xref: /freebsd/sys/dev/iscsi/iscsi.c (revision c9dbb1cc52b063bbd9ab078a7afc89a8696da659)
1 /*-
2  * Copyright (c) 2012 The FreeBSD Foundation
3  * All rights reserved.
4  *
5  * This software was developed by Edward Tomasz Napierala under sponsorship
6  * from the FreeBSD Foundation.
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  * 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  *
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
21  * FOR 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 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/param.h>
35 #include <sys/condvar.h>
36 #include <sys/conf.h>
37 #include <sys/endian.h>
38 #include <sys/eventhandler.h>
39 #include <sys/file.h>
40 #include <sys/kernel.h>
41 #include <sys/kthread.h>
42 #include <sys/lock.h>
43 #include <sys/malloc.h>
44 #include <sys/mutex.h>
45 #include <sys/module.h>
46 #include <sys/sysctl.h>
47 #include <sys/systm.h>
48 #include <sys/sx.h>
49 #include <vm/uma.h>
50 
51 #include <cam/cam.h>
52 #include <cam/cam_ccb.h>
53 #include <cam/cam_xpt.h>
54 #include <cam/cam_debug.h>
55 #include <cam/cam_sim.h>
56 #include <cam/cam_xpt_sim.h>
57 #include <cam/cam_xpt_periph.h>
58 #include <cam/cam_periph.h>
59 #include <cam/scsi/scsi_all.h>
60 #include <cam/scsi/scsi_message.h>
61 
62 #include <dev/iscsi/icl.h>
63 #include <dev/iscsi/icl_wrappers.h>
64 #include <dev/iscsi/iscsi_ioctl.h>
65 #include <dev/iscsi/iscsi_proto.h>
66 #include <dev/iscsi/iscsi.h>
67 
68 #ifdef ICL_KERNEL_PROXY
69 #include <sys/socketvar.h>
70 #endif
71 
72 #ifdef ICL_KERNEL_PROXY
73 FEATURE(iscsi_kernel_proxy, "iSCSI initiator built with ICL_KERNEL_PROXY");
74 #endif
75 
76 /*
77  * XXX: This is global so the iscsi_unload() can access it.
78  * 	Think about how to do this properly.
79  */
80 static struct iscsi_softc	*sc;
81 
82 SYSCTL_NODE(_kern, OID_AUTO, iscsi, CTLFLAG_RD, 0, "iSCSI initiator");
83 static int debug = 1;
84 SYSCTL_INT(_kern_iscsi, OID_AUTO, debug, CTLFLAG_RWTUN,
85     &debug, 0, "Enable debug messages");
86 static int ping_timeout = 5;
87 SYSCTL_INT(_kern_iscsi, OID_AUTO, ping_timeout, CTLFLAG_RWTUN, &ping_timeout,
88     0, "Timeout for ping (NOP-Out) requests, in seconds");
89 static int iscsid_timeout = 60;
90 SYSCTL_INT(_kern_iscsi, OID_AUTO, iscsid_timeout, CTLFLAG_RWTUN, &iscsid_timeout,
91     0, "Time to wait for iscsid(8) to handle reconnection, in seconds");
92 static int login_timeout = 60;
93 SYSCTL_INT(_kern_iscsi, OID_AUTO, login_timeout, CTLFLAG_RWTUN, &login_timeout,
94     0, "Time to wait for iscsid(8) to finish Login Phase, in seconds");
95 static int maxtags = 255;
96 SYSCTL_INT(_kern_iscsi, OID_AUTO, maxtags, CTLFLAG_RWTUN, &maxtags,
97     0, "Max number of IO requests queued");
98 static int fail_on_disconnection = 0;
99 SYSCTL_INT(_kern_iscsi, OID_AUTO, fail_on_disconnection, CTLFLAG_RWTUN,
100     &fail_on_disconnection, 0, "Destroy CAM SIM on connection failure");
101 
102 static MALLOC_DEFINE(M_ISCSI, "iSCSI", "iSCSI initiator");
103 static uma_zone_t iscsi_outstanding_zone;
104 
105 #define	CONN_SESSION(X)	((struct iscsi_session *)X->ic_prv0)
106 #define	PDU_SESSION(X)	(CONN_SESSION(X->ip_conn))
107 
108 #define	ISCSI_DEBUG(X, ...)						\
109 	do {								\
110 		if (debug > 1) 						\
111 			printf("%s: " X "\n", __func__, ## __VA_ARGS__);\
112 	} while (0)
113 
114 #define	ISCSI_WARN(X, ...)						\
115 	do {								\
116 		if (debug > 0) {					\
117 			printf("WARNING: %s: " X "\n",			\
118 			    __func__, ## __VA_ARGS__);			\
119 		}							\
120 	} while (0)
121 
122 #define	ISCSI_SESSION_DEBUG(S, X, ...)					\
123 	do {								\
124 		if (debug > 1) {					\
125 			printf("%s: %s (%s): " X "\n",			\
126 			    __func__, S->is_conf.isc_target_addr,	\
127 			    S->is_conf.isc_target, ## __VA_ARGS__);	\
128 		}							\
129 	} while (0)
130 
131 #define	ISCSI_SESSION_WARN(S, X, ...)					\
132 	do {								\
133 		if (debug > 0) {					\
134 			printf("WARNING: %s (%s): " X "\n",		\
135 			    S->is_conf.isc_target_addr,			\
136 			    S->is_conf.isc_target, ## __VA_ARGS__);	\
137 		}							\
138 	} while (0)
139 
140 #define ISCSI_SESSION_LOCK(X)		mtx_lock(&X->is_lock)
141 #define ISCSI_SESSION_UNLOCK(X)		mtx_unlock(&X->is_lock)
142 #define ISCSI_SESSION_LOCK_ASSERT(X)	mtx_assert(&X->is_lock, MA_OWNED)
143 #define ISCSI_SESSION_LOCK_ASSERT_NOT(X) mtx_assert(&X->is_lock, MA_NOTOWNED)
144 
145 static int	iscsi_ioctl(struct cdev *dev, u_long cmd, caddr_t arg,
146 		    int mode, struct thread *td);
147 
148 static struct cdevsw iscsi_cdevsw = {
149      .d_version = D_VERSION,
150      .d_ioctl   = iscsi_ioctl,
151      .d_name    = "iscsi",
152 };
153 
154 static void	iscsi_pdu_queue_locked(struct icl_pdu *request);
155 static void	iscsi_pdu_queue(struct icl_pdu *request);
156 static void	iscsi_pdu_update_statsn(const struct icl_pdu *response);
157 static void	iscsi_pdu_handle_nop_in(struct icl_pdu *response);
158 static void	iscsi_pdu_handle_scsi_response(struct icl_pdu *response);
159 static void	iscsi_pdu_handle_task_response(struct icl_pdu *response);
160 static void	iscsi_pdu_handle_data_in(struct icl_pdu *response);
161 static void	iscsi_pdu_handle_logout_response(struct icl_pdu *response);
162 static void	iscsi_pdu_handle_r2t(struct icl_pdu *response);
163 static void	iscsi_pdu_handle_async_message(struct icl_pdu *response);
164 static void	iscsi_pdu_handle_reject(struct icl_pdu *response);
165 static void	iscsi_session_reconnect(struct iscsi_session *is);
166 static void	iscsi_session_terminate(struct iscsi_session *is);
167 static void	iscsi_action(struct cam_sim *sim, union ccb *ccb);
168 static void	iscsi_poll(struct cam_sim *sim);
169 static struct iscsi_outstanding	*iscsi_outstanding_find(struct iscsi_session *is,
170 		    uint32_t initiator_task_tag);
171 static struct iscsi_outstanding	*iscsi_outstanding_add(struct iscsi_session *is,
172 		    union ccb *ccb, uint32_t *initiator_task_tagp);
173 static void	iscsi_outstanding_remove(struct iscsi_session *is,
174 		    struct iscsi_outstanding *io);
175 
176 static bool
177 iscsi_pdu_prepare(struct icl_pdu *request)
178 {
179 	struct iscsi_session *is;
180 	struct iscsi_bhs_scsi_command *bhssc;
181 
182 	is = PDU_SESSION(request);
183 
184 	ISCSI_SESSION_LOCK_ASSERT(is);
185 
186 	/*
187 	 * We're only using fields common for all the request
188 	 * (initiator -> target) PDUs.
189 	 */
190 	bhssc = (struct iscsi_bhs_scsi_command *)request->ip_bhs;
191 
192 	/*
193 	 * Data-Out PDU does not contain CmdSN.
194 	 */
195 	if (bhssc->bhssc_opcode != ISCSI_BHS_OPCODE_SCSI_DATA_OUT) {
196 		if (ISCSI_SNGT(is->is_cmdsn, is->is_maxcmdsn) &&
197 		    (bhssc->bhssc_opcode & ISCSI_BHS_OPCODE_IMMEDIATE) == 0) {
198 			/*
199 			 * Current MaxCmdSN prevents us from sending any more
200 			 * SCSI Command PDUs to the target; postpone the PDU.
201 			 * It will get resent by either iscsi_pdu_queue(),
202 			 * or by maintenance thread.
203 			 */
204 #if 0
205 			ISCSI_SESSION_DEBUG(is, "postponing send, CmdSN %u, "
206 			    "ExpCmdSN %u, MaxCmdSN %u, opcode 0x%x",
207 			    is->is_cmdsn, is->is_expcmdsn, is->is_maxcmdsn,
208 			    bhssc->bhssc_opcode);
209 #endif
210 			return (true);
211 		}
212 		bhssc->bhssc_cmdsn = htonl(is->is_cmdsn);
213 		if ((bhssc->bhssc_opcode & ISCSI_BHS_OPCODE_IMMEDIATE) == 0)
214 			is->is_cmdsn++;
215 	}
216 	bhssc->bhssc_expstatsn = htonl(is->is_statsn + 1);
217 
218 	return (false);
219 }
220 
221 static void
222 iscsi_session_send_postponed(struct iscsi_session *is)
223 {
224 	struct icl_pdu *request;
225 	bool postpone;
226 
227 	ISCSI_SESSION_LOCK_ASSERT(is);
228 
229 	while (!STAILQ_EMPTY(&is->is_postponed)) {
230 		request = STAILQ_FIRST(&is->is_postponed);
231 		postpone = iscsi_pdu_prepare(request);
232 		if (postpone)
233 			break;
234 		STAILQ_REMOVE_HEAD(&is->is_postponed, ip_next);
235 		icl_pdu_queue(request);
236 	}
237 }
238 
239 static void
240 iscsi_pdu_queue_locked(struct icl_pdu *request)
241 {
242 	struct iscsi_session *is;
243 	bool postpone;
244 
245 	is = PDU_SESSION(request);
246 	ISCSI_SESSION_LOCK_ASSERT(is);
247 	iscsi_session_send_postponed(is);
248 	postpone = iscsi_pdu_prepare(request);
249 	if (postpone) {
250 		STAILQ_INSERT_TAIL(&is->is_postponed, request, ip_next);
251 		return;
252 	}
253 	icl_pdu_queue(request);
254 }
255 
256 static void
257 iscsi_pdu_queue(struct icl_pdu *request)
258 {
259 	struct iscsi_session *is;
260 
261 	is = PDU_SESSION(request);
262 	ISCSI_SESSION_LOCK(is);
263 	iscsi_pdu_queue_locked(request);
264 	ISCSI_SESSION_UNLOCK(is);
265 }
266 
267 static void
268 iscsi_session_logout(struct iscsi_session *is)
269 {
270 	struct icl_pdu *request;
271 	struct iscsi_bhs_logout_request *bhslr;
272 
273 	request = icl_pdu_new(is->is_conn, M_NOWAIT);
274 	if (request == NULL)
275 		return;
276 
277 	bhslr = (struct iscsi_bhs_logout_request *)request->ip_bhs;
278 	bhslr->bhslr_opcode = ISCSI_BHS_OPCODE_LOGOUT_REQUEST;
279 	bhslr->bhslr_reason = BHSLR_REASON_CLOSE_SESSION;
280 	iscsi_pdu_queue_locked(request);
281 }
282 
283 static void
284 iscsi_session_terminate_task(struct iscsi_session *is,
285     struct iscsi_outstanding *io, bool requeue)
286 {
287 
288 	if (io->io_ccb != NULL) {
289 		io->io_ccb->ccb_h.status &= ~(CAM_SIM_QUEUED | CAM_STATUS_MASK);
290 		if (requeue)
291 			io->io_ccb->ccb_h.status |= CAM_REQUEUE_REQ;
292 		else
293 			io->io_ccb->ccb_h.status |= CAM_REQ_ABORTED;
294 		if ((io->io_ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
295 			io->io_ccb->ccb_h.status |= CAM_DEV_QFRZN;
296 			xpt_freeze_devq(io->io_ccb->ccb_h.path, 1);
297 			ISCSI_SESSION_DEBUG(is, "freezing devq");
298 		}
299 		xpt_done(io->io_ccb);
300 	}
301 	iscsi_outstanding_remove(is, io);
302 }
303 
304 static void
305 iscsi_session_terminate_tasks(struct iscsi_session *is, bool requeue)
306 {
307 	struct iscsi_outstanding *io, *tmp;
308 
309 	ISCSI_SESSION_LOCK_ASSERT(is);
310 
311 	TAILQ_FOREACH_SAFE(io, &is->is_outstanding, io_next, tmp) {
312 		iscsi_session_terminate_task(is, io, requeue);
313 	}
314 }
315 
316 static void
317 iscsi_session_cleanup(struct iscsi_session *is, bool destroy_sim)
318 {
319 	struct icl_pdu *pdu;
320 
321 	ISCSI_SESSION_LOCK_ASSERT(is);
322 
323 	/*
324 	 * Don't queue any new PDUs.
325 	 */
326 	if (is->is_sim != NULL && is->is_simq_frozen == false) {
327 		ISCSI_SESSION_DEBUG(is, "freezing");
328 		xpt_freeze_simq(is->is_sim, 1);
329 		is->is_simq_frozen = true;
330 	}
331 
332 	/*
333 	 * Remove postponed PDUs.
334 	 */
335 	while (!STAILQ_EMPTY(&is->is_postponed)) {
336 		pdu = STAILQ_FIRST(&is->is_postponed);
337 		STAILQ_REMOVE_HEAD(&is->is_postponed, ip_next);
338 		icl_pdu_free(pdu);
339 	}
340 
341 	if (destroy_sim == false) {
342 		/*
343 		 * Terminate SCSI tasks, asking CAM to requeue them.
344 		 */
345 		iscsi_session_terminate_tasks(is, true);
346 		return;
347 	}
348 
349 	iscsi_session_terminate_tasks(is, false);
350 
351 	if (is->is_sim == NULL)
352 		return;
353 
354 	ISCSI_SESSION_DEBUG(is, "deregistering SIM");
355 	xpt_async(AC_LOST_DEVICE, is->is_path, NULL);
356 
357 	if (is->is_simq_frozen) {
358 		xpt_release_simq(is->is_sim, 1);
359 		is->is_simq_frozen = false;
360 	}
361 
362 	xpt_free_path(is->is_path);
363 	is->is_path = NULL;
364 	xpt_bus_deregister(cam_sim_path(is->is_sim));
365 	cam_sim_free(is->is_sim, TRUE /*free_devq*/);
366 	is->is_sim = NULL;
367 	is->is_devq = NULL;
368 }
369 
370 static void
371 iscsi_maintenance_thread_reconnect(struct iscsi_session *is)
372 {
373 
374 	icl_conn_close(is->is_conn);
375 
376 	ISCSI_SESSION_LOCK(is);
377 
378 	is->is_connected = false;
379 	is->is_reconnecting = false;
380 	is->is_login_phase = false;
381 
382 #ifdef ICL_KERNEL_PROXY
383 	if (is->is_login_pdu != NULL) {
384 		icl_pdu_free(is->is_login_pdu);
385 		is->is_login_pdu = NULL;
386 	}
387 	cv_signal(&is->is_login_cv);
388 #endif
389 
390 	if (fail_on_disconnection) {
391 		ISCSI_SESSION_DEBUG(is, "connection failed, destroying devices");
392 		iscsi_session_cleanup(is, true);
393 	} else {
394 		iscsi_session_cleanup(is, false);
395 	}
396 
397 	KASSERT(TAILQ_EMPTY(&is->is_outstanding),
398 	    ("destroying session with active tasks"));
399 	KASSERT(STAILQ_EMPTY(&is->is_postponed),
400 	    ("destroying session with postponed PDUs"));
401 
402 	/*
403 	 * Request immediate reconnection from iscsid(8).
404 	 */
405 	//ISCSI_SESSION_DEBUG(is, "waking up iscsid(8)");
406 	is->is_waiting_for_iscsid = true;
407 	strlcpy(is->is_reason, "Waiting for iscsid(8)", sizeof(is->is_reason));
408 	is->is_timeout = 0;
409 	ISCSI_SESSION_UNLOCK(is);
410 	cv_signal(&is->is_softc->sc_cv);
411 }
412 
413 static void
414 iscsi_maintenance_thread_terminate(struct iscsi_session *is)
415 {
416 	struct iscsi_softc *sc;
417 
418 	sc = is->is_softc;
419 	sx_xlock(&sc->sc_lock);
420 	TAILQ_REMOVE(&sc->sc_sessions, is, is_next);
421 	sx_xunlock(&sc->sc_lock);
422 
423 	icl_conn_close(is->is_conn);
424 	callout_drain(&is->is_callout);
425 
426 	ISCSI_SESSION_LOCK(is);
427 
428 	KASSERT(is->is_terminating, ("is_terminating == false"));
429 
430 #ifdef ICL_KERNEL_PROXY
431 	if (is->is_login_pdu != NULL) {
432 		icl_pdu_free(is->is_login_pdu);
433 		is->is_login_pdu = NULL;
434 	}
435 	cv_signal(&is->is_login_cv);
436 #endif
437 
438 	iscsi_session_cleanup(is, true);
439 
440 	KASSERT(TAILQ_EMPTY(&is->is_outstanding),
441 	    ("destroying session with active tasks"));
442 	KASSERT(STAILQ_EMPTY(&is->is_postponed),
443 	    ("destroying session with postponed PDUs"));
444 
445 	ISCSI_SESSION_UNLOCK(is);
446 
447 	icl_conn_free(is->is_conn);
448 	mtx_destroy(&is->is_lock);
449 	cv_destroy(&is->is_maintenance_cv);
450 #ifdef ICL_KERNEL_PROXY
451 	cv_destroy(&is->is_login_cv);
452 #endif
453 	ISCSI_SESSION_DEBUG(is, "terminated");
454 	free(is, M_ISCSI);
455 
456 	/*
457 	 * The iscsi_unload() routine might be waiting.
458 	 */
459 	cv_signal(&sc->sc_cv);
460 }
461 
462 static void
463 iscsi_maintenance_thread(void *arg)
464 {
465 	struct iscsi_session *is;
466 
467 	is = arg;
468 
469 	for (;;) {
470 		ISCSI_SESSION_LOCK(is);
471 		if (is->is_reconnecting == false &&
472 		    is->is_terminating == false &&
473 		    STAILQ_EMPTY(&is->is_postponed))
474 			cv_wait(&is->is_maintenance_cv, &is->is_lock);
475 
476 		if (is->is_reconnecting) {
477 			ISCSI_SESSION_UNLOCK(is);
478 			iscsi_maintenance_thread_reconnect(is);
479 			continue;
480 		}
481 
482 		if (is->is_terminating) {
483 			ISCSI_SESSION_UNLOCK(is);
484 			iscsi_maintenance_thread_terminate(is);
485 			kthread_exit();
486 			return;
487 		}
488 
489 		iscsi_session_send_postponed(is);
490 		ISCSI_SESSION_UNLOCK(is);
491 	}
492 }
493 
494 static void
495 iscsi_session_reconnect(struct iscsi_session *is)
496 {
497 
498 	/*
499 	 * XXX: We can't use locking here, because
500 	 * 	it's being called from various contexts.
501 	 * 	Hope it doesn't break anything.
502 	 */
503 	if (is->is_reconnecting)
504 		return;
505 
506 	is->is_reconnecting = true;
507 	cv_signal(&is->is_maintenance_cv);
508 }
509 
510 static void
511 iscsi_session_terminate(struct iscsi_session *is)
512 {
513 
514 	if (is->is_terminating)
515 		return;
516 
517 	is->is_terminating = true;
518 
519 #if 0
520 	iscsi_session_logout(is);
521 #endif
522 	cv_signal(&is->is_maintenance_cv);
523 }
524 
525 static void
526 iscsi_callout(void *context)
527 {
528 	struct icl_pdu *request;
529 	struct iscsi_bhs_nop_out *bhsno;
530 	struct iscsi_session *is;
531 	bool reconnect_needed = false;
532 
533 	is = context;
534 
535 	ISCSI_SESSION_LOCK(is);
536 	if (is->is_terminating) {
537 		ISCSI_SESSION_UNLOCK(is);
538 		return;
539 	}
540 
541 	callout_schedule(&is->is_callout, 1 * hz);
542 
543 	is->is_timeout++;
544 
545 	if (is->is_waiting_for_iscsid) {
546 		if (iscsid_timeout > 0 && is->is_timeout > iscsid_timeout) {
547 			ISCSI_SESSION_WARN(is, "timed out waiting for iscsid(8) "
548 			    "for %d seconds; reconnecting",
549 			    is->is_timeout);
550 			reconnect_needed = true;
551 		}
552 		goto out;
553 	}
554 
555 	if (is->is_login_phase) {
556 		if (login_timeout > 0 && is->is_timeout > login_timeout) {
557 			ISCSI_SESSION_WARN(is, "login timed out after %d seconds; "
558 			    "reconnecting", is->is_timeout);
559 			reconnect_needed = true;
560 		}
561 		goto out;
562 	}
563 
564 	if (ping_timeout <= 0) {
565 		/*
566 		 * Pings are disabled.  Don't send NOP-Out in this case.
567 		 * Reset the timeout, to avoid triggering reconnection,
568 		 * should the user decide to reenable them.
569 		 */
570 		is->is_timeout = 0;
571 		goto out;
572 	}
573 
574 	if (is->is_timeout >= ping_timeout) {
575 		ISCSI_SESSION_WARN(is, "no ping reply (NOP-In) after %d seconds; "
576 		    "reconnecting", ping_timeout);
577 		reconnect_needed = true;
578 		goto out;
579 	}
580 
581 	ISCSI_SESSION_UNLOCK(is);
582 
583 	/*
584 	 * If the ping was reset less than one second ago - which means
585 	 * that we've received some PDU during the last second - assume
586 	 * the traffic flows correctly and don't bother sending a NOP-Out.
587 	 *
588 	 * (It's 2 - one for one second, and one for incrementing is_timeout
589 	 * earlier in this routine.)
590 	 */
591 	if (is->is_timeout < 2)
592 		return;
593 
594 	request = icl_pdu_new(is->is_conn, M_NOWAIT);
595 	if (request == NULL) {
596 		ISCSI_SESSION_WARN(is, "failed to allocate PDU");
597 		return;
598 	}
599 	bhsno = (struct iscsi_bhs_nop_out *)request->ip_bhs;
600 	bhsno->bhsno_opcode = ISCSI_BHS_OPCODE_NOP_OUT |
601 	    ISCSI_BHS_OPCODE_IMMEDIATE;
602 	bhsno->bhsno_flags = 0x80;
603 	bhsno->bhsno_target_transfer_tag = 0xffffffff;
604 	iscsi_pdu_queue(request);
605 	return;
606 
607 out:
608 	ISCSI_SESSION_UNLOCK(is);
609 
610 	if (reconnect_needed)
611 		iscsi_session_reconnect(is);
612 }
613 
614 static void
615 iscsi_pdu_update_statsn(const struct icl_pdu *response)
616 {
617 	const struct iscsi_bhs_data_in *bhsdi;
618 	struct iscsi_session *is;
619 	uint32_t expcmdsn, maxcmdsn, statsn;
620 
621 	is = PDU_SESSION(response);
622 
623 	ISCSI_SESSION_LOCK_ASSERT(is);
624 
625 	/*
626 	 * We're only using fields common for all the response
627 	 * (target -> initiator) PDUs.
628 	 */
629 	bhsdi = (const struct iscsi_bhs_data_in *)response->ip_bhs;
630 	/*
631 	 * Ok, I lied.  In case of Data-In, "The fields StatSN, Status,
632 	 * and Residual Count only have meaningful content if the S bit
633 	 * is set to 1", so we also need to check the bit specific for
634 	 * Data-In PDU.
635 	 */
636 	if (bhsdi->bhsdi_opcode != ISCSI_BHS_OPCODE_SCSI_DATA_IN ||
637 	    (bhsdi->bhsdi_flags & BHSDI_FLAGS_S) != 0) {
638 		statsn = ntohl(bhsdi->bhsdi_statsn);
639 		if (statsn != is->is_statsn && statsn != (is->is_statsn + 1)) {
640 			/* XXX: This is normal situation for MCS */
641 			ISCSI_SESSION_WARN(is, "PDU 0x%x StatSN %u != "
642 			    "session ExpStatSN %u (or + 1); reconnecting",
643 			    bhsdi->bhsdi_opcode, statsn, is->is_statsn);
644 			iscsi_session_reconnect(is);
645 		}
646 		if (ISCSI_SNGT(statsn, is->is_statsn))
647 			is->is_statsn = statsn;
648 	}
649 
650 	expcmdsn = ntohl(bhsdi->bhsdi_expcmdsn);
651 	maxcmdsn = ntohl(bhsdi->bhsdi_maxcmdsn);
652 
653 	if (ISCSI_SNLT(maxcmdsn + 1, expcmdsn)) {
654 		ISCSI_SESSION_DEBUG(is,
655 		    "PDU MaxCmdSN %u + 1 < PDU ExpCmdSN %u; ignoring",
656 		    maxcmdsn, expcmdsn);
657 	} else {
658 		if (ISCSI_SNGT(maxcmdsn, is->is_maxcmdsn)) {
659 			is->is_maxcmdsn = maxcmdsn;
660 
661 			/*
662 			 * Command window increased; kick the maintanance thread
663 			 * to send out postponed commands.
664 			 */
665 			if (!STAILQ_EMPTY(&is->is_postponed))
666 				cv_signal(&is->is_maintenance_cv);
667 		} else if (ISCSI_SNLT(maxcmdsn, is->is_maxcmdsn)) {
668 			/* XXX: This is normal situation for MCS */
669 			ISCSI_SESSION_DEBUG(is,
670 			    "PDU MaxCmdSN %u < session MaxCmdSN %u; ignoring",
671 			    maxcmdsn, is->is_maxcmdsn);
672 		}
673 
674 		if (ISCSI_SNGT(expcmdsn, is->is_expcmdsn)) {
675 			is->is_expcmdsn = expcmdsn;
676 		} else if (ISCSI_SNLT(expcmdsn, is->is_expcmdsn)) {
677 			/* XXX: This is normal situation for MCS */
678 			ISCSI_SESSION_DEBUG(is,
679 			    "PDU ExpCmdSN %u < session ExpCmdSN %u; ignoring",
680 			    expcmdsn, is->is_expcmdsn);
681 		}
682 	}
683 
684 	/*
685 	 * Every incoming PDU - not just NOP-In - resets the ping timer.
686 	 * The purpose of the timeout is to reset the connection when it stalls;
687 	 * we don't want this to happen when NOP-In or NOP-Out ends up delayed
688 	 * in some queue.
689 	 */
690 	is->is_timeout = 0;
691 }
692 
693 static void
694 iscsi_receive_callback(struct icl_pdu *response)
695 {
696 	struct iscsi_session *is;
697 
698 	is = PDU_SESSION(response);
699 
700 	ISCSI_SESSION_LOCK(is);
701 
702 #ifdef ICL_KERNEL_PROXY
703 	if (is->is_login_phase) {
704 		if (is->is_login_pdu == NULL)
705 			is->is_login_pdu = response;
706 		else
707 			icl_pdu_free(response);
708 		ISCSI_SESSION_UNLOCK(is);
709 		cv_signal(&is->is_login_cv);
710 		return;
711 	}
712 #endif
713 
714 	iscsi_pdu_update_statsn(response);
715 
716 	/*
717 	 * The handling routine is responsible for freeing the PDU
718 	 * when it's no longer needed.
719 	 */
720 	switch (response->ip_bhs->bhs_opcode) {
721 	case ISCSI_BHS_OPCODE_NOP_IN:
722 		iscsi_pdu_handle_nop_in(response);
723 		ISCSI_SESSION_UNLOCK(is);
724 		break;
725 	case ISCSI_BHS_OPCODE_SCSI_RESPONSE:
726 		iscsi_pdu_handle_scsi_response(response);
727 		/* Session lock dropped inside. */
728 		ISCSI_SESSION_LOCK_ASSERT_NOT(is);
729 		break;
730 	case ISCSI_BHS_OPCODE_TASK_RESPONSE:
731 		iscsi_pdu_handle_task_response(response);
732 		ISCSI_SESSION_UNLOCK(is);
733 		break;
734 	case ISCSI_BHS_OPCODE_SCSI_DATA_IN:
735 		iscsi_pdu_handle_data_in(response);
736 		/* Session lock dropped inside. */
737 		ISCSI_SESSION_LOCK_ASSERT_NOT(is);
738 		break;
739 	case ISCSI_BHS_OPCODE_LOGOUT_RESPONSE:
740 		iscsi_pdu_handle_logout_response(response);
741 		ISCSI_SESSION_UNLOCK(is);
742 		break;
743 	case ISCSI_BHS_OPCODE_R2T:
744 		iscsi_pdu_handle_r2t(response);
745 		ISCSI_SESSION_UNLOCK(is);
746 		break;
747 	case ISCSI_BHS_OPCODE_ASYNC_MESSAGE:
748 		iscsi_pdu_handle_async_message(response);
749 		ISCSI_SESSION_UNLOCK(is);
750 		break;
751 	case ISCSI_BHS_OPCODE_REJECT:
752 		iscsi_pdu_handle_reject(response);
753 		ISCSI_SESSION_UNLOCK(is);
754 		break;
755 	default:
756 		ISCSI_SESSION_WARN(is, "received PDU with unsupported "
757 		    "opcode 0x%x; reconnecting",
758 		    response->ip_bhs->bhs_opcode);
759 		iscsi_session_reconnect(is);
760 		ISCSI_SESSION_UNLOCK(is);
761 		icl_pdu_free(response);
762 	}
763 }
764 
765 static void
766 iscsi_error_callback(struct icl_conn *ic)
767 {
768 	struct iscsi_session *is;
769 
770 	is = CONN_SESSION(ic);
771 
772 	ISCSI_SESSION_WARN(is, "connection error; reconnecting");
773 	iscsi_session_reconnect(is);
774 }
775 
776 static void
777 iscsi_pdu_handle_nop_in(struct icl_pdu *response)
778 {
779 	struct iscsi_session *is;
780 	struct iscsi_bhs_nop_out *bhsno;
781 	struct iscsi_bhs_nop_in *bhsni;
782 	struct icl_pdu *request;
783 	void *data = NULL;
784 	size_t datasize;
785 	int error;
786 
787 	is = PDU_SESSION(response);
788 	bhsni = (struct iscsi_bhs_nop_in *)response->ip_bhs;
789 
790 	if (bhsni->bhsni_target_transfer_tag == 0xffffffff) {
791 		/*
792 		 * Nothing to do; iscsi_pdu_update_statsn() already
793 		 * zeroed the timeout.
794 		 */
795 		icl_pdu_free(response);
796 		return;
797 	}
798 
799 	datasize = icl_pdu_data_segment_length(response);
800 	if (datasize > 0) {
801 		data = malloc(datasize, M_ISCSI, M_NOWAIT | M_ZERO);
802 		if (data == NULL) {
803 			ISCSI_SESSION_WARN(is, "failed to allocate memory; "
804 			    "reconnecting");
805 			icl_pdu_free(response);
806 			iscsi_session_reconnect(is);
807 			return;
808 		}
809 		icl_pdu_get_data(response, 0, data, datasize);
810 	}
811 
812 	request = icl_pdu_new(response->ip_conn, M_NOWAIT);
813 	if (request == NULL) {
814 		ISCSI_SESSION_WARN(is, "failed to allocate memory; "
815 		    "reconnecting");
816 		free(data, M_ISCSI);
817 		icl_pdu_free(response);
818 		iscsi_session_reconnect(is);
819 		return;
820 	}
821 	bhsno = (struct iscsi_bhs_nop_out *)request->ip_bhs;
822 	bhsno->bhsno_opcode = ISCSI_BHS_OPCODE_NOP_OUT |
823 	    ISCSI_BHS_OPCODE_IMMEDIATE;
824 	bhsno->bhsno_flags = 0x80;
825 	bhsno->bhsno_initiator_task_tag = 0xffffffff;
826 	bhsno->bhsno_target_transfer_tag = bhsni->bhsni_target_transfer_tag;
827 	if (datasize > 0) {
828 		error = icl_pdu_append_data(request, data, datasize, M_NOWAIT);
829 		if (error != 0) {
830 			ISCSI_SESSION_WARN(is, "failed to allocate memory; "
831 			    "reconnecting");
832 			free(data, M_ISCSI);
833 			icl_pdu_free(request);
834 			icl_pdu_free(response);
835 			iscsi_session_reconnect(is);
836 			return;
837 		}
838 		free(data, M_ISCSI);
839 	}
840 
841 	icl_pdu_free(response);
842 	iscsi_pdu_queue_locked(request);
843 }
844 
845 static void
846 iscsi_pdu_handle_scsi_response(struct icl_pdu *response)
847 {
848 	struct iscsi_bhs_scsi_response *bhssr;
849 	struct iscsi_outstanding *io;
850 	struct iscsi_session *is;
851 	union ccb *ccb;
852 	struct ccb_scsiio *csio;
853 	size_t data_segment_len, received;
854 	uint16_t sense_len;
855 
856 	is = PDU_SESSION(response);
857 
858 	bhssr = (struct iscsi_bhs_scsi_response *)response->ip_bhs;
859 	io = iscsi_outstanding_find(is, bhssr->bhssr_initiator_task_tag);
860 	if (io == NULL || io->io_ccb == NULL) {
861 		ISCSI_SESSION_WARN(is, "bad itt 0x%x", bhssr->bhssr_initiator_task_tag);
862 		icl_pdu_free(response);
863 		iscsi_session_reconnect(is);
864 		ISCSI_SESSION_UNLOCK(is);
865 		return;
866 	}
867 
868 	ccb = io->io_ccb;
869 	received = io->io_received;
870 	iscsi_outstanding_remove(is, io);
871 	ISCSI_SESSION_UNLOCK(is);
872 
873 	if (bhssr->bhssr_response != BHSSR_RESPONSE_COMMAND_COMPLETED) {
874 		ISCSI_SESSION_WARN(is, "service response 0x%x", bhssr->bhssr_response);
875  		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
876  			xpt_freeze_devq(ccb->ccb_h.path, 1);
877 			ISCSI_SESSION_DEBUG(is, "freezing devq");
878 		}
879  		ccb->ccb_h.status = CAM_REQ_CMP_ERR | CAM_DEV_QFRZN;
880 	} else if (bhssr->bhssr_status == 0) {
881 		ccb->ccb_h.status = CAM_REQ_CMP;
882 	} else {
883  		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
884  			xpt_freeze_devq(ccb->ccb_h.path, 1);
885 			ISCSI_SESSION_DEBUG(is, "freezing devq");
886 		}
887  		ccb->ccb_h.status = CAM_SCSI_STATUS_ERROR | CAM_DEV_QFRZN;
888 		ccb->csio.scsi_status = bhssr->bhssr_status;
889 	}
890 
891 	csio = &ccb->csio;
892 	data_segment_len = icl_pdu_data_segment_length(response);
893 	if (data_segment_len > 0) {
894 		if (data_segment_len < sizeof(sense_len)) {
895 			ISCSI_SESSION_WARN(is, "truncated data segment (%zd bytes)",
896 			    data_segment_len);
897 			if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
898 				xpt_freeze_devq(ccb->ccb_h.path, 1);
899 				ISCSI_SESSION_DEBUG(is, "freezing devq");
900 			}
901 			ccb->ccb_h.status = CAM_REQ_CMP_ERR | CAM_DEV_QFRZN;
902 			goto out;
903 		}
904 		icl_pdu_get_data(response, 0, &sense_len, sizeof(sense_len));
905 		sense_len = ntohs(sense_len);
906 #if 0
907 		ISCSI_SESSION_DEBUG(is, "sense_len %d, data len %zd",
908 		    sense_len, data_segment_len);
909 #endif
910 		if (sizeof(sense_len) + sense_len > data_segment_len) {
911 			ISCSI_SESSION_WARN(is, "truncated data segment "
912 			    "(%zd bytes, should be %zd)",
913 			    data_segment_len, sizeof(sense_len) + sense_len);
914 			if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
915 				xpt_freeze_devq(ccb->ccb_h.path, 1);
916 				ISCSI_SESSION_DEBUG(is, "freezing devq");
917 			}
918 			ccb->ccb_h.status = CAM_REQ_CMP_ERR | CAM_DEV_QFRZN;
919 			goto out;
920 		} else if (sizeof(sense_len) + sense_len < data_segment_len)
921 			ISCSI_SESSION_WARN(is, "oversize data segment "
922 			    "(%zd bytes, should be %zd)",
923 			    data_segment_len, sizeof(sense_len) + sense_len);
924 		if (sense_len > csio->sense_len) {
925 			ISCSI_SESSION_DEBUG(is, "truncating sense from %d to %d",
926 			    sense_len, csio->sense_len);
927 			sense_len = csio->sense_len;
928 		}
929 		icl_pdu_get_data(response, sizeof(sense_len), &csio->sense_data, sense_len);
930 		csio->sense_resid = csio->sense_len - sense_len;
931 		ccb->ccb_h.status |= CAM_AUTOSNS_VALID;
932 	}
933 
934 out:
935 	if (bhssr->bhssr_flags & BHSSR_FLAGS_RESIDUAL_UNDERFLOW)
936 		csio->resid = ntohl(bhssr->bhssr_residual_count);
937 
938 	if ((csio->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_IN) {
939 		KASSERT(received <= csio->dxfer_len,
940 		    ("received > csio->dxfer_len"));
941 		if (received < csio->dxfer_len) {
942 			if (csio->resid != csio->dxfer_len - received) {
943 				ISCSI_SESSION_WARN(is, "underflow mismatch: "
944 				    "target indicates %d, we calculated %zd",
945 				    csio->resid, csio->dxfer_len - received);
946 			}
947 			csio->resid = csio->dxfer_len - received;
948 		}
949 	}
950 
951 	xpt_done(ccb);
952 	icl_pdu_free(response);
953 }
954 
955 static void
956 iscsi_pdu_handle_task_response(struct icl_pdu *response)
957 {
958 	struct iscsi_bhs_task_management_response *bhstmr;
959 	struct iscsi_outstanding *io, *aio;
960 	struct iscsi_session *is;
961 
962 	is = PDU_SESSION(response);
963 
964 	bhstmr = (struct iscsi_bhs_task_management_response *)response->ip_bhs;
965 	io = iscsi_outstanding_find(is, bhstmr->bhstmr_initiator_task_tag);
966 	if (io == NULL || io->io_ccb != NULL) {
967 		ISCSI_SESSION_WARN(is, "bad itt 0x%x",
968 		    bhstmr->bhstmr_initiator_task_tag);
969 		icl_pdu_free(response);
970 		iscsi_session_reconnect(is);
971 		return;
972 	}
973 
974 	if (bhstmr->bhstmr_response != BHSTMR_RESPONSE_FUNCTION_COMPLETE) {
975 		ISCSI_SESSION_WARN(is, "task response 0x%x",
976 		    bhstmr->bhstmr_response);
977 	} else {
978 		aio = iscsi_outstanding_find(is, io->io_datasn);
979 		if (aio != NULL && aio->io_ccb != NULL)
980 			iscsi_session_terminate_task(is, aio, false);
981 	}
982 
983 	iscsi_outstanding_remove(is, io);
984 	icl_pdu_free(response);
985 }
986 
987 static void
988 iscsi_pdu_handle_data_in(struct icl_pdu *response)
989 {
990 	struct iscsi_bhs_data_in *bhsdi;
991 	struct iscsi_outstanding *io;
992 	struct iscsi_session *is;
993 	union ccb *ccb;
994 	struct ccb_scsiio *csio;
995 	size_t data_segment_len, received, oreceived;
996 
997 	is = PDU_SESSION(response);
998 	bhsdi = (struct iscsi_bhs_data_in *)response->ip_bhs;
999 	io = iscsi_outstanding_find(is, bhsdi->bhsdi_initiator_task_tag);
1000 	if (io == NULL || io->io_ccb == NULL) {
1001 		ISCSI_SESSION_WARN(is, "bad itt 0x%x", bhsdi->bhsdi_initiator_task_tag);
1002 		icl_pdu_free(response);
1003 		iscsi_session_reconnect(is);
1004 		ISCSI_SESSION_UNLOCK(is);
1005 		return;
1006 	}
1007 
1008 	data_segment_len = icl_pdu_data_segment_length(response);
1009 	if (data_segment_len == 0) {
1010 		/*
1011 		 * "The sending of 0 length data segments should be avoided,
1012 		 * but initiators and targets MUST be able to properly receive
1013 		 * 0 length data segments."
1014 		 */
1015 		ISCSI_SESSION_UNLOCK(is);
1016 		icl_pdu_free(response);
1017 		return;
1018 	}
1019 
1020 	/*
1021 	 * We need to track this for security reasons - without it, malicious target
1022 	 * could respond to SCSI READ without sending Data-In PDUs, which would result
1023 	 * in read operation on the initiator side returning random kernel data.
1024 	 */
1025 	if (ntohl(bhsdi->bhsdi_buffer_offset) != io->io_received) {
1026 		ISCSI_SESSION_WARN(is, "data out of order; expected offset %zd, got %zd",
1027 		    io->io_received, (size_t)ntohl(bhsdi->bhsdi_buffer_offset));
1028 		icl_pdu_free(response);
1029 		iscsi_session_reconnect(is);
1030 		ISCSI_SESSION_UNLOCK(is);
1031 		return;
1032 	}
1033 
1034 	ccb = io->io_ccb;
1035 	csio = &ccb->csio;
1036 
1037 	if (io->io_received + data_segment_len > csio->dxfer_len) {
1038 		ISCSI_SESSION_WARN(is, "oversize data segment (%zd bytes "
1039 		    "at offset %zd, buffer is %d)",
1040 		    data_segment_len, io->io_received, csio->dxfer_len);
1041 		icl_pdu_free(response);
1042 		iscsi_session_reconnect(is);
1043 		ISCSI_SESSION_UNLOCK(is);
1044 		return;
1045 	}
1046 
1047 	oreceived = io->io_received;
1048 	io->io_received += data_segment_len;
1049 	received = io->io_received;
1050 	if ((bhsdi->bhsdi_flags & BHSDI_FLAGS_S) != 0)
1051 		iscsi_outstanding_remove(is, io);
1052 	ISCSI_SESSION_UNLOCK(is);
1053 
1054 	icl_pdu_get_data(response, 0, csio->data_ptr + oreceived, data_segment_len);
1055 
1056 	/*
1057 	 * XXX: Check DataSN.
1058 	 * XXX: Check F.
1059 	 */
1060 	if ((bhsdi->bhsdi_flags & BHSDI_FLAGS_S) == 0) {
1061 		/*
1062 		 * Nothing more to do.
1063 		 */
1064 		icl_pdu_free(response);
1065 		return;
1066 	}
1067 
1068 	//ISCSI_SESSION_DEBUG(is, "got S flag; status 0x%x", bhsdi->bhsdi_status);
1069 	if (bhsdi->bhsdi_status == 0) {
1070 		ccb->ccb_h.status = CAM_REQ_CMP;
1071 	} else {
1072 		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
1073 			xpt_freeze_devq(ccb->ccb_h.path, 1);
1074 			ISCSI_SESSION_DEBUG(is, "freezing devq");
1075 		}
1076 		ccb->ccb_h.status = CAM_SCSI_STATUS_ERROR | CAM_DEV_QFRZN;
1077 		csio->scsi_status = bhsdi->bhsdi_status;
1078 	}
1079 
1080 	if ((csio->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_IN) {
1081 		KASSERT(received <= csio->dxfer_len,
1082 		    ("received > csio->dxfer_len"));
1083 		if (received < csio->dxfer_len) {
1084 			csio->resid = ntohl(bhsdi->bhsdi_residual_count);
1085 			if (csio->resid != csio->dxfer_len - received) {
1086 				ISCSI_SESSION_WARN(is, "underflow mismatch: "
1087 				    "target indicates %d, we calculated %zd",
1088 				    csio->resid, csio->dxfer_len - received);
1089 			}
1090 			csio->resid = csio->dxfer_len - received;
1091 		}
1092 	}
1093 
1094 	xpt_done(ccb);
1095 	icl_pdu_free(response);
1096 }
1097 
1098 static void
1099 iscsi_pdu_handle_logout_response(struct icl_pdu *response)
1100 {
1101 
1102 	ISCSI_SESSION_DEBUG(PDU_SESSION(response), "logout response");
1103 	icl_pdu_free(response);
1104 }
1105 
1106 static void
1107 iscsi_pdu_handle_r2t(struct icl_pdu *response)
1108 {
1109 	struct icl_pdu *request;
1110 	struct iscsi_session *is;
1111 	struct iscsi_bhs_r2t *bhsr2t;
1112 	struct iscsi_bhs_data_out *bhsdo;
1113 	struct iscsi_outstanding *io;
1114 	struct ccb_scsiio *csio;
1115 	size_t off, len, total_len;
1116 	int error;
1117 
1118 	is = PDU_SESSION(response);
1119 
1120 	bhsr2t = (struct iscsi_bhs_r2t *)response->ip_bhs;
1121 	io = iscsi_outstanding_find(is, bhsr2t->bhsr2t_initiator_task_tag);
1122 	if (io == NULL || io->io_ccb == NULL) {
1123 		ISCSI_SESSION_WARN(is, "bad itt 0x%x; reconnecting",
1124 		    bhsr2t->bhsr2t_initiator_task_tag);
1125 		icl_pdu_free(response);
1126 		iscsi_session_reconnect(is);
1127 		return;
1128 	}
1129 
1130 	csio = &io->io_ccb->csio;
1131 
1132 	if ((csio->ccb_h.flags & CAM_DIR_MASK) != CAM_DIR_OUT) {
1133 		ISCSI_SESSION_WARN(is, "received R2T for read command; reconnecting");
1134 		icl_pdu_free(response);
1135 		iscsi_session_reconnect(is);
1136 		return;
1137 	}
1138 
1139 	/*
1140 	 * XXX: Verify R2TSN.
1141 	 */
1142 
1143 	io->io_datasn = 0;
1144 
1145 	off = ntohl(bhsr2t->bhsr2t_buffer_offset);
1146 	if (off > csio->dxfer_len) {
1147 		ISCSI_SESSION_WARN(is, "target requested invalid offset "
1148 		    "%zd, buffer is is %d; reconnecting", off, csio->dxfer_len);
1149 		icl_pdu_free(response);
1150 		iscsi_session_reconnect(is);
1151 		return;
1152 	}
1153 
1154 	total_len = ntohl(bhsr2t->bhsr2t_desired_data_transfer_length);
1155 	if (total_len == 0 || total_len > csio->dxfer_len) {
1156 		ISCSI_SESSION_WARN(is, "target requested invalid length "
1157 		    "%zd, buffer is %d; reconnecting", total_len, csio->dxfer_len);
1158 		icl_pdu_free(response);
1159 		iscsi_session_reconnect(is);
1160 		return;
1161 	}
1162 
1163 	//ISCSI_SESSION_DEBUG(is, "r2t; off %zd, len %zd", off, total_len);
1164 
1165 	for (;;) {
1166 		len = total_len;
1167 
1168 		if (len > is->is_max_data_segment_length)
1169 			len = is->is_max_data_segment_length;
1170 
1171 		if (off + len > csio->dxfer_len) {
1172 			ISCSI_SESSION_WARN(is, "target requested invalid "
1173 			    "length/offset %zd, buffer is %d; reconnecting",
1174 			    off + len, csio->dxfer_len);
1175 			icl_pdu_free(response);
1176 			iscsi_session_reconnect(is);
1177 			return;
1178 		}
1179 
1180 		request = icl_pdu_new(response->ip_conn, M_NOWAIT);
1181 		if (request == NULL) {
1182 			icl_pdu_free(response);
1183 			iscsi_session_reconnect(is);
1184 			return;
1185 		}
1186 
1187 		bhsdo = (struct iscsi_bhs_data_out *)request->ip_bhs;
1188 		bhsdo->bhsdo_opcode = ISCSI_BHS_OPCODE_SCSI_DATA_OUT;
1189 		bhsdo->bhsdo_lun = bhsr2t->bhsr2t_lun;
1190 		bhsdo->bhsdo_initiator_task_tag =
1191 		    bhsr2t->bhsr2t_initiator_task_tag;
1192 		bhsdo->bhsdo_target_transfer_tag =
1193 		    bhsr2t->bhsr2t_target_transfer_tag;
1194 		bhsdo->bhsdo_datasn = htonl(io->io_datasn++);
1195 		bhsdo->bhsdo_buffer_offset = htonl(off);
1196 		error = icl_pdu_append_data(request, csio->data_ptr + off, len,
1197 		    M_NOWAIT);
1198 		if (error != 0) {
1199 			ISCSI_SESSION_WARN(is, "failed to allocate memory; "
1200 			    "reconnecting");
1201 			icl_pdu_free(request);
1202 			icl_pdu_free(response);
1203 			iscsi_session_reconnect(is);
1204 			return;
1205 		}
1206 
1207 		off += len;
1208 		total_len -= len;
1209 
1210 		if (total_len == 0) {
1211 			bhsdo->bhsdo_flags |= BHSDO_FLAGS_F;
1212 			//ISCSI_SESSION_DEBUG(is, "setting F, off %zd", off);
1213 		} else {
1214 			//ISCSI_SESSION_DEBUG(is, "not finished, off %zd", off);
1215 		}
1216 
1217 		iscsi_pdu_queue_locked(request);
1218 
1219 		if (total_len == 0)
1220 			break;
1221 	}
1222 
1223 	icl_pdu_free(response);
1224 }
1225 
1226 static void
1227 iscsi_pdu_handle_async_message(struct icl_pdu *response)
1228 {
1229 	struct iscsi_bhs_asynchronous_message *bhsam;
1230 	struct iscsi_session *is;
1231 
1232 	is = PDU_SESSION(response);
1233 	bhsam = (struct iscsi_bhs_asynchronous_message *)response->ip_bhs;
1234 	switch (bhsam->bhsam_async_event) {
1235 	case BHSAM_EVENT_TARGET_REQUESTS_LOGOUT:
1236 		ISCSI_SESSION_WARN(is, "target requests logout; removing session");
1237 		iscsi_session_logout(is);
1238 		iscsi_session_terminate(is);
1239 		break;
1240 	case BHSAM_EVENT_TARGET_TERMINATES_CONNECTION:
1241 		ISCSI_SESSION_WARN(is, "target indicates it will drop drop the connection");
1242 		break;
1243 	case BHSAM_EVENT_TARGET_TERMINATES_SESSION:
1244 		ISCSI_SESSION_WARN(is, "target indicates it will drop drop the session");
1245 		break;
1246 	default:
1247 		/*
1248 		 * XXX: Technically, we're obligated to also handle
1249 		 * 	parameter renegotiation.
1250 		 */
1251 		ISCSI_SESSION_WARN(is, "ignoring AsyncEvent %d", bhsam->bhsam_async_event);
1252 		break;
1253 	}
1254 
1255 	icl_pdu_free(response);
1256 }
1257 
1258 static void
1259 iscsi_pdu_handle_reject(struct icl_pdu *response)
1260 {
1261 	struct iscsi_bhs_reject *bhsr;
1262 	struct iscsi_session *is;
1263 
1264 	is = PDU_SESSION(response);
1265 	bhsr = (struct iscsi_bhs_reject *)response->ip_bhs;
1266 	ISCSI_SESSION_WARN(is, "received Reject PDU, reason 0x%x; protocol error?",
1267 	    bhsr->bhsr_reason);
1268 
1269 	icl_pdu_free(response);
1270 }
1271 
1272 static int
1273 iscsi_ioctl_daemon_wait(struct iscsi_softc *sc,
1274     struct iscsi_daemon_request *request)
1275 {
1276 	struct iscsi_session *is;
1277 	int error;
1278 
1279 	sx_slock(&sc->sc_lock);
1280 	for (;;) {
1281 		TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1282 			ISCSI_SESSION_LOCK(is);
1283 			if (is->is_waiting_for_iscsid)
1284 				break;
1285 			ISCSI_SESSION_UNLOCK(is);
1286 		}
1287 
1288 		if (is == NULL) {
1289 			/*
1290 			 * No session requires attention from iscsid(8); wait.
1291 			 */
1292 			error = cv_wait_sig(&sc->sc_cv, &sc->sc_lock);
1293 			if (error != 0) {
1294 				sx_sunlock(&sc->sc_lock);
1295 				return (error);
1296 			}
1297 			continue;
1298 		}
1299 
1300 		is->is_waiting_for_iscsid = false;
1301 		is->is_login_phase = true;
1302 		is->is_reason[0] = '\0';
1303 		ISCSI_SESSION_UNLOCK(is);
1304 
1305 		request->idr_session_id = is->is_id;
1306 		memcpy(&request->idr_isid, &is->is_isid,
1307 		    sizeof(request->idr_isid));
1308 		request->idr_tsih = 0;	/* New or reinstated session. */
1309 		memcpy(&request->idr_conf, &is->is_conf,
1310 		    sizeof(request->idr_conf));
1311 
1312 		error = icl_limits(is->is_conf.isc_offload,
1313 		    &request->idr_limits.isl_max_data_segment_length);
1314 		if (error != 0) {
1315 			ISCSI_SESSION_WARN(is, "icl_limits for offload \"%s\" "
1316 			    "failed with error %d", is->is_conf.isc_offload,
1317 			    error);
1318 			sx_sunlock(&sc->sc_lock);
1319 			return (error);
1320 		}
1321 
1322 		sx_sunlock(&sc->sc_lock);
1323 		return (0);
1324 	}
1325 }
1326 
1327 static int
1328 iscsi_ioctl_daemon_handoff(struct iscsi_softc *sc,
1329     struct iscsi_daemon_handoff *handoff)
1330 {
1331 	struct iscsi_session *is;
1332 	int error;
1333 
1334 	sx_slock(&sc->sc_lock);
1335 
1336 	/*
1337 	 * Find the session to hand off socket to.
1338 	 */
1339 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1340 		if (is->is_id == handoff->idh_session_id)
1341 			break;
1342 	}
1343 	if (is == NULL) {
1344 		sx_sunlock(&sc->sc_lock);
1345 		return (ESRCH);
1346 	}
1347 	ISCSI_SESSION_LOCK(is);
1348 	if (is->is_conf.isc_discovery || is->is_terminating) {
1349 		ISCSI_SESSION_UNLOCK(is);
1350 		sx_sunlock(&sc->sc_lock);
1351 		return (EINVAL);
1352 	}
1353 	if (is->is_connected) {
1354 		/*
1355 		 * This might have happened because another iscsid(8)
1356 		 * instance handed off the connection in the meantime.
1357 		 * Just return.
1358 		 */
1359 		ISCSI_SESSION_WARN(is, "handoff on already connected "
1360 		    "session");
1361 		ISCSI_SESSION_UNLOCK(is);
1362 		sx_sunlock(&sc->sc_lock);
1363 		return (EBUSY);
1364 	}
1365 
1366 	strlcpy(is->is_target_alias, handoff->idh_target_alias,
1367 	    sizeof(is->is_target_alias));
1368 	is->is_tsih = handoff->idh_tsih;
1369 	is->is_statsn = handoff->idh_statsn;
1370 	is->is_initial_r2t = handoff->idh_initial_r2t;
1371 	is->is_immediate_data = handoff->idh_immediate_data;
1372 	is->is_max_data_segment_length = handoff->idh_max_data_segment_length;
1373 	is->is_max_burst_length = handoff->idh_max_burst_length;
1374 	is->is_first_burst_length = handoff->idh_first_burst_length;
1375 
1376 	if (handoff->idh_header_digest == ISCSI_DIGEST_CRC32C)
1377 		is->is_conn->ic_header_crc32c = true;
1378 	else
1379 		is->is_conn->ic_header_crc32c = false;
1380 	if (handoff->idh_data_digest == ISCSI_DIGEST_CRC32C)
1381 		is->is_conn->ic_data_crc32c = true;
1382 	else
1383 		is->is_conn->ic_data_crc32c = false;
1384 
1385 	is->is_cmdsn = 0;
1386 	is->is_expcmdsn = 0;
1387 	is->is_maxcmdsn = 0;
1388 	is->is_waiting_for_iscsid = false;
1389 	is->is_login_phase = false;
1390 	is->is_timeout = 0;
1391 	is->is_connected = true;
1392 	is->is_reason[0] = '\0';
1393 
1394 	ISCSI_SESSION_UNLOCK(is);
1395 
1396 #ifdef ICL_KERNEL_PROXY
1397 	if (handoff->idh_socket != 0) {
1398 #endif
1399 		/*
1400 		 * Handoff without using ICL proxy.
1401 		 */
1402 		error = icl_conn_handoff(is->is_conn, handoff->idh_socket);
1403 		if (error != 0) {
1404 			sx_sunlock(&sc->sc_lock);
1405 			iscsi_session_terminate(is);
1406 			return (error);
1407 		}
1408 #ifdef ICL_KERNEL_PROXY
1409 	}
1410 #endif
1411 
1412 	sx_sunlock(&sc->sc_lock);
1413 
1414 	if (is->is_sim != NULL) {
1415 		/*
1416 		 * When reconnecting, there already is SIM allocated for the session.
1417 		 */
1418 		KASSERT(is->is_simq_frozen, ("reconnect without frozen simq"));
1419 		ISCSI_SESSION_LOCK(is);
1420 		ISCSI_SESSION_DEBUG(is, "releasing");
1421 		xpt_release_simq(is->is_sim, 1);
1422 		is->is_simq_frozen = false;
1423 		ISCSI_SESSION_UNLOCK(is);
1424 
1425 	} else {
1426 		ISCSI_SESSION_LOCK(is);
1427 		is->is_devq = cam_simq_alloc(maxtags);
1428 		if (is->is_devq == NULL) {
1429 			ISCSI_SESSION_WARN(is, "failed to allocate simq");
1430 			iscsi_session_terminate(is);
1431 			return (ENOMEM);
1432 		}
1433 
1434 		is->is_sim = cam_sim_alloc(iscsi_action, iscsi_poll, "iscsi",
1435 		    is, is->is_id /* unit */, &is->is_lock,
1436 		    1, maxtags, is->is_devq);
1437 		if (is->is_sim == NULL) {
1438 			ISCSI_SESSION_UNLOCK(is);
1439 			ISCSI_SESSION_WARN(is, "failed to allocate SIM");
1440 			cam_simq_free(is->is_devq);
1441 			iscsi_session_terminate(is);
1442 			return (ENOMEM);
1443 		}
1444 
1445 		error = xpt_bus_register(is->is_sim, NULL, 0);
1446 		if (error != 0) {
1447 			ISCSI_SESSION_UNLOCK(is);
1448 			ISCSI_SESSION_WARN(is, "failed to register bus");
1449 			iscsi_session_terminate(is);
1450 			return (ENOMEM);
1451 		}
1452 
1453 		error = xpt_create_path(&is->is_path, /*periph*/NULL,
1454 		    cam_sim_path(is->is_sim), CAM_TARGET_WILDCARD,
1455 		    CAM_LUN_WILDCARD);
1456 		if (error != CAM_REQ_CMP) {
1457 			ISCSI_SESSION_UNLOCK(is);
1458 			ISCSI_SESSION_WARN(is, "failed to create path");
1459 			iscsi_session_terminate(is);
1460 			return (ENOMEM);
1461 		}
1462 		ISCSI_SESSION_UNLOCK(is);
1463 	}
1464 
1465 	return (0);
1466 }
1467 
1468 static int
1469 iscsi_ioctl_daemon_fail(struct iscsi_softc *sc,
1470     struct iscsi_daemon_fail *fail)
1471 {
1472 	struct iscsi_session *is;
1473 
1474 	sx_slock(&sc->sc_lock);
1475 
1476 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1477 		if (is->is_id == fail->idf_session_id)
1478 			break;
1479 	}
1480 	if (is == NULL) {
1481 		sx_sunlock(&sc->sc_lock);
1482 		return (ESRCH);
1483 	}
1484 	ISCSI_SESSION_LOCK(is);
1485 	ISCSI_SESSION_DEBUG(is, "iscsid(8) failed: %s",
1486 	    fail->idf_reason);
1487 	strlcpy(is->is_reason, fail->idf_reason, sizeof(is->is_reason));
1488 	//is->is_waiting_for_iscsid = false;
1489 	//is->is_login_phase = true;
1490 	//iscsi_session_reconnect(is);
1491 	ISCSI_SESSION_UNLOCK(is);
1492 	sx_sunlock(&sc->sc_lock);
1493 
1494 	return (0);
1495 }
1496 
1497 #ifdef ICL_KERNEL_PROXY
1498 static int
1499 iscsi_ioctl_daemon_connect(struct iscsi_softc *sc,
1500     struct iscsi_daemon_connect *idc)
1501 {
1502 	struct iscsi_session *is;
1503 	struct sockaddr *from_sa, *to_sa;
1504 	int error;
1505 
1506 	sx_slock(&sc->sc_lock);
1507 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1508 		if (is->is_id == idc->idc_session_id)
1509 			break;
1510 	}
1511 	if (is == NULL) {
1512 		sx_sunlock(&sc->sc_lock);
1513 		return (ESRCH);
1514 	}
1515 	sx_sunlock(&sc->sc_lock);
1516 
1517 	if (idc->idc_from_addrlen > 0) {
1518 		error = getsockaddr(&from_sa, (void *)idc->idc_from_addr, idc->idc_from_addrlen);
1519 		if (error != 0) {
1520 			ISCSI_SESSION_WARN(is,
1521 			    "getsockaddr failed with error %d", error);
1522 			return (error);
1523 		}
1524 	} else {
1525 		from_sa = NULL;
1526 	}
1527 	error = getsockaddr(&to_sa, (void *)idc->idc_to_addr, idc->idc_to_addrlen);
1528 	if (error != 0) {
1529 		ISCSI_SESSION_WARN(is, "getsockaddr failed with error %d",
1530 		    error);
1531 		free(from_sa, M_SONAME);
1532 		return (error);
1533 	}
1534 
1535 	ISCSI_SESSION_LOCK(is);
1536 	is->is_waiting_for_iscsid = false;
1537 	is->is_login_phase = true;
1538 	is->is_timeout = 0;
1539 	ISCSI_SESSION_UNLOCK(is);
1540 
1541 	error = icl_conn_connect(is->is_conn, idc->idc_iser, idc->idc_domain,
1542 	    idc->idc_socktype, idc->idc_protocol, from_sa, to_sa);
1543 	free(from_sa, M_SONAME);
1544 	free(to_sa, M_SONAME);
1545 
1546 	/*
1547 	 * Digests are always disabled during login phase.
1548 	 */
1549 	is->is_conn->ic_header_crc32c = false;
1550 	is->is_conn->ic_data_crc32c = false;
1551 
1552 	return (error);
1553 }
1554 
1555 static int
1556 iscsi_ioctl_daemon_send(struct iscsi_softc *sc,
1557     struct iscsi_daemon_send *ids)
1558 {
1559 	struct iscsi_session *is;
1560 	struct icl_pdu *ip;
1561 	size_t datalen;
1562 	void *data;
1563 	int error;
1564 
1565 	sx_slock(&sc->sc_lock);
1566 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1567 		if (is->is_id == ids->ids_session_id)
1568 			break;
1569 	}
1570 	if (is == NULL) {
1571 		sx_sunlock(&sc->sc_lock);
1572 		return (ESRCH);
1573 	}
1574 	sx_sunlock(&sc->sc_lock);
1575 
1576 	if (is->is_login_phase == false)
1577 		return (EBUSY);
1578 
1579 	if (is->is_terminating || is->is_reconnecting)
1580 		return (EIO);
1581 
1582 	datalen = ids->ids_data_segment_len;
1583 	if (datalen > ISCSI_MAX_DATA_SEGMENT_LENGTH)
1584 		return (EINVAL);
1585 	if (datalen > 0) {
1586 		data = malloc(datalen, M_ISCSI, M_WAITOK);
1587 		error = copyin(ids->ids_data_segment, data, datalen);
1588 		if (error != 0) {
1589 			free(data, M_ISCSI);
1590 			return (error);
1591 		}
1592 	}
1593 
1594 	ip = icl_pdu_new(is->is_conn, M_WAITOK);
1595 	memcpy(ip->ip_bhs, ids->ids_bhs, sizeof(*ip->ip_bhs));
1596 	if (datalen > 0) {
1597 		error = icl_pdu_append_data(ip, data, datalen, M_WAITOK);
1598 		KASSERT(error == 0, ("icl_pdu_append_data(..., M_WAITOK) failed"));
1599 		free(data, M_ISCSI);
1600 	}
1601 	icl_pdu_queue(ip);
1602 
1603 	return (0);
1604 }
1605 
1606 static int
1607 iscsi_ioctl_daemon_receive(struct iscsi_softc *sc,
1608     struct iscsi_daemon_receive *idr)
1609 {
1610 	struct iscsi_session *is;
1611 	struct icl_pdu *ip;
1612 	void *data;
1613 
1614 	sx_slock(&sc->sc_lock);
1615 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1616 		if (is->is_id == idr->idr_session_id)
1617 			break;
1618 	}
1619 	if (is == NULL) {
1620 		sx_sunlock(&sc->sc_lock);
1621 		return (ESRCH);
1622 	}
1623 	sx_sunlock(&sc->sc_lock);
1624 
1625 	if (is->is_login_phase == false)
1626 		return (EBUSY);
1627 
1628 	ISCSI_SESSION_LOCK(is);
1629 	while (is->is_login_pdu == NULL &&
1630 	    is->is_terminating == false &&
1631 	    is->is_reconnecting == false)
1632 		cv_wait(&is->is_login_cv, &is->is_lock);
1633 	if (is->is_terminating || is->is_reconnecting) {
1634 		ISCSI_SESSION_UNLOCK(is);
1635 		return (EIO);
1636 	}
1637 	ip = is->is_login_pdu;
1638 	is->is_login_pdu = NULL;
1639 	ISCSI_SESSION_UNLOCK(is);
1640 
1641 	if (ip->ip_data_len > idr->idr_data_segment_len) {
1642 		icl_pdu_free(ip);
1643 		return (EMSGSIZE);
1644 	}
1645 
1646 	copyout(ip->ip_bhs, idr->idr_bhs, sizeof(*ip->ip_bhs));
1647 	if (ip->ip_data_len > 0) {
1648 		data = malloc(ip->ip_data_len, M_ISCSI, M_WAITOK);
1649 		icl_pdu_get_data(ip, 0, data, ip->ip_data_len);
1650 		copyout(data, idr->idr_data_segment, ip->ip_data_len);
1651 		free(data, M_ISCSI);
1652 	}
1653 
1654 	icl_pdu_free(ip);
1655 
1656 	return (0);
1657 }
1658 #endif /* ICL_KERNEL_PROXY */
1659 
1660 static void
1661 iscsi_sanitize_session_conf(struct iscsi_session_conf *isc)
1662 {
1663 	/*
1664 	 * Just make sure all the fields are null-terminated.
1665 	 *
1666 	 * XXX: This is not particularly secure.  We should
1667 	 * 	create our own conf and then copy in relevant
1668 	 * 	fields.
1669 	 */
1670 	isc->isc_initiator[ISCSI_NAME_LEN - 1] = '\0';
1671 	isc->isc_initiator_addr[ISCSI_ADDR_LEN - 1] = '\0';
1672 	isc->isc_initiator_alias[ISCSI_ALIAS_LEN - 1] = '\0';
1673 	isc->isc_target[ISCSI_NAME_LEN - 1] = '\0';
1674 	isc->isc_target_addr[ISCSI_ADDR_LEN - 1] = '\0';
1675 	isc->isc_user[ISCSI_NAME_LEN - 1] = '\0';
1676 	isc->isc_secret[ISCSI_SECRET_LEN - 1] = '\0';
1677 	isc->isc_mutual_user[ISCSI_NAME_LEN - 1] = '\0';
1678 	isc->isc_mutual_secret[ISCSI_SECRET_LEN - 1] = '\0';
1679 }
1680 
1681 static bool
1682 iscsi_valid_session_conf(const struct iscsi_session_conf *isc)
1683 {
1684 
1685 	if (isc->isc_initiator[0] == '\0') {
1686 		ISCSI_DEBUG("empty isc_initiator");
1687 		return (false);
1688 	}
1689 
1690 	if (isc->isc_target_addr[0] == '\0') {
1691 		ISCSI_DEBUG("empty isc_target_addr");
1692 		return (false);
1693 	}
1694 
1695 	if (isc->isc_discovery != 0 && isc->isc_target[0] != 0) {
1696 		ISCSI_DEBUG("non-empty isc_target for discovery session");
1697 		return (false);
1698 	}
1699 
1700 	if (isc->isc_discovery == 0 && isc->isc_target[0] == 0) {
1701 		ISCSI_DEBUG("empty isc_target for non-discovery session");
1702 		return (false);
1703 	}
1704 
1705 	return (true);
1706 }
1707 
1708 static int
1709 iscsi_ioctl_session_add(struct iscsi_softc *sc, struct iscsi_session_add *isa)
1710 {
1711 	struct iscsi_session *is;
1712 	const struct iscsi_session *is2;
1713 	int error;
1714 
1715 	iscsi_sanitize_session_conf(&isa->isa_conf);
1716 	if (iscsi_valid_session_conf(&isa->isa_conf) == false)
1717 		return (EINVAL);
1718 
1719 	is = malloc(sizeof(*is), M_ISCSI, M_ZERO | M_WAITOK);
1720 	memcpy(&is->is_conf, &isa->isa_conf, sizeof(is->is_conf));
1721 
1722 	sx_xlock(&sc->sc_lock);
1723 
1724 	/*
1725 	 * Prevent duplicates.
1726 	 */
1727 	TAILQ_FOREACH(is2, &sc->sc_sessions, is_next) {
1728 		if (!!is->is_conf.isc_discovery !=
1729 		    !!is2->is_conf.isc_discovery)
1730 			continue;
1731 
1732 		if (strcmp(is->is_conf.isc_target_addr,
1733 		    is2->is_conf.isc_target_addr) != 0)
1734 			continue;
1735 
1736 		if (is->is_conf.isc_discovery == 0 &&
1737 		    strcmp(is->is_conf.isc_target,
1738 		    is2->is_conf.isc_target) != 0)
1739 			continue;
1740 
1741 		sx_xunlock(&sc->sc_lock);
1742 		free(is, M_ISCSI);
1743 		return (EBUSY);
1744 	}
1745 
1746 	is->is_conn = icl_new_conn(is->is_conf.isc_offload,
1747 	    "iscsi", &is->is_lock);
1748 	if (is->is_conn == NULL) {
1749 		sx_xunlock(&sc->sc_lock);
1750 		free(is, M_ISCSI);
1751 		return (EINVAL);
1752 	}
1753 	is->is_conn->ic_receive = iscsi_receive_callback;
1754 	is->is_conn->ic_error = iscsi_error_callback;
1755 	is->is_conn->ic_prv0 = is;
1756 	TAILQ_INIT(&is->is_outstanding);
1757 	STAILQ_INIT(&is->is_postponed);
1758 	mtx_init(&is->is_lock, "iscsi_lock", NULL, MTX_DEF);
1759 	cv_init(&is->is_maintenance_cv, "iscsi_mt");
1760 #ifdef ICL_KERNEL_PROXY
1761 	cv_init(&is->is_login_cv, "iscsi_login");
1762 #endif
1763 
1764 	is->is_softc = sc;
1765 	sc->sc_last_session_id++;
1766 	is->is_id = sc->sc_last_session_id;
1767 	is->is_isid[0] = 0x80; /* RFC 3720, 10.12.5: 10b, "Random" ISID. */
1768 	arc4rand(&is->is_isid[1], 5, 0);
1769 	is->is_tsih = 0;
1770 	callout_init(&is->is_callout, 1);
1771 
1772 	error = kthread_add(iscsi_maintenance_thread, is, NULL, NULL, 0, 0, "iscsimt");
1773 	if (error != 0) {
1774 		ISCSI_SESSION_WARN(is, "kthread_add(9) failed with error %d", error);
1775 		sx_xunlock(&sc->sc_lock);
1776 		return (error);
1777 	}
1778 
1779 	callout_reset(&is->is_callout, 1 * hz, iscsi_callout, is);
1780 	TAILQ_INSERT_TAIL(&sc->sc_sessions, is, is_next);
1781 
1782 	/*
1783 	 * Trigger immediate reconnection.
1784 	 */
1785 	ISCSI_SESSION_LOCK(is);
1786 	is->is_waiting_for_iscsid = true;
1787 	strlcpy(is->is_reason, "Waiting for iscsid(8)", sizeof(is->is_reason));
1788 	ISCSI_SESSION_UNLOCK(is);
1789 	cv_signal(&sc->sc_cv);
1790 
1791 	sx_xunlock(&sc->sc_lock);
1792 
1793 	return (0);
1794 }
1795 
1796 static bool
1797 iscsi_session_conf_matches(unsigned int id1, const struct iscsi_session_conf *c1,
1798     unsigned int id2, const struct iscsi_session_conf *c2)
1799 {
1800 
1801 	if (id2 != 0 && id2 != id1)
1802 		return (false);
1803 	if (c2->isc_target[0] != '\0' &&
1804 	    strcmp(c1->isc_target, c2->isc_target) != 0)
1805 		return (false);
1806 	if (c2->isc_target_addr[0] != '\0' &&
1807 	    strcmp(c1->isc_target_addr, c2->isc_target_addr) != 0)
1808 		return (false);
1809 	return (true);
1810 }
1811 
1812 static int
1813 iscsi_ioctl_session_remove(struct iscsi_softc *sc,
1814     struct iscsi_session_remove *isr)
1815 {
1816 	struct iscsi_session *is, *tmp;
1817 	bool found = false;
1818 
1819 	iscsi_sanitize_session_conf(&isr->isr_conf);
1820 
1821 	sx_xlock(&sc->sc_lock);
1822 	TAILQ_FOREACH_SAFE(is, &sc->sc_sessions, is_next, tmp) {
1823 		ISCSI_SESSION_LOCK(is);
1824 		if (iscsi_session_conf_matches(is->is_id, &is->is_conf,
1825 		    isr->isr_session_id, &isr->isr_conf)) {
1826 			found = true;
1827 			iscsi_session_logout(is);
1828 			iscsi_session_terminate(is);
1829 		}
1830 		ISCSI_SESSION_UNLOCK(is);
1831 	}
1832 	sx_xunlock(&sc->sc_lock);
1833 
1834 	if (!found)
1835 		return (ESRCH);
1836 
1837 	return (0);
1838 }
1839 
1840 static int
1841 iscsi_ioctl_session_list(struct iscsi_softc *sc, struct iscsi_session_list *isl)
1842 {
1843 	int error;
1844 	unsigned int i = 0;
1845 	struct iscsi_session *is;
1846 	struct iscsi_session_state iss;
1847 
1848 	sx_slock(&sc->sc_lock);
1849 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1850 		if (i >= isl->isl_nentries) {
1851 			sx_sunlock(&sc->sc_lock);
1852 			return (EMSGSIZE);
1853 		}
1854 		memset(&iss, 0, sizeof(iss));
1855 		memcpy(&iss.iss_conf, &is->is_conf, sizeof(iss.iss_conf));
1856 		iss.iss_id = is->is_id;
1857 		strlcpy(iss.iss_target_alias, is->is_target_alias, sizeof(iss.iss_target_alias));
1858 		strlcpy(iss.iss_reason, is->is_reason, sizeof(iss.iss_reason));
1859 		strlcpy(iss.iss_offload, is->is_conn->ic_offload, sizeof(iss.iss_offload));
1860 
1861 		if (is->is_conn->ic_header_crc32c)
1862 			iss.iss_header_digest = ISCSI_DIGEST_CRC32C;
1863 		else
1864 			iss.iss_header_digest = ISCSI_DIGEST_NONE;
1865 
1866 		if (is->is_conn->ic_data_crc32c)
1867 			iss.iss_data_digest = ISCSI_DIGEST_CRC32C;
1868 		else
1869 			iss.iss_data_digest = ISCSI_DIGEST_NONE;
1870 
1871 		iss.iss_max_data_segment_length = is->is_max_data_segment_length;
1872 		iss.iss_immediate_data = is->is_immediate_data;
1873 		iss.iss_connected = is->is_connected;
1874 
1875 		error = copyout(&iss, isl->isl_pstates + i, sizeof(iss));
1876 		if (error != 0) {
1877 			sx_sunlock(&sc->sc_lock);
1878 			return (error);
1879 		}
1880 		i++;
1881 	}
1882 	sx_sunlock(&sc->sc_lock);
1883 
1884 	isl->isl_nentries = i;
1885 
1886 	return (0);
1887 }
1888 
1889 static int
1890 iscsi_ioctl_session_modify(struct iscsi_softc *sc,
1891     struct iscsi_session_modify *ism)
1892 {
1893 	struct iscsi_session *is;
1894 
1895 	iscsi_sanitize_session_conf(&ism->ism_conf);
1896 	if (iscsi_valid_session_conf(&ism->ism_conf) == false)
1897 		return (EINVAL);
1898 
1899 	sx_xlock(&sc->sc_lock);
1900 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
1901 		ISCSI_SESSION_LOCK(is);
1902 		if (is->is_id == ism->ism_session_id)
1903 			break;
1904 		ISCSI_SESSION_UNLOCK(is);
1905 	}
1906 	if (is == NULL) {
1907 		sx_xunlock(&sc->sc_lock);
1908 		return (ESRCH);
1909 	}
1910 	sx_xunlock(&sc->sc_lock);
1911 
1912 	memcpy(&is->is_conf, &ism->ism_conf, sizeof(is->is_conf));
1913 	ISCSI_SESSION_UNLOCK(is);
1914 
1915 	iscsi_session_reconnect(is);
1916 
1917 	return (0);
1918 }
1919 
1920 static int
1921 iscsi_ioctl(struct cdev *dev, u_long cmd, caddr_t arg, int mode,
1922     struct thread *td)
1923 {
1924 	struct iscsi_softc *sc;
1925 
1926 	sc = dev->si_drv1;
1927 
1928 	switch (cmd) {
1929 	case ISCSIDWAIT:
1930 		return (iscsi_ioctl_daemon_wait(sc,
1931 		    (struct iscsi_daemon_request *)arg));
1932 	case ISCSIDHANDOFF:
1933 		return (iscsi_ioctl_daemon_handoff(sc,
1934 		    (struct iscsi_daemon_handoff *)arg));
1935 	case ISCSIDFAIL:
1936 		return (iscsi_ioctl_daemon_fail(sc,
1937 		    (struct iscsi_daemon_fail *)arg));
1938 #ifdef ICL_KERNEL_PROXY
1939 	case ISCSIDCONNECT:
1940 		return (iscsi_ioctl_daemon_connect(sc,
1941 		    (struct iscsi_daemon_connect *)arg));
1942 	case ISCSIDSEND:
1943 		return (iscsi_ioctl_daemon_send(sc,
1944 		    (struct iscsi_daemon_send *)arg));
1945 	case ISCSIDRECEIVE:
1946 		return (iscsi_ioctl_daemon_receive(sc,
1947 		    (struct iscsi_daemon_receive *)arg));
1948 #endif /* ICL_KERNEL_PROXY */
1949 	case ISCSISADD:
1950 		return (iscsi_ioctl_session_add(sc,
1951 		    (struct iscsi_session_add *)arg));
1952 	case ISCSISREMOVE:
1953 		return (iscsi_ioctl_session_remove(sc,
1954 		    (struct iscsi_session_remove *)arg));
1955 	case ISCSISLIST:
1956 		return (iscsi_ioctl_session_list(sc,
1957 		    (struct iscsi_session_list *)arg));
1958 	case ISCSISMODIFY:
1959 		return (iscsi_ioctl_session_modify(sc,
1960 		    (struct iscsi_session_modify *)arg));
1961 	default:
1962 		return (EINVAL);
1963 	}
1964 }
1965 
1966 static struct iscsi_outstanding *
1967 iscsi_outstanding_find(struct iscsi_session *is, uint32_t initiator_task_tag)
1968 {
1969 	struct iscsi_outstanding *io;
1970 
1971 	ISCSI_SESSION_LOCK_ASSERT(is);
1972 
1973 	TAILQ_FOREACH(io, &is->is_outstanding, io_next) {
1974 		if (io->io_initiator_task_tag == initiator_task_tag)
1975 			return (io);
1976 	}
1977 	return (NULL);
1978 }
1979 
1980 static struct iscsi_outstanding *
1981 iscsi_outstanding_find_ccb(struct iscsi_session *is, union ccb *ccb)
1982 {
1983 	struct iscsi_outstanding *io;
1984 
1985 	ISCSI_SESSION_LOCK_ASSERT(is);
1986 
1987 	TAILQ_FOREACH(io, &is->is_outstanding, io_next) {
1988 		if (io->io_ccb == ccb)
1989 			return (io);
1990 	}
1991 	return (NULL);
1992 }
1993 
1994 static struct iscsi_outstanding *
1995 iscsi_outstanding_add(struct iscsi_session *is,
1996     union ccb *ccb, uint32_t *initiator_task_tagp)
1997 {
1998 	struct iscsi_outstanding *io;
1999 	int error;
2000 
2001 	ISCSI_SESSION_LOCK_ASSERT(is);
2002 
2003 	io = uma_zalloc(iscsi_outstanding_zone, M_NOWAIT | M_ZERO);
2004 	if (io == NULL) {
2005 		ISCSI_SESSION_WARN(is, "failed to allocate %zd bytes",
2006 		    sizeof(*io));
2007 		return (NULL);
2008 	}
2009 
2010 	error = icl_conn_task_setup(is->is_conn, &ccb->csio,
2011 	    initiator_task_tagp, &io->io_icl_prv);
2012 	if (error != 0) {
2013 		ISCSI_SESSION_WARN(is,
2014 		    "icl_conn_task_setup() failed with error %d", error);
2015 		uma_zfree(iscsi_outstanding_zone, io);
2016 		return (NULL);
2017 	}
2018 
2019 	KASSERT(iscsi_outstanding_find(is, *initiator_task_tagp) == NULL,
2020 	    ("initiator_task_tag 0x%x already added", *initiator_task_tagp));
2021 
2022 	io->io_initiator_task_tag = *initiator_task_tagp;
2023 	io->io_ccb = ccb;
2024 	TAILQ_INSERT_TAIL(&is->is_outstanding, io, io_next);
2025 	return (io);
2026 }
2027 
2028 static void
2029 iscsi_outstanding_remove(struct iscsi_session *is, struct iscsi_outstanding *io)
2030 {
2031 
2032 	ISCSI_SESSION_LOCK_ASSERT(is);
2033 
2034 	icl_conn_task_done(is->is_conn, io->io_icl_prv);
2035 	TAILQ_REMOVE(&is->is_outstanding, io, io_next);
2036 	uma_zfree(iscsi_outstanding_zone, io);
2037 }
2038 
2039 static void
2040 iscsi_action_abort(struct iscsi_session *is, union ccb *ccb)
2041 {
2042 	struct icl_pdu *request;
2043 	struct iscsi_bhs_task_management_request *bhstmr;
2044 	struct ccb_abort *cab = &ccb->cab;
2045 	struct iscsi_outstanding *io, *aio;
2046 	uint32_t initiator_task_tag;
2047 
2048 	ISCSI_SESSION_LOCK_ASSERT(is);
2049 
2050 #if 0
2051 	KASSERT(is->is_login_phase == false, ("%s called during Login Phase", __func__));
2052 #else
2053 	if (is->is_login_phase) {
2054 		ccb->ccb_h.status = CAM_REQ_ABORTED;
2055 		xpt_done(ccb);
2056 		return;
2057 	}
2058 #endif
2059 
2060 	aio = iscsi_outstanding_find_ccb(is, cab->abort_ccb);
2061 	if (aio == NULL) {
2062 		ccb->ccb_h.status = CAM_REQ_CMP;
2063 		xpt_done(ccb);
2064 		return;
2065 	}
2066 
2067 	request = icl_pdu_new(is->is_conn, M_NOWAIT);
2068 	if (request == NULL) {
2069 		ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
2070 		xpt_done(ccb);
2071 		return;
2072 	}
2073 
2074 	initiator_task_tag = is->is_initiator_task_tag++;
2075 
2076 	io = iscsi_outstanding_add(is, NULL, &initiator_task_tag);
2077 	if (io == NULL) {
2078 		icl_pdu_free(request);
2079 		ccb->ccb_h.status = CAM_RESRC_UNAVAIL;
2080 		xpt_done(ccb);
2081 		return;
2082 	}
2083 	io->io_datasn = aio->io_initiator_task_tag;
2084 
2085 	bhstmr = (struct iscsi_bhs_task_management_request *)request->ip_bhs;
2086 	bhstmr->bhstmr_opcode = ISCSI_BHS_OPCODE_TASK_REQUEST;
2087 	bhstmr->bhstmr_function = 0x80 | BHSTMR_FUNCTION_ABORT_TASK;
2088 	bhstmr->bhstmr_lun = htobe64(CAM_EXTLUN_BYTE_SWIZZLE(ccb->ccb_h.target_lun));
2089 	bhstmr->bhstmr_initiator_task_tag = initiator_task_tag;
2090 	bhstmr->bhstmr_referenced_task_tag = aio->io_initiator_task_tag;
2091 
2092 	iscsi_pdu_queue_locked(request);
2093 }
2094 
2095 static void
2096 iscsi_action_scsiio(struct iscsi_session *is, union ccb *ccb)
2097 {
2098 	struct icl_pdu *request;
2099 	struct iscsi_bhs_scsi_command *bhssc;
2100 	struct ccb_scsiio *csio;
2101 	struct iscsi_outstanding *io;
2102 	size_t len;
2103 	uint32_t initiator_task_tag;
2104 	int error;
2105 
2106 	ISCSI_SESSION_LOCK_ASSERT(is);
2107 
2108 #if 0
2109 	KASSERT(is->is_login_phase == false, ("%s called during Login Phase", __func__));
2110 #else
2111 	if (is->is_login_phase) {
2112 		ISCSI_SESSION_DEBUG(is, "called during login phase");
2113 		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
2114 			xpt_freeze_devq(ccb->ccb_h.path, 1);
2115 			ISCSI_SESSION_DEBUG(is, "freezing devq");
2116 		}
2117 		ccb->ccb_h.status = CAM_REQ_ABORTED | CAM_DEV_QFRZN;
2118 		xpt_done(ccb);
2119 		return;
2120 	}
2121 #endif
2122 
2123 	request = icl_pdu_new(is->is_conn, M_NOWAIT);
2124 	if (request == NULL) {
2125 		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
2126 			xpt_freeze_devq(ccb->ccb_h.path, 1);
2127 			ISCSI_SESSION_DEBUG(is, "freezing devq");
2128 		}
2129 		ccb->ccb_h.status = CAM_RESRC_UNAVAIL | CAM_DEV_QFRZN;
2130 		xpt_done(ccb);
2131 		return;
2132 	}
2133 
2134 	initiator_task_tag = is->is_initiator_task_tag++;
2135 	io = iscsi_outstanding_add(is, ccb, &initiator_task_tag);
2136 	if (io == NULL) {
2137 		icl_pdu_free(request);
2138 		if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
2139 			xpt_freeze_devq(ccb->ccb_h.path, 1);
2140 			ISCSI_SESSION_DEBUG(is, "freezing devq");
2141 		}
2142 		ccb->ccb_h.status = CAM_RESRC_UNAVAIL | CAM_DEV_QFRZN;
2143 		xpt_done(ccb);
2144 		return;
2145 	}
2146 
2147 	csio = &ccb->csio;
2148 	bhssc = (struct iscsi_bhs_scsi_command *)request->ip_bhs;
2149 	bhssc->bhssc_opcode = ISCSI_BHS_OPCODE_SCSI_COMMAND;
2150 	bhssc->bhssc_flags |= BHSSC_FLAGS_F;
2151 	switch (csio->ccb_h.flags & CAM_DIR_MASK) {
2152 	case CAM_DIR_IN:
2153 		bhssc->bhssc_flags |= BHSSC_FLAGS_R;
2154 		break;
2155 	case CAM_DIR_OUT:
2156 		bhssc->bhssc_flags |= BHSSC_FLAGS_W;
2157 		break;
2158 	}
2159 
2160 	if ((ccb->ccb_h.flags & CAM_TAG_ACTION_VALID) != 0) {
2161 		switch (csio->tag_action) {
2162 		case MSG_HEAD_OF_Q_TAG:
2163 			bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_HOQ;
2164 			break;
2165 		case MSG_ORDERED_Q_TAG:
2166 			bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_ORDERED;
2167 			break;
2168 		case MSG_ACA_TASK:
2169 			bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_ACA;
2170 			break;
2171 		case MSG_SIMPLE_Q_TAG:
2172 		default:
2173 			bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_SIMPLE;
2174 			break;
2175 		}
2176 	} else
2177 		bhssc->bhssc_flags |= BHSSC_FLAGS_ATTR_UNTAGGED;
2178 
2179 	bhssc->bhssc_lun = htobe64(CAM_EXTLUN_BYTE_SWIZZLE(ccb->ccb_h.target_lun));
2180 	bhssc->bhssc_initiator_task_tag = initiator_task_tag;
2181 	bhssc->bhssc_expected_data_transfer_length = htonl(csio->dxfer_len);
2182 	KASSERT(csio->cdb_len <= sizeof(bhssc->bhssc_cdb),
2183 	    ("unsupported CDB size %zd", (size_t)csio->cdb_len));
2184 
2185 	if (csio->ccb_h.flags & CAM_CDB_POINTER)
2186 		memcpy(&bhssc->bhssc_cdb, csio->cdb_io.cdb_ptr, csio->cdb_len);
2187 	else
2188 		memcpy(&bhssc->bhssc_cdb, csio->cdb_io.cdb_bytes, csio->cdb_len);
2189 
2190 	if (is->is_immediate_data &&
2191 	    (csio->ccb_h.flags & CAM_DIR_MASK) == CAM_DIR_OUT) {
2192 		len = csio->dxfer_len;
2193 		//ISCSI_SESSION_DEBUG(is, "adding %zd of immediate data", len);
2194 		if (len > is->is_first_burst_length) {
2195 			ISCSI_SESSION_DEBUG(is, "len %zd -> %zd", len, is->is_first_burst_length);
2196 			len = is->is_first_burst_length;
2197 		}
2198 		if (len > is->is_max_data_segment_length) {
2199 			ISCSI_SESSION_DEBUG(is, "len %zd -> %zd", len, is->is_max_data_segment_length);
2200 			len = is->is_max_data_segment_length;
2201 		}
2202 
2203 		error = icl_pdu_append_data(request, csio->data_ptr, len, M_NOWAIT);
2204 		if (error != 0) {
2205 			icl_pdu_free(request);
2206 			if ((ccb->ccb_h.status & CAM_DEV_QFRZN) == 0) {
2207 				xpt_freeze_devq(ccb->ccb_h.path, 1);
2208 				ISCSI_SESSION_DEBUG(is, "freezing devq");
2209 			}
2210 			ccb->ccb_h.status = CAM_RESRC_UNAVAIL | CAM_DEV_QFRZN;
2211 			xpt_done(ccb);
2212 			return;
2213 		}
2214 	}
2215 	iscsi_pdu_queue_locked(request);
2216 }
2217 
2218 static void
2219 iscsi_action(struct cam_sim *sim, union ccb *ccb)
2220 {
2221 	struct iscsi_session *is;
2222 
2223 	is = cam_sim_softc(sim);
2224 
2225 	ISCSI_SESSION_LOCK_ASSERT(is);
2226 
2227 	if (is->is_terminating ||
2228 	    (is->is_connected == false && fail_on_disconnection)) {
2229 		ccb->ccb_h.status = CAM_DEV_NOT_THERE;
2230 		xpt_done(ccb);
2231 		return;
2232 	}
2233 
2234 	switch (ccb->ccb_h.func_code) {
2235 	case XPT_PATH_INQ:
2236 	{
2237 		struct ccb_pathinq *cpi = &ccb->cpi;
2238 
2239 		cpi->version_num = 1;
2240 		cpi->hba_inquiry = PI_TAG_ABLE;
2241 		cpi->target_sprt = 0;
2242 		cpi->hba_misc = PIM_EXTLUNS;
2243 		cpi->hba_eng_cnt = 0;
2244 		cpi->max_target = 0;
2245 		/*
2246 		 * Note that the variable below is only relevant for targets
2247 		 * that don't claim compliance with anything above SPC2, which
2248 		 * means they don't support REPORT_LUNS.
2249 		 */
2250 		cpi->max_lun = 255;
2251 		cpi->initiator_id = ~0;
2252 		strlcpy(cpi->sim_vid, "FreeBSD", SIM_IDLEN);
2253 		strlcpy(cpi->hba_vid, "iSCSI", HBA_IDLEN);
2254 		strlcpy(cpi->dev_name, cam_sim_name(sim), DEV_IDLEN);
2255 		cpi->unit_number = cam_sim_unit(sim);
2256 		cpi->bus_id = cam_sim_bus(sim);
2257 		cpi->base_transfer_speed = 150000; /* XXX */
2258 		cpi->transport = XPORT_ISCSI;
2259 		cpi->transport_version = 0;
2260 		cpi->protocol = PROTO_SCSI;
2261 		cpi->protocol_version = SCSI_REV_SPC3;
2262 		cpi->maxio = MAXPHYS;
2263 		cpi->ccb_h.status = CAM_REQ_CMP;
2264 		break;
2265 	}
2266 	case XPT_GET_TRAN_SETTINGS:
2267 	{
2268 		struct ccb_trans_settings	*cts;
2269 		struct ccb_trans_settings_scsi	*scsi;
2270 
2271 		cts = &ccb->cts;
2272 		scsi = &cts->proto_specific.scsi;
2273 
2274 		cts->protocol = PROTO_SCSI;
2275 		cts->protocol_version = SCSI_REV_SPC3;
2276 		cts->transport = XPORT_ISCSI;
2277 		cts->transport_version = 0;
2278 		scsi->valid = CTS_SCSI_VALID_TQ;
2279 		scsi->flags = CTS_SCSI_FLAGS_TAG_ENB;
2280 		cts->ccb_h.status = CAM_REQ_CMP;
2281 		break;
2282 	}
2283 	case XPT_CALC_GEOMETRY:
2284 		cam_calc_geometry(&ccb->ccg, /*extended*/1);
2285 		ccb->ccb_h.status = CAM_REQ_CMP;
2286 		break;
2287 #if 0
2288 	/*
2289 	 * XXX: What's the point?
2290 	 */
2291 	case XPT_RESET_BUS:
2292 	case XPT_TERM_IO:
2293 		ISCSI_SESSION_DEBUG(is, "faking success for reset, abort, or term_io");
2294 		ccb->ccb_h.status = CAM_REQ_CMP;
2295 		break;
2296 #endif
2297 	case XPT_ABORT:
2298 		iscsi_action_abort(is, ccb);
2299 		return;
2300 	case XPT_SCSI_IO:
2301 		iscsi_action_scsiio(is, ccb);
2302 		return;
2303 	default:
2304 #if 0
2305 		ISCSI_SESSION_DEBUG(is, "got unsupported code 0x%x", ccb->ccb_h.func_code);
2306 #endif
2307 		ccb->ccb_h.status = CAM_FUNC_NOTAVAIL;
2308 		break;
2309 	}
2310 	xpt_done(ccb);
2311 }
2312 
2313 static void
2314 iscsi_poll(struct cam_sim *sim)
2315 {
2316 
2317 	KASSERT(0, ("%s: you're not supposed to be here", __func__));
2318 }
2319 
2320 static void
2321 iscsi_shutdown(struct iscsi_softc *sc)
2322 {
2323 	struct iscsi_session *is;
2324 
2325 	/*
2326 	 * Trying to reconnect during system shutdown would lead to hang.
2327 	 */
2328 	fail_on_disconnection = 1;
2329 
2330 	/*
2331 	 * If we have any sessions waiting for reconnection, request
2332 	 * maintenance thread to fail them immediately instead of waiting
2333 	 * for reconnect timeout.
2334 	 */
2335 	sx_slock(&sc->sc_lock);
2336 	TAILQ_FOREACH(is, &sc->sc_sessions, is_next) {
2337 		ISCSI_SESSION_LOCK(is);
2338 		if (is->is_waiting_for_iscsid)
2339 			iscsi_session_reconnect(is);
2340 		ISCSI_SESSION_UNLOCK(is);
2341 	}
2342 	sx_sunlock(&sc->sc_lock);
2343 }
2344 
2345 static int
2346 iscsi_load(void)
2347 {
2348 	int error;
2349 
2350 	sc = malloc(sizeof(*sc), M_ISCSI, M_ZERO | M_WAITOK);
2351 	sx_init(&sc->sc_lock, "iscsi");
2352 	TAILQ_INIT(&sc->sc_sessions);
2353 	cv_init(&sc->sc_cv, "iscsi_cv");
2354 
2355 	iscsi_outstanding_zone = uma_zcreate("iscsi_outstanding",
2356 	    sizeof(struct iscsi_outstanding), NULL, NULL, NULL, NULL,
2357 	    UMA_ALIGN_PTR, 0);
2358 
2359 	error = make_dev_p(MAKEDEV_CHECKNAME, &sc->sc_cdev, &iscsi_cdevsw,
2360 	    NULL, UID_ROOT, GID_WHEEL, 0600, "iscsi");
2361 	if (error != 0) {
2362 		ISCSI_WARN("failed to create device node, error %d", error);
2363 		return (error);
2364 	}
2365 	sc->sc_cdev->si_drv1 = sc;
2366 
2367 	sc->sc_shutdown_eh = EVENTHANDLER_REGISTER(shutdown_pre_sync,
2368 	    iscsi_shutdown, sc, SHUTDOWN_PRI_FIRST);
2369 
2370 	return (0);
2371 }
2372 
2373 static int
2374 iscsi_unload(void)
2375 {
2376 	struct iscsi_session *is, *tmp;
2377 
2378 	if (sc->sc_cdev != NULL) {
2379 		ISCSI_DEBUG("removing device node");
2380 		destroy_dev(sc->sc_cdev);
2381 		ISCSI_DEBUG("device node removed");
2382 	}
2383 
2384 	if (sc->sc_shutdown_eh != NULL)
2385 		EVENTHANDLER_DEREGISTER(shutdown_pre_sync, sc->sc_shutdown_eh);
2386 
2387 	sx_slock(&sc->sc_lock);
2388 	TAILQ_FOREACH_SAFE(is, &sc->sc_sessions, is_next, tmp)
2389 		iscsi_session_terminate(is);
2390 	while(!TAILQ_EMPTY(&sc->sc_sessions)) {
2391 		ISCSI_DEBUG("waiting for sessions to terminate");
2392 		cv_wait(&sc->sc_cv, &sc->sc_lock);
2393 	}
2394 	ISCSI_DEBUG("all sessions terminated");
2395 	sx_sunlock(&sc->sc_lock);
2396 
2397 	uma_zdestroy(iscsi_outstanding_zone);
2398 	sx_destroy(&sc->sc_lock);
2399 	cv_destroy(&sc->sc_cv);
2400 	free(sc, M_ISCSI);
2401 	return (0);
2402 }
2403 
2404 static int
2405 iscsi_quiesce(void)
2406 {
2407 	sx_slock(&sc->sc_lock);
2408 	if (!TAILQ_EMPTY(&sc->sc_sessions)) {
2409 		sx_sunlock(&sc->sc_lock);
2410 		return (EBUSY);
2411 	}
2412 	sx_sunlock(&sc->sc_lock);
2413 	return (0);
2414 }
2415 
2416 static int
2417 iscsi_modevent(module_t mod, int what, void *arg)
2418 {
2419 	int error;
2420 
2421 	switch (what) {
2422 	case MOD_LOAD:
2423 		error = iscsi_load();
2424 		break;
2425 	case MOD_UNLOAD:
2426 		error = iscsi_unload();
2427 		break;
2428 	case MOD_QUIESCE:
2429 		error = iscsi_quiesce();
2430 		break;
2431 	default:
2432 		error = EINVAL;
2433 		break;
2434 	}
2435 	return (error);
2436 }
2437 
2438 moduledata_t iscsi_data = {
2439 	"iscsi",
2440 	iscsi_modevent,
2441 	0
2442 };
2443 
2444 DECLARE_MODULE(iscsi, iscsi_data, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
2445 MODULE_DEPEND(iscsi, cam, 1, 1, 1);
2446 MODULE_DEPEND(iscsi, icl, 1, 1, 1);
2447