>
39 #include <sys/vnode.h>
40 #include <sys/lock.h>
41 #include <sys/mutex.h>
42 #include <sys/devicestat.h>
43 
44 #include <cam/cam.h>
45 #include <cam/cam_ccb.h>
46 #include <cam/cam_periph.h>
47 #include <cam/cam_xpt_periph.h>
48 #include <cam/scsi/scsi_targetio.h>
49 
50 /* Transaction information attached to each CCB sent by the user */
51 struct targ_cmd_descr {
52 	struct cam_periph_map_info  mapinfo;
53 	TAILQ_ENTRY(targ_cmd_descr) tqe;
54 	union ccb *user_ccb;
55 	int	   priority;
56 	int	   func_code;
57 };
58 
59 /* Offset into the private CCB area for storing our descriptor */
60 #define targ_descr	periph_priv.entries[1].ptr
61 
62 TAILQ_HEAD(descr_queue, targ_cmd_descr);
63 
64 typedef enum {
65 	TARG_STATE_RESV		= 0x00, /* Invalid state */
66 	TARG_STATE_OPENED	= 0x01, /* Device opened, softc initialized */
67 	TARG_STATE_LUN_ENABLED	= 0x02  /* Device enabled for a path */
68 } targ_state;
69 
70 /* Per-instance device software context */
71 struct targ_softc {
72 	/* CCBs (CTIOs, ATIOs, INOTs) pending on the controller */
73 	struct ccb_queue	 pending_ccb_queue;
74 
75 	/* Command descriptors awaiting CTIO resources from the XPT */
76 	struct descr_queue	 work_queue;
77 
78 	/* Command descriptors that have been aborted back to the user. */
79 	struct descr_queue	 abort_queue;
80 
81 	/*
82 	 * Queue of CCBs that have been copied out to userland, but our
83 	 * userland daemon has not yet seen.
84 	 */
85 	struct ccb_queue	 user_ccb_queue;
86 
87 	struct cam_periph	*periph;
88 	struct cam_path		*path;
89 	targ_state		 state;
90 	struct selinfo		 read_select;
91 	struct devstat		 device_stats;
92 	struct mtx		 mtx;
93 };
94 
95 static d_open_t		targopen;
96 static d_close_t	targclose;
97 static d_read_t		targread;
98 static d_write_t	targwrite;
99 static d_ioctl_t	targioctl;
100 static d_poll_t		targpoll;
101 static d_kqfilter_t	targkqfilter;
102 static void		targreadfiltdetach(struct knote *kn);
103 static int		targreadfilt(struct knote *kn, long hint);
104 static struct filterops targread_filtops =
105 	{ 1, NULL, targreadfiltdetach, targreadfilt };
106 
107 static struct cdevsw targ_cdevsw = {
108 	.d_version =	D_VERSION,
109 	.d_flags =	D_NEEDGIANT,
110 	.d_open =	targopen,
111 	.d_close =	targclose,
112 	.d_read =	targread,
113 	.d_write =	targwrite,
114 	.d_ioctl =	targioctl,
115 	.d_poll =	targpoll,
116 	.d_name =	"targ",
117 	.d_kqfilter =	targkqfilter
118 };
119 
120 static cam_status	targendislun(struct cam_path *path, int enable,
121 				     int grp6_len, int grp7_len);
122 static cam_status	targenable(struct targ_softc *softc,
123 				   struct cam_path *path,
124 				   int grp6_len, int grp7_len);
125 static cam_status	targdisable(struct targ_softc *softc);
126 static periph_ctor_t    targctor;
127 static periph_dtor_t    targdtor;
128 static periph_start_t   targstart;
129 static int		targusermerge(struct targ_softc *softc,
130 				      struct targ_cmd_descr *descr,
131 				      union ccb *ccb);
132 static int		targsendccb(struct targ_softc *softc, union ccb *ccb,
133 				    struct targ_cmd_descr *descr);
134 static void		targdone(struct cam_periph *periph,
135 				 union  ccb *done_ccb);
136 static int		targreturnccb(struct targ_softc *softc,
137 				      union  ccb *ccb);
138 static union ccb *	targgetccb(struct targ_softc *softc, xpt_opcode type,
139 				   int priority);
140 static void		targfreeccb(struct targ_softc *softc, union ccb *ccb);
141 static struct targ_cmd_descr *
142 			targgetdescr(struct targ_softc *softc);
143 static periph_init_t	targinit;
144 static void		targclone(void *arg, char *name, int namelen,
145 				  struct cdev **dev);
146 static void		targasync(void *callback_arg, u_int32_t code,
147 				  struct cam_path *path, void *arg);
148 static void		abort_all_pending(struct targ_softc *softc);
149 static void		notify_user(struct targ_softc *softc);
150 static int		targcamstatus(cam_status status);
151 static size_t		targccblen(xpt_opcode func_code);
152 
153 static struct periph_driver targdriver =
154 {
155 	targinit, "targ",
156 	TAILQ_HEAD_INITIALIZER(targdriver.units), /* generation */ 0
157 };
158 PERIPHDRIVER_DECLARE(targ, targdriver);
159 
160 static struct mtx		targ_mtx;
161 #define TARG_LOCK(softc)	mtx_lock(&(softc)->mtx)
162 #define TARG_UNLOCK(softc)	mtx_unlock(&(softc)->mtx)
163 
164 static MALLOC_DEFINE(M_TARG, "TARG", "TARG data");
165 
166 /* Create softc and initialize it. Only one proc can open each targ device. */
167 static int
168 targopen(struct cdev *dev, int flags, int fmt, struct thread *td)
169 {
170 	struct targ_softc *softc;
171 
172 	mtx_lock(&targ_mtx);
173 	if (dev->si_drv1 != 0) {
174 		mtx_unlock(&targ_mtx);
175 		return (EBUSY);
176 	}
177 
178 	/* Mark device busy before any potentially blocking operations */
179 	dev->si_drv1 = (void *)~0;
180 	mtx_unlock(&targ_mtx);
181 
182 	/* Create the targ device, allocate its softc, initialize it */
183 	if ((dev->si_flags & SI_NAMED) == 0) {
184 		make_dev(&targ_cdevsw, minor(dev), UID_ROOT, GID_WHEEL, 0600,
185 			 "targ%d", dev2unit(dev));
186 	}
187 	MALLOC(softc, struct targ_softc *, sizeof(*softc), M_TARG,
188 	       M_WAITOK | M_ZERO);
189 	dev->si_drv1 = softc;
190 	softc->state = TARG_STATE_OPENED;
191 	softc->periph = NULL;
192 	softc->path = NULL;
193 	mtx_init(&softc->mtx, devtoname(dev), "targ cdev", MTX_DEF);
194 
195 	TAILQ_INIT(&softc->pending_ccb_queue);
196 	TAILQ_INIT(&softc->work_queue);
197 	TAILQ_INIT(&softc->abort_queue);
198 	TAILQ_INIT(&softc->user_ccb_queue);
199 	knlist_init(&softc->read_select.si_note, &softc->mtx);
200 
201 	return (0);
202 }
203 
204 /* Disable LUN if enabled and teardown softc */
205 static int
206 targclose(struct cdev *dev, int flag, int fmt, struct thread *td)
207 {
208 	struct targ_softc     *softc;
209 	int    error;
210 
211 	softc = (struct targ_softc *)dev->si_drv1;
212 	TARG_LOCK(softc);
213 	error = targdisable(softc);
214 	if (error == CAM_REQ_CMP) {
215 		dev->si_drv1 = 0;
216 		mtx_lock(&targ_mtx);
217 		if (softc->periph != NULL) {
218 			cam_periph_invalidate(softc->periph);
219 			softc->periph = NULL;
220 		}
221 		mtx_unlock(&targ_mtx);
222 		TARG_UNLOCK(softc);
223 		mtx_destroy(&softc->mtx);
224 		destroy_dev(dev);
225 		FREE(softc, M_TARG);
226 	} else {
227 		TARG_UNLOCK(softc);
228 	}
229 	return (error);
230 }
231 
232 /* Enable/disable LUNs, set debugging level */
233 static int
234 targioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flag, struct thread *td)
235 {
236 	struct targ_softc *softc;
237 	cam_status	   status;
238 
239 	softc = (struct targ_softc *)dev->si_drv1;
240 
241 	switch (cmd) {
242 	case TARGIOCENABLE:
243 	{
244 		struct ioc_enable_lun	*new_lun;
245 		struct cam_path		*path;
246 
247 		new_lun = (struct ioc_enable_lun *)addr;
248 		status = xpt_create_path(&path, /*periph*/NULL,
249 					 new_lun->path_id,
250 					 new_lun->target_id,
251 					 new_lun->lun_id);
252 		if (status != CAM_REQ_CMP) {
253 			printf("Couldn't create path, status %#x\n", status);
254 			break;
255 		}
256 		TARG_LOCK(softc);
257 		status = targenable(softc, path, new_lun->grp6_len,
258 				    new_lun->grp7_len);
259 		TARG_UNLOCK(softc);
260 		xpt_free_path(path);
261 		break;
262 	}
263 	case TARGIOCDISABLE:
264 		TARG_LOCK(softc);
265 		status = targdisable(softc);
266 		TARG_UNLOCK(softc);
267 		break;
268 	case TARGIOCDEBUG:
269 	{
270 #ifdef	CAMDEBUG
271 		struct ccb_debug cdbg;
272 
273 		bzero(&cdbg, sizeof cdbg);
274 		if (*((int *)addr) != 0)
275 			cdbg.flags = CAM_DEBUG_PERIPH;
276 		else
277 			cdbg.flags = CAM_DEBUG_NONE;
278 		xpt_setup_ccb(&cdbg.ccb_h, softc->path, /*priority*/0);
279 		cdbg.ccb_h.func_code = XPT_DEBUG;
280 		cdbg.ccb_h.cbfcnp = targdone;
281 
282 		/* If no periph available, disallow debugging changes */
283 		TARG_LOCK(softc);
284 		if ((softc->state & TARG_STATE_LUN_ENABLED) == 0) {
285 			status = CAM_DEV_NOT_THERE;
286 			TARG_UNLOCK(softc);
287 			break;
288 		}
289 		xpt_action((union ccb *)&cdbg);
290 		TARG_UNLOCK(softc);
291 		status = cdbg.ccb_h.status & CAM_STATUS_MASK;
292 #else
293 		status = CAM_FUNC_NOTAVAIL;
294 #endif
295 		break;
296 	}
297 	default:
298 		status = CAM_PROVIDE_FAIL;
299 		break;
300 	}
301 
302 	return (targcamstatus(status));
303 }
304 
305 /* Writes are always ready, reads wait for user_ccb_queue or abort_queue */
306 static int
307 targpoll(struct cdev *dev, int poll_events, struct thread *td)
308 {
309 	struct targ_softc *softc;
310 	int	revents;
311 
312 	softc = (struct targ_softc *)dev->si_drv1;
313 
314 	/* Poll for write() is always ok. */
315 	revents = poll_events & (POLLOUT | POLLWRNORM);
316 	if ((poll_events & (POLLIN | POLLRDNORM)) != 0) {
317 		/* Poll for read() depends on user and abort queues. */
318 		TARG_LOCK(softc);
319 		if (!TAILQ_EMPTY(&softc->user_ccb_queue) ||
320 		    !TAILQ_EMPTY(&softc->abort_queue)) {
321 			revents |= poll_events & (POLLIN | POLLRDNORM);
322 		}
323 		/* Only sleep if the user didn't poll for write. */
324 		if (revents == 0)
325 			selrecord(td, &softc->read_select);
326 		TARG_UNLOCK(softc);
327 	}
328 
329 	return (revents);
330 }
331 
332 static int
333 targkqfilter(struct cdev *dev, struct knote *kn)
334 {
335 	struct  targ_softc *softc;
336 
337 	softc = (struct targ_softc *)dev->si_drv1;
338 	kn->kn_hook = (caddr_t)softc;
339 	kn->kn_fop = &targread_filtops;
340 	knlist_add(&softc->read_select.si_note, kn, 0);
341 	return (0);
342 }
343 
344 static void
345 targreadfiltdetach(struct knote *kn)
346 {
347 	struct  targ_softc *softc;
348 
349 	softc = (struct targ_softc *)kn->kn_hook;
350 	knlist_remove(&softc->read_select.si_note, kn, 0);
351 }
352 
353 /* Notify the user's kqueue when the user queue or abort queue gets a CCB */
354 static int
355 targreadfilt(struct knote *kn, long hint)
356 {
357 	struct targ_softc *softc;
358 	int	retval;
359 
360 	softc = (struct targ_softc *)kn->kn_hook;
361 	retval = !TAILQ_EMPTY(&softc->user_ccb_queue) ||
362 		 !TAILQ_EMPTY(&softc->abort_queue);
363 	return (retval);
364 }
365 
366 /* Send the HBA the enable/disable message */
367 static cam_status
368 targendislun(struct cam_path *path, int enable, int grp6_len, int grp7_len)
369 {
370 	struct ccb_en_lun en_ccb;
371 	cam_status	  status;
372 
373 	/* Tell the lun to begin answering selects */
374 	xpt_setup_ccb(&en_ccb.ccb_h, path, /*priority*/1);
375 	en_ccb.ccb_h.func_code = XPT_EN_LUN;
376 	/* Don't need support for any vendor specific commands */
377 	en_ccb.grp6_len = grp6_len;
378 	en_ccb.grp7_len = grp7_len;
379 	en_ccb.enable = enable ? 1 : 0;
380 	xpt_action((union ccb *)&en_ccb);
381 	status = en_ccb.ccb_h.status & CAM_STATUS_MASK;
382 	if (status != CAM_REQ_CMP) {
383 		xpt_print_path(path);
384 		printf("%sable lun CCB rejected, status %#x\n",
385 		       enable ? "en" : "dis", status);
386 	}
387 	return (status);
388 }
389 
390 /* Enable target mode on a LUN, given its path */
391 static cam_status
392 targenable(struct targ_softc *softc, struct cam_path *path, int grp6_len,
393 	   int grp7_len)
394 {
395 	struct cam_periph *periph;
396 	struct ccb_pathinq cpi;
397 	cam_status	   status;
398 
399 	if ((softc->state & TARG_STATE_LUN_ENABLED) != 0)
400 		return (CAM_LUN_ALRDY_ENA);
401 
402 	/* Make sure SIM supports target mode */
403 	xpt_setup_ccb(&cpi.ccb_h, path, /*priority*/1);
404 	cpi.ccb_h.func_code = XPT_PATH_INQ;
405 	xpt_action((union ccb *)&cpi);
406 	status = cpi.ccb_h.status & CAM_STATUS_MASK;
407 	if (status != CAM_REQ_CMP) {
408 		printf("pathinq failed, status %#x\n", status);
409 		goto enable_fail;
410 	}
411 	if ((cpi.target_sprt & PIT_PROCESSOR) == 0) {
412 		printf("controller does not support target mode\n");
413 		status = CAM_FUNC_NOTAVAIL;
414 		goto enable_fail;
415 	}
416 
417 	/* Destroy any periph on our path if it is disabled */
418 	mtx_lock(&targ_mtx);
419 	periph = cam_periph_find(path, "targ");
420 	if (periph != NULL) {
421 		struct targ_softc *del_softc;
422 
423 		del_softc = (struct targ_softc *)periph->softc;
424 		if ((del_softc->state & TARG_STATE_LUN_ENABLED) == 0) {
425 			cam_periph_invalidate(del_softc->periph);
426 			del_softc->periph = NULL;
427 		} else {
428 			printf("Requested path still in use by targ%d\n",
429 			       periph->unit_number);
430 			mtx_unlock(&targ_mtx);
431 			status = CAM_LUN_ALRDY_ENA;
432 			goto enable_fail;
433 		}
434 	}
435 
436 	/* Create a periph instance attached to this path */
437 	status = cam_periph_alloc(targctor, NULL, targdtor, targstart,
438 			"targ", CAM_PERIPH_BIO, path, targasync, 0, softc);
439 	mtx_unlock(&targ_mtx);
440 	if (status != CAM_REQ_CMP) {
441 		printf("cam_periph_alloc failed, status %#x\n", status);
442 		goto enable_fail;
443 	}
444 
445 	/* Ensure that the periph now exists. */
446 	if (cam_periph_find(path, "targ") == NULL) {
447 		panic("targenable: succeeded but no periph?");
448 		/* NOTREACHED */
449 	}
450 
451 	/* Send the enable lun message */
452 	status = targendislun(path, /*enable*/1, grp6_len, grp7_len);
453 	if (status != CAM_REQ_CMP) {
454 		printf("enable lun failed, status %#x\n", status);
455 		goto enable_fail;
456 	}
457 	softc->state |= TARG_STATE_LUN_ENABLED;
458 
459 enable_fail:
460 	return (status);
461 }
462 
463 /* Disable this softc's target instance if enabled */
464 static cam_status
465 targdisable(struct targ_softc *softc)
466 {
467 	cam_status status;
468 
469 	if ((softc->state & TARG_STATE_LUN_ENABLED) == 0)
470 		return (CAM_REQ_CMP);
471 
472 	CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targdisable\n"));
473 
474 	/* Abort any ccbs pending on the controller */
475 	abort_all_pending(softc);
476 
477 	/* Disable this lun */
478 	status = targendislun(softc->path, /*enable*/0,
479 			      /*grp6_len*/0, /*grp7_len*/0);
480 	if (status == CAM_REQ_CMP)
481 		softc->state &= ~TARG_STATE_LUN_ENABLED;
482 	else
483 		printf("Disable lun failed, status %#x\n", status);
484 
485 	return (status);
486 }
487 
488 /* Initialize a periph (called from cam_periph_alloc) */
489 static cam_status
490 targctor(struct cam_periph *periph, void *arg)
491 {
492 	struct targ_softc *softc;
493 
494 	/* Store pointer to softc for periph-driven routines */
495 	softc = (struct targ_softc *)arg;
496 	periph->softc = softc;
497 	softc->periph = periph;
498 	softc->path = periph->path;
499 	return (CAM_REQ_CMP);
500 }
501 
502 static void
503 targdtor(struct cam_periph *periph)
504 {
505 	struct targ_softc     *softc;
506 	struct ccb_hdr	      *ccb_h;
507 	struct targ_cmd_descr *descr;
508 
509 	softc = (struct targ_softc *)periph->softc;
510 
511 	/*
512 	 * targdisable() aborts CCBs back to the user and leaves them
513 	 * on user_ccb_queue and abort_queue in case the user is still
514 	 * interested in them.  We free them now.
515 	 */
516 	while ((ccb_h = TAILQ_FIRST(&softc->user_ccb_queue)) != NULL) {
517 		TAILQ_REMOVE(&softc->user_ccb_queue, ccb_h, periph_links.tqe);
518 		targfreeccb(softc, (union ccb *)ccb_h);
519 	}
520 	while ((descr = TAILQ_FIRST(&softc->abort_queue)) != NULL) {
521 		TAILQ_REMOVE(&softc->abort_queue, descr, tqe);
522 		FREE(descr, M_TARG);
523 	}
524 
525 	softc->periph = NULL;
526 	softc->path = NULL;
527 	periph->softc = NULL;
528 }
529 
530 /* Receive CCBs from user mode proc and send them to the HBA */
531 static int
532 targwrite(struct cdev *dev, struct uio *uio, int ioflag)
533 {
534 	union ccb *user_ccb;
535 	struct targ_softc *softc;
536 	struct targ_cmd_descr *descr;
537 	int write_len, error;
538 	int func_code, priority;
539 
540 	softc = (struct targ_softc *)dev->si_drv1;
541 	write_len = error = 0;
542 	CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
543 		  ("write - uio_resid %d\n", uio->uio_resid));
544 	while (uio->uio_resid >= sizeof(user_ccb) && error == 0) {
545 		union ccb *ccb;
546 		int error;
547 
548 		error = uiomove((caddr_t)&user_ccb, sizeof(user_ccb), uio);
549 		if (error != 0) {
550 			CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
551 				  ("write - uiomove failed (%d)\n", error));
552 			break;
553 		}
554 		priority = fuword32(&user_ccb->ccb_h.pinfo.priority);
555 		if (priority == -1) {
556 			error = EINVAL;
557 			break;
558 		}
559 		func_code = fuword32(&user_ccb->ccb_h.func_code);
560 		switch (func_code) {
561 		case XPT_ACCEPT_TARGET_IO:
562 		case XPT_IMMED_NOTIFY:
563 			ccb = targgetccb(softc, func_code, priority);
564 			descr = (struct targ_cmd_descr *)ccb->ccb_h.targ_descr;
565 			descr->user_ccb = user_ccb;
566 			descr->func_code = func_code;
567 			CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
568 				  ("Sent ATIO/INOT (%p)\n", user_ccb));
569 			xpt_action(ccb);
570 			TARG_LOCK(softc);
571 			TAILQ_INSERT_TAIL(&softc->pending_ccb_queue,
572 					  &ccb->ccb_h,
573 					  periph_links.tqe);
574 			TARG_UNLOCK(softc);
575 			break;
576 		default:
577 			if ((func_code & XPT_FC_QUEUED) != 0) {
578 				CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
579 					  ("Sending queued ccb %#x (%p)\n",
580 					  func_code, user_ccb));
581 				descr = targgetdescr(softc);
582 				descr->user_ccb = user_ccb;
583 				descr->priority = priority;
584 				descr->func_code = func_code;
585 				TARG_LOCK(softc);
586 				TAILQ_INSERT_TAIL(&softc->work_queue,
587 						  descr, tqe);
588 				TARG_UNLOCK(softc);
589 				xpt_schedule(softc->periph, priority);
590 			} else {
591 				CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
592 					  ("Sending inline ccb %#x (%p)\n",
593 					  func_code, user_ccb));
594 				ccb = targgetccb(softc, func_code, priority);
595 				descr = (struct targ_cmd_descr *)
596 					 ccb->ccb_h.targ_descr;
597 				descr->user_ccb = user_ccb;
598 				descr->priority = priority;
599 				descr->func_code = func_code;
600 				if (targusermerge(softc, descr, ccb) != EFAULT)
601 					targsendccb(softc, ccb, descr);
602 				targreturnccb(softc, ccb);
603 			}
604 			break;
605 		}
606 		write_len += sizeof(user_ccb);
607 	}
608 
609 	/*
610 	 * If we've successfully taken in some amount of
611 	 * data, return success for that data first.  If
612 	 * an error is persistent, it will be reported
613 	 * on the next write.
614 	 */
615 	if (error != 0 && write_len == 0)
616 		return (error);
617 	if (write_len == 0 && uio->uio_resid != 0)
618 		return (ENOSPC);
619 	return (0);
620 }
621 
622 /* Process requests (descrs) via the periph-supplied CCBs */
623 static void
624 targstart(struct cam_periph *periph, union ccb *start_ccb)
625 {
626 	struct targ_softc *softc;
627 	struct targ_cmd_descr *descr, *next_descr;
628 	int error;
629 
630 	softc = (struct targ_softc *)periph->softc;
631 	CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targstart %p\n", start_ccb));
632 
633 	TARG_LOCK(softc);
634 	descr = TAILQ_FIRST(&softc->work_queue);
635 	if (descr == NULL) {
636 		TARG_UNLOCK(softc);
637 		xpt_release_ccb(start_ccb);
638 	} else {
639 		TAILQ_REMOVE(&softc->work_queue, descr, tqe);
640 		next_descr = TAILQ_FIRST(&softc->work_queue);
641 		TARG_UNLOCK(softc);
642 
643 		/* Initiate a transaction using the descr and supplied CCB */
644 		error = targusermerge(softc, descr, start_ccb);
645 		if (error == 0)
646 			error = targsendccb(softc, start_ccb, descr);
647 		if (error != 0) {
648 			xpt_print_path(periph->path);
649 			printf("targsendccb failed, err %d\n", error);
650 			xpt_release_ccb(start_ccb);
651 			suword(&descr->user_ccb->ccb_h.status,
652 			       CAM_REQ_CMP_ERR);
653 			TARG_LOCK(softc);
654 			TAILQ_INSERT_TAIL(&softc->abort_queue, descr, tqe);
655 			TARG_UNLOCK(softc);
656 			notify_user(softc);
657 		}
658 
659 		/* If we have more work to do, stay scheduled */
660 		if (next_descr != NULL)
661 			xpt_schedule(periph, next_descr->priority);
662 	}
663 }
664 
665 static int
666 targusermerge(struct targ_softc *softc, struct targ_cmd_descr *descr,
667 	      union ccb *ccb)
668 {
669 	struct ccb_hdr *u_ccbh, *k_ccbh;
670 	size_t ccb_len;
671 	int error;
672 
673 	u_ccbh = &descr->user_ccb->ccb_h;
674 	k_ccbh = &ccb->ccb_h;
675 
676 	/*
677 	 * There are some fields in the CCB header that need to be
678 	 * preserved, the rest we get from the user ccb. (See xpt_merge_ccb)
679 	 */
680 	xpt_setup_ccb(k_ccbh, softc->path, descr->priority);
681 	k_ccbh->retry_count = fuword32(&u_ccbh->retry_count);
682 	k_ccbh->func_code = descr->func_code;
683 	k_ccbh->flags = fuword32(&u_ccbh->flags);
684 	k_ccbh->timeout = fuword32(&u_ccbh->timeout);
685 	ccb_len = targccblen(k_ccbh->func_code) - sizeof(struct ccb_hdr);
686 	error = copyin(u_ccbh + 1, k_ccbh + 1, ccb_len);
687 	if (error != 0) {
688 		k_ccbh->status = CAM_REQ_CMP_ERR;
689 		return (error);
690 	}
691 
692 	/* Translate usermode abort_ccb pointer to its kernel counterpart */
693 	if (k_ccbh->func_code == XPT_ABORT) {
694 		struct ccb_abort *cab;
695 		struct ccb_hdr *ccb_h;
696 
697 		cab = (struct ccb_abort *)ccb;
698 		TARG_LOCK(softc);
699 		TAILQ_FOREACH(ccb_h, &softc->pending_ccb_queue,
700 		    periph_links.tqe) {
701 			struct targ_cmd_descr *ab_descr;
702 
703 			ab_descr = (struct targ_cmd_descr *)ccb_h->targ_descr;
704 			if (ab_descr->user_ccb == cab->abort_ccb) {
705 				CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
706 					  ("Changing abort for %p to %p\n",
707 					  cab->abort_ccb, ccb_h));
708 				cab->abort_ccb = (union ccb *)ccb_h;
709 				break;
710 			}
711 		}
712 		TARG_UNLOCK(softc);
713 		/* CCB not found, set appropriate status */
714 		if (ccb_h == NULL) {
715 			k_ccbh->status = CAM_PATH_INVALID;
716 			error = ESRCH;
717 		}
718 	}
719 
720 	return (error);
721 }
722 
723 /* Build and send a kernel CCB formed from descr->user_ccb */
724 static int
725 targsendccb(struct targ_softc *softc, union ccb *ccb,
726 	    struct targ_cmd_descr *descr)
727 {
728 	struct cam_periph_map_info *mapinfo;
729 	struct ccb_hdr *ccb_h;
730 	int error;
731 
732 	ccb_h = &ccb->ccb_h;
733 	mapinfo = &descr->mapinfo;
734 	mapinfo->num_bufs_used = 0;
735 
736 	/*
737 	 * There's no way for the user to have a completion
738 	 * function, so we put our own completion function in here.
739 	 * We also stash in a reference to our descriptor so targreturnccb()
740 	 * can find our mapping info.
741 	 */
742 	ccb_h->cbfcnp = targdone;
743 	ccb_h->targ_descr = descr;
744 
745 	/*
746 	 * We only attempt to map the user memory into kernel space
747 	 * if they haven't passed in a physical memory pointer,
748 	 * and if there is actually an I/O operation to perform.
749 	 * Right now cam_periph_mapmem() only supports SCSI and device
750 	 * match CCBs.  For the SCSI CCBs, we only pass the CCB in if
751 	 * there's actually data to map.  cam_periph_mapmem() will do the
752 	 * right thing, even if there isn't data to map, but since CCBs
753 	 * without data are a reasonably common occurance (e.g. test unit
754 	 * ready), it will save a few cycles if we check for it here.
755 	 */
756 	if (((ccb_h->flags & CAM_DATA_PHYS) == 0)
757 	 && (((ccb_h->func_code == XPT_CONT_TARGET_IO)
758 	    && ((ccb_h->flags & CAM_DIR_MASK) != CAM_DIR_NONE))
759 	  || (ccb_h->func_code == XPT_DEV_MATCH))) {
760 
761 		error = cam_periph_mapmem(ccb, mapinfo);
762 
763 		/*
764 		 * cam_periph_mapmem returned an error, we can't continue.
765 		 * Return the error to the user.
766 		 */
767 		if (error) {
768 			ccb_h->status = CAM_REQ_CMP_ERR;
769 			mapinfo->num_bufs_used = 0;
770 			return (error);
771 		}
772 	}
773 
774 	/*
775 	 * Once queued on the pending CCB list, this CCB will be protected
776 	 * by our error recovery handler.
777 	 */
778 	CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("sendccb %p\n", ccb));
779 	if (XPT_FC_IS_QUEUED(ccb)) {
780 		TARG_LOCK(softc);
781 		TAILQ_INSERT_TAIL(&softc->pending_ccb_queue, ccb_h,
782 				  periph_links.tqe);
783 		TARG_UNLOCK(softc);
784 	}
785 	xpt_action(ccb);
786 
787 	return (0);
788 }
789 
790 /* Completion routine for CCBs (called at splsoftcam) */
791 static void
792 targdone(struct cam_periph *periph, union ccb *done_ccb)
793 {
794 	struct targ_softc *softc;
795 	cam_status status;
796 
797 	CAM_DEBUG(periph->path, CAM_DEBUG_PERIPH, ("targdone %p\n", done_ccb));
798 	softc = (struct targ_softc *)periph->softc;
799 	TARG_LOCK(softc);
800 	TAILQ_REMOVE(&softc->pending_ccb_queue, &done_ccb->ccb_h,
801 		     periph_links.tqe);
802 	status = done_ccb->ccb_h.status & CAM_STATUS_MASK;
803 
804 	/* If we're no longer enabled, throw away CCB */
805 	if ((softc->state & TARG_STATE_LUN_ENABLED) == 0) {
806 		targfreeccb(softc, done_ccb);
807 		TARG_UNLOCK(softc);
808 		return;
809 	}
810 	/* abort_all_pending() waits for pending queue to be empty */
811 	if (TAILQ_EMPTY(&softc->pending_ccb_queue))
812 		wakeup(&softc->pending_ccb_queue);
813 
814 	switch (done_ccb->ccb_h.func_code) {
815 	/* All FC_*_QUEUED CCBs go back to userland */
816 	case XPT_IMMED_NOTIFY:
817 	case XPT_ACCEPT_TARGET_IO:
818 	case XPT_CONT_TARGET_IO:
819 		TAILQ_INSERT_TAIL(&softc->user_ccb_queue, &done_ccb->ccb_h,
820 				  periph_links.tqe);
821 		TARG_UNLOCK(softc);
822 		notify_user(softc);
823 		break;
824 	default:
825 		panic("targdone: impossible xpt opcode %#x",
826 		      done_ccb->ccb_h.func_code);
827 		/* NOTREACHED */
828 	}
829 }
830 
831 /* Return CCBs to the user from the user queue and abort queue */
832 static int
833 targread(struct cdev *dev, struct uio *uio, int ioflag)
834 {
835 	struct descr_queue	*abort_queue;
836 	struct targ_cmd_descr	*user_descr;
837 	struct targ_softc	*softc;
838 	struct ccb_queue  *user_queue;
839 	struct ccb_hdr	  *ccb_h;
840 	union  ccb	  *user_ccb;
841 	int		   read_len, error;
842 
843 	error = 0;
844 	read_len = 0;
845 	softc = (struct targ_softc *)dev->si_drv1;
846 	user_queue = &softc->user_ccb_queue;
847 	abort_queue = &softc->abort_queue;
848 	CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targread\n"));
849 
850 	/* If no data is available, wait or return immediately */
851 	TARG_LOCK(softc);
852 	ccb_h = TAILQ_FIRST(user_queue);
853 	user_descr = TAILQ_FIRST(abort_queue);
854 	while (ccb_h == NULL && user_descr == NULL) {
855 		if ((ioflag & IO_NDELAY) == 0) {
856 			error = msleep(user_queue, &softc->mtx,
857 				       PRIBIO | PCATCH, "targrd", 0);
858 			ccb_h = TAILQ_FIRST(user_queue);
859 			user_descr = TAILQ_FIRST(abort_queue);
860 			if (error != 0) {
861 				if (error == ERESTART) {
862 					continue;
863 				} else {
864 					TARG_UNLOCK(softc);
865 					goto read_fail;
866 				}
867 			}
868 		} else {
869 			TARG_UNLOCK(softc);
870 			return (EAGAIN);
871 		}
872 	}
873 
874 	/* Data is available so fill the user's buffer */
875 	while (ccb_h != NULL) {
876 		struct targ_cmd_descr *descr;
877 
878 		if (uio->uio_resid < sizeof(user_ccb))
879 			break;
880 		TAILQ_REMOVE(user_queue, ccb_h, periph_links.tqe);
881 		TARG_UNLOCK(softc);
882 		descr = (struct targ_cmd_descr *)ccb_h->targ_descr;
883 		user_ccb = descr->user_ccb;
884 		CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
885 			  ("targread ccb %p (%p)\n", ccb_h, user_ccb));
886 		error = targreturnccb(softc, (union ccb *)ccb_h);
887 		if (error != 0)
888 			goto read_fail;
889 		error = uiomove((caddr_t)&user_ccb, sizeof(user_ccb), uio);
890 		if (error != 0)
891 			goto read_fail;
892 		read_len += sizeof(user_ccb);
893 
894 		TARG_LOCK(softc);
895 		ccb_h = TAILQ_FIRST(user_queue);
896 	}
897 
898 	/* Flush out any aborted descriptors */
899 	while (user_descr != NULL) {
900 		if (uio->uio_resid < sizeof(user_ccb))
901 			break;
902 		TAILQ_REMOVE(abort_queue, user_descr, tqe);
903 		TARG_UNLOCK(softc);
904 		user_ccb = user_descr->user_ccb;
905 		CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
906 			  ("targread aborted descr %p (%p)\n",
907 			  user_descr, user_ccb));
908 		suword(&user_ccb->ccb_h.status, CAM_REQ_ABORTED);
909 		error = uiomove((caddr_t)&user_ccb, sizeof(user_ccb), uio);
910 		if (error != 0)
911 			goto read_fail;
912 		read_len += sizeof(user_ccb);
913 
914 		TARG_LOCK(softc);
915 		user_descr = TAILQ_FIRST(abort_queue);
916 	}
917 	TARG_UNLOCK(softc);
918 
919 	/*
920 	 * If we've successfully read some amount of data, don't report an
921 	 * error.  If the error is persistent, it will be reported on the
922 	 * next read().
923 	 */
924 	if (read_len == 0 && uio->uio_resid != 0)
925 		error = ENOSPC;
926 
927 read_fail:
928 	return (error);
929 }
930 
931 /* Copy completed ccb back to the user */
932 static int
933 targreturnccb(struct targ_softc *softc, union ccb *ccb)
934 {
935 	struct targ_cmd_descr *descr;
936 	struct ccb_hdr *u_ccbh;
937 	size_t ccb_len;
938 	int error;
939 
940 	CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("targreturnccb %p\n", ccb));
941 	descr = (struct targ_cmd_descr *)ccb->ccb_h.targ_descr;
942 	u_ccbh = &descr->user_ccb->ccb_h;
943 
944 	/* Copy out the central portion of the ccb_hdr */
945 	copyout(&ccb->ccb_h.retry_count, &u_ccbh->retry_count,
946 		offsetof(struct ccb_hdr, periph_priv) -
947 		offsetof(struct ccb_hdr, retry_count));
948 
949 	/* Copy out the rest of the ccb (after the ccb_hdr) */
950 	ccb_len = targccblen(ccb->ccb_h.func_code) - sizeof(struct ccb_hdr);
951 	if (descr->mapinfo.num_bufs_used != 0)
952 		cam_periph_unmapmem(ccb, &descr->mapinfo);
953 	error = copyout(&ccb->ccb_h + 1, u_ccbh + 1, ccb_len);
954 	if (error != 0) {
955 		xpt_print_path(softc->path);
956 		printf("targreturnccb - CCB copyout failed (%d)\n",
957 		       error);
958 	}
959 	/* Free CCB or send back to devq. */
960 	targfreeccb(softc, ccb);
961 
962 	return (error);
963 }
964 
965 static union ccb *
966 targgetccb(struct targ_softc *softc, xpt_opcode type, int priority)
967 {
968 	union ccb *ccb;
969 	int ccb_len;
970 
971 	ccb_len = targccblen(type);
972 	MALLOC(ccb, union ccb *, ccb_len, M_TARG, M_WAITOK);
973 	CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("getccb %p\n", ccb));
974 
975 	xpt_setup_ccb(&ccb->ccb_h, softc->path, priority);
976 	ccb->ccb_h.func_code = type;
977 	ccb->ccb_h.cbfcnp = targdone;
978 	ccb->ccb_h.targ_descr = targgetdescr(softc);
979 	return (ccb);
980 }
981 
982 static void
983 targfreeccb(struct targ_softc *softc, union ccb *ccb)
984 {
985 	CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH, ("targfreeccb descr %p and\n",
986 			ccb->ccb_h.targ_descr));
987 	FREE(ccb->ccb_h.targ_descr, M_TARG);
988 
989 	switch (ccb->ccb_h.func_code) {
990 	case XPT_ACCEPT_TARGET_IO:
991 	case XPT_IMMED_NOTIFY:
992 		CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH, ("freeing ccb %p\n", ccb));
993 		FREE(ccb, M_TARG);
994 		break;
995 	default:
996 		/* Send back CCB if we got it from the periph */
997 		if (XPT_FC_IS_QUEUED(ccb)) {
998 			CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH,
999 					("returning queued ccb %p\n", ccb));
1000 			xpt_release_ccb(ccb);
1001 		} else {
1002 			CAM_DEBUG_PRINT(CAM_DEBUG_PERIPH,
1003 					("freeing ccb %p\n", ccb));
1004 			FREE(ccb, M_TARG);
1005 		}
1006 		break;
1007 	}
1008 }
1009 
1010 static struct targ_cmd_descr *
1011 targgetdescr(struct targ_softc *softc)
1012 {
1013 	struct targ_cmd_descr *descr;
1014 
1015 	MALLOC(descr, struct targ_cmd_descr *, sizeof(*descr), M_TARG,
1016 	       M_WAITOK);
1017 	descr->mapinfo.num_bufs_used = 0;
1018 	return (descr);
1019 }
1020 
1021 static void
1022 targinit(void)
1023 {
1024 	mtx_init(&targ_mtx, "targ global", NULL, MTX_DEF);
1025 	EVENTHANDLER_REGISTER(dev_clone, targclone, 0, 1000);
1026 }
1027 
1028 static void
1029 targclone(void *arg, char *name, int namelen, struct cdev **dev)
1030 {
1031 	int u;
1032 
1033 	if (*dev != NULL)
1034 		return;
1035 	if (dev_stdclone(name, NULL, "targ", &u) != 1)
1036 		return;
1037 	*dev = make_dev(&targ_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL,
1038 			0600, "targ%d", u);
1039 	(*dev)->si_flags |= SI_CHEAPCLONE;
1040 }
1041 
1042 static void
1043 targasync(void *callback_arg, u_int32_t code, struct cam_path *path, void *arg)
1044 {
1045 	/* All events are handled in usermode by INOTs */
1046 	panic("targasync() called, should be an INOT instead");
1047 }
1048 
1049 /* Cancel all pending requests and CCBs awaiting work. */
1050 static void
1051 abort_all_pending(struct targ_softc *softc)
1052 {
1053 	struct targ_cmd_descr   *descr;
1054 	struct ccb_abort	 cab;
1055 	struct ccb_hdr		*ccb_h;
1056 
1057 	CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH, ("abort_all_pending\n"));
1058 
1059 	/* First abort the descriptors awaiting resources */
1060 	while ((descr = TAILQ_FIRST(&softc->work_queue)) != NULL) {
1061 		CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
1062 			  ("Aborting descr from workq %p\n", descr));
1063 		TAILQ_REMOVE(&softc->work_queue, descr, tqe);
1064 		TAILQ_INSERT_TAIL(&softc->abort_queue, descr, tqe);
1065 	}
1066 
1067 	/*
1068 	 * Then abort all pending CCBs.
1069 	 * targdone() will return the aborted CCB via user_ccb_queue
1070 	 */
1071 	xpt_setup_ccb(&cab.ccb_h, softc->path, /*priority*/0);
1072 	cab.ccb_h.func_code = XPT_ABORT;
1073 	cab.ccb_h.status = CAM_REQ_CMP_ERR;
1074 	TAILQ_FOREACH(ccb_h, &softc->pending_ccb_queue, periph_links.tqe) {
1075 		CAM_DEBUG(softc->path, CAM_DEBUG_PERIPH,
1076 			  ("Aborting pending CCB %p\n", ccb_h));
1077 		cab.abort_ccb = (union ccb *)ccb_h;
1078 		xpt_action((union ccb *)&cab);
1079 		if (cab.ccb_h.status != CAM_REQ_CMP) {
1080 			xpt_print_path(cab.ccb_h.path);
1081 			printf("Unable to abort CCB, status %#x\n",
1082 			       cab.ccb_h.status);
1083 		}
1084 	}
1085 
1086 	/* If we aborted at least one pending CCB ok, wait for it. */
1087 	if (cab.ccb_h.status == CAM_REQ_CMP) {
1088 		msleep(&softc->pending_ccb_queue, &softc->mtx,
1089 		       PRIBIO | PCATCH, "tgabrt", 0);
1090 	}
1091 
1092 	/* If we aborted anything from the work queue, wakeup user. */
1093 	if (!TAILQ_EMPTY(&softc->user_ccb_queue)
1094 	 || !TAILQ_EMPTY(&softc->abort_queue))
1095 		notify_user(softc);
1096 }
1097 
1098 /* Notify the user that data is ready */
1099 static void
1100 notify_user(struct targ_softc *softc)
1101 {
1102 	/*
1103 	 * Notify users sleeping via poll(), kqueue(), and
1104 	 * blocking read().
1105 	 */
1106 	selwakeuppri(&softc->read_select, PRIBIO);
1107 	KNOTE_LOCKED(&softc->read_select.si_note, 0);
1108 	wakeup(&softc->user_ccb_queue);
1109 }
1110 
1111 /* Convert CAM status to errno values */
1112 static int
1113 targcamstatus(cam_status status)
1114 {
1115 	switch (status & CAM_STATUS_MASK) {
1116 	case CAM_REQ_CMP:	/* CCB request completed without error */
1117 		return (0);
1118 	case CAM_REQ_INPROG:	/* CCB request is in progress */
1119 		return (EINPROGRESS);
1120 	case CAM_REQ_CMP_ERR:	/* CCB request completed with an error */
1121 		return (EIO);
1122 	case CAM_PROVIDE_FAIL:	/* Unable to provide requested capability */
1123 		return (ENOTTY);
1124 	case CAM_FUNC_NOTAVAIL:	/* The requested function is not available */
1125 		return (ENOTSUP);
1126 	case CAM_LUN_ALRDY_ENA:	/* LUN is already enabled for target mode */
1127 		return (EADDRINUSE);
1128 	case CAM_PATH_INVALID:	/* Supplied Path ID is invalid */
1129 	case CAM_DEV_NOT_THERE:	/* SCSI Device Not Installed/there */
1130 		return (ENOENT);
1131 	case CAM_REQ_ABORTED:	/* CCB request aborted by the host */
1132 		return (ECANCELED);
1133 	case CAM_CMD_TIMEOUT:	/* Command timeout */
1134 		return (ETIMEDOUT);
1135 	case CAM_REQUEUE_REQ:	/* Requeue to preserve transaction ordering */
1136 		return (EAGAIN);
1137 	case CAM_REQ_INVALID:	/* CCB request was invalid */
1138 		return (EINVAL);
1139 	case CAM_RESRC_UNAVAIL:	/* Resource Unavailable */
1140 		return (ENOMEM);
1141 	case CAM_BUSY:		/* CAM subsytem is busy */
1142 	case CAM_UA_ABORT:	/* Unable to abort CCB request */
1143 		return (EBUSY);
1144 	default:
1145 		return (ENXIO);
1146 	}
1147 }
1148 
1149 static size_t
1150 targccblen(xpt_opcode func_code)
1151 {
1152 	int len;
1153 
1154 	/* Codes we expect to see as a target */
1155 	switch (func_code) {
1156 	case XPT_CONT_TARGET_IO:
1157 	case XPT_SCSI_IO:
1158 		len = sizeof(struct ccb_scsiio);
1159 		break;
1160 	case XPT_ACCEPT_TARGET_IO:
1161 		len = sizeof(struct ccb_accept_tio);
1162 		break;
1163 	case XPT_IMMED_NOTIFY:
1164 		len = sizeof(struct ccb_immed_notify);
1165 		break;
1166 	case XPT_REL_SIMQ:
1167 		len = sizeof(struct ccb_relsim);
1168 		break;
1169 	case XPT_PATH_INQ:
1170 		len = sizeof(struct ccb_pathinq);
1171 		break;
1172 	case XPT_DEBUG:
1173 		len = sizeof(struct ccb_debug);
1174 		break;
1175 	case XPT_ABORT:
1176 		len = sizeof(struct ccb_abort);
1177 		break;
1178 	case XPT_EN_LUN:
1179 		len = sizeof(struct ccb_en_lun);
1180 		break;
1181 	default:
1182 		len = sizeof(union ccb);
1183 		break;
1184 	}
1185 
1186 	return (len);
1187 }
1188