xref: /freebsd/share/examples/scsi_target/scsi_cmds.c (revision f81cdf24ba5436367377f7c8e8f51f6df2a75ca7)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * SCSI Disk Emulator
5  *
6  * Copyright (c) 2002 Nate Lawson.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions, and the following disclaimer,
14  *    without modification, immediately at the beginning of the file.
15  * 2. The name of the author may not be used to endorse or promote products
16  *    derived from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
22  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <stdio.h>
32 #include <stddef.h>
33 #include <stdarg.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <err.h>
37 #include <aio.h>
38 #include <unistd.h>
39 #include <assert.h>
40 #include <sys/param.h>
41 #include <sys/types.h>
42 
43 #include <cam/cam.h>
44 #include <cam/cam_ccb.h>
45 #include <cam/scsi/scsi_all.h>
46 #include <cam/scsi/scsi_targetio.h>
47 #include "scsi_target.h"
48 
49 typedef int targ_start_func(struct ccb_accept_tio *, struct ccb_scsiio *);
50 typedef void targ_done_func(struct ccb_accept_tio *, struct ccb_scsiio *,
51 			      io_ops);
52 #ifndef	REPORT_LUNS
53 #define	REPORT_LUNS	0xa0
54 #endif
55 
56 struct targ_cdb_handlers {
57 	u_int8_t	  cmd;
58 	targ_start_func  *start;
59 	targ_done_func	 *done;
60 #define ILLEGAL_CDB	  0xFF
61 };
62 
63 static targ_start_func		tcmd_inquiry;
64 static targ_start_func		tcmd_req_sense;
65 static targ_start_func		tcmd_rd_cap;
66 #ifdef READ_16
67 static targ_start_func		tcmd_rd_cap16;
68 #endif
69 static targ_start_func		tcmd_rdwr;
70 static targ_start_func		tcmd_rdwr_decode;
71 static targ_done_func		tcmd_rdwr_done;
72 static targ_start_func		tcmd_null_ok;
73 static targ_start_func		tcmd_illegal_req;
74 static int			start_io(struct ccb_accept_tio *atio,
75 					 struct ccb_scsiio *ctio, int dir);
76 static int init_inquiry(u_int16_t req_flags, u_int16_t sim_flags);
77 static struct initiator_state *
78 			tcmd_get_istate(u_int init_id);
79 static void cdb_debug(u_int8_t *cdb, const char *msg, ...);
80 
81 static struct targ_cdb_handlers cdb_handlers[] = {
82 	{ READ_10,		tcmd_rdwr,		tcmd_rdwr_done },
83 	{ WRITE_10,		tcmd_rdwr,		tcmd_rdwr_done },
84 	{ READ_6,		tcmd_rdwr,		tcmd_rdwr_done },
85 	{ WRITE_6,		tcmd_rdwr,		tcmd_rdwr_done },
86 	{ INQUIRY,		tcmd_inquiry,		NULL },
87 	{ REQUEST_SENSE,	tcmd_req_sense,		NULL },
88 	{ READ_CAPACITY,	tcmd_rd_cap,		NULL },
89 	{ TEST_UNIT_READY,	tcmd_null_ok,		NULL },
90 	{ START_STOP_UNIT,	tcmd_null_ok,		NULL },
91 	{ SYNCHRONIZE_CACHE,	tcmd_null_ok,		NULL },
92 	{ MODE_SENSE_6,		tcmd_illegal_req,	NULL },
93 	{ MODE_SELECT_6,	tcmd_illegal_req,	NULL },
94 	{ REPORT_LUNS,		tcmd_illegal_req,	NULL },
95 #ifdef READ_16
96 	{ READ_16,		tcmd_rdwr,		tcmd_rdwr_done },
97 	{ WRITE_16,		tcmd_rdwr,		tcmd_rdwr_done },
98 	{ SERVICE_ACTION_IN,	tcmd_rd_cap16,		NULL },
99 #endif
100 	{ ILLEGAL_CDB,		NULL,			NULL }
101 };
102 
103 static struct scsi_inquiry_data inq_data;
104 static struct initiator_state istates[MAX_INITIATORS];
105 extern int		debug;
106 extern off_t		volume_size;
107 extern u_int		sector_size;
108 extern size_t		buf_size;
109 
110 cam_status
111 tcmd_init(u_int16_t req_inq_flags, u_int16_t sim_inq_flags)
112 {
113 	struct initiator_state *istate;
114 	int i, ret;
115 
116 	/* Initialize our inquiry data */
117 	ret = init_inquiry(req_inq_flags, sim_inq_flags);
118 	if (ret != 0)
119         	return (ret);
120 
121 	/* We start out life with a UA to indicate power-on/reset. */
122 	for (i = 0; i < MAX_INITIATORS; i++) {
123 		istate = tcmd_get_istate(i);
124 		bzero(istate, sizeof(*istate));
125 		istate->pending_ua = UA_POWER_ON;
126 	}
127 
128 	return (0);
129 }
130 
131 /* Caller allocates CTIO, sets its init_id
132 return 0 if done, 1 if more processing needed
133 on 0, caller sets SEND_STATUS */
134 int
135 tcmd_handle(struct ccb_accept_tio *atio, struct ccb_scsiio *ctio, io_ops event)
136 {
137 	static struct targ_cdb_handlers *last_cmd;
138 	struct initiator_state *istate;
139 	struct atio_descr *a_descr;
140 	int ret;
141 
142 	if (debug) {
143 		warnx("tcmd_handle atio %p ctio %p atioflags %#x", atio, ctio,
144 		      atio->ccb_h.flags);
145 	}
146 	ret = 0;
147 	a_descr = (struct atio_descr *)atio->ccb_h.targ_descr;
148 
149 	/* Do a full lookup if one-behind cache failed */
150 	if (last_cmd == NULL || last_cmd->cmd != a_descr->cdb[0]) {
151 		struct targ_cdb_handlers *h;
152 
153 		for (h = cdb_handlers; h->cmd != ILLEGAL_CDB; h++) {
154 			if (a_descr->cdb[0] == h->cmd)
155 				break;
156 		}
157 		last_cmd = h;
158 	}
159 
160 	/* call completion and exit */
161 	if (event != ATIO_WORK) {
162 		if (last_cmd->done != NULL)
163 			last_cmd->done(atio, ctio, event);
164 		else
165 			free_ccb((union ccb *)ctio);
166 		return (1);
167 	}
168 
169 	if (last_cmd->cmd == ILLEGAL_CDB) {
170 		if (event != ATIO_WORK) {
171 			warnx("no done func for %#x???", a_descr->cdb[0]);
172 			abort();
173 		}
174 		/* Not found, return illegal request */
175 		warnx("cdb %#x not handled", a_descr->cdb[0]);
176 		tcmd_illegal_req(atio, ctio);
177 		send_ccb((union ccb *)ctio, /*priority*/1);
178 		return (0);
179 	}
180 
181 	istate = tcmd_get_istate(ctio->init_id);
182 	if (istate == NULL) {
183 		tcmd_illegal_req(atio, ctio);
184 		send_ccb((union ccb *)ctio, /*priority*/1);
185 		return (0);
186 	}
187 
188 	if (istate->pending_ca == 0 && istate->pending_ua != 0 &&
189 	    a_descr->cdb[0] != INQUIRY) {
190 		tcmd_sense(ctio->init_id, ctio, SSD_KEY_UNIT_ATTENTION,
191 			   0x29, istate->pending_ua == UA_POWER_ON ? 1 : 2);
192 		istate->pending_ca = CA_UNIT_ATTN;
193 		if (debug) {
194 			cdb_debug(a_descr->cdb, "UA active for %u: ",
195 				  atio->init_id);
196 		}
197 		send_ccb((union ccb *)ctio, /*priority*/1);
198 		return (0);
199 	}
200 
201 	/* Store current CA and UA for later */
202 	istate->orig_ua = istate->pending_ua;
203 	istate->orig_ca = istate->pending_ca;
204 
205 	/*
206 	 * As per SAM2, any command that occurs
207 	 * after a CA is reported, clears the CA.  We must
208 	 * also clear the UA condition, if any, that caused
209 	 * the CA to occur assuming the UA is not for a
210 	 * persistent condition.
211 	 */
212 	istate->pending_ca = CA_NONE;
213 	if (istate->orig_ca == CA_UNIT_ATTN)
214 		istate->pending_ua = UA_NONE;
215 
216 	/* If we have a valid handler, call start or completion function */
217 	if (last_cmd->cmd != ILLEGAL_CDB) {
218 		ret = last_cmd->start(atio, ctio);
219 		/* XXX hack */
220 		if (last_cmd->start != tcmd_rdwr) {
221 			a_descr->init_req += ctio->dxfer_len;
222 			send_ccb((union ccb *)ctio, /*priority*/1);
223 		}
224 	}
225 
226 	return (ret);
227 }
228 
229 static struct initiator_state *
230 tcmd_get_istate(u_int init_id)
231 {
232 	if (init_id >= MAX_INITIATORS) {
233 		warnx("illegal init_id %d, max %d", init_id, MAX_INITIATORS - 1);
234 		return (NULL);
235 	} else {
236 		return (&istates[init_id]);
237 	}
238 }
239 
240 void
241 tcmd_sense(u_int init_id, struct ccb_scsiio *ctio, u_int8_t flags,
242 	       u_int8_t asc, u_int8_t ascq)
243 {
244 	struct initiator_state *istate;
245 	struct scsi_sense_data_fixed *sense;
246 
247 	/* Set our initiator's istate */
248 	istate = tcmd_get_istate(init_id);
249 	if (istate == NULL)
250 		return;
251 	istate->pending_ca |= CA_CMD_SENSE; /* XXX set instead of or? */
252 	sense = (struct scsi_sense_data_fixed *)&istate->sense_data;
253 	bzero(sense, sizeof(*sense));
254 	sense->error_code = SSD_CURRENT_ERROR;
255 	sense->flags = flags;
256 	sense->add_sense_code = asc;
257 	sense->add_sense_code_qual = ascq;
258 	sense->extra_len =
259 		offsetof(struct scsi_sense_data_fixed, sense_key_spec[2]) -
260 		offsetof(struct scsi_sense_data_fixed, extra_len);
261 
262 	/* Fill out the supplied CTIO */
263 	if (ctio != NULL) {
264 		bcopy(sense, &ctio->sense_data, sizeof(*sense));
265 		ctio->sense_len = sizeof(*sense);  /* XXX */
266 		ctio->ccb_h.flags &= ~CAM_DIR_MASK;
267 		ctio->ccb_h.flags |= CAM_DIR_NONE | CAM_SEND_SENSE |
268 				     CAM_SEND_STATUS;
269 		ctio->dxfer_len = 0;
270 		ctio->scsi_status = SCSI_STATUS_CHECK_COND;
271 	}
272 }
273 
274 void
275 tcmd_ua(u_int init_id, ua_types new_ua)
276 {
277 	struct initiator_state *istate;
278 	u_int start, end;
279 
280 	if (init_id == CAM_TARGET_WILDCARD) {
281 		start = 0;
282 		end = MAX_INITIATORS - 1;
283 	} else {
284 		start = end = init_id;
285 	}
286 
287 	for (; start <= end; start++) {
288 		istate = tcmd_get_istate(start);
289 		if (istate == NULL)
290 			break;
291 		istate->pending_ua = new_ua;
292 	}
293 }
294 
295 static int
296 tcmd_inquiry(struct ccb_accept_tio *atio, struct ccb_scsiio *ctio)
297 {
298 	struct scsi_inquiry *inq;
299 	struct atio_descr *a_descr;
300 	struct initiator_state *istate;
301 	struct scsi_sense_data_fixed *sense;
302 
303 	a_descr = (struct atio_descr *)atio->ccb_h.targ_descr;
304 	inq = (struct scsi_inquiry *)a_descr->cdb;
305 
306 	if (debug)
307 		cdb_debug(a_descr->cdb, "INQUIRY from %u: ", atio->init_id);
308 	/*
309 	 * Validate the command.  We don't support any VPD pages, so
310 	 * complain if EVPD or CMDDT is set.
311 	 */
312 	istate = tcmd_get_istate(ctio->init_id);
313 	sense = (struct scsi_sense_data_fixed *)&istate->sense_data;
314 	if ((inq->byte2 & SI_EVPD) != 0) {
315 		tcmd_illegal_req(atio, ctio);
316 		sense->sense_key_spec[0] = SSD_SCS_VALID | SSD_FIELDPTR_CMD |
317 			SSD_BITPTR_VALID | /*bit value*/1;
318 		sense->sense_key_spec[1] = 0;
319 		sense->sense_key_spec[2] =
320 			offsetof(struct scsi_inquiry, byte2);
321 	} else if (inq->page_code != 0) {
322 		tcmd_illegal_req(atio, ctio);
323 		sense->sense_key_spec[0] = SSD_SCS_VALID | SSD_FIELDPTR_CMD;
324 		sense->sense_key_spec[1] = 0;
325 		sense->sense_key_spec[2] =
326 			offsetof(struct scsi_inquiry, page_code);
327 	} else {
328 		bcopy(&inq_data, ctio->data_ptr, sizeof(inq_data));
329 		ctio->dxfer_len = inq_data.additional_length + 4;
330 		ctio->dxfer_len = min(ctio->dxfer_len,
331 				      scsi_2btoul(inq->length));
332 		ctio->ccb_h.flags |= CAM_DIR_IN | CAM_SEND_STATUS;
333 		ctio->scsi_status = SCSI_STATUS_OK;
334 	}
335 	return (0);
336 }
337 
338 /* Initialize the inquiry response structure with the requested flags */
339 static int
340 init_inquiry(u_int16_t req_flags, u_int16_t sim_flags)
341 {
342 	struct scsi_inquiry_data *inq;
343 
344 	inq = &inq_data;
345 	bzero(inq, sizeof(*inq));
346 	inq->device = T_DIRECT | (SID_QUAL_LU_CONNECTED << 5);
347 #ifdef SCSI_REV_SPC
348 	inq->version = SCSI_REV_SPC; /* was 2 */
349 #else
350 	inq->version = SCSI_REV_3; /* was 2 */
351 #endif
352 
353 	/*
354 	 * XXX cpi.hba_inquiry doesn't support Addr16 so we give the
355 	 * user what they want if they ask for it.
356 	 */
357 	if ((req_flags & SID_Addr16) != 0) {
358 		sim_flags |= SID_Addr16;
359 		warnx("Not sure SIM supports Addr16 but enabling it anyway");
360 	}
361 
362 	/* Advertise only what the SIM can actually support */
363 	req_flags &= sim_flags;
364 	scsi_ulto2b(req_flags, &inq->spc2_flags);
365 
366 	inq->response_format = 2; /* SCSI2 Inquiry Format */
367 	inq->additional_length = SHORT_INQUIRY_LENGTH -
368 		offsetof(struct scsi_inquiry_data, additional_length);
369 	bcopy("FreeBSD ", inq->vendor, SID_VENDOR_SIZE);
370 	bcopy("Emulated Disk   ", inq->product, SID_PRODUCT_SIZE);
371 	bcopy("0.1 ", inq->revision, SID_REVISION_SIZE);
372 	return (0);
373 }
374 
375 static int
376 tcmd_req_sense(struct ccb_accept_tio *atio, struct ccb_scsiio *ctio)
377 {
378 	struct scsi_request_sense *rsense;
379 	struct scsi_sense_data_fixed *sense;
380 	struct initiator_state *istate;
381 	size_t dlen;
382 	struct atio_descr *a_descr;
383 
384 	a_descr = (struct atio_descr *)atio->ccb_h.targ_descr;
385 	rsense = (struct scsi_request_sense *)a_descr->cdb;
386 
387 	istate = tcmd_get_istate(ctio->init_id);
388 	sense = (struct scsi_sense_data_fixed *)&istate->sense_data;
389 
390 	if (debug) {
391 		cdb_debug(a_descr->cdb, "REQ SENSE from %u: ", atio->init_id);
392 		warnx("Sending sense: %#x %#x %#x", sense->flags,
393 		      sense->add_sense_code, sense->add_sense_code_qual);
394 	}
395 
396 	if (istate->orig_ca == 0) {
397 		tcmd_sense(ctio->init_id, NULL, SSD_KEY_NO_SENSE, 0, 0);
398 		warnx("REQUEST SENSE from %u but no pending CA!",
399 		      ctio->init_id);
400 	}
401 
402 	bcopy(sense, ctio->data_ptr, sizeof(struct scsi_sense_data));
403 	dlen = offsetof(struct scsi_sense_data_fixed, extra_len) +
404 			sense->extra_len + 1;
405 	ctio->dxfer_len = min(dlen, SCSI_CDB6_LEN(rsense->length));
406 	ctio->ccb_h.flags |= CAM_DIR_IN | CAM_SEND_STATUS;
407 	ctio->scsi_status = SCSI_STATUS_OK;
408 	return (0);
409 }
410 
411 static int
412 tcmd_rd_cap(struct ccb_accept_tio *atio, struct ccb_scsiio *ctio)
413 {
414 	struct scsi_read_capacity_data *srp;
415 	struct atio_descr *a_descr;
416 	uint32_t vsize;
417 
418 	a_descr = (struct atio_descr *)atio->ccb_h.targ_descr;
419 	srp = (struct scsi_read_capacity_data *)ctio->data_ptr;
420 
421 	if (volume_size > 0xffffffff)
422 		vsize = 0xffffffff;
423 	else
424 		vsize = (uint32_t)(volume_size - 1);
425 
426 	if (debug) {
427 		cdb_debug(a_descr->cdb, "READ CAP from %u (%u, %u): ",
428 			  atio->init_id, vsize, sector_size);
429 	}
430 
431 	bzero(srp, sizeof(*srp));
432 	scsi_ulto4b(vsize, srp->addr);
433 	scsi_ulto4b(sector_size, srp->length);
434 
435 	ctio->dxfer_len = sizeof(*srp);
436 	ctio->ccb_h.flags |= CAM_DIR_IN | CAM_SEND_STATUS;
437 	ctio->scsi_status = SCSI_STATUS_OK;
438 	return (0);
439 }
440 
441 #ifdef READ_16
442 static int
443 tcmd_rd_cap16(struct ccb_accept_tio *atio, struct ccb_scsiio *ctio)
444 {
445 	struct scsi_read_capacity_16 *scsi_cmd;
446 	struct scsi_read_capacity_data_long *srp;
447 	struct atio_descr *a_descr;
448 
449 	a_descr = (struct atio_descr *)atio->ccb_h.targ_descr;
450 	scsi_cmd = (struct scsi_read_capacity_16 *)a_descr->cdb;
451 	srp = (struct scsi_read_capacity_data_long *)ctio->data_ptr;
452 
453 	if (scsi_cmd->service_action != SRC16_SERVICE_ACTION) {
454 		tcmd_illegal_req(atio, ctio);
455 		return (0);
456 	}
457 
458 	if (debug) {
459 		cdb_debug(a_descr->cdb, "READ CAP16 from %u (%u, %u): ",
460 			  atio->init_id, volume_size - 1, sector_size);
461 	}
462 
463 	bzero(srp, sizeof(*srp));
464 	scsi_u64to8b(volume_size - 1, srp->addr);
465 	scsi_ulto4b(sector_size, srp->length);
466 
467 	ctio->dxfer_len = sizeof(*srp);
468 	ctio->ccb_h.flags |= CAM_DIR_IN | CAM_SEND_STATUS;
469 	ctio->scsi_status = SCSI_STATUS_OK;
470 	return (0);
471 }
472 #endif
473 
474 static int
475 tcmd_rdwr(struct ccb_accept_tio *atio, struct ccb_scsiio *ctio)
476 {
477 	struct atio_descr *a_descr;
478 	struct ctio_descr *c_descr;
479 	int ret;
480 
481 	a_descr = (struct atio_descr *)atio->ccb_h.targ_descr;
482 	c_descr = (struct ctio_descr *)ctio->ccb_h.targ_descr;
483 
484 	/* Command needs to be decoded */
485 	if ((a_descr->flags & CAM_DIR_MASK) == CAM_DIR_BOTH) {
486 		if (debug)
487 			warnx("Calling rdwr_decode");
488 		ret = tcmd_rdwr_decode(atio, ctio);
489 		if (ret == 0) {
490 			send_ccb((union ccb *)ctio, /*priority*/1);
491 			return (0);
492 		}
493 	}
494 	ctio->ccb_h.flags |= a_descr->flags;
495 
496 	/* Call appropriate work function */
497 	if ((a_descr->flags & CAM_DIR_IN) != 0) {
498 		ret = start_io(atio, ctio, CAM_DIR_IN);
499 		if (debug)
500 			warnx("Starting %p DIR_IN @" OFF_FMT ":%u",
501 			    a_descr, c_descr->offset, a_descr->targ_req);
502 	} else {
503 		ret = start_io(atio, ctio, CAM_DIR_OUT);
504 		if (debug)
505 			warnx("Starting %p DIR_OUT @" OFF_FMT ":%u",
506 			    a_descr, c_descr->offset, a_descr->init_req);
507 	}
508 
509 	return (ret);
510 }
511 
512 static int
513 tcmd_rdwr_decode(struct ccb_accept_tio *atio, struct ccb_scsiio *ctio)
514 {
515 	uint64_t blkno;
516 	uint32_t count;
517 	struct atio_descr *a_descr;
518 	u_int8_t *cdb;
519 
520 	a_descr = (struct atio_descr *)atio->ccb_h.targ_descr;
521 	cdb = a_descr->cdb;
522 	if (debug)
523 		cdb_debug(cdb, "R/W from %u: ", atio->init_id);
524 
525 	switch (cdb[0]) {
526 	case READ_6:
527 	case WRITE_6:
528 	{
529 		struct scsi_rw_6 *rw_6 = (struct scsi_rw_6 *)cdb;
530 		blkno = scsi_3btoul(rw_6->addr);
531 		count = rw_6->length;
532 		break;
533 	}
534 	case READ_10:
535 	case WRITE_10:
536 	{
537 		struct scsi_rw_10 *rw_10 = (struct scsi_rw_10 *)cdb;
538 		blkno = scsi_4btoul(rw_10->addr);
539 		count = scsi_2btoul(rw_10->length);
540 		break;
541 	}
542 #ifdef READ_16
543 	case READ_16:
544 	case WRITE_16:
545 	{
546 		struct scsi_rw_16 *rw_16 = (struct scsi_rw_16 *)cdb;
547 		blkno = scsi_8btou64(rw_16->addr);
548 		count = scsi_4btoul(rw_16->length);
549 		break;
550 	}
551 #endif
552 	default:
553 		tcmd_illegal_req(atio, ctio);
554 		return (0);
555 	}
556 	if (blkno + count > volume_size) {
557 		warnx("Attempt to access past end of volume");
558 		tcmd_sense(ctio->init_id, ctio,
559 			   SSD_KEY_ILLEGAL_REQUEST, 0x21, 0);
560 		return (0);
561 	}
562 
563 	/* Get an (overall) data length and set direction */
564 	a_descr->base_off = ((off_t)blkno) * sector_size;
565 	a_descr->total_len = count * sector_size;
566 	if (a_descr->total_len == 0) {
567 		if (debug)
568 			warnx("r/w 0 blocks @ blkno " OFF_FMT, blkno);
569 		tcmd_null_ok(atio, ctio);
570 		return (0);
571 	} else if (cdb[0] == WRITE_6 || cdb[0] == WRITE_10) {
572 		a_descr->flags |= CAM_DIR_OUT;
573 		if (debug)
574 			warnx("write %u blocks @ blkno " OFF_FMT, count, blkno);
575 	} else {
576 		a_descr->flags |= CAM_DIR_IN;
577 		if (debug)
578 			warnx("read %u blocks @ blkno " OFF_FMT,  count, blkno);
579 	}
580 	return (1);
581 }
582 
583 static int
584 start_io(struct ccb_accept_tio *atio, struct ccb_scsiio *ctio, int dir)
585 {
586 	struct atio_descr *a_descr;
587 	struct ctio_descr *c_descr;
588 	int ret;
589 
590 	/* Set up common structures */
591 	a_descr = (struct atio_descr *)atio->ccb_h.targ_descr;
592 	c_descr = (struct ctio_descr *)ctio->ccb_h.targ_descr;
593 
594 	if (dir == CAM_DIR_IN) {
595 		c_descr->offset = a_descr->base_off + a_descr->targ_req;
596 		ctio->dxfer_len = a_descr->total_len - a_descr->targ_req;
597 	} else {
598 		c_descr->offset = a_descr->base_off + a_descr->init_req;
599 		ctio->dxfer_len = a_descr->total_len - a_descr->init_req;
600 	}
601 	ctio->dxfer_len = min(ctio->dxfer_len, buf_size);
602 	assert(ctio->dxfer_len >= 0);
603 
604 	c_descr->aiocb.aio_offset = c_descr->offset;
605 	c_descr->aiocb.aio_nbytes = ctio->dxfer_len;
606 
607 	/* If DIR_IN, start read from target, otherwise begin CTIO xfer. */
608 	ret = 1;
609 	if (dir == CAM_DIR_IN) {
610 		if (notaio) {
611 			if (debug)
612 				warnx("read sync %lu @ block " OFF_FMT,
613 				    (unsigned long)
614 				    (ctio->dxfer_len / sector_size),
615 				    c_descr->offset / sector_size);
616 			if (lseek(c_descr->aiocb.aio_fildes,
617 			    c_descr->aiocb.aio_offset, SEEK_SET) < 0) {
618 				perror("lseek");
619 				err(1, "lseek");
620 			}
621 			if (read(c_descr->aiocb.aio_fildes,
622 			    (void *)c_descr->aiocb.aio_buf,
623 			    ctio->dxfer_len) != ctio->dxfer_len) {
624 				err(1, "read");
625 			}
626 		} else {
627 			if (debug)
628 				warnx("read async %lu @ block " OFF_FMT,
629 				    (unsigned long)
630 				    (ctio->dxfer_len / sector_size),
631 				    c_descr->offset / sector_size);
632 			if (aio_read(&c_descr->aiocb) < 0) {
633 				err(1, "aio_read"); /* XXX */
634 			}
635 		}
636 		a_descr->targ_req += ctio->dxfer_len;
637 		/* if we're done, we can mark the CCB as to send status */
638 		if (a_descr->targ_req == a_descr->total_len) {
639 			ctio->ccb_h.flags |= CAM_SEND_STATUS;
640 			ctio->scsi_status = SCSI_STATUS_OK;
641 			ret = 0;
642 		}
643 		if (notaio)
644 			tcmd_rdwr_done(atio, ctio, AIO_DONE);
645 	} else {
646 		if (a_descr->targ_ack == a_descr->total_len)
647 			tcmd_null_ok(atio, ctio);
648 		a_descr->init_req += ctio->dxfer_len;
649 		if (a_descr->init_req == a_descr->total_len &&
650 		    ctio->dxfer_len > 0) {
651 			/*
652 			 * If data phase done, remove atio from workq.
653 			 * The completion handler will call work_atio to
654 			 * send the final status.
655 			 */
656 			ret = 0;
657 		}
658 		send_ccb((union ccb *)ctio, /*priority*/1);
659 	}
660 
661 	return (ret);
662 }
663 
664 static void
665 tcmd_rdwr_done(struct ccb_accept_tio *atio, struct ccb_scsiio *ctio,
666 	       io_ops event)
667 {
668 	struct atio_descr *a_descr;
669 	struct ctio_descr *c_descr;
670 
671 	a_descr = (struct atio_descr *)atio->ccb_h.targ_descr;
672 	c_descr = (struct ctio_descr *)ctio->ccb_h.targ_descr;
673 
674 	switch (event) {
675 	case AIO_DONE:
676 		if (!notaio && aio_return(&c_descr->aiocb) < 0) {
677 			warn("aio_return error");
678 			/* XXX */
679 			tcmd_sense(ctio->init_id, ctio,
680 				   SSD_KEY_MEDIUM_ERROR, 0, 0);
681 			send_ccb((union ccb *)ctio, /*priority*/1);
682 			break;
683 		}
684 		a_descr->targ_ack += ctio->dxfer_len;
685 		if ((a_descr->flags & CAM_DIR_IN) != 0) {
686 			if (debug) {
687 				if (notaio)
688 					warnx("sending CTIO for AIO read");
689 				else
690 					warnx("sending CTIO for sync read");
691 			}
692 			a_descr->init_req += ctio->dxfer_len;
693 			send_ccb((union ccb *)ctio, /*priority*/1);
694 		} else {
695 			/* Use work function to send final status */
696 			if (a_descr->init_req == a_descr->total_len)
697 				work_atio(atio);
698 			if (debug)
699 				warnx("AIO done freeing CTIO");
700 			free_ccb((union ccb *)ctio);
701 		}
702 		break;
703 	case CTIO_DONE:
704 		switch (ctio->ccb_h.status & CAM_STATUS_MASK) {
705 		case CAM_REQ_CMP:
706 			break;
707 		case CAM_REQUEUE_REQ:
708 			warnx("requeueing request");
709 			if ((a_descr->flags & CAM_DIR_MASK) == CAM_DIR_OUT) {
710 				if (aio_write(&c_descr->aiocb) < 0) {
711 					err(1, "aio_write"); /* XXX */
712 				}
713 			} else {
714 				if (aio_read(&c_descr->aiocb) < 0) {
715 					err(1, "aio_read"); /* XXX */
716 				}
717 			}
718 			return;
719 		default:
720 			errx(1, "CTIO failed, status %#x", ctio->ccb_h.status);
721 		}
722 		a_descr->init_ack += ctio->dxfer_len;
723 		if ((a_descr->flags & CAM_DIR_MASK) == CAM_DIR_OUT &&
724 		    ctio->dxfer_len > 0) {
725 			a_descr->targ_req += ctio->dxfer_len;
726 			if (notaio) {
727 				if (debug)
728 					warnx("write sync %lu @ block "
729 					    OFF_FMT, (unsigned long)
730 					    (ctio->dxfer_len / sector_size),
731 					    c_descr->offset / sector_size);
732 				if (lseek(c_descr->aiocb.aio_fildes,
733 				    c_descr->aiocb.aio_offset, SEEK_SET) < 0) {
734 					perror("lseek");
735 					err(1, "lseek");
736 				}
737 				if (write(c_descr->aiocb.aio_fildes,
738 				    (void *) c_descr->aiocb.aio_buf,
739 				    ctio->dxfer_len) != ctio->dxfer_len) {
740 					err(1, "write");
741 				}
742 				tcmd_rdwr_done(atio, ctio, AIO_DONE);
743 			} else {
744 				if (debug)
745 					warnx("write async %lu @ block "
746 					    OFF_FMT, (unsigned long)
747 					    (ctio->dxfer_len / sector_size),
748 					    c_descr->offset / sector_size);
749 				if (aio_write(&c_descr->aiocb) < 0) {
750 					err(1, "aio_write"); /* XXX */
751 				}
752 			}
753 		} else {
754 			if (debug)
755 				warnx("CTIO done freeing CTIO");
756 			free_ccb((union ccb *)ctio);
757 		}
758 		break;
759 	default:
760 		warnx("Unknown completion code %d", event);
761 		abort();
762 		/* NOTREACHED */
763 	}
764 }
765 
766 /* Simple ok message used by TUR, SYNC_CACHE, etc. */
767 static int
768 tcmd_null_ok(struct ccb_accept_tio *atio, struct ccb_scsiio *ctio)
769 {
770 	if (debug) {
771 		struct atio_descr *a_descr;
772 
773 		a_descr = (struct atio_descr *)atio->ccb_h.targ_descr;
774 		cdb_debug(a_descr->cdb, "Sending null ok to %u : ", atio->init_id);
775 	}
776 
777 	ctio->dxfer_len = 0;
778 	ctio->ccb_h.flags &= ~CAM_DIR_MASK;
779 	ctio->ccb_h.flags |= CAM_DIR_NONE | CAM_SEND_STATUS;
780 	ctio->scsi_status = SCSI_STATUS_OK;
781 	return (0);
782 }
783 
784 /* Simple illegal request message used by MODE SENSE, etc. */
785 static int
786 tcmd_illegal_req(struct ccb_accept_tio *atio, struct ccb_scsiio *ctio)
787 {
788 	if (debug) {
789 		struct atio_descr *a_descr;
790 
791 		a_descr = (struct atio_descr *)atio->ccb_h.targ_descr;
792 		cdb_debug(a_descr->cdb, "Sending ill req to %u: ", atio->init_id);
793 	}
794 
795 	tcmd_sense(atio->init_id, ctio, SSD_KEY_ILLEGAL_REQUEST,
796 		   /*asc*/0x24, /*ascq*/0);
797 	return (0);
798 }
799 
800 static void
801 cdb_debug(u_int8_t *cdb, const char *msg, ...)
802 {
803 	char msg_buf[512];
804 	int len;
805 	va_list ap;
806 
807 	va_start(ap, msg);
808 	vsnprintf(msg_buf, sizeof(msg_buf), msg, ap);
809 	va_end(ap);
810 	len = strlen(msg_buf);
811 	scsi_cdb_string(cdb, msg_buf + len, sizeof(msg_buf) - len);
812 	warnx("%s", msg_buf);
813 }
814