xref: /freebsd/share/examples/scsi_target/scsi_target.c (revision f7c32ed617858bcd22f8d1b03199099d50125721)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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  * $FreeBSD$
31  */
32 
33 #include <sys/types.h>
34 #include <ctype.h>
35 #include <errno.h>
36 #include <err.h>
37 #include <fcntl.h>
38 #include <signal.h>
39 #include <stddef.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <sysexits.h>
44 #include <unistd.h>
45 #include <aio.h>
46 #include <assert.h>
47 #include <sys/stat.h>
48 #include <sys/queue.h>
49 #include <sys/event.h>
50 #include <sys/param.h>
51 #include <sys/disk.h>
52 #include <cam/cam_queue.h>
53 #include <cam/scsi/scsi_all.h>
54 #include <cam/scsi/scsi_targetio.h>
55 #include <cam/scsi/scsi_message.h>
56 #include "scsi_target.h"
57 
58 /* Maximum amount to transfer per CTIO */
59 #define MAX_XFER	MAXPHYS
60 /* Maximum number of allocated CTIOs */
61 #define MAX_CTIOS	64
62 /* Maximum sector size for emulated volume */
63 #define MAX_SECTOR	32768
64 
65 /* Global variables */
66 int		debug;
67 int		notaio = 0;
68 off_t		volume_size;
69 u_int		sector_size;
70 size_t		buf_size;
71 
72 /* Local variables */
73 static int    targ_fd;
74 static int    kq_fd;
75 static int    file_fd;
76 static int    num_ctios;
77 static struct ccb_queue		pending_queue;
78 static struct ccb_queue		work_queue;
79 static struct ioc_enable_lun	ioc_enlun = {
80 	CAM_BUS_WILDCARD,
81 	CAM_TARGET_WILDCARD,
82 	CAM_LUN_WILDCARD
83 };
84 
85 /* Local functions */
86 static void		cleanup(void);
87 static int		init_ccbs(void);
88 static void		request_loop(void);
89 static void		handle_read(void);
90 /* static int		work_atio(struct ccb_accept_tio *); */
91 static void		queue_io(struct ccb_scsiio *);
92 static int		run_queue(struct ccb_accept_tio *);
93 static int		work_inot(struct ccb_immediate_notify *);
94 static struct ccb_scsiio *
95 			get_ctio(void);
96 /* static void		free_ccb(union ccb *); */
97 static cam_status	get_sim_flags(u_int16_t *);
98 static void		rel_simq(void);
99 static void		abort_all_pending(void);
100 static void		usage(void);
101 
102 int
103 main(int argc, char *argv[])
104 {
105 	int ch;
106 	char *file_name;
107 	u_int16_t req_flags, sim_flags;
108 	off_t user_size;
109 
110 	/* Initialize */
111 	debug = 0;
112 	req_flags = sim_flags = 0;
113 	user_size = 0;
114 	targ_fd = file_fd = kq_fd = -1;
115 	num_ctios = 0;
116 	sector_size = SECTOR_SIZE;
117 	buf_size = DFLTPHYS;
118 
119 	/* Prepare resource pools */
120 	TAILQ_INIT(&pending_queue);
121 	TAILQ_INIT(&work_queue);
122 
123 	while ((ch = getopt(argc, argv, "AdSTYb:c:s:W:")) != -1) {
124 		switch(ch) {
125 		case 'A':
126 			req_flags |= SID_Addr16;
127 			break;
128 		case 'd':
129 			debug = 1;
130 			break;
131 		case 'S':
132 			req_flags |= SID_Sync;
133 			break;
134 		case 'T':
135 			req_flags |= SID_CmdQue;
136 			break;
137 		case 'b':
138 			buf_size = atoi(optarg);
139 			if (buf_size < 256 || buf_size > MAX_XFER)
140 				errx(1, "Unreasonable buf size: %s", optarg);
141 			break;
142 		case 'c':
143 			sector_size = atoi(optarg);
144 			if (sector_size < 512 || sector_size > MAX_SECTOR)
145 				errx(1, "Unreasonable sector size: %s", optarg);
146 			break;
147 		case 's':
148 		{
149 			int last, shift = 0;
150 
151 			last = strlen(optarg) - 1;
152 			if (last > 0) {
153 				switch (tolower(optarg[last])) {
154 				case 'e':
155 					shift += 10;
156 					/* FALLTHROUGH */
157 				case 'p':
158 					shift += 10;
159 					/* FALLTHROUGH */
160 				case 't':
161 					shift += 10;
162 					/* FALLTHROUGH */
163 				case 'g':
164 					shift += 10;
165 					/* FALLTHROUGH */
166 				case 'm':
167 					shift += 10;
168 					/* FALLTHROUGH */
169 				case 'k':
170 					shift += 10;
171 					optarg[last] = 0;
172 					break;
173 				}
174 			}
175 			user_size = strtoll(optarg, (char **)NULL, /*base*/10);
176 			user_size <<= shift;
177 			if (user_size < 0)
178 				errx(1, "Unreasonable volume size: %s", optarg);
179 			break;
180 		}
181 		case 'W':
182 			req_flags &= ~(SID_WBus16 | SID_WBus32);
183 			switch (atoi(optarg)) {
184 			case 8:
185 				/* Leave req_flags zeroed */
186 				break;
187 			case 16:
188 				req_flags |= SID_WBus16;
189 				break;
190 			case 32:
191 				req_flags |= SID_WBus32;
192 				break;
193 			default:
194 				warnx("Width %s not supported", optarg);
195 				usage();
196 				/* NOTREACHED */
197 			}
198 			break;
199 		case 'Y':
200 			notaio = 1;
201 			break;
202 		default:
203 			usage();
204 			/* NOTREACHED */
205 		}
206 	}
207 	argc -= optind;
208 	argv += optind;
209 
210 	if (argc != 2)
211 		usage();
212 
213 	sscanf(argv[0], "%u:%u:%u", &ioc_enlun.path_id, &ioc_enlun.target_id,
214 	       &ioc_enlun.lun_id);
215 	file_name = argv[1];
216 
217 	if (ioc_enlun.path_id == CAM_BUS_WILDCARD ||
218 	    ioc_enlun.target_id == CAM_TARGET_WILDCARD ||
219 	    ioc_enlun.lun_id == CAM_LUN_WILDCARD) {
220 		warnx("Incomplete target path specified");
221 		usage();
222 		/* NOTREACHED */
223 	}
224 	/* We don't support any vendor-specific commands */
225 	ioc_enlun.grp6_len = 0;
226 	ioc_enlun.grp7_len = 0;
227 
228 	/* Open backing store for IO */
229 	file_fd = open(file_name, O_RDWR);
230 	if (file_fd < 0)
231 		errx(EX_NOINPUT, "open backing store file");
232 
233 	/* Check backing store size or use the size user gave us */
234 	if (user_size == 0) {
235 		struct stat st;
236 
237 		if (fstat(file_fd, &st) < 0)
238 			err(1, "fstat file");
239 #if __FreeBSD_version >= 500000
240 		if ((st.st_mode & S_IFCHR) != 0) {
241 			/* raw device */
242 			off_t mediasize;
243 			if (ioctl(file_fd, DIOCGMEDIASIZE, &mediasize) < 0)
244 				err(1, "DIOCGMEDIASIZE");
245 
246 			/* XXX get sector size by ioctl()?? */
247 			volume_size = mediasize / sector_size;
248 		} else
249 #endif
250 			volume_size = st.st_size / sector_size;
251 	} else {
252 		volume_size = user_size / sector_size;
253 	}
254 	if (debug)
255 		warnx("volume_size: %d bytes x " OFF_FMT " sectors",
256 		    sector_size, volume_size);
257 
258 	if (volume_size <= 0)
259 		errx(1, "volume must be larger than %d", sector_size);
260 
261 	if (notaio == 0) {
262 		struct aiocb aio, *aiop;
263 
264 		/* See if we have we have working AIO support */
265 		memset(&aio, 0, sizeof(aio));
266 		aio.aio_buf = malloc(sector_size);
267 		if (aio.aio_buf == NULL)
268 			err(1, "malloc");
269 		aio.aio_fildes = file_fd;
270 		aio.aio_offset = 0;
271 		aio.aio_nbytes = sector_size;
272 		signal(SIGSYS, SIG_IGN);
273 		if (aio_read(&aio) != 0) {
274 			printf("AIO support is not available- switchin to"
275 			       " single-threaded mode.\n");
276 			notaio = 1;
277 		} else {
278 			if (aio_waitcomplete(&aiop, NULL) != sector_size)
279 				err(1, "aio_waitcomplete");
280 			assert(aiop == &aio);
281 			signal(SIGSYS, SIG_DFL);
282 		}
283 		free((void *)aio.aio_buf);
284 		if (debug && notaio == 0)
285 			warnx("aio support tested ok");
286 	}
287 
288 	targ_fd = open("/dev/targ", O_RDWR);
289 	if (targ_fd < 0)
290     	    err(1, "/dev/targ");
291 	else
292 	    warnx("opened /dev/targ");
293 
294 	/* The first three are handled by kevent() later */
295 	signal(SIGHUP, SIG_IGN);
296 	signal(SIGINT, SIG_IGN);
297 	signal(SIGTERM, SIG_IGN);
298 	signal(SIGPROF, SIG_IGN);
299 	signal(SIGALRM, SIG_IGN);
300 	signal(SIGSTOP, SIG_IGN);
301 	signal(SIGTSTP, SIG_IGN);
302 
303 	/* Register a cleanup handler to run when exiting */
304 	atexit(cleanup);
305 
306 	/* Enable listening on the specified LUN */
307 	if (ioctl(targ_fd, TARGIOCENABLE, &ioc_enlun) != 0)
308 		err(1, "TARGIOCENABLE");
309 
310 	/* Enable debugging if requested */
311 	if (debug) {
312 		if (ioctl(targ_fd, TARGIOCDEBUG, &debug) != 0)
313 			warnx("TARGIOCDEBUG");
314 	}
315 
316 	/* Set up inquiry data according to what SIM supports */
317 	if (get_sim_flags(&sim_flags) != CAM_REQ_CMP)
318 		errx(1, "get_sim_flags");
319 
320 	if (tcmd_init(req_flags, sim_flags) != 0)
321 		errx(1, "Initializing tcmd subsystem failed");
322 
323 	/* Queue ATIOs and INOTs on descriptor */
324 	if (init_ccbs() != 0)
325 		errx(1, "init_ccbs failed");
326 
327 	if (debug)
328 		warnx("main loop beginning");
329 
330 	request_loop();
331 
332 	exit(0);
333 }
334 
335 static void
336 cleanup()
337 {
338 	struct ccb_hdr *ccb_h;
339 
340 	if (debug) {
341 		warnx("cleanup called");
342 		debug = 0;
343 		ioctl(targ_fd, TARGIOCDEBUG, &debug);
344 	}
345 	ioctl(targ_fd, TARGIOCDISABLE, NULL);
346 	close(targ_fd);
347 
348 	while ((ccb_h = TAILQ_FIRST(&pending_queue)) != NULL) {
349 		TAILQ_REMOVE(&pending_queue, ccb_h, periph_links.tqe);
350 		free_ccb((union ccb *)ccb_h);
351 	}
352 	while ((ccb_h = TAILQ_FIRST(&work_queue)) != NULL) {
353 		TAILQ_REMOVE(&work_queue, ccb_h, periph_links.tqe);
354 		free_ccb((union ccb *)ccb_h);
355 	}
356 
357 	if (kq_fd != -1)
358 		close(kq_fd);
359 }
360 
361 /* Allocate ATIOs/INOTs and queue on HBA */
362 static int
363 init_ccbs()
364 {
365 	int i;
366 
367 	for (i = 0; i < MAX_INITIATORS; i++) {
368 		struct ccb_accept_tio *atio;
369 		struct atio_descr *a_descr;
370 		struct ccb_immediate_notify *inot;
371 
372 		atio = (struct ccb_accept_tio *)malloc(sizeof(*atio));
373 		if (atio == NULL) {
374 			warn("malloc ATIO");
375 			return (-1);
376 		}
377 		a_descr = (struct atio_descr *)malloc(sizeof(*a_descr));
378 		if (a_descr == NULL) {
379 			free(atio);
380 			warn("malloc atio_descr");
381 			return (-1);
382 		}
383 		atio->ccb_h.func_code = XPT_ACCEPT_TARGET_IO;
384 		atio->ccb_h.targ_descr = a_descr;
385 		send_ccb((union ccb *)atio, /*priority*/1);
386 
387 		inot = (struct ccb_immediate_notify *)malloc(sizeof(*inot));
388 		if (inot == NULL) {
389 			warn("malloc INOT");
390 			return (-1);
391 		}
392 		inot->ccb_h.func_code = XPT_IMMEDIATE_NOTIFY;
393 		send_ccb((union ccb *)inot, /*priority*/1);
394 	}
395 
396 	return (0);
397 }
398 
399 static void
400 request_loop()
401 {
402 	struct kevent events[MAX_EVENTS];
403 	struct timespec ts, *tptr;
404 	int quit;
405 
406 	/* Register kqueue for event notification */
407 	if ((kq_fd = kqueue()) < 0)
408 		err(1, "init kqueue");
409 
410 	/* Set up some default events */
411 	EV_SET(&events[0], SIGHUP, EVFILT_SIGNAL, EV_ADD|EV_ENABLE, 0, 0, 0);
412 	EV_SET(&events[1], SIGINT, EVFILT_SIGNAL, EV_ADD|EV_ENABLE, 0, 0, 0);
413 	EV_SET(&events[2], SIGTERM, EVFILT_SIGNAL, EV_ADD|EV_ENABLE, 0, 0, 0);
414 	EV_SET(&events[3], targ_fd, EVFILT_READ, EV_ADD|EV_ENABLE, 0, 0, 0);
415 	if (kevent(kq_fd, events, 4, NULL, 0, NULL) < 0)
416 		err(1, "kevent signal registration");
417 
418 	ts.tv_sec = 0;
419 	ts.tv_nsec = 0;
420 	tptr = NULL;
421 	quit = 0;
422 
423 	/* Loop until user signal */
424 	while (quit == 0) {
425 		int retval, i, oo;
426 		struct ccb_hdr *ccb_h;
427 
428 		/* Check for the next signal, read ready, or AIO completion */
429 		retval = kevent(kq_fd, NULL, 0, events, MAX_EVENTS, tptr);
430 		if (retval < 0) {
431 			if (errno == EINTR) {
432 				if (debug)
433 					warnx("EINTR, looping");
434 				continue;
435             		}
436 			else {
437 				err(1, "kevent failed");
438 			}
439 		} else if (retval > MAX_EVENTS) {
440 			errx(1, "kevent returned more events than allocated?");
441 		}
442 
443 		/* Process all received events. */
444 		for (oo = i = 0; i < retval; i++) {
445 			if ((events[i].flags & EV_ERROR) != 0)
446 				errx(1, "kevent registration failed");
447 
448 			switch (events[i].filter) {
449 			case EVFILT_READ:
450 				if (debug)
451 					warnx("read ready");
452 				handle_read();
453 				break;
454 			case EVFILT_AIO:
455 			{
456 				struct ccb_scsiio *ctio;
457 				struct ctio_descr *c_descr;
458 				if (debug)
459 					warnx("aio ready");
460 
461 				ctio = (struct ccb_scsiio *)events[i].udata;
462 				c_descr = (struct ctio_descr *)
463 					  ctio->ccb_h.targ_descr;
464 				c_descr->event = AIO_DONE;
465 				/* Queue on the appropriate ATIO */
466 				queue_io(ctio);
467 				/* Process any queued completions. */
468 				oo += run_queue(c_descr->atio);
469 				break;
470 			}
471 			case EVFILT_SIGNAL:
472 				if (debug)
473 					warnx("signal ready, setting quit");
474 				quit = 1;
475 				break;
476 			default:
477 				warnx("unknown event %d", events[i].filter);
478 				break;
479 			}
480 
481 			if (debug)
482 				warnx("event %d done", events[i].filter);
483 		}
484 
485 		if (oo) {
486 			tptr = &ts;
487 			continue;
488 		}
489 
490 		/* Grab the first CCB and perform one work unit. */
491 		if ((ccb_h = TAILQ_FIRST(&work_queue)) != NULL) {
492 			union ccb *ccb;
493 
494 			ccb = (union ccb *)ccb_h;
495 			switch (ccb_h->func_code) {
496 			case XPT_ACCEPT_TARGET_IO:
497 				/* Start one more transfer. */
498 				retval = work_atio(&ccb->atio);
499 				break;
500 			case XPT_IMMEDIATE_NOTIFY:
501 				retval = work_inot(&ccb->cin1);
502 				break;
503 			default:
504 				warnx("Unhandled ccb type %#x on workq",
505 				      ccb_h->func_code);
506 				abort();
507 				/* NOTREACHED */
508 			}
509 
510 			/* Assume work function handled the exception */
511 			if ((ccb_h->status & CAM_DEV_QFRZN) != 0) {
512 				if (debug) {
513 					warnx("Queue frozen receiving CCB, "
514 					      "releasing");
515 				}
516 				rel_simq();
517 			}
518 
519 			/* No more work needed for this command. */
520 			if (retval == 0) {
521 				TAILQ_REMOVE(&work_queue, ccb_h,
522 					     periph_links.tqe);
523 			}
524 		}
525 
526 		/*
527 		 * Poll for new events (i.e. completions) while we
528 		 * are processing CCBs on the work_queue. Once it's
529 		 * empty, use an infinite wait.
530 		 */
531 		if (!TAILQ_EMPTY(&work_queue))
532 			tptr = &ts;
533 		else
534 			tptr = NULL;
535 	}
536 }
537 
538 /* CCBs are ready from the kernel */
539 static void
540 handle_read()
541 {
542 	union ccb *ccb_array[MAX_INITIATORS], *ccb;
543 	int ccb_count, i, oo;
544 
545 	ccb_count = read(targ_fd, ccb_array, sizeof(ccb_array));
546 	if (ccb_count <= 0) {
547 		warn("read ccb ptrs");
548 		return;
549 	}
550 	ccb_count /= sizeof(union ccb *);
551 	if (ccb_count < 1) {
552 		warnx("truncated read ccb ptr?");
553 		return;
554 	}
555 
556 	for (i = 0; i < ccb_count; i++) {
557 		ccb = ccb_array[i];
558 		TAILQ_REMOVE(&pending_queue, &ccb->ccb_h, periph_links.tqe);
559 
560 		switch (ccb->ccb_h.func_code) {
561 		case XPT_ACCEPT_TARGET_IO:
562 		{
563 			struct ccb_accept_tio *atio;
564 			struct atio_descr *a_descr;
565 
566 			/* Initialize ATIO descr for this transaction */
567 			atio = &ccb->atio;
568 			a_descr = (struct atio_descr *)atio->ccb_h.targ_descr;
569 			bzero(a_descr, sizeof(*a_descr));
570 			TAILQ_INIT(&a_descr->cmplt_io);
571 			a_descr->flags = atio->ccb_h.flags &
572 				(CAM_DIS_DISCONNECT | CAM_TAG_ACTION_VALID);
573 			/* XXX add a_descr->priority */
574 			if ((atio->ccb_h.flags & CAM_CDB_POINTER) == 0)
575 				a_descr->cdb = atio->cdb_io.cdb_bytes;
576 			else
577 				a_descr->cdb = atio->cdb_io.cdb_ptr;
578 
579 			/* ATIOs are processed in FIFO order */
580 			TAILQ_INSERT_TAIL(&work_queue, &ccb->ccb_h,
581 					  periph_links.tqe);
582 			break;
583 		}
584 		case XPT_CONT_TARGET_IO:
585 		{
586 			struct ccb_scsiio *ctio;
587 			struct ctio_descr *c_descr;
588 
589 			ctio = &ccb->ctio;
590 			c_descr = (struct ctio_descr *)ctio->ccb_h.targ_descr;
591 			c_descr->event = CTIO_DONE;
592 			/* Queue on the appropriate ATIO */
593 			queue_io(ctio);
594 			/* Process any queued completions. */
595 			oo += run_queue(c_descr->atio);
596 			break;
597 		}
598 		case XPT_IMMEDIATE_NOTIFY:
599 			/* INOTs are handled with priority */
600 			TAILQ_INSERT_HEAD(&work_queue, &ccb->ccb_h,
601 					  periph_links.tqe);
602 			break;
603 		default:
604 			warnx("Unhandled ccb type %#x in handle_read",
605 			      ccb->ccb_h.func_code);
606 			break;
607 		}
608 	}
609 }
610 
611 /* Process an ATIO CCB from the kernel */
612 int
613 work_atio(struct ccb_accept_tio *atio)
614 {
615 	struct ccb_scsiio *ctio;
616 	struct atio_descr *a_descr;
617 	struct ctio_descr *c_descr;
618 	cam_status status;
619 	int ret;
620 
621 	if (debug)
622 		warnx("Working on ATIO %p", atio);
623 
624 	a_descr = (struct atio_descr *)atio->ccb_h.targ_descr;
625 
626 	/* Get a CTIO and initialize it according to our known parameters */
627 	ctio = get_ctio();
628 	if (ctio == NULL) {
629 		return (1);
630 	}
631 	ret = 0;
632 	ctio->ccb_h.flags = a_descr->flags;
633 	ctio->tag_id = atio->tag_id;
634 	ctio->init_id = atio->init_id;
635 	/* XXX priority needs to be added to a_descr */
636 	c_descr = (struct ctio_descr *)ctio->ccb_h.targ_descr;
637 	c_descr->atio = atio;
638 	if ((a_descr->flags & CAM_DIR_IN) != 0)
639 		c_descr->offset = a_descr->base_off + a_descr->targ_req;
640 	else if ((a_descr->flags & CAM_DIR_MASK) == CAM_DIR_OUT)
641 		c_descr->offset = a_descr->base_off + a_descr->init_req;
642 	else
643 		c_descr->offset = a_descr->base_off;
644 
645 	/*
646 	 * Return a check condition if there was an error while
647 	 * receiving this ATIO.
648 	 */
649 	if (atio->sense_len != 0) {
650 		struct scsi_sense_data_fixed *sense;
651 
652 		if (debug) {
653 			warnx("ATIO with %u bytes sense received",
654 			      atio->sense_len);
655 		}
656 		sense = (struct scsi_sense_data_fixed *)&atio->sense_data;
657 		tcmd_sense(ctio->init_id, ctio, sense->flags,
658 			   sense->add_sense_code, sense->add_sense_code_qual);
659 		send_ccb((union ccb *)ctio, /*priority*/1);
660 		return (0);
661 	}
662 
663 	status = atio->ccb_h.status & CAM_STATUS_MASK;
664 	switch (status) {
665 	case CAM_CDB_RECVD:
666 		ret = tcmd_handle(atio, ctio, ATIO_WORK);
667 		break;
668 	case CAM_REQ_ABORTED:
669 		warn("ATIO %p aborted", a_descr);
670 		/* Requeue on HBA */
671 		TAILQ_REMOVE(&work_queue, &atio->ccb_h, periph_links.tqe);
672 		send_ccb((union ccb *)atio, /*priority*/1);
673 		ret = 1;
674 		break;
675 	default:
676 		warnx("ATIO completed with unhandled status %#x", status);
677 		abort();
678 		/* NOTREACHED */
679 		break;
680 	}
681 
682 	return (ret);
683 }
684 
685 static void
686 queue_io(struct ccb_scsiio *ctio)
687 {
688 	struct ccb_hdr *ccb_h;
689 	struct io_queue *ioq;
690 	struct ctio_descr *c_descr;
691 
692 	c_descr = (struct ctio_descr *)ctio->ccb_h.targ_descr;
693 	if (c_descr->atio == NULL) {
694 		errx(1, "CTIO %p has NULL ATIO", ctio);
695 	}
696 	ioq = &((struct atio_descr *)c_descr->atio->ccb_h.targ_descr)->cmplt_io;
697 
698 	if (TAILQ_EMPTY(ioq)) {
699 		TAILQ_INSERT_HEAD(ioq, &ctio->ccb_h, periph_links.tqe);
700 		return;
701 	}
702 
703 	TAILQ_FOREACH_REVERSE(ccb_h, ioq, io_queue, periph_links.tqe) {
704 		struct ctio_descr *curr_descr =
705 		    (struct ctio_descr *)ccb_h->targ_descr;
706 		if (curr_descr->offset <= c_descr->offset) {
707 			break;
708 		}
709 	}
710 
711 	if (ccb_h) {
712 		TAILQ_INSERT_AFTER(ioq, ccb_h, &ctio->ccb_h, periph_links.tqe);
713 	} else {
714 		TAILQ_INSERT_HEAD(ioq, &ctio->ccb_h, periph_links.tqe);
715 	}
716 }
717 
718 /*
719  * Go through all completed AIO/CTIOs for a given ATIO and advance data
720  * counts, start continuation IO, etc.
721  */
722 static int
723 run_queue(struct ccb_accept_tio *atio)
724 {
725 	struct atio_descr *a_descr;
726 	struct ccb_hdr *ccb_h;
727 	int sent_status, event;
728 
729 	if (atio == NULL)
730 		return (0);
731 
732 	a_descr = (struct atio_descr *)atio->ccb_h.targ_descr;
733 
734 	while ((ccb_h = TAILQ_FIRST(&a_descr->cmplt_io)) != NULL) {
735 		struct ccb_scsiio *ctio;
736 		struct ctio_descr *c_descr;
737 
738 		ctio = (struct ccb_scsiio *)ccb_h;
739 		c_descr = (struct ctio_descr *)ctio->ccb_h.targ_descr;
740 
741 		if (ctio->ccb_h.status == CAM_REQ_ABORTED) {
742 			TAILQ_REMOVE(&a_descr->cmplt_io, ccb_h,
743 				     periph_links.tqe);
744 			free_ccb((union ccb *)ctio);
745 			send_ccb((union ccb *)atio, /*priority*/1);
746 			continue;
747 		}
748 
749 		/* If completed item is in range, call handler */
750 		if ((c_descr->event == AIO_DONE &&
751 		    c_descr->offset == a_descr->base_off + a_descr->targ_ack)
752 		 || (c_descr->event == CTIO_DONE &&
753 		    c_descr->offset == a_descr->base_off + a_descr->init_ack)) {
754 			sent_status = (ccb_h->flags & CAM_SEND_STATUS) != 0;
755 			event = c_descr->event;
756 
757 			TAILQ_REMOVE(&a_descr->cmplt_io, ccb_h,
758 				     periph_links.tqe);
759 			tcmd_handle(atio, ctio, c_descr->event);
760 
761 			/* If entire transfer complete, send back ATIO */
762 			if (sent_status != 0 && event == CTIO_DONE)
763 				send_ccb((union ccb *)atio, /*priority*/1);
764 		} else {
765 			/* Gap in offsets so wait until later callback */
766 			if (/* debug */ 1)
767 				warnx("IO %p:%p out of order %s",  ccb_h,
768 				    a_descr, c_descr->event == AIO_DONE?
769 				    "aio" : "ctio");
770 			return (1);
771 		}
772 	}
773 	return (0);
774 }
775 
776 static int
777 work_inot(struct ccb_immediate_notify *inot)
778 {
779 	cam_status status;
780 
781 	if (debug)
782 		warnx("Working on INOT %p", inot);
783 
784 	status = inot->ccb_h.status;
785 	status &= CAM_STATUS_MASK;
786 
787 	switch (status) {
788 	case CAM_SCSI_BUS_RESET:
789 		tcmd_ua(CAM_TARGET_WILDCARD, UA_BUS_RESET);
790 		abort_all_pending();
791 		break;
792 	case CAM_BDR_SENT:
793 		tcmd_ua(CAM_TARGET_WILDCARD, UA_BDR);
794 		abort_all_pending();
795 		break;
796 	case CAM_MESSAGE_RECV:
797 		switch (inot->arg) {
798 		case MSG_TASK_COMPLETE:
799 		case MSG_INITIATOR_DET_ERR:
800 		case MSG_ABORT_TASK_SET:
801 		case MSG_MESSAGE_REJECT:
802 		case MSG_NOOP:
803 		case MSG_PARITY_ERROR:
804 		case MSG_TARGET_RESET:
805 		case MSG_ABORT_TASK:
806 		case MSG_CLEAR_TASK_SET:
807 		default:
808 			warnx("INOT message %#x", inot->arg);
809 			break;
810 		}
811 		break;
812 	case CAM_REQ_ABORTED:
813 		warnx("INOT %p aborted", inot);
814 		break;
815 	default:
816 		warnx("Unhandled INOT status %#x", status);
817 		break;
818 	}
819 
820 	/* Requeue on SIM */
821 	TAILQ_REMOVE(&work_queue, &inot->ccb_h, periph_links.tqe);
822 	send_ccb((union ccb *)inot, /*priority*/1);
823 
824 	return (1);
825 }
826 
827 void
828 send_ccb(union ccb *ccb, int priority)
829 {
830 	if (debug)
831 		warnx("sending ccb (%#x)", ccb->ccb_h.func_code);
832 	ccb->ccb_h.pinfo.priority = priority;
833 	if (XPT_FC_IS_QUEUED(ccb)) {
834 		TAILQ_INSERT_TAIL(&pending_queue, &ccb->ccb_h,
835 				  periph_links.tqe);
836 	}
837 	if (write(targ_fd, &ccb, sizeof(ccb)) != sizeof(ccb)) {
838 		warn("write ccb");
839 		ccb->ccb_h.status = CAM_PROVIDE_FAIL;
840 	}
841 }
842 
843 /* Return a CTIO/descr/buf combo from the freelist or malloc one */
844 static struct ccb_scsiio *
845 get_ctio()
846 {
847 	struct ccb_scsiio *ctio;
848 	struct ctio_descr *c_descr;
849 	struct sigevent *se;
850 
851 	if (num_ctios == MAX_CTIOS) {
852 		warnx("at CTIO max");
853 		return (NULL);
854 	}
855 
856 	ctio = (struct ccb_scsiio *)malloc(sizeof(*ctio));
857 	if (ctio == NULL) {
858 		warn("malloc CTIO");
859 		return (NULL);
860 	}
861 	c_descr = (struct ctio_descr *)malloc(sizeof(*c_descr));
862 	if (c_descr == NULL) {
863 		free(ctio);
864 		warn("malloc ctio_descr");
865 		return (NULL);
866 	}
867 	c_descr->buf = malloc(buf_size);
868 	if (c_descr->buf == NULL) {
869 		free(c_descr);
870 		free(ctio);
871 		warn("malloc backing store");
872 		return (NULL);
873 	}
874 	num_ctios++;
875 
876 	/* Initialize CTIO, CTIO descr, and AIO */
877 	ctio->ccb_h.func_code = XPT_CONT_TARGET_IO;
878 	ctio->ccb_h.retry_count = 2;
879 	ctio->ccb_h.timeout = CAM_TIME_INFINITY;
880 	ctio->data_ptr = c_descr->buf;
881 	ctio->ccb_h.targ_descr = c_descr;
882 	c_descr->aiocb.aio_buf = c_descr->buf;
883 	c_descr->aiocb.aio_fildes = file_fd;
884 	se = &c_descr->aiocb.aio_sigevent;
885 	se->sigev_notify = SIGEV_KEVENT;
886 	se->sigev_notify_kqueue = kq_fd;
887 	se->sigev_value.sival_ptr = ctio;
888 
889 	return (ctio);
890 }
891 
892 void
893 free_ccb(union ccb *ccb)
894 {
895 	switch (ccb->ccb_h.func_code) {
896 	case XPT_CONT_TARGET_IO:
897 	{
898 		struct ctio_descr *c_descr;
899 
900 		c_descr = (struct ctio_descr *)ccb->ccb_h.targ_descr;
901 		free(c_descr->buf);
902 		num_ctios--;
903 		/* FALLTHROUGH */
904 	}
905 	case XPT_ACCEPT_TARGET_IO:
906 		free(ccb->ccb_h.targ_descr);
907 		/* FALLTHROUGH */
908 	case XPT_IMMEDIATE_NOTIFY:
909 	default:
910 		free(ccb);
911 		break;
912 	}
913 }
914 
915 static cam_status
916 get_sim_flags(u_int16_t *flags)
917 {
918 	struct ccb_pathinq cpi;
919 	cam_status status;
920 
921 	/* Find SIM capabilities */
922 	bzero(&cpi, sizeof(cpi));
923 	cpi.ccb_h.func_code = XPT_PATH_INQ;
924 	send_ccb((union ccb *)&cpi, /*priority*/1);
925 	status = cpi.ccb_h.status & CAM_STATUS_MASK;
926 	if (status != CAM_REQ_CMP) {
927 		fprintf(stderr, "CPI failed, status %#x\n", status);
928 		return (status);
929 	}
930 
931 	/* Can only enable on controllers that support target mode */
932 	if ((cpi.target_sprt & PIT_PROCESSOR) == 0) {
933 		fprintf(stderr, "HBA does not support target mode\n");
934 		status = CAM_PATH_INVALID;
935 		return (status);
936 	}
937 
938 	*flags = cpi.hba_inquiry;
939 	return (status);
940 }
941 
942 static void
943 rel_simq()
944 {
945 	struct ccb_relsim crs;
946 
947 	bzero(&crs, sizeof(crs));
948 	crs.ccb_h.func_code = XPT_REL_SIMQ;
949 	crs.release_flags = RELSIM_RELEASE_AFTER_QEMPTY;
950 	crs.openings = 0;
951 	crs.release_timeout = 0;
952 	crs.qfrozen_cnt = 0;
953 	send_ccb((union ccb *)&crs, /*priority*/0);
954 }
955 
956 /* Cancel all pending CCBs. */
957 static void
958 abort_all_pending()
959 {
960 	struct ccb_abort	 cab;
961 	struct ccb_hdr		*ccb_h;
962 
963 	if (debug)
964 		  warnx("abort_all_pending");
965 
966 	bzero(&cab, sizeof(cab));
967 	cab.ccb_h.func_code = XPT_ABORT;
968 	TAILQ_FOREACH(ccb_h, &pending_queue, periph_links.tqe) {
969 		if (debug)
970 			  warnx("Aborting pending CCB %p\n", ccb_h);
971 		cab.abort_ccb = (union ccb *)ccb_h;
972 		send_ccb((union ccb *)&cab, /*priority*/1);
973 		if (cab.ccb_h.status != CAM_REQ_CMP) {
974 			warnx("Unable to abort CCB, status %#x\n",
975 			       cab.ccb_h.status);
976 		}
977 	}
978 }
979 
980 static void
981 usage()
982 {
983 	fprintf(stderr,
984 		"Usage: scsi_target [-AdSTY] [-b bufsize] [-c sectorsize]\n"
985 		"\t\t[-r numbufs] [-s volsize] [-W 8,16,32]\n"
986 		"\t\tbus:target:lun filename\n");
987 	exit(1);
988 }
989